CHIRON CORP
10-K, 1996-03-28
IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES
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                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
                                   FORM 10-K
 
/X/           ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                 SECURITIES EXCHANGE ACT OF 1934 [FEE REQUIRED]
                                       OR
/ /         TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
               SECURITIES EXCHANGE ACT OF 1934 [NO FEE REQUIRED]
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1995
                          COMMISSION FILE NO. 0-12798
                            ------------------------
                               CHIRON CORPORATION
             (Exact name of Registrant as specified in its charter)
 
<TABLE>
<S>                                            <C>
                  DELAWARE                                      94-2754624
          (State of Incorporation)                   (IRS Employer Identification No.)
</TABLE>
 
                               4560 HORTON STREET
                          EMERYVILLE, CALIFORNIA 94608
              (Address of principal executive offices) (Zip Code)
 
       Registrant's telephone number, including area code: (510) 655-8730
        Securities registered pursuant to Section 12(b) of the Act: None
          Securities registered pursuant to Section 12(g) of the Act:
                         COMMON STOCK, $0.01 PAR VALUE
               WARRANTS TO PURCHASE COMMON STOCK, $0.01 PAR VALUE
 
Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12  months (or  for such shorter  period that  the Registrant was
required to  file  such  reports), and  (2)  has  been subject  to  such  filing
requirements for the past 90 days.
 
                            Yes __X__        No ____
 
Indicate  by check mark if disclosure of  delinquent filers pursuant to Item 405
of Regulation S-K is  not contained herein,  and will not  be contained, to  the
best  of Registrant's knowledge,  in definitive proxy  or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K.
- -------
 
The aggregate  market  value  of  voting stock  held  by  nonaffiliates  of  the
Registrant as of March 1, 1996, was $2,391,730,000.
 
The  number of shares outstanding of each  of the Registrant's classes of common
stock as of March 1, 1996:
 
<TABLE>
<CAPTION>
                     TITLE OF CLASS                                           NUMBER OF SHARES
- --------------------------------------------------------  --------------------------------------------------------
<S>                                                       <C>
             Common Stock, $0.01 par value                                       42,109,984
</TABLE>
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
The Company's  Consolidated  Financial  Statements for  the  fiscal  year  ended
December  31, 1995, are incorporated  by reference into Parts  II and IV of this
Form 10-K Report and are filed as Exhibit 13 to this Form 10-K Report.
 
Portions of the  Proxy Statement for  the Annual Meeting  of Stockholders to  be
held  on  May 16,  1996, are  incorporated by  reference into  Part III  of this
Report.
 
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                                     PART I
 
ITEM 1.  BUSINESS
 
    THIS  REPORT  CONTAINS  FORWARD-LOOKING STATEMENTS  THAT  INVOLVE  RISKS AND
UNCERTAINTIES RELATING TO THE FUTURE FINANCIAL PERFORMANCE OF CHIRON CORPORATION
(THE "COMPANY" OR "CHIRON"), AND ACTUAL EVENTS OR RESULTS MAY DIFFER MATERIALLY.
IN EVALUATING SUCH  STATEMENTS, STOCKHOLDERS AND  INVESTORS SHOULD  SPECIFICALLY
CONSIDER  THE VARIOUS  FACTORS IDENTIFIED  UNDER THE  CAPTION "FACTORS  THAT MAY
AFFECT FUTURE OPERATING  RESULTS" CONTAINED IN  THE MANAGEMENT'S DISCUSSION  AND
ANALYSIS   OF  FINANCIAL  CONDITION  AND   RESULTS  OF  OPERATIONS  IN  CHIRON'S
CONSOLIDATED FINANCIAL STATEMENTS INCORPORATED BY  REFERENCE IN THIS FORM  10-K,
WHICH  COULD CAUSE ACTUAL  RESULTS TO DIFFER MATERIALLY  FROM THOSE INDICATED BY
SUCH FORWARD-LOOKING STATEMENTS.
 
    Chiron is  a diversified,  science-driven  healthcare company  that  applies
biotechnology  and other techniques of modern  biology and chemistry to develop,
produce and sell products intended to improve the quality of life by diagnosing,
preventing and  treating  human  disease.  Chiron  participates  in  four  human
healthcare  markets:  diagnostics,  including  immunodiagnostics,  critical care
diagnostics and new quantitative probe tests; therapeutics, with an emphasis  on
oncology,  serious infectious diseases and critical care diseases; pediatric and
adult vaccines; and ophthalmic surgical  products for the correction of  vision.
Chiron  also develops or acquires new technologies, employing these technologies
to discover  new products  for the  Company or  for its  partners. For  example,
Chiron  is developing a new generation of chemical therapeutics through advanced
techniques of drug design and discovery  and is conducting an active program  in
gene therapy.
 
    Effective  January 1,  1995, Chiron  began a  biotechnology partnership with
Ciba-Geigy Limited, of Basel, Switzerland ("Ciba") whereby Ciba acquired a  49.9
percent  ownership interest  in Chiron  common stock.  At the  same time, Chiron
acquired Ciba's  Ciba  Corning Diagnostics  Corp.  ("CCD") business  and  Ciba's
interests  in Chiron Biocine Company (formerly  The Biocine Company) and Biocine
S.p.A. (through JV  Vax B.V., a  Netherlands company). In  addition, Chiron  and
Ciba  agreed to cooperate in  research, development, manufacturing and marketing
of biotechnology products on an  arms-length basis, while remaining  independent
to pursue other opportunities. For a further description of the partnership with
Ciba,  see  Part  II,  Item  8.,  Note  2  of  Notes  to  Consolidated Financial
Statements.  Chiron  operates  through  the  following  business  units:  Chiron
Diagnostics,  which includes the  CCD business, quantitative  probe tests and an
interest in  a  joint  immunodiagnostic  business;  Chiron  Biocine,  a  vaccine
business  which includes Biocine S.p.A.; Chiron Therapeutics; and Chiron Vision,
the Company's ophthalmic business. A  fifth business unit, Chiron  Technologies,
manages  the  Company's research  and clinical  development programs  other than
diagnostics and vaccines  and develops new  technologies with potential  utility
throughout Chiron.
 
    Chiron was incorporated in California in 1981 and reincorporated in Delaware
in  1987. A  global organization  with facilities  on four  continents, Chiron's
corporate headquarters is located at 4560 Horton Street, Emeryville,  California
94608-2916, and its telephone number at that address is (510) 655-8730.
 
CHIRON DIAGNOSTICS
 
    Chiron,  through its Chiron  Diagnostics business unit  and its wholly-owned
subsidiary CCD  (collectively  "Chiron  Diagnostics"), is  one  of  the  world's
largest providers of critical blood analyte systems used to measure blood gases,
blood  electrolytes  and metabolites.  These systems  are  used by  hospitals to
diagnose and monitor patients in critical care settings. Chiron Diagnostics also
markets the  ACS:180-Registered  Trademark-  and  ACS:180  Plus-TM-,  which  are
automated,  high-throughput  random access  immunodiagnostic  instrument systems
used by  hospital and  reference  laboratories to  detect and  measure  thyroid,
anemia, fertility, cancer and STAT cardiac indicators.
 
    Chiron  Diagnostics develops branched  DNA ("bDNA") probe  tests to quantify
levels of virus and other indicators of disease. Clinical evidence suggests that
Chiron's bDNA probe tests  may have utility  in predicting disease  progression,
selection    of    patients   for    treatment    based   on    probability   of
 
                                       1
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response and monitoring response to therapy. Chiron is selling bDNA probe  tests
for  human  immunodeficiency  virus  ("HIV"),  hepatitis  C  virus  ("HCV"), and
hepatitis B virus ("HBV") for Research Use Only in the United States and Europe.
The United States Food and Drug  Administration ("FDA") has accepted for  review
Chiron's application to market its bDNA probe test for HIV in the United States.
Chiron  has licensed  rights to  sell bDNA  probe tests  in Japan  and Taiwan to
Daiichi Pure Chemicals Co., Ltd. ("Daiichi"). Daiichi currently markets Chiron's
Quantiplex-TM- bDNA tests for HCV and HBV in Japan.
 
    Chiron has built a joint business  with a significant worldwide presence  in
the  immunodiagnostic market  with Ortho  Diagnostic Systems,  Inc. ("Ortho"), a
Johnson & Johnson company, based largely on sales of tests used to screen  blood
for the potential presence of HCV. The joint business sells a full line of tests
required  to screen blood  for hepatitis viruses  and retroviruses, and provides
confirmatory tests  and microplate-based  instrument  systems to  automate  test
performance  and data collection.  Chiron and Ortho share  equally in the pretax
operating earnings generated by the joint business. The joint business holds the
immunodiagnostic rights  to Chiron's  hepatitis  and retrovirus  technology  and
receives  royalty  payments for  the sale  of HCV  tests by  Abbott Laboratories
("Abbott") and Pasteur  Sanofi Diagnostics. In  1995, Chiron and  Ortho began  a
collaboration  with Genelabs Technologies, Inc. ("Genelabs") regarding hepatitis
G virus. Under  the terms  of the  collaboration agreement,  the joint  business
received certain immunodiagnostic rights to the Genelabs technology. Chiron also
has  an option to  share equally in  the pretax operating  earnings generated by
Johnson & Johnson's home HIV test, currently under review by the FDA.
 
CHIRON BIOCINE
 
    Chiron Biocine, headquartered in Emeryville with operations in Siena, Italy,
is the Company's business to develop  and market new vaccines. Chiron  Biocine's
present business is based primarily on the sale of non-recombinant pediatric and
flu  vaccines in Italy and,  to a lesser extent,  in Southern Europe, the Middle
East, the Far East, Africa, South America, and to international health  services
such  as the World Health Organization. Among  its products is a new genetically
engineered  acellular  pertussis   (whooping  cough)   vaccine,  combined   with
diphtheria  and tetanus ("DTaP"), currently marketed in Italy. Chiron Biocine is
preparing applications  to market  the DTaP  vaccine in  the United  States  and
Europe, based on the results of large-scale government-sponsored trials in Italy
that  showed the Chiron acellular pertussis  vaccine is safer and more effective
than a current whole-cell pertussis vaccine.
 
    Chiron Biocine is developing a new generation of vaccines for serious  adult
infections  such as  herpes simplex virus,  type 2 ("HSV-2")  or genital herpes,
cytomegalovirus ("CMV") and HCV.  These vaccines utilize genetically  engineered
antigens  which are  displayed in  a manner  that mimics  the appearance  of the
actual agent, combined in a formulation  with adjuvants that amplify the  immune
response.  In 1996, Chiron Biocine announced that, based on a preliminary review
of clinical trial  data, a  vaccine formulation designed  to treat  HSV-2 had  a
statistically  significant  benefit on  several disease  indicators but  did not
reach statistical significance on its primary endpoint. A separate Phase 3 trial
of a vaccine designed to prevent HSV-2 is underway and scheduled to be completed
in 1996. Phase 2 trials  of a CMV vaccine are  underway in the United States.  A
Phase  1 trial of an HIV vaccine  is underway in Thailand, in collaboration with
the Royal Army and the United States  Department of the Army. A vaccine for  HCV
is  in preclinical trials. Chiron Biocine is also collaborating with NABI in the
development of a new  family of human immunotherapeutic  products, based on  the
vaccines  of  Chiron  Biocine and  initially  focused  on the  development  of a
hyperimmune globulin product to prevent and treat CMV infections.
 
    In February 1996, Chiron  and Behringwerke AG, a  subsidiary of Hoechst  AG,
entered  into an agreement whereby Chiron will purchase a 49 percent interest in
the human vaccine business of Behringwerke AG for Deutsche mark 171.5 million in
cash. Chiron has an option to purchase  the remaining 51 percent in March  1998,
1999,  2000 or 2001, and  Behringwerke AG has the  option to have Chiron acquire
the remaining 51  percent interest in  March 2001. Behringwerke  AG, one of  the
largest
 
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vaccine  suppliers  in  Germany,  manufactures  and  markets  vaccines  for flu,
diphtheria, tetanus, pertussis,  rabies, tick-borne encephalitis,  tuberculosis,
cholera,  an oral  vaccine for polio,  and, under license  from other companies,
distributes vaccines  in  Germany  for measles,  mumps,  rubella,  hepatitis  B,
typhoid  fever, pneumonia, haemophilus influenza as well as an inactivated polio
vaccine.
 
    During the  period of  mutual  ownership, Chiron  and Behringwerke  AG  will
operate  the vaccine business as a joint  venture. The joint venture is designed
to provide an outlet for Chiron Biocine's new vaccines in the German market  and
to  expand its presence in  the European vaccine market.  Chiron will report its
share of the  joint venture's results  as equity in  earnings of  unconsolidated
joint  businesses.  Consummation  of  the  transaction  is  subject  to  certain
conditions, including  regulatory approvals  and customary  conditions prior  to
closing.
 
    In  addition to its  Chiron Biocine activities,  Chiron has received royalty
payments since 1986  from the  sales of Recombivax-Registered  Trademark- HB,  a
vaccine  against HBV developed,  manufactured and marketed by  Merck & Co., Inc.
("Merck"), using technology developed by Chiron.
Recombivax-Registered  Trademark-  HB  was  the  first  vaccine  using   genetic
engineering to be licensed by the FDA for human use.
 
CHIRON THERAPEUTICS
 
    Chiron  Therapeutics, Chiron's  hospital and large  clinic-based business in
the  United  States  and  Europe,  markets  products  for  use  principally   by
oncologists.    Its   leading   product   is   Proleukin-Registered   Trademark-
(aldesleukin), interleukin-2, the first treatment approved for metastatic kidney
cancer. In the United States, Chiron also markets generic chemotherapy drugs  as
part of a joint venture with Ben Venue Laboratories, Inc. In addition, on behalf
of   Ciba   Pharmaceuticals,   Chiron   promotes   Aredia-Registered  Trademark-
(pamidronate  disodium  for  injection),  a  drug  to  treat  hypercalcimia   of
malignancy, Paget's disease and osteolytic bone lesions of multiple myeloma.
 
    Chiron Therapeutics manufactures Betaseron-Registered Trademark- (interferon
beta-1b) for Berlex Laboratories, Inc., a United States affiliate of Schering AG
of  Berlin, Germany ("Schering"), which markets the product in the United States
and Canada. In Europe,  Schering is marketing the  product under the trade  name
Betaferon-TM-,  manufactured  by  Boehringer Ingelheim,  for  which  Chiron will
receive a royalty.
 
CHIRON VISION
 
    Chiron Vision is  the Company's  business in  ophthalmic surgical  products,
with  sales in the United States and 15 other countries. Chiron Vision's line of
products for the surgical correction of  vision includes both hard and  foldable
intraocular  lenses  for  cataract  replacement  surgeries,  phacoemulsification
instruments for  small-incision  cataract  surgeries,  and  refractive  surgical
instruments  including corneal shapers and excimer lasers. In March 1995, Chiron
Vision expanded  its presence  in the  United States  and European  markets  for
cataract  surgery products  through the  acquisition of  the ophthalmic surgical
division of IOLAB,  a Johnson &  Johnson company. Following  the acquisition  of
IOLAB, Chiron Vision initiated a global restructuring of the combined operations
to enhance manufacturing, marketing and management efficiencies.
 
    In  March 1996, Chiron  Vision received FDA approval  to begin marketing the
Vitrasert-TM- Implant to deliver ganciclovir for the treatment of CMV  retinitis
in  people  with AIDS.  In Phase  3 clinical  trials, the  Vitrasert-TM- Implant
demonstrated a clinically important improvement over intravenously  administered
ganciclovir  in delaying  the progression  of CMV  in these  individuals. Chiron
Vision is co-marketing  the Vitrasert-TM-  Implant worldwide,  including in  the
United  States  and  Europe,  with  Hoffmann-La  Roche,  Inc.  ("Roche"),  which
manufactures and markets ganciclovir.
 
CHIRON TECHNOLOGIES
 
    Chiron  Technologies   applies   enabling  technologies   in   combinatorial
chemistry,  gene therapy and  recombinant proteins to  develop products intended
for use as therapeutics,  and develops new  technologies with potential  utility
throughout   the  Company.  Chiron  Technologies   combines  the  Company's  own
proprietary technologies  in  combinatorial  chemistry,  robotic  screening  and
selection and molecular biology with the knowledge and participation of a select
group  of leading  academic scientists in  the fields of  structural biology and
bio-organic  chemistry.  Chiron  also   engages  in  collaborations  to   create
 
                                       3
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libraries   of  compounds   for  characterization   and  screening   with  other
pharmaceutical companies,  including  Janssen  Pharmaceutica  NV,  a  Johnson  &
Johnson company, and Ciba, as well as with organizations in other fields such as
Dow Elanco, an agricultural company.
 
    Chiron  augmented  its  program  in gene  therapy  with  the  acquisition in
September 1995  of Viagene,  Inc., now  known as  Chiron Viagene.  Through  this
program,  Chiron is developing gene therapy and gene transfer products, and drug
activation technology for the prevention and treatment of a broad range of human
diseases. Chiron's gene  therapy program includes  collaborations with  Ribozyme
Pharmaceuticals, Inc., Progenitor, Inc., and the Virus Research Institute.
 
    Chiron,  in collaboration with Johnson &  Johnson, is developing a series of
growth factors to treat topical wounds. In September 1995, Chiron and Johnson  &
Johnson  announced that  the two  companies have  reviewed favorable preliminary
Phase   3    clinical    trial   data    on    their   wound    healing    agent
Regranex-Registered   Trademark-   (becaplermin),   a   formulation   containing
recombinant human platelet-derived  growth factor (rhPDGF),  and are  proceeding
with  regulatory  applications. Chiron  manufactures  rhPDGF in  bulk  for final
formulation  into   Regranex-Registered  Trademark-.   Johnson  &   Johnson   is
responsible for clinical development, regulatory matters, marketing and sales.
 
    Chiron  is  collaborating with  Cephalon, Inc.  ("Cephalon") to  develop and
market products for the treatment of neurological disorders. During 1995, Chiron
and Cephalon announced that  Myotrophin-TM- (insulin-like growth factor,  IGF-1)
had shown a favorable result in Phase 2/3 trials in the United States and Europe
for the treatment of amytrophic lateral sclerosis (ALS or Lou Gehrig's Disease).
Subsequently,  the FDA asked for further  information about these trials. If the
requested information is  deemed insufficient  by the  FDA, additional  clinical
trials may be required before a marketing application can be submitted by Chiron
and  Cephalon. Following an  analysis of data  from a Phase  2 trial, Chiron has
decided to discontinue  its own clinical  development of IGF-1  for acute  renal
failure. Chiron is considering further clinical development of IGF-1.
 
    In the area of cardiovascular disease, Chiron has begun a collaboration with
G.D.  Searle  &  Co.  ("Searle"), to  develop  tissue  factor  pathway inhibitor
("TFPI"), a coagulation inhibitor with potential applications in thrombotic  and
inflammatory  diseases, trauma and critical care. Chiron and Searle have begun a
Phase 2 clinical trial studying the use of TFPI in microvascular surgery.
 
COMPETITION
 
    Chiron  competes  against  a  large   number  of  other  biotechnology   and
pharmaceutical  companies in the United States and internationally, and although
no single company competes in every area of Chiron's interests, the  competition
is  intense  and  expected to  increase.  Biotechnology and  drug  discovery are
rapidly evolving fields in which  new developments frequently result in  product
obsolescence  and price competition. To compete effectively, Chiron's direct and
joint businesses invest heavily in research, maintain multiple sales forces that
concentrate efforts on  individual classes of  customers, and spend  significant
amounts  on  advertising, promotion  and  selling. Substantial  consolidation is
underway in the global healthcare industry,  and is expected to produce  greater
efficiencies and even more intense competition.
 
    In  the diagnostic  market, the  major competitor  to both  the Chiron-Ortho
joint business and to  the Chiron Diagnostics business  is Abbott. In  addition,
although  initial patents for the Chiron HCV  invention have been issued and are
being upheld through litigation, the joint business faces continued  competition
from  a number of  unlicensed sellers of HCV  tests including Murex Diagnostics,
Ltd., a  subsidiary  of  International  Murex  Technologies  Corp.,  and  United
Biomedical, Inc. (see Part I, Item 3.). Other companies in Japan and Europe have
introduced,  or may be preparing to  introduce, competing HCV tests. In addition
to Abbott, Chiron faces  competition in the  immunoassay market from  Boehringer
Mannheim  and Johnson  & Johnson,  which purchased  the diagnostic  and clinical
chemistry business  of Eastman  Kodak. Chiron's  bDNA probe  tests compete  with
products from affiliates of Roche (which is developing tests based on polymerase
chain reaction), Abbott and Digene
 
                                       4
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and  may  compete  with Gene-Trak  Systems  and Gen-Probe  Incorporated.  In the
critical  blood  analyte  market,  Chiron  Diagnostics  faces  competition  from
Radiometer Medical A/S and Instrumentation Laboratory Company.
 
    Four  large  companies  hold the  greatest  share of  the  worldwide vaccine
market: Merck  and  SmithKline  Beecham ("SmithKline"),  both  of  which  market
pediatric vaccines and the only widely sold recombinant vaccines for hepatitis B
infection;  Lederle Praxis  Biologics ("Lederle"),  a division  of American Home
Products; and the combination of Connaught Laboratories, Inc. ("Connaught"), and
Pasteur Merieux Serums  et Vaccins  (which separately has  a strategic  alliance
with  Merck), both  of which sell  pediatric vaccines.  SmithKline and Connaught
both have acellular pertussis vaccines that demonstrated superiority compared to
a currently marketed whole-cell pertussis vaccine, and have indicated that their
United  States  regulatory  applications   for  such  vaccines  are   completed.
SmithKline and Lederle are developing vaccines for genital herpes.
 
    In  the therapeutics  market, Proleukin-Registered  Trademark- competes with
alpha interferon sold by Schering Plough Corporation and by Roche as a treatment
for  metastatic  kidney  cancer.  Several  other  biotechnology  companies   are
developing  IL-2  or  other  interferons  as  immune-system-based  therapies for
cancers and infectious diseases, including Roche, Genentech, Inc. ("Genentech"),
and Amgen Inc. Approximately  30 companies compete in  the United States  market
for  anticancer  chemotherapies, including  Bristol-Myers Squibb  Company, which
accounts  for  nearly  half  the   market.  Chiron's  therapeutic  products   in
development  for  cancer, infectious  diseases  and cardiovascular  disease face
competition from  companies such  as  Genetics Institute,  Immunex  Corporation,
Genentech  and many other  biotechnology companies. Aredia-Registered Trademark-
may face competition from other bone growth factors.
 
    Chiron Vision  competes  against  numerous  healthcare,  pharmaceutical  and
biotechnology  companies in the  research, development and  marketing of devices
and therapeutic  products for  the ophthalmic  surgery market.  Chiron  Vision's
competition  in  its largest  product line,  intraocular lenses,  includes Alcon
Laboratories, Inc., a division of Nestle SA; Allergan, Inc.; Pharmacia AB; Storz
Instrument Company, a subsidiary of  American Home Products; and Staar  Surgical
Co. Gilead Sciences, Inc., has a systemically injectable pharmaceutical that may
compete against Chiron Vision's ganciclovir Vitrasert-TM- Implant, and which has
been  recommended for regulatory approval.  Summit Technology, Inc. has received
approval, and has  begun marketing  in the United  States, an  excimer laser  to
correct  vision. VISX, Inc., which has  cross-licensed its patents with those of
Chiron Vision outside the  United States, has an  excimer laser under review  at
the FDA.
 
    Betaseron-Registered  Trademark-, the  only product  licensed in  the United
States to treat relapsing-remitting multiple sclerosis, began usage by  patients
in October 1993. Potential competing products to Betaseron-Registered Trademark-
in  the  United  States and  Europe  include  two products  that  have completed
clinical trials.  Of these  two  products, a  recombinant beta  interferon  from
Biogen,  Inc. ("Biogen")  has been  recommended for  regulatory approval  in the
United States. Other companies have entered, or are preparing to enter, products
into clinical  trials for  multiple sclerosis.  In Europe,  Schering's  product,
Betaferon-TM-,  faces competition  from Ares  Serono. In  Italy and  Spain, Ares
Serono sells an extracted form of beta interferon which is used for, among other
purposes,  treatment  of  multiple  sclerosis,  and  holds  licenses  for  other
indications in several countries, including Germany.
 
    A   significant  amount  of  research   in  biotechnology  is  performed  in
universities and nonprofit research  organizations. These entities are  becoming
more  active  in  seeking patent  protection  and licensing  revenues  for their
discoveries. The competition  among large pharmaceutical  companies and  smaller
biotechnology  companies  to acquire  technologies from  these entities  also is
intensifying. While Chiron actively collaborates with such entities in  research
and has and will continue to license their technologies for further development,
these  institutions also compete with Chiron to recruit scientific personnel and
to establish proprietary technology positions.
 
                                       5
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MANUFACTURING
 
    Chiron  currently  has  licensed  manufacturing  facilities  in  Emeryville,
California,  for the  production of  biologicals. During  1995, construction was
completed on  additional  manufacturing  facilities  in  Vacaville,  California.
Chiron  also  has manufacturing  facilities in  Puerto  Rico and  Amsterdam, The
Netherlands. During  1995, the  Company began  producing certain  quantities  of
rhPDGF  and TFPI  in the  Vacaville facility  and anticipates  utilizing the St.
Louis facility  to  produce clinical  grade  materials for  Phase  1, 2,  and  3
clinical  trials  for HSV,  CMV and  HIV  products. Due  to lower  than expected
domestic commercial  demand for  the Company's  Betaseron-Registered  Trademark-
product,  the Puerto Rico facility was idled and the regulatory approval process
for Betaseron-Registered Trademark- fermentation  in the Amsterdam facility  was
suspended.  The Amsterdam facility is currently being used for the production of
bacterial vaccines and clinical grade materials and as a pilot plant for process
development.
 
    In 1995,  the  Company began  construction  activities for  a  manufacturing
facility  in Italy to be used in the production of bacterial vaccines, including
acellular pertussis. Regulatory approvals for  each of the facilities  described
above  are  necessary before  Chiron can  begin  any new  commercial production.
Failure to  obtain all  necessary  approvals and  permits would  materially  and
adversely affect the continued development and introduction of Chiron products.
 
    Following  the acquisition of IOLAB, Chiron Vision consolidated the majority
of its domestic operations at IOLAB's facilities in Claremont, California.  This
consolidation  resulted  in the  closure of  leased manufacturing  facilities in
Huntington, West Virginia; and  Rapid City, South  Dakota. Chiron Vision  leases
additional  manufacturing facilities  in Irvine,  California; Lyon,  France; and
Munich, Germany.
 
    CCD  owns   manufacturing  facilities   in  Oberlin,   Ohio;  and   Walpole,
Massachusetts.   Other   manufacturing  sites   are  leased   including  Irvine,
California; Alameda, California; Medfield, Massachusetts; and Sudbury,  England.
All CCD facilities were certified ISO 9000 in 1995.
 
MAJOR CUSTOMERS
 
    During  1995, no  single customer contributed  ten percent or  more to total
revenues.  Ciba  and  its  affiliates  are  related  parties  and   collectively
contributed  11  percent and  13 percent  of  total revenues  in 1994  and 1993,
respectively. Johnson  & Johnson  and  its affiliates  are related  parties  and
collectively contributed 22 percent and 32 percent of total revenues during 1994
and  1993, respectively.  Sales of  Betaseron-Registered Trademark-  to Chiron's
marketing partner accounted for less than ten percent of total revenues in  1995
and 1993, and 23 percent in 1994.
 
    For  a discussion of revenues by geographic area, see Part II, Item 8., Note
11 of Notes to Consolidated Financial Statements.
 
RESEARCH AND DEVELOPMENT
 
    The Company's two  primary sources  of new product  candidates are  internal
research  and development and collaboration  and licensing with other healthcare
companies. Research and  development expense  for the years  ended December  31,
1995,  1994 and 1993,  including payments to  collaborative partners, was $343.8
million, $166.2 million and $140.0 million, respectively. Under contracts  where
reimbursement is based upon work performed, the related research and development
expenses  were $51.8 million, $72.4 million and  $61.5 million in 1995, 1994 and
1993, respectively.
 
RAW MATERIALS
 
    Raw materials and laboratory supplies utilized in the Company's research are
generally available from several commercial sources. In certain projects, sample
tissues and cell strains used for the Company's research and development may  be
difficult  to  obtain. The  Company relies  upon its  good relations  with other
researchers and institutions to obtain the majority of such strains and samples.
Sources include blood banks, hospitals, universities and national  laboratories.
Most  raw materials necessary  for process development,  production scale-up and
commercial  manufacturing  are  generally  available  from  multiple  commercial
sources.    However,   certain    processes   require    materials   from   sole
 
                                       6
<PAGE>
sources or materials that are difficult for suppliers to produce and certify  to
the  Company's specifications  or for  which the raw  materials may  be in short
supply. Although  Chiron  maintains  an  awareness of  the  condition  of  these
suppliers, their ability to supply the Company's needs and the market conditions
for  these  materials, there  is  a risk  that  material shortages  could impact
production efforts.  The  Company  believes  that  its  relationships  with  its
commercial suppliers are good.
 
GOVERNMENT REGULATION
 
    Regulation by governmental agencies in the United States and other countries
is  a  significant  and changing  factor  in Chiron's  research  and development
effort, and in the Company's plans to produce and market both approved  products
and  those nearing approval. Intent to market products in Europe brings an added
regulatory burden, as the role of the European Economic Community has  increased
significantly in recent years.
 
    The  Company's products  (both marketed  and investigational)  in the United
States are primarily biologicals, but  also include drugs, diagnostic tests  and
instruments  and ophthalmic devices. All are regulated under the Food, Drug, and
Cosmetic Act ("FDCA")  and supporting regulations.  The biological products  are
additionally  regulated  under  the  Public  Health  Service  Act  ("PHSA")  and
supporting regulations. Licensing of a  biological product in the United  States
is  accompanied  by a  requirement to  simultaneously license  the manufacturing
establishment.
 
    Licensing of the  establishment includes a  requirement that all  facilities
used  to  manufacture,  fill,  test and  distribute  the  product  in interstate
commerce be inspected and approved by the FDA's Center for Biologics  Evaluation
and  Research.  The  review and  inspection  process  includes a  review  of all
labeling, including the vial,  carton, box and packers,  as well as  promotional
and advertising materials.
 
    The  FDA is  proposing to  amend the  biologics regulation  to eliminate the
establishment   license   application    requirement   for    well-characterized
biotechnology  products licensed under the PHSA.  The proposed rule would exempt
well-characterized biotechnology products, licensed under the PHSA, from certain
biologics  regulations  and  harmonize  the  requirements  applicable  to  these
products with those applicable to similar drug products approved under the FDCA.
 
    Since   every  FDA  decision  requires  submission  of  an  application  and
substantial supporting documentation (such as a New Drug Application,  Premarket
Approval  Application,  Product  License Application,  or  Establishment License
Application), the preparation  of the  documentation, its  submission and  audit
review  determines the speed with which a  research program is translated into a
marketed product.
 
    Licensing procedures  in the  European  Union ("EU")  were revised  in  1995
leading to the estab-
lishment  of  the  following  two  new  registration  procedures:  a Centralized
Procedure for  licensing of  medicinal products  derived from  the use  of  high
technology/biotechnology  processes,  and  a Decentralized  Procedure  whereby a
license granted in one Member  State of the EU  is mutually recognized by  other
Member  States, leading to  the granting of equivalent  licenses in those Member
States recognizing the original license.
 
    The Centralized Procedure is mandatory for those medicinal products  derived
from genetic engineering/monoclonal antibody technologies and optional for other
high  technology-derived medicinal  products and  any drug  with a  new chemical
entity as an active substance, a new delivery system of significant  innovation,
or  an  entirely  new  indication  of  significant  therapeutic  interest.  This
procedure leads to the  granting of a  single license for the  entire EU by  the
newly established European Medicines Evaluation Agency based in London.
 
    For  existing national licensing procedures,  a transition period to January
1, 1998  will exist.  At that  time, the  Decentralized Procedure  will  replace
independent national licensing of products in the EU.
 
    Due  to insufficient experience to date, it  is unclear what impact, if any,
these revised procedures will have for the registration of products in Europe.
 
                                       7
<PAGE>
PATENTS AND PROPRIETARY RIGHTS
 
    Intellectual property  (e.g.,  patents,  trade secrets  and  trademarks)  is
important  to the business  of the Company.  Chiron and its  subsidiaries have a
substantial number of  pending patent  applications and granted  patents in  the
United  States  and in  foreign countries.  It is  not known  how many  of these
pending patent applications will be granted as patents, and at least some of the
pending  applications  will  be  abandoned.  A  number  of  patents  and  patent
applications   owned   by  third   parties   have  been   licensed  exclusively,
semi-exclusively or nonexclusively  to Chiron  and its subsidiaries  for one  or
more  fields of use. Chiron and its subsidiaries also own a number of trademarks
in the United States and foreign countries.
 
    Due to unresolved issues regarding the scope of protection provided by  such
patents,  as well as the  possibility of patents being  granted to others, there
can be  no assurance  that  the patents  owned or  licensed  to Chiron  and  its
subsidiaries  will  provide substantial  protection  or commercial  benefit. The
rapid rate of development and the intense research efforts throughout the  world
in  biotechnology,  the significant  time  lag between  the  filing of  a patent
application  and  its  review  by  appropriate  authorities  and  the  lack   of
significant legal precedent involving biotechnology inventions make it difficult
to  predict accurately  the breadth  or degree  of protection  that patents will
afford Chiron's or its subsidiaries' biotechnology products or their  underlying
technology.  It  is also  difficult  to predict  whether  valid patents  will be
granted based  on biotechnology  patent  applications or,  if such  patents  are
granted,  to predict the nature  and scope of the claims  of such patents or the
extent to which they may be enforceable.
 
    Important legal questions remain to be  resolved as to the extent and  scope
of  available patent  protection in the  United States and  abroad. Under United
States law,  although a  patent has  a statutory  presumption of  validity,  the
issuance  of a patent is not conclusive as  to validity or as to the enforceable
scope of  its claims.  Accordingly,  there can  be  no assurance  that  Chiron's
patents   will  afford   legal  protection  against   competitors  with  similar
inventions, nor  can  there  be any  assurance  that  the patents  will  not  be
infringed  or designed around by  others or that others  will not obtain patents
that Chiron would need to license or design around.
 
    Trade secrets and  confidential information  are likely to  be important  to
Chiron's  commercial  success.  Although  Chiron and  its  subsidiaries  seek to
protect  trade  secrets  and  confidential   information  they  believe  to   be
significant,  there  can be  no assurance  that others  will not  either develop
independently the same or similar  trade secrets or confidential information  or
obtain  access to such  trade secrets or  confidential information. Furthermore,
there can be no  assurance others have  not obtained or  will not obtain  patent
protection  that will preclude Chiron or its subsidiaries from using their trade
secrets or confidential information.
 
    Most countries  limit  the  enforceability  of  patents  against  government
agencies  or government contractors. Generally, the  patent owner may be limited
to monetary relief  and may be  unable to  enjoin infringement. This  can be  of
particular  importance  in countries  where a  major customer  of Chiron  or its
licensees is a governmental  agency. The inability  to enjoin such  infringement
and  the  necessity  of  relying  exclusively  on  monetary  compensation  could
materially  diminish  the  value  of  a  particular  patent.  Furthermore,  many
countries  (including European  countries) have compulsory  licensing laws under
which third parties may compel the grant of non-exclusive licenses under certain
circumstances (for  example, failure  to "work"  the invention  in the  country,
patenting  of  improvements by  a third  party  or failure  to supply  a product
related to health and safety). The  mere existence of such limits on  injunctive
relief and compulsory licensing systems could force Chiron to grant a license it
would not have otherwise granted.
 
    Chiron  is  aware that  others,  including various  competitors, educational
institutions  and   governmental  organizations   have  intellectual   property,
particularly  patents and pending patent applications,  in the United States and
other  countries  potentially   useful  or   necessary  to   Chiron's  and   its
subsidiaries' businesses including vaccines, diagnostics, therapeutics, oncology
and  ophthalmics. Some  of these  patents and  applications claim  only specific
products or methods of making such products, while
 
                                       8
<PAGE>
others claim  more  general  processes  or  techniques.  There  may  be  similar
third-party  intellectual property  important to the  business of  Chiron or its
subsidiaries of which the Company is not  currently aware. It is likely that  in
the  future others will obtain patents  or develop proprietary rights that might
be necessary or  useful for the  manufacture, use  or sale of  some products  by
Chiron  or  its  subsidiaries.  Certain  of  these  patents  or  rights  may  be
sufficiently  broad  to  prevent  or  delay  Chiron  or  its  subsidiaries  from
practicing  necessary technology, including the  manufacture and/or marketing of
products important to Chiron's current and future business. The scope,  validity
and  enforceability of such patents,  if granted, the extent  to which Chiron or
its subsidiaries may wish or need to obtain licenses thereunder and the cost and
availability of such  licenses are  not susceptible to  accurate prediction.  If
Chiron  or  its  subsidiaries  do  not obtain  such  licenses,  products  may be
withdrawn from the market, or delays could be encountered in market introduction
while an attempt is made to design around such patents. Alternatively, Chiron or
its subsidiaries could find  that the development, manufacture  or sale of  such
products is foreclosed. Chiron or its subsidiaries could incur substantial costs
in challenging the validity or scope of such patents.
 
    Chiron  is  currently involved  in legal  proceedings involving  patents and
expects that litigation relating  to the validity and  scope of its patents  and
proprietary  rights and  those of  third parties will  continue to  arise in the
future (see Part I, Item 3.).  Substantial costs could be incurred in  defending
the  validity  or  scope  of patents  owned  by  or licensed  to  Chiron  or its
subsidiaries. If  Chiron  and  its  subsidiaries are  unable  to  obtain  strong
proprietary rights to protect a product after the expenditure of funds to obtain
regulatory  approval,  competitors  may  be able  to  market  competing products
without being required to undertake  the same lengthy and expensive  development
efforts that Chiron and its subsidiaries already have completed. In these cases,
it  is  possible that  price competition  could  become a  principal competitive
factor in the marketing of such products.  If Chiron or any of its  subsidiaries
should lose litigation with respect to third party intellectual property rights,
Chiron  and its subsidiaries could be  precluded from manufacturing or marketing
certain products and incur substantial liability for damages and attorney fees.
 
EMPLOYEES
 
    At December 31, 1995, Chiron and its subsidiaries employed 6,894 people on a
full-time and part-time basis in  eight principal locations on four  continents.
Of  Chiron's  employees,  3,789  were  involved  in  research,  development  and
manufacturing efforts  and 3,105  were involved  in operations,  administration,
sales and marketing and finance.
 
ITEM 2.  PROPERTIES
 
    Chiron's  operations are  conducted in  owned and  leased facilities located
throughout the world. Chiron's principal  facilities are located in  Emeryville,
California,  and  are  used  for  research  and  development,  manufacturing and
administrative activities. Although  the Company  leases the  majority of  these
facilities,  Chiron  owns certain  facilities as  well as  land held  for future
expansion.
 
    The Company owns manufacturing facilities located in Vacaville,  California;
St. Louis, Missouri; and Amsterdam, The Netherlands. Certain of these facilities
have  available  capacity due  to lower  than expected  domestic demand  for the
Company's  Betaseron-Registered   Trademark-  product.   Chiron  also   owns   a
manufacturing facility in Puerto Rico which is currently idled due to lower than
expected  demand  for Betaseron-Registered  Trademark-.  Chiron leases  and owns
manufacturing facilities  in Italy  for the  production of  pediatric and  adult
vaccines.  In 1995, Chiron  commenced construction in  Italy to build additional
manufacturing facilities for the production of bacterial vaccines.
 
    Chiron  owns  manufacturing  facilities  in  Oberlin,  Ohio;  and   Walpole,
Massachusetts,  which are used for the development and manufacture of diagnostic
products. The Company also owns a sales and administrative facility in  Norwood,
Massachusetts,  and a  sales office and  warehouse in  Halstead, England. Chiron
leases manufacturing facilities  relating to its  diagnostic products in  Irvine
and Alameda, California; Medfield, Massachusetts; and Sudbury, England.
 
                                       9
<PAGE>
    The  Company owns administrative and  manufacturing facilities in Claremont,
California, and  leases manufacturing  facilities in  Irvine, California;  Lyon,
France;  and  Munich,  Germany,  which  are  used  in  the  Company's ophthalmic
business.
 
    Chiron leases additional facilities in  14 cities across the United  States.
These  properties  are primarily  sales and  service  offices. The  Company also
leases additional facilities  in Canada, Mexico,  England, Switzerland,  Sweden,
Spain,  Italy,  The Netherlands,  Germany,  France, Belgium,  Austria, Portugal,
Poland, Taiwan, Singapore, Korea, Japan  and Australia, primarily for sales  and
service offices.
 
    The  Company believes  its present facilities  are adequate  for its current
needs. The Company continually evaluates future requirements for its facilities.
 
ITEM 3.  LEGAL PROCEEDINGS
 
    ABBOTT  LABORATORIES.    On  December  13,  1993,  Chiron  filed  a   patent
infringement  action against Abbott in the  United States District Court for the
Northern District  of  California.  The  suit,  which  alleges  infringement  of
Chiron's  U.S. Patent  No. 5,156,949  ("the '949  patent"), claiming  the use of
recombinant envelope antigens in  immunoassays for HIV  antibodies, is based  on
Abbott's  sale of  unlicensed HIV immunoassay  tests which are  believed to fall
within the scope of one or more patent claims. Abbott is defending this suit  on
the  basis of invalidity and  non-infringement. Chiron is requesting unspecified
damages and injunctive relief.  Cross motions for  summary judgment on  Abbott's
defenses  of inequitable conduct and prior invention were filed. After argument,
the Court granted  portions of Chiron's  motion but denied  Abbott's motion  for
summary  judgment.  Subsequently, the  United States  Patent &  Trademark Office
declared an interference  between the '949  patent and an  application owned  by
Centocor  and the U.S. government. Chiron is the junior party. The Court refused
Abbott's request to stay the  litigation pending resolution of the  interference
and has scheduled a trial for April 7, 1996.
 
    On  April 26, 1994,  Abbott filed suit  against Chiron in  the United States
District Court for the Northern District of Illinois, Eastern Division, alleging
that the Company has,  by making, using and  selling nucleic acid  hybridization
assays,  infringed three  U.S. patents  owned by  third parties  and licensed to
Abbott. Abbott  is  seeking injunctive  relief  and damages  in  an  unspecified
amount.  The Company believes that it  has substantial defenses and is defending
this suit vigorously. Trial is currently scheduled for July 15, 1996.
 
    ALLERGAN MEDICAL OPTICS.  On December 8, 1992, Allergan Medical Optics filed
a lawsuit  in the  United States  District  Court for  the Central  District  of
California  against Chiron and Chiron IntraOptics (now Chiron Vision) (together,
"Chiron"). The complaint alleged  that a mechanical inserter  used to place  the
Chiron  foldable intraocular lens in the eye during cataract surgery infringes a
patent licensed exclusively to Allergan.  Allergan sought an injunction  against
sales of the inserter, damages in an unspecified amount, and attorneys' fees. On
November  27,  1995, Chiron  Vision  and Allergan  reached  a settlement  in the
lawsuit. Chiron signed a Final Consent Judgment in exchange for a license to the
subject patent.
 
    ADVANCED CHEMTECH.  On  August 11, 1994, Advanced  ChemTech, Inc. brought  a
lawsuit  against  Chiron in  the United  States District  Court for  the Western
District of Kentucky, Louisville Division, asserting that certain Chiron patents
relating to peptide mixtures are invalid  and unenforceable and that Chiron  has
engaged  in unfair  competition and unfair  business practices  in asserting its
patent rights.  Advanced ChemTech  is asking  the Court  to: (1)  find that  the
patent  at issue is  invalid and unenforceable; (2)  find that Advanced ChemTech
does not infringe the patents; and (3) award damages according to proof.  Chiron
has answered and counterclaimed for infringement of its patents. Chiron believes
that  it  has  substantial  defenses against  the  claims  asserted  by Advanced
ChemTech.
 
    DANIEL W. BRADLEY.  On  December 20, 1994, Dr.  Daniel W. Bradley, a  former
scientist  at the U.S. Centers  for Disease Control (the  "CDC") brought suit in
the United States District Court for the Northern District of California against
Chiron,   Ortho,    certain    employees    of   Chiron,    and    the    United
 
                                       10
<PAGE>
States  government.  Subsequently,  Bradley  dismissed the  United  States  as a
defendant. Bradley, who collaborated with Chiron scientists on research that led
to the discovery of HCV, alleges he had been wrongly excluded as an inventor  of
HCV.  He requests various forms of relief,  including declarations that he is an
inventor of  Chiron's  patents  related  to  HCV  and  that  these  patents  are
unenforceable.  Bradley further seeks monetary  damages and a constructive trust
on all past and  future profits derived from  Chiron's HCV invention, which  are
estimated  by Bradley to be in excess of  $1 billion, as well as penalties under
federal and state Racketeering and Corrupt Organization (RICO) statutes.  Chiron
believes  Bradley's claims  to inventorship and  his suit are  without merit and
that substantial defenses  exist. In 1990,  Bradley and the  CDC entered into  a
settlement  agreement regarding  their respective  claims of  inventorship under
which any rights either might have were assigned to Chiron. Chiron believes that
the settlement agreement is  valid and bars substantially  all of the claims  in
the  subject  litigation. Chiron  and  the other  defendants  filed a  motion to
dismiss  Bradley's  First  Amended  Complaint.  The  Court  dismissed  Bradley's
complaint  for failure to  state a claim  upon which relief  can be granted, but
allowed Bradley  to file  an amended  complaint. Chiron  has filed  a motion  to
dismiss Bradley's Second Amended Complaint.
 
    CARNEGIE  MELLON UNIVERSITY. On August  20, 1994, Carnegie Mellon University
and Three  Rivers Biologicals,  Inc.  brought a  lawsuit  in the  United  States
District  Court  for the  Western District  of Pennsylvania  against Hoffmann-La
Roche, Inc., Roche Molecular Systems, Inc., the Perkin-Elmer Corporation, Chiron
and its wholly-owned subsidiary, Cetus  Oncology Corporation, claiming that  the
defendants  infringed certain United States patents relating to plasmids for the
expression of DNA Polymerase  I and to  plasmids providing for  nick-translation
activity.  Carnegie Mellon  and Three Rivers  Biologicals are  seeking a finding
that the defendants willfully infringed the patents at issue, injunctive  relief
and  damages according  to proof.  All defendants  have answered  the complaint.
Venue of the case was changed to  the Northern District of California on  motion
by  Chiron. Discovery  is ongoing.  The facts  of the  case, including potential
indemnification rights or obligations among the defendants, are currently  under
review. However, Chiron believes that it and Cetus have significant defenses.
 
    EVANS.   On  November 8,  1995, the Tribunal  of Brescia,  an Italian Court,
dismissed a lawsuit brought by Evans Medical Limited (a division of Medeva  plc)
("Evans") against Chiron's Italian vaccine business, Biocine S.p.A., and against
Nuova  Chimica Medica s.r.1., a distributor.  Evans sought injunctive relief via
an emergency procedure. The  suit alleged that the  p69 antigen used in  Biocine
S.p.A.'s recombinant acellular pertussis vaccines
(Acelluvax-Registered   Trademark-  and   Acelluvax-Registered  Trademark-  DTP)
infringed Evans' Italian counterpart  to its European  patent No. 162,639  ("the
'639  patent").  This  patent is  licensed  by Evans  exclusively  to SmithKline
Beecham Biologicals S.A. Counterpart patents are pending or have been issued  in
other jurisdictions, including the United States. Earlier in the year, Evans had
brought  a similar  proceeding against  Biocine S.p.A.  and its  distributor for
emergency injunctive  relief  in the  same  Court.  Following a  June  26,  1995
hearing, Evans abandoned that proceeding.
 
    Biocine S.p.A. previously had opposed issuance of the '639 patent before the
European  Patent Office ("EPO") and has appealed  the finding reached by the EPO
in that opposition proceeding. Biocine S.p.A.  filed an action against Evans  in
Milan on October 23, 1995 alleging invalidity of the same patent that formed the
basis  for the two Italian  suits discussed above. Biocine  S.p.A. later filed a
claim against Evans for non-infringement  with the Milan Court. Evans'  response
to  the Milan actions was filed in February 1996. Also in February 1996, Biocine
S.p.A. filed an action alleging invalidity and non-infringement of Evans'  Dutch
equivalent  to the '639 patent in The  Netherlands. Chiron believes that it does
not infringe any valid claim in the '639 patent or in its foreign counterparts.
 
    MUREX DIAGNOSTICS, LTD.   In a  series of  actions, the first  of which  was
brought  on  March 2,  1992, Chiron,  together with  Ortho and  Ortho Diagnostic
Systems, Ltd. (collectively, "Ortho"), filed suit in the High Court for  England
and  Wales against Murex  Diagnostics, Ltd. ("Murex"),  alleging infringement of
Chiron's U.K. Patent No.  2,212,511 ("the '511 patent")  as a result of  Murex's
manufacture  and sale of HCV immunoassay kits  in the U.K. Murex is a subsidiary
of International Murex Technologies Corp., a Canadian company. Chiron and  Ortho
sought injunctive relief and unspecified damages.
 
                                       11
<PAGE>
On  May 27, 1994, the High Court  granted judgment for Chiron and Ortho, holding
the '511 patent  valid and infringed,  and ordered  Murex to pay  damages in  an
amount  to  be  determined. Both  Murex  and the  Chiron/Ortho  parties appealed
various aspects of the High Court's  judgment. Chiron's and Ortho's request  for
an  injunction was  granted on November  30, 1994. Following  an interim damages
inquiry which was  held in  February 1996,  the Court  ordered Murex  to pay  L6
million  (approximately $9  million) to  Chiron/Ortho by  February 23,  1996. On
February 22, 1996, Murex, which had changed its name to Specialist  Diagnostics,
Ltd., filed a petition for voluntary liquidation. There can be no assurance when
or whether Chiron and Ortho will be able to collect this damage award. A damages
inquiry is scheduled for July 1996.
 
    In  a series of rulings on November 2  and 7, 1995, the U.K. Court of Appeal
held that, with the exception  of one claim, the '511  patent is valid and  that
Chiron  could amend the patent and proceed with the damages inquiry. The parties
have applied for leave to appeal to the House of Lords.
 
    Chiron is informed that officials within the British Ministry of Health have
in the past raised  the possibility of authorizing  Murex's infringement of  the
'511 patent under the "Crown use" provisions of British law, with respect to the
sale  of HCV immunoassay  kits to the British  National Health Service. Further,
Murex has stated  that it will  apply for  a compulsory license  under the  '511
patent.
 
    Infringement  proceedings  against  Murex  on  German  and  European patents
corresponding to the '511  patent also have  been filed by  Chiron and Ortho  in
Germany,  Italy, The  Netherlands and Belgium.  On January 23,  1995, Chiron and
Ortho were granted an injunction in Germany. On May 8, 1995, Chiron was  granted
a cross-border preliminary injunction by the Dutch Court preventing infringement
by  Murex  and  certain of  its  affiliates covering  The  Netherlands, Belgium,
France, Spain and Luxembourg. Murex has  brought an action in Australia  seeking
revocation  of  the  Australian  counterpart  of  the  '511  patent.  Chiron has
counterclaimed for infringement. That matter is  scheduled for trial in June  of
1996.
 
    ORGANON  TEKNIKA,  LTD.   On May  4, 1994,  Chiron instituted  summary legal
proceedings against Organon  Teknika, B.V., Akzo  Pharma, B.V., subsidiaries  of
Akzo   N.V.  (all  subsidiaries  of  Akzo  N.V.  (collectively  referred  to  as
"Organon")), and United Biomedical, Inc. ("UBI"), the supplier of Organon's  HCV
antigens and kits, in the District Court of the Hague, The Netherlands, alleging
infringement  of European Patent No. 318,216 ("the  '216 patent") as a result of
the defendants' manufacture and sale of HCV immunoassay kits. On July 22,  1994,
Chiron  was  granted  a  cross-border  preliminary  injunction  against  further
infringement, including sale  of the UBI  kit, by Organon  in Austria,  Belgium,
Switzerland,  Germany,  Spain,  France,  Italy,  Liechtenstein,  Luxembourg, The
Netherlands and Sweden. Organon and UBI appealed the injunction. The '216 patent
is a counterpart of the British '511 patent. Infringement proceedings brought by
Chiron and Ortho were also pending  against Organon in Italy and Belgium  (based
on  the '216 patent), and consolidated with the actions against Murex, described
above. Chiron, Ortho, and Organon settled all European HCV litigation on October
9, 1995, and Chiron  and Ortho were compensated  for past infringement. UBI  did
not  participate  in the  settlement, and  has  been ordered  to pay  Ortho Ltd.
damages by the U.K.  Court of Appeal,  along with Murex,  as described above.  A
damages inquiry has not yet been scheduled.
 
    SICOR.    In April  1991, Alco  Chemicals, Ltd.  ("Alco") and  Sicor, S.p.A.
("Sicor"), former suppliers of bulk doxorubicin to Cetus Ben Venue  Therapeutics
("CBVT"),  filed  suit in  the  United States  District  Court for  the Northern
District of California against Cetus  Oncology Corporation ("Cetus"), Ben  Venue
Laboratories,  Inc. ("Ben Venue"), CBVT and  Erbamont, Inc. ("Erbamont") and its
affiliates. Plaintiffs claim  that they had  distribution and supply  agreements
with CBVT relative to a product called doxorubicin hydrochloride. Sicor had been
prevented  from manufacturing  product for CBVT  since September  1990. In March
1991, CBVT entered  into an agreement  with Erbamont which  provided for,  among
other  things, the settlement of several legal proceedings then pending relating
to Erbamont's alleged doxorubicin proprietary  rights, and the exclusive  supply
of  doxorubicin to CBVT by  Erbamont. The Sicor complaint  alleges breach of the
CBVT contract to  purchase bulk  doxorubicin from  Sicor, as  well as  antitrust
violations   and   interference   with  contract   and   prospective  advantage,
 
                                       12
<PAGE>
and sought unspecified damages. Plaintiffs assert in separate counts against all
of the Cetus  parties that their  contracts with CBVT  have been breached,  that
inducement  of  such breaches  has been  tortious, that  plaintiffs' prospective
economic relations have been tortiously  frustrated, that the Cetus parties  are
indebted to plaintiffs on past accounts said to relate to the joint financing of
earlier  litigation, and that plaintiffs' distribution and supply of doxorubicin
has been foreclosed by reason of violations of the federal antitrust laws. Cetus
has denied  any  entitlement  to  recovery  in this  lawsuit  and  has  filed  a
counterclaim  against the plaintiffs  for fraud and breach  of contract based on
Sicor's failure to deliver the bulk product. Sicor's antitrust claims have  been
dismissed  on motion and Sicor has  dismissed its claims against Erbamont. Sicor
filed a summary judgment motion with  respect to the counterclaims of the  Cetus
parties.  On February  2, 1996,  the District  Court granted  that motion  in an
opinion which the  Company is currently  studying. The Company  believes it  has
substantial  defenses  to the  Sicor claims.  A  related arbitration  before the
International Chamber of Commerce in New  York brought by Sicor against  Chiron,
Cetus,  and  Ben Venue  has  been stayed  pending  the resolution  of  the Cetus
parties' counterclaims in the litigation described above.
 
    In February 1995, Sicor and Alco filed a further action in the United States
District Court for the Northern District of California against CBVT for  amounts
allegedly  owed by CBVT  to Sicor and  Alco for the  supply of doxorubicin, plus
interest and attorneys' fees. This case has  been assigned to the same judge  as
the  above-referenced  District Court  case. The  Company  believes that  it has
significant defenses to these claims.
 
    SCRIPPS CLINIC.   The Company is  defending a lawsuit  filed on November  8,
1983,  by the Scripps  Clinic and Research  Foundation and Revlon,  Inc., in the
United States District Court  for the Northern  District of California  alleging
that  Chiron's research  program to synthesize  a protein  associated with human
blood  clotting  ("Factor  VIII:C")   through  genetic  engineering   techniques
infringes plaintiffs' rights under a patent for purified Factor VIII:C. The suit
seeks  an injunction  against further infringement,  an accounting, compensatory
damages of at least $10 million and  punitive damages in the same amount.  After
the  trial court  granted summary  judgment in  favor of  Chiron, the plaintiffs
appealed. Appeal Nos. 89-1541, -1542, -1543,  -1646 and -1647 were filed in  the
United  States Court  of Appeals  for the  Federal Circuit.  The Appellate Court
reversed the trial court, finding that summary judgment was not appropriate  and
directing  that a number of issues be tried, including the issues of inequitable
conduct on the  part of Scripps,  patent validity, and  patent infringement.  No
trial  date has  been set  and it  is unclear  when a  date will  be set. Chiron
intends to vigorously assert its defenses at trial.
 
    SUMMIT.  On September 29, 1994, Summit Technology Ireland B.V., a subsidiary
of Summit Technology, Inc., a manufacturer of ophthalmic lasers, filed a  patent
infringement  action in the  Regional Court of  Dusseldorf, Germany, against two
German subsidiaries of Chiron Vision (Chiron Technolas and Chiron Adatomed), and
their respective managing directors. The  suit alleged that the manufacture  and
sale in Germany of the Technolas-Registered Trademark-
Keracor-Registered   Trademark-   '116  excimer   laser  infringed   the  German
counterpart of a European patent held by Summit. Summit sought injunctive relief
and damages which it estimated  at Deutsche mark 2  million. On August 3,  1995,
the  German Court  granted judgment  in favor  of Summit,  granted an injunction
against  defendants'  further   infringement  and  awarded   damages  for   past
infringement  in  an  amount to  be  determined.  On September  1,  1995, Summit
enforced the judgment and  the injunction by posting  security in the amount  of
Deutsche  mark 2 million. The Company's  appeal of the Regional Court's decision
is pending. Chiron Technolas, Chiron Vision's sole source of ophthalmic  lasers,
continues  to manufacture  ophthalmic excimer  lasers, which  are distributed by
Chiron Vision and its  subsidiaries. The Company  believes these activities  are
outside  the scope of the judgment and  injunction of the German Regional Court.
The Company has also initiated a separate judicial action in Germany seeking  to
invalidate Summit's patent.
 
    AMERICAN  HOME  PRODUCTS.    On  April  27,  1995,  American  Home  Products
Corporation ("AHP")  filed suit  against Chiron  in the  Superior Court  in  New
Castle  County,  Delaware,  claiming  compensatory,  consequential  and punitive
damages based  on an  alleged breach  and repudiation  by Chiron  of a  contract
pursuant  to which Chiron  had agreed to  purchase certain assets  from AHP. The
case has been settled and was ordered dismissed on December 2, 1995.
 
                                       13
<PAGE>
    BRILLIANT TRADING CO., WOLFSON.  Following the announcement by Chiron of the
signing of  a definitive  agreement to  acquire Viagene,  Inc. ("Viagene"),  two
lawsuits  purporting to be class actions were filed on April 24 and May 1, 1995,
respectively, in the Court  of Chancery of the  State of Delaware against  named
directors  and officers of Viagene and against  Viagene and Chiron. In one case,
Chiron is  sued on  a  theory that  it aided  and  abetted alleged  breaches  of
fiduciary  duty by  Viagene's directors and  officers in  approving the proposed
acquisition by Chiron. In the other case, Chiron is sued for alleged breaches of
fiduciary  duty  as  a  controlling  stockholder  of  Viagene.  Plaintiffs  seek
declaratory  and injunctive relief,  an accounting and  costs and disbursements.
Defendants have  received an  open  extension of  time  to answer  or  otherwise
respond. Chiron believes these suits are without merit.
 
    STOCKHOLDER  LITIGATION.    In  November 1994,  Chiron,  its  directors, and
certain of its officers were sued  in three essentially identical actions  filed
as  class actions on behalf of  Chiron stockholders, alleging that the directors
had violated their fiduciary  duty by failing to  maximize stockholder value  in
connection  with  the  series  of transactions  affected  with  Ciba  which were
announced on November 20, 1994, by, among other things, not taking all  possible
steps  to seek out and encourage the best offer for the Company once the Company
had been put in play. Two of the actions filed respectively on November 14, 1994
and November 22, 1994 (HANNA V. CHIRON CORP., ET AL., C.A. No. 13874, and DEZUBE
V. CHIRON CORPORATION ET AL., C.A. 13896) were filed in the Court of Chancery of
the State of Delaware in and for New Castle County. The complaints in both cases
ask for  injunctive relief,  rescission and  attorneys' fees.  Plaintiff in  the
HANNA  action additionally seeks damages in  an unspecified amount. Plaintiff in
the DEZUBE action  additionally seeks  an accounting. The  complaints have  been
answered by all defendants, who deny the material allegations of the complaints.
The  third action was filed in the Superior Court of California, Alameda County,
Northern Division, on December 1, 1994 (PERERA ET AL., V. CHIRON CORPORATION  ET
AL., C.A. No. 744522-2). Plaintiff sought injunctive and declaratory relief, and
an  accounting, costs and disbursements, including attorneys' and experts' fees,
and other relief.
 
    On October  17, 1995,  the PERERA  plaintiffs commenced  a new  action  (the
"Federal  Action") in the United States District Court for the Northern District
of California, against  the same defendants  and Ciba-Geigy, Ltd.,  Ciba-Geigy's
Chairman Alex Krauer, Ciba-Geigy Corporation, and Ciba Biotech Partnership, Inc.
(collectively, the "Ciba Defendants"). The Federal Action asserts both state and
federal  claims, including a claim under Sections  10(b), 14(d) and 14(e) of the
Securities Exchange Act  of 1934, and  seeks damages and  injunctive relief.  On
October  23, 1995,  in light  of the  filing of  the Federal  Action, the PERERA
action was dismissed by stipulation of the parties.
 
    Plaintiffs and all  of the defendants  other than the  Ciba Defendants  have
entered  into an agreement to  settle the Federal Action  on a class-wide basis,
subject to approval by the Court. Under the terms of that settlement  agreement,
Chiron  will  pay  plaintiffs' counsel  up  to  $300,000 in  attorneys  fees and
expenses, as  may be  awarded by  the Court,  and will  pay the  costs of  class
notice.   Chiron  has  no  other  financial  obligations  under  the  settlement
agreement, which also  contemplates that the  HANNA and DEZUBE  actions will  be
dismissed  as moot  following approval  of the  settlement and  dismissal of the
Federal Action. It is presently expected  that the settlement will be  presented
to  the District Court for preliminary approval  at a status conference in March
1996, and that  a final  approval hearing will  be scheduled  within two  months
thereafter, following notice to the plaintiff class.
 
                                       14
<PAGE>
ITEM 4.  SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
 
    No  matters were brought to  a vote of Chiron's  stockholders in the quarter
ended December 31, 1995.
 
                      EXECUTIVE OFFICERS OF THE REGISTRANT
 
    The executive officers of  the Company, who serve  at the discretion of  the
Board of Directors, are as follows:
 
<TABLE>
<CAPTION>
              NAME                AGE                    TITLE
- --------------------------------  ---  -----------------------------------------
<S>                               <C>  <C>
William J. Rutter, Ph.D.          67   Chairman of the Board
Edward E. Penhoet, Ph.D.          55   President and Chief Executive Officer
Renato Fuchs, Ph.D.               53   Senior Vice President, Manufacturing and
                                        Development Operations
William G. Green, Esq.            51   Senior Vice President, General Counsel
                                        and Secretary
Pablo D.T. Valenzuela, Ph.D.      54   Senior Vice President, Biologicals
                                        Research and Development; Office of the
                                        President, Chiron Diagnostics
Lewis T. Williams, M.D., Ph.D.    47   Senior Vice President; President, Chiron
                                        Technologies
Dennis L. Winger                  48   Senior Vice President, Finance and
                                        Administration, and Chief Financial
                                        Officer
Robert P. Blackburn, Esq.         39   Vice President and Chief Patent Counsel
Kenneth J. Conway                 47   Senior Vice President, Ciba Corning
                                        Diagnostics; Office of the President,
                                        Chiron Diagnostics
Keith A. Costa                    58   Executive Vice President, Ciba Corning
                                        Diagnostics; Office of the President,
                                        Chiron Diagnostics
Rajen K. Dalal                    42   Vice President, Corporate Planning and
                                        Business Development
Dino Dina, M.D.                   49   Vice President, Virology and Vaccine
                                        Development; President, Chiron Biocine
                                        Company
Alain Herrera, M.D.               45   Vice President; President, Chiron
                                        Therapeutics Europe
Edward Kenney                     51   Division Vice President, Chiron
                                        Therapeutics
William J. Link, Ph.D.            49   Vice President; Chairman and Chief
                                        Executive Officer, Chiron Vision
Mario Lorenzoni                   54   Vice President; Chief Executive Officer,
                                        Biocine S.p.A.
Bernardita Mendez, Ph.D.          43   Vice President, Regulatory and Quality
                                        Affairs
Walter H. Moos, Ph.D.             41   Vice President, Research and Development,
                                        Chiron Technologies
Frances L. Tuttle                 48   Senior Vice President, Ciba Corning
                                        Diagnostics; Office of the President,
                                        Chiron Diagnostics
Mickey S. Urdea, Ph.D.            43   Vice President, Nucleic Acid Systems
                                        Research and Development
</TABLE>
 
                                       15
<PAGE>
    DR.  RUTTER, a co-founder of the Company,  has served as its Chairman of the
Board since the  Company's inception  in 1981. He  was Director  of the  Hormone
Research  Institute  at  the  University of  California,  San  Francisco Medical
Center, from 1983 to May 1989 and has  been on the faculty at the University  of
California,  San Francisco, since 1969, becoming  Professor Emeritus in 1991. He
has served as Director of Ciba-Geigy Ltd. since 1995.
 
    DR. PENHOET, a co-founder of the  Company, has been Chief Executive  Officer
and  a Director since  the Company's inception  in 1981, and  was President from
1981 to 1989 and Vice Chairman from  1989 until 1993. Dr. Penhoet reassumed  the
title of President, effective April 1, 1993. He has been a faculty member at the
University of California, Berkeley, for 24 years.
 
    DR.  FUCHS joined  the Company as  Senior Vice  President, Manufacturing and
Development Operations, in  1993. From 1988  until joining Chiron,  he was  with
Centocor,  Inc.,  most  recently  as  Senior  Vice  President  of Pharmaceutical
Development, responsible for process development of antibody products.
 
    MR. GREEN  joined the  Company  as Vice  President  and General  Counsel  in
October  1990,  having  served as  Secretary  or Assistant  Secretary  since the
Company's inception in 1981. In February 1992, he became Senior Vice  President,
Secretary  and General Counsel. From  1981 to 1990, he was  a partner in the San
Francisco law firm of Brobeck, Phleger & Harrison.
 
    DR. VALENZUELA, a co-founder of the Company, became Senior Vice President in
March 1989, and a member of the Office of the President, Chiron Diagnostics,  in
October 1995, having served as Vice President and Director of Research since the
Company's   inception  in  1981.  He  was  associated  with  the  University  of
California, San  Francisco,  and also  has  held adjunct  faculty  positions  at
Catholic University in Santiago, Chile.
 
    DR.  WILLIAMS joined the Company in August 1994 as Senior Vice President and
President of Chiron Technologies. From 1988 until joining the Company, he was  a
professor  of medicine at the University  of California, San Francisco. Prior to
joining UCSF, he was on the faculty  of Harvard Medical School. In addition,  he
was  a co-founder and director of COR Therapeutics, Inc. from 1988 until joining
the Company.
 
    MR. WINGER joined the Company in August 1989 as Vice President, Finance  and
Administration,  and Chief Financial  Officer. He became  Senior Vice President,
Finance and Administration, and  Chief Financial Officer,  in February 1992.  He
was Vice President and Chief Financial Officer of The Cooper Companies from 1987
to 1989.
 
    MR.  BLACKBURN joined the Company in  April 1989 as Director of Intellectual
Property. He became Vice  President and Chief Patent  Counsel in February  1992.
Prior  to joining  the Company, he  was a  partner in the  law firm  of Ciotti &
Murashige, Irell & Manella.
 
    MR. CONWAY joined the  Company in January 1995  as Senior Vice President  of
CCD,  as a result of the Company's acquisition of CCD. He has held that position
since 1991. In October 1995, he was appointed  as a member of the Office of  the
President for Chiron Diagnostics.
 
    MR.  COSTA joined the Company in January 1995 as Executive Vice President of
CCD, a  position he  has  held since  December 1988.  In  October 1995,  he  was
appointed as a member of the Office of the President for Chiron Diagnostics.
 
    MR.  DALAL  joined  Chiron in  December  1991 as  Vice  President, Corporate
Planning. From 1983 until joining Chiron,  he was employed by the  international
consulting  firm of  McKinsey & Company,  where he  performed general management
consulting in  the  firm's  pharmaceuticals,  medical  devices  and  diagnostics
industries practice.
 
    DR.  DINA joined the  Company as Director  of Virology in  1982. In November
1990, he  became  Vice  President,  Virology and  Vaccine  Development,  and  in
February  1993, Vice President, Virology and Vaccine Development, and President,
Chiron Biocine.
 
                                       16
<PAGE>
    DR.  HERRERA  was  promoted  to  Vice  President  and  President  of  Chiron
Therapeutics  Europe in 1993. From 1991 until  1993, he was Managing Director of
the Company's EuroCetus office in France. From 1987 until joining Chiron, he was
Managing Director of Pierre Fabre Oncologie Laboratories.
 
    MR. KENNEY joined  the Company in  1991 as  a result of  the acquisition  of
Cetus Corporation as Vice President, Marketing and Sales. Prior to that date, he
held   the  position  of   Senior  Director,  Marketing   Group,  at  Cetus  for
approximately four years.
 
    DR. LINK joined the  Company as President of  Chiron Ophthalmics, Inc.  (now
"Chiron  Vision") in February 1986  and held that title  until 1995. In November
1990 he became Vice President  of the Company, in  January 1992 he became  Chief
Executive  Officer, Chiron Vision, and in  April 1995 he became Chairman, Chiron
Vision.
 
    MR. LORENZONI joined the Company in January 1995 as Vice President and Chief
Executive Officer of Biocine  S.p.A. Prior to joining  the Company, he had  been
Chief  Executive Officer of Biocine S.p.A.  since 1994, and Managing Director of
Biocine S.p.A. since 1992. Prior to 1992, he was Vice Director of Ciba Italy.
 
    DR. MENDEZ  joined the  Company  in 1984  in Scientific  Affairs,  following
post-doctoral  studies  at the  University of  California, Berkeley.  She became
Director of Regulatory and  Patent Affairs in  1987, Vice President,  Regulatory
Affairs,  in  February  1992  and,  in  February  1993,  became  Vice President,
Regulatory and Quality Affairs.
 
    DR. MOOS joined Chiron in October 1991  as a Vice President of Research  and
Development  and Director  of Chemical  Therapeutics. He  became Vice President,
Chemical Therapeutics  Research  and  Development, in  February  1992  and  Vice
President,  Research and  Development, Chiron  Technologies, in  1994. From 1982
until joining  Chiron,  he  was with  the  Parke-Davis  Pharmaceutical  Research
Division  of the Warner-Lambert Company, where he last held the position of Vice
President, Neuro-
science and Biological  Chemistry. Dr.  Moos has  been an  Adjunct Professor  of
Pharmaceutical  Chemistry at the University  of California, San Francisco, since
1992.
 
    MS. TUTTLE joined the  Company in January 1995  as Senior Vice President  of
CCD in charge of Worldwide Marketing and Strategic Planning, a position she held
from  1994 to February 1996.  In October 1995, she was  appointed as a member of
the Office of the President for Chiron  Diagnostics. From 1990 to 1994, she  was
Executive Director of Manufacturing Operations for CCD.
 
    DR. URDEA joined the Company in 1981 after a post-doctoral fellowship at the
University   of  California,  San  Francisco,  and  has  directed  nucleic  acid
diagnostic research and development efforts at Chiron since that time. He became
Vice President, Nucleic Acid Systems Research and Development, in February 1992.
 
                                       17
<PAGE>
                                    PART II
 
ITEM 5.  MARKET FOR THE REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER
         MATTERS
 
    The information under the caption "Market Price of Common Stock" on page  49
of  the 1995 Consolidated Financial Statements,  which is included as Exhibit 13
to this Form 10-K Report, is incorporated herein by reference.
 
ITEM 6.  SELECTED FINANCIAL DATA
<TABLE>
<CAPTION>
                                                                   YEAR ENDED DECEMBER 31,
                                           -----------------------------------------------------------------------
                                                1995           1994           1993          1992          1991
                                           --------------  -------------  ------------  ------------  ------------
<S>                                        <C>             <C>            <C>           <C>           <C>
                                                            (IN THOUSANDS, EXCEPT PER SHARE DATA)
Consolidated Statement of Operations
 Data:
  Total revenues.........................  $    1,100,582  $     453,979  $    317,535  $    246,260  $    141,498
  Income (loss) from operations..........        (482,428)        42,400        15,138       (95,544)     (455,765)
  Other income (expense), net............          (8,346)       (10,403)        7,949         6,973        12,997
  Income (loss) before extraordinary
   item..................................        (512,463)        18,325        18,384       (92,595)     (444,650)
  Net income (loss)......................        (512,463)        18,325        18,384       (99,252)     (444,650)
  Income (loss) per share before
   extraordinary item....................          (12.62)          0.53          0.55         (3.07)       (22.54)
  Net income (loss) per share............          (12.62)          0.53          0.55         (3.29)       (22.54)
  Weighted average shares outstanding....          40,610         34,293        33,681        30,200        19,724
 
<CAPTION>
 
                                                                        DECEMBER 31,
                                           -----------------------------------------------------------------------
                                                1995           1994           1993          1992          1991
                                           --------------  -------------  ------------  ------------  ------------
                                                            (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                        <C>             <C>            <C>           <C>           <C>
Consolidated Balance Sheet Data:
  Working capital........................  $      268,408  $     314,174  $    256,419  $    250,874  $    486,826
  Total assets...........................       1,490,198      1,049,742       968,597       701,115       907,162
  Long-term debt, excluding current
   portion...............................         413,248        338,061       332,991       110,681       247,466
  Accumulated deficit....................      (1,087,699)      (575,236)     (593,561)     (611,945)     (511,783)
  Stockholders' equity...................         672,412        572,631       522,289       478,681       505,617
 
Number of employees......................           6,894          2,668         2,179         1,867         1,706
</TABLE>
 
    On January 8, 1992, Chiron combined with IntraOptics, Inc. in a  transaction
accounted  for as a pooling-of-interests. All periods have been restated for the
effects of  this  combination.  On  December 12,  1991,  Chiron  acquired  Cetus
Corporation  ("Cetus")  in  a  merger  accounted  for  by  the  purchase method;
therefore, the operating  results of  Cetus are included  from the  date of  the
acquisition.
 
    On  May 10, 1994, Chiron  acquired Laboratoires Domilens, S.A. ("Domilens"),
in a transaction accounted for by the purchase method; therefore, the  operating
results of Domilens are included from the date of the acquisition.
 
    Effective  January 1, 1995, under a  series of agreements between Chiron and
Ciba, Chiron acquired  CCD and  Ciba's interest  in Chiron  Biocine Company  and
Biocine  S.p.A.  The acquisition  of  those entities  was  accounted for  by the
purchase method;  therefore,  the  operating  results  for  those  entities  are
included  for the  entire year.  On March 31,  1995, Chiron  Vision acquired the
surgical division of IOLAB from Johnson & Johnson in a transaction accounted for
by the purchase method; therefore, the  operating results of IOLAB are  included
from  the  date  of the  acquisition.  On  September 29,  1995,  Chiron acquired
Viagene, Inc. in a transaction accounted for by the purchase method;  therefore,
the  operating  results of  Viagene,  Inc. are  included  from the  date  of the
acquisition.
 
                                       18
<PAGE>
    The Company has paid no cash dividends and does not expect to pay  dividends
in the foreseeable future.
 
ITEM 7.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
         OF OPERATIONS
 
    The  information under the caption  "Management's Discussion and Analysis of
Financial Condition  and  Results of  Operations"  on  pages 1-12  of  the  1995
Consolidated  Financial Statements which is included  as Exhibit 13 to this Form
10-K Report is incorporated herein by reference.
 
ITEM 8.  FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
 
    The financial statements and supplementary data  on pages 13-47 of the  1995
Consolidated  Financial Statements which is included  as Exhibit 13 to this Form
10-K Report are incorporated herein by reference.
 
ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
         FINANCIAL DISCLOSURE
 
    The Company's current reports on Form 8-K dated March 7, 1994, and March 25,
1994, are incorporated herein by reference.
 
                                    PART III
 
ITEM 10.  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT
 
    The information under the captions  "Election of Directors" and  "Compliance
with  Section 16(a) of the Securities Exchange  Act of 1934" in the Registrant's
Proxy Statement for the  Annual Meeting of  Stockholders to be  held on May  16,
1996, is incorporated herein by reference.
 
    Information  as to Chiron's executive officers appears  at the end of Part I
of this Report.
 
ITEM 11.  EXECUTIVE COMPENSATION
 
    The  information  under   the  caption  "Executive   Compensation"  in   the
Registrant's  Proxy Statement for the Annual  Meeting of Stockholders to be held
on May 16, 1996, is incorporated herein by reference.
 
ITEM 12.  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
 
    The information under  the captions "Principal  Stockholders" and  "Security
Ownership  of Management"  in the  Registrant's Proxy  Statement for  the Annual
Meeting of Stockholders to be  held on May 16,  1996, is incorporated herein  by
reference.
 
ITEM 13.  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
    The  information under the captions "Related Transactions" and "Compensation
Committee Interlocks  and  Insider  Participation"  in  the  Registrant's  Proxy
Statement  for the Annual Meeting of Stockholders to be held on May 16, 1996, is
incorporated herein by reference.
 
                                    PART IV
 
ITEM 14.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K
 
a)  1. FINANCIAL STATEMENTS
 
    The Consolidated Financial  Statements and Notes  to Consolidated  Financial
Statements   appearing  on  pages  13-47  of  the  1995  Consolidated  Financial
Statements, which is included  as Exhibit 13  to this Form  10-K Report and  the
Reports  of Independent Auditors appearing on pages 30 and 31 of this Form 10-K,
are incorporated herein by reference.
 
