AVIRON
DEF 14A, 1999-04-26
BIOLOGICAL PRODUCTS, (NO DIAGNOSTIC SUBSTANCES)
Previous: EUPHONIX INC \CA\, 10-K, 1999-04-26
Next: SENSUS DRUG DEVELOPMENT CORP, RW, 1999-04-26





                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 14A
                                 (Rule 14a-101)

                     INFORMATION REQUIRED IN PROXY STATEMENT

                            SCHEDULE 14A INFORMATION
                Proxy Statement Pursuant to Section 14(a) of the
                         Securities Exchange Act of 1934

Filed by the Registrant [X]
Filed by a Party other than the Registrant [_]

Check the appropriate box:

[_]  Preliminary Proxy Statement             [_]  Confidential, For Use of the
[X]  Definitive Proxy Statement                   Commission Only (as permitted
[_]  Definitive Additional Materials              by Rule 14a-6(e)(2))
[_]  Soliciting Material Pursuant to
     Rule 14a-11(c) or Rule 14a-12

                                     Aviron
- --------------------------------------------------------------------------------
                (Name of Registrant as Specified In Its Charter)


- --------------------------------------------------------------------------------
    (Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)


Payment of Filing Fee (Check the appropriate box):

[X]  No fee required.
[_]  Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11.


________________________________________________________________________________
1)   Title of each class of securities to which transaction applies:


________________________________________________________________________________
2)   Aggregate number of securities to which transaction applies:


________________________________________________________________________________
3)   Per unit price or other underlying value of transaction  computed  pursuant
     to Exchange  Act Rule 0-11 (set forth the amount on which the filing fee is
     calculated and state how it was determined):


________________________________________________________________________________
4)   Proposed maximum aggregate value of transaction:


________________________________________________________________________________
5)   Total fee paid:

     [_]  Fee paid previously with preliminary materials:


________________________________________________________________________________

     [_]  Check box if any part of the fee is offset as provided by Exchange Act
          Rule  0-11(a)(2)  and identify the filing for which the offsetting fee
          was paid  previously.  Identify  the previous  filing by  registration
          statement number, or the form or schedule and the date of its filing.

          1)   Amount previously paid:

          2)   Form, Schedule or Registration Statement No.:

          3)   Filing Party:

          4)   Date Filed:


<PAGE>


                                     AVIRON
                            297 North Bernardo Avenue
                             Mountain View, CA 94043

                                   ----------

                    NOTICE OF ANNUAL MEETING OF STOCKHOLDERS
                           TO BE HELD ON JUNE 3, 1999

                                   ----------


TO THE STOCKHOLDERS OF AVIRON:

     NOTICE IS HEREBY GIVEN that the Annual Meeting of Stockholders of AVIRON, a
Delaware corporation (the "Company"),  will be held on Thursday, June 3, 1999 at
8:00 a.m. local time at the Company's  principal  executive offices at 297 North
Bernardo Avenue, Mountain View, CA 94043 for the following purposes:

     1.   To elect two directors to hold office until the 2002 Annual Meeting of
          Stockholders and until their successors are elected.

     2.   To approve an amendment to the Company's 1996 Equity Incentive Plan to
          increase the aggregate number of shares of Common Stock authorized for
          issuance under such plan by 780,000 shares, to 4,030,000 shares.

     3.   To ratify the selection of Ernst & Young LLP as  independent  auditors
          of the Company for its fiscal year ending December 31, 1999.

     4.   To  transact  such other  business  as may  properly  come  before the
          meeting or any adjournment or postponement thereof.

     The  foregoing  items of  business  are more fully  described  in the Proxy
Statement accompanying this Notice.

     The Board of Directors has fixed the close of business on April 15, 1999 as
the record date for the determination of stockholders  entitled to notice of and
to vote at this Annual Meeting and at any adjournment or postponement thereof.


                                        By Order of the Board of Directors

                                        /s/ Alan C. Mendelson

                                        Alan C. Mendelson
                                        Secretary

Mountain View, California
April 26, 1999


- --------------------------------------------------------------------------------
     All  Stockholders  are  cordially  invited to attend the meeting in person.
Whether or not you expect to attend the meeting, please complete, date, sign and
return the  enclosed  proxy as  promptly  as  possible  in order to ensure  your
representation  at the meeting.  A return  envelope (which is postage prepaid if
mailed in the United  States) is  enclosed  for that  purpose.  Even if you have
given your proxy, you may still vote in person if you attend the meeting. Please
note, however, that if your shares are held of record by a broker, bank or other
nominee  and you wish to vote at the  meeting,  you must  obtain from the record
holder a proxy issued in your name.
- --------------------------------------------------------------------------------
<PAGE>

                                     AVIRON
                            297 North Bernardo Avenue
                             Mountain View, CA 94043


                                 PROXY STATEMENT
                       FOR ANNUAL MEETING OF STOCKHOLDERS


                                 April 26, 1999


                 INFORMATION CONCERNING SOLICITATION AND VOTING


GENERAL

     The  enclosed  proxy is  solicited  on behalf of the Board of  Directors of
Aviron, a Delaware corporation (the "Company"), for use at the Annual Meeting of
Stockholders to be held on Thursday,  June 3, 1999 at 8:00 a.m., local time (the
"Annual  Meeting"),  or at any  adjournment  or  postponement  thereof,  for the
purposes set forth herein and in the accompanying Notice of Annual Meeting.  The
Annual Meeting will be held at the Company's  principal executive offices at 297
North Bernardo Avenue, Mountain View, CA 94043. The Company intends to mail this
proxy statement and  accompanying  proxy card on or about April 26, 1999, to all
stockholders entitled to vote at the Annual Meeting.

SOLICITATION

     The Company will bear the entire cost of solicitation of proxies, including
preparation,  assembly,  printing and mailing of this proxy statement, the proxy
and any additional information furnished to stockholders. Copies of solicitation
materials  will  be  furnished  to  banks,  brokerage  houses,  fiduciaries  and
custodians  holding in their names shares of Common Stock  beneficially owned by
others to forward to such beneficial  owners.  The Company may reimburse persons
representing  beneficial  owners of Common  Stock for their costs of  forwarding
solicitation  materials to such  beneficial  owners.  Original  solicitation  of
proxies  by  mail  may  be  supplemented  by  telephone,  telegram  or  personal
solicitation by directors, officers or other regular employees of the Company or
at  the  Company's  request,  by  Corporate  Investor  Communications,  Inc.  No
additional  compensation  will be paid to  directors,  officers or other regular
employees for such services, but Corporate Investor Communications, Inc. will be
paid its customary fee, estimated to be about $5,000, if it renders solicitation
services.

VOTING RIGHTS AND OUTSTANDING SHARES

     Only  holders of record of Common  Stock at the close of  business on April
15, 1999,  will be entitled to notice of and to vote at the Annual  Meeting.  At
the close of  business  on April 15,  1999,  the  Company  had  outstanding  and
entitled to vote 15,768,680 shares of Common Stock.

     Each holder of record of Common  Stock on such date will be entitled to one
vote for each share held on all matters to be voted upon at the Annual Meeting.

     All votes will be tabulated by the inspector of election  appointed for the
meeting,   who  will  separately   tabulate   affirmative  and  negative  votes,
abstentions  and  broker  non-votes.  Abstentions  will be counted  towards  the
tabulation  of votes cast on proposals  presented to the  stockholders  and will
have the same effect as negative votes.  Broker  non-votes are counted towards a
quorum, but are not counted for any purpose in determining  whether a matter has
been approved.

REVOCABILITY OF PROXIES

     Any person giving a proxy  pursuant to this  solicitation  has the power to
revoke it at any time  before it is voted.  It may be revoked by filing with the
Secretary of the Company at the  Company's  principal  executive  offices at 297
North Bernardo Avenue, Mountain View, CA 94043 a written notice of revocation or
a duly  executed  proxy  bearing a later date, or it may be revoked by attending
the meeting and voting in person. Attendance at the meeting will not, by itself,
revoke a proxy.


                                       1
<PAGE>



STOCKHOLDER PROPOSALS

     Pursuant  to Rule 14a-8 of the  Securities  and  Exchange  Commission,  the
deadline for  submitting a  stockholder  proposal for inclusion in the Company's
proxy  statement  and form of proxy for the  Company's  2000  Annual  Meeting of
Stockholders  is  December  24,  1999.   Pursuant  to  the  Company's   By-laws,
stockholders  who wish to bring matters or propose  nominees for director at the
Company's 2000 Annual Meeting of Stockholders must provide specified information
to the Company  between March 5, 2000 and April 4, 2000.  Stockholders  are also
advised to review the Company's By-laws,  which contain additional  requirements
with  respect  to  advance   notice  of   stockholder   proposals  and  director
nominations.

                                   PROPOSAL 1
                              ELECTION OF DIRECTORS

     The Company's  Restated  Certificate of  Incorporation  and By-laws provide
that the Board of  Directors  shall be divided  into three  classes,  each class
consisting,  as  nearly  as  possible,  of  one-third  of the  total  number  of
directors,  with each class having a three-year term. Vacancies on the Board may
be filled only by persons  elected by a majority of the remaining  directors.  A
director elected by the Board to fill a vacancy  (including a vacancy created by
an increase in the Board of Directors) shall serve for the remainder of the full
term of the class of  directors  in which the  vacancy  occurred  and until such
director's successor is elected and qualified.

     The Board of Directors is presently composed of five members. There are two
directors in the class whose term of office  expires in 1999,  of which both are
standing for re-election. The nominees for election to this class, Jane E. Shaw,
Ph.D. and Paul H.  Klingenstein  are currently  directors of the Company both of
whom were  previously  elected  by the  stockholders.  If  elected at the Annual
Meeting, Dr. Shaw and Mr. Klingenstein would serve until the 2002 Annual Meeting
and until their  successors  are elected and  qualified,  or until their earlier
death, resignation or removal.

     Directors  are  elected by a  plurality  of the votes  present in person or
represented by proxy and entitled to vote at the meeting.  Shares represented by
executed  proxies will be voted, if authority to do so is not withheld,  for the
election of the nominee  named  below.  In the event that the nominee  should be
unavailable  for election as a result of an unexpected  occurrence,  such shares
will be voted for the  election of such  substitute  nominee as  management  may
propose.  Dr. Shaw and Mr.  Klingenstein  have  agreed to serve if elected,  and
management has no reason to believe that they will be unable to serve.

     Set forth  below is  biographical  information  for the  nominees  and each
person  whose  term of office  as a  director  will  continue  after the  Annual
Meeting.

NOMINEES FOR ELECTION FOR A THREE-YEAR TERM EXPIRING AT THE 2002 ANNUAL MEETING

     Paul H.  Klingenstein,  age 43, has been a director  of the  Company  since
1993. Mr. Klingenstein has been the Managing Director of Aberdare Ventures since
1999. From 1986 until 1997, Mr. Klingenstein was associated with Accel Partners,
a venture  capital  firm,  where he was a General  Partner  since 1988.  He is a
director of several  private  healthcare and  biopharmaceutical  companies.  Mr.
Klingenstein  holds an A.B. from Harvard  University and an M.B.A. from Stanford
University.

     Jane E. Shaw, Ph.D., age 60, has been a director of the Company since 1996.
Dr. Shaw is currently the Chairman and Chief Executive Officer of AeroGen, Inc.,
a biopharmaceutical company. She founded The Stable Network, a biopharmaceutical
consulting company, in 1995. From 1987 to 1994, Dr. Shaw was President and Chief
Operating Officer of ALZA Corporation, a pharmaceutical company. Dr. Shaw joined
ALZA Corporation in 1970 where she held several  positions  including  Principal
Scientist and Director of ALZA Corporation.  Dr.Shaw is also a director of Intel
Corporation,  McKesson Corporation and Boise Cascade Corporation. Dr. Shaw holds
a B.Sc. and a Ph.D. in physiology from Birmingham  University,  England,  and an
honorary Sc.D. from the Worcester Polytechnic Institute.


                        THE BOARD OF DIRECTORS RECOMMENDS
                     A VOTE IN FAVOR OF THE NAMED NOMINEES.


                                       2
<PAGE>


DIRECTORS CONTINUING IN OFFICE UNTIL THE 2000 ANNUAL MEETING

     J. Leighton Read, M.D., age 48, a founder of the Company, has been Chairman
and Chief  Executive  Officer of the Company since 1992 and was Chief  Financial
Officer of the Company from 1992 until 1996. In 1989, he co-founded Affymax N.V.
with Dr. Alejandro Zaffaroni,  serving initially as its Executive Vice President
and Chief  Operating  Officer and later,  from 1990 to 1991, as President of the
Pharma Division and as a Managing  Director of the parent company.  From 1991 to
1993,  Dr.  Read  was  a  principal  with  Interhealth  Limited,  an  investment
partnership.  He has served on the  boards of a number of private  biotechnology
companies  and is  currently  on the board of CV  Therapeutics,  Inc.,  and AxyS
Pharmaceuticals,  Inc.,  both of which  are  biotechnology  companies,  and is a
member of the Biotechnology  Industry  Organization (BIO) Board of Directors and
Emerging  Companies Section Governing Body. Dr. Read holds a B.S. in Biology and
Psychology  from Rice University and an M.D. from the University of Texas Health
Science Center at San Antonio.

     Reid W. Dennis,  age 72, has been a director of the Company since 1992. Mr.
Dennis has been active in venture  capital  investments  since 1952.  He founded
Institutional Venture Partners ("IVP"), a venture capital firm, in 1980, and has
acted as a General Partner of IVP since that time. He is currently a director of
Cohesion  Technologies,  Inc., as well as several private companies.  Mr. Dennis
holds a B.S. in Electrical Engineering and an M.B.A. from Stanford University.

DIRECTOR CONTINUING IN OFFICE UNTIL THE 2001 ANNUAL MEETING

     Bernard  Roizman,  Sc.D.,  age 70, has been a director of the Company since
1992. Dr. Roizman has been the Joseph Regenstein Distinguished Service Professor
of Virology at the  University  of Chicago  since 1984.  He holds B.A.  and M.S.
degrees from Temple  University and an Sc.D. from The Johns Hopkins  University.
Dr. Roizman is also a member of the Company's Scientific Advisory Board.

BOARD COMMITTEES AND MEETINGS

     During the year ended December 31, 1998, the Board of Directors held seven
meetings. The Board has an Audit Committee and a Compensation Committee.

     The Audit Committee meets with the Company's  independent auditors at least
annually  to review the results of the annual  audit and  discuss the  financial
statements; recommends to the Board the independent auditors to be retained; and
receives and considers  the  accountants'  comments as to controls,  adequacy of
staff and management  performance  and  procedures in connection  with audit and
financial  controls.  The Audit  Committee  is  composed  of three  non-employee
directors: Mr. Dennis, Mr. Klingenstein and Dr. Roizman. The Audit Committee met
twice during 1998. In addition,  Audit  Committee  business was performed at two
regular meetings of the Board.