                                       19
<PAGE>
    2. FINANCIAL STATEMENT SCHEDULES
 
    Schedule II -- Valuation and Qualifying Accounts
 
    All other  schedules are  omitted,  since the  required information  is  not
present  or is not  present in amounts  sufficient to require  submission of the
schedule, or because the  information required is  included in the  consolidated
financial statements and notes hereto.
 
b)  REPORTS ON FORM 8-K
 
    On  November 13, 1995, Chiron filed Amendment No. 1 to its current report on
Form 8-K,  dated  September  29, 1995,  to  include  under Item  7  the  audited
financial  statements of Viagene, Inc. and proforma combined condensed financial
information.
 
c)  EXHIBITS
 
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                           EXHIBIT
- -----------  ------------------------------------------------------------------------------------
<S>          <C>
      2.01   Agreement and Plan of Merger, made as of February 6, 1987, incorporated by reference
             to Exhibit 2.01 of the Registrant's Form 10-Q report for the period ended  September
             30, 1994.
      3.01   Restated  Certificate of  Incorporation of  the Registrant,  dated August  18, 1987,
             incorporated by reference to Exhibit 3.01  of the Registrant's Form 10-K report  for
             fiscal year 1991.
      3.02   Certificate of Amendment of Restated Certificate of Incorporation of the Registrant,
             dated  December  12,  1991,  incorporated  by  reference  to  Exhibit  3.01  of  the
             Registrant's Form 10-K report for fiscal year 1991.
      3.03   Bylaws of the Registrant, as amended,  incorporated by reference to Exhibit 3.03  of
             the Registrant's Form 10-K report for fiscal year 1994.
      4.01   Indenture,  dated as of  May 21, 1987,  between Cetus Corporation  and Bankers Trust
             Company, Trustee, incorporated by reference to Exhibit 4.01 of the Registrant's Form
             10-Q report for the period ended September 30, 1994.
      4.02   First  Supplemental  Indenture,  dated  as  of  December  12,  1991,  by  and  among
             Registrant,  Cetus Corporation, and Bankers Trust Company, incorporated by reference
             to Exhibit 4.02 of the Registrant's Form 10-K report for fiscal year 1992.
      4.03   Indenture, dated as of November 15, 1993, between Registrant and The First  National
             Bank  of  Boston, as  Trustee,  incorporated by  reference  to Exhibit  4.03  of the
             Registrant's Form 10-K report for fiscal year 1993.
      4.04   Rights Agreement, dated as of August  25, 1994, between the Company and  Continental
             Stock  Transfer & Trust Company, which  includes the Certificate of Designations for
             the Series A Junior Participating  Preferred Stock as Exhibit  A, the form of  Right
             Certificate  as Exhibit B and the Summary  of Rights to Purchase Preferred Shares as
             Exhibit C, incorporated  by reference to  Exhibit 4.04 of  the Registrant's  current
             report on Form 8-K dated August 25, 1994.
      4.05   Amendment  No. 1 to Rights  Agreement dated as of  November 20, 1994, between Chiron
             Corporation  and  Continental  Stock  Transfer  &  Trust  Company,  incorporated  by
             reference  to Exhibit  4.05 of  the Registrant's current  report on  Form 8-K, dated
             November 20, 1994.
      4.06   $1,000,000 County of Lorain, Ohio Variable Rate Industrial Revenue Bonds dated as of
             July 1, 1984, due  July 1, 2014,  incorporated by reference to  Exhibit 4.06 of  the
             Registrant's  Form 10-Q report  for the period  ended April 2,  1995. The Registrant
             agrees to furnish to the Commission upon  request a copy of such agreement which  it
             has elected not to file under the provisions of Regulation 601(b)(4)(iii).
</TABLE>
 
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  EXHIBIT
  NUMBER                                           EXHIBIT
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<S>          <C>
      4.07   $1,000,000  Walpole Industrial Development Authority  6.75% Industrial Revenue Bonds
             dated as of July  1, 1979, due  July 1, 2004, incorporated  by reference to  Exhibit
             4.07  of the Registrant's Form  10-Q report for the period  ended April 2, 1995. The
             Registrant agrees to furnish to the Commission upon request a copy of such agreement
             which it has elected not to file under the provisions of Regulation 601(b)(4)(iii).
     10.01   Lease between Registrant and BGR Associates, a California limited partnership, dated
             May 26, 1989, incorporated  by reference to Exhibit  10.01 of the Registrant's  Form
             10-Q report for the period ended September 30, 1994.
     10.02   First Amendment to Lease between Registrant and BGR Associates, a California limited
             partnership.
     10.03   Lease  between Registrant and  BGR Associates II,  a California limited partnership,
             dated May 26, 1989, incorporated by  reference to Exhibit 10.02 of the  Registrant's
             Form 10-Q report for the period ended September 30, 1994.
     10.04   First  Amendment to  Lease between  Registrant and  BGR Associates  II, a California
             limited partnership, dated as of March 15, 1995.
     10.05   Agreement and Plan of  Merger dated as  of April 23, 1995  between Viagene, Inc.,  a
             Delaware  corporation, and Chiron Corporation,  incorporated by reference to Exhibit
             10.67 of the Registrant's current report on Form 8-K dated April 24, 1995.
     10.06   Stockholders' Agreement dated  as of April  23, 1995 among  certain stockholders  of
             Viagene,  Inc.,  a Delaware  corporation,  and Chiron  Corporation,  incorporated by
             reference to Exhibit  10.68 of  the Registrant's current  report on  Form 8-K  dated
             April 24, 1995.
     10.07   Stock and Asset Purchase Agreement dated as of March 6, 1995, by and among Johnson &
             Johnson,  a New Jersey corporation, Site Microsurgical Systems, Inc., a Pennsylvania
             corporation, and Chiron Corporation and Amendment No. 1 to Stock and Asset  Purchase
             Agreement,  entered  into  March 31,  1995  by  and among  Johnson  &  Johnson, Site
             Microsurgical Systems, Inc.  and Chiron  Corporation, incorporated  by reference  to
             Exhibit  10.05 of the  Registrant's Form 10-Q  report for the  period ended April 2,
             1995.
     10.08   Revolving Credit Facility dated as of March 24, 1995, between Chiron Corporation and
             Swiss Bank Corporation, San Francisco  Branch, incorporated by reference to  Exhibit
             10.06 of the Registrant's Form 10-Q report for the period ended April 2, 1995.
     10.09   Joint  Venture Agreement  by and  between Chiron  Biocine Corporation,  a California
             corporation, and CIBA-GEIGY Biocine Corporation, a Delaware corporation, dated April
             15, 1987 (with certain confidential information deleted), incorporated by  reference
             to  Exhibit 10.23 of the  Registrant's Form 8 filed  with the Commission on February
             14, 1992.
     10.10   Amendment  to  Biocine  Joint  Venture  Agreement  by  and  between  Chiron  Biocine
             Corporation,  a  California  corporation,  and  CIBA-GEIGY  Biocine  Corporation,  a
             Delaware corporation, effective as of January 1, 1992, incorporated by reference  to
             Exhibit 10.63 to Registrant's Form 10-Q report for the period ended June 30, 1992.
     10.11   Research  and License Agreement by and between Registrant and The Biocine Company, a
             Delaware partnership, dated  April 15, 1987  (with certain confidential  information
             deleted),  incorporated by  reference to  Exhibit 10.24  of the  Registrant's Form 8
             filed with the Commission on February 14, 1992.
     10.12   License  Agreement  by  and  between  CIBA-GEIGY  Biocine  Corporation,  a  Delaware
             corporation,  and The Biocine Company, a  Delaware partnership, dated April 15, 1987
             (with certain  confidential  information  deleted),  incorporated  by  reference  to
             Exhibit  10.25 of the Registrant's Form 8  filed with the Commission on February 14,
             1992.
</TABLE>
 
                                       21
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<CAPTION>
  EXHIBIT
  NUMBER                                           EXHIBIT
- -----------  ------------------------------------------------------------------------------------
<S>          <C>
     10.13   License  Agreement  by  and  between   Chiron  Biocine  Corporation,  a   California
             corporation,  and The Biocine Company, a  Delaware partnership, dated April 15, 1987
             (with certain  confidential  information  deleted),  incorporated  by  reference  to
             Exhibit  10.26 of the Registrant's Form 8  filed with the Commission on February 14,
             1992.
     10.14   Letter  Agreement  signed   by  CIBA-GEIGY  Corporation,   dated  April  15,   1987,
             incorporated  by reference to Exhibit 10.13 of the Registrant's Form 10-Q report for
             the period ended September 30, 1994.
     10.15   Agreement between the Registrant  and Ortho Diagnostic Systems,  Inc., a New  Jersey
             corporation, dated August 17, 1989, and Amendment to Collaboration Agreement between
             Ortho Diagnostic Systems, Inc. and Registrant, dated December 22, 1989 (with certain
             confidential information deleted), incorporated by reference to Exhibit 10.14 of the
             Registrant's Form 10-Q report for the period ended September 30, 1994.
     10.16   License  and Supply Agreement  between Ortho Diagnostic Systems,  Inc., a New Jersey
             corporation, the Registrant and Abbott Laboratories, an Illinois corporation,  dated
             August  17, 1989  (with certain  confidential information  deleted), incorporated by
             reference to Exhibit  10.15 of  the Registrant's Form  10-Q report  for the  quarter
             ended June 30, 1994.
     10.17   Chiron  1991 Stock Option Plan, as amended,  incorporated by reference to Annex 1 of
             the Registrant's Proxy Statement dated April 18, 1995.*
     10.18   Forms of Option Agreements, Chiron 1991 Stock Option Plan, as amended,  incorporated
             by  reference to Exhibit 10.17 of the  Registrant's Form 10-K report for fiscal year
             1993.*
     10.19   Forms of  Option Agreements,  Cetus Corporation  Amended and  Restated Common  Stock
             Option  Plan, incorporated by  reference to Exhibit 10.33  of Registrant's Form 10-K
             report for fiscal year 1991.*
     10.20   Forms of Supplemental Letter concerning the assumption of Cetus Corporation  options
             by  Chiron, incorporated  by reference  to Exhibit  10.34 of  Registrant's Form 10-K
             report for fiscal year 1991.*
     10.21   Agreement and Plan of Reorganization dated as  of October 11, 1991 by and among  the
             Registrant,  Chiron Ophthalmics, Inc., COI  Acquisition Corp., IntraOptics, Inc. and
             James R.  Cook, M.D.,  incorporated by  reference to  Exhibit 28.2  of  Registrant's
             current report on Form 8-K dated October 14, 1991.
     10.22   Indemnification Agreement between the Registrant and Dr. William J. Rutter, dated as
             of  February  12,  1987  (which  form  of  agreement  is  used  for  each  member of
             Registrant's Board of Directors), incorporated by reference to Exhibit 10.21 of  the
             Registrant's Form 10-Q report for the period ended September 30, 1994.
     10.23   Stock  Purchase  Agreement  by and  between  the  Registrant and  Johnson  & Johnson
             Development Corporation, a corporation organized and existing under the laws of  the
             State  of New  Jersey, dated  as of  October 3,  1986, incorporated  by reference to
             Exhibit 10.22 of the  Registrant's Form 10-Q report  for the period ended  September
             30, 1994.
     10.24   Ciba  Corning  Diagnostics  Corp.  Policies,  Guidelines  and  Procedures  regarding
             Severance Pay.*
     10.25   Form of Debenture Purchase Agreement between the Registrant and CIBA-GEIGY, Limited,
             a corporation organized and existing under  the laws of Switzerland, dated June  22,
             1990,  incorporated  by reference  to Exhibit  10.25 of  the Registrant's  Form 10-K
             report for fiscal year 1994.
     10.26   Chiron  Corporation  1.90%  Convertible  Subordinated  Note  due  2000,  Series   B,
             incorporated  by reference to Exhibit 10.25 of the Registrant's Form 10-K report for
             fiscal year 1993.
</TABLE>
 
                                       22
<PAGE>
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<CAPTION>
  EXHIBIT
  NUMBER                                           EXHIBIT
- -----------  ------------------------------------------------------------------------------------
<S>          <C>
     10.27   Investment Agreement dated as of November  20, 1994 among Ciba-Geigy Limited,  Ciba-
             Geigy   Corporation,  Ciba   Biotech  Partnership,  Inc.   and  Chiron  Corporation,
             incorporated by reference  to Exhibit 10.54  of the Registrant's  current report  on
             Form 8-K dated November 20, 1994.
     10.28   Governance  Agreement dated as of November  20, 1994 among Ciba-Geigy Limited, Ciba-
             Geigy Corporation and Chiron Corporation, incorporated by reference to Exhibit 10.55
             of the Registrant's current report on Form 8-K dated November 20, 1994.
     10.29   Subscription Agreement dated as of November 20, 1994 among Ciba-Geigy Limited, Ciba-
             Geigy  Corporation,  Ciba   Biotech  Partnership,  Inc.   and  Chiron   Corporation,
             incorporated  by reference  to Exhibit 10.56  of the Registrant's  current report on
             Form 8-K dated November 20, 1994.
     10.30   Cooperation and Collaboration Agreement dated as of November 20, 1994, between Ciba-
             Geigy Limited and Chiron Corporation, incorporated by reference to Exhibit 10.57  of
             the Registrant's current report on Form 8-K dated November 20, 1994.
     10.31   Registration  Rights Agreement  dated as of  November 20, 1994  between Ciba Biotech
             Partnership, Inc. and Chiron Corporation, incorporated by reference to Exhibit 10.58
             of the Registrant's current report on Form 8-K dated November 20, 1994.
     10.32   Market Price  Option  Agreement dated  as  of  November 20,  1994  among  Ciba-Geigy
             Limited,   Ciba-Geigy  Corporation,  Ciba  Biotech   Partnership,  Inc.  and  Chiron
             Corporation, incorporated by reference to Exhibit 10.59 of the Registrant's  current
             report on Form 8-K dated November 20, 1994.
     10.33   Amendment  dated  as  of  January  3,  1995  among  Ciba-Geigy  Limited,  Ciba-Geigy
             Corporation, Ciba Biotech Partnership, Inc. and Chiron Corporation, incorporated  by
             reference  to Exhibit  10.60 of  the Registrant's current  report on  Form 8-K dated
             January 4, 1995.
     10.34   Supplemental Agreement  dated  as  of  January 3,  1995  among  Ciba-Geigy  Limited,
             Ciba-Geigy  Corporation,  Ciba  Biotech Partnership,  Inc.  and  Chiron Corporation,
             incorporated by reference  to Exhibit 10.61  of the Registrant's  current report  on
             Form 8-K dated January 4, 1995.
     10.35   Amendment  with Respect to Employee Stock Option Arrangements dated as of January 3,
             1995 among  Ciba-Geigy Limited,  Ciba-Geigy Corporation,  Ciba Biotech  Partnership,
             Inc.  and  Chiron Corporation,  incorporated by  reference to  Exhibit 10.62  of the
             Registrant's current report on Form 8-K dated January 4, 1995.*
     10.36   Supplemental Benefits Agreement, dated July 21, 1989, between the Registrant and Dr.
             William J. Rutter, incorporated  by reference to Exhibit  10.27 of the  Registrant's
             Form 10-Q report for the period ended September 30, 1994.*
     10.37   Lease  dated as  of July 1,  1983 between  Cetus Corporation and  H.B. Chapman, Jr.,
             incorporated by reference to Exhibit 10.28 of the Registrant's Form 10-Q report  for
             the period ended September 30, 1994.
     10.38   Amendment  to Lease, made as  of March 20, 1990, amending  Lease dated July 1, 1983,
             between Harold B. Chapman, Jr. and  Cetus Corporation, incorporated by reference  to
             Exhibit  10.37 of the  Registrant's Form 10-Q  report for the  period ended April 2,
             1995.
     10.39   Second Amendment to Lease made as of January 1, 1995 between Harold B. Chapman,  Jr.
             and the Registrant.
     10.40   Lease  commencing  March 1,  1987,  between EuroCetus  B.V.  and the  Municipal Land
             Company of the City of Amsterdam (Translation).
</TABLE>
 
                                       23
<PAGE>
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                           EXHIBIT
- -----------  ------------------------------------------------------------------------------------
<S>          <C>
     10.41   Form of Option Agreement (with  Purchase Agreements attached thereto) between  Cetus
             Corporation and each former limited partner of Cetus Healthcare Limited Partnership,
             a  California limited partnership, incorporated by reference to Exhibit 10.31 of the
             Registrant's Form 10-Q report for the period ended September 30, 1994.
     10.42   Form of Option Agreement (with forms of Purchase Agreements attached thereto), dated
             December 30, 1986,  between Cetus  Corporation and  each former  limited partner  of
             Cetus   Healthcare  Limited  Partnership  II,   a  California  limited  partnership,
             incorporated by reference to Exhibit 10.32 of the Registrant's Form 10-Q report  for
             the period ended September 30, 1994.
     10.43   Big-O  Property  Purchase and  Leaseback Agreement,  dated as  of October  31, 1988,
             between Cetus  Corporation and  Richard  K. Robbins,  incorporated by  reference  to
             Exhibit  10.33 of the Registrant's  Form 10-Q report for  the period ended September
             30, 1994.
     10.44   Triple Net Lease dated  as of January  20, 1989, between  Cetus Corporation and  BGR
             Associates  III,  a  California  limited  partnership,  and  Marin  County  Exchange
             Corporation, incorporated by  reference to  Exhibit 10.34 of  the Registrant's  Form
             10-Q report for the period ended September 30, 1994.
     10.45   License  Agreement between the  Registrant and the  Board of Trustees  of the Leland
             Stanford Junior University, dated  December 15, 1981,  incorporated by reference  to
             Exhibit  10.07 of the Registrant's  Form 10-Q report for  the period ended September
             30, 1994.
     10.46   Stock Purchase and Warrant  Agreement dated May 9,  1989, between Cetus  Corporation
             and  Hoffmann-La  Roche Inc.,  incorporated  by reference  to  Exhibit 10.36  of the
             Registrant's Form 10-Q report for the period ended September 30, 1994.
     10.47   Letter Agreement, dated  as of  December 12, 1991,  relating to  Stock Purchase  and
             Warrant  Agreement between  Registrant and  Hoffmann-La Roche  Inc., incorporated by
             reference to Exhibit 10.59 of Registrant's Form 10-K report for fiscal year 1991.
     10.48   Agreement and Plan of  Merger dated as  of July 21, 1991,  by and among  Registrant,
             Chiron Acquisition Subsidiary, Inc. and Cetus Corporation, incorporated by reference
             to Exhibit 28.2 of Registrant's Form 8-K report dated July 22, 1991.
     10.49   Letter  Agreement dated  September 26,  1990 between  the Registrant  and William G.
             Green, incorporated by  reference to  Exhibit 10.41  of the  Registrant's Form  10-K
             report for fiscal year 1992.*
     10.50   Letter  Agreement  dated  December 18,  1991  between Registrant  and  Jack Schuler,
             incorporated by reference to Exhibit 10.42 of the Registrant's Form 10-K report  for
             fiscal year 1992.*
     10.51   Lease  between  Sclavo S.p.A.  and  Biocine Sclavo  S.p.A.,  dated January  7, 1992,
             incorporated by reference to Exhibit 10.49 of the Registrant's Form 10-Q report  for
             the period ended April 2, 1995.
     10.52   Agreement  made as of  November 11, 1993  by and between  Kodak Clinical Diagnostics
             Limited, a company  registered in  England, and  Ciba Corning  Diagnostics Corp.,  a
             Delaware  corporation,  and  Letter  dated  October  7,  1994  from  Kodak  Clinical
             Diagnostics Limited to Ciba Corning Diagnostics Corp., incorporated by reference  to
             Exhibit 10.50 of Amendment No. 1 to the Registrant's Form 10-Q report for the period
             ended  April  2, 1995.  [Certain  information has  been  omitted from  the Agreement
             pursuant to a  request by  Registrant for  confidential treatment  pursuant to  Rule
             24b-2.]
     10.53   Letter  Agreement dated  September 9, 1991  between the Registrant  and Walter Moos,
             incorporated by reference to Exhibit 10.47 of the Registrant's Form 10-K report  for
             fiscal year 1992.*
</TABLE>
 
                                       24
<PAGE>
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                           EXHIBIT
- -----------  ------------------------------------------------------------------------------------
<S>          <C>
     10.54   Letter  Agreement between  the Registrant and  Walter Moos, dated  February 1, 1993,
             incorporated by reference to Exhibit 10.48 of the Registrant's Form 10-K report  for
             fiscal year 1992.*
     10.55   Letter   Agreement  between  Registrant  and  Renato  Fuchs,  dated  May  13,  1993,
             incorporated by reference to Exhibit 10.47 of the Registrant's Form 10-K report  for
             fiscal year 1993.*
     10.56   Agreement  made as of  December 6, 1984, by  and between Corning  Glass Works, a New
             York corporation, and  Bioanalysis Limited,  a company incorporated  in England  and
             Wales,  and Letter  dated July  26, 1985 from  Bioanalysis Limited  to Corning Glass
             Works, incorporated by  reference to  Exhibit 10.54  of the  Registrant's Form  10-Q
             report  for the period  ended April 2,  1995. [Certain information  has been omitted
             from the Agreement pursuant  to a request by  Registrant for confidential  treatment
             pursuant to Rule 24b-2.]
     10.57   Description of Executive Officer Variable Compensation Program.
     10.58   Chiron   Corporation  1995  Executive  Officer   Variable  Cash  Compensation  Plan,
             incorporated by reference to Annex 2 of the Registrant's Proxy Statement dated April
             18, 1995.*
     10.59   Regulatory Filing, Development  and Supply Agreement  between the Registrant,  Cetus
             Oncology  Corporation, a wholly-owned subsidiary of the Registrant, and Schering AG,
             a German company, dated  as of May 10,  1993 (with certain confidential  information
             deleted),  incorporated by  reference to Exhibit  10.50 of  the Registrant's current
             report on Form 8-K dated February 9, 1994.
     10.60   Letter Agreement dated December 30, 1993 by and between Registrant and Schering  AG,
             a  German company (with  certain confidential information  deleted), incorporated by
             reference to Exhibit  10.51 of  the Registrant's Form  10-K report  for fiscal  year
             1993.
     10.61   Guaranty,  dated as of September  29, 1994, made by  Registrant, in favor of Bankers
             Trust Company,  as  trustee, incorporated  by  reference  to Exhibit  10.52  of  the
             Registrant's Form 10-Q report for the period ended September 30, 1994.
     10.62   Guaranty, dated as of September 29, 1994, made by Cetus Corporation, in favor of The
             First  National Bank  of Boston,  as trustee,  incorporated by  reference to Exhibit
             10.53 of the Registrant's Form 10-Q report for the period ended September 30, 1994.
     10.63   Letter Agreements dated  September 11, 1992,  July 15, 1994  and September 14,  1994
             between  the Registrant and Lewis T.  Williams, incorporated by reference to Exhibit
             10.54 of the Registrant's Form 10-Q report for the period ended September 30, 1994.*
     10.64   Letter dated  January 4,  1995 to  C. William  Zadel, incorporated  by reference  to
             Exhibit 10.65 of the Registrant's Form 10-K report for fiscal year 1994.*
     10.65   Letter dated June 28, 1995 to C. William Zadel.
     10.66   Letter to Dino Dina dated April 24, 1984, incorporated by reference to Exhibit 10.66
             of the Registrant's Form 10-K report for fiscal year 1994.*
     10.67   Research  Agreement, dated as of July 15,  1985, between Ciba-Geigy Limited, a Swiss
             corporation,  and   Ciba  Corning   Diagnostics  Corp.,   a  Delaware   corporation,
             incorporated  by reference to Exhibit 10.64 of the Registrant's Form 10-Q report for
             the period ended April 2, 1995.
     10.68   Licensing Agreement, effective December 18, 1986, by and between Miles Laboratories,
             Inc., a  Delaware  corporation,  and  Ciba Corning  Diagnostics  Corp.,  a  Delaware
             corporation,  and Letter dated December 18, 1992 from Ciba Corning Diagnostics Corp.
             to Miles Laboratories, Inc., incorporated by reference to Exhibit 10.65 of Amendment
             No. 1 to  the Registrant's  Form 10-Q  report for the  period ended  April 2,  1995.
             [Certain  information has been omitted  from the Agreement pursuant  to a request by
             Registrant for confidential treatment pursuant to Rule 24b-2.]
</TABLE>
 
                                       25
<PAGE>
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                           EXHIBIT
- -----------  ------------------------------------------------------------------------------------
<S>          <C>
     10.69   Magnetocluster Binding Assay Technology Agreement, dated as of January 21, 1983,  by
             and  between  Bioclinical Group,  Inc., a  Delaware  corporation, and  Corning Glass
             Works, a  New  York corporation,  incorporated  by  reference to  Exhibit  10.66  of
             Amendment  No. 1 to the Registrant's Form 10-Q  report for the period ended April 2,
             1995. [Certain information has been omitted from the Agreement pursuant to a request
             by Registrant for confidential treatment pursuant to Rule 24b-2.]
     10.70   Turn-back License Agreement, dated as of May  30, 1986, by and between Ciba  Corning
             Diagnostics  Corp., a Delaware corporation, and Advanced Magnetics, Inc., a Delaware
             corporation, incorporated by  reference to  Exhibit 10.67 of  the Registrant's  Form
             10-Q  report  for the  period ended  April  2, 1995.  [Certain information  has been
             omitted from the  Agreement pursuant  to a  request by  Registrant for  confidential
             treatment pursuant to Rule 24b-2.]
     10.71   Settlement  Agreement, dated August 30, 1989, between Ciba Corning Diagnostics Corp.
             and Advanced Magnetics,  Inc., incorporated  by reference  to Exhibit  10.68 of  the
             Registrant's  Form  10-Q  report  for  the  period  ended  April  2,  1995. [Certain
             information has been omitted from the Agreement pursuant to a request by  Registrant
             for confidential treatment pursuant to Rule 24b-2.]
     10.72   Lease  made and entered into December 17,  1984 between BGR Associates, a California
             limited partnership, and Cetus Corporation and Amendment to Lease dated December 17,
             1984 entered into effective February 1,  1986, incorporated by reference to  Exhibit
             10.69 of the Registrant's Form 10-Q report for the period ended April 2, 1995.
     10.73   Second  Amendment to  Lease dated  as of  March 15,  1995 between  BGR Associates, a
             California limited partnership, and Registrant.
     10.74   Agreement, effective as of December 21, 1988, by and between Hoffmann-La Roche Inc.,
             a New  Jersey  corporation, and  Cetus  Corporation, incorporated  by  reference  to
             Exhibit  10.70 of the  Registrant's Form 10-Q  report for the  period ended April 2,
             1995. [Certain information has been omitted from the Agreement pursuant to a request
             by Registrant for confidential treatment pursuant to Rule 24b-2.]
     10.75   Agreement, effective as  of December  21, 1988, by  and among  F. Hoffmann-La  Roche
             Ltd.,  a Swiss corporation, Cetus Corporation,  and EuroCetus International, B.V., a
             Netherlands Antilles corporation, incorporated by reference to Exhibit 10.71 of  the
             Registrant's  Form  10-Q  report  for  the  period  ended  April  2,  1995. [Certain
             information has been omitted from the Agreement pursuant to a request by  Registrant
             for confidential treatment pursuant to Rule 24b-2.]
     10.76   Agreement, by and between Cetus Oncology Corporation, EuroCetus International, N.V.,
             and  F. Hoffmann-La Roche  Ltd., incorporated by  reference to Exhibit  10.72 of the
             Registrant's Form  10-Q  report  for  the  period  ended  April  2,  1995.  [Certain
             information  has been omitted from the Agreement pursuant to a request by Registrant
             for confidential treatment pursuant to Rule 24b-2.]
     10.77   Agreement commencing  January 1,  1991,  between EuroCetus  B.V. and  the  Municipal
             Development Corporation (Translation), incorporated by reference to Exhibit 10.41 of
             the Registrant's Form 10-K report for fiscal year 1994.
     10.78   Settlement  Agreement on Purified  IL-2, made as  of April 14,  1995, by and between
             Cetus Oncology Corporation,  dba Chiron  Therapeutics, a  Delaware corporation,  and
             Takeda  Chemical Industries, Ltd., a Japanese corporation, incorporated by reference
             to Exhibit 10.74 of the Registrant's Form  10-Q report for the period ended July  2,
             1995. [Certain information has been omitted from the Agreement pursuant to a request
             by Registrant for confidential treatment pursuant to Rule 24b-2.]
</TABLE>
 
                                       26
<PAGE>
<TABLE>
<CAPTION>
  EXHIBIT
  NUMBER                                           EXHIBIT
- -----------  ------------------------------------------------------------------------------------
<S>          <C>
     10.79   License  Agreement made  and entered  into December  1, 1987,  by and  between Sloan
             Kettering Institute for Cancer Research, a not-for-profit New York corporation,  and
             Cetus  Corporation, incorporated by  reference to Exhibit  10.75 of the Registrant's
             Form 10-Q report for the  period ended July 2,  1995. [Certain information has  been
             omitted  from the  Agreement pursuant  to a  request by  Registrant for confidential
             treatment pursuant to Rule 24b-2.]
     10.80   Chiron  Funding  L.L.C.  Limited  Liability  Company  Agreement,  entered  into  and
             effective  as of December 28, 1995, among the Registrant, Chiron Biocine Company and
             Biocine S.p.A. and  Ciba-Geigy Corporation.  [Certain information  has been  omitted
             from  the Agreement pursuant  to a request by  Registrant for confidential treatment
             pursuant to Rule 24b-2.]
     10.81   Agreement between  Ciba-Geigy Limited  and the  Registrant made  November 15,  1995.
             [Certain  information has been omitted  from the Agreement pursuant  to a request by
             Registrant for confidential treatment pursuant to Rule 24b-2.]
     10.82   Reimbursement Agreement dated as  of March 24, 1995,  between Ciba-Geigy Limited,  a
             Swiss corporation, and the Registrant, incorporated by reference to Exhibit 10.76 of
             the Registrant's Form 10-Q report for the period ended July 2, 1995.
     10.83   Promissory  Note, as  amended and  restated, dated January  1, 1995  by Ciba Corning
             Diagnostics Corp.
     10.84   Commercial  lease  between  Domilyon  Corporation  and  Domilens  Laboratories   and
             Amendment No. 1 to Commercial Lease dated May 9, 1994.
     10.85   Agreement between the Registrant and Cephalon, Inc. dated as of January 7, 1994, and
             Letter Agreements between the Registrant and Cephalon dated January 13, 1995 and May
             23,  1995. [Certain information has  been omitted from the  Agreements pursuant to a
             request by Registrant for confidential treatment pursuant to Rule 24b-2.]
        11   Statement of Computation of Earnings per Share.
        13   Consolidated Financial Statements.
        21   List of Subsidiaries of the Registrant.
      23.1   Consent of KPMG  Peat Marwick LLP,  Independent Auditors. The  consent set forth  on
             page 32 is incorporated herein by reference.
      23.2   Consent of Ernst & Young LLP, Independent Auditors. The consent set forth on page 33
             is incorporated herein by reference.
        24   Power  of  Attorney.  The  Power  of  Attorney set  forth  on  pages  28  and  29 is
             incorporated herein by reference.
        27   Financial Data Schedule.
</TABLE>
 
- ------------------------
* Management contract, compensatory plan or arrangement.
 
                                       27
<PAGE>
                                   SIGNATURES
 
    Pursuant  to  the requirements  of  Section 13  or  15(d) of  the Securities
Exchange Act of 1934, the Registrant has duly caused this Report to be signed on
its behalf by the undersigned, thereunto duly authorized.
 
    Date: March 28, 1996
 
                                          CHIRON CORPORATION
 
                                          By        /s/ EDWARD E. PENHOET
 
                                             -----------------------------------
                                                  Edward E. Penhoet, Ph.D.
                                                PRESIDENT AND CHIEF EXECUTIVE
                                                           OFFICER
 
                               POWER OF ATTORNEY
 
KNOW ALL PERSONS BY THESE PRESENTS:
 
    That the undersigned officers and directors of Chiron Corporation do  hereby
constitute  and appoint Edward E. Penhoet,  Ph.D., and William J. Rutter, Ph.D.,
and each of them,  the lawful attorney  and agent or  attorneys and agents  with
power and authority to do any and all acts and things and to execute any and all
instruments which said attorneys and agents, or either of them, determine may be
necessary  or advisable or required to  enable Chiron Corporation to comply with
the Securities Exchange Act of 1934, as amended, and any rules or regulations or
requirements of the Securities and  Exchange Commission in connection with  this
Form  10- K Report. Without  limiting the generality of  the foregoing power and
authority, the powers granted include the power and authority to sign the  names
of  the undersigned officers and directors  in the capacities indicated below to
this Form 10-K  report or  amendments or supplements  thereto, and  each of  the
undersigned  hereby ratifies and confirms all  that said attorneys and agents or
either of them, shall  do or cause to  be done by virtue  hereof. This Power  of
Attorney may be signed in several counterparts.
 
                                       28
<PAGE>
    IN  WITNESS  WHEREOF, each  of the  undersigned has  executed this  Power of
Attorney as of the date indicated opposite his name.
 
    Pursuant to the  requirements of the  Securities Exchange Act  of 1934,  the
Report  has  been  signed  below  by the  following  persons  on  behalf  of the
Registrant and in the capacities and on the dates indicated.
 
<TABLE>
<CAPTION>
             SIGNATURE                         TITLE                  DATE
- -----------------------------------  -------------------------  ----------------
<C>                                  <S>                        <C>
 
       /s/ EDWARD E. PENHOET
- -----------------------------------  President and Chief         March 28, 1996
     Edward E. Penhoet, Ph.D.         Executive Officer
 
                                     Senior Vice President,
                                      Finance and
       /s/ DENNIS L. WINGER           Administration, Chief
- -----------------------------------   Financial Officer, and     March 28, 1996
         Dennis L. Winger             Principal Accounting
                                      Officer
 
       /s/ WILLIAM J. RUTTER
- -----------------------------------  Chairman of the Board of    March 28, 1996
     William J. Rutter, Ph.D.         Directors
 
       /s/ LEWIS W. COLEMAN
- -----------------------------------  Director                    March 28, 1996
         Lewis W. Coleman
 
       /s/ PIERRE E. DOUAZE
- -----------------------------------  Director                    March 28, 1996
         Pierre E. Douaze
 
         /s/ DONALD GLASER
- -----------------------------------  Director                    March 28, 1996
       Donald Glaser, Ph.D.
 
          /s/ ALEX KRAUER
- -----------------------------------  Director                    March 28, 1996
        Alex Krauer, Ph.D.
 
    /s/ FRANCOIS L'EPLATTENIER
- -----------------------------------  Director                    March 28, 1996
   Francois L'Eplattenier, Ph.D.
 
        /s/ HENRI SCHRAMEK
- -----------------------------------  Director                    March 28, 1996
       Henri Schramek, Ph.D.
 
         /s/ JACK SCHULER
- -----------------------------------  Director                    March 28, 1996
           Jack Schuler
 
      /s/ PIETER J. STRIJKERT
- -----------------------------------  Director                    March 28, 1996
    Pieter J. Strijkert, Ph.D.
</TABLE>
 
                                       29
<PAGE>
             REPORT OF KPMG PEAT MARWICK LLP, INDEPENDENT AUDITORS
 
The Board of Directors and Stockholders
Chiron Corporation:
 
    We  have  audited the  accompanying  consolidated balance  sheets  of Chiron
Corporation and subsidiaries as  of December 31, 1995  and 1994 and the  related
consolidated  statements of operations, stockholders'  equity and cash flows for
the years  then  ended.  In  connection with  our  audits  of  the  consolidated
financial  statements, we also have audited  the financial statement schedule as
listed in the  accompanying index. These  consolidated financial statements  and
the  financial  statement  schedule  are  the  responsibility  of  the Company's
management. Our responsibility is  to express an  opinion on these  consolidated
financial statements and the financial statement schedule based on our audits.
 
    We  conducted  our audits  in  accordance with  generally  accepted auditing
standards. Those standards require that we plan and perform the audit to  obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also  includes
assessing  the  accounting principles  used  and significant  estimates  made by
management, as well as evaluating the overall financial statement  presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
    In  our  opinion, the  consolidated financial  statements referred  to above
present fairly,  in all  material  respects, the  financial position  of  Chiron
Corporation  and subsidiaries as of December 31,  1995 and 1994, and the results
of their operations and their cash flows for the years then ended, in conformity
with generally accepted accounting principles. Also in our opinion, the  related
financial   statement  schedule,  when  considered  in  relation  to  the  basic
consolidated financial  statements taken  as a  whole, presents  fairly, in  all
material respects, the information set forth therein.
 
                                          KPMG Peat Marwick LLP
 
San Francisco, California
February 20, 1996
 
                                       30
<PAGE>
               REPORT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS
 
The Board of Directors and Stockholders
Chiron Corporation
 
    We  have audited  the consolidated  statements of  operations, stockholders'
equity and cash  flows of  Chiron Corporation for  the year  ended December  31,
1993,   included  in  the  1995  Consolidated  Financial  Statements  of  Chiron
Corporation included  as  Exhibit 13.  Our  audit also  included  the  financial
statement  schedule of Chiron Corporation for  the year ended December 31, 1993,
listed in the Index at Item  14(a). These financial statements and schedule  are
the responsibility of the Company's management. Our responsibility is to express
an opinion on these financial statements and schedule based on our audit.
 
    We  conducted  our  audit  in accordance  with  generally  accepted auditing
standards. Those standards require that we plan and perform the audit to  obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also  includes
assessing  the  accounting principles  used  and significant  estimates  made by
management, as well as evaluating the overall financial statement  presentation.
We believe that our audit provides a reasonable basis for our opinion.
 
    In  our  opinion, the  consolidated financial  statements referred  to above
present  fairly,  in  all  material   respects,  the  consolidated  results   of
operations, changes in stockholders' equity and cash flows of Chiron Corporation
for  the year  ended December  31, 1993,  in conformity  with generally accepted
accounting principles. Also,  in our  opinion, the  related financial  statement
schedule,  when  considered  in  relation to  the  basic  consolidated financial
statements taken  as a  whole,  presents fairly  in  all material  respects  the
information set forth therein.
 
                                          ERNST & YOUNG LLP
 
San Francisco, California
February 25, 1994
 
                                       31
<PAGE>
             CONSENT OF KPMG PEAT MARWICK LLP, INDEPENDENT AUDITORS
 
    We  consent to the incorporation by reference in the Registration Statements
(File  Numbers  33-20181,  33-35182,  2-90595,  33-23899,  33-58305,   33-44477,
33-65024,  33-65177, 33-45822, 33-63297 and 33-65175 on Form S-8 and File Number
33-43574 on Form  S-3) pertaining to  the Chiron Corporation  1982 Stock  Option
Plan,  the 1988 Employee  Stock Purchase Plan,  the 1991 Stock  Option Plan, the
IntraOptics, Inc. 1986 Incentive Stock Option  Plan, as amended, the 1989  Stock
Option  Plan of Viagene, Inc., the Viagene  Employee Stock Purchase Plan and the
shares issuable to certain  warrant holders and in  the related prospectuses  of
our  report dated February 20, 1996, relating to the consolidated balance sheets
of Chiron Corporation and subsidiaries as of December 31, 1995 and 1994, and the
related consolidated statements  of operations, stockholders'  equity, and  cash
flows for the years then ended and the related schedule, which report appears in
the December 31, 1995 annual report on Form 10-K of Chiron Corporation.
 
                                          KPMG Peat Marwick LLP
 
San Francisco, California
March 26, 1996
 
                                       32
<PAGE>
               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS
 
    We  consent to the incorporation by reference in the Registration Statements
of Chiron Corporation  (Forms S-8, Nos.  33-20181, 33-35182, 2-90595,  33-23899,
33-44477,  33-45822, 33-65024,  33-58305, 33-63297, 33-65175  and 33-65177, Form
S-3 No. 33-43574 and Form S-4 No. 33-60503) pertaining to the 1982 Stock  Option
Plan,  the 1988 Employee Stock Purchase Plan,  and the 1991 Stock Option Plan of
Chiron Corporation,  the IntraOptics,  Inc. 1986  Incentive Stock  Option  Plan,
certain  warrants (the "Cetus  Warrants"), the 1989 Stock  Option Plan, the 1993
Incentive Stock Option Plan,  and the Employee Stock  Purchase Plan of  Viagene,
Inc.  and certain shares related to the  acquisition of Viagene, Inc. and in the
related prospectuses of our report dated February 25, 1994, with respect to  the
consolidated  statements of operations, stockholders'  equity and cash flows and
schedule of Chiron Corporation for the year ended December 31, 1993 included and
incorporated herein by reference in this Annual Report (Form 10-K) for the  year
ended December 31, 1995.
 
                                          ERNST & YOUNG LLP
 
San Francisco, California
March 26, 1996
 
                                       33
<PAGE>
                               CHIRON CORPORATION
                       INDEX TO FINANCIAL STATEMENTS AND
                         FINANCIAL STATEMENT SCHEDULES
 
<TABLE>
<CAPTION>
                                                                                PAGES OF 1995
                                                                                CONSOLIDATED
                                                                                  FINANCIAL
                                                                                 STATEMENTS
                                                                                INCORPORATED       FORM 10-K
                                                                                BY REFERENCE         PAGE
                                                                               ---------------  ---------------
<S>                                                                            <C>              <C>
Financial Statements and Notes...............................................          1-47               --
Report of KPMG Peat Marwick LLP..............................................            --               30
Report of Ernst & Young LLP..................................................            --               31
Schedule II -- Valuation and Qualifying Accounts.............................            --               35
</TABLE>
 
                                       34
<PAGE>
                               CHIRON CORPORATION
                                  SCHEDULE II
                       VALUATION AND QUALIFYING ACCOUNTS
                  YEARS ENDED DECEMBER 31, 1995, 1994 AND 1993
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                         ADDITIONS
                                                 -------------------------
                                    BALANCE AT   CHARGED TO    CHARGED TO                                  BALANCE
                                     BEGINNING    COSTS AND      OTHER                                     AT END
DESCRIPTION                           OF YEAR     EXPENSES      ACCOUNTS    DEDUCTIONS   RECLASSIFICATIONS  OF YEAR
- ----------------------------------  -----------  -----------  ------------  -----------  ---------------  ---------
<S>                                 <C>          <C>          <C>           <C>          <C>              <C>
1995:
  Accounts receivable.............   $   7,210    $   8,815   $   6,680(1)   $  (4,181)     $      --     $  18,524
1994:
  Accounts receivable.............       5,194        5,880       2,424(1)      (4,880)        (1,408)(2)     7,210
1993:
  Accounts receivable.............       2,525        4,012          --         (1,343)            --         5,194
</TABLE>
 
- ------------------------
(1) Represents accounts receivable allowances as of the acquisition date related
    to acquired businesses.
 
(2) Represents amounts reclassified to other current liabilities.
 
                                       35

<PAGE>

                                                                Exhibit 10.02


                            FIRST AMENDMENT TO LEASE

     This Agreement amends and modifies that certain Triple Net Lease (the 
"Lease") between BGR ASSOCIATES, a California Limited Partnership as lessor 
and CHIRON CORPORATION, a California Corporation as lessee dated May 26, 1989 
with respect to 4560 Horton Street, Emeryville, California.

1.   AMENDMENT TO LEASE:

     This document amends and modifies the Lease. Except as expressly 
modified by the provisions of this amendment, the Lease shall remain in full 
force and effect.

2.   MODIFICATION OF PARAGRAPH 1.2:

     Paragraph 1.2 of the Lease entitled "LEASE TERM" is hereby modified by 
changing from "ten (10) years" in the third line of said paragraph to "twelve 
(12) years."

3.   AMENDMENT TO PARAGRAPH 3.2:

     "EXTENSION OF INITIAL TERM":  The reference in the third line of paragraph 
3.2 of the Lease to the "Initial Ten (10) year term" is hereby modified and 
amended to read "the Initial Twelve (12) year term" and the reference in the 
last line of said paragraph to "eleven (11) years" is hereby modified to read 
"thirteen (13) years".

4.   MODIFICATION TO PARAGRAPH 3.3:

     "OPTION TO TERMINATE":  Paragraph 3.3 is deleted.

5.   MODIFICATION TO PARAGRAPH 4.2:

     "ANNUAL RENT ADJUSTMENT":  The first sentence of paragraph 4.2 is hereby 
modified to read as follows:

          "During the first ten (10) years of the Lease Term and
          during any extension of the Lease Term pursuant to
          paragraph 19.0 of this Lease, the Base Monthly Rent
          specified in paragraph 1.3 shall be subject to annual
          increases determined by reference to the Consumer Price
          Index for All Urban Consumers, San Francisco-Oakland-San Jose,
          California. All Items (1992-84-100), published by the United
          States Bureau of Labor Statistics (the "CPI")."



<PAGE>

The following language shall be inserted after the first sentence of 
paragraph 4.2 of the Lease:

          "During the eleventh and twelfth year of the Lease Term,
          the Base Monthly Rent shall be identical to the Base
          Monthly Rent due and payable under the terms of the
          Lease for the last month of the tenth year of the 
          Lease Term."

6.   CONFLICT RESOLUTION:

     In the event of any conflict between the provisions of this amendment 
and the provisions of the Lease, the provisions of this amendment shall 
prevail.

This agreement entered into at Emeryville, California as of October 1, 1993.


     LANDLORD                                     TENANT

BGR ASSOCIATES, A CALIFORNIA               CHIRON CORPORATION, A
     LIMITED PARTNERSHIP                   CALIFORNIA CORPORATION


By: ________________________               By: _____________________

Address for Notices:                       Address for Notices:
1120 Nye Street                            4560 Horton Street
San Rafael, CA  94901                      Emeryville, CA  94608

                                    -2-

<PAGE>

                                                                Exhibit 10.04

                           FIRST AMENDMENT TO LEASE


     THIS FIRST AMENDMENT TO LEASE ("First Amendment") is entered into 
effective as of March 15, 1995, by and between BGR ASSOCIATES II, A 
CALIFORNIA LIMITED PARTNERSHIP ("Lessor"), and CHIRON CORPORATION, a Delaware 
corporation ("Lessee"), with reference to the following facts:

     A.  Lessor and Lessee are parties to that certain Triple Net Lease dated 
May 26, 1989, entered into by Lessor and Lessee's predecessor, Chiron 
Corporation, a California corporation (the "Lease"). The property covered by 
the Lease is located in Emeryville, California, and is more particularly 
described in the Lease. The Term of the Lease expires August 14, 1999; and 
Lessee has the right to extend the Term of the Lease for two (2) terms of 
five (5) years each.

     B.  Lessor, Lessee and certain other parties related to Lessor have 
entered into that certain Option Agreement of even date herewith (the "Option 
Agreement"), pursuant to which Lessor has been granted to Lessee the option, 
subject to the terms and conditions of the Option Agreement, to purchase the 
property covered by the Lease as well as other property in the vicinity 
thereof. As provided for in Section 5.b of the Option Agreement, Lessee has 
agreed to extend the Term of the Lease through August 14, 2000, as part of 
the consideration to Lessor for granting such option to Lessee.

     C.  Lessor and Lessee are entering into this First Amendment pursuant to 
Section 5.d of the Option Agreement to further evidence the extension of the 
Term of the Lease as provided for in the Option Agreement.

     NOW, THEREFORE, in consideration of the foregoing, and for other good 
and valuable consideration, the receipt and adequacy of which are hereby 
acknowledged, Lessor and Lessee hereby agree as follows (capitalized terms 
used herein but not herein defined shall have the meaning ascribed to them in 
the Lease):

     1.  AMENDMENT OF PARAGRAPH 1.2.  Lessor and Lessee hereby agree that, as 
provided in the Option Agreement, the Term of the Lease is extended through 
August 14, 2000; and in furtherance of the foregoing, Lessor and Lessee 
hereby amend Paragraph 1.2 of the Lease by deleting therefrom the words "Ten 
(10) years" at the beginning of said paragraph and substituting therefor the 
words "Eleven (11) years."



<PAGE>

     2.  TERMS OF LEASE.  The terms of the Lease for the period from August 
15, 1999, through August 14, 2000, shall be the same as the terms of the 
Lease prior to August 15, 1999, without any adjustment to the base monthly 
rent for the period from April 15, 1999, through August 14, 2000 (i.e., the 
base monthly rent in effect as of August 15, 1999, shall remain in effect 
through August 14, 2000). In addition, the terms of Paragraph 18 of the Lease 
providing for two (2) extension options of five (5) years each shall remain 
in effect, with the first extension term, if exercised, commencing on August 
15, 2000.

     3.  STATUS OF LEASE.  Except as amended hereby, the Lease remains 
unamended; and as amended hereby, the Lease and all the terms and conditions 
thereof remain in full force and effect.

     4.  COUNTERPARTS.  This First Amendment may be executed in multiple 
counterparts, each of which shall constitute an original hereof, and all of 
which taken together shall constitute one and the same agreement.

     IN WITNESS WHEREOF, Lessor and Lessee have executed this First Amendment 
as of the date first set forth above.

LESSEE:                                       LESSOR:

CHIRON CORPORATION,                           BGR ASSOCIATES II, A CALIFORNIA
a Delaware corporation                        LIMITED PARTNERSHIP

By:  __________________________________       By: ______________________________
                                                  Richard K. Robbins
Its: __________________________________           Managing General Partner


                                         2

<PAGE>

                                                                Exhibit 10.24


CIBA-CORNING                                 -Ciba Corning Diagnostics Corp.
                                              Human Resources

                                             -POLICIES, GUIDELINES
                                              AND PROCEDURES


- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------


SEVERANCE PAY                           Effective 08/01/89
                                        Revised   04/01/92
POLICY

The Company recognizes that in some involuntary terminations an employee should
receive severance pay to help bridge the period of unemployment, if any.  
Severance pay will only be paid for involuntary terminations that are not 
because of gross negligence and/or misconduct (see Human Resource Policy, 
G-10, Disciplinary Actions).

GUIDELINES

Severance Pay offered to regular full-time employees will be in accordance with 
the following schedule subject to the restrictions noted below:


Salary                             Years of Service
- ------                             ----------------

                2-4       >4-8      >8-12    >12-16    >16-20    >20-24

< $30k           4          8         12        16        20        24

$30-$39.9        6         10         14        18        20        24

$40-$49.9        8         12         16        18        20        24

$50-$59.9       10         14         18        20        20        24

$60-$69.9       12         16         20        22        24        24

$70-$79.9       16         20         22        24        24        24

$80-$89.9       20         24         24        24        24        24


- -    Under 2 years of service or over 24 years of service, or salary over $90k
     will be handled on a case-by-case basis.

- -    Outplacement assistance is considered an exception and requires a general
     release.


Severance Pay                1 of 4                                     H-30.1


<PAGE>


     Bonus amounts in excess of 10% above base salary will be counted as base 
     salary in determining weeks of severance benefit (average of last 8 
     quarters of bonus).

Everyone will receive a minimum of one-half the calculated benefit no matter how
soon a job is found.  Severance payments will cease when a new job is found 
(after minimum payment period).  Severance payments above the minimum amount 
will be given on week-by-week basis based upon a concerted job search.

PROCEDURES

1.   The Supervisor should consider all aspects of the situation before deciding
     to ask an employee to leave the Company immediately upon notification.  All
     separations must be handled to protect both the interests of the employee 
     and the Company.  Because the reasons for separation vary considerably, 
     each case should be carefully reviewed and planned before taking action.  
     The appropriate Human Resource Manager must be included in the review and 
     planning stage and concur with the actions to be taken.

2.   Severance Pay will not be granted for voluntary separations.

3.   Severance Pay will not be granted for involuntary terminations that are 
     because of gross negligence and/or misconduct.

4.   Severance Pay is calculated based on the employee's last day worked.

5.   Severance Pay will end should the employee be rehired by Ciba Corning or 
     hired by Ciba-Geigy and its affiliates.

6.   Severance Pay is conditional based upon the fact that the employee's 
     conduct during the severance period is not detrimental to the Company.

7.   Severance Pay will be mailed on each regular pay day through the period.  
     It is not issued as a lump sum payment.

8.   Benefit continuation during the severance period will be handled as 
     follows:

     MEDICAL - Continues with standard payroll deductions until the last day of 
     the month of the last day paid.  The Group Insurance Department will send 
     an eligibility notice for continuation of coverage (COBRA) at the end of 
     the severance period.  The length of continuation is based from the last


Severance Pay               2 of 4                                    H-30.1

<PAGE>


     day worked.  The employee also has the right to convert their policy to a
     individual policy with the Insurance Company within 31 days.

     DENTAL - Continues with standard payroll deductions until the last day of 
     the month of the last day paid.  The Group Insurance Department will send 
     an eligibility notice for continuation of coverage (COBRA) at the end of 
     the severance period.  The length of continuation is based form the last 
     day worked. There is no conversions rights for dental coverage.

      FLEXIBLE SPENDING ACCOUNTS (FSA) - Contributions to the FSA's will stop 
      for the severance period.  The employee will have until March 31 of the 
     following year to claim expenses incurred up until the last day worked 
     (Federal Law).  Left over money will be forfeited.

     LIFE INSURANCE - Company provided life insurance continues until the 
     last day of the month of the last day paid as doses the employee paid 
     insurance if standard payroll deductions continue.  The employee has the 
     right to convert their policy to an individual policy with the Insurance 
     Company within 31 days.

     DISABILITY INSURANCE PLANS - Disability protection ends on the last day 
     worked.

     INVESTMENT PLAN - Employee and company contributions stop during the 
     severance period.  To receive a disbursement, the employee must complete 
     an Investment Plan Termination Notice.

     If the employees last day paid is close to the end of a quarter, a 
     completed termination notice must be submitted immediately to ensure 
     receipt of the disbursement within 90 days.  If the form is not received 
     until sometime in the following quarter, the employee will not receive 
     their disbursement until 90 days from the end of that quarter.

     VACATION AND HOLIDAY PAY - Earned and unused vacation and holiday pay 
     will be added to the last day worked and paid prior to the Severance pay
     in order to extend the severance period.

     OTHER BENEFITS - All other benefits end on the last day worked.


Severance Pay                3 of 4                                    H-30.1

<PAGE>


9.   All employees receiving severance will receive a "Memo of Understanding" 
     which will document the pertinent provisions of their severance package.  
     This document will only be issued through the Human Resources Department.

10.  The Vice President, Human Resources reserves the sole power to define 
     severance benefits in unclear circumstances.  Any variations from this 
     policy must have the prior approval of the Vice President, Human Resources.
     See attached Severance Policy Exception Approval Form.

11.  When processing a termination, the end date of the full severance period 
     should be entered as the last date paid.  If it is determined that a 
     concerted job effort is not being made or if new employment is found prior 
     to the end of the full severance period, it is the responsibility of the 
     Human Resource Manager to process a change for an earlier last date paid.


Severance Pay                4 of 4                                    H-30.1

<PAGE>


                         PRIVATE DISTRIBUTION ONLY



             ADDENDUM TO SEVERANCE PAY POLICY - REVISED 04/92

     The Severance Pay Policy Benefits are determined on a case by case basis 
for employees with salaries and service that exceed the Policy matrix.  This 
addendum is intended to apply to corporate officers only.

     1.   The Number of Severance Weeks for officer personnel will be 104 weeks.
One half of this benefit (52 weeks) will be the minimum payout period.  
Severance payments will continue on a week by week basis for up to another 52 
weeks or until another job is found.

     2.   Executive level outplacement assistance will be part of this severance
policy.

     3.   The pay for the severance period will consist of base pay plus target
levels for all bonus and incentive programs.

     All other aspects of the published policy will apply.


<PAGE>

                                                                Exhibit 10.39

                           SECOND AMENDMENT TO LEASE


     THIS SECOND AMENDMENT TO LEASE ("Second Amendment") is made as of the 
1st day of January, 1995, between HAROLD B. CHAPMAN, JR., an individual 
("Chapman"), and CHIRON CORPORATION, a Delaware corporation ("Chiron").

     THIS SECOND AMENDMENT IS ENTERED on the basis of the following facts, 
intentions and understandings of the parties:

     A.  Chapman, as the lessor, and Cetus Corporation ("Cetus"), as the 
lessee, entered a Lease ("Original Lease") dated as of July 1, 1983. Chiron 
is the successor to Cetus.

     B.  The Original Lease relates to premises ("Premises") commonly known 
as Building M and Building G located at 1400 and 1450 53rd Street in 
Emeryville, California. The Premises are more particularly described in the 
Original Lease.

     C.  Chapman and Cetus entered an Amendment to Lease ("First Amendment") 
dated as of March 20, 1990. The Original Lease as amended by the First 
Amendment is hereinafter referred to as the "Lease." Terms which are 
capitalized in this Second Amendment and not defined herein shall have the 
meanings set forth in the Lease.

     D.  Chapman and Chiron now desire to amend the Lease as provided in this 
Second Amendment.

     E.  Also as of the date of this Second Amendment, Chapman and Chiron are 
entering an Option Agreement pursuant to which Chapman is granting to Chiron 
an option to purchase the Premises. The Option Agreement is not to alter the 
Lease (as amended by this Second Amendment) in any way.

     F.  The Term of the Lease is seven (7) years, commencing on July 1, 
1983. The Lease provides that Chiron has the option to extend the Lease for 
nine (9) additional terms of two (2) years each.  Chiron has already exercised
three (3) of the two (2) year extensions, with the Term of the Lease, as 
extended prior to this Second Amendment, to expire on July 1, 1996.

     G.  Chiron desires by this Second Amendment to extend the Term of the 
Lease by two (2) additional terms of two (2) years, such that (i) the Term of 
the Lease after the extensions pursuant to this Second Amendment shall expire 
on June 30, 2000, and (ii) Chiron will have the right, in accordance with the 
terms of the Lease (as amended by this Second Amendment), to extend the


                                      1.



<PAGE>

Term of the Lease after June 30, 2000 by four (4) additional terms of two (2) 
years each.

     NOW THEREFORE, IN CONSIDERATION of the mutual covenants and promises the 
parties, the parties agree as follows:

     1.  EXERCISE OF OPTIONS. By this Second Amendment, Chiron hereby 
exercises two (2) options to extend the Term of the Lease for two (2) years 
each. The extensions pursuant to this exercise shall commence on July 1, 
1996, and extend through June 30, 2000.

     2.  REVISED SECTION 10.1.  The first sentence of Section 10.1 shall 
state in its entirety as follows:  "Cetus at its own expense shall carry 
throughout the term hereof property insurance on the Premises to replace the 
Building in compliance with current building codes."

     3.  NO MODIFICATION OF LEASE.  No terms of the Option Agreement shall 
alter or modify in any way the terms of the Lease (as amended). For example, 
the failure of Chiron to exercise the option, granted in the Option 
Agreement, to purchase the Premises shall not affect Chiron's rights under the 
Lease (as amended).

     4.  SUCCESSORS AND ASSIGNS.  This Second Amendment shall be binding upon 
and shall inure to the benefit of the parties hereto and their respective 
heirs, executors, administrators, successors in interest and assigns.

     5.  REMAINDER OF LEASE UNAFFECTED.  Except as expressly amended by this 
Second Amendment, the Lease shall remain in full force and effect and 
unamended.

     IN WITNESS WHEREOF, the parties hereto have executed this Second 
Amendment, on the date(s) set forth below, as of the day and year first above 
written.

                                                 "Chapman"

                                                 /s/ Harold B. Chapman, Jr.
                                                 --------------------------
                                                 Harold B. Chapman, Jr., an
                                                 individual


                                      2.



<PAGE>

                                                 "Chiron"

                                                 Chiron Corporation, a
                                                 Delaware corporation


                                                 By  /s/
                                                    --------------------

                                                 Its  Vice President
                                                     -------------------

                                                 Date  June 7, 1995
                                                      ------------------


                                      3.               

<PAGE>

                                                                Exhibit 10.40

Dr. Robert A. Fildes                                                     Undated
President and Chief Executive Officer
Cetus Corporation
1400 Fifty Third Street
Emeryville, CA 94608
U.S.A.



Re: Offer of premises in long lease
     Amatel III

- -----------------------------------

Dear Mr. Fildes,

With reference to the discussions with you, I hereby advise you that after
acceptance on your part of the following conditions the City government will
propose to give in long lease to you the premises at the Pietersbergweg as
reflected on the attached drawing 74 '87 with dotted and diagonal line shading 
at initial annual rent-charge (canon) of Dfl. 162.000, - i.e. Dfl. 40, --per
m TO THE POWER OF 2; the commencement date of the long lease will be March 1, 
1987.

The surface of the premises amounts to approximately 4050 m TO THE POWER OF 2. 
On the premises a commercial building must be erected to be used for a 
biotechnological business whereby office space will take no more than 70% of 
the aggregate floor surface while no construction is permitted on the premises
indicated with crossed line shading.

At the same time premises with a surface of approximately 4050 TO THE POWER 
OF 2  shall be reserved for a period up to two years after completion of the 
building or ultimately until March 1, 1991, as indicated on the attached drawing
74 '87 with crossed line shading.

No reservation fee will be due by you during this period.

The annual rent-charge will be determined on and is due from the moment that you
will put the premises into use. The long lease will also commence on that date.
The destination and the use of the reserved premises is equal to the above
premises.

CONDITIONS OF LONG LEASE

The issue in long lease shall occur under the "General Conditions for continuing
long lease" dated 1966 EXCEPT FOR APPLICATION OF ARTICLE 3, PAR. 14 OF THE
GENERAL CONDITIONS. For your information I enclose an information folder. On the
basis of the General Conditions the premises will be issued in long lease for
an indefinite period of time at a fixed annual rent-charge; each time after five
years the annual
<PAGE>

                                                                           - 2 -

rent-charge will be adjusted to the changed value of the money. Each time after
50 years the annual rent-charge will be adjusted again in mutual consultation
between the City and the lessee or - in absence of mutual agreement - by three
experts. The lessee, may, if so desired redeem in advance the rent-charge due
over a fifty year term of long lease.

Apart from the General Conditions the following special regulations will be in
force:

1.   The building to be erected on the premises is destined to be business
     premises and to be used as office and laboratory. Parking, loading and
     unloading must occur on the premises.

2.   Construction of the premises must have been completed within 24 months
     after the commencement date of the long lease.

3.   Within the term as referred to under 2 the lessee must have provided for
     hardening or planting on the unbuilt part of the premises and must so
     maintain it subsequently; at the satisfaction of Mayor and Aldermen.

4a.  The lessee must permit that cables, service-pipes, tubes etc. will be put
     in the unbuilt part of the premises and will be maintained for the benefit
     of the municipal services and companies, as well as for telecommunication.

4b.  Damages resulting from the above mentioned works shall be repaired or
     compensated by or on behalf of the contractor of these works.

ACCEPTANCE OF PREMISES IN LONG LEASE

The premises will be delivered to you in a state ripe for construction conform
the municipal guidelines in this respect. This means that obstacles and/or
foundation remains in the ground (if any) will be removed and that the premises,
if necessary, will be supplemented with sand and will be levelled. During the
supplementation with sand the starting point will be a closed sand distribution
system during the construction. In connection with the exact specifications you
should contact through my department in an early stage the section Land and
Water Works of the Public Works Department.

For further data concerning the acceptance of the long lease premises I refer to
the attached brochure "What you should know further".

FINANCIAL DATA

The annual rent-charge of Dfl. 162.000, -- is based on a land price of Dfl. 450.
- -- and a rental percentage of 8.9%. The

<PAGE>

                                                                             -3-

canon must be paid in advance in two equal semi-annual installments as referred
to on the attached invoice no. 708349.

If you wish to pay in advance the rental over the full rental period of 50 years
the redemption price amounts to Dfl. 2.034.035, --. This amount is due as of the
date that the long lease right commences or is deemed to have commenced and must
ultimately be paid upon execution of the long lease deed before a notary. During
the period (if any) between commencement date of the long lease and payment
interest is due the rate being equal to the legal interest rate. As of March 1,
1987 the long lease is deemed to become effective.

Conform article 31 of the General Conditions all cost relating to the issue of
the premises in long lease (such as a notary fee, land register fee, taxes) are
for your account.

I draw your attention to the fact that value added (BTW) is due on the amount of
the land price of the premises in long lease at the rate applicable at the time
of the execution of the notarial deed.


FINAL PROVISIONS

- -    EXECUTION OF NOTARIAL DEED

     As it appears that you will begin to use the premises prior to the
     execution of the long lease deed, parties shall act as if the long lease
     deed already has been registered in the public registers as of March 1,
     1987, which date shall be deemed to be the commencement date of the long
     lease.

     I draw now already your attention to the fact that a notary located in this
     city must be instructed to execute the long lease deed.

- -    ACCEPTANCE

     I request you to advise me within one month after the date of this letter
     whether you agree with the above by returning the attached note of
     acceptance.

     Thereafter I shall request Mayor and Aldermen to submit the issue in long
     lease for ratification by the municipal council.

     I have sent a copy of the long lease offer for advice to the municipal
     department of Physical Planning and Public Works; I shall advise you of any
     further conditions to be put if the advice so requires.


<PAGE>

                                                                           - 4 -

For further information or clarification of this offer you may contact the
official of my department referred to in the heading of this letter.

                                                      The Municipal Land Company

                                                              (Signed illegible)

Attachments    1. Drawing
               2. General Conditions
               3. Invoice annual rent-charge
               4. What you should know further
               5. Note of acceptance


<PAGE>

                                                                           - 4 -

                                                                     Translation


                                                                    File number:

                                                                    Plan number:

                                                                       Premises:

NOTE OF ACCEPTANCE

(The undersigned)

hereby declares to agree with the offer in long lease as is made by the
Municipal Land Company of Amsterdam in its letter ref. no._______of
(date)_______.

In addition the undersigned declares (not) to make use of the opportunity to
redeem the rental-charge (canon) at this moment.

The rental-charge (canon) of Dfl._______will be paid per (date)_______by
transfer to postal account no. 4600062 of the Municipal Land Company of
Amsterdam.

The undersigned declares to charge notary_______with the execution of the long
lease deed.

Place

Date

Signature 

<PAGE>

                                                      EXHIBIT 10.57

                       DESCRIPTION OF CHIRON'S 1995
             EXECUTIVE OFFICER VARIABLE COMPENSATION PROGRAM


      Decisions on compensation (base salary and variable compensation) of 
Chiron Corporation's ("Chiron" or the "Company") executive officers are made 
by the Compensation Committee of the Board of Directors. Except to the extent 
provided under the Chiron Corporation 1995 Executive Officer Variable Cash 
Compensation Plan, the Compensation Committee has based its decisions 
regarding compensation in fiscal year 1995 for executive officers as a group, 
on (i) a qualitative evaluation of the Company's overall performance in 1995, 
including the strategic repositioning of the Company's business units (the 
acquisition and integration of Ciba Corning Diagnostics Corp. into Chiron 
Diagnostics, the acquisition and integration of IOLAB's surgical business 
into Chiron Vision, the acquisition and integration of Viagene, Inc. into 
Chiron Technologies) and the development and implementation of strategic 
initiatives to position each business unit for sustainable and profitable 
growth and to play an important role in the markets it serves; (ii) analysis of
compensation programs and amounts paid for comparable benchmark positions in 
other biotechnology, high technology and pharmaceutical companies; and (iii) 
subjective assessment of each executive officer's individual performance and, 
where relevant, the performance of the officer's business unit or functional 
area of responsibility.


      For 1995, the Compensation Committee continued the Company's approach 
that base salaries for executive officers should be measured by reference to 
the median (50th percentile) of salaries for benchmark positions in 
comparator companies. Further, the Compensation Committee provided that a 
significant portion of total cash compensation (salary plus variable cash 
compensation) in the form of annual variable cash compensation potential 
should be "at risk", dependent on individual, business unit, and overall 
Company performance. Variable cash compensation for executive officers 
overall was targeted to yield total cash compensation at the 50th percentile, 
but with the opportunity up to 75th percentile, of total cash compensation as 
shown by comparative data.






<PAGE>

                                                                Exhibit 10.65

[CHIRON LETTERHEAD]


June 28, 1995



Mr. C. William Zadel
President and Chief Executive Officer
Ciba Corning Diagnostics Corp
63 North Street
Medfield, MA  02052-1688

Dear Bill:

This letter confirms the terms of our understanding regarding the termination of
your employment with Ciba Corning Diagnostics Corp. ("CCD").

You have expressed the intention to resign your offices as President and Chief
Executive Officer of CCD and otherwise to terminate your employment with CCD.
You have offered to continue to serve in these capacities during a transitional
period, ending not sooner than August 31, 1995 and not later than December 31,
1995, during which time a successor would be recruited by Chiron, in
consideration of a mutually acceptable severance and termination agreement.
This letter represents that agreement.

     1.  You will continue to serve as the President and Chief Executive Officer
of CCD until that date specified by Chiron in writing, which shall be not
earlier than August 31, 1995 and not later than December 31, 1995 (the
"Termination Date").  Except as otherwise specifically provided in this Letter
Agreement, all of your existing employment benefits will continue until the
Termination Date, in accordance with their terms as of May 18, 1995, and then
they will cease.

     2.  Your base salary is increased effective June 1, 1995 by 7% to $342,400
per annum ("Base Salary"), payable periodically with the regular CCD payroll.
Your Base Salary will continue to be paid to the Termination Date and then shall
cease to be paid.

     3.  On or promptly following the Termination Date, CCD shall pay to you the
amounts then owing, if any, under its normal policies for terminating employees
for earned vacation and sick leave.

<PAGE>

C. William Zadel
June 28, 1995
Page 2



     4.  Promptly following completion of the 1995 audit of CCD, CCD shall pay
to you the amount that would have been earned by you under the CCD Annual
Incentive Plan for the full 1995 fiscal year, without regard to the actual
Termination Date.

     5.  You will not receive any payment for 1995 under the CCD Long-term
Incentive Plan.  In lieu thereof, CCD shall pay to you the amount of $171,200 on
a date following the Termination Date to be mutually agreed, but in no event
later than January 31, 1996.

     6.  On January 1, 1996 and  January 1, 1997, CCD will pay to you lump sum
payments of $650,560 and $325,280 respectively, representing approximately 18
months of cash compensation in salary and target short-term and long-term cash
compensation.  In addition, provided that you have not then accepted a Successor
Position (as defined below), commencing with the first full calendar month
following the elapse of 18 months from the Termination Date, CCD will pay to you
a further monthly severance amount equal to $54,213 per month up to six months
and $28,533 per month up to an additional six months, until you accept a
Successor Position, but in no event for more than 12 months in the aggregate.

     7.  Until such time as you accept a Successor Position,  CCD will maintain
in effect for your benefit at its expense the medical, dental and life insurance
coverage that you presently enjoy under CCD's existing policies.  The maximum
time of this benefit is 30 months after the Termination Date.  In addition, in
lieu of participation in the post-retirement medical program established for
eligible CCD employees following the close of the transaction, Chiron will make
you a lump sum cash payment of $33,000.

     8.  The term "Successor Position" means such full-time and permanent
employment as you may accept in your discretion, including self-employment as a
consultant, or retirement.

     9.  All payments provided herein shall be subject to all applicable
withholding obligations of CCD.

<PAGE>

C. William Zadel
June 28, 1995
Page 3



     10.  Nothing in this Letter Agreement alters your rights as vested under
the CCD Pension Plan in accordance with the terms of that plan as of  May 18,
1995.

     11.  All Chiron stock options granted to you shall be cancelled without
having become vested as of the Termination Date.

     12.  The obligations of CCD and Chiron under this Letter Agreement are
conditioned upon your performance of your responsibilities to the best of your
ability as President and Chief Executive Officer of CCD through the Termination
Date, including without limitation the management of the business and operations
of CCD in the ordinary course, the facilitation and implementation of the plan
to integrate CCD and the Diagnostics Division of Chiron and the execution of all
applicable policies and directions for the governance of CCD as adopted from
time to time by its Board of Directors, or by Chiron as its sole stockholder,
and upon your agreement to provide reasonable consultation, advise and
assistance to CCD and Chiron following the Termination Date from time to time at
their reasonable request and at their expense.

     13.  This Letter Agreement contains and constitutes the entire
understanding and agreement between CCD and you respecting your employment with
CCD and supersedes and cancels all previous written or verbal negotiations,
agreements, commitments, and writings in connection herewith.  It also
represents the complete compromise, accord, and satisfaction of any and all
claims that you may have or acquire regarding the termination of your employment
by CCD, and, except with respect to any rights, obligations or duties arising
out of this Letter Agreement, claims for unemployment and workers' compensation
benefits in accordance with applicable law, or any right that you have to
benefits under this Letter Agreement or any company employee benefit plan in
accordance with the Employee Retirement Income Security Act, all of which are
expressly excluded from this release, you hereby release and discharge CCD,
Chiron and their respective officers, directors, and stockholders from any
liability, obligation, claim or cause of action relating to or arising out of
your employment by CCD and/or its termination, including any claim arising under
that certain letter to you dated January 4, 1995 and signed on behalf of Chiron
by Edward E. Penhoet or under any other written or oral agreement or any course
of dealing, custom or practice or otherwise.

<PAGE>

C. William Zadel
June 28, 1995
Page 4



     14.  This Letter Agreement shall be binding upon CCD and you and may not be
released, discharged, abandoned, supplemented, amended, changed, or modified in
any manner, orally or otherwise, except by an instrument in writing of
concurrent or subsequent date, signed by a duly-authorized officer or
representative of each of CCD and you.

     15.  The terms of this Letter Agreement are contractual in nature and not a
mere recital.  This Letter Agreement shall be governed by and construed in
accordance with the laws of the Commonwealth of Massachusetts.  This Letter
Agreement may be executed in two or more counterparts, each of which shall be
deemed an original, but all of which together shall constitute one and the same
instrument, and in pleading or proving any provision of this Letter Agreement it
shall not be necessary to produce more than one such counterpart.

     16.  You hereby confirm your continuing obligations to preserve the
confidentiality of all trade secrets and other proprietary information acquired
by you from or through CCD, Chiron, Ciba-Geigy, Ltd., including without
limitation scientific information and results, customer lists, and business and
strategic plans.

     If the foregoing correctly reflects our understanding, please sign and
return to me one copy of this Letter Agreement.

CHIRON CORPORATION

By /s/ William J. Rutter
   ------------------
Its       Chairman
   ------------------

AGREED:

/s/ C. William Zadel
- ---------------------
C. William Zadel


July 5, 1995
- ---------------------
Date

<PAGE>

                                                                Exhibit 10.73

                          SECOND AMENDMENT TO LEASE


     THIS SECOND AMENDMENT TO LEASE ("Second Amendment") is entered into 
effective as of March 15, 1995, by and between BGR ASSOCIATES, A CALIFORNIA 
LIMITED PARTNERSHIP ("Lessor"), and CHIRON CORPORATION, a Delaware 
corporation ("Lessee"), with reference to the following facts:

     A.  Lessor and Lessee are parties to that certain Lease dated December 
17, 1984, entered into by Lessor and Lessee's predecessor, Cetus Corporation, 
as amended by an Amendment to Lease dated February 1, 1986 (as so amended, 
the "Lease"). The property covered by the Lease is located in Emeryville, 
California, and is more particularly described in the Lease.

     B.  Lessor, Lessee and certain other parties related to Lessor have 
entered into that certain Option Agreement of even date herewith (the "Option 
Agreement"), pursuant to which Lessor has been granted to Lessee the option, 
subject to the terms and conditions of the Option Agreement, to purchase the 
property covered by the Lease as well as other property in the vicinity 
thereof. As provided for in Section 5.a of the Option Agreement, Lessee has 
agreed to waive certain rights to terminate the Lease as part of the 
consideration to Lessor for granting such option to Lessee.

     C.  Lessor and Lessee are entering into this Second Amendment pursuant 
to Section 5.d of the Option Agreement to further evidence Lessee's waiver of 
termination rights as provided for in the Option Agreement.

     NOW, THEREFORE, in consideration of the foregoing, and for other good 
and valuable consideration, the receipt and adequacy of which are hereby 
acknowledged, Lessor and Lessee hereby agree as follows (capitalized terms 
used herein but not herein defined shall have the meaning ascribed to them in 
the Lease):

     1.  AMENDMENT OF PARAGRAPH 3.2.  As provided in the Option Agreement, 
Lessee has irrevocably waived and relinquished its right under Paragraph 3.2 
of the Lease to terminate the Lease as of June 30, 1996, and June 30, 1998; 
and in furtherance of the foregoing, Lessor and Lessee hereby amend 
Paragraph 3.2 of the Lease by deleting therefrom the words "second, fourth, 
sixth, eighth" in the third sentence of said paragraph, which sentence begins 
in the tenth (10th) line of said paragraph with the phrase "Notwithstanding 
anything to the contrary in this Lease, ..."



<PAGE>

     2.  STATUS OF LEASE.  Except as amended hereby, the Lease remains 
unamended; and as amended hereby, the Lease and all the terms and conditions 
thereof remain in full force and effect.

     3.  COUNTERPARTS. This Second Amendment may be executed in multiple 
counterparts, each of which shall constitute an original hereof, and all of 
which taken together shall constitute one and the same agreement.

     IN WITNESS WHEREOF, Lessor and Lessee have executed this Second Amendment
as of the date first set forth above.


LESSEE:                                 LESSOR:

CHIRON CORPORATION,                     BGR ASSOCIATES, A CALIFORNIA
a Delaware corporation                  LIMITED PARTNERSHIP


By:  ___________________________        By:  _____________________________
                                             Richard K. Robbins
Its: ___________________________             Managing General Partner


                                     2

<PAGE>

                                                                Exhibit 10.80

                          [CONFIDENTIAL TREATMENT REQUESTED]

[Certain information has been omitted herein pursuant to a request for 
confidential treatment pursuant to Rule 24b-2.]


                              CHIRON FUNDING L.L.C.

                       LIMITED LIABILITY COMPANY AGREEMENT


     THIS LIMITED LIABILITY COMPANY AGREEMENT (this ``Agreement") is entered
into and effective as of December 28, 1995 (the "Effective Date"), among Chiron
Corporation, a Delaware corporation ("Chiron"), Chiron Biocine Company and
Biocine S.p.A., both of which are wholly owned Affiliates of Chiron, and Ciba-
Geigy Corporation, a New York  corporation ("Ciba"), Chiron, its Affiliates and
Ciba are sometimes referred to herein as the "Members".

                                        I
                            FORMATION OF THE COMPANY

     I.1  FORMATION AND EFFECTIVE DATE.  The parties hereby agree to organize a
limited liability company (the ``Company") under the Delaware Limited Liability
Company Act, (the "Act").  Prior to execution of this Agreement, as the Initial
Member, Chiron has caused a Certificate of Formation conforming to the
requirements of the Act to be executed and filed with the Office of the
Secretary of State of the State of Delaware.  The Company shall commence
business on or about the Effective Date.

     1.2  NAME AND PRINCIPAL PLACE OF BUSINESS.  The name of the Company is
"Chiron Funding L.L.C.".  The principal place of business of the Company shall
be in such place or places as the Members determine from time to time, with the
initial such principal place of business being located in 4560 Horton Street,
Emeryville, California.

     1.3  AGREEMENT AMONG MEMBERS.  For and in consideration of the mutual
covenants herein contained and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the Members hereby
agree to the terms and conditions of this Agreement, as it may from time to time
be amended in accordance with its terms.  Except to the extent a provision of
the Agreement expressly incorporates federal income tax rules by reference to
sections of the Code or Treasury Regulations or is expressly prohibited or
ineffective under the Act, the Agreement shall govern, even when inconsistent
with, or different from, the provisions of the Act or any other law or rule.

     1.4  SCOPE OF BUSINESS.  The Company may engage in any lawful business
permitted by the Act or the laws of any jurisdiction in which the Company may do
business.

                                        1

<PAGE>

     The Company shall have the authority to do all things necessary or
convenient to accomplish its purpose and operate its business as described in
this Section 1.4, subject to the provisions of this Agreement.

     1.5  NO STATE-LAW PARTNERSHIP.  The Members intend that the Company not be
a partnership (including, without limitation, a limited partnership) or joint
venture, and that no Member be a partner or joint venturer of any other Member,
for any purposes other than federal and state tax purposes, and this Agreement
should not be construed to suggest otherwise.

     1.6  DEFINITIONS.  All references in this Agreement to financial
statements, assets, liabilities, profits and losses and similar accounting items
with respect to the Company shall mean such items prepared or determined using
the accrual method of accounting and the application of generally accepted
accounting principles as from time to time in effect in the United States.

     For purposes of this Agreement, the following shall have the meanings set
forth respectively after each:

          "ACCOUNTING PERIOD" shall mean the Fiscal Year; provided, however,
that an interim closing of the books of the Company shall take place if, within
an Accounting Period, additional capital is contributed to or amounts are
distributed by or withdrawn from the Company, if such contribution, distribution
or withdrawal results in a change in the allocation of subsequent profits,
losses, contributions or distributions.

          "AFFILIATES" of Chiron shall mean all corporations, or other entities,
more than 50% of whose shares or voting interests are owned, directly or
indirectly, by Chiron; "Affiliates" of Ciba shall mean Ciba Geigy Limited of
Basle Switzerland and all corporations, or entities, more than 50% of whose
shares or voting interests are owned, directly or indirectly, by Ciba-Geigy
Limited.

          "CAPITAL ACCOUNT" of a Member shall mean the separate Capital Account
maintained in accordance with Article 5.

          "CAPITAL CONTRIBUTION" of a Member shall mean the assets or property
contributed to the Company by or on behalf of any member as consideration for a
Membership Interest.  For the purposes of this Agreement, the value of property
contributed shall be deemed equal to each member"s share of the maximum Net
Purchased Amount under Section 2.3.2.

          "CODE" shall mean the Internal Revenue Code of 1986, as amended.

          "FISCAL YEAR" shall mean the 52 or 53 week period beginning on the
Monday closest to January 1 and ending on the Sunday closest to December 31 of
each year, or as otherwise required by law.

                                        2

<PAGE>

          "MEMBERSHIP INTEREST" shall mean the rights of a Member in
distributions (liquidating or otherwise) and allocations of the profits, losses,
gains, deductions and credits of the Company.

          "NET INCOME OR NET LOSS" shall mean for any Fiscal Year the amount
computed as of the last day thereof of the net income or loss computed under
generally accepted accounting principles.

          "PERCENTAGE INTEREST" shall mean with respect to any Member, a
fraction (expressed as a percentage), the numerator of which is the total of the
Member's Capital Contribution and the denominator of which is the total of all
Capital Contributions of all Members.

          "TREASURY REGULATIONS" means regulations issued by the U.S. Treasury
Department pursuant to the Code.


                                       II
           CONTRIBUTIONS TO CAPITAL; TRANSFERS OF MEMBERSHIP INTEREST

     2.1  INITIAL CONTRIBUTIONS AND TRANSFERS.  As of the execution date of this
Agreement, the following have occurred:

          2.1.1     INITIAL CONTRIBUTION BY CHIRON AND ITS AFFILIATES.  Chiron
and its Affiliates have  first made the following contribution to capital in
return for 100% of the Membership Interests in the Company.  The portion of such
Membership Interests held by each of Chiron and its Affiliates is set forth in
Exhibit A.  Such 100% of Membership Interests consists of 250,000 units of
Membership Interest, each referred to herein from time to time as a "Unit".
Chiron and its Affiliates have contributed the following:

          (a)  CASH.  Cash in the amount of $2500.00.

          (b)  ROYALTY.  A royalty agreement in the form of Exhibit B (the
       "Royalty Agreement") with respect to royalties on certain specified
       products (the "Products") arising from Funded Projects, as defined in
       Section 2.3.4.

          (c)  CO-PROMOTION OPTION.  The option to co-promote all of those
       Products identified as "Adult Vaccines" on Schedule A of the Royalty
       Agreement (the "Adult Vaccines") in all countries of the world other
       than North America and Europe in which the Company, directly or
       indirectly, through Ciba or otherwise, reasonably has the field sales
       force and other promotional infrastructure necessary to successfully
       promote the Adult Vaccines.  In determining such adequacy, the
       capabilities of Ciba's sales force and promotional infrastructure or
       the sales force and promotional infrastructure of any Ciba Affiliate
       shall be deemed to be the field sales force and promotional
       infrastructure of the

                                        3

<PAGE>

          Company, in all countries where Ciba elects to undertake co-promotion
          activities.  The option to co-promote shall not apply to any Products
          other than Adult Vaccines.  Such option shall be exercisable by the
          Company, on a country by country basis, by written notice to Chiron,
          at any time until 180 days following the granting of the first
          regulatory approval in North America or Europe to market and sell the
          first Adult Vaccine for which such regulatory approval is obtained.
          This option shall terminate automatically as to all Adult Vaccines, in
          any country, with respect to which the option is not exercised by the
          Company within the time limit set forth above, it being understood
          that it may be in the interests of the parties to explore, without
          obligation, a broadening and/or extension of such co-promotion.

               (i)  Upon exercise of the option by the Company, the parties
          shall negotiate in good faith a co-promotion agreement for the
          Adult Vaccines in the countries as to which the Company has
          exercised its co-promotion option, on commercially reasonable
          terms, which shall include (A) a pre-tax  co-promotion profit to
          the Company of not less than [CONFIDENTIAL TREATMENT REQUESTED] of 
          Net Sales of Adult Vaccines in such countries, (B) an obligation of 
          reasonable diligence, (C) a reservation in favor of Chiron of the 
          right to market to international public organizations such as UNICEF 
          and W.H.O., with an appropriate compensation to be paid to the Company
          for any co-promotional activity agreed to be provided by the Company
          supporting such international sales, and (D) such other terms as
          the parties may then agree.  The co-promotion right shall expire
          as to each Adult Vaccine six (6) years after the first commercial
          sale, on a country by country and product by product basis.

               (ii)  The Company agrees to exercise such option only in the
          event that the Company is able to contract with Ciba (or other
          entity acceptable to Ciba and Chiron) to perform the co-promotion
          activities.

               (iii)  The Company, and in the event that the Company has granted
          co-promotion rights hereunder to Ciba, the Company and Ciba shall
          keep accurate books and records as to its co-promotion, which
          books and records shall be subject to audit by Chiron, in the
          same manner as set forth in Section 3.05.

               (iv)  All obligations and rights of Ciba under this Section
          2.1.1(c) may be assigned to and performed by any of Ciba's
          Affiliates.

          2.1.2     INITIAL TRANSFER OF MEMBERSHIP INTEREST TO CIBA.  Chiron
and/or its Affiliates have transferred to Ciba 12,000 Units of Membership
Interest in the Company in consideration of U.S. $12,000,000.

     2.2  FURTHER CONTRIBUTIONS AND CREATION OF ADDITIONAL MEMBERSHIP INTEREST.
At any time, upon request of Chiron, and subject to the approval of Ciba
pursuant to Section 2.3.4,

                                        4

<PAGE>

Chiron, directly or through its wholly owned affiliates, shall have the right to
receive additional Membership Interest in the Company, subject to a maximum of
300,000 aggregate Units of  Membership Interest in the Company held by all
Members, in return for additional contributions of capital to the Company as
follows:

          (a)  CASH.   Cash in an amount equal to the One Cent ($0.01) per Unit.

          (b)  PRODUCT RIGHTS.   Chiron shall grant to the Company the right to
      participate in commercial opportunities with respect to additional
      products other than the Products, based on one or more of the
      following structures, to be determined at Chiron"s election, but
      subject to approval by Ciba:

               (i) ROYALTY INTEREST.  Chiron may grant to the Company the right
          to receive a royalty on net sales of such products, subject to
          acceptable terms and conditions, such as those set forth in the
          Royalty Agreement.

               (ii)  MARKETING OR PROMOTION RIGHTS.  Chiron may grant to the
          Company the right to participate in the marketing and/or selling in
          selected markets of the identified product(s).  In such event, the
          parties would agree upon a supply arrangement under which Chiron would
          manufacture the products for sale through the Company or upon co-
          promotion arrangements under which the Company would market products
          sold through Chiron.  Such rights would be subject to acceptable terms
          and conditions, such as stated in Section 2.1.1(c) above.

               (iii)  PROFITS INTEREST.  Chiron may grant to the Company the
          right to receive a stated percentage of pre-tax profits and losses
          from the sale of products developed, manufactured and marketed by
          Chiron arising from the contributed project or products subject to
          acceptable terms and conditions.

     2.3  SALE OF MEMBERSHIP INTEREST TO CIBA.

          2.3.1     CIBA OBLIGATION.    From time to time at Chiron's request,
subject to the limitations set forth in this Section 2.3, during the period
commencing with the date hereof (the "Effective Date") and ending on December
31, 1999 (such period referred to herein as the "Funding Period"), Ciba agrees
to purchase and Chiron, or its Affiliate, agrees to sell to Ciba Units of
Membership Interest in the Company at a price of One Thousand Dollars ($1000.00)
per Unit.

          2.3.2     AGGREGATE PURCHASE LIMITATIONS.  Ciba's obligation to
purchase Units hereunder shall be subject to the following limitations:

                                        5

<PAGE>

               (a)  The Net Purchased Amount, as defined below, shall not exceed
          Two Hundred Fifty Million Dollars (U.S. $250,000,000); provided,
          however, that such amount may be increased, at Chiron's request, to a
          maximum of Three Hundred Million Dollars (U.S. $300,000,000) pursuant
          to the Section 5.12 of the 1994 Investment Agreement.  "Net Purchased
          Amount" shall mean, at any time, the aggregate amount paid to Chiron
          or its Affiliates by Ciba for the purchase of Units pursuant to this
          Agreement, which shall include the $12,000,000 received by Chiron in
          return for the initial transfer of Units to Ciba hereunder.  The Net
          Purchased Amount will be reduced by the aggregate amount of any
          dividends or other capital distributions actually paid by the Company
          to Ciba and any profits to Ciba from co-promotion or marketing
          activity by Ciba pursuant to Section 2.1.1(c), in each case, through
          the date of any required purchase of Units.

               (b)  The Net Purchased Amount shall not exceed at any time one
          hundred percent (100%) of the R&D Costs, as defined below, incurred
          during the Funding Period  by Chiron and its Affiliates (including
          without limitation Chiron Biocine Company and Biocine S.p.A.)
          initially with respect to all subunit vaccines and traditional
          vaccines and with respect to IGF-1 (collectively, the "Funded
          Projects").  In the event that additional Funded Projects are added
          pursuant to Sections 2.1.4 and 2.3.4, R&D Costs associated with such
          projects shall be added to the preceding sentence.  As used herein,
          the "R&D Costs" for a given period shall mean the fully burdened,
          fairly allocated costs of Chiron, on a consolidated basis, of
          research, development, and regulatory approval activities with respect
          to Funded Projects, as determined under Chiron's normal project
          accounting practices, including reasonable and customary allocations
          of indirect and overhead expenses and charges in the nature of
          depreciation and amortization of capitalized cost, general and
          administrative expenses, and out-of-pocket expenses, to the extent
          that any of the foregoing were or are incurred on or after January 1,
          1995.  R&D Costs shall include Chiron's share of expenses of  R& D
          Costs of joint businesses with respect to Funded Projects.

          2.3.3     TIMING LIMITATIONS. In no event shall Ciba be obligated to
purchase Units such that the purchase price paid exceeds

          a)   Thirty-four Million Dollars (U.S. $34,000,000) in 1995;

          b)   In 1996, One Hundred Sixteen Million Dollars (U.S. $116,000,000),
             plus any unused portion of the funding limit for 1995 pursuant to
             section 2.3.3(a); and

          c)   For subsequent calendar years, equal annual portions of the
             remaining unexpended aggregate amount under Section 2.3.2 above.

          2.3.4     FUNDED PROJECTS.   Chiron agrees to use the proceeds of
sales of Units to Ciba hereunder solely for the purpose of research, 
development and regulatory approval

                                        6

<PAGE>

          activities with respect to Funded Projects, determined in accordance
          with this Section 2.3.4.
               (a)  In conjunction with any request by Chiron for the issuance
          of additional Units pursuant to Section 2.2, Chiron shall provide to
          Ciba proposals for research and development programs which Chiron
          desires to fund or partially fund as Funded Projects through the sale
          of such additional Units to Ciba.  No limitation shall be placed upon
          the number of Funded Projects that Chiron may present to Ciba during
          the Funding Period.

               (b)   Upon acceptance by Ciba of a proposal pursuant to Section
          2.3.4(a), the Company shall be authorized to issue additional Units
          pursuant to Section 2.2, and the proposed project shall become a
          Funded Project.  A Funded Project shall remain a Funded Project for
          purposes of this Agreement unless or until  Chiron elects, in its sole
          discretion, to discontinue research and development with respect to
          such project.  Chiron will manage the research with respect to Funded
          Projects in its sole discretion.

               (c)  Chiron will prepare, in consultation with Ciba,  annual and
          quarterly forecasts of the R&D Costs for each Funded Project.

          2.3.5     SALES OF UNITS.  From time to time, not more frequently than
once per fiscal quarter and prior to the conclusion of the fiscal quarter,
Chiron shall provide Ciba with a written notice of the amount of Units that it
or its Affiliates wish to sell to Ciba, and the associated purchase price, all
in accordance with the provisions of this Article 2.  Such purchase price shall
not exceed the lesser of  (i) 100% of R&D Costs of the Funded Projects incurred
on or after January 1, 1995 and not previously funded through sales of Units
hereunder; or (ii) the maximum funding obligation of Ciba pursuant to Section
2.3.3 for the period  in question.  Ciba shall purchase the requested amount of
Units, by paying the purchase price in U.S. dollars in immediately available
funds, by wire transfer, unless otherwise mutually agreed.  The purchase price
shall be due and payable within thirty (30) days following the notice delivered
by Chiron to Ciba pursuant to this Section 2.3.5.

          2.3.6     NO OTHER TRANSFER OF MEMBERSHIP INTEREST.   Chiron, its
Affiliates and Ciba agree that none of them shall transfer any Membership
Interest in the Company, nor shall the Company issue any new Membership
Interest, to any third party without the prior written consent of both Chiron
and Ciba; except that Ciba may transfer its Membership Interest, or cause future
Membership Interests to be purchased by, Ciba"s parent corporation or any wholly
owned subsidiary of Ciba"s parent corporation. Chiron further agrees that it
will not assign or transfer to a third party a controlling interest in any
Chiron Affiliate which is also a Member of the Company without the prior written
consent of Ciba.

          2.3.7  RETAINED INTEREST BY CHIRON.  In order to assure that the
Company has two Members at all times, Chiron agrees to retain and not to sell to
Ciba pursuant to this Section 2.3 at least one Unit of Membership in the
Company.

                                        7

<PAGE>

                                   ARTICLE III
                    CHIRON RESEARCH AND DEVELOPMENT ACTIVITY

     3.1  DILIGENCE.  Chiron and its Affiliates shall use reasonable commercial
diligence to pursue and complete the research and to develop, test, gain
regulatory approval for, market and sell the Products. In the event that less
than 100% of the R & D Costs of a Funded Project is provided to Chiron
hereunder, Chiron nevertheless shall spend its own portion of such R & D Costs
in conducting activities related to the Funded Project.

     3.2.  ALLOCATION OF FUNDING.  Where a Funded Project includes more than one
product under development, and in the event that more than one Funded Project is
subject to funding hereunder, funds received by Chiron or its Affiliates through
sales of Units shall be allocated, among the Products within a Funded Project,
and among Funded Projects, in Chiron's sole discretion.

     3.3  NO WARRANTY OF SUCCESS.  CHIRON MAKES NO WARRANTIES OR GUARANTEES OF
ANY KIND THAT THE RESEARCH AND DEVELOPMENT ACTIVITIES FUNDED  HEREUNDER WILL BE
SUCCESSFUL OR WILL ACTUALLY RESULT IN ANY PRODUCTS BEING MARKETED OR SOLD.

     3.4  RIGHTS TO INVENTIONS.  Nothing in this Agreement will cause Ciba or
the Company to obtain any ownership or license rights in any patent or other
intellectual property rights of Chiron in connection with any Funded Project; or
any other right or license not specifically granted herein or in the Royalty
Agreement.  Chiron will own the right, title and interest in and to any new
inventions arising in the course of any Funded Project, to the extent such
inventions are made by Chiron, its employees, agents or assignors.

     3.5  AUDIT RIGHTS.  Chiron and its Affiliates agree to keep accurate books
and records of the funding received through sales of Units hereunder, and the R
& D Costs incurred with respect to Funded Projects.  Ciba shall have the right,
at its own expense, for a period of three (3) years after the end of the Funding
Period, to have an independent certified public accountant ("CPA") reasonably
acceptable to Chiron examine the relevant books and records of Chiron and its
Affiliates, during normal business hours, at the principal offices of Chiron,
upon two (2) weeks advance written request, to verify the R & D Costs; provided,
however, that such audits shall not occur more than once per year.  Said CPA
shall be under confidentiality obligations to Chiron, to reveal  only whether
there is an error in the R & D Costs reported to Ciba, and if so, the amount of
such error.

                                        8

<PAGE>

                                   ARTICLE IV
                        REPURCHASE OF MEMBERSHIP INTEREST

     4.1  RIGHT TO REPURCHASE UNITS.  Chiron and/or its Affiliates shall have
the right (the "Buy-Out Right") to repurchase from Ciba all Units sold to Ciba
under this Agreement upon tender by Chiron to Ciba of payment in the amount of
the Buyout Amount (as hereinafter defined) in effect at the time of such tender;
provided that such right shall expire if such tender is not made prior to
January 1, 2002.

     As used herein, "Buyout Amount" shall mean an amount equal to (i) the sum
of all Unit purchase payments made by Ciba prior to the date of such tender
pursuant to this Agreement, PLUS (ii) interest thereon from the date of payment
until the date of such tender at a rate equal to LIBOR determined and compounded
on a quarterly basis,  LESS (iii)  the aggregate amount of any dividends or
other capital distributions received or receivable by Ciba from the Company and
any pre-tax profits received by Ciba from co-promotion or marketing activity by
Ciba pursuant to Section 2.1.1(c), to the date of such tender, which exceed the
pre-tax profits which would ordinarily be payable to a third party conducting
such co-promotion or marketing activity, LESS (iv) interest on the amounts
referenced in (iii) above from the date of actual receipt of such amount by Ciba
until the date of such tender at a rate equal to LIBOR determined and compounded
on a quarterly basis.  For the purposes of this Agreement, "LIBOR" means, with
respect to any calendar quarter, the three month U.S. Dollar rate as quoted by
the British Bankers Association (Bloomberg page "BBA", Telerate page "3767") as
of 11:00 a.m., London time, on the day that is two London banking days prior to
the commencement of such calendar quarter.

     4.2  FORM OF PAYMENT.    Chiron shall be entitled to make the payment of
the Buyout Amount in the form of cash, in immediately available funds, or Chiron
Common Stock ("Chiron Stock"), or a combination of the two.  If Chiron shall
elect to employ Chiron Stock for the purposes of making such payment, such
Chiron Stock shall be valued at its Fair Market Value as of the date immediately
preceding the date on which such payment shall be made.  As used herein, "Fair
Market Value" shall mean, as of any date of determination, the average of the
closing sale prices of Chiron Stock during the 10 trading day period immediately
preceding such date of determination on the principal United States securities
exchange registered under the Exchange Act on which Chiron Stock is listed, or,
if Chiron Stock is not listed on any such exchange, the average of the closing
sale prices or the closing bid quotations of the Chiron Stock during the 10
trading day period preceding such date of determination on the NASDAQ National
Market or any comparable system then in use, or, if no such quotations are
available, the fair market value of the Chiron Stock as of such date of
determination as determined in good  faith by a majority of the Independent
Directors,  as defined in that certain Governance Agreement among Ciba, Chiron
and Ciba-Geigy Corporation dated as of November 20, 1994.

                                        9

<PAGE>

     4.3  EFFECT ON CO-PROMOTION RIGHT.  If, at the time of repurchase by Chiron
of Units pursuant to this Article 4, the Company has exercised the option to co-
promote the Adult Vaccines in one or more countries, pursuant to Section
2.1.1(c), and has contracted with Ciba to perform such obligations, Ciba shall
have the right to continue to co-promote Adult Vaccines then subject to said
right in such countries for the remainder of the term of such co-promotion
rights, all on the terms set forth in Section 2.1.1(c), or the right to expand
its co-promotion rights as provided in Section 4.4.

     4.4  RESIDUAL RIGHTS.   In the event that Chiron exercises its right to
repurchase all of the Units pursuant to this Article 4, Chiron agrees to grant
to Ciba the option (the "Residual Rights Option") to expand its marketing
rights, if any, with respect to all Adult Vaccines, as provided in this Section
4.04 (the "Residual Rights").  If exercised, Ciba would have the right to
convert its co-promotion right into the right to exclusively market and sell all
Adult Vaccines, in all countries of the world other than North America and
Europe, in which Ciba then has exercised its right to co-promote any Adult
Vaccine pursuant to Section 2.1.1(c) and to extend such exclusive marketing for
a period of six (6) years from the later of the date of Ciba's exercise of the
Residual Rights Option or the first approval for commercial sale, on a product
by product basis.

               (a)  The Residual Rights Option shall be exercisable by Ciba, by
          written notice to Chiron,  during the 60 days following Chiron's
          exercise of its Buy-out Right.  Upon exercise of the Residual Rights
          Option by Ciba, the parties shall negotiate in good faith an agreement
          under which Chiron would manufacture and supply, and Ciba would
          market, sell and distribute, the Adult Vaccines in the countries as to
          which Ciba has Residual Rights, all on commercially reasonable terms,
          including reasonable and customary distributor obligations to use
          diligence and to pursue and pay the cost of regulatory approvals and
          other marketing, selling and product introduction activities.

               (b)  Such agreement shall provide for a pre-tax distributor
          profit to Ciba of not less than [CONFIDENTIAL TREATMENT REQUESTED] 
          of Net Sales by Ciba of Adult Vaccines in such countries.  In the 
          event that the Net Purchased Amount, as defined in Section 2.3.2 is 
          less than $250,000,000, such minimum pre-tax distribution profit 
          payable to Ciba hereunder will be reduced by multiplying 
          [CONFIDENTIAL TREATMENT REQUESTED] of net 
          sales by the following fraction:

                         Net Purchased Amount
                         --------------------
                        $250,000,000

               (c)  Ciba's exclusive rights pursuant to this Section 4.4 shall
          be subject to the continuation of such promotional and sales activity
          as Chiron may be  permitted to conduct under any applicable co-
          promotion and other marketing agreements entered into between Chiron
          and the Company or Ciba prior to the exercise of Chiron's Buy-Out
          Right and to the negotiation of equitable and reasonable terms for (i)
          the phase out of such activity by Chiron after the expiration of the
          original terms of such agreements and (ii)

                                       10

<PAGE>

          compensating Ciba for the reduction of such exclusivity by reason of
          Chiron's continued activity.


     4.5  COOPERATION.  Chiron and Ciba shall meet and confer from time to time
to consider whether and to what extent it is in their respective best interests
to permit Chiron or any third party to participate in the marketing of Adult
Vaccines on a country by country basis.  Nothing in this Section 4.5, however,
shall obligate the Company or Ciba either (i) to exercise the options to acquire
co-promotion rights or Residual Rights or (ii) if Ciba exercises the option to
acquire the Residual Rights, to alter the Residual Rights as set forth in
Section 4.4, except to the extent that Ciba determines it to be in its best
interest to do so in the reasonable exercise of its discretion.


                                    ARTICLE V
                                CAPITAL ACCOUNTS

     CAPITAL ACCOUNTS.  The Company shall establish and maintain an individual
Capital Account for each of the Members in accordance with Treasury Regulation
1.704-1(b)(2)(iv).


                                   ARTICLE VI
                               MEETINGS OF MEMBERS

     6.1  PLACE OF MEETINGS.  All meetings of Members shall be held at the
principal place of business of the Company or at such other place as may be
designated from time to time by the Members.

     6.2  ANNUAL MEETING.  An annual meeting of Members for the election of the
Board of Directors and for the transaction of such other business as may
properly be brought before the meeting shall be held on such date designated by
the Board of Directors but not less frequently than once each fiscal year.

     6.3  SPECIAL MEETINGS.  Special meetings of Members may be called at any
time by the Members or by any Member upon written request.

     6.4  QUORUM.  A quorum shall be present at a meeting of Members only if
Chiron and Ciba are present in person or represented by proxy.

     6.5  VOTING AND PROXIES.  Each Member shall have a number of votes equal to
the number of Units of Membership Interest held by it.

     However, the Members hereby agree that:

                                       11

<PAGE>

          (i)    the Company shall not enter into any agreements or conduct any
               transactions, other than those specifically authorized in this
               Agreement or the Royalty Agreement, without the approval of both
               Chiron and Ciba.

          (ii)   Ciba shall have the right to require that the Company exercise
               its rights under this Agreement, including without limitation 
               the co-promotion option, and under the Royalty Agreement. Each 
               of Chiron and Ciba shall be authorized to enforce against the 
               other any and all rights of the Company against such other 
               party.

     6.6  ACTION WITHOUT MEETING.  Any action required or permitted to be taken
at any annual or special meeting of Members of the Company may be taken without
a meeting, without prior notice and without a vote, if a consent in writing,
setting forth the action so taken, is signed by all Members.

     6.7  PARTICIPATION BY TELEPHONE.  Members may participate in a meeting
through use of conference telephone or similar communications equipment, so long
as all Members participating in such meeting can hear one another.


                                   ARTICLE VII
                                   MANAGEMENT

     7.1  BOARD OF DIRECTORS.

             (a) AUTHORITY OF THE BOARD OF DIRECTORS.  Subject to Section 6.5
and except for situations in which the approval of the Members is required by
this Agreement or by applicable law, the day-to-day management of the business
and affairs of the Company shall be vested in the Board of Directors, which
power and authority shall be subject to delegation by the Board of Directors to
the officers and other agents of the Company in the manner provided herein.

             (b) ELECTION OF BOARD OF DIRECTORS.  The Board of Directors shall
consist of three members, two of which shall be appointed by the Member holding
the majority of Units of Membership Interest, with the remaining Director
appointed by the other Member.  Unless otherwise agreed by the Members, one
Director appointed by each Member will have appropriate scientific background.
For this purpose, Chiron shall be deemed to hold the Units held by its
Affiliates.

                 The initial Directors will be William Green and Dennis Winger;
provided that as soon as practicable following the execution of this Agreement,
Chiron and Ciba shall elect directors in accordance with the preceding
paragraph.

                                       12

<PAGE>

                 Thereafter, the members of the Board of Directors shall be
elected at the annual meeting of Members and shall hold office until their
successors have been elected and qualified, or until their death, resignation or
removal, in accordance with this Section 7.1.

             (c) VACANCIES; REMOVAL; RESIGNATION.  Any vacancy occurring on the
Board of Directors may be filled by the party who shall have initially elected
the Director whose position shall have become vacant.  A Director elected to
fill a vacancy shall be elected for the unexpired term of his or her predecessor
in office.  A Director may be removed and a new Director elected by the written
action of only the Member who initially elected the Director to be removed,
pursuant to Section 7.1(b) above.  Any Director may resign at any time.

     7.2     CHANGE IN HOLDER OF MAJORITY OF UNITS.    In the event that Ciba
acquires a majority interest in the Company, the parties agree to hold a Members
meeting within thirty (30) days following the date on which such majority
interest is acquired.  At such meeting, new Directors shall be elected pursuant
to Section 7.1, and new officers shall be appointed pursuant to Section 7.3.


     7.3     OFFICERS.

            (a)     APPOINTMENT.  Unless otherwise agreed, the Company shall
have three officers, with the President and one other officer appointed by the
Directors designated by the holder of a majority of Units, and the remaining
officer appointed by the Directors designated by the other Member.

                    The initial officers of the Company shall be Dennis Winger,
President, and William Green, Secretary; provided that as soon as practicable
following execution of this Agreement, the Directors designated by Ciba shall
appoint a third officer of the Company.

             (b)    AUTHORITY.  Any officers so designated shall have such
authority and perform such duties as the Board of Directors may, from time to
time, delegate to them.  Unless the Members decide otherwise, if the title is
one commonly used for officers of a business corporation formed under the
Delaware General Corporation Law, the assignment of such title shall constitute
the delegation to such officer of the authority and duties that are normally
associated with that office, subject to any specific delegation of authority and
duties made to such officer by the Members or the Board of Directors.  Each
officer shall hold office until his or her successor shall be duly designated
and shall qualify or until his death or until he shall resign or shall have been
removed in the manner hereinafter provided.  Any number of offices may be held
by the same person.

             (c)    VACANCIES; REMOVAL; RESIGNATION.  Any officer may resign as
such at any time.  Such resignation shall be made in writing and shall take
effect at the time specified therein, or if

                                       13

<PAGE>

no time be specified, at the time of its receipt by the Board of Directors.  The
acceptance of a resignation shall not be necessary to make it effective, unless
expressly so provided in the resignation.  Any officer may be removed as such,
either with or without cause, by the Directors who appointed such officer.  Any
vacancy occurring in any office of the Company may be filled by the Directors
who had the authority to elect the officer holding such position.

     7.4  STANDARD OF CARE.

          (a)  It is understood that the business of the Company involves a
degree of risk.  The Board of Directors shall not be liable, responsible or
accountable in damages or otherwise to any Member for, and the Company shall
indemnify and save harmless the Board of Directors from and against, any loss or
damage incurred by reason of any act or omission performed or omitted by it in
good faith on behalf of the Company and in a manner reasonably believed by it to
be within the scope of the authority granted to it by this Agreement, provided
that the Board of Directors was not guilty of gross negligence or willful
misconduct with respect to such act or omission.  Any act or omission performed
or omitted by the Board of Directors in good faith on advice of counsel,
accountants and other independent experts to the Company shall be conclusively
deemed to have been performed or omitted by the Board of Directors in good
faith.

          (b)  The Board of Directors acting in good faith, may rely upon, and
shall be protected in acting or refraining from acting upon, any resolution,
certificate, statement, instrument, opinion, report, notice, request, consent,
order, bond, debenture or other paper or document believed by it to be genuine
and to have been signed or presented by the proper party or parties.

                                  ARTICLE VIII
                             ACCOUNTING AND RECORDS

     8.1  FINANCIAL AND TAX REPORTING.  The Company shall prepare its financial
statements in accordance with generally accepted accounting principles as from
time to time in effect using the accrual method of accounting on a Fiscal Year
basis, and shall prepare its income tax information returns on a Fiscal Year
basis, using the method of accounting required under the Code and Treasury
Regulations or when one or more alternative methods are available, using the
method of accounting which the Board of Directors deems appropriate.

     8.2  SUPERVISION; INSPECTION OF BOOKS.  Proper and complete books of
account and records of the business of the Company shall be kept under the
supervision of the Board of Directors at the Company's principal office or at
such other place as designated by the Board of Directors.  Such books and
records shall be open to inspection, audit and copying by any Member, or its
designated representative, upon reasonable notice at any time during business
hours for any purpose reasonably related to the Member's interest in the
Company.  Any


                                       14

<PAGE>

information so obtained or copied shall be kept and maintained in strictest
confidence except as required by law.

     8.3  RELIANCE ON RECORDS AND BOOKS OF ACCOUNT.  Any Member shall be fully
protected in relying in good faith upon the records and books of account of the
Company and upon such information, opinions, reports or statements presented to
the Company by its Board of Directors, any of its other Members, officers, or by
any other person, as to matters the Member reasonably believes are within such
other person's professional or expert competence and who has been selected with
reasonable care by or on behalf of the Company, including information, opinions,
reports or statements as to the value and amount of the assets, liabilities,
profits or losses of the Company or any other facts pertinent to the existence
and amount of assets from which distributions to Members might properly be paid.

     8.4  TAX RETURNS.  The Member who is named the "tax matters partner"
pursuant to Section 9.3(f) shall, on or before the due date prescribed by law
(including any extensions of time), file a federal income tax information return
and transmit to each Member a schedule showing such Member's distributive share
of the Company's taxable income, deductions and credits, and all other
information necessary for such members timely to file their Federal income tax
returns.  Such Member similarly shall file all appropriate state and local
income tax returns or information returns on behalf of the Company.  The Board
of Directors shall, from time to time as appropriate under Section 6654 of the
Code, provide to the Members interim financial information regarding the Company
so that the Members and/or the direct or indirect equity holders of any Member
may timely determine their quarterly federal estimated tax obligations.


                                   ARTICLE IX
                                   ALLOCATIONS

     9.1  ALLOCATION OF NET INCOME OR NET LOSS.

          (a)  For each Accounting Period, Net Loss shall be allocated as
follows:

                  (i)  First, to the extent that the Capital Account of any
Member (determined after giving effect to adjustments attributable to any
contributions made or distributions received during that Accounting Period)
exceeds the amount of distribution to which such Member would be entitled to
receive under Section 13.4 were the Company to be dissolved and its assets
distributed in liquidation, then to each Member having such excess in proportion
to such excess;

                  (ii)  Second, any remaining Net Loss shall be allocated to
Members in proportion to their Percentage Interests.

                                       15

<PAGE>

          (b)  For each Accounting Period, Net Income shall be allocated as
follows:

               (i)   First to the extent that the Capital Account of any Member
(determined after giving effect to adjustments attributable to any contributions
made or distributions received during that Accounting Period) is less than the
amount of distribution to which such Member would be entitled under Section 13.4
were the Company to be dissolved and its assets distributed in liquidation, then
Net Income shall be allocated to each Member having a shortfall in the
proportion to such shortfall;

               (ii)  Second, any remaining Net Income shall be allocated to
Members in proportion to their Percentage Interests.

     9.2  TIME OF ALLOCATIONS.  The Net Income or Net Loss of the Company for
each Accounting Period shall be allocated to the Members' Capital Accounts
during the Accounting Period in accordance with the provisions of this Article
IX.

     9.3  SPECIAL TAX PROVISIONS.

          (a)  TAX ALLOCATIONS.  Except as otherwise provided in this
Article IX, items of Company income, gain, loss or deduction recognized for
income tax purposes shall be allocated in the same manner that the corresponding
items entering into the calculation of Net Income and Net Loss are allocated
pursuant to this Agreement.

          (b)  SECTION 704(c) ADJUSTMENTS.  In accordance with Code Section
704(c) and the Treasury Regulations thereunder, items of income, gain, loss and
deduction with respect to an asset, if any, contributed to the capital of the
Company shall, solely for tax purposes, be allocated between the Members so as
to take account of any variation between the adjusted basis of such property to
the Company for Federal income tax purposes and its fair value upon contribution
to the Company.  Upon a revaluation of the Members' Capital Accounts under this
Agreement to reflect unrealized gain or loss accruing during any Accounting
Period, subsequent allocations of items of income, gain, loss and deduction for
tax purposes shall be adjusted to take account of any variation between the
adjusted tax basis and the adjusted value of the Company's assets in accordance
with the principles of Code Section 704(c) and subparagraph (d) and (g) of
Treasury Regulation Section 1.704-1(b)(2)(iv).

          (c)  OTHER.  The allocations provided herein shall be subject to the
following exceptions:

               (i)  LIMITATIONS OF LOSSES.  A Member's Capital Account shall not
be allocated any item of Net Loss to the extent such allocation would cause such
Capital Account to have a negative balance (computed in accordance with the
principles of Treasury Regulation Section 1.704-1(b)(2)(ii)(d)) in excess of any
amount such Member is obligated to restore (or

                                       16

<PAGE>

deemed to be obligated to restore under Treasury Regulation Section 1.704-
1(b)(2)) to the Company.

               (ii)  QUALIFIED INCOME OFFSET.  If any Member unexpectedly
receives any adjustments, allocations or distributions which would cause its
Capital Account to have a negative balance (computed with such adjustments as
are required under the Treasury Regulations) in excess of any amount such Member
is obligated to restore (or deemed to be obligated to restore under Treasury
Regulation Section 1.704-1(b)(2)) to the Company, then special allocations of
Net Income (and items thereof), together with corresponding tax items, shall be
made as quickly as possible so as to comply with the "qualified income offset"
provisions of Treasury Regulation Section 1.704-1(b)(2)(ii)(d).

               (iii) SUBSEQUENT ALLOCATIONS.  Any special allocations pursuant
to the foregoing provisions of this subsection (c) shall be taken into account
as soon as possible in computing subsequent allocations of Net Income or Net
Loss (and items thereof), together with corresponding tax items, so that over
the term of the Company the aggregate amount of any Net Income or Net Loss
allocated to each Member shall, to the extent possible, be equal to the
aggregate amount that would have been allocated to each such Member if the
allocations pursuant to the foregoing provisions of this subsection (c) had not
occurred.

             (d) SECTION 754 ELECTION.  A Section 754 election shall be made for
the Company.  In the event of an adjustment to the adjusted tax basis of any
Company asset under Code Section 734(b) or Code Section 743(b) pursuant to a
Section 754 election by the Company, subsequent allocations of tax items shall
reflect such adjustment consistent with the Treasury Regulations promulgated
under Sections 704, 734 and 743 of the Code.

             (e) ALLOCATIONS UPON TRANSFERS OF COMPANY INTERESTS.  If, during an
Accounting Period, a Member (the "Transferring Member") transfers all or part
of its interest in the Company to another Member, items of Net Income and Net
Loss, together with corresponding tax items, that otherwise would have been
allocated to the Transferring Member with regard to such Accounting Period shall
be allocated between the Transferring Member and the other Member in accordance
with their respective interests in the Company during the Accounting Period
using any method permitted by Section 706 of the Code and selected by the Board
of Directors.

             (f) TAX MATTERS PARTNER.  The " tax matters partner" of the Company
within the meaning of Section 6231(a)(7) of the Code shall be Chiron, provided
Ciba shall have the right, upon notice to Chiron, to become the "tax matters
partner", for any year in which as of the beginning of such year it held a
majority of the Membership Units in the Company.  The tax matters partner shall
act for and on behalf of the Company to the extent required under Sections 6221
through 6233 of the Code and shall provide timely notification to the Members of
all proposed adjustments to, or administrative proceedings regarding, Company
tax items.

                                       17

<PAGE>

             (g) ADJUSTMENTS TO TAXABLE INCOME UPON EXAMINATION.  If upon
examination of any tax return an adjustment is made by any tax authority and
agreed to by the Company for any Accounting Period, such adjustment shall be
allocated among Members in accordance with the provisions of Section 9.1(a) and
(b). No such adjustment shall be agreed to by the Company, except with the
unanimous consent of the Unit holders.




                                    ARTICLE X
                                  DISTRIBUTIONS

     10.1 DISTRIBUTIONS AND WITHDRAWALS.  Distributions and withdrawals shall be
made as follows:

          (a)  DISTRIBUTION OF AVAILABLE CASH.  To the extent the Company's cash
on hand exceeds its current and anticipated needs, including, without
limitation, needs for operating expenses, debt service, acquisitions, reserves
and mandatory distributions, if any, including distributions in liquidation, the
Board of Directors, with the consent of all Members, may make distributions to
the Members pro rata in accordance with their respective Capital Account
balances.

          (b)  DISTRIBUTIONS IN KIND.

                  (i)  The Board of Directors, with the consent of all Members,
may elect to distribute any non-cash assets held by the Company in kind to the
Members pro rata in accordance with their respective Capital Account balances

                  (ii)  Any non-cash assets distributed in kind shall be subject
to such conditions and restrictions as are legally required or as are
contractually imposed on the Company and its successors.

                                       18

<PAGE>

          (c)  NO OTHER WITHDRAWALS.  Except as provided in this Section 10.1,
no withdrawals or distributions are permitted or required.

          (d)  EFFECT OF WITHHOLDING.  To the extent the Company reasonably
determines that it is required to withhold and pay any amount for local, state,
federal and/or foreign taxes with respect to any Member, the Company is hereby
expressly authorized to make such payment.  The amount of any such payment shall
be treated as an advance from the Company to the Member with respect to whom the
withholding and payment were required, and the Company is hereby expressly
authorized to collect repayment of such advance out of any and all distributions
which are then or may thereafter become payable to such Member.  This Section
10.1(d) shall not preclude the Company from pursuing any other remedy which may
be available.



                                   ARTICLE XI
                   INDEMNIFICATION AND LIMITATION OF LIABILITY

     11.1 INDEMNIFICATION WITH RESPECT TO MANAGEMENT OF THE COMPANY.

          (a)  The Company shall indemnify and hold harmless the Members, the
Board of Directors, officers, employees and agents of the Company, and the
partners, shareholders, controlling persons, officers, directors and employees
of any of the foregoing (herein referred to as "Indemnitees") from and against
any and all loss, claims, damages, liabilities joint and several, expenses,
judgments, fines, settlements and other amounts arising from any and all claims
(including reasonable legal expenses), demands, actions, suits or proceedings
(civil, criminal, administrative or investigative) in which they may be
involved, as a party or otherwise, by reason of their management of, or
involvement in, the affairs of the Company, or rendering of advice or
consultation with respect thereto, or which relate to the Company, its
properties, business or affairs; provided in all cases that in connection
therewith the Indemnitee shall have met the standard of care described for
members of the Board of Directors in Section 7.4 hereof.  Such indemnification
shall be to the fullest extent permitted by applicable law.

          (b)  Expenses (including attorneys' fees) incurred in defending any
proceeding under subsection (a) may be paid by the Company in advance of the
final disposition of such proceeding upon receipt of an undertaking by or on
behalf of the Indemnitee or Person to repay such amount if it shall ultimately
be determined that the Indemnitee or Person is not entitled to be indemnified by
the Company as authorized hereunder.

          (c)  The indemnification provided by this Section 11.1 shall not be
deemed to be exclusive of any other rights to which any person may be entitled
under any agreement, or as a matter of law, or otherwise, both as to action in a
person"s official capacity and to action in another capacity.

                                       19

<PAGE>


          (d)  If directed by the Members, the Board of Directors shall purchase
and maintain insurance on behalf of itself, the Company, the Members, officers,
employees or agents of the Company and any other Indemnitees at the expense of
the Company, against any liability asserted against or incurred by them in any
such capacity whether or not the Company would have the power to indemnify such
Persons against such liability under the provisions of this Agreement.

     11.2 LIMITATION OF LIABILITY.  Notwithstanding anything to the contrary
herein contained, the debts, obligations and liabilities of the Company shall be
solely the debts, obligations and liabilities of the Company; and no Member
shall be obligated personally for any such debt, obligation or liability of the
Company solely be reason of being a Member of the Company, except if otherwise
provided by the Act.

     11.3 INDEMNIFICATION REGARDING PRODUCTS ARISING FROM FUNDED PROJECTS.

     Chiron agrees to indemnify, defend and hold the Company and Ciba harmless
from and against any and all claims, losses, damages, liabilities, costs and
expenses (including reasonable attorneys' fees) (collectively, "Claims") arising
as a result of Chiron's research and development activities which are funded
pursuant to this Agreement, or as a result of the manufacture, use or sale of
any product arising from a Funded Project, except to the extent that such Claims
result from (i) marketing, sale or promotion of the product by the Company,
Ciba, or their respective affiliates or licensees, in deviation from the
approved labeling for the product in question, or (ii) negligence or willful
misconduct of the Company, Ciba, or their respective employees, agents or
consultants.  Ciba agrees to indemnify, defend and hold Chiron harmless from and
against Claims resulting from (i) or (ii) above.

     The party seeking indemnification hereunder ("indemnified party") agrees to
notify the other party (the "indemnifying party") promptly after receipt of
notice of any Claim, and to cooperate with the indemnifying party in connection
with the investigation and defense of any Claim. The indemnifying party shall
have the right to control such defense, using counsel selected by the
indemnifying party, provided that the indemnified party shall have the right to
participate in such defense through its own counsel, at its sole expense. The
indemnifying party shall have the sole right to control the settlement or
disposition of any such Claim, provided that the indemnifying party shall not
settle or compromise any Claim in any manner which would materially adversely
impact the rights or activities of the indemnified party without prior written
consent of the indemnified party, as the case may be, which consent shall not be
unreasonably withheld.

                                       20

<PAGE>

                                   ARTICLE XII
                                 CONFIDENTIALITY

     12.1 During the term of this Agreement and for a period of five (5) years
following the expiration or termination of this Agreement, the Company and Ciba
agree to maintain in confidence all confidential or proprietary information of
Chiron ("Confidential Information") which is disclosed to the Company or Ciba
pursuant to this Agreement.  The Company and Ciba shall use such Confidential
Information only as permitted by this Agreement and shall not disclose the same
to anyone other than its employees, agents or consultants, as are necessary for
the purposes of this Agreement.  Any such disclosure shall be on terms and
conditions at least as restrictive as those contained herein.

     12.2 The foregoing obligation of confidentiality shall not apply to the
extent that (a) the Company and Ciba are required to disclose information by
law, order or regulation of a governmental agency or a court of competent
jurisdiction, and provides Chiron with reasonable notice prior to such
disclosure, and cooperates with Chiron in seeking such protection for such
disclosed information as Chiron may determine; or  (b) the Company or Ciba can
demonstrate that:  (i)  the information was at the time of receipt already in
the public domain or thereafter entered the public domain other than as a result
of actions of the Company, Ciba, or any of their respective employees,
consultants, or agents, in violation hereof; (ii) the information was rightfully
known by the Company and Ciba prior to the date of receipt hereunder; or (iii)
the  information was disclosed to the Company or Ciba by a third party  source
not under a duty of confidentiality to Chiron; or (iv) the information was
independently developed by the Company or Ciba by employees, agents or
consultants who had no access to the Confidential Information.


                                  ARTICLE XIII
                                   TERMINATION

     13.1 TERMINATION.  The Company shall be dissolved, its assets disposed of
and its affairs wound up upon the first to occur of the following:

          (a)  upon the expiration of the 20-year period commencing with the
date of this Agreement;

          (b)  upon the agreement of Members holding at least 98% of all
Membership Interest; or

          (c)  upon the entry of a decree of judicial dissolution under the Act.

                                       21

<PAGE>

     13.2 EFFECT OF DISSOLUTION.  Upon dissolution, the Company shall cease
carrying on, as distinguished from winding up, its business, but the Company is
not terminated, and continues until the winding up of the affairs of the Company
is completed and a Certificate of Cancellation has been filed with the Delaware
Secretary of State.

     13.3 WINDING UP AND CERTIFICATE OF CANCELLATION.  The winding up of the
Company shall be completed when all debts, liabilities and obligations of the
Company have been paid and discharged or reasonably adequate provision therefor
has been made, and all of the remaining property and assets of the Company have
been distributed to the Members.  Upon the completion of winding up of the
Company, a Certificate of Cancellation shall be filed with the Delaware
Secretary of State.

     13.4 DISTRIBUTION OF ASSETS.  Upon dissolution and winding up of the
Company, the affairs of the Company shall be wound up and the Company liquidated
by the Board of Directors.  The assets of the Company shall be distributed as
follows in accordance with the Act:

          (a)  to creditors of the Company in the order of priority provided by
law;

          (b)  to Members for any amounts the Company owes them, other than in
respect of their interest in the Company capital and profits; and

          (c)  to the Members in accordance with Article X.



                                   ARTICLE XIV
                    ACTION BY CIBA MEMBERS OF CHIRON BOARD


          Ciba agrees that the members of the Chiron Board of Directors which
are designated by Ciba pursuant to that certain Governance Agreement dated as of
November 20, 1994, shall refrain from voting, or otherwise acting to direct or
control Chiron, with respect to any matter relating to the Funded Projects,
Chiron's ownership of Membership Interest in the Company, or Chiron's exercise
of its rights to repurchase Membership Interest in the Company hereunder.

                                   ARTICLE XV
                                  MISCELLANEOUS

     15.1 OBLIGATIONS UNDER OTHER AGREEMENTS.  The promotional and marketing
options hereunder are in lieu of the application of Sections 3.02 and 4.02 of
that certain Cooperation and Collaboration Agreement between Chiron and Ciba
dated as of November 20, 1994, with respect to all products arising from the
Funded Projects. All obligations in such Sections are suspended


                                       22

<PAGE>

during the term of this Agreement, the Royalty Agreement and any co-promotion or
marketing agreements hereunder with respect to the products covered hereby and
thereby.

     15.2 ASSIGNMENT.   Neither party shall have the right to assign any of its
rights or obligations hereunder to any unaffiliated third party without the
prior written consent of the other party hereto, which consent shall not be
unreasonably withheld.  Subject to the foregoing, this Agreement shall be
binding on, and inure to the benefit of, the parties, their successors and
permitted assigns.

     15.3 SEVERABILITY.    If any provision of this Agreement should be held
invalid or unenforceable, the remaining provisions hereof shall be unaffected
and shall remain in full force and effect without regard to such invalid or
unenforceable provisions, provided that such remainder is consistent with the
intent of the parties as evidenced by this Agreement as a whole.

     15.4 AMENDMENT.    This Agreement may not be modified or amended except in
writing signed by all Members.

     15.5 ENTIRE AGREEMENT.    This Agreement and the Amended and Restated
Royalty Agreement  represent the entire agreement of the parties with respect to
the subject matter hereof, and supersedes all prior negotiations and agreements,
including without limitation Exhibit B to the 1994 Investment Agreement, and the
Investment, Research Support and Marketing Agreement originally executed as of
September 29, 1995 together with the Royalty Agreement which constituted
Schedule 1.03 thereto and all other exhibits and schedules thereto.

     15.6 GOVERNING LAW.  This Agreement shall be governed by and construed in
accordance with the laws of the State of Delaware.

     15.7 COUNTERPARTS.  This Agreement may be executed in one or more
counterparts, each of which shall be deemed an original, and all of which
together shall constitute a single agreement.

     IN WITNESS WHEREOF, the parties hereto have executed this Company Agreement
as of the day and year first above written.

MEMBERS:


CHIRON CORPORATION

By:  William Rutter
     ---------------

Title: Chairman
      ---------

                                       23

<PAGE>

CHIRON BIOCINE COMPANY

By:  William Green
     -------------

Title: Secretary
       ---------


BIOCINE S.p.A.

By:  William Rutter    William Green
     --------------    -------------

Title: Director          Director
       --------          --------

CIBA-GEIGY CORPORATION

By:  John McGraw
    ------------
     John McGraw
Title:    Vice President


Exhibits: A    Initial Membership Interests of Chiron and its Affiliates
          B    Royalty Agreement

                                       24

<PAGE>

                                    EXHIBIT A

            INITIAL MEMBERSHIP INTERESTS OF CHIRON AND ITS AFFILIATES




[CONFIDENTIAL TREATMENT REQUESTED]

<PAGE>

                                                                Exhibit B


                                ROYALTY AGREEMENT



     This Amended and Restated Royalty Agreement is made effective as of
December 28, 1995, by and between Chiron Corporation ("Chiron"), a Delaware
corporation, Chiron Biocine Company and Biocine S.p.A., both wholly owned
Affiliates of Chiron, and Chiron Funding L.L.C., a Delaware Limited Liability
Company (the "Company"), and replaces and supersedes in full that certain
Royalty Agreement previously entered into by and among Chiron and Chiron Funding
Corporation as of September 29, 1995.

RECITALS.

     Chiron and its Affiliates and Ciba-Geigy Corporation ("Ciba"), a New York
corporation, have entered into a Limited Liability Company Agreement  of even
date herewith (the "LLC Agreement"), with respect to the formation and operation
of the Company.  The parties wish to set forth the terms under which Chiron will
pay to the Company royalties on certain products arising from the Funded
Projects, which products are identified on Schedule A hereto (the "Products"),
as contemplated in Section 2.1.1(b) of the LLC Agreement.

AGREEMENTS.

All capitalized terms not defined in this Agreement shall have the meanings set
forth in the LLC Agreement.

1.   ROYALTIES

     1.01   OBLIGATION TO PAY ROYALTIES.  In consideration of the Membership
     Interests in the Company issued to Chiron and its Affiliates pursuant to
     Section 2.1.1 of the LLC Agreement, and subject to the terms and conditions
     set forth herein, Chiron and its Affiliates hereby agree to pay to the
     Company royalties on the Products during the Royalty Term set forth in
     Section 3.  Such royalties for each Product shall be a percentage of
     worldwide Net Sales, as defined below, calculated as follows.

     1.02  BASE ROYALTY RATE FOR BASE NET SALES AMOUNT.  If total annualized
     worldwide Net Sales for all Products during a given year within the Royalty
     Term are less than or equal to the amounts shown on Schedule B hereto, the
     royalty rate shall be  [CONFIDENTIAL TREATMENT REQUESTED] of Net Sales
     (the "Base Royalty Rate").


                                        1
<PAGE>


     1.03  ROYALTY RATE FOR NET SALES IN EXCESS OF BASE NET SALES AMOUNT.  In
     the event that annualized Net Sales of all Products during any year of the
     Royalty Term exceed the amounts set forth in Schedule B, the Base Royalty
     Rate shall be reduced ratably, up to a maximum reduction of [CONFIDENTIAL 
     TREATMENT REQUESTED] in the event that annualized Net Sales are greater 
     than or equal to [CONFIDENTIAL TREATMENT REQUESTED] of the amounts shown 
     in Schedule B. For annualized Net Sales amounts between those set forth on
     Schedule B and [CONFIDENTIAL TREATMENT REQUESTED] of such amounts, the Base
     Royalty Rate shall be reduced based on the following formula:

     Royalty Rate =  [CONFIDENTIAL TREATMENT REQUESTED]

     For example, if actual annualized Net Sales in 2002 were greater than or
     equal to U.S. $2,022,000,000, the Royalty Rate would be

            [CONFIDENTIAL TREATMENT REQUESTED]

     However, if actual annualized Net Sales in 2002 were U.S.$1,617,600,000,
     the Royalty Rate would be

            [CONFIDENTIAL TREATMENT REQUESTED]

     1.04  ADJUSTMENT FOR LACK OF PATENT PROTECTION.  All royalties payable
     hereunder shall be reduced by [CONFIDENTIAL TREATMENT REQUESTED] with 
     respect to Net Sales in any country in which the sale of the Product in
     question is not covered by any patents or patent applications held by 
     Chiron or its Affiliates, whether due to the lack of patent applications,
     adjudicated invalidity of patents, or expiration of patents prior to the 
     end of the royalty term.

     1.05  "AFFILIATES."  As used herein, Affiliates of Chiron shall include all
     entities controlled by Chiron, but shall not include the Company and shall
     not include Ciba or any entity controlled by or under common control with
     Ciba which is not also controlled by Chiron.  Affiliates of Chiron
     specifically include Chiron Biocine Company and Biocine S.p.A.


22.  NET SALES.  As used herein, "Net Sales" means the invoiced price of a
product sold by Chiron, its Affiliates or licensees, less (i) discounts,
rebates, chargebacks and allowances; (ii) credits or refunds for returned or
damaged goods; (iii) sales, use, excise, value added and similar taxes; (iv)
customs, export and import duties and other governmental charges; (v)
transportation and insurance charges; (vi) royalties payable to third parties;
(vii) costs incurred by Chiron, including amounts payable in damages or
settlement, in defending claims by third parties that the products infringe
third party intellectual property rights.


                                        2
<PAGE>


     In the event that a Product is sold in combination with another active
ingredient, or with a delivery system not developed as part of the Product, or
with instrumentation, or with other components in a kit, or with services
related to the use of the product (all collectively referred to as "Other
Components", and the resulting product referred to as a "Combination Product"),
the parties shall reasonably determine the portion of Net Sales of the
Combination Product which should be allocated to the Product.  If the Product
and the Other Components are sold separately, the Net Sales for the purpose of
this Agreement shall be determined by multiplying the gross invoiced price of
the Combination Product, less the deductions specified above, by a the fraction
[CONFIDENTIAL TREATMENT REQUESTED], where [CONFIDENTIAL TREATMENT REQUESTED].  
If no such separate sales are made, the appropriate allocation shall be 
negotiated in good faith by the parties.

 3.  ROYALTY TERM. Royalties shall be payable hereunder with respect to Net
Sales of Products occurring on or after October 1, 2001.  Royalties shall
continue to be payable, on a Product by Product basis, with respect to Net Sales
occurring within ten years from the later of October 1, 2001 or the date of
first commercial sale of the Product in question.   If, at the end of the
Royalty Term, Ciba has not received, through its share of royalties paid to the
Company hereunder and its share of co-promotion profits pursuant to Section
2.11(c) of the LLC Agreement, an aggregate amount equal to the sum of all Unit
purchase payments made by Ciba pursuant to Section 2.3 of the LLC Agreement plus
interest thereon from the date of such payments at a rate equal to LIBOR, as
defined in Section 4.1 of the LLC Agreement,  then the Royalty Term shall be
extended until such time as Ciba has received such aggregate  amount.


4.   ROYALTY PAYMENTS AND REPORTS

     4.01.  PAYMENTS.  All royalties payable to the Company hereunder shall be
     paid in U.S. Dollars, on a quarterly  basis within ninety (90) days
     following the close of Chiron's fiscal quarter, with respect to Net Sales
     of Products during such fiscal quarter.

     4.02.  REPORTS.  Each royalty payment shall be accompanied by  a written
     report setting forth in reasonable detail the Net Sales of Products by
     Chiron, its affiliates and licensees during the applicable period and the
     resulting calculation of the royalty payment due hereunder.   For the
     purposes of determining royalties hereunder, Net Sales shall be calculated
     in the currency of the country of sale and then converted to U.S. Dollars
     in accordance with Chiron's standard accounting practices.

     4.03.  TAXES.  If law or regulation requires withholding of any taxes on
     payments with respect to Net Sales in any given country to Chiron, its
     affiliates or licensees, or on payments due to the Company hereunder,  such
     taxes will be deducted  on a country-by-country basis from such remittable
     payment, and the amounts due to


                                        3
<PAGE>


     the Company hereunder shall be remitted net of such withheld taxes.  Chiron
     shall provide the Company with documentation of any such withholding or
     other taxes paid hereunder with respect to tax liability of the Company.

     4.04.  BLOCKED CURRENCY.  If, in any country, the transfer of payment to
     Chiron,  its Affiliates or sublicensees with respect to Net Sales, or the
     transfer of royalties to the Company hereunder, is prohibited by law or
     regulation, the payment obligations to the Company hereunder with respect
     to the amounts so restricted shall be fully satisfied upon payment of the
     amounts due to the Company in local currency to a bank account in the
     Company's name in such country.  The parties agree to cooperate in their
     efforts to resolve any such blocked currency situation.


5.  AUDIT RIGHTS.  Chiron and its Affiliates agree to keep accurate books and
records of the sales of all Products.  The Company and Ciba shall have the
right, at Ciba's expense, for a period of three (3) years after each report
delivered pursuant to Section 4.02 to have an independent certified public
accountant ("CPA") reasonably acceptable to Chiron examine the relevant books
and records Chiron and its Affiliates, during normal business hours, at the
principal offices of Chiron or the Affiliate in question, upon two (2) weeks
advance written request, to verify the calculation of any royalty payment;
provided, however, that such audits shall not occur more than once per year.
Said CPA shall be under confidentiality obligations to Chiron and its
Affiliates, to reveal  only whether there is an error in the calculation of a
royalty payment owed hereunder, and if so, the amount of such error.

6.  ENTIRE AGREEMENT.  This Agreement, including any schedules and exhibits
hereto, constitutes the entire agreement of the parties with respect to the
subject matter hereof, and supersedes all prior agreements, negotiations and
understandings.  Without limiting the foregoing, this Agreement supersedes and
replaces in full that certain Royalty Agreement by and between Chiron and Chiron
Funding Corporation dated as of September 29, 1995.


                                        4
<PAGE>


     Executed by the parties as of the date first written above.

CHIRON CORPORATION                 CHIRON FUNDING L.L.C.


By                                 By
  ----------------------             ------------------------

Title                              Title
     -------------------                ---------------------


CHIRON BIOCINE COMPANY        BIOCINE S.P.A.

By                                 By
  ----------------------             ------------------------

Title                              Title
     -------------------                ---------------------


Schedules:  A       Products
            B       Base Net Sales


                                        5
<PAGE>


                                   SCHEDULE A

                     PRODUCTS ARISING FROM FUNDED PROJECTS
                         WHICH ARE SUBJECT TO ROYALTIES

                                 ADULT VACCINES

THE FOLLOWING SUBUNIT PROTEIN BASED VACCINES (DNA AND NUCLEOTIDE VACCINES ARE
EXCLUDED):

Herpes Simplex Virus Vaccine (prophylactic and therapeutic use)

Hepatitis C Virus Vaccine (prophylactic and therapeutic use)

Cytomegalovirus Vaccine

Adjuvanted Hepatitis B Vaccine

Human Papilloma Virus Vaccine

Human Immunodeficiency Virus Vaccine


                               PEDIATRIC VACCINES

THE FOLLOWING SUBUNIT PROTEIN BASED OR TRADITIONAL VACCINES (DNA AND NUCLEOTIDE
VACCINES ARE EXCLUDED):

Acellular Pertussis - Diphtheria - Tetanus Vaccine (aPDT) (but not acellular
pertussis, diphtheria or tetanus vaccines sold separately)

Meningococcus C Vaccine (Men C)

Haemophilus Influenza Vaccine (Hib)

Combinations of two or more of aPDT, Men C and Hib


                                      OTHER

Insulin-like Growth Factor 1


                                        6
<PAGE>


                                   SCHEDULE B

                     TOTAL NET SALES ON ALL PRODUCTS BY YEAR
                                (BASE NET SALES)

                            MILLIONS OF U.S. DOLLARS


<TABLE>
                    <S>            <C>
                    Q4   2001      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2002      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2003      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2004      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2005      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2006      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2007      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2008      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2009      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2010      $    [CONFIDENTIAL TREATMENT REQUESTED]
                         2011      $    [CONFIDENTIAL TREATMENT REQUESTED]
</TABLE>


                                        7


<PAGE>

                                                                Exhibit 10.81

                        [CONFIDENTIAL TREATMENT REQUESTED]

[Certain information has been omitted herein pursuant to a request for
confidential treatment pursuant to Rule 24b-2.]


THIS  AGREEMENT is made this 15th day of November, 1995

                                     between

                               CIBA-GEIGY LIMITED
                 of Klybeckstrasse 141, 4002 Basel, Switzerland,
                       (hereinafter referred to as "Ciba")

                                       and

                               CHIRON CORPORATION
            of 4560 Horton Street, Emeryville, California 94608, USA,
                     (hereinafter  referred to as "Chiron")



INTRODUCTION

A. Chiron and its affiliates have accumulated considerable experience and
     technology in the Technology Transfer Field, as defined below.

B. Ciba wishes to gain access to Chiron's technology within the Technology
     Transfer Field and to use it for the purpose of identifying or discovering
     drugs, as well as identifying or discovering compounds suitable for use in
     areas other than pharmaceuticals in which Ciba is or becomes active.

C. Chiron is willing to provide Ciba with access to  technology within the
     Technology Transfer Field, and any improvements it makes thereto during a
     specified period following the date of this Agreement.  Both Ciba and
     Chiron are willing to collaborate in a research and development program
     aimed at the enhancement of such technology, it being the intention of the
     parties that Ciba will be free to use such transferred technology and such
     improvements during and after the term of this Agreement, subject to the
     terms set forth herein.

D. In addition, Chiron has considerable experience and expertise in utilizing
     the technology within the Technology Transfer Field to design and
     synthesize combinatorial libraries and in applying these technologies to
     the discovery and development of pharmaceutical products.  The parties
     intend to collaborate with a view to the  ultimate discovery and
     development of new drugs for the targets which are selected as provided
     below.

<PAGE>

                                       -2-

E. This Agreement represents the technology transfer and research and
     development collaboration between the parties which is contemplated in
     Section 2.05 of that certain Cooperation and Collaboration Agreement dated
     as of November 20, 1994 (the "Cooperation Agreement").


THEREFORE, THE PARTIES HEREBY AGREE AS FOLLOWS:


1.   DEFINITIONS

1.1  "AFFILIATE" means in the case of each party any entity that directly or
indirectly controls, is controlled by, or is under common control with that
party.  For such purpose the term "control"  means ownership or control of at
least 50% of the voting interest in the entity in question.  Chiron, Ciba and
their respective Affiliates shall not be considered Affiliates of each other for
the purposes of this Agreement, regardless of the percentage ownership interest
which Ciba may hold in Chiron.

1.2  "CHIRON LICENSED TECHNOLOGY" means all inventions, know-how, trade secrets,
and other proprietary information  (whether patented or not), which are owned by
Chiron or its current Affiliates, or their respective employees or assignors, as
of the date of execution of this Agreement: (i) which are within the Technology
Transfer Field as the same is defined as at the date of execution of this
Agreement, or as the same may be redefined during the five years following such
date pursuant to Section 1.30; (ii) as to which Chiron has the right to grant to
Ciba a license hereunder, subject to Section 3.2.2; and (iii) which Ciba elects
to license pursuant to Section 3.1.2.

1.3  "CHIRON LICENSED TECHNOLOGY IMPROVEMENTS"  means inventions, know-how,
trade secrets and proprietary information (whether patented or not) within the
Technology Transfer Field, which are invented or developed by Chiron or its
Affiliates, or their respective employees or assignors, subject to Section 1.30,
within five (5) years after the date of this Agreement, with the right to
license to Ciba hereunder, all subject to Section 3.2.2.

1.4  "CHIRON LICENSED TECHNOLOGY PATENTS" means all patents and patent
applications (including provisionals, divisionals, continuations, continuations
in part, reissues, re-examinations, substitutions, additions and any extensions
to such patents) claiming Chiron Licensed Technology or Chiron Licensed
Technology Improvements made within the period referenced in Section 1.3.

1.5  "CHIRON PRODUCT" means a product developed and commercialized by Chiron
pursuant to Section 4.3.

1.6  "CIBA LICENSED TECHNOLOGY" means all inventions, know-how, trade secrets,
and other proprietary information  (whether patented or not), which are owned by
Ciba or its current Affiliates, or their respective employees or assignors, as
of the date of execution of this Agreement: (i) which are within the Technology
Transfer Field as the same is defined as at the date of execution

<PAGE>

                                       -3-

of this Agreement, or as the same may be redefined during the five years
following such date pursuant to Section 1.30; and (ii) as to which Ciba has the
right to grant to Chiron a license hereunder, subject to Section 3.2.2.

1.7  "CIBA LICENSED TECHNOLOGY IMPROVEMENTS"  means inventions, know-how, trade
secrets and proprietary information (whether patented or not) within the
Technology Transfer Field, which are invented or developed by Ciba or its
Affiliates, or their respective employees or assignors, subject to Section 1.30,
within five (5) years after the date of this Agreement, with the right to
license to Chiron hereunder, all subject to Section 3.2.2.

1.8  "CIBA LICENSED TECHNOLOGY PATENTS" means all patents and patent
applications (including provisionals, divisionals, continuations, continuations
in part, reissues, re-examinations, substitutions, additions and any extensions
to such patents) claiming Ciba Licensed Technology or Ciba Licensed Technology
Improvements made within the period referenced in Section 1.7.

1.9  "CIBA PRODUCT" means a product developed and commercialized by Ciba
pursuant to Section 4.3.

1.10 "COMBINATORIAL LIBRARY"  means a library or mixture of compounds, including
the compounds contained or proposed to be contained therein, produced using
Combinatorial Technology.

     "CHIRON COMBINATORIAL LIBRARY"  means a Combinatorial Library designed
       and/or synthesized or acquired by Chiron (alone or with third parties and
       available for sublicense to Ciba under the terms and conditions of this
       Agreement) prior to the execution date hereof or during the term of the
       Target Collaboration.

     "CIBA COMBINATORIAL LIBRARY" means a Combinatorial Library designed and/or
       synthesized or acquired by Ciba (alone or with third parties)  without
       the assistance of or involvement of Chiron in the design or synthesis
       of such library; provided that the mere use by Ciba of Chiron Licensed
       Technology shall not be considered assistance or involvement of Chiron
       for the purpose of this definition.

     "JOINT COMBINATORIAL LIBRARY" means a Combinatorial Library, as to which
       Ciba and Chiron each perform inventive or creative acts in designing the
       library, and/or contribute proprietary components or compositions to the
       library.

1.11 "COMBINATORIAL TECHNOLOGY" means methods and materials for the production,
design,  synthesis, characterization and/or use of synthetic, non-peptide
chemical libraries, either as individual compounds or mixtures thereof, using
combination and/or permutation strategies with respect to the structural
components, e.g. organic scaffold or polymeric or oligomeric backbone structures
and chemistries, together with sidechain or substituent chemistries; such
libraries generated using

<PAGE>

                                       -4-

chemical strategies based on (i) solid-phase or solid supported systems, e.g.
resins and/or supported spatial arrays (e.g. pins), or (ii) solution chemistry.

1.12 "COMPOUND HIT" means a singular molecular entity identified as having
biological activity at a level to be agreed upon by the parties, which would
typically be a 50% effect (estimated ED(50)) at less than or equal to 100
nanomolar, which identification results from the screening of Combinatorial
Libraries pursuant to the Target Collaboration.

1.13 "COMPOUND PATENT" means a patent or patent application claiming an
invention or discovery made pursuant to the Target Collaboration, which is
specific to a lead compound and a genus of compounds reasonably expected to have
the same or similar activity.  Patentability of a Compound Patent is premised on
the activity of the lead compound(s).  A Compound Patent may include claims to
the compounds per se, methods of making the compounds, methods of using the
compounds, formulations and the like, as appropriate.

1.14 "EDC" means a compound directed against a Selected Target which has
undergone extensive preclinical animal studies, formulation and production work,
and is identified as suitable to be prepared for tolerability studies in human
volunteers by the appropriate TARB of Ciba or the equivalent body of Chiron.

1.15 "FTE" means the full time equivalent effort, for one year, of one person
who participates directly in  the technology transfer or the research and
development activities contemplated under this Agreement, on behalf of one of
the parties hereto.  Chiron will use its standard cost accounting procedure in
determining FTE support and will fairly allocate costs among its various
programs.  Such participation includes, without limitation, production of
chemical, biological and/or other materials or reagents provided for use under
this Agreement (and the resupply thereof if shelf stock is provided, as
reasonably determined by Chiron).

1.16 "JOINT PRODUCT" means a product developed and commercialized by Ciba and
Chiron under a co-development arrangement  pursuant to Section 4.3.

1.17 "LIBRARY PATENT" means a patent or patent application claiming an invention
or discovery which is specific to a group of compounds related by structure but
not necessarily activity (i.e., a library).  A Library Patent will include
claims to the library as a composition, and or methods for making and using a
library as appropriate.  Patentability of a Library Patent is premised on the
use of the library to find active compounds for one or more targets.  A Library
Patent may disclose and claim one or more compounds identified from the library
(including compositions and methods of making and using) without being
considered a Compound Patent.

1.18 "NET SALES" means the total revenue from commercial sales received by a
party hereto, its Affiliates and/or licensees from the sale of a product subject
to royalties hereunder ("Royalty Bearing Product") to independent third parties
less the following amounts : (i) discounts, including

<PAGE>

                                       -5-

cash discounts, trade allowances or rebates actually allowed or granted, (ii)
credits or allowances actually granted upon claims or returns, regardless of the
party requesting the return, (iii) separately itemized freight charges paid for
delivery and (iv) taxes or other governmental charges levied on or measured by
the invoiced amount, whether absorbed by the billing party or the billed party.

In the event that the Royalty Bearing Product is sold in the form of a
combination product or kit containing one or more active ingredient components
or a delivery system ("Combination Product") then the Net Sales for such
Combination Product will be calculated by multiplying actual Net Sales of such
Combination by the fraction A/(A+B) where A is the fair market price of the
Royalty Bearing Product if such were sold separately as the only active
ingredient therein and B is the fair market price of additional active
ingredient components.  If the Royalty Bearing Product and other active
components are not sold separately, or if a delivery system is an integral part
of the Combination Product and adds significant  value, the parties will in good
faith negotiate a formula to determine the amount of Net Sales to which the
royalty will be applicable, which formula will reflect the Royalty Bearing
Product's and/or delivery system's contribution to the Combination  Product.

1.19 "RESEARCH COMPOUND" means a compound directed at a Selected Target and
identified as a potential candidate for Early Compound Evaluation by Ciba's
Therapeutic/Indication Area Management, or by the equivalent body at Chiron,
based on such criteria as completion of screening in primary, selectivity and
cellular assays, and preliminary IN VIVO pharmacology studies.

1.20      "RESTRICTED TARGET" means a Target in relation to which, because of
pre-existing commitments of Chiron to third parties, Chiron is not permitted to
grant Ciba a license to use the Chiron Licensed Technology or the Chiron
Licensed Technology Improvements transferred to Ciba hereunder for the purpose
of research and development with respect to  pharmaceuticals for human use.  A
list of Restricted Targets is attached hereto as Exhibit D, which shall be
amended from time to time by eliminating one or more Restricted Targets, in the
event that such pre-existing commitments by Chiron to third parties are
terminated as to any such Targets.

1.21      "SCIENCE COMMITTEE" means the Science Committee created pursuant to
the Cooperation Agreement.

1.22 "SELECTED TARGET" means a Target selected pursuant to Section 4.1.1 to be
the subject of the Target Collaboration, or a Target selected for addition to
the Target Collaboration pursuant to Section 4.2.5 or 4.2.6.

1.23 "STEERING COMMITTEE" means the committee to be established pursuant to
Article 2 hereof.

1.24 "TARB"  means a Therapeutic Area Review Board of Ciba.

<PAGE>

                                       -6-




1.25 "TARGET" means one molecular entity, such as, but not limited to, a
receptor or an enzyme, together with its subtypes or isozymes, based on
scientific knowledge as it exists at the time of target selection.  The parties
will mutually agree on the precise definition of any Target at the time it is
selected as a Selected Target hereunder.

For clarity of understanding, and by way of example rather than limitation:
     

     [CONFIDENTIAL TREATMENT REQUESTED]


1.26 "TARGET COLLABORATION" means the research and development program conducted
by the parties pursuant to Article 4 of this Agreement.

1.27 "TARGET COLLABORATION FIELD" means the discovery, optimization and
development of small molecule compounds directed against a Selected Target for
human therapeutic use. The Target Collaboration Field specifically excludes
vaccines; diagnostics and therapeutic monitoring tests; antisense, aptamers and
related anti-gene therapies; and gene transfer  technology.

1.28 "TARGET PROJECT TEAM" means a team to be established for the purposes of
the Target Collaboration pursuant to Section 4.2.2 hereof.

1.29 "TECHNOLOGY IMPROVEMENT COLLABORATION" means the research and development
program conducted by the parties for the purpose of developing improvements
within the Technology Transfer Field pursuant to Section 3.3.

1.30 "TECHNOLOGY TRANSFER FIELD" means solid-phase or solid supported organic
chemistry  and related Combinatorial Technology based techniques for drug
discovery and optimization in preclinical research and development, for use in
the research and development of pharmaceuticals for human use or research and
development of other products (e.g. agricultural products), and including but
not limited to the following, all as applied to Combinatorial Technology: (i)
pins and/or resins, particularly the optimization of solid phases, grafted
surfaces and linkers, i.e., extending from the inert substrate to and including
the reactive moiety of the linker(s); (ii) methods and procedures for use
thereof, i.e., for performing solid-phase organic chemistry thereon, including
conditions for performing organic reactions generally and/or certain types or
classes of organic reactions specifically (e.g., solvent(s), temperature,
catalyst(s) and the like); (iii) formats, e.g., multipin systems or other
spatially addressable arrays, including automation software therefor, and
robotics technology for compound synthesis, including automation software
therefor; (iv) analytics to monitor the preceding; (v) computational chemistry,
including molecular modeling, diversity modeling and data handling techniques
for creating and maintaining data bases, and informatics; (vi) assay methods,
including robotics technology (with automation software therefor) and affinity
selection-mass spectrometry; and (vii) in vitro and in vivo test systems for
assessment of safety,

<PAGE>

                                       -7-

efficacy and pharmacokinetics (including ADME characteristics).  Notwithstanding
the foregoing, the Technology Transfer Field specifically excludes (a) peptides
and biological molecules; (b) all existing and future Chiron Combinatorial
Libraries and compounds contained therein; (c) Chiron information relating to,
or Chiron participation in, the application of any of the foregoing techniques
to the design, synthesis and/or characterization of specific compound sets or
libraries or individual compounds or materials, or the use or application
thereof; (d) medicinal chemistry; (e) specific assays and/or targets;  and (f)
all  biological and chemical results and data, including existing and future
Chiron databases.

The parties recognize that the definition of the Technology Transfer Field may
evolve over the five years following the date of this Agreement.  The precise
extent of the definition of the Technology Transfer Field in the future, and the
decision of whether any particular invention or technology of either party is
Chiron Licensed Technology or a Chiron Licensed Technology Improvement, on the
one hand, or Ciba Licensed Technology or a Ciba Licensed Technology Improvement,
on the other hand, will be based on the following principles:

     1.   The Chiron technology which is within the Technology Transfer Field as
            of the date of this Agreement is described in Exhibit B.

     2.   In the absence of agreement to the contrary, neither the Technology
            Transfer Field nor the licenses granted under Sections 3.5.1 or
            3.5.2 shall be deemed to cover, or allow either party access to
            the other party's technology other than Combinatorial Technology
            based research and development techniques.

     3.   On the other hand, both parties intend that the licenses granted under
            Sections 3.5.1 and 3.5.2 will provide each party with access to
            technologies of the other  party (the "licensor") which both (i)
            become a routine part of the licensor's Combinatorial Technology
            based research and development techniques, such routine use not
            to be artificially delayed, and (ii) the Steering Committee
            determines are necessary or important to maintain the
            Combinatorial Technology program of the licensor at the state of
            the art.


1.31 "THIRD PARTY EXCLUDED TARGETS" means, for the purposes of Article 4 only,
all Targets for which, as of the time of any relevant decision hereunder
relating to Third Party Excluded Targets, Chiron has an obligation to a third
party, as further described below. Initially, the Third Party Excluded Targets
shall be those Targets identified in Exhibit A.  Chiron shall have the right, at
any time, immediately on written notice to Ciba, to amend Exhibit A by adding as
additional Third Party Excluded Targets those Targets as to which Chiron (i) has
granted rights to any third party; or (ii) is engaged in active negotiations
with a third party which have resulted in an agreed upon term sheet. Targets to
which the foregoing criteria no longer apply shall be deleted.

<PAGE>

                                       -8-

1.32 "TRANSFER PROJECT TEAM" means a project team to be established pursuant to
Section 3.1.4 hereof.


2    STEERING COMMITTEE

2.1  The parties will establish a Steering Committee for the purposes of
       supervising the Technology Transfer, implementation of the technology
       development plans and resolving any conflicts arising in the course of
       the development and the Target Collaboration.  The Steering Committee
       shall have such even number of members as the parties shall agree, half
       of the members being appointed by each party, with each of Chiron and
       Ciba having one vote.  In the event of deadlock on any issue, such issue
       shall be referred for decision to the Science Committee.

2.2  The Steering Committee shall monitor the progress of the Technology
       Transfer, technology development plans and the Target Collaboration on a
       regular basis and shall have the power to alter the Technology Transfer
       timetable, technology development plans and the Target Collaboration as
       necessary from time to time.  The Steering Committee shall meet not less
       than twice per year, and the location of such meetings shall alternate
       between Emeryville and Basel, all unless otherwise agreed by the parties.


3    TECHNOLOGY TRANSFER ARRANGEMENTS

3.1  TRANSFER OF TECHNOLOGY

3.1.1     Attached hereto as Exhibit B is a summary description of the
       technology owned by Chiron within the Technology Transfer Field as of the
       date of this Agreement.

3.1.2     Ciba will notify Chiron as soon as practicable which of such
       technology it wishes to license.  It is acknowledged and agreed that each
       such notification need not be comprehensive, and that Ciba may call for
       additional technology it wishes to license from Chiron by serving notice
       on Chiron specifying the additional technology required at any time
       during the five years following execution of this Agreement.  (The
       information specified in such notices shall determine which technology
       within the Technology Transfer Field will be Chiron Licensed Technology
       hereunder).  As soon as practicable after the first notification the
       parties will agree to a timetable for the transfer of sufficient
       information and instruction to Ciba to enable it to practice the Chiron
       Licensed Technology and the manner in which such information is to be
       transferred (i.e., visits by Chiron personnel to Ciba's premises or vice
       versa).

<PAGE>

                                       -9-

     The goal of the parties is to cause Ciba to be fully informed and able to
       practice the Chiron Licensed Technology not later than [CONFIDENTIAL
       TREATMENT REQUESTED] from the date on which the relevant Chiron 
       Licensed Technology was first identified by Ciba and notified to Chiron.
       Chiron agrees to devote the FTE effort required pursuant to Section 3.1.5
       to the accomplishment of such goal and the goal regarding installation of
       equipment during such period, as set forth in Section 3.1.3.

3.1.3     Chiron will supply Ciba with a list of the equipment which in Chiron's
       view will be required by Ciba to enable Ciba to practice the Chiron
       Licensed Technology and to conduct Ciba's activities pursuant to the
       Technology Improvement Collaboration and the Target Collaboration.  Ciba
       will be responsible for obtaining all equipment, and for the assembly and
       installation of such equipment as is purchased.  To the extent that any
       such equipment has to be specially manufactured, Chiron will at Ciba's
       expense either manufacture the same and sell it to Ciba at [CONFIDENTIAL
       TREATMENT REQUESTED], or will procure its manufacture for Ciba by a third
       party on terms to be agreed in advance with Ciba.

     Within the limitations of the FTE commitment pursuant to Section 3.1.5,
       Chiron will send suitably qualified and experienced employees to
       Ciba's premises to assist Ciba in the installation of the equipment.
       Chiron will also provide training for an agreed number of Ciba employees
       in the use of the equipment.

     Subject, in the case of Chiron, to the limitations of the FTE commitment
       pursuant to Section 3.1.5, Chiron and Ciba both agree to use reasonable
       commercial efforts to have the equipment installed and operational at
       Ciba's premises not later than [CONFIDENTIAL TREATMENT REQUESTED] from
       the date on which Chiron Licensed Technology is first identified pursuant
       to Section 3.1.2, with a target of [CONFIDENTIAL TREATMENT REQUESTED] 
       following such date.

3.1.4     To facilitate the transfer of information regarding the Chiron
       Licensed Technology pursuant to this Section 3.1, a project team ("the
       Transfer Project Team") will be formed if either party so requests.  The
       members of the Transfer Project Team shall be selected on the basis of
       their experience and suitability having regard to the nature of the
       information to be transferred.

<PAGE>

                                      -10-

3.1.5     To assist in the transfer of information regarding the Chiron Licensed
       Technology pursuant to this Section 3.1, unless otherwise agreed in
       writing, Chiron shall make available the services of [CONFIDENTIAL 
       TREATMENT REQUESTED] FTEs (being suitably qualified and experienced) in
       each of the first and second years after execution of this Agreement and 
       [CONFIDENTIAL TREATMENT REQUESTED] FTEs in each of the third, fourth and 
       fifth years after execution of this Agreement, the cumulative number of 
       FTEs being not less than [CONFIDENTIAL TREATMENT REQUESTED] nor more than
       [CONFIDENTIAL TREATMENT REQUESTED] over the 5 years. The actual FTE 
       commitment, within such ranges, shall be mutually determined by the 
       parties from time to time.  Any balance of such FTE's not used in 
       connection with technology transfer may be used in the Target 
       Collaboration  (without affecting the FTE commitments set forth in
       Section 4.2.4) or in the Technology Improvement Collaboration, at Ciba's
       election.

     Ciba shall pay Chiron's fully-burdened cost of the provision of the FTEs
       provided pursuant to this Section 3.1.5.  The initial rate shall be U.S.
       [CONFIDENTIAL TREATMENT REQUESTED] per FTE per year, this amount to be 
       increased annually, effective January 1 of each calendar year, based on
       increases in the [CONFIDENTIAL TREATMENT REQUESTED] for the previous 
       calendar year.  This payment compensates Chiron for all ordinary travel
       and subsistence expenses incurred by such FTE's, but excludes expenses of
       extraordinary travel or exceptionally long stays, which shall be 
       separately reimbursed in amounts to be mutually agreed upon by the 
       parties. For the purposes of this Section 3.1.5, travel which exceeds (i)
       travel necessary to attend meetings of the Transfer Project Team and/or 
       Steering Committee, plus (ii) [CONFIDENTIAL TREATMENT REQUESTED] days per
       year per FTE, shall be considered extraordinary travel or exceptionally 
       long stays.

     The annual cost of such FTEs shall be due and payable in equal semi-annual
       installments in advance, according to the following schedule.  The first
       such payment shall be based on [CONFIDENTIAL TREATMENT REQUESTED] 
       FTE's, and shall be due and payable upon execution of this Agreement, to
       cover the FTE cost through December 31, 1995, on a prorated basis.  
       Thereafter,  FTE payments for each semi-annual period shall be due and 
       payable on each  January 15 and July 15 until the end of the fifth year 
       following execution of this  Agreement, the final payment also being 
       prorated.

     If the level of effort by Chiron is less than an average, on an annual
       basis, of the number of FTE's required and funded pursuant to this
       Section 3.1.5,  Ciba will be entitled to additional FTE effort in
       subsequent semi-annual periods, such that the required annual average is
       restored.  Conversely, if the average annual level of effort by Chiron
       exceeds the number of FTE's required and funded pursuant to this Section
       3.1.5, Chiron will be entitled to reduce the FTE effort in subsequent
       semi-annual periods, such that the required annual average is restored.

     From time to time during the five years following the execution of this
       Agreement, each party shall be entitled, at its own expense, to locate an
       agreed number of its employees at the premises of the other party, for
       such periods as may be agreed, for the purposes of the transfer of
       information regarding the Chiron Licensed Technology and Chiron Licensed

<PAGE>

                                      -11-

       Technology Improvements, on the one hand, and the Ciba Licensed
       Technology and Ciba Licensed Technology Improvements on the other hand.
       All such visits shall be subject to the confidentiality obligations set
       forth in Article 9.

3.1.6     Attached hereto as Exhibit C is a complete list of the Chiron patents
       which are available for license hereunder, whether as part of the
       Technology Transfer Field or pursuant to Section 3.2.3, as of the date of
       execution of this Agreement.  Chiron will update this list once every
       year during the term of this Agreement.

3.1.7     Although divisions of Ciba other than the Pharma Division as well as
       corporate units of Ciba may be involved in the transfer of information
       regarding the Chiron Licensed Technology, the prime point of contact
       within Ciba shall be the Pharma Division.  Ciba will be solely
       responsible for transferring such information and technology to, and
       acquiring and installing equipment for, its other divisions and corporate
       units.

3.1.8     In consideration of the licenses granted pursuant to Section 3.5,
       Ciba will pay Chiron the sum of Twenty-six Million Dollars ($26,000,000),
       payable as follows:

     $5,500,000 upon execution of this Agreement;
     [CONFIDENTIAL TREATMENT REQUESTED] upon the first anniversary of the 
                execution of this Agreement;
     [CONFIDENTIAL TREATMENT REQUESTED] upon the second anniversary of the 
                execution of this Agreement;
     [CONFIDENTIAL TREATMENT REQUESTED] upon the third anniversary of the 
                execution of this Agreement;
     [CONFIDENTIAL TREATMENT REQUESTED] upon the fourth anniversary of the 
                execution of this Agreement;
                and
     [CONFIDENTIAL TREATMENT REQUESTED] upon the fifth anniversary of the 
                execution of this Agreement.

3.1.9     Chiron will keep records of the time spent by its FTEs pursuant to
       this Section 3.1, as well as pursuant to Sections 3.2 and 3.3, including
       the transfer of information relating to Chiron Licensed Technology
       Improvements.  Ciba shall have the right to have these records audited in
       the same manner as is set forth in Section 7.4.  Chiron will report the
       level of FTE effort to Ciba on a semi-annual basis.

3.1.10    As soon as practicable following execution of this Agreement, Ciba
             will inform Chiron of the Ciba Licensed Technology available for
             license to Chiron hereunder.  The parties will mutually arrange for
             transfer of the Ciba Licensed Technology to Chiron as part of the
             technology transfer process pursuant to this Section 3.1.


3.2  IMPROVEMENTS AND ACQUIRED TECHNOLOGY

3.2.1     In connection with the licenses granted pursuant to Section 3.5,  each
       party will keep the other informed during the five years following the
       execution of this Agreement of all Chiron Licensed Technology
       Improvements and all Ciba Licensed Technology Improvements, respectively.
       Pursuant to Section 1.30, each party will keep the other

<PAGE>

                                      -12-

       informed of developments which may cause the definition of the Technology
       Transfer Field to expand, and of technology of the informing party which
       may become Chiron Licensed Technology or Ciba Licensed Technology,
       respectively, in the event of such an expansion of such definition.  The
       parties will develop methods for effectively exchanging information about
       improvements, which will include consideration of such matters at the
       regular meetings of the Transfer Project Team and Steering Committee.
       Through the Steering Committee, the parties will keep appropriate records
       to identify the Chiron Licensed Technology Improvements and the Ciba
       Licensed Technology Improvements.  Methods of exchanging information may
       also include visits pursuant to Section 3.1.5 (last paragraph), seminars
       or other scientific exchanges.


3.2.2     In the event that (i) either party currently holds technology which is
       within the Technology Transfer Field but which is subject to obligations
       to third parties; or (ii) either party acquires in the future, by
       purchase, license or otherwise, Subject Technology, as defined below; or
       (iii) either party acquires an Affiliate which holds Subject Technology;
       in the case of (ii) or (iii), within the five years following the
       execution of this Agreement; such party agrees, if so requested by the
       other party, to include such technology within licenses granted pursuant
       to Section 3.5.1 or 3.5.2, as the case may be, subject to the conditions
       set forth in this Section 3.2.2.  For the purposes hereof, Subject
       Technology means technology within the Technology Transfer Field which,
       in the case of Chiron, would have been Chiron Licensed Technology or
       Chiron Licensed Technology Improvements had it been invented solely by
       Chiron, and in the case of Ciba, would have been Ciba Licensed Technology
       or Ciba Licensed Technology Improvements, had it been invented solely by
       Ciba.

     Such licenses shall be subject to the following conditions:

     (i)   Such acquiring party has the right to obtain such technology and to
             license it to the other party hereunder; and

     (ii)  If the technology in question is acquired or licensed from a third
             party, the license of such technology to the other party
             hereunder shall be subject to all terms and conditions which are
             imposed by such third party with respect thereto, including without
             limitation payment of all royalties which are due and payable to
             the third party with respect to the use of such technology  by the
             other party pursuant to this Agreement; and

     (iii) In the case of acquisitions after the execution date hereof, if the
             acquiring party has paid consideration to acquire the Affiliate or
             the technology in question, prior to license of such technology
             hereunder, the parties shall reasonably negotiate in good faith
             compensation to the acquiring party which will result in a fair
             sharing by the parties of the acquisition cost of the technology,
             considering their respective interests therein.

<PAGE>

                                      -13-

3.2.3     In the event that Ciba wishes to obtain sublicenses to [CONFIDENTIAL 
       TREATMENT REQUESTED] currently licensed or assigned to Chiron and subject
       to obligations to third parties, the provisions of Section 3.2.2 shall 
       apply to such sublicenses.


3.3  JOINT IMPROVEMENT OF TECHNOLOGY

3.3.1     During the five (5) years following the execution of this Agreement,
       Ciba and Chiron may cooperate with a view to the development of
       improvements within the Technology Transfer Field, in accordance with
       technology development plans to be agreed by the parties.  Any such
       projects which are mutually agreed upon shall, unless otherwise agreed,
       be equally funded by the parties.  Except as expressly set forth in this
       Agreement, each party shall be free to use and to grant sublicenses under
       any joint inventions resulting from such cooperation.

3.3.2     The Steering Committee may nominate one or more Development Project
       Teams to implement the development plans.

3.3.3     For joint improvements of technology which are claimed in patent
       applications or patents, the Steering Committee shall determine what
       compensation, if any, shall be received by one party in the event that
       the other party licenses any such joint improvement to a third party,
       using the criteria set forth in Section 3.5.2(b) with respect to
       compensation.  Any dispute concerning such compensation shall be referred
       to the Science Committee.

3.4  TITLE TO NEW INVENTIONS AND PATENT RIGHTS

3.4.1     Subject to the licenses granted pursuant to Section 3.5, as between
       the parties hereto, ownership of new inventions within the Technology
       Transfer Field, whether made individually or as part of the Technology
       Improvement Collaboration pursuant to Section 3.3, shall be based on the
       principles set forth below.  For clarity of understanding, the parties
       agree that new inventions pursuant to the Target Collaboration leading to
       Compound Patents or Library Patents shall not be deemed within the
       Technology Transfer Field, and shall be governed by Section 4.6, rather
       than by this Section.

     (a)  If the new invention is a patentable improvement to the Chiron
             Licensed Technology, such invention shall be assigned
             to Chiron. The ultimate assignee of the invention shall be
             determined by the parties, prior to filing a patent application if
             reasonably possible, according to the following considerations:

           (i)       If the new invention was made solely by Chiron employees
                        or assignors, the assignment shall remain with Chiron.

<PAGE>

                                      -14-

           (ii)      If the new invention was made solely by Ciba employees or
                        assignors, or jointly by Ciba employees and Chiron
                        employees and/or their respective assignors, the
                        ultimate assignee shall be determined according to
                        inventorship under U.S. patent law, unless the parties
                        agree that a different disposition should occur.
                        Ownership of patent applications filed outside the
                        U.S. shall be determined according to inventorship.
                        Inventorship shall be determined under U.S. patent
                        law.

     (b)   If the new invention is a patentable improvement to the Ciba
              Licensed Technology, such invention shall be assigned to Ciba.
              The ultimate assignee of the invention shall be determined by the
              parties, prior to filing a patent application if reasonably
              possible, according to the following considerations:

            (i)  If the new invention was made solely by Ciba employees or
                    assignors,  the assignment shall remain with Ciba.

            (ii) If the new invention was made solely by Chiron employees or
                    assignors, or jointly by Ciba employees and Chiron
                    employees and/or their respective assignors, the ultimate
                    assignee shall be determined according to inventorship
                    under U.S. patent law, unless the parties agree that a
                    different disposition should occur.  Ownership of patent
                    applications filed outside the U.S. shall be determined
                    according to inventorship.  Inventorship shall be
                    determined under U.S. patent law.

          (c)  If the new invention represents new technology, rather than an
                  improvement to the Chiron Licensed Technology or the Ciba
                  Licensed Technology as the case may be:

               (i)  If the invention is made by employees or assignors of one
                       party hereto (or its Affiliates), whether solely or
                       jointly with employees or assignors of a third party,
                       such invention shall be assigned to the party which is
                       the employer or assignee of the inventor (subject to such
                       ownership interests as may vest in any such third party).

               (ii) If such invention is made jointly by employees or assignors
                       of Chiron or its Affiliates, on the one hand, and by
                       employees or assignors of Ciba or its Affiliates, on the
                       other hand, such invention shall be assigned to the
                       parties jointly.

              (iii) Inventorship shall be determined in accordance with United
                       States Patent Law.

<PAGE>

                                      -15-

     (d)  For the purposes of this Section 3.4.1, an "assignor" of a party is an
            individual under an obligation to assign patent rights to that
            party, e.g., a consultant retained by that party.


3.4.2     Chiron shall have the sole right to file, maintain and prosecute
     patents with respect to the Chiron Licensed Technology and with respect to
     inventions or discoveries finally assigned to Chiron.  Chiron agrees to
     keep Ciba reasonably informed as to the status of the Chiron Licensed
     Technology Patents.

3.4.3     Ciba shall have the sole right to file, maintain and prosecute patents
     with respect to  Ciba Licensed Technology and with respect to inventions or
     discoveries finally assigned to Ciba.  Ciba agrees to keep Chiron
     reasonably informed as to the status of the Ciba Licensed Technology
     Patents.

3.4.4     In the case of an invention or discovery owned jointly by the parties,
     the Steering Committee shall decide which party shall be responsible for
     filing the patent application(s), if any, in respect thereof.  Joint
     patents shall be the joint property of both parties, who shall  share the
     costs of filing applications and of maintenance.


3.5  TECHNOLOGY LICENSES AND OPTIONS

3.5.1     Subject to the terms, conditions and limitations of this Agreement,
     Chiron hereby grants to Ciba a perpetual, worldwide, non-exclusive,
     royalty-free license to use internally, including use by Ciba in third
     party collaborations,  the Chiron Licensed Technology and the Chiron
     Licensed Technology Improvements, including without limitation the Chiron
     Licensed Technology Patents, for the purpose of research and development,
     and to make, have made, use and sell products arising as a result of such
     research and development, except that (i) such license shall be limited as
     provided in this Section 3.5.1; and (ii) Ciba's rights with respect to
     products arising from the Target Collaboration shall be governed by Article
     4 hereof.  Such license expressly excludes any right to make, have made, or
     sell the Chiron Licensed Technology or the Chiron Licensed Technology
     Improvements themselves as products for research use.

     (a)  For Chiron Licensed Technology Improvements which are not claimed in
            Chiron Licensed Technology Patents, and are not otherwise
            determined by the Steering Committee to merit restrictions
            on sublicensing under the criteria set forth in Section 3.5.2(b), 
            and represent improvements to Ciba Licensed Technology only, 
            rather than to the Chiron Licensed Technology, Ciba shall have the
            right to grant sub-licenses to such Chiron Licensed Technology 
            Improvements hereunder to third parties [CONFIDENTIAL TREATMENT 
            REQUESTED].

<PAGE>

                                      -16-

     (b)  Save as mentioned at (a) in this Section 3.5.1, Ciba shall not have
            the right to grant sublicenses under Chiron Licensed Technology and
            Chiron Licensed Technology Improvements except to Affiliates of
            Ciba, without the prior written consent of Chiron.

     (c)  Ciba shall not use the Chiron Licensed Technology or Chiron Licensed
            Technology Improvements for research or development with respect to
            the Restricted Targets, without Chiron's prior written consent,
            subject to the following:

          (i)  [CONFIDENTIAL TREATMENT REQUESTED]

          (ii) Nothing herein shall preclude Ciba from utilizing Ciba Licensed
                 Technology, or improvements invented by Ciba to the Ciba
                 Licensed Technology, or technology acquired by Ciba from third
                 parties, against the Restricted Targets.

         (iii) Nothing herein shall preclude Ciba from utilizing, against the
                 Restricted Targets, technology which is within the public
                 domain, unless and until patents are issued covering such
                 technology.

          (iv) As of the first anniversary of the execution of this Agreement,
                 the parties will mutually determine the impact of these
                 restrictions.  If, as of such date, no Restricted Targets
                 remain, these restrictions shall be deemed to have no impact.
                 If, as of such date, any Restricted Targets remain, the parties
                 shall determine whether, as of such date, the restrictions
                 imposed under this Section 3.5.1(c) actually preclude the use
                 of Chiron Licensed Technology in an active research project of
                 Ciba against a Restricted Target as to which Ciba would, absent
                 such restrictions, utilize the Chiron Licensed Technology.  If
                 not, the restrictions shall be deemed to have no impact.  If
                 so, Chiron agrees that Ciba shall be entitled to a credit of
                 [CONFIDENTIAL TREATMENT REQUESTED] for each Restricted Target
                 as to which use of the Chiron Licensed Technology in an active
                 Ciba program is actually precluded, up to a maximum of 
                 [CONFIDENTIAL TREATMENT REQUESTED].