     The Compensation  Committee makes  recommendations  concerning salaries and
incentive compensation,  awards stock options to employees and consultants under
the Company's stock option plans and otherwise  determines  compensation  levels
and  performs  such  other  functions  regarding  compensation  as the Board may
delegate. The Compensation Committee is composed of two non-employee  directors:
Dr. Shaw and Mr.Klingenstein.  The Compensation  Committee met four times during
1998.

     During the year ended December 31, 1998, all directors attended 75% or more
of the  aggregate  of the meetings of the Board held during the period for which
he or she was a  director.  All  committee  members  except  Mr.  Dennis and Dr.
Roizman  attended 75% or more of the aggregate of the meetings of the committees
on which he or she  served,  held  during  the  period for which he or she was a
committee member.


                                       3
<PAGE>



                                   PROPOSAL 2
               APPROVAL OF 1996 EQUITY INCENTIVE PLAN, AS AMENDED

     In  March  1996,  the  Board of  Directors  adopted,  and the  stockholders
subsequently  approved, the Company's 1996 Equity Incentive Plan (the "Incentive
Plan") as an amendment  and  restatement  of its 1992 Stock  Option  Plan.  As a
result of a series of  amendments,  as of April 1, 1999,  there  were  3,250,000
shares reserved for issuance under the Incentive Plan. The Board has amended the
Incentive  Plan,  subject to  stockholder  approval,  to increase the  aggregate
number of shares of Common Stock  authorized  for issuance  under the  Incentive
Plan by 780,000 shares to 4,030,000 shares.  This increase  represents less than
five percent of the outstanding Common Stock of the Company as of April 1, 1999.

     As of April 1, 1999,  options (net of canceled or expired options) covering
an aggregate of 2,230,232  shares of the Company's Common Stock had been granted
under the Incentive  Plan,  and 1,019,768  shares (plus any shares that might in
the future be returned to the  Incentive  Plan as a result of  cancellations  or
expiration of options)  remained  available for future grant under the Incentive
Plan.

     The Company  faces  competition  for  qualified  individuals  from numerous
pharmaceutical,  biopharmaceutical and biotechnology companies, universities and
other research institutions.  In amending the Incentive Plan, the Board reviewed
the  number of shares  set aside by  competing  Companies  for  employee  equity
incentive  plans and believes  that the  Company's  increased  share  reserve is
consistent with competitive practices.  Since the Company is highly dependent on
the principal  members of its scientific and  management  staff,  attracting and
retaining such personnel  will be critical to the Company's  success.  To pursue
its product  development  and marketing  plans,  the Company will be required to
hire  additional   qualified   scientific  personnel  to  perform  research  and
development,  as well as personnel with expertise in conducting clinical trials,
government regulation, manufacturing,  marketing and sales. The Company believes
that equity  incentives will be an important  factor in attracting and retaining
such employees.  In addition,  the Company's  current  scientific and management
staff will require additional equity incentives to ensure long-term  motivation.
The Board  believes  that the  increase  in the share  reserve  will  enable the
Company to meet these needs.

     Stockholders  are  requested in this Proposal 2 to approve the amendment of
the Incentive Plan. If the stockholders fail to approve this Proposal 2, options
granted  under the  Incentive  Plan  after the  Annual  Meeting in excess of the
existing share reserve may not qualify as performance-based compensation and, in
some  circumstances,  the Company may be denied a business expense deduction for
compensation  recognized in connection with the exercise of these stock options.
The  affirmative  vote of the  holders  of a majority  of the shares  present in
person or  represented  by proxy and  entitled  to vote at the  meeting  will be
required to approve the amendment to the  Incentive  Plan.  Abstentions  will be
counted  toward the  tabulation  of votes  cast on  proposals  presented  to the
stockholders  and will have the same effect as negative votes.  Broker non-votes
are counted towards a quorum, but are not counted for any purpose in determining
whether this matter has been approved.

                        THE BOARD OF DIRECTORS RECOMMENDS
                         A VOTE IN FAVOR OF PROPOSAL 2.

     The essential features of the Incentive Plan are outlined below:

GENERAL

     The Incentive  Plan  provides for the grant or issuance of incentive  stock
options to employees and nonstatutory  stock options,  restricted stock purchase
awards, stock bonuses,  and stock appreciation rights to consultants,  employees
and  directors  (collectively  "Stock  Awards").  To date only  incentive  stock
options and  nonstatutory  stock  options have been awarded  under the Incentive
Plan.  Incentive  stock options granted under the Incentive Plan are intended to
qualify as "incentive  stock  options"  within the meaning of Section 422 of the
Internal  Revenue Code of 1986,  as amended  (the  "Code").  Nonstatutory  stock
options  granted  under  the  Incentive  Plan are  intended  not to  qualify  as
incentive stock options under the Code. See "Federal Income Tax Information" for
a  discussion  of the  tax  treatment  of the  various  awards  included  in the
Incentive Plan.

PURPOSE

     The Incentive Plan provides a means by which selected employees  (including
officers) and directors of, and consultants to, the Company, and its affiliates,
may be given an  opportunity  to  purchase  Common  Stock  of the


                                       4
<PAGE>


Company.  The  Company,  by means of the  Incentive  Plan,  seeks to retain  the
services of persons who are now employees or directors of or  consultants to the
Company or its  affiliates,  to secure and retain the services of new employees,
directors and consultants,  and to provide  incentives for such persons to exert
maximum efforts for the success of the Company and its affiliates.

ADMINISTRATION

     The Incentive Plan is  administered by the Board unless and until the Board
delegates  administration  to a  committee  composed of not fewer than two Board
members,  all of the members of which committee must be  non-employee  directors
(unless the Board expressly  declares that such requirement shall not apply) and
may  also  be,  in  the  discretion  of  the  Board,   outside   directors.   If
administration  has been  delegated to a committee,  the committee will have, in
connection with the  administration  of the Incentive Plan, the powers possessed
by the Board, subject,  however, to such resolutions,  not inconsistent with the
provisions  of the  Incentive  Plan,  as may be adopted from time to time by the
Board. The Board or committee may delegate to a committee of one or more members
of the Board the authority to grant Stock Awards to eligible persons who are not
then subject to Section 16 of the  Securities  Exchange Act of 1934,  as amended
(the  "Exchange  Act") and/or who are either (i) not then  employees  covered by
Section  162(m) of the Code and are not expected to be covered by Section 162(m)
of the Code at the time of  recognition  of income  resulting  from  such  Stock
Award,  or (ii) not persons with respect to whom the Company wishes to avoid the
application  of Section 162(m) of the Code. The Board may abolish such committee
at any time and revest in the Board the  administration  of the Incentive  Plan.
The  Board  has  delegated  the  administration  of the  Incentive  Plan  to the
Compensation  Committee  of the  Board.  As  used  herein  with  respect  to the
Incentive Plan, the "Board" refers to the  Compensation  Committee as well as to
the Board of Directors itself.

     The Board has the power to determine from time to time which of the persons
eligible  under the Incentive  Plan shall be granted  Stock Awards,  the type of
Stock Awards to be granted,  when and how each Stock Award shall be granted,  to
construe and interpret the Incentive Plan and Stock Awards granted under it, and
to establish, amend and revoke rules and regulations for its administration. The
Board may  correct  any  defect  in the  Incentive  Plan or in any  Stock  Award
agreement to make the Incentive Plan fully effective.  Any interpretation of the
Incentive  Plan by the Board and any  decision by the Board under the  Incentive
Plan shall be final and binding on all persons.

STOCK SUBJECT TO THE INCENTIVE PLAN

     Subject  to  stockholder  approval  of this  Proposal  2, an  aggregate  of
4,030,000  shares of Common Stock is reserved for issuance  under the  Incentive
Plan.  If any Stock Award  (other than a stock  appreciation  right)  expires or
terminates,  in whole or in part,  without  having been  exercised in full,  the
stock not  purchased  under such Stock  Award  will  revert to and again  become
available for issuance under the Incentive Plan. The Common Stock subject to the
Incentive Plan may be unissued shares or reacquired shares, bought on the market
or otherwise.

ELIGIBILITY

     Incentive  stock  options may be granted  only to  employees.  Nonstatutory
stock options,  restricted  stock  purchase  awards,  stock  bonuses,  and stock
appreciation rights may be granted only to employees, directors or consultants.

     No person is eligible for the grant of an incentive stock option if, at the
time of grant,  such person owns stock possessing more than ten percent (10%) of
the total  combined  voting power of all classes of stock of the Company  unless
the exercise  price of such option is at least one hundred ten percent (110%) of
the fair market value of such Common Stock  subject to the option at the date of
grant and the option is not  exercisable  after the expiration of five (5) years
from the date of grant, or in the case of a restricted stock purchase award, the
purchase  price is at least one hundred  percent (100%) of the fair market value
of Common Stock subject to the restricted stock purchase award at date of grant.
For incentive  stock options granted under the Incentive Plan the aggregate fair
market  value,  determined  at the time of grant,  of the shares of Common Stock
with  respect to which such  options  are  exercisable  for the first time by an
optionee  during any calendar  year (under all such plans of the Company and its
affiliates) may not exceed $100,000.


                                       5
<PAGE>


TERMS OF OPTIONS

     The following is a description  of the  permissible  terms of options under
the Incentive Plan.  Individual  option grants may be more restrictive as to any
or all of the permissible terms described below.

     Exercise  Price;  Payment.  The exercise  price of incentive  stock options
under  the  Incentive  Plan may not be less  than the fair  market  value of the
Common Stock subject to the option on the date of the option grant,  and in some
cases (see  "Eligibility"  above), may not be less than 110% of such fair market
value.  The exercise price of nonstatutory  options under the Incentive Plan may
not be less than 85% of the fair market value of the Common Stock subject to the
option on the date of the option grant.  As of April 1, 1999,  the closing price
of the Common  Stock as reported on the Nasdaq  Stock  Market was  $19.0625  per
share.

     In the event of a decline in the value of the Company's  Common Stock,  the
Board  has  the  authority  to  offer   employees  the  opportunity  to  replace
outstanding higher priced options,  whether incentive or nonstatutory,  with new
lower priced options.  The Board also has the authority to include as part of an
option  agreement a provision  entitling the optionee to a further option in the
event that the optionee exercises his or her option by surrendering other shares
of Common Stock as payment of the exercise price.

     The exercise price of options granted under the Incentive Plan must be paid
either:  (a)  in  cash  at the  time  the  option  is  exercised;  or (b) at the
discretion  of the Board,  (i) by delivery of other Common Stock of the Company,
(ii)  pursuant to a deferred  payment  arrangement;  or (c) in any other form of
legal consideration acceptable to the Board.

     Option  Exercise.  Options  granted  under the  Incentive  Plan may  become
exercisable in cumulative increments ("vest") as determined by the Board. Shares
covered by currently outstanding options under the Incentive Plan typically vest
in 50 installments during the optionee's employment or services as a consultant.
Shares covered by options  granted in the future under the Incentive Plan may be
subject to different  vesting  terms.  The Board has the power to accelerate the
time during which an option may be exercised. In addition, options granted under
the Incentive Plan may permit  exercise prior to vesting,  but in such event the
optionee  may be  required  to  enter  into an  early  exercise  stock  purchase
agreement  that allows the Company to repurchase  shares not yet vested at their
exercise  price should the optionee leave the employ of the Company or terminate
his or her  relationship  as a consultant  or director  before  vesting.  To the
extent provided by the terms of an option,  an optionee may satisfy any federal,
state or local tax  withholding  obligation  relating  to the  exercise  of such
option by a cash payment upon exercise, by authorizing the Company to withhold a
portion  of  the  stock  otherwise  issuable  to  the  optionee,  by  delivering
already-owned stock of the Company or by a combination of these means.

     Term.  The maximum term of options under the  Incentive  Plan is ten years,
except that in certain cases (see "Eligibility") the maximum term is five years.

TERMS OF STOCK BONUSES AND PURCHASES OF RESTRICTED STOCK

     Purchase Price;  Payment. The Board will determine the purchase price under
each restricted stock purchase agreement. The purchase price of stock subject to
a restricted  stock purchase  agreement must be paid either:  (i) in cash at the
time of purchase;  (ii) at the discretion of the Board,  according to a deferred
payment or other  arrangement  with the person to whom the Common Stock is sold;
or (iii) in any other form of legal  consideration that may be acceptable to the
Board in its discretion.  Eligible participants may be awarded stock pursuant to
a stock bonus agreement in consideration of past services  actually  rendered to
the Company or for its benefit.

     Repurchase. Shares of Common Stock sold or awarded under the Incentive Plan
may, but need not, be subject to a repurchase  option in favor of the Company in
accordance  with a vesting  schedule  determined  by the  Board.  In the event a
person  ceases  to be an  employee  of or ceases  to serve as a  director  of or
consultant  to the  Company or an  affiliate  of the  Company,  the  Company may
repurchase  or otherwise  reacquire any or all of the shares of the Common Stock
held by that person that have not vested as of the date of termination under the
terms of the stock bonus or  restricted  stock  purchase  agreement  between the
Company and such person.

STOCK APPRECIATION RIGHTS

     The Board may grant stock appreciation rights to employees or directors of,
or consultants to, the Company or its affiliates.  The Incentive Plan authorizes
three types of stock appreciation rights.


                                       6
<PAGE>


     Tandem Stock Appreciation Rights. Tandem stock appreciation rights are tied
to an underlying  option and require the holder to elect whether to exercise the
underlying  option or to surrender the option for an  appreciation  distribution
equal to the market price of the vested shares purchasable under the surrendered
option less the aggregate  exercise price payable for such shares.  Appreciation
distributions  payable upon exercise of tandem stock appreciation rights must be
made in cash.

     Concurrent Stock Appreciation Rights.  Concurrent stock appreciation rights
are tied to an  underlying  option and are exercised  automatically  at the same
time the underlying  option is exercised.  The holder  receives an  appreciation
distribution  equal to the market price of the vested shares purchased under the
option less the aggregate  exercise price payable for such shares.  Appreciation
distributions payable upon exercise of concurrent stock appreciation rights must
be made in cash.

     Independent  Stock  Appreciation  Rights.  Independent  stock  appreciation
rights are granted independently of any option and entitle the holder to receive
upon exercise an appreciation distribution equal to the market price of a number
of shares equal to the number of share equivalents to which the holder is vested
under the independent  stock  appreciation  right less than fair market value of
such  number of shares  of stock on the date of grant of the  independent  stock
appreciation  rights.   Appreciation  distributions  payable  upon  exercise  of
independent stock appreciation rights may, at the Board's discretion, be made in
cash, in shares of the Common Stock or a combination thereof.