               Such credit shall be applied against the consideration payable by
                 Ciba pursuant to Section 3.1.8.  If there is one Restricted
                 Target resulting in such preclusion, such credit shall be
                 implemented by reducing the payment due upon [CONFIDENTIAL 
                 TREATMENT REQUESTED] of this Agreement to [CONFIDENTIAL 

<PAGE>

                                      -17-
                 TREATMENT REQUESTED]. If there are two or more Restricted
                 Targets resulting in such preclusion, the payment due upon 
                 [CONFIDENTIAL TREATMENT REQUESTED] of this Agreement shall be
                 reduced to [CONFIDENTIAL TREATMENT REQUESTED] and, the payment
                 due upon [CONFIDENTIAL TREATMENT REQUESTED] of this
                 Agreement shall be reduced to [CONFIDENTIAL TREATMENT 
                 REQUESTED]. Except as provided herein, all consideration for 
                 the licenses granted in this Section 3.5 shall remain payable 
                 as provided in Section 3.1.8.


3.5.2     Subject to the terms, conditions and limitations of this Agreement,
     Ciba hereby grants to Chiron a perpetual, worldwide, non-exclusive license
     to use internally, including use by Chiron in third party collaborations,
     the Ciba Licensed Technology and the Ciba Licensed Technology Improvements,
     including without limitation the Ciba Licensed Technology Patents, for the
     purpose of research and development, and to make, have made, use and sell
     products arising as a result of such research and development,  except that
     Chiron's rights with respect to products arising from the Target
     Collaboration shall be governed by Article 4 hereof.  Such license
     expressly excludes any right to make, have made, or sell the Ciba Licensed
     Technology or the Ciba Licensed Technology Improvements themselves as
     products for research use.

     (a)  For Ciba Licensed Technology or Ciba Licensed Technology Improvements
               which are not claimed in Ciba Licensed Technology Patents
               and are not otherwise determined by the Steering Committee to
               merit compensation or restrictions on sublicensing under the
               criteria set forth in Section 3.5.2(b), Chiron shall have the
               right to grant sublicenses to such Ciba Licensed Technology or
               Ciba Licensed Technology Improvements hereunder to third parties,
               [CONFIDENTIAL TREATMENT REQUESTED].

     (b)  For Ciba Licensed Technology or Ciba Licensed Technology Improvements
               which are claimed in Ciba Licensed Technology Patents, the
               Steering Committee will determine whether the invention
               merits restrictions on sublicensing and/or compensation to
               Ciba, based on such factors as uniqueness, competitive
               advantage, and commercial value.  It is understood that the
               fact that an invention is claimed in a patent application or
               patent is not itself sufficient to justify either
               restrictions on sublicensing or compensation.  On an
               exceptional basis, a series of non-patented inventions, when
               taken and used together, may also be deemed by the Steering
               Committee to merit  restrictions on sublicensing and/or
               compensation.

     (c)  Based on the criteria set forth in Section 3.5.2(b), the Steering
               Committee may determine (i) that Chiron will not have the
               right to grant sublicenses under the invention in question to
               third parties, other than its Affiliates, without the prior
               written consent of Ciba; or (ii) that Ciba is entitled to
               reasonable compensation for Chiron's internal use and/or
               sublicense of the invention in question, in which event,

<PAGE>

                                      -18-
               the amount of such compensation will be negotiated in good faith;
               provided always that the [CONFIDENTIAL TREATMENT REQUESTED]
               payable to Ciba for Chiron's internal use of Ciba Licensed
               Technology or Ciba Licensed Technology Improvements hereunder
               during the five years following the date of this Agreement shall
               not exceed [CONFIDENTIAL TREATMENT REQUESTED]. Any dispute with
               respect to any such determinations shall be referred to the
               Science Committee for resolution.


3.5.3     The parties acknowledge that Ciba wishes to use the Chiron Licensed
     Technology to independently design, synthesize and/or analyze new
     Combinatorial Libraries, and to use such libraries and the compounds
     contained therein without restriction. The parties further acknowledge
     that, due to current commitments, and to potential future commitments which
     Chiron is free to make, both internally and with third parties, as
     reflected in Section 1.30, Chiron will not provide to Ciba any
     Combinatorial Libraries or any assistance or collaborative effort in the
     design or synthesis of libraries, except subject to restrictions as to
     their use.  As a result, and for clarity of understanding, the parties
     agree as follows:

     (a)  The Chiron Licensed Technology and the Chiron Licensed Technology
               Improvements will not include any Combinatorial Libraries
               and Chiron will not provide Ciba with any assistance in designing
               or synthesizing specific Combinatorial Libraries, except as part
               of the Target Collaboration, and subject to all of the terms and
               conditions thereof.

     (b)  Pursuant to the Target Collaboration, Chiron will provide
               Combinatorial Libraries to Ciba, will assist Ciba in designing
               Combinatorial Libraries, and will work cooperatively to design
               and synthesize Combinatorial Libraries, all for use in the Target
               Collaboration only.

     (c)  Each party agrees that it will not design or synthesize any
               Combinatorial Libraries which it knows or has reason to know
               duplicate Combinatorial Libraries provided or disclosed by the
               other party for use in the Target Collaboration, except with the
               prior written consent of the other party.  In the event such
               consent is granted, the grantee agrees to use such Combinatorial
               Libraries only for the purposes of the Target Collaboration
               pursuant to Article 4, except with the other party's prior
               written consent and on terms to be negotiated in good faith.
               Ciba further agrees not to utilize any Chiron or Joint
               Combinatorial Libraries, or compounds included therein or
               developed through the Target Collaboration, against Third Party
               Excluded Targets.  Use of Joint Libraries is further governed by
               Section 4.8.3.

<PAGE>

                                      -19-

4    TARGET COLLABORATION

     The Target Collaboration shall commence upon Ciba's selection of the
initial Selected Targets ("the Commencement Date"), which shall not be later
than [CONFIDENTIAL TREATMENT REQUESTED] after the date of execution of this 
Agreement.  The Target Collaboration  shall continue for three years 
following the Commencement Date, extendable for up to two additional years 
under the same FTE funding terms as are set forth in Section 4.2.4,
[CONFIDENTIAL TREATMENT REQUESTED].


4.1  TARGET SELECTION

4.1.1     As soon as practicable after execution of this Agreement, Ciba shall
     provide to Chiron  a list of Targets in which Ciba is interested, other
     than Third Party Excluded Targets.  The parties shall meet and discuss the
     Targets on such list and the respective capabilities of the parties in
     these areas, and shall together determine a group of potential Targets,
     from which Ciba shall select two (2) initial Selected Targets.  It is
     acknowledged that as to Targets on which Chiron has done prior work which
     the parties then agree will be used within the Target Collaboration, or as
     to which the parties then agree that Chiron will provide proprietary
     biology not generally available to researchers in the area, either of which
     constitute additional value to the Target Collaboration beyond the value of
     Chiron's Combinatorial Technology capabilities and Combinatorial Libraries,
     Chiron will be entitled to reasonable compensation for the additional value
     added.  As part of the foregoing discussions, the parties will mutually
     agree upon applicable compensation, if any, with respect to a Target prior
     to Ciba's selection of that Target as a Selected Target.

4.1.2     Upon request by Ciba and receipt of the payments required pursuant to
     Section 4.2.3 Chiron will provide Ciba with sufficient quantities of
     existing Chiron Combinatorial Libraries for the purpose of screening
     against the Selected Targets.

4.1.3     Chiron shall have no obligation to provide Ciba, for use in the Target
     Collaboration, any Chiron Combinatorial Library developed  by Chiron
     jointly with a third party, or developed solely by Chiron but pursuant to
     the terms of an agreement with a third party, or developed for Chiron's use
     outside the Target Collaboration.   Chiron Combinatorial Libraries
     developed jointly with or under agreement with third parties will not be
     available for use in the Target Collaboration unless such third party
     consents, and shall then be subject to such additional terms and conditions
     as may be imposed by the third party.  Chiron will inform Ciba of any such
     additional terms and conditions prior to the use of any such Chiron
     Combinatorial Library hereunder.

<PAGE>

                                      -20-

4.2  RESEARCH PROGRAM

4.2.1     The parties agree to enter into a research program to utilize
     Combinatorial Libraries, including libraries designed pursuant to such
     research program, to screen against the Selected Targets, to optimize hits
     and to produce sets of compounds achieving Research Compound or above
     status in the Target Collaboration Field.  Once the Selected Targets have
     been determined pursuant to Section 4.1, the parties agree that during the
     term of the Target Collaboration they will collaborate exclusively with
     each other in the Target Collaboration Field with respect to the Selected
     Targets, subject to the following:

     (a)  The parties recognize that this Agreement is intended to focus on
            compound discovery, optimization and development within the
            Target Collaboration Field.  The parties agree to include within the
            Target Collaboration any internal programs or collaborations which
            would otherwise constitute competing discovery and optimization
            programs with respect to the Selected Targets within the Target
            Collaboration Field.  However, Ciba will not be precluded from
            acquiring rights to and pursuing, independently of the Target
            Collaboration, individual third party compounds against the Selected
            Target which have already reached at least the Research Compound
            Stage, provided that no data or information arising from the Target
            Collaboration is used in connection with such development. In such
            event, the Target Collaboration as to such Selected Target will
            continue to be governed by all terms of this Agreement, including
            without limitation the diligence obligations set forth in Section
            4.3.10.

     (b)  Either party may from time to time wish to acquire technology or
            collaborate with third parties within the Target Collaboration
            Field to enhance the prospect of success and be included within
            the Target Collaboration (e.g. with a university in the
            development of an assay).  Since such transactions may have
            financial impact on, or affect intellectual property, confidential
            information or product rights of, the other party hereunder, neither
            party will enter into such a transaction without the approval of the
            other party, which approval shall not be unreasonably withheld.  If
            one party bears the financial burden of such a third party
            collaboration, the parties will reasonably discuss whether an
            adjustment should be made to the compensation payable to such party
            pursuant to Section 4.3.

     (c)  Nothing herein shall restrict either party from establishing programs
               outside the Target Collaboration Field with respect to the same
               Selected Targets,  including for example and without limitation,
               biological or gene therapy approaches to such Selected Targets.

     (d)  Both parties acknowledge that Chiron is currently party to, and may in
               the future enter into additional, target collaborations with
               third parties.  Chiron may also enter into

<PAGE>


                                      -21-

            future transactions with third parties  which involve technology
            transfer independent of collaborations on specific targets.  With
            respect to any such arrangements, the parties understand as follows:

          (i)   Chiron will not provide third parties with Chiron Combinatorial
                  Libraries or licenses under Chiron Library Patents, or
                  actively participate with third parties in the design
                  of new Combinatorial Libraries or compounds, for use
                  with the Selected Targets during the term of the Target
                  Collaboration, or otherwise in violation of the licenses
                  granted pursuant to Section 4.7.1 hereunder.  With respect to
                  target specific collaborations which Chiron enters into after
                  the execution date of this Agreement, Chiron will impose
                  restrictions on third party use of selectivity assays directed
                  toward  Ciba's Selected Targets which are similar to the
                  restrictions set forth in Section 4.2.11(a).

          (ii)  However, Chiron will not be required to restrict future third
                  party recipients of technology transfer from utilizing
                  the transferred technology to design or synthesize
                  Combinatorial Libraries for use against any target, including
                  Selected Targets, provided that Chiron does not participate in
                  such design or grant licenses in violation of Section
                  4.2.1(d)(i).

          (iii) In the course of target collaborations with third parties,
                  compounds may be identified against targets other than
                  Selected Targets, which compounds prove useful against the
                  Ciba Indications, as identified under Section 4.3.  Chiron
                  shall not be required to restrict the ability of any third
                  party to pursue all indications of such compounds, despite the
                  fact that some overlap with the Ciba Indications may exist;
                  except in the event that the compound itself is licensed
                  exclusively to Ciba pursuant to Section 4.7.1(b).

          (iv)  Ciba acknowledges that Chiron and/or its Affiliate, Chiron
                  Mimotopes Pty Ltd, currently engage in the design and
                  sale of pins for use in organic chemistry, and will
                  continue to engage in such business, including
                  progressively newer generations of pins.  Chiron
                  Mimotopes currently does, and will continue to, engage
                  in synthesis of peptides and other compounds based on
                  specifications provided by third parties.  Chiron and
                  Chiron Mimotopes will not be required to impose any
                  target restrictions with respect to any such sales or
                  services.


4.2.2     The Target Collaboration shall be implemented by project teams
     ("Target Project Teams"), membership of which will be according to the
     needs of the particular project.  The leaders of the Target Project Teams
     shall be nominated by the Steering Committee.  In the

<PAGE>

                                      -22-

     event of deadlock on any matter the Target Project Teams shall refer such
     matter to the Steering Committee.

With respect to the Target Collaboration, the Steering Committee shall function
     as defined in Article 2, except that Ciba's views shall prevail, subject to
     all other terms of this Article 4, in the selection of, replacement of, or
     abandonment of, Selected Targets.

4.2.3     In consideration of the exclusive rights given to it with respect to
     the Selected Targets Ciba shall make a once and for all payment to Chiron
     of [CONFIDENTIAL TREATMENT REQUESTED] for each of the two initial 
     Selected Targets, ([CONFIDENTIAL TREATMENT REQUESTED] in total).  This 
     amount shall be payable upon  the Commencement Date.

4.2.4     In addition, Ciba shall pay Chiron's fully-burdened costs per year per
     FTE actively engaged in the Target Collaboration.  The initial rate shall
     be [CONFIDENTIAL TREATMENT REQUESTED] per FTE per year, this amount to be 
     increased annually, effective January 1 of each calendar year, based on 
     increases in the [CONFIDENTIAL TREATMENT REQUESTED] for the previous 
     calendar year.  Such indexing shall occur initially as of January 1, 1996,
     regardless of whether payments pursuant to this Section 4.2.4 have then 
     occurred.  This  payment compensates Chiron for all ordinary travel and 
     subsistence expenses incurred by such FTE's, but excludes expenses of 
     extraordinary travel or exceptionally long stays, which shall be separately
     reimbursed in amounts to be mutually agreed upon by the parties.  For the 
     purposes of this Section 4.2.4, travel which exceeds (i) travel necessary 
     to attend meetings of the Target Project Team and/or Steering Committee, 
     plus (ii) [CONFIDENTIAL TREATMENT REQUESTED] days per year per FTE,  shall
     be considered extraordinary travel or exceptionally long stays.

   Unless otherwise agreed in writing, Chiron shall make available an average of
     [CONFIDENTIAL TREATMENT REQUESTED] FTEs per year for each of the two 
     Selected Targets. Such FTEs shall include a balanced group of Ph.D. or 
     equivalent and other scientists. For the avoidance of doubt, if research 
     effort on one of the Selected Targets is reduced or terminated before the 
     end of the Target Collaboration, the FTE's employed on that Target shall 
     be deployed on the remaining Selected Target or Targets for the remainder 
     of the Target Collaboration.

   The annual cost of such FTEs shall be due and payable in equal semi-annual
     installments in advance, on the following schedule.  The first such payment
     shall be due and payable upon the Commencement Date, and shall cover the
     FTE cost from such date through the end of the then current semi-annual
     period, on a prorated basis.  Thereafter, FTE payments for each semi-annual
     period shall be due and payable on each January 15 and July 15  for the
     remainder of the term of the Target Collaboration the last payment also
     being prorated.

<PAGE>

                                      -23-

4.2.5     Ciba may elect to add up to two Selected Targets, increasing the total
     number of Selected Targets to a maximum of four at any time.  Collaboration
     on any such additional Selected Targets shall continue for a minimum of two
     years, and Ciba agrees to extend the Target Collaboration as necessary to
     accommodate such requirement.  The proposed additional Targets shall be
     selected by Ciba in the same manner as is provided in Section 4.1.1 and
     shall not be Third Party Excluded Targets. Ciba agrees to pay a one time
     fee of [CONFIDENTIAL TREATMENT REQUESTED] per Target added.  At the time 
     a Target is added, the parties shall mutually agree upon the number of 
     additional FTE's needed in connection with each such Target and the cost 
     thereof.  Ciba agrees to  pay for the FTE cost of, and Chiron agrees to 
     make available, such additional FTE's, all in the same manner as is set 
     forth in Section 4.2.4.

4.2.6     The parties agree to work on each Selected Target for a reasonable
     period of time.  Ciba may elect to abandon any of the Selected Targets at
     any time during the term of the Target Collaboration for scientific,
     technical or commercial reasons, on written notice to Chiron.  Ciba shall
     select a replacement Selected Target for each abandoned Target, to the
     extent necessary to maintain at least two Selected Targets within the
     Target Collaboration; provided that if a Selected Target is abandoned
     within the last six months of the Target Collaboration, Ciba need not
     select a replacement, so long as Ciba continues to pay for the full 
     [CONFIDENTIAL TREATMENT REQUESTED] FTE commitment pursuant to Section 
     4.2.4. Replacement Selected Targets will be selected in the same manner
     as is provided in Section 4.1.1 and shall not be Third Party Excluded 
     Targets.  Collaboration on any such replacement Selected Target shall 
     continue for a minimum of two years, and the collaboration shall be 
     extended as necessary to allow for such two year period.  No further 
     payment shall be made by Ciba pursuant to Section 4.2.3 for a Target 
     selected to replace any Selected Target.

4.2.7     Ciba and Chiron shall cooperate in the use of assays developed prior
     to or during the Target Collaboration by Ciba and/or Chiron for the
     identification or further characterization of a compound or compounds for
     the two Selected Targets.

     Each party agrees not to use outside the Target Collaboration any assays
       which have been independently developed by the other party outside the
       Target Collaboration and provided for use in the Target Collaboration,
       except with the prior written consent of the providing party and on terms
       to be negotiated in good faith.

     From time to time, Ciba may request Chiron to utilize the FTE's provided
       pursuant to Section 4.2.4 to develop new assays with respect to the
       Selected Targets.  Chiron agrees to undertake such assay development
       subject to availability of resources for such work. If such development
       involves then existing proprietary biology of Chiron which adds value,
       Chiron will be entitled to mutually agreed compensation for the value
       added in the same manner as is provided in Section 4.1.1.   New assays
       developed as part of the Target Collaboration will

<PAGE>

                                      -24-

       be available to both parties for use outside the Target Collaboration,
without compensation to the other party except pursuant to the preceding
sentence.

4.2.8     The Target Project Teams shall meet as often as may be required for
     the purposes of the collaboration but in any event not less than four times
     per year, again unless otherwise agreed by the parties.  Written reports of
     such meetings and of the status of the individual projects shall be
     submitted to the Steering Committee.  Unless otherwise agreed, meetings
     shall alternate between the relevant sites of Chiron and Ciba.

4.2.9     Chiron will keep records of the time spent by its FTEs on the Target
     Collaboration.  Ciba shall have the right to have these records audited, in
     the same manner as is set forth in Section 7.4. Chiron will report the
     level of FTE effort to Ciba on a semi-annual basis.   During the course of
     the Target Collaboration, Chiron will notify Ciba if it becomes apparent
     that the level of effort at Chiron is expected to exceed the level required
     under Section 4.2.4.

     If the level of effort is less than an average, on an annual basis, of the
       number of FTE's required pursuant to Section 4.2.4,  Ciba will be
       entitled  to additional FTE effort in subsequent semi-annual periods,
       such that the required annual average is restored. Conversely, if the
       average annual level of effort by Chiron exceeds the number of FTE's
       required and funded pursuant to Section 4.2.4, Chiron will be entitled to
       reduce the FTE effort in subsequent semi-annual periods, such that the
       required annual average is restored.  At the end of the Target
       Collaboration, the parties will restore any such imbalance between actual
       and funded FTE's either through appropriate payments or refunds, or
       through an extension of the Target Collaboration until the balance is
       restored.

4.2.10    If a Selected Target is abandoned pursuant to Section 4.2.6, ownership
            and all rights to all data and information resulting from the Target
            Collaboration with respect to such abandoned Target shall be
            determined as follows, subject to the provisions of Section 4.2.11:

          (a)  Either party shall be free to use, without further compensation
                    to the other, information generally applicable to
                    the abandoned Target or to multiple targets, such as assay
                    technology, animal models, etc.  Either party shall also be
                    free to use information otherwise in the public domain.

          (b)  Chiron shall have the exclusive right to use all unpublished
                    compound specific information, including without limitation
                    bioactivity and profile information (collectively, the
                    "Compound Data") with respect to the abandoned Target,
                    subject to payment of a royalty to Ciba on any products
                    resulting from the use of such Compound Data, at a rate
                    between [CONFIDENTIAL TREATMENT REQUESTED], to be mutually
                    determined.  Such rights shall include the patent licenses
                    granted pursuant to

<PAGE>

                                      -25-

                    Section 4.7.2(c).  Chiron shall have the right to use the
                    Compound Data to conduct research and development of such
                    products alone or with a third party. For the purposes of
                    Article 9 hereof, the Compound Data will be deemed
                    Proprietary Information of Chiron following the abandonment
                    of the Selected Target.

               (i)   From such time as Chiron elects to proceed with a third
                         party, Ciba shall have no right to resume research and
                         development using the  Compound Data with respect to
                         the abandoned Target.

               (ii)  If Chiron is not proceeding with a third party and Ciba
                         wishes to resume research and development with respect
                         to the abandoned Target using Compound Data, Ciba will
                         have the following rights:

                    (aa) If Ciba wishes to resume within five (5) years after
                              the Commencement Date and Chiron has not
                              commenced its own research and development program
                              with respect to the abandoned Target, Ciba may add
                              the abandoned Target to the collaboration as a
                              Selected Target pursuant to Section 4.2.5, or may
                              replace another Selected Target with the abandoned
                              Target pursuant to Section 4.2.6.

                    (bb) If Ciba wishes to resume within five (5) years after
                              the Commencement Date and Chiron has commenced its
                              own research and development program with respect
                              to the abandoned Target, Ciba may buy in to a co-
                              development program with Chiron in the same manner
                              as is set forth in Section 4.3.6.

                    (cc) If Ciba wishes to resume more than five (5) years after
                              the Commencement Date, which period may be
                              extended as provided below, Ciba shall be free to
                              pursue the abandoned Target using the Compound
                              Data, subject to payment of a royalty to Chiron on
                              any products resulting from such information at a
                              rate between [CONFIDENTIAL TREATMENT REQUESTED], 
                              to be mutually determined. If Chiron is then 
                              pursuing the abandoned target, alone or with 
                              third parties, Ciba will not be entitled to any 
                              licenses under any patents covering the Compound 
                              Data which have been assigned or exclusively 
                              licensed to Chiron.  If Chiron has also abandoned
                              the target at that point, Ciba will be entitled to
                              such licenses under such patents as will enable 
                              Ciba to proceed, and Chiron will retain such 
                              rights as

<PAGE>

                                      -26-

                              will enable Chiron to resume its activity with
                              respect to such target in the future, unless
                              otherwise agreed by the parties at the time. The
                              five (5) year period referenced in this
                              subsection (cc) shall be reasonably extended if
                              the Selected Target is abandoned late in the
                              Target Collaboration, to allow Chiron reasonable
                              time to either commence its own activities with
                              respect to such target, or to seek a third party
                              collaborator.

4.2.11    The parties recognize that in the course of the collaboration, the
            parties will test Compound Hits and potential Research Compounds in
            assays directed toward Targets other than Selected Targets for
            selectivity purposes.

          (a)  If the selectivity assay is directed toward a Third Party
                    Excluded Target, Ciba shall have the right to use
                    the results only for the purpose of determining selectivity
                    of its compounds against the Selected Target.  If the assay
                    identifies activity against the Third Party Excluded Target,
                    the parties shall reasonably discuss whether Chiron will
                    have the right to use such results with its third party
                    collaborator in a research and development program against
                    the Third Party Excluded Target, subject to a reasonable
                    royalty to Ciba at a rate between [CONFIDENTIAL TREATMENT 
                    REQUESTED].  In the absence of such an arrangement, neither
                    party shall have any rights to use the data in any program
                    directed against the Third Party Excluded Target.

          (b)  If the selectivity assay identifies activity against any Target
                              other than a Third Party Excluded Target, the
                              parties will consider whether such other Target
                              should be included within the Target Collaboration
                              as an added or replacement Target.  If not, the
                              parties will mutually determine the respective
                              rights of either or both of them to use such
                              results in independent programs directed toward
                              such Target and the appropriate compensation
                              therefor, which shall consist of a reasonable
                              royalty at a rate between [CONFIDENTIAL 
                              TREATMENT REQUESTED].

<PAGE>

                                      -27-

4.3  RESEARCH COMPOUNDS AND DEVELOPMENT CANDIDATES

     The provisions of this Section 4.3 shall apply only to compounds that
       achieve Research Compound status or above within [CONFIDENTIAL 
       TREATMENT REQUESTED]years after the end of the Target Collaboration.
       As to such compounds, the parties agree that product development and 
       commercialization rights will be allocated as follows:

4.3.1     For each of the Selected Targets, once Compound Hits have been
       identified through the primary Target assay, Ciba will prepare a
       preclinical research and development plan, including protocols and
       timetables for profiling and other steps necessary to move Compound Hits
       to the Research Compound stage in the indication(s) of primary interest
       to Ciba (the "Ciba Indications").  The plan will be submitted to the
       Steering Committee for information purposes.  Based on the plan, the
       Steering Committee will agree on the criteria for success, for the
       purpose of determining which compounds will become available for Chiron
       development pursuant to Section 4.3.3.

4.3.2     Compounds meeting the criteria for success determined under Section
       4.3.1 will be available for development by Ciba.  While the parties
       anticipate that Ciba's development program will focus on the Ciba
       Indications, Ciba shall have the right to fully develop any compound it
       selects as an EDC for any indications except that Ciba agrees not to
       pursue any compound arising from the Target Collaboration against the
       indications set forth in Exhibit E without Chiron's prior written
       consent.

4.3.3     Compounds which are not tested or do not meet the criteria for success
       determined under Section 4.3.1 will become available for development by
       Chiron in indication(s) (the "Chiron Indications") other than the Ciba
       Indications, subject to the provisions of this Section 4.3. At its
       meetings, the Steering Committee will review which compounds become
       available for Chiron development pursuant to this Section 4.3.3.  If
       Chiron wishes to proceed with development of such compounds in the Chiron
       Indications, Chiron will prepare a preclinical research and development
       plan, including protocols and timetables for profiling and other steps
       necessary to move Compound Hits to the Research Compound stage in the
       Chiron Indications.  Such plan will be submitted for information purposes
       to the Steering Committee.  Based on the plan, the Steering Committee
       will agree on the criteria for success.   Development rights to compounds
       which do not meet the criteria for success under the Chiron plan shall be
       subject to mutual agreement.

     Ciba retains the right to continue to screen, in the Ciba Indications,
       compounds which are available for Chiron development pursuant to this
       Section 4.3.3.


4.3.4     Chiron agrees not to pursue regulatory approval of any compounds for
     the same or  overlapping indications to the Ciba Indications, as the Ciba
     Indications are identified as of

<PAGE>

                                      -28-

     the earlier of [CONFIDENTIAL TREATMENT REQUESTED]. If the Ciba Indications
     change after that point, the provisions of Section 4.3.6 shall govern.
     Chiron shall have the right to fully develop any compound it selects as an
     EDC for any indications other than the Ciba Indications identified as 
     provided in this Section 4.3.4.

   The determination of whether Chiron Indications are the same or overlapping
     with the Ciba Indications shall be made jointly by Ciba and Chiron, and
     shall be based on all relevant information available at that time. Relevant
     considerations include differences in Target subtype or isozyme, chemical
     structure, pharmacology, mode of administration,  therapeutic or toxicity
     profile, or expected disease indications.  Examples of anticipated
     overlapping indications include the following, without limitation:
     serotonin re-uptake inhibitors for anxiety and depression; estrogen
     receptor antagonists for breast and ovarian cancer; estrogen replacement
     for menopause and osteoporosis; ACE inhibitors for hypertension, congestive
     heart failure and renal insufficiency.

4.3.5     The parties will communicate with each other as to the progress of
     their respective development programs, and will share with each other the
     results of such programs.  To the extent that such programs continue during
     the [CONFIDENTIAL TREATMENT REQUESTED] following the end of the Target 
     Collaboration, such communication shall also continue during that period; 
     and the Steering Committee will continue to meet during that period as 
     necessary to carry out the provisions of this Section 4.3.

4.3.6     If Chiron is developing a compound for Chiron Indications pursuant to
     Section 4.3.3, and Ciba, as a result of its continued testing in the Ciba
     Indications, determines that it is also interested in developing such
     Chiron compound for Ciba Indications, or if it becomes apparent through
     other available data that the Chiron compound also has utility in the Ciba
     Indications, Ciba has the right to buy in to a co-development program with
     Chiron with respect to such compound.  Unless otherwise agreed, the parties
     will then proceed with a joint development program with further costs
     shared equally, 50/50 profit sharing, and shared marketing rights, all on
     commercially reasonable terms to be negotiated by the parties.

   Ciba may exercise this buy in right at any time prior to [CONFIDENTIAL 
       TREATMENT REQUESTED] at a mutually agreed upon buy in price, to be 
       determined based upon each party's investment in the research and 
       development of such compound to the date of buy in, investment by 
       either party in generating preclinical and clinical data with respect
       to other compounds that is useful in the development of such compound,
       the risk assumed by each party to such date,  and the market potential
       likely to result from each party's indication rights.

<PAGE>

                                      -29-

4.3.7     If Chiron wishes to engage a partner to develop any compound under
     this Section 4.3, Chiron agrees to offer Ciba the right of first
     negotiation to co-develop such compound.

4.3.8     (a)  Ciba shall make a milestone payment of [CONFIDENTIAL TREATMENT 
            REQUESTED] on [CONFIDENTIAL TREATMENT REQUESTED].

     (b)  For Ciba EDCs, which are developed exclusively by Ciba, the following
            milestone payments shall be made by Ciba to Chiron:

          - [CONFIDENTIAL TREATMENT REQUESTED]
               and

          - [CONFIDENTIAL TREATMENT REQUESTED]

       For clarity of understanding, the milestones referred to in Section
          4.3.8(a) and (b) shall each be payable only once for each
          compound; such that the maximum aggregate milestone payments for a
          single compound will be [CONFIDENTIAL TREATMENT REQUESTED].

       (c)  Chiron will not be required to pay milestones with respect to its
               EDCs or Chiron Products.

       (d)  For each Ciba Product, Ciba shall pay to Chiron royalties on Net
               Sales made by Ciba, its Affiliates or licensees, at the rate 
               of [CONFIDENTIAL TREATMENT REQUESTED] of Net Sales if aggregate
               annualized worldwide Net Sales for that Ciba Product do not 
               exceed [CONFIDENTIAL TREATMENT REQUESTED], and [CONFIDENTIAL 
               TREATMENT REQUESTED] of Net Sales if aggregate annualized 
               worldwide Net Sales for that Ciba Product exceed 
               [CONFIDENTIAL TREATMENT REQUESTED].

            For Chiron Products, Chiron shall pay to Ciba royalties at the rate
               of [CONFIDENTIAL TREATMENT REQUESTED] of Net Sales made by 
               Chiron, its Affiliates or licensees.

            In the event that, on a country by country basis, a Ciba Product or
               a Chiron Product is not covered by a patent which prevents the
               lawful manufacture, use or sale of such product by a third party,
               or the relevant patent has expired,  the royalties otherwise
               payable hereunder with respect to the sale of such Ciba Product
               or Chiron Product in such country shall be reduced by 
               [CONFIDENTIAL TREATMENT REQUESTED].

<PAGE>

                                      -30-

            Should either party have to pay royalties to a third party under an
               issued valid claim of  a third party patent which is infringed 
               by the manufacture or sale of a Ciba Product or a Chiron 
               Product, including royalties payable to third parties pursuant 
               to Sections 3.2.2, 3.2.3 or 4.1.3, [CONFIDENTIAL TREATMENT 
               REQUESTED] of the royalties payable to such third party shall be
               deducted from royalties due to Ciba or Chiron hereunder, 
               provided, however, that in no event shall the aggregate 
               reductions in royalties arising from this paragraph and/or the 
               preceding paragraph result in royalties on a Ciba Product of 
               less than [CONFIDENTIAL TREATMENT REQUESTED] of Net Sales if 
               aggregate annualized worldwide Net Sales of that Ciba Product 
               do not exceed [CONFIDENTIAL TREATMENT REQUESTED] or less than 
               [CONFIDENTIAL TREATMENT REQUESTED] of Net Sales if aggregate 
               annualized worldwide Net Sales exceed [CONFIDENTIAL TREATMENT 
               REQUESTED], or in royalties on Chiron Products of less than 
               [CONFIDENTIAL TREATMENT REQUESTED] of Net Sales.

            Royalties shall be paid until expiry of the patents on a country by
               country basis or for [CONFIDENTIAL TREATMENT REQUESTED] from the 
               first commercial launch in each country, whichever is longer.

            If "off-label" prescribing or administration of a Chiron Product or
               a Ciba Product should result in a significant loss of revenue to
               the other party with respect to its products developed hereunder,
               the parties agree to meet and discuss whether adjustments to
               royalties on either product are appropriate.

4.3.9     For the purposes of this Section 4.3, a Ciba Product or a Chiron
       Product includes all products containing the same active compound, or a
       compound which is a derived from the active compound (such as a different
       salt, ester, crystal form or the like), regardless of other differences,
       such as dose, dosage form, indication and the like.

4.3.10    Unless the parties are engaged in co-development of a compound, each
            party agrees to use commercially reasonable diligence to develop and
            commercialize at [CONFIDENTIAL TREATMENT REQUESTED] per Selected 
            Target, in the case of Ciba, and [CONFIDENTIAL TREATMENT REQUESTED]
            in the case of Chiron.  Each party will keep the other informed of 
            its development of products under this Section 4.3, not less 
            frequently once per year. In the event that Ciba fails to 
            diligently pursue development and commercialization of 
            [CONFIDENTIAL TREATMENT REQUESTED] per Selected Target,  Ciba 
            shall either abandon such Selected Target pursuant to Section 4.2.6,
            or invite Chiron to participate in the co-development of compound(s)
            for such Selected Target.  In the event that Chiron fails to pursue
            diligently the development and commercialization of [CONFIDENTIAL 
            TREATMENT REQUESTED] Chiron shall either abandon such product or 
            invite Ciba to participate in co-development of compound(s) for such
            Selected Target.


4.4  COMPOUNDS NOT ACHIEVING RESEARCH COMPOUND STATUS

<PAGE>

                                      -31-

       The arrangements set out in Section 4.3 shall not apply to any compounds
          that do not achieve Research Compound status or above by the end
          of the [CONFIDENTIAL TREATMENT REQUESTED] period following the end of
          the Target Collaboration. At the end of such [CONFIDENTIAL TREATMENT 
          REQUESTED] period, the parties will meet and inventory all compounds 
          at or near Research Compound stage or above, and the indications 
          thereof, being pursued by either party under this Agreement at that 
          time.  Either party will be free to develop and commercialize any 
          compounds arising from this Collaboration which are not at least at 
          or near Research Compound stage at the end of such [CONFIDENTIAL 
          TREATMENT REQUESTED] period, without royalty or milestone obligations
          to the other party; provided that (i) Ciba agrees not to pursue such 
          compounds for Third Party Excluded Targets identified at the time of 
          such inventory; and (ii) for an additional [CONFIDENTIAL TREATMENT 
          REQUESTED], neither party will pursue any such compounds for any
          indications of compounds being pursued by the other party under this
          Agreement, as identified in such inventory.


4.5  PRODUCTS DEVELOPED INDEPENDENTLY OF THE TARGET COLLABORATION

     The provisions of this Article 4 shall not apply to any compounds developed
       independently by Ciba, by Chiron or by a third party, prior to or
       after the term of the Target Collaboration, or during such term to the
       extent permitted under Section 4.2.1,  so long as such independent
       development is  without the use of data or information arising from the
       Target Collaboration.


4.6  TITLE TO NEW INVENTIONS AND PATENT RIGHTS

4.6.1     New inventions and discoveries shall be owned as follows:

     (a)  All Compound Patents based on inventions or discoveries made pursuant
            to the Target Collaboration shall be owned [CONFIDENTIAL TREATMENT 
            REQUESTED].  Each party shall require its employees, agents, and 
            consultants  to assign any such inventions [CONFIDENTIAL TREATMENT 
            REQUESTED], as of the date the invention was made.

     (b)  Library Patents with respect to Chiron Combinatorial Libraries shall
            be owned by Chiron; Library Patents with respect to Ciba
            Combinatorial Libraries shall be owned by Ciba; and Library Patents
            with respect to Joint Combinatorial Libraries shall be owned by the
            parties jointly.

     (c)  All inventions or discoveries made pursuant to the Target
            Collaboration which do not result in Compound Patents or Library
            Patents, but are inventions within the Technology Transfer Field
            shall be governed by Section 3.4.1.

<PAGE>

                                      -32-


     (d)  All inventions or discoveries which are not governed by Section 3.4.1
               or by the remaining provisions of this Section 4.6.1 shall be
               owned based on inventorship, as determined in accordance with
               United States patent law.

4.6.2     Patents and patent applications shall be drafted, filed, prosecuted
     and maintained by the party owning the patent rights.  The parties shall
     agree which party is to draft, file, prosecute and maintain joint patents
     on a case-by-case basis.  In all cases, each party shall keep the other
     party informed as to the status and progress of all relevant patents and
     patent applications; and shall draft, file, prosecute and maintain joint
     patents and patent applications in consultation with the other party.

4.6.3  The parties shall be jointly responsible for all expenses associated with
     the filing, prosecution and maintenance of joint patents, including
     Compound Patents.


4.7  LICENSES

4.7.1     Subject to the terms and conditions of this Agreement, Chiron hereby
     grants the following licenses to Ciba:

     (a)    A worldwide exclusive license, without right to sublicense, during
               the term of the Target Collaboration, under Chiron
               Library Patents and Chiron know-how and trade secrets relating to
               Chiron Combinatorial Libraries, to screen Chiron Combinatorial
               Libraries against the Selected Targets.  Such license shall
               automatically terminate as to Selected Targets which are
               abandoned by Ciba.

     (b)    A worldwide exclusive license under Chiron's interest in Compound
               Patents to develop, make, have made, use and sell Ciba
               Products.  Ciba shall have the right to grant sublicenses under
               such license to Affiliates of Ciba, and to third parties;
               provided that Ciba's rights to sublicense the manufacture or sale
               of Ciba Products to third parties shall be subject to the terms
               and conditions of the Cooperation Agreement.

4.7.2       Subject to the terms and conditions of this Agreement, Ciba hereby
       grants the following licenses to Chiron:

     (a)  A worldwide, non-exclusive license, without right to sublicense,
               during the term of the Target Collaboration, under Ciba Library
               Patents and Ciba know-how and trade secrets related to Ciba
               Combinatorial Libraries, to screen Ciba Combinatorial Libraries
               against Selected Targets pursuant to the Target Collaboration.

<PAGE>

                                      -33-

       (b)  A worldwide exclusive license under Ciba's interest in Compound
               Patents to develop, make, have made, use and sell
               Chiron Products.  Chiron shall have the right to grant
               sublicenses under such licenses to Affiliates of Chiron, and to
               third parties; provided that Chiron's rights to sublicense the
               manufacture or sale of Chiron Products to third parties shall be
               subject to the terms and conditions of the  Cooperation
               Agreement.

       (c)     With respect to Selected Targets abandoned by Ciba, Ciba shall
               assign to Chiron its interest in any Compound Patents, use
               patents or any other patents arising from the Compound Data to
               Chiron.  Chiron shall retain the exclusive right, under all such
               patents, to make, have made, use and sell products directed
               against the abandoned Target, with right to sublicense to Chiron
               Affiliates or third parties, all in accordance with Section
               4.2.10.  In the event that compounds identified pursuant to the
               Target Collaboration as active against the abandoned Target were
               made by Ciba prior to the execution of this Agreement, Ciba shall
               grant to Chiron a worldwide exclusive license to make, have made,
               use and sell such compounds in Chiron Products against the
               abandoned Target.  Ciba shall retain rights to such compounds for
               use other than against the abandoned Target.


4.8  USE OF COMBINATORIAL LIBRARIES

4.8.1     The parties acknowledge that the Chiron Combinatorial Libraries
     screened pursuant to the Target Collaboration will also be screened by
     Chiron, its Affiliates and contractors, and by third parties outside this
     collaboration. The rights of the parties with respect to compounds
     identified through this collaboration will be subject to rights arising as
     a result of such use of the libraries outside this collaboration.  The
     parties agree that the determination of ownership, patent and license
     rights to compounds contained in Chiron Combinatorial Libraries shall be
     based on the first to invent the subject matter in question, as determined
     under U.S. Patent Law.  Except as expressly stated in Section 3.5 or
     Section 4.7, no implied rights or licenses are granted hereunder to any
     inventions or patent rights arising outside this Agreement, including
     without limitation rights under dominating patent claims.  The following
     principles shall apply.

   (a)    Ciba agrees to notify Chiron in writing as soon as possible following
            identification of any Compound Hit.  Chiron shall be entitled to
            rely on the content and timing of receipt of notices of
            identification of compounds received from all users of Chiron
            Combinatorial Libraries as evidence of which party is first to
            invent and in determining whether conflicts exist.

   (b)    If, at any time, Chiron believes in good faith that a conflict exists
            among parties who are each entitled to exclusive rights to
            compounds contained in Chiron Combinatorial Libraries, with respect
            to patent applications filed or to be filed by

<PAGE>

                                      -34-

            Chiron, Chiron shall notify each party involved of the existence of
            the conflict, the claims of such party which are involved, and the
            identity of (but not the specific compounds or claims of) the other
            party.  Ciba hereby consents to such notification under Article 9
            hereof.  Chiron shall not be required to take any action in filing
            new patent applications or amending existing applications with
            respect to the conflicting subject matter, except on instructions
            approved by both parties to the conflict.  However, Chiron shall
            have the right, but not the obligation, to take such actions as
            Chiron believes in good faith will protect the rights of both
            parties to the conflict, pending receipt of such jointly approved
            instructions (e.g. filing potentially conflicting applications,
            combining conflicting subject matter into a CIP application, filing
            continuations of applications to prevent double patenting rejections
            of another application, etc.)

4.8.2     Ciba retains the right to use Ciba Combinatorial Libraries (and any
       other libraries owned by Ciba) outside the Target Collaboration; and
       Chiron retains the right to use Chiron Combinatorial Libraries (and any
       other libraries owned by Chiron) outside the Target Collaboration, in
       each case without restriction, except as expressly provided herein.

4.8.3     Each party shall have the right to use Joint Combinatorial Libraries
       outside the Target Collaboration, subject to the following conditions:

     (a)    Ciba shall not use any Joint Combinatorial Library in connection
               with Third Party Excluded Targets, determined as of the time of
               creation of the Joint Library.

     (b)    In the event that either party (the "providing party") reasonably
               believes that its strategic proprietary rights to components
               which such party provided for a Joint Combinatorial Library would
               be jeopardized by use of such library by a third party, the
               providing party may preclude third party use of such Joint
               Combinatorial Library, or the parts thereof containing such
               proprietary component, without the prior consent of the providing
               party.  The providing party will notify the other party of any
               such intended restrictions at the time of the design or
               development of the Joint Combinatorial Library, and in any event
               at the request of the other party prior to the use of the Joint
               Combinatorial Library outside the Target Collaboration.

     (c)  In the event of use of a Joint Combinatorial Library outside the
               Target Collaboration by one party, the parties shall reasonably
               and mutually determine if the other party should be entitled to a
               royalty on products arising from such use.  Such royalty, if any,
               shall be at a rate between [CONFIDENTIAL TREATMENT REQUESTED] of 
               Net Sales, to be mutually determined, based on such factors as 
               the uniqueness of the library or the proprietary nature of its 
               components.  At the time of determination of the royalty rate, 
               the parties will also determine the time period during which use
               of the Joint Library will result in a

<PAGE>

                                      -35-
               royalty on products arising from such use, which time period will
               be reassessed by the parties three years following the end of the
               Target Collaboration.


5  PATENT ENFORCEMENT

5.1  In general, the owner of any patent shall have the right to enforce such
       patent against third parties at the owner's expense, and the owner shall
       be entitled to all recoveries.  In the case of jointly owned patents, the
       parties shall mutually determine how to proceed.

5.2  Each party shall notify the other party of any third party infringement
       activity of which it becomes aware; and each party shall reasonably
       cooperate with the other party in connection with the enforcement of
       patent rights pursuant to this Article  5.


6  INDEMNITY; NO WARRANTIES

6.1  In the event that a Ciba Product or a Chiron Product is developed solely by
       Ciba or solely by Chiron, under the terms of this Agreement, or in the
       event that either party develops a product outside this collaboration
       under licenses granted under this Agreement, the developing party agrees
       to indemnify, defend and hold harmless the non-developing party and its
       Affiliates, and their respective officers, directors, shareholders, and
       employees, from and against all claims, losses, costs, damages and
       liability of any kind, including without limitation attorneys fees,
       (collectively "Liabilities") arising in connection with the development,
       manufacture, use or sale of such product, except for Liabilities arising
       as a result of  breach by the non-developing party of its obligations
       under this Agreement, or any manufacturing, marketing or other agreement
       with respect to the product in question.  The indemnified party shall not
       make any admission of liability nor take any other action which could
       prejudice the defence of such claim or lawsuit by the indemnifying party.

6.2  In the event that a product is co-developed by both parties pursuant to
       this Agreement, each party (the "indemnifying party")  agrees to
       indemnify, defend and hold harmless the other party and its Affiliates,
       and their respective officers, directors, shareholders, and employees,
       (collectively, the "indemnified party"), from and against all Liabilities
       arising from the wilful misconduct, failure to comply with applicable
       law, regulation or government order, or breach of this Agreement, or any
       related agreements, by the indemnifying party in connection with the
       development, manufacture, use or sale of such product.

     In the event that any Liability arises in connection with the development,
       manufacture, use or sale of such a product which is not covered by
       the previous paragraph, the party sued shall be responsible for its own
       defense at its own expense.  Such party shall be entitled to deduct the
       cost of such defense, as well as all damages or other amounts paid in
       settlement or

<PAGE>

                                      -36-

       disposition of such matter, from Net Sales of the product in question
       prior to the allocation of the profits between the parties.

6.3  In all cases, the indemnified party shall promptly notify the indemnifying
       party of receipt of any claim or lawsuit subject to Section 6.1 or 6.2,
       and shall cooperate with the indemnifying party in connection with the
       investigation and defense of such claim or lawsuit.  The indemnifying
       party shall have the right to control the defense, with counsel of its
       choice, provided that the indemnified party shall have the right to be
       represented by advisory counsel at its own expense.  The indemnifying
       party shall not settle or dispose of the matter in any manner which could
       affect the rights or liability of the indemnified party without the
       indemnified party's prior written consent, which shall not be
       unreasonably withheld.

6.4  EXCEPT AS EXPRESSLY STATED IN THIS AGREEMENT, NEITHER PARTY MAKES ANY
       WARRANTY, AND EACH PARTY EXPRESSLY DISCLAIMS ALL DISCLAIMS ALL IMPLIED
       WARRANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
       PARTICULAR PURPOSE, WITH RESPECT TO ANY COMBINATORIAL LIBRARIES OR OTHER
       BIOLOGICAL OR CHEMICAL MATERIALS OR INFORMATION PROVIDED TO THE OTHER
       PARTY PURSUANT TO THIS AGREEMENT.

     Each party acknowledges that all Combinatorial Libraries and other
       biological or chemical materials provided by the other party pursuant to
       this Agreement are experimental and  agrees to take reasonable
       precautions to prevent personal injury, illness and/or property damage
       with respect to its handling and use thereof.


7  PAYMENTS AND ACCOUNTING

7.1  All payments hereunder shall be made in U.S. Dollars.

7.2  Each party shall keep true and correct accounts of sales of all products in
       respect of which royalties are payable to the other party pursuant to
       this Agreement, and the calculation of Net Sales and royalties with
       respect thereto, and shall deliver to the other party written statements
       thereof in such form as both shall agree upon within sixty (60) days
       following the end of each calendar quarter and at the same time shall pay
       to the other party the amount of such royalties shown to be due.

7.3  All royalties shall be earned in the local currency of the country where
       the applicable Net Sales are made, but shall be converted for payment
       into U.S. Dollars, in accordance with the standard procedures used by the
       paying party in converting currencies of worldwide product sales for its
       products generally.

<PAGE>

                                      -37-

     If royalties cannot be remitted from a country, the parties will work
        together to arrive at an equitable solution for paying such royalties
        to the other party.

     Any withholding or other tax that the paying party is required by law to
        withhold and pay on behalf of the other party with respect to the
        royalties payable to the other party under this Agreement shall be
        deducted from said royalties and paid  contemporaneously with the
        remittance to the other party; provided, however, that in regard to
        any tax so deducted, the paying party shall furnish the other party
        with proper evidence of the taxes paid on its behalf.

7.4  Each party shall have the right to have an independent certified public
        accountant of its own selection and at its own expense,
        except one to whom the other party may have reasonable objection,
        examine the relevant books and records of account of the other party
        during reasonable business hours, to determine whether appropriate
        accounting and payment have been made hereunder.  Said independent
        certified public accountant shall treat as confidential, and shall not
        disclose to party requesting the audit, any other information not
        pertaining to the royalty amounts payable under this Agreement.  Such
        examination can be undertaken at any time within two years after the
        date on which such royalty amounts were due and payable.


8    PUBLIC ANNOUNCEMENTS

     The parties will mutually agree on a press release to be issued upon
       execution of this Agreement. Neither party shall make any subsequent 
       public announcement concerning the terms of this Agreement not 
       previously made public without the prior written approval of the other 
       party with regard to the form, content and precise timing of such 
       announcement, except such as may be required to be made by either party 
       in order to comply with applicable law, regulations or court orders.  
       Such consent shall not be unreasonably withheld or delayed by the other 
       party. Prior to any such public announcement, the party wishing to make
       the announcement will submit a draft of the proposed announcement to the
       other party in sufficient time to enable the other party to consider and 
       comment thereon. Nothing in this section shall preclude disclosures by 
       either party to third parties under confidentiality restrictions in 
       order to carry out the purposes of this Agreement or to define the scope
       of rights which may be granted to a third party without violating this 
       Agreement.


9    CONFIDENTIALITY

9.1  Except as specifically authorized under the terms of this Agreement each
       party shall, for the term of this Agreement and for five (5) years after
       its termination for any reason whatsoever, treat any proprietary
       information disclosed to it by the other party as strictly confidential,

<PAGE>

                                      -38-

       and shall not disclose such proprietary information to third parties or
       use it for purposes other than those authorized herein.

     Except as set forth in the exceptions hereinafter any information, data or
       material, including without limitation, software, technology, business
       plans or information, communicated to the other which is identified as
       confidential, or which the other party has reason to believe is
       confidential, will be deemed and treated as Proprietary Information.

     Proprietary Information also includes proprietary chemical, physical or
       biological materials exchanged pursuant to this Agreement. Access to such
       Proprietary Information will be limited to those employees or consultants
       of the party receiving such information or of such party's Affiliates or
       sublicensees, who reasonably require such information in order to carry
       out activities authorized pursuant to this Agreement. Such employees or
       consultants will be advised of the confidential nature of the Proprietary
       Information and the related confidentiality undertaking.

     Proprietary Information shall not include, and the above confidentiality
       undertaking shall in  no event restrict or impair each party's right to
       use or disclose any information which:

     (a)  at the time of disclosure is in the public domain or thereafter
            becomes part of the public through no fault of the party receiving
            such information;

     (b)  the party receiving such information can conclusively establish that
            it was in its possession prior to the time of disclosure;

     (c)  is independently made available to the party receiving such
            information by a third party who is not thereby in violation of a
            confidential relationship with the other party; or

     (d)  the receiving party can establish was independently developed without
            use of the Proprietary Information of the other party.

     The receiving party shall not be restricted from disclosing such
       information as is  required to be disclosed by law, regulation, or court
       or governmental order, provided that the receiving party reasonably
       notifies the disclosing party prior to such disclosure of such
       requirement.

     Upon termination of this Agreement, and provided the Proprietary
       Information is still of a confidential nature, the party recipient of the
       Proprietary Information will upon request from the disclosing party
       either return any such information or destroy the same.

9.2  Information which is developed in the course of the Target Collaboration,
       and which is not within any of the exceptions to Proprietary Information
       set forth in Section 9.1, may be used by the parties outside the Target
       Collaboration as set forth in Article 4.  To the extent

<PAGE>

                                      -39-

       permitted by Article 4, such information may be disclosed to third
       parties, subject to confidentiality obligations not less restrictive than
       those set forth in Section 9.1.

     Neither party will publish or publicly disclose results arising from the
       Target Collaboration without the prior consent of the other party, which
       consent shall not be unreasonably withheld.  Each party agrees to provide
       to the other a copy of any proposed publication or public disclosure of
       such results for review and comment, at least forty-five (45) days prior
       to release for publication or disclosure.


10 TERM AND TERMINATION

10.1 The Target Collaboration shall have the term set forth in Article 4.

10.2 Unless terminated earlier under Section 10.3, this Agreement shall continue
       in full force and effect until the expiration of all annual payment,
       milestone or royalty obligations of either party under Articles 3 and 4,
       and the expiration of all obligations with respect to co-development or
       profit sharing under Article 4.  Upon expiration of this Agreement under
       this Section 10.2, the parties shall each have fully paid-up licenses,
       respectively, under Sections 3.5.1, 3.5.2, 4.7.1(b) and 4.7.2(b) and (c);
       and the provisions identified in Section 10.3(e) shall survive expiration
       hereof.

10.3 (a)  In the event of material breach of this Agreement by either party,
            which is not cured within sixty (60) days following receipt of
            written notice of the alleged default from the non-breaching party,
            the matter shall be submitted for resolution to the chief executive
            officers of each party.

     (b)  The parties acknowledge that under this Agreement, each party holds a
            complex series of ongoing technology rights and licenses,
            development rights and obligations, and economic rights and
            obligations, the breach of which may not be adequately compensated
            in monetary damages alone.  The parties therefore agree that each
            may be entitled to remedies in the nature of specific performance of
            the obligations of the other.

     (c)  Each party further waives the right to terminate this Agreement in its
            entirety in the event of breach by the other party, except
            in the event that termination (i) is mutually agreed upon by the
            parties, or (ii) is ordered by a court of competent jurisdiction,
            after consideration of all relevant rights and obligations of the
            parties under the Agreement, and the rights and remedies of the non-
            breaching party in law or equity,  including, without limitation,
            the extent to which the non-breaching party can be adequately
            protected through remedies other than complete termination of the
            Agreement.

<PAGE>

                                      -40-

     (d)  In the event of termination of this Agreement pursuant to this Section
            10.3, unless otherwise specifically agreed or ordered
            pursuant thereto, the following provisions shall survive
            termination, together with any and all rights and obligations
            accrued prior to the date of termination:

          (i)   To the extent Ciba has paid in full all of its obligations under
                    Article 3: Section 3.5.1;

          (ii)  To the extent applicable to any development candidates or
                    products which remain under development
                    or commercialization by either party following such
                    termination: Sections 4.3, 4.7.1(b), 4.7.2(b) and (c), and
                    7; and

          (iii) In addition to those set forth in Section 10.3(d)(i) or (ii),
                    the following Sections shall survive any early termination
                    of this Agreement: 3.5.2 and the provisions identified in
                    Section 10.3(e) below.

     (e)  The following provisions shall survive any expiration or early
            termination of this Agreement, together with any other obligations
            of either party which have accrued as of the effective date of
            termination or expiration: Sections 3.4, 3.5.3, 4.2.7, 4.2.10,
            4.2.11, 4.4, 4.5, 4.6, 4.8, and Articles 5, 6, 8, 9, 10 and 11.

10.4 All licenses granted under this Agreement are deemed to be, for purposes of
          Section 365(n) of the U.S. Bankruptcy Code, licenses of right to
          "intellectual property" as defined in Section 101 of such Code.  The
          parties agree that the licensee may fully exercise all of its rights
          and elections under the Bankruptcy Code.  The parties further agree
          that, in the event a licensee elects to retain its rights as a
          licensee under such Code, the licensee shall be entitled to complete
          access to any technology licensed to it hereunder and all embodiments
          of such technology.  Such embodiments of the technology shall be
          delivered to the licensee not later than (a) the commencement of
          bankruptcy proceedings against the licensor, upon written request,
          unless the licensor elects to perform its obligations under this
          Agreement, or (b) if not delivered under (a) above,  upon the
          rejection of this Agreement by or on behalf of the licensor, upon
          written request.

10.5 IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER FOR LOST PROFITS OR
          ANY CONSEQUENTIAL, INCIDENTAL OR INDIRECT DAMAGES TO THE OTHER PARTY,
          HOWEVER CAUSED, IN CONNECTION WITH THIS AGREEMENT; PROVIDED THAT
          NOTHING IN THIS SECTION 10.5 SHALL LIMIT THE INDEMNIFICATION
          OBLIGATIONS OF EITHER PARTY PURSUANT TO ARTICLE 6 AS TO CONSEQUENTIAL,
          INCIDENTAL OR INDIRECT DAMAGES TO THIRD PARTIES FOR WHICH THE
          INDEMNITEE MAY BE LIABLE.

<PAGE>

                                      -41-


11   MISCELLANEOUS

11.1 Neither party shall have the right to assign its rights or obligations
       under this Agreement to any third party other than an Affiliate of such
       party without the prior written consent of the other party, which consent
       shall not be unreasonably withheld.  This Agreement shall be binding on,
       and inure to the benefit of, the permitted successors and assigns of the
       parties.

11.2 Pursuant to this Agreement, each party has certain rights to grant
       sublicenses  hereunder to Affiliates and, in some cases, to third
       parties.  In addition, it is contemplated that each party may wish to
       involve one or more of its Affiliates in research and development
       activities conducted by such party pursuant to this Agreement.

   (i)    Neither party shall transfer or disclose to any of its Affiliates (a)
            any Proprietary Information of the other party, including,
            without limitation, technology, improvements, Combinatorial
            Libraries, or other chemical or biological materials, or (b) any
            Joint Combinatorial Libraries, or (c) any data or information with
            respect to, or arising from, any of the foregoing;   unless such
            Affiliate has agreed in writing to be bound by all of the terms and
            conditions of this Agreement as though the Affiliate were a party
            hereto.

   (ii)   All permitted sublicenses and/or assignments by either party of any of
            its rights under this Agreement shall be subject to all of the
            terms and conditions of this Agreement, which shall be binding on
            the sublicensees and/or assignees.

11.3 The parties hereto are independent contractors.  Nothing contained herein
       shall constitute either party the agent of the other party for any
       purpose whatsoever, or constitute the parties as partners or joint
       venturers.  Employees of each party remain employees of said party and
       shall be considered at no time agents of or render a fiduciary duty to
       the other party.  Neither party hereto shall have any implied right or
       authority to assume or create any obligations on behalf of or in the name
       of the other party or to bind the other party to any other contract,
       agreement or undertaking with any third party.

11.4 No amendment, waiver or modification of this Agreement shall be valid or
       binding on either party unless made in writing signed by both parties.
       The failure of either party to enforce any provision of this Agreement at
       any time shall not be construed as a present or future waiver of such or
       any other provision of this Agreement.  The express waiver by either
       party of any provision or requirement hereunder shall not operate as a
       future waiver of such or any other provision or requirement.

<PAGE>

                                      -42-

11.5  In the event that any provision in this Agreement shall be held to be
        unlawful or invalid in any jurisdiction, the meaning of such provision
        shall be construed to the greatest extent possible so as to render it
        enforceable.  If no such construction can render such provision
        enforceable, it shall be severed, and the remainder of the Agreement
        shall remain in full force and effect, only to the extent that such
        remainder is consistent with the intentions of the parties as evidenced
        by this Agreement as a whole.  The parties shall use best efforts to
        negotiate in good faith a reasonable substitute, valid and enforceable
        provision effective in such jurisdiction.

11.6  Any notice required or permitted to be given by either party under this
        Agreement shall be in writing, addressed, in the case of Chiron, to its
        Chief Executive Officer, with copy to its General Counsel, and in the
        case of Ciba, to its head of the Pharma Division, with copy to its
        General Counsel, at the respective addresses of the parties shown in 
        the first paragraph of this Agreement, or such other address as may 
        from time to time by indicated in a notice given under this Section 
        11.5.  All notices shall be sent by certified or registered first class
        mail, telefax confirmed by certified or registered first class mail, or
        personal delivery, and shall be effective on receipt at the address
        referenced above.

11.7  Neither party will be deemed in breach of this Agreement as a result of
        default, delay or failure to perform by such party which is due to 
        causes beyond the reasonable control of such party, including without
        limitation, fire, earthquake, acts of God, severe weather, acts of war,
        strikes, lockouts or other labor disputes, riots, civil disturbances,
        actions or inactions of governmental authorities (except in response to
        a breach by such party), or epidemics.  In the event of any such force
        majeure, the party affected shall promptly notify the other party, shall
        use all reasonable efforts to overcome such force majeure, and shall 
        keep the other party informed with respect thereto.

11.8  All headings and captions used in this Agreement are for convenience 
        only, and are not intended to have substantive effect.

11.9  This Agreement may be executed by the parties in one or more identical
        counterparts, all of which together shall constitute this Agreement.

11.10 This Agreement shall be governed by and construed in accordance with
        the laws of the State of New York.

11.11 This Agreement constitutes the entire agreement of the parties with
        respect to the subject matter hereof, and supersedes all previous
        agreements, understandings and negotiations, whether oral or 
        written, with respect to such subject matter.

<PAGE>

                                      -43-

Executed and effective as of the date first set forth above.


CIBA-GEIGY Limited

By: R. Paioni                     By: R.E. Walker
   -------------------------          ---------------------------

Title: Head of Pharma Licensing   Title: Division Counsel
      -------------------------         -------------------------

CHIRON CORPORATION

By: Walter Moos
    ---------------------------
Title: Vice President
      -------------------------

<PAGE>

                                      -44-

                                    EXHIBIT A
                          THIRD PARTY EXCLUDED TARGETS
                                     1 page
                         [CONFIDENTIAL TREATMENT REQUESTED]


                                   EXHIBIT B
                               CHIRON TECHNOLOGY
                                    17 pages
                         [CONFIDENTIAL TREATMENT REQUESTED]

                                    EXHIBIT C
                     CHIRON COMBINATORIAL CHEMISTRY PATENTS
                                     2 pages
                         [CONFIDENTIAL TREATMENT REQUESTED]

                                    EXHIBIT D
                               RESTRICTED TARGETS
                                     1 page
                         [CONFIDENTIAL TREATMENT REQUESTED]

                                    EXHIBIT E
                             PROHIBITED INDICATIONS
                                     1 page
                         [CONFIDENTIAL TREATMENT REQUESTED]



<PAGE>

                                 PROMISSORY NOTE

                             as Amended and Restated


$50,760,000                                                   New York, New York
                                                                 January 1, 1995


          FOR VALUE RECEIVED, the undersigned, CIBA CORNING DIAGNOSTICS CORP., a
Delaware corporation ("DIAGNOSTICS"), hereby promises to pay to the order of
CIBA-GEIGY LIMITED, a Swiss Corporation ("CIBA"), an amount equal to Fifty
million seven hundred sixty thousand Dollars ($50,760,000).  The entire
principal amount outstanding on this Note shall be repaid on January 1, 2000 (or
if such date is not a Business Day on the next succeeding Business Day).
Interest shall be payable on the same date as the principal amount, as provided
above, at an interest rate determined in accordance with the next paragraph of
this Note on the outstanding balance of the Note (computed on the basis of the
actual number of days principal is outstanding from and including the date
hereof, to but excluding the date of repayment, in a year of 365 days) and
compounded on a semi-annual basis.  All payments shall be made in lawful money
of the United States of America in immediately available funds to Ciba at Swiss
Bank Corporation, New York, NY, Account Number 0-452-702625-00 or such other
account as Ciba may designate in writing.  Payments received for value after
3:00 p.m., New York City time, shall be treated as being received on the next
succeeding Business Day.

          During the period that (i) there are loans outstanding under the
credit facility (the "CREDIT FACILITY") referred to in Section 5.12 of the
Investment Agreement dated as of November 20, 1994, among Ciba, Ciba-Geigy
Corporation, a New York corporation, CIBA Biotech Partnership Inc., a Delaware
corporation, and Chiron Corporation, a Delaware corporation ("CHIRON"), the
interest rate per annum on the outstanding balance of this Note shall be the
weighted average interest rate per annum for all outstanding loans to Chiron
under the Credit Facility and the interest rate hereunder shall be adjusted from
time to time simultaneously with any adjustment of such interest rate under the
Credit Facility and (ii) there are no loans outstanding under the Credit
Facility, the interest rate per annum on the outstanding balance of this Note
shall be a floating rate at all times during each calendar quarter during such
period equal to LIBOR plus 0.20%.  During such

<PAGE>

                                                                               2

times that the interest rate is determined in accordance with clause (i) of the
preceding sentence, Diagnostics shall notify Ciba in writing within 30 Business
Days of the end of each calendar quarter (or, with respect to the last calendar
quarter prior to the maturity of this Note, by the end of such calendar quarter)
of the information necessary to determine such interest rate and, promptly
thereafter, Ciba shall advise Diagnostics in writing of its determination of
such interest rate, and Ciba's determination thereof shall be final absent
manifest error.  During such times that the interest rate is determined in
accordance with clause (ii) of the preceding sentence, Ciba, on the first
business Day of each calendar quarter, shall advise Diagnostics in writing of
its determination of such interest rate (including any resetting thereof in
accordance with the definition of LIBOR), and Ciba's determination thereof shall
be final absent manifest error.

          Time shall be of the essence with regard to the repayment to Ciba of
all sums due and payable under this Note.

          Diagnostics promises to pay interest, on demand, on any overdue
principal and, to the extent permitted by law, overdue interest from their due
date at the rate of 10% per annum, compounded quarterly (the "DEFAULT RATE").
Diagnostics also agrees to pay on demand all costs and expenses of collecting
and enforcing this Note incurred by Ciba or any assignee.  Such costs and
expenses include, without limitation, reasonable costs of counsel.  Interest
shall accrue on unpaid costs and expenses from the date of demand to the date
of payment at the Default Rate.

          Anything herein to the contrary notwithstanding, if during any period
for which interest in computed hereunder, the amount of interest computed on the
basis provided for in this Note, together with all fees, charges and other
payments which are treated as interest under applicable law, as provided for
herein or in any other document executed in connection herewith, would exceed
the amount of such interest computed on the basis of the Highest Lawful Rate (as
defined below), Diagnostics shall not be obligated to pay, and Ciba shall not be
entitled to charge, collect, receive, reserve or take, interest in excess of the
Highest Lawful Rate, and during any such period the interest payable hereunder
shall be computed on the basis of the Highest Lawful Rate.  As used herein,
"HIGHEST LAWFUL RATE" means the maximum non-usurious rate of interest, as in
effect from time to time, which may be charged, contracted

<PAGE>

                                                                               3

for, reserved, received or collected by Ciba in connection with this Note under
applicable law.

          Capitalized terms appearing in this Note if not defined in the
operative paragraph hereof are defined in the DEFINITIONS section appearing at
the end of this Note.

          Diagnostics has the right at any time and from time to time to prepay
principal and any accrued unpaid interest thereon, in whole or in part, upon at
least five day's prior written or telecopy notice (or telephone notice promptly
confirmed by written or telecopy notice) to Ciba with a copy to Swiss Bank
Corporation.  Any such prepayments shall be applied, first, against any accrued
unpaid interest then outstanding under the Note and, second, against the
principal amount then outstanding under the Note as of the date of such
prepayment.  Prepayment of any amount of the principal of or interest on this
Note shall in no way extend the date of maturity.  Such amounts prepaid may not
be reborrowed.

          Diagnostics hereby waives diligence, presentment, demand, protest and
notice of any kind whatsoever.  The nonexercise by the holder or assignee of any
of its rights hereunder in any particular instance shall not constitute a waiver
thereof in that or any subsequent instance.

          The payment and any prepayments of the principal hereof and interest
hereon and the respective dates thereof shall be endorsed by the holder hereof
on the schedule attached hereto and made a part hereof or on a continuation
thereof which shall be attached hereto and made a part hereof, or otherwise
recorded by such holder in its internal records; PROVIDED, HOWEVER, that the
failure of the holder hereof to make such a notation or any error in such
notation shall not affect the obligations or Diagnostics under this Note.

COVENANTS

          Diagnostics covenants and agrees with Ciba that, so long as any
principal or interest under this Note (or cost or expense of collecting or
enforcing this Note) shall be unpaid, unless (i) Chiron agrees to guarantee the
principal and interest payable under this Note pursuant to an agreement
satisfactory in form and substance to Ciba or (ii) Ciba shall otherwise consent
in writing, Diagnostics

<PAGE>

                                                                               4

will not, and will not cause or permit any of its subsidiaries to:

          (a) Create, incur, assume or permit to exist any Lien on any property
     or assets (including stock or other securities of any person, including any
     subsidiary) now owned or hereafter acquired by it or on any income or
     revenues or rights in respect of any thereof, (x) except to the extent the
     obligations of Diagnostics under this Note are equally and ratably secured
     by such property or assets pursuant to documentation in form and substance
     reasonably satisfactory to Ciba and (y) except:

                 (i) Liens on property or assets of Diagnostics and its
          subsidiaries existing on the date hereof; PROVIDED that such Liens
          shall secure only those obligations which they secure on the date
          hereof;

                (ii) any Lien existing on any property or asset prior to the
          acquisition thereof by Diagnostics or any subsidiary; PROVIDED that
          (x) such Lien is not created in contemplation of or in connection with
          such acquisition and (y) such Lien does not apply to any other
          property or assets of Diagnostics or any subsidiary;

               (iii) Liens for taxes not yet due or which are being contested;

                (iv) carriers', warehousemen's, mechanic's, materialmen's,
          repairmen's or other like Liens arising in the ordinary course of
          business and securing obligations that are not due or which are being
          contested;

                 (v) pledges and deposits made in the ordinary course of
          business in compliance with workmen's compensation, unemployment
          insurance and other social security laws or regulations;

                (vi) deposits to secure the performance of bids, trade contracts
          (other than for Indebtedness), leases (other than capital lease
          obligations), statutory obligations, surety and appeal bonds,
          performance bonds and other obligations of a like nature incurred in
          the ordinary course of business;

<PAGE>

                                                                               5

               (vii) zoning restrictions, easements, rights-of-way, restrictions
          on use of real property and other similar encumbrances incurred in the
          ordinary course of business which, in the aggregate, are not
          substantial in amount and do not materially detract from the value of
          the property subject thereto or interfere with the ordinary conduct of
          the business of Diagnostics or any of its subsidiaries;

              (viii) purchase money security interests in real property,
          improvements thereto or tangible personal property hereafter acquired
          (or, in the case of improvements, constructed) by Diagnostics or any
          subsidiary; PROVIDED that (A) such security interests are incurred,
          and the Indebtedness secured thereby is created, within 90 days after
          such acquisition (or construction), (B) the Indebtedness secured
          thereby does not exceed 100% of the lesser of the cost or the fair
          market value of such real property, improvements or equipment at the
          time of such acquisition (or construction) and (C) such security
          interests do not apply to any other property or assets of Diagnostics
          or any of its subsidiaries;

                (ix) Liens on any property or assets of Diagnostics' foreign
          subsidiaries; PROVIDED, that Diagnostics and its U.S. subsidiaries
          shall not transfer property or assets to Diagnostics' foreign
          subsidiaries for the purpose of avoiding the prohibition of this
          paragraph (a);

                 (x) judgment Liens, if, within 60 days after the entry thereof,
          the judgment secured thereby shall have been discharged, vacated,
          reversed or execution thereof shall have been stayed pending appeal,
          or shall have been discharged, vacated or reversed within 60 days
          after expiration of any such stay;

                (xi) Liens to secure indebtedness from time to time outstanding;
          PROVIDED, that any such indebtedness secured by Liens which are not
          otherwise permitted by clauses (i) through (x) above or clause (xii)
          below does not exceed $25 million in the aggregate; and

<PAGE>

                                                                               6

               (xii) extensions, renewals and replacements of Liens permitted
          under clauses (i) through (xi) above, PROVIDED, that any such
          extension, renewal or replacement Lien shall be limited to the
          property encumbered by the Lien extended, renewed or replaced and 
          the principal amount of indebtedness secured by any such extension, 
          renewal or replaacement Lien shall not exceed the principal amount 
          of the indebtedness secured by the Lien extended, renewed or replaced
          which is outstanding at the time of such extension, renewal or
          replacement.

          (b)  Cause, through any action or otherwise (including the declaration
     or making of any dividend or distribution with respect to its capital stock
     or through the transfer or disposition of any assets), other than through
     the operation of their businesses in the ordinary course, the consolidated
     shareholders' equity of Diagnostics and its consolidated subsidiaries at
     any time to be less than the greater of (A) $84 million and (B) the sum of
     X minus Y minus Z, where X equals $135 million, Y equals the amount of any
     purchase accounting adjustments to Diagnostics' consolidated shareholders'
     equity arising out of the transactions contemplated by the Investment
     Agreement, and Z equals the amount of any reductions in Diagnostics'
     consolidated shareholders' equity arising out of any agreement with Ciba by
     Chiron to assume sponsorship of or any liability under any defined benefit
     pension plan or any supplemental retirement plan covering employees of
     Diagnostics or its subsidiaries (all as determined in accordance with U.S.
     generally accepted accounting principles consistently applied).

<PAGE>

                                                                               7

EVENTS OF DEFAULT

          In case of the happening of any of the following events ("EVENTS OF
     DEFAULT"):

          (a) Chiron or Diagnostics shall assert, or a court of competent
     jurisdiction shall determine pursuant to a final, nonappealable judgment,
     that this Note (subject to applicable bankruptcy, insolvency, fraudulent
     transfer, reorganization, moratorium and other laws affecting creditors'
     rights generally) shall not be enforceable in accordance with its terms;

          (b) a failure to perform or observe any term, covenant or agreement
     contained above under the caption "COVENANTS" in this Note, which failure
     is not cured within 30 days of such failure;

          (c) a failure to perform or observe any term, covenant or agreement
     contained in this Note (other than those referred to in the preceding
     clause (b)), which failure is not cured within 30 days of receipt by
     Diagnostics of notice of such default;

          (d) an involuntary proceeding shall be commenced or an involuntary
     petition shall be filed in a court of competent jurisdiction seeking (i)
     relief in respect of Chiron, Diagnostics or any of their Significant U.S.
     Subsidiaries, or of a substantial part of the property or assets of Chiron,
     Diagnostics or any of their Significant U.S. Subsidiaries, under Title 11
     of the United States Code, as now constituted or hereafter amended, or any
     other Federal or state bankruptcy, insolvency, receivership or similar law,
     (ii) the appointment of a receiver, trustee, custodian, sequestrator,
     conservator or similar official for Chiron, Diagnostics or any of their
     Significant U.S. Subsidiaries or for a substantial part of the property or
     assets of Chiron, Diagnostics or any of their Significant U.S.
     Subsidiaries, or (iii) the winding-up or liquidation of chiron, 
     Diagnostics or any of their significant U.S. Subidiaries, and such 
     proceeding  or petition is not dismissed within 60 days or an order 
     for relief is entered against Diagnostics, Chiron or such Significant 
     U.S. Subsidiary, as applicable;

          (e) Chiron or its subsidiaries (except Diagnostics and its
     subsidiaries) shall fail collectively to own

<PAGE>

                                                                               8

     more than 50% of the voting stock of Diagnostics or any successor entity;
     and

          (f) Chiron, Diagnostics or any of their Significant U.S. Subsidiaries
     shall (i) voluntarily commence any proceeding or file any petition seeking
     relief under Title 11 of the United States Code, as now constituted or
     hereafter amended, or any other Federal or state bankruptcy, insolvency,
     receivership or similar law, (ii) consent to the institution of, or fail to
     contest in a timely and appropriate manner, any proceeding or the filing of
     any petition described in (d) above, (iii) apply for or consent to the
     appointment of a receiver, trustee, custodian, sequestrator, conservator or
     similar official for Chiron, Diagnostics or any of their Significant U.S.
     Subsidiaries or for a substantial part of the property or assets of Chiron,
     Diagnostics or any of their Significant U.S. Subsidiaries, (iv) file an
     answer admitting the material allegations of a petition filed against it in
     any such proceeding, (v) make a general assignment for the benefit of
     creditors, (vi) become unable, admit in writing its inability or fail
     generally to pay its debts as they become due or (vii) take any action for
     the purpose of effecting any of the foregoing;

then, and in every such event (other than an event with respect to Chiron,
Diagnostics or any of their Significant U.S. Subsidiaries described in paragraph
(d) or (f) above), and at any time thereafter during the continuance of such
event, Ciba may, by notice to Diagnostics, take the following action:  declare
any and all principal or interest (and any other amounts) then outstanding to be
forthwith due and payable in whole or in part, whereupon the principal of this
Note so declared to be due and payable, together with accrued interest thereon
(and any other amounts), shall become forthwith due and payable, without
presentment, demand, protest or any other notice of any kind, all of which are
hereby expressly waived by Diagnostics, anything contained herein to the
contrary notwithstanding; and in any event with respect to Diagnostics described
in paragraph (d) or (f) above, the principal then outstanding, together with
accrued interest thereon (and any other amounts), shall automatically become due
and payable, without presentment, demand, protest or any other notice of any
kind, all of which are expressly waived by Diagnostics, anything contained
herein to the contrary notwithstanding.

<PAGE>

                                                                               9

DEFINITIONS

          "BUSINESS DAY" shall mean any day (other than a day which is a
Saturday, Sunday or legal holiday in the State of New York) on which banks are
open for business in New York City.

          "LIBOR" shall mean, with respect to any calendar quarter, the
arithmetic mean of the offered rates for deposits in U.S. dollars for a
principal amount closest to the principal amount outstanding at such time under
this Note for a period of 90 days which appear on the Reuters Screen LIBO Page
(on the Reuter Monitor Money Rate Service) as of 11:00 a.m., London time, on the
day that is two London banking days prior to the commencement of such calendar
quarter.

          "LIEN" shall mean, with respect to any asset, any mortgage, lien,
pledge, charge, security interest or encumbrance of any kind in respect of such
asset.  For the purposes of this Note, Diagnostics or any subsidiary of
Diagnostics shall be deemed to own subject to a Lien any asset which it has
acquired or holds subject to the interest of a vendor or lessor under any
conditional sale agreement, capital lease or other title retention agreement
relating to such asset.

          "SIGNIFICANT U.S. SUBSIDIARY" shall mean, with respect to any person,
any subsidiary of such person that constitutes a significant subsidiary within
the meaning of Rule 1-02 of Regulation S-X promulgated by the Securities and
Exchange Commission and that is a U.S. subsidiary of such person.

          This note has been amended and restated in the form hereof in order to
adjust the principal amount hereof.  Notwithstanding such amendment and
restatement, this Note is made on and as of the date first above written and all
references in this Note to its date shall refer to such above written date.

<PAGE>

                                                                              10

          This Note shall be construed in accordance with and governed by the
laws of the State of New York.


                                             CIBA CORNING DIAGNOSTICS
                                             CORP.,



                                             by  Robert L. Sullivan
                                                 ----------------------
                                                 Name:  Robert L. Sullivan
                                                 Title: Senior Vice President

<PAGE>

                                                                              11

                                    Payments
                                    --------

Payments                 Payments                           Name of Person
of                       of                                 Making
Principal                Interest            Date           Notation
- ---------                --------            ----           --------



<PAGE>

                                                                Exhibit 10.84

[BENEMANN TRANSLATION CENTER LETTERHEAD]



[Translator's note: the bottom of every page of the Lease is initialed by both
parties.]

                                   COMMERCIAL LEASE


BETWEEN THE UNDERSIGNED:

DOMILYON CORPORATION, with FRF 15,000,000 in assets, which became a private
corporation on October 19, 1992,

headquartered at 321 avenue Jean Jaures, LYON 69007, LYON Trade and Company
Register registration number D 348 447 285,

Represented by Mr. Jean-Michel BONABOSCH, acting in his capacity as Director

                                                  Hereinafter "Landlord"
                                                    ON THE ONE HAND

AND

"DOMILENS LABORATORIES" corporation, with FRF 43,500,000 in assets,

headquartered at 321 avenue Jean Jaures, LYON 69007, LYON Trade and Company
Register registration number B 327 032 629,

Represented by Mr. Francois PERRARD, its Chief Executive Officer, specially
authorized to negotiate and sign this document,

                                                  Hereinafter "Tenant"
                                                    ON THE OTHER HAND


GIVEN THE FOLLOWING:

By private agreement dated January 2, 1990, DOMILYON Corporation leased DOMILENS
Corporation the premises discussed in this lease and which shall be described
hereafter. Given that extensive alterations have been carried out, the parties
have agreed to cancel this lease prior to its termination date and to enter into
a new one, the terms of which follow:


                                         -1-

<PAGE>


THE PARTIES HAVE AGREED UPON THE FOLLOWING:

CHAPTER 1 - GENERAL CONTRACT TERMS

*ARTICLE 1 - PURPOSE OF LEASE AND DESCRIPTION OF PREMISES

Landlord leases to Tenant, who agrees to use the premises referred to in the
"specific terms".

*ARTICLE 2 - STARTING DATE AND TERM OF LEASE

This Lease shall take effect on the date indicated in the "specific terms".

*ARTICLE 3 - INVENTORY OF PREMISES

Tenant, having previously occupied the leased premises, hereby admits knowledge
of said premises and exempts Landlord from providing a more detailed description
than that appearing in the "specific terms". Tenant accepts the premises "as
is", without the possibility of demanding any repairs or improvements.

By way of clarification, any difference between the measurements and surfaces
mentioned in this Lease or from diagrams that might be attached, and the real
dimensions of the premises, shall not justify a reduction or increase of rent,
as the parties refer to the existing "as is" condition of the premises.

If the leased premises are located in a building which has just been
constructed, Tenant shall bear the inconveniences arising from poor workmanship
and other inherent defects, even, as the case may arise, those resulting from
construction on the entire building in which they may be located, without the
possibility of claiming any compensation or rent reduction from Landlord.

Tenant agrees to allow free access to its premises to companies responsible for
performing work necessary to remedy complaints, as well as to repair problems
that might be noticed in the future.

An inventory of the premises shall be drawn up between both parties, at the
expense of Tenant within a maximum of fifteen days of Tenant's entering the
premises. Failing this, the premises shall be considered to have been leased in
perfect condition.

- --------------------------------------------------------------------------------
[N.B. It is mandatory that articles marked with an asterisk (*) be completed in
the specific terms (chapter II).]


                                         -2-

<PAGE>


*ARTICLE 4 - TERMS OF LEASE

1) USE AND ENJOYMENT

*The premises must be occupied exclusively for the use and purpose envisioned in
the "specific terms".

Tenant shall use the premises peacefully and in such a way not to disturb the
peace of neighbors and third parties.

Tenant must personally occupy the leased premises and may not assign possession
to anyone, in any manner, even temporarily, or free of charge or precariously.

If the leased premises are a part of a whole divided into parcels or a jointly
owned property, or a regulated zone, or constitute only a subparcel of a whole
belonging to Landlord or of a whole divided into subparcels, Tenant agrees to
respect the provisions of the "conditions of contract", the zoning regulations,
the rules of the property owners' association, the regulations of the jointly
owned property, by-laws, or any and all covenants involving the leased premises
and mentioned in the specific terms.

This Lease does not contain any guaranty of exclusivity or non-competition by
Landlord, who reserves the right to lease any premises for the exercise of any
activities similar or identical to those of Tenant.

2) SAFETY REGULATIONS

Tenant must take care to respect the administrative regulations and safety rules
pertaining to the category of building containing the leased premises.
Notwithstanding Civil Code article 1721 Landlord assumes no duty to guaranty.

3) ADMINISTRATIVE AUTHORIZATIONS

Tenant shall be personally responsible for securing all authorizations stemming
from the legislative, statutory (notably Town Planning Code, articles L 510.1
and R 510.1 ET SEQ, if the premises are located in the Paris region),
administrative or other rules, concerning the use of the leased premises and, as
the case may arise, their use by the public. Tenant may in no way disturb or
pursue Landlord in this connection. Tenant must satisfy all the formalities and
pay all costs which might prove necessary to the pursuit of its activity and
consequently release Landlord from any liability that might ensue in this
connection.


                                         -3-

<PAGE>


4) SUBLETTING AND ASSIGNMENT

a) SUBLETTING

Any partial or total sub-letting is prohibited.

b) ASSIGNMENT

Tenant may not assign in any way its interest in this Lease without the previous
written consent of Landlord, except to a party acquiring Tenant's company.

In any case, Tenant shall remain joint guarantor of the successive sublessor(s),
as much for the payment of rent and incidentals as for the fulfillment of any
clauses  or terms of the Lease, without the possibility of protest or the
benefit discussion or division.

Subletting may occur only by a deed executed and authenticated by Landlord's
notary; Landlord must be notified by registered letter with return receipt
requested to participate in this deed. Landlord shall be sent an enforceable
copy of this deed at no cost to Landlord.

5) DUTY TO FURNISH AND DEVELOP THE PREMISES

Tenant must constantly and at all times furnish the premises with enough
equipment and furniture of sufficient quantity and value to cover payment of
rent and performance of the terms of this Lease. Tenant must use the premises
effectively and without interruption for the activity outlined below.

6) CONSTRUCTION WORK

a) REPAIR AND MAINTENANCE WORK

Tenant shall be responsible not only for rental repairs and minor maintenance
(Civil Code, art. 1720, paragraph 2 and art. 1754, paragraph 1), but also for
any type of repairs, including major repairs defined by Civil Code article 606,
regardless of their extent and regardless of the cause of the deterioration
(fault or defect of construction, dilapidation, etc....), even in the case of
force majeure. This applies to both the building itself as well as to its
equipment.


                                         -4-

<PAGE>


Tenant must immediately notify Landlord with written confirmation of all repairs
incumbent upon Landlord, as well as of all deterioration, damages or accidents
befalling the leased premises or caused by them, under penalty of being held
liable for the consequences that might result from Tenant's silence or delay.
Tenant has a duty, as the case may arise, to notify the Landlord of poor
workmanship, faults or defects affecting the buildings, for the purpose of
executing biennial or decennial guaranties.

Tenant, at its expense, immediately must eliminate all rodents and other
parasites that might appear in the leased premises. Tenant must take all the
necessary protective measures against frost.

Upon Tenant's departure, Tenant, at its expense, must prove, by an inventory of
the premises drawn up between both parties, that the premises are in an
excellent condition of upkeep and repair of any kind in accordance with the
above stipulations. Failing this, Tenant must pay Landlord the cost of necessary
restoration work. This amount shall not be covered by the deposit hereinafter
discussed.

b) IMPROVEMENTS AND ALTERATIONS

Tenant may not make any alterations, or add installations or fixtures, which
would affect the basic structure or modify the interior layout of the leased
premises without Landlord's previous written authorization. Landlord may require
the supervision of his architect whose fees shall be paid by Tenant.

The diagrams and descriptions of alterations, installations, or fixtures planned
by Tenant must be attached to the request for authorization.

Upon Tenant's departure, all alterations, installation, improvements and
additions that Tenant may have effectuated shall become, by accession and
without compensation, the property of Landlord, unless Landlord prefers to
request the restoration of the premises to their original condition exclusively
at Tenant's expense, even if Landlord authorized the changes.

c) ALTERATIONS IMPOSED BY REGULATIONS

Tenant furthermore shall be responsible for all work, regardless of cost,
imposed in the building by either legislative or regulatory rules or by
administrative injunctions, especially all work involving health and safety,
even in the event of force majeure.

Tenant waives recourse in such an event to Civil Code, articles 1755, 1719,
paragraphs 2 and 3 and 1720.


                                         -5-

<PAGE>


d) RULES PERTAINING TO CONSTRUCTION WORK

In the case of default by Tenant, Landlord may arrange for completion of
construction work described in a) and c). Tenant shall reimburse the cost of
this work upon Landlord's first request.

Tenant is solely responsible for performance for all construction work described
in paragraphs a), b) and c) above. Tenant shall have no claim against Landlord.
Tenant shall secure all administrative or other authorizations and subscribe to
any insurance policies which prove necessary, in particular, legally required
policies. Tenant shall require that these companies offer sufficient coverage
for Tenant's professional, contractual, ex delicto and quasi ex delicto
responsibilities.

Tenant may not request any reduction in rent or contract cancellation,
regardless of the duration and extent of construction work, whether the work is
performed by Tenant or Landlord, and in the latter case expressly
notwithstanding Civil Code article 1724.

If the leased premises are a part of a jointly owned property or constitute only
a subparcel of a building belonging to Landlord, the Tenant's duties to perform,
listed above, involve only construction work relating to the Tenant's leased
subparcels.

Regarding construction work on common areas, decided upon and carried out by the
property owners' association or Landlord, Tenant shall have to reimburse
Landlord its share of expenditures corresponding to the leased premises.

*7) SIGNS

The posting of /[handwritten] additional [signature]/ outdoor signs or of
billboards is prohibited without Landlord's advance written approval, which is
indicated, in this Lease, in the "specific terms". Tenant must conform to
Landlord's regulations in the case that Tenant wishes to post any inscription or
indications of its business name or purpose in the common areas of the building.

8) LIABILITIES AND CLAIMS

Tenant may make no request for a rent reduction, nor may Tenant have any claim
against Landlord:

- -    in the event of interruption or of poor functioning of the various building
     services.

- -    in the event of theft, looting, damages or other illegal acts committed in
     the leased premises. In particular, Landlord does not assume any obligation
     to provide surveillance.


                                         -6-

<PAGE>


Tenant waives any claim against Landlord for prevention of enjoyment due to
third parties, and is personally responsible for actions taken against third
parties. The Tenant shall exercise Landlord's rights to prosecute in these
circumstances.

9) INSURANCE

a) Tenant, at its expense, must obtain and maintain, for the entire term of this
Lease, for its furniture, equipment, windows, fixtures, and installations,
insurance against risk of fire, explosions, flooding, and claims from neighbors
and third parties, acts of malevolence, terrorism, sabotage, riots and popular
uprisings.

b) Tenant, at its expense, must also, as occupant, insure its civil liability
for all bodily or material damages, which might be caused to third parties, due
to Tenant's occupation of the premises, due to its employees or agents, or due
to the existence or use of its fixtures and installations.

c) Additionally, Tenant's insurance policies must provide that their
cancellation may not take effect until fifteen days after the insurer provides
notice to Landlord. Tenant waives and shall have its insurance company waive any
claim against Landlord.

d) Tenant shall tender to Landlord, at Landlord's first request, proof that the
above-discussed policies have been signed and that the corresponding premiums
have been paid.

It is expressly agreed that any payments due to Tenant by all insurance
companies in the event of an accident, regardless of cause, shall be assigned to
Landlord, as needed, up to the amounts which may be due.

e) Landlord shall be personally responsible for insuring the building at normal
market rates, but Tenant shall reimburse Landlord's premiums.

10) LEVIES AND TAXES

Tenant must pay all charges imposed by the city, police and garbage collections
services that are normally charged to tenants, in such a way that Landlord shall
not be disturbed in this connection. In particular, Tenant must pay the
professional tax and all levies incumbent upon Tenant but for which Landlord is
or might be held responsible in any way. Tenant must prove payment of any claim,
in any case, eight days at least before leaving the leased premises.

11) UTILITIES

Tenant shall be responsible for all subscriptions to water, electricity,
telephone services, etc....


                                         -7-

<PAGE>


12) VISITATION OF PREMISES

During the Lease term, Tenant must allow Landlord's representatives to visit the
leased premises at any time, in order to check upon their condition; and Tenant
must tender any requested proof that the terms of the Lease are being fulfilled.

During the six months preceding expiration of the Lease, Tenant must allow any
person Landlord authorizes to visit the leased premises any day from 9:00 a.m.
to 11:00 a.m. and from 2:00 p.m. to 5:00 p.m., except holidays. Tenant must
during this time allow Landlord to post a notice or sign indicating that the
premises are for lease.

* ARTICLE 5 - FINANCIAL TERMS OF LEASE

1) RENT

Rent is due from the date the Lease takes effect.

a) BASE ANNUAL RENT

*This Lease is agreed upon and accepted for an annual rent, before taxes, the
amount of which is indicated hereafter in the "specific terms".

This rent shall be payable quarterly, each trimester and in advance, on the
first day of the first month of each civil trimester.

Rent for the period between the starting date of this Lease and the expiration
of the pending civil trimester at that date shall be paid at the time the Lease
takes effect.

Landlord hereby opts for the application of the value-added tax on revenues from
this location.

This tax shall be charged to Tenant, who agrees to pay Landlord at the same time
as the corresponding periodical rent before taxes. Tenant also agrees to pay all
taxes which might be substituted for or added to the value-added tax by
regulations.


                                         -8-

<PAGE>

In the event of Tenant's failure to pay rent, corresponding V.A.T., or expenses,
on the due date, Tenant shall owe Landlord an amount equal to .75% plus taxes
per month of delay or fraction of month of delay. This amount, based on the
total of the unpaid amount when due, shall automatically become due without
advance notice. Payment of this amount does not allow Tenant to further delay
any payments due.

*b) INDEXING OF ANNUAL RENT

Annual rent shall be indexed on the national index of the cost of construction,
published each trimester by the INSEE [Census Bureau].

The index used for the determination of base annual rent is indicated in the
"specific terms".

Consequently, annual rent shall be adjusted automatically each year on the
anniversary of this Lease"s starting date in the same manner and the same
proportion of the year-to-year variation of the index of the same trimester.

In the event that publication of this index is delayed, rent can be
provisionally calculated on the basis of the previously published index.

The modification of rent is automatic and requires no notification. In the event
that the modification is not calculated immediately, this shall not in any way
alter the right of either party to subsequently demand its retroactive
application.

Should the INSEE index cease to be published and not be replaced by an official
index, it shall be replaced by an equivalent index chosen either amicably
between the parties, or, failing an amicable agreement, by a valuation made by a
single expert, designated either by mutual agreement between the parties or by
order of the Presiding Judge of the District Court, issued on the petition of
the most diligent party. Tenant shall be exclusively responsible for the cost of
the valuation and for court costs. The expert shall act as common representative
of the parties in accordance with Civil Code article 1592, the provisions of
which have been extended to rentals.

This escalator clause is an essential and requisite clause without which
Landlord would not have contracted this Lease. Therefore, its partial or total
non-application shall authorize Landlord, and only Landlord, to demand
cancellation of the Lease without penalty.


                                         -9-

<PAGE>


*2) EXPENSES

Landlord considers the rent as net of expenses. Tenant shall pay all expenses,
services, supplies, taxes and expenditures related to the leased premises,
including, in particular, the Property Tax, expenses incumbent upon Landlord as
a member of a Union or Unions, as well as insurance premiums for the building,
and major repairs defined by Civil Code article 606.

Nevertheless, in the event that Landlord must pay any amounts on behalf of
Tenant, Tenant shall have to reimburse Landlord immediately upon the first
request.

Expenses normally incumbent upon Landlord, but contractually transferred to
Tenant, are fiscally assimilated into a supplement to the rent. Consequently,
the V.A.T. shall apply to these expenses.

*Tenant shall pay Landlord, with the trimestral rent check, a deposit for
expenses calculated on the base of projected expenditures for the year. An
adjustment shall be made based upon the final accounting of the expenses
relative to the leased premises. The total of the deposit shall be revised each
year by reference to the actual evolution of expenses. The first trimestral
deposit is determined by the "specific terms".

*3) GUARANTY DEPOSIT

Upon signing this Lease, Tenant paid a guaranty deposit to Landlord, who hereby
acknowledges receipt, in an amount equal to three months of rent including all
taxes. The deposit amount shall be specified in the "specific terms".

The guaranty deposit shall be applied, at the expiration of the Lease or at the
time of its anticipated cancellation, regardless of cause, to payment of all
sums that Tenant might owe Landlord. However, Tenant may not in any case charge
rents and expenses against this deposit.

At the time of each annual review of rent, the deposit shall be increased or
reduced so that it always equals three months of rent including all taxes.
Increased payments or reimbursements must be made upon the first request.

In the event of cancellation of this Lease due to non-performance by Tenant of
one of its duties, the guaranty deposit shall be retained by Landlord for
damages, without prejudice to Landlord's right to payment of rents incurred or
to be incurred until the end of the pending triennial period, of the cost of
repairs at Tenant's expense, and without prejudice to damages and interest
payments which might be owing to Landlord.


                                         -10-

<PAGE>


ARTICLE 6 - TERMINATION CLAUSE

The parties expressly agree that in the event of failure to pay, upon the due
date, a single term of rent, corresponding V.A.T., or expenses, or in the event
of failure to perform any of the other stipulations of this Lease, the Lease
shall be canceled automatically, if Landlord wishes, without having to give
notice at law of this cancellation, one month after an order to pay or notice by
out-of-court act to perform remain unfruitful.

Landlord shall regain free access to the premises simply by evicting Tenant by
summary judgment. Subsequent offers may not stop the effect of this clause.
There shall be no prejudice to Landlord's right to payment of rents incurred or
to be incurred until the end of the pending triennial period or of the cost of
repairs which are Tenant's responsibility. There shall be no prejudice to any
other dues, rights or actions.

*ARTICLE 7 - GUARANTIES

These are indicated and set out in the "specific terms".

ARTICLE 8 - REGISTRATION

This Lease shall be registered by Landlord at Tenant"s expense.

ARTICLE 9 - MISCELLANEOUS EXPENSES

Tenant must pay all expenses, taxes, and fees of this Lease and those which are
a consequence of it.

*ARTICLE 10 - DOCUMENTS TENDERED TO TENANT

These are indicated in the "specific terms".


                                         -11-

<PAGE>


ARTICLE 11 - CHOICE OF DOMICILE AND JURISDICTION

For the execution of these documents, Landlord elects its domicile in its
registered office and Tenant in the leased premises.

THE PARTIES AGREE THAT ALL DISPUTES RELATING TO THIS DEED SHALL BE EXCLUSIVELY
THE JURISDICTION OF THE COURTS OF THE LANDLORD S REGISTERED OFFICE.


CHAPTER II - SPECIFIC TERMS OF CONTRACT

This chapter II treats only the articles in the general terms which are
completed or modified for the purposes of this contract.

ARTICLE 1 - DESCRIPTION OF PREMISES

- - Building: 321 avenue Jean Jaures, LYON 69007

- - Leased premises:

     On level 0 [the ground floor]:
          - premises for shops and industrial premises measuring 2785 m(2)

     On level 2 [the third floor]:
     - offices measuring                                808 m(2)
     - industrial premises measuring                   1382 m(2)
     - passageways measuring                            577 m(2)
     - bathrooms/toilets measuring                       18 m(2)
                                                       -------
     For a total of                                    2785 m(2)

Additionally, 70 basement parking spots and 7 outdoor parking spots.

Diagrams of the leased premises are attached hereto.

ARTICLE 2 - STARTING DATE AND TERM OF LEASE

This Lease is agreed to and accepted for a term of nine entire consecutive
years, beginning October first one-thousand nine-hundred ninety-two (October 1,
1992) and ending October first two-thousand one (October 1, 2001), with the
exception of the option of triennial cancellation, provided for by the decree of
September 30, 1953. The parties nevertheless agree that Tenant cannot cancel
this Lease prior to October first one-thousand nine-hundred ninety-eight
(October 1, 1998).


                                         -12-

<PAGE>


ARTICLE 4 - TERMS OF LEASE

1) USE OF PREMISES

Tenant shall use the leased premises for commercial use for the needs of its
manufacturing, trading, import, and export of any medical, particularly ocular,
equipment and prostheses, as well as for any equipment necessary for production,
for pharmaceutical development, and for development of micro-mechanics.

4) SUBLETTING AND ASSIGNMENT

As of now, Tenant DOMILENS LABORATORIES corporation, is authorized to sublet all
or part of the below-described premises to any subsidiary company or sister
company or company of which it owns over 34% equity.

7) SIGNS (1)

/handwritten:  The outdoor signs and billboards in existence today, and of which
Landlord and Tenant hereby declare full knowledge, are authorized as needed.
[signature]/

ARTICLE 5 - FINANCIAL TERMS OF LEASE

1) RENT

a) BASE ANNUAL RENT

- - Base annual rent before taxes..........................   FRF 9,750,000

- - V.A.T..................................................   FRF 1,813,500
                                                           --------------
- - Base annual rent including all taxes...................  FRF 11,563,500

- --------------------------
(1) Specify the terms of posting signs or write "none".


                                         -13-

<PAGE>


b) INDEXING OF BASE ANNUAL RENT

Index used for determining base annual rent:
Index for the second trimester of 1992.

3) EXPENSES

- - First trimestral deposit....................   FRF   to be specified later

3) GUARANTY DEPOSIT

The guaranty deposit, which equals one trimester of rent, before taxes, is fixed
for the first year of the lease at FRF 2,437,500.

ARTICLE 7 - GUARANTIES

None.





                    [city:]
                           ---------------------
                    [date:]
                           ---------------------
                    Two original copies



Landlord,                          Tenant,

/signature/                             /signature/


                                         -14-

<PAGE>

                                                                Exhibit 10.84

[Translator's note: every page of this amendment, except the signature page, is
initialed at the bottom by both parties.]


AMENDMENT NO. 1

BETWEEN THE UNDERSIGNED:

DOMILYON CORPORATION, with FRF 15,000,000 in assets, which became a Private
Corporation on October 19, 1992, headquartered at 32 RUE DE LISBONNE, PARIS
75008, PARIS Trade and Company Register registration number B 348 447 285 (94 B
01767)

represented by Mr. Alain LEMAITRE, acting in his capacity as Director

                                                  Hereinafter "Landlord"

                                                    on the one hand

and

"DOMILENS LABORATORIES" corporation, with FRF 43,500,000 in assets,
headquartered at 321 avenue Jean Jaures, LYON 69007, LYON Trade and Company
Register registration number B 327 032 629,

represented by Mr. Francois PERRARD, its Chief Executive Officer, fully
empowered to negotiate and sign this document,

                                                  Hereinafter "Tenant"
                                                    on the other hand

                                                              .../...


                                         -15-

<PAGE>


                                        REPORT


On October 1, 1992, DOMILENS LABORATORIES Corporation began leasing premises in
a building located at 321 Avenue Jean Jaures, LYON 7th district:

- - on level A.O. [ground floor] - business area:

     *    premises for shops and industrial premises measuring approximately
          2785 m(2)

- - on level A2 [third floor] - business area:

     *    premises for offices, industrial use, and passageways measuring 2785
          m(2)

- - 70 basement parking spots and 7 outdoor spots.
DOMILENS Corporation, given its new organization, wishes to return certain
premises and lease others.

Under these conditions, DOMILENS Corporation met with owner DOMILYON Corporation
and, by mutual agreement, the parties have agreed upon the following:

ARTICLE 1

The description of the premises as it appears in Chapter II, Article 1 of the
above-referenced Lease, is replaced by the following description:

- - Leased premises:

- - on level B2 (third floor) of the offices area,

     *    the entirety of premises for offices, passageways, and
          bathrooms/toilets amounting to a surface area measuring approximately
          450 m(2)

- - on level A0 [ground floor] - business area

     *    premises for shops, industrial use, offices and passageways,
          bathrooms, and toilets amounting to a surface area measuring
          approximately 1796 m(2)

- - on level A2 [third floor] - business area

     *    the entire floor comprising offices, industrial premises, clean rooms,
          passageways, and bathrooms/toilets amounting to a surface area
          measuring approximately 2,785 m(2)


                                         -16-

<PAGE>


- - on A4 - business area

     *    Premises for use as offices, laboratories, and passageways amounting
          to a total surface area measuring approximately 464 m(2)

- - on level B-1 (first basement of the office parcel)

     *    filing area with a surface area measuring approximately 138 m(2)

- - 70 basement parking spots and 7 outdoor spots.

Diagrams of the premises so described are attached hereto.

ARTICLE 2

Tenant agrees to vacate the premises it is returning on September 1, 1994 at the
latest, except for the premises located on A4 (business area) which must be
vacated now. Tenant agrees to return these premises in a good state of
cleanliness, upkeep and rental repairs, but Tenant shall not owe Landlord for
repairs or restoration following disorder from construction stemming from
biennial or decennial guaranties of perfect completion, or following any faulty
construction or completion as stated in article 3 below.

An inventory of premises absolutely must be completed within a maximum of eight
days following the starting date of this amendment, in order to make note of
exiting disorder arising from the above guaranties.

ARTICLE 3

The first paragraph of article 4 (6) (a), repair and maintenance work is
modified as follows:

Tenant shall be responsible not only for rental repairs and minor maintenance,
but also for major repairs defined by Civil Code article 606, except disorder
linked to construction defects arising from the usual guaranties of perfect
completion or from biennial or decennial guarantee, or having been listed as one
of Landlord's reservations at the time of receipt of the building.

By the same token, Tenant shall not be obligated to contribute to the cost of
construction work stemming from one of the above-listed circumstances, in the
event that the cost of restoration work is less than the deductible anticipated
in Landlord's damages-construction policy.


                                         -17-

<PAGE>


ARTICLE 4

Notwithstanding articles 2-1 and 2-8 of the site's by-laws, established
subsequent to the starting date of the Lease between Tenant and Landlord, and,
in particular, as regards payment of compensation in the event of use of the
common areas or of the presence of signs, it is hereby established that Tenant
shall be free to maintain its existing equipment in the known common areas, with
the exception of the common areas located on level 1 [floor 2] (cafeteria,
kitchenette, lounge, infirmary, showers ....) at the starting date of this
amendment, as well as the outdoor signs, without compensation or fees of any
nature, other than those arising from the use, repair or renewal of it own
fixtures, as this right was taken into consideration at the time the rent was
fixed.

ARTICLE 5

As long as Landlord will not have set up a reception area in the entryway of the
building, common to all occupants, Tenant shall be authorized to maintain the
reception area currently in existence for its sole use, at its sole expense,
according to its own schedule, and without additional compensation or fees to
Landlord, as long as Tenant wishes, within the limits of the condition explained
above.

ARTICLE 6

As Tenant is not in the business of delivering services in the building to the
occupants, Landlord expressly authorizes Tenant to disconnect from its
switchboard system and from its access control system, all the connections no
longer corresponding to its establishment.

ARTICLE 7

Given the Tenant's particular business, the parties agree to meet in order to
define by mutual agreement the level of services to provide Tenant, except for
the services whose conditions of operation are under the direct control of
Tenant.

ARTICLE 8

Beginning August 1, 1994, contracts with EDF [electricity and gas company] shall
be at the expense of Landlord as general services. Beforehand, Tenant shall meet
with Landlord to finalize the separation of electric supplies and the metering
of this energy.


                                         -18-

<PAGE>


ARTICLE 9

All other provisions of this Lease remain unchanged, in particular the financial
provisions.

ARTICLE 10

This amendment shall take effect on May 10, 1994







Paris, May 9, 1994

/signature/


                                         -19-


<PAGE>

                                                                Exhibit 10.85

                        [CONFIDENTIAL TREATMENT REQUESTED]

[Certain information has been omitted herein pursuant to a request for
confidential treatment pursuant to Rule 24b-2.]

- -------------------------------------------------------------------------------









                                   AGREEMENT


                                    between


                              CHIRON CORPORATION


                                      and


                                CEPHALON, INC.






                                January 7, 1994









- -------------------------------------------------------------------------------


<PAGE>


                               TABLE OF CONTENTS

                                                                      PAGE NO.
                                                                      --------

                             PART I - DEFINITIONS

                            ARTICLE 1 - DEFINITIONS

Affiliate.................................................................   2
Allowable Expense.........................................................   2
Alternate Facility........................................................   2
bFGF......................................................................   2
Calendar Quarter..........................................................   2
Cardioxane................................................................   2
CCP.......................................................................   2
Cephalon..................................................................   2
Cephalon Agreements.......................................................   2
Cephalon Facility.........................................................   2
Cephalon Technology.......................................................   3
Chiron....................................................................   3
Chiron Agreements.........................................................   3
Chiron Facility...........................................................   3
Chiron Product............................................................   3
Chiron Technology.........................................................   3
CIBA......................................................................   3
CIBA Agreement............................................................   3
Collaboration.............................................................   3
Commercialization Date....................................................   4
Compound..................................................................   4
Continuing Licensee.......................................................   4
Cost......................................................................   4
Development Committee.....................................................   4
Development Plan..........................................................   4
Effective Date............................................................   4
Field.....................................................................   4
GMP Grade.................................................................   4
IND.......................................................................   4
JV........................................................................   5
Joint Technology..........................................................   5
JV Technology.............................................................   5
Major Market..............................................................   5
Management Committee......................................................   5
Manufacturing Information.................................................   5
Marketing Committee.......................................................   5
Market Exclusivity........................................................   5
Marketing Plan............................................................   5
NDA.......................................................................   5
Net Sales.................................................................   6
Operating Losses..........................................................   6
Operating Profits.........................................................   6
Pricing Approval..........................................................   7
Product...................................................................   7


                                      -i-



<PAGE>


Regulatory Approval.......................................................   7
Regulatory Standards......................................................   7
Royalty Territory.........................................................   7
SIBIA Rights..............................................................   7
SOD.......................................................................   7
Specifications............................................................   7
Technical Information.....................................................   7
Territory.................................................................   8
Third Party Royalties.....................................................   8
Trademark.................................................................   8





                     PART II - ACTIVITIES IN MAJOR MARKETS

          ARTICLE 2 - PURPOSE, MANAGEMENT, ETC. OF THE COLLABORATION

SECTION 2.1        Purpose of Collaboration...............................   8
SECTION 2.2        Structure..............................................   8
SECTION 2.3        Management Committee...................................   8
SECTION 2.4        Development Committee..................................   9
SECTION 2.5        Membership; Duties of Members and Alternate Members....   9
SECTION 2.6        Authorized Actions.....................................  10
SECTION 2.7        Meetings...............................................  10
SECTION 2.8        Locations of Meetings..................................  10
SECTION 2.9        Conduct of Meetings....................................  10
SECTION 2.10       Additional Committees..................................  11
SECTION 2.11       Exclusion from Allowable Expenses......................  11
SECTION 2.12       Cooperation of Collaborators...........................  11
SECTION 2.13       Duties of Collaborators................................  11

                   ARTICLE 3 - RESEARCH AND DEVELOPMENT ACTIVITIES

SECTION 3.1        Priorities; Plans; Budgets.............................  11
SECTION 3.2        Clinical Supplies of Products..........................  13
SECTION 3.3        Regulatory Approvals...................................  14
SECTION 3.4        Balancing of Development Costs.........................  15

           ARTICLE 4 - COMMERCIALIZATION ACTIVITIES IN MAJOR MARKETS

SECTION 4.1        Marketing Strategy in Major Markets....................  16
SECTION 4.2        Responsibilities of the Parties........................  17
SECTION 4.3        Commercialization of Products..........................  18
SECTION 4.4        Labelling..............................................  18
SECTION 4.5        Manufacture of Commercial Supplies of Products.........  18
SECTION 4.6        Activities of Chiron Outside the Field.................  21

                             ARTICLE 5 - LICENSES

SECTION 5.1        Cross-Licenses Prior to Formation of JV................  23
SECTION 5.2        Licenses to JV.........................................  24
SECTION 5.3        Licenses from JV to Collaborators in the Major Markets.  24


                                     -ii-


<PAGE>


SECTION 5.4        License from JV to Chiron in the Royalty Territory.....  24
SECTION 5.5        Optional Rights........................................  24
SECTION 5.6        Retained Rights........................................  26
SECTION 5.7        Prior Rights...........................................  26
SECTION 5.8        Inventions.............................................  26
SECTION 5.9        New Technologies.......................................  26
SECTION 5.10       Maintenance of Technology..............................  27
SECTION 5.11       Sublicensing of Technology.............................  27
SECTION 5.12       Disclosure of Technology...............................  27

                   ARTICLE 6 - COMPENSATION IN MAJOR MARKETS

SECTION 6.1        Equal Sharing of Operating Profits and Losses..........  28
SECTION 6.2        Special Allocations....................................  28
SECTION 6.3        Off-Label Sales in the Major Markets...................  29
SECTION 6.4        Royalties to Chiron on Sales of Chiron Products........  29
SECTION 6.5        Calculation of Operating Profits.......................  31

                  PART III - ACTIVITIES IN ROYALTY TERRITORY

          ARTICLE 7 - DEVELOPMENT AND COMMERCIALIZATION ACTIVITIES IN
                               ROYALTY TERRITORY

SECTION 7.1        Development and Commercialization Responsibilities.....  32
SECTION 7.2        Coordination with Collaboration........................  32
SECTION 7.3        Diligence in Commercialization of Products.............  33
SECTION 7.4        Ownership of Data......................................  33
SECTION 7.5        No Allowable Expenses..................................  33
SECTION 7.6        Assistance by the JV...................................  33
SECTION 7.7        Contingent Cephalon Marketing Rights...................  33

                    ARTICLE 8 - ROYALTIES AND REPORTS, ETC.

SECTION 8.1        Royalties..............................................  34
SECTION 8.2        Royalty Rate Adjustments...............................  34
SECTION 8.3        Allocation of Net Sales in the Royalty Territory.......  36
SECTION 8.4        Third Party Royalties..................................  36
SECTION 8.5        Payment of Royalties...................................  37
SECTION 8.6        Reports................................................  37
SECTION 8.7        Currency Restrictions..................................  37
SECTION 8.8        Taxes..................................................  37


                                     -iii-


<PAGE>


                         PART IV - GENERAL PROVISIONS

                   ARTICLE 9 - INTELLECTUAL PROPERTY MATTERS


SECTION 9.1        Intellectual Property Protections......................  38
SECTION 9.2        Defense of Infringement Claims.........................  38
SECTION 9.3        Prosecution of Third Party Infringements...............  39
SECTION 9.4        Joinder................................................  40
SECTION 9.5        Settlement of Claims...................................  40
SECTION 9.6        Cooperation............................................  40
SECTION 9.7        Trademark Matters......................................  41

                       ARTICLE 10 - PAYMENTS AND RECORDS

SECTION 10.1       Payments...............................................  42
SECTION 10.2       Books and Records; Accounting..........................  42

                   ARTICLE 11 - CERTAIN REGULATORY MATTERS

SECTION 11.1       Governmental Inspections and Inquiries.................  43
SECTION 11.2       Adverse Reactions......................................  43
SECTION 11.3       Recalls and Market Withdrawals.........................  43

                      ARTICLE 12 - CONFIDENTIALITY, ETC.


SECTION 12.1       Confidentiality........................................  44
SECTION 12.2       Injunctive Relief......................................  45
SECTION 12.3       Publicity..............................................  45

        ARTICLE 13 - CERTAIN REPRESENTATIONS, WARRANTIES AND COVENANTS

SECTION 13.1       Corporate Status and Authority.........................  46
SECTION 13.2       No Inconsistent Agreements.............................  47

            ARTICLE 14 - DISCLAIMER, INDEMNIFICATION AND INSURANCE

SECTION 14.1       No Warranty............................................  47
SECTION 14.2       Defense of Claims in Territory.........................  47
SECTION 14.3       Costs and Expenses.....................................  47
SECTION 14.4       Indemnity for Excluded Liabilities.....................  48
SECTION 14.5       Procedures for Indemnification.........................  48
SECTION 14.6       Settlements, etc.......................................  48
SECTION 14.7       Limitation of Liability................................  48
SECTION 14.8       Insurance..............................................  49

                        ARTICLE 15 - DISPUTE RESOLUTION

SECTION 15.1       Dispute Resolution.....................................  49
SECTION 15.2       Arbitration............................................  49


                                     -iv-


<PAGE>


                       ARTICLE 16 - TERM AND TERMINATION

SECTION 16.1       Term...................................................  50
SECTION 16.2       Termination of Agreement in Full.......................  50
SECTION 16.3       Action upon Change of Control..........................  50
SECTION 16.4       Partial Termination in Royalty Territory...............  51
SECTION 16.5       Rights and Obligations on Termination..................  51
SECTION 16.6       Termination upon CCP Transfer..........................  54
SECTION 16.7       Effective Date of Termination..........................  54
SECTION 16.8       Survival...............................................  54
SECTION 16.9       Remedies not Exclusive.................................  54

                          ARTICLE 17 - MISCELLANEOUS

SECTION 17.1       Entire Agreement; Amendment............................  54
SECTION 17.2       References to CIBA.....................................  55
SECTION 17.3       Force Majeure..........................................  55
SECTION 17.4       No Interference with Existing Businesses...............  55
SECTION 17.5       Compliance with Law....................................  55
SECTION 17.6       Waiver.................................................  55
SECTION 17.7       No Assignment..........................................  55
SECTION 17.8       Severability...........................................  56
SECTION 17.9       Notices................................................  56
SECTION 17.10      Pronouns...............................................  57
SECTION 17.11      Further Instruments....................................  57
SECTION 17.12      Governing Law..........................................  57
SECTION 17.13      Counterparts...........................................  57


SCHEDULE I          - Third Party Agreements

SCHEDULE II         - Field Exclusion

SCHEDULE III        - SOD Technology

SCHEDULE IV         - Third Party Royalties

SCHEDULE V          - Development Expenses for Transition Period

SCHEDULE VI         - Allowable Expenses and Accounting Principles

SCHEDULE VII        - Preferred Indications of Chiron

SCHEDULE VIII       - Cephalon Nonfield Indications


EXHIBIT A           - Specifications


                                      -v- 

<PAGE>


                                   AGREEMENT

    This AGREEMENT, dated as of January 7, 1994, is made by and between CHIRON
CORPORATION, a Delaware corporation ("Chiron"), and CEPHALON, INC., a Delaware
corporation ("Cephalon").  Chiron and Cephalon are sometimes referred to 
herein as "Collaborators" and individually as a "Collaborator".

                                  BACKGROUND

    A.   Cephalon possesses certain intellectual property rights (including a 
license from Cephalon Clinical Partners, L.P. ("CCP")) relating to uses of 
insulin-like growth factor 1 ("IGF-1") for certain neurological diseases, 
disorders and conditions (such as amyotrophic lateral sclerosis ("ALS") and 
peripheral neuropathies) and its production and use as a therapeutic agent in 
man.  Cephalon has an ongoing clinical development program relating to IGF-1 
as a therapeutic agent for ALS and certain peripheral neuropathies.  Cephalon 
wishes to have the benefit of Chiron's expertise in the development and 
production of IGF-1 for neurological disorders.

    B.   Chiron possesses certain intellectual property rights (including a 
license from Ciba-Geigy Ltd. ("CIBA")) relating to uses of IGF-1 for certain 
neurological diseases, disorders and conditions (such as diabetic 
neuropathy), and its production and use as a therapeutic agent in man.  
Chiron wishes to have the benefit of Cephalon's expertise in the development 
of therapeutic compounds in the neurological field.

    C.   Chiron and Cephalon have substantial development programs relating 
to their respective uses of IGF-1.

    D.  Chiron possesses certain intellectual property rights and is 
otherwise developing other compounds and methodologies that offer promise of 
therapeutic application in neurological applications, together with and 
independent of IGF-1.

    E.   Cephalon intends to develop a sales and marketing expertise focusing 
principally on the neurology market.

    F.   Cephalon and Chiron believe that a joint development program that 
optimizes the contributions of each of Cephalon and Chiron will accelerate 
the beneficial application of IGF-1 and other compounds to address important 
unmet needs for therapeutic products applicable to neurological diseases, 
disorders and conditions and will be in their mutual and individual best 
interests.

     NOW, THEREFORE, in consideration of the mutual covenants contained 
herein, and intending to be legally bound hereby, the parties agree as 
follows:



<PAGE>

                             PART I - DEFINITIONS

                           ARTICLE 1 - DEFINITIONS

     As used in this Agreement, the following terms shall have the 
corresponding meanings set forth below:

     (a) "AFFILIATE" means any individual or entity directly or indirectly 
controlling, controlled by or under common control with, a party to this 
Agreement.  Without limiting the foregoing, the direct or indirect ownership 
of over 50% of the outstanding voting securities of an entity, or the right 
to receive over 50% of the profits or earnings of an entity, shall be deemed 
to constitute control.

    (b)  "ALLOWABLE EXPENSE" means the Costs incurred by the JV or a 
Collaborator under this Agreement pursuant to a budget approved by the 
Management Committee (including a budget contained in a Development Plan) or 
that are otherwise approved by the Management Committee as an Allowable 
Expense.  The term "Allowable Expense" also shall include the Costs incurred 
by a party in a Major Market pursuant to Sections 9.2(c), 9.3(b), 9.3(e) and 
9.6 (patent defense and prosecution), Section 11.3 (recalls and withdrawals) 
or Section 14.3 (joint liability claims) to the extent such Costs are 
determined by the Management Committee to be reasonable.

    (c)  "ALTERNATE FACILITY" has the meaning specified in Section 4.5(a) 
hereof.

    (d)  "bFGF" means basic Fibroblast Growth Factor.

    (e)  "CALENDAR QUARTER" means each three-month period beginning on 
January 1, April 1, July 1 and October 1 of each year.

    (f)  "CARDIOXANE-TRADEMARK-" means the substance known by the chemical 
name of dexrazoxane, and any analogues or derivatives thereof.

    (g)  "CCP" means Cephalon Clinical Partners, L.P.

    (h)  "CEPHALON" means Cephalon, Inc. and any Affiliate thereof.

    (i)  "CEPHALON AGREEMENTS" means the agreements specified on Schedule I 
hereto pursuant to Section 13.1 hereof.

    (j)  "CEPHALON FACILITY" means the facility of Cephalon located at 9000 
Virginia Manor Road, Suite 290, Beltsville, Maryland 20705, or any other 
facility of Cephalon approved by the Management Committee for use in the 
manufacture of Products under this Agreement.


                                      -2-

<PAGE>


    (k)  "CEPHALON TECHNOLOGY" means any existing or future (i) patent 
application or issued patent owned or possessed (by license or otherwise) by 
Cephalon containing a claim that would be infringed by the manufacture, use 
or sale of a Product in the Territory, including any addition, continuation, 
continuation-in-part, division, extension or renewal thereof, (ii) Technical 
Information owned or possessed (by license or otherwise) by Cephalon, (iii) 
the rights of Cephalon in and to any Trademark and (iv) all rights of Cephalon
in and to Joint Technology related to a Product; in each case, to the extent
Cephalon has the right to license or sublicense any such right.  The term 
"Cephalon Technology" shall not include the SIBIA Rights, unless otherwise 
agreed in writing by Cephalon and either Chiron or the JV pursuant to Section 
5.5 hereof.

    (l)  "CHIRON" means Chiron Corporation and any Affiliate thereof.

    (m)  "CHIRON AGREEMENTS" means the agreements specified on Schedule I 
hereto pursuant to Section 13.1 hereof.

    (n)  "CHIRON FACILITY" means the facility or facilities of Chiron 
approved by the Management Committee for use in the manufacture of Products 
under this Agreement.

    (o)  "CHIRON PRODUCT" means any Product of Chiron or the Collaboration in 
the field that contains SOD, Cardioxane or bFGF, whether alone or in 
combination with an active ingredient other than IGF-1.

    (p)  "CHIRON TECHNOLOGY" means any existing or future (i) patent 
application or issued patent owned or possessed (by license or otherwise) by 
Chiron containing a claim that would be infringed by the manufacture, use or 
sale of a Product in the Territory, including any addition, continuation, 
continuation-in-part, division, extension or renewal thereof, (ii) Technical 
Information owned or possessed (by license or otherwise) by Chiron, (iii) the 
rights of Chiron in and to any Trademark, and (iv) all rights of Chiron in 
and to Joint Technology related to a Product; in each case, to the extent 
Chiron has the right to license or sublicense any such right.

    (q)  "CIBA" means Ciba-Geigy Ltd.

    (r)  "CIBA AGREEMENT" means the Agreement and License between Chiron and 
CIBA dated as of December 31, 1993.

    (s)  "COLLABORATION" means the business of developing and commercializing 
Products within the Territory, whether conducted directly by Cephalon and 
Chiron or through the JV.


                                      -3-

<PAGE>


    (t)  "COMMERCIALIZATION DATE" means the date of the first commercial sale 
of a Product in a Major Market following Regulatory Approval.

    (u)  "COMPOUND" means each of IGF-1, SOD, Cardioxane and bFGF and any 
composition or product added by the parties to the Collaboration in 
accordance with Section 5.9(b) hereof.

    (v)  "CONTINUING LICENSEE" has the meaning specified in Article 16.5 
hereof.

    (w)  "COST" means the fully burdened, fairly allocated internal costs of 
a party, on a consolidated basis, including reasonable and customary 
allocations of indirect and overhead expense and charges in the nature of 
depreciation and amortization of capitalized cost, and out-of-pocket 
expenses, to the extent any of the foregoing were incurred in accordance with 
the accounting methodology authorized pursuant to Section 2.3(c) hereof.  The 
term "Cost" also shall include an interest charge for working capital made 
available by a Collaborator for inventory and receivables related to the 
Products, upon terms to be approved by the Management Committee.  A 
Collaborator shall not be required to make working capital available for such 
purposes.  

    (x)  "DEVELOPMENT COMMITTEE" means the committee established pursuant to 
Section 2.4 hereof.

    (y)  "DEVELOPMENT PLAN" has the meaning specified in Section 3.1 hereof.

    (z)  "EFFECTIVE DATE" means the first date when both Cephalon and Chiron 
have executed this Agreement.

    (aa) "FIELD" means the prophylactic and/or therapeutic treatment of 
neurological diseases and disorders in humans including, without limitation, 
ALS and peripheral neuropathies such as post-polio syndrome, 
chemotherapy-induced peripheral neuropathy, diabetic neuropathy and 
Charcot-Marie-Tooth syndrome.  The "Field" does not include the uses defined 
in SCHEDULE II hereto.

    (ab) "GMP GRADE" means production of a Product in accordance with the 
Regulatory Standards and the process and procedures described in the 
Manufacturing Information.

    (ac) "IND" means an application for an Investigational Exemption for a 
New Drug filed with the FDA with respect to a Product, or any comparable 
filing made with a regulatory authority outside the United States.


                                      -4-

<PAGE>


    (ad) "JV" means the joint venture to be established by Cephalon and 
Chiron in accordance with Section 2.2 hereof.

    (ae) "JOINT TECHNOLOGY" means any invention or discovery, whether or not 
patentable and whether or not in the Field (i) that is made solely or jointly 
by a JV employee, or (ii) as to which Cephalon and Chiron would be deemed 
joint inventors in accordance with U.S. patent laws.

    (af) "JV TECHNOLOGY" has the meaning specified in Section 5.2(c) hereof.

    (ag) "MAJOR MARKET" means (i) each of the United States, Canada, Mexico, 
Austria, Finland, Norway, Sweden and Switzerland and each member country of 
the European Economic Community ("EEC") as constituted on the Effective Date, 
whether or not any such country remains a member of the EEC during the term 
of this Agreement; and (ii) any country which joins the EEC after the 
Effective Date.  If any of the specified countries dissolves or otherwise 
converts into constituent parts, any country or countries resulting from such 
dissolution shall automatically be included in the definition of "Major 
Market".

    (ah) "MANAGEMENT COMMITTEE" means the committee established pursuant to 
Section 2.3 hereof.

    (ai) "MANUFACTURING INFORMATION" means all chemistry, formulation, 
manufacturing, quality control and other information required to be included 
in as IND or NDA for a Product.

    (aj) "MARKETING COMMITTEE" means the committee to be established pursuant 
to Section 4.1 hereof.


    (ak) "MARKET EXCLUSIVITY" means, with respect to a Product, any of the 
following: (i) sale of the Product in the country in question would infringe 
a claim of an issued patent owned or possessed (by license or otherwise) in 
whole or in part by a Collaborator or the JV that has not expired or been 
held invalid or unenforceable by a court of competent jurisdiction in a final 
and nonappealable or non-appealed judgment, or (ii) the Product or the 
indication for the Product enjoys market exclusivity by reason of any statute,
regulation, rule or order of a governmental authority in the country.

    (al) "MARKETING PLAN" has the meaning specified in Section 4.1 hereof.

    (am) "NDA" means a New Drug Application or a Product License Application 
filed with the FDA with respect to a Product, or any comparable filing made 
with a regulatory authority outside the United States.


                                      -5-


<PAGE>


    (an) "NET SALES" means the invoiced price of a Product charged to an 
unaffiliated end user in the Territory (i.e., a third party whose use is 
intended to result in the consumption or destruction of the Product), net of 
returns and rejections, and after deducting, (i) sales or similar taxes, 
packaging charges, freight and insurance, to the extent charged to the 
purchaser or directly attributable to the specific sale, (ii) cash, trade and 
quantity discounts actually allowed and taken, and (iii) allowances, rebates 
and commissions actually taken or paid.  With respect to sales of a Product 
in the Royalty Territory, if a Product is sold with a single invoiced price 
in combination with another therapeutically active component or components or 
as a combination with diagnostic products where one or more components or 
products are not Products, Net Sales under such circumstances shall be 
calculated by multiplying Net Sales of the combination by the fraction A/(A 
B), in which A is the invoiced price of the Products, if sold separately, and 
B is the total invoiced price of any other active components or components in 
combination, if sold separately.  If the Product and/or the active components 
or components in the combination are not sold separately, the values of the 
individual components shall be reasonably determined by the Management 
Committee.  The value of the components of the combination will be based on, 
but not limited to, the cost of manufacturing, the value of comparable 
components marketed by others and the potential value based on the current 
cost of diagnosing and treating the disease.  In the case of a combination 
product marketed by the Collaboration in the Major Markets, the Management 
Committee shall determine the portion of the invoiced price of such product 
that is to be treated as Net Sales under this Agreement.

    (ao) "OPERATING LOSSES" means any negative number which results from the 
calculation of Operating Profits.

    (ap) "OPERATING PROFITS" means for the applicable accounting period, the 
sum of: [CONFIDENTIAL TREATMENT REQUESTED]; LESS [CONFIDENTIAL TREATMENT 
REQUESTED] for the applicable accounting period.


                                      -6-

<PAGE>


    (aq) "PRICING APPROVAL" means any pricing or third party reimbursement 
approval required for the marketing of a Product.

    (ar) "PRODUCT" or "PRODUCTS" means any product consisting of or 
containing a Compound, whether alone or in combination with another active 
ingredient, to the extent that it is being developed for a use or is used, or 
has received Regulatory Approval for a use, in the Field. The term "Products" 
excludes any product containing a Compound to the extent it is being 
developed for a use or is used, or has received Regulatory Approval for a 
use, outside the Field, except to the extent provided under Sections 6.2, 6.3 
and 8.3 hereof. The term "Products" also excludes any composition of Chiron 
or Cephalon that does not contain a Compound, even if such composition is 
used within the Field.

    (as) "REGULATORY APPROVAL" means any marketing authorization (including 
authorizations approving an NDA) required for a Product, exclusive of Pricing 
Approvals.

    (at) "REGULATORY STANDARDS" means (i) the facility license requirements 
and the current Good Manufacturing Practice regulations of the FDA applicable 
to the manufacturing facility for, or the production, storage or handling of 
Products, and (ii) any standards of any governmental authority, whether 
within or outside the United States (including, without limitation, the 
Environmental Protection Agency, OSHA and state and local authorities), that 
apply to the manufacturing facility for, or the production, storage or 
handling of, Products.

    (au) "ROYALTY TERRITORY" means the portion of the Territory other than 
the Major Markets.

    (av) "SIBIA RIGHTS" means the patent rights, know-how and other 
intellectual property rights licensed by Cephalon from The Salk Institute of 
Biotechnology/Industrial Associates, Inc. pursuant to the License Agreement 
dated March 5, 1992.

    (aw) "SOD" means superoxide dismutase compounds and related technology 
described on SCHEDULE III hereto.

    (ax) "SPECIFICATIONS" means the manufacturing, quality control, 
packaging, labelling, shipping and storage specifications for each Product, 
to be agreed to by the parties in writing after the Effective Date and made a 
part of this Agreement as EXHIBIT A hereto. All Products shall be supplied 
under this Agreement in final, finished and vialed form suitable for end use.

    (ay) "TECHNICAL INFORMATION" means know-how, trade secrets, technical 
information, formulae, processes and data


                                      -7-


<PAGE>


owned or possessed (by license or otherwise) by a Collaborator which relate 
to the composition, manufacture or use of a Product, including, without 
limitation, preclinical or clinical results.

    (az) "TERRITORY" means the world excluding Japan.

    (ba) "THIRD PARTY ROYALTIES" means the royalties payable to third party 
licensors in the Major Markets under the agreements specified on SCHEDULE IV 
hereto and any additional royalties payable in the Major Markets by the JV in 
accordance with Section 5.9(a) hereof.

    (bb) "TRADEMARK" means any trademark, tradename or trade dress designated 
in writing by the Collaboration for use with a Product in the Territory, 
whether pending, allowed or registered.

                     PART II - ACTIVITIES IN MAJOR MARKETS

         ARTICLE 2 - PURPOSE, MANAGEMENT, ETC. OF THE COLLABORATION

    SECTION 2.1  PURPOSE OF COLLABORATION.  The purpose of the Collaboration 
is to conduct research, product development and clinical activities and seek 
Regulatory Approvals related to Products in the Territory and to 
commercialize Products in the Territory. The parties will collaborate 
exclusively with each other with respect to the development and 
commercialization of the Products in the Territory and the Field. The parties 
intend to share equally in certain costs of developing Products in the Major 
Markets and in any ultimate Operating Profits or Losses.

    SECTION 2.2  STRUCTURE.  Chiron and Cephalon will conduct the 
Collaboration pursuant to this Agreement until they establish a separate 
legal entity for such purpose (the "JV"). The JV shall be formed no later 
than the filing of the first application for Regulatory Approval of a 
Product in the Territory. The JV, whether a partnership or a corporation 
(the "JV"), shall be established in a written amendment or supplement to this 
Agreement signed by Cephalon and Chiron.

    SECTION 2.3  MANAGEMENT COMMITTEE.

         (a)  ESTABLISHMENT.  The Collaboration, whether conducted directly 
by Cephalon and Chiron or through the JV, will be managed by a Management 
Committee, which is hereby established to carry out the business of the 
Collaboration and implement the provisions of this Agreement.

         (b)  AUTHORITY.  The Management Committee shall exercise such powers 
as it deems necessary or desirable to further the purposes of the 
Collaboration in the mutual best


                                      -8-


<PAGE>


interests of the Collaborators, except to the extent that such powers are 
reserved to the Collaborators by this Agreement. In particular, the 
Management Committee shall be responsible for (i) approving an annual 
development plan and budget for the Collaboration, (ii) reviewing the 
performance (including the cost-effectiveness) of each Collaborator's and the 
JV's activities, (iii) establishing the accounting methodologies for Costs, 
Allowable Expenses and the calculation of Operating Profits in accordance 
with paragraph (c) below, and (iv) approving acquisitions of technology from 
third parties or the Collaborators pursuant to Section 5.9 hereof.

         (c)  ACCOUNTING METHODOLOGY.  Initially, each Collaborator shall 
apply its internal cost accounting principles and methodology in determining 
Costs incurred with respect to the Collaboration, which shall be consistent 
with generally accepted accounting principles and with the principles and 
methodology applied by the Collaborator to its other projects and reasonably 
acceptable to the Management Committee. The Management Committee shall review 
the internal cost accounting principles and methodology of the Collaborators 
and as soon as practicable, but in no event later than receipt of the first 
Regulatory Approval of a Product in a Major Market, shall establish a 
statement of cost accounting principles and methodology, consistent with 
generally accepted accounting principles, to be used by each Collaborator and 
the JV in recording and reporting Costs as Allowable Expenses and calculating 
Operating Profits under this Agreement. The approved statement shall be 
attached to this Agreement as SCHEDULE VI. Any disagreement with respect to 
the development of the principles and methodologies to be set forth in 
SCHEDULE VI shall be resolved by a reputable firm of independent public 
accountants selected by the Collaborators.

    SECTION 2.4  DEVELOPMENT COMMITTEE.  A Development Committee is hereby 
established under the supervision of the Management Committee to monitor all 
research and development activities of the Collaboration, to carry out all 
other obligations assigned to it under this Agreement or by the Management 
Committee, and to make recommendations to the Management Committee with 
respect to its activities. In particular, the Development Committee shall be 
responsible for (i) preparing a preliminary annual development plan 
containing project plans, schedules and annual budgets for approval by the 
Management Committee, (ii) approving regulatory efforts of the Collaboration, 
including the design of clinical trials to be conducted for each Product in 
the Major Markets to the extent provided in Section 3.1, the identification of 
clinical trial sites and the preparation and approval of clinical trial 
protocols, and (iii) monitoring the progress of clinical activities.

    SECTION 2.5  MEMBERSHIP, DUTIES OF MEMBERS AND ALTERNATE MEMBERS.  Each 
Collaborator shall appoint 50% of the members of


                                      -9-



<PAGE>


the Management Committee and Development Committee.  The Collaborators shall 
designate the initial members promptly after the Effective Date.  The 
Management Committee members shall be members of the senior management of the 
designating Collaborator.  Each Collaborator may remove and replace its 
representatives on the Management Committee and the Development Committee at 
any time, without cause, upon written notice to the other Collaborator.  An 
alternate member designated by a Collaborator shall be entitled to vote only 
in the absence of a regular member designated by such Collaborator.  All 
references to "members" in this Agreement refers to the regular members and 
any alternate member acting in the place of a regular member.

    SECTION 2.6  AUTHORIZED ACTIONS.  Any action or decision by the 
Management Committee or Development Committee must be authorized by the 
approval of a majority of each party's designated members on the Committee, 
unless otherwise specified in this Agreement.  If the Development Committee 
can not agree on a particular matter, the matter shall be submitted for 
resolution to the Management Committee.  If the Management Committee can not 
agree on a particular matter, the matter shall be submitted for resolution in 
accordance with Article 15 hereof.

    SECTION 2.7  MEETINGS.

    (a)  FREQUENCY.  The regular meetings of the Management Committee and 
Development Committee shall be scheduled by a consensus of a majority of the 
members.  Any meetings of the two Committees may be combined into a joint 
meeting.  In no event, however, shall the Management Committee meet less 
frequently than twice each year or the Development Committee meet less 
frequently than quarterly.  A special meeting of the Management Committee or 
the Development Committee also may be called by any two members of the 
applicable Committee.

    (b)  NOTICE.  Notice of the date, time and place of every regular or 
special meeting and a proposed agenda for the meeting shall be provided to 
the members, no later than fifteen (15) days prior to the scheduled date of 
the meeting (unless notice is waived in writing by the member).

    SECTION 2.8  LOCATIONS OF MEETINGS.  The regular and special meetings of 
the Management Committee and the Development Committee shall alternate 
between the principal business offices of each Collaborator, unless otherwise 
agreed by a majority of the members of the applicable Committee.

    SECTION 2.9  CONDUCT OF MEETINGS.  Any regular or special meeting of the 
Management Committee or the Development Committee may be conducted in person 
or by conference telephone.  The Management Committee and the Development 
Committee may act without a meeting if a written consent to the action is 
signed by


                                     -10-


<PAGE>


a majority of each party's designated members of the applicable Committee.  
Minutes reflecting actions taken at meetings shall be maintained with the 
books and records of the Collaboration and shall be distributed to the 
Collaborators upon request.

    SECTION 2.10  ADDITIONAL COMMITTEES.  The Management Committee may, from 
time to time, delegate specific powers to special-purpose committees of the 
Management Committee, other than the Development Committee.  Any additional 
committees, including the Marketing Committee to be established under Section 
4.1 shall be constituted and shall operate in accordance with the procedures 
of this Article 2.

    SECTION 2.11  EXCLUSION FROM ALLOWABLE EXPENSES.  All costs and expenses 
incurred by a Collaborator in attending Management Committee, Development 
Committee or other committee meetings and in otherwise conducting 
negotiations and relations with the other Collaborator shall by borne by the 
party incurring the expense and shall not be treated as an Allowable Expense, 
unless specified in SCHEDULE VI or authorized by the Management Committee.

    SECTION 2.12  COOPERATION OF COLLABORATORS.  Each Collaborator shall 
furnish to the Management Committee or other applicable committee, subject to 
the confidentiality obligations specified in Article 12 hereof, all 
information that is reasonably required for purposes of this Agreement.

    SECTION 2.13  DUTIES OF COLLABORATORS.  Each Collaborator shall perform 
its functions under this Agreement in a manner it believes in good faith to 
be consistent with the intention of the parties in entering into this 
Agreement. Nothing in this Agreement is intended to create a fiduciary duty of
one Collaborator to the other, nor shall it be deemed to require either 
Collaborator to expend funds or commit resources in excess of those approved 
by the Management Committee.

                 ARTICLE 3 - RESEARCH AND DEVELOPMENT ACTIVITIES

    SECTION 3.1  PRIORITIES; PLANS; BUDGETS.

    (a)  PRIORITIES.  The Development Committee, subject to the approval of 
the Management Committee, shall establish the research, development and 
regulatory strategies related to the Products in the Field.  The initial 
priority of the Collaboration shall be assigned to the development of IGF-1 
for use in treating ALS and peripheral neuropathies.

    (b)  ANNUAL PLAN AND BUDGET.  Attached as Schedule V hereto is the 
initial development budget for each Collaborator's research and development 
activities (including third party


                                     -11-


<PAGE>


subcontractors) related to Products in the Major Markets for the period from 
October 1, 1993 through December 31, 1993.  For each calendar year beginning 
January 1, 1994, the Development Committee shall prepare and submit to the 
Management Committee for approval an annual development plan and budget for 
Products in the Major Markets.  The plans and budgets included in SCHEDULE V 
and each subsequent development plan and budget approved by the Management 
Committee are referred to in this Agreement as the "Development Plans".


    (c)  IMPLEMENTATION.  The Development Plans will set forth the 
responsibilities of each Collaborator.  The parties anticipate that the 
regulatory strategies specified in the Development Plan will be implemented 
by Cephalon, who will be responsible for, among other things, the conduct of  
all clinical trials of Products in the Major Markets (including 
post-approval, quality of life, cost-benefit and any other studies necessary 
for Regulatory or Pricing Approvals in the Major Markets), the recruitment of 
investigators, the monitoring of clinical trials and the performance of any 
other activities required to obtain Regulatory Approvals and Pricing 
Approvals in the Major Markets.  Each party will make available its clinical 
and regulatory assets to the extent specified in the applicable Development 
Plan.  The design of the clinical trials for IGF-1 that were initiated by 
Cephalon prior to the Effective Date are hereby deemed to be approved.  The 
Development Committee will prepare for submission to the Management Committee 
the design of the clinical trials that are to be initiated for Products after 
the Effective Date.

    (d)  ASSISTANCE BY EUROCETUS.  If determined to be cost-effective by the 
Management Committee, Cephalon may contract separately with EuroCetus, B.V., 
a subsidiary of Chiron, for assistance in the clinical development of SOD 
bFGF and Cardioxane in the Major Markets outside North America.  Cephalon 
will reimburse EuroCetus directly for the costs of providing such service, 
with the reimbursement treated as an Allowable Expense of Cephalon.

    (e)  CLINICAL DATA.  All clinical data obtained from any studies 
conducted pursuant to the Development Plans shall be jointly owned by 
Cephalon and Chiron and may be used by either Collaborator inside the Field 
and inside the Territory, subject to the JV's right to use all such data for 
purposes of the Collaboration in the Territory.  All clinical data related to 
a Product that is developed pursuant to the Development Plans may be used by 
either Collaborator or its licensees or joint development partners outside 
the Field or outside the Territory only to the extent required by applicable 
law (such as to report adverse experiences) and, in the case of data related 
to a Product containing a Compound other than IGF-1, may be used for any 
other purpose by a Collaborator or its licensees or joint development 
partners outside the Field or outside the Territory


                                     -12-


<PAGE>


upon commercially reasonable terms. In addition to the permitted uses 
described above, all clinical data related to a Product containing IGF-1 (i)
may be used by CCP, inside or outside the Field, to the extent required under 
the applicable Cephalon Agreement, and (ii) may be used by Kyowa Hakko Kogyo in
Japan to the extent required by law (such as to report adverse experiences) 
or for any other purpose upon commercially reasonable terms if Cephalon is 
obligated to provide Kyowa with exclusive use of such data in Japan; and 
(iii) may be used by Chiron and Cephalon outside the Field and inside the 
Territory upon commercially reasonable terms. If Cephalon is not obligated to
provide Kyowa Hakko Kogyo with the exclusive use of such data, Chiron may 
use the clinical data in Japan upon commercially reasonable terms. The grant 
of rights to use clinical data as specified in this paragraph (e) shall not 
be deemed to grant any express or implied rights or license in or to any other 
intellectual property of a Collaborator.

         (f)  REPORTS.  Each Collaborator shall report to the Development 
Committee, upon reasonable request (but not less than every three months), 
the status of its activities under the applicable Development Plan. The report
may be in writing or, at the option of the Collaborator, in an oral 
presentation made at the Development Committee meeting.

     SECTION 3.2  CLINICAL SUPPLIES OF PRODUCTS.

         (a)  GENERAL.  For Products other than IGF-1, the parties agree that 
Chiron shall manufacture the Collaboration's requirements of all finished 
Products to be used for clinical trials and other development activities 
under this Agreement, unless otherwise determined by the Management Committee.

         (b)  CLINICAL SUPPLIES OF IGF-1.  The Management Committee shall 
determine the appropriate time for Chiron to begin supplying IGF-1 for 
clinical purposes. Until that time, Cephalon will continue to use supplies of 
IGF-1 produced at the Cephalon Facility for clinical trials of IGF-1, 
including supplies needed to complete the U.S and European clinical trials of 
IGF-1 in treating ALS and the pilot trials of IGF-1 in treating peripheral 
neuropathies.

         (c)  SCALE-UP OF CHIRON FACILITY.  Chiron will use the Chiron 
Facility at Vacaville, California (the "Vacaville Facility") to manufacture 
the Collaboration's requirements of IGF-1 for clinical purposes in accordance 
with the Development Plans. Chiron will make reasonable efforts, including 
making capital investments, to scale-up and expand the applicable Chiron 
Facility as needed to allow sufficient GMP Grade Product to be made in 
accordance with the quantity, schedule and other requirements of the 
applicable Development Plan. Without limiting the foregoing, Chiron will 
proceed to install [CONFIDENTIAL TREATMENT REQUESTED]


                                      -13-


<PAGE>

[CONFIDENTIAL TREATMENT REQUESTED] at its Vacaville facility. The capital costs
incurred by Chiron for the scale-up activities shall not be an Allowable Expense
(except to the extent depreciation charges are included as a Cost). Chiron shall
take such other steps as may be commercially reasonable so that the Product 
produced at the Chiron Facility is acceptable for purposes of obtaining 
Regulatory Approvals in the Major Markets in accordance with the Development 
Plans.

         (d)  CEPHALON FACILITY.  Chiron and Cephalon will use the Cephalon 
Facility to supply IGF-1 for clinical supplies, as described in paragraph 
(b), and may use the Cephalon Facility as the Alternate Facility pursuant to 
Section 4.5 hereof. Chiron and Cephalon also will discuss using the Cephalon 
Facility to manufacture products of Chiron (other than Products) or, to the 
extent determined by the Management Committee to be cost-effective, other 
Products, provided that neither party is obligated to enter into an agreement 
to use the Cephalon Facility for any such purposes.

     SECTION 3.3  REGULATORY APPROVALS.

         (a)  ESTABLISHMENT LICENSES.  A Collaborator who supplies a Product 
to the Collaboration will be responsible for complying with all establishment 
registration requirements and obtaining all other applicable approvals 
required for the production of Products at the applicable manufacturing 
facility (collectively, "ELAs").

         (b)  REGULATORY AND PRICING APPROVALS.  It is intended that all 
Regulatory Approvals and Pricing Approvals relating to Products in the Field 
within the Major Markets will be owned by the Collaboration and will be 
registered in the name of the JV, unless otherwise required by law, and the 
JV shall be organized to permit such ownership. INDs and other pre-market 
clearances related to a Product shall be owned by the party conducting the 
clinical trials of the Product in the Field, unless otherwise required by 
law. To the extent that any INDs or other premarketing clearances or 
approvals related to any of the Products in the Field within the Major Markets 
are registered in the name of either Collaborator, such Collaborator will take 
such actions permitted by law as maybe necessary to transfer such clearances 
and approvals to the JV and otherwise will exercise its rights under all such 
clearances and approvals in a manner consistent with this Agreement.

         (c)  DILIGENCE.  Each Collaborator shall use all commercially 
reasonable efforts, commensurate with those efforts used for its other 
products of similar potential and consistent with its obligations under the 
Development Plans, to diligently obtain the approvals it is responsible for 
under the Development


                                     -14-


<PAGE>

Plans. Notwithstanding the foregoing, each Collaborator acknowledges that 
there can be no assurance that any ELA, Regulatory Approval or Pricing 
Approval will be obtained for a Product in any Major Market.

     SECTION 3.4  BALANCING OF DEVELOPMENT COSTS.

         (a)  BALANCING.  The parties deem their initial contribution of 
technology to the Collaboration with respect to IGF-1 to be of equal value. 
The parties intend that the Allowable Expenses funded by each of them to 
manufacture and develop Products in the Major Markets during the period 
between October 1, 1993 and the Commercialization Date will be equal as of 
the Commercialization Date.

         (i)  Each party shall fund its own Allowable Expenses under the 
    Development Plans through December 31, 1994 or, if later, the date when a 
    Collaborator has incurred an aggregate of $20 million in Allowable Expenses
    under the Development Plans; provided, however, that prior to that date 
    either Collaborator may, but shall not be required to, reimburse the other 
    Collaborator for any deficiency in the equal funding of Allowable Expenses,
    bearing interest at the per annum rate equal to the greater of the Prime 
    Rate as reported in the BLOOMBERG FINANCIAL MARKETS, COMMODITIES & NEWS (or
    any mutually acceptable successor thereto) or the rate of interest imputed 
    for the purposes of Federal income taxes (as such, the "Balancing Rate") on
    the amount of such deficiency as calculated as of the end of each Calendar 
    Quarter; but in no event shall the Balancing Rate exceed the maximum 
    interest rate allowed by applicable law.

          (ii) From and after the later of December 31, 1994 or the date when 
    one of the Collaborators has funded an aggregate of $20 million in Allowable
    Expenses under the Development Plans, the other party shall reimburse such 
    party for 100% of the Allowable Expenses funded thereafter by such party, 
    plus interest at the Balancing Rate on the amount of such deficiency as 
    calculated as of the end of each Calendar Quarter for the period of the 
    deficiency, until the aggregate Allowable Expenses (excluding interest) 
    funded by both parties since October 1, 1993 are shared equally (i.e., 
    balanced). Once the aggregate Allowable Expenses have been balanced, each
    party shall be responsible for funding 50% of the aggregate Allowable 
    Expenses incurred thereafter by the parties. The adjustments for Allowable
    Expenses shall be made on a quarterly basis under Section 6.5(b) hereof.

         (iii) If the Commercialization Date occurs before the Allowable 
    Expenses incurred under the Development Plans are balanced in full, the 
    balancing shall continue under


                                     -15-
<PAGE>


    clause (ii) for such expenses in addition to any balancing required under 
    Section 6.2(a) hereof.

              (iv) Notwithstanding anything to the contrary in this Section 
    3.4, if the Agreement is terminated for any reason before the Allowable 
    Expenses are balanced in full under clauses (i) or (ii) or Section 6.2(a), 
    then there shall be no balancing required except as may occur under Section 
    16.5(a).

          ARTICLE 4 - COMMERCIALIZATION ACTIVITIES IN MAJOR MARKETS

    SECTION 4.1  MARKETING STRATEGY IN MAJOR MARKETS.  The Management 
Committee shall establish a Marketing Committee which shall be responsible 
for developing a marketing strategy for each Product on a country-by-country 
basis within the Major Markets. The marketing strategy for each year shall be 
included in a marketing plan that is approved by the Management Committee (as 
so approved, a "Marketing Plan"). Each Collaborator shall appoint 50% of the 
permanent and alternate members of the Marketing Committee. Any action or 
decision by the Marketing Committee must be authorized by the approval of a 
majority of each party's designated members on the committee, unless 
otherwise specified in this Agreement. If the Marketing Committee can not 
agree on a particular matter, the matter shall be submitted for resolution to 
the Management Committee. If the Management Committee can not agree on a 
particular matter, the matter shall be submitted for resolution in accordance 
with Article 15 hereof.

    Without limiting the Marketing Committee's functions, the Marketing 
Committee shall, subject to the Management Committee's approval of the 
Marketing Plan and subject to Section 4.6:

              (i)  select the Trademark and the form of label, package insert 
    and packaging for each Product in each Major Market, subject to Section 9.7 
    hereof;

              (ii)  determine the pricing and reimbursement strategy for each 
    Product in each Major Market;

              (iii)  coordinate pre-launch activities for Products in the 
    Major Markets, including symposia and other marketing efforts;

              (iv)  establish the schedule for Product launch in each Major 
    Market;

              (v)  establish anticipated sales targets for each Product in 
    each Major Market;


                                     -16-


<PAGE>


              (vi)  identify the estimated capacity of Chiron and Cephalon 
(if applicable), to be used for the production of Products containing IGF-1 
pursuant to Section 4.5(b).

    SECTION 4.2  RESPONSIBILITIES OF THE PARTIES.

         (a)  ALLOCATION OF RESPONSIBILITIES.  The Marketing Plan shall 
identify the responsibilities of each Collaborator (or its third party 
subcontractors) in the promotion, marketing and distribution of Products in 
the Major Markets. In determining the appropriate allocation of 
responsibilities, the objective of the Marketing Committee is to maximize the 
efficiency and effectiveness of the commercialization of the Products in the 
Major Markets. Except as provided in this Article 4 or as otherwise 
determined by the Management Committee, Chiron will be responsible for 
marketing the Products in the Major Markets consistent with the Marketing 
Plan and will perform all distribution functions related to the Products, 
including, without limitation, distributor and wholesaler contracts, 
warehousing, order taking and processing, delivery, invoicing, collections and 
returns. However, the parties understand that (i) pursuant to the CIBA 
Agreement, CIBA has a right of first refusal under certain circumstances to 
sell or promote (including copromotion of) Products containing IGF-1 in the 
Territory, and (ii) Cephalon has the exclusive right to detail Products 
directly to neurologists in the Major Markets. The Management Committee shall 
determine whether a third party marketing arrangement is appropriate in any 
country or countries in the Major Markets and its approval shall be required 
with respect to the terms of any selling or promotion arrangement with CIBA 
on behalf of the JV, which arrangement shall be consistent with the terms of 
this Agreement; the Management Committee's approval shall not be withheld 
except on the grounds that the agreement is commercially unreasonable.

         (b)  DILIGENCE.  To the extent a Collaborator is responsible for any 
of the promotion, marketing or distribution of Products in the Major Markets, 
it shall perform such activities using commercially reasonable efforts, 
commensurate with those efforts used for its other products of similar 
potential and consistent with its obligations under the applicable Marketing 
Plans.

         (c)  EXPANSION OF RIGHTS.

              (i)  Cephalon shall have the right (but not the obligation) to 
detail Products directly to all purchasers in a country in the Major Markets 
if at any time during the term of this Agreement (A) Chiron, directly or 
indirectly, participates in the marketing or sale of any product (other than 
a product containing a Compound) that is approved for the same indication as 
a Product marketed or sold in that country by Chiron on behalf


                                     -17-


<PAGE>


of the Collaboration, and (B) Chiron has failed to diligently market the 
Product under Section 4.2(b) above in that country. The election by Cephalon 
to expand its rights to detail Products shall not affect Chiron's rights 
under the terms of this Agreement.

              (ii)  Chiron shall have the right (but not the obligation) to 
sell Products directly to neurologists in a country in the Major Markets if 
at any time during the term of this Agreement (A) Cephalon, directly or 
indirectly, participates in the marketing or sale of any product (other than 
a product containing a Compound) that is approved for the same indication as 
a Product detailed in that country by Cephalon on behalf of the 
Collaboration, and (B) Cephalon has failed to diligently detail the Product 
under Section 4.2(b) above in that country. The election by Chiron to expand 
its rights to market Products shall not affect Cephalon's rights under the 
terms of this Agreement.

         (d)  ALLOWABLE EXPENSES.  In no event shall the Allowable Expenses 
related to a detailing, selling or marketing activity exceed the Costs of the 
most cost-effective alternative for the Product, as determined by the 
Management Committee. The difference, if any, between the Costs of a 
Collaborator permitted as an Allowable Expense and its actual costs shall be 
the responsibility of that Collaborator.

    SECTION 4.3  COMMERCIALIZATION OF PRODUCTS.  The parties will explore and 
implement, to the extent feasible, an arrangement that will permit each 
Collaborator to report an approximately equal amount of Net Sales of Products 
in the Major Markets for each accounting period, in accordance with generally 
accepted accounting principles. Such arrangement, for example, could involve 
dividing the sales markets for Products on a geographic basis.

    SECTION 4.4  LABELLING.  Subject to Section 4.6, the label, package 
insert, packaging, advertising and promotional materials for each Product 
shall be approved by the Management Committee. All such materials shall 
identify the names of both Collaborators, unless prohibited by applicable 
law.

    SECTION 4.5  MANUFACTURE OF COMMERCIAL SUPPLIES OF PRODUCTS.

         (a)  GENERAL.  Except as otherwise provided in this Section 4.5, the 
Collaboration shall obtain all of its requirements for Products from Chiron. 
It is expected that Chiron will manufacture the commercial supplies of 
Products containing Compounds other than IGF-1. It is expected that Chiron 
will use its Vacaville Facility and Cephalon will use the Cephalon Facility 
for the production of commercial supplies of Products containing IGF-1 to the 
extent contemplated under paragraph (b) below. Each of the Collaborators, to 
the extent that it is manufacturing Products for the Collaboration, shall


                                     -18-


<PAGE>


use commercially reasonable efforts to manufacture and supply the finished 
Products for commercial purposes of the Collaboration in a cost-effective 
manner and in accordance with the terms of this Agreement and a supplemental 
manufacturing agreement to be entered into by the parties consistent with the 
terms of this Section 4.5.

    (b)  ALLOCATION OF CAPACITY FOR PRODUCTS CONTAINING IGF-1.  Chiron will 
use commercially reasonable efforts, including the making of capital 
investments, to scale-up and expand the Vacaville Facility to up to 
[CONFIDENTIAL TREATMENT REQUESTED] capacity to produce GMP Grade IGF-1 in 
quantities sufficient for the Collaboration's commercial purposes as specified 
in the Marketing Plans. At the time of the initial determination by the 
Management Committee that the [CONFIDENTIAL TREATMENT REQUESTED] capacity of 
the Vacaville Facility is not adequate to meet the forseeable requirements of 
the Collaboration, Cephalon may elect to use the Cephalon Facility as an 
Alternate Facility to provide the additional increments of capacity, not to 
exceed [CONFIDENTIAL TREATMENT REQUESTED] of capacity in the aggregate.  Any 
such election must be made promptly by Cephalon, but no later than thirty (30) 
days after the Management Committee's determination is made.  In such event, 
Cephalon will use commercially reasonable efforts, including the making of 
capital investments, to scale-up and expand its manufacturing facility in 
Beltsville, Maryland to provide GMP Grade IGF-1 for such purpose. In the event
that the IGF-1 Product requirements of the Collaboration exceed the allocated 
manufacturing capacity at the Chiron Facility and the Cephalon Facility, then 
Chiron shall use commercially reasonable efforts to expand its Vacaville 
Facility or another Chiron facility to produce quantities of Products 
sufficient for the Collaboration's commercial purposes as specified in the 
Marketing Plans.  The schedule for meeting commercial scale capacity for the 
Chiron Facility and the Cephalon Facility will be determined by the Management 
Committee, taking into account the quantities of IGF-1 required by the 
Collaboration, the anticipated regulatory schedule and the time and resources 
required to complete additional capital improvements. Each Collaborator shall 
take such other steps as may be commercially reasonable so that the Product 
produced at its facility or facilities meets the projected shipment schedules 
under the applicable Marketing Plan.

    (c)  EXCESS MANUFACTURING CAPACITY.  If the dedicated manufacturing 
capacity for the Products at the Chiron Facility and the manufacturing 
capacity at the Cephalon Facility as approved in the Marketing Plan is 
greater than the actual demand from the Products, then the supply requirements 
for the Products shall be allocated between the Chiron Facility and the 
Cephalon Facility as determined by the Management Committee.


                                     -19-


<PAGE>


    (d)  SUPPLY SHORTAGES AND INTERRUPTIONS.  If the manufacturing capacity 
at the Chiron Facility and the Cephalon Facility which is allocated to the 
manufacture of the Products under the applicable Marketing Plan is not 
adequate to meet the market demand for a Product, each Collaborator will 
allocate its other manufacturing capacity, if any, which is used to 
manufacture the Compound contained in such Product for the production of such 
Product in order to supply such Product in an amount equal to the lesser of 
(i) the Product quantities allocated to such Collaborator as set forth in the 
applicable Marketing Plan or (ii) such Collaborator's percentage of the 
Product supply as set forth in the Marketing Plan multiplied by the actual 
market demand for such Product.  If a force majeure event under Section 17.3 
affects the supply of a Product from the capacity allocated to a Collaborator 
under a Marketing Plan, the Collaborator may allocate such capacity ratably  
between the Collaboration's requirements and any supply obligations of the 
Collaborator to a third party.  If the Collaborators cannot satisfy their 
obligations to make a Product under this Agreement for a period of sixty (60) 
consecutive days, including any failure caused by a force majeure event under 
Section 17.3 hereof, the Management Committee shall designate a manufacturer 
(which may be a Collaborator) to make the Product until the Collaborators 
are able to resume supply of the Products under the terms of this Agreement.

    (e)  COST-EFFECTIVENESS.  The Management Committee will be responsible 
for reviewing the cost-effectiveness of the supply of each Product and to 
determine the amount of the manufacturing costs of each Collaborator that 
will be permitted as an Allowable Expense. [CONFIDENTIAL TREATMENT REQUESTED]
In reviewing the cost-effectiveness of the supply of each Product, the 
Management Committee may compare the Costs of manufacturing a Product at the
Chiron Facility and at the Cephalon Facility.  If the per unit cost of 
manufacturing a Product is higher at one of these facilities, the Management
Committee shall review the cost-effectiveness of such manufacturing and shall
determine the amount of the manufacturing costs that will be permitted as an 
Allowable Expense; provided, however, that in considering the cost-
effectiveness of the manufacturing and the Costs permitted as Allowable 
Expenses, the Management Committee shall recognize that a reasonable difference
in the costs of manufacturing at the Chiron Facility and the Cephalon Facility 
is to be expected in relation to the costs and benefits of maintaining an 
Alternative Facility, and is permitted as an Allowable Expense.

    (f)  PRODUCT QUALITY.  Each Collaborator agrees that each shipment of the 
Products manufactured by it will conform to the applicable Specifications and 
will be made, stored, packaged, 


                                     -20-


<PAGE>


labeled and controlled by it in accordance with the process and procedures 
contained in the applicable Regulatory Standards.  Neither Collaborator will 
modify any process or procedure used in the manufacture of a Product without 
notifying the Management Committee and allowing the Management Committee time 
to file any required notices with the applicable regulatory authorities and 
obtain any regulatory approvals required in connection with the modification. 
EXCEPT AS EXPRESSLY SET FORTH IN THE PRECEDING SENTENCE, NEITHER 
COLLABORATOR MAKES ANY EXPRESS OR IMPLIED WARRANTIES, STATUTORY OR OTHERWISE, 
CONCERNING THE PRODUCTS.  SPECIFICALLY, BUT WITHOUT LIMITING THE FOREGOING, 
NEITHER COLLABORATOR MAKES ANY EXPRESS OR IMPLIED WARRANTY OF 
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR OTHERWISE, QUALITY OR 
USEFULNESS OF THE PRODUCTS.


    (g)  FACILITY AUDIT AND INSPECTIONS.  A Collaborator manufacturing 
Products shall, upon reasonable advance notice, permit the other Collaborator 
or any other authorized representative of the Collaboration to audit the 
supplying Collaborator's manufacturing process and the manufacturing, 
production and control records for the Products.  Any such inspection shall be 
conducted subject to the confidentiality obligations under this Agreement.  
The supplying Collaborator shall take appropriate actions to adopt reasonable 
suggestions of the other Collaborator to correct any deficiencies identified 
by such inspection or audit.  To supplement this provision, the other 
Collaborator also may make arrangements, at its cost and expense (which 
shall not be an Allowable Expense), to have one of its employees located on 
the premises of the Chiron Facility or the Alternate Facility, as the case 
may be, to participate in the monitoring of Product manufacture.

    (h)  DEPOSIT OF BIOLOGICAL MATERIALS.  Each Collaborator shall deposit 
with a mutually agreeable depository (such as the ATCC), upon terms customary 
in the industry, all biological materials used in its manufacturing process, 
and shall provide all manufacturing information required to enable a third 
party to assume the manufacturing of Products under paragraph (e) above or 
Section 16.5 hereof.

    SECTION 4.6  ACTIVITIES OF CHIRON OUTSIDE THE FIELD.

    (a)  Cephalon recognizes that Chiron has development programs, and in the 
future may initiate development programs, with respect to the Compounds for 
indications outside the Field (a "Chiron Indication Product").  Nothing in 
this Agreement shall be construed to limit such rights as Chiron may 
otherwise have to develop or commercialize a Chiron Indication Product.  
Except as provided in this Article 4.6, all aspects of development and 
commercialization for Chiron Indication Products including, without 
limitation, clinical development, regulatory strategy and filings, marketing 
strategy and tactics, including pricing, may


                                     -21-


<PAGE>


be determined solely by Chiron. Without limiting the generality of the 
foregoing, for example, Chiron may determine the contents of labelling and 
package inserts for any Chiron Indication Product and may determine the 
prices at which any such product will be sold, even if the Chiron Indication 
Product is identical to a Product (other than with respect to labelling and 
package inserts). Chiron may make such determinations in its discretion 
notwithstanding that such determinations may effect the corresponding aspect 
of the Collaboration's development and commercialization of any Product that 
is based upon the same Compound in a manner that may or may not be in the 
best interest of the Collaboration.

         (b)  Notwithstanding (a) above, Chiron agrees to meet and confer in 
good faith with Cephalon and consider any recommendation Cephalon may make 
with respect to any action by Chiron with respect to Chiron Indication 
Products that Cephalon reasonably believes may have any material effects upon 
the development or commercialization of Products. Further, to the extent that 
any aspect of the development or commercialization of a Chiron Indication 
Product is related solely to the corresponding aspect of a Product approved 
for sale in the Field based upon the same Compound, Chiron shall take 
reasonable steps to conform such aspect of the Chiron Indication Product to 
the decisions of the Management Committee regarding the corresponding aspect 
of such Product. If a Collaborator is developing a product containing a 
Compound for commercialization outside the Field, the Collaborators will use 
commercially reasonable efforts to design the Collaboration's Product so that 
it would be differentiated from such product.

              To the extent that a Chiron Indication Product and a Product 
based upon the same Compound are differentiated such that a decision by 
Chiron with respect to an aspect of the Chiron Indication Product does not 
determine a corresponding aspect of the Product, Chiron shall take reasonable 
steps to preserve the differentiating aspect of the Chiron Indication Product 
so as to facilitate the implementation of decisions of the Management 
Committee regarding the corresponding aspect of the Product.

         (c)  Any Chiron Indication Product may be marketed under a 
tradename, tradedress and trademark chosen by, owned by and registered by 
Chiron. If Chiron elects to use the tradename, tradedress and trademark owned 
by or registered to the JV for a product that is both a Product and a Chiron 
Indication Product, the JV shall thereupon hold the trademark, tradedress 
and/or tradename for the benefit of both Chiron and the Collaboration and 
any goodwill related to the use thereof by the Parties within the Field shall 
accrue to the JV and any goodwill related to the use thereof by Chiron 
outside the Field shall accrue to the benefit of Chiron. Conversely, if the 
JV elects to use a tradename, tradedress and/or trademark owned and 
registered by


                                     -22-


<PAGE>


Chiron with respect to such product, Chiron shall hold the trademark, 
tradedress and/or tradename for the benefit of both Chiron and the 
Collaboration and any goodwill related to the use thereof by the Parties 
within the Field shall accrue to the JV and by Chiron outside the Field shall 
accrue to the benefit of Chiron.

              If a Chiron Indication Product has received Regulatory Approval 
in the Territory prior to the receipt by the Collaboration of Regulatory 
Approval of a Product containing the same Compound and Chiron reasonably 
determines after consultation with the Management Committee that the Product 
is not substantially differentiated from a Chiron Indication Product, Chiron 
may elect to require the Collaboration to market such Product under the same 
tradename, tradedress or trademark as is used in connection with such Chiron 
Indication Product. If a Product has received Regulatory Approval in the 
Territory prior to the receipt by Chiron of Regulatory Approval of a Chiron 
Indication Product containing the same Compound, the Collaboration may 
continue to use the tradename, tradedress or trademark approved by the 
Management Committee notwithstanding the subsequent approval of such Chiron 
Indication Product.

                             ARTICLE 5 - LICENSES

    SECTION 5.1  CROSS-LICENSES PRIOR TO FORMATION OF JV.

         (a)  PATENT RIGHTS.  Cephalon hereby grants to Chiron a 
royalty-free, nonexclusive license or sublicense in and to the patent rights 
included in the Cephalon Technology for use in the Field to develop and use 
Products in the Territory in accordance with the Development Plans. Chiron 
hereby grants to Cephalon a royalty-free, nonexclusive license or sublicense 
in and to the patent rights included in the Chiron Technology for use in the 
Field to develop and use Products in the Territory in accordance with the 
Development Plans. The cross-licenses in this clause (a) shall terminate 
upon the effectiveness of the licenses in Sections 5.2 and 5.3.

         (b)  PERPETUAL KNOW-HOW LICENSES.  Subject to the restrictions on the 
use of clinical data set forth in Section 3.1(e), Cephalon hereby grants to 
Chiron a perpetual, nonexclusive, royalty-free license (except for the 
royalty payable to the JV under Section 8.1 hereof) to all Technical 
Information included in the Cephalon Technology in the Territory, for any use 
by Chiron, whether inside or outside the Field. Subject to Section 3.1(e) and 
7.4, Chiron hereby grants to Cephalon a perpetual, nonexclusive, royalty-free 
license or sublicense (except for the royalty payable to the Chiron under 
Section 6.4 hereof) to all Technical Information that is included


                                     -23-


<PAGE>


in the Chiron Technology in the Territory, for any use by Cephalon, whether 
inside or outside the Field.

    SECTION 5.2  LICENSES TO JV.

         (a)  CEPHALON.  Upon the formation of the JV, Cephalon will grant to 
the JV an exclusive license in and to the Cephalon Technology for use in the 
Field to develop, make, have made, use and sell Products in the Territory, 
subject to the perpetual cross-licenses under Section 5.1(b).