ADJUSTMENT PROVISIONS

     If there is any  change  in the  stock  subject  to the  Incentive  Plan or
subject to any Stock Award  granted under the  Incentive  Plan (through  merger,
consolidation,  reorganization,  recapitalization,  stock dividend,  dividend in
property  other than cash,  stock split,  liquidating  dividend,  combination of
shares,  exchange of shares,  change in corporate structure or other transaction
not involving the receipt of consideration  by the Company),  the Incentive Plan
and Stock Awards outstanding thereunder will be appropriately adjusted as to the
class and the maximum  number of shares subject to such plan, the maximum number
of shares  which may be granted to an  employee  during a calendar  year and the
class, number of shares and price per share of stock subject to such outstanding
Stock Awards.

EFFECT OF CERTAIN CORPORATE EVENTS

     The  Incentive  Plan  provides  that,  in the  event  of a  dissolution  or
liquidation of the Company,  sale of all or  substantially  all of the Company's
assets, specified type of merger or other corporate reorganization (a "Change of
Control"),  to the extent  permitted by law,  any  surviving  corporation  shall
assume any Stock Awards outstanding under the Incentive Plan, substitute similar
Stock Awards for those  outstanding under the Incentive Plan or such outstanding
Stock  Awards  will  continue  in  full  force  and  effect.  If  any  surviving
corporation declines to assume Stock Awards outstanding under the Incentive Plan
or to substitute similar Stock Awards,  then for Stock Awards held by any person
then performing services as an employee, director or consultant, the time during
which such Stock  Awards may be  exercised  will be  accelerated  and such Stock
Awards  terminated if not exercised prior to such event.  The  acceleration of a
Stock Award in the event of an  acquisition  or similar  corporate  event may be
viewed as an anti-takeover provision,  which may have the effect of discouraging
a proposal to acquire or otherwise obtain control of the Company.

DURATION, AMENDMENT AND TERMINATION

     The Board may suspend or terminate the Incentive  Plan without  stockholder
approval  or  ratification  at any  time or from  time to  time.  Unless  sooner
terminated, the Incentive Plan will terminate in March 2006.

     The Board may also  amend  the  Incentive  Plan at any time or from time to
time.   However,   no  amendment  will  be  effective  unless  approved  by  the
stockholders of the Company within twelve months before or after its adoption by
the Board if the amendment  would: (a) modify the requirements as to eligibility
for participation (to the extent such modification requires stockholder approval
in order  for the  Incentive  Plan to  satisfy  Section  422 of the  Code);  (b)
increase the number of shares reserved for issuance upon exercise of options; or
(c) change any other  provision of the  Incentive  Plan in any other way if such
modification requires stockholder approval in order to comply with Rule 16b-3 of
the Exchange Act, or satisfy the  requirements  of Section 422 of the Code.  The
Board may submit  any other  amendment  to the  Incentive  Plan for  stockholder
approval, including, but not limited to, amendments


                                       7
<PAGE>


intended to satisfy the requirements of Section 162(m) of the Code regarding the
exclusion  of   performance-based   compensation  from  the  limitation  on  the
deductibility of compensation paid to certain employees.

RESTRICTIONS ON TRANSFER

     Under the Incentive  Plan, an incentive stock option can not be transferred
by  the  optionee  otherwise  than  by  will  or by  the  laws  of  descent  and
distribution  and,  during the  lifetime of an  optionee,  such an option may be
exercised only by the optionee.  A  nonstatutory  stock option or an independent
stock  appreciation  right may not be transferred except by will, by the laws of
descent and  distribution  or pursuant to a domestic  relations  order or as may
otherwise be provided in the Stock Award agreement. In any case, an optionee may
designate  in writing a third party who may  exercise the option in the event of
the optionee's  death.  Rights under a stock bonus or restricted  stock purchase
agreement are transferable only by will, by the laws of descent and distribution
or pursuant to a domestic relations order or to the extent transfer is expressly
authorized  by the  terms of the  applicable  stock  bonus or  restricted  stock
purchase  agreement.  A tandem  stock  appreciation  right or  concurrent  stock
appreciation  right may be transferred  only by the method(s)  applicable to the
underlying option. In addition,  any shares subject to repurchase by the Company
under an early exercise stock purchase  agreement may be subject to restrictions
on transfer which the Board deems appropriate.

FEDERAL INCOME TAX INFORMATION

     Long-term  capital gains currently are generally subject to lower tax rates
than ordinary income or short-term  capital gains. The maximum long-term capital
gains rate for federal  income tax purposes is  currently  20% while the maximum
ordinary  income rate and short-term  capital gains rate is  effectively  39.6%.
Slightly  different rules may apply to participants who acquire stock subject to
certain  repurchase  options or who are subject to Section 16(b) of the Exchange
Act.

     Incentive  Stock Options.  Incentive stock options under the Incentive Plan
are  intended to be eligible  for the  favorable  federal  income tax  treatment
accorded "incentive stock options" under the Code.

     There  generally are no federal income tax  consequences to the participant
or the Company by reason of the grant or exercise of an incentive  stock option.
However,   the  exercise  of  an   incentive   stock  option  may  increase  the
participant's alternative minimum tax liability, if any.

     If a  participant  holds stock  acquired  through  exercise of an incentive
stock option for at least two years from the date on which the option is granted
and at least one year from the date on which the shares are  transferred  to the
participant  upon exercise of the option,  any gain or loss on a disposition  of
such stock will be a long-term capital gain or loss.

     Generally,  if the participant  disposes of the stock before the expiration
of either of these holding periods (a "disqualifying disposition"),  then at the
time of disposition the participant  will realize taxable  ordinary income equal
to the lesser of (i) the excess of the stock's  fair market value on the date of
exercise over the exercise price, or (ii) the participant's actual gain, if any,
on the purchase and sale. The participant's additional gain or any loss upon the
disqualifying  disposition  will  be a  capital  gain  or  loss,  which  will be
long-term  or  short-term  depending on whether the stock was held for more than
one year.

     To the extent the  participant  recognizes  ordinary  income by reason of a
disqualifying  disposition,  the Company will generally be entitled  (subject to
the requirement of reasonableness,  the provisions of Section 162(m) of the Code
and the satisfaction of a tax reporting obligation) to a corresponding  business
expense deduction in the tax year in which the disqualifying disposition occurs.

     Nonstatutory  Stock Options,  Restricted  Stock  Purchase  Awards and Stock
Bonuses.  Nonstatutory stock options, restricted stock purchase awards and stock
bonuses  granted under the Incentive Plan  generally have the following  federal
income tax consequences:

     There are no tax  consequences  to the participant or the Company by reason
of the grant.  Upon  acquisition  of the stock,  the  participant  normally will
recognize  taxable  ordinary income equal to the excess,  if any, of the stock's
fair market value on the acquisition date over the purchase price.  However,  to
the extent the stock is subject to certain  types of vesting  restrictions,  the
taxable  event will be delayed until the vesting  restrictions  lapse unless the
participant  elects  to be  taxed on  receipt  of the  stock.  With  respect  to
employees,  the Company is generally  required to withhold from regular wages or
supplemental  wage payments an amount based on the ordinary  income


                                       8
<PAGE>


recognized.  Subject to the  requirement  of  reasonableness,  the provisions of
Section 162(m) of the Code and the  satisfaction of a tax reporting  obligation,
the Company will generally be entitled to a business expense  deduction equal to
the taxable ordinary income realized by the participant.

     Upon  disposition of the stock,  the  participant  will recognize a capital
gain or loss equal to the  difference  between the selling  price and the sum of
the amount paid for such stock plus any amount  recognized  as  ordinary  income
upon acquisition (or vesting) of the stock.  Such gain or loss will be long-term
or  short-term  depending  on whether the stock was held for more than one year.
Slightly  different rules may apply to participants who acquire stock subject to
certain  repurchase  options or who are subject to Section 16(b) of the Exchange
Act.

     Stock  Appreciation  Rights. No taxable income is realized upon the receipt
of a stock appreciation right, but upon exercise of the stock appreciation right
the fair market value of the shares (or cash in lieu of shares) received must be
treated as  compensation  taxable as ordinary  income to the  participant in the
year of such  exercise.  Generally,  with respect to  employees,  the Company is
required to withhold from the payment made on exercise of the stock appreciation
right or from regular wages or supplemental wage payments an amount based on the
ordinary  income  recognized.  Subject  to the  requirement  of  reasonableness,
Section 162(m) of the Code and the satisfaction of a reporting  obligation,  the
Company will be entitled to a business  expense  deduction  equal to the taxable
ordinary income recognized by the participant.

     Potential  Limitation  on Company  Deductions.  Section  162(m) of the Code
denies a deduction to any  publicly-held  corporation for  compensation  paid to
certain "covered employees" in a taxable year to the extent that compensation to
such  covered  employee  exceeds $1 million.  It is possible  that  compensation
attributable  to awards,  when  combined  with all other  types of  compensation
received by a covered employee from the Company, may cause this limitation to be
exceeded in any particular year.

     Certain  kinds  of  compensation,  including  qualified  "performance-based
compensation,"  are  disregarded  for purposes of the deduction  limitation.  In
accordance with Treasury  regulations issued under Section 162(m),  compensation
attributable  to stock  options and stock  appreciation  rights will  qualify as
performance-based  compensation  if  the  award  is  granted  by a  compensation
committee  comprised  solely of  "outside  directors"  and  either  (i) the plan
contains a per-employee limitation on the number of shares for which such awards
may be  granted  during a  specified  period,  the  per-employee  limitation  is
approved by the  stockholders,  and the  exercise  price of the award is no less
than the fair market value of the stock on the date of grant,  or (ii) the award
is granted (or  exercisable)  only upon the achievement (as certified in writing
by the compensation  committee) of an objective  performance goal established in
writing  by the  compensation  committee  while  the  outcome  is  substantially
uncertain, and the award is approved by stockholders.

     Compensation  attributable  to  restricted  stock  and stock  bonuses  will
qualify  as  performance-based  compensation,  provided  that:  (i) the award is
granted by a compensation  committee comprised solely of "outside directors" and
(ii) the  purchase  price of the award is no less than the fair market  value of
the stock on the date of  grant.  Stock  bonuses  qualify  as  performance-based
compensation under the Treasury  regulations only if (i) the award is granted by
a compensation committee comprised solely of "outside directors," (ii) the award
is  granted  (or  exercisable)   only  upon  the  achievement  of  an  objective
performance goal established in writing by the compensation  committee while the
outcome is substantially  uncertain,  (iii) the compensation committee certifies
in  writing  prior to the  granting  (or  exercisability)  of the award that the
performance  goal  has  been  satisfied  and  (iv)  prior  to the  granting  (or
exercisability)  of the award,  stockholders have approved the material terms of
the award  (including  the  class of  employees  eligible  for such  award,  the
business criteria on which the performance goal is based, and the maximum amount
- -- or formula used to calculate  the amount -- payable  upon  attainment  of the
performance goal).


                                       9
<PAGE>


                                   PROPOSAL 3
                RATIFICATION OF SELECTION OF INDEPENDENT AUDITORS

     The Board of  Directors  has  selected  Ernst & Young LLP as the  Company's
independent  auditors  for the fiscal year ending  December  31,  1999,  and has
further  directed that management  submit the selection of independent  auditors
for  ratification by the  stockholders at the Annual Meeting.  Ernst & Young LLP
has audited the  Company's  financial  statements  since its  inception in 1991.
Representatives  of Ernst & Young LLP are  expected  to be present at the Annual
Meeting, will have an opportunity to make a statement if they so desire and will
be available to respond to appropriate questions.

     Stockholder  ratification  of the  selection  of  Ernst & Young  LLP as the
Company's  independent  auditors  is not  required by the  Company's  By-laws or
otherwise.  However,  the Board is submitting the selection of Ernst & Young LLP
to the stockholders for ratification as a matter of good corporate practice.  If
the stockholders fail to ratify the selection, the Audit Committee and the Board
will  reconsider  whether or not to retain that firm.  Even if the  selection is
ratified,  the Audit Committee and the Board in their  discretion may direct the
appointment  of  different  independent  auditors at any time during the year if
they  determine that such a change would be in the best interests of the Company
and its stockholders.

     The affirmative  vote of the holders of a majority of the shares present in
person or  represented  by proxy and entitled to vote at the Annual Meeting will
be required to ratify the selection of Ernst & Young LLP.


                        THE BOARD OF DIRECTORS RECOMMENDS
                         A VOTE IN FAVOR OF PROPOSAL 3.


                                       10
<PAGE>


                              SECURITY OWNERSHIP OF
                    CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

     The following table sets forth certain information  regarding the ownership
of the  Company's  Common  Stock as of April 15, 1999 by: (i) each  director and
nominee for director;  (ii) each of the executive  officers named in the Summary
Compensation  Table  employed by the Company in that capacity on April 15, 1999;
(iii) all executive  officers and directors of the Company as a group;  and (iv)
all those known by the Company to be beneficial owners of more than five percent
of its Common Stock.

                                                        Beneficial Ownership(1)
                                                       ------------------------
                                                       Number of      Percentage
          Beneficial Owner                               Shares        of Total
          ----------------                             ---------       --------
     Biotech Invest, S.A ...........................   2,655,286        16.84%
     Swiss Bank Tower                                                 
     Panama 1                                                         
     Republic of Panama                                               
     Oracle Partners, L.P. (2) .....................     983,700         6.24%
     712 Fifth Avenue, 45th Floor                                     
     New York, NY 10019                                               
     J. Leighton Read, M.D. (3) ....................     497,193         3.13%
     Fred Kurland (4) ..............................      37,176            *
     Carol A. Olson (5) ............................      76,753            *
     Reid W. Dennis (6) ............................      37,176            *
     Paul H. Klingenstein (7) ......................      24,679            *
     Bernard Roizman, Sc.D. (8) ....................     184,200         1.17%
     Jane E. Shaw, Ph.D. (9) .......................      36,829            *
     All directors and executive officers as a group                  
       (7 persons) (10) ............................     894,501         5.58%
                                                                       
- ----------                                                          
*    Represents  beneficial  ownership of less than 1% of the outstanding shares
     of the Company's Common Stock.

(1)  Beneficial  ownership is  determined  in  accordance  with the rules of the
     Securities  and  Exchange  Commission  and  generally  includes  voting  or
     investment  power with respect to  securities.  Beneficial  ownership  also
     includes  shares  of  stock  subject  to  options  and  warrants  currently
     exercisable or convertible, or exercisable or convertible within 60 days of
     the date of this table.  Percentage  of  beneficial  ownership  is based on
     15,768,680 shares of Common Stock outstanding as of April 15, 1999.