         (b)  CHIRON.  Upon the formation of the JV, Chiron will grant to the 
JV an exclusive license in and to the Chiron Technology for use in the Field 
to develop, make, have made, use and sell Products in the Territory, subject 
to the perpetual cross-licenses under Section 5.1(b).

         (c)  JV TECHNOLOGY.  All rights licensed to the JV by the 
Collaborators pursuant to this Article 5, together with any invention or 
discovery, whether or not patentable, made solely or jointly by a JV employee 
after the Effective Date, are collectively referred to herein as the "JV 
Technology".

    SECTION 5.3  LICENSES FROM JV TO COLLABORATORS IN THE MAJOR MARKETS.  
Effective upon the formation of the JV, the JV hereby grants to each of 
Cephalon and Chiron a nonexclusive, royalty-free license, with no right to 
sublicense, in and to the JV Technology, to the extent required for each 
party to conduct its responsibilities in the Major Markets under this 
Agreement or any Development Plan or Marketing Plan.

    SECTION 5.4  LICENSE FROM JV TO CHIRON IN THE ROYALTY TERRITORY.  
Effective upon the formation of the JV, the JV hereby grants to Chiron an 
exclusive, worldwide right and license in and to the JV Technology to make, 
have made, use and sell Products in the Royalty Territory, subject to the 
royalty obligation and other terms and conditions of Article 8 hereof.

    SECTION 5.5  OPTIONAL RIGHTS.

         (a)  SIBIA RIGHTS.  Cephalon hereby grants to Chiron and the JV a 
nonexclusive option to include in the license under Sections 5.1 or 5.2, as 
applicable, the SIBIA Rights of Cephalon inside the Field. If Chiron or the 
JV elects in writing to exercise the option inside the Field for purposes of 
the Collaboration, the SIBIA Rights shall automatically become part of the 
Cephalon Technology and any third party royalties payable as a result of the 
use by the JV of the SIBIA Rights in the Major Markets shall be deemed a 
Third Party Royalty to be paid by the JV. [CONFIDENTIAL TREATMENT REQUESTED]

                                     -24-





<PAGE>

[CONFIDENTIAL TREATMENT REQUESTED] If at any time prior to Chiron's exercise 
of its option Cephalon proposes to transfer or terminate any of the SIBIA 
Rights, Cephalon shall provide Chiron with notice thereof, sufficiently in 
advance to allow Chiron to exercise its option or otherwise obtain such rights
directly from SIBIA. If Chiron exercises its option, Cephalon shall maintain 
the SIBIA Rights in accordance with the provisions of Section 5.10.

         (b)  CEPHALON IGF-1 TECHNOLOGY OUTSIDE THE FIELD.
Except as provided in this Section 5.5; Cephalon shall not develop or 
commercialize with any third party, or license intellectual property rights 
from any third party related to the development or commercialization of a 
product containing IGF-1 for an indication outside the Field using Cephalon 
Technology or any proprietary technology that it developed pursuant to the 
Development Plans, without the prior written consent of Chiron. Cephalon 
currently owns or has license rights to certain technology relating to the 
use of IGF-1 for indications outside the Field ("Nonfield Indications"). All 
of these Nonfield Indications and the related technology rights are 
identified on Schedule VIII hereto. In addition, Cephalon may develop, in the 
course of performing activities pursuant to the Development Plans or 
otherwise, data which indicates that IGF-1 may have utility for an indication 
outside the Field (the "Additional Nonfield Indications"). Cephalon shall 
notify Chiron in writing if it develops any such data with respect to an 
Additional Nonfield Indication, and such notice shall contain a summary of such
data in reasonable detail to enable Chiron to analyze the merits of the 
possible utility. Cephalon hereby grants to Chiron the right to obtain from 
Cephalon, exclusive rights to the technology and related Technical Information
for any of the Nonfield Indications and Additional Nonfield Indications for use
outside the Field. Chiron shall notify Cephalon if it wishes to negotiate a
transaction with respect to a Nonfield Indication or Additional Nonfield 
Indication. If Chiron and Cephalon, after good faith negotiations, have failed
to reach agreement within 90 days as to the appropriate terms and fair market 
compensation for such indication, the parties will submit the determination of 
fair market compensation to arbitration pursuant to Section 15.2 hereof. 
Notwithstanding the foregoing, Chiron may elect to have the Collaboration 
obtain such rights to the Nonfield Indication or Additional Nonfield 
Indication on terms mutually acceptable to Chiron and Cephalon. The parties 
intend that such terms shall reflect a profit participation for Cephalon that 
represents the economic equivalent of a commercially reasonable royalty and the
equal sharing by Chiron and Cephalon of future development costs


                                     -25-


<PAGE>


with respect to such indication. The rights of Chiron under this Section 5.5(b) 
are subject to any approvals of the CCP Board of Directors or partners 
required under the applicable Cephalon Agreements. Cephalon shall use its best 
efforts to obtain such approvals, if required.

     SECTION 5.6  RETAINED RIGHTS.  Each of Chiron and Cephalon reserves the 
right to use, respectively, the Chiron Technology and the Cephalon 
Technology, for any purpose whatsoever outside the Field and/or outside the 
Territory, without liability to the other party or to the JV, except as may 
be otherwise specified in Sections 5.5(b), and 6.2(b) and 6.3 hereof.

     SECTION 5.7  PRIOR RIGHTS.  The rights granted or to be granted by 
Cephalon to Chiron and the JV under this Agreement are subject in all 
respects to the prior rights of third parties under the Cephalon Agreements. 
The rights granted or to be granted by Chiron to Cephalon and the JV under 
this Agreement are subject in all respects to the prior rights of third 
parties under the Chiron Agreements.

     SECTION 5.8  INVENTIONS.  All inventions and discoveries resulting from 
the Collaboration, whether or not patentable, shall be owned by the 
Collaborator making the invention or discovery. All Joint Technology shall be 
owned by the JV or, in the absence of the JV, by the Collaborators jointly.

     SECTION 5.9  NEW TECHNOLOGIES.  

         (a)  THIRD-PARTY RIGHTS.  The Management Committee may acquire from 
third parties, if commercially reasonable, such rights to new technology in 
the Field as are necessary or desirable for the JV, directly or indirectly, 
to make, use and sell Products. The JV (and not the Collaborators 
individually) shall be responsible for any payments or royalties for such 
rights attributable to the sale of Products in the Major Markets owing to a 
third party under an agreement approved by the Management Committee.

         (b)  ADDITIONAL TECHNOLOGY OF COLLABORATORS.  The parties 
contemplate that Chiron's biologically-active small molecules and its 
proprietary molecular diversity technology and other proprietary Chiron 
compounds other than the Chiron Products may be added to the Collaboration, 
upon terms to be mutually agreed to by the Collaborators. Similarly, Cephalon 
and Chiron may from time to time agree in writing to include within the scope 
of this Agreement any other composition, product or technology of a 
Collaborator, upon terms to be mutually agreed to by the Collaborators. Unless
and until an agreement is executed providing for the addition of technology to
the Collaboration, the Collaborator shall be free to develop or dispose of such
technology in any manner it sees fit.


                                     -26-


<PAGE>


     SECTION 5.10  MAINTENANCE OF TECHNOLOGY.  In addition to its 
obligations under Section 9.1, Cephalon and Chiron shall notify the other 
Collaborator before allowing any intellectual property right included in the 
Cephalon Technology or the Chiron Technology, as applicable, the loss of 
which would have a material adverse effect on the business of the 
Collaboration to lapse, expire or terminate before its stated expiration or 
termination date, sufficiently in advance to allow the other Collaborator to 
seek to obtain the rights to such technology. Each Collaborator shall use 
all commercially reasonable efforts to maintain in full force and effect any 
license or other agreement pursuant to which it derives rights included in 
the Cephalon Technology or the Chiron Technology, as the case may be, the 
loss of which would have a material adverse effect on the business of the 
Collaboration and shall promptly notify the other if it receives notice or 
otherwise becomes aware of any default under any such agreement. Without 
limiting the foregoing, neither Collaborator shall amend or modify any such 
third-party agreement in a manner that would limit the benefits or expand the 
obligations of the Collaboration with respect to any such rights without the 
prior consent of the other Collaborator, which consent shall not be unreasonably
withheld. Neither Collaborator shall transfer or assign to an unaffiliated party
any such third party agreement or any other intellectual property right that is
licensed to the other Collaborator or the JV under this Agreement, without the 
prior approval of the Management Committee.

     SECTION 5.11  SUBLICENSING OF TECHNOLOGY.  Cephalon may sublicense its 
rights under Section 5.1(b) to its licensees or sublicensees to the extent 
required by the corresponding Cephalon Agreement, and Chiron may sublicense 
its rights to its licensees or sublicensees. The JV may sublicense all or 
part of the JV Technology to one or more third parties, subject to the 
execution by the third party of a sublicense agreement satisfactory to the 
Management Committee.

     SECTION 5.12  DISCLOSURE OF TECHNOLOGY.  Promptly after the Effective 
Date and from time to time thereafter during the term of this Agreement, each 
Collaborator shall promptly disclose to the other the Technical Information 
which becomes known to it to the extent licensed to the other Collaborator or 
the JV under this Article 5. In addition, each Collaborator shall promptly
disclose to the other Collaborator, in writing, any invention 
or discovery included in its license to the other Collaborator of the 
Cephalon Technology or Chiron Technology, as the case may be, under Article 5.


                                     -27-


<PAGE>


                  ARTICLE 6 - COMPENSATION IN MAJOR MARKETS

    SECTION 6.1  EQUAL SHARING OF OPERATING PROFITS AND LOSSES.  The 
Operating Profits and Operating Losses shall be shared equally by Cephalon 
and Chiron, except for the special allocation described in Section 6.2(a) 
hereof.

    SECTION 6.2  SPECIAL ALLOCATIONS.

         (a)  BALANCING OF COSTS AFTER COMMERCIALIZATION DATE.  To the extent 
the Allowable Expenses of the Collaborators are not equally funded as of the 
Commercialization Date, the Collaborator who funded the greater share of 
Allowable Expenses shall be entitled to receive from sales of Products in the 
Major Markets, prior to the allocation of Operating Profits under Section 
6.1, a special allocation equal to [CONFIDENTIAL TREATMENT REQUESTED] plus 
[CONFIDENTIAL TREATMENT REQUESTED]. These credits shall be applied until
the Collaborator has received 100% of its excess Allowable Expenses as of the 
Commercialization Date, plus interest at the Balancing Rate (as defined in 
Section 3.4) on the amount of such excess for the period of the excess amount.

         (b)  SALES FOR DIABETES.  The parties acknowledge that sales of a 
Product containing IGF-1 for diabetic neuropathy may overlap with sales of a 
product containing IGF-1 for diabetes. The parties therefore agree that if an
IGF-1 Product of the JV receives Regulatory Approval for the treatment of
diabetic neuropathy or a Collaborator receives Regulatory Approval in the 
Territory of another product containing IGF-1 for the treatment of diabetes,
the Collaborators will [CONFIDENTIAL TREATMENT REQUESTED] The allocation 
established by the parties shall apply regardless of which indication is 
approved first, and shall apply in lieu of any provisions of Section 6.3 
that might otherwise be applicable.


                                     -28-


<PAGE>


    SECTION 6.3  OFF-LABEL SALES IN THE MAJOR MARKETS.

         (a)  If a Product of the Collaboration receives Regulatory Approval 
in the Field in a country in the Major Markets prior to the receipt by Chiron 
(or its licensee or joint development partner) of Regulatory Approval in such 
country of a product containing the same Compound for an indication outside 
the Field then all sales of such Product used for an indication (whether 
inside or outside the Field) in that country shall be included in the Net 
Sales used to calculate Operating Profits and, if applicable, any royalty 
payable to Chiron pursuant to Section 6.4 with respect to such country; 
provided that all costs and expenses associated with such Net Sales shall be 
included as an Allowable Expense. Notwithstanding the foregoing, [CONFIDENTIAL
TREATMENT REQUESTED] shall be excluded from the Net Sales used to calculate 
Operating Profits and, if applicable, any royalty payable to Chiron pursuant 
to Section 6.4 and in lieu thereof Chiron shall pay to the JV a royalty equal to
[CONFIDENTIAL TREATMENT REQUESTED]; provided that all costs and expenses 
associated with such excluded Net Sales shall not be included as an Allowable 
Expense. [CONFIDENTIAL TREATMENT REQUESTED]

         (b)  Upon the receipt by Chiron (or its licensee or joint 
development partner) of Regulatory Approval of a product outside the Field 
containing the same Compound as a Product, in a country in the Major Markets, 
all sales thereafter of the Product for use in any indication outside the 
Field in such country (according to market reports accepted in the industry) 
shall not be counted for purposes of calculating, with respect to such 
country (i) Operating Profits, (ii) any royalty payable to the JV under 
Section 6.3(a) above, or (iii) any royalty payable to Chiron pursuant to 
Section 6.4. All Costs associated with such sales shall not be permitted as 
Allowable Expenses for any purpose.

    SECTION 6.4  ROYALTIES TO CHIRON ON SALES OF CHIRON PRODUCTS.

         (a)  BASE ROYALTY.  The JV shall pay to Chiron a reasonable royalty 
on Net Sales of Chiron Products in the Major Markets. The royalty rate for 
each Chiron Product shall be negotiated by Cephalon and Chiron in good faith 
no later than the time an application for a Regulatory Approval is submitted 
in a Major Market for the corresponding Chiron Product. The royalty rate 
shall be the amount a third party would be willing to pay,


                                     -29-


<PAGE>


taking into consideration all relevant factors, including the value of the 
technology contributed by Chiron, the market opportunity for the Chiron 
Product, the availability of patent protection, the necessity of paying 
royalties to third parties, and the Costs and risks incurred or to be 
incurred by the Collaborators for development of the Chiron Product. The 
royalty rate for Net Sales of Products in the Major Markets shall not be less 
than [CONFIDENTIAL TREATMENT REQUESTED] nor more than [CONFIDENTIAL TREATMENT 
REQUESTED] for a Chiron Product having Market Exclusivity (but which maximum 
rate shall not be more than [CONFIDENTIAL TREATMENT REQUESTED] in the case of a
Chiron Product if the preclinical and Phase I clinical data that is provided by
Chiron is substantially sufficient to permit clinical testing of the 
corresponding Product in the Field), and shall not be less than [CONFIDENTIAL
TREATMENT REQUESTED] nor more than [CONFIDENTIAL TREATMENT REQUESTED] for other 
Chiron Products.

         (b)  ADJUSTMENTS TO ROYALTY

              (i)  The royalty payable under Section 6.4(a) for a Chiron 
Product with Market Exclusivity in a particular country in the Major Markets 
shall be reduced by an equitable amount to be determined by the Management 
Committee with respect to Net Sales of such Chiron Product in the country if 
a product containing the same Compound either (A) is being sold by a third 
party (other than third parties having rights through a Collaborator) in that 
country for the same indication, or (B) is approved for an indication in that 
country covered by the patent used to establish Market Exclusivity for the 
indication in the same country and there is no other basis for establishing 
Market Exclusivity as to the Chiron Product indication in that country.

              (ii)  The royalty payable under Section 6.4(a) for a Chiron 
Product without Market Exclusivity in a particular country in the Major 
Markets shall be increased to the rate used in a country where the Chiron 
Product has Market Exclusivity, if Chiron can reasonably demonstrate that 
even without Market Exclusivity, there is no significant competition for the 
Chiron Product with respect to the indication for which the Chiron Product 
received Regulatory Approval in the country. For purposes of this provision, 
"significant competition" means sales of a product by a third party or third 
parties (other than third parties having rights through a Collaborator) 
constitute more [CONFIDENTIAL TREATMENT REQUESTED]

              (iii)  If a royalty rate determined pursuant to Section 6.4(a) 
is such that the JV's profit percentage from sales of Chiron Products in the 
Major Markets is greater than or less than the percentage anticipated by the 
parties as of the Effective Date, Cephalon and Chiron shall meet and confer 
as to whether the royalty rates should be increased or decreased to


                                     -30-


<PAGE>


provide the JV and Chiron with a fair allocation of the economic benefits in 
the Major Markets.  Any such adjustment may be made on a country-by-country 
and Product-by-Product basis.

    SECTION 6.5  CALCULATION OF OPERATING PROFITS.

    (a)  PRIOR TO FORMATION OF JV.

         (i)  REPORTING.  Within twenty-one (21) days after the end of each 
month after the Effective Date until the formation of the JV, Cephalon shall 
submit to Chiron a report detailing all Allowable Expenses funded by Cephalon 
for the applicable month.  Within thirty (30) business days after the end of 
a Calendar Quarter, Cephalon shall also submit to Chiron a final report 
detailing all Allowable Expenses funded by Cephalon for the applicable 
quarter.  


         (ii)  STATEMENT OF ALLOWABLE EXPENSES.  Based on the reports of 
Cephalon, Chiron shall prepare a pro forma statement of its Allowable 
Expenses, combined Allowable Expenses and an inception-to-date report of each 
Collaborator's Allowable Expenses which it shall send to Cephalon no later 
than forty (40) days after the end of the applicable month.  In addition, 
based on the quarterly reports of Cephalon, Chiron shall prepare a final pro 
forma statement of combined Allowable Expenses and a final inception-to-date 
report of each Collaborator's Allowable Expenses for the Cephalon Quarter, 
which it shall send to Cephalon no later than sixty (60) days after the end 
of the Calendar Quarter.  Within fifteen (15) days after receiving the 
monthly report, the Collaborators shall make any payments, if required, to 
accomplish balancing under Section 3.4 (a) (ii) hereof.

         (iii)  CONFIRMATION.  Each Collaborator's chief financial officer 
shall confirm on an annual basis that the quarterly reports furnished during 
the year were prepared in accordance with the accounting principles and 
methodology authorized pursuant to Section 2.3 (c) hereof.

    (b)  JV REPORTING.  Prior to the formation of the JV, the Management 
Committee will determine the appropriate reporting requirements and 
procedures, including the timing and method of calculating the preliminary 
and the final Operating Profits of the JV, the reporting of Net Sales in the 
Royalty Territory and the manner in which payments or refunds of overpayments 
will be made, but in no event shall such payments be made less frequently 
than sixty (60) days after each Calendar Quarter.  The reporting requirements 
and procedures of the JV will be based on the approved Marketing Plans.  The 
Management Committee shall review the reporting requirements and procedures 
of the JV when appropriate in light of changes to the Marketing Plans, 
changes in or financial statement reporting requirements.  Notwithstanding 
the foregoing, the Collaborators agree that Chiron will be responsible for 
compiling the financial statements


                                     -31-


<PAGE>


of the JV and, if the JV is organized as a partnership, shall be the Tax 
Partner for federal income tax purposes.

                 PART III - ACTIVITIES IN ROYALTY TERRITORY

    ARTICLE 7 - DEVELOPMENT AND COMMERCIALIZATION ACTIVITIES IN 
                ROYALTY TERRITORY

    SECTION 7.1  DEVELOPMENT AND COMMERCIALIZATION RESPONSIBILITIES.  Chiron 
shall be responsible for conducting, at its own cost and expense, all 
activities relating to the development, manufacture and marketing of the 
Products in the Royalty Territory including, without limitation the 
establishment of a sales force or distribution network and the promotion and 
sale of Products.  All Regulatory Approvals and Pricing Approvals in the 
Royalty Territory shall be in the name of Chiron.

    SECTION 7.2  COORDINATION WITH COLLABORATION.

    (a)  Chiron shall consult with the Development and Marketing Committees 
with respect to the following activities:

         (i)  the preparation of its development and marketing plans for the 
              Products in the Royalty Territory;

         (ii)  the preparation of Product labelling and promotional materials 
               to be used with Products in the Royalty Territory; 

         (iii)  the designation of Trademarks for the Products in the Royalty 
                Territory; and 

         (iv)  the choice of supplier of the Products to be developed or sold 
               in the Royalty Territory.

Subject to Section 4.6, the plans for these activities will be submitted to 
the Management Committee for review and approval reasonably in advance of the 
specified activity, which approval shall not be withheld except on the 
grounds that the proposal is commercially unreasonable.  The members of the 
Management Committee in reviewing and approving the proposed activities of 
Chiron shall act in the interests of the Collaboration and not with regard to 
the individual interests of Chiron or Cephalon.  Chiron shall keep the 
Management Committee informed of its progress under its development and 
marketing plans in the Royalty Territory.

    (b)  Chiron shall not sublicense or enter into any comarketing, 
copromotion or similar arrangement in the Royalty Territory without the prior 
approval of the Management Committee

                                     -32-


<PAGE>


(which consent shall not be unreasonably withheld), excluding wholesaling, 
distribution and consignment arrangements, where the third party does not 
market or promote the Products. Nothwithstanding the foregoing, CIBA is 
hereby approved for purposes of marketing Products in the Royalty Territory, 
upon terms to be approved by the Management Committee (which approval shall 
not be withheld except on the grounds that the terms are commercially 
unreasonable).

    SECTION 7.3 DILIGENCE IN COMMERCIALIZATION OF PRODUCTS. Chiron shall use 
commercially reasonable efforts, commensurate with those efforts used for its 
other products of similar potential and consistent with its obligations under 
the development and marketing plans approved under Section 7.2 hereof, to 
commercialize the products in the Royalty Territory and to obtain all 
Regulatory Approvals and Pricing Approvals needed in the Royalty Territory 
for such purposes.


    SECTION 7.4 OWNERSHIP OF DATA. All clinical data developed by Chiron for 
purposes of Regulatory Approvals in the Royalty Territory shall be owned by 
Chiron, but may be used in the Field and Territory by Chiron, Cephalon and 
the JV pursuant to the licenses granted under Article 5 hereof and may be 
used by Chiron outside the Field and outside the Territory without limitation.

    SECTION 7.5 NO ALLOWABLE EXPENSES. None of the costs and expenses 
incurred by Chiron in connection with the Royalty Territory shall be an 
Allowable Expense hereunder unless expressly approved as such by the 
Management Committee.

    SECTION 7.6 ASSISTANCE BY THE JV. Chiron may request the assistance of the 
JV or Cephalon in the development and commercialization activities related to 
the Product. Any such assistance shall be provided upon mutually acceptable 
terms.

    SECTION 7.7 CONTINGENT CEPHALON MARKETING RIGHTS.

         (a) EVENTS. Cephalon shall have the right (but not the obligation) to 
detail Products in a country within the Royalty Territory if:

              (i) Chiron participates, directly or indirectly, in the 
                  marketing, sale or distribution of any product in that
                  country that directly competes with an indication included
                  in a Regulatory Approval for a Product in the same country;
                  and

              (ii) Chiron has failed to diligently develop and commercialize 
                   such Product under Section 7.3 hereof in that country.


                                     -33-
<PAGE>

          (b)  PROCEDURES.  Cephalon shall give Chiron written notice of the 
existence of the conditions described in clause (a) above, and Chiron shall 
have a period of 90 days in which to cure. If the conditions have not been 
adequately cured in Cephalon's reasonable judgment by the end of such period, 
Cephalon's right to detail shall be effective upon written notice from 
Cephalon to Chiron at which time Cephalon shall be entitled to detail all 
Products in such country on a nonexclusive basis. Cephalon shall be paid a 
reasonable fee by the JV for such activities and Cephalon's costs to detail 
the Products shall not be an Allowable Expense. Chiron's obligations to 
compensate the JV under Article 8 shall continue as to any Products continued 
to be marketed and sold by it or detailed by Cephalon, except that the 
royalty payable with respect to such Net Sales shall be reduced to the rate 
determined under Section 8.1(b) hereof as to any Product that Cephalon is 
detailing. The election by Cephalon to detail Products in the Royalty 
Territory shall not affect Chiron's rights under this Agreement.

                  ARTICLE 8 - ROYALTIES AND REPORTS, ETC.

     SECTION 8.1  ROYALTIES.  In consideration of the licenses granted to 
Chiron under Section 5.4 hereof, Chiron shall pay to the JV in each country 
within the Royalty Territory a royalty equal to:

          (a)  [CONFIDENTIAL TREATMENT REQUESTED] of the Net Sales of a Product
containing IGF-1 for a particular indication in any country where the Product 
has Market Exclusivity for that indication; and

          (b)  [CONFIDENTIAL TREATMENT REQUESTED] of the Net Sales of a Product
containing IGF-1 for a particular indication in any country where the Product 
does not have Market Exclusivity for that indication; and

          (c)  in the case of any Product containing a Compound other than 
IGF-1, a reasonable royalty to be negotiated by the Collaborators in good 
faith (which shall be not less than [CONFIDENTIAL TREATMENT REQUESTED] of Net 
Sales), to be determined upon the request of either Collaborator but in no event
later than the first commercialization of a Product in the Royalty Territory.

     SECTION 8.2  ROYALTY RATE ADJUSTMENTS.

          (a)  The royalty rate payable under Section 8.1(a) shall be reduced 
by an equitable amount to be determined by the Management Committee with 
respect to a Product in a country in the Royalty Territory if a product 
containing the same Compound either (i) is being sold by a third party (other 
than a third party having rights through a Collaborator) in that country for 
the same indication, or (ii) is approved for an indication in that country 
covered by the patent used to establish Market

                               -34-

<PAGE>

Exclusivity for the indication in the same country and there is no other basis 
for establishing Market Exclusivity as to the Product indication in that 
country.

          (b)  The royalty rate payable under Section 8.1(b) for a particular 
country in the Royalty Territory shall be increased to the rate specified in 
Section 8.1(a) with respect to a Product in such country in the Royalty 
Territory if Cephalon can reasonably demonstrate that even without Market 
Exclusivity, there is no significant competition for the Product in that 
country with respect to the indication for which the Product received 
Regulatory Approval in the country. For purposes of this provision, 
"significant competition" means sales of a product by a third party or third 
parties (other than third parties authorized by a Collaborator under this 
Agreement) constitute more than [CONFIDENTIAL TREATMENT REQUESTED]

          (c)  If a royalty rate specified in Section 8.1 is such that Chiron, 
after paying such royalties, would not receive a fair return on sales of the 
Products because of market conditions outside of its control, Cephalon and 
Chiron shall meet and confer as to whether the royalty rates should be 
reduced to provide Chiron with a fair allocation of the economic 
benefits in the Royalty Territory. Conversely, if the royalty rates specified 
in Section 8.1 are such that the JV's share of profits from the royalties on 
sales of Products in the Royalty Territory is less than the share of profits 
anticipated by the parties as of the Effective Date, Cephalon and Chiron shall 
meet and confer as to whether the royalty rates should be increased to 
provide the JV with a fair allocation of the economic benefits in the Royalty 
Territory, but in no event shall any such increase exceed a royalty rate of 
[CONFIDENTIAL TREATMENT REQUESTED] of Net Sales. Any such adjustment may be made
on a country-by-country and Product-by-Product basis.

          (d)  The royalty rates payable by Chiron to the JV under Section 
8.1 shall be subject to increase to provide Cephalon with a share of 
Operating Profits of the JV that is sufficient to pay any royalty or other 
compensation Cephalon may owe CCP under an Amended and Restated Product 
Development Agreement dated as of August 11, 1992 (the "CCP Agreement"), in a 
country within the CCP Territory. For purposes of this clause (d), the term 
"CCP Territory" means the geographic area encompassed by the following 
countries on the date hereof: Albania, Andorra, Bulgaria, the Commonwealth of 
Independent States, Cyprus, Czechoslovakia, Gibraltar, Hungary, Iceland, 
Liechtenstein, Malta, Monaco, Poland, Romania, San Marino, Turkey and 
Yugoslavia. The term "CCP Territory" shall also include the geographic area 
encompassed by any of the republics that were formerly part of the U.S.S.R. 
and Yugoslavia, regardless of whether such republics are as of the date hereof 
members of the

                                    -35-

<PAGE>

Commonwealth of Independent States or Yugoslavia, as applicable. Chiron and 
Cephalon shall meet and confer as to whether the royalty ratees payable by 
Chiron to the JV under Section 8.1 should be increased with respect to any 
country or Product to provide Cephalon with a share of Operating Profits of 
the JV that is sufficient to provide a fair return to Cephalon.

          (e)  The royalty rates under Section 8.1 also are subject to 
reduction under Sections 9.2 and 9.3 hereof.

     SECTION 8.3  ALLOCATIONS OF NET SALES IN THE ROYALTY TERRITORY.

          (a)  OFF-LABEL SALES.  If a Product of the Collaboration receives 
Regulatory Approval in the Royalty Territory prior to the receipt by Chiron 
(or its licensee or joint development partner) of Regulatory Approval in the 
Royalty Territory of a product containing the same Compound as the Product 
for an indication outside the Field, then all sales of such Product used for 
any indication (whether inside or outside the Field) in the Royalty Territory 
shall be included in the Net Sales used to calculate the royalty payable by 
Chiron pursuant to Section 8.1. Notwithstanding the foregoing, [CONFIDENTIAL 
TREATMENT REQUESTED] All sales of the Product used in any indication outside 
the Field (according to market reports accepted in the industry) in a country 
in the Royalty Territory shall be excluded for purposes of calculating the 
royalty payable by Chiron pursuant to Section 8.1 in such country when Chiron
(or its licensee or joint development partner) receives Regulatory Approval 
for an indication outside the Field for such Product either in such country 
itself or in any country in the Major Markets, whichever occurs first.

          (b)  SALES FOR DIABETES.  The portion of Net Sales in any country in 
the Royalty Territory that is deemed to be sales of an IGF-1 Product for 
diabetic neuropathy in such country shall be determined in accordance with 
Section 6.2(b).

     SECTION 8.4  THIRD PARTY ROYALTIES.  Chiron shall be responsible for any 
royalties or other compensation owed by either Collaborator under the 
agreements specified on SCHEDULE IV to any third party as a result of 
Chiron's commercialization of Products in the Royalty Territory including, 
without limitation, compensation payable pursuant to the CIBA Agreement and 
pursuant to the SIBIA Rights. Notwithstanding the foregoing: (i) Cephalon 
shall be responsible for any royalties owed by it pursuant to the CCP 
Agreement, (ii) Chiron may offset royalties

                                 -36-


<PAGE>

payable to certain third parties to the extent provided in Section 9.2(e), 
and (iii) Chiron may include in the determination of Net Sales subject to 
royalty under Section 8.1, a deduction for any royalty payable to a third 
party in any country in the Royalty Territory under any license or similar 
agreement that has been approved by the Management Committee under Section 
5.9, but in no event shall the total deductions for such royalties reduce the 
royalty payment by more than 50% in the aggregate.

   SECTION 8.5  PAYMENT OF ROYALTIES. Royalties payable to the JV under 
Section 8.1 shall be due within sixty (60) days after the end of the Calendar 
Quarter in which Net Sales were recorded by Chiron.

   SECTION 8.6  REPORTS. Unless otherwise agreed by Cephalon and Chiron, 
Chiron shall deliver to the JV within sixty (60) days after the end of each 
Calendar Quarter in which royalties are due a report of the chief financial 
officer of Chiron, setting forth in reasonable detail the calculation of the 
royalties payable to the JV for such Calendar Quarter, including the Net 
Sales on a Product by Product and country-by-country basis. In addition, 
within ninety (90) days after the close of each calendar year, Chiron, upon 
Cephalon's request, shall cause its independent public accountants to prepare 
a report confirming the procedures performed in reviewing the accuracy of the 
aggregate Net Sales and calculation of royalties payable to the JV under 
Section 8.1 for that calendar year. Cephalon shall reimburse Chiron for the 
reasonable costs of such review.

   SECTION 8.7  CURRENCY RESTRICTIONS. If Chiron is prevented from making any 
royalty payment to the JV under this Agreement by virtue of restrictions on 
currency conversion or repatriation under the statutes, laws, codes or 
governmental regulations of the country from which the payment is to be made, 
then such royalty payments may be paid by depositing them in the currency in 
which accrued to the JV's account in a bank acceptable to the JV in the 
country whose currency is involved.

   SECTION 8.8  TAXES. All taxes, assessments and fees of any nature levied or 
incurred on account of any payments accruing under this Agreement by 
national, state or local governments in the Royalty Territory, will be 
assumed and paid by Chiron, except taxes levied thereon as income to the JV. 
If taxes payable by the JV are required to be withheld by Chiron, they will 
be deducted from such payments due to the JV and will be paid by Chiron for 
the account of the JV.

                                      -37-
<PAGE>

                         PART IV - GENERAL PROVISIONS

                  ARTICLE 9 - INTELLECTUAL PROPERTY MATTERS

   SECTION 9.1  INTELLECTUAL PROPERTY PROTECTIONS.

      (a) CONTROL. Each Collaborator shall be responsible for and shall have 
the right to control the prosecution, maintenance, reissue, reexamination, 
renewal and extension of the patent applications, issued patents and 
Trademarks included in the intellectual property in the Territory licensed by 
it to the other Collaborator or to the JV pursuant to Article 5 hereof. Each 
Collaborator, upon reasonable request, shall report to the Management 
Committee the status of any such activities and shall furnish copies of any 
correspondence, file wrappers, office actions and such other documents as the 
Management Committee shall reasonably require to monitor the activities in 
the Territory. If a Collaborator elects not to continue the prosecution of 
any application, reissue, reexamination, renewal or extension or to pay any 
maintenance fee related to any such intellectual property right, it shall 
notify the Management Committee of such decision at least thirty (30) days in 
advance of the due date for such action or payment, and the other 
Collaborator shall have the right, but not the obligation, to assume 
responsibility therefor. Cephalon shall be responsible for coordinating its 
activities with CCP and Chiron shall be responsible for coordinating its 
activities with CIBA.

      (b) COOPERATION. Each Collaborator shall cooperate with the other 
Collaborator to facilitate the activities under paragraph (a) above, 
including, without limitation, executing all lawful papers and instruments 
and making all rightful oaths and declarations as may be necessary in the 
preparation and prosecution of the patent applications, issued patents, 
Trademarks and other rights included in the JV Technology or in the transfer 
of any prosecution obligations under Section 9.1(a).

      (c) ALLOWABLE EXPENSES. The Costs incurred by a Collaborator under this 
Section 9.1 shall be an Allowable Expense to the extent approved by the 
Management Committee as attributable to the Products in the Major Markets. 
The Costs incurred by a Collaborator that are attributable to the Products in 
the Royalty Territory shall be borne by the Collaborator.

   SECTION 9.2  DEFENSE OF INFRINGEMENT CLAIMS.

      (a) NOTICE. If a claim is asserted against Chiron, Cephalon or the JV 
by a third party alleging infringement of the third party's intellectual 
property rights resulting from the development, manufacture, use or sale of a 
Product in the 

                                      -38-
<PAGE>

Territory, it shall promptly notify the other parties of such claim.

      (b) DEFENSE OF CLAIM. The Collaborator against whom the claim has been 
made shall control the defense of a claim attributable to the Products in the 
Major Markets. Chiron shall be obligated to defend Cephalon and to control 
the defense of a claim asserted in the Royalty Territory.

      (c) COSTS AND JUDGMENTS IN THE MAJOR MARKETS. The reasonable Costs 
(including any judgments or monetary damages awarded in an action) incurred 
by a Collaborator in defending an infringement claim shall be an Allowable 
Expense to the extent approved by the Management Committee as attributable to 
the Products in the Major Markets.

      (d) COSTS AND JUDGMENTS IN THE ROYALTY TERRITORY. Chiron shall pay its 
out-of-pocket costs (including attorneys' fees) of defending a claim 
attributable to the Products in the Royalty Territory, except that Chiron 
may apply 100% of its reasonable out-of-pocket costs actually incurred 
(including reasonable attorneys' fees) as a credit against any royalty 
payments payable to the JV under Section 8.1 hereof. If any damages 
(excluding punitive or exemplary damages) awarded against Chiron in a 
judgment or order related to such claim are stated to be compensation to the 
plaintiff for lost sales, 50% of such amount, to the extent not covered by 
insurance, may be offset against the royalties payable under Section 8.1. If 
Chiron licenses intellectual property rights to settle such claim in a 
settlement that has been approved by Cephalon, Chiron may reduce the 
royalties payable under Section 8.1 by 50% of the royalty payable to the 
third party.

   SECTION 9.3  PROSECUTION OF THIRD PARTY INFRINGEMENTS.

      (a) NOTICE. Cephalon and Chiron shall promptly give written notice to 
the other party and to the Management Committee of any infringement or 
possible infringement of any of the JV Technology by a third party in the 
Territory.

      (b) CONTROL OF PROSECUTION IN THE MAJOR MARKETS. The Collaborator 
owning the infringed technology right may, at its discretion, take such steps 
as it deems necessary or desirable to prosecute any such infringement 
attributable to Products in the Major Markets. If the Collaborator owning the 
technology right does not bring suit or take other appropriate action within 
120 days after receiving notice of such claim, the JV (or the Collaborator, 
if the JV so elects) shall have the right, but not the obligation, to bring 
suit or take other appropriate action with respect to the infringed right. 
If the right consists of a joint invention or other JV Technology not owned 
solely by a 

                                      -39-
<PAGE>

Collaborator, the Management Committee shall determine the appropriate 
procedures for handling the alleged infringement.

          (c) COSTS AND RECOVERIES IN THE MAJOR MARKETS.  All monetary 
damages awarded in any action against a third party under paragraph (b) that 
are attributable to a Product within the Major Markets shall be treated as Net 
Sales of the Collaboration in the calculation of Operating Profits. The JV 
may retain 100% of any recovery in any proceeding brought by it, except that 
any recovery explicitly attributable to a subject matter other than the 
Products shall be remitted to the Collaborator who owns the technology right 
at issue.

          (d)  CONTROL OF PROSECUTION IN THE ROYALTY TERRITORY.  The JV, 
through the Management Committee, shall have the right, but not the 
obligation, to control the prosecution of an infringement claim attributable 
to the Products in the Royalty Territory. If within forty-five (45) days after 
receiving notice of such claim, the JV informs Chiron that it declines to 
prosecute any such claim, Chiron shall have the right, but not the 
obligation, to bring the claim.

          (e)  COSTS AND RECOVERIES IN THE ROYALTY TERRITORY.  The 
prosecuting party shall pay its out-of-pocket costs (including attorneys' 
fees) of prosecuting the claim and shall be entitled to retain any award in 
such action, except that if Chiron prosecutes the claim, it shall pay the JV 
a royalty under Section 8.1 as to any portion of an award it receives that is 
stated to be compensation for lost sales (after deducting a proportionate share 
of Chiron's legal costs and expenses attributable to the award).

     SECTION 9.4  JOINDER.  Any party prosecuting or defending a claim under 
this Article 9 shall have the right to join the other party in such 
proceeding, only if it is necessary to use the other party's name to prosecute 
or defend such action; however, the prosecuting party shall indemnify the 
joined party against any liabilities asserted against the joined party solely 
by virtue of being named in the prosecution and independent of any conduct by 
the joined party.

     SECTION 9.5  SETTLEMENT OF CLAIMS.  Neither Collaborator may settle a 
claim described in this Article 9 without the consent of the other 
Collaborator, if such settlement would impose any monetary obligation on the 
JV or the other Collaborator or require the JV or the other Collaborator to 
submit to an injunction or otherwise limit the JV's or the other 
Collaborator's rights under this Agreement.

     SECTION 9.6  COOPERATION.  In conducting the defense or prosecution of 
any claim described in this Article 9, Cephalon and Chiron shall consult with 
and keep the Management Committee

                               - 40 -

<PAGE>

informed of the status of the action. Upon reasonable request, the JV and the 
Collaborators shall assist the person or persons controlling the defense or 
prosecution of an infringement claim, the Costs of which shall be an 
Allowable Expense to the extent attributable to the Products in the Major 
Markets. In addition, any Collaborator or the JV may protect its interests in 
such matter by participating in the proceeding, through attorneys of its 
choice, the Costs of which shall not be an Allowable Expense.

     SECTION 9.7  TRADEMARK MATTERS.

          (a)  TRADEMARKS IN MAJOR MARKETS.  Subject to Section 4.6, the 
Marketing Committee shall approve the Trademarks to be used for each Product 
in the Major Markets.

          (b)  TRADEMARKS IN ROYALTY TERRITORY.  Chiron's selection of 
Trademarks for Products in the Royalty Territory is subject to Section 7.2 
hereof. Chiron agrees that any rights arising to it from the use of the 
Trademarks in the Royalty Territory and any goodwill related thereto shall 
inure to the benefit of the JV to the extent it is the same or substantially 
similar to a Trademark used in the Major Markets for the corresponding 
Product.

          (c)  TRADEMARK PROTECTIONS.  Subject to Section 4.6, the Marketing 
Committee shall establish procedures and restrictions on use of the 
Trademarks for Products in the Territory to be observed by the JV and the 
Collaborators to ensure maintenance of the Trademarks in accordance with good 
trademark practice.

          (d)  OWNERSHIP.  Subject to Section 4.6, all Trademarks for Products 
in the Territory created after the Effective Date shall be deemed Joint 
Technology and may be used by a Collaborator with a product containing the 
corresponding Compound outside the Field or outside the Territory, subject 
to the rights of Kyowa Hakko under the applicable Cephalon Agreement.

          (e)  NO CONTEST.  To the extent permitted by applicable law, 
neither Collaborator shall, during the term of this Agreement, contest the 
other Collaborator's ownership of the Trademarks licensed to the JV under 
this Agreement or take any action adverse to the ownership of such Trademarks 
by the other Collaborator or its successors or assigns.

          (f)  INSPECTION RIGHTS.  The JV and each Collaborator shall have 
the right, upon reasonable notice and during normal business hours, to 
inspect the relevant facilities of the other Collaborator to ensure 
compliance by the other Collaborator with this Section 9.7. Any such 
inspection shall be subject to the confidentiality obligations of the 
inspecting party under Article 12 hereof.

                                  - 41 -

<PAGE>

                    ARTICLE 10 - PAYMENTS AND RECORDS

     SECTION 10.1  PAYMENTS.

          (a)  PLACE OF PAYMENT.  All payments to a Collaborator or the JV 
under this Agreement shall be made by wire transfer in immediately available 
funds in legal currency of the United States to the account designated in 
writing by each Collaborator or the JV, as applicable, from time to time.

          (b)  CURRENCY CONVERSION.  Any amount received in a currency other 
than U.S. dollars shall be converted into U.S. dollars using the average 
for the month in which the amount was received of the composite conversion 
rate for each business day in such month of the non-U.S. currency into U.S. 
dollars as reported in the BLOOMBERG FINANCIAL MARKETS, COMMODITIES & NEWS (or 
any mutually acceptable successor thereto).

          (c)  LATE PAYMENT.  Payments hereunder shall be deemed paid as of 
the day on which they are received at the account designated pursuant to 
paragraph (a) above. Any payment which is not paid within fourteen (14) days 
after the date when due shall accrue interest thereon from such date until 
the date of its payment in full at one (1) percentage point over the per 
annum interest rate published as the Prime Rate as reported in the BLOOMBERG 
FINANCIAL MARKETS, COMMODITIES & NEWS (or any mutually acceptable successor 
thereto), but in no event shall such rate exceed the maximum rate permitted 
by applicable law.

     SECTION 10.2  BOOKS AND RECORDS; ACCOUNTING.

          (a)  MAINTENANCE OF RECORDS.  The Collaborators and Chiron, on 
behalf of the JV shall maintain complete and accurate books of account in 
accordance with generally accepted accounting principles and the principles 
specified in Schedule V hereto, consistently applied, in sufficient detail to 
allow the calculation of Allowable Expenses and Operating Profits under 
Article 6 and the calculation of royalties under Article 8 to be verified. 
The Collaborators and the JV shall retain such records for so long as the 
Management Committee shall specify, and, in the event of a disagreement as to 
the necessity of retention, or upon the dissolution of the JV, either 
Collaborator may take possession of such records or copies thereof.

          (b)  ACCESS AND INSPECTION.  The Collaborators shall have 
reasonable access to the books and records of the JV while in the possession 
of the JV, and each Collaborator, at its own expense (which shall not be an 
Allowable Expense) and upon reasonable prior notice, shall have the right to 
have such books and records examined and audited by outside auditors. Each 
Collaborator shall make its relevant books and records available

                              - 42 -

<PAGE>


for inspection and audit by the independent accountant of the JV or of the 
other Collaborator, at the expense of the inspecting party (which shall not 
be an Allowable Expense), not more than once each calendar year, upon 
reasonable prior notice and during normal business hours. Any inspection of 
the JV's or a Collaborator's books and records shall be conducted subject to 
the confidentiality obligations under Article 12 hereof.


                    ARTICLE 11 - CERTAIN REGULATORY MATTERS

             SECTION 11.1 GOVERNMENTAL INSPECTIONS AND INQUIRIES

         (a) Each Collaborator shall advise the Management Committee of any 
governmental visits to, or written or oral inquiries about, any facilities or 
procedures for the manufacture, storage or handling of a Product in the 
Territory, promptly (but in no event later than fifteen (15) calendar days) 
after such visit or inquiry. Each Collaborator shall furnish to the Management 
Committee, within fifteen (15) days after receipt, a copy of any report or 
correspondence issued by the governmental authority in connection with such 
visit or inquiry, purged only of confidential or proprietary 
information that is unrelated to the Products or the activities under this
Agreement.

         (b) Each Collaborator also shall advise the other Collaborator of 
any inquiry, notice or investigation initiated or made by any governmental 
authority relating to the promotion, advertisement, marketing or sale of the 
Products or any of its other activities under this Agreement.  The 
Collaborators shall cooperate and consult with each other in responding to 
the governmental authority.

    SECTION 11.2 ADVERSE REACTIONS.  The Development Committee shall 
establish procedures by which each Collaborator will receive notice from the 
other Collaborator and the JV, and will report to the JV and the other 
Collaborator, any adverse drug reactions related to a Product (including 
events related to products containing the same active ingredient as 
Products outside the Field and/or outside the Territory). The procedures shall 
be established by the Development Committee promptly after the Effective Date. 
Until such procedures ard approved, each Collaborator shall use its customary 
procedures in complying with the reporting requirements of applicable law and 
shall promptly furnish a written copy of any such report to the other 
Collaborator. Prior to the establishment of the JV, Cephalon shall serve as 
the reporting party for adverse events related to the Products.

     SECTION 11.3 RECALLS AND MARKET WITHDRAWALS. If at any time (i) any 
governmental or regulatory authority issues a request, directive, or order 
that a Product be recalled or


                                     -43-


<PAGE>


withdrawn, or (ii) a court of competent jurisdiction orders such a recall or 
withdrawal in a Major Market, or (iii) the Management Committee determines 
that a Product should be recalled in a Major Market, the parties shall take 
all appropriate corrective actions to effect the recall or withdrawal. If a 
dispute about the necessity of a recall can not be resolved in accordance 
with Section 15.1 hereof, either Collaborator may order a recall (without 
proceeding to arbitration under Section 15.2) if in its reasonable judgment 
it is required to do so by law. The cost and expenses of notification and 
destruction or return of the recalled or withdrawn Product in a Major Market 
shall be an Allowable Expense.

                      ARTICLE 12 - CONFIDENTIALITY, ETC.

     SECTION 12.1 CONFIDENTIALITY.

          (a) INFORMATION RECEIVED FROM OTHER PARTY. Each Collaborator (a 
"Recipient") will keep in confidence any confidential or proprietary 
information (the "Confidential Information") received from the other 
Collaborator (the "Furnishing Party"), whether furnished before or after 
the Effective Date. The foregoing obligations shall not apply to, and the 
definition of "Confidential Information" does not include:

              (i) information that at the time of the use or disclosure by 
    the Recipient was already in the public domain other than through the 
    fault of the Recipient or its employees, licensees, agents or 
    subcontractors, in violation hereof;

              (ii) information that was rightfully known by the Recipient (as
    shown by its written records) prior to the date of disclosure by the 
    Furnishing Party to the Recipient in connection with this Agreement; or

              (iii) information that was received by the Recipient on an 
    unrestricted basis from a source under no duty of confidentiality to the
    Furnishing Party; or

              (iv) information that Recipient believes in good faith is
    required to be disclosed to comply with any applicable law, regulation or
    order of a government authority of court of competent jurisdiction 
    (including any securities laws applicable to a Collaborator), in which 
    event the disclosing party shall use all reasonable efforts to advise the
    other Collaborator in advance of the need for such disclosure; or


                                     -44-


<PAGE>


              (v) information that is independently developed by the 
    Recipient without reliance on the Confidential Information.

Notwithstanding the foregoing, it is understood that each Collaborator may 
disclose Confidential Information to its employees, licensees, consultants, 
contractors and agents if such persons are subject in writing to obligations 
of confidentiality with respect to such information to the same extent the 
Collaborator is so obligated hereunder.

    INFORMATION DEVELOPED FOR COLLABORATION. Information in the Field 
that is developed by a Collaborator in the conduct of a specific objective or 
activity under a Development Plan and which would be proprietary to the 
Collaborator shall be treated as Confidential Information by both 
Collaborators. Any disclosure or publication of such information shall be 
subject to the approval of the Management Committee (which approval shall not 
be unreasonably withheld). A Collaborator shall not be obligated to treat any 
other information developed by it (whether before or during the Collaboration)
as Confidential Information.

    SECTION 12.2 INJUNCTIVE RELIEF. Each Collaborator acknowledges that damages 
for breach of the covenants contained in Section 12.1 would be an inadequate 
remedy, and that in the event of any such breach, the other Collaborator 
shall be entitled to seek injunctive or other equitable relief in addition to 
any and all remedies available at law or in equity, including the recovery of 
damages and reasonable attorneys' fees.

    SECTION 12.3 PUBLICITY. The Collaborators shall consult with each other 
and coordinate all press releases and similar public announcements by the 
Collaborator concerning the existence and terms of this Agreement and the 
activities and progress of the Collaboration.  The Collaborators shall not 
disclose the confidential terms of such agreements to any third parties 
without the prior written consent of the other party or parties thereto. This 
Section 12.3 shall not apply to the extent that any disclosure is (a) of 
information in the public domain other than through the fault of the 
Collaborator or its employees, licensees, agents or subcontractors, in 
violation hereof, (b) believed in good faith to be required to comply with 
any applicable law, regulation or order of a government authority of court of 
competent jurisdiction (including any securities laws applicable to a 
Collaborator), in which event the disclosing party shall use all reasonable 
efforts to advise the other Collaborator in advance of the need for such 
disclosure, or (c) is made, under confidentiality, to a recipient who is a 
licensor, licensee or potential licensor or licensee and to whom such 
disclosure is reasonably required to define the scope of rights


                                     -45-


<PAGE>


which could be granted to the recipient without violating the terms of this 
Agreement.

         ARTICLE 13 - CERTAIN REPRESENTATIONS, WARRANTIES AND COVENANTS

     SECTION 13.1  CORPORATE STATUS AND AUTHORITY.  Each Collaborator 
represents to the other that as of the date hereof:

     (a)  it is a corporation duly organized, validly existing and in good 
standing under the laws of the jurisdiction of its incorporation;

     (b)  it has the corporate power and authority to execute, deliver and 
perform this Agreement;

     (c)  the execution, delivery and performance of this Agreement has been 
duly authorized by all necessary corporate action on the part of each 
Collaborator and the Agreement is binding and enforceable in accordance 
with its terms;

     (d)  the execution, delivery and performance of this Agreement by such 
party (i) does not conflict with, or constitute a breach or default under its 
Certificate of Incorporation, bylaws, or any law, order, judgment or 
governmental rule or regulation applicable to it, and (ii) does not conflict 
with, or constitute a breach or default under or require any consent or 
approval not obtained under, any provision of any material agreement, 
contract, commitment or instrument to which it is a party;

     (e)  to its knowledge, it owns all patents, know-how and other 
intellectual property rights included as of the Effective Date in its license 
to the other Collaborator under Section 5.1 hereof, except for rights 
licensed from or granted to third parties under the agreements listed on 
SCHEDULE I hereof;

     (f)  to its knowledge, it is not required to obtain the consent or 
approval of any third party to perform its obligations under this Agreement, 
or to license or transfer such rights to the other Collaborator or to the JV 
as contemplated under this Agreement; and

     (g)  in the case of Chiron, to its knowledge and except as disclosed 
to Cephalon in writing, it owns all patents, knowhow and other intellectual 
property rights required for use in the manufacture of the Products, except 
for the rights specified on SCHEDULE I hereto, which are licensed by 
Chiron from the third parties specified therein, and it has not received any 
notice from a third party indicating that the manufacture of Products by 
Chiron would infringe any intellectual property rights of any third party.

                                      -46-

<PAGE>

      SECTION 13.2  NO INCONSISTENT AGREEMENTS.  Neither Collaborator shall 
enter into any oral or written agreement after the date hereof that would be 
inconsistent with its obligations under this Agreement or deprive the other 
Collaborator of the benefits of the Collaboration in any substantial respect.

           ARTICLE 14 -- DISCLAIMER, INDEMNIFICATION AND INSURANCE

      SECTION 14.1  NO WARRANTY.  EXCEPT AS EXPRESSLY SET FORTH IN ARTICLE 8 
HEREOF, NEITHER COLLABORATOR MAKES ANY EXPRESS OR IMPLIED WARRANTIES, 
STATUTORY OR OTHERWISE, CONCERNING THE PRODUCTS OR THE TECHNOLOGY LICENSED BY 
IT TO THE OTHER COLLABORATOR OR TO THE JV, NOR DOES THE JV MAKES ANY EXPRESS 
OR IMPLIED WARRANTIES, STATUTORY OR OTHERWISE, CONCERNING THE JV TECHNOLOGY, 
THE PRODUCTS OR ANY INFORMATION LICENSED TO A COLLABORATOR UNDER THIS 
AGREEMENT. WITHOUT LIMITING THE FOREGOING, NEITHER COLLABORATOR NOR THE JV 
MAKES ANY EXPRESS OR IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A 
PARTICULAR PURPOSE OR OTHERWISE, QUALITY OR USEFULNESS OF THE JV TECHNOLOGY 
OR THE PRODUCTS.

      SECTION 14.2  DEFENSE OF CLAIMS IN TERRITORY.  Except as provided in 
Article 9 hereof, each Collaborator and the JV shall be responsible for 
defending itself against any liabilities, losses, costs, damages and expenses 
(including reasonable attorneys' fees and costs) (collectively, 
"Liabilities") resulting from a claim asserted by a third party arising out 
of the manufacture, marketing, sale or use of a Product in the Territory, 
including, without limitation, any claim in the nature of product liability 
(whether under theories of strict liability, negligence, breach of warranty 
or otherwise). If any such claim is asserted against both Collaborators 
and/or the JV, the Management Committee shall control the defense of the 
claim.

      SECTION 14.3  COSTS AND EXPENSES.

          (a)  MAJOR MARKETS.  Except as provided in Article 9 hereof, the 
Costs (including any judgments or monetary damages awarded in an action) 
incurred by the Collaborators or the JV in defending against any claim 
described in Section 14.2 shall be an Allowable Expense to the extent 
attributable to the Products in the Major Markets, unless the claim is caused 
by: (i) the breach by the Collaborator or the JV of any covenant, 
representation or warranty contained in this Agreement, or (ii) any act or 
omission constituting gross negligence or willful misconduct by the 
Collaborator or the JV in the development, manufacturing, labelling, 
promotion, marketing or sale of a Product or any other activity conducted by 
it under this Agreement (each, an "Excluded Liability").

                                      -47-


<PAGE>

          (b)  ROYALTY TERRITORY.  Except as provided in Article 9 hereof, 
the Costs (including any judgments or monetary damages awarded in an action) 
incurred by the Collaborators or the JV in defending against any claim 
described in Section 14.2 shall be borne by the defending party (and shall 
not be an Allowable Expense) to the extent attributable to the Products in 
the Royalty Territory, unless the claim constitutes an Excluded Liability of 
the other Collaborator, in which case the defending party may seek indemnity 
from the other Collaborator under Section 14.4 hereof.

      SECTION 14.4  INDEMNITY FOR EXCLUDED LIABILITIES.  Each Collaborator 
and the JV (as such, an "Indemnifying Party") shall indemnify, defend and 
hold harmless the other Collaborator and the JV and its and their employees, 
officers, directors and agents (as such, an "Indemnified Party") from and 
against any Liabilities which the Indemnified Party may incur, suffer or be 
required to pay resulting from or arising in connection with (i) any Excluded 
Liability of the Indemnifying Party, (ii) any breach by the Indemnifying 
Party of any agreement listed on SCHEDULE I to which it or an Affiliate is a 
party, or (iii) the successful enforcement by an Indemnified Party of any of 
the foregoing.

      SECTION 14.5  PROCEDURES FOR INDEMNIFICATION. The obligations of the 
Indemnifying Party under this Article 14 are conditioned upon the delivery of 
written notice to the Indemnifying Party of any potential Liability, promptly 
after the Indemnified Party becomes aware of such potential Liability. The 
Indemnifying Party shall have the right to assume the defense of any suit or 
claim related to the Liability if it has assumed responsibility for the 
Liability in writing. If the Indemnifying Party defends the suit or claim, 
the Indemnified Party may participate in (but not control) the defense 
thereof, at its sole cost and expense (which shall not be an Allowable 
Expense).

      SECTION 14.6  SETTLEMENTS, ETC.  Neither Collaborator may settle a 
claim or action under this Article 14 without the consent of the other 
Collaborator, if such settlement would impose any monetary obligation on the 
JV or the other Collaborator or require the JV or the other Collaborator to 
submit to an injunction or otherwise limit the other party's rights under 
this Agreement.

      SECTION 14.7  LIMITATION OF LIABILITY.  With respect to any claim by 
one party against the other arising out of the performance or failure of 
performance of the other party under this Agreement, the liability of one 
party to the other party for such breach shall be limited under this 
Agreement or otherwise at law or equity to direct damages only; in no event 
shall a party be liable to the other party for indirect, incidental or 
consequential damages including, without limitation, lost profits.

                                      -48-

<PAGE>

   SECTION 14.8 INSURANCE. The Management Committee shall determine from time 
to time the types and amount of insurance coverage, if any, to be maintained 
by the JV and by each Collaborator to insure against the activities of the 
Collaborators and the Collaboration. The Costs incurred by a Collaborator in 
maintaining any insurance policy at the direction of the Management Committee 
shall be an Allowable Expense to the extent authorized by the Management 
Committee as attributable to its activities with respect to Products in the 
Major Markets and otherwise shall be the responsibility of the Collaborator.

                        ARTICLE 15 - DISPUTE RESOLUTION

      SECTION 15.1 DISPUTE RESOLUTION. If any dispute arises under this 
Agreement which can not be resolved expeditiously by the Management Committee 
after due consideration, the matter shall be submitted to the Chairman of 
Chiron and the Chief Executive Officer of Cephalon for resolution. If the two 
executives can not resolve the dispute to their mutual satisfaction within 
thirty (30) days, the dispute shall be referred to arbitration under Section 
15.2 below.

      SECTION 15.2 ARBITRATION.

      (a) Except as provided in subsection (d) hereof, all disputes arising 
between Cephalon and Chiron under this Agreement that have not been resolved 
pursuant to Section 15.1 shall be settled by arbitration conducted in the 
English language in accordance with the procedures of the Commercial Rules of 
the American Arbitration Association, before a panel of three arbitrators, 
one of whom is selected by Cephalon, one of whom is selected by Chiron, and 
one of whom is selected by Cephalon and Chiron (or by the other two 
arbitrators, if the parties cannot agree). The parties shall request an 
expedited hearing for any dispute related to a nonpayment hereunder, and 
shall otherwise cooperate with each other in causing the arbitration to be 
held in as efficient and expeditious a manner as practicable. Any arbitration 
proceeding instituted by a Collaborator shall be brought in the principal 
place of business of the defending party.

      (b) Any award rendered by the arbitrators shall be binding upon the 
parties hereto and shall be final, subject to review by a court of competent 
jurisdiction under the statutory standard of review applicable to 
arbitrations. Judgment upon the award may be entered in any court of record 
of competent jurisdiction.

      (c) Each party shall pay its own expenses of arbitration and the 
expenses of the arbitrators shall be equally shared unless otherwise ordered 
by the arbitrators.

                                     -49-
<PAGE>

      (d) Notwithstanding anything contained in this Section 15.2, each party 
shall have the right to institute judicial proceedings against the other 
party or anyone acting by, through or under such other party in order to (i) 
enforce the instituting party's rights hereunder through specific 
performance, injunction or similar equitable relief, or (ii) enforce its 
rights under Article 12 hereof.

                      ARTICLE 16 - TERM AND TERMINATION

   SECTION 16.1 TERM. This Agreement shall commence as of the Effective Date 
and shall continue until the last sale of a Product in the Territory pursuant 
to Article 4 or Article 7, unless terminated earlier in accordance with this 
Article 16.

   SECTION 16.2 TERMINATION OF AGREEMENT IN FULL.

      (a) TERMINATION FOR COMMERCIAL FAILURE. This Agreement may be 
terminated in full by either Collaborator, upon 180 calendar days written 
notice to the other Collaborator, if in the good faith conclusion of the 
terminating Collaborator, there is no reasonable, objective basis for further 
development of any Product within the Field. The terminated Collaborator 
shall, at its election, be a "Continuing Licensee" for purposes of Section 
16.5(b) hereof.

      (b) TERMINATION UPON BREACH. This Agreement may be terminated in full 
by either Collaborator upon material breach by the other Collaborator of any 
covenant, representation or warranty of this Agreement such that the 
non-breaching party is denied in a substantial respect the economic benefit 
of this Agreement and such breach is not substantially cured within sixty 
(60) calendar days after the non-breaching Collaborator gives the breaching 
Collaborator written notice of such breach. The terminating Collaborator 
shall, at its election, be a "Continuing Licensee" for purposes of Section 
16.5(b) hereof.

      (c) TERMINATION BY MUTUAL AGREEMENT. This Agreement may be terminated 
in whole or in part at any time by mutual written agreement of the 
Collaborators.

      SECTION 16.3 ACTIONS UPON CHANGE OF CONTROL. If either Collaborator 
experiences one or more of the following events (a "Change of Control"):

            (i) any person or group (other than a Collaborator or a group 
      including a Collaborator) becomes after the date hereof (whether by
      tender or exchange offer or otherwise) the beneficial owner, directly or
      indirectly, of securities of the Collaborator representing 50% or more

                                     -50-
<PAGE>

      of the combined voting power of such Collaborator's then outstanding 
      voting securities;

            (ii) the membership of the Collaborator's Board of Directors 
      changes as a result of one or more contested elections within a two 
      year period such that individuals who were members of such Board prior 
      to any such contested election no longer make up a majority of such 
      Board; or

            (iii) stockholders of the Collaborator approve a merger, plan of
      consolidation, the sale or disposition of all or substantially all of 
      such Collaborator's assets, or a plan of partial or complete liquidation
      of such Collaborator;

then the Collaborator experiencing the Change of Control shall promptly 
furnish the other Collaborator with written notice describing such event 
(reasonably in advance of such event, if possible, but in no event later than 
ten (10) days after such event).

   SECTION 16.4 PARTIAL TERMINATION IN ROYALTY TERRITORY.  Chiron may 
terminate its rights in any country in the Royalty Territory, in whole or as 
to any Product, without cause, upon 180 days written notice to the JV.

   SECTION  16.5 RIGHTS AND OBLIGATIONS ON TERMINATION.

   (a) BALANCING. Upon termination of this Agreement pursuant to Section 
16.2, the Collaborators shall balance any remaining deficiency in the equal 
funding of Allowable Expenses between the parties in a transaction (such as a 
purchase of assets) that is mutually acceptable to the parties and, at the 
option of the Collaborator balancing the deficiency, does not result in a 
current charge to the earnings of such Collaborator.

   (b) RIGHTS OF A CONTINUING LICENSEE.

            (I) SURVIVING LICENSES. A Collaborator who is a Continuing 
      Licensee may elect to have the applicable licenses granted to it or to 
      the JV under Article 5 convert into an exclusive license to the 
      Continuing Licensee, which shall survive termination of this Agreement 
      until the Continuing Licensee ceases to develop or commercialize 
      Products. The other Collaborator shall transfer to the Continuing 
      Licensee, upon request, all Confidential Information necessary or 
      useful for the manufacture, use or sale of the applicable Product in 
      its possession. In addition, the Continuing Licensee may elect to cause 
      the other Collaborator and the JV to transfer all Regulatory Approvals, 
      Pricing Approvals, marketing approvals, customer lists, contracts, 
      information or any other right that is necessary or useful for the 
      development, manufacture, use,

                                     -51-
<PAGE>

marketing or sale of the applicable Product or Products. The other 
Collaborator shall take such steps as are reasonably required to transfer all 
such approvals, contracts, information and rights to enable the Continuing 
Licensee to assume the business of developing, marketing and selling the 
applicable Product or Products.

     (ii) SUPPLY OF PRODUCTS. If the Continuing Licensee is not supplying 
any of the applicable Product or Products under this Agreement, it may either 
require the other party to continue to supply the applicable Product or 
Products, upon the terms and for the period described below, or cause the 
other party to transfer the required technology to the Continuing Licensee.

     If a Continuing Licensee elects to require the other party to continue 
to supply Products, it shall pay the supplying party, on a quarterly basis, 
an amount equal to [CONFIDENTIAL TREATMENT REQUESTED] for all Products 
continued to be supplied hereunder. The supplying party shall only be 
obligated to supply Products for a reasonable transition period, which period 
shall not exceed [CONFIDENTIAL TREATMENT REQUESTED] from the date that the 
Collaborator elects to become a Continuing Licensee. The Continuing Licensee
shall use all commercially reasonable efforts to identify a replacement 
manufacturer or establish a manufacturing facility for the Products in a 
timely manner. The supplying party shall take such steps as are reasonably 
required to enable the Continuing Licensee to assume the business of producing
the Products. If for any reason the supplying party is not legally permitted 
to transfer the necessary technology or rights to the Continuing Licensee for 
these purposes, the supplying party will continue to provide the applicable 
Product or Products under this Agreement or to otherwise make available to the
Continuing Licensee the benefits of this Section 16.4, pursuant to 
commercially reasonable terms to be mutually agreed upon by the parties. Any 
amounts owed by the Continuing Licensee for Product supply under this 
Agreement shall be set off against the amount, if any, of unbalanced 
Allowable Expenses of the Continuing Licensee existing as of the effective 
termination date of this Agreement.

    If a Continuing Licensee elects to cause a transfer of the required 
technology to manufacture Products, the transferring party shall take such 
steps as are reasonably required to enable the Continuing Licensee to 
manufacture (or have manufactured) the Products, including, without 
limitation, by providing to the Continuing Licensee: (x) all manufacturing 
information and descriptions of the applicable technology and processes in 
sufficient detail to permit the manufacture of the Products in commercial 
quantities in an efficient manner; (y) samples of all organisms or 
other biological material used in producing such Products; and (z) training 
of personnel as may be


                                        -52-

<PAGE>

necessary to permit the manufacture of the Products. The Continuing Licensee 
shall pay the transferring party a royalty on sales of Products at a rate to 
be negotiated by the parties in good faith at the time of such license, but 
shall not be more than [CONFIDENTIAL TREATMENT REQUESTED] of the royalties 
payable by Chiron under Article 8 hereof.

     (c) NON-COMPETE. A Collaborator that is not a Continuing Licensee shall 
refrain from selling Products in the Field in the Territory and shall 
refrain from participating, directly or indirectly, in any business, 
partnership, collaboration, license arrangement or other enterprise engaged 
in the business of the development, manufacture, marketing, use, distribution 
or sale of Products in the Field and in the Territory for a period of five 
(5) years after the termination date.

    (d) ROYALTY TERRITORY.

        (i) Cephalon shall have the right to assume Chiron's rights and 
     obligations as to any country or Product in the Royalty Territory upon 
     any termination of such country or Product under Section 16.4. However,
     no such assumption by Cephalon shall operate as waiver of or otherwise 
     extinguish Chiron's obligations for liabilities accrued prior to the 
     termination date. Chiron shall cooperate with Cephalon to allow Cephalon
     to conduct its business under this Agreement in a timely manner, including
     taking such steps as are reasonably required to allow Cephalon to obtain 
     supplies of Products for purposes of this Agreement. 

        (ii) Upon termination of a country or Product in the Royalty Territory
     by Chiron pursuant to Section 16.4, Chiron shall promptly deliver to the 
     JV or Cephalon, as applicable, all promotional materials and other data, 
     information, test results, marketing information, customer lists and 
     records, distributor lists and records, and any other information under 
     Chiron's control that is related to the manufacture, marketing or sale of
     the applicable Product or Products in the applicable country or countries
     within the Royalty Territory. Chiron also shall promptly transfer any 
     Regulatory Approvals and Pricing Approvals for the applicable Product or 
     Products in the applicable country or countries in the Royalty Territory
     to the JV or Cephalon, as applicable, to the extent permitted by law.

        (iii) Chiron may sell remaining inventory and finished goods for a 
     Product or Products as to which Chiron has terminated pursuant to Section 
     16.4 for a period not to exceed six (6) months, subject to the royalty 
     obligations and other provisions of this Agreement. Any inventory of

                                    -53-


<PAGE>

     Product remaining at the end of such period shall be transferred 
     pursuant to the instructions of the JV or Cephalon, the costs of which 
     shall be borne by the JV or Cephalon, as applicable.


     SECTION 16.6 TERMINATION UPON CCP TRANSFER. If for any reason Cephalon, 
after consultation with Chiron, either elects not to exercise its right to 
purchase the limited partnership interests of CCP under the Purchase 
Agreement included in the Cephalon Agreements, or Cephalon's rights under 
this Agreement are transferred to CCP for any other reason (including breach 
under the terms of the applicable Cephalon Agreements), Cephalon may transfer 
its rights under this Agreement to CCP, unless either CCP or Chiron elects to 
terminate this Agreement, upon 90 days written notice of termination to the 
other. In the event of such termination, any license to a Continuing Licensee 
under Section 16.5 hereof also shall terminate, the Chiron Technology shall 
revert to Chiron and the Cephalon Technology shall revert to CCP, subject to 
the perpetual licenses under Section 5.1 hereof.

     SECTION 16.7 EFFECTIVE DATE OF TERMINATION. Unless otherwise provided 
herein, a termination notice pursuant to this Article 16 shall be effective 
on the date of delivery of written notice of termination to the other party 
hereto.

     SECTION 16.8 SURVIVAL. Neither Collaborator nor the JV shall be relieved 
of its obligations to pay any sums of money due or payable or accrued under 
this Agreement as of the date of such termination. All accounts between the 
Collaborators and the JV shall be settled in full within ninety (90) days 
following the termination of this Agreement under Section 16.2. Article 12, 
Section 16.5 and this Section 16.7 shall survive the termination of this 
Agreement. In addition, any provision required to interpret and enforce the 
parties rights and obligations under this Agreement also shall survive to the 
extent required for the full observation and performance of this Agreement in 
accordance with its terms.

    SECTION 16.9 REMEDIES NOT EXCLUSIVE. Termination by either Collaborator 
pursuant to this Article 16 shall not prejudice any other remedy that such 
party might have in law or equity with the exception, however, of claiming 
compensation for loss or damages resulting from such termination.


                            ARTICLE 17 - MISCELLANEOUS

     SECTION 17.1 ENTIRE AGREEMENT; AMENDMENT. This Agreement contains the 
entire understanding of the Collaborators with respect to the subject matter 
hereof and supersedes all previous verbal and written agreements, 
representations and warranties.

                                     -54-


<PAGE>

This Agreement may be released, waived or modified only by written agreement 
signed by the party against whom enforcement of any release, waiver, 
modification, or other change is sought.

     SECTION 17.2  REFERENCES TO CIBA.  All references to CIBA in this 
Agreement shall be effective for so long as CIBA has the right of first 
refusal to sell or promote products containing IGF-1 under the CIBA 
Agreement. If at any time CIBA ceases to have such right, all references to 
CIBA's rights and obligations under this Agreement shall be of no further 
force and effect.

     SECTION 17.3  FORCE MAJEURE.  Failure of any party to perform its 
obligations under this Agreement (except the obligation to make payments) 
shall not subject such party to any liability or place them in breach of any 
term or condition of this Agreement to the other party if such failure is 
caused by any cause beyond the reasonable control of such nonperforming 
party, including without limitation acts of God, fire, explosion, flood, 
drought, war, riot, sabotage, embargo, strikes or other labor trouble, 
failure in whole or in part of suppliers to deliver on schedule materials, 
equipment or machinery, interruption of or delay in transportation, a 
national health emergency or compliance with any order or regulation of any 
government entity acting with color of right.

      SECTION 17.4  NO INTERFERENCE WITH EXISTING BUSINESSES.  Each of Chiron 
and Cephalon acknowledges that the other party is engaged in the business of 
developing, manufacturing, marketing and selling products, including Products 
outside the Field and products other than Products within the Field. Nothing 
in this Agreement shall prevent either Collaborator from continuing to carry 
on its business or to enter into agreements with third parties except as 
expressly provided in Sections 4.6, 5.5 and 16.5(c) hereof.

      SECTION 17.5  COMPLIANCE WITH LAW.  Each Collaborator shall comply with 
all laws, rules and regulations which are material to the conduct of its 
activities under this Agreement.

      SECTION 17.6  WAIVER.  The failure of a party to enforce any breach or 
provision of this Agreement shall not constitute a continuing waiver of such 
breach or provision and such party may at any time thereafter act upon or 
enforce such breach or provision of this Agreement. Any waiver of breach 
executed by either party shall affect only the specific breach and shall not 
operate as a waiver of any subsequent or preceding breach.

      SECTION 17.7  NO ASSIGNMENT.  No Collaborator may sell, assign, pledge 
or otherwise dispose of all or any portion of its interest in the 
Collaboration or right thereto without the prior written consent of the other 
Collaborator, except that no such consent is required for any transfer to an 
Affiliate or to a 

                                      -55-

<PAGE>

successor to substantially all of the Collaborator's business. Subject to the 
foregoing, this Agreement shall inure to the benefit of and be binding upon 
the Collaborators and their respective permitted successors and assigns.

      SECTION 17.8  SEVERABILITY.  If any clause or provisions of this 
Agreement is declared invalid or unenforceable by a court of competent 
jurisdiction, such provision shall be severed and the remaining provisions of 
the Agreement shall continue in full force and effect. The parties shall use 
their best efforts to agree upon a valid and enforceable provision as a 
substitute for the severed provision, taking into account the intent of this 
Agreement.

      SECTION 17.9  NOTICES.  Any notice, request or other communication 
required to be given pursuant to the provisions of this Agreement shall be in 
writing and shall be deemed to be given when delivered in person or five days 
after being deposited in the United States mail, postage prepaid, certified, 
return receipt requested, or by overnight courier (return receipt requested), 
to the parties addressed as follows:

         (a)  If to Chiron to:

              Chiron Corporation
              4560 Horton Street
              Emeryville, California  94608
              Attn:  Office of the President
              Tel:  (510)  655-8730
              FAX:  (510)  654-5360

              With a copy to:

              Law Department
              Chiron Corporation
              Tel:  (510)  655-8730
              FAX:  (510)  654-5360

         (b)  If to Cephalon, to

              Cephalon, Inc.
              145 Brandywine Parkway
              West Chester, PA  19380
              Attn:  President
              Tel:  (215)  344-0200
              FAX:  (215)  344-7253

                                      -56-

<PAGE>
              With a copy to:

              Barbara S. Schilberg
              Morgan, Lewis & Bockius
              2000 One Logan Square
              Philadelphia, PA  19013
              Tel:  (215)  963-5000
              FAX:  (215)  963-5299

Either party may change its address or its FAX number by giving the other 
party written notice, delivered in accordance with this Section.

      SECTION 17.10  PRONOUNS.  All pronouns and any variations thereof shall 
be deemed to refer to the masculine, feminine, neuter, singular or plural, as 
the context may require.

      SECTION 17.11  FURTHER INSTRUMENTS.  Each Collaborator shall execute 
and deliver such further instruments and do such further reasonable acts and 
things as reasonably may be required to carry out the intent and purpose of 
this Agreement.

      SECTION 17.12  GOVERNING LAW.  The validity, performance, construction, 
and effect of this Agreement will be governed by the laws of the State of 
Delaware, without giving effect to conflict of law rules.

      SECTION 17.13  COUNTERPARTS.  This Agreement shall become binding when 
any one or more counterparts hereof, individually or taken together, bears 
the signature of each of the parties hereto. This Agreement may be executed 
in any number of counterparts, each of which shall be an original as against 
the party whose signature appears thereon, but all of which taken together 
shall constitute but one and the same instrument.

                                      -57-
<PAGE>

    IN WITNESS WHEREOF, each party has caused this Agreement to be signed by 
its duly authorized officer as of the date first above written.

CHIRON CORPORATION                        CEPHALON, INC.



By: /s/ William J. Rutter, Ph.D.          By: /s/ Frank Baldino, Jr.
    -------------------------------          --------------------------------
    Name: William J. Rutter, Ph.D.        Name:  Frank Baldino, Jr.
    Title: Chairman                       Title: President and Chief
                                                 Executive Officer

<PAGE>
                                  SCHEDULE I

                            THIRD PARTY AGREEMENTS




[CONFIDENTIAL TREATMENT REQUESTED]







                                      -59-

<PAGE>

  
[CONFIDENTIAL TREATMENT REQUESTED]





                                      -60-

<PAGE>
                                   SCHEDULE II

                                  FIELD EXCLUSION


[CONFIDENTIAL TREATMENT REQUESTED]


                                      -61-

<PAGE>
                                  SCHEDULE III

                                 SOD TECHNOLOGY


[CONFIDENTIAL TREATMENT REQUESTED]


                                      -62-
<PAGE>
                                 SCHEDULE IV

                            THIRD PARTY ROYALTIES



[CONFIDENTIAL TREATMENT REQUESTED]



                                     -63-

<PAGE>

                                   SCHEDULE V

                   DEVELOPMENT EXPENSES FOR TRANSITION PERIOD



[CONFIDENTIAL TREATMENT REQUESTED]




                                      -64-

<PAGE>

                                  SCHEDULE VI

                 ALLOWABLE EXPENSES AND ACCOUNTING PRINCIPLES

      To be prepared in accordance with Section 2.3(c).

                                      -65-

<PAGE>
                                  SCHEDULE VII

                         PREFERRED INDICATIONS OF CHIRON

[CONFIDENTIAL TREATMENT REQUESTED]


                                      -66-

<PAGE>
                                  SCHEDULE VIII

                          CEPHALON NONFIELD INDICATIONS

[CONFIDENTIAL TREATMENT REQUESTED]

                                      -67-

<PAGE>

                                                                Exhibit 10.85

                        [CONFIDENTIAL TREATMENT REQUESTED]

[Certain information has been omitted herein pursuant to a request for
confidential treatment pursuant to Rule 24b-2.]


                           [Letterhead]


                                        January 13, 1995

VIA FEDERAL EXPRESS

Chiron Corporation
4560 Horton Street
Emeryville, CA  94608
Attention: William H. Green, Esq.

      Re:  COLLABORATION AGREEMENT

Gentlemen:

      This letter is intended to confirm certain mutual understandings in 
connection with the Agreement between Cephalon, Inc. and Chiron Corporation 
dated January 7, 1994 (the "Agreement") related to the joint development and 
commercialization of IGF-1 and other specified compounds. All capitalized 
terms not otherwise defined herein are used as defined in the Agreement.

1.    The 1994 budget of Allowable Expenses by Cephalon for the use of IGF-1 
      in the treatment of ALS has been approved by the Management Committee 
      in the form attached as EXHIBIT A to this letter.

2.    The 1994 budget of [CONFIDENTIAL TREATMENT REQUESTED of Allowable 
      Expenses by Chiron for IGF-1 has been approved by the Management 
      Committee.

3.    Section 6.1 of the Agreement is amended to read in its entirety as 
      follows:

           "SECTION 6.1  SHARING OF OPERATING PROFITS AND LOSSES.  The 
           Operating Profits and Operating Losses from the Major Markets and 
           the Royalty Territory shall be shared equally by Cephalon and 
           Chiron, except (i) for the special allocation described in 
           Section 6.2(a) hereof, and (ii) Cephalon shall receive from the JV 
           a royalty of [CONFIDENTIAL TREATMENT REQUESTED] in the Major Markets
           in Europe (i.e., the EC and EFTA countries) of a Product containing
           IGF-1 for use in treating ALS, before Operating Profits and 
           Operating Losses are calculated."

<PAGE>

Chiron Corporation
January 13, 1995
Page 2

4.    Cephalon will be responsible for the Costs related to the IGF-1 program 
      that were incurred by Cephalon in 1994, as specified on EXHIBIT B 
      hereto, and for any other Costs related to the European ALS study that 
      are designated as non-Allowable Expenses in the 1995 budget to be 
      approved by the Management Committee (all of such Costs being referred 
      to as the ""Reimbursable Costs"). However, Cephalon shall be entitled 
      to make draws under the Line of Credit Note to fund one-half of the 
      Reimbursable Costs, not to exceed $10 million. The Line of Credit Note 
      is hereby amended to the extent required to permit such draws and is 
      further amended to extend the Maturity Date of the Note by one year, to 
      January 6, 2000.

5.    Chiron shall have no right to receive any of the Operating Profits from 
      Net Sales in the Major Markets in Europe of a Product containing IGF-1 
      for use in treating ALS, unless it elects to repurchase its rights by 
      reimbursing Cephalon for the Reimbursable Costs, by written notice to 
      Cephalon delivered at any time before the earlier of (i) filing by 
      Cephalon of the first request for regulatory approval to market a 
      product containing IGF-1 in a Major Market, or (ii) the Maturity Date 
      of the Line of Credit Note. To repurchase such rights, Chiron shall 
      reimburse Cephalon for 50% of the Reimbursable Costs, plus interest 
      accrued at [CONFIDENTIAL TREATMENT REQUESTED], compounded annually from
      the date the Reimbursable Cost was incurred. The reimbursement shall 
      be paid out of Chiron's share of Operating Profits in the Territory from
      Net Sales of a Product containing IGF-1 for use in treating ALS. All of 
      Chiron's share of Operating Profits in the Territory will be subject to 
      the reimbursement, on a dollar-for-dollar basis, until the Reimbursable 
      Costs, plus accrued interest, have been paid in full. All such 
      reimbursements shall be applied first, to pay accrued interest and second,
      to pay the principal of the Reimbursed Costs. Chiron may at any time 
      prepay the Reimbursable Costs, plus interest accrued to the date of 
      prepayment.

      If Chiron elects to reimburse the Reimbursable Costs, Cephalon shall 
      repay the outstanding principal of the Line of Credit Note related to 
      the draws used to fund the Reimbursable Costs in an amount equal to, and 
      concurrently with, each payment by Chiron of Reimbursable Costs. If 
      Chiron gives written notice of its election to repurchase such rights, 
      the Maturity Date of the Line of Credit Note shall automatically be 
      extended to the extent required to permit the payment by Cephalon of 
      such principal of the Note concurrently with reimbursement by Chiron of 
      the Reimbursable Costs.

<PAGE>

Chiron Corporation
January 13, 1995
Page 3

      If the foregoing accurately reflects your understanding as to these 
matters, please indicate your agreement in the space provided below.

                                       Very truly yours,

                                       /s/ Bruce A. Peacock

                                       Bruce A. Peacock
                                       Executive Vice President &
                                       Chief Operating Officer

Accepted and agreed to by:

CHIRON CORPORATION



By: /s/ William G. Green
   ------------------------------


cc:   Frank Baldino, Jr., Ph.D.
      Barbara S. Schilberg, Esq.
<PAGE>

                                                                    EXHIBIT A



[CONFIDENTIAL TREATMENT REQUESTED]






<PAGE>

                                                             EXHIBIT B



[CONFIDENTIAL TREATMENT REQUESTED]



<PAGE>

                    [CONFIDENTIAL TREATMENT REQUESTED]

[Certain information has been omitted herein pursuant to a request for 
confidential treatment pursuant to Rule 24b-2.]

                                                                Exhibit 10.85



                                                May 23, 1995

VIA FAX

Chiron Corporation
4560 Horton Street
Emeryville, CA  94606
Attention:  William Green, Esq.

      Re:  AMENDMENT TO AGREEMENT

Gentlemen:

      This letter is to confirm our understanding as to certain matters under 
the Agreement dated January 7, 1994 between Cephalon, Inc. and Chiron 
Corporation, as amended (the "Agreement"). All terms not otherwise defined 
herein are used as defined in the Agreement.

      1.   If Chiron is not for any reason manufacturing on behalf of the 
Collaboration commercial supplies of a Product containing IGF-1, and 
Cephalon is manufacturing the Product, Cephalon will receive [CONFIDENTIAL
TREATMENT REQUESTED] of the Operating Profits from the Major Markets and the 
Royalty Territory, and Section 6.1 of the Agreement is hereby amended to add a 
new clause (iii) after the word "except", which states in its entirety as 
follows:

      "(iii) if Chiron is not for any reason manufacturing on behalf of the 
      Collaboration commercial supplies of a Product containing IGF-1, 
      Cephalon will receive an additional [CONFIDENTIAL TREATMENT REQUESTED] of 
      the Operating Profits from the Major Markets and the Royalty Territory 
      attributable to Net Sales of any such Product that was manufactured by 
      Cephalon (the 'Manufacturing Premium') (i.e., for a total share of 
      [CONFIDENTIAL TREATMENT REQUESTED] of such Operating Profits)."

      2.   The payment by the Collaboration of Manufacturing Premium does not 
operate as a waiver of any party's rights or obligations under the Agreement, 
including Chiron's obligations to manufacture Products in accordance with the 
terms of the Agreement.