(2)  Based on a  Schedule  13G filed by Oracle  Partners,  L.P.  reporting  such
     beneficial ownership as of December 31, 1998.

(3)  Includes  an  aggregate  of 110,000  shares  acquired  pursuant to an early
     exercise of stock  options,  of which an aggregate of 7,400 will be subject
     to repurchase by the Company 60 days from April 15, 1999.  Also includes an
     aggregate of 32,000 shares held by The Travis Read 1993 Trust and The Haley
     Read 1993 Trust (the  "Trusts") of which Robert  Fitzwilson is the trustee.
     Dr. Read disclaims  beneficial  ownership of the shares held by the Trusts.
     Also includes  97,000 shares Dr. Read has the right to acquire  pursuant to
     options exercisable within 60 days of April 15, 1999.

(4)  Includes  36,400  shares Mr.  Kurland has the right to acquire  pursuant to
     options exercisable within 60 days of April 15, 1999.

(5)  Includes  75,497  shares  Ms.  Olson has the right to acquire  pursuant  to
     options exercisable within 60 days of April 15, 1999.

(6)  Includes 3,546 shares held by Institutional  Venture Management V, of which
     Mr. Dennis is a general partner.  Mr. Dennis disclaims beneficial ownership
     of the shares held by  Institutional  Venture  Management  V, except to the
     extent of his pecuniary  interest  therein.  Also includes 3,000 shares Mr.
     Dennis has the right to acquire pursuant to options  exercisable  within 60
     days of April 15, 1999.

(7)  Includes 7,950 shares Mr. Klingenstein has the right to acquire pursuant to
     options exercisable within 60 days of April 15, 1999.


                                       11
<PAGE>


(8)  Includes  10,200  shares Dr.  Roizman has the right to acquire  pursuant to
     options exercisable within 60 days of April 15, 1999.

(9)  Includes  2,000  shares  held by Peter  F.  Carpenter  and  Jane  Elizabeth
     Carpenter Trustees of the Carpenter 1983 Family Trust and 1,600 shares held
     by Peter Frederick and Jane Elizabeth  Carpenter  Trustees of the Carpenter
     1985  Irrevocable  Trust (the  "Trusts").  Dr.  Shaw  disclaims  beneficial
     ownership of the shares held by the Trusts. Also includes 27,229 shares Dr.
     Shaw has the right to acquire  pursuant  to options  exercisable  within 60
     days of April 15, 1999.

(10) Includes 3,546 shares held by an entity  affiliated  with a director of the
     Company as  described  in  footnote 6 above and 257,276  shares  subject to
     options exercisable within 60 days of April 15, 1999.

SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

     Section  16(a)  of the  Securities  Exchange  Act  requires  the  Company's
directors and executive officers, and persons who own more than ten percent of a
registered  class  of the  Company's  equity  securities,  to file  with the SEC
initial reports of ownership and reports of changes in ownership of Common Stock
and other equity securities of the Company. Officers, directors and greater than
ten percent  stockholders  are required by SEC regulation to furnish the Company
with copies of all Section 16(a) forms they file.

     To the Company's knowledge,  based solely on a review of the copies of such
reports  furnished  to the  Company and  written  representations  that no other
reports were required, during the year ended December 31, 1998 all Section 16(a)
filing  requirements  were complied with by its officers,  directors and greater
than ten percent beneficial owners.


                                       12
<PAGE>


                             EXECUTIVE COMPENSATION


COMPENSATION OF DIRECTORS

     Since June 1998,  each  non-employee  director of the Company has  received
cash  compensation  for  their  services,  in  addition  to being  eligible  for
reimbursement for their expenses incurred in connection with attendance at Board
and committee  meetings in accordance with Company policy. The cash compensation
includes a retainer of $1,000 per month,  plus $500 per Board  Meeting  attended
and $300 per Committee  Meeting  attended.  However,  should a Committee Meeting
fall on the same date as a Board Meeting,  such  non-employee  director receives
only the $500 Board Meeting attendance stipend.

     Each non-employee director of the Company also receives stock option grants
under the 1996  Non-Employee  Directors'  Stock  Option  Plan  (the  "Directors'
Plan"). The maximum number of shares of Common Stock that may be issued pursuant
to options granted under the Directors' Plan is 200,000.  The Directors' Plan is
administered   by  the  Board  of   Directors,   unless   the  Board   delegates
administration  to a  committee  comprised  of not less than two  members of the
Board.

     Option grants under the Directors' Plan are non-discretionary.  Pursuant to
the terms of the  Directors'  Plan,  each  director of the Company not otherwise
employed  by the  Company and who is first  elected as a  non-employee  director
automatically  will be granted  an option to  purchase  15,000  shares of Common
Stock upon such  election.  In  addition,  on  December  31, of each year,  each
director  who has served as a  non-employee  director  since  December 31 of the
immediately  preceding year is automatically  granted under the Directors' Plan,
without  any  further  action  by the  Company,  the Board of  Directors  or the
stockholders of the Company,  an option to purchase 3,000 shares of Common Stock
of the Company. If the non-employee  director has not served as a director since
December  31 of the  immediately  preceding  year,  he or  she is  automatically
granted  an  option to  purchase  the  number  of shares of Common  Stock of the
Company (rounded up to the nearest whole share)  determined by multiplying 3,000
shares by a fraction,  the  numerator  of which is the number of days the person
continuously  has been a non-employee  director as of the date of such grant and
the  denominator  of which is 365. No other  options may be granted at any other
time under the Directors' Plan.

     The exercise price of options under the Directors' Plan is equal to 100% of
the fair market value of the Common  Stock  subject to the option on the date of
the grant.  Options granted under the Directors' Plan may not be exercised until
the date upon which such  optionee,  or the affiliate of such  optionee,  as the
case may be, has  provided  one year of  continuous  service  as a  non-employee
director following the date of grant of such option, whereupon such option shall
become  exercisable  as to 33% of the option  shares,  34% of the option  shares
shall become exercisable two years after the date of grant, and 33% shall become
exercisable  three years after the date of grant,  in accordance with its terms.
The  term of  options  granted  under  the  Directors'  Plan is ten  years.  The
Directors' Plan will terminate in March 2006,  unless earlier  terminated by the
Board.

     In  the  event  of  a  merger,   consolidation,   reverse   reorganization,
dissolution,  sale of substantially all of the assets of the Company, or certain
changes in the beneficial ownership of the Company's securities  representing at
least  a 50%  change  of such  ownership,  the  options  outstanding  under  the
Directors' Plan will automatically become fully vested and will terminate if not
exercised prior to such event.

     During  the last  fiscal  year,  the  Company  granted  options  under  the
Directors' Plan covering 3,000 shares to each of Mr. Dennis,  Mr.  Klingenstein,
Dr. Roizman,  and Dr. Shaw, at an exercise price per share of $25.875,  the fair
market  value of such  Common  Stock on the date of grant.  As of April 1, 1999,
options for an aggregate of 990 shares of the  Company's  Common Stock have been
exercised under the Directors' Plan.


                                       13
<PAGE>


COMPENSATION OF EXECUTIVE OFFICERS


                             SUMMARY OF COMPENSATION

     The  following  table shows for the fiscal  years ended  December 31, 1998,
December 31, 1997,  and December 31, 1996,  compensation  awarded or paid to, or
earned by, the Company's  Chief  Executive  Officer and its two other  executive
officers at December 31, 1998 (the "Named Executive Officers"):


                           SUMMARY COMPENSATION TABLE

<TABLE>
<CAPTION>
                                                                                      Long-Term
                                                           Annual                   Compensation
                                                        Compensation                    Awards
                                           ---------------------------------------- ------------
                                                                          Other      Securities
                                                                         Annual        Under-        All Other
                                                                      Compensation      Lying      Compensation
Name and Principal Position      Year      Salary($)      Bonus($)         ($)       Options(#)       ($)(1)
- --------------------             ----      ---------     ----------     ---------   ------------   ------------
<S>                              <C>       <C>             <C>          <C>            <C>             <C>
J. Leighton Read, M.D .......    1998      275,000         50,000           --         250,000           290
   Chairman and                  1997      260,000         80,000       31,726(2)       25,000           574
   Chief Executive Officer       1996      230,000             --       78,420(3)       50,000         1,427
                                                                                      
Fred Kurland(4) .............    1998      223,955         25,000           --         100,000           283
   Senior Vice President and     1997           --             --           --              --            --
   Chief Financial Officer       1996           --             --           --              --            --
                                                                                      
Carol A. Olson(5) ...........    1998      143,013         40,000           --         166,617            93
   Senior Vice President,        1997           --             --           --              --            --
   Commercial Development        1996           --             --           --              --            --
</TABLE>

- ----------
(1)  Includes group term life insurance paid by the Company.

(2)  Includes  $20,739 of  reimbursement  for income taxes and $10,987 in income
     tax  gross-up in  connection  with the early  exercise of stock  options in
     1996.

(3)  Includes  reimbursement  by the Company of $62,500 in  connection  with the
     early exercise of stock options.

(4)  Mr. Kurland joined the Company in January 1998.

(5)  Ms. Olson joined the Company in May 1998.

                        STOCK OPTION GRANTS AND EXERCISES

     The  following  tables show for the fiscal year ended  December  31,  1998,
certain information regarding options granted to, exercised by, and held at year
end by, the Named Executive Officers:


                        OPTION GRANTS IN LAST FISCAL YEAR

<TABLE>
<CAPTION>
                                                                                                  Potential Realizable
                                       Individual Grants (4)                                        Value at Assumed  
                                   -----------------------------                                     Annual Rates of  
                                     Number of      % of Total                                         Stock Price    
                                    Securities        Options                                       Appreciation for  
                                    Underlying      Granted to     Exercise or                     Option Term ($)(3) 
                                      Option       Employees in    Base Price    Expiration      ----------------------
Name                               Granted (#)    Fiscal Year(1)    ($/Sh)(2)       Date           5% ($)      10% ($)
- ----                               -----------    --------------   -----------   ----------      ---------    ---------
<S>                                  <C>              <C>             <C>         <C>            <C>          <C>      
J. Leighton Read, M.D .........      150,000          14.04           25.625      02/03/08       2,417,314    6,125,948
                                     100,000           9.36           27.563      06/03/08       1,733,391    4,392,753
Fred Kurland ..................      100,000           9.36           24.750      01/21/08       1,556,514    3,944,513
Carol A. Olson ................        1,617           0.15           24.875      03/11/08          25,296       64,105
                                     150,000          14.04           25.375      05/07/08       2,393,730    6,066,182
                                      15,000           1.40           14.938      09/09/08         140,912      357,098
</TABLE>

- ----------
(1)  Based on an  aggregate  of  1,068,717  options  granted  to  employees  and
     directors  of the Company in fiscal  1998,  including  the Named  Executive
     Officers set forth in the "Summary  Compensation Table" above and directors
     set forth in "Director Compensation" above.

(2)  The exercise  price is equal to 100% of the fair market value of the Common
     Stock on the date of grant.


                                       14
<PAGE>


(3)  The  potential  realizable  value  is  calculated  based on the term of the
     option at the time of grant (ten years).  Stock price  appreciation of five
     percent and ten percent is assumed  pursuant  to rules  promulgated  by the
     Securities  and Exchange  Commission  and does not  represent the Company's
     prediction of its stock price performance.  The potential  realizable value
     at 5% and 10%  appreciation  is  calculated  by assuming  that the exercise
     price  appreciates  at the indicated rate for the entire term of the option
     and that the option is exercised at the exercise price and sold on the last
     day of its term at the appreciated price.

(4)  Each of the options  listed in the table was granted  under the 1996 Equity
     Incentive   Plan  and  vest  ratably  over  fifty  months.   Under  certain
     circumstances  following  a change of  control,  the vesting of such option
     grants may accelerate and become immediately exercisable.

                AGGREGATED OPTION EXERCISES IN LAST FISCAL YEAR,
                      AND FISCAL YEAR-END OPTION VALUES(1)

<TABLE>
<CAPTION>
                                       Number of Securities            Value of Unexercised
                                      Underlying Unexercised           In-the-Money Options
                                   Options at December 31, 1998       at December 31, 1998(2)
Name                               (#) Exercisable/Unexercisable   ($) Exercisable/Unexercisable
- ----                               -----------------------------    ----------------------------
<S>                                        <C>                            <C>         
J. Leighton Read, M.D .........            61,000/214,000                 187,625/259,250
Fred Kurland ..................                 0/100,000                       0/112,500
Carol A. Olson ................            12,397/165,000                  33,957/239,063
</TABLE>

- ----------
(1)  During the fiscal year ended  December 31, 1998 no shares were  acquired on
     exercise  by the  Named  Executive  Officers  set  forth  in  the  "Summary
     Compensation Table" above.

(2)  Based on the closing  price of the  Company's  Common  Stock  ($25.875)  on
     December 31, 1998 as reported on the Nasdaq Stock Market, less the exercise
     price,  without  taking  into  account  any taxes  that may be  payable  in
     connection  with  the  transaction,  multiplied  by the  number  of  shares
     underlying the option.

EMPLOYEE STOCK PURCHASE PLAN

     In  March  1996,  the  Board  adopted,  and the  stockholders  subsequently
approved,  the 1996 Employee Stock Purchase Plan (the  "Purchase  Plan").  As of
April 1, 1999,  there were 350,000  shares of Common Stock reserved for issuance
under the Purchase Plan. The Purchase Plan is intended to qualify as an employee
stock  purchase  plan within the  meaning of Section 423 of the Code.  Under the
Purchase  Plan, the Board of Directors may authorize  participation  by eligible
employees,  including officers,  in periodic offerings following the adoption of
the Purchase Plan. The offering  period for any offering will be no more than 27
months.

     As of April 1, 1999,  purchase rights (net of canceled or expired  purchase
rights) covering an aggregate of 71,513 shares of the Company's Common Stock had
been granted under the Purchase  Plan,  and 178,487 shares of Common Stock (plus
any shares that might in the future be returned to the Purchase Plan as a result
of  cancellations  or expiration of purchase rights) remain available for future
grant under the Purchase Plan.

     Employees are eligible to  participate if they are employed by the Company,
or an  affiliate of the Company  designated  by the Board of  Directors,  for at
least 20 hours per week and are employed by the Company,  or an affiliate of the
Company  designated  by the Board,  for at least five months per calendar  year.
Employees who  participate  in an offering can have up to 15% of their  earnings
withheld pursuant to the Purchase Plan. The amount withheld will then be used to
purchase shares of the Common Stock on specified  dates  determined by the Board
of Directors.  The price of Common Stock  purchased under the Purchase Plan will
be equal to 85% of the lower of the fair market value of the Common Stock on the
commencement  date of each offering  period or on the specified  purchase  date.
Employees  may end their  participation  in the  offering at any time during the
offering period.  Participation  ends automatically on termination of employment
with the Company.

     In the  event of a merger,  reorganization,  consolidation  or  liquidation
involving the Company,  in which the Company is not the  surviving  corporation,
the Board of  Directors  has  discretion  to provide that each right to purchase
Common Stock will be assumed or an equivalent right substituted by the successor
corporation,  or the Board may shorten the  offering  period and provide for all
sums collected by payroll deductions to be applied to purchase stock immediately
prior to such merger or other  transaction.  The Purchase Plan will terminate at
the Board's  discretion.  The Board has the  authority to amend or terminate the
Purchase  Plan,  subject to the  limitation  that no such  action may  adversely
affect any outstanding rights to purchase Common Stock.


                                       15
<PAGE>



        REPORT OF THE COMPENSATION COMMITTEE OF THE BOARD OF DIRECTORS ON
                             EXECUTIVE COMPENSATION


COMPENSATION COMMITTEE REPORT(1)

     The  Compensation  Committee  of the Board of  Directors  ("Committee")  is
composed  of Dr.  Shaw and  Mr.Klingenstein,  neither  of whom  have  ever  been
officers  or  employees  of  the  Company.  The  Committee  is  responsible  for
establishing the Company's  compensation  programs for all employees,  including
executives.  For executive  officers,  the Committee  evaluates  performance and
determines compensation policies and levels.

     Compensation Philosophy

     The  goals  of the  compensation  program  are to align  compensation  with
business objectives and performance and to enable the Company to attract, retain
and reward  executive  officers and other key  employees  who  contribute to the
long-term  success of the  Company  and to  motivate  them to enhance  long-term
stockholder value. Key elements of this philosophy are:

     o    The Company pays competitively with other biotechnology companies with
          which  the  Company  competes  for  talent.  To  ensure  that  pay  is
          competitive,  the  Company  compares  its  pay  practices  with  these
          companies and sets its pay parameters based on this review.

     o    The  Company   provides   significant   equity-based   incentives  for
          executives  and other key  employees to ensure that they are motivated
          over the long term to respond to the Company's business challenges and
          opportunities as owners and not just as employees.

     Salary.  The Committee  annually reviews each executive  officer's  salary.
When  reviewing  salaries,  the  Committee  considers  individual  and corporate
performance,  levels of responsibility,  prior experience,  breadth of knowledge
and competitive pay practices.

     Cash Bonus.  The Company  established  a bonus plan in January 1998 and the
Committee  annually reviews each executive  officer's bonus, the aggregate bonus
pool for the Company and the bonus allocations by employee position.  Payment of
cash bonuses is tied to the accomplishment of specific corporate  milestones set
at the  beginning  of  the  year  and  to  each  individual  officer's  year-end
performance review.

     Equity  Incentives.  The Company's equity incentive program consists of the
1996  Equity  Incentive  Plan and the 1996  Employee  Stock  Purchase  Plan (the
"Purchase  Plan").  The option program utilizes vesting periods  (generally four
years) to  encourage  key  employees  to continue in the employ of the  Company.
Through option grants, executives receive significant equity incentives to build
long-term stockholder value. Grants are made at 100% of fair market value on the
date of grant.  Executives receive value from these grants only if the Company's
Common  Stock  appreciates  over the long  term.  The size of  option  grants is
determined based on competitive practices in the biotechnology  industry and the
Company's  philosophy  of  significantly  linking  executive  compensation  with
stockholder   interests.   The  Committee  believes  this  approach  creates  an
appropriate  focus on longer term objectives and promotes  executive  retention.
The Board  granted  options to purchase an  aggregate  of 516,617  shares of the
Company's Common Stock to the Named Executive Officers during 1998.

     The Company  established  the Purchase Plan both to encourage  employees to
continue  in  the  employ  of the  Company  and to  motivate  employees  through
ownership interest in the Company. Under the Purchase Plan, employees, including
officers,  may have up to 15% of their earnings withheld for purchases of Common
Stock on  certain  dates  specified  by the  Board.  The price of  Common  Stock
purchased  will be equal to 85% of the  lower  of the fair  market  value of the
Common Stock on the relevant  purchase date or commencement date of the relevant
offering period. There were two offerings during fiscal 1998.


- ----------

(1)  Notwithstanding  anything to the contrary set forth in any of the Company's
     previous  filings  under  the  Securities  Act of 1933,  as  amended,  (the
     "Securities  Act")  or the  Exchange  Act  that  might  incorporate  future
     filings, including this Proxy Statement, in whole or in part, the following
     report  and  Performance  Graph on page 18  shall  not be  incorporated  by
     reference  into any  such  filings.  The  Committee's  objective  is to set
     executive  compensation  at the market  average  when  compared  to leading
     companies  in  the  biotechnology   industry.  The  primary  components  of
     executive  compensation  are base salary,  annual  incentives and long-term
     equity incentives.


                                       16
<PAGE>


CHIEF EXECUTIVE OFFICER COMPENSATION

     Dr. Read's salary during 1998 as President and Chief Executive  Officer was
$275,000.  Following the Committee's review of the Company's performance against
corporate  milestones  for 1998 and Dr.  Read's  performance  during  1998,  the
Committee  awarded  Dr. Read a 1998 merit bonus of  $50,000.  In  addition,  the
Committee has set Dr. Read's annual salary for 1999 at $300,000.  In determining
Dr. Read's 1998 bonus and 1999 salary,  the Committee  took into account (i) Dr.
Read's recent  performance  as CEO of the Company,  (ii) the scope of Dr. Read's
responsibilities,  and  (iii) the  Board's  confidence  in Dr.  Read to lead the
Company's continued development. Considering these factors, in February 1999 Dr.
Read was  granted  an option to  purchase  50,000  shares of Common  Stock as an
incentive for future performance.

FEDERAL TAX CONSIDERATIONS

     Section 162(m) of the Internal Revenue Code (the "Code") limits the Company
to a  deduction  for federal  income tax  purposes of no more than $1 million of
compensation  paid to  certain  Named  Executive  Officers  in a  taxable  year.
Compensation  above  $1  million  may be  deducted  if it is  "performance-based
compensation" within the meaning of the Code.

     The statute  containing  this law and the applicable  Treasury  regulations
offer  a  number  of  transitional   exceptions  to  this  deduction  limit  for
pre-existing  compensation  plans,  arrangements  and  binding  contracts.  As a
result, the Compensation Committee believes that at the present time it is quite
unlikely that the compensation  paid to any Named Executive Officer in a taxable
year which is subject to the deduction limit will exceed $1 million.  Therefore,
the  Compensation  Committee has not yet  established  a policy for  determining
which forms of incentive  compensation  awarded to its Named Executive  Officers
shall  be  designed  to  qualify  as   "performance-based   compensation."   The
Compensation  Committee  intends to  continue  to  evaluate  the  effects of the
statute and any applicable Treasury  regulations and to comply with Code Section
162(m) in the future to the extent  consistent  with the best  interests  of the
Company.

CONCLUSION

     Through the plans described  above, a significant  portion of the Company's
compensation  program  and  Dr.Read's  compensation  are  contingent  on Company
performance,  and  realization  of benefits is closely  linked to  increases  in
long-term stockholder value. The Company remains committed to this philosophy of
pay for  performance,  recognizing  that the  competitive  market  for  talented
executives  and the  volatility of the  Company's  business may result in highly
variable compensation for a particular time period.


                                        COMPENSATION COMMITTEE
                                        Paul H. Klingenstein
                                        Jane E. Shaw, Ph.D.



                                       17
<PAGE>


PERFORMANCE MEASUREMENT COMPARISON(2)

     The following graph shows the total stockholder  return of an investment of
$100 in cash on November 5, 1996 for (i) the Company's  Common  Stock,  (ii) the
Nasdaq Stock  Market-U.S.  Index (the "Nasdaq Stock  Market-U.S.") and (iii) the
Nasdaq  Pharmaceutical  Index (the "Nasdaq  Pharmaceutical").  All values assume
reinvestment  of the full  amount  of all  dividends  and are  calculated  as of
December 31 of each year:










                               [PERFORMANCE GRAPH]











                                     11/05/96    12/31/96    12/31/97   12/31/98
                                      -------     -------     -------    -------
     AVIRON ......................       $100       $ 94       $339       $323
     NASDAQ Stock Market (U.S.) ..        100        105        129        182
     NASDAQ Pharmaceutical .......        100        105        108        139

- ----------

(2)  This Section is not  "soliciting  material," is not deemed "filed" with the
     Securities  and  Exchange  Commission  and  is not  to be  incorporated  by
     reference  in any filing of the  Company  under the  Securities  Act or the
     Exchange Act whether made before or after the date hereof and  irrespective
     of any general incorporation language in any such filing.


                                       18
<PAGE>


                              CERTAIN TRANSACTIONS

     Prior to joining the Company in May 1998,  Ms. Olson was a partner with the
Churchill  Madison  Group.  During the fiscal year ended  December 31, 1998, the
Company made payments to the Churchill Madison Group of approximately $1,154,000
for marketing research  services.  No services have been rendered to the Company
by the Churchill Madison Group since Ms. Olson joined the Company.

     In June 1998, the Company  granted an option  covering 15,000 shares to Mr.
Klingenstein,  at an exercise price per share of $27.5625, the fair market value
of such Common Stock on the date of grant, for his services as an advisor to the
Company.

     The Company has entered into indemnity agreements with certain officers and
directors  which  provide,  among other things,  that the Company will indemnify
such officer or director, under the circumstances and to the extent provided for
therein,  for expenses,  damages,  judgments,  fines and  settlements  he may be
required to pay in actions or proceedings  which he is or may be made a party be
reason of his position as a director, officer or other agent of the Company, and
otherwise to the full extent  permitted  under  Delaware  law and the  Company's
By-laws.


                                  OTHER MATTERS

     The Board of Directors knows of no other matters that will be presented for
consideration  at the Annual Meeting.  If any other matters are properly brought
before the meeting, it is the intention of the persons named in the accompanying
proxy to vote on such matters in accordance with their best judgment.


                                        By Order of the Board of Directors

                                        /s/ Alan C. Mendelson

                                        Alan C. Mendelson
                                        Secretary

April 26, 1999


Report to the United States Securities and Exchange  Commission on Form 10-K for
the fiscal year ended December 31, 1998 is available without charge upon written
request  to:  Corporate  Communications,  Aviron,  297  North  Bernardo  Avenue,
Mountain View, CA 94043.

<PAGE>


                                     AVIRON

                           1996 EQUITY INCENTIVE PLAN

                              Adopted March 6, 1996

                     Approved By Stockholders July 22, 1996

                Amended by the Board of Directors March 12, 1998

               Amendment Approved by the Stockholders June 4, 1998

                Amended by the Board of Directors April 12, 1999

              Amendment Approved by the Stockholders June __, 1999



1.   PURPOSES.

     (a) The  purpose  of the  Plan is to  provide  a means  by  which  selected
Employees of and  Consultants  to the Company and its Affiliates may be given an
opportunity  to  benefit  from  increases  in value of the stock of the  Company
through the granting of (i) Incentive  Stock Options,  (ii)  Nonstatutory  Stock
Options,  (iii) stock bonuses, (iv) rights to purchase restricted stock, and (v)
stock  appreciation  rights, all as defined below. The Plan is successor to, and
restatement of, the Company's 1992 Stock Option Plan.

     (b) The  Company,  by means of the Plan,  seeks to retain the  services  of
persons who are now Employees and Directors of or Consultants to the Company, to
secure and retain the services of new Employees and Consultants,  and to provide
incentives  for such  persons to exert  maximum  efforts  for the success of the
Company and its Affiliates.

     (c) The Company  intends that the Stock Awards issued under the Plan shall,
in the  discretion  of the Board or any  Committee to which  responsibility  for
administration  of the Plan has been delegated  pursuant to subsection  3(c), be
either (i) Options  granted  pursuant to Section 6 hereof,  including  Incentive
Stock Options and  Nonstatutory  Stock Options,  (ii) stock bonuses or rights to
purchase  restricted stock granted pursuant to Section 7 hereof,  or (iii) stock
appreciation  rights granted pursuant to Section 8 hereof.  All Options shall be
separately  designated  Incentive Stock Options or Nonstatutory Stock Options at
the time of grant,  and in such  form as issued  pursuant  to  Section  6, and a
separate  certificate  or  certificates  will be issued for shares  purchased on
exercise of each type of Option.

2.   DEFINITIONS.

     (a)  "Affiliate"  means any parent  corporation or subsidiary  corporation,
whether now or hereafter existing, as those terms are defined in Sections 424(e)
and (f) respectively, of the Code.

     (b) "Board" means the Board of Directors of the Company.


                                       1.
<PAGE>


     (c) "Code" means the Internal Revenue Code of 1986, as amended.

     (d) "Committee" means a Committee appointed by the Board in accordance with
subsection 3(c) of the Plan.

     (e) "Company" means Aviron, a Delaware corporation.

     (f) "Concurrent  Stock  Appreciation  Right" or "Concurrent  Right" means a
right granted pursuant to subsection 8(b)(2) of the Plan.

     (g)  "Consultant"  means any person,  including an advisor,  engaged by the
Company or an Affiliate to render consulting services and who is compensated for
such services,  provided that the term "Consultant"  shall not include Directors
who are paid only a director's fee by the Company or who are not  compensated by
the Company for their services as Directors.

     (h) "Continuous  Status as an Employee,  Director or Consultant"  means the
employment or  relationship  as a Director or Consultant is not  interrupted  or
terminated.  The Board, in its sole discretion, may determine whether Continuous
Status as an Employee, Director or Consultant shall be considered interrupted in
the case of: (i) any leave of absence  approved  by the  Board,  including  sick
leave,  military leave,  or any other personal leave; or (ii) transfers  between
locations of the Company or between the Company, Affiliates or their successors.

     (i) "Covered  Employee" means the chief executive  officer and the four (4)
other highest compensated officers of the Company for whom total compensation is
required to be reported to  shareholders  under the Exchange  Act, as determined
for purposes of Section 162(m) of the Code.

     (j) "Director" means a member of the Board.

     (k) "Employee" means any person, including Officers and Directors, employed
by the Company or any  Affiliate of the Company.  Neither  service as a Director
nor payment of a director's fee by the Company shall be sufficient to constitute
"employment" by the Company.