      3.   Chiron has elected not to participate in Cephalon's option to 
buy-down the royalty rate and license fees payable under a License Agreement 
dated March 5, 1992, as amended, between Cephalon and The Salk Institute of 
Biotechnology/Industrial Associates, Inc ("SIBIA"). Even if Cephalon 
exercises its option to buy-down the SIBIA compensation, the Collaboration 
will nevertheless continue to be responsible for the full amount of the 
compensation (royalties and license fees) owed to SIBIA under the SIBIA 
License as in effect before such buy-down, to the extent such compensation 
results from the activities of the Collaboration. The payments of SIBIA

<PAGE>


Chiron Corporation
May 23, 1995
Page 2

compensation will be made to Cephalon, who will remit the appropriate amount
to SIBIA. As an illustration, assuming that before the buy-down the royalty
owed to SIBIA on sales of a Product in the Field is
[CONFIDENTIAL TREATMENT REQUESTED] and that Cephalon buys down
[CONFIDENTIAL TREATMENT REQUESTED] of the SIBIA royalty, the Collaboration
will pay Cephalon the [CONFIDENTIAL TREATMENT REQUESTED] royalty and Cephalon
will remit the [CONFIDENTIAL TREATMENT REQUESTED] royalty to SIBIA.

     If the above accurately describes our understanding, please indicate 
your agreement in the space provided below.

                                            Sincerely yours,

                                            /s/ Bruce A. Peacock

                                            Bruce A. Peacock
                                            Executive Vice President and
                                            Chief Operating Officer

Acknowledged and agreed to by:

CHIRON CORPORATION



By: /s/ William G. Green

<PAGE>

                                 EXHIBIT 11

                            CHIRON CORPORATION
               STATEMENT OF COMPUTATION OF EARNINGS PER SHARE

<TABLE>
<CAPTION>
                                                          Year Ended December 31,
                                             --------------------------------------------
                                                  1995            1994            1993
                                             --------------    -----------    -----------
<S>                                          <C>               <C>            <C>
EARNINGS PER SHARE
   Net income (loss) available for
      common shares and common
      stock equivalent shares deemed
      to have a dilutive effect              $(512,463,000)    $18,325,000    $18,384,000
                                             --------------    -----------    -----------
Primary earnings (loss) per share            $      (12.62)    $      0.53    $      0.55
                                             --------------    -----------    -----------

Fully diluted earnings (loss) per share      $      (12.62)    $      0.53    $      0.54
                                             --------------    -----------    -----------
Shares used in primary earnings (loss)
   per share computation:
      Weighted average common shares
         outstanding                             40,610,000     32,972,000     32,094,000
      Weighted average dilutive 
         incremental common shares
         issuable from exercise of
         warrants                                        --         68,000         45,000
      Weighted average dilutive 
         incremental common shares
         issuable under employee
         stock option programs                           --      1,253,000      1,542,000
                                             --------------    -----------    -----------
      Total common shares and
         common stock equivalent
         shares deemed to have a
         dilutive effect                         40,610,000     34,293,000     33,681,000
                                             --------------    -----------    -----------
Shares used in fully dilutive earnings
   (loss) per share computation:
      Weighted average common shares
         outstanding                             40,610,000     32,972,000     32,094,000
      Weighted average dilutive 
         incremental common
         shares issuable from
         exercise of warrants                            --        103,000        89,000
      Weighted average dilutive
         incremental common shares
         issuable under employee
         stock option programs                           --      1,638,000      2,116,000
                                             --------------    -----------    -----------
      Total common shares and 
         common stock equivalent
         shares deemed to have a 
         dilutive effect                         40,610,000     34,713,000     34,299,000
                                             --------------    -----------    -----------
                                             --------------    -----------    -----------

</TABLE>

<PAGE>
                               CHIRON CORPORATION
                       CONSOLIDATED FINANCIAL STATEMENTS
 
<TABLE>
<S>                                                                     <C>
Management's Discussion and Analysis..................................           1
Consolidated Financial Statements.....................................          13
Notes to Consolidated Financial Statements............................          18
Report of Independent Auditors........................................          48
Market Price of Common Stock..........................................          49
</TABLE>
<PAGE>
                    MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 FINANCIAL CONDITION AND RESULTS OF OPERATIONS
 
OVERVIEW
 
    THE  DISCUSSION BELOW CONTAINS FORWARD-LOOKING STATEMENTS THAT INVOLVE RISKS
AND UNCERTAINTIES  RELATING  TO  THE  FUTURE  FINANCIAL  PERFORMANCE  OF  CHIRON
CORPORATION (THE "COMPANY" OR "CHIRON"), AND ACTUAL EVENTS OR RESULTS MAY DIFFER
MATERIALLY.  IN EVALUATING  SUCH STATEMENTS,  STOCKHOLDERS AND  INVESTORS SHOULD
SPECIFICALLY CONSIDER THE VARIOUS FACTORS IDENTIFIED UNDER THE CAPTION  "FACTORS
THAT  MAY AFFECT FUTURE  OPERATING RESULTS" WHICH COULD  CAUSE ACTUAL RESULTS TO
DIFFER MATERIALLY FROM THOSE INDICATED BY SUCH FORWARD-LOOKING STATEMENTS.
 
    Chiron is  a diversified,  science-driven  healthcare company  that  applies
biotechnology  and other techniques of modern  biology and chemistry to develop,
produce and sell products intended to improve the quality of life by diagnosing,
preventing and  treating  human  disease.  Chiron  participates  in  four  human
healthcare  markets: (i) diagnostics, including blood screening tests, automated
immunodiagnostic systems, critical  blood analyte systems  and new  quantitative
probe tests; (ii) therapeutics, with an emphasis on oncology, serious infectious
diseases  and  critical  care  diseases;  (iii)  adult  and  pediatric vaccines,
including vaccines  under development  and  a genetically  engineered  acellular
pertussis  vaccine,  currently on  the market  in Italy  and for  which clinical
trials have been completed in the United States and Europe; and (iv)  ophthalmic
surgical  products,  including instruments  and  devices used  for  the surgical
correction of vision and an intraocular  implant to deliver drugs into the  eye.
Chiron  also develops or acquires new technologies, employing these technologies
to discover  new products  for the  Company or  for its  partners. For  example,
Chiron  is developing a new generation of chemical therapeutics through advanced
techniques of drug design and discovery  and is conducting an active program  in
gene therapy.
 
ACQUISITIONS
 
    As   discussed  further  in  Note  2  of  Notes  to  Consolidated  Financial
Statements, effective  January 1,  1995, under  a series  of agreements  between
Chiron  and  Ciba-Geigy Limited  of  Basel, Switzerland  ("Ciba"),  including an
investment agreement, a cooperation and collaboration agreement and a governance
agreement  (collectively  the  "Agreements"),  Ciba  obtained  a  49.9   percent
ownership interest in Chiron common stock (now approximately 47 percent). At the
same  time, Chiron acquired all of the  outstanding common stock of Ciba Corning
Diagnostics Corp.  ("CCD")  and  Ciba's  interests  in  Chiron  Biocine  Company
(formerly  The  Biocine Company)  and  Biocine S.p.A.  (through  JV Vax  B.V., a
Netherlands company), in  exchange for  6.6 million  newly-issued Chiron  common
shares  and a cash payment of $23.5  million. The acquisitions of CCD and Ciba's
interests in Chiron Biocine Company and Biocine S.p.A. were accounted for  under
the  purchase  method of  accounting  and resulted  in  a $222.9  million charge
against earnings for purchased in-process technology. The results of  operations
of  CCD,  Biocine S.p.A.  and Chiron  Biocine Company  are included  in Chiron's
consolidated operating results from January 1, 1995, forward. Chiron's share  of
the operating results of Biocine S.p.A. and Chiron Biocine Company were included
in  the Company's  1994 and  1993 operating results  under the  equity method of
accounting.
 
    In connection with the Agreements, Ciba agreed to guarantee $425 million  of
new  debt for Chiron and agreed to  provide $250 million (which may be increased
up to $300  million subject to  certain reductions in  the debt guarantee)  over
five  years  in support  of research  at Chiron,  and Chiron  has the  option of
issuing up to $500 million of new equity to Ciba.
 
    During 1995,  Chiron  and Ciba  entered  into a  limited  liability  company
agreement  to utilize  research funding  provided by  Ciba, as  discussed above.
Under the terms  of the  agreement, Ciba  will fund  from time  to time  through
December 31, 1999, at Chiron's request, research and development costs for adult
vaccines,  pediatric vaccines  and insulin-like growth  factor-1. Annual funding
amounts are subject  to certain  limitations. In  return, Ciba  will receive  an
interest in a stream of variable
 
                                       1
<PAGE>
royalties  from  future  worldwide  sales  of  certain  adult  vaccines, certain
pediatric vaccines and insulin-like growth factor-1. Royalties will be paid  for
a minimum period of ten years, subject to an extension under certain conditions,
following the later of October 1, 2001, or the date of the first commercial sale
of  individual products  covered by the  agreement. In addition,  Ciba will also
receive an interest  in promotional  rights, in  countries other  than in  North
America and Europe, for certain adult vaccines.
 
    Under  the  terms of  the  agreement Chiron  was  granted an  option through
December 31, 2001, to  repurchase Ciba's interest, at  cost plus an  agreed-upon
return. In addition, if Chiron chooses to exercise the option, Ciba will receive
an  option to acquire exclusive marketing  rights, in countries other than those
in North America and Europe, with respect to certain adult vaccines in countries
in which Ciba has exercised its co-promotion rights. Pursuant to the  agreement,
Chiron received $27 million of funding from Ciba during 1995, which was recorded
as  collaborative agreement  revenues. Chiron  anticipates receiving substantial
additional funding from  Ciba in future  periods, pursuant to  the terms of  the
agreements.
 
    As   discussed  further  in  Note  2  of  Notes  to  Consolidated  Financial
Statements, on March 31, 1995, Chiron  Vision acquired the surgical division  of
IOLAB  from Johnson & Johnson for approximately $95 million. The acquisition was
accounted for under the purchase method  of accounting, and resulted in a  $10.3
million charge against earnings for purchased in-process technology. The Company
recorded  additional charges for  restructuring and integration-related expenses
totaling $16.9 million. IOLAB's results  of operations are included in  Chiron's
consolidated operating results from March 31, 1995, forward.
 
    As   discussed  further  in  Note  2  of  Notes  to  Consolidated  Financial
Statements, on September 29,  1995, Chiron acquired  all the outstanding  common
stock  of Viagene, Inc. ("Viagene") in  exchange for approximately $35.5 million
in cash and 916,000  shares of Chiron common  stock. Additionally, on  September
29,  1995, unexercised options  to purchase Viagene  common stock were converted
into options to purchase  approximately 132,000 shares  of Chiron common  stock.
The  acquisition was accounted  for under the purchase  method of accounting and
resulted  in  an  approximately  $130.3  million  charge  against  earnings  for
purchased in-process technology. Viagene's results of operations are included in
Chiron's  consolidated operating results from September 29, 1995, forward. Prior
to September 29,  1995, Chiron  accounted for its  interest in  Viagene at  fair
value as a marketable equity investment.
 
RESULTS OF OPERATIONS
 
    REVENUES
 
    The  Company's revenues  are derived  from a  variety of  sources, including
product sales, joint business arrangements, collaborative agreements and product
royalty agreements. Product sales,  Chiron's largest revenue category,  consists
of  the following product lines in the human healthcare industry for each of the
three years ended December 31:
 
<TABLE>
<CAPTION>
                                                                           1995         1994         1993
                                                                        -----------  -----------  -----------
<S>                                                                     <C>          <C>          <C>
                                                                                   (IN THOUSANDS)
Diagnostic products...................................................  $   541,113  $    21,678  $    13,704
Ophthalmic products...................................................      176,951      106,062       82,129
Vaccine products......................................................       74,885           --           --
Betaseron-Registered Trademark-.......................................       67,666      100,121       11,774
Oncology products.....................................................       58,042       43,254       38,417
Other products........................................................        4,196        4,851        1,869
                                                                        -----------  -----------  -----------
                                                                        $   922,853  $   275,966  $   147,893
                                                                        -----------  -----------  -----------
                                                                        -----------  -----------  -----------
</TABLE>
 
    As a result of the January 1995 acquisition of CCD, diagnostic product sales
now represent the largest component of product sales. For 1995, CCD added $510.1
million of new revenues to Chiron's
 
                                       2
<PAGE>
operating results. CCD's product sales for 1994 and 1993, which are not included
in Chiron's results, were $455.7  million and $423.1 million, respectively.  CCD
product  sales  include direct  sales and  sales-type leases  of fully-automated
random-access immunodiagnostic (ACS-TM-) testing systems and reagents for  these
systems,  as well as sales of critical blood analyte systems (CBA-TM-), clinical
chemistry products  and manual  immunodiagnostic  systems. Sales  of  diagnostic
systems  often include  the sale of  service and  maintenance contracts. Revenue
from these contracts  is included  in product  sales revenue  and is  recognized
ratably  over the  life of  the contracts.  Both of  CCD's major  product lines,
immunodiagnostic systems and  CBA systems,  have continued  to increase  between
years  due  to  increased  market  penetration,  particularly  in  international
markets, ongoing menu expansion of existing ACS systems and the introduction  in
1995  of a new CBA  system product line (the  800 Series-TM-). Product sales for
CCD would  have  been approximately  $17.8  million  lower in  1995  if  foreign
currency exchange rates had remained the same as in 1994.
 
    Diagnostic  product sales also include sales  of nucleic acid probe products
and instrumentation and sales of antigens and RIBA-Registered Trademark-  tests.
Nucleic  acid probe products accounted for  substantially all of the increase in
this category  of revenue  in 1994  over 1993  as Chiron  began marketing  these
products for research use in early 1993. Nucleic acid probe products are sold at
cost  to Daiichi Pure Chemical Co.,  Ltd. ("Daiichi"), which markets the product
in Japan and pays Chiron a royalty based upon its sales of the product.  Nucleic
acid  probe products are also sold by Chiron on a Research Use Only basis in the
United States and Europe. Antigens and RIBA-Registered Trademark- test kits  are
sold  at cost to Ortho Diagnostic Systems, Inc. ("Ortho"), Chiron's partner in a
joint diagnostic business.
 
    Sales of ophthalmic products continued to increase between years due to  the
impact  of the May 1994 acquisition  of Laboratoires Domilens S.A. ("Domilens"),
the March 1995 acquisition of the surgical division of IOLAB and increased sales
of products incorporating foldable  lens technology. Domilens contributed  $26.1
million and $13.3 million of product sales for the years ended December 31, 1995
and  1994, respectively. The net impact of the acquisition of IOLAB and Domilens
and a change in the marketplace favoring foldable lens technology-based products
resulted in  increased sales  of  $70.9 million  in  1995. Sales  of  refractive
surgery  products in 1995  were substantially consistent with  that of 1994. The
impact of the  Domilens acquisition  and expanded  sales of  excimer lasers  and
corneal  shapers in 1994 resulted in product  sales growth of $23.9 million over
1993.
 
    Prior to  Chiron's  acquisition of  Ciba's  interest in  Biocine  S.p.A.  on
January  1, 1995, the Company's share of the operating results of Biocine S.p.A.
were included as joint business revenues. Subsequent to January 1, 1995, Biocine
S.p.A. is consolidated as a wholly-owned  subsidiary of Chiron with its  vaccine
sales  reflected as  a component of  total product sales.  Vaccine product sales
consist of  sales of  pediatric and  adult vaccines  primarily in  Italy and  to
public   health  organizations.   Biocine  S.p.A.'s   vaccine  products  include
Acelluvax-Registered Trademark-,  a  recombinant  acellular  pertussis  vaccine;
Agrippal-Registered  Trademark-, a flu vaccine;  and Polioral-TM-, an oral polio
vaccine. Sales of Biocine S.p.A.'s flu  vaccine are seasonal, with strong  sales
generally occurring during the pre-flu season in the fourth quarter of the year.
Biocine  S.p.A.'s product  sales for  1994 and 1993,  which are  not included in
Chiron's results,  were  $56.7  million and  $45.8  million,  respectively.  The
increase  in Biocine  S.p.A.'s vaccine product  sales between 1995  and 1994 and
between 1994 and 1993 are due to increasing sales of
Acelluvax-Registered Trademark- and Polioral-TM- between each respective period.
 
    Under the terms  of a  development and  supply agreement  with Schering  AG,
Germany   ("Schering"),  and  its  U.S.  affiliate,  Berlex  Laboratories,  Inc.
("Berlex"), Chiron  manufactures  Betaseron-Registered  Trademark-  for  Berlex.
Through  December 31, 1994,  Chiron manufactured Betaseron-Registered Trademark-
under the  terms of  an amended  development and  supply agreement  whereby  the
Company  received payment  for the  product upon  shipment to  Berlex. Effective
January 1, 1995,  Chiron exercised  its option  to revert  to the  terms of  the
original  Betaseron-Registered Trademark- supply agreement. Under those original
terms, Chiron earns a partial  payment for Betaseron-Registered Trademark-  upon
shipment  to Berlex and a subsequent payment for Betaseron-Registered Trademark-
upon Berlex's net sales of the product.
 
                                       3
<PAGE>
    Because adequate  inventory  levels had  previously  been built  by  Berlex,
Chiron  did not ship any commercial-use vials  during the first quarter of 1995.
The combined impact in 1995 of the reversion to the terms of the original supply
agreement and a six percent reduction in volumes shipped to Berlex resulted in a
decrease in Betaseron-Registered Trademark- revenues  from 1994 to 1995.  Future
levels  of Chiron's  Betaseron-Registered Trademark- shipments  will depend upon
the rate at which  new patients are enrolled  from existing and future  markets,
the  extent  to  which  patients,  once  enrolled,  remain  compliant  with  the
prescribed   treatment    regimen   and    continue   to    regularly    receive
Betaseron-Registered Trademark-, and the timing of approval and market launch of
competing products, including another beta interferon product.
 
    Betaseron-Registered Trademark- product sales increased in 1994 over that of
1993   as   1994  was   the  first   full  year   of  commercial   shipments  of
Betaseron-Registered  Trademark-  and  as  Berlex  continued  to  build  product
inventories  sufficient to supply all of  the patients on the initial enrollment
list.
 
    Sales of  oncology  products, principally  Proleukin-Registered  Trademark-,
increased between 1994 and 1995 due to an increase in
Proleukin-Registered  Trademark- quantities sold  of 23 percent  and 24 percent,
respectively, in the European and domestic markets, as well as an increase of 14
percent and three percent, respectively, in  average net unit selling prices  in
the European and domestic markets. Oncology product sales increased from 1993 to
1994  as vials of  Proleukin-Registered Trademark- sold  increased by 11 percent
and  13  percent,   respectively,  in   the  European   and  domestic   markets.
Proleukin-Registered  Trademark- net unit sales prices increased by nine percent
in Europe but remained constant between 1994 and 1993 in the domestic market.
 
    The Company markets many  of its commercial  products internationally. As  a
result, product revenues in almost all product lines are affected by fluctuating
foreign currency exchange rates. Foreign product sales were approximately $519.4
million,  $71.6 million and $47.0 million for the years ended December 31, 1995,
1994 and 1993, respectively. International  sales of diagnostic products by  CCD
and  vaccine  sales by  Biocine S.p.A.  accounted for  substantially all  of the
increase in foreign product  sales from 1994 to  1995. Product sales would  have
been  approximately $26.1 million  lower in 1995 if  currency exchange rates had
remained the same as in  1994. In 1994, product sales  would have been lower  by
approximately  $1.1 million if currency exchange  rates had remained the same as
in 1993.  For the  year ended  December 31,  1995, approximately  56 percent  of
Chiron's  product sales  were denominated in  foreign currencies.  For the years
ended December  31, 1994  and 1993,  approximately 26  percent and  32  percent,
respectively,  of Chiron's product sales were denominated in foreign currencies.
Therefore, changing currency exchange rates have had, and will continue to have,
an impact on Chiron's  results. The Company's  other revenues, discussed  below,
are largely denominated in U.S. dollars.
 
    An  important  source of  Chiron's revenues  arises from  its equity  in the
earnings of unconsolidated  joint businesses.  As of December  31, 1995,  Chiron
owned  a 50 percent equity interest in  two joint businesses: a joint diagnostic
business with Ortho  and a  generic cancer chemotherapeutics  business with  Ben
Venue  Laboratories,  Inc. Chiron's  one-half interest  in the  pretax operating
earnings of  its joint  diagnostic business  with Ortho  represents the  largest
component of joint business revenues. These revenues are recorded by Chiron on a
one-month  lag based upon estimates supplied by Ortho and are subject to a final
annual accounting during the first quarter of the subsequent year. While  Chiron
and  Ortho believe  that these estimates  reasonably portray the  results of the
joint business, there can be no assurance that subsequent adjustment will not be
required. Chiron recorded joint diagnostic  business revenues of $76.9  million,
$74.3 million, and $77.1 million for the years ended December 31, 1995, 1994 and
1993,  respectively. Revenue amounts include a nominal amount recognized in 1995
and 1994 as a  result of the  final 1994 and  1993 accounting respectively,  and
$6.6  million recognized in 1993  as a result of  the final 1992 accounting. The
Company anticipates that adjustments arising from the final 1995 accounting will
not be significant. Excluding  the impact of  these prior adjustments,  Chiron's
share of the profits of the joint business has increased slightly throughout the
three-year period ended December 31, 1995.
 
                                       4
<PAGE>
    Approximately  78 percent  of the sales  of the  Chiron-Ortho joint business
arise from sales  of hepatitis C  virus ("HCV") tests.  The joint business  also
receives a royalty from Abbott Laboratories ("Abbott") for Abbott's sales of HCV
tests,  which use  the Chiron technology  and which compete  directly with tests
marketed by Ortho.
 
    During 1994, the American  Red Cross ("Red  Cross") renegotiated a  contract
with  the Chiron-Ortho joint business which resulted in a lower selling price on
HCV tests.  During 1995,  the revenues  of the  joint business  continued to  be
negatively  impacted by  lower product  margins resulting  from the renegotiated
contract. Revenues were also negatively impacted  as a result of changes in  the
product  mix whereby the proportion of higher  margin HCV tests sold relative to
other lower-margin  products  decreased  in  1995 as  compared  to  1994.  Joint
business  profits  were  also  impacted by  increased  research  and development
spending due to the  ongoing development of new  products and costs incurred  to
increase  market share in certain foreign  markets. The impact on joint business
profits from reduced  margins and additional  research and development  spending
was  offset by increased royalty revenues and  by the Company's share of a legal
settlement received from  a competitor regarding  certain European HCV  patents.
During  1994, the revenues of the  joint business were negatively impacted, when
compared to 1993,  by the renegotiated  supply contract with  the Red Cross  and
expiring  supply  contracts  with  members of  the  Council  of  Community Blood
Centers.
 
    As noted  previously, prior  to  January 1,  1995,  the Company's  share  of
Biocine  S.p.A.'s  profits were  included as  joint  business revenue.  In 1994,
Chiron and Ciba  entered into a  settlement agreement with  the former owner  of
Biocine  S.p.A. regarding a dispute over representations made in connection with
the acquisition of Biocine  S.p.A. Included in joint  business results for  1994
was  approximately $4.8 million representing  Chiron's share of this settlement.
Without the  impact of  the  settlement, Chiron's  joint business  revenue  from
Biocine S.p.A. for 1994 was $2.5 million and, for 1993, was not significant. The
increase  in revenue from 1993 to 1994 was due primarily to increased sales from
a new  pertussis vaccine  and reduced  reserves  for the  return of  unused  flu
vaccine.
 
    Results for Chiron's equity interest in the generic cancer chemotherapeutics
business were not significant in any of the years in the three-year period ended
December 31, 1995.
 
    Collaborative  agreement  revenue  consists of  fees  received  for research
services as  they  are  performed,  fees  received  for  completed  research  or
technology, fees received upon attainment of benchmarks specified in the related
research  agreements, and proceeds of sales  of biological materials to research
partners for clinical and preclinical testing. Collaborative agreement  revenues
decreased  from 1994 to 1995  due to the January  1, 1995, acquisition of Ciba's
interest in Chiron Biocine  Company. Prior to  the acquisition, Chiron  received
reimbursement  for its vaccine research expenses from Chiron Biocine Company and
recorded such  reimbursement  as  collaborative  agreement  revenue.  After  the
acquisition,  Chiron Biocine Company became  a wholly-owned subsidiary of Chiron
and thus no  longer provides research  revenues to Chiron.  For the years  ended
December 31, 1994 and 1993, the Company recognized revenues of $40.9 million and
$35.4  million, respectively, from Chiron  Biocine Company. Further contributing
to the decrease in revenues in 1995  was the completion of a nucleic acid  probe
development  program with Daiichi and a payment received as reimbursement from a
collaborative research partner,  each of  which provided 1994  revenues of  $3.0
million.  Offsetting  these  decreases  was $27.0  million  of  research funding
received from Ciba under the terms of a limited liability company agreement,  as
discussed  previously. Also included as collaborative agreement revenues in 1995
was $5.5  million  received  from  Ciba for  non-exclusive  access  to  Chiron's
combinatorial  chemistry techniques. Collaborative  agreement revenues decreased
slightly from 1993 to 1994.
 
    Other revenues consist principally  of product royalties, government  grants
and  sales fees earned by the Company  for sales and marketing services rendered
on behalf  of its  generic  chemotherapeutics joint  venture  and on  behalf  of
Ciba-Geigy.  Royalty revenue, the largest component of other revenues, increased
from $14.8 million and  $17.1 million in 1993  and 1994, respectively, to  $22.5
million in 1995.
 
                                       5
<PAGE>
In  both years, this increase was largely  due to increased sales of recombinant
human insulin and Japanese nucleic probe products. Other revenues also increased
in   1995   due   to   sales   fees   received   from   Ciba   for   sales    of
Aredia-Registered  Trademark-, for which Chiron  began earning sales fee revenue
in late 1994,  and nucleic  probes reference laboratory  service revenues  which
contributed  additional revenues of $4.2 million and $2.9 million, respectively,
in 1995.
 
    COSTS AND EXPENSES
 
    Cost of  sales  increased consistent  with  the increase  in  product  sales
between  years. Gross profit margins increased from  54 percent in both 1993 and
1994, respectively, to 55 percent in 1995. The gross profit margin was  affected
negatively  throughout  1995  as  a  result  of  a  reversion  to  the  original
Betaseron-Registered Trademark-  supply  agreement,  discussed  previously,  and
additional   operating  expenses  associated  with  the  Company's  Puerto  Rico
manufacturing facility which  was idled  during 1995.  Offsetting this  downward
pressure  was the addition  of CCD's and Biocine  S.p.A.'s higher margin product
sales in 1995. Gross  margin percentages may  fluctuate significantly in  future
periods as the Company's product mix continues to evolve and as the costs of new
facilities are included in cost of goods sold.
 
    Research  and development expenses increased  significantly between 1994 and
1995, largely due to the acquisitions of CCD and Biocine S.p.A. CCD and  Biocine
S.p.A.  added $71.3  million and  $25.1 million,  respectively, in  research and
development expenses  for 1995.  For the  years  ended 1994  and 1993,  CCD  and
Biocine S.p.A. incurred research and development costs of $61.5 million and $9.2
million,  and  $62.0  million  and $6.3  million,  respectively,  which  are not
included in Chiron's results. Research and development activities at CCD consist
primarily of product development of  new clinical diagnostic testing systems  or
extensions  of test menus on existing  systems. Also included is the development
of quality control products and the  development of data management software  to
be  used  within  a diagnostic  testing  system,  or between  the  system  and a
customer's laboratory information system. Research and development activities at
Biocine S.p.A. consist  of development of  new pediatric and  adult vaccines  as
well as efforts to obtain regulatory approvals of certain vaccines in the United
States  and  Europe. Adjusting  for the  impact  of the  acquisition of  CCD and
Biocine S.p.A.,  Chiron's research  and development  expenses increased  as  the
Company's  products in  development continue to  move towards commercialization,
and as the  Company entered  into a  number of  collaborative arrangements  with
other  pharmaceutical and biotechnology companies  for the research, development
and  marketing  of  certain  technologies   and  products.  As  part  of   these
collaborative  arrangements, Chiron has  made various investments  in the equity
securities of the collaborative partners and,  in some cases, agreed to  provide
specified levels of funding to the collaboration. As discussed further in Note 4
of  Notes to  Consolidated Financial Statements,  new collaborative arrangements
entered into by Chiron during 1995 include the following:
 
    - In March  1995, the  Company reached  an agreement  with Progenitor,  Inc.
      ("Progenitor"),  a  subsidiary  of Interneuron  Pharmaceuticals,  Inc., to
      collaborate in the  development and commercialization  of therapeutic  and
      vaccine  products  incorporating  Progenitor's  proprietary  gene  therapy
      technology. Under the agreement, Chiron received a license to Progenitor's
      nonviral gene expression system for use in the development of products for
      the treatment of certain cancers and cardiovascular disorders, development
      of infectious disease vaccines and  for development of certain other  gene
      therapy products. Chiron will have the right to manufacture and market any
      resulting  products of  the collaboration. In  return for  the license and
      other rights, Chiron made certain financial commitments to Progenitor.  In
      addition,  Progenitor will receive a royalty  from any commercial sales of
      products resulting from the collaboration.
 
    - In  March  1995,   the  Company   reached  an   agreement  with   Genelabs
      Technologies,    Inc.   ("Genelabs"),   whereby    Chiron   and   Genelabs
      cross-licensed certain rights  to HCV,  hepatitis G  virus ("HGV"),  human
      T-cell  leukemia virus -- I ("HTLV-I")  and human T-cell leukemia virus --
      II ("HTLV-II")  diagnostic tests.  Under  the agreement,  Chiron  acquired
      certain rights to develop
 
                                       6
<PAGE>
      and  market  diagnostic  products for  the  detection of  HGV,  HTLV-I and
      HTLV-II. In return, Genelabs acquired development and marketing rights  in
      Asia,  except  Japan,  for  certain  products  incorporating  Chiron's HCV
      technology. Ortho, Chiron's joint diagnostic business partner, has  agreed
      to  participate  as  Chiron's  equal  partner  in  the  collaboration with
      Genelabs and,  therefore, will  share equally  in all  payments under  the
      agreement, including equity investments.
 
    - In  March 1995, the Company reached  an agreement with New York University
      ("NYU") under which Chiron acquired  rights to optical mapping  technology
      for  use  by  Chiron and  its  sublicensee,  Ciba, in  the  development of
      diagnostics, therapeutics and vaccines. Chiron also acquired the right  to
      commercialize  a  potential optical  mapping  instrument. In  exchange for
      these rights, Chiron and Ciba made certain financial commitments to NYU.
 
    Also included in  1995 are payments  totaling $25.3 million  related to  the
funding of certain collaboration expenses and the purchase of additional program
rights from Cephalon, Inc., an existing collaboration partner.
 
    Expenditures   were   also  incurred   during   1995  relating   to  ongoing
collaboration efforts entered into during prior years. During 1995, $8.8 million
was paid pursuant to a collaboration with  G.D. Searle & Co. ("Searle") for  the
development  and marketing of Tissue Factor Pathway Inhibitor ("TFPI") products;
$3.5 million of research  and development expense was  recognized pursuant to  a
collaboration  for  the  development  and  marketing  of  products incorporating
certain drug delivery technologies developed by DepoTech Corporation; and a $1.5
million payment  was  made  pursuant  to  a  collaboration  with  CytoMed,  Inc.
("CytoMed") for the research, development and marketing of complement inhibitors
with   therapeutic  and  diagnostic  applications.  Additionally,  as  discussed
previously, Chiron Viagene was acquired by the  Company at the end of the  third
quarter  of 1995. Chiron Viagene is engaged  in the discovery and development of
gene transfer drugs for  the treatment of severe  viral infections, cancers  and
other  diseases and added an additional $6.0 million of research and development
expense during 1995.
 
    These new or continuing collaborations and program rights payments discussed
above contributed  an  additional  $56.0 million  to  research  and  development
expense  in 1995. The Company  also increased spending at  Chiron Vision by $6.2
million over that of 1994 due to a general increase in costs resulting from  the
acquisition  of IOLAB and inclusion  of a full year  of research and development
activity at Domilens. In addition,  research and development expenses  increased
due   to   higher   levels   of  spending   on   the   development   of  certain
phacoemulsification products  and greater  clinical activity  for certain  other
products.  In 1996,  the Company expects  that research  and development expense
will increase over  prior years, as  Chiron continues to  incur expenses in  its
collaborations,  including  those discussed  above,  and as  Chiron  expands its
diagnostics, vaccines,  therapeutics and  ophthalmics clinical  trials.  Product
development,  manufacturing start-up, and regulatory expenses will also increase
in future periods as Chiron  anticipates manufacturing and marketing  additional
products.
 
    Between  1994 and 1993,  research and development  expenses increased as the
Company entered  into  collaboration arrangements  and  incurred costs  to  move
products  in development towards commercialization. New collaboration agreements
in 1994  resulting  in increased  research  and development  expense  over  1993
included the following:
 
    - Chiron  and  CytoMed  entered  into  a  collaboration  agreement  for  the
      research,  development  and  marketing   of  complement  inhibitors   with
      therapeutic  and diagnostic  applications. Chiron  agreed to  make certain
      milestone payments and to reimburse CytoMed for a portion of its  research
      and  development  expense  during  1995  and  1996.  Additionally,  Chiron
      invested $1.3  million in  CytoMed capital  stock and  warrants which  was
      expensed in 1994.
 
                                       7
<PAGE>
    - Chiron and Searle entered into a collaboration agreement for the research,
      development  and marketing  of TFPI products.  Chiron made  a $3.5 million
      payment to  Searle  and  agreed  to  fund  its  own  collaboration-related
      expenses through 1994. In 1994, Chiron's research and development expenses
      related to this collaboration totaled approximately $6.5 million.
 
    These  collaborations,  among others,  added  approximately $9.1  million of
research and  development expenses  in 1994.  Spending in  the vaccines  program
increased  by approximately  $11.2 million over  1993 due to  clinical trial and
manufacturing expenses  for  vaccines  then in  development.  Additionally,  the
Company  purchased an option from Johnson & Johnson to participate in a home HIV
testing business, of which $5.8 million was expensed in 1994.
 
    Selling, general  and administrative  expenses ("SG&A  expenses")  increased
significantly  from 1994 to 1995 primarily due  to the impact of the acquisition
of CCD and Biocine S.p.A. CCD and Biocine S.p.A. added $179.5 million and  $18.2
million,  respectively, in SG&A expenses  in 1995. For the  years ended 1994 and
1993, CCD and Biocine S.p.A. incurred SG&A expenses of $157.8 million and  $21.8
million,  and  $149.4 million  and $18.7  million,  respectively, which  are not
included in  Chiron's results.  SG&A expenses  in the  ophthalmic business  were
higher  in 1995 due to  the acquisition of IOLAB  and increased costs related to
the ophthalmic sales force,  resulting from the  integration of Chiron  Vision's
operations  with  IOLAB. Selling  and marketing  expenses represent  the largest
portion of total  SG&A expenses  in all  periods as  Chiron devoted  significant
resources to support sales volumes in the diagnostics, ophthalmics, therapeutics
and vaccines product lines. SG&A expenses increased between 1993 and 1994 due to
the  acquisition of Domilens, which added $5.8 million of SG&A expenses in 1994,
and higher legal costs associated with Chiron's defense of HCV patents.
 
    The write-off of purchased in-process technology consists of $222.9  million
for  the acquisitions of CCD, Biocine  S.p.A. and Chiron Biocine Company, $130.3
million for the acquisition of Viagene and $10.3 million for the acquisition  of
IOLAB.  Also  included  was  $1.8  million  related  to  the  acquisition  of an
additional interest in a subsidiary of Chiron Vision. The fair value of the  net
assets  acquired  in the  acquisitions of  CCD,  Biocine S.p.A.,  Chiron Biocine
Company and  IOLAB, including  in-process technology,  were estimated  based  on
independent  valuations of the  acquired net assets.  The fair value  of the net
assets acquired in the Viagene acquisition  were determined to be equal to  book
value as Viagene was an early-stage company with no intangible assets other than
in-process  technology. Amounts  allocated to  base technology  for CCD, Biocine
S.p.A.  and  IOLAB  were  $21.6   million,  $6.6  million  and  $27.0   million,
respectively,  and are being amortized over periods  ranging from 10 to 15 years
using the straight-line  method. Approximately  $11.6 million  was allocated  to
goodwill for IOLAB and is being amortized using the straight-line method over 15
years.
 
    In 1995, costs related to the Ciba transaction consist primarily of employee
payments  and related  tax liabilities  and legal  and investment  advisor fees.
Under the  Agreements  reached with  Ciba,  Ciba reimbursed  the  Company  $24.8
million  for  a portion  of  the employee  payments  and such  reimbursement was
recorded as a capital contribution.
 
    Restructuring and  reorganization costs  in 1995  represent certain  accrued
costs  of integrating the acquired businesses with Chiron's existing businesses,
costs related to the idling of the Company's Puerto Rico manufacturing  facility
and  the  scaling-back of  manufacturing operations  at the  Company's Amsterdam
facility, and costs  related to the  write-down of duplicate  facilities at  the
Company's  Emeryville,  California,  headquarters. Also  included  was  a charge
related to the change in plans  to expand the Company's Emeryville research  and
administrative  facilities.  Of  the $39.1  million  in total  charges  in 1995,
approximately $27.1 million  related to  write-downs of  assets, including  $8.0
million  related to the change in plans  for expansion of the Company's research
and administrative facilities. The remaining charges of $12.0 million  consisted
of  employee costs of $5.5 million and lease termination and other costs of $6.5
million. The majority  of the remaining  accrued costs are  expected to be  paid
through 1996.
 
                                       8
<PAGE>
    Other  operating expenses consist primarily of the amortization of purchased
technologies and goodwill. The increase in other operating expenses in 1995 over
that of 1994 is the result of increased amortization of purchased  technologies,
goodwill  and other intangible assets arising from the 1995 acquisitions of CCD,
Biocine S.p.A. and IOLAB. Purchased  technology and goodwill arising from  these
acquisitions  are  being  amortized over  periods  from  10 to  15  years. Other
intangible assets acquired, such  as the assigned fair  value of customer  lists
and  tradename, are  being amortized  over periods  from 10  to 15  years. Other
operating expenses in 1994 are primarily comprised of amortization of  purchased
technologies.  Other operating expenses  in 1993 also included  a credit of $6.0
million arising from the settlement of a legal dispute.
 
    OTHER ITEMS
 
    Other income (expense), net, consists primarily of investment income on  the
Company's  cash  and investment  balances  and interest  expense  on convertible
subordinated debentures, other debt and capital leases. Included in other income
(expense), net, in 1995 is additional interest expense of $6.8 million  relating
to  debt acquired as a result of the acquisition of CCD and Biocine S.p.A. and a
gain on the sale  of land of  $3.0 million. Also contributing  to the change  in
other  income (expense), net, from 1994 to 1995 is a decrease of $4.0 million in
1995 of interest  capitalized on  the Company's capital  projects. Other  income
(expense), net, decreased between 1993 and 1994 largely as a result of increased
interest   expense  associated  with   the  Company's  convertible  subordinated
debentures issued in  November 1993,  and the write-down  of certain  marketable
investments in 1994 whose fluctuation in fair value was deemed to be "other than
temporary" under Statement of Financial Accounting Standards No. 115.
 
    The  provision for income taxes in  1995 consists primarily of foreign taxes
on certain foreign operations of the  Company. The amount of foreign taxes  paid
by the Company increased in 1995 over 1994 largely due to the acquisition of CCD
and  Biocine S.p.A.,  each of  which have  operations in  foreign countries upon
which income tax is paid. Contributing to  the change in the effective tax  rate
from 1994 to 1995 is the write-off of purchased in-process technologies in 1995,
substantially  all of which is  not deductible for income  tax purposes and thus
does not create a  tax benefit in  1995. The effective  tax rate increased  from
1993 to 1994 due to federal net operating loss benefits which were substantially
depleted in 1993. Also contributing to the increase in the effective tax rate in
1994  over 1993  was the  write-down of  certain marketable  investments in 1994
which did not create a corresponding tax benefit.
 
LIQUIDITY AND CAPITAL RESOURCES
 
    Chiron's capital requirements are  funded from public  and private sales  of
equity  and convertible  debt and  cash provided  by operations.  In addition to
these sources of capital, future capital requirements may be financed through  a
combination   of  debt,  utilization   of  funding  from   Ciba,  possible  off-
balance-sheet financing (such as R&D limited partnerships and operating leases),
cash generated  from operations  and the  use of  existing cash  and  investment
balances. Until required for operations, Chiron's policy is to keep its cash and
investments   in  a   diversified  portfolio   of  investment   grade  financial
instruments, including  money market  instruments,  corporate notes  and  bonds,
government or government agency securities, or other debt securities. By policy,
the  amount  of  credit  exposure  to  any  one  institution  is  limited. These
investments are generally not collateralized  and primarily mature within  three
years.  Investments with maturities in  excess of one year  are presented on the
balance sheet as noncurrent investments. To  the extent that Chiron has  balance
sheet  exposure resulting from  completed transactions denominated  in a foreign
currency, the Company's policy is to mitigate exposure to exchange rate  changes
by  entering  into  forward  currency  contracts.  These  contracts  are settled
quarterly. At December 31,  1995, the Company  had outstanding forward  currency
contracts totaling approximately $65.1 million. In addition, although there were
no amounts
 
                                       9
<PAGE>
outstanding  at  December  31,  1995,  the  Company  has  commenced  a  program,
consisting of purchased average rate options,  designed to reduce the impact  of
fluctuating  foreign  currency  exchange  rates on  the  results  of anticipated
transactions.
 
    In 1993, Chiron began a major  manufacturing expansion designed to meet  the
projected  demand for products recently approved or  that are in the late stages
of  development.  The  Company  has  expanded  its  production  capability   for
Betaseron-Registered  Trademark-  by  improving  its  production  facilities  in
Emeryville, California, The Netherlands and through the purchase and  subsequent
investments  in a  pharmaceutical fill  and finishing  facility in  Puerto Rico.
Additionally, Chiron is expanding its vaccine production facilities in Italy and
has completed the construction of a  facility in Vacaville, California, for  use
in  growth factor production and has completed a remodeling effort in a facility
in St.  Louis, Missouri.  The Company  has also  completed the  construction  of
additional  administration, research and  development, and production facilities
for its diagnostic systems products  in Walpole, Massachusetts. The majority  of
Chiron's  capital  expenditures  of  $101.1  million  in  1995  related  to  the
manufacturing expansion activities discussed above.
 
    In 1995, the Company decided to idle its Puerto Rico facility and scale-back
the manufacturing operations at the Company's Amsterdam facility. This  decision
was  based on the belief that current demand for Betaseron-Registered Trademark-
can be adequately  supplied with  the expanded manufacturing  capability at  the
Company's  Emeryville, California, facility. Full  utilization of the additional
Betaseron-Registered  Trademark-   manufacturing  capability   will  require   a
significant  increase in product  demand. If this  substantial increase does not
occur, a significant  portion of  Betaseron-Registered Trademark-  manufacturing
capability  will  be underutilized.  Chiron  is considering  alternative options
concerning the Puerto Rico facility,  including manufacturing other products  in
that  facility. The facility in Amsterdam is currently being used for production
of bacterial vaccines,  production of clinical  grade materials and  as a  pilot
plant for process development.
 
    In  future periods,  Chiron expects  that substantial  capital spending will
continue as the  Company begins  expansion of its  administrative, research  and
development  facilities in Emeryville.  This expansion is  projected to occur in
stages over the next thirty years. The Company anticipates entering into leasing
arrangements which will provide third-party funding for a significant portion of
the expansion.
 
    Chiron's liquidity may be further impacted in future periods by its decision
to fund its share of expenses in certain of its joint ventures and collaboration
arrangements.  Over  the   next  several  years,   Chiron  anticipates   funding
collaborations  with a number of its  research partners, and may make additional
equity investments in collaborative partners.
 
    During the year ended December 31, 1995, cash and cash equivalents decreased
by approximately $10.6 million. Of this amount, approximately $34.0 million  was
used  in the Company's operating activities,  compared to $15.2 million provided
by operating activities in 1994. In 1993, operating activities provided cash  of
approximately $15.4 million.
 
    Investing  activities consumed cash of $43.1  million in 1995, versus $107.4
million and $140.3 million in 1994 and 1993, respectively, largely in support of
continued capital expansion and  the acquisitions of  IOLAB and Viagene.  Chiron
received  $14.2 million, net  of cash paid,  in its acquisition  of CCD, Biocine
S.p.A. and Chiron Biocine Company. Net  of cash acquired, Chiron expended  $95.0
million  and $28.6 million, respectively, to  acquire IOLAB and Viagene. Capital
expenditures on  plant and  equipment were  $101.1 million  during 1995,  versus
$105.7  million and $115.2 million in 1994 and 1993, respectively. Cash provided
by financing activities of $66.6 million in 1995 largely reflects cash  proceeds
of  $24.8 million received from  Ciba as a capital  contribution pursuant to the
Agreements, as discussed previously, as well as $31.6 million and $9.0  million,
respectively,  received from the  exercise of stock options  and for issuance of
stock under the Company's employee stock purchase plan.
 
                                       10
<PAGE>
    Chiron believes that its cash and  cash equivalents and short and  long-term
investments,  together  with  funds  provided  by  operations  and  the  funding
arrangements discussed above will  be sufficient to  meet its cash  requirements
during the upcoming twelve months and through the foreseeable future.
 
SUBSEQUENT EVENT
 
    On  February 17, 1996,  Chiron and Behringwerke AG,  a subsidiary of Hoechst
AG, reached an agreement whereby Chiron  will purchase a 49 percent interest  in
the human vaccine business of Behringwerke AG for Deutsche mark 171.5 million in
cash.  Under the terms  of the agreement,  Chiron has an  option to purchase the
remaining 51 percent interest in March 1998, 1999, 2000 or 2001 and Behringwerke
AG has the option to  have Chiron acquire the  remaining 51 percent interest  in
March  2001. During the  period of mutual ownership,  Chiron and Behringwerke AG
will operate the  vaccine business as  a joint venture.  Chiron will report  its
share  of the  joint venture's results  as equity in  earnings of unconsolidated
joint  businesses.  Consummation  of  the  transaction  is  subject  to  certain
conditions,  including regulatory  approvals and  customary conditions  prior to
closing.
 
FACTORS THAT MAY AFFECT FUTURE OPERATING RESULTS
 
    Chiron wishes  to  caution stockholders  and  investors that  the  following
important  factors, among others, in some cases have affected, and in the future
could  affect,  Chiron's  actual  results   and  could  cause  Chiron's   actual
consolidated  results  for the  first  quarter of  1996,  and beyond,  to differ
materially from those expressed in any forward-looking statements made by, or on
behalf of, Chiron. The  statements under this caption  are intended to serve  as
cautionary  statements within the  meaning of the  Private Securities Litigation
Reform Act of 1995. The  following information is not  intended to limit in  any
way the characterization of other statements or information under other captions
as cautionary statements for such purpose:
 
    - Delays,   difficulties  or   failure  in   obtaining  regulatory  approval
      (including approval of  its facilities for  production) for the  Company's
      products,  including  delays  or difficulties  in  development  because of
      insufficient proof of safety or efficacy.
 
    - Inability to maintain or initiate third party arrangements which  generate
      revenues,  in the form of license  fees, research and development support,
      royalties and  other  payments, in  return  for rights  in  technology  or
      products under development by the Company.
 
    - Delays  or difficulties in developing  and acquiring production technology
      and technical and managerial personnel to manufacture novel  biotechnology
      products  in commercial quantities  at reasonable costs  and in compliance
      with  applicable  quality  assurance  and  environmental  regulations  and
      governmental permitting requirements.
 
    - Difficulties   in  obtaining  key  raw  materials  and  supplies  for  the
      manufacture of the Company's products.
 
    - Increased  and  irregular  costs  of  development,  regulatory   approval,
      manufacture, sales, and marketing associated with introduction of products
      in the late stage of development.
 
    - Difficulties  in launching  or marketing  the Company's  products, many of
      which are novel products based  on biotechnology, and unpredictability  of
      customer acceptance of such products.
 
    - The  ability  and  willingness  of  customers  to  substitute  competitive
      products for  the  Company's  products once  other  products  for  similar
      indications are approved for marketing.
 
    - Continued  flattened  growth rate  in the  Betaseron-Registered Trademark-
      customer base in the  U.S.; the extent to  which patients, once  enrolled,
      remain  compliant with  the prescribed  treatment regimen  and continue to
      regularly receive  Betaseron-Registered Trademark-;  timing, approval  and
      market  launch of  competing products,  including another  beta interferon
      product; pricing,  promotional and  marketing decisions  by the  Company's
      partner, Schering.
 
                                       11
<PAGE>
    - Continued  lower  product margins  resulting  from the  Chiron-Ortho joint
      business' renegotiated contract  with the American  Red Cross; changes  in
      the  product mix  whereby the proportion  of higher margin  HCV tests sold
      relative to other lower  margin products is  less; continued increases  in
      research  and development  spending in order  to develop  new products and
      increase market share; introduction of competing tests by unlicensed third
      parties.
 
    - Continued or increased pressure to reduce selling prices of the  Company's
      products  and  possible negative  effect on  CCD  revenues as  product mix
      shifts from manual to automated equipment.
 
    - Underutilization of the Company's existing or new manufacturing facilities
      or of any facility expansions, resulting in production inefficiencies  and
      higher  costs; start-up costs and  inefficiencies and delays and increased
      depreciation costs  in connection  with  the start  of production  in  new
      plants and expansions.
 
    - The   cost  of   acquiring  in-process  technology,   either  by  license,
      collaboration or purchase of another entity.
 
    - Amount and rate of growth in Chiron's selling, general and  administrative
      expenses;  and the impact of unusual  or infrequent charges resulting from
      Chiron's ongoing evaluation of its business strategies and  organizational
      structures, including the continued costs of integration of newly acquired
      businesses.
 
    - The  acquisition of fixed  assets and other  assets, including inventories
      and receivables;  and the  making  or incurring  of any  expenditures  and
      expenses,   including,  among   others,  depreciation   and  research  and
      development expenses; any revaluation of assets, including, among  others,
      the Company's investments in the equity securities of other companies with
      whom  it collaborates,  or related  expenses, and  the amount  of, and any
      changes to, tax rates.
 
    - The ability or inability  of Chiron to obtain,  or hedge against,  foreign
      currency, foreign exchange rates and fluctuations in those rates.
 
    - The  costs  and  other  effects  of  legal  and  administrative  cases and
      proceedings (whether civil, such  as product-related or environmental,  or
      criminal);  settlements and investigations;  developments or assertions by
      or against Chiron relating to  intellectual property rights and  licenses;
      the  issuance and use of patents  and proprietary technology by Chiron and
      its competitors, including the possible  negative effect on the  Company's
      ability  to develop,  manufacture and  sell its  products in circumstances
      where it is unable to obtain licenses to patents which may be required for
      such products.
 
    - Failure of corporate partners to commercialize successfully the  Company's
      products  or to  retain and  expand the  markets served  by the commercial
      collaborations;  conflicts   of   interest,  priorities   and   commercial
      strategies  which  may  arise  between  the  Company  and  such  corporate
      partners.
 
    - Health  care  reform  and  the  reimbursement  status  of  newly  approved
      healthcare products.
 
                                       12
<PAGE>
                               CHIRON CORPORATION
                          CONSOLIDATED BALANCE SHEETS
                       (IN THOUSANDS, EXCEPT SHARE DATA)
                                     ASSETS
 
<TABLE>
<CAPTION>
                                                                                              DECEMBER 31,
                                                                                      ----------------------------
                                                                                          1995           1994
                                                                                      -------------  -------------
<S>                                                                                   <C>            <C>
Current assets:
  Cash and cash equivalents.........................................................  $      74,318  $      84,876
  Short-term investments in marketable debt securities..............................         61,066        137,619
                                                                                      -------------  -------------
    Total cash and short-term investments in marketable debt securities.............        135,384        222,495
  Accounts receivable, net of allowances of $18,524 in 1995 and
   $7,210 in 1994:
    Related parties.................................................................         30,157         42,694
    Unrelated parties...............................................................        255,622         97,782
                                                                                      -------------  -------------
                                                                                            285,779        140,476
  Inventories.......................................................................        165,941         47,592
  Other current assets..............................................................         49,899         23,252
                                                                                      -------------  -------------
    Total current assets............................................................        637,003        433,815
Noncurrent investments in marketable debt securities................................         88,833        171,328
Property, plant, equipment and leasehold improvements, at cost:
  Land and buildings................................................................        208,233         60,930
  Laboratory, production and office equipment.......................................        292,828        140,438
  Leasehold improvements............................................................         95,472         82,145
  Construction in progress..........................................................         62,046         78,998
                                                                                      -------------  -------------
                                                                                            658,579        362,511
  Less accumulated depreciation and amortization....................................       (140,761)       (76,337)
                                                                                      -------------  -------------
    Net property, plant, equipment and leasehold improvements.......................        517,818        286,174
Purchased technology, net of accumulated amortization of $21,508 in 1995 and $13,854
 in 1994............................................................................         80,600         35,878
Other intangible assets, net of accumulated amortization of $27,712 in 1995 and
 $19,731 in 1994....................................................................         71,571         49,925
Investments in equity securities and affiliated companies...........................         54,359         51,425
Other assets........................................................................         40,014         21,197
                                                                                      -------------  -------------
                                                                                      $   1,490,198  $   1,049,742
                                                                                      -------------  -------------
                                                                                      -------------  -------------
</TABLE>
 
                                  (Continued)
 
          The accompanying Notes to Consolidated Financial Statements
                    are an integral part of this statement.
 
                                       13
<PAGE>
                               CHIRON CORPORATION
                          CONSOLIDATED BALANCE SHEETS
                       (IN THOUSANDS, EXCEPT SHARE DATA)
                      LIABILITIES AND STOCKHOLDERS' EQUITY
 
<TABLE>
<CAPTION>
                                                                                              DECEMBER 31,
                                                                                      ----------------------------
                                                                                          1995           1994
                                                                                      -------------  -------------
<S>                                                                                   <C>            <C>
Current liabilities:
  Accounts payable..................................................................  $      81,081  $      27,778
  Accrued compensation and related expenses.........................................         56,994         24,010
  Short-term borrowings.............................................................         50,036             --
  Current portion of unearned revenue...............................................         20,838          1,544
  Taxes payable.....................................................................         27,551         10,060
  Payable to The Biocine Company....................................................             --          8,645
  Other current liabilities.........................................................        132,095         47,604
                                                                                      -------------  -------------
    Total current liabilities.......................................................        368,595        119,641
Long-term debt:
  Payable to Ciba...................................................................         62,949          8,729
  Unrelated parties.................................................................        350,299        329,332
                                                                                      -------------  -------------
                                                                                            413,248        338,061
Other noncurrent liabilities........................................................         35,943         19,409
Commitments and contingencies
Stockholders' equity:
  Preferred stock, $0.01 par value; 5,000,000 shares authorized;
   none outstanding.................................................................             --             --
  Common stock, $0.01 par value; 99,500,000 shares authorized; 41,737,849
   outstanding (33,378,937 outstanding at December 31, 1994)........................            417            334
  Restricted common stock, $0.01 par value; 500,000 shares authorized; none
   outstanding......................................................................             --             --
  Additional paid-in capital........................................................      1,727,711      1,161,942
  Accumulated deficit...............................................................     (1,087,699)      (575,236)
  Cumulative foreign currency translation adjustment................................            721         (1,719)
  Unrealized gain (loss) from investments...........................................         31,262        (12,690)
                                                                                      -------------  -------------
    Total stockholders' equity......................................................        672,412        572,631
                                                                                      -------------  -------------
                                                                                      $   1,490,198  $   1,049,742
                                                                                      -------------  -------------
                                                                                      -------------  -------------
</TABLE>
 
          The accompanying Notes to Consolidated Financial Statements
                    are an integral part of this statement.
 
                                       14
<PAGE>
                               CHIRON CORPORATION
                     CONSOLIDATED STATEMENTS OF OPERATIONS
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                  YEAR ENDED DECEMBER 31,
                                                                          ----------------------------------------
                                                                              1995           1994         1993
                                                                          -------------  ------------  -----------
<S>                                                                       <C>            <C>           <C>
Revenues:
  Product sales, net:
    Related parties.....................................................  $      21,483  $     11,787  $    11,382
    Unrelated parties...................................................        901,370       264,179      136,511
                                                                          -------------  ------------  -----------
                                                                                922,853       275,966      147,893
  Equity in earnings of unconsolidated joint businesses.................         80,356        82,395       77,739
  Collaborative agreement revenues:
    Related parties.....................................................         47,921        53,970       51,226
    Unrelated parties...................................................         10,160        13,531       17,717
                                                                          -------------  ------------  -----------
                                                                                 58,081        67,501       68,943
  Other revenues:
    Related parties.....................................................         11,156         5,439        2,831
    Unrelated parties...................................................         28,136        22,678       20,129
                                                                          -------------  ------------  -----------
                                                                                 39,292        28,117       22,960
                                                                          -------------  ------------  -----------
      Total revenues....................................................      1,100,582       453,979      317,535
Expenses:
  Cost of sales.........................................................        415,798       128,209       68,484
  Research and development..............................................        343,752       166,175      140,030
  Selling, general and administrative...................................        357,066       109,990       95,790
  Write-off of purchased in-process technologies........................        365,286            --           --
  Costs related to Ciba transaction.....................................         49,407         2,117           --
  Restructuring and reorganization charges..............................         39,056            --           --
  Other operating expenses..............................................         12,645         5,088       (1,907)
                                                                          -------------  ------------  -----------
      Total expenses....................................................      1,583,010       411,579      302,397
                                                                          -------------  ------------  -----------
Income (loss) from operations...........................................       (482,428)       42,400       15,138
Other income (expense), net.............................................         (8,346)      (10,403)       7,949
                                                                          -------------  ------------  -----------
Income (loss) before income taxes.......................................       (490,774)       31,997       23,087
Provision for income taxes..............................................         21,689        13,672        4,703
                                                                          -------------  ------------  -----------
Net income (loss).......................................................  $    (512,463) $     18,325  $    18,384
                                                                          -------------  ------------  -----------
                                                                          -------------  ------------  -----------
Net income (loss) per share.............................................  $      (12.62) $       0.53  $      0.55
                                                                          -------------  ------------  -----------
                                                                          -------------  ------------  -----------
Weighted average number of shares used in calculating per share
 amounts................................................................         40,610        34,293       33,681
                                                                          -------------  ------------  -----------
                                                                          -------------  ------------  -----------
</TABLE>
 
          The accompanying Notes to Consolidated Financial Statements
                    are an integral part of this statement.
 
                                       15
<PAGE>
                               CHIRON CORPORATION
                CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                         CUMULATIVE
                                                                                           FOREIGN    UNREALIZED
                                          COMMON STOCK        ADDITIONAL                  CURRENCY    GAIN (LOSS)     TOTAL
                                     ----------------------    PAID-IN     ACCUMULATED   TRANSLATION     FROM      STOCKHOLDERS'
                                      SHARES      AMOUNT       CAPITAL       DEFICIT     ADJUSTMENT   INVESTMENTS     EQUITY
                                     ---------  -----------  ------------  ------------  -----------  -----------  ------------
<S>                                  <C>        <C>          <C>           <C>           <C>          <C>          <C>
Balances at December 31, 1992......     31,713   $     317   $  1,093,851  $   (611,945)  $  (3,542)   $      --    $  478,681
Exercise of stock options..........        842           9         25,467            --          --           --        25,476
Employee stock purchase plan.......        122           1          5,425            --          --           --         5,426
Foreign currency translation
 adjustment........................         --          --             --            --      (5,678)          --        (5,678)
Net income.........................         --          --             --        18,384          --           --        18,384
                                     ---------       -----   ------------  ------------  -----------  -----------  ------------
Balances at December 31, 1993......     32,677         327      1,124,743      (593,561)     (9,220)          --       522,289
Exercise of stock options,
 including tax effect..............        394           4         21,943            --          --           --        21,947
Exercise of warrants...............        150           1          7,874            --          --           --         7,875
Employee stock purchase plan.......        158           2          7,382            --          --           --         7,384
Foreign currency translation
 adjustment........................         --          --             --            --       7,501           --         7,501
Unrealized loss from investments...         --          --             --            --          --      (12,690)      (12,690)
Net income.........................         --          --             --        18,325          --           --        18,325
                                     ---------       -----   ------------  ------------  -----------  -----------  ------------
Balances at December 31, 1994......     33,379         334      1,161,942      (575,236)     (1,719)     (12,690)      572,631
Issuance of common stock to
 Ciba-Geigy........................      6,600          66        407,484            --          --           --       407,550
Capital contribution by Ciba-
 Geigy.............................         --          --         24,845            --          --           --        24,845
Issuance of common stock and stock
 options related to the Viagene
 acquisition.......................        916           9         91,393            --          --           --        91,402
Exercise of stock options,
 including tax effect..............        670           6         32,921            --          --           --        32,927
Exercise of stock warrants.........         --          --             97            --          --           --            97
Employee stock purchase plan.......        173           2          9,029            --          --           --         9,031
Foreign currency translation
 adjustment........................         --          --             --            --       2,440           --         2,440
Unrealized gain from investments...         --          --             --            --          --       43,952        43,952
Net loss...........................         --          --             --      (512,463)         --           --      (512,463)
                                     ---------       -----   ------------  ------------  -----------  -----------  ------------
Balances at December 31, 1995......     41,738   $     417   $  1,727,711  $ (1,087,699)  $     721    $  31,262    $  672,412
                                     ---------       -----   ------------  ------------  -----------  -----------  ------------
                                     ---------       -----   ------------  ------------  -----------  -----------  ------------
</TABLE>
 
          The accompanying Notes to Consolidated Financial Statements
                    are an integral part of this statement.
 
                                       16
<PAGE>
                               CHIRON CORPORATION
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                  YEAR ENDED DECEMBER 31,
                                                                          ----------------------------------------
                                                                              1995          1994          1993
                                                                          ------------  ------------  ------------
<S>                                                                       <C>           <C>           <C>
Cash flows from operating activities:
  Net income (loss).....................................................  $   (512,463) $     18,325  $     18,384
  Adjustments to reconcile net income (loss) to net cash provided by
   (used in) operating activities:
    Depreciation and amortization.......................................        99,097        49,429        25,040
    Write-off of purchased in-process technologies......................       365,286            --            --
    Write-offs of fixed assets..........................................        18,400            --           477
    Reserves............................................................        11,321        15,892         5,740
    Deferred income taxes...............................................         9,041            --         4,680
    Settlement of Cetus acquisition contingencies.......................            --            --       (13,387)
    Write-down of investments in equity securities......................            --        11,607            --
    Undistributed (earnings) loss of affiliates.........................        (3,944)       (5,666)          112
    Changes, excluding effect of acquisitions, to:
      Accounts receivable...............................................         2,000       (58,019)      (18,086)
      Inventories.......................................................       (36,094)       (7,394)      (18,302)
      Other current assets..............................................       (21,462)      (13,692)          201
      Accounts payable and accrued expenses.............................         7,719         8,535         5,530
      Payable to The Biocine Company....................................            --         1,658         6,049
      Other current liabilities.........................................        21,808         2,542        (6,687)
      Current portion of unearned revenue...............................         5,979       (10,132)        9,294
      Other noncurrent liabilities......................................          (719)        2,086        (3,596)
                                                                          ------------  ------------  ------------
        Net cash provided by (used in) operating activities.............       (34,031)       15,171        15,449
Cash flows from investing activities:
  Purchase of investments in marketable debt securities.................      (158,533)     (180,365)     (680,657)
  Sale and maturity of investments in marketable debt securities........       334,117       232,900       686,006
  Businesses acquired, net of cash acquired.............................      (112,633)      (17,726)           --
  Capital expenditures..................................................      (101,052)     (105,691)     (115,185)
  Investments in equity securities and affiliates.......................          (900)      (24,010)      (20,385)
  Increase in other assets..............................................        (4,124)      (12,525)      (10,103)
                                                                          ------------  ------------  ------------
        Net cash used in investing activities...........................       (43,125)     (107,417)     (140,324)
Cash flows from financing activities:
  Net borrowings under line of credit arrangements......................         4,686            --            --
  Proceeds from issuance of convertible debentures and long-term debt...           860            --       209,363
  Proceeds from issuance of common stock................................        40,772        27,126        28,598
  Proceeds from capital contribution from Ciba..........................        24,845            --            --
  Repayment of notes payable and capital leases.........................        (4,565)       (6,520)       (2,319)
                                                                          ------------  ------------  ------------
        Net cash provided by financing activities.......................        66,598        20,606       235,642
                                                                          ------------  ------------  ------------
        Net increase (decrease) in cash and cash equivalents............       (10,558)      (71,640)      110,767
Cash and cash equivalents at beginning of the year......................        84,876       156,516        45,749
                                                                          ------------  ------------  ------------
Cash and cash equivalents at end of the year............................  $     74,318  $     84,876  $    156,516
                                                                          ------------  ------------  ------------
                                                                          ------------  ------------  ------------
</TABLE>
 
          The accompanying Notes to Consolidated Financial Statements
                    are an integral part of this statement.
 
                                       17
<PAGE>
                               CHIRON CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                               DECEMBER 31, 1995
 
NOTE 1 -- THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
    THE COMPANY
 
    Chiron   Corporation  (the   "Company"  or   "Chiron")  is   a  diversified,
science-driven  healthcare  company   that  applies   biotechnology  and   other
techniques of modern biology and chemistry to develop, produce and sell products
intended  to improve the quality of  life by diagnosing, preventing and treating
human disease.  Chiron participates  in four  global human  healthcare  markets:
diagnostics, therapeutics, pediatric and adult vaccines, and ophthalmic surgical
products.  Chiron also has  research programs underway in  gene therapy and gene
transfer, combinatorial chemistry, cardiovascular disease and critical care.
 
    Chiron's  diagnostic  business  includes  immunodiagnostics,  critical  care
diagnostics  and quantitative probe  tests. Chiron, through  its subsidiary Ciba
Corning Diagnostics Corp. ("CCD"), provides critical blood analyte systems which
are used  by  hospitals  to  diagnose and  monitor  patients  in  critical  care
settings.  Chiron  also  provides  blood screening  tests,  used  to  detect the
presence of hepatitis viruses and retroviruses, through its joint business  with
Ortho  Diagnostic Systems, Inc. ("Ortho"), a Johnson & Johnson company. Chiron's
therapeutics business emphasizes oncology and infectious diseases, and  provides
products  to  hospitals  and large  clinics  in  the United  States  and Europe.
Chiron's vaccine  business is  based primarily  on the  sale of  non-recombinant
pediatric  and flu vaccines in  Italy and to a  lesser extent in Southern Europe
and other  geographic  regions and  to  certain international  health  services.
Chiron  is also involved in  the development and marketing  of new pediatric and
adult vaccines. Through  its ophthalmic business,  Chiron provides products  for
the  surgical correction  of vision,  as well  as intraocular  implants for drug
delivery to the eye.  Chiron's ophthalmic business markets  its products in  the
United States, Europe, and other geographic regions.
 
    BASIS OF PRESENTATION
 
    The  consolidated financial statements  include the accounts  of the Company
and its majority-owned subsidiaries.  All significant intercompany accounts  and
transactions  have  been  eliminated  in  consolidation.  Investments  in  joint
ventures, partnerships and interests in which  Chiron has an equity interest  of
50  percent or  less are accounted  for using the  equity or cost  method, or in
accordance with Statement of Financial Accounting Standards No. 115, "Accounting
for Certain  Investments  in  Debt  and  Equity  Securities"  ("SFAS  115"),  as
appropriate.  Certain foreign subsidiaries are accounted for on a one-month lag.
Certain previously reported amounts have  been reclassified to conform with  the
current   period  presentation.  The  preparation  of  financial  statements  in
conformity with generally accepted accounting principles requires management  to
make  estimates and assumptions  that affect the reported  amounts of assets and
liabilities and disclosure of contingent assets  and liabilities at the date  of
the  financial  statements and  the reported  amounts  of revenues  and expenses
during the reporting period. Actual  results could differ materially from  those
estimates.
 
    FISCAL YEAR
 
    During  1995, the Company changed its fiscal year from December 31 each year
to a 52 or 53-week year ending on the Sunday nearest the last day in December of
each year. Therefore, the 1995 fiscal year ended on December 31 and was 52 weeks
long. Fiscal 1994 and 1993 were under  the calendar year ending on December  31.
For  presentation purposes, dates used  in the consolidated financial statements
and notes refer to the calendar month end.
 
                                       18
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 1 -- THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
    CASH EQUIVALENTS AND INVESTMENTS
 
    All highly liquid investments with a maturity of three months or less at the
date of purchase  are considered to  be cash equivalents.  Cash equivalents  and
short-term  investments consist  principally of  money market  instruments which
include:   corporate   notes,    corporate   bonds,    time   deposits,    Euro-
dollar  certificates of deposits, commercial paper, and government or government
agency securities.  Noncurrent  investments  consist  principally  of  corporate
notes,   corporate  bonds,  government  or  government  agency  securities,  and
investments in affiliated companies.
 
    INVENTORIES
 
    Pharmaceutical inventories are stated at the  lower of cost or market  using
the  average cost method or, in the case of vaccine products, using the last-in,
first-out ("LIFO")  method. Diagnostic  and ophthalmic  products are  valued  at
cost,  using the first-in,  first-out ("FIFO") method which  is less than market
value. Inventories consist of the following:
 
<TABLE>
<CAPTION>
                                                                                    1995        1994
                                                                                 -----------  ---------
<S>                                                                              <C>          <C>
                                                                                     (IN THOUSANDS)
Finished goods.................................................................  $    96,327  $  24,402
Work in process................................................................       28,794      8,650
Raw materials..................................................................       40,820     14,540
                                                                                 -----------  ---------
                                                                                 $   165,941  $  47,592
                                                                                 -----------  ---------
                                                                                 -----------  ---------
</TABLE>
 
    PROPERTY, PLANT, EQUIPMENT AND LEASEHOLD IMPROVEMENTS
 
    Property, plant, equipment  and leasehold improvements  are stated at  cost.
Depreciation  on  property, plant  and  equipment, including  assets  held under
capital leases,  is computed  by  the straight-line  method over  the  estimated
useful  lives of the assets (3 to 10 years  for equipment and 15 to 40 years for
buildings). Capitalized start-up  costs for  completed manufacturing  facilities
are   amortized  over  3  years.  Leasehold  improvements  are  amortized  on  a
straight-line basis over the remaining fixed lease term or asset life, whichever
is shorter.
 
    LONG-LIVED ASSETS, INCLUDING INTANGIBLE ASSETS
 
    In accordance  with Statement  of Financial  Accounting Standards  No.  121,
"Accounting for the Impairment of Long-Lived Assets and for Long-Lived Assets to
be  Disposed Of", the Company evaluates whether changes have occurred that would
require revision of the remaining estimated lives of recorded long-lived assets,
including intangible assets, or rendered  those assets not recoverable. If  such
circumstances  arise, recoverability is determined by comparing the undiscounted
net cash  flows of  long-lived  assets to  their  respective recorded  net  book
values.  The  amount  of impairment,  if  any,  is measured  based  on projected
discounted net cash flows using an appropriate discount rate. At this time,  the
Company  believes that no significant impairment of long-lived assets, including
intangible assets, has occurred  and that no reduction  of the estimated  useful
lives of such assets is warranted.
 
    Intangible  assets consist primarily of purchased technologies, goodwill and
patents and are amortized on a  straight-line basis over their estimated  useful
lives  ranging from  8 to  17 years.  Amortization expense  for the  years ended
December 31,  1995, 1994  and 1993,  was $19.2  million, $9.5  million and  $6.1
million,  respectively. Amortization of purchased  technologies and goodwill are
primarily included in "Other operating expenses" and amortization of patents  is
primarily  included in  "Research and  development expense"  in the Consolidated
Statement of Operations.
 
                                       19
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 1 -- THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
    REVENUE
 
    Revenue from product sales consists of shipments of diagnostic materials and
instruments,  ophthalmic   and  vaccine   products,  therapeutics,   and   other
biologicals  and  is generally  recognized upon  shipment. Revenue  from service
contracts is recognized ratably over the life of the contract. Revenue from  the
sale  of equipment under sales-type leases is recognized at the inception of the
lease. All of  the types of  revenues discussed above  are included in  "Product
sales,  net" in the Consolidated Statement  of Operations. During 1994 and 1993,
Chiron recognized Betaseron-Registered Trademark- revenues under the terms of an
amended  supply  agreement  whereby  Chiron  recognized  the  majority  of   its
Betaseron-Registered  Trademark- revenues  upon shipment  of the  product to its
marketing partner.  During  1995, the  Company  reverted  to the  terms  of  the
original  supply agreement.  Under the terms  of the  original agreement, Chiron
recognizes a  partial share  of  Betaseron-Registered Trademark-  revenues  upon
shipment  and an  additional share  upon subsequent sale  of the  product by its
marketing partner.
 
    Equity  in  earnings  of  unconsolidated  joint  businesses  represents  the
Company's  share of  the pretax  operating results  generated by  its commercial
joint businesses. Collaborative agreement revenue is earned and recognized based
upon work performed, upon the sale  of product rights, upon shipment of  product
for use in preclinical and clinical testing or upon the attainment of benchmarks
specified  in  the related  agreements. Under  contracts where  reimbursement is
based upon work performed,  the related research  and development expenses  were
$51.8  million,  $72.4  million  and  $61.5  million  in  1995,  1994  and 1993,
respectively. Other revenues consist primarily of royalty payments under license
agreements, sales fees  and grants  from federal  or state  governments and  are
recognized when earned.
 
    PER SHARE DATA
 
    Per  share information is based on the weighted average number of common and
dilutive common equivalent shares  outstanding. Common equivalent shares  result
from  the assumed exercise of outstanding stock options and warrants that have a
dilutive effect when applying  the treasury stock method.  Shares assumed to  be
issued  upon conversion of the Company's convertible debentures are not included
for any of the periods presented  since their inclusion would be  anti-dilutive.
Fully  diluted per share data  has not been presented,  as the amounts would not
differ materially from primary per share data.
 
    STATEMENT OF CASH FLOWS
 
    Supplemental disclosure to the Consolidated Statement of Cash Flows for  the
years ended December 31, 1995, 1994 and 1993, is as follows:
 
<TABLE>
<CAPTION>
                                                                          1995       1994       1993
                                                                        ---------  ---------  ---------
<S>                                                                     <C>        <C>        <C>
                                                                                (IN THOUSANDS)
Tax effect of stock option deductions.................................  $     912  $   9,895  $  --
Cash paid for interest................................................     18,603     12,866      8,518
Cash paid for income taxes............................................      8,597      1,263      2,393
</TABLE>
 
                                       20
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 1 -- THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
    Supplemental disclosure regarding noncash investing and financing activities
is as follows:
 
<TABLE>
<CAPTION>
                                                                          1995        1994       1993
                                                                      ------------  ---------  ---------
<S>                                                                   <C>           <C>        <C>
                                                                                (IN THOUSANDS)
Acquisitions:
  Fair value of assets acquired.....................................  $    962,124  $  42,810  $  --
  Liabilities assumed...............................................      (289,025)   (24,103)    --
  Acquisition costs.................................................        (6,013)    --         --
  Stock and options issued..........................................      (498,952)    --         --
  Carrying value of original investment.............................       (14,130)    --         --
                                                                      ------------  ---------  ---------
Total cash paid.....................................................  $    154,004  $  18,707  $  --
                                                                      ------------  ---------  ---------
                                                                      ------------  ---------  ---------
</TABLE>
 
    During 1995, Chiron acquired all of the outstanding common stock of CCD, the
interests  of  Ciba-Geigy Ltd.  and its  affiliates  ("Ciba") in  Chiron Biocine
Company (formerly The Biocine Company) and Biocine S.p.A. (through JV Vax  B.V.,
a  Netherlands  company), in  exchange for  6.6  million newly-issued  shares of
Chiron common stock  and a  cash payment  of $23.5  million. The  fair value  of
assets acquired in the transaction was $694.9 million, and liabilities of $261.5
million were assumed by the Company.
 
    During  1995, Chiron  acquired the surgical  products division  of IOLAB for
approximately $95.0 million in  cash. The fair value  of assets acquired in  the
transaction  (including goodwill and purchased in-process technology) was $108.8
million, and liabilities of $12.8 million were assumed by the Company.
 
    During 1995, Chiron acquired all of the outstanding common stock of Viagene,
Inc.  ("Viagene"),  not  previously  owned  by  the  Company,  in  exchange  for
approximately  $35.5 million in cash and  916,000 shares of Chiron common stock.
Additionally, unexercised options to purchase Viagene stock were converted  into
options  to purchase  approximately 132,000 shares  of Chiron  common stock. The
fair value of  assets acquired (including  purchased in-process technology)  was
$158.5 million, and liabilities of $14.7 million were assumed by the Company.
 
    During  1994,  Chiron  acquired all  of  the  common stock  of  Domilens for
approximately $18.7 million  in cash.  In connection with  the acquisition,  the
fair  value  of  assets acquired  (including  goodwill) was  $42.8  million, and
liabilities of $24.1 million were assumed by the Company.
 
    FOREIGN CURRENCY
 
    The  assets  and   liabilities  of  subsidiaries   and  equity   investments
denominated in foreign currencies are translated at the exchange rates in effect
at  the appropriate year-end. The revenues and expenses of such subsidiaries and
investments are  translated at  the average  exchange rates  for the  period  of
operation.   Adjustments  resulting  from  such  translations  are  included  in
cumulative foreign  currency translation  adjustment,  a separate  component  of
stockholders'  equity. Local foreign  currencies are generally  considered to be
the functional currency.
 
    The Company  enters  into  various foreign  currency  hedging  contracts  to
provide  an  economic hedge  against fluctuations  in foreign  currency exchange
rates that  may  affect certain  transactions.  The Company  has  established  a
control  environment which includes policies  and procedures for risk assessment
and  the  approval,  reporting  and  monitoring  of  foreign  currency   hedging
activities. The use of specific foreign currency hedging contracts is determined
by  the Company's objective  to hedge material  foreign receivables and payables
for which the costs of hedging are not excessive. The
 
                                       21
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 1 -- THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
Company does  not use  hedging contracts  for trading  or speculative  purposes.
Counterparties  to these  hedging agreements  are major  international financial
institutions. All foreign  currency contracts are  denominated in currencies  of
major  industrial  countries (primarily  the German  mark, Japanese  yen, French
franc, and Australian dollar).  The hedging contracts  are generally settled  at
the  end  of  each  quarter  with gains  or  losses  recorded  in  "Other income
(expense), net" to offset  losses or gains on  foreign currency receivables  and
payables.  Foreign currency transaction  gains and losses, net  of the impact of
hedging, were not significant  for the years ended  December 13, 1995, 1994  and
1993.
 
    CONCENTRATION OF CREDIT RISK
 
    Financial instruments that potentially subject the Company to concentrations
of  credit  risk  consist principally  of  cash investments  and  trade accounts
receivable. The  Company  invests  cash  which is  not  required  for  immediate
operating  needs principally in a diversified portfolio of financial instruments
issued by  institutions with  investment-grade credit  ratings. By  policy,  the
amount  of credit exposure to any  one institution is limited. These investments
are generally not collateralized  and primarily mature  within three years.  The
Company   has  not  experienced   any  significant  realized   losses  on  these
investments.
 
    The Company  has  not  experienced  any  credit  losses  from  its  accounts
receivable  from joint  business partners or  collaborative research agreements,
and none are currently expected. Other  accounts receivable arise from sales  to
customers  of  ophthalmic,  therapeutic, vaccine  and  diagnostic  products. The
Company performs ongoing  credit evaluations  of these  customers and  generally
does  not  require  collateral.  Reserves  are  maintained  for  potential trade
receivable  credit  losses,  and  such  losses  have  been  within  management's
expectations.
 
    RETIREMENT SAVINGS PLAN
 
    The  Company  maintains a  defined-contribution  savings plan  under Section
401(k) of the Internal Revenue Code. The plan covers substantially all full-time
U.S. employees.  Participating employees  may defer  a portion  of their  pretax
earnings  up  to the  Internal Revenue  Service  annual contribution  limit. The
Company matches employee  contributions according  to a  specified formula.  The
Company's  matching contributions  totaled $2.2  million, $1.8  million and $1.3
million in 1995, 1994 and 1993, respectively.
 
    MAJOR CUSTOMERS
 
    During 1995, no  single customer contributed  ten percent or  more to  total
revenues. As discussed in Notes 2 and 4, Ciba is a related party and contributed
11  percent and 13 percent of total  revenues in 1994 and 1993, respectively. As
discussed in Note 4,  Johnson & Johnson and  its affiliates are related  parties
and  collectively contributed 22 percent and 32 percent of total revenues during
1994  and  1993,  respectively.  Sales  of  Betaseron-Registered  Trademark-  to
Chiron's marketing partner accounted for less than ten percent of total revenues
in 1995 and 1993, and 23 percent in 1994.
 
NOTE 2 -- BUSINESS COMBINATIONS
 
    TRANSACTION WITH CIBA
 
    Effective  January 1, 1995, under a  series of agreements between Chiron and
Ciba,  including  an  investment  agreement,  a  cooperation  and  collaboration
agreement  and a governance agreement (collectively "Agreements"), Ciba obtained
a 49.9 percent ownership interest in  Chiron common stock (now approximately  47
percent),  partially  through a  tender offer  for  approximately 38  percent of
Chiron's outstanding common stock for $117  per share. At the same time,  Chiron
acquired all of the
 
                                       22
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 2 -- BUSINESS COMBINATIONS (CONTINUED)
outstanding  common stock of  CCD and Ciba's interest  in Chiron Biocine Company
and Biocine S.p.A. in exchange for 6.6 million newly-issued Chiron common shares
and a cash payment  of $23.5 million. Prior  to the acquisition, Chiron  Biocine
Company  and Biocine S.p.A.  were joint businesses between  Chiron and Ciba with
each having a 50 percent ownership interest. CCD is involved in the  manufacture
and sale of diagnostic and immunodiagnostic products. Chiron Biocine Company and
Biocine  S.p.A. are involved in the research,  development and sale of adult and
pediatric vaccines. These acquisitions of Chiron common stock by Ciba,  together
with  Ciba's prior holdings  of approximately 1.4 million  shares, result in the
aforementioned 49.9 percent ownership of the Company's common stock.
 
    Under the terms of the Agreements, Ciba is entitled to name three members to
Chiron's Board of Directors and has limited rights to review and approve certain
Chiron transactions.  In connection  with  the Agreements,  Ciba has  agreed  to
guarantee  $425 million of  new debt for  Chiron and has  agreed to provide $250
million (which may be increased up to $300 million subject to certain reductions
in the debt guarantee) through 1999 in support of research at Chiron, and Chiron
has the option of issuing up to $500 million of new equity to Ciba.
 
    The acquisitions of CCD and Ciba's  interests in Chiron Biocine Company  and
Biocine S.p.A. (the "Acquisitions") were accounted for under the purchase method
of  accounting. The purchase price of approximately $433.4 million was allocated
to the acquired assets and assumed  liabilities based upon their estimated  fair
value  on the acquisition date. The fair value of the net assets acquired in the
Acquisitions, including purchased in-process technology, was estimated based  on
an  independent valuation  of the  acquired net  assets. The  aggregate purchase
price of approximately $433.4 million  was less than the  fair value of the  net
assets  acquired  by  approximately  $57.3  million.  This  amount  was  ratably
allocated as a reduction of the noncurrent assets of the acquired companies.  In
connection with the acquisition, liabilities were assumed as follows:
 
<TABLE>
<CAPTION>
                                                                                          (IN THOUSANDS)
<S>                                                                                       <C>
Fair value of assets acquired, net of negative goodwill.................................   $    694,895
Common stock issued.....................................................................       (407,550)
Cash paid...............................................................................        (23,504)
Acquisition costs.......................................................................         (2,304)
                                                                                          --------------
Liabilities assumed.....................................................................   $    261,537
                                                                                          --------------
                                                                                          --------------
</TABLE>
 
    As   required  under   generally  accepted   accounting  principles,  Chiron
recognized as an expense the amount allocated to purchased in-process technology
resulting in  a  noncash  charge  against  earnings  of  $222.9  million.  Other
transaction-related  charges totaling $49.4 million related to employee payments
and the  related  taxes,  and  legal  and  investment  advisor  fees  were  also
recognized as expenses. Ciba agreed to reimburse the Company $24.8 million for a
portion  of the employee payments and such  reimbursement has been recorded as a
capital contribution. Other purchased  intangible assets of approximately  $25.6
million  consisting of base technology are  being amortized over their estimated
useful lives of 10 to 15 years, using the straight-line method.
 
    The operations  of  CCD,  Biocine  S.p.A. and  Chiron  Biocine  Company  are
included  in  Chiron's  consolidated  operating  results  from  January  1, 1995
forward. Chiron's interest in the operating results of Biocine S.p.A. and Chiron
Biocine Company were included in the  Company's 1994 and 1993 operating  results
under the equity method of accounting.
 
                                       23
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 2 -- BUSINESS COMBINATIONS (CONTINUED)
    During  1995,  Chiron  and Ciba  entered  into a  limited  liability company
agreement to  utilize research  funding to  be provided  by Ciba,  as  discussed
above.  Under  the terms  of the  agreement, Ciba  will fund  from time  to time
through December 31, 1999, at  Chiron's request, research and development  costs
for  adult vaccines, pediatric vaccines and insulin-like growth factor-1. Annual
funding amounts are subject to certain limitations. In return, Ciba will receive
an interest in  a stream of  variable royalties from  future worldwide sales  of
certain  adult  vaccines,  certain pediatric  vaccines  and  insulin-like growth
factor-1. Royalties will be paid for a  minimum period of ten years, subject  to
an  extension under certain conditions, following  the later of October 1, 2001,
or the date of the first commercial  sale of individual products covered by  the
agreement.  In  addition,  Ciba will  also  receive an  interest  in promotional
rights, in countries other than in  North America and Europe, for certain  adult
vaccines.
 
    Under  the  terms of  the agreement,  Chiron was  granted an  option through
December 31, 2001, to  repurchase Ciba's interest, at  cost plus an  agreed-upon
return. In addition, if Chiron chooses to exercise the option, Ciba will receive
an option to acquire certain exclusive marketing rights, in countries other than
those  in North America  and Europe, with  respect to certain  adult vaccines in
countries in which Ciba has exercised  its co-promotion rights. Pursuant to  the
agreement, Chiron received $27.0 million of funding from Ciba during 1995, which
Chiron   recorded  as  collaborative   agreement  revenues.  Chiron  anticipates
receiving substantial additional funding from  Ciba in future periods,  pursuant
to the terms of the agreement.
 
    ACQUISITION OF IOLAB
 
    On  March 31, 1995,  Chiron Vision acquired  the ophthalmic surgical product
division of IOLAB from  Johnson & Johnson for  approximately $95.0 million.  The
acquisition  was  accounted for  under the  purchase  method of  accounting, and
accordingly,  IOLAB's  financial   results  have  been   included  in   Chiron's
consolidated results of operations from the date of purchase. The purchase price
was  allocated to the  acquired assets and assumed  liabilities based upon their
estimated fair value on the acquisition date.  The fair value of the net  assets
acquired,  including in-process  technology, was estimated  based on independent
valuations of  the acquired  net  assets. In  connection with  the  acquisition,
liabilities were assumed as follows:
 
<TABLE>
<CAPTION>
                                                                                          (IN THOUSANDS)
<S>                                                                                       <C>
Fair value of assets acquired...........................................................   $    108,768
Cash paid...............................................................................        (95,000)
Acquisition costs.......................................................................         (1,013)
                                                                                          --------------
Liabilities assumed.....................................................................   $     12,755
                                                                                          --------------
                                                                                          --------------
</TABLE>
 
    The amount allocated to purchased in-process technology of $10.3 million was
charged  against  earnings  in  the  first  quarter  of  1995.  Other  purchased
intangible assets of approximately $46.5 million consisting of base  technology,
goodwill,  trade  name  and  a  customer list  are  being  amortized  over their
estimated useful lives of 10 to  15 years using the straight-line method.  Also,
the   Company   recorded  additional   charges   for  IOLAB   restructuring  and
integration-related expenses totaling $16.9 million in 1995 (Note 3).
 
    ACQUISITION OF VIAGENE
 
    On September 29, 1995, Chiron acquired  all of the outstanding common  stock
of  Viagene, not previously owned by  the Company, in exchange for approximately
$35.5 million in cash and 916,000
 
                                       24
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 2 -- BUSINESS COMBINATIONS (CONTINUED)
shares of Chiron common stock. Additionally, on September 29, 1995,  unexercised
options to purchase Viagene common stock were converted into options to purchase
approximately  132,000 shares of Chiron common stock. Viagene is a biotechnology
company involved in  the discovery,  development and  commercialization of  gene
transfer  products for the  treatment or prevention  of severe viral infections,
cancers and other  diseases. Prior  to the  acquisition, Chiron  had an  ongoing
collaboration  with Viagene  in the  area of gene  therapy and,  pursuant to the
collaboration arrangement, held an investment in the outstanding voting stock of
Viagene with a carrying value, net of  unrealized gains and a realized loss,  of
approximately $14.1 million as of September 29, 1995.
 
    The  Viagene acquisition has been accounted for under the purchase method of
accounting. The purchase price of approximately $143.7 million was allocated  to
the  acquired assets  and assumed  liabilities based  upon their  estimated fair
value on the acquisition date.  In connection with the acquisition,  liabilities
were assumed as follows:
 
<TABLE>
<CAPTION>
                                                                                          (IN THOUSANDS)
<S>                                                                                       <C>
Fair value of assets acquired...........................................................   $    158,461
Carrying value of original investment in Viagene........................................        (14,130)
Common stock and options issued.........................................................        (91,402)
Cash paid...............................................................................        (35,500)
Acquisition costs.......................................................................         (2,696)
                                                                                          --------------
Liabilities assumed.....................................................................   $     14,733
                                                                                          --------------
                                                                                          --------------
</TABLE>
 
    As   required  under   generally  accepted   accounting  principles,  Chiron
recognized as an expense the amount allocated to purchased in-process technology
in the third quarter of 1995. This resulted in a noncash charge against earnings
of $130.3 million. The results of operations of Viagene are included in Chiron's
consolidated operating results from September 29, 1995 forward.
 
    PROFORMA FINANCIAL INFORMATION
 
    The following  unaudited  pro  forma information  presents  the  results  of
operations  of Chiron, CCD,  Biocine S.p.A., Chiron  Biocine Company and Viagene
for the years ended December 31, 1995 and 1994, with pro forma adjustments as if
the acquisitions  had  been consummated  as  of  the beginning  of  the  periods
presented.  This pro forma information does not purport to be indicative of what
would have occurred  had the  acquisitions been  made as  of those  dates or  of
results  which  may occur  in the  future.  The pro  forma information  does not
include the write-off of  purchased in-process technology  of $222.9 million  or
other  transaction-related  costs totaling  $49.4  million (related  to employee
payments and the  related taxes, and  investment advisor and  legal fees)  which
were  recognized as  expense during  1995, relating  to the  acquisition of CCD,
Biocine S.p.A. and Chiron Biocine Company. Also, the pro forma information  does
not  include the  write-off of  purchased in-process  technology related  to the
Viagene acquisition of $130.3 million.
<TABLE>
<CAPTION>
                                                                               YEAR ENDED DECEMBER 31,
                                                                              --------------------------
                                                                                  1995          1994
                                                                              -------------  -----------
<S>                                                                           <C>            <C>
                                                                                (IN THOUSANDS, EXCEPT
                                                                                   PER SHARE DATA)
 
<CAPTION>
                                                                                     (UNAUDITED)
<S>                                                                           <C>            <C>
Total revenues..............................................................  $   1,107,958  $   968,568
Income (loss) before non-recurring charges..................................       (127,212)      17,806
Income (loss) before non-recurring charges per share........................          (3.13)        0.43
</TABLE>
 
                                       25
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 3 -- RESTRUCTURING AND REORGANIZATION COSTS
    During  1995,   Chiron  recorded   $39.1   million  in   restructuring   and
reorganization charges, including $16.9 million arising from the acquisition and
integration  of IOLAB (Note  2), representing the  expected costs of integrating
the acquired business with Chiron's existing business as well as write-downs  of
certain previously capitalized costs. Of the total charge of $39.1 million, $8.0
million  is due to a change in plans to expand the Company's Emeryville research
and development  facilities,  $7.7 million  is  related  to the  idling  of  the
Company's  Puerto Rico manufacturing  facility and $1.0 million  is related to a
scale-back of manufacturing operations at the Company's Amsterdam facility.  The
majority  of these  facility-related charges, as  well as $3.7  million of other
facility-related charges, have  been paid  in 1995.  Employee termination  costs
related to the Company's restructuring were not significant.
 
    Of  the $16.9  million recorded  as a  result of  the acquisition  of IOLAB,
approximately $6.7  million related  to  write-downs of  previously  capitalized
facility  and  inventory costs.  The remaining  $10.2  million consists  of $5.5
million of employee termination costs and $4.7 million of lease termination  and
other  costs. Chiron Vision  plans to consolidate  its European intraocular lens
manufacturing operations  into  its facility  in  Lyon, France,  and  the  North
American  manufacturing operations  into its facility  in Claremont, California.
The related  workforce  reduction  is  the  result  of  increased  manufacturing
efficiencies  as plants are closed, a  concentration of research and development
efforts and an  elimination of overlap  in sales and  marketing and general  and
administrative  areas. The integration  process is expected  to be substantially
completed by the end of 1997.
 
    The current status of the accrued restructuring charges is summarized below:
 
<TABLE>
<CAPTION>
                                                                                  AMOUNT
                                                                  AMOUNT OF      UTILIZED     AMOUNT TO
                                                                    TOTAL        THROUGH     BE UTILIZED
                                                                RESTRUCTURING  DECEMBER 31,   IN FUTURE
                                                                   CHARGE          1995        PERIODS
                                                                -------------  ------------  -----------
<S>                                                             <C>            <C>           <C>
                                                                             (IN THOUSANDS)
Chiron Vision restructuring charges:
  Employee-related costs......................................   $     5,506    $   (3,627)   $   1,879
  Facility and lease termination costs........................         6,242        (2,380)       3,862
  Duplicate and excess inventory..............................         3,476        (1,632)       1,844
  Other.......................................................         1,724          (280)       1,444
                                                                -------------  ------------  -----------
                                                                      16,948        (7,919)       9,029
Puerto Rico manufacturing facility............................         7,650        (3,562)       4,088
Postponement of Emeryville facility expansion.................         7,990        (7,990)      --
Amsterdam manufacturing facilities............................         1,000        (1,000)      --
Other facility-related........................................         3,718        (3,718)      --
Other.........................................................         1,750        (1,249)         501
                                                                -------------  ------------  -----------
                                                                 $    39,056    $  (25,438)   $  13,618
                                                                -------------  ------------  -----------
                                                                -------------  ------------  -----------
</TABLE>
 
NOTE 4 -- COLLABORATIONS AND JOINT BUSINESS ARRANGEMENTS
 
    GENERAL
 
    The Company has  entered into  a number of  collaborative arrangements  with
other  pharmaceutical  and  biotechnology  companies  for  the  development  and
marketing  of  certain  technologies  and   products.  The  majority  of   these
collaborations  are in the  development or clinical trial  phase. Chiron and its
collaborative partners generally  contribute certain  technologies and  research
efforts to the
 
                                       26
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 4 -- COLLABORATIONS AND JOINT BUSINESS ARRANGEMENTS (CONTINUED)
collaboration.  In  addition,  Chiron  and  its  collaborative  partners commit,
subject to certain limitations and cancellation clauses, to share in the funding
of the collaborations' ongoing research and clinical trial costs. Chiron,  under
certain  of the arrangements, has  purchased equity securities, including common
and preferred stock and warrants to purchase common and preferred stock, of  the
collaborative partner.
 
    DIAGNOSTIC JOINT BUSINESS
 
    In  1989, Chiron  entered into an  agreement with Ortho  to jointly develop,
manufacture and market certain immunoassay diagnostic products. Under the  terms
of  the agreement,  Chiron receives 50  percent of the  pretax operating profits
generated by the joint business and  is reimbursed for its continuing  research,
development  and  manufacturing costs.  Ortho  and Chiron  also  licensed Abbott
Laboratories and  Pasteur  Sanofi  Diagnostics to  sell  their  own  immunoassay
diagnostic  tests  for  hepatitis  C using  certain  technology  from  the joint
business.
 
    Chiron records its share of profits of the Chiron-Ortho diagnostic  business
on  a  one-month lag  using  estimates provided  by  Ortho. These  estimates are
subject to a final adjustment 90 days  after the end of each calendar year,  and
profit  sharing distributions are payable to Chiron within 90 days after the end
of each quarter. At December 31, 1995 and 1994, $19.6 million and $18.7 million,
respectively, were due from Ortho for profit sharing and reimbursement of costs.
Chiron's 50  percent share  of the  profits from  the joint  business was  $76.9
million  in  1995,  of  which  $1.8  million was  a  result  of  the  final 1994
accounting. In  1994,  Chiron recognized  $74.3  million  as its  share  of  the
profits,   including  a  negligible  adjustment   relating  to  the  final  1993
accounting. In  1993,  Chiron recognized  $77.1  million  as its  share  of  the
profits,  of  which $6.6  million was  a  result of  the final  1992 accounting.
Revenues recognized under the cost  reimbursement portion of the agreement  with
Ortho  for  collaborative research  were $9.6  million,  $8.5 million,  and $9.8
million in 1995, 1994 and 1993, respectively. Revenues recognized under the cost
reimbursement portion of the agreement with  Ortho for product sales were  $16.1
million, $11.8 million and $11.4 million in 1995, 1994 and 1993, respectively.
 
    CEPHALON, INC. ("CEPHALON")
 
    In  January 1994,  Chiron and Cephalon  established a  collaboration for the
research, development and  marketing of  certain products for  the treatment  of
neurological  disorders. Under the  terms of the  agreement, Chiron and Cephalon
will each  contribute certain  technology and  licenses and  will share  profits
equally.  Each party was responsible for its own collaboration-related expenses,
subject to certain  conditions, until total  collaboration-related expenses  are
equalized  or until the products  reach commercialization. Chiron invested $15.0
million in  equity  securities of  Cephalon  in 1994.  The  cumulative  expenses
incurred by Chiron and Cephalon were equalized during the third quarter of 1995,
and  thereafter, all expenses are to be shared equally. Research and development
expenses recognized by  Chiron related  to this  agreement for  the years  ended
December 31, 1995 and 1994, were $25.3 million and $5.4 million, respectively.
 
    DEPOTECH CORPORATION ("DEPOTECH")
 
    In  March  1994, Chiron  entered  into an  agreement  with DepoTech  for the
research, development and  marketing of certain  products incorporating  certain
drug  delivery technologies developed by DepoTech, and in some cases, certain of
Chiron's therapeutic compounds. Under the terms of the agreement, Chiron  agreed
to   make  specified  payments  to  DepoTech  upon  the  attainment  of  product
development milestones, and agreed to fund  all or a portion of the  development
costs  of the  collaboration in exchange  for marketing rights  to the resulting
commercial products. In addition, the parties
 
                                       27
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 4 -- COLLABORATIONS AND JOINT BUSINESS ARRANGEMENTS (CONTINUED)
agreed to share  in the revenues  of any resulting  commercial products.  During
1994,  Chiron invested $3.5  million in equity securities  of DepoTech. In 1995,
DepoTech reached the  first milestone,  and accordingly, a  warrant to  purchase
capital  stock  of DepoTech  was converted  into a  technology license  fee, and
Chiron commenced funding its portion of  development costs, resulting in a  $3.5
million  charge to research and development  expense for the year ended December
31, 1995.
 
    G.D. SEARLE & CO. ("SEARLE")
 
    In October 1994, Chiron entered  into a collaboration agreement with  Searle
for  the research, development and marketing of Tissue Factor Pathway Inhibitor.
Under the terms of the agreement, Chiron made a $3.5 million payment to  Searle,
which  was expensed in 1994. Except for  this payment, each party agreed to fund
its own collaboration-related  expenses through  1994. In 1995,  in addition  to
funding its equal share of continuing development expenses, Chiron exercised its
option  to accelerate the  funding of certain development  expenses of Searle in
exchange for  a  right of  first  negotiation to  manufacture  certain  clinical
supplies.  Accordingly, Chiron  paid $8.8  million to  Searle in  1995 which was
recorded as research and development  expense. Future development expenses  will
be shared equally by the parties.
 
    PROGENITOR, INC. ("PROGENITOR")
 
    In  March  1995,  the  Company  reached  an  agreement  with  Progenitor,  a
subsidiary  of  Interneuron  Pharmaceuticals,   Inc.,  to  collaborate  in   the
development   and   commercialization  of   therapeutic  and   vaccine  products
incorporating  Progenitor's  proprietary  gene  therapy  technology.  Under  the
agreement,  Chiron received a  license to Progenitor's  nonviral gene expression
system for  use in  the development  of products  for the  treatment of  certain
cancers and cardiovascular disorders, development of infectious disease vaccines
and for development of certain other gene therapy products. Chiron will have the
right  to manufacture and market any resulting products of the collaboration. In
return for the license and other rights, Chiron made an initial license  payment
of  $2.5 million to  Progenitor, which was recorded  as research and development
expense in  1995.  Under the  agreement,  Chiron  is required  to  make  certain
additional license and milestone payments to Progenitor. In addition, Progenitor
will  receive a royalty from any commercial sales of products resulting from the
collaboration.
 
    GENELABS TECHNOLOGIES, INC. ("GENELABS")
 
    In March  1995, the  Company  reached an  agreement with  Genelabs,  whereby
Chiron  and Genelabs cross-licensed certain rights to hepatitis C virus ("HCV");
hepatitis G  virus ("HGV"),  a  hepatitis virus  discovered by  Genelabs;  human
T-cell  leukemia virus  -- I  ("HTLV-I") and human  T-cell leukemia  virus -- II
("HTLV-II") diagnostic  tests.  Under  the agreement,  Chiron  acquired  certain
rights  to  develop and  market diagnostic  products for  the detection  of HGV,
HTLV-I and  HTLV-II.  In return,  Genelabs  acquired development  and  marketing
rights  in Asia, except  Japan, for certain  products incorporating Chiron's HCV
technology.  Ortho,  Chiron's  joint  diagnostic  business  partner,  agreed  to
participate  as Chiron's  equal partner in  the collaboration  with Genelabs and
therefore will  share equally  in all  payments under  the agreement,  including
equity  investments. Chiron  and Ortho  agreed to pay  $5.0 million  in up front
license fees and up  to $9.0 million in  HGV development milestones. Chiron  and
Ortho  also agreed to  invest a total  of $10.0 million  in equity securities of
Genelabs. Also, under  the terms  of the agreement,  Chiron and  Ortho have  the
option  to acquire substantially all of  the diagnostics business of Genelabs in
the year 2000 through the conversion of the $10.0 million equity investment  for
approximately  one-half of the  business and an additional  payment equal to the
then
 
                                       28
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 4 -- COLLABORATIONS AND JOINT BUSINESS ARRANGEMENTS (CONTINUED)
fair market value  of the  remaining half.  Under a  separate agreement,  Chiron
agreed  to pay Genelabs  $1.0 million in cash  in exchange for  a right of first
refusal to obtain an  exclusive license to Genelabs'  HGV technology for use  in
vaccines.  Chiron paid Genelabs a total of  $8.5 million during 1995 pursuant to
the terms of these agreements.  Of this total, $2.1  million was recorded as  an
investment  in securities of Genelabs and  $6.4 million was recorded as research
and development expense.
 
    NEW YORK UNIVERSITY ("NYU")
 
    In March 1995, the Company reached an agreement with NYU for the license  of
optical  mapping  technology for  use by  Chiron and  its sublicensee,  Ciba, in
development of diagnostics, therapeutics and vaccines, and Chiron also  acquired
the  right to  commercialize a potential  optical mapping  instrument. Under the
terms of the agreement, Chiron made a $5.0 million initial payment to NYU, which
was recorded as research  and development expense in  1995, for the license  and
for  funding certain research facilities at NYU. If Chiron and NYU both agree to
continue development  of  the  instrument,  Chiron will  be  obligated  to  make
milestone  payments totaling $4.0 million to  NYU and will make royalty payments
to NYU based upon any future product sales of the instrument, subject to certain
minimum royalties. In addition, Ciba has agreed to make certain further research
payments to NYU in connection with development of the instrument in exchange for
the sublicense and in exchange for royalty payments by Chiron to Ciba based upon
sales of the instrument.
 
    CIBA
 
    In November 1995,  Chiron and  Ciba entered into  a collaboration  agreement
through  which Ciba acquired a non-exclusive, perpetual license to broadly apply
Chiron's combinatorial chemistry  technologies in Ciba's  research programs.  In
addition,  Chiron and  Ciba agreed to  collaborate on the  identification of new
drug candidates for specific disease targets. In exchange for these rights, Ciba
agreed to pay certain license, milestone and royalty payments to Chiron.
 
    Under the terms  of the agreement,  Ciba will pay  $26.0 million to  Chiron,
over  a five-year period and subject to certain adjustments, in exchange for the
non-exclusive, perpetual  license to  utilize Chiron's  combinatorial  chemistry
techniques.  In  the fourth  quarter  of 1995,  Chiron  received a  $5.5 million
payment from Ciba pursuant to the agreement which was recorded as  collaborative
research agreement revenues from related parties.
 
    In  addition, Ciba agreed to make certain payments to Chiron in exchange for
access to Chiron's technology, chemical libraries and exclusive rights  relating
to  specific drug discovery targets. Ciba was  also granted the right to develop
and market products resulting  from the drug discovery  targets in exchange  for
certain   milestone  and  royalty   payments  to  Chiron.   Chiron  was  granted
commercialization rights to  products developed  for non-competing  indications,
subject  to the payment of royalties to  Ciba. Ciba also agreed to fund Chiron's
activities relating to the collaboration for a period of three years, extendible
to five years at Ciba's option.
 
NOTE 5 -- FAIR VALUE OF FINANCIAL INSTRUMENTS
 
    MARKETABLE SECURITIES
 
    In accordance with the requirements of SFAS 115, the Company has  classified
its  investments in certain debt  and equity securities as "available-for-sale."
Such investments are recorded at fair  value, with unrealized gains and  losses,
deemed  by the Company as temporary in  nature, reported as a separate component
of stockholders' equity.
 
                                       29
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 5 -- FAIR VALUE OF FINANCIAL INSTRUMENTS (CONTINUED)
    At December 31, available-for-sale securities consisted of the following:
 
<TABLE>
<CAPTION>
                                                   1995                                            1994
                              ----------------------------------------------  -----------------------------------------------
                              ADJUSTED   UNREALIZED   UNREALIZED     FAIR     ADJUSTED   UNREALIZED   UNREALIZED
                                COST        GAINS       LOSSES       VALUE      COST        GAINS       LOSSES    FAIR VALUE
                              ---------  -----------  -----------  ---------  ---------  -----------  ----------  -----------
<S>                           <C>        <C>          <C>          <C>        <C>        <C>          <C>         <C>
                                                                      (IN THOUSANDS)
U.S. Government
 securities.................  $  69,659   $     298    $    (125)  $  69,832  $ 126,971   $     137   $   (3,124) $   123,984
Mortgage-backed
 securities.................     11,317          17          (43)     11,291      2,029          --         (710)       1,319
Corporate debt securities...    130,150         128         (213)    130,065    269,559         302       (3,663)     266,198
                              ---------  -----------  -----------  ---------  ---------  -----------  ----------  -----------
                                211,126         443         (381)    211,188    398,559         439       (7,497)     391,501
Marketable equity
 securities.................      9,100      31,200           --      40,300     20,729          --       (5,632)      15,097
                              ---------  -----------  -----------  ---------  ---------  -----------  ----------  -----------
                              $ 220,226   $  31,643    $    (381)  $ 251,488  $ 419,288   $     439   $  (13,129) $   406,598
                              ---------  -----------  -----------  ---------  ---------  -----------  ----------  -----------
                              ---------  -----------  -----------  ---------  ---------  -----------  ----------  -----------
</TABLE>
 
    At December 31, these securities were classified in the Consolidated Balance
Sheet as follows:
 
<TABLE>
<CAPTION>
                                                                                   1995         1994
                                                                                -----------  -----------
<S>                                                                             <C>          <C>
                                                                                     (IN THOUSANDS)
Cash equivalents..............................................................  $    61,289  $    82,554
Short-term investments in marketable debt securities..........................       61,066      137,619
Noncurrent investments in marketable debt securities..........................       88,833      171,328
Investments in equity securities and affiliated companies.....................       40,300       15,097
                                                                                -----------  -----------
                                                                                $   251,488  $   406,598
                                                                                -----------  -----------
                                                                                -----------  -----------
</TABLE>
 
    The cost and estimated fair  value of available-for-sale debt securities  as
of December 31, 1995, by contractual maturity, consisted of the following:
 
<TABLE>
<CAPTION>
                                                                                 ADJUSTED
                                                                                   COST      FAIR VALUE
                                                                                -----------  -----------
<S>                                                                             <C>          <C>
                                                                                     (IN THOUSANDS)
Due in one year or less.......................................................  $   122,418  $   122,355
Due in one to three years.....................................................       77,391       77,542
Due thereafter................................................................           --           --
                                                                                -----------  -----------
                                                                                    199,809      199,897
Mortgage-backed securities....................................................       11,317       11,291
                                                                                -----------  -----------
                                                                                $   211,126  $   211,188
                                                                                -----------  -----------
                                                                                -----------  -----------
</TABLE>
 
    The  proceeds received during  1995 and 1994  from the sale  and maturity of
securities held as  available-for-sale were $334.1  million and $232.9  million,
respectively. During 1995, the gross realized gains and gross realized losses on
sales  of  securities  held as  available-for-sale  were $0.4  million  and $3.5
million, respectively.  Gross realized  gains and  losses during  1994 were  not
significant.   The  cost   of  securities  sold   was  based   on  the  specific
identification method. The change in the  net unrealized holding gain (loss)  on
available-for-sale securities, included as a separate component of stockholders'
equity for 1995 and 1994, was $44.0 million and $(12.7) million, respectively.
 
                                       30
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 5 -- FAIR VALUE OF FINANCIAL INSTRUMENTS (CONTINUED)
    OTHER FINANCIAL INSTRUMENTS
 
    The  carrying amounts and fair values of the Company's financial instruments
other than those accounted for in accordance  with SFAS 115 at December 31,  are
as follows:
 
<TABLE>
<CAPTION>
                                                                1995                      1994
                                                      ------------------------  ------------------------
                                                       CARRYING/                 CARRYING/
                                                       NOTIONAL                  NOTIONAL
                                                        AMOUNT     FAIR VALUE     AMOUNT     FAIR VALUE
                                                      -----------  -----------  -----------  -----------
<S>                                                   <C>          <C>          <C>          <C>
                                                                        (IN THOUSANDS)
Nonmarketable equity investments (accounted for
 under the cost method).............................  $     9,209  $     9,209  $    10,365  $    10,365
Notes receivable....................................        3,519        3,073       17,646       16,892
Deposits............................................        4,643        4,509          754          754
Long-term debt:
  Convertible subordinated debentures...............      312,467      360,677      305,494      259,247
  Notes payable.....................................       64,755       64,741        6,306        6,306
Foreign currency hedging contracts (off-balance
 sheet financial instruments).......................       65,106       65,188       12,866       12,885
</TABLE>
 
    Nonmarketable  equity  investments which  are accounted  for using  the cost
method have carrying values which  approximate fair values. Estimating the  fair
value  of the Company's interests  in nonmarketable equity investments accounted
for under the equity  method is not  practicable because of  the lack of  quoted
market  prices  and  the inability  to  estimate fair  values  without incurring
excessive costs.  The carrying  amounts of  these investments  reflected in  the
accompanying consolidated financial statements at December 31, 1995 and 1994, of
$4.9  million and $26.0 million,  respectively, represent the investments Chiron
has made to date as well as Chiron's share of the results of operations for  the
time  periods  the  investments  were  held,  less  distributions  and dividends
received from the investee.
 
    The fair values of the notes receivable  and the notes payable are based  on
the  discounted value of expected future cash  flows. The fair value of deposits
is based on  the discounted value  of expected future  cash flows using  current
rates  for  assets  with  similar  maturities.  The  fair  value  of convertible
subordinated debentures is based on the market price at the close of business on
December 31, 1995 and 1994.
 
    The fair  value  of foreign  currency  hedging  contracts is  based  on  the
exchange  rate in  effect on  the last  business day  of the  year. The notional
amount approximates the fair value as the majority of the contracts were entered
into shortly before year-end.
 
                                       31
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 6 -- DEBT OBLIGATIONS AND CAPITAL LEASES
    At December 31, 1995 and 1994, long-term debt and capital lease  obligations
consist of the following:
 
<TABLE>
<CAPTION>
                                                                                   1995         1994
                                                                                -----------  -----------
<S>                                                                             <C>          <C>
                                                                                     (IN THOUSANDS)
1.9 percent convertible subordinated debentures...............................  $   225,215  $   220,076
5.25 percent convertible subordinated debentures..............................       87,252       85,418
Capital lease obligations.....................................................       38,940       29,722
Note payable to Ciba..........................................................       54,016           --
Other notes payable...........................................................       14,765        6,306
                                                                                -----------  -----------
                                                                                    420,188      341,522
Less current portion..........................................................        6,940        3,461
                                                                                -----------  -----------
                                                                                $   413,248  $   338,061
                                                                                -----------  -----------
                                                                                -----------  -----------
</TABLE>
 
    In  1993, Chiron issued 1.9 percent convertible subordinated debentures with
a face value of $253.9 million and a yield to maturity of 4.5 percent. The notes
are convertible, at  the holders' option,  into common stock  at 8.6 shares  per
$1,000 principal amount and are due in 2000. Interest is paid semi-annually. The
debentures  may be redeemed by the Company at any time after November 1996, at a
redemption price starting at $905.78 per $1,000 principal amount increasing to a
redemption price equal to 100 percent  of the principal amount at maturity.  The
debentures  are carried net of an initial  issue discount of $39.3 million which
is being amortized over  the life of the  debentures using the interest  method.
Debentures  with a carrying value of $8.9  million and $8.7 million were held by
Ciba at December 31, 1995 and 1994, respectively.
 
    Cetus Oncology Corporation's ("Cetus") 5.25 percent convertible subordinated
debentures are  due  in 2002,  have  a face  value  of $100.0  million  and  are
convertible  at the holders' option at any  time into common stock at 8.1 shares
per $1,000 principal  amount. Interest is  paid annually. At  the option of  the
Company,  the  debentures may  be  redeemed at  any  time at  face  value. These
debentures are carried at a discount  and the difference between the face  value
of  the debentures and their present value  is being accreted over the remaining
term of  the  debentures  using  the interest  method.  Chiron  and  Cetus  have
cross-guaranteed their respective convertible subordinated debentures.
 
    Capital lease obligations consist primarily of one lease bearing an interest
rate  of 10.5 percent and maturing in  2004. The gross amount of land, buildings
and equipment leased  under noncancelable capital  leases totaled $23.8  million
and  $14.1 million  and accumulated depreciation  totaled $5.2  million and $4.0
million at  December 31,  1995  and 1994,  respectively. Future  payments  under
capital  lease obligations  (including interest of  approximately $35.0 million)
are as  follows: 1996  --  $5.3 million,  1997 --  $5.7  million, 1998  --  $5.0
million,  1999  --  $4.0  million,  2000  --  $3.7  million  and  $50.2  million
thereafter.
 
    The note payable to Ciba for approximately $54.0 million was assumed by  the
Company as part of the acquisition of CCD. The note bears interest at a variable
rate  based on LIBOR (approximately 5.8 percent at December 31, 1995) and is due
in 2000 together with accrued interest.
 
                                       32
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 6 -- DEBT OBLIGATIONS AND CAPITAL LEASES (CONTINUED)
    At December 31, 1995, the Company had various notes payable with an  average
interest  rate of  6.7 percent  and maturities  ranging from  1996 through 2014.
Maturities of notes payable for years 1996 through 2000 are as follows: 1996  --
$4.7  million, 1997 -- $1.6 million, 1998 -- $1.6 million, 1999 -- $1.7 million,
2000 -- $1.8 million and $3.4 million thereafter.
 
    Short-term borrowings totaled $50.0 million as of December 31, 1995. As part
of the acquisition  of CCD, borrowings  under revolving foreign  line of  credit
arrangements  were assumed by the  Company totaling approximately $39.8 million,
bearing interest at rates  which average approximately  2.2 percent at  December
31,  1995. During 1995, the Company entered  into a revolving, unsecured line of
credit arrangement with an international bank under which the Company may borrow
up to  $50.0 million.  This credit  facility  is guaranteed  by Ciba  and  bears
interest at a rate based on LIBOR (approximately 5.8 percent on the $1.0 million
outstanding   at  December  31,  1995).  The  remaining  portion  of  short-term
borrowings  consists  primarily  of  foreign  lines  of  credit  and   overdraft
facilities  maintained for Biocine S.p.A. These borrowings totaled approximately
$4.8 million at December 31, 1995, and  bear interest at an average rate of  5.5
percent.  Unused lines of credit or commitments with banks totaled approximately
$122.6 million at December 31, 1995.
 
NOTE 7 -- COMMITMENTS AND CONTINGENCIES
 
    LEASES
 
    Chiron leases  laboratory, office  and  manufacturing facilities,  land  and
equipment  under noncancelable  operating leases  which expire  at various times
through 2037. Rent expense was $28.0 million in 1995, $12.7 million in 1994, and
$9.0 million in 1993.
 
    Future minimum lease  payments under these  leases are as  follows: 1996  --
$25.7  million, 1997  -- $21.2  million, 1998  -- $17.1  million, 1999  -- $13.1
million, 2000 -- $10.8 million and $25.2 million thereafter.
 
    CETUS HEALTHCARE LIMITED PARTNERSHIPS
 
    Pursuant to certain agreements between  the Company and the former  partners
of  Cetus Healthcare Limited  Partnership ("CHLP"), the  Company is obligated to
fund development of certain CHLP products through regulatory approval if,  based
on  the  Company's  assessment,  the products  are  believed  to  be technically
feasible and commercially viable. Because of the inherent uncertainties both  as
to  the  likelihood  of  any  particular  product  continuing  to  be  viewed as
technically feasible and commercially  viable and as to  the cost of  developing
any  particular product  through regulatory approval,  the Company  is unable to
estimate future costs of developing the products subject to this obligation.  In
addition,  the former partners  of CHLP are  entitled to payments  on net sales,
royalties or other fees received by Chiron for certain products.
 
    In December 1990, Cetus  exercised its purchase options  to acquire all  the
limited  partners'  interest in  Cetus  Healthcare Limited  Partnership  II. The
former partners are entitled to receive a  fixed percentage of the net sales  of
certain  products in  Europe (through December  31, 2005) and  the United States
(until certain aggregate returns are realized).
 
                                       33
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 7 -- COMMITMENTS AND CONTINGENCIES (CONTINUED)
    OTHER COMMITMENTS
 
    In connection  with the  expansion of  its manufacturing  capabilities,  the
Company   had   various  commitments   under  construction   contracts  totaling
approximately  $14.8  million  at  December  31,  1995.  The  Company  also  had
performance  bonds outstanding in the amount of  $6.9 million as of December 31,
1995, primarily in connection with sales to public health authorities.
 
NOTE 8 -- STOCKHOLDERS' EQUITY
 
    STOCK OPTION PLANS
 
    In December  1991, Chiron  adopted  a stock  option  plan ("1991  Plan")  to
replace and supersede the separate plans maintained by Chiron, Cetus and certain
Chiron subsidiaries. The 1991 Plan provides for the grant to employees of either
nonqualified  or incentive options  and the grant  to directors, consultants and
contractors of nonqualified options. Incentive options are to be granted at  not
less  than  the fair  market value  of common  stock  at the  date of  grant and
nonqualified options at  not less  than 85 percent  of such  fair market  value.
Options are exercisable as determined by the Board of Directors.
 
    Initially,  the 1991 Plan  had reserved and  available for issuance, options
for 4.5 million shares of Chiron  common stock and restricted common stock  plus
any remaining shares of common stock and restricted stock remaining for issuance
under the Chiron 1982 Stock Option Plan and 1984 Nonqualified Stock Option Plan.
This  amount is increased annually by a number of shares equal to 1.5 percent of
the number  of shares  of common  stock outstanding  plus shares  issuable  upon
conversion   or  exercise  of  outstanding  warrants,  options  and  convertible
securities. For 1995, this increase in  shares available for grant was  627,268.
At December 31, 1995, a total of 2,075,368 shares were available for grant under
the 1991 Plan.
 
    A summary of stock option activity follows:
 
<TABLE>
<CAPTION>
                                                                 1995           1994           1993
                                                             -------------  -------------  -------------
<S>                                                          <C>            <C>            <C>
Outstanding options at January 1,..........................      4,946,884      4,342,618      4,207,545
  Granted..................................................      2,626,904      1,166,982      1,175,834
  Forfeited................................................       (301,834)      (168,834)      (198,721)
  Surrendered against payment by Ciba......................       (767,740)            --             --
  Exercised................................................       (669,801)      (393,882)      (842,040)
                                                             -------------  -------------  -------------
Outstanding options at December 31,........................      5,834,413      4,946,884      4,342,618
                                                             -------------  -------------  -------------
Exercisable options at December 31,........................      2,214,947      2,566,805      1,972,065
Average exercise price of outstanding options at December
 31,.......................................................  $       59.03  $       51.28  $       45.03
Average exercise price of options exercised during
 the year..................................................  $       42.42  $       32.80  $       26.22
Average exercise price of options granted during
 the year..................................................  $       65.32  $       70.67  $       61.93
</TABLE>
 
    EMPLOYEE STOCK PURCHASE PLAN
 
    Chiron has a stock purchase plan in which eligible employees may participate
through  payroll deductions. A total of  1,750,000 shares have been reserved for
issuance under the plan, of which 954,118 shares were available for purchase  at
December 31, 1995. At the end of each quarter, funds
 
                                       34
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 8 -- STOCKHOLDERS' EQUITY (CONTINUED)
deducted  from  participating employees'  salaries are  used to  purchase common
stock at 85 percent of the lower of market value at the quarterly purchase  date
or  the employees' eligibility date for  participation. Purchases of shares made
under the plan were 172,665 in 1995, 157,891 in 1994 and 121,840 in 1993.
 
    COMMON STOCK WARRANTS
 
    As a result of the acquisition of Cetus, the following warrants to  purchase
Chiron common stock are outstanding at December 31, 1995:
 
<TABLE>
<CAPTION>
  NUMBER OF    EXERCISE
   SHARES        PRICE        EXPIRATION DATE
- -------------  ---------  -----------------------
<S>            <C>        <C>
     291,938   $   95.33        December 15, 1996
     150,000       52.50        December 31, 1998
</TABLE>
 
    The  $95.33 warrants are  currently exercisable. The  $52.50 warrants become
exercisable upon  reaching  $50.0  million  in annual  worldwide  sales  of  the
Company's Proleukin-Registered Trademark- product.
 
    PREFERRED SHARE PURCHASE RIGHTS
 
    On  August  25, 1994,  the  Board of  Directors  of the  Company  declared a
dividend of one preferred share purchase right ("a right") for each  outstanding
share  of common  stock of  the Company. Each  right entitles  the holder, under
certain circumstances, to purchase from the Company one one-hundredth of a share
of Series A Junior Participating  Preferred Stock of the  Company at a price  of
$325,  subject to  adjustment. The  rights are to  be distributed  to holders of
Chiron common stock upon the acquisition by a third party of certain percentages
of Chiron common stock. As part of the agreements with Ciba, Chiron amended  the
Rights  Agreement such that  Ciba would not  be "an acquiring  person" under the
Rights Agreement and therefore,  the purchase of  an approximately 49.9  percent
interest  in Chiron common stock  by Ciba did not  result in distribution of the
rights.
 
NOTE 9 -- INCOME TAXES
 
    COMPONENTS OF PRE-TAX EARNINGS
 
    For financial  reporting  purposes,  "Income  (loss)  before  income  taxes"
includes the following components for the years ended December 31,:
 
<TABLE>
<CAPTION>
                                                                        1995        1994        1993
                                                                    ------------  ---------  ----------
<S>                                                                 <C>           <C>        <C>
                                                                              (IN THOUSANDS)
United States.....................................................  $   (492,842) $  36,829  $   33,331
Foreign...........................................................         2,068     (4,832)    (10,244)
                                                                    ------------  ---------  ----------
                                                                    $   (490,774) $  31,997  $   23,087
                                                                    ------------  ---------  ----------
                                                                    ------------  ---------  ----------
</TABLE>
 
                                       35
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 9 -- INCOME TAXES (CONTINUED)
    COMPONENTS OF PROVISION FOR INCOME TAXES
 
    Significant  components of the provision for income taxes are as follows for
the years ended December 31,:
 
<TABLE>
<CAPTION>
                                                                       1995         1994        1993
                                                                   ------------  ----------  ----------
<S>                                                                <C>           <C>         <C>
                                                                              (IN THOUSANDS)
Current:
  Federal........................................................  $         --  $   10,741  $     (290)
  State..........................................................         1,807       2,227        (144)
  Foreign........................................................         9,901         266         457
                                                                   ------------  ----------  ----------
                                                                         11,708      13,234          23
Deferred:
  Federal........................................................            --          --       1,113
  State..........................................................            --          --          --
  Foreign........................................................         1,260          --          --
                                                                   ------------  ----------  ----------
                                                                          1,260          --       1,113
Charge in lieu of taxes resulting from recognition of acquired
 tax benefits that are allocated to reduce noncurrent intangible
 assets related to the acquired entity...........................         8,721         438       3,567
                                                                   ------------  ----------  ----------
Total provision..................................................  $     21,689  $   13,672  $    4,703
                                                                   ------------  ----------  ----------
                                                                   ------------  ----------  ----------
</TABLE>
 
    The tax benefit  related to tax  deductions for the  Company's stock  option
plans  is recorded as an increase to paid-in capital when realized. Tax benefits
of approximately $0.9 million  in 1995, $9.9  million in 1994  and none in  1993
were realized.
 
                                       36
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)
                               December 31, 1995
 
NOTE 9 -- INCOME TAXES (CONTINUED)
    RATE RECONCILIATION
 
    The  reconciliation  of  the provision  for  income taxes,  computed  at the
statutory United States income tax rate,  to the reported amounts is as  follows
for the years ended December 31,:
 
<TABLE>
<CAPTION>
                                                                         1995        1994       1993
                                                                     ------------  ---------  ---------
<S>                                                                  <C>           <C>        <C>
                                                                               (IN THOUSANDS)
Federal tax provision (benefit) at statutory rates.................  $   (171,771) $  11,199  $   8,080
Tax effect of write-off of purchased in-process
 technology........................................................       127,850     --         --
State taxes, net of federal benefit................................         4,895      2,300       (144)
Foreign income taxes...............................................        16,794        266        457
Losses of foreign subsidiaries not providing benefit in current
 year..............................................................          (724)     2,247      4,020
Amortization of intangible assets..................................           696        927      1,006
Effect of net operating loss carryforward..........................        31,691     --         (6,569)
Nontaxable earnings of joint business..............................       --          (2,547)    --
Nondeductible expenses related to Ciba transaction.................         9,308        875     --
Utilization of deferred tax assets not previously
 benefited.........................................................       --          (2,246)    (2,549)
Other..............................................................         2,950        651        402
                                                                     ------------  ---------  ---------
Provision for income taxes.........................................  $     21,689  $  13,672  $   4,703
                                                                     ------------  ---------  ---------
                                                                     ------------  ---------  ---------
</TABLE>
 
                                       37
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 9 -- INCOME TAXES (CONTINUED)
    SUMMARY OF DEFERRED INCOME TAXES
 
    Deferred  income taxes reflect the net  tax effects of temporary differences
between the carrying amounts of  assets and liabilities for financial  reporting
purposes and the amounts used for income tax purposes and the tax effects of net
operating loss and credit carryforwards. Significant components of the Company's
deferred income tax liabilities and assets are as follows:
 
<TABLE>
<CAPTION>
                                                                                     DECEMBER 31,
                                                                              --------------------------
                                                                                  1995          1994
                                                                              ------------  ------------
<S>                                                                           <C>           <C>
                                                                                    (IN THOUSANDS)
Deferred income tax liabilities:
  Basis differences -- purchase accounting..................................  $     19,537  $     10,214
  Patent costs expensed for tax purposes....................................         7,205         5,981
  Other.....................................................................         5,036            --
                                                                              ------------  ------------
                                                                                    31,778        16,195
Deferred income tax assets:
  Basis differences -- purchase accounting and intangibles..................        89,074        93,328
  Depreciation and purchased technologies...................................        22,345         8,155
  Reserves and expense accruals.............................................        43,458        16,063
  Net operating loss carryovers.............................................       128,681        22,659
  Business credit carryforwards.............................................        26,162        10,182
  Other.....................................................................        12,498        13,518
                                                                              ------------  ------------
                                                                                   322,218       163,905
  Less valuation allowance..................................................      (286,757)     (147,710)
                                                                              ------------  ------------
                                                                                    35,461        16,195
                                                                              ------------  ------------
Net deferred income tax asset...............................................  $      3,683  $    --
                                                                              ------------  ------------
                                                                              ------------  ------------
</TABLE>
 
    The  net change in the valuation allowance  for the years ended December 31,
1995 and  1994, was  an  increase of  $139.0 million  and  a decrease  of  $13.9
million, respectively.
 
    Subsequently recognized tax benefits relating to the valuation allowance for
deferred tax assets as of December 31, 1995, will be allocated as follows:
 
<TABLE>
<CAPTION>
                                                                                          (IN THOUSANDS)
<S>                                                                                       <C>
Income tax benefit......................................................................   $    209,192
Goodwill and other noncurrent intangible assets.........................................         38,809
Additional paid-in capital..............................................................         38,756
                                                                                          --------------
                                                                                           $    286,757
                                                                                          --------------
                                                                                          --------------
</TABLE>
 
                                       38
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 9 -- INCOME TAXES (CONTINUED)
    TAX OPERATING LOSS AND CREDIT CARRYFORWARDS
 
    The  following presents the carryforwards as  of December 31, 1995 which are
available to offset future income tax liabilities:
 
<TABLE>
<CAPTION>
                                                                                          (IN THOUSANDS)
<S>                                                                                       <C>
Federal net operating loss carryforwards expiring from 2002 through 2010................   $    237,181
State net operating loss carryforwards expiring from 1996 through 2010..................        115,398
Foreign net operating loss carryforwards principally carried forward indefinitely.......        104,797
Federal tax credit carryforwards expiring from 1997 through 2009........................         16,717
State tax credit carryforwards expiring from 1997 through 2010..........................          9,445
</TABLE>
 
NOTE 10 -- OTHER INCOME (EXPENSE), NET
    Other income (expense), net, for each of the three years ended December  31,
consists of the following:
 
<TABLE>
<CAPTION>
                                                                        1995        1994       1993
                                                                     ----------  ----------  ---------
<S>                                                                  <C>         <C>         <C>
                                                                              (IN THOUSANDS)
Interest and dividend income.......................................  $   22,301  $   20,343  $  16,154
Capitalized interest...............................................         420       4,405      1,857
Interest expense and related costs on convertible debentures.......     (17,827)    (16,782)    (8,861)
Write-downs of investments.........................................          --     (11,607)        --
Other interest expense.............................................     (12,535)     (3,404)    (3,366)
Net realized gain (loss) on sale of debt securities................      (3,037)     (2,234)     1,276
Realized/unrealized gain (loss) on foreign exchange transactions...        (193)        156       (405)
Other..............................................................       2,525      (1,280)     1,294
                                                                     ----------  ----------  ---------
                                                                     $   (8,346) $  (10,403) $   7,949
                                                                     ----------  ----------  ---------
                                                                     ----------  ----------  ---------
</TABLE>
 
NOTE 11 -- GEOGRAPHIC AREA INFORMATION
    Chiron  operates in  the global healthcare  industry in  four major markets:
diagnostics,  ophthalmics,  vaccines   and  therapeutics.  The   Company  is   a
multinational corporation with operations in many countries including the United
States,  Canada, France, Germany, the United Kingdom, Italy, The Netherlands and
Australia. Transfers between geographic  areas represent intercompany sales  and
are  accounted for based on established  sales prices between related companies.
In computing earnings from operations  for foreign subsidiaries, no  allocations
of general corporate expenses or interest have been made. Identifiable assets of
foreign  geographic  areas  relate  to the  operating  assets  of  the Company's
subsidiaries in those countries. Domestic assets consist of all operating assets
of the Company located within the United States.
 
    Results of foreign operations  for 1995 consist  of ophthalmic and  oncology
sales  in  addition to  sales of  vaccines and  diagnostic products.  Results of
foreign operations  for  1994  and  1993 consist  primarily  of  ophthalmic  and
oncology product sales.
 
                                       39
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 11 -- GEOGRAPHIC AREA INFORMATION (CONTINUED)
    Information about the Company's operations in different geographic areas for
the three years ended December 31, 1995, is as follows:
 
<TABLE>
<CAPTION>
                            DOMESTIC       EUROPE     ASIA/PACIFIC   OTHER    ELIMINATIONS  CONSOLIDATED
                          -------------  -----------  -----------  ---------  ------------  -------------
<S>                       <C>            <C>          <C>          <C>        <C>           <C>
                                                          (IN THOUSANDS)
1995:
  Sales to unaffiliated
   customers............  $     592,524  $   348,392  $   136,668  $  22,998   $   --       $   1,100,582
  Transfers between
   geographic areas.....        178,084       46,819          586     --         (225,489)       --
                          -------------  -----------  -----------  ---------  ------------  -------------
  Total revenue.........        770,608      395,211      137,254     22,998     (225,489)      1,100,582
  Net loss..............       (453,524)     (37,234)      (1,222)    (4,898)     (15,585)       (512,463)
  Identifiable assets...      1,901,145      292,628       87,684     12,272     (803,531)      1,490,198
1994:
  Sales to unaffiliated
   customers............  $     379,917  $    65,569  $     5,322  $   3,171   $   --       $     453,979
  Transfers between
   geographic areas.....         22,919        1,108        1,370     --          (25,397)       --
                          -------------  -----------  -----------  ---------  ------------  -------------
  Total revenue.........        402,836       66,677        6,692      3,171      (25,397)        453,979
  Net income (loss).....         25,356       (3,456)        (732)    (1,327)      (1,516)         18,325
  Identifiable assets...      1,091,648       62,034        1,345     (1,017)    (104,268)      1,049,742
1993:
  Sales to unaffiliated
   customers............  $     266,671  $    40,829  $     4,932  $   5,103   $   --       $     317,535
  Transfers between
   geographic areas.....         22,917       11,585        1,189     --          (35,691)       --
                          -------------  -----------  -----------  ---------  ------------  -------------
  Total revenue.........        289,588       52,414        6,121      5,103      (35,691)        317,535
  Net income (loss).....         29,114      (12,410)        (130)       144        1,666          18,384
  Identifiable assets...      1,038,047       17,604        2,043      1,006      (90,103)        968,597
</TABLE>
 
    Revenues  by customer  location, including  both local  revenues and exports
from other locations, were as follows:
 
<TABLE>
<CAPTION>
                                                                         YEAR ENDED DECEMBER 31,
                                                                 ---------------------------------------
                                                                     1995          1994         1993
                                                                 -------------  -----------  -----------
<S>                                                              <C>            <C>          <C>
                                                                             (IN THOUSANDS)
North America..................................................  $     502,090  $   344,569  $   233,940
Europe.........................................................        367,521       86,804       66,286
Asia and Pacific Basin.........................................        169,367       17,982       15,810
South America, Africa and Other................................         61,604        4,624        1,499
                                                                 -------------  -----------  -----------
                                                                 $   1,100,582  $   453,979  $   317,535
                                                                 -------------  -----------  -----------
                                                                 -------------  -----------  -----------
</TABLE>
 
                                       40
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 12 -- LEGAL PROCEEDINGS
    The Company  is  involved  in  litigation in  the  ordinary  course  of  its
business.  While  the  ultimate  outcome  of  litigation  cannot  be  accurately
predicted, based upon  information presently  known to  management, the  Company
does  not believe  that the ultimate  resolution of any  such litigation matter,
including the matters  described below,  should have a  material adverse  effect
upon its financial statements as presented herein.
 
    ABBOTT   LABORATORIES.    On  December  13,  1993,  Chiron  filed  a  patent
infringement action against Abbott in the  United States District Court for  the
Northern  District  of  California.  The  suit,  which  alleges  infringement of
Chiron's U.S. Patent  No. 5,156,949  ("the '949  patent"), claiming  the use  of
recombinant  envelope antigens in  immunoassays for HIV  antibodies, is based on
Abbott's sale of  unlicensed HIV immunoassay  tests which are  believed to  fall
within  the scope of one or more patent claims. Abbott is defending this suit on
the basis of invalidity and  non-infringement. Chiron is requesting  unspecified
damages  and injunctive relief.  Cross motions for  summary judgment on Abbott's
defenses of inequitable conduct and prior invention were filed. After  argument,
the  Court granted  portions of Chiron's  motion but denied  Abbott's motion for
summary judgment.  Subsequently, the  United States  Patent &  Trademark  Office
declared  an interference  between the '949  patent and an  application owned by
Centocor and the U.S. government. Chiron is the junior party. The Court  refused
Abbott's  request to stay the litigation  pending resolution of the interference
and has scheduled a trial for April 7, 1996.
 
    On April 26,  1994, Abbott filed  suit against Chiron  in the United  States
District Court for the Northern District of Illinois, Eastern Division, alleging
that  the Company has,  by making, using and  selling nucleic acid hybridization
assays, infringed three  U.S. patents  owned by  third parties  and licensed  to
Abbott.  Abbott  is  seeking injunctive  relief  and damages  in  an unspecified
amount. The Company believes that it  has substantial defenses and is  defending
this suit vigorously. Trial is currently scheduled for July 15, 1996.
 
    ALLERGAN MEDICAL OPTICS.  On December 8, 1992, Allergan Medical Optics filed
a  lawsuit  in the  United States  District  Court for  the Central  District of
California against Chiron and Chiron Intra-
Optics (now Chiron Vision)  (together, "Chiron"). The  complaint alleged that  a
mechanical  inserter used to  place the Chiron foldable  intraocular lens in the
eye during cataract surgery infringes a patent licensed exclusively to Allergan.
Allergan sought  an injunction  against sales  of the  inserter, damages  in  an
unspecified amount, and attorneys' fees. On November 27, 1995, Chiron Vision and
Allergan  reached a  settlement in  the lawsuit.  Chiron signed  a Final Consent
Judgment in exchange for a license to the subject patent.
 
    ADVANCED CHEMTECH.  On  August 11, 1994, Advanced  ChemTech, Inc. brought  a
lawsuit  against  Chiron in  the United  States District  Court for  the Western
District of Kentucky, Louisville Division, asserting that certain Chiron patents
relating to peptide mixtures are invalid  and unenforceable and that Chiron  has
engaged  in unfair  competition and unfair  business practices  in asserting its
patent rights.  Advanced ChemTech  is asking  the Court  to: (1)  find that  the
patent  at issue is  invalid and unenforceable; (2)  find that Advanced ChemTech
does not infringe the patents; and (3) award damages according to proof.  Chiron
has answered and counterclaimed for infringement of its patents. Chiron believes
that  it  has  substantial  defenses against  the  claims  asserted  by Advanced
ChemTech.
 
    DANIEL W. BRADLEY.  On  December 20, 1994, Dr.  Daniel W. Bradley, a  former
scientist  at the U.S. Centers  for Disease Control (the  "CDC") brought suit in
the United States District Court for the Northern District of California against
Chiron,   Ortho,    certain    employees    of   Chiron,    and    the    United
 
                                       41
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 12 -- LEGAL PROCEEDINGS (CONTINUED)
States  government.  Subsequently,  Bradley  dismissed the  United  States  as a
defendant. Bradley, who collaborated with Chiron scientists on research that led
to the discovery of HCV, alleges he had been wrongly excluded as an inventor  of
HCV.  He requests various forms of relief,  including declarations that he is an
inventor of  Chiron's  patents  related  to  HCV  and  that  these  patents  are
unenforceable.  Bradley further seeks monetary  damages and a constructive trust
on all past and  future profits derived from  Chiron's HCV invention, which  are
estimated  by Bradley to be in excess of  $1 billion, as well as penalties under
federal and state Racketeering and Corrupt Organization (RICO) statutes.  Chiron
believes  Bradley's claims  to inventorship and  his suit are  without merit and
that substantial defenses  exist. In 1990,  Bradley and the  CDC entered into  a
settlement  agreement regarding  their respective  claims of  inventorship under
which any rights either might have were assigned to Chiron. Chiron believes that
the settlement agreement is  valid and bars substantially  all of the claims  in
the  subject  litigation. Chiron  and  the other  defendants  filed a  motion to
dismiss  Bradley's  First  Amended  Complaint.  The  Court  dismissed  Bradley's
complaint  for failure to  state a claim  upon which relief  can be granted, but
allowed Bradley  to file  an amended  complaint. Chiron  has filed  a motion  to
dismiss Bradley's Second Amended Complaint.
 
    CARNEGIE  MELLON UNIVERSITY.  On August 20, 1994, Carnegie Mellon University
and Three  Rivers Biologicals,  Inc.  brought a  lawsuit  in the  United  States
District  Court  for the  Western District  of Pennsylvania  against Hoffmann-La
Roche, Inc., Roche Molecular Systems, Inc., the Perkin-Elmer Corporation, Chiron
and its wholly-owned subsidiary, Cetus  Oncology Corporation, claiming that  the
defendants  infringed certain United States patents relating to plasmids for the
expression of DNA Polymerase  I and to  plasmids providing for  nick-translation
activity.  Carnegie Mellon  and Three Rivers  Biologicals are  seeking a finding
that the defendants willfully infringed the patents at issue, injunctive  relief
and  damages according  to proof.  All defendants  have answered  the complaint.
Venue of the case was changed to  the Northern District of California on  motion
by  Chiron. Discovery  is ongoing.  The facts  of the  case, including potential
indemnification rights or obligations among the defendants, are currently  under
review. However, Chiron believes that it and Cetus have significant defenses.
 
    EVANS.   On  November 8,  1995, the Tribunal  of Brescia,  an Italian Court,
dismissed a lawsuit brought by Evans Medical Limited (a division of Medeva  plc)
("Evans") against Chiron's Italian vaccine business, Biocine S.p.A., and against
Nuova  Chimica Medica s.r.l., a distributor.  Evans sought injunctive relief via
an emergency procedure. The  suit alleged that the  p69 antigen used in  Biocine
S.p.A.'s recombinant acellular pertussis vaccines
(Acelluvax-Registered   Trademark-  and   Acelluvax-Registered  Trademark-  DTP)
infringed Evans' Italian counterpart  to its European  patent No. 162,639  ("the
'639  patent").  This  patent is  licensed  by Evans  exclusively  to SmithKline
Beecham Biologicals S.A. Counterpart patents are pending or have been issued  in
other jurisdictions, including the United States. Earlier in the year, Evans had
brought  a similar  proceeding against  Biocine S.p.A.  and its  distributor for
emergency injunctive  relief  in the  same  Court.  Following a  June  26,  1995
hearing, Evans abandoned that proceeding.
 
    Biocine S.p.A. previously had opposed issuance of the '639 patent before the
European  Patent Office ("EPO") and has appealed  the finding reached by the EPO
in that opposition proceeding. Biocine S.p.A.  filed an action against Evans  in
Milan on October 23, 1995 alleging invalidity of the same patent that formed the
basis  for the two Italian  suits discussed above. Biocine  S.p.A. later filed a
claim against Evans for non-infringement  with the Milan Court. Evans'  response
to the Milan actions
 
                                       42
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 12 -- LEGAL PROCEEDINGS (CONTINUED)
was  filed in  February 1996.  Also in  February 1996,  Biocine S.p.A.  filed an
action alleging invalidity  and non-infringement of  Evans' Dutch equivalent  to
the  '639 patent in The  Netherlands. Chiron believes that  it does not infringe
any valid claim in the '639 patent or in its foreign counterparts.
 
    MUREX DIAGNOSTICS, LTD.   In a  series of  actions, the first  of which  was
brought  on  March 2,  1992, Chiron,  together with  Ortho and  Ortho Diagnostic
Systems, Ltd. (collectively, "Ortho"), filed suit in the High Court for  England
and  Wales against Murex  Diagnostics, Ltd. ("Murex"),  alleging infringement of
Chiron's U.K. Patent No.  2,212,511 ("the '511 patent")  as a result of  Murex's
manufacture  and sale of HCV immunoassay kits  in the U.K. Murex is a subsidiary
of International Murex Technologies Corp., a Canadian company. Chiron and  Ortho
sought  injunctive relief  and unspecified  damages. On  May 27,  1994, the High
Court granted judgment for Chiron and  Ortho, holding the '511 patent valid  and
infringed,  and ordered Murex to pay damages in an amount to be determined. Both
Murex and the Chiron/Ortho parties appealed various aspects of the High  Court's
judgment. Chiron's and Ortho's request for an injunction was granted on November
30,  1994. Following an interim damages inquiry which was held in February 1996,
the Court  ordered  Murex  to  pay L6  million  (approximately  $9  million)  to
Chiron/Ortho  by  February 23,  1996.  On February  22,  1996, Murex,  which had
changed its name to Specialist Diagnostics, Ltd., filed a petition for voluntary
liquidation. There can be no assurance when or whether Chiron and Ortho will  be
able to collect this damage award. A damages inquiry is scheduled for July 1996.
 
    In  a series of rulings on November 2  and 7, 1995, the U.K. Court of Appeal
held that, with the exception  of one claim, the '511  patent is valid and  that
Chiron  could amend the patent and proceed with the damages inquiry. The parties
have applied for leave to appeal to the House of Lords.
 
    Chiron is informed that officials within the British Ministry of Health have
in the past raised  the possibility of authorizing  Murex's infringement of  the
'511 patent under the "Crown use" provisions of British law, with respect to the
sale  of HCV immunoassay  kits to the British  National Health Service. Further,
Murex has stated  that it will  apply for  a compulsory license  under the  '511
patent.
 
    Infringement  proceedings  against  Murex  on  German  and  European patents
corresponding to the '511  patent also have  been filed by  Chiron and Ortho  in
Germany,  Italy, The  Netherlands and Belgium.  On January 23,  1995, Chiron and
Ortho were granted an injunction in Germany. On May 8, 1995, Chiron was  granted
a cross-border preliminary injunction by the Dutch Court preventing infringement
by  Murex  and  certain of  its  affiliates covering  The  Netherlands, Belgium,
France, Spain and Luxembourg. Murex has  brought an action in Australia  seeking
revocation  of  the  Australian  counterpart  of  the  '511  patent.  Chiron has
counterclaimed for infringement. That matter is  scheduled for trial in June  of
1996.
 
    ORGANON  TEKNIKA,  LTD.   On May  4, 1994,  Chiron instituted  summary legal
proceedings against Organon  Teknika, B.V., Akzo  Pharma, B.V., subsidiaries  of
Akzo   N.V.  (all  subsidiaries  of  Akzo  N.V.  (collectively  referred  to  as
"Organon")), and United Biomedical, Inc. ("UBI"), the supplier of Organon's  HCV
antigens and kits, in the District Court of the Hague, The Netherlands, alleging
infringement  of European Patent No. 318,216 ("the  '216 patent") as a result of
the defendants' manufacture and sale of HCV immunoassay kits. On July 22,  1994,
Chiron  was  granted  a  cross-border  preliminary  injunction  against  further
infringement, including sale  of the UBI  kit, by Organon  in Austria,  Belgium,
Switzerland,  Germany,  Spain,  France,  Italy,  Liechtenstein,  Luxembourg, The
Netherlands and Sweden. Organon and UBI appealed the injunction. The '216 patent
is a counterpart of the British '511 patent. Infringement proceedings brought by
Chiron and Ortho were also pending against
 
                                       43
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 12 -- LEGAL PROCEEDINGS (CONTINUED)
Organon in Italy and Belgium (based  on the '216 patent), and consolidated  with
the  actions against Murex, described above.  Chiron, Ortho, and Organon settled
all European  HCV litigation  on October  9,  1995, and  Chiron and  Ortho  were
compensated  for past infringement.  UBI did not  participate in the settlement,
and has been  ordered to pay  Ortho Ltd. damages  by the U.K.  Court of  Appeal,
along  with  Murex, as  described  above. A  damages  inquiry has  not  yet been
scheduled.
 
    SICOR.   In April  1991, Alco  Chemicals, Ltd.  ("Alco") and  Sicor,  S.p.A.
("Sicor"),  former suppliers of bulk doxorubicin to Cetus Ben Venue Therapeutics
("CBVT"), filed  suit in  the  United States  District  Court for  the  Northern
District  of California against Cetus  Oncology Corporation ("Cetus"), Ben Venue
Laboratories, Inc. ("Ben Venue"), CBVT  and Erbamont, Inc. ("Erbamont") and  its
affiliates.  Plaintiffs claim that  they had distribution  and supply agreements
with CBVT relative to a product called doxorubicin hydrochloride. Sicor had been
prevented from manufacturing  product for  CBVT since September  1990. In  March
1991,  CBVT entered  into an agreement  with Erbamont which  provided for, among
other things, the settlement of several legal proceedings then pending  relating
to  Erbamont's alleged doxorubicin proprietary  rights, and the exclusive supply
of doxorubicin to CBVT  by Erbamont. The Sicor  complaint alleges breach of  the
CBVT  contract to  purchase bulk  doxorubicin from  Sicor, as  well as antitrust
violations and interference with contract and prospective advantage, and  sought
unspecified  damages. Plaintiffs  assert in separate  counts against  all of the
Cetus parties that their contracts with CBVT have been breached, that inducement
of such  breaches  has  been tortious,  that  plaintiffs'  prospective  economic
relations  have been tortiously frustrated, that  the Cetus parties are indebted
to plaintiffs on past accounts said to relate to the joint financing of  earlier
litigation, and that plaintiffs' distribution and supply of doxorubicin has been
foreclosed  by reason  of violations  of the  federal antitrust  laws. Cetus has
denied any entitlement to recovery in this lawsuit and has filed a  counterclaim
against the plaintiffs for fraud and breach of contract based on Sicor's failure
to  deliver the  bulk product. Sicor's  antitrust claims have  been dismissed on
motion and  Sicor has  dismissed  its claims  against  Erbamont. Sicor  filed  a
summary  judgment motion with respect to the counterclaims of the Cetus parties.
On February 2, 1996, the District Court granted that motion in an opinion  which
the  Company  is currently  studying. The  Company  believes it  has substantial
defenses to the  Sicor claims.  A related arbitration  before the  International
Chamber  of Commerce in New York brought by Sicor against Chiron, Cetus, and Ben
Venue has been stayed pending the resolution of the Cetus parties' counterclaims
in the litigation described above.
 
    In February 1995, Sicor and Alco filed a further action in the United States
District Court for the Northern District of California against CBVT for  amounts
allegedly  owed by CBVT  to Sicor and  Alco for the  supply of doxorubicin, plus
interest and attorneys' fees. This case has  been assigned to the same judge  as
the  above-referenced  District Court  case. The  Company  believes that  it has
significant defenses to these claims.
 
    SCRIPPS CLINIC.   The Company is  defending a lawsuit  filed on November  8,
1983,  by the Scripps  Clinic and Research  Foundation and Revlon,  Inc., in the
United States District Court  for the Northern  District of California  alleging
that  Chiron's research  program to synthesize  a protein  associated with human
blood  clotting  ("Factor  VIII:C")   through  genetic  engineering   techniques
infringes plaintiffs' rights under a patent for purified Factor VIII:C. The suit
seeks  an injunction  against further infringement,  an accounting, compensatory
damages of at least $10 million and  punitive damages in the same amount.  After
the  trial court  granted summary  judgment in  favor of  Chiron, the plaintiffs
appealed. Appeal Nos. 89-1541, -1542, -1543,  -1646 and -1647 were filed in  the
United  States Court  of Appeals  for the  Federal Circuit.  The Appellate Court
reversed the trial court, finding that summary judgment
 
                                       44
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 12 -- LEGAL PROCEEDINGS (CONTINUED)
was not appropriate and  directing that a number  of issues be tried,  including
the  issues of inequitable conduct on the  part of Scripps, patent validity, and
patent infringement. No trial date  has been set and it  is unclear when a  date
will be set. Chiron intends to vigorously assert its defenses at trial.
 
    SUMMIT.  On September 29, 1994, Summit Technology Ireland B.V., a subsidiary
of  Summit Technology, Inc., a manufacturer of ophthalmic lasers, filed a patent
infringement action in the  Regional Court of  Dusseldorf, Germany, against  two
German subsidiaries of Chiron Vision (Chiron Technolas and Chiron Adatomed), and
their  respective managing directors. The suit  alleged that the manufacture and
sale in Germany of the Technolas-Registered Trademark-
Keracor-Registered  Trademark-   '116  excimer   laser  infringed   the   German
counterpart of a European patent held by Summit. Summit sought injunctive relief
and  damages which it estimated  at Deutsche mark 2  million. On August 3, 1995,
the German Court  granted judgment  in favor  of Summit,  granted an  injunction
against   defendants'  further   infringement  and  awarded   damages  for  past
infringement in  an  amount to  be  determined.  On September  1,  1995,  Summit
enforced  the judgment and the  injunction by posting security  in the amount of
Deutsche mark 2 million. The Company's  appeal of the Regional Court's  decision
is  pending. Chiron Technolas, Chiron Vision's sole source of ophthalmic lasers,
continues to manufacture  ophthalmic excimer  lasers, which  are distributed  by
Chiron  Vision and its  subsidiaries. The Company  believes these activities are
outside the scope of the judgment  and injunction of the German Regional  Court.
The  Company has also initiated a separate judicial action in Germany seeking to
invalidate Summit's patent.
 
    AMERICAN  HOME  PRODUCTS.    On  April  27,  1995,  American  Home  Products
Corporation  ("AHP")  filed suit  against Chiron  in the  Superior Court  in New
Castle County,  Delaware,  claiming  compensatory,  consequential  and  punitive
damages  based on  an alleged  breach and  repudiation by  Chiron of  a contract
pursuant to which  Chiron had agreed  to purchase certain  assets from AHP.  The
case has been settled and was ordered dismissed on December 2, 1995.
 
    BRILLIANT TRADING CO., WOLFSON.  Following the announcement by Chiron of the
signing  of a  definitive agreement  to acquire  Viagene, Inc.  ("Viagene"), two
lawsuits purporting to be class actions were filed on April 24 and May 1,  1995,
respectively,  in the Court of  Chancery of the State  of Delaware against named
directors and officers of Viagene and  against Viagene and Chiron. In one  case,
Chiron  is  sued on  a  theory that  it aided  and  abetted alleged  breaches of
fiduciary duty by  Viagene's directors  and officers in  approving the  proposed
acquisition by Chiron. In the other case, Chiron is sued for alleged breaches of
fiduciary  duty  as  a  controlling  stockholder  of  Viagene.  Plaintiffs  seek
declaratory and injunctive  relief, an accounting  and costs and  disbursements.
Defendants  have  received an  open  extension of  time  to answer  or otherwise
respond. Chiron believes these suits are without merit.
 
    STOCKHOLDER LITIGATION.    In  November 1994,  Chiron,  its  directors,  and
certain  of its officers were sued  in three essentially identical actions filed
as class actions on behalf of  Chiron stockholders, alleging that the  directors
had  violated their fiduciary  duty by failing to  maximize stockholder value in
connection with  the  series  of  transactions affected  with  Ciba  which  were
announced  on November 20, 1994, by, among other things, not taking all possible
steps to seek out and encourage the best offer for the Company once the  Company
had been put in play. Two of the actions filed respectively on November 14, 1994
and November 22, 1994 (HANNA V. CHIRON CORP., ET AL., C.A. No. 13874, and DEZUBE
V. CHIRON CORPORATION ET AL., C.A. 13896) were filed in the Court of Chancery of
the State of Delaware in and for New Castle County. The complaints in both cases
ask  for injunctive  relief, rescission  and attorneys'  fees. Plaintiff  in the
HANNA action additionally seeks damages  in an unspecified amount. Plaintiff  in
the  DEZUBE action  additionally seeks an  accounting. The  complaints have been
answered
 
                                       45
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 12 -- LEGAL PROCEEDINGS (CONTINUED)
by all defendants,  who deny  the material  allegations of  the complaints.  The
third  action was  filed in  the Superior  Court of  California, Alameda County,
Northern Division, on December 1, 1994 (PERERA ET AL., V. CHIRON CORPORATION  ET
AL., C.A. No. 744522-2). Plaintiff sought injunctive and declaratory relief, and
an  accounting, costs and disbursements, including attorneys' and experts' fees,
and other relief.
 
    On October  17, 1995,  the PERERA  plaintiffs commenced  a new  action  (the
"Federal  Action") in the United States District Court for the Northern District
of California, against  the same defendants  and Ciba-Geigy, Ltd.,  Ciba-Geigy's
Chairman Alex Krauer, Ciba-Geigy Corporation, and Ciba Biotech Partnership, Inc.
(collectively, the "Ciba Defendants"). The Federal Action asserts both state and
federal  claims, including a claim under Sections  10(b), 14(d) and 14(e) of the
Securities Exchange Act  of 1934, and  seeks damages and  injunctive relief.  On
October  23, 1995,  in light  of the  filing of  the Federal  Action, the PERERA
action was dismissed by stipulation of the parties.
 
    Plaintiffs and all  of the defendants  other than the  Ciba Defendants  have
entered  into an agreement to  settle the Federal Action  on a class-wide basis,
subject to approval by the Court. Under the terms of that settlement  agreement,
Chiron  will  pay  plaintiffs' counsel  up  to  $300,000 in  attorneys  fees and
expenses, as  may be  awarded by  the Court,  and will  pay the  costs of  class
notice.   Chiron  has  no  other  financial  obligations  under  the  settlement
agreement, which also  contemplates that the  HANNA and DEZUBE  actions will  be
dismissed  as moot  following approval  of the  settlement and  dismissal of the
Federal Action. It is presently expected  that the settlement will be  presented
to  the District Court for preliminary approval  at a status conference in March
1996, and that  a final  approval hearing will  be scheduled  within two  months
thereafter, following notice to the plaintiff class.
 
NOTE 13 -- QUARTERLY FINANCIAL DATA (UNAUDITED)
<TABLE>
<CAPTION>
                                                                            1995
                                                    ----------------------------------------------------
                                                      DEC. 31      SEPT. 30      JUNE 30      MAR. 31
                                                    -----------  ------------  -----------  ------------
<S>                                                 <C>          <C>           <C>          <C>
                                                           (IN THOUSANDS, EXCEPT PER SHARE DATA)
Revenues..........................................  $   325,897  $    274,688  $   281,752  $    218,246
Gross margin......................................      145,846       127,798      139,786        93,627
Net income (loss).................................       17,592      (145,107)         830      (385,778)
Net income (loss) per share.......................         0.40         (3.59)        0.02         (9.64)
 
<CAPTION>
 
                                                                            1994
                                                    ----------------------------------------------------
                                                      DEC. 31      SEPT. 30      JUNE 30      MAR. 31
                                                    -----------  ------------  -----------  ------------
                                                           (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                                 <C>          <C>           <C>          <C>
Revenues..........................................  $   134,280  $    128,207  $   100,111  $     91,381
Gross margin......................................       46,918        45,476       31,603        23,760
Net income (loss).................................       (4,169)       12,567        5,110         4,817
Net income (loss) per share.......................        (0.13)         0.37         0.15          0.14
</TABLE>
 
    The  Company believes that quarterly  results are not necessarily indicative
of results for a full  year; therefore, the Company  should be evaluated on  the
basis of annual financial information.
 
    As  discussed in Notes 2 and 3, the  first quarter of 1995 included a $230.7
million write-off of purchased in-process technology related to the acquisitions
of CCD, Ciba's interest in Chiron Biocine Company and Biocine S.p.A., and IOLAB.
The   first   quarter   also   included    other   charges   related   to    the
 
                                       46
<PAGE>
                               CHIRON CORPORATION
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
                               DECEMBER 31, 1995
 
NOTE 13 -- QUARTERLY FINANCIAL DATA (UNAUDITED) (CONTINUED)
Ciba  transaction totaling  $49.5 million, and  restructuring-related charges of
$37.6 million. The third quarter of 1995 included a $130.3 million write-off  of
purchased in-process technology related to the Viagene acquisition.
 
    The fourth quarter of 1994 included a charge to earnings of $11.6 million to
write-down  the carrying value of investments in marketable equity securities of
Viagene and Cephalon.
 
NOTE 14 -- SUBSEQUENT EVENT
    On February 17, 1996,  Chiron and Behringwerke AG,  a subsidiary of  Hoechst
AG,  reached an agreement whereby Chiron will  purchase a 49 percent interest in
the human vaccine business of Behringwerke AG for Deutsche mark 171.5 million in
cash. Under the terms  of the agreement,  Chiron has an  option to purchase  the
remaining 51 percent interest in March 1998, 1999, 2000 or 2001 and Behringwerke
AG  has the option to  have Chiron acquire the  remaining 51 percent interest in
March 2001. During the  period of mutual ownership,  Chiron and Behringwerke  AG
will  operate the vaccine  business as a  joint venture. Chiron  will report its
share of the  joint venture's results  as equity in  earnings of  unconsolidated
joint  businesses.  Consummation  of  the  transaction  is  subject  to  certain
conditions, including  regulatory approvals  and customary  conditions prior  to
closing.
 
                                       47
<PAGE>
                         REPORT OF INDEPENDENT AUDITORS
 
The Board of Directors and Stockholders
Chiron Corporation:
 
    We  have  audited the  accompanying  consolidated balance  sheets  of Chiron
Corporation and subsidiaries as of December  31, 1995 and 1994, and the  related
consolidated  statements of operations, stockholders'  equity and cash flows for
the years then ended. These financial  statements are the responsibility of  the
Company's  management.  Our responsibility  is to  express  an opinion  on these
financial  statements  based  on  our  audits.  The  accompanying   consolidated
statements  of  operations,  stockholders'  equity  and  cash  flows  of  Chiron
Corporation and subsidiaries for the year ended December 31, 1993, were  audited
by  other auditors  whose report thereon  dated February 25,  1994, expressed an
unqualified opinion on those statements.
 
    We conducted  our  audits in  accordance  with generally  accepted  auditing
standards.  Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence  supporting
the  amounts and disclosures in the financial statements. An audit also includes
assessing the  accounting  principles used  and  significant estimates  made  by
management,  as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
    In our  opinion, the  consolidated financial  statements referred  to  above
present  fairly,  in all  material respects,  the  financial position  of Chiron
Corporation and subsidiaries as of December  31, 1995 and 1994, and the  results
of their operations and their cash flows for the years then ended, in conformity
with generally accepted accounting principles.
 
                                          KPMG Peat Marwick LLP
 
San Francisco, California
February 20, 1996
 
                                       48
<PAGE>
                               CHIRON CORPORATION
                          MARKET PRICE OF COMMON STOCK
 
    The  common stock  of Chiron  Corporation is  traded in  the NASDAQ National
Market System under the symbol CHIR. As  of December 31, 1995, there were  8,078
holders  of record of  Chiron common stock,  846 remaining holders  of record of
Cetus common stock and 45 remaining  holders of record of Viagene common  stock.
The  Company has  declared no  cash dividends since  its inception  and does not
expect to pay any  dividends in the foreseeable  future. The quarterly high  and
low  closing sales  price of  Chiron common  stock for  1995 and  1994 are shown
below.
 
<TABLE>
<CAPTION>
                                                                                   1995                     1994
                                                                           ---------------------    --------------------
                                                                             HIGH         LOW         HIGH        LOW
                                                                           ---------    --------    --------    --------
<S>                                                                        <C>          <C>         <C>         <C>
First Quarter...........................................................   $  81        $ 51 3/4    $ 96        $ 63 1/2
Second Quarter..........................................................      68 3/4      47 3/4      69 1/2      53 3/4
Third Quarter...........................................................     101 3/4      62 1/2      74 1/4      50 3/4
Fourth Quarter..........................................................     113 3/4      83          85          56 1/4
</TABLE>
 
                                       49

<PAGE>

                                   EXHIBIT 21

                   LIST OF SUBSIDIARIES OF CHIRON CORPORATION

                                                            JURISDICTION OF
                                                            INCORPORATION OR
SUBSIDIARY                                                    ORGANIZATION
- ----------------------------------------------------------------------------

Cetus Oncology Corporation (d/b/a Chiron Therapeutics)      Delaware, USA
    Cetus Generic Corporation                               Delaware, USA
    Chiron b.v.                                             Netherlands
        EuroCetus Nederland b.v.                            Netherlands
    Chiron GmbH                                             Germany
    Chiron France Sarl                                      France
    Chiron Italia Srl                                       Italy
    Chiron UK Ltd.                                          United Kingdom
    Chiron lberia SA                                        Spain
    Cetus Trading A.G.                                      Switzerland
Chiron Partners                                             California, USA
Chiron Alpha Corporation                                    California, USA
Chiron Properties, Inc.                                     California, USA
Chiron Biocine Acquisition Corporation                      Delaware, USA
Chiron Biocine Corporation                                  California, USA
    Chiron (Bermuda) Ltd.                                   Bermuda
Chiron Biocine b.v.                                         Netherlands
    Biocine, SpA                                            Italy
        Biocine Sarl                                        France
Chiron Mimotopes Pty., Ltd.                                 Australia
Chiron Mimotopes U.S.                                       California, USA
Chiron Beta Corporation                                     California, USA
Chiron Redevelopment Corporation                            Missouri, USA
Chiron Diagnostics S.A.                                     France
Chiron Foreign Sales Corporation                            U.S. Virgin Islands
Chiron Viagene, Inc.                                        Delaware, USA
Ciba Corning Diagnostics Corp.                              Delaware, USA
    Ciba Diagnostics Australia Pty. Ltd.                    Australia
        Ciba Corning Diagnostics Australia Pty. Limited     Australia
            Australian Diagnostics Corporation Pty. Ltd.    Australia
    Ciba Corning Diagnostics GmbH                           Austria
    Ciba Corning Diagnostics s.a./n.v.                      Belgium
    Ciba Corning Canada Inc.                                Canada
    Ciba Corning Diagnostics Limited                        England
        Ciba Corning Diagnostics Netherlands Ltd.           England
    Ciba Corning Diagnostics S.A.                           France
    Ciba Corning Diagnostics GmbH                           Germany
    Ciba Corning Diagnostics (H.K.) Ltd.                    Hong Kong
        Ciba Corning Marketing Services (H.K.) Ltd.         Hong Kong
    Ciba Corning Diagnostics SpA                            Italy
    Ciba Corning Diagnostics K.K.                           Japan

<PAGE>

                              EXHIBIT 21 CONTINUED

                   LIST OF SUBSIDIARIES OF CHIRON CORPORATION

                                                            JURISDICTION OF
                                                            INCORPORATION OR
SUBSIDIARY                                                    ORGANIZATION
- ----------------------------------------------------------------------------

    Ciba Corning Diagnostics de Mexico, S.A. de C.V.        Mexico
    Ciba Corning Korea, Ltd.                                Korea
    Ciba Corning Diagnostics Sp.z.o.o.                      Poland
    Ciba Corning Diagnostics S.A.                           Spain
    Ciba Corning Diagnostics A.G.                           Switzerland
    Ciba Corning Diagnostics Foreign Sales Corporation      U.S. Virgin Islands
    Ciba Corning Diagnostics Co., Ltd.                      Taiwan
    Ciba Corning Diagnostics, Lda.                          Portugal
Chiron Vision Corporation                                   Delaware, USA
    Adatomed GmbH                                           Germany
    IOL - GmbH                                              Germany
    Magnum Diamond                                          South Dakota, USA
    New Gluco, Inc.                                         Delaware, USA
    Chiron Vision Australia                                 Australia
    Chiron Vision UK, Ltd.                                  United Kingdom
    Chiron Vision Canada, Inc.                              Canada
    Chiron Vision France, SA                                France
    Domilens                                                France
        Chiron Vision Espana SA                             Spain
            Domilens S.A.                                   Sweden
            Domilens, Inc.                                  Delaware, USA
    Iolab Corporation                                       Delaware, USA
    Chiron Vision (Singapore) Pte, Ltd.                     Singapore
    Chiron Vision Italia S.r.l.                             Italy
    Hardlens Co., Inc.                                      California, USA
    Softlens Co., Inc.                                      California, USA
    Chiron Technolas Opthalmologische Systeme GmbH          Germany

<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CHIRON
CORPORATION'S CONSOLIDATED BALANCE SHEET DATED DECEMBER 31, 1995, AND
CONSOLIDATED STATEMENT OF OPERATIONS FOR THE YEAR ENDED DECEMBER 31, 1995, AND
NOTES THERETO AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1995
<PERIOD-START>                             JAN-01-1995
<PERIOD-END>                               DEC-31-1995
<CASH>                                          74,318
<SECURITIES>                                   149,899<F1>
<RECEIVABLES>                                  285,779
<ALLOWANCES>                                    18,524
<INVENTORY>                                    165,941
<CURRENT-ASSETS>                               637,003
<PP&E>                                         658,579
<DEPRECIATION>                                 140,761
<TOTAL-ASSETS>                               1,490,198
<CURRENT-LIABILITIES>                          368,595
<BONDS>                                        420,188<F2>
                                0
                                          0
<COMMON>                                           417
<OTHER-SE>                                     671,995<F3>
<TOTAL-LIABILITY-AND-EQUITY>                 1,490,198
<SALES>                                        922,853
<TOTAL-REVENUES>                             1,100,582
<CGS>                                          415,798
<TOTAL-COSTS>                                  415,798
<OTHER-EXPENSES>                             1,167,212<F4>
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                              30,362<F5>
<INCOME-PRETAX>                              (490,774)
<INCOME-TAX>                                    21,689
<INCOME-CONTINUING>                          (512,463)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                 (512,463)
<EPS-PRIMARY>                                  (12.62)
<EPS-DILUTED>                                  (12.62)
<FN>
<F1>CONSISTS OF BOTH SHORT-TERM AND NONCURRENT INVESTMENTS IN MARKETABLE DEBT
SECURITIES.
<F2>CONSISTS OF CONVERTIBLE SUBORDINATED DEBENTURES, CAPITAL LEASE OBLIGATIONS AND
NOTES PAYABLE.
<F3>CONSISTS OF ADDITIONAL PAID-IN CAPITAL, ACCUMULATED DEFICIT, CUMULATIVE FOREIGN
CURRENCY TRANSLATION ADJUSTMENT AND UNREALIZED GAIN FROM INVESTMENTS.
<F4>CONSISTS OF RESEARCH AND DEVELOPMENT; SELLING, GENERAL AND ADMINISTRATIVE;
WRITE-OFF OF IN-PROCESS TECHNOLOGIES; COSTS RELATED TO CIBA TRANSACTION;
RESTRUCTURING AND REORGANIZATION CHARGES AND OTHER OPERATING EXPENSES.
<F5>CONSISTS OF INTEREST EXPENSE AND RELATED COSTS ON CONVERTIBLE DEBENTURES AND
OTHER INTEREST EXPENSE.
</FN>
        

</TABLE>


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