     (l) "Exchange Act" means the Securities Exchange Act of 1934, as amended.

     (m) "Fair  Market  Value"  means,  as of any date,  the value of the common
stock of the Company determined as follows:

          (1) If the common stock is listed on any established stock exchange or
     a national market system,  including without limitation the National Market
     of The Nasdaq  Stock  Market,  the Fair  Market  Value of a share of common
     stock shall be the closing  sales price for such stock (or the closing bid,
     if no sales were  reported)  as quoted on such system or  exchange  (or the
     exchange  with the greatest  volume of trading in common stock) on the last
     market  trading day prior to the day of  determination,  as reported in the
     Wall Street Journal or such other source as the Board deems reliable;


                                       2.
<PAGE>


          (2) If the common  stock is quoted on The Nasdaq Stock Market (but not
     on the  National  Market  thereof) or is  regularly  quoted by a recognized
     securities  dealer but  selling  prices are not  reported,  the Fair Market
     Value of a share of  common  stock  shall be the mean  between  the bid and
     asked prices for the common  stock on the last market  trading day prior to
     the day of  determination,  as reported in the Wall Street  Journal or such
     other source as the Board deems reliable;

          (3) In the absence of an established  market for the common stock, the
     Fair Market Value shall be determined in good faith by the Board.

     (n)  "Incentive  Stock  Option"  means an Option  intended to qualify as an
incentive  stock  option  within the  meaning of Section 422 of the Code and the
regulations promulgated thereunder.

     (o) "Independent Stock Appreciation  Right" or "Independent  Right" means a
right granted pursuant to subsection 8(b)(3) of the Plan.

     (p)  "Non-Employee  Director"  means a  Director  who  either  (i) is not a
current  Employee  or Officer of the Company or a  subsidiary,  does not receive
compensation  (directly  or  indirectly)  from the  Company  or its  parent or a
subsidiary  for services  rendered as a consultant or in any capacity other than
as a Director (except for an amount as to which disclosure would not be required
under Item 404(a) of Regulation S-K  promulgated  pursuant to the Securities Act
("Regulation S-K")), does not possess an interest in any transaction as to which
disclosure  would be  required  under Item 404(a) of  Regulation  S-K and is not
engaged in a business  relationship  as to which  disclosure  would be  required
under  Item  404(b)  of  Regulation  S-K;  or (ii)  is  otherwise  considered  a
"non-employee director" for purposes of Rule 16b-3.

     (q) "Nonstatutory  Stock Option" means an Option not intended to qualify as
an Incentive Stock Option.

     (r)  "Officer"  means a person who is an officer of the Company  within the
meaning  of  Section  16 of the  Exchange  Act and  the  rules  and  regulations
promulgated thereunder.

     (s) "Option" means a stock option granted pursuant to the Plan.

     (t) "Option Agreement" means a written agreement between the Company and an
Optionee evidencing the terms and conditions of an individual Option grant. Each
Option Agreement shall be subject to the terms and conditions of the Plan.

     (u) "Optionee" means a person who holds an outstanding Option.

     (v)  "Outside  Director"  means a Director  who either (i) is not a current
employee of the Company or an  "affiliated  corporation"  (within the meaning of
Treasury  regulations  promulgated  under Section 162(m) of the Code),  is not a
former  employee  of  the  Company  or  an  "affiliated  corporation"  receiving
compensation  for prior  services  (other than  benefits  under a tax  qualified
pension plan), was not an officer of the Company or an "affiliated  corporation"
at any time, and is not currently receiving direct or indirect remuneration from
the Company or an  "affiliated  corporation"  for services in any capacity other
than as a Director,  or (ii) is otherwise  considered an "outside  director" for
purposes of Section 162(m) of the Code.


                                       3.
<PAGE>


     (w) "Plan" means this Aviron 1996 Equity Incentive Plan.

     (x) "Rule 16b-3"  means Rule 16b-3 of the Exchange Act or any  successor to
Rule 16b-3,  as in effect when discretion is being exercised with respect to the
Plan.

     (y) "Stock  Appreciation  Right"  means any of the various  types of rights
which may be granted under Section 8 of the Plan.

     (z) "Stock  Award" means any right  granted  under the Plan,  including any
Option,  any stock bonus, any right to purchase  restricted stock, and any Stock
Appreciation Right.

     (aa) "Stock Award Agreement" means a written  agreement between the Company
and a  holder  of a Stock  Award  evidencing  the  terms  and  conditions  of an
individual Stock Award grant. Each Stock Award Agreement shall be subject to the
terms and conditions of the Plan.

     (bb)  "Tandem  Stock  Appreciation  Right" or "Tandem  Right" means a right
granted pursuant to subsection 8(b)(1) of the Plan.

3.   ADMINISTRATION.

     (a) The Plan shall be  administered by the Board unless and until the Board
delegates  administration  to a Committee,  as provided in subsection  3(c). Any
interpretation  of the Plan by the Board and any decision by the Board under the
Plan shall be final and binding on all persons.

     (b) The Board shall have the power,  subject to, and within the limitations
of, the express provisions of the Plan:

          (1) To determine from time to time which of the persons eligible under
     the Plan shall be granted Stock Awards; when and how each Stock Award shall
     be granted;  whether a Stock Award will be an  Incentive  Stock  Option,  a
     Nonstatutory  Stock Option,  a stock bonus, a right to purchase  restricted
     stock, a Stock Appreciation  Right, or a combination of the foregoing;  the
     provisions  of each Stock  Award  granted  (which  need not be  identical),
     including  the time or times when a person  shall be  permitted  to receive
     stock  pursuant to a Stock  Award;  whether a person  shall be permitted to
     receive stock upon exercise of an Independent Stock Appreciation Right; and
     the number of shares  with  respect to which a Stock Award shall be granted
     to each such person.

          (2) To construe and interpret the Plan and Stock Awards  granted under
     it,  and to  establish,  amend and  revoke  rules and  regulations  for its
     administration.  The Board, in the exercise of this power,  may correct any
     defect,  omission  or  inconsistency  in the  Plan  or in any  Stock  Award
     Agreement,  in a manner  and to the  extent  it  shall  deem  necessary  or
     expedient to make the Plan fully effective.

          (3) To amend the Plan or a Stock Award as provided in Section 14.


                                       4.
<PAGE>


          (4) Generally, to exercise such powers and to perform such acts as the
     Board deems  necessary or  expedient  to promote the best  interests of the
     Company which are not in conflict with the provisions of the Plan.

     (c) The  Board  may  delegate  administration  of the  Plan to a  committee
composed of not fewer than two (2) members (the "Committee"), all of the members
of  which  Committee  may  be,  in the  discretion  of the  Board,  Non-Employee
Directors and may also be, in the discretion of the Board, Outside Directors. If
administration  is  delegated  to a  Committee,  the  Committee  shall have,  in
connection with the administration of the Plan, the powers theretofore possessed
by the Board (and  references  in this Plan to the Board shall  thereafter be to
the Committee), subject, however, to such resolutions, not inconsistent with the
provisions  of the Plan,  as may be adopted from time to time by the Board.  The
Board  may  abolish  the  Committee  at any time and  revest  in the  Board  the
administration  of the Plan.  Notwithstanding  anything in this Section 3 to the
contrary,  at any time the Board or the Committee may delegate to a committee of
one or more members of the Board the authority to grant Stock Awards to eligible
persons who (1) are not then  subject to Section 16 of the  Exchange  Act and/or
(2) are either (i) not then Covered Employees and are not expected to be Covered
Employees at the time of recognition of income  resulting from such Stock Award,
or (ii) not  persons  with  respect  to whom the  Company  wishes  to avoid  the
application of Section 162(m) of the Code.

4.   SHARES SUBJECT TO THE PLAN.

     (a) Subject to the  provisions of Section 13 relating to  adjustments  upon
changes in stock,  the stock that may be issued  pursuant to Stock  Awards shall
not exceed in the aggregate four million thirty thousand  (4,030,000)  shares of
the Company's  common  stock.  If any Stock Award shall for any reason expire or
otherwise terminate, in whole or in part, without having been exercised in full,
the stock not  acquired  under such Stock Award shall revert to and again become
available  for issuance  under the Plan.  Shares  subject to Stock  Appreciation
Rights exercised in accordance with Section 8 of the Plan shall not be available
for subsequent issuance under the Plan.

     (b) The stock  subject  to the Plan may be  unissued  shares or  reacquired
shares, bought on the market or otherwise.

5.   ELIGIBILITY.

     (a)  Incentive  Stock  Options and Stock  Appreciation  Rights  appurtenant
thereto may be granted only to  Employees.  Stock  Awards  other than  Incentive
Stock Options and Stock Appreciation  Rights appurtenant  thereto may be granted
to Employees, Consultants or Non-Employee Directors.

     (b) A Non-Employee Director shall be eligible for the benefits of the Plan,
provided,  however,  that any grant to a Non-Employee  Director shall not exceed
the lesser of (1) 1% of the shares of Common  Stock  outstanding  on the date of
grant or, (2) 25,000 shares.


                                       5.
<PAGE>


     (c) No person shall be eligible for the grant of an Incentive  Stock Option
if, at the time of grant,  such  person  owns (or is deemed to own  pursuant  to
Section 424(d) of the Code) stock  possessing more than ten percent (10%) of the
total combined  voting power of all classes of stock of the Company or of any of
its Affiliates  unless the exercise price of such Option is at least one hundred
ten percent  (110%) of the Fair Market  Value of such stock at the date of grant
and the Option is not  exercisable  after the  expiration of five (5) years from
the date of grant,  or in the case of a restricted  stock  purchase  award,  the
purchase  price is at least one hundred  percent (100%) of the Fair Market Value
of such stock at the date of grant.

     (d) Subject to the  provisions of Section 13 relating to  adjustments  upon
changes in stock,  no person  shall be eligible to be granted  Options and Stock
Appreciation  Rights covering more than three hundred thousand  (300,000) shares
of the Company's common stock in any calendar year.

     (e) Consultants.

          (i) A Consultant  shall not be eligible for the grant of a Stock Award
     if,  at the time of  grant,  a Form S-8  Registration  Statement  under the
     Securities  Act ("Form S-8") is not available to register  either the offer
     or the sale of the Company's  securities to such Consultant  because of the
     nature of the services that the Consultant is providing to the Company,  or
     because the Consultant is not a natural person, or as otherwise provided by
     the rules governing the use of Form S-8, unless the Company determines both
     (i) that such grant (A) shall be  registered  in another  manner  under the
     Securities Act (e.g., on a Form S-3 Registration Statement) or (B) does not
     require  registration  under the Securities Act in order to comply with the
     requirements of the Securities Act, if applicable, and (ii) that such grant
     complies with the securities laws of all other relevant jurisdictions.

          (ii)  As  of  April  7,  1999  Form  S-8  generally  is  available  to
     consultants  and advisors only if (i) they are natural  persons;  (ii) they
     provide bona fide services to the issuer,  its parents,  its majority-owned
     subsidiaries or  majority-owned  subsidiaries of the issuer's  parent;  and
     (iii)  the  services  are  not in  connection  with  the  offer  or sale of
     securities  in a  capital-raising  transaction,  and  do  not  directly  or
     indirectly promote or maintain a market for the issuer's securities.

6.   OPTION PROVISIONS.

     Each  Option  shall be in such  form  and  shall  contain  such  terms  and
conditions  as the Board  shall deem  appropriate.  The  provisions  of separate
Options  need  not  be  identical,   but  each  Option  shall  include  (through
incorporation of provisions  hereof by reference in the Option or otherwise) the
substance of each of the following provisions:

     (a) Term. No Option shall be  exercisable  after the expiration of ten (10)
years from the date it was granted.


                                       6.
<PAGE>


     (b) Price.  The exercise price of each Incentive  Stock Option shall be not
less  than one  hundred  percent  (100%) of the Fair  Market  Value of the stock
subject to the Option on the date the Option is granted; the exercise price of a
Nonstatutory  Stock Option shall be not less than  eighty-five  percent (85%) of
the Fair Market Value of the stock  subject to the Option on the date the Option
is granted.  Notwithstanding  the  foregoing,  an Incentive  Stock Option may be
granted  with an  exercise  price  lower  than that set  forth in the  preceding
sentence if such Option is granted pursuant to an assumption or substitution for
another  option in a manner  satisfying  the provisions of Section 424(a) of the
Code.

     (c)  Consideration.  The purchase  price of stock  acquired  pursuant to an
Option  shall be paid,  to the  extent  permitted  by  applicable  statutes  and
regulations,  either (i) in cash at the time the Option is exercised, or (ii) at
the  discretion of the Board or the  Committee,  at the time of the grant of the
Option, (A) by delivery to the Company of other common stock of the Company, (B)
according to a deferred payment or other arrangement (which may include, without
limiting the generality of the  foregoing,  the use of other common stock of the
Company)  with the person to whom the Option is granted or to whom the Option is
transferred  pursuant  to  subsection  6(d),  or (C) in any other  form of legal
consideration that may be acceptable to the Board.

     In the case of any deferred payment arrangement,  interest shall be payable
at least annually and shall be charged at the minimum rate of interest necessary
to avoid the treatment as interest, under any applicable provisions of the Code,
of any  amounts  other than  amounts  stated to be interest  under the  deferred
payment arrangement.  Further, the "par value" of any stock subject to an Option
shall not be payable pursuant to a deferred payment arrangement.

     (d)  Transferability.  An Incentive  Stock Option shall not be transferable
except  by will  or by the  laws of  descent  and  distribution,  and  shall  be
exercisable during the lifetime of the person to whom the Incentive Stock Option
is  granted  only by such  person.  A  Nonstatutory  Stock  Option  shall not be
transferable except by will, by the laws of descent and distribution or pursuant
to a domestic  relations order satisfying the requirements of Rule 16b-3 and any
administrative interpretations or pronouncements thereunder (a "DRO"), and shall
be  exercisable  during the lifetime of the person to whom the Option is granted
only by such person or any  transferee  pursuant to a DRO.  Notwithstanding  the
foregoing,  the person to whom the Option is granted may, by delivering  written
notice to the Company, in a form satisfactory to the Company,  designate a third
party  who,  in the  event of the death of the  Optionee,  shall  thereafter  be
entitled to exercise the Option.

     (e) Vesting.  The total number of shares of stock subject to an Option may,
but need not, be allotted in periodic  installments (which may, but need not, be
equal).  The Option  Agreement may provide that from time to time during each of
such  installment  periods,  the  Option may become  exercisable  ("vest")  with
respect  to some  or all of the  shares  allotted  to  that  period,  and may be
exercised  with  respect to some or all of the shares  allotted  to such  period
and/or any prior period as to which the Option  became  vested but was not fully
exercised.  The Option may be subject to such other terms and  conditions on the
time or times when it may be  exercised  (which may be based on  performance  or
other  criteria)  as the  Board may deem  appropriate.  The  provisions  of this
subsection  6(e) are  subject to any Option  provisions  governing  the  minimum
number of shares as to which an Option may be exercised.


                                       7.
<PAGE>


     (f)  Termination of Employment or Relationship as a Director or Consultant.
In the  event an  Optionee's  Continuous  Status  as an  Employee,  Director  or
Consultant terminates (other than upon the Optionee's death or disability),  the
Optionee  may  exercise  his or her Option (to the extent that the  Optionee was
entitled to exercise it at the date of termination)  but only within such period
of time  ending  on the  earlier  of (i) the date  three  (3)  months  after the
termination  of the  Optionee's  Continuous  Status as an Employee,  Director or
Consultant (or such longer or shorter period specified in the Option Agreement),
or (ii) the  expiration  of the term of the  Option as set  forth in the  Option
Agreement.  If, after  termination,  the  Optionee  does not exercise his or her
Option  within the time  specified  in the Option  Agreement,  the Option  shall
terminate,  and the shares  covered  by such  Option  shall  revert to and again
become available for issuance under the Plan.

     An Optionee's Option Agreement may also provide that if the exercise of the
Option  following the  termination  of the  Optionee's  Continuous  Status as an
Employee,  Director,  or  Consultant  (other than upon the  Optionee's  death or
disability)  would result in liability  under Section 16(b) of the Exchange Act,
then the Option shall terminate on the earlier of (i) the expiration of the term
of the Option set forth in the Option  Agreement,  or (ii) the tenth  (10th) day
after the last date on which such exercise would result in such liability  under
Section 16(b) of the Exchange Act.  Finally,  an Optionee's Option Agreement may
also provide that if the exercise of the Option following the termination of the
Optionee's Continuous Status as an Employee,  Director or Consultant (other than
upon the Optionee's death or disability)  would be prohibited at any time solely
because the issuance of shares would violate the registration requirements under
the Act, then the Option shall terminate on the earlier of (i) the expiration of
the term of the Option set forth in the first paragraph of this subsection 6(f),
or (ii) the expiration of a period of three (3) months after the  termination of
the Optionee's  Continuous Status as an Employee,  Director or Consultant during
which the exercise of the Option would not be in violation of such  registration
requirements.

     (g) Disability of Optionee. In the event an Optionee's Continuous Status as
an Employee,  Director or Consultant  terminates  as a result of the  Optionee's
disability,  the Optionee may exercise his or her Option (to the extent that the
Optionee  was  entitled  to exercise  it at the date of  termination),  but only
within  such  period of time  ending on the  earlier of (i) the date twelve (12)
months following such termination (or such longer or shorter period specified in
the Option  Agreement),  or (ii) the expiration of the term of the Option as set
forth in the Option Agreement.  If, at the date of termination,  the Optionee is
not entitled to exercise  his or her entire  Option,  the shares  covered by the
unexercisable  portion of the Option shall revert to and again become  available
for issuance  under the Plan.  If,  after  termination,  the  Optionee  does not
exercise his or her Option within the time  specified  herein,  the Option shall
terminate,  and the shares  covered  by such  Option  shall  revert to and again
become available for issuance under the Plan.

     (h) Death of Optionee.  In the event of the death of an Optionee during, or
within a period specified in the Option after the termination of, the Optionee's
Continuous  Status as an  Employee,  Director or  Consultant,  the Option may be
exercised (to the extent the Optionee was entitled to exercise the Option at the
date of death) by the Optionee's  estate,  by a person who acquired the right to
exercise  the Option by  bequest or  inheritance  or by a person  designated  to


                                       8.
<PAGE>


exercise the option upon the Optionee's  death pursuant to subsection  6(d), but
only within the period  ending on the earlier of (i) the date twelve (12) months
following the date of death (or such longer or shorter  period  specified in the
Option  Agreement),  or (ii) the  expiration  of the term of such  Option as set
forth in the Option  Agreement.  If, at the time of death,  the Optionee was not
entitled  to  exercise  his or her  entire  Option,  the  shares  covered by the
unexercisable  portion of the Option shall revert to and again become  available
for issuance under the Plan. If, after death, the Option is not exercised within
the time specified herein, the Option shall terminate, and the shares covered by
such Option shall revert to and again become  available  for issuance  under the
Plan.

     (i) Early  Exercise.  The Option  may,  but need not,  include a  provision
whereby  the  Optionee  may elect at any time  while an  Employee,  Director  or
Consultant to exercise the Option as to any part or all of the shares subject to
the Option  prior to the full  vesting of the  Option.  Any  unvested  shares so
purchased may be subject to a repurchase right in favor of the Company or to any
other restriction the Board determines to be appropriate.

     (j) Re-Load Options. Without in any way limiting the authority of the Board
or  Committee to make or not to make grants of Options  hereunder,  the Board or
Committee shall have the authority (but not an obligation) to include as part of
any Option  Agreement a provision  entitling the Optionee to a further Option (a
"Re-Load  Option") in the event the Optionee  exercises the Option  evidenced by
the Option  agreement,  in whole or in part,  by  surrendering  other  shares of
Common Stock in  accordance  with this Plan and the terms and  conditions of the
Option  Agreement.  Any such Re-Load  Option (i) shall be for a number of shares
equal to the number of shares  surrendered  as part or all of the exercise price
of such  Option;  (ii)  shall have an  expiration  date which is the same as the
expiration  date of the Option the  exercise of which gave rise to such  Re-Load
Option;  and (iii)  shall have an  exercise  price which is equal to one hundred
percent  (100%) of the Fair  Market  Value of the  Common  Stock  subject to the
Re-Load Option on the date of exercise of the original  Option.  Notwithstanding
the foregoing,  a Re-Load Option which is an Incentive Stock Option and which is
granted to a 10%  stockholder (as described in subsection  5(c)),  shall have an
exercise  price which is equal to one  hundred  ten  percent  (110%) of the Fair
Market Value of the stock subject to the Re-Load  Option on the date of exercise
of the  original  Option and shall have a term which is no longer  than five (5)
years.

     Any such Re-Load Option may be an Incentive  Stock Option or a Nonstatutory
Stock  Option,  as the Board or Committee may designate at the time of the grant
of the original Option;  provided,  however, that the designation of any Re-Load
Option as an Incentive Stock Option shall be subject to the one hundred thousand
dollar ($100,000) annual limitation on exercisability of Incentive Stock Options
described  in  subsection  12(d) of the Plan and in Section  422(d) of the Code.
There shall be no Re-Load Options on a Re-Load  Option.  Any such Re-Load Option
shall be subject to the availability of sufficient  shares under subsection 4(a)
and  shall be  subject  to such  other  terms  and  conditions  as the  Board or
Committee may determine which are not inconsistent  with the express  provisions
of the Plan regarding the terms of Options.


                                       9.
<PAGE>


7.   TERMS OF STOCK BONUSES AND PURCHASES OF RESTRICTED STOCK.

     Each stock bonus or restricted  stock purchase  agreement  shall be in such
form and shall  contain such terms and  conditions as the Board or the Committee
shall deem  appropriate.  The terms and  conditions of stock bonus or restricted
stock  purchase  agreements  may  change  from  time to time,  and the terms and
conditions of separate agreements need not be identical, but each stock bonus or
restricted  stock purchase  agreement shall include  (through  incorporation  of
provisions  hereof by reference in the agreement or otherwise)  the substance of
each of the following provisions as appropriate:

     (a) Purchase Price. The purchase price under each restricted stock purchase
agreement  shall be such amount as the Board or Committee  shall  determine  and
designate in such  agreement  but in no event shall the  purchase  price be less
than eighty-five percent (85%) of the stock's Fair Market Value on the date such
award is made.  Notwithstanding  the  foregoing,  the Board or the Committee may
determine that eligible  participants  in the Plan may be awarded stock pursuant
to a stock bonus agreement in consideration  for past services actually rendered
to the Company for its benefit.

     (b)  Transferability.  No rights  under a stock bonus or  restricted  stock
purchase  agreement shall be transferable  except by will or the laws of descent
and distribution or pursuant to a qualified  domestic relations order satisfying
the  requirements  of Rule  16b-3  and  any  administrative  interpretations  or
pronouncements thereunder, so long as stock awarded under such agreement remains
subject to the terms of the agreement.

     (c) Consideration. The purchase price of stock acquired pursuant to a stock
purchase  agreement  shall be paid either:  (i) in cash at the time of purchase;
(ii) at the  discretion of the Board or the  Committee,  according to a deferred
payment or other arrangement with the person to whom the stock is sold; or (iii)
in any other form of legal  consideration that may be acceptable to the Board or
the Committee in its discretion. Notwithstanding the foregoing, the Board or the
Committee to which administration of the Plan has been delegated may award stock
pursuant to a stock bonus agreement in consideration  for past services actually
rendered to the Company or for its benefit.

     (d) Vesting.  Shares of stock sold or awarded  under the Plan may, but need
not, be subject to a  repurchase  option in favor of the  Company in  accordance
with a vesting schedule to be determined by the Board or the Committee.

     (e)  Termination of Employment or Relationship as a Director or Consultant.
In the event a  Participant's  Continuous  Status as an  Employee,  Director  or
Consultant terminates,  the Company may repurchase or otherwise reacquire any or
all of the shares of stock held by that  person  which have not vested as of the
date of  termination  under  the terms of the stock  bonus or  restricted  stock
purchase agreement between the Company and such person.

8.   STOCK APPRECIATION RIGHTS.

     (a) The Board or Committee shall have full power and authority, exercisable
in its sole  discretion,  to grant Stock  Appreciation  Rights under the Plan to
Employees and Consultants. To exercise any outstanding Stock Appreciation Right,
the holder must provide  written notice of


                                      10.
<PAGE>


exercise to the Company in  compliance  with the  provisions  of the Stock Award
Agreement  evidencing such right. If a Stock Appreciation Right is granted to an
individual  who is at the time  subject to Section  16(b) of the Exchange Act (a
"Section 16(b) Insider"),  the Stock Award Agreement of grant shall  incorporate
all the terms and conditions at the time necessary to assure that the subsequent
exercise  of such  right  shall  qualify  for  the  safe-harbor  exemption  from
short-swing  profit  liability  provided  by Rule  16b-3  promulgated  under the
Exchange  Act (or any  successor  rule or  regulation).  Except as  provided  in
subsection  5(d),  no  limitation  shall exist on the  aggregate  amount of cash
payments the Company may make under the Plan in connection  with the exercise of
Stock Appreciation Rights.

     (b)  Three  types of Stock  Appreciation  Rights  shall be  authorized  for
issuance under the Plan:

          (1) Tandem Stock Appreciation Rights. Tandem Stock Appreciation Rights
     will be granted appurtenant to an Option, and shall, except as specifically
     set forth in this  Section 8, be  subject to the same terms and  conditions
     applicable  to the  particular  Option grant to which it  pertains.  Tandem
     Stock  Appreciation  Rights will  require  the holder to elect  between the
     exercise of the underlying Option for shares of stock and the surrender, in
     whole or in part,  of such  Option for an  appreciation  distribution.  The
     appreciation distribution payable on the exercised Tandem Right shall be in
     cash (or, if so provided,  in an equivalent number of shares of stock based
     on Fair Market Value on the date of the Option  surrender)  in an amount up
     to the  excess  of (A) the Fair  Market  Value  (on the date of the  Option
     surrender)  of the number of shares of stock covered by that portion of the
     surrendered  Option in which the Optionee is vested over (B) the  aggregate
     exercise price payable for such vested shares.

          (2) Concurrent Stock  Appreciation  Rights.  Concurrent Rights will be
     granted appurtenant to an Option and may apply to all or any portion of the
     shares of stock  subject to the  underlying  Option  and  shall,  except as
     specifically  set forth in this Section 8, be subject to the same terms and
     conditions  applicable to the particular Option grant to which it pertains.
     A Concurrent  Right shall be exercised  automatically  at the same time the
     underlying  Option is exercised  with respect to the  particular  shares of
     stock to which the Concurrent Right pertains. The appreciation distribution
     payable  on an  exercised  Concurrent  Right  shall be in cash  (or,  if so
     provided,  in an equivalent  number of shares of stock based on Fair Market
     Value on the date of the  exercise  of the  Concurrent  Right) in an amount
     equal to such portion as shall be  determined by the Board or the Committee
     at the time of the grant of the  excess of (A) the  aggregate  Fair  Market
     Value (on the date of the exercise of the  Concurrent  Right) of the vested
     shares of stock purchased under the underlying Option which have Concurrent
     Rights  appurtenant to them over (B) the aggregate  exercise price paid for
     such shares.

          (3) Independent Stock Appreciation Rights.  Independent Rights will be
     granted  independently of any Option and shall,  except as specifically set
     forth in this  Section  8, be  subject  to the same  terms  and  conditions
     applicable  to  Nonstatutory  Stock Options as set forth in Section 6. They
     shall be denominated in share  equivalents.  The appreciation  distribution
     payable on the  exercised  Independent  Right shall be not greater  than an
     amount equal to the excess of (A) the  aggregate  Fair Market Value (on the
     date of the  exercise  of the  Independent  Right) of a number of shares of
     Company stock equal to the number of share  equivalents in


                                      11.
<PAGE>



     which the holder is vested under such  Independent  Right, and with respect
     to which the holder is exercising the Independent  Right on such date, over
     (B) the  aggregate  Fair  Market  Value  (on the  date of the  grant of the
     Independent  Right)  of  such  number  of  shares  of  Company  stock.  The
     appreciation  distribution payable on the exercised Independent Right shall
     be in cash or, if so provided,  in an equivalent  number of shares of stock
     based on Fair Market Value on the date of the  exercise of the  Independent
     Right.

9.   CANCELLATION AND RE-GRANT OF OPTIONS.

     (a) The Board or the Committee  shall have the authority to effect,  at any
time and from time to time, (i) the repricing of any outstanding  Options and/or
any Stock Appreciation Rights under the Plan and/or (ii) with the consent of any
adversely  affected  holders of Options and/or Stock  Appreciation  Rights,  the
cancellation of any  outstanding  Options and/or any Stock  Appreciation  Rights
under the Plan and the grant in  substitution  therefor  of new  Options  and/or
Stock Appreciation  Rights under the Plan covering the same or different numbers
of shares of  stock,  but  having  an  exercise  price per share not less  than:
eighty-five  percent  (85%) of the Fair Market  Value for a  Nonstatutory  Stock
Option,  one hundred  percent  (100%) of the Fair Market Value in the case of an
Incentive  Stock Option or, in the case of an  Incentive  Stock Option held by a
10% stockholder (as described in subsection 5(c)), not less than one hundred ten
percent  (110%)  of the Fair  Market  Value  per share of stock on the new grant
date.  Notwithstanding  the  foregoing,  the Board or the Committee may grant an
Option and/or Stock  Appreciation  Right with an exercise  price lower than that
set forth above if such Option  and/or  Stock  Appreciation  Right is granted as
part of a transaction to which section 424(a) of the Code applies.

     (b) Shares subject to an Option or Stock  Appreciation Right canceled under
this Section 9 shall continue to be counted against the maximum award of Options
and Stock  Appreciation  Rights  permitted to be granted  pursuant to subsection
5(d) of the Plan.  The  repricing of an Option and/or Stock  Appreciation  Right
under this Section 9, resulting in a reduction of the exercise  price,  shall be
deemed to be a  cancellation  of the original  Option and/or Stock  Appreciation
Right and the grant of a substitute Option and/or Stock  Appreciation  Right; in
the event of such repricing,  both the original and the substituted  Options and
Stock Appreciation Rights shall be counted against the maximum awards of Options
and Stock  Appreciation  Rights  permitted to be granted  pursuant to subsection
5(d) of the Plan.  The  provisions of this  subsection  9(b) shall be applicable
only to the extent required by Section 162(m) of the Code.

10.  COVENANTS OF THE COMPANY.

     (a) During the terms of the Stock Awards,  the Company shall keep available
at all times  the  number of shares of stock  required  to  satisfy  such  Stock
Awards.

     (b) The Company  shall seek to obtain from each  regulatory  commission  or
agency having  jurisdiction  over the Plan such  authority as may be required to
issue and sell  shares of stock  upon  exercise  of the Stock  Award;  provided,
however,  that this undertaking  shall not require the Company to register under
the Securities Act of 1933, as amended (the  "Securities  Act") either the Plan,
any Stock Award or any stock issued or issuable pursuant to any such


                                      12.
<PAGE>


Stock Award. If, after reasonable efforts,  the Company is unable to obtain from
any such  regulatory  commission or agency the  authority  which counsel for the
Company  deems  necessary  for the lawful  issuance  and sale of stock under the
Plan,  the Company shall be relieved from any liability for failure to issue and
sell stock upon exercise of such Stock Awards unless and until such authority is
obtained.

11.  USE OF PROCEEDS FROM STOCK.

     Proceeds from the sale of stock  pursuant to Stock Awards shall  constitute
general funds of the Company.

12.  MISCELLANEOUS.

     (a) The Board shall have the power to accelerate  the time at which a Stock
Award may first be  exercised or the time during which a Stock Award or any part
thereof will vest pursuant to subsection 6(e), 7(d) or 8(b), notwithstanding the
provisions  in the  Stock  Award  stating  the  time at  which  it may  first be
exercised or the time during which it will vest.

     (b) Neither an Employee,  a Consultant nor any person to whom a Stock Award
is transferred in accordance  with the Plan shall be deemed to be the holder of,
or to have any of the rights of a holder with respect to, any shares  subject to
such Stock Award unless and until such person has satisfied all requirements for
exercise of the Stock Award pursuant to its terms.

     (c) Nothing in the Plan or any  instrument  executed or Stock Award granted
pursuant  thereto shall confer upon any Employee,  Consultant or other holder of
Stock Awards any right to continue in the employ of the Company or any Affiliate
or to continue  acting as a Consultant  or shall affect the right of the Company
or any  Affiliate to terminate  the  employment  of any Employee with or without
notice and with or without cause, or the right to terminate the  relationship of
any  Consultant  pursuant to the terms of such  Consultant's  agreement with the
Company or Affiliate.

     (d) To the extent that the aggregate  Fair Market Value  (determined at the
time of grant) of stock  with  respect  to which  Incentive  Stock  Options  are
exercisable  for the first time by any Optionee  during any calendar  year under
all plans of the Company and its Affiliates exceeds one hundred thousand dollars
($100,000),  the Options or portions  thereof which exceed such limit (according
to the order in which they were granted) shall be treated as Nonstatutory  Stock
Options.

     (e) The Company may require any person to whom a Stock Award is granted, or
any person to whom a Stock Award is transferred in accordance  with the Plan, as
a condition of exercising or acquiring stock under any Stock Award,  (1) to give
written assurances satisfactory to the Company as to such person's knowledge and
experience  in  financial  and  business  matters  and/or to employ a  purchaser
representative  reasonably  satisfactory to the Company who is knowledgeable and
experienced in financial and business matters,  and that he or she is capable of
evaluating, alone or together with the purchaser representative,  the merits and
risks  of  exercising  the  Stock  Award;  and  (2) to give  written  assurances
satisfactory  to the Company  stating  that such person is  acquiring  the stock
subject to the Stock Award for such person's own account and not


                                      13.
<PAGE>


with any present  intention of selling or otherwise  distributing the stock. The
foregoing requirements,  and any assurances given pursuant to such requirements,
shall be  inoperative  if (i) the  issuance of the shares  upon the  exercise or
acquisition  of stock  under the Stock  Award has been  registered  under a then
currently effective  registration statement under the Securities Act, or (ii) as
to any  particular  requirement,  a  determination  is made by  counsel  for the
Company that such  requirement  need not be met in the  circumstances  under the
then applicable  securities laws. The Company may, upon advice of counsel to the
Company,  place  legends  on stock  certificates  issued  under the Plan as such
counsel  deems  necessary  or  appropriate  in order to comply  with  applicable
securities laws, including, but not limited to, legends restricting the transfer
of the stock.

     (f) To the extent  provided  by the terms of a Stock Award  Agreement,  the
person to whom a Stock Award is granted may satisfy any federal,  state or local
tax  withholding  obligation  relating to the exercise or  acquisition  of stock
under a Stock Award by any of the following  means or by a  combination  of such
means:  (1) tendering a cash payment;  (2)  authorizing  the Company to withhold
shares from the shares of the common stock otherwise issuable to the participant
as a result of the exercise or  acquisition  of stock under the Stock Award;  or
(3) delivering to the Company owned and unencumbered  shares of the common stock
of the Company.

13.  ADJUSTMENTS UPON CHANGES IN STOCK.

     (a) If any change is made in the stock  subject to the Plan,  or subject to
any Stock Award,  without the receipt of  consideration  by the Company (through
merger, consolidation, reorganization, recapitalization,  reincorporation, stock
dividend,  dividend  in  property  other than  cash,  stock  split,  liquidating
dividend,  combination  of  shares,  exchange  of  shares,  change in  corporate
structure or other transaction not involving the receipt of consideration by the
Company),  the Plan will be appropriately  adjusted in the class(es) and maximum
number of shares subject to the Plan pursuant to subsection 4(a) and the maximum
number of  shares  subject  to award to any  person  during  any  calendar  year
pursuant  to  subsection  5(d),  and  the  outstanding   Stock  Awards  will  be
appropriately adjusted in the class(es) and number of shares and price per share
of stock subject to such outstanding  Stock Awards.  Such  adjustments  shall be
made by the Board or the Committee,  the  determination of which shall be final,
binding and conclusive.  (The  conversion of any  convertible  securities of the
Company  shall not be treated as a  "transaction  not  involving  the receipt of
consideration by the Company".)

     (b) In the  event  of:  (1) a  dissolution,  liquidation  or sale of all or
substantially all of the assets of the Company; (2) a merger or consolidation in
which the Company is not the surviving  corporation;  or (3) a reverse merger in
which the Company is the surviving  corporation  but the shares of the Company's
common  stock  outstanding  immediately  preceding  the merger are  converted by
virtue of the merger  into other  property,  whether in the form of  securities,
cash or  otherwise,  then to the extent  permitted  by  applicable  law: (i) any
surviving corporation or an Affiliate of such surviving corporation shall assume
any Stock Awards  outstanding  under the Plan or shall substitute  similar Stock
Awards for those  outstanding  under the Plan,  or (ii) such Stock  Awards shall
continue in full force and effect.  In the event any surviving  corporation  and
its Affiliates  refuse to assume or continue such Stock Awards, or to substitute
similar options for


                                      14.
<PAGE>


those  outstanding  under the Plan,  then,  with respect to Stock Awards held by
persons then performing  services as Employees,  Directors or  Consultants,  the
time during which such Stock Awards may be exercised  shall be  accelerated  and
the Stock Awards terminated if not exercised prior to such event.

14.  AMENDMENT OF THE PLAN AND STOCK AWARDS.

     (a) The  Board at any  time,  and from  time to time,  may  amend the Plan.
However,  except as provided in Section 13 relating to adjustments  upon changes
in stock, no amendment shall be effective unless approved by the stockholders of
the  Company  within  twelve  (12)  months  before or after the  adoption of the
amendment,  where  the  amendment  will  modify  the Plan in any way that  would
require  stockholder  approval in order for the Plan to satisfy the requirements
of Section 422 of the Code or to comply with the  requirements  of Rule 16b-3 or
any Nasdaq or securities exchange listing requirements (e.g., an increase in the
number of shares available for awards or a change to eligibility for Awards).

     (b) The Board may in its sole discretion  submit any other amendment to the
Plan for stockholder approval,  including, but not limited to, amendments to the
Plan intended to satisfy the  requirements of Section 162(m) of the Code and the
regulations  promulgated thereunder regarding the exclusion of performance-based
compensation  from the limit on corporate  deductibility of compensation paid to
certain executive officers.

     (c) It is expressly  contemplated  that the Board may amend the Plan in any
respect the Board deems necessary or advisable to provide eligible  Employees or
Consultants  with the maximum  benefits  provided  or to be  provided  under the
provisions of the Code and the regulations  promulgated  thereunder  relating to
Incentive Stock Options and/or to bring the Plan and/or  Incentive Stock Options
granted under it into compliance therewith.

     (d) Rights and obligations  under any Stock Award granted before  amendment
of the Plan shall not be  impaired by any  amendment  of the Plan unless (i) the
Company  requests  the consent of the person to whom the Stock Award was granted
and (ii) such person consents in writing.

     (e) The  Board at any time,  and from time to time,  may amend the terms of
any one or more Stock Award; provided,  however, that the rights and obligations
under any Stock Award shall not be impaired by any such amendment unless (i) the
Company  requests  the consent of the person to whom the Stock Award was granted
and (ii) such person consents in writing.


                                      15.
<PAGE>


15.  TERMINATION OR SUSPENSION OF THE PLAN.

     (a) The Board may suspend or terminate the Plan at any time.  Unless sooner
terminated,  the Plan shall  terminate  ten (10) years from the date the Plan is
adopted by the Board or approved by the  stockholders of the Company,  whichever
is  earlier.  No Stock  Awards may be  granted  under the Plan while the Plan is
suspended or after it is terminated.

     (b) Rights and obligations  under any Stock Award granted while the Plan is
in effect shall not be impaired by suspension or termination of the Plan, except
with the consent of the person to whom the Stock Award was granted.

16.  EFFECTIVE DATE OF PLAN.

     The Plan shall become  effective as determined  by the Board,  but no Stock
Awards  granted under the Plan shall be exercised  unless and until the Plan has
been approved by the stockholders of the Company, which approval shall be within
twelve (12) months before or after the date the Plan is adopted by the Board.


<PAGE>




                                   DETACH HERE


                                      PROXY

                                     AVIRON

                            297 North Bernardo Avenue
                         Mountain View, California 94043

                       SOLICITED BY THE BOARD OF DIRECTORS
                     FOR THE ANNUAL MEETING OF STOCKHOLDERS

     The undersigned hereby appoints J. Leighton Read, M.D. and Fred Kurland, or
either of them, each with the power of substitution,  and hereby authorizes them
to represent  and to vote,  as  designated  on the reverse  side,  all shares of
common  stock of Aviron (the  "Company")  held of record by the  undersigned  on
April 15, 1999 at the Annual Meeting of  Stockholders to be held on June 3, 1999
and any adjournments thereof.

     THIS  PROXY  WHEN  PROPERLY  EXECUTED  WILL BE  VOTED  AS  DIRECTED,  IF NO
DIRECTION  IS GIVEN WITH RESPECT TO A  PARTICULAR  PROPOSAL,  THIS PROXY WILL BE
VOTED FOR SUCH PROPOSAL.

     PLEASE MARK,  DATE,  SIGN, AND RETURN THIS PROXY CARD  PROMPTLY,  USING THE
ENCLOSED ENVELOPE. NO POSTAGE IS REQUIRED IF MAILED IN THE UNITED STATES.


- -----------                                                          -----------
SEE REVERSE        CONTINUED AND TO BE SIGNED ON REVERSE SIDE        SEE REVERSE
   SIDE                                                                 SIDE    
- -----------                                                          -----------

 
<PAGE>


Dear Stockholder:

Please take note of the important  information  enclosed with this Proxy.  There
are a number of issues related to the operation of the Company that require your
immediate attention.

Your vote counts, and you are strongly encouraged to exercise your right to vote
your shares.

Please  mark the boxes on the proxy card to  indicate  how your  shares  will be
voted.  Then sign the card,  detach it and return your prompt  consideration  of
these matters.

Sincerely,

Aviron




                                   DETACH HERE


|_|  Please mark
     votes as in
     this example.


1.   Election of two Directors.
                                                     
     Nominee:  Paul H. Klingenstein 

          FOR                      WITHHELD

          |_|                         |_|
                                                     
     Nominee:  Jane E. Shaw, Ph.D.                

          FOR                      WITHHELD

          |_|                         |_|
                                                     
2.   Approve the Company's 1996 Equity  Incentive Plan, as amended,  to increase
     the  aggregate  number of shares of Common  Stock  authorized  for issuance
     under such plan by 780,000 shares, to 4,030,000 shares.

          FOR                       AGAINST                      ABSTAIN

          |_|                         |_|                          |_|
                                                     
3.   Ratify the appointment of Ernst & Young LLP as independent  auditors of the
     Company  for its  fiscal  year  ending  December  31,  1999. 

          FOR                       AGAINST                      ABSTAIN

          |_|                         |_|                          |_|
                                                     
4.   In their  discretion,  the  proxies are  authorized  to vote upon any other
     business that may properly come before the meeting. 

Please sign  exactly as name  appears  hereon.  Joint  owners  should each sign.
Executors, administrators,  trustees, guardians or other fiduciaries should give
full title as such. If signing for a corporation,  please sign in full corporate
name by a duly authorized officer.


<PAGE>



Signature:                                             Date:  
          --------------------------------------------       -------------------



Signature:                                             Date:  
          --------------------------------------------       -------------------




                                       2.




© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission