TRIMERIS INC
S-1/A, 1997-09-08
COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH
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<PAGE>
   
   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 8, 1997
    

                           REGISTRATION NO. 333-31109

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON D.C. 20549

   
                                AMENDMENT NO. 2
    

                                       TO

                                    FORM S-1

                             REGISTRATION STATEMENT

                                     UNDER

                           THE SECURITIES ACT OF 1933

                                 TRIMERIS, INC.

             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                   <C>                         <C>
             DELAWARE                         8733                56-1808663
   (State or other jurisdiction        (Primary Standard       (I.R.S. Employer
of incorporation or Organization)   Industrial Code Number)   Identification No.)
</TABLE>

                        4727 UNIVERSITY DRIVE, SUITE 100
                          DURHAM, NORTH CAROLINA 27707
                                 (919) 419-6050

         (Address, including zip code, and telephone number, including
            area code, of registrant's principal executive offices)

                              DR. M. ROSS JOHNSON
                       PRESIDENT, CHIEF EXECUTIVE OFFICER
                          AND CHIEF SCIENTIFIC OFFICER
                        4727 UNIVERSITY DRIVE, SUITE 100
                          DURHAM, NORTH CAROLINA 27707
                                 (919) 419-6050

           (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

                                   COPIES TO:

<TABLE>
<CAPTION>
                         COUNSEL TO COMPANY                              COUNSEL TO UNDERWRITERS
    <S>                               <C>                            <C>
    FRED D. HUTCHISON, ESQUIRE        JOHN B. WATKINS, ESQUIRE       ALEXANDER D. LYNCH, ESQUIRE
    HUTCHISON & MASON PLLC            WILMER, CUTLER & PICKERING     BROBECK, PHLEGER & HARRISON LLP
    4011 WESTCHASE BOULEVARD          2445 M ST., N.W.               1633 BROADWAY
    SUITE 400                         WASHINGTON, D.C. 20037         47TH FLOOR
    RALEIGH, NORTH CAROLINA 27607     (202) 663-6000                 NEW YORK, NEW YORK 10019
    (919) 829-9600                                                   (212) 581-1600
</TABLE>

          APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO PUBLIC:
  As soon as practicable after this Registration Statement becomes effective.

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, check the following box. [ ]
     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. [ ]
     If this Form is a post-effective amendment filed pursuant to Rule 462(b)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [ ]
     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [ ]

     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933, OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION, ACTING
PURSUANT TO SAID SECTION 8(A), MAY DETERMINE.

<PAGE>

(A redherring appears on the left side of page, rotated 90 degrees with the
following text:)

Information contained herein is subject to completion or amendment. A
registration statement relating to these securities has been filed with the
Securities and Exchange Commission. These securities may not be sold nor may
offers to buy be accepted prior to the time the registration statement becomes
effective. This prospectus shall not constitute an offer to sell or the
solicitation of an offer to buy, nor shall there be any sale of these
securities in any jurisdiction in which such offer, solicitation or sale would
be unlawful prior to registration or qualification under the securities laws of
any such jurisdiction.

   
                 SUBJECT TO COMPLETION, DATED SEPTEMBER 8, 1997
    
PROSPECTUS
                                2,500,000 Shares
                                   (logo)
                                 Trimeris, Inc.

                                  Common Stock

   
       All of the 2,500,000 shares of Common Stock offered hereby (the
"Offering") are being sold by Trimeris, Inc., a development stage company with a
limited operating history ("Trimeris" or the "Company"). The Company has
incurred losses since its inception, had an accumulated deficit of approximately
$21.4 million as of June 30, 1997, and expects to incur substantial losses for
the foreseeable future. Prior to this Offering, there has been no public market
for the Common Stock of the Company. It is currently estimated that the initial
public offering price will be between $12.00 and $14.00 per share. See
"Underwriting" for a discussion of the factors to be considered in determining
the initial public offering price. The Common Stock has been approved for
quotation on the Nasdaq National Market under the symbol "TRMS," subject to
official notice of issuance.
    

       THE COMMON STOCK OFFERED HEREBY INVOLVES A HIGH DEGREE OF RISK. SEE "RISK
FACTORS," BEGINNING ON PAGE 6.

THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
   EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
     SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION
       PASSED UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY
         REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

[CAPTION]
<TABLE>
<S>                                         <C>                       <C>                       <C>
                                                    Price to           Underwriting Discounts         Proceeds to
                                                     Public              and Commissions(1)            Company(2)
<S>                                         <C>                       <C>                       <C>
Per Share...............................               $                         $                         $
Total(3)................................               $                         $                         $
</TABLE>

1.  For information regarding indemnification of the Underwriters, see
    "Underwriting."
2.  Before deducting expenses of the Offering payable by the Company, estimated
    at approximately $800,000.
3.  The Company has granted the Underwriters an option, exercisable within 30
    days from the date hereof, to purchase up to 375,000 additional shares of
    Common Stock on the same terms and conditions as set forth above, solely to
    cover over-allotments, if any. If such option is exercised in full, total
    Price to Public will be $     , Underwriting Discounts and Commissions will
    be $     and Proceeds to the Company will be $     . See "Underwriting."

     The shares of Common Stock offered by the Underwriters are subject to prior
sale, receipt and acceptance by them and subject to the right of the
Underwriters to reject any order in whole or in part and to certain other
conditions. It is expected that delivery of such shares will be made through the
offices of UBS Securities LLC, 299 Park Avenue, New York, New York, on or about
      , 1997.

UBS Securities                                             Montgomery Securities

               , 1997

<PAGE>
                  [Model for T-20 inhibition of HIV Fusion and
          infection of a host cell as more fully described on page 25]

     CERTAIN PERSONS PARTICIPATING IN THIS OFFERING MAY ENGAGE IN TRANSACTIONS
THAT STABILIZE, MAINTAIN OR OTHERWISE AFFECT THE PRICE OF THE COMMON STOCK.
SPECIFICALLY, THE UNDERWRITERS MAY OVERALLOT IN CONNECTION WITH THE OFFERING AND
MAY BID FOR AND PURCHASE SHARES OF THE COMMON STOCK IN THE OPEN MARKET. FOR A
DESCRIPTION OF THESE ACTIVITIES, SEE "UNDERWRITING."

                                       2

<PAGE>
                               PROSPECTUS SUMMARY

     THE FOLLOWING SUMMARY IS QUALIFIED IN ITS ENTIRETY BY THE MORE DETAILED
INFORMATION AND THE FINANCIAL STATEMENTS AND NOTES THERETO APPEARING ELSEWHERE
IN THIS PROSPECTUS, INCLUDING THE INFORMATION UNDER "RISK FACTORS." THIS
PROSPECTUS CONTAINS FORWARD-LOOKING STATEMENTS WHICH INVOLVE RISKS AND
UNCERTAINTIES. THE COMPANY'S ACTUAL RESULTS MAY DIFFER SIGNIFICANTLY FROM THE
RESULTS DISCUSSED IN THESE FORWARD-LOOKING STATEMENTS. FACTORS THAT MIGHT CAUSE
SUCH A DIFFERENCE INCLUDE, BUT ARE NOT LIMITED TO, THOSE SET FORTH UNDER "RISK
FACTORS" AND ELSEWHERE IN THIS PROSPECTUS.

                                  THE COMPANY

   
     Trimeris is a biopharmaceutical company engaged in the discovery and
development of novel therapeutic agents that block viral infection by inhibiting
viral fusion with host cells. Viral fusion is a complex process by which viruses
attach to and penetrate host cells. The Company's lead product candidate, T-20,
inhibits fusion of the Human Immunodeficiency Virus-1 ("HIV") with host cells.
T-20 has been tested in a multidose Phase I/II clinical trial as a monotherapy
for HIV-infected patients in the United States. The results from this clinical
trial indicate that short-term administration of T-20 in an intravenous
formulation is safe and well tolerated. Furthermore, all four patients in the
clinical trial who received the highest dose of T-20 experienced a reduction in
HIV viral load to below detectable levels (less than 500 copies/ml) during the
treatment period. T-20 and the Company's other product candidates are designed
to inhibit viral fusion, unlike other currently approved therapeutic agents that
target replicating viruses inside already infected cells. The Company has
developed a proprietary technology platform in the field of fusion inhibition,
which is being applied to the discovery and development of novel products for
the treatment of a variety of viral diseases.
    

   
     T-20 is a proprietary 36 amino acid synthetic peptide which has
demonstrated significant inhibition of HIV in preclinical testing. In the Phase
I/II clinical trial, no drug-related adverse events were recorded and no
dose-limiting toxicities were observed for any patient during the treatment
period. A dose-dependent decrease in HIV viral load and a dose-dependent
increase in the patients' CD4+ T-cell count were also observed. All four
patients who received the highest dose of T-20 (100 mg every 12 hours for 14
consecutive days) experienced a decrease in HIV viral load to below detectable
levels (less than 500 copies/ml) during the treatment period.
    

   
     The Company is preparing to begin a Phase II clinical trial in HIV-infected
patients in the United States that will compare delivery of a constant
therapeutic dose by a continuous, subcutaneous infusion pump to delivery by
intermittent, subcutaneous injections. The Company believes that delivery of a
continuous therapeutic dose may inhibit viral fusion more effectively than other
delivery mechanisms. After completion of the continuous, subcutaneous infusion
Phase II trial, the Company intends to begin a Phase II pivotal trial in a
larger population of HIV-infected patients who are either resistant to, or
intolerant of, currently approved antiviral therapies. Concurrently with the
start of the pivotal Phase II clinical trial, the Company intends to begin a
trial of T-20 in HIV-infected pediatric patients. In addition, throughout the
T-20 clinical process, the Company intends to work with the United States Food
and Drug Administration (the "FDA") to design and implement a clinical trial
strategy involving the administration of T-20 to HIV-infected patients in
combination with approved HIV antiviral agents.
    

   
     HIV infection causes Acquired Immunodeficiency Syndrome ("AIDS"), which is
the leading cause of death in the United States of men and women between the
ages of 25 and 44. Currently approved HIV antivirals inhibit reverse
transcriptase ("RT") and protease, two viral enzymes which are required for HIV
replication. RT and protease inhibitors must penetrate HIV-infected host cells
in order to be effective. HIV is prone to mutations that produce resistance to
RT and protease inhibitors. In an effort to overcome drug resistance, physicians
have begun to use RT and protease inhibitors in various combinations. While
combination therapy with RT and protease inhibitors represents an advance in the
treatment of HIV infection, it has not yet proven to be a cure. Moreover,
although these combinations have slowed the emergence of resistance, new mutant
strains have been identified which are resistant to several of the drugs
currently used in combination therapy. Due to the complexity of the dosing
regimens for many combination therapies, which can include 14-16 pills taken at
six to eight specific times during the
    

                                       3

<PAGE>
day, and the toxic side effects that can result from the use of such drugs, many
patients are unable to, or fail to, follow the recommended dosing regimens. Such
noncompliance leads to a reduction in the effectiveness of such drugs and an
increased opportunity for the development of resistance.

     The Company believes that T-20 may offer a new paradigm for the treatment
of HIV. Preclinical testing and early clinical trial results suggest that T-20
is less toxic than currently approved HIV antivirals. The Company believes that
T-20's reduced toxicity is due to its unique extracellular mechanism of action
and its chemical structure. Furthermore, the Company believes that the delivery
of a continuous therapeutic dose of T-20 by subcutaneous infusion will enhance
patient compliance, thereby reducing the likelihood of the development of
resistance.

     Through its study of the HIV fusion process, the Company has developed a
proprietary technology platform aimed at discovering antiviral compounds to
treat other diseases. The cornerstone of this platform is the Company's
Computerized Anti-Fusion Searching Technology ("CAST"), a proprietary computer
algorithm which identifies target sequences within certain viral proteins that
have the potential to interact during the fusion process. CAST has enabled the
Company to design product candidates for Respiratory Syncytial Virus ("RSV") and
Human Parainfluenza Virus ("HPIV") fusion inhibition. The Company has
identified, and filed patent applications disclosing, numerous discrete peptide
sequences, which include potential fusion targets in other viruses such as
hepatitis B and C, influenza and herpes.
 
     T-786 is the Company's lead product candidate for treatment of RSV
infection, which is a significant cause of pediatric bronchiolitis and
pneumonia. T-786 is a proprietary 36 amino acid synthetic peptide which shows
potent, specific and selective inhibition of RSV infection IN VITRO. T-786
significantly reduced the level of viral infection in an animal model.
Preclinical testing of T-786 is currently in progress. Upon successful
completion of these preclinical tests, the Company anticipates that it will
begin clinical trials with T-786 in 1998.
 
     The Company was incorporated under Delaware law as SL-1 Pharmaceuticals,
Inc. on January 7, 1993 and changed its name to Trimeris, Inc. on February 11,
1993. The Company's principal executive office is located at 4727 University
Drive, Durham, North Carolina 27707, and its telephone number is (919) 419-6050.
 
     UNLESS OTHERWISE INDICATED, ALL INFORMATION IN THIS PROSPECTUS (I) ASSUMES
THE UNDERWRITERS' OVER-ALLOTMENT OPTION IS NOT EXERCISED, (II) REFLECTS THE
AUTOMATIC CONVERSION UPON THE COMPLETION OF THIS OFFERING OF ALL OUTSTANDING
SHARES OF PREFERRED STOCK INTO 6,261,615 SHARES OF COMMON STOCK (THE "PREFERRED
STOCK CONVERSION"), AND (III) REFLECTS THE FILING OF A THIRD AMENDED AND
RESTATED CERTIFICATE OF INCORPORATION OF THE COMPANY WHICH, AMONG OTHER THINGS,
WILL AUTHORIZE 10,000,000 SHARES OF UNDESIGNATED PREFERRED STOCK. SEE
"DESCRIPTION OF CAPITAL STOCK," "CAPITALIZATION" AND "UNDERWRITING."
 
     THE COMPANY HAS FILED FOR REGISTRATION OF "TRIMERIS" AND THE COMPANY'S LOGO
AS TRADEMARKS AND SERVICE MARKS OF THE COMPANY. THIS PROSPECTUS ALSO INCLUDES
TRADEMARKS AND TRADE NAMES OF COMPANIES OTHER THAN THE COMPANY.
 
                                       4
 
<PAGE>
                                  THE OFFERING

<TABLE>
<S>                                                     <C>
Common Stock Offered..................................  2,500,000 shares
Common Stock Outstanding after this Offering..........  9,864,676 shares (1)
Use of Proceeds.......................................  To fund increased research and development activities, to
                                                        fund the expansion of facilities, to provide working
                                                        capital and to fund other general corporate purposes. See
                                                        "Use of Proceeds."
Proposed Nasdaq National Market Symbol................  TRMS
</TABLE>
 
                             SUMMARY FINANCIAL DATA
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)

                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
   
<TABLE>
<CAPTION>
                                PERIOD FROM INCEPTION                                      FOR THE           CUMULATIVE
                                  (JANUARY 7, 1993)               FOR THE             SIX MONTHS ENDED     FROM INCEPTION
                                       THROUGH           YEARS ENDED DECEMBER 31,         JUNE 30,        (JANUARY 7, 1993)
                                  DECEMBER 31, 1993      1994      1995      1996      1996      1997     TO JUNE 30, 1997
<S>                             <C>                     <C>       <C>       <C>       <C>       <C>       <C>
                                                                                         (UNAUDITED)         (UNAUDITED)
STATEMENT OF OPERATIONS DATA:
Revenue.......................         $    --          $    --   $   104   $    55   $    --   $   212       $     371
Research and development
  expenses....................             691            2,747     4,012     5,146     2,278     2,859          15,455
Operating loss................          (1,322)          (3,694)   (5,428)   (6,852)   (3,080)   (3,433)        (20,730)
Other income (expenses).......              11             (250)     (311)     (120)      (54)      (45)           (713)
Net loss......................          (1,311)          (3,944)   (5,739)   (6,972)   (3,134)   (3,478)        (21,443)
Pro forma net loss per share
  (2) (3).....................                                              $ (1.48)            $  (.59)
Pro forma weighted average
  shares used in computing pro
  forma net loss per share (2)
  (3).........................                                                4,705               5,880
</TABLE>
    
 
<TABLE>
<CAPTION>
                                                                                        AS OF JUNE 30, 1997
                                                                                            (UNAUDITED)
                                                                                              PRO       PRO FORMA AS
                                                                                ACTUAL     FORMA (3)    ADJUSTED (4)
<S>                                                                             <C>        <C>          <C>
BALANCE SHEET DATA:
Cash and cash equivalents....................................................   $ 8,912    $   8,912      $ 38,337
Working capital..............................................................     8,019        8,019        37,444
Total assets.................................................................    10,585       10,585        40,010
Notes payable and capital lease obligations, less current portion............       488          488           488
Accumulated deficit..........................................................   (21,443)     (21,443)      (21,443)
Total stockholders' equity...................................................     8,847        8,847        38,272
</TABLE>

(1) Based on the number of shares outstanding as of June 30, 1997. Excludes (i)
    260,361 shares of Common Stock reserved for issuance pursuant to stock
    options outstanding as of June 30, 1997 and (ii) an aggregate of 56,684
    shares of Common Stock issuable upon the exercise of warrants outstanding as
    of June 30, 1997. Also excludes an aggregate of 254,188 shares of Common
    Stock reserved for future issuance as of June 30, 1997 under the Company's
    New Stock Option Plan (the "Stock Option Plan"). See "Management -- Stock
    Option Plans," "Description of Capital Stock" and Note 5 of Notes to
    Financial Statements.
 
(2) Computed on the basis described in Note 1 of Notes to Financial Statements.
 
(3) Pro forma to give effect to the automatic conversion upon the completion of
    this Offering of all outstanding shares of the Company's Series A, B, C and
    D Preferred Stock, par value $.001 per share (the "Preferred Stock"), into
    6,261,615 shares of Common Stock.
 
(4) Adjusted to give effect to the sale of 2,500,000 shares of Common Stock
    offered hereby at an assumed initial public offering price of $13.00 per
    share after deducting the underwriting discounts and commissions and
    estimated offering expenses payable by the Company. See "Use of Proceeds"
    and "Capitalization."
 
                                       5
 
<PAGE>
                                  RISK FACTORS
 
     PROSPECTIVE INVESTORS IN THE SHARES OFFERED HEREBY SHOULD CAREFULLY
CONSIDER THE FOLLOWING RISK FACTORS, IN ADDITION TO THE OTHER INFORMATION
CONTAINED IN THIS PROSPECTUS. THIS PROSPECTUS CONTAINS FORWARD-LOOKING
STATEMENTS WHICH INVOLVE RISKS AND UNCERTAINTIES. THE COMPANY'S ACTUAL RESULTS
COULD DIFFER MATERIALLY FROM THOSE ANTICIPATED IN THESE FORWARD-LOOKING
STATEMENTS AS A RESULT OF CERTAIN FACTORS, INCLUDING THOSE SET FORTH IN THE
FOLLOWING RISK FACTORS AND ELSEWHERE IN THIS PROSPECTUS.
 
   
     DEVELOPMENT STAGE COMPANY. The Company commenced operations in January 1993
and is subject to all of the business risks associated with a biopharmaceutical
company in the early stage of development, including constraints on the
Company's financial, personnel and other resources, and uncertainties regarding
the Company's novel product discovery and development programs. Prospective
investors, therefore, have limited historical financial information about the
Company upon which to base their evaluation of the Company's performance and an
investment in the shares offered hereby. Since its inception, substantially all
of the Company's resources have been dedicated to the development, patenting,
preclinical testing and a Phase I/II clinical trial of T-20, the development of
its proprietary technology platform, and research and development and
preclinical testing of other potential product candidates and compounds
discovered by the Company. The Company has yet to generate any revenues from
product sales or royalties, and there can be no assurance that it will be able
to generate any such revenues or royalties in the future. Product candidates and
compounds discovered by the Company and developed through the Company's product
development programs will require significant additional, time-consuming and
costly research and development, preclinical testing and extensive clinical
trials prior to submission of any regulatory application for commercial use. See
"Management's Discussion and Analysis of Financial Condition and Results of
Operations -- Overview."
    
 
   
     HISTORY OF OPERATING LOSSES; ACCUMULATED DEFICIT; UNCERTAINTY OF FUTURE
PROFITABILITY. The Company has incurred losses since its inception. As of June
30, 1997, the Company's accumulated deficit was approximately $21.4 million.
Such losses have resulted principally from expenses incurred in the Company's
research and development activities associated with the development, patenting,
preclinical testing and a Phase I/II clinical trial of T-20, the development of
its proprietary technology platform, research and development and preclinical
testing of other potential product candidates and compounds discovered by the
Company, and from general and administrative expenses. The Company expects to
incur substantial losses for the foreseeable future and expects losses to
increase as the Company's research and development, preclinical testing and
clinical trial efforts expand. The amount and timing of the Company's operating
expenses will depend on several factors, including the status of the Company's
research and development activities, product candidate and compound discovery
and development efforts, including preclinical testing and clinical trials, the
timing of regulatory actions, the costs involved in preparing, filing,
prosecuting, maintaining, protecting and enforcing patent claims and other
proprietary rights, the ability of the Company to establish, internally or
through relationships with third parties, manufacturing, sales, marketing and
distribution capabilities, technological and other changes in the competitive
landscape, changes in the Company's existing research and development
relationships and strategic alliances, evaluation of the commercial viability of
potential product candidates and other factors, many of which are outside of the
Company's control. As a result, the Company believes that period-to-period
comparisons of financial results in the future are not necessarily meaningful
and results of operations in prior periods should not be relied upon as an
indication of future performance. Any deviations in results of operations from
levels expected by securities analysts and investors could have a material
adverse effect on the market price of the Common Stock. The Company's ability to
achieve profitability will depend, in part, upon its or its collaborative
partners' ability to successfully develop and obtain regulatory approval for
T-20 and other product candidates and compounds discovered by the Company, and
to develop the capacity, either internally or through relationships with third
parties, to manufacture, sell, market and distribute approved products, if any.
There can be no assurance that the Company will ever generate significant
revenues or achieve profitable operations. See "Use of Proceeds," "Management's
Discussion and Analysis of Financial Condition and Results of
Operations -- Overview" and "Business -- Programs and Product Candidates Under
Development."
    
 
     DEPENDENCE ON A SINGLE PRODUCT CANDIDATE. T-20 is the only product
candidate developed by the Company which has been tested in humans. The
Company's success will depend, in significant part, upon the ability of the
Company to establish the safety and effectiveness of T-20 in humans, to obtain
the requisite regulatory approvals
 
                                       6

<PAGE>
for the commercialization of T-20, to establish relationships for the
commercial-scale production of T-20 at acceptable cost and with appropriate
quality, to successfully market T-20, and to achieve market acceptance of T-20
by the medical community, including health care providers and third-party
payors. Failure of the Company or its collaborative partners to successfully
develop and commercialize T-20 would have a material adverse effect on the
Company's business, financial condition and results of operations. See
"Business -- Programs and Product Candidates Under Development."
 
     TECHNOLOGICAL UNCERTAINTY. The Company's product development programs are
based upon a novel technology designed to facilitate the discovery of product
candidates and compounds which are designed to treat viral infection through the
inhibition of viral fusion. The Company is not aware of any other approved
antiviral pharmaceutical products which target the inhibition of viral fusion.
Accordingly, product development utilizing the Company's novel mechanism of
action involves a high degree of risk, is highly uncertain, and could result in
unanticipated developments, clinical or regulatory delays, unexpected adverse
side effects or inadequate therapeutic effectiveness, any of which could slow or
suspend the Company's product development efforts which could have a material
adverse effect on the Company's business, financial condition and results of
operations. There can be no assurance that the Company's technologies will lead
to the discovery and development of any commercially viable products, that the
Company's research or product development efforts as to any particular product
candidate or compound will be successfully completed, that any such product
candidates or compounds will be proven to be safe and effective, or that
required regulatory approvals will be obtained. The Company's development
programs are subject to the risks inherent in the development of new products
using new technologies and approaches. There can be no assurance that unforeseen
problems will not develop with these technologies or applications, that the
Company will be able to address successfully technological challenges it
encounters in its research and development programs or that commercially
feasible product candidates or compounds will ultimately be developed by the
Company. See "Business -- Programs and Product Candidates Under Development" and
" -- Clinical Development Programs."
 
   
     UNCERTAINTIES RELATED TO CLINICAL TRIALS AND CLINICAL TRIAL STRATEGY.
Before obtaining required regulatory approvals for the commercial sale of any of
its product candidates or compounds, the Company must demonstrate through
preclinical testing and clinical trials that each product candidate or compound
is safe and effective for use in humans for each target indication. To date, the
Company has conducted initial preclinical testing of certain of its product
candidates and has conducted a Phase I/II clinical trial of T-20. The Company
intends to conduct a Phase II clinical trial and a pivotal clinical trial of
T-20. These clinical trials will involve a relatively small patient population.
No assurance can be given that the results of early clinical trials will support
the commencement of further clinical trials of T-20, that the results of the
clinical trials will support the Company's applications for regulatory approval,
or that regulatory authorities will not require the Company to conduct
additional clinical trials either prior to, or after, regulatory approval is
obtained. The Company may find, at any stage of this complex process, that
potential product candidates or compounds that appeared promising in preclinical
testing and early clinical trials do not demonstrate safety or effectiveness on
a larger scale in advanced clinical trials or do not receive the requisite
regulatory approvals. Accordingly, any product development program undertaken by
the Company may be curtailed, redirected or eliminated at any time, which could
result in delays in conducting further preclinical testing and clinical trials,
in unexpected adverse events in further preclinical testing and clinical trials,
and in additional development expenses. Furthermore, administration of the
Company's potential product candidates or compounds may prove to have
undesirable or unintended side effects in humans. The occurrence of side effects
could interrupt, delay or halt clinical trials of each such product candidate or
compound and could delay or prevent its approval by the FDA or foreign
regulatory authorities for any and all targeted indications. The Company or the
FDA may suspend or terminate clinical trials at any time if it is believed that
the trial participants are being exposed to unacceptable health risks. In
addition, this Prospectus reflects the Company's estimates regarding the timing
of future preclinical testing and clinical trials. Such preclinical testing and
clinical trials may be delayed or cancelled for a number of reasons, including
the receipt of unanticipated, adverse or ambiguous results from preclinical
testing or clinical trials, the demonstration of undesirable or unintended side
effects, the inability to locate, recruit and qualify sufficient numbers of
patients, lack of funding, the inability to locate or recruit scientists to
undertake or complete planned preclinical testing or clinical trials, the
redesign of the Company's preclinical testing or clinical trial programs, the
inability to manufacture or acquire sufficient quantities
    
 
                                       7
 
<PAGE>
of the particular product candidate or any other components required for
preclinical testing or clinical trials, regulatory delays or other regulatory
actions, changes in focus of the Company's or its collaborators' development
efforts, and the disclosure of clinical trial results by competitors.
Accordingly, no assurance can be given that the Company's preclinical testing or
clinical trials will commence on their target dates, or at all. Delays in such
testing and trials could delay regulatory approval for the Company's product
candidates, delay commercialization of the Company's product candidates,
increase operating expenses, result in the expenditure of additional capital,
cause the diversion of management time and attention, or create adverse market
perception about the Company and its product candidates, any of which could have
a material adverse effect on the Company's business, financial condition and
results of operations.
 
     The rate of completion of the Company's clinical trials will depend upon,
among other factors, obtaining or manufacturing adequate amounts of the
Company's product candidates from third-party manufacturers and sufficient
patient enrollment. See "Business -- Lack of Manufacturing Capabilities" for a
description of certain risks associated with the manufacturing of the Company's
product candidates and compounds. Patient enrollment is a function of many
factors, including the size of the patient population, the nature of the
protocol, the proximity of patients to clinical sites and the eligibility
criteria for the clinical trial. Delays in planned patient enrollment may result
in increased costs or delays or both, which could have a material adverse effect
on the Company's business, financial condition and results of operations. See
"Business -- Programs and Product Candidates Under Development" and
" -- Government Regulation."
 
   
     DEPENDENCE ON COLLABORATIONS AND LICENSES WITH OTHERS. The Company intends
to consider entering into collaborative and license arrangements with
collaborative partners, licensees and third parties to seek regulatory approval
of and to manufacture and commercialize certain of its existing and potential
product candidates and compounds. Accordingly, the Company's success will
depend, in part, upon the subsequent success of such third parties in performing
preclinical testing and clinical trials, obtaining the requisite regulatory
approvals, scaling up manufacturing, successfully commercializing the licensed
product candidates or compounds and otherwise performing their obligations.
There can be no assurance that the Company will be able to maintain its existing
arrangements or enter into acceptable collaborative and license arrangements in
the future on acceptable terms, if at all, that such arrangements will be
successful, that the parties with which the Company has or may establish
arrangements will perform their obligations under such arrangements, or that
potential collaborators will not compete with the Company by seeking alternative
means of developing therapeutics for the diseases targeted by the Company. There
can also be no assurance that the Company's existing or any future arrangements
will lead to the development of product candidates or compounds with commercial
potential, that the Company will be able to obtain proprietary rights or
licenses for the proprietary rights with respect to any technology or product
candidates or compounds developed in connection with these arrangements, or that
the Company will be able to ensure the confidentiality of any proprietary rights
and information developed in such arrangements or prevent the public disclosure
thereof. The Company currently has a license from Duke University, and in the
future may require additional licenses from these or other parties, to
effectively develop potential product candidates and compounds. Pursuant to a
license agreement with Duke University (the "Duke License"), the Company has
obtained an exclusive, worldwide license to existing and certain future
technologies in the field of antiviral therapeutics developed by several
researchers at Duke University for the life of each particular patent filed in
connection with such technologies. Unless the Duke License is renewed, the
Company will not be entitled to any additional technologies developed after 2000
or after any earlier termination. None of the technologies licensed by the
Company from Duke University is the subject of a separate individual license
agreement. Rather, the Company's rights to such technologies are licensed solely
pursuant to the Duke License. The early termination of the Duke License due to
the Company's failure to develop the licensed technologies or the failure of the
Company to renew the Duke License on acceptable terms, or at all, could have a
material adverse effect on the Company's business, financial condition and
results of operations. In addition, the Company is currently negotiating a
license with a third party to acquire a related technology. Pursuant to a
Cooperative and Strategic Alliance Agreement (the "MiniMed Agreement"), the
Company and MiniMed Inc. ("MiniMed") have agreed to jointly design, develop and
implement a system for the continual delivery of T-20 utilizing the MiniMed
continuous infusion pump. The failure of the Company and MiniMed to achieve
their collective objectives could have a material adverse effect on the
Company's business, financial condition and results of operations. In addition,
the Company has received two Small
    
 
                                       8
 
<PAGE>
   
Business Innovation Research ("SBIR") grants from the National Institutes of
Health and entered into an investigative contract with a third party to identify
certain pharmaceutical compounds. There can be no assurance that the funding
provided by such SBIR grants will be sufficient to complete the studies
contemplated by such programs or that the Company will receive any additional
future grants or funding under any of these programs. There can be no assurance
that such license or agreements can be maintained or that additional licenses
can be obtained on acceptable terms, if at all, or will be renewable if
obtained, or that the patents underlying such licenses, if any, will be valid
and enforceable, or that the proprietary nature of the patented technology
underlying such licenses will remain proprietary. See "Business -- License and
Collaborative Agreements."
    
 
     FUTURE CAPITAL NEEDS; UNCERTAINTY OF ADDITIONAL FUNDING. The Company has
experienced negative cash flows from operations since its inception and does not
anticipate generating sufficient positive cash flows to fund its operations in
the foreseeable future. The Company has expended, and expects to continue to
expend in the future, substantial funds to pursue its product candidate and
compound discovery and development efforts, including expenditures for continued
clinical trials of T-20, research and development and preclinical testing of
other potential product candidates and compounds discovered by the Company and
the development of its proprietary technology platform. The Company expects that
its existing capital resources, together with the net proceeds of this Offering
and the interest earned thereon, will be adequate to fund its capital
requirements through 1998. However, the Company's future capital requirements
and the adequacy of available funds will depend on many factors, including the
results of the clinical trials relating to T-20, the progress and scope of the
Company's product development programs, the magnitude of these programs, the
results of preclinical testing and clinical trials, the need for additional
facilities based on the results of these clinical trials and other product
development programs, changes in the focus and direction of the Company's
product development programs, the costs involved in preparing, filing,
prosecuting, maintaining, protecting and enforcing patent claims and other
intellectual property rights, competitive factors and technological advances,
the cost, timing and outcome of regulatory reviews, changes in the requirements
of the FDA, administrative and legal expenses, evaluation of the commercial
viability of potential product candidates and compounds, the establishment of
capacity, either internally or through the establishment of relationships with
third parties, for manufacturing, sales, marketing and distribution functions
and other factors, many of which are outside of the Company's control. Thus,
there can be no assurance that the net proceeds of this Offering, together with
the interest earned thereon, will be sufficient to fund the Company's capital
requirements during the period discussed above. The Company believes that
substantial additional funds will be required to continue to fund its operations
and that the Company will be required to obtain additional funds through equity
or debt financings or licenses, agreements or other arrangements with partners
and others, or from other sources. The terms of any such equity financings may
be dilutive to stockholders, and the terms of any debt financings may contain
restrictive covenants which limit the Company's ability to pursue certain
courses of action. There can be no assurance that such funds will be available
to the Company on acceptable terms, if at all, or that any such financings will
be adequate to meet the Company's future capital requirements. If adequate funds
are not available, the Company may be required to delay, scale-back or eliminate
certain aspects of its preclinical testing, clinical trials and research and
development programs or attempt to obtain funds through arrangements with
collaborative partners or others that may require the Company to relinquish
rights to certain of its technologies or product candidates or compounds, which
could have a material adverse effect on the Company's business, financial
condition and results of operations. See "Use of Proceeds" and "Management's
Discussion and Analysis of Financial Condition and Results of
Operations -- Liquidity and Capital Resources."
 
     UNCERTAINTY REGARDING PATENTS AND PROPRIETARY RIGHTS. The Company's success
will depend, in part, on its ability, and the ability of its collaborators or
licensors, to obtain protection for its products and technologies under United
States and foreign patent laws, to preserve its trade secrets, and to operate
without infringing the proprietary rights of third parties. Because of the
substantial length of time and expense associated with bringing new products
through development to the marketplace, the pharmaceutical and biotechnology
industries place considerable importance on obtaining, and maintaining, patent
and trade secret protection for new technologies, products and processes.
 
   
     The Company has obtained rights to certain patents and patent applications
and may, in the future, seek rights from third parties to additional patents and
patent applications. The Company is currently negotiating a license
    
 
                                       9
 
<PAGE>
   
with a third party to acquire a related technology. There can be no assurance
that patent applications relating to the Company's potential products or
technologies will result in patents being issued, that any issued patents will
afford adequate protection to the Company, or that such patents will not be
challenged, invalidated, infringed or circumvented. Furthermore, there can be no
assurance that others have not developed, or will not develop, similar products
or technologies that will compete with those of the Company without infringing
upon the Company's intellectual property rights.
    
 
     Legal standards relating to the scope of claims and the validity of patents
in the biopharmaceutical industry are uncertain and still evolving, and no
assurance can be given as to the degree of protection that will be afforded any
patents issued to, or licensed by, the Company. There can be no assurance that,
if challenged by others in litigation, any patents assigned to or licensed by
the Company, will not be found invalid. Furthermore, there can be no assurance
that the Company's activities would not infringe patents owned by others.
Defense and prosecution of patent matters can be expensive and time-consuming
and, regardless of whether the outcome is favorable to the Company, can result
in the diversion of substantial financial, management and other resources. An
adverse outcome could subject the Company to significant liability to third
parties, require the Company to obtain licenses from third parties, or require
the Company to cease any related research and development activities and product
sales. No assurance can be given that any licenses required under any such
patents or proprietary rights would be made available on terms acceptable to the
Company, if at all. Moreover, the laws of certain countries may not protect the
Company's proprietary rights to the same extent as U.S. law.
 
   
     The Company also relies on trade secrets, know-how and other proprietary
information, which it seeks to protect, in part, through the use of
confidentiality agreements with employees, consultants, advisors, and others.
There can be no assurance that such agreements will provide adequate protection
for the Company's trade secrets, know-how, or other proprietary information in
the event of any unauthorized use or disclosure, that employees of the Company,
consultants, advisors or others will maintain the confidentiality of such trade
secrets or proprietary information, or that the trade secrets or proprietary
know-how of the Company will not otherwise become known, or be independently
developed, by competitors.
    
 
     In January 1997, the United States Patent and Trademark Office (the
"USPTO") instituted an interference proceeding between an issued patent licensed
by the Company from Duke University and a pending patent application owned by a
third party. An interference proceeding is an action, in the USPTO, to determine
which, of several parties, is entitled to a patent. An interference proceeding
may be instituted when the USPTO believes that a pending patent application and
an issued patent claim the same patentable subject matter. The Company believes
that no interference-in-fact exists, i.e., that the parties to the interference
are not claiming the same patentable invention, and, through its licensor, the
Company is taking all reasonable action to have the interference proceeding
dismissed. However, no assurance can be given that the interference proceeding
will be dismissed. Furthermore, no assurance can be given that, should the
interference proceeding continue, as between the two parties to the
interference, the Company's licensor will be found to be the first inventor of
the invention which is declared to be the subject matter of the interference
proceeding. Failure of the Company's licensor to prevail in the interference
proceeding and any loss of the involved patent rights could have a material
adverse effect on the Company's business, financial condition and results of
operations. See "Business -- Patents, Proprietary Technology and Trade Secrets."
 
     EXTENSIVE GOVERNMENT REGULATION; NO ASSURANCE OF REGULATORY APPROVAL. Human
pharmaceutical products are subject to lengthy and rigorous preclinical testing
and clinical trials and other extensive, costly and time-consuming procedures
mandated by the FDA and foreign regulatory authorities. The regulatory approval
process, which includes the establishment of the safety and effectiveness of
each product candidate and compound for each target indication and confirmation
by the FDA that good laboratory, clinical and manufacturing practices were
maintained during testing and manufacturing, typically takes a number of years,
varying based upon the type, complexity and novelty of the pharmaceutical
product. This process requires the expenditure of substantial resources and
gives larger companies with greater financial resources a competitive advantage
over the Company. To date, no product candidate or compound being evaluated by
the Company has been submitted for approval by the FDA or any other regulatory
authority for commercialization, and there can be no assurance that any such
product candidate or compound will ever be approved for commercialization or
that the Company will be able to
 
                                       10
 
<PAGE>
obtain the labeling claims desired for its product candidates or compounds.
There can be no assurance that submission to the FDA of a request for
authorization to conduct clinical trials on an investigational drug will be
approved on a trial basis, if at all. There can be no assurance that if clinical
trials are successfully completed, the Company will be able to submit a New Drug
Application ("NDA") in a timely manner or that any such NDA will be approved by
the FDA. The approval process is affected by a number of factors, including the
severity of the targeted indications, the availability of alternative treatments
and the risks and benefits demonstrated in the clinical trials. The FDA may
reject an NDA if applicable regulatory criteria are not satisfied, or may
require additional clinical trials or information with respect to the product
candidate or compound. Even if FDA approval is obtained, further clinical
trials, including post-market trials, may be required in order to provide
additional data on safety and will be required in order to obtain approval for
the use of a product as treatment for clinical indications other than those for
which the product was initially approved. The FDA will also require post-market
reporting and may require surveillance programs to monitor the side effects of
any approved products. Results of post-market programs may limit the further
marketing, manufacturing process or labeling, and an NDA supplement may be
required to be submitted to the FDA. Any failure of the Company to successfully
complete its clinical trials and obtain approvals of corresponding NDAs would
have a material adverse effect on the Company's business, financial condition
and results of operations. The Company is and will continue to be dependent upon
the laboratories conducting its preclinical testing and clinical trials to
maintain both good laboratory and good clinical practices, and, if any of the
Company's product candidates or compounds obtain the requisite regulatory
approvals, the Company will be dependent upon any third-party manufacturers of
its products to maintain compliance with the FDA's good manufacturing practice
("GMP") requirements. Various federal and foreign statutes and regulations also
govern or influence the manufacturing, safety, labeling, storage, record-keeping
and marketing of pharmaceutical products.
 
   
     The process of obtaining these approvals and the subsequent compliance with
appropriate United States and foreign statutes and regulations are
time-consuming and will require the expenditure of substantial resources by the
Company. In addition, these requirements and processes vary widely from country
to country. The time required for completing preclinical testing and clinical
trials is uncertain, and the FDA approval process is unpredictable and
uncertain, and no assurance can be given that necessary approvals will be
granted on a timely basis, or at all. The Company may decide to replace a
product candidate or compound in preclinical testing and/or clinical trials with
a modified product candidate or compound, thus extending the development period.
In addition, the FDA or similar foreign regulatory authorities may require
additional clinical trials, which could result in increased costs and
significant development delays. Delays or rejections may also be encountered
based upon changes in legislation, administrative action or FDA policy during
the period of product development and FDA review, including changes in FDA
policy relating to clinical testing guidelines for the use of the Company's
product candidates or compounds in children. Similar delays or rejections may be
encountered in other countries.
    
 
     While certain of the Company's product candidates and compounds, including
T-20, have been and will continue to be designed to treat serious or
life-threatening illnesses, such product candidates and compounds may not
qualify for accelerated development and/or approval under FDA regulations and,
even if some of the Company's product candidates or compounds qualify for
accelerated development and/or approval, they may not be approved for marketing
on an accelerated basis, or at all. There can be no assurance that, even after
substantial time and expenditures, any of the Company's product candidates or
compounds under development will receive commercialization approval in any
country on a timely basis, or at all. If the Company is unable to demonstrate
the safety and effectiveness of its product candidates and compounds to the
satisfaction of the FDA or foreign regulatory authorities, the Company will be
unable to commercialize its product candidates and compounds and the Company's
business, financial condition and results of operations would be materially and
adversely affected. Furthermore, even if regulatory approval of a product
candidate or compound is obtained, the approval may entail limitations on the
indicated uses for which the product candidate or compound may be marketed. A
marketed product or compound, its manufacturer and the manufacturer's facilities
are subject to continual review and periodic inspections, and subsequent
discovery of previously unknown problems with a product, compound, manufacturer
or facility may result in restrictions on such product, compound, manufacturer
or facility, including withdrawal of the product or compound from the market.
The failure to comply with applicable regulatory requirements can, among other
things, result in fines, injunctions, civil penalties, total or partial
suspension of regulatory approvals, refusal
 
                                       11
 
<PAGE>
to approve pending applications, refusal to permit exports from the United
States, recalls or seizures of products or compounds, operating and production
restrictions and criminal prosecutions. Further, FDA policy may change and
additional government regulations may be established that could prevent or delay
regulatory approval of the Company's product candidates or compounds.
 
     The effect of governmental regulation may be to delay the marketing of new
products or compounds for a considerable period of time, to impose costly
requirements on the Company's activities or to provide a competitive advantage
to other companies that compete with the Company. Adverse clinical results by
others could have a negative impact on the regulatory process and timing with
respect to the development and approval of the Company's product candidates or
compounds. A delay in obtaining or failure to obtain regulatory approvals could
have a material adverse effect on the Company's business, financial condition
and results of operations. The extent and character of potentially adverse
governmental regulation that may arise from future legislation or administrative
action cannot be predicted.
 
   
     In April 1997, the Company and MiniMed entered into the MiniMed Agreement
pursuant to which the parties have agreed to jointly design, develop and
implement a system for the delivery of T-20 utilizing the MiniMed continuous
infusion pump. There can be no assurance that the FDA will approve, on a timely
basis, if at all, the delivery of T-20 utilizing the MiniMed continuous infusion
pump. The failure of the Company and MiniMed to collectively develop a continual
T-20 delivery system which receives FDA approval on a timely basis could have a
material adverse effect on the Company's business, financial condition and
results of operations.
    
 
     The Company and its existing and potential future collaborative partners
are also subject to various federal, state and local laws and regulations
relating to safe working conditions, laboratory and manufacturing practices, the
experimental use of animals and the use and disposal of hazardous or potentially
hazardous substances, including radioactive compounds and infectious disease
agents, used in connection with the Company's product development programs.
Compliance with such laws, regulations and requirements may be costly and
time-consuming and the failure to maintain such compliance by the Company or its
existing and future collaborative partners could have a material adverse effect
on the Company's business, financial condition and results of operations.
 
     In addition, this Prospectus reflects the Company's estimates regarding
future regulatory submission dates. Regulatory submissions can be delayed, or
plans to submit proposed products can be cancelled, for a number of reasons,
including the receipt of unanticipated preclinical testing or clinical trial
reports, changes in regulations, adoption of new, or unanticipated enforcement
of existing, regulations, technological developments and competitive
developments. Accordingly, no assurance can be given that the Company's
anticipated submissions will be made on their target dates, or at all. Delays in
such submissions could have a material adverse effect on the Company's business,
financial condition and results of operations. See "Business -- Government
Regulation."
 
     INTENSE COMPETITION. The Company is engaged in segments of the
biopharmaceutical industry, including the treatment of HIV, that are intensely
competitive and rapidly changing. If successfully developed and approved, the
product candidates and compounds that the Company is currently developing will
compete with numerous existing therapies. For example, 11 drugs are currently
approved for the treatment of HIV. In addition, a number of companies are
pursuing the development of novel pharmaceutical products that target the same
diseases that the Company is targeting, and some companies, including several
multinational pharmaceutical companies, are simultaneously marketing several
different drugs and may therefore be able to market their own combination drug
therapies. The Company believes that a significant number of drugs are currently
under development and will become available in the future for the treatment of
HIV. The Company anticipates that it will face intense and increasing
competition in the future as new products enter the market and advanced
technologies become available. There can be no assurance that existing products
or new products for the treatment of HIV developed by the Company's competitors,
including Glaxo Wellcome plc ("Glaxo"), Merck & Co., Inc. ("Merck") and Abbott
Laboratories, Inc. ("Abbott"), will not be more effective, or more effectively
marketed and sold, than T-20, should it be successfully developed and receive
regulatory approval, or any other therapeutic for HIV that may be developed by
the Company. Competitive products or the development by others of a cure or new
treatment methods may render the Company's technologies and products and
compounds obsolete, noncompetitive or uneconomical prior to the
 
                                       12
 
<PAGE>
Company's recovery of development or commercialization expenses incurred with
respect to any such technologies or products or compounds. Many of the Company's
competitors have significantly greater financial, technical and human resources
than the Company and may be better equipped to develop, manufacture, sell,
market and distribute products. In addition, many of these companies have
extensive experience in preclinical testing and clinical trials, obtaining FDA
and other regulatory approvals and manufacturing and marketing pharmaceutical
products. Many of these competitors also have products that have been approved
or are in late-stage development and operate large, well-funded research and
development programs. Smaller companies may also prove to be significant
competitors, particularly through collaborative arrangements with large
pharmaceutical and biotechnology companies. Furthermore, academic institutions,
governmental agencies and other public and private research organizations are
becoming increasingly aware of the commercial value of their inventions and are
more actively seeking to commercialize the technology they have developed.
 
     New developments in areas in which the Company is conducting its research
and development are expected to continue at a rapid pace in both industry and
academia. If the Company's product candidates and compounds are successfully
developed and approved, the Company will face competition based on the safety
and effectiveness of its products and compounds, the timing and scope of
regulatory approvals, availability of manufacturing, sales, marketing and
distribution capabilities, reimbursement coverage, price and patent position.
There can be no assurance that the Company's competitors will not develop more
effective or more affordable technologies or products, or achieve earlier patent
protection, product development or product commercialization than the Company.
Accordingly, the Company's competitors may succeed in commercializing products
more rapidly or effectively than the Company, which could have a material
adverse effect on the Company's business, financial condition and results of
operations. See "Business -- Competition."
 
     LACK OF MANUFACTURING CAPABILITIES. The Company has no experience in
manufacturing pharmaceuticals and has no commercial manufacturing capacity. The
Company has established relationships and intends to establish additional
relationships with third-party manufacturers for the production of quantities of
its product candidates or compounds sufficient to conduct its planned
preclinical testing and clinical trials and the commercial production of any
approved products or compounds. There can be no assurance that the Company will
be able to retain or establish relationships with third-party manufacturers on
acceptable terms, if at all, or that such third-party manufacturers will be able
to manufacture products in commercial quantities under GMP requirements on a
cost-effective basis. The Company's anticipated peptide-based therapeutics are
difficult and expensive to manufacture using existing technologies. The Company,
and its third-party manufacturers, are currently using solid-phase sequential
peptide synthesis to manufacture T-20. This chemical methodology is inherently
inefficient and complex. Due to technical limitations, solid-phase sequential
peptide synthesis is the most expensive way to chemically assemble the Company's
current peptide product candidates, including T-20. There can be no assurance
that the Company or its third-party manufacturers will be able to manufacture
T-20 on a cost-effective basis or that the Company will be successful in its
efforts to develop an alternative, more efficient manufacturing method for T-20
or any of its other peptide product candidates. The Company's dependence upon
third parties for the manufacture of its products, product candidates and
compounds may materially and adversely affect the Company's profit margins and
its ability to develop and commercialize product candidates, products and
compounds on a timely and competitive basis. Further, there can be no assurance
that manufacturing or quality control problems will not arise in connection with
the manufacture of the Company's products, product candidates or compounds or
that third-party manufacturers will maintain the necessary governmental licenses
and approvals to continue manufacturing the Company's products, product
candidates or compounds. Any failure to maintain existing or establish new
relationships with third parties for the Company's manufacturing requirements on
a timely basis and on acceptable terms would have a material adverse effect on
the Company's business, financial condition and results of operations. See
"Business -- Manufacturing."
 
     LACK OF SALES, MARKETING AND DISTRIBUTION CAPABILITIES. The Company has no
experience in sales, marketing or distribution of pharmaceuticals and currently
has no personnel employed in any such capacities. Some therapeutics for HIV can
be marketed to a concentrated group of physicians in a relatively narrow
geographic scope. The Company may consider developing internal sales, marketing
and distribution capabilities for T-20, should it be successfully developed and
receive regulatory approval. For the remainder of the Company's product
candidates
 
                                       13
 
<PAGE>
and compounds, should they be successfully developed and receive regulatory
approval, the Company may rely on marketing partners or other arrangements with
third parties which have established distribution systems and direct sales
forces for the sales, marketing, and distribution of such products and
compounds. In the event that the Company is unable to reach agreement with one
or more marketing partners to market these other products and compounds, the
Company would be required to develop internal sales, marketing and distribution
capabilities for such products and compounds. There can be no assurance that the
Company will be able to establish sales, marketing or distribution capabilities
or make arrangements with third parties to perform such activities on acceptable
terms, if at all, or that any internal capabilities or third-party arrangements
will be cost-effective. The failure to establish such capabilities would have a
material adverse effect on the Company's business, financial condition and
results of operations.
 
     In addition, any third parties with which the Company establishes sales,
marketing or distribution arrangements may have significant control over
important aspects of the commercialization of the Company's products and
compounds, including market identification, marketing methods, pricing,
composition of sales force and promotional activities. For example, the MiniMed
Agreement contemplates that MiniMed will participate in the sales, marketing and
distribution of any products jointly developed by the parties. There can be no
assurance that the Company will be able to control the amount and timing of
resources that MiniMed or any other third party may devote to the Company's
products or compounds or prevent any third party from pursuing alternative
technologies or products that could result in the development of products that
compete with the Company's products and the withdrawal of support for the
Company's products. See "Business -- Sales, Marketing and Distribution."
 
     UNCERTAINTY OF MARKET ACCEPTANCE. The Company's success will depend upon
the acceptance by the medical community, including health care providers and
third-party payors, of the Company's antifusion technology as a safe and
effective means of treating viral infection. The Company's success will
additionally be dependent upon the acceptance by the medical community,
including health care providers and third-party payors, of any products or
compounds developed by the Company. The degree of market acceptance will depend
upon a number of factors, including the establishment and demonstration in
clinical trials of the safety and effectiveness of the Company's products and
compounds, the receipt and scope of regulatory approvals, the demonstration of
the potential advantages of the Company's products and compounds over existing
treatment methods, and the reimbursement policies of government and third-party
payors with respect to antiviral therapeutics based upon blocking viral fusion.
Moreover, companies that market and sell HIV antivirals and other HIV-related
therapeutics have from time to time been subject to protests and boycotts by
patient advocacy and activist groups. These protests and boycotts have focused
on, among other things, availability of such therapeutics and pricing concerns.
Market acceptance of such therapeutics, including any products or compounds that
the Company may develop, will be dependent, in part, on the continued support by
such groups. There can be no assurance that the Company's products or compounds
will achieve significant market acceptance on a timely basis, or at all. Failure
of some or all of the Company's products, if successfully developed, to achieve
significant market acceptance would have a material adverse effect on the
Company's business, financial condition and results of operations.
 
     DEPENDENCE ON THIRD PARTIES FOR CLINICAL TRIALS. The Company has engaged,
and intends to continue to engage, third-party contract research organizations
("CROs") to perform certain functions in connection with the development of the
Company's product candidates and compounds. The Company intends to design
clinical trials, but have CROs conduct the clinical trials, and the Company will
rely on the CROs to perform many important aspects of the clinical trials. As a
result, these aspects of the Company's product development programs will be
outside the direct control of the Company. There can be no assurance that the
CROs or other third parties will perform all of their obligations under their
arrangements with the Company. In addition, there can be no assurance that any
such arrangements will be renewed or any new arrangements will be available on
acceptable terms, if at all, or that any such arrangements, if entered into,
will be successful. In the event that the CROs do not perform clinical trials in
a satisfactory manner or breach their obligations to the Company, the
commercialization of any product candidate or compound may be delayed or
precluded, which could have a material adverse effect on the Company's business,
financial condition and results of operations.
 
     UNCERTAINTY OF THIRD-PARTY REIMBURSEMENT AND HEALTH CARE REFORM MEASURES.
In the United States and elsewhere, sales of prescription pharmaceuticals are
dependent, in part, on the availability of reimbursement to the
 
                                       14
 
<PAGE>
consumer from third-party payors, such as government agencies and private
insurance plans. Third-party payors are increasingly challenging the prices
charged for medical products and services in an effort to promote cost
containment measures and alternative health care delivery systems and they may
mandate predetermined discounts from list prices. If the Company succeeds in
bringing one or more products or compounds to the market, there can be no
assurance that these products or compounds will be considered cost-effective or
that reimbursement to the consumer will be available or will be sufficient to
allow the Company or its potential collaborative partners to sell the Company's
products or compounds on a competitive basis. The business and financial
condition of pharmaceutical companies will continue to be affected by economic,
political and regulatory influences, including the efforts of governments and
third-party payors to contain or reduce the cost of health care through various
means. A number of legislative and regulatory proposals aimed at changing the
health care system have been proposed in recent years. Because of the high cost
of the treatment of AIDS or HIV using combination therapy, many state
legislatures are reassessing reimbursement policies for such therapy. In
addition, an increasing emphasis on managed care in the United States to reduce
the overall costs of health care has and will continue to increase the pressure
on pharmaceutical pricing. While the Company cannot predict whether legislative
or regulatory proposals will be adopted or the effect those proposals or managed
care efforts may have, the announcement and/or adoption of such proposals or
efforts could have a material adverse effect on the Company's business,
financial condition and results of operations. See "Business -- Third Party
Reimbursement and Health Care Reform Measures."
 
     HAZARDOUS MATERIALS. The Company's product development programs involve the
controlled use of hazardous materials, chemicals, viruses and various
radioactive compounds, including Class IV type hazardous materials. Although the
Company believes that its handling and disposing of such materials comply with
the standards prescribed by state and federal regulations, the risk of
accidental contamination or injury from these materials cannot be completely
eliminated. In the event of such an accident, the Company could be held liable
for any damages or fines that result and any such liability could exceed the
resources of the Company. The Company may incur substantial additional costs to
comply with environmental regulations if the Company develops manufacturing
capacity.
 
     ABSENCE OF PRODUCT LIABILITY INSURANCE; INSURANCE RISKS. The Company's
business will expose it to potential product liability risks that are inherent
in the testing, manufacturing and marketing of pharmaceutical products. There
can be no assurance that product liability claims will not be asserted against
the Company. In addition, the use of pharmaceutical products that may be
developed by the Company's potential collaborators in clinical trials and the
subsequent sale of products by the Company or its potential collaborators may
cause the Company to bear a portion of those risks. A successful product
liability claim or series of claims brought against the Company could have a
material adverse effect on the Company's business, financial condition and
results of operations. The Company does not currently have any product liability
insurance relating to clinical trials or any products or compounds it may
develop and there can be no assurance that the Company will be able to obtain or
maintain adequate product liability insurance on acceptable terms, if at all, or
that such insurance will provide adequate coverage against potential
liabilities. Furthermore, there can be no assurance that any collaborators or
licensees of the Company will agree to indemnify the Company, be sufficiently
insured, or have a net worth sufficient to satisfy any product liability claims.
Claims or losses in excess of any product liability insurance coverage that may
be obtained by the Company could have a material adverse effect on the Company's
business, financial condition and results of operations.
 
     NEED TO ATTRACT AND RETAIN KEY OFFICERS, EMPLOYEES AND CONSULTANTS. The
Company is highly dependent upon the efforts of the principal members of its
scientific and management staff. The loss of the services of one or more members
of the Company's scientific or management staff could significantly delay or
prevent the achievement of the Company's research, development or business
objectives and could have a material adverse effect on the Company's business,
financial condition and results of operations. At present, the Company only has
individual employment agreements with Dr. Johnson, the Company's President,
Chief Executive Officer and Chief Scientific Officer, and Mr. Megaro, the
Company's Chief Operating Officer, Chief Financial Officer, Executive Vice
President and Secretary. In addition, the Company relies on consultants and
advisors, including the members of its Scientific Advisory Board, to assist the
Company in formulating its research and development strategy. The loss of
 
                                       15
 
<PAGE>
the services of certain members of the Company's Scientific Advisory Board or
certain consultants could materially and adversely affect the Company to the
extent that the Company is pursuing research or development in areas of such
scientific advisor's or consultant's expertise. Due to the specialized
scientific nature of the Company's business, the Company is also highly
dependent upon its ability to attract and retain qualified scientific, technical
and key management personnel. There is intense competition for qualified
personnel in the areas of the Company's activities by academic institutions,
biotechnology companies and pharmaceutical companies and there can be no
assurance that the Company will be able to continue to attract and retain the
qualified personnel necessary for the development of its existing business and
its expansion into areas and activities requiring additional expertise. The loss
of, or failure to recruit, scientific, technical, and managerial personnel could
have a material adverse effect on the Company's business, financial condition
and results of operations.
 
     The Company's scientific advisors and consultants may be employed by or
have consulting agreements with entities other than the Company, some of which
may compete with the Company. To the extent that members of the Company's
Scientific Advisory Board or the consultants have consulting arrangements with
or become employed by any competitor of the Company, the Company's business,
financial condition or results of operations could be materially and adversely
affected. Under certain circumstances, inventions or processes independently
discovered by the scientific advisors or the consultants will remain the
property of such persons or their employers. In addition, the institutions with
which the scientific advisors and the consultants are affiliated may make
available the research services of their scientific and other skilled personnel,
including the scientific advisors and the consultants, to competitors of the
Company pursuant to sponsored research agreements. Under such sponsored research
agreements, such institutions may be obligated to assign or license to a
competitor of the Company patents and other proprietary information that may
result from research sponsored by an entity other than the Company, including
research performed by a scientific advisor or a consultant for a competitor of
the Company.
 
   
     The Company requires all employees, consultants and certain of its
contractors to enter into confidentiality agreements that prohibit the
disclosure of confidential information to anyone outside the Company and require
disclosure and assignment to the Company of their ideas, developments,
discoveries or inventions developed during the course of their service to the
Company. However, no assurance can be given that competitors of the Company will
not gain access to trade secrets and other proprietary information developed by
the Company and disclosed to the scientific advisors and the consultants. See
"Business -- Human Resources," " -- Scientific Advisory Board" and "Management."
    
 
     SHARES ELIGIBLE FOR FUTURE SALE. Sales of substantial amounts of Common
Stock (including shares issued upon the exercise of outstanding options and
warrants) in the public market after this Offering or the prospect of such sales
could materially and adversely affect the market price of the Common Stock and
may have a material adverse effect on the Company's ability to raise any
necessary capital to fund its future operations. Upon completion of this
Offering, the Company will have 9,880,325 shares of Common Stock outstanding
(assuming no exercise of options and warrants outstanding as of August 27,
1997). Of these shares, the 2,500,000 shares offered hereby will be freely
tradeable without restrictions or further registration under the Securities Act
of 1933, as amended (the "Securities Act"), except that any shares held by
"affiliates" of the Company within the meaning of the Securities Act will be
subject to the resale limitations of Rule 144 promulgated under the Securities
Act ("Rule 144"). The remaining 7,380,325 outstanding shares are "restricted"
securities that may be sold only if registered under the Securities Act, or sold
in accordance with an applicable exemption from registration, such as Rule 144.
Rule 144 imposes a holding period with respect to securities purchased directly
from an issuer or an "affiliate" of an issuer.
 
   
     The officers and directors of the Company and other holders of Common Stock
who together hold 7,366,303 shares of Common Stock have agreed not to sell,
offer, make any short sale or otherwise dispose of or enter into any contract,
arrangement or commitment to sell or otherwise dispose of any Common Stock
without the prior written consent of UBS Securities LLC for a period of 180 days
from the date of this Prospectus (the "Lock-up Agreements"). Approximately
231,117 shares of Common Stock will be eligible for resale in the public market
without restriction in reliance on Rule 144(k) immediately following the
completion of this Offering, 225,944 shares of which are subject to the Lock-up
Agreements. An additional 769,238 (763,331 shares of which are subject to the
Lock-up Agreements) will be eligible for resale in the public market pursuant to
Rule 701 under the Securities Act beginning approximately 90 days after the
effective date of this Prospectus, except to the extent that
    
 
                                       16
 
<PAGE>
such shares are subject to vesting restrictions or certain contractual
restrictions on sale or transfer pursuant to agreements with the Company. After
the expiration of the 180-day lock-up period, an additional 3,739,158 shares of
Common Stock will be eligible for resale in the public market pursuant to Rule
144. From time to time thereafter, the remaining shares of Common Stock
outstanding will become eligible for resale in the public market pursuant to
Rule 144.
 
   
     Approximately 90 days after the completion of this Offering, the Company
intends to file a registration statement on Form S-8 under the Securities Act to
register the future issuance of shares of Common Stock reserved for issuance
under the Company's Stock Option Plan. As of August 27, 1997, 244,006 shares of
Common Stock were reserved for issuance pursuant to outstanding options and
254,894 shares of Common Stock were reserved for future issuance under the
Company's Stock Option Plan. Such registration statement will automatically
become effective upon filing. Accordingly, shares registered thereunder will,
subject to Rule 144 limitations applicable to affiliates, be available for sale
in the public market, except to the extent that such shares are subject to
vesting restrictions with the Company or certain contractual restrictions on
sale or transfer (including options covering 242,829 shares which are subject to
Lock-up Agreements). After this Offering, the holders of approximately 6,261,615
shares of Common Stock and the holders of warrants to purchase an aggregate of
56,684 shares of Common Stock will be entitled to certain demand and piggyback
rights with respect to the registration of such shares under the Securities Act.
If such holders, by exercising their demand registration rights, cause a large
number of securities to be registered and sold in the public market, such sales
could have an adverse effect on the market price of the Company's Common Stock.
If the Company, either on its own behalf or on behalf of certain stockholders,
were to initiate a registration and include shares held by such holders pursuant
to the exercise of their piggyback registration rights, such sales could have a
material adverse effect on the Company's ability to raise needed capital. See
"Certain Transactions," "Shares Eligible for Future Sale," "Description of
Capital Stock -- Registration Rights" and "Underwriting."
    
 
     CONTROL BY DIRECTORS, EXECUTIVE OFFICERS AND AFFILIATED ENTITIES. The
Company's directors, executive officers and entities affiliated with them will,
in the aggregate, beneficially own approximately 35.1% of the Company's
outstanding shares of Common Stock following the completion of this Offering (or
approximately 33.8% if the Underwriters exercise their over-allotment option in
full). As a result, these stockholders, if acting together, would be able to
significantly influence all matters requiring approval by the stockholders of
the Company, including the election of directors and the approval of mergers and
consolidations, sales of all or substantially all of the assets of the Company
or other business combination transactions. This may discourage a tender offer
for the Company's Common Stock or a change in control of the Company. See
"Principal Stockholders" and "Description of Capital Stock."
 
     ANTI-TAKEOVER EFFECT OF CERTAIN CHARTER AND BYLAW PROVISIONS. The Company's
Board of Directors is authorized to issue up to 10,000,000 shares of Preferred
Stock and to determine the price, rights, preferences and limitations of those
shares without any further vote or action by the Company's stockholders. The
rights of the holders of Common Stock will be subject to, and may be adversely
affected by, the rights of the holders of any Preferred Stock that may be issued
in the future. While the Company has no present intention to issue shares of
Preferred Stock, such issuance could have the effect of making it more difficult
for a third party to acquire a majority of the outstanding voting stock of the
Company. In addition, the Company is subject to the provisions of Section 203 of
the Delaware General Corporation Law (the "DGCL") which, subject to certain
exceptions, prohibits the Company from engaging in certain business combinations
with certain stockholders (each, an "interested stockholder") for a period of
three years after the date of the transaction in which the stockholder became an
interested stockholder, unless the business combination is approved in a
prescribed manner. The application of Section 203 could have the effect of
delaying or preventing a change of control of the Company. The Company's Third
Amended and Restated Certificate of Incorporation provides for staggered terms
for the members of the Board of Directors. The staggered Board of Directors, the
Company's Third Amended and Certificate of Incorporation and certain provisions
of the DGCL may have the effect of delaying, deterring or preventing a change in
control of the Company, may discourage bids for the Common Stock at a premium
over the market price and may adversely affect the market price, and the voting
and other rights of the holders, of the Common Stock. See "Description of
Capital Stock -- Delaware Law and Certain Charter Provisions."
 
                                       17
 
<PAGE>
     NO PRIOR MARKET FOR COMMON STOCK; POSSIBLE VOLATILITY OF STOCK PRICE. Prior
to this Offering, there has been no public market for the Company's Common Stock
and there can be no assurance that an active public market for the Common Stock
will develop or be sustained after this Offering or that the market price of the
Common Stock will not decline below the initial public offering price. The
initial public offering price will be determined by negotiations between the
Company and the representatives of the Underwriters and may not be indicative of
the market price at which the Common Stock of the Company will trade after this
Offering. Among the factors to be considered in such negotiations, in addition
to prevailing market conditions, are certain financial information of the
Company, market valuations of other companies that the Company and the
representatives of the several underwriters believe to be comparable to the
Company, estimates of the business potential of the Company, the present state
of the Company's development and other factors deemed relevant. The initial
public offering price set forth on the cover page of this Prospectus should not,
however, be considered an indication of the actual value of the Common Stock.
Such price is subject to change as a result of market conditions and other
factors. There can be no assurance that an active trading market will develop
for the Common Stock or that the Common Stock will trade in the public market
subsequent to this Offering at or above the initial offering price.
 
     The market price of the Common Stock, like that of the securities of many
other biotechnology and pharmaceutical companies, is likely to be highly
volatile. Factors such as announcements of technological innovations or new
products by the Company or its competitors, preclinical testing or clinical
trial results relating to or regulatory approvals or disapprovals of the
Company's or competitors' product candidates, government regulation, health care
legislation, developments or disputes concerning patent or other proprietary
rights of the Company or its competitors, including litigation, fluctuations in
the Company's operating results, and market prices of the capital stock of
biotechnology and pharmaceutical companies in general could have a significant
impact on the future market price of the Common Stock. In addition, the stock
market has from time to time experienced extreme price and volume fluctuations
that may be unrelated to the operating performance of particular companies. In
addition, in the past, following periods of volatility in the market price of
the securities of companies in the biotechnology and pharmaceutical industries,
securities class action litigation has often been instituted against those
companies. Such litigation, if instituted against the Company, could result in
substantial costs and a diversion of management attention and resources, which
would have a material adverse effect on the Company's business, financial
condition and results of operations. The realization of any of the risks
described in these "Risk Factors" could have a dramatic and adverse impact on
the market price of the Common Stock. See "Underwriting."
 
     BROAD DISCRETION IN USE OF PROCEEDS. The net proceeds of the Offering will
be added to the Company's working capital and will be available for research and
development, capital expenditures, working capital and general corporate
purposes. As of the date of this Prospectus, the Company cannot specify with
certainty the particular uses for the net proceeds to be received upon
completion of this Offering. Accordingly, the Company's management will have
broad discretion in the application of the net proceeds. See "Use of Proceeds"
and "Management's Discussion and Analysis of Financial Condition and Results of
Operations."
 
     IMMEDIATE AND SUBSTANTIAL DILUTION. Purchasers of the Common Stock offered
hereby will incur an immediate and substantial dilution in the net tangible book
value of the Common Stock from the initial public offering price. The current
stockholders of the Company, including the Company's directors and officers,
acquired their shares of Common Stock for consideration substantially less than
the initial public offering price of the shares of Common Stock offered hereby.
Additionally, the Company has issued options to acquire shares of the Common
Stock at prices significantly below the initial public offering price. To the
extent outstanding options to purchase the Common Stock are exercised, there
will be further dilution. See "Dilution."
 
     NO DIVIDENDS. The Company has not paid cash dividends on its Common Stock
since its inception and does not anticipate paying cash dividends in the
foreseeable future. See "Dividend Policy."
 
                                       18
 
<PAGE>
                                USE OF PROCEEDS
 
     The net proceeds to the Company from the sale of the 2,500,000 shares of
Common Stock offered hereby at an assumed initial public offering price of
$13.00 per share are estimated to be approximately $29.4 million (approximately
$34.0 million if the Underwriters' over-allotment option is exercised in full),
after deducting the underwriting discounts and commissions and estimated
offering expenses payable by the Company.
 
     The Company intends to use the net proceeds of this Offering to fund the
continued clinical trials of T-20, increased research and development
activities, including ongoing development of the Company's technologies,
preclinical testing and clinical trials, and other costs associated with the
Company's product discovery and development programs. The Company also intends,
depending on the results of ongoing preclinical testing and clinical trials, to
use some of the net proceeds for the expansion of its facilities. The remainder
of the aggregate net proceeds will be used to provide working capital and to
fund other general corporate purposes. The amounts actually expended for each
purpose and the timing of such expenditures may vary significantly depending
upon a number of factors, including the status of the Company's research,
product candidate and compound discovery and development efforts, including
preclinical testing and clinical trials, the timing of regulatory actions, the
costs involved in preparing, filing, prosecuting, maintaining, protecting and
enforcing patent claims and other proprietary rights, the ability of the Company
to establish, internally or through relationships with third parties,
manufacturing, sales, marketing and distribution capabilities, technological and
other changes in the competitive landscape, changes in the Company's existing
research and development relationships and strategic alliances, evaluation of
the commercial viability of potential product candidates and compounds, needs
for additional facilities and other factors, many of which are outside of the
Company's control. As of the date of this Prospectus, the Company cannot specify
with certainty the particular uses for the net proceeds to be received upon
completion of this Offering. Accordingly, the Company's management will have
broad discretion in the application of the net proceeds. The Company may also
use a portion of the net proceeds to acquire or invest in businesses, products
and technologies that are complementary to those of the Company, although the
Company currently has no agreements and is not involved in any negotiations with
respect to any such transactions.
 
     Pending such uses, the Company intends to invest the net proceeds in
investment grade, interest-bearing securities, including, without limitation,
obligations of the U.S. government or U.S. government agencies and other highly
rated liquid debt instruments.
 
                                DIVIDEND POLICY
 
     The Company has not paid any dividends on its Common Stock since its
inception. The Company currently intends to retain any future earnings to fund
its operations and, therefore, does not anticipate paying any cash dividends in
the foreseeable future.
 
                                       19
 
<PAGE>
                                 CAPITALIZATION
 
     The following table sets forth, as of June 30, 1997, (i) the actual
capitalization of the Company, (ii) the pro forma capitalization of the Company
after giving effect to the Preferred Stock Conversion and the filing of the
Company's Third Amended and Restated Certificate of Incorporation upon the
completion of the Offering, and (iii) the pro forma capitalization of the
Company as adjusted to give effect to the sale of the 2,500,000 shares of Common
Stock offered hereby at an assumed initial public offering price of $13.00 per
share and after deducting the underwriting discounts and commissions and
estimated offering expenses payable by the Company. The table should be read in
conjunction with the Financial Statements and the related Notes thereto included
elsewhere in this Prospectus.
 
<TABLE>
<CAPTION>
                                                                                         AS OF JUNE 30, 1997
                                                                                                           PRO FORMA
                                                                                  ACTUAL     PRO FORMA    AS ADJUSTED
<S>                                                                              <C>         <C>          <C>
Notes payable and obligations under capital leases,
  excluding current installments..............................................   $    488    $    488      $     488
Stockholders' equity (deficit):
  Series A, B, C and D Preferred Stock........................................         53          --             --
  Preferred Stock, $.001 par value
     per share, 10,000,000 shares authorized and no shares issued and
     outstanding..............................................................         --          --             --
  Common Stock, $.001 par value per share,
     80,000,000 shares authorized 1,092,472 shares issued
     and outstanding, actual; 7,354,087 shares issued and outstanding, pro
     forma and 9,854,087 shares issued and outstanding, pro forma as adjusted
     (1)......................................................................          1           7             10
  Additional paid-in capital..................................................     32,435      32,482         61,904
  Deficit accumulated during the development stage............................    (21,443)    (21,443 )      (21,443)
  Deferred compensation.......................................................     (1,935)     (1,935 )       (1,935)
Notes receivable from stockholders............................................       (264)       (264 )         (264)
     Total stockholders' equity...............................................      8,847       8,847         38,272
     Total capitalization.....................................................   $  9,335    $  9,335      $  38,760
</TABLE>
 
(1) Excludes (i) 10,589 shares of Common Stock issued by the Company after June
    30, 1997, (ii) 260,361 shares of Common Stock reserved for issuance pursuant
    to stock options outstanding as of June 30, 1997 at a weighted average
    exercise price of $.36 per share, and (iii) 56,684 shares of Common Stock
    issuable upon exercise of warrants outstanding as of June 30, 1997 at a
    weighted average exercise price of $4.25 per share. Also excludes an
    aggregate of 254,188 shares of Common Stock reserved for future issuance
    under the Company's Stock Option Plan as of June 30, 1997. See
    "Management -- Stock Option Plans," "Description of Capital Stock" and Note
    1 of Notes to Financial Statements.
 
                                       20
 
<PAGE>
                                    DILUTION
 
     The pro forma net tangible book value of the Company's Common Stock as of
June 30, 1997 was approximately $8.3 million, or $1.13 per share, after giving
effect to the Preferred Stock Conversion. After giving effect to the sale by the
Company of the 2,500,000 shares of Common Stock offered hereby at an assumed
initial public offering price of $13.00 per share (after deducting the
underwriting discounts and commissions and estimated offering expenses payable
by the Company), the pro forma net tangible book value of the Company as of June
30, 1997 would have been approximately $37.8 million, or $3.83 per share. This
represents an immediate increase in net tangible book value of $2.70 per share
to existing stockholders and an immediate dilution in net tangible book value of
$9.17 per share to purchasers in this Offering. "Net tangible book value"
represents the amount of tangible assets of the Company less total liabilities.
Dilution represents the difference between the amount per share paid by
purchasers in this Offering and the pro forma net tangible book value per share
upon completion of this Offering. The following table illustrates this per share
dilution:
 
<TABLE>
<S>                                                                         <C>      <C>
Assumed initial public offering price per share..........................            $13.00
  Pro forma net tangible book value per share as of June 30, 1997........   $1.13
  Increase in book value per share attributable to new investors.........    2.70
Pro forma net tangible book value per share after this Offering..........              3.83
Dilution per share to new investors (1)..................................            $ 9.17
</TABLE>
 
(1) If the Underwriters' over-allotment is exercised in full, the dilution to
    new investors will be $8.86 per share.
 
     The following table sets forth, on a pro forma basis as of June 30, 1997,
the difference between the number of shares of Common Stock purchased from the
Company, the total consideration paid and the average price per share paid by
the existing holders of Common Stock and by the new investors, after giving
effect to the Preferred Stock Conversion and before deducting the underwriting
discounts and commissions and estimated offering expenses payable by the
Company, at an assumed initial public offering price of $13.00 per share:
 
<TABLE>
<CAPTION>
                                                                                                              AVERAGE
                                                           SHARES PURCHASED        TOTAL CONSIDERATION       PRICE PER
                                                          NUMBER      PERCENT       AMOUNT       PERCENT       SHARE
<S>                                                      <C>          <C>         <C>            <C>         <C>
Existing stockholders.................................   7,354,087         75%    $30,488,588         48%      $ 4.15
New investors.........................................   2,500,000         25      32,500,000         52        13.00
       Total..........................................   9,854,087        100%    $62,988,588        100%      $ 6.39
</TABLE>
 
   
     The foregoing tables assume no exercise of outstanding options or warrants.
As of June 30, 1997, (i) 260,361 shares of Common Stock were issuable upon
exercise of outstanding stock options at a weighted average exercise price of
$.36 per share, and (ii) an aggregate of 56,684 shares of Common Stock were
issuable upon the exercise of outstanding warrants at a weighted-average
exercise price of $4.25 per share. Also excludes an aggregate of 254,188 shares
of Common Stock reserved for future issuance under the Company's Stock Option
Plan as of June 30, 1997. To the extent the outstanding options are exercised,
there will be further dilution to new investors. See "Capitalization," and
"Management -- Stock Option Plans," "Description of Capital Stock" and Note 1 of
Notes to Financial Statements.
    
 
                                       21
 
<PAGE>
                            SELECTED FINANCIAL DATA
 
     The selected financial data set forth below with respect to the Company's
Statement of Operations for the years ended December 31, 1994, 1995 and 1996 and
with respect to the Company's Balance Sheets as of December 31, 1995 and 1996
are derived from the audited Financial Statements of the Company which are
included elsewhere in this Prospectus and are qualified by reference to such
Financial Statements and the related Notes thereto. Statements of Operations
data for the period from inception (January 7, 1993) through December 31, 1993
and Balance Sheet data at December 31, 1993 and 1994 are derived from audited
Financial Statements of the Company not included herein. The selected financial
data as of June 30, 1997 and for the six months ended June 30, 1996 and 1997 are
derived from unaudited Financial Statements included elsewhere in this
Prospectus. The unaudited Financial Statements include all adjustments,
consisting only of normal recurring adjustments, that the Company considers
necessary for the fair presentation of its financial position and the results of
its operations for those periods. Operating results for the six months ended
June 30, 1997 are not necessarily indicative of the results that may be expected
for the year ending December 31, 1997. The selected financial data set forth
below is qualified in its entirety by, and should be read in conjunction with,
the Financial Statements, the related Notes thereto and "Management's Discussion
and Analysis of Financial Condition and Results of Operations" included
elsewhere in this Prospectus.
 
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
   
<TABLE>
<CAPTION>
                                    PERIOD FROM
                                     INCEPTION                                            FOR THE           CUMULATIVE
                                 (JANUARY 7, 1993)               FOR THE             SIX MONTHS ENDED     FROM INCEPTION
                                THROUGH DECEMBER 31,    YEARS ENDED DECEMBER 31,         JUNE 30,        (JANUARY 7, 1993)
                                        1993            1994      1995      1996      1996      1997     TO JUNE 30, 1997
<S>                             <C>                    <C>       <C>       <C>       <C>       <C>       <C>
                                        (IN THOUSANDS, EXCEPT PER SHARE DATA)      (UNAUDITED)              (UNAUDITED)
STATEMENTS OF OPERATIONS DATA:
Revenue.........................       $     --        $    --   $   104   $    55   $    --   $   212       $     371
Operating expense:
Research and development
  expenses......................            691          2,747     4,012     5,146     2,278     2,859          15,455
General and administrative
  expenses......................            631            947     1,520     1,761       802       786           5,646
    Total operating expenses....          1,322          3,694     5,532     6,907     3,080     3,645          21,101
Operating loss..................         (1,322)        (3,694)   (5,428)   (6,852)   (3,080)   (3,433)        (20,730)
Interest income.................             16              8        49        47        32        33             154
Interest expense................             (5)          (258)     (360)     (167)      (86)      (78)           (867)
    Total other income
    (expense)...................             11           (250)     (311)     (120)      (54)      (45)           (713)
    Net loss....................       $ (1,311)       $(3,944)  $(5,739)  $(6,972)  $(3,134)  $(3,478)      $ (21,443)
Pro forma net loss per share
  (1)(2)........................                                           $ (1.48)            $  (.59)
Pro forma weighted average
  shares used in computing pro
  forma net loss per share
  (1)(2)........................                                             4,705               5,880
</TABLE>
    
 
<TABLE>
<CAPTION>
                                                                                                                    AS OF
                                                                                    AS OF DECEMBER 31,             JUNE 30,
                                                                            1993      1994      1995      1996       1997
<S>                                                                        <C>       <C>       <C>       <C>       <C>
                                                                                         (IN THOUSANDS)         (UNAUDITED)
BALANCE SHEET DATA:
Cash and cash equivalents................................................  $   509   $   277   $ 1,343   $   132   $  8,912
Working capital (deficiency).............................................      183    (4,067)      322    (1,305)     8,019
Total assets.............................................................    1,802     1,873     3,058     1,684     10,585
Long-term notes payable and capital lease obligations, less current
  portion................................................................      401       751       703       576        488
Accumulated deficit......................................................   (1,311)   (5,254)  (10,994)  (17,965)   (21,443)
Total stockholders' equity...............................................      701    (3,236)    1,324      (409)     8,847
</TABLE>
 
(1) Computed on the basis described in Note 1 of Notes to Financial Statements.
(2) Pro forma to give effect to the Preferred Stock Conversion.
 
                                       22
 
<PAGE>
                    MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 FINANCIAL CONDITION AND RESULTS OF OPERATIONS
 
     THE FOLLOWING DISCUSSION OF THE FINANCIAL CONDITION AND RESULTS OF
OPERATIONS OF THE COMPANY SHOULD BE READ IN CONJUNCTION WITH THE FINANCIAL
STATEMENTS AND THE RELATED NOTES THERETO INCLUDED ELSEWHERE IN THIS PROSPECTUS.
THIS PROSPECTUS CONTAINS FORWARD-LOOKING STATEMENTS THAT INVOLVE RISKS AND
UNCERTAINTIES. THE COMPANY'S ACTUAL RESULTS MAY DIFFER SIGNIFICANTLY FROM THE
RESULTS DISCUSSED IN THE FORWARD-LOOKING STATEMENTS. FACTORS THAT MIGHT CAUSE OR
CONTRIBUTE TO SUCH DIFFERENCES INCLUDE, BUT ARE NOT LIMITED TO, THOSE DISCUSSED
UNDER "RISK FACTORS," "MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
CONDITION AND RESULTS OF OPERATIONS," AND "BUSINESS," AS WELL AS THOSE DISCUSSED
ELSEWHERE IN THIS PROSPECTUS.
 
OVERVIEW
 
     Trimeris commenced operations in January 1993, has a limited operating
history and is a development stage company. Since its inception, substantially
all of the Company's resources have been dedicated to the development,
patenting, preclinical testing and a Phase I/II clinical trial of T-20, the
development of its proprietary technology platform and research and development
and preclinical testing of other potential product candidates and compounds
discovered by the Company. The Company has incurred losses since its inception
and, as of June 30, 1997, had an accumulated deficit of approximately $21.4
million. The Company has received revenue solely from SBIR grants and an
investigative contract and has yet to generate any revenue from product sales or
royalties, and there can be no assurance that it will be able to generate any
such revenues or royalties in the future.
 
     Product candidates and compounds discovered by the Company and developed
through the Company's product development programs will require significant
additional, time-consuming and costly research and development, preclinical
testing and extensive clinical trials prior to submission of any regulatory
application for commercial use. The Company has incurred losses since its
inception. Such losses have resulted principally from expenses incurred in the
Company's research and development activities associated with the development,
patenting, preclinical testing and a Phase I/II clinical trial of T-20, the
development of its proprietary technology platform, research and development and
preclinical testing of other potential product candidates and compounds
discovered by the Company, and from general and administrative expenses. The
Company expects to incur substantial losses for the foreseeable future and
expects losses to increase as the Company's research and development,
preclinical testing and clinical trial efforts expand. The amount and timing of
the Company's operating expenses will depend on several factors, including the
status of the Company's research and development activities, product candidate
and compound discovery and development efforts, including preclinical testing
and clinical trials, the timing of regulatory actions, the costs involved in
preparing, filing, prosecuting, maintaining, protecting and enforcing patent
claims and other proprietary rights, the ability of the Company to establish,
internally or through relationships with third parties, manufacturing, sales,
marketing and distribution capabilities, technological and other changes in the
competitive landscape, changes in the Company's existing research and
development relationships and strategic alliances, evaluation of the commercial
viability of potential product candidates and other factors, many of which are
outside of the Company's control. As a result, the Company believes that
period-to-period comparisons of financial results in the future are not
necessarily meaningful and results of operations in prior periods should not be
relied upon as an indication of future performance. Any deviations in results
from operations from levels expected by securities analysts and investors could
have a material adverse effect on the market price of the Common Stock. The
Company's ability to achieve profitability will depend, in part, upon its or its
collaborated partners' ability to successfully develop and obtain regulatory
approval for T-20 and other product candidates and compounds discovered by the
Company, and to develop the capacity, either internally or through relationships
with third parties, to manufacture, sell, market and distribute approved
products, if any. There can be no assurance that the Company will ever generate
significant revenues or achieve profitable operations. See "Risk
Factors -- Development Stage Company" and " -- History of Operating Losses;
Accumulated Deficit; Uncertainty of Future Profitability."
 
                                       23
 
<PAGE>
RESULTS OF OPERATIONS
 
  COMPARISON OF SIX MONTHS ENDED JUNE 30, 1996 AND 1997
 
     REVENUE. There was no revenue recognized for the six months ended June 30,
1996. Revenue recognized for the six months ended June 30, 1997 consisted of
approximately $112,000 of income from SBIR grants, and $100,000 from an
investigative contract.
 
   
     RESEARCH AND DEVELOPMENT EXPENSES. Total research and development expenses
increased from approximately $2.3 million for the six months ended June 30, 1996
to approximately $2.9 million for the six months ended June 30, 1997. The
increase is primarily due to increased costs related to additional personnel and
related laboratory research supplies to support these personnel and the
continuation of a Phase I/II clinical trial for T-20. Total research personnel
were 24 and 28 at June 30, 1996 and 1997, respectively. The Company expects its
research and development expenses to increase substantially in the future due to
continued expansion of product development activities, including preclinical
testing and clinical trials.
    
 
     GENERAL AND ADMINISTRATIVE EXPENSES. Total general and administrative
expenses decreased from approximately $802,000 for the six months ended June 30,
1996 to approximately $786,000 for the six months ended June 30, 1997. The
Company expects its administrative expenses to increase in the future to support
the expansion of its product development activities.
 
     OTHER INCOME (EXPENSE). Other income (expense) consists of interest income
and expense. Total other expenses decreased from approximately $55,000 for the
six months ended June 30, 1996 to $45,000 for the six months ended June 30,
1997. This change was primarily due to fluctuations in cash balances and
borrowings.
 
  COMPARISON OF YEARS ENDED DECEMBER 31, 1994, 1995 AND 1996
 
     REVENUE. Total revenue was approximately $0, $104,000 and $54,000 for 1994,
1995 and 1996, respectively. An SBIR grant was received in 1995, and revenue was
recognized as earned under this grant in 1995 and 1996.
 
   
     RESEARCH AND DEVELOPMENT EXPENSES. Total research and development expenses
increased from $2.7 million in 1994 to approximately $4.0 million in 1995 and
increased to approximately $5.1 million in 1996. The increases are primarily due
to increased costs related to additional personnel and related laboratory
research supplies to support these personnel. During 1996, the Company began a
Phase I/II clinical trial for T-20 and incurred costs associated with these
clinical trials. Total research personnel were 17, 25 and 25 at December 31,
1994, 1995 and 1996, respectively.
    
 
     GENERAL AND ADMINISTRATIVE EXPENSES. Total general and administrative
expenses increased from approximately $948,000 in 1994 to approximately $1.5
million in 1995, and increased to approximately $1.8 million in 1996. These
increases are primarily due to increased costs related to additional personnel
and professional fees incurred in the patent application process.
 
     OTHER INCOME (EXPENSE). Other income (expense) consists of interest income
and expense. Total other expense increased from approximately $250,000 in 1994
to approximately $311,000 in 1995 and decreased to approximately $120,000 in
1996. The increase from 1994 to 1995 was primarily due to an increase in
interest expense of approximately $102,000 net of an increase in interest income
of approximately $41,000. The decrease from 1995 to 1996 was primarily due to a
reduction in interest expense of approximately $193,000 as a result of the
exchange of notes payable for preferred stock during 1995.
 
LIQUIDITY AND CAPITAL RESOURCES
 
     Since inception, the Company has financed its operations primarily through
the private placement of equity securities, the issuance of notes to
stockholders and equipment lease financing. Net cash used by operating
activities was approximately $3.8 million, approximately $4.8 million and
approximately $5.8 million in 1994, 1995 and 1996, respectively, and
approximately $2.9 million and approximately $3.5 million for the six months
ended June 30, 1996 and June 30, 1997, respectively. The cash used by operating
activities was used primarily to fund research and development and general and
administrative expenses. Cash provided by financing activities was approximately
$3.6 million, approximately $6.1 million, and approximately $4.8 million in
1994, 1995 and 1996,
 
                                       24
 
<PAGE>
respectively, and approximately $3.3 million and approximately $12.4 million for
the six months ended June 30, 1996 and 1997, respectively. The cash provided by
financing activities was primarily from the sale of equity securities and notes
to stockholders.
 
     As of June 30, 1997, the Company had approximately $8.9 million in cash and
cash equivalents compared to approximately $132,000 as of December 31, 1996. The
increase resulted from the receipt of approximately $12.8 million from the sale
of equity securities during 1997, partially offset by approximately $3.5 million
used by operations.
 
   
     The Company has experienced negative cash flows from operations since its
inception and does not anticipate generating sufficient positive cash flows to
fund its operations in the foreseeable future. The Company has expended, and
expects to continue to expend in the future, substantial funds to pursue its
product candidate and compound discovery and development efforts, including
expenditures for continued clinical trials of T-20, research and development and
preclinical testing of other product candidates and compounds discovered by the
Company and the development of its proprietary technology platform. As of June
30, 1997, the Company had commitments to purchase approximately $2.0 million of
product candidate materials and expects to expend approximately $900,000 in
capital expenditures through the end of 1997. These expenditures may be financed
with capital or operating leases, debt or working capital. The Company expects
that its existing capital resources, together with the net proceeds of the
Offering and the interest earned thereon, will be adequate to fund its capital
requirements through 1998. However, the Company's future capital requirements
and the adequacy of available funds will depend on many factors, including the
results of the clinical trials relating to T-20, the progress and scope of the
Company's product development programs, the magnitude of these programs, the
results of preclinical testing and clinical trials, the need for additional
facilities based on the results of these clinical trials and other product
development programs, changes in the focus and direction of the Company's
product development programs, the costs involved in preparing, filing,
processing, maintaining, protecting and enforcing patent claims and other
intellectual property rights, competitive factors and technological advances,
the cost, timing and outcome of regulatory reviews, changes in the requirements
of the FDA, administrative and legal expenses, evaluation of the commercial
viability of potential product candidates and compounds, the establishment of
capacity, either internally or through relationships with third parties, for
manufacturing, sales, marketing and distribution functions and other factors,
many of which are outside of the Company's control. Thus, there can be no
assurance that the net proceeds of this Offering, together with the interest
earned thereon, will be sufficient to fund the Company's capital requirements
during the period discussed above. The Company believes that substantial
additional funds will be required to continue to fund its operations and that
the Company will be required to obtain additional funds through equity or debt
financing or licenses, agreements or other arrangements with collaborative
partners and others, or from other sources. The terms of any such equity
financings may be dilutive to stockholders and the terms of any debt financings
may contain restrictive covenants which limit the Company's ability to pursue
certain courses of action. There can be no assurance that such funds will be
available to the Company on acceptable terms, if at all, or that such financings
will be adequate to meet the Company's future capital requirements. If adequate
funds are not available, the Company may be required to delay, scale-back or
eliminate certain aspects of its preclinical testing, clinical trials and
research and development programs or attempt to obtain funds through
arrangements with collaborative partners or others that may require the Company
to relinquish rights to certain of its technologies or product candidates or
compounds, which could have a material adverse effect on the Company's business,
financial condition and results of operations. See "Risk Factors -- Future
Capital Needs; Uncertainty of Additional Funding" and "Use of Proceeds."
    
 
NET OPERATING LOSS CARRYFORWARDS
 
   
     As of June 30, 1997, the Company had a net operating loss carryforward of
approximately $21 million. The Company has recognized a valuation allowance
equal to the deferred asset represented by this net operating loss carryforward
and therefore recognized no tax benefit. The Company's ability to utilize its
net operating loss carryforwards may be subject to an annual limitation in
future periods pursuant to the "change in ownership rules" under Section 382 of
the Internal Revenue Code of 1986, as amended (the "Code"). See Note 6 of Notes
to Financial Statements.
    
 
                                       25
 
<PAGE>
                                    BUSINESS
 
THE COMPANY
 
   
     Trimeris is a biopharmaceutical company engaged in the discovery and
development of novel therapeutic agents that block viral infection by inhibiting
viral fusion with host cells. Viral fusion is a complex process by which viruses
attach to and penetrate host cells. The Company's lead product candidate, T-20,
inhibits fusion of HIV with host cells. T-20 has been tested in a multidose
Phase I/II clinical trial as a monotherapy for HIV-infected patients in the
United States. The results from this clinical trial indicate that short-term
administration of T-20 in an intravenous formulation is safe and well tolerated.
Furthermore, all four patients in the clinical trial who received the highest
dose of T-20 experienced a reduction in HIV viral load to below detectable
levels (less than 500 copies/ml) during the treatment period. T-20 and the
Company's other product candidates are designed to inhibit viral fusion, unlike
other currently approved therapeutic agents that target replicating viruses
inside already infected cells. The Company has developed a proprietary
technology platform in the field of fusion inhibition, which is being applied to
the discovery and development of novel products for the treatment of a variety
of viral diseases.
    
 
   
     The Company is a development stage company. Since its inception,
substantially all of the Company's resources have been dedicated to the
development, patenting, preclinical testing and a Phase I/II clinical trial of
T-20, the development of the Company's proprietary technology platform, and
research and development and preclinical testing of other potential product
candidates and compounds discovered by the Company.
    
 
OVERVIEW OF VIRAL DISEASE
 
     Viruses are infectious particles which contain either RNA or DNA and rely
on host cells to maintain their life cycle. Outside a host cell, a virus
particle cannot replicate. However, after infecting a host cell, a virus
exploits the metabolic mechanisms of that host cell to reproduce and make new
infectious virus particles that can infect other cells.
 
   
     The genetic material of viruses is surrounded by a protein coat, called a
nucleocapsid. The nucleocapsid of certain viruses, known as enveloped viruses
(HIV, RSV, HPIV, influenza and hepatitis B and C), is surrounded by a bilayer
membrane consisting of both lipids and proteins. Certain of these viral proteins
facilitate the binding process of the virus to the host cell. These proteins
contain peptide domains that associate with one another to form coiled coils
during the infection process. These coiled-coil protein domains come together in
very specific structural rearrangements that help the viral membrane fuse with
the host cell membrane. This coiled-coil interaction permits the viral fusion
process to take place, thereby allowing the virus to inject its genetic material
into the host cell. Using HIV as an example, the following diagrams illustrate a
typical life cycle of a virus and the process by which certain viruses infect a
host cell.
    
 
                                 HIV LIFE CYCLE

                             [Depiction of the HIV Life
                             Cycle as more fully described
                                        below]


   
STEP 1: HIV attaches to the surface of a human immune cell when the gp120
protein binds to a particular host cell receptor. After attachment, gp120 is
stripped away from the virus and certain peptide domains within the gp41
transmembrane protein
    

                                       26

<PAGE>
rearrange and bind to each other very tightly to form coiled coils which mediate
the fusion of the viral and host cell membranes. STEP 2: The virus injects its
genetic material (RNA) into the cell. An HIV viral enzyme (reverse
transcriptase) then converts this RNA into DNA. STEP 3: The viral DNA is
transported to the nucleus and is integrated into the host cell's chromosomes.
STEP 4: The infected cell begins to produce new viral RNA, which then uses a
portion of the host cell's protein synthesis machinery to make many different
viral proteins. STEP 5: The viral enzyme called protease cuts these new proteins
into smaller pieces. STEP 6: These protein pieces assemble with the HIV RNA and
lipids to make new infectious virus particles. STEP 7: Mature HIV particles are
released from the surface of the infected cell to begin a new cycle of
infection.

                              MODEL FOR HIV FUSION

                               [Depiction of Model for
                              HIV Fusion as more fully
                                  described below]

   
(1) PRE-FUSION: The HIV gp41 protein contains two peptide domains which are
predicted to associate with one another to help the virus fuse with the host
cell membrane. However, these two peptide domains are presumably kept apart by
the gp120 protein in a pre-fusion state until the virus attaches to a host cell.
(2) ATTACHMENT: The gp120 protein is stripped away from the virus after gp120
binds to host cell receptors. The two specific peptide domains within the gp41
protein can then rearrange and bind to each other very tightly to form a
coiled-coil structure. In doing so, the tip of the gp41 protein is now
positioned to penetrate the host cell membrane. (3) FUSION: The virus is now
drawn closer to the host cell membrane surface and the viral and host cell
membranes fuse together. (4) PENETRATION: Once the membranes fuse together, the
virus can inject its genetic material into the host cell and the infection
process is completed. NOTE: The gp120 and gp41 protein structures are enlarged
in comparison to the size of the virus to show detail.
    
 
                                       27
 
<PAGE>
THE COMPANY'S TECHNOLOGY
 
     The Company's academic founders, Dr. Dani Bolognesi and Dr. Thomas
Matthews, both of the Duke University Center for AIDS Research, have discovered
a novel method to block HIV infection by inhibiting viral fusion with host
cells. This discovery was licensed to the Company and led to the Company's
development of its proprietary technology platform. The Company is using its
proprietary techonology platform to support its discovery and development
programs. Unlike therapeutic agents targeting viral replication processes inside
host cells, the Company's product candidates prevent one of the first steps in
the infection process that occurs outside of the host cell. The Company's goal
is to use its expertise in the field of fusion inhibition to discover, develop
and market novel peptides or small molecules to inhibit viral fusion for the
treatment of a variety of diseases.
 
   
     T-20, the Company's lead product candidate, inhibits HIV infection. T-20 is
a proprietary 36 amino acid synthetic peptide that binds to a key peptide domain
of the HIV gp41 protein and blocks HIV viral fusion by interfering with the
interactions between peptide domains within viral proteins that are required for
HIV entry into a host cell. In a multidose Phase I/II clinical trial, T-20
exhibited dose-dependent anti-HIV activity while eliciting no drug-related
adverse events and no dose-limiting toxicities during the treatment period. The
following diagram illustrates the use of T-20 to inhibit viral fusion.
    
 
                    MODEL FOR T-20 INHIBITION OF HIV FUSION
 
   
                             [Depiction of the use of
                             T-20 to block viral fusion
                           as more fully described below]
                             

The gp120 protein is stripped away from the virus after gp120 binds to a
particular host cell receptor. Two specific peptide domains in the gp41 protein
are thus freed and can bind to one another to form a coiled coil. However, if
T-20 is present in the bloodstream, it binds very tightly to one of the two
peptide domains within the gp41 protein. Therefore, T-20 blocks the ability of
gp41 to form a natural, coiled-coil structure. As a result, the tip of the gp41
protein does not effectively penetrate the host cell membrane. Since the virus
cannot penetrate and inject its genetic material into the cell, HIV infection of
the host cell is inhibited. NOTE: The gp120 and gp41 protein structures are
enlarged in comparison to the size of the virus to show detail.
    
 
                                       28
 
<PAGE>
     Through its study of the HIV fusion process, the Company has developed a
proprietary technology platform aimed at discovering antiviral compounds. The
cornerstone of this platform is CAST, a proprietary computer algorithm which
identifies target sequences within certain viral proteins that have the
potential to interact during the fusion process. Once identified by the CAST
algorithm, these target sequences form the basis for designing highly selective
and potent peptide inhibitors of viral fusion. CAST has enabled the Company to
design product candidates for RSV and HPIV fusion inhibition. The Company has
identified, and has filed patent applications disclosing, numerous discrete
peptide sequences, which include potential fusion targets in other viruses such
as hepatitis B and C, influenza and herpes.
 
     In addition to viral targets, CAST has identified protein sequences which
may have a role in bacterial pathogenesis, thus providing the Company with the
basis for future work aimed at the potential discovery of antibiotic agents.
Ultimately, the Company plans to explore CAST-identified sequences across a wide
range of targets, including those associated with cancer, immunology and
neurology.
 
PROGRAMS AND PRODUCT CANDIDATES UNDER DEVELOPMENT
 
     The following table describes the various stages of development of the
Company's programs and product candidates.
 
   
<TABLE>
<CAPTION>
          INDICATION                    PRODUCT CANDIDATE              DEVELOPMENT STATUS(1)
<S>                               <C>                              <C>
  HIV                             T-20                              Phase I/II Completed
  RSV                             T-786                             Preclinical
  HIV                             Second generation inhibitors      Preclinical
  RSV                             Small molecules                   Preclinical
  HPIV                            T-205                             Research
  HPIV                            Small molecules                   Research
  HIV                             Small molecules                   Research
  Influenza Virus                 Small molecules                   Discovery
  Hepatitis B Virus               Small molecules                   Discovery
  Hepatitis C Virus               Small molecules                   Discovery
  Epstein-Barr Virus              Small molecules                   Discovery
(1) "Phase I/II Completed" indicates that the product candidate has been tested in a Phase I/II
    clinical trial for safety and preliminary indications of biological activity in a limited
    patient population. "Preclinical" indicates that the Company is testing a product candidate
    in animal models. "Research" indicates the Company is pursuing the discovery of prototype
    compounds and evaluating prototype compounds in IN VITRO testing. "Discovery" indicates that
    the Company is developing assay systems to screen chemical libraries of small molecules. See
    "Risk Factors -- Uncertainties Related to Clinical Trials and Clinical Trial Strategy,"
    " -- Extensive Government Regulation; No Assurance of Regulatory Approval" and
    "Business -- Government Regulation."
</TABLE>
    

CLINICAL DEVELOPMENT PROGRAM

  T-20

   
     T-20 is a proprietary compound which has demonstrated significant
inhibition of HIV in preclinical testing. T-20 has been tested in a Phase I/II
clinical trial in which T-20 exhibited dose-dependent anti-HIV activity while
eliciting no drug-related adverse events and no dose-limiting toxicities during
the treatment period. T-20 inhibits HIV viral fusion with host cells and thus
operates by a completely different mechanism of action than any other currently
approved HIV antiviral. HIV targets primarily the human immune cells known as
CD4+ T-cells and macrophages. HIV-infected cells ultimately lose their immune
function, leading to eventual degeneration of the immune system, which results
in opportunistic infections, neurological dysfunctions, neoplasms and death.
    

     T-20 is a 36 amino acid synthetic peptide whose sequence is derived from
the gp41 protein of HIV. In preclinical testing, T-20 displayed potent antiviral
activity and reduced HIV viral load significantly in animal

                                       29

<PAGE>
   
models. In those tests, T-20 displayed notable pharmaceutical properties,
including long half-life, significant bioavailability, chemical stability and
rapid distribution into lymphatic tissue, a major reservoir of HIV. In August
1997, the Company concluded a Phase I/II clinical trial in which an intravenous
formulation of T-20 was administered to HIV-infected patients. The clinical
trial consisted of four groups of four patients, with each group receiving a
different dose of T-20. Patients received doses of T-20 at either 3 mg, 10 mg,
30 mg or 100 mg by bolus intravenous infusion every 12 hours for 14 consecutive
days. No drug-related adverse events were recorded and no dose-limiting
toxicities were observed for any patient during the treatment period.
Furthermore, a dose-dependent decrease in HIV viral load and a dose-dependent
increase in CD4+ T-cell count were observed.
    

   
     All four patients who received the 100 mg dose experienced a decrease in
HIV viral load to below detectable levels (less than 500 copies/ml) during the
treatment period. The lower limit of detection of the assay used for this trial
is 500 copies/ml, which is equivalent to 2.70 log10 . The data from the clinical
trial thus indicate that the 100 mg dose group of patients experienced a minimum
decrease of at least 1.50 log10 in HIV viral load. The following table
summarizes the results of this clinical trial.
    

   
                     T-20 PHASE I/II CLINICAL TRIAL RESULTS
    

   
<TABLE>
<CAPTION>                               MEAN HIV VIRAL LOAD (1)
                                                                  CHANGE
T-20 DOSE (2)       BASELINE           DAY 14             LOG(10)          PERCENT
<S>               <C>               <C>               <C>               <C>
      3 mg             4.82              4.71             (0.11)             (22)%
     10 mg             5.12              5.06             (0.06)             (13)
     30 mg             4.95              4.47             (0.48)             (61)
    100 mg             4.20              2.70(3)          (1.50)             (97)
</TABLE>
    

   
      (1) Copies/ml plasma (reported in log10).
    
 
   
      (2) Administered every 12 hours for 14 consecutive days.
    
 
   
      (3) 2.70 log10 is the lower limit of detection of the assay used for this
          trial.
    
 
   
     The criteria for enrollment set forth in the trial protocol required that
participants (1) either have stopped taking antiretroviral drug therapy at least
15 days prior to initiating treatment with T-20 or have never received such drug
therapy, (2) have CD4+ T-cell counts above 100 cells/ml and (3) have HIV viral
loads of in excess of 10,000 copies/ml.
    
 
     There can be no assurance that the results from the Phase I/II clinical
trial will support future clinical trials or will be predictive of results that
will be obtained in pivotal clinical trials.
 
  T-20 CLINICAL DEVELOPMENT
 
   
     The Company believes that delivery of a continuous therapeutic dose of T-20
using a subcutaneous infusion delivery system may suppress HIV more effectively
than other delivery mechanisms. Accordingly, the Company, together with MiniMed,
is developing a continuous, subcutaneous infusion delivery system for
administering T-20. The Company believes that the ease of use of a continuous,
subcutaneous infusion delivery system may increase patient compliance. In
addition, the Company believes that such a system may reduce the amount of T-20
necessary to maintain effective HIV suppression. The Company is preparing to
begin a Phase II clinical trial that will compare delivery of a constant
therapeutic dose of T-20 by a continuous, subcutaneous infusion pump to delivery
by intermittent, subcutaneous injections. The Company anticipates that this
clinical trial will be conducted at the University of Alabama at Birmingham
under the supervision of Dr. Michael Saag and at the UCLA Medical Center under
the supervision of Dr. Ron Mitsuyasu. Each site is expected to enroll 16 to 24
HIV-infected patients and measure pharmacokinetics of T-20 drug delivery using
the continuous, subcutaneous infusion pump and the effect of this treatment
approach on primary surrogate markers. This trial will also analyze the T-20
dosing range
    
 
                                       30
 
<PAGE>
when using the MiniMed continuous, subcutaneous infusion pump. The Company
anticipates that this Phase II clinical trial will be completed in the first
quarter of 1998.
 
     After completion of the continuous, subcutaneous infusion Phase II trial,
the Company intends to begin a pivotal Phase II trial in a larger population of
HIV-infected patients who are either resistant to, or intolerant of, currently
approved antiviral therapies (RT and protease inhibitors). Historically, pivotal
Phase II trials of this type involving HIV antivirals have included
approximately 300-400 patients and have taken approximately 18-24 months to
complete. The Company anticipates that this pivotal Phase II trial will begin in
the first half of 1998. Concurrently with the start of the pivotal Phase II
trial, the Company intends to begin a study of T-20 in HIV-infected pediatric
patients. Historically, studies of this type involving HIV antivirals have
included approximately 40-60 pediatric patients and have taken approximately
18-30 months to complete.
 
     Throughout the T-20 clinical trial process, the Company intends to work
with the FDA to design and implement a clinical trial strategy involving the
administration of T-20 to HIV-infected patients in combination with approved HIV
antiviral agents. The Company also believes that it will be able to conduct its
T-20 clinical trial programs pursuant to the accelerated approval procedure
authorized by the FDA for drugs intended to treat serious or life-threatening
illnesses. However, there can be no assurance that T-20 will be eligible for
accelerated development and/or approval under these regulations. Further, there
can be no assurance that T-20 (if eligible for accelerated development and/or
approval under these regulations) will be approved by the FDA for marketing on
an accelerated basis, or at all. The anticipated timing of the Company's T-20
clinical trials may be delayed or cancelled for a number of reasons, including
the receipt of unanticipated T-20 clinical trial results, changes in the focus
of the Company or its collaborators, financial requirements and resources,
manufacturing issues, technological developments and competitive factors.
Accordingly, no assurance can be given that the Company's T-20 clinical trials
will commence on their target dates, or at all. Delays in such clinical trials
could have a material adverse effect on the Company's business, financial
condition and results of operations. See "Risk Factors -- Extensive Government
Regulation; No Assurance of Regulatory Approval," " -- Uncertainties Related to
Clinical Trials and Clinical Trial Strategy" and "Business -- Government
Regulation."
 
  HIV MARKET AND EXISTING THERAPIES
 
   
     HIV infection causes AIDS, which is the leading cause of death in the
United States in men and women between the ages of 25 and 44. The World Health
Organization estimates that, as of late 1996, approximately 750,000 people were
infected with HIV in the United States, and approximately 510,000 people were
infected in Western Europe.
    
 
   
     The first drugs approved in the United States to treat HIV infection
inhibit the synthesis of virus DNA from viral RNA in infected cells by targeting
RT, the viral enzyme essential for such synthesis. Approved RT inhibitors
include AZT, 3TC, ddI, ddC, d4T, nevirapine and delavirdine. Worldwide sales of
RT inhibitors were approximately $1.0 billion in 1996. A second class of HIV
antivirals inhibits HIV protease, a viral enzyme required to cleave newly
synthesized viral proteins into the correct size so the virus can assemble
itself into new infectious virus particles. Approved HIV protease inhibitors
include indinavir, ritonavir, saquinavir and nelfinavir mesilate. Worldwide
sales of protease inhibitors were approximately $400 million in 1996 and are
projected to grow significantly over the next several years.
    
 
     HIV is prone to mutations that produce resistance to RT and protease
inhibitors. Once resistance emerges to one drug, these strains may also be
resistant to most, if not all, of the drugs in the same chemical or functional
class (a phenomenon known as cross-resistance). In an effort to overcome such
resistance, physicians have begun to use RT and protease inhibitors in various
combinations. While combination therapy with RT and protease inhibitors
represents an advance in treatment of HIV infection, combination therapy has not
yet proven to be a cure. Moreover, although these combination therapies have
slowed the emergence of resistance, new mutant strains have been identified
which are resistant to several of the drugs currently used in combination
therapy.
 
     Equally problematic is that even brief instances of non-compliance with the
strict drug dosing regimens associated with these combination therapies may
reduce the effectiveness of combination therapy and can accelerate the emergence
of resistance. For example, in order to maintain a high blood level of the drug
and to present a
 
                                       31
 
<PAGE>
continuous challenge to the targeted virus, many current drugs require complex
dosing, with some medications to be taken with meals and some on an empty
stomach. A typical combination therapy regimen includes 14 to 16 pills taken at
six to eight times during the day. This type of complex dosing regimen can
easily lead to noncompliance or only partial compliance. Orally administered,
small molecule drugs such as RT and protease inhibitors generally reach peak
levels in the bloodstream within a short period of time after being taken by the
patient. Drug levels then gradually fall over time as the drug is either
absorbed into tissues or is eliminated from the body. At the point in the day
when the drug level reaches its lowest concentration in the bloodstream (prior
to the patient's taking another dose), the drug level may not be sufficiently
high to effectively inhibit the virus. If a patient misses a dose or delays
taking the drug for a short period of time, the drug level in the body will fall
even lower, thus allowing the virus to replicate and potentially develop
resistant strains. The Company believes that one solution to this problem is
drug delivery using a continuous, subcutaneous infusion system through which a
controlled, programmable amount of the drug could be delivered throughout the
day.
 
   
     Toxicity is also an issue associated with the use of RT and protease
inhibitors. Accumulating data indicate that certain patients are unable to take
RT and protease inhibitors, either alone or in combination, due to toxic side
effects, including gastrointestinal disorders, peripheral neuropathy and kidney
stones. Furthermore, recent information has suggested that protease inhibitors
may cause diabetes-like symptoms in some patients. Clinical studies with some RT
and protease inhibitors indicate that a significant number of HIV-positive
patients discontinue therapy soon after they begin treatment because (i) they
cannot tolerate the toxic side effects, (ii) they rapidly become resistant to
these therapies, or (iii) demands of the drug dosing regimen (the number of
pills the patients are required to take on a strict schedule) are too great. If
the side effects of the drugs prove too severe, or if a patient's virus becomes
resistant to available drug combinations, there are no other antiviral
treatments currently available.
    
 
  T-20 COMMERCIALIZATION STRATEGY
 
     The Company has entered into a strategic alliance with MiniMed under which
the parties will collaborate to deliver T-20 using MiniMed's continuous infusion
pump. MiniMed pumps, currently used for insulin therapy, are generally attached
to a belt, strapped to a leg or draped on a cord around the neck. These pumps
weigh approximately 3.5 ounces and are approximately the size of a pager. The
Company expects that MiniMed will play an active role in the marketing of its
pump for T-20 delivery and will provide patient support and product service for
the pump and related disposable products. The Company plans to work directly
with MiniMed to pursue necessary regulatory approvals for the delivery of T-20
using the MiniMed pump. See "Risk Factors  -- Dependence on Collaborations and
Licenses with Others," " -- Extensive Government Regulation; No Assurance of
Regulatory Approvals," "Business -- License and Collaborative Agreements" and
" -- Government Regulation."
 
     The manufacture of peptides requires significant expertise, facilities and
equipment. Accordingly, the Company has elected to work with several third-party
contract manufacturers to supply quantities of T-20 to be used in the Company's
currently planned clinical trials. The Company may continue to rely on
third-party manufacturers throughout the clinical and initial commercialization
phases of T-20 development. The Company has also established an in-house T-20
manufacturing process development and control team that is attempting to develop
an improved process for the synthetic manufacture of T-20, which may result in
increased production volume and lower unit costs. See
"Business -- Manufacturing" and "Risk Factors -- Lack of Manufacturing
Capabilities" for a discussion of manufacturing processes and certain risks
associated with manufacturing peptides.
 
     The Company does not currently have sales, marketing or distribution
capabilities and is evaluating strategies for the sale, marketing and
distribution of T-20, including developing internal capabilities and entering
into collaborative arrangements. The Company believes that it may be feasible to
develop internal sales, marketing and distribution capability for T-20, since
the market for HIV therapeutics is comprised of a concentrated group of
physicians in medical practices that treat HIV patients. The Company will
continue to explore alternative opportunities to market T-20, either internally
or in conjunction with appropriate marketing partners. See "Risk Factors -- Lack
of Sales, Marketing and Distribution Capabilities" and "Business -- Sales,
Marketing and Distribution."
 
                                       32
 
<PAGE>
PRECLINICAL DEVELOPMENT PROGRAMS
 
     The Company is using its proprietary technology platform to discover and
develop fusion inhibitors for other viral diseases where there are substantial
unmet medical needs.
 
  T-786
 
   
     T-786 is the Company's lead product candidate for the treatment of RSV
infection, which is a significant cause of pediatric bronchiolitis and
pneumonia. Each year in the United States, 11 out of 100 children younger than
one year of age are infected with RSV, more than 90,000 infants are hospitalized
with RSV infections, and over 4,500 deaths are attributed to RSV. There is
currently only one product approved for the treatment of RSV infection, and the
Company believes that this product is used sparingly because its effectiveness
is limited and its side effects are significant.
    
 
     T-786 is a proprietary 36 amino acid synthetic peptide derived from a CAST
predicted domain of the RSV fusion protein. T-786 shows potent, specific and
selective inhibition of RSV infection IN VITRO. In preclinical testing, T-786
significantly reduced the level of viral infection in an animal model. Because
RSV infects lung tissue primarily, the Company believes that aerosol delivery of
its RSV therapeutic directly to the lung may be the most effective method for
administering T-786. The Company is currently developing an aerosol formulation
of T-786 for preclinical evaluation. Preclinical testing of T-786 is currently
in progress. Upon successful completion of these tests, the Company anticipates
that it will begin clinical trials for T-786 in 1998.
 
  SECOND-GENERATION HIV FUSION INHIBITORS
 
     Using CAST, the Company has designed proprietary second-generation, peptide
HIV fusion inhibitors which bind to regions of the HIV fusion protein target
that are different from the region bound by T-20. In preclinical testing, these
second-generation compounds have been shown to be highly effective against a
wide range of HIV strains IN VITRO. In preclinical testing, these compounds have
demonstrated pharmaceutical characteristics distinct from T-20. The Company
believes that these second-generation compounds could provide a range of future
options for the continuing treatment of HIV infection. The Company expects to
begin testing its lead second-generation HIV fusion inhibitor in animal models
in the fourth quarter of 1997.
 
  ANTI-RSV SMALL MOLECULES
 
     The Company has identified a series of small-molecule inhibitors of RSV
infection using its high-throughput screening assays. These assays were designed
based upon the CAST platform. Using its proprietary knowledge of the chemical
structure of these compounds, the Company has developed a number of analogs
which have demonstrated potency against RSV in preclinical testing. Several of
these analogs have also demonstrated low toxicity. The Company is continuing to
synthesize analogs of these compounds to evaluate their pharmaceutical
properties and will continue preclinical testing to identify lead compounds.
 
RESEARCH AND DISCOVERY PROGRAMS
 
     The Company is leveraging its proprietary technology platform and expertise
in viral fusion to discover and develop lead compounds and product candidates to
treat a variety of diseases caused by other viruses.
 
  ANTI-HPIV COMPOUNDS
 
     Using CAST, the Company has developed a series of proprietary peptides
which inhibit HPIV IN VITRO. T-205, the Company's lead anti-HPIV peptide, was
derived from a coiled-coil domain of the HPIV fusion protein. T-205 shows
specific, selective and potent inhibition of HPIV infection IN VITRO. HPIV is a
cause of respiratory disease in young infants. There are no drugs currently
approved for the treatment of HPIV. The Company is conducting a research program
to evaluate T-205 and other peptide candidates for possible advancement to
preclinical development.
 
     The Company has also discovered several small-molecule inhibitors of HPIV
using the Company's high-throughput HPIV screening assay. This assay was
designed based on the CAST platform. These compounds show
 
                                       33
 
<PAGE>
potent, dose-response inhibition of HPIV IN VITRO. The Company is currently
synthesizing analogs of these compounds to evaluate their pharmaceutical
properties.
 
  ANTI-HIV SMALL MOLECULES
 
     The Company has indentified a series of small-molecule compounds which
inhibit HIV infection IN VITRO using the Company's high-throughput HIV screening
assays. These assays were designed based on the CAST platform. The Company plans
to continue screening its chemical libraries to discover additional anti-HIV
small-molecule compounds.
 
  INFLUENZA VIRUS
 
     The Company has initiated an early-stage discovery program to create a
high-throughput screening assay based on CAST to identify potential
small-molecule inhibitors of influenza viral fusion. The Company has established
a collaboration with Dr. Judith White at the University of Virginia to assist in
the discovery and development of fusion inhibitors for influenza virus.
 
  HEPATITIS B AND C VIRUS
 
   
     The Company has initiated early-stage discovery programs to create
high-throughput screening assays that can identify potential small-molecule
inhibitors of the hepatitis B and C viruses. Additionally, in collaboration with
Dr. Timothy Block of the Thomas Jefferson Medical School, the Company plans to
synthesize and test peptides derived from CAST-identified regions of the
hepatitis B virus. The Company has been awarded a Phase I SBIR grant from the
Department of Health and Human Services for this program.
    
 
  EPSTEIN-BARR VIRUS
 
     The Company has initiated an early-stage discovery program in Epstein-Barr
virus ("EBV") through a collaboration with Dr. Joseph Pagano of the University
of North Carolina at Chapel Hill. EBV causes infectious mononucleosis and has
been linked to a variety of cancers. Dr. Pagano is working with the Company's
scientists to develop a strategy for inhibiting a key protein required for EBV
replication. Using CAST, the Company has identified key interactive peptide
domains within this molecular target and has synthesized peptide inhibitors for
the molecular target IN VITRO.
 
BUSINESS STRATEGY
 
     The Company's goal is to become a leader in anti-fusion viral therapy. To
achieve this objective, the principal elements of the Company's strategy are to:
 
   
     (Bullet) VALIDATE FUSION INHIBITION THERAPY BY OBTAINING REGULATORY
              APPROVAL FOR T-20. T-20 has been shown in preclinical testing to
              inhibit HIV fusion. T-20 has been tested in a Phase I/II clinical
              trial, and the Company anticipates that a Phase II pivotal trial
              will begin in the first half of 1998. The Company believes that it
              will be able to conduct its pivotal T-20 clinical trials program
              pursuant to the accelerated approval procedure authorized by the
              FDA for drugs intended to treat serious or life-threatening
              illnesses. The Company believes that regulatory approval of T-20,
              if obtained, will provide important evidence to support the
              validity of viral fusion inhibition therapy.
    
 
     (Bullet) LEVERAGE ANTI-FUSION EXPERTISE TO DEVELOP OTHER ANTIVIRAL
              THERAPIES. The Company believes that its proprietary technology
              platform, including CAST, is applicable to many other viral
              targets that may be susceptible to fusion inhibition. For example,
              using CAST, the Company designed T-786 for treatment of RSV
              infection. Upon the successful completion of preclinical testing,
              the Company anticipates that it will begin clinical trials of
              T-786 in 1998. The Company also has research and discovery
              programs to identify compounds to inhibit fusion of other viruses,
              including HPIV, influenza, hepatitis B and C, and EBV.
              Additionally, as the Company refines and enhances CAST, the
              Company believes that it will be able to develop new,
              high-throughput screening assays for multiple targets.
 
                                       34
 
<PAGE>
     (Bullet) TAILOR COMMERCIALIZATION CAPABILITIES TO SPECIFIC PRODUCT MARKETS.
              The Company intends to evaluate the appropriate commercializaton
              strategy for each of its product candidates, depending on the size
              and nature of the market. For example, the Company believes that
              it may develop its own capability to sell and market T-20 in the
              United States because a relatively small number of physicians
              write the majority of prescriptions for HIV drugs in the United
              States.
 
MANUFACTURING
 
     The Company has no experience in manufacturing pharmaceuticals and has no
commercial manufacturing capacity. The Company has established relationships and
intends to establish additional relationships with third-party manufacturers for
the production of quantities of its product candidates or compounds sufficient
to conduct its planned preclinical testing and clinical trials and the
commercial production of any approved products or compounds.
 
     Three different methods are currently available for the synthetic
manufacture of peptides such as T-20, namely solid-phase sequential peptide
synthesis, peptide synthesis by fragment condensation and solution-phase peptide
synthesis. In solid-phase sequential peptide synthesis, peptides are
synthetically manufactured by sequentially linking together amino acids to form
a peptide chain. The peptide chain is attached to a solid support from which the
finished peptide is chemically released after completion of this amino acid
assembly process. Because of certain technical limitations inherent in this
process that limit its efficiency, solid-phase sequential peptide synthesis is
the most expensive way to chemically assemble the Company's current peptide
product candidates, including T-20. Peptides may also be manufactured using a
process known as peptide synthesis by fragment condensation, in which peptide
segments that match sequential regions along the parent peptide sequence are
synthesized using solid-phase peptide chemistry techniques. This process is
technically more difficult to accomplish than solid-phase sequential peptide
synthesis and may not lead to a process that is commercially feasible. However,
if successful, this process is generally more economical than solid-phase
sequential peptide synthesis for peptides that are longer than approximately 15
amino acids in length. In the third peptide manufacturing method, solution-phase
peptide synthesis, peptides are synthetically manufactured by linking all amino
acids together in the peptide chain entirely in solution. This chemical assembly
process is technically the most difficult to design and implement and may be
technically infeasible on a commercial scale for peptides longer than
approximately 15 amino acids. However, the Company believes that cost savings
may be achieved beyond those possible using fragment condensation peptide
synthesis if technical difficulties with the technology are overcome.
 
   
     The Company and its third-party manufacturers have manufactured sufficient
quantities of T-20 using solid-phase sequential peptide synthesis to complete
preclinical testing and the Phase I/II clinical trial. The Company has entered
into agreements with two contract manufacturers for the solid-phase sequential
peptide synthetic manufacture of T-20 for use in clinical trials. The Company
has also established a manufacturing process development and control team
consisting of four individuals with significant pharmaceutical experience in
peptide and small organic molecule process development and manufacturing. This
team is currently working to implement a strategy to manufacture T-20 using
peptide synthesis by fragment condensation. The Company anticipates that such a
process may be available to support later-stage T-20 clinical trial needs. This
team will also coordinate process implementation with third-party manufacturers
and help to ensure regulatory compliance in the manufacturing process. Although
the Company has no plans at present to evaluate solution-phase peptide synthesis
for T-20, the Company may chose to evaluate the use of this process for T-20 in
the future. There can be no assurance that the Company or its third-party
manufacturers will be able to manufacture T-20 on a cost-effective basis or that
the Company will be successful in its efforts to develop an alternative, more
efficient manufacturing method for T-20 or any of its other peptide product
candidates.
    
 
     There can be no assurance that the Company will be able to retain or
establish relationships with any third-party manufacturers on acceptable terms,
if at all, or that such third-party manufacturers will be able to manufacture
products in commercial quantities under GMP requirements on a cost-effective
basis. The Company's dependence upon third parties for the manufacture of its
products, product candidates and compounds may adversely affect the Company's
profit margins and its ability to develop and commercialize product candidates,
products and compounds on a timely and competitive basis. Further, there can be
no assurance that manufacturing or quality
 
                                       35
 
<PAGE>
control problems will not arise in connection with the manufacture of the
Company's products, product candidates or compounds or that third-party
manufacturers will maintain the necessary governmental licenses and approvals to
continue manufacturing the Company's products, product candidates or compounds.
Any failure to maintain existing or establish new relationships with third
parties for the Company's manufacturing requirements on a timely basis and on
acceptable terms would have a material adverse effect on the Company's business,
financial condition and results of operations. See "Risk Factors -- Lack of
Manufacturing Capabilities" and " -- Extensive Government Regulation; No
Assurance of Regulatory Approval."
 
LICENSING AND COLLABORATIVE AGREEMENTS
 
   
     The Company intends to consider entering into collaborative and licensing
arrangements with collaborative partners, licensees and third parties to seek
regulatory approval of and to manufacture and commercialize certain of its
existing and potential product candidates and compounds. These collaborations
could provide the Company with funding, research and development resources,
access to libraries of diverse compounds and clinical development,
manufacturing, sales, marketing and distribution capabilities. Accordingly, the
Company's success will depend, in part, upon the subsequent success of such
third parties in performing preclinical testing and clinical trials, obtaining
the requisite regulatory approvals, scaling up manufacturing, successfully
commercializing the licensed product candidates or compounds and otherwise
performing their obligations. There can be no assurance that the Company will be
able to maintain its existing arrangements or enter into acceptable
collaborative and license arrangements in the future on acceptable terms, if at
all, that such arrangements will be successful, that the parties with which the
Company has or may establish arrangements will perform their obligations under
the arrangements, or that potential collaborators will not compete with the
Company by seeking alternative means of developing therapeutics for the diseases
targeted by the Company. There can also be no assurance that the Company's
existing or any future arrangements will lead to the development of product
candidates or compounds with commercial potential, that the Company will be able
to obtain proprietary rights or licenses for proprietary rights with respect to
any technology developed in connection with these arrangements, or that the
Company will be able to ensure the confidentiality of any proprietary rights and
information developed in such arrangements or prevent the public disclosure
thereof. The Company currently has a license from Duke University (as described
below), and in the future may require additional licenses from these or other
parties, to effectively develop potential product candidates and compounds. The
Company is currently negotiating a license with a third party to acquire a
related technology.
    
 
   
     The Company has received approximately $300,000 from SBIR grants. The first
grant, "Screens for Identifying HIV Fusion Inhibitors -- Phase I," was completed
during 1995. Phase II of that grant, in the amount of $365,000, is currently in
progress with a projected completion date in March 1998. Another grant, "Peptide
Therapeutics for the Liver Cancer Pathogen HBV," was begun during 1996 and
completed in 1997. There can be no assurance that the funding provided by such
grants will be sufficient to complete the studies contemplated by such programs
or that the Company will receive any additional future grants under any of these
programs.
    
 
     The Company also received approximately $100,000 from a third party under
an investigative contract. The purpose of this contract was to identify
pharmaceutical compounds in late stage clinical development that may be licensed
for sale in the United States and other foreign countries. There can be no
assurance that the Company will receive any additional funding under this or any
other similar contract.
 
     In April 1997, the Company and MiniMed entered into the MiniMed Agreement.
Under the agreement, the Company and MiniMed will collaborate in the development
and delivery of therapies for the treatment of targeted indications by combining
the continuous infusion delivery pump of MiniMed and the antiviral product
candidates and compounds being developed by the Company. The first collaborative
project under the terms of the agreement will involve the continuous delivery of
T-20. The parties intend to initiate clinical trials for the delivery of T-20
with MiniMed's continuous infusion delivery pump in the third quarter of 1997.
While MiniMed's continuous infusion pump has been approved for the continuous,
subcutaneous infusion of other therapies, there can be no assurance that the FDA
will approve on a timely basis, if at all, the use of the delivery of T-20
utilizing the MiniMed continuous infusion pump. The parties are evaluating other
product candidates and compounds for inclusion under the agreement. Under the
terms of the agreement, a joint management committee will determine an
 
                                       36
 
<PAGE>
   
implementation strategy for each collaborative project. The agreement contains
certain exclusivity and noncompetition provisions, subject to the Company's
right, under certain circumstances, to terminate such obligations with respect
to T-20 in exchange for certain royalty payments. The failure of the Company and
MiniMed to achieve their collective objectives could have a material adverse
effect on the Company's business, financial condition and results of operations.
    
 
     Pursuant to the Duke License, the Company has obtained from Duke University
an exclusive, worldwide, royalty-free license to all discoveries and inventions
in the field of antiviral therapeutics emanating from the laboratories of Drs.
Dani Bolognesi, Thomas J. Matthews, Michael Greenberg and Kent Weinhold of the
Duke University Center for AIDS Research for the period from February 3, 1993
until February 2, 2000. The Company's rights to each of these discoveries and
inventions expire upon the expiration of the life of the particular patent.
Multiple discoveries and inventions have flowed to the Company under the Duke
License and include those upon which United States patents have been issued.
None of the technologies licensed by the Company from Duke University is the
subject of a separate license agreement. Rather, the Company's rights to such
technologies are licensed solely pursuant to the Duke License. While the Company
believes it will be able to successfully negotiate an extension or renewal of
the Duke License, there can be no assurance that the Company will be able to
obtain such an extension or renewal or that such an extension or renewal will be
on acceptable terms. The early termination of the Duke License or the failure of
the Company to renew the Duke License on acceptable terms, if at all, could have
a material adverse effect on the Company's business, financial condition and
results of operations. See "Risk Factors -- License and Collaborative
Agreements" and " -- Extensive Government Regulation; No Assurance of Regulatory
Approval."
 
SALES, MARKETING AND DISTRIBUTION
 
     The Company has no experience in sales, marketing or distribution of
pharmaceuticals and currently has no personnel employed in any such capacities.
However, the Company intends to develop such capability in certain areas. For
example, because a relatively small number of physicians write the majority of
prescriptions for HIV drugs in the United States, the Company intends to
consider developing in-house sales, marketing and distribution capabilities to
address the market. In other areas, however, the Company may rely on marketing
partners or other arrangements with third parties which have established
distribution systems and direct sales forces for the sales, marketing and
distribution of such products and compounds. In the event that the Company is
unable to reach agreement with one or more marketing partners to market these
other products and compounds, it may be required to develop internal sales,
marketing and distribution capabilities for such products and compounds. There
can be no assurance that the Company will be able to establish sales, marketing
or distribution capabilities or make arrangements with third parties to perform
such activities on acceptable terms, if at all, or that any internal
capabilities or third-party arrangements will be cost-effective. The failure to
establish such capabilities would have a material adverse effect on the
Company's business, financial condition and results of operations.
 
     In addition, any third parties with which the Company establishes sales,
marketing or distribution arrangements may have significant control over
important aspects of the commercialization of the Company's products, and
compounds including market identification, marketing methods, pricing,
composition of sales force and promotional activities. For example, the MiniMed
Agreement contemplates that MiniMed will participate in the sales, marketing and
distribution of any products jointly developed by the parties. There can be no
assurance that the Company will be able to control the amount and timing of
resources that MiniMed or any other third party may devote to the Company's
products or compounds or prevent any third party from pursuing alternative
technologies or products that could result in the development of products that
compete with the Company's products and compounds and the withdrawal of support
for the Company's products and compounds. See "Risk Factors -- Lack of Sales,
Marketing and Distribution Capabilities."
 
PATENTS, PROPRIETARY TECHNOLOGY AND TRADE SECRETS
 
     The Company's success will depend, in part, on its ability, and the ability
of its collaborators or licensors, to obtain protection for its products and
technologies under United States and foreign patent laws, to preserve its trade
secrets and to operate without infringing the proprietary rights of third
parties. Because of the substantial
 
                                       37
 
<PAGE>
length of time and expense associated with bringing new products through
development to the marketplace, the pharmaceutical and biotechnology industries
place considerable importance on obtaining, and maintaining, patent and trade
secret protection for new technologies, products and processes.
 
   
     As of August 15, 1997, the Company was the sole assignee of one pending
United States patent application and one pending patent application under the
Patent Cooperation Treaty designating the United States, directed to
combinatorial therapy employing its proprietary antifusion peptides and other
therapeutic agents, and the owner of one pending provisional application,
directed to certain antifusion chemical compounds discovered by the Company's
proprietary screening method. In addition, as of August 15, 1997, the Company
was the assignee or owner, along with Duke University, of 14 pending United
States applications, along with certain corresponding foreign patent
applications, directed to numerous antifusion peptides and their therapeutic
uses. Under the Duke License, the Company is the exclusive licensee under Duke
University's rights in these jointly-owned patent applications, as well as the
exclusive licensee under three issued United States patents, six pending United
States patent applications, and certain corresponding foreign patent
applications directed to antifusion peptides. The Company is currently
negotiating a license with a third party to acquire a related technology.
    
 
     Legal standards relating to the scope of claims and the validity of patents
in the biotechnology industry are uncertain and still evolving, and no assurance
can be given as to the degree of protection that will be afforded any patents
issued to, or licensed by, the Company. There can be no assurance that, if
challenged by others in litigation, any patents assigned to, or licensed by, the
Company, will not be found invalid. Furthermore, there can be no assurance that
the Company's activities will not infringe patents owned by others. Defense and
prosecution of patent matters can be expensive and time-consuming, and
regardless of whether the outcome is favorable to the Company, can result in the
diversion of substantial financial, management and other resources. An adverse
outcome could subject the Company to significant liability to third parties,
require the Company to obtain licenses from third parties, or require the
Company to cease any related product sales. No assurance can be given that any
licenses required under any such patents or proprietary rights would be made
available on terms acceptable to the Company, if at all. Moreover, the laws of
certain countries may not protect the Company's proprietary rights to the same
extent as U.S. law.
 
     The Company also relies on trade secrets, know-how and other proprietary
information, which it seeks to protect, in part, through the use of
confidentiality agreements with employees, consultants, advisors and others.
There can be no assurance that such agreements will provide adequate protection
for the Company's trade secrets, know-how, or other proprietary information in
the event of any unauthorized disclosure, that employees of the Company,
consultants, advisors, or others, will maintain the confidentiality of such
trade secrets or proprietary information, or that the trade secrets or
proprietary know-how of the Company will not otherwise become known, or be
independently developed by, competitors.
 
     In January 1997, the USPTO instituted an interference proceeding between an
issued patent licensed by the Company from Duke University and a pending patent
application owned by a third party. An interference proceeding is an action, in
the USPTO, to determine which, of several parties, is entitled to a patent. An
interference proceeding may be instituted when the USPTO believes that a pending
patent application and an issued patent claim the same patentable subject
matter. The Company believes that no interference-in-fact exists, i.e., that the
parties to the interference are not claiming the same patentable invention, and,
through its licensor, the Company is taking all reasonable action to have the
interference proceeding dismissed. However, no assurance can be given that the
interference proceeding will be dismissed. Furthermore, no assurance can be
given that, should the interference proceeding continue, as between the two
parties to the interference, the Company's licensor will be found to be the
first inventor of the invention which is declared to be the subject matter of
the interference proceeding. Failure of the Company's licensor to prevail in the
interference proceeding and any loss of the involved patent rights could have a
material adverse effect on the Company's business, financial results and results
of operations. See "Risk Factors -- Patents, Proprietary, Technology and Trade
Secrets."
 
COMPETITION
 
     The Company is engaged in segments of the biopharmaceutical industry,
including the treatment of HIV, that are intensely competitive and rapidly
changing. If successfully developed and approved, the product candidates
 
                                       38
 
<PAGE>
and compounds that the Company is currently developing will compete with
numerous existing therapies. For example, 11 drugs are currently approved for
the treatment of HIV. In addition, a number of companies are pursuing the
development of novel pharmaceutical products that target the same diseases that
the Company is targeting, and some companies, including several multinational
pharmaceutical companies, are simultaneously marketing several different drugs
and may therefore be able to market their own combination drug therapies. The
Company believes that a significant number of drugs are currently under
development and will become available in the future for the treatment of HIV.
 
     Although the Company believes that there is a significant future market for
therapeutics that treat HIV and other viral diseases, the Company anticipates
that it will face intense and increasing competition in the future as new
products enter the market and advanced technologies become available. There can
be no assurance that existing products or new products for the treatment of HIV
developed by the Company's competitors, including Glaxo, Merck and Abbott, will
not be more effective, or more effectively marketed and sold, than T-20, should
it be successfully developed and receive regulatory approval, or any other
therapeutic for HIV that may be developed by the Company. Competitive products
or the development by others of a cure or new treatment methods may render the
Company's technologies and products and compounds obsolete, noncompetitive or
uneconomical prior to the Company's recovery of development or commercialization
expenses incurred with respect to any such technologies or products or
compounds. Many of the Company's competitors have significantly greater
financial, technical and human resources than the Company and may be better
equipped to develop, manufacture, sell, market and distribute products. In
addition, many of these companies have extensive experience in preclinical
testing and clinical trials, obtaining FDA and other regulatory approvals and
manufacturing and marketing pharmaceutical products. For use individually or in
combination therapy, many of these competitors also have products that have been
approved or are in late-stage development and operate large, well-funded
research and development programs. Smaller companies may also prove to be
significant competitors, particularly through collaborative arrangements with
large pharmaceutical and biotechnology companies. Furthermore, academic
institutions, governmental agencies and other public and private research
organizations are becoming increasingly aware of the commercial value of their
inventions and are more actively seeking to commercialize the technology they
have developed.
 
     New developments in areas in which the Company is conducting its research
and development are expected to continue at a rapid pace in both industry and
academia. If the Company's product candidates and compounds are successfully
developed and approved, the Company will face competition based on the safety
and effectiveness of its products and compounds, the timing and scope of
regulatory approvals, availability of manufacturing, sales, marketing and
distribution capabilities, reimbursement coverage, price and patent position.
There can be no assurance that the Company's competitors will not develop more
effective or more affordable technology or products, or achieve earlier patent
protection, product development or product commercialization than the Company.
Accordingly, the Company's competitors may succeed in commercializing products
more rapidly or effectively than the Company, which could have a material
adverse effect on the Company's business, financial condition and results of
operations. See "Risk Factors -- Intense Competition."
 
GOVERNMENT REGULATION
 
     Human pharmaceutical products are subject to lengthy and rigorous
preclinical testing and clinical trials and other extensive, costly and
time-consuming procedures mandated by the FDA and foreign regulatory
authorities. The regulatory approval process, which includes the establishment
of the safety and effectiveness of each product candidate and compound for each
target indication and confirmation by the FDA that good laboratory, clinical and
manufacturing practices were maintained during testing and manufacturing,
typically takes a number of years, varying based upon the type, complexity and
novelty of the pharmaceutical product. This process requires the expenditure of
substantial resources and gives larger companies with greater financial
resources a competitive advantage over the Company. To date, no product
candidate or compound being evaluated by the Company has been submitted for
approval by the FDA or any other regulatory authority for commercialization, and
there can be no assurance that any such product candidate or compound will ever
be approved for commercialization or that the Company will be able to obtain the
labeling claims desired for its product candidates or compounds.
 
                                       39
 
<PAGE>
     The steps required by the FDA before new drugs may be marketed in the
United States include: (i) preclinical studies; (ii) the submission to the FDA
of a request for authorization to conduct clinical trials on an investigational
drug (an "IND"); (iii) adequate and well-controlled clinical trials to establish
the safety and efficacy of the drug for its intended use; (iv) submission to the
FDA of an NDA; and (v) review and approval of the NDA by the FDA before the drug
may be shipped or sold commercially.
 
     In the United States, preclinical testing includes both IN VITRO and IN
VIVO laboratory evaluation and characterization of the safety and efficacy of a
drug and its formulation. Laboratories involved in preclinical testing must
comply with FDA regulations regarding good laboratory practices. Preclinical
testing results are submitted to the FDA as part of the IND and, unless there is
objection by the FDA, the IND will become effective 30 days following its
receipt by the FDA. There can be no assurance that submission of an IND will
result in the commencement of human clinical trials.
 
     Clinical trials, which involve the administration of the investigational
drug to healthy volunteers or to patients under the supervision of a qualified
principal investigator, are typically conducted in three sequential phases,
although the phases may overlap with one another. Clinical trials must be
conducted in accordance with good clinical procedures under protocols that
detail the objectives of the clinical trial, the parameters to be used to
monitor safety and the effectiveness criteria to be evaluated. Each protocol
must be submitted to the FDA as part of the IND. Further, each clinical trial
must be conducted under the auspices of an independent Institutional Review
Board (an "IRB") at the institution where the clinical trial will be conducted.
The IRB will consider, among other things, ethical factors, the safety of human
subjects and the possible liability of the institution. Compounds must be
formulated according to GMP requirements.
 
     Phase I clinical trials represent the initial administration of the
investigational drug to a small group of healthy human subjects or, more rarely,
to a group of selected patients with a targeted disease or disorder. The goal of
Phase I clinical trials is typically to test for safety (adverse effects), dose
tolerance, absorption, bio-distribution, metabolism, excretion and clinical
pharmacokinetics.
 
     Phase II clinical trials involve a small sample of the actual intended
patient population and seek to assess the effectiveness of the drug for the
specific targeted indications, to determine dose tolerance and the optimal dose
range and to gather additional information relating to safety and potential
adverse effects.
 
     Once the investigational drug is found to have some effectiveness and the
acceptable safety profile in the targeted patient population, Phase III clinical
trials are initiated to establish further clinical safety and effectiveness of
the investigational drug in a broader sample of the general patient population
at geographically dispersed study sites in order to determine the overall
risk-benefit ratio of the drug and to provide an adequate basis for all
physician labeling. The results of the research and product development,
manufacturing, preclinical testing, clinical trials and related information are
submitted to the FDA in the form of an NDA for approval of the marketing and
shipment of the drug.
 
     The approval process is affected by a number of factors, including the
severity of the targeted indications, the availability of alternative treatments
and the risks and benefits demonstrated in the clinical trials. The FDA may
reject an NDA if applicable regulatory criteria are not satisfied, or may
require additional testing or information with respect to the product candidate
or compound. Even if FDA approval is obtained, further clinical trials,
including post-market trials, may be required in order to provide additional
data on safety and will be required in order to obtain approval for the use of a
product as treatment for clinical indications other than those for which the
product was initially approved. The FDA will also require post-market reporting
and may require surveillance programs to monitor the side effects of any
approved products. Results of post-market programs may limit the further
marketing, manufacturing process or labeling, and an NDA supplement may be
required to be submitted to the FDA. Any failure of the Company to successfully
complete its clinical trials and obtain approvals of corresponding NDAs would
have a material adverse effect on the Company's business, financial condition
and results of operations. The Company is and will continue to be dependent upon
the laboratories conducting its preclinical testing and clinical trials to
maintain both good laboratory and good clinical practices, and, if any of the
Company's product candidates or compounds obtain the requisite regulatory
approvals, the Company will be dependent
 
                                       40
 
<PAGE>
upon the manufacturers of its products to maintain compliance with GMP
requirements. Various federal and foreign statutes and regulations also govern
or influence the manufacturing, safety, labeling, storage, record-keeping and
marketing of pharmaceutical products.
 
   
     The process of obtaining these approvals and the subsequent compliance with
appropriate United States and foreign statutes and regulations are
time-consuming and will require the expenditure of substantial resources by the
Company. In addition, these requirements and processes vary widely from country
to country. The time required for completing preclinical testing and clinical
trials is uncertain, and the FDA approval process is unpredictable and
uncertain, and no assurance can be given that necessary approvals will be
granted on a timely basis, or at all. The Company may decide to replace a
product candidate or compound in preclinical testing and/or clinical trials with
a modified product candidate or compound, thus extending the development period.
In addition, the FDA or similar foreign regulatory authorities may require
additional clinical trials, which could result in increased costs and
significant development delays. Delays or rejections may also be encountered
based upon changes in legislation, administrative action or FDA policy during
the period of product development and FDA review, including changes in FDA
policy relating to clinical testing guidelines for the use of the Company's
product candidates or compounds in children. Similar delays or rejections may be
encountered in other countries.
    
 
     In 1988, the FDA issued regulations to expedite the development, evaluation
and marketing of drugs for life-threatening and severely debilitating illnesses,
especially where no alternative therapy exists. These procedures encourage early
consultation between the IND sponsors and the FDA in the preclinical testing and
clinical trial phases to determine what evidence will be necessary for marketing
approval and to assist the sponsors in designing clinical trials. Under this
program, the FDA works closely with the IND sponsors to accelerate and condense
Phase II clinical trials, which may, in some cases, eliminate the need to
conduct Phase III trials or limit the scope of Phase III trials. Under these
regulations, the FDA may require postmarketing clinical trials ("Phase IV
trials") to obtain additional information on the drug's risks, benefits and
optimal use. In 1992, the FDA issued regulations establishing an accelerated NDA
approval procedure for certain drugs under Subpart H of the agency's NDA
approval regulations ("Subpart H Regulations"). The Subpart H Regulations
provide for accelerated NDA approval for new drugs intended to treat serious or
life-threatening diseases where the drugs provide a meaningful therapeutic
advantage over existing treatment. Under this accelerated approval procedure,
the FDA may approve a drug based on evidence from adequate and well-controlled
studies of the drug's effect on a surrogate endpoint that reasonably suggest
clinical benefits, or on evidence of the drug's effect on a clinical endpoint
other than survival or irreversible morbidity. This approval is conditional on
the favorable completion of trials to establish and define the degree of
clinical benefits to the patient. Such post-market clinical trials would usually
be underway when the product obtains this accelerated approval. If, after
approval, a post-market clinical trial establishes that the drug does not
perform as expected, or if post-market restrictions are not adhered to or are
not adequate to ensure the safe use of the drug, or other evidence demonstrates
that the product is not safe and/or effective under its conditions of use, the
FDA may withdraw approval. These two accelerated approval procedures for
expediting the clinical evaluation and approval of certain drugs may shorten the
drug development process by as much as two to three years.
 
     While certain of the Company's product candidates and compounds, including
T-20, have been designed to treat serious or life-threatening illnesses, such
product candidates and compounds may not qualify for accelerated development
and/or approval under FDA regulations and, even if some of the Company's product
candidates qualify for accelerated development and/or approval, they may not be
approved for marketing on an accelerated basis, or at all. There can be no
assurance that, even after substantial time and expenditures, any of the
Company's product candidates or compounds under development will receive
commercialization approval in any country on a timely basis, or at all. If the
Company is unable to demonstrate the safety and effectiveness of its product
candidates and compounds to the satisfaction of the FDA or foreign regulatory
authorities, the Company will be unable to commercialize its product candidates
and compounds; and the Company's business, financial condition and results of
operations would be materially and adversely affected. Furthermore, even if
regulatory approval of a product candidate or compound is obtained, the approval
may entail limitations on the indicated uses for which the product candidate or
compound may be marketed. A marketed product or compound, its manufacturer and
the manufacturer's facilities are subject to continual review and periodic
inspections, and subsequent discovery of previously unknown problems with a
product, compound, manufacturer or facility may result in restrictions on
 
                                       41
 
<PAGE>
such product, compound, manufacturer or facility, including withdrawal of the
product or compound from the market. The failure to comply with applicable
regulatory requirements can, among other things, result in fines, injunctions,
civil penalties, total or partial suspension of regulatory approvals, refusal to
approve pending applications, refusal to permit exports from the United States,
recalls or seizures of products, operating and production restrictions and
criminal prosecutions. Further, FDA policy may change and additional government
regulations may be established that could prevent or delay regulatory approval
of the Company's product candidates or compounds.
 
     The effect of governmental regulation may be to delay the marketing of new
products or compounds for a considerable period of time, to impose costly
requirements on the Company's activities or to provide a competitive advantage
to other companies that compete with the Company. Adverse clinical results by
others could have a negative impact on the regulatory process and timing with
respect to the development and approval of the Company's product candidates or
compounds. A delay in obtaining or failure to obtain regulatory approvals could
have a material adverse effect on the Company's business, financial condition
and results of operations. The extent and character of potentially adverse
governmental regulation that may arise from future legislation or administrative
action cannot be predicted.
 
     In April 1997, the Company and MiniMed entered into the MiniMed Agreement
pursuant to which the parties have agreed to jointly design, develop and
implement a system for the continual delivery of T-20 utilizing the MiniMed
continuous infusion pump. There can be no assurance that the FDA will approve
the delivery of T-20 utilizing the MiniMed continuous infusion pump on a timely
basis, if at all. The failure of the Company and MiniMed to collectively develop
a continual T-20 delivery system which receives FDA approval on a timely basis
could have a material adverse effect on the Company's business, financial
condition and results of operations.
 
     The Company and its existing and potential future collaborative partners
are also subject to various federal, state and local laws and regulations
relating to safe working conditions, laboratory and manufacturing practices, the
experimental use of animals and the use and disposal of hazardous or potentially
hazardous substances, including radioactive compounds and infectious disease
agents, used in connection with the Company's product development programs.
Compliance with such laws, regulations and requirements may be costly and
time-consuming and the failure to maintain such compliance by the Company or its
existing and future collaborative partners could have a material adverse effect
on the Company's business, financial condition and results of operations.
 
     In addition, this Prospectus reflects the Company's estimates regarding
future regulatory submission dates. Regulatory submissions can be delayed, or
plans to submit proposed products can be cancelled, for a number of reasons,
including the receipt of unanticipated, adverse or ambiguous results from
preclinical testing or clinical trials, the demonstration of undesirable or
unintended side effects, the inability to locate, recruit and qualify sufficient
numbers of patients, lack of funding, the inability to locate or recruit
scientists to undertake or complete planned preclinical testing or clinical
trials, the redesign of the Company's preclinical testing or clinical trial
programs, the inability to manufacture or acquire sufficient quantities of the
particular product candidate or any other components required for preclinical
testing or clinical trials, regulatory delays or other regulatory actions,
changes in focus of the Company's or its collaborators' development efforts, and
the disclosure of clinical trial results by competitors. Accordingly, no
assurances can be given that the Company's anticipated submissions will be made
on their target dates, or at all. Delays in such submissions could delay
regulatory approval for the Company's product candidates, delay
commercialization of the Company's product candidates, increase operating
expenses, result in the expenditure of additional capital, cause the diversion
of management time and attention, or create adverse market perception about the
Company and its product candidates, any of which could have a material adverse
effect on the Company's business, financial condition and results of operations.
See "Business -- Government Regulation."
 
THIRD PARTY REIMBURSEMENT AND HEALTH CARE REFORM MEASURES
 
     In the United States and elsewhere, sales of prescription pharmaceuticals
are dependent, in part, on the availability of reimbursement to the consumer
from third-party payors, such as government agencies and private insurance
plans. Third-party payors are increasingly challenging the prices charged for
medical products and services in an effort to promote cost containment measures
and alternative health care delivery systems and they may mandate
 
                                       42
 
<PAGE>
predetermined discounts from list prices. If the Company succeeds in bringing
one or more products or compounds to the market, there can be no assurance that
these products or compounds will be considered cost-effective or that
reimbursement to the consumer will be available or will be sufficient to allow
the Company to sell its products or compounds on a competitive basis. The
business and financial condition of pharmaceutical companies will continue to be
affected by economic, political and regulatory influences, including the efforts
of governments and third-party payors to contain or reduce the cost of health
care through various means. A number of legislative and regulatory proposals
aimed at changing the health care system have been proposed in recent years.
Because of the high cost of the treatment of AIDS or HIV using combination
therapy, many state legislatures are reassessing reimbursement policies for such
therapy. In addition, an increasing emphasis on managed care in the United
States to reduce the overall costs of health care has and will continue to
increase the pressure on pharmaceutical pricing. While the Company cannot
predict whether legislative or regulatory proposals will be adopted or the
effect such proposals or managed care efforts may have on its business, the
announcement and/or adoption of such proposals or efforts could have a material
adverse effect on the Company's business, financial condition and results of
operations. See "Risk Factors -- Uncertainty of Third Party Reimbursement and
Health Care Reform Measures."
 
FACILITIES
 
     The Company currently leases approximately 21,000 square feet of laboratory
and office space at 4727 University Drive, Suite 100, Durham, North Carolina.
The Company leases this space under a sublease agreement which expires on
September 30, 1999. Depending on the results of clinical trials and the progress
of the Company's product development programs, the Company may require
facilities in addition to those currently under lease. The Company believes that
there will be suitable facilities available as needed.
 
LEGAL PROCEEDINGS
 
     The Company is not a party to any material legal proceedings.
 
HUMAN RESOURCES
 
     As of June 30, 1997, the Company had 37 full-time employees, including a
technical scientific staff of 29. None of the Company's employees are covered by
collective bargaining arrangements, and management considers relations with its
employees to be good. See "Risk Factors -- Need to Attract and Retain Key
Officers, Employees and Consultants."
 
SCIENTIFIC ADVISORY BOARD
 
     The Company has assembled a Scientific Advisory Board (the "SAB") comprised
of eight individuals (the "Scientific Advisors") who are leaders in the fields
of viral disease research and treatment.
 
     Members of the SAB review the Company's research, development and operating
activities and are available for consultation with the Company's management and
staff relating to their respective areas of expertise. The SAB holds regular
meetings. Several of the individual Scientific Advisors have separate consulting
relationships with the Company and meet more frequently, on an individual basis,
with the Company's management and staff to discuss the Company's ongoing
research and development projects. Certain of the Scientific Advisors own Common
Stock and/or hold options to purchase Common Stock. The Scientific Advisors are
expected to devote only a small portion of their time to the business of the
Company.
 
     The Scientific Advisors are all employed by entities other than the
Company. Each Scientific Advisor has entered into a letter agreement with the
Company that contains confidentiality and non-disclosure provisions that
prohibit the disclosure of confidential information to anyone outside the
Company. Such letter agreements also provide that all inventions, discoveries or
other intellectual property that come to the attention of or are discovered by
the Scientific Advisor while performing services under the letter agreement with
the Company will be assigned to the Company. The current members of the SAB are
as follows:
 
     DANI P. BOLOGNESI, PH.D. James B. Duke Professor of Surgery, Professor of
Microbiology/Immunology, Vice Chairman of the Department of Surgery for Research
and Development, Director of the Duke University Center for AIDS
Research -- Duke University.
 
                                       43
 
<PAGE>
     ROBERT C. GALLO, M.D. Professor and Director, Institute of Human
Virology -- University of Maryland Biotechnology Institute.
 
     ERIC HUNTER, PH.D. Professor of Microbiology, Director, Center for AIDS
Research -- The University of Alabama at Birmingham.
 
     THOMAS J. MATTHEWS, PH.D. Associate Professor of Experimental
Surgery -- Duke University.
 
     JOSEPH S. PAGANO, M.D. Professor of Medicine and Microbiology and
Immunology, Director of The Lineberger Comprehensive Cancer Center -- The
University of North Carolina at Chapel Hill.
 
     JEROME J. SCHENTAG, PHARM.D. Professor of Pharmacy and Pharmaceutics,
Director, The Clinical Pharmacokinetics Laboratory, Millard Fillmore Hospital,
Director, Center for Clinical Pharmacy Research -- The State University of New
York at Buffalo School of Pharmacy.
 
     JUDITH M. WHITE, PH.D. Professor of Cell Biology and
Microbiology -- University of Virginia.
 
     RICHARD J. WHITLEY, M.D. Loeb Eminent Scholar Chair in Pediatrics,
Professor of Pediatrics, Microbiology and Medicine -- The University of Alabama
at Birmingham.
 
                                       44
 
<PAGE>
                                   MANAGEMENT
 
EXECUTIVE OFFICERS, DIRECTORS AND KEY EMPLOYEES
 
     The following table sets forth certain information with respect to
executive officers, directors and certain key employees of the Company:
 
<TABLE>
<CAPTION>
NAME                                                     AGE      POSITION
 
<S>                                                    <C>        <C>
M. Ross Johnson, Ph.D...............................     52       President, Chief Executive Officer, Chief Scientific
                                                                    Officer and Director
 
Matthew A. Megaro...................................     39       Chief Operating Officer, Chief Financial Officer,
                                                                    Executive Vice President and Secretary
 
Samuel Hopkins, Ph.D................................     38       Vice President of Medical Affairs
 
Dennis M. Lambert, Ph.D.............................     50       Vice President of Biological and Molecular Sciences
 
M.C. Kang, Ph.D.....................................     45       Director of Chemistry
 
Michael A. Recny, Ph.D..............................     41       Director of Business Development
 
Timothy J. Creech...................................     36       Director of Finance
 
Jesse I. Treu, Ph.D.(1).............................     50       Chairman of the Board of Directors
 
Dani P. Bolognesi, Ph.D.(2).........................     56       Director
 
Brian H. Dovey(2)...................................     55       Director
 
Andrew S. McCreath(1)...............................     41       Director
 
Charles A. Sanders, M.D.(1)(2)......................     65       Director
</TABLE>
 
(1) Member of the Audit Committee.
(2) Member of the Compensation Committee.
 
M. ROSS JOHNSON, PH.D. joined the Company as Chief Scientific Officer and a
Director in January 1995 and was named President and Chief Executive Officer in
March 1996. Prior to joining the Company, Dr. Johnson was President and Chief
Executive Officer of Parnassus Pharmaceuticals, Inc. ("Parnassus"), a
biopharmaceutical company, from March 1994 to October 1994. In October 1994,
Parnassus filed for protection under the United States Bankruptcy Code. From
1987 to March 1994, Dr. Johnson served as Vice President of the Chemical
Development Division and Division of Chemistry, respectively, at Glaxo, a
multinational pharmaceutical company. Prior to joining Glaxo, Dr. Johnson held a
number of scientific management positions at Pfizer Inc., a multinational
pharmaceutical company. Dr. Johnson received his Ph.D. degree in Organic
Chemistry from the University of California at Santa Barbara.
 
   
MATTHEW A. MEGARO joined the Company as Chief Financial Officer and Vice
President of Business Development in March 1995 and was named Chief Operating
Officer, Executive Vice President and Secretary of the Company in June 1997.
Prior to joining the Company, Mr. Megaro was Chief Operating Officer of
Parnassus from January 1994 to October 1994. In October 1994, Parnassus filed
for protection under the United States Bankruptcy Code. Prior to joining
Parnassus, Mr. Megaro was Chief Financial Officer and Vice President of Finance
and Administration of Athena Neurosciences, Inc., a biopharmaceutical company,
from 1988 to January 1994.
    
 
SAMUEL HOPKINS, PH.D. joined the Company as Director of Drug Development in
April 1995 and was named Vice President of Medical Affairs in June 1997. Prior
to joining the Company, Dr. Hopkins was Director of Oncology and Antiviral Drug
Product Development and Senior Clinical Research Scientist, respectively, at
Cato Research, Ltd., a contract research organization from 1991 to April 1995.
From 1987 to 1991, Dr. Hopkins was a Senior Research Scientist in the Division
of Virology at Burroughs Wellcome Co., a multinational pharmaceutical company.
Dr. Hopkins received his Ph.D. degree in Biochemisty and Biophysics from the
Medical College of Virginia.
 
DENNIS M. LAMBERT, PH.D. joined the Company as Director of Virology in March
1993, was named Senior Director of Virology and Molecular Biology in September
1995, and was named Vice President of Biological Molecular
 
                                       45
 
<PAGE>
Sciences in June 1997. Prior to joining the Company, Dr. Lambert was Assistant
Director, Department of Molecular Virology and Host Defense, at SmithKline
Beecham Corp., a pharmaceutical company, from 1988 to July 1993. Dr. Lambert
received his Ph.D. degree in Microbiology/Virology from Indiana State University
at Terre Haute.
 
M.C. KANG, PH.D. joined the Company as a consultant in October 1995 and was
named Director of Chemistry in August 1996. Prior to joining the Company, Dr.
Kang held various positions at Glaxo from 1990 to October 1995, most recently
serving as Director of Chemical Development. Prior to joining Glaxo, Dr. Kang
was a Development Chemist in the Medical Products Division at E.I. DuPont de
Nemours and Company, a chemical company from 1986 to 1990. Dr. Kang received his
Ph.D. degree in Synthetic Organic Chemistry from Oregon State University.
 
MICHAEL A. RECNY, PH.D. joined the Company as Director of Biochemical Sciences
in March 1995, and was named Director of Business Development in November 1996.
Prior to joining the Company, Dr. Recny was Senior Director of Biological
Sciences at Parnassus from November 1993 to October 1994. From 1988 to November
1993, Dr. Recny was Director of Protein Biochemistry at Procept, Inc., a
biopharmaceutical company. Prior to joining Procept, Inc., Dr. Recny was a Staff
Scientist/Laboratory Head at Genetics Institute Inc., a biopharmaceutical
company. Dr. Recny received his Ph.D. degree in Biochemistry from the University
of Illinois at Urbana-Champaign.
 
TIMOTHY J. CREECH, C.P.A. joined the Company as Director of Finance in July
1997. Prior to joining the Company, Mr. Creech was Corporate Controller at
Performance Awareness Corporation, a software company, from July 1996 to June
1997. From December 1993 to July 1996, Mr. Creech was Director of Finance at
Avant! Corporation, a software company. From 1990 to December 1993, Mr. Creech
was a senior manager at KPMG Peat Marwick LLP, independent auditors for the
Company.
 
JESSE I. TREU, PH.D. has been Chairman of the Board of Directors of the Company
since its inception. Dr. Treu has been a general partner of Domain Associates, a
venture capital firm specializing in investments in life sciences, since 1986.
Dr. Treu serves on the Boards of Directors of Biosite Diagnostics, Inc. and
GelTex Pharmaceuticals, Inc. Dr. Treu received his Ph.D. in Physics from
Princeton University.
 
DANI P. BOLOGNESI, PH.D. was a founder of the Company and has been a Director
since its inception. Dr. Bolognesi has held a number of positions at Duke
University since 1971, and now serves as James B. Duke Professor of Surgery,
Professor of Microbiology/Immunology, Vice Chairman of the Department of Surgery
for Research and Development and Director of the Duke University Center for AIDS
Research. Dr. Bolognesi is the Co-Chair of the National Institute of Allergy and
Infectious Diseases Vaccine Working Group ("NIAID"), Chair of the Office of AIDS
Research Coordinating Committee for Vaccines, Chair of the Office of AIDS
Research Task Force Vaccine Reasearch and Development Area Review Panel, Chair
of the panel to recommend strategies for the long-term care of the United States
biomedical chimpanzee population, and is a member of the NIAID Vaccine Selection
Committee. Dr. Bolognesi received his Ph.D. in Virology from Duke University.
 
BRIAN H. DOVEY has been a Director of the Company since its inception. Mr. Dovey
has been a general partner of Domain Associates, a venture capital firm
specializing in investments in life sciences, since 1988. Mr. Dovey is President
of the National Venture Capital Association and is a member of the Boards of
Trustees of the Coriell Institute and the University of Pennsylvania School of
Nursing. Mr. Dovey is Chairman of the Board of Directors of Creative
BioMolecules and also serves on the Boards of Directors of Connetics
Corporation, Geron Corporation, NABI and Vivus, Inc.
 
   
ANDREW S. MCCREATH, C.F.A. has been a Director of the Company since October
1996. In January 1996, Mr. McCreath became a founding partner of Lawrence &
Company Inc., a private investment firm in Toronto, Canada, which specializes in
the technology, health care, and leisure industries. From 1991 to December 1995,
Mr. McCreath served as a partner and director of Gordon Capital Corporation, a
Canadian investment bank. Mr. McCreath serves on the Board of Directors of
Galaxy Brands International.
    
 
CHARLES A. SANDERS, M.D. has been a Director of the Company since October 1996.
From 1989 to May 1995, Dr. Sanders was Chairman of the Board of Directors and
Chief Executive Officer of Glaxo and a member of the Board of Directors of Glaxo
plc. Prior to joining Glaxo, Dr. Sanders held a number of positions at Squibb
Corporation, a multinational pharmaceutical corporation, including Vice
Chairman, Chief Executive Officer of the Science
 
                                       46
 
<PAGE>
and Technology Group and Chairman of the Science and Technology Committee of the
Board. Dr. Sanders serves on the Boards of Directors of Magainin
Pharmaceuticals, Vertex Pharmaceuticals and Staff Mark, Inc. Dr. Sanders
received an M.D. degree from Southwestern Medical College of the University of
Texas.
 
BOARD OF DIRECTORS
 
     In accordance with the terms of the Company's Third Amended and Restated
Certificate of Incorporation to be filed upon the completion of this Offering,
the Board of Directors of the Company will be divided into three classes,
denominated Class I, Class II and Class III, with members of each class holding
office for staggered three-year terms. At each annual stockholder meeting
commencing with the 1998 annual meeting, the successors to the Directors whose
terms expire will be elected to serve from the time of their election and
qualification until the third annual meeting of stockholders following their
election or until a successor has been duly elected and qualified. Officers
serve at the discretion of the Board.
 
     The Compensation Committee of the Board was established in April 1997 to
determine the salaries and incentive compensation of the executive officers of
the Company and to provide recommendations for the salaries and incentive
compensation of the other employees and consultants of the Company. The
Compensation Committee also administers the Company's benefit plans, including
the Stock Option Plan. Mr. Dovey serves as the Chairman of the Compensation
Committee and the other members of the committee are Drs. Bolognesi and Sanders.
 
     The Audit Committee of the Board was established in July 1997 to review,
act on and report to the Board with respect to various auditing and accounting
matters, including the selection of the Company's independent auditors, the
scope of the annual audits, the fees to be paid to the independent auditors, the
performance of the Company's independent auditors and the accounting practices
of the Company. Dr. Treu serves as the Chairman of the Audit Committee and the
other members of the committee are Mr. McCreath and Dr. Sanders.
 
                                       47
 
<PAGE>
EXECUTIVE COMPENSATION
 
     The following table sets forth certain information with respect to the
annual and long-term compensation paid by the Company during the fiscal year
ended December 31, 1996 to the Company's President and Chief Executive Officer
and to the Company's two other most highly compensated executive officers who
were serving as executive officers and whose 1996 compensation exceeded $100,000
(collectively, the "Named Executive Officers").
 
                           SUMMARY COMPENSATION TABLE
 
<TABLE>
<CAPTION>
                                                                                          LONG TERM
                                                                                        COMPENSATION
                                                                                         SECURITIES
                                                         ANNUAL COMPENSATION             UNDERLYING           ALL OTHER
NAME AND PRINCIPAL POSITION                        YEAR      SALARY        BONUS         OPTIONS(#)          COMPENSATION
<S>                                                <C>     <C>           <C>          <C>                  <C>
M. Ross Johnson (1)                                1996     $ 238,800     $50,000           117,648(2)       $         --
  President, Chief Executive Officer and Chief
  Scientific Officer
Richard A. Franco (3)                              1996        60,000          --            94,118(2)            244,897(4)
  Former President and Chief Executive Officer
Matthew A. Megaro                                  1996       160,300      34,000            51,765(2)                 --
  Chief Operating Officer, Chief Financial
  Officer,
  Executive Vice President and Secretary
Max N. Wallace (5)                                 1996       144,900      26,000            52,765(2)                 --
  Former Executive Vice President, General
  Counsel and Secretary
</TABLE>
 
(1) Dr. Johnson was named President and Chief Executive Officer of the Company
    in April 1996.
 
(2) For information regarding the vesting and subsequent exercise of these
    options, see the table entitled Option Grants in the Year Ended December 31,
    1996 and the notes thereto and "Certain Transactions."
 
(3) Mr. Franco resigned as President and Chief Executive Officer of the Company
    in March 1996.
 
(4) Consists of amounts paid to Mr. Franco following the termination of his
    employment with the Company pursuant to a severance arrangement with the
    Company.
 
(5) Mr. Wallace resigned as Executive Vice President, General Counsel and
    Secretary in July 1997.
 
                                       48
 
<PAGE>
STOCK OPTION INFORMATION
 
     The following table sets forth certain information concerning stock options
granted to the Named Executive Officers of the Company during the year ended
December 31, 1996. No stock appreciation rights were granted to any of the Named
Executive Officers during 1996 and no stock appreciation rights were outstanding
as of December 31, 1996.
 
              OPTIONS GRANTED IN THE YEAR ENDED DECEMBER 31, 1996
 
   
<TABLE>
<CAPTION>
                                                                                                 POTENTIAL REALIZABLE
                                                                                                       VALUE AT
                                                    INDIVIDUAL GRANTS                            ASSUMED ANNUAL RATES
                                 NUMBER OF        PERCENT OF                                              OF
                                SECURITIES           TOTAL                                            STOCK PRICE
                                UNDERLYING      OPTIONS GRANTED    EXERCISE                          APPRECIATION
                                  OPTIONS       TO EMPLOYEES IN    PRICE PER    EXPIRATION        FOR OPTION TERM(3)
NAME                           GRANTED(#)(1)         1996          SHARE(2)        DATE            5%            10%
<S>                            <C>              <C>                <C>          <C>              <C>           <C>
M. Ross Johnson                    117,648(4)          24%           $ .34       05/01/06        $25,156       $63,750
Richard A. Franco                   94,118             19              .34       03/25/06         20,125        51,000
Matthew A. Megaro                   51,765(5)          11              .34       05/01/06         11,069        28,050
Max N. Wallace                      52,765(6)          11              .34       05/01/06         11,282        28,592
</TABLE>
    
 
(1) These options were granted under the Company's Stock Option Plan.
 
(2) The exercise price per share of the options was equal to the fair market
    value of the Common Stock on the date of grant as determined by the Board of
    Directors.
 
(3) The potential realizable value of the options reported above was calculated
    by assuming that the market price of the Common Stock of the Company
    appreciates 5% and 10% compounded annually over the term of the options (10
    years). These assumed annual rates of appreciation were used in compliance
    with the rules of the Securities and Exchange Commission and are not
    intended to forecast future prices appreciation of the Common Stock of the
    Company. These amounts do not represent the Company's estimate of future
    stock price performance. The actual value realized from the options could be
    substantially higher or lower than the values reported above, depending upon
    the future appreciation or depreciation of the Common Stock during the
    option period and the timing of exercise of the options.
 
(4) In October 1996, the Board of Directors granted options to purchase 35,295
    shares, 35,295 shares and 47,058 shares which were scheduled to vest ratably
    over a 48-month period which commenced in January 1995, July 1995 and March
    1996, respectively. In May 1997, the Board of Directors accelerated the
    vesting of these options subject to certain restrictions on the underlying
    shares of Common Stock which lapse over the same period of time over which
    the options were to vest. See "Certain Transactions."
 
(5) In October 1996, the Board of Directors granted options to purchase 23,530
    shares, 23,530 shares and 4,705 shares which were scheduled to vest ratably
    over a 48-month period which commenced in March 1995, July 1995 and March
    1996, respectively. In May 1997, the Board of Directors accelerated the
    vesting of these options subject to certain restrictions on the underlying
    shares of Common Stock which lapse over the same period of time over which
    the options were to vest. See "Certain Transactions."
 
(6) In October 1996, the Board of Directors granted options to purchase 17,648
    shares, 27,648 shares and 7,469 shares which were scheduled to vest ratably
    over a 48-month period which commenced in March 1993, July 1995 and March
    1996, respectively. In May 1997, the Board of Directors accelerated the
    vesting of these options subject to certain restrictions on the underlying
    shares of Common Stock which lapse over the same period of time over which
    the options were to vest. On July 10, 1997, Mr. Wallace resigned as an
    officer and Director of the Company and entered into an agreement with the
    Company pursuant to which the vesting of 3,971 of such underlying shares was
    accelerated and the other restrictions applicable to such 3,971 shares
    terminated. See "Certain Transactions."
 
                                       49
 
<PAGE>
YEAR-END OPTION TABLE
 
     The following table sets forth certain information concerning stock options
exercised by the Named Executive Officers during 1996, the number of options
held by the Named Executive Officers as of December 31, 1996, and the value of
any in-the-money options as of December 31, 1996.
 
  AGGREGATED OPTION EXERCISES IN THE YEAR ENDED DECEMBER 31, 1996 AND YEAR-END
                                 OPTION VALUES
 
   
<TABLE>
<CAPTION>
                                                                 NUMBER OF SECURITIES
                                                                      UNDERLYING                   VALUE OF UNEXERCISED
                                                               UNEXERCISED OPTIONS AS OF          IN-THE-MONEY OPTIONS AS
                                          SHARES ACQUIRED      DECEMBER 31, 1996 (1)(#)          OF DECEMBER 31, 1996 (2)
NAME                                      ON EXERCISE (#)    EXERCISABLE     UNEXERCISABLE     EXERCISABLE     UNEXERCISABLE
<S>                                       <C>                <C>             <C>               <C>             <C>
M. Ross Johnson                                    --           39,718           77,930         $  502,830       $ 986,594
Richard A. Franco                              27,452               --               --                 --              --
Matthew A. Megaro                                  --           20,322           31,443            257,281         398,061
Max N. Wallace                                     --           28,232           24,533            357,419         310,588
</TABLE>
    
 
(1) In May 1997, the Board of Directors accelerated all options set forth below
    subject to certain restrictions on the underlying shares of Common Stock
    which lapse over time. See the table entitled Options Granted in the Year
    Ended December 31, 1996 and the notes thereto and "Certain Transactions."
 
(2) There was no public trading market for the Common Stock as of December 31,
    1996. Accordingly, these values have been calculated on the basis of an
    assumed initial public offering price of $13.00 per share, less the
    applicable exercise price per share, multiplied by the number of shares
    underlying such options.
 
STOCK OPTION PLANS
 
     The Company's Stock Option Plan was adopted by the Board of Directors in
May 1996 and approved by the stockholders in July 1996. In April 1997, the Stock
Option Plan was amended by the Board of Directors to increase the number of
shares of Common Stock authorized for issuance thereunder. This amendment to the
Stock Option Plan was approved by the stockholders of the Company in June 1997.
A total of 852,941 shares of Common Stock have been authorized for issuance
under the Stock Option Plan. As of June 30, 1997, options to purchase a total of
348,042 shares of Common Stock had been exercised, options to purchase a total
of 260,361 shares at a weighted average exercise price of $.36 per share were
outstanding, and 254,188 shares remained available for future option grants.
 
     The Stock Option Plan provides for the grant to employees of the Company
(including officers and employee directors) of "incentive stock options" within
the meaning of Section 422 of the Code and for the grant of nonstatutory stock
options to employees, Directors, consultants, advisors or other independent
contractors of the Company. To the extent an optionee would have the right in
any calendar year to exercise for the first time one or more incentive stock
options for shares having an aggregate fair market value (under all plans of the
Company and determined for each share as of the date the option to purchase the
share was granted) in excess of $100,000, any such options will be treated as
nonstatutory stock options.
 
     The Stock Option Plan is administered by the Board of Directors or a
committee of the Board of Directors. Subject to the provisions of the Stock
Option Plan, the Board determines the terms of options granted under the Stock
Option Plan, including the number of shares subject to the option, exercise
price, term and exercisability. The exercise price of all incentive stock
options granted under the Stock Option Plan must be at least equal to the fair
market value of the Common Stock of the Company on the date of grant. The
exercise price of any incentive stock option granted to an optionee who owns
stock representing more than 10% of the voting power of the Company's
outstanding capital stock (a "10% Stockholder") must equal at least 110% of the
fair market value of the Common Stock on the date of grant. The Board determines
the term of options. The term of a stock option granted under the Stock Option
Plan may not exceed ten years; provided, however, that the term of an incentive
stock option may not exceed five years for 10% Stockholders. No option may be
transferred or assigned by the optionee other than by will or the laws of
descent or distribution.
 
     In the event an optionee ceases to be employed by the Company for any
reason other than death or disability, each outstanding option held by such
optionee will terminate and cease to be exercisable no later than three months
after the date of such cessation of employment. Should the optionee's employment
terminate by reason of death or
 
                                       50
 
<PAGE>
disability (within the meaning of Section 22(e)(3) of the Code), each
outstanding option held by such optionee will terminate and cease to be
exercisable no later than twelve months after the date of held by such optionee
such cessation of employment. An optionee's employment shall be deemed to have
terminated on account of death if the optionee dies within three months
following such cessation of employment.
 
   
     In the event of certain transactions involving changes in control of the
Company, the Stock Option Plan provides that the Board may elect, in its sole
discretion, to provide that any unexercisable portion of all options will
accelerate so that each option will be fully exercisable for all of the shares
subject to such option as of a date prior to the effective date of the
transaction as the Board so determines, conditioned upon the consummation of
such transfer of control. The Board may further elect, in its sole discretion,
to provide that any options which become exercisable solely by reason of
transfer of control and which are not exercised as of the date such transfer of
control will terminate effective as of the date of a transfer of control. The
Board may terminate or amend the Stock Option Plan at any time; provided
however, that without the approval of the Company's stockholders, there shall be
(a) no increase in the total number of shares of stock covered by the Stock
Option Plan (except in the case of a stock dividend, stock split, reverse stock
split, combination, reclassification or similar change in the Common Stock), (b)
no change in the class of persons eligible to receive incentive stock options,
and (c) no extension of the period during which incentive stock options may be
granted beyond the date which is ten years following the date the Stock Option
Plan is adopted by the Company or the date the Stock Option Plan is approved by
the stockholders of the Company. In any event, no amendment may adversely affect
any then outstanding option or any unexercised portion thereof, without the
consent of the optionee, unless such amendment is required to enable an option
designated as an incentive stock option to qualify as an incentive stock option.
If not previously terminated, the Stock Option Plan will terminate in 2006.
    
 
     As of June 30, 1997, the Company had outstanding 9,412 nonqualifed stock
options under its previous stock option plan at a weighted average exercise
price of $.43 per share. The Board of Directors has determined not to grant
additional options under such plan.
 
EMPLOYEE STOCK PURCHASE PLAN
 
     In August 1997, the Board of Directors adopted, and the stockholders of the
Company approved, the Company's 1997 Employee Stock Purchase Plan (the "ESPP"),
contingent upon and subject to the consummation of the Offering. The ESPP is
intended to encourage ownership of the Company's Common Stock by employees of
the Company. A maximum of 250,000 shares of Common Stock have been reserved for
purchase under the ESPP (subject to certain adjustments under the ESPP). No
options to purchase shares of Common Stock have been granted and no shares of
Common Stock have been purchased under the ESPP. The ESPP is administered by the
Compensation Committee of the Board of Directors, or such other committee as the
Board designates (the "Committee").
 
     For eligible employees who have become participants in the ESPP, the ESPP
provides for the automatic grant of options to purchase shares of Common Stock
("Options"). The Options are granted on the first day of an offering period
("Offering Period"). Offering Periods are successive and overlapping 24 month
periods beginning on the first trading day on or after December 1 and June 1 of
each year, and each Offering Period contains four exercise periods ("Purchase
Period"), each of which is approximately six months. The first Offering Period,
however, will run from completion of the Offering through May 31, 1999, and the
first Purchase Period will run from completion of the Offering through May 31,
1998. Employees of the Company who have been employed by the Company before the
beginning of an Offering Period may participate in the ESPP for that Offering
Period.
 
     Payroll deductions are accumulated in an account for each participant,
based on the amounts the participant requests be withheld. The accumulated
amounts are used at the end of each Purchase Period to purchase shares of Common
Stock pursuant to the Option. The purchase price of a share of Common Stock
under an Option will equal 85% of the lower of the fair market value of a share
(a) on the first day of the Offering Period or (b) on the last day of the
relevant Exercise Period. Options may not be assigned or transferred. No
participant may purchase shares having a fair market value (determined as of the
beginning of the Offering Period) exceeding $25,000 in any calendar year, nor
may a participant purchase shares if the participant would own shares or hold
outstanding options to purchase shares, or both, possessing 5% or more of the
total combined voting power or value of all
 
                                       51
 
<PAGE>
classes of shares of the Company. A participant may withdraw from an Offering
Period at any time without affecting his or her eligibility to participate in
future Offering Periods.
 
     There are no tax consequences to either the participant or the Company when
the Option is issued. When shares are issued upon the exercise of the Option,
there are no tax consequences to the participant (except to the extent that any
excess in the fair market value of the Common Stock over the exercise price
constitutes a tax preference item which requires payment of the alternative
minimum tax) or to the Company. A participant's Option will terminate and his or
her accumulated account balance will be returned if such participant ceases to
be employed by the Company.
 
     If a participant disposes of shares purchased under the ESPP at least two
years after the first day of the applicable Offering Period and at least one
year after the date of purchase, the participant will recognize ordinary income
in the year of disposition equal to the amount of the discount. The amount of
ordinary income recognized by a participant will be added to the participant's
basis in the shares. Any additional gain recognized upon the disposition will be
long-term capital gain. The Company will not generally be entitled to a
deduction if the participant complies with these holding periods.
 
     If a participant disposes of shares purchased under the ESPP within two
years from the first day of the applicable Offering Period or within one year
from the date of purchase (a "disqualifying disposition"), the participant will
recognize ordinary income in the year of such disposition equal to the lesser of
(i) the amount by which the fair market value of the shares on the date the
shares were purchased exceeded the purchase price and (ii) the amount by which
the fair market value of the shares on the date of disposition exceeded the
purchase price. The amount of ordinary income will be added to the participant's
basis in the shares, and any additional gain or resulting loss recognized on the
disposition of the shares will be a capital gain or loss. The Company will
generally be entitled to a deduction in the year of the disqualifying
disposition equal to the amount of ordinary income recognized by the participant
as a result of the disposition.
 
     The ESPP provides that in the event of a "Substantial Corporate Change" the
offering will terminate unless provision is made in writing for (i) the
assumption or continuation of outstanding elections or (ii) the substitution for
Options or grants of Options covering securities of a successor corporation. For
purposes of the ESPP, events constituting a "Substantial Corporate Change" are
(i) dissolution or liquidation of the Company, (ii) a merger, consolidation or
reorganization of the Company in which the Company is not the surviving
corporation, (iii) the sale of substantially all of the Company's assets or (iv)
any transaction approved by the Board of Directors that results in any person or
entity owning 100% of the combined voting power of all classes of stock of the
Company. The Board of Directors may terminate or amend the ESPP at any time. Any
amendment to the ESPP that (i) materially increases the benefits to
participants, (ii) materially increases the number of securities that may be
issued under the ESPP, or (iii) materially modifies the eligibility requirements
for participation in the ESPP must be approved by the stockholders of the
Company.
 
     If any change is made to the stock issuable under the ESPP by reason of any
recapitalization, reclassification, stock split, reverse stock split,
combination of shares, exchange of shares, stock dividend or other distribution
payable in capital stock, or some other increase or decrease in such Common
Stock occurs without the Company's receiving consideration, appropriate
adjustment will be made to the shares subject to the ESPP and the number of
shares that a participant may purchase with respect to an Option.
 
EMPLOYMENT AGREEMENTS
 
     In December 1994, the Company entered into an employment arrangement with
Dr. Johnson, its President, Chief Executive Officer and Chief Scientific
Officer. Pursuant to this arrangement, Dr. Johnson is entitled to receive
minimum annual compensation of $225,000, an annual bonus based upon the
achievement of certain milestones and all health insurance and other benefits
generally made available to the Company's employees. In the event that Dr.
Johnson's employment is terminated for any reason other than for cause, Dr.
Johnson's employment arrangement provides that Dr. Johnson is entitled to his
base salary and benefits for one year from the date of such termination.
 
     In February 1995, the Company entered into an employment arrangement with
Mr. Megaro, its Chief Operating Officer, Chief Financial Officer, Executive Vice
President and Secretary. Pursuant to this arrangement, Mr.
 
                                       52
 
<PAGE>
Megaro is entitled to receive minimum annual compensation of $130,000, an annual
bonus based upon the achievement of certain milestones and all health insurance
and other benefits generally made available to the Company's employees. In the
event that Mr. Megaro's employment is terminated for any reason other than for
cause, Mr. Megaro's employment arrangement provides that Mr. Megaro is entitled
to his base salary and benefits for up to six months from the date of such
termination, subject to certain limitations.
 
     On July 10, 1997, Mr. Wallace resigned as an officer and Director of the
Company and entered into an agreement with the Company pursuant to which he will
serve as a consultant to the Company until December 31, 1997. Thereafter, Mr.
Wallace will receive severance payments until June 30, 1998 based on his annual
salary at the time of his resignation. In addition, the Company has agreed to
terminate its right of repurchase and other restrictions with respect to
approximately 24,015 shares of Common Stock held by Mr. Wallace for which such
restrictions would not otherwise have lapsed at the time of his resignation.
 
COMPENSATION OF DIRECTORS
 
     The Company does not currently compensate its Directors for attending Board
or committee meetings, but reimburses Directors for their reasonable travel
expenses incurred in connection with attending meetings of the Board or
committees of the Board. Also, non-employee Directors are entitled to be granted
options under the Company's Stock Option Plan. The Company intends to reevaluate
its policy with respect to compensation of non-employee Directors after
completion of this Offering. On October 21, 1996, the Company granted Dr.
Sanders options to purchase 5,883 shares of Common Stock at an exercise price of
$.34 per share.
 
COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION
 
     Effective April 10, 1997, the Board of Directors established a Compensation
Committee which is responsible for determining the salaries and incentive
compensation of the executive officers of the Company and to provide
recommendations for the salaries and incentive compensation of the other
employees and consultants of the Company. The Compensation Committe also
administers the Company's benefit plans, including the Stock Option Plan. Mr.
Dovey serves as the Chairman of the Compensation Committee and the other members
of the committee are Drs. Bolognesi and Sanders. None of Mr. Dovey, Dr.
Bolognesi, nor Dr. Sanders was an officer or employee of the Company during 1996
or any prior year. During 1996 and prior to the formation of the Compensation
Committee, the Board of Directors as a whole made decisions relating to
compensation of the Company's executive officers. Dr. Johnson, the Company's
President, Chief Executive Officer and Chief Scientific Officer, Mr. Wallace,
the Company's former Executive Vice President, General Counsel and Secretary and
Mr. Franco, the Company's former President and Chief Executive Officer,
participated in all such discussions and decisions concerning the compensation
of executive officers of the Company, except that Dr. Johnson and Messrs.
Wallace and Franco were excluded from discussions regarding their own
compensation.
 
                                       53
 
<PAGE>
                              CERTAIN TRANSACTIONS
 
     Since February 1995, the Company has issued an aggregate of 274,511 shares
of Common Stock to Dr. Johnson, the Company's President, Chief Executive Officer
and Chief Scientific Officer at an aggregate purchase price of $123,300, or a
weighted average purchase price of $.45 per share. In June 1997, the Company
issued to Dr. Johnson an aggregate of 127,060 shares of Common Stock at an
aggregate purchase price of $54,636, or $.43 per share, in consideration for a
full recourse secured promissory note payable to the Company, which bears
interest at eight percent per annum and is due in June 1999. In May 1997, the
Company issued to Dr. Johnson an aggregate of 117,648 shares of Common Stock
upon the exercise of certain options granted to Dr. Johnson at an aggregate
exercise price of $40,000, or $.34 per share, in consideration for a full
recourse secured promissory note payable to the Company, which bears interest at
eight percent per annum and is due in May 1999. In April 1997, the Company
issued to Dr. Johnson an aggregate of 33,333 shares of Series C Preferred Stock
(convertible into 3,922 shares of Common Stock upon the completion of the
Offering) at an aggregate purchase price of $20,000, or $.60 per share. Certain
shares of Common Stock purchased from the Company by Dr. Johnson are subject to
the Company's right of repurchase and certain other restrictions which lapse
over a period of time.
 
     Since March 1995, the Company has issued an aggregate of 146,079 shares of
Common Stock to Mr. Megaro, the Company's Chief Operating Officer, Chief
Financial Officer, Executive Vice President and Secretary at an aggregate
purchase price of $80,000, or a weighted average purchase price of $.55 per
share. In June 1997, the Company issued Mr. Megaro an aggregate of 76,471 shares
of Common Stock at an aggregate purchase price of $32,883, or $.43 per share, in
consideration for a full recourse secured promissory note payable to the Company
which bears interest at eight percent per annum and is due in June 1999. In May
1997, the Company issued Mr. Megaro an aggregate of 51,765 shares of Common
Stock upon the exercise of certain options granted to Mr. Megaro at an aggregate
exercise price of $17,600, or $.34 per share, in consideration for a full
recourse secured promissory note payable to the Company which bears interest at
eight percent per annum and is due in May 1999. In April 1997, the Company
issued Mr. Megaro an aggregate of 41,667 shares of Series C Preferred Stock
(convertible into 4,902 shares of Common Stock upon the completion of the
Offering) at an aggregate purchase price of $25,000, or $.60 per share. Certain
shares of Common Stock purchased from the Company by Mr. Megaro are subject to
the Company's right of repurchase and certain other restrictions which lapse
over a period of time.
 
     Since March 1995, the Company has issued an aggregate of 129,705 shares of
Common Stock to Mr. Wallace, the Company's former Executive Vice President,
General Counsel and Secretary at an aggregate purchase price of $37,790, or a
weighted average purchase price of $.29 per share. In June 1997, the Company
issued Mr. Wallace an aggregate of 34,589 shares of Common Stock at an aggregate
purchase price of $14,874, or $.43 per share, in consideration for a full
recourse secured promissory note payable to the Company which bears interest at
eight percent per annum and is due in June 1999. In May 1997, the Company issued
Mr. Wallace an aggregate of 52,765 shares of Common Stock upon the exercise of
certain options granted to Mr. Wallace at an aggregate exercise price of
$17,941, or $.34 per share, in consideration for a full recourse secured
promissory note payable to the Company which bears interest at eight percent per
annum and is due in May 1999.
 
     On July 10, 1997, Mr. Wallace resigned as an officer and Director of the
Company and entered into an agreement with the Company pursuant to which he will
serve as a consultant to the Company until December 31, 1997. Thereafter, Mr.
Wallace will receive severance payments until June 30, 1998 based on his annual
salary at the time of his resignation. In addition, the Company has agreed to
terminate its right of repurchase and other restrictions with respect to
approximately 24,015 shares of Common Stock held by Mr. Wallace for which such
restrictions would not otherwise have lapsed at the time of his resignation.
 
                                       54
 
<PAGE>
     The following table summarizes the shares of Preferred Stock purchased by
affiliates of the Directors and the holders of more than five percent (5%) of
the Common Stock. See the table entitled "Principal Stockholders" and the notes
thereto for further information relating to the beneficial ownership of such
shares.
 
<TABLE>
<CAPTION>
                                                SERIES A           SERIES B           SERIES C
                                             PREFERRED STOCK    PREFERRED STOCK    PREFERRED STOCK
<S>                                          <C>                <C>                <C>
Domain Partners II, L.P. (1)..............      2,000,000          11,095,920
Domain Partners III, L.P. (2).............                          5,932,528         2,061,997
DP III Associates, L.P. (2)...............                            206,466            71,336
Biotechnology Investments Limited (3).....      1,000,000           6,900,650         2,866,668
Lawrence & Company Inc. (4)...............                                            2,283,334
Sentron Medical, Inc......................                          2,000,000         1,333,334
</TABLE>
 
(1) Dr. Treu and Mr. Dovey are general partners of One Palmer Square Associates,
    II, L.P., the general partner of Domain Partners II, L.P.
 
(2) Dr. Treu and Mr. Dovey are general partners of One Palmer Square Associates,
    III, L.P., the general partner of Domain Partners III, L.P. and DP III
    Associates, L.P.
 
(3) Pursuant to a contractual agreement, Domain Associates is the U.S. venture
    capital advisor to Biotechnology Investments Limited. Dr. Treu and Mr. Dovey
    are general partners of Domain Associates.
 
(4) Mr. McCreath is a founding partner of Lawrence & Company Inc.
 
     For information regarding employment agreements with Named Executive
Officers, see "Management -- Employment Agreements." For information regarding
compensation of Directors, see "Management -- Compensation of Directors."
 
                                       55
 
<PAGE>
                             PRINCIPAL STOCKHOLDERS
 
     The following table sets forth certain information regarding the beneficial
ownership of the Company's Common Stock as of August 27, 1997 (after giving
effect to the Preferred Stock Conversion) and as adjusted to give effect to the
sale of the shares of Common Stock offered hereby, by (i) each person (or group
of affiliated persons) who is known by the Company to own beneficially 5% or
more of the outstanding shares of Common Stock, (ii) each Named Executive
Officer, (iii) each of the Company's Directors, and (iv) all Directors and
executive officers of the Company as a group.
 
<TABLE>
<CAPTION>
                                                                                   NUMBER OF              PERCENTAGE
                                                                                     SHARES              OWNERSHIP(1)
                                                                                  BENEFICIALLY        BEFORE      AFTER
BENEFICIAL OWNER                                                                    OWNED(1)         OFFERING    OFFERING
<S>                                                                              <C>                 <C>         <C>
Domain Partners II, L.P. (2)..................................................        2,570,559         34.8%       26.0%
Domain Partners III, L.P. (2).................................................        2,570,559         34.8        26.0
DP III Associates, L.P. (2)...................................................        2,570,559         34.8        26.0
Biotechnology Investments Limited (3).........................................        1,295,068         17.5        13.1
Sentron Medical, Inc. (4).....................................................          392,158          5.3         4.0
M. Ross Johnson (5)...........................................................          188,994          2.6         1.9
Matthew A. Megaro (6).........................................................          146,079          2.0         1.5
Max N. Wallace (7)............................................................          132,149          1.8         1.3
Richard A. Franco.............................................................           53,334            *           *
Jesse I. Treu (2).............................................................        2,570,559         34.8        26.0
Dani P. Bolognesi (8).........................................................           98,813          1.3         1.0
Brian H. Dovey (2)............................................................        2,570,559         34.8        26.0
Charles A. Sanders (9)........................................................           11,765            *           *
Andrew A. McCreath (10).......................................................          268,628          3.7         2.7
All executive officers and directors as a
group (eight persons) (11)....................................................        3,464,603         46.9        35.1
</TABLE>
 
* Less than one percent.
 
 (1) Applicable percentage ownership is based on 7,380,325 shares of Common
     Stock outstanding as of August 27, 1997 after giving effect to the
     Preferred Stock Conversion. Beneficial ownership is determined in
     accordance with the rules of the Securities and Exchange Commission based
     on factors including voting or investment power with respect to securities.
     Shares of Common Stock subject to options, warrants and convertible notes
     currently exercisable or convertible, or exercisable or convertible within
     60 days after August 27, 1997, are deemed outstanding for computing the
     percentage ownership of the person or entity holding such securities, but
     are not deemed outstanding for computing the percentage ownership of any
     other person or entity. Except as indicated, and subject to community
     property laws where applicable, the persons named in the table above have
     sole voting and investment power with respect to all shares of Common Stock
     as beneficially owned by them, and there are no other affiliations among
     the stockholders listed in the table.
 (2) Consists of shares held by affiliated entities as follows: (i) 1,597,342
     shares beneficially owned by Domain Partners II, L.P., whose general
     partner is One Palmer Square Associates II, L.P.; (ii) 940,533 shares
     beneficially owned by Domain Partners III, L.P., whose general partner is
     One Palmer Square Associates III, L.P.; and (iii) 32,684 shares
     beneficially owned by DP III Associates, L.P., whose general partner is One
     Palmer Square Associates III, L.P. Dr. Treu and Mr. Dovey are general
     partners of One Palmer Square Associates II, L.P. and One Palmer Square
     Associates III, L.P. In such capacities, Dr. Treu and Mr. Dovey each may be
     deemed to be the beneficial owner of such shares, although each disclaims
     such beneficial ownership except to the extent of his pecuniary interest,
     if any. The address for Domain Partners II, L.P., Domain Partners III,
     L.P., DP III Associates, L.P., Dr. Treu and Mr. Dovey is One Palmer Square,
     Princeton, New Jersey 08542.
 (3) Biotechnology Investments Limited ("BIL") has entered into a contractual
     arrangement with Domain Associates whereby Domain Associates serves as the
     United States venture capital advisor to BIL. Domain Associates has neither
     voting nor investment power over BIL's shares. Dr. Treu and Mr. Dovey are
     general partners of Domain Associates. The address for BIL is St. Peter
     Port House, Sausmarez Street, St. Peter Port, Guernsey, GY13PH, Channel
     Islands.
 (4) The address for Sentron Medical, Inc. is 4445 Lake Forest Drive, Suite 600,
     Cincinnati, Ohio 45242.
 (5) Includes 179,645 shares subject to certain contractual restrictions, which
     restrictions lapse with respect to 8,037 shares within 60 days after August
     27, 1997. Does not include an aggregate of 85,518 shares beneficially owned
     by Michael Johnson and Greg Johnson, Mr. Johnson's sons, who have sole
     voting and investment power of such shares and as to which shares Mr.
     Johnson disclaims beneficial ownership.
 
                                       56
 
<PAGE>
   
 (6) Includes (i) 91,756 shares subject to certain contractual restrictions,
     which restrictions lapse with respect to 3,955 shares within 60 days after
     August 27, 1997, and (ii) an aggregate of 47,076 shares beneficially owned
     by Matthew A. Megaro as custodian for Anthony Megaro and Arianna Megaro,
     Mr. Megaro's son and daughter.
    
 (7) Includes (i) 29,543 shares subject to certain contractual restrictions,
     which restrictions lapse with respect to 1,442 shares within 60 days after
     August 27, 1997 and (ii) 2,443 shares beneficially owned by Diana Parrish,
     Mr. Wallace's wife. For information concerning the subsequent lapsing of
     these restrictions, see "Certain Transactions."
 (8) Includes 13,652 shares that Dr. Bolognesi may acquire pursuant to stock
     options exercisable within 60 days after August 27, 1997 and the following
     shares as to which Dr. Bolognesi disclaims beneficial ownership: (i) 11,765
     shares beneficially owned by James C. Bolognesi Irrevocable Trust, for
     which James C. Bolognesi, Dr. Bolognesi's son, is the sole beneficiary and
     Sarah Bolognesi, Dr. Bolognesi's wife, is the sole trustee; (ii) 11,765
     shares beneficially owned by Michael P. Bolognesi Irrevocable Trust, for
     which Michael P. Bolognesi, Dr. Bolognesi's son, is the sole beneficiary
     and Sarah Bolognesi is the sole trustee; and (iii) 5,748 shares that Sarah
     Bolognesi may acquire pursuant to certain stock options exercisable within
     60 days after August 27, 1997.
 (9) Includes 1,961 shares that Dr. Sanders may acquire pursuant to stock
     options exercisable within 60 days after August 27, 1997.
(10) Includes 268,628 shares beneficially owned by Lawrence & Company Inc., of
     which Mr. McCreath is a partner. In such capacity, Mr. McCreath may be
     deemed to be the beneficial owner of such shares, although he disclaims
     such beneficial ownership except to the extent of his pecuniary interest,
     if any.
(11) See notes (2)-(10).
 
                                       57
 
<PAGE>
                          DESCRIPTION OF CAPITAL STOCK
 
     The authorized capital stock of the Company consists of 30,000,000 shares
of Common Stock and 10,000,000 shares of Preferred Stock (after giving effect to
the Preferred Stock Conversion and the filing of the Third Amended and Restated
Certificate of Incorporation upon the completion of this Offering). The
following description of the capital stock of the Company is a summary, does not
purport to be complete, is subject to, and qualified in its entirety by, the
provisions of the Third Amended and Restated Certificate of Incorporation, which
is filed as an exhibit to the Registration Statement of which this Prospectus is
a part, and by applicable law.
 
COMMON STOCK
 
     As of June 30, 1997, there were 7,354,087 shares of Common Stock
outstanding, as adjusted to reflect the Preferred Stock Conversion upon the
completion of this Offering, held of record by 70 stockholders.
 
     The holders of Common Stock are entitled to one vote for each share held on
all matters submitted to a vote of stockholders and do not have cumulative
voting rights. Holders of Common Stock are entitled to receive ratably such
dividends, if any, as may be declared from time to time by the Board of
Directors out of funds legally available therefor, subject to any preferential
dividend rights applicable to any outstanding Preferred Stock that may be issued
in the future. The Company has not declared or paid cash dividends on its
capital stock. The Company currently intends to retain any future earnings to
fund its operations and, therefore, does not anticipate paying any cash
dividends in the foreseeable future. See "Dividend Policy."
 
     In the event of liquidation, dissolution or winding up of the Company, the
holders of Common Stock are entitled to share ratably in all assets of the
Company remaining after the payment of all debts and other liabilities, subject
to the prior distribution rights of shares of Preferred Stock if any, then
outstanding. There are no preemptive, subscription or conversion rights
applicable to the Common Stock. The outstanding shares of Common Stock are, and
the shares offered by the Company in this Offering will be, when issued and paid
for, validly issued, fully paid and nonassessable. The rights, preferences and
privileges of holders of Common Stock are subject to the rights of the holders
of shares of any class or series of Preferred Stock that the Company may
designate and issue in the future.
 
PREFERRED STOCK
 
     The Board of Directors has the authority, without action by the
stockholders, to designate and issue 10,000,000 shares of Preferred Stock in one
or more series and to designate the rights, preferences and limitations of all
series, any or all of which may be superior to the rights of the Common Stock.
It is not possible to state the actual effect of the issuance of any shares of
Preferred Stock upon the rights of the holders of Common Stock until the Board
of Directors determines the specific rights of the holders of Preferred Stock.
However, the effects might include, among others, restricting dividends on
Common Stock, diluting the voting power of the Common Stock, impairing the
liquidation rights of the Common Stock, and making it more difficult for a third
party to acquire the Company, which could have the effect of discouraging a
third party from acquiring, or deterring a third party from paying a premium to
acquire, a majority of the outstanding voting stock of the Company. The Company
has no present plans to issue any shares of Preferred Stock. See "Risk
Factors -- Anti-Takeover Effect of Certain Charter and Bylaw Provisions."
 
WARRANTS
 
     As of June 30, 1997, the Company had outstanding warrants entitling the
purchasers thereof to purchase a total of 56,684 shares of Common Stock at a
weighted-average exercise price of $4.25 per share (the "Warrants"). The
Warrants have expiration dates ranging from 2003 to 2005.
 
REGISTRATION RIGHTS
 
     The holders, or their permitted transferees, of approximately 6,261,615
shares of Common Stock and 56,684 shares of Common Stock issuable upon exercise
of the Warrants (the "Registrable Securities") are entitled to certain rights
with respect to the registration of such shares under the Securities Act. These
rights are provided under
 
                                       58
 
<PAGE>
the terms of certain agreements between the Company and holders of Registrable
Securities. Subject to certain limitations set forth in the agreements, certain
of the holders may require the Company, at its expense, on not more than two
occasions, to file a registration statement under the Securities Act with
respect to the public resale of Registrable Securities. If the Company proposes
to register any of its securities under the Securities Act, either for its own
account or for the account of other security holders, the holders of Registrable
Securities are entitled to notice of the registration and are entitled to
include, at the Company's expense, such shares therein, subject to certain
conditions and limitations. Further, the holders of Registrable Securities may
require the Company at its expense to register their shares on Form S-3 when the
use of such form becomes available to the Company, subject to certain conditions
and limitations. All registration expenses must be borne by the Company and all
selling expenses relating to Registrable Securities must be borne by the holder
of the securities being registered.
 
DELAWARE LAW AND CERTAIN CHARTER PROVISIONS
 
     The Company is subject to the provisions of DGCL Section 203 which, subject
to certain exceptions, prohibits the Company from engaging in certain business
combinations with interested stockholders for a period of three years after the
date of the transaction in which the stockholder became an interested
stockholder, unless the business combination is approved in a prescribed manner.
A "business combination" includes a merger, asset sale or other transaction
resulting in a financial benefit to the stockholder. For purposes of Section
203, an "interested stockholder" is a person who, together with affiliates and
associates, owns (or within three years prior, did own) 15% or more of the
corporation's voting stock. The application of Section 203 could have the effect
of delaying or preventing a change of control of the Company.
 
     The Company's Third Amended and Restated Certificate of Incorporation
provides that effective upon this Offering, each director will serve for a
three-year term and that approximately one-third of the directors are to be
elected annually. Candidates for directors shall be nominated only by the Board
of Directors or by a stockholder who gives written notice to the Company in the
manner prescribed by the Bylaws. The number of directors may be fixed by
resolution of the Board of Directors. The Board currently consists of six
members and the Board may appoint new directors to fill vacancies or newly
created directorships between stockholder meetings. The Third Amended and
Restated Certificate of Incorporation does not provide for cumulative voting at
stockholder meetings for election of directors. A director may be removed from
office only for cause by the affirmative vote of a majority of the combined
voting power of the then outstanding shares of stock entitled to vote generally
in the election of directors or without cause by the affirmative vote of at
least two-thirds of the voting power of the outstanding shares of stock entitled
to vote in the election of directors. Any action required or permitted to be
taken by stockholders of the Company must be effected at a duly called annual or
special meeting of stockholders and may not be effected by written consent. The
staggered Board of Directors, the Company's Third Amended and Restated
Certificate of Incorporation and certain other provisions of the DGCL may have
the effect of delaying, deterring or preventing a change in control of the
Company, may discourage bids for the Common Stock at a premium over the market
price and may adversely affect the market price, and the voting and other rights
of the holders, of the Common Stock.
 
   
TRANSFER AGENT
    
 
   
     The transfer agent for the Company's Common Stock is Wachovia Bank of North
Carolina, N.A.
    
 
                                       59
 
<PAGE>
                        SHARES ELIGIBLE FOR FUTURE SALE
 
     Prior to this Offering, there has been no market for the Common Stock of
the Company. Future sales of substantial amounts of Common Stock (including
shares issued upon the exercise of outstanding options and warrants) in the
public market after this Offering or the prospect of such sales could materially
and adversely affect the market price of the Common Stock prevailing from time
to time. Sales of substantial amounts of Common Stock of the Company in the
public market after the restrictions described below lapse could also materially
and adversely affect the prevailing market price of the Common Stock and the
ability of the Company to raise equity capital in the future.
 
     Upon the completion of this Offering, the Company will have 9,880,325
shares of Common Stock outstanding (assuming no exercise of options and warrants
outstanding as of August 27, 1997). Of these shares, the 2,500,000 shares sold
in this Offering will be freely tradeable without restrictions unless held by
"affiliates" of the Company as that term is defined in Rule 144 under the
Securities Act. The remaining 7,380,325 shares were issued and sold in reliance
upon certain exemptions from the registration requirements of the Securities
Act. These shares may be sold in the public market only if registered, or
pursuant to an exemption from such registration, such as Rule 144 or Rule 144(k)
under the Securities Act.
 
   
     Approximately 231,117 shares of Common Stock will be eligible for resale in
the public market without restriction in reliance on Rule 144(k) immediately
following the completion of this Offering, 225,944 shares of which are subject
to the Lock-up Agreements described below. An additional 769,238 shares (763,331
shares of which are subject to the Lock-up Agreements) will be eligible for
resale in the public market pursuant to Rule 701 under the Securities Act
beginning approximately 90 days after the effective date of this Prospectus,
except to the extent that such shares are subject to vesting restrictions or
certain contractual restrictions on sale or transfer pursuant to agreements with
the Company. After the expiration of the 180-day lock-up period described below,
an additional 3,739,158 shares of Common Stock will be eligible for resale in
the public market pursuant to Rule 144. From time to time thereafter, the
remaining shares of Common Stock outstanding will become eligible for resale in
the public market pursuant to Rule 144.
    
 
   
     In general, under Rule 144 as currently in effect, any person (or persons
whose shares are aggregated), who has beneficially owned restricted securities
(as that term is defined in Rule 144) for at least one year is entitled to sell,
within any three month period, a number of such securities that does not exceed
the greater of one percent of the then outstanding class of securities (in the
case of the Common Stock, approximately 98,803 shares, based on the number of
shares to be outstanding after this Offering) or the average weekly trading
volume in such securities in the public market during the four calendar weeks
preceding the filing of the seller's Form 144, provided certain requirements
concerning availability of public information concerning the issuer of the
restricted securities, manner of sale and notice of sale are satisfied. A person
who is not an affiliate of the issuer, has not been an affiliate within three
months prior to the sale and has beneficially owned the restricted securities
for at least two years is entitled to sell such shares under Rule 144(k) without
regard to any of the limitations described above. Rule 144 also provides that
affiliates who are selling shares that are not restricted securities must
nonetheless comply with the same restrictions applicable to restricted
securities with the exception of the holding period requirement. The one-year
and two-year holding periods described above do not begin to run until the full
purchase price or other consideration is paid by the person acquiring the
restricted securities from the issuer or an affiliate of the issuer and may
include the holding period of a prior owner who is not an affiliate of the
issuer.
    
 
     Securities issued in reliance on Rule 701 (such as shares of Common Stock
issued before the completion of this Offering upon the exercise of options) are
also restricted securities and, beginning approximately 90 days after the
effective date of this Prospectus, may be resold by persons other than
affiliates of the Company subject only to the manner of sale provisions of Rule
144 and may be resold by affiliates under Rule 144 without compliance with the
one-year holding period.
 
   
     The executive officers, directors, employees and certain other stockholders
of the Company, who together beneficially own or have dispositive power over
7,366,303 shares of Common Stock outstanding prior to this Offering, have agreed
that they will not sell, offer, make any short sale or otherwise dispose of or
enter into any contract, arrangement or commitment to sell or otherwise dispose
of any shares of Common Stock or securities
    
 
                                       60
 
<PAGE>
exerciseable into or convertible into shares of Common Stock owned by them for a
period of 180 days after the date of this Prospectus without the prior written
consent of UBS Securities LLC.
 
   
     Approximately 90 days after the completion of this Offering, the Company
intends to file a registration statement on Form S-8 under the Securities Act to
register the future issuance of shares of Common Stock reserved for issuance
under the Company's stock option plan. As of August 27, 1997, 244,006 shares of
Common Stock were reserved for issuance pursuant to outstanding options and
254,894 shares of Common Stock were reserved for future issuance under the
Company's stock option plan. Such registration statement will automatically
become effective upon filing. Accordingly, shares registered thereunder will,
subject to Rule 144 limitations applicable to affiliates, be available for sale
in the public market, except to the extent that such shares are subject to
vesting restrictions with the Company or certain contractual restrictions on
sale or transfer (including options covering 242,829 shares which are subject to
Lock-up Agreements). After this Offering, the holders of approximately 6,261,215
shares of Common Stock and the holders of warrants to purchase an aggregate of
56,684 shares of Common Stock will be entitled to certain demand and piggyback
rights with respect to the registration of such shares under the Securities Act.
If such holders, by exercising their demand registration rights, cause a large
number of securities to be registered and sold in the public market, such sales
could have an adverse effect on the market price of the Company's Common Stock.
If the Company, either on its own behalf or on behalf of certain stockholders,
were to initiate a registration and include shares held by such holders pursuant
to the exercise of their piggyback registration rights, such sales could have a
material adverse effect on the Company's ability to raise needed capital. See
"Certain Transactions," "Shares Eligible for Future Sale," "Description of
Capital Stock -- Registration Rights" and "Underwriting."
    
 
                                       61
 
<PAGE>
                                  UNDERWRITING
 
     Subject to the terms and conditions of the Underwriting Agreement, the
underwriters named below (the "Underwriters"), for whom UBS Securities LLC and
Montgomery Securities are acting as representatives (the "Representatives"),
have agreed to purchase from the Company the following respective number of
shares of Common Stock:
 
<TABLE>
<CAPTION>
UNDERWRITERS                                                           SHARES
<S>                                                                   <C>
UBS Securities LLC.................................................
Montgomery Securities..............................................
 
       Total.......................................................   2,500,000
</TABLE>
 
     The Underwriting Agreement provides that the obligations of the
Underwriters are subject to certain conditions precedent, including the absence
of any material adverse change in the Company's business and the receipt of
certain certificates, opinions and letters from the Company and its counsel. The
nature of the Underwriters' obligation is such that they are committed to
purchase all shares of Common Stock offered hereby if any such shares are
purchased. The Underwriting Agreement contains certain provisions whereby if any
Underwriter defaults in its obligations to purchase shares, and the aggregate
obligations of the Underwriters so defaulting do not exceed ten percent of the
shares offered hereby, the remaining Underwriters, or some of them, must assume
such obligations.
 
   
     The Underwriters have advised the Company that the Underwriters propose to
offer the shares of the Common Stock directly to the public at the offering
price set forth on the cover of this Prospectus, and to certain dealers at such
price less a concession not in excess of $     per share. The Underwriters may
allow and such dealers may reallow a concession not in excess of $     per share
to certain other dealers. After the public offering of the shares of Common
Stock, the Offering price and other selling terms may be changed by the
Underwriters.
    
 
   
     The Company has granted to the Underwriters an option, exercisable no later
than 30 days after the date of this Prospectus, to purchase up to 375,000
additional shares of Common Stock to cover over-allotments, if any, at the
public offering price set forth on the cover page of this Prospectus, less the
underwriting discounts and commissions. To the extent that the Underwriters
exercise this option, each of the Underwriters will have a firm commitment to
purchase approximately the same percentage thereof which the number of shares of
Common Stock to be purchased by it shown in the above table bears to the total
number of shares of Common Stock offered hereby. The Company will be obligated,
pursuant to the option, to sell such shares to the Underwriters.
    
 
     In connection with the Offering, the Underwriters may engage in
transactions that stabilize, maintain or otherwise affect the price of the
Common Stock. Specifically, the Underwriters may overallot the Offering,
creating a syndicate short position. In addition, the Underwriters may bid for
and purchase shares of Common Stock in the open market to cover syndicate short
positions or to stabilize the price of the Common Stock. Finally, the
Underwriters may reclaim selling concessions from syndicate members in the
Offering if the syndicate repurchases previously distributed Common Stock in
syndicate covering transactions, in stabilizing transactions or otherwise. Any
of these activities may stabilize or maintain the market price of the Common
Stock above independent market levels. The Underwriters are not required to
engage in these activities, and may end any of these activities at any time.
 
                                       62
 
<PAGE>
     The Company has agreed to indemnify the Underwriters against certain
liabilities, including liabilities under the Securities Act.
 
   
     The executive officers, directors, employees and certain other stockholders
of the Company who beneficially own or have dispositive power over substantially
all of the shares of Common Stock outstanding prior to this Offering, including
Common Stock to be issued upon the completion of this Offering pursuant to the
Preferred Stock Conversion, have agreed that they will not, without the prior
written consent of UBS Securities LLC, offer, sell or otherwise dispose of any
shares of Common Stock or securities exchangeable for or convertible into shares
of Common Stock owned by them for a period of 180 days after the date of this
Prospectus. The Company has agreed that it will not, without the prior written
consent of UBS Securities LLC, offer, sell or otherwise dispose of any shares of
Common Stock for a period of 180 days after the date of this Prospectus, except
that the Company may grant options under the Stock Option Plan and may issue
shares pursuant to other currently outstanding options.
    
 
     The Representatives have advised the Company that the Underwriters do not
intend to confirm sales to any account over which they exercise discretionary
authority in excess of five percent of the number of shares of Common Stock
offered hereby.
 
     In June 1997, an entity affiliated with UBS Securities LLC purchased in
connection with the Company's Series D Preferred Stock financing an aggregate of
2,000,000 shares of Series D Preferred Stock at a price of $.75 per share. Such
Preferred Stock will convert into 235,295 shares of Common Stock upon the
completion of this Offering.
 
     Prior to this Offering, there has been no public market for the Common
Stock of the Company. The initial public offering price will be determined by
negotiations between the Company and the Representatives and may not be
indicative of the market price at which the Common Stock of the Company will
trade after this Offering. Among the factors to be considered in such
negotiations, in addition to prevailing market conditions, are certain financial
information of the Company, market valuations of other companies that the
Company and the Representatives believe to be comparable to the Company,
estimates of the business potential of the Company, the present state of the
Company's development and other factors deemed relevant. The initial public
offering price set forth on the cover page of this Prospectus should not,
however, be considered an indication of the actual value of the Common Stock.
Such price is subject to change as a result of market conditions and other
factors. There can be no assurance that an active trading market will develop
for the Common Stock or that the Common Stock will trade in the public market
subsequent to this Offering at or above the initial offering price.
 
                                       63
 
<PAGE>
                                 LEGAL MATTERS
 
   
     The validity of the shares of Common Stock offered hereby will be passed
upon for the Company by Hutchison & Mason PLLC, Raleigh, North Carolina, counsel
to the Company. Certain legal matters will be passed upon for the Company by
Wilmer, Cutler & Pickering, Washington D.C., special counsel to the Company. As
of the date of this Prospectus, two members of Hutchison & Mason PLLC
beneficially own an aggregate of 3,530 shares of the Company's Common Stock and
a partner of Wilmer, Cutler & Pickering beneficially owns 9,804 shares of the
Company's Common Stock. A principal of AspenTree Capital, consultant to the
Company and beneficial owner of 26,865 shares of the Company's Common Stock and
options to purchase Common Stock, exercisable as to 3,603 shares within 60 days
after September 1, 1997, serves as a consultant to Wilmer, Cutler & Pickering on
certain matters other than those relating to the Company. Certain legal matters
will be passed upon for the Underwriters by Brobeck, Phleger & Harrison LLP, New
York, New York.
    
 
                                    EXPERTS
 
     The financial statements of the Company, as of December 31, 1995 and 1996
and for each of the years in the three-year period ended December 31, 1996, and
the period from inception (January 7, 1993) to December 31, 1996 have been
included herein and in the Registration Statement in reliance upon the report of
KPMG Peat Marwick LLP, independent certified public accountants, appearing
elsewhere herein, and upon the authority of said firm as experts in accounting
and auditing.
 
     The statements in this Prospectus under the captions "Risk
Factors -- Uncertainty Regarding Patents and Proprietary Rights" and
"Business -- Patents, Proprietary Technology and Trade Secrets", relating to
U.S. patent matters, have been reviewed and approved by Pennie & Edmonds LLP,
New York, New York, patent counsel to the Company, and are included herein in
reliance upon such review and approval by the firm as experts in U.S. patent
law.
 
                             ADDITIONAL INFORMATION
 
     The Company has filed with the Securities and Exchange Commission (the
"Commission") a Registration Statement on Form S-l under the Securities Act with
respect to the Common Stock offered hereby. This Prospectus, which is a part of
the Registration Statement, does not contain all of the information set forth in
the Registration Statement and the exhibits and schedules hereto. For further
information with respect to the Company and the Common Stock offered hereby,
reference is hereby made to such Registration Statement and to the exhibits and
schedules filed as a part thereof. Statements made in this Prospectus concerning
the contents of any contracts or documents are not necessarily complete, and, in
each such instance, if such contract or document is filed as an exhibit to the
Registration Statement, reference is made to such exhibit for a more complete
description, and each such statement is qualified in its entirety by reference
to such exhibit. Any interested party may inspect the Registration Statement,
without charge, at the public reference facilities of the Commission at Room
1024, Judiciary Plaza, 450 Fifth Street, N.W., Washington, D.C. 20549 and copies
of all or any portion of the Registration Statement, including exhibits and
schedules thereto, may be obtained at prescribed rates from the Public Reference
Section of the Commission at its principal office at Room 1024, 450 Fifth
Street, N.W., Washington, D.C. 20549 and at the Commission's public reference
facilities in Chicago, Illinois and New York, New York. The Commission maintains
a World Wide Web site that will contain reports, proxy and information
statements and other information regarding the Company. The address of such site
is http://www.sec.gov.
 
     As a result of the filing of this Registration Statement and the completion
of the Offering contemplated hereby, the Company will become subject to the
periodic reporting requirements of the Securities Exchange Act of 1934, as
amended, and in accordance therewith will be required to file reports and other
information with the Commission. Such reports and other information can be
inspected and copied at the public reference facilities maintained by the
Commission at its principal offices.
 
     The Company intends to furnish its stockholders annual reports containing
financial statements audited by its independent auditors and quarterly reports
containing unaudited financial information for the first three quarters of each
fiscal year.
 
                                       64
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                         INDEX TO FINANCIAL STATEMENTS
 
<TABLE>
<CAPTION>
                                                                                                               PAGE
<S>                                                                                                            <C>
Independent Auditors' Report................................................................................    F-2
Balance Sheets at December 31, 1995 and 1996 and June 30, 1997 (unaudited)..................................    F-3
Statements of Operations for the Years Ended December 31, 1994, 1995,
  and 1996 and for the Six Months Ended June 30, 1996 (unaudited) and 1997
  (unaudited) and for the period from Inception to December 31, 1996........................................    F-4
Statements of Stockholders' Equity (Deficit) for the Years Ended December 31, 1993, 1994,
  1995, and 1996 and for the Six Months Ended June 30, 1997 (unaudited).....................................    F-5
Statements of Cash Flows for the Years Ended December 31, 1994, 1995,
  and 1996 and for the Six Months Ended June 30, 1996 (unaudited) and 1997
  (unaudited) and for the period from Inception to December 31, 1996........................................    F-6
Notes to Financial Statements...............................................................................    F-7
</TABLE>
 
                                      F-1
 
<PAGE>
                          INDEPENDENT AUDITORS' REPORT
 
The Board of Directors and Stockholders
Trimeris, Inc.:
 
     We have audited the accompanying balance sheets of Trimeris, Inc. (A
Development Stage Company) (the "Company") as of December 31, 1995 and 1996, and
the related statements of operations, stockholders' equity (deficit), and cash
flows for each of the years in the three-year period ended December 31, 1996 and
for the cumulative period from the date of inception to December 31, 1996. These
financial statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements based on
our audits.
 
     We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
     In our opinion, the financial statements referred to above present fairly,
in all material respects, the financial position of the Company as of December
31, 1995 and 1996, and the results of its operations and its cash flows for each
of the years in the three-year period ended December 31, 1996, and for the
cumulative period from the date of inception to December 31, 1996, in conformity
with generally accepted accounting principles.
 
March 17, 1997 except for
  Note 11(a) as to which the
  date is June 30, 1997
 
Raleigh, North Carolina                                    KPMG PEAT MARWICK LLP
 
                                      F-2
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                                 BALANCE SHEETS
 
<TABLE>
<CAPTION>
                                                                                                                     PRO FORMA
                                                                                                   AS OF JUNE      STOCKHOLDERS'
                                                                      AS OF DECEMBER 31,               30,         EQUITY AS OF
                                                                     1995             1996            1997         JUNE 30, 1997
<S>                                                              <C>              <C>             <C>              <C>
                                                                                                   (UNAUDITED)      (UNAUDITED)
ASSETS
Current assets:
  Cash and cash equivalents....................................  $   1,343,346    $    131,540    $   8,912,343
  Accounts receivable..........................................            793          32,752           44,758
  Loans to employees...........................................             --           2,985               --
  Prepaid expenses.............................................          9,564          45,470          311,753
      Total current assets.....................................      1,353,703         212,747        9,268,854
Property, furniture and equipment, net of accumulated
  depreciation of $921,135, $1,611,544 and $1,911,663 at
  December 31, 1995, 1996 and June 30, 1997 (unaudited),
  respectively.................................................      1,230,394         896,672          698,372
Other assets:
  Equipment held for resale, less allowance of $60,972, $54,029
    and $54,029 at December 31, 1995, 1996 and June 30, 1997
    (unaudited), respectively..................................         60,972          54,029           54,029
  Exclusive license agreement, net of accumulated amortizaton
    of $6,632, $9,044 and $10,250 at December 31, 1995, 1996
    and June 30, 1997 (unaudited), respectively................         34,368          31,956           30,750
  Patent costs.................................................        298,154         412,619          444,949
  Equipment deposits...........................................         58,830          58,830           58,830
  Other assets, net of accumulated amortization of $10,233,
    $14,531 and $16,518 at December 31, 1995, 1996 and June 30,
    1997
    (unaudited), respectively..................................         21,427          16,876           28,967
      Total other assets.......................................        473,751         574,310          617,525
      Total assets.............................................  $   3,057,848    $  1,683,729    $  10,584,751
LIABILITIES AND STOCKHOLDERS' EQUITY (DEFICIT)
Current liabilities:
  Accounts payable.............................................  $     118,016    $    254,845    $     337,173
  Current installments of obligations under capital leases.....        527,406         500,248          332,332
  Accrued expenses.............................................        385,797         762,548          580,012
      Total current liabilities................................      1,031,219       1,517,641        1,249,517
Notes payable..................................................        166,718         259,000          260,000
Obligations under capital leases, excluding current
  installments.................................................        536,184         316,537          228,111
      Total liabilities........................................      1,734,121       2,093,178        1,737,628
Stockholders' equity (deficit):
  Series A Preferred Stock at $.001 par value per share.
    3,000,000 shares authorized, issued and outstanding........          3,000           3,000            3,000    $         --
  Series B Preferred Stock at $.001 par value per share.
    29,000,000 shares authorized; issued and outstanding
    20,635,564 and 27,135,564 shares at December 31, 1995, 1996
    and June 30, 1997 (unaudited), respectively................         20,636          27,136           27,136              --
  Series C Preferred Stock at $.001 per share. 20,000,000
    shares authorized; issued and outstanding 3,333,335 and
    13,317,740 shares at December 31, 1996 and June 30, 1997
    (unaudited), respectively..................................             --           3,333           13,317              --
  Series D Preferred Stock at $.001 par value per share
    10,666,667 shares authorized; issued and outstanding
    9,047,962 at
    June 30, 1997 (unaudited)..................................             --              --            9,048              --
  Common Stock at $.001 par value per share. Authorized
    80,000,000 shares; issued and outstanding 352,412, 436,688
    and 1,092,472 shares at December 31, 1995, 1996 and June
    30, 1997 (unaudited), respectively.........................            353             437            1,092           7,354
  Additional paid-in capital...................................     12,293,582      17,535,897       32,434,995      32,481,234
  Deficit accumulated during the development stage.............    (10,993,844)    (17,965,252)     (21,442,925)    (21,442,925 )
  Deferred compensation........................................             --              --       (1,935,000)     (1,935,000 )
  Notes receivable from stockholders...........................             --         (14,000)        (263,540)       (263,540 )
      Total stockholders' equity (deficit).....................      1,323,727        (409,449)       8,847,123    $  8,847,123
Commitments and contingencies (notes 2, 10, and 11)
      Total liabilities and stockholders' equity (deficit).....  $   3,057,848    $  1,683,729    $  10,584,751
</TABLE>
 
                See accompanying notes to financial statements.
 
                                      F-3
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                            STATEMENTS OF OPERATIONS
 
<TABLE>
<CAPTION>
                                                                    CUMULATIVE
                                                                  FROM INCEPTION
                                                                    (JANUARY 7,              FOR THE               CUMULATIVE
                                                                       1993)            SIX MONTHS ENDED         FROM INCEPTION
                           FOR THE YEARS ENDED DECEMBER 31,       TO DECEMBER 31,           JUNE 30,            (JANUARY 7, 1993)
                           1994          1995          1996            1996            1996          1997       TO JUNE 30, 1997
<S>                     <C>           <C>           <C>           <C>               <C>           <C>           <C>
                                                                                           (UNAUDITED)             (UNAUDITED)
Revenue...............  $        --   $   104,453   $    54,465    $     158,918    $        --   $   211,875     $     370,793
Operating expenses:
  Research and
    development.......    2,746,867     4,011,875     5,146,072       12,596,163      2,278,084     2,858,785        15,454,948
  General and
    administrative....      947,518     1,520,974     1,759,965        4,859,704        801,547       786,445         5,646,149
      Total operating
         expenses.....    3,694,385     5,532,849     6,906,037       17,455,867      3,079,631     3,645,230        21,101,097
  Operating loss......   (3,694,385)   (5,428,396)   (6,851,572)     (17,296,949)    (3,079,631)   (3,433,355)      (20,730,304)
Other income
 (expense):
  Interest income.....        8,611        49,176        46,992          121,449         31,672        33,319           154,768
  Interest expense....     (258,191)     (360,158)     (166,828)        (789,752)       (85,623)      (77,637)         (867,389)
                           (249,580)     (310,982)     (119,836)        (668,303)       (53,951)      (44,318)         (712,621)
  Net loss............  $(3,943,965)  $(5,739,378)  $(6,971,408)   $ (17,965,252)   $(3,133,582)  $(3,477,673)    $ (21,442,925)
Pro forma net loss
 per share............                              $     (1.48)                                  $     (0.59)
Pro forma weighted
 average shares used
 in per share
 computations.........                                4,705,000                                     5,880,000
</TABLE>
 
                See accompanying notes to financial statements.
 
                                      F-4
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                  STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT)
 
  YEARS ENDED DECEMBER 31, 1993, 1994, 1995 AND 1996, AND THE SIX MONTHS ENDED
                           JUNE 30, 1997 (UNAUDITED)
<TABLE>
<CAPTION>
                                                                                    DEFICIT
                                                                                  ACCUMULATED                     NOTES
                             PREFERRED STOCK       COMMON STOCK     ADDITIONAL    DURING THE                    RECEIVABLE
                             NUMBER      PAR      NUMBER     PAR      PAID-IN     DEVELOPMENT     DEFERRED         FROM
                           OF SHARES    VALUE   OF SHARES   VALUE     CAPITAL        STAGE      COMPENSATION   STOCKHOLDERS
<S>                        <C>         <C>      <C>         <C>     <C>          <C>            <C>            <C>
Balance at January 7,
 1993.....................         --  $    --          --  $   --  $        --  $      --  --             --    $       --
Issuances of Common
 Stock....................         --       --     217,647     218        1,632             --             --            --
Issuances of Series A
 Preferred Stock..........  3,000,000    3,000          --      --    1,997,000             --             --            --
Stock issuance costs......         --       --          --      --      (33,813)            --             --            --
Common Stock issued in
 exchange for exclusive
 license..................         --       --      96,471      96       40,904             --             --            --
Common Stock issued in
 exchange for consulting
 services.................         --       --       5,882       6        2,494             --             --            --
Loss for the period.......         --       --          --      --           --     (1,310,501)            --            --
Balance as of December 31,
 1993.....................  3,000,000    3,000     320,000     320    2,008,217     (1,310,501)            --            --
Issuances of Common
 Stock....................         --       --      11,911      12        5,051             --             --            --
Common Stock issued in
 exchange for consulting
 services.................         --       --       4,706       5        1,995             --             --            --
Loss for the period.......         --       --          --      --           --     (3,943,965)            --            --
Balance as of December 31,
 1994.....................  3,000,000    3,000     336,617     337    2,015,263     (5,254,466)            --            --
Issuances of Common
 Stock....................         --       --      15,795      16        7,894             --             --            --
Issuance of Series B
 Preferred Stock.......... 20,635,564   20,636          --      --   10,297,146             --             --            --
Stock issuance costs......         --       --          --      --      (26,721)            --             --            --
Loss for the period.......         --       --          --      --           --     (5,739,378)            --            --
Balance as of December 31,
 1995..................... 23,635,564   23,636     352,412     353   12,293,582    (10,993,844)            --            --
Issuances of Common
 Stock....................         --       --      83,688      84       28,370             --             --            --
Common Stock issued in
 exchange for consulting
 services.................         --       --         588      --          200             --             --            --
Issuances of Series B
 Preferred Stock..........  6,500,000    6,500          --      --    3,243,500             --             --            --
Issuances of Series C
 Preferred Stock..........  3,333,335    3,333          --      --    1,996,668             --             --            --
Stock issuance costs......         --       --          --      --      (26,423)            --             --            --
Loss for the period.......         --       --          --      --           --     (6,971,408)            --            --
Notes receivable from
 stockholders for the
 purchase of shares.......         --       --          --      --           --             --             --       (14,000)
Balance as of December 31,
 1996..................... 33,468,899   33,469     436,688     437   17,535,897    (17,965,252)            --       (14,000)
Issuances of Series C
 Preferred Stock..........  9,984,405    9,984          --      --    5,980,658             --             --            --
Issuances of Series D
 Preferred Stock..........  9,047,962    9,048          --      --    6,776,923             --             --            --
Issuances of Common
 Stock....................         --       --     656,494     656      251,198             --             --      (249,540)
Repurchase of Common
 Stock....................         --       --        (710)     (1)        (301)            --             --            --
Stock issuance costs......         --       --          --      --     (109,380)            --             --            --
Issuance of Common Stock
 and options at below
 market value.............         --       --          --      --    2,000,000             --     (2,000,000)           --
Amortization of deferred
 compensation.............         --       --          --      --           --             --         65,000            --
Loss for the period.......         --       --          --      --           --     (3,477,673)            --            --
Balance as of June 30,
 1997 (unaudited)......... 52,501,266  $52,501   1,092,472  $1,092  $32,434,995  $ (21,442,925) $  (1,935,000)   $ (263,540)
 
<CAPTION>
                                 NET
                            STOCKHOLDERS'
                               EQUITY
                              (DEFICIT)
<S>                        <C>
Balance at January 7,
 1993.....................   $         --
Issuances of Common
 Stock....................          1,850
Issuances of Series A
 Preferred Stock..........      2,000,000
Stock issuance costs......        (33,813)
Common Stock issued in
 exchange for exclusive
 license..................         41,000
Common Stock issued in
 exchange for consulting
 services.................          2,500
Loss for the period.......     (1,310,501)
Balance as of December 31,
 1993.....................        701,036
Issuances of Common
 Stock....................          5,063
Common Stock issued in
 exchange for consulting
 services.................          2,000
Loss for the period.......     (3,943,965)
Balance as of December 31,
 1994.....................     (3,235,866)
Issuances of Common
 Stock....................          7,910
Issuance of Series B
 Preferred Stock..........     10,317,782
Stock issuance costs......        (26,721)
Loss for the period.......     (5,739,378)
Balance as of December 31,
 1995.....................      1,323,727
Issuances of Common
 Stock....................         28,454
Common Stock issued in
 exchange for consulting
 services.................            200
Issuances of Series B
 Preferred Stock..........      3,250,000
Issuances of Series C
 Preferred Stock..........      2,000,001
Stock issuance costs......        (26,423)
Loss for the period.......     (6,971,408)
Notes receivable from
 stockholders for the
 purchase of shares.......        (14,000)
Balance as of December 31,
 1996.....................       (409,449)
Issuances of Series C
 Preferred Stock..........      5,990,642
Issuances of Series D
 Preferred Stock..........      6,785,971
Issuances of Common
 Stock....................          2,314
Repurchase of Common
 Stock....................           (302)
Stock issuance costs......       (109,380)
Issuance of Common Stock
 and options at below
 market value.............             --
Amortization of deferred
 compensation.............         65,000
Loss for the period.......     (3,477,673)
Balance as of June 30,
 1997 (unaudited).........   $  8,847,123
</TABLE>
 
                See accompanying notes to financial statements.
 
                                      F-5
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                            STATEMENTS OF CASH FLOWS
 
<TABLE>
<CAPTION>
                                                                                       CUMULATIVE
                                                                                     FROM INCEPTION
                                                                                       (JANUARY 7,     FOR THE SIX MONTHS ENDED
                                                                                          1993)
                                              FOR THE YEARS ENDED DECEMBER 31,       TO DECEMBER 31,           JUNE 30,
                                              1994          1995          1996            1996            1996          1997
<S>                                        <C>           <C>           <C>           <C>               <C>           <C>
                                                                                                              (UNAUDITED)
Cash flows from operating activities:
  Net Loss...............................  $(3,943,965)  $(5,739,378)  $(6,971,408)   $  (17,965,252)  $(3,133,582)  $(3,477,673)
  Adjustments to reconcile net loss to
    net cash used by operating
    activities:
    Depreciation and amortization of
      property, furniture and
      equipment..........................      356,009       543,796       690,419         1,631,486       324,270       300,109
    Other amortization...................        7,055         6,707         8,699            25,565         1,206        66,206
    Provision for equipment held for
      resale.............................       16,821            --            --            60,972            --            --
    Stock issued for consulting
      services...........................        2,000            --           200             4,700            --            --
    Stock issued to repay interest on
      notes to stockholders..............           --       194,521            --           194,521            --            --
    Debt issued for research and
      development........................           --            --       193,350           193,350            --            --
    Loss on disposal of property and
      equipment..........................       16,686            --            --            16,686            --            --
    Decrease (increase) in assets:
    Accounts receivable and loans to
      employees..........................       (8,223)        7,430       (34,944)          (35,737)       (7,449)       (9,021)
    Prepaid expenses.....................        2,680        (3,574)      (35,906)          (45,470)         (112)     (266,283)
    Other assets.........................         (719)      (16,260)          253           (68,651)        2,401       (12,091)
    Increase (decrease) in liabilities:
    Accounts payable.....................     (351,554)      (20,409)      136,829           254,845        45,605        82,328
    Accrued expenses.....................      137,275       270,778       183,401           673,292      (111,906)     (182,536)
    Net cash used by operating
      activities.........................   (3,765,935)   (4,756,389)   (5,829,107)      (15,059,693)   (2,879,567)   (3,498,961)
Cash flows from investing activities:
  Purchase of property and equipment.....      (57,608)      (97,467)      (26,529)         (430,469)     (234,032)     (101,809)
  Equipment held for resale..............       21,475            --         6,943          (115,001)        6,943            --
  Organizational costs...................           --            --            --            (8,217)           --            --
  Patent costs...........................      (20,474)     (213,454)     (116,454)         (414,608)      (76,418)      (32,330)
    Net cash used in investing
      activities.........................      (56,607)     (310,921)     (136,040)         (968,295)     (303,507)     (134,139)
Cash flows from financing activities:
  Proceeds from issuance of notes
    payable..............................    3,600,000     2,716,718        92,282         6,409,000        71,782         1,000
  Lease costs............................           --            --            --           (13,371)           --            --
  Proceeds from financing................      265,650            --            --                --            --            --
  Principal payments under capital lease
    obligations..........................     (281,067)     (432,958)     (576,973)       (1,297,589)      (62,659)     (256,342)
  Proceeds from issuance of Common
    Stock................................        5,063         7,910        14,454            29,277            --         2,314
  Proceeds from issuance of Preferred
    Stock................................           --     3,869,167     5,250,001        11,119,168     3,244,664    12,776,613
  Repurchase of Common Stock.............           --            --            --                --            --          (302)
  Stock issuance costs...................           --       (26,721)      (26,423)          (86,957)           --      (109,380)
    Net cash provided by financing
      activities.........................    3,589,646     6,134,116     4,753,341        16,159,528     3,253,787    12,413,903
    Net increase (decrease) in cash and
      cash equivalents...................     (232,896)    1,066,806    (1,211,806)          131,540        70,713     8,780,803
Cash and cash equivalents at beginning of
  period.................................      509,436       276,540     1,343,346                --     1,343,346       131,540
Cash and cash equivalents at end of
  period.................................  $   276,540   $ 1,343,346   $   131,540    $      131,540   $ 1,414,059   $ 8,912,343
Supplemental disclosure of cash flow
  information:
  Cash paid during the period for
    interest.............................  $   154,097   $   178,913   $   154,228    $      691,728   $    85,623   $    56,233
</TABLE>
 
Supplemental disclosures of noncash investing and financing activities are
described in Note 8.
 
                See accompanying notes to financial statements.
 
                                      F-6
 
<PAGE>
                                 TRIMERIS, INC.
 
                         (A DEVELOPMENT STAGE COMPANY)
 
                         NOTES TO FINANCIAL STATEMENTS
 
1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
  ORGANIZATION
 
     Trimeris, Inc. was incorporated on January 7, 1993 to discover and develop
novel therapeutic agents that block viral infection by inhibiting viral fusion
with host cells. The financial statements have been prepared in accordance with
Statement of Financial Accounting Standards No. 7, "Accounting and Reporting by
Development Stage Enterprises," to recognize the fact that the Company is
devoting substantially all of its efforts to establishing a new business and
planned principal operations have not commenced.
 
  CASH EQUIVALENTS
 
     The Company considers all highly liquid debt instruments with an original
maturity of three months or less to be cash equivalents.
 
  PROPERTY, FURNITURE AND EQUIPMENT
 
     Property, furniture and equipment are recorded at cost. Property, furniture
and equipment under capital leases are initially recorded at the present value
of minimum lease payments at the inception of the lease.
 
     Depreciation is calculated using the straight-line method over the
estimated useful lives of the assets. Property, furniture and equipment held
under capital leases and leasehold improvements are amortized using the straight
line method over the lesser of the lease term or estimated useful life of the
asset.
 
  ORGANIZATION COSTS
 
     Organization costs are amortized using the straight-line method over five
years.
 
  EXCLUSIVE LICENSE
 
     The exclusive license is amortized using the straight-line method over
seventeen years.
 
  PATENTS
 
     The costs of patents are capitalized and will be amortized using the
straight-line method over the remaining lives of the patents from the date the
patents are granted.
 
  RESEARCH AND DEVELOPMENT
 
     Research and development costs are charged to operations as incurred.
 
  DEFERRED FINANCING COSTS
 
     Financing costs were incurred as part of the Company's capital lease
agreements and are amortized straight-line over the lease term.
 
  INCOME TAXES
 
     The Company uses the asset and liability method of accounting for income
taxes.
 
  USE OF ESTIMATES
 
     The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect the reported amounts of assets and liabilities and
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the
reporting period. Actual results could differ from those estimates.
 
                                      F-7
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                   NOTES TO FINANCIAL STATEMENTS -- CONTINUED
 
1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES -- Continued
  PRO FORMA STOCKHOLDERS' EQUITY (UNAUDITED)
 
     Upon the completion of the Company's initial public offering (the
"Offering") of Common Stock (the "Common Stock"), all of the outstanding shares
of Series A, B, C, and D Preferred Stock (the "Preferred Stock") will convert
into 6,261,615 shares of Common Stock. The unaudited pro forma presentation of
stockholders' equity has been prepared giving effect to the conversion of all
the Preferred Stock into Common Stock on June 30, 1997, assuming that the
initial public offering price per share in connection with this Offering is
$13.00.
 
  PRO FORMA NET LOSS PER SHARE (UNAUDITED)
 
     The pro forma net loss per share is computed based upon the weighted
average number of common shares and common equivalent shares (using the treasury
stock method) outstanding after certain adjustments described below. Common
equivalent shares are not included in the per share calculations where the
effect of their inclusion would be anti-dilutive, except that, in accordance
with Securities and Exchange Commission Staff Accounting Bulletin No. 83, all
common and common equivalent shares issued during the twelve-month period prior
to the initial filing of the registration statement relating to the Offering,
even when anti-dilutive, have been included in the calculation as if they were
outstanding for all periods, using the treasury stock method and an assumed
initial public offering price of $13.00 per share. The pro forma net loss per
common share gives effect to the mandatory conversion of all outstanding shares
of Preferred Stock into 6,261,615 shares of Common Stock upon the completion of
this Offering.
 
  HISTORICAL NET LOSS PER COMMON SHARE
 
     Net loss per common share on a historical basis is computed in the same
manner as pro forma net loss per common share, except that Series A, B, C and D
Preferred Stock are not assumed to be converted. Net loss per common share on a
historical basis is as follows:
 
<TABLE>
<CAPTION>
                                                                                                 SIX MONTHS
                                                     YEAR ENDED DECEMBER 31,                   ENDED JUNE 30,
                                               1994           1995           1996           1996           1997
<S>                                         <C>            <C>            <C>            <C>            <C>
                                                                                                (UNAUDITED)
Net loss to common stockholders..........   $(3,943,965)   $(5,739,378)   $(6,971,408)   $(3,133,582)   $(3,477,673)
Net loss per common share................   $     (3.57)   $     (5.06)   $     (6.04)   $     (2.77)   $     (2.96)
Weighted average number of common and
  common equivalent shares outstanding...     1,105,000      1,134,000      1,154,000      1,133,000      1,173,000
</TABLE>
 
     Fully diluted net loss per common share is the same as primary net loss per
common share.
 
  STOCK SPLIT
 
     Effective July 11, 1997, the Company declared a one for eight and one-half
reverse stock split for common shareholders. This stock split has been
retroactively applied and all periods presented have been restated. The
conversion prices for the Preferred Stock discussed in Note 4 will be adjusted
for this reverse stock split.
 
                                      F-8
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                   NOTES TO FINANCIAL STATEMENTS -- CONTINUED
 
2. LEASES
 
     The Company is obligated under various capital leases for furniture and
equipment that expire at various dates during the next four years. The gross
amount of furniture and equipment and related accumulated amortization recorded
under capital leases and included in property, furniture and equipment were as
follows at December 31, 1995, 1996 and June 30, 1997 (unaudited):
 
<TABLE>
<CAPTION>
                                                                                 JUNE 30,
                                                      1995          1996           1997
<S>                                                <C>           <C>            <C>
                                                                                (UNAUDITED)
Furniture and equipment.........................   $1,790,110    $ 1,930,423    $ 1,980,665
Less accumulated amortization...................     (780,082)    (1,084,160)    (1,347,996)
                                                   $1,010,028    $   846,263    $   632,669
</TABLE>
 
     The Company also has several non-cancelable operating leases, primarily for
office space and office equipment, that extend through September 1999. Rental
expense, including maintenance charges, for operating leases during 1994, 1995,
1996 and the six months ended June 30, 1996 (unaudited) and 1997 (unaudited) was
$454,307, $532,146, $552,001, $254,717 and $300,018 respectively.
 
     Future minimum lease payments under non-cancelable operating leases (with
initial or remaining lease terms in excess of one year) and future minimum
capital lease payments as of December 31, 1996 are:
 
<TABLE>
<CAPTION>
                                                                    CAPITAL     OPERATING
                                                                     LEASES       LEASES
<S>                                                                 <C>         <C>
Year ending December 31:
  1997...........................................................   $552,675    $  514,774
  1998...........................................................    274,991       520,721
  1999...........................................................    114,871       419,255
  2000...........................................................      7,117            --
  Total minimum lease payments...................................    949,654    $1,454,750
  Less amount representing interest..............................    132,869
  Present value of net minimum capital lease payments............    816,785
Less current installments of obligations under capital leases....    500,248
  Obligations under capital leases, excluding current
     installments................................................   $316,537
</TABLE>
 
     Additionally, under a warrant agreement dated August 24, 1993 with a
lessor, the Company issued warrants to acquire Series B Preferred Stock at the
initial Series B Preferred Stock per share offering price, such that the
aggregate purchase price for the shares equals $118,756. The warrants shall be
exercisable prior to the earlier of the tenth annual anniversary date of the
grant date or fifth anniversary date of Trimeris' Initial Public Offering. The
shares have not been issued as of December 31, 1996.
 
     During the year ended December 31, 1995, the lease with the aforementioned
lessor was amended to increase the credit limit by $750,000 to $2.0 million. As
part of this amendment, Trimeris granted the lessor additional warrants to
purchase shares valued at $71,250 of Series B Preferred Stock at the initial per
share offering price.
 
3. NOTES PAYABLE
 
     In March 1995, the Company entered into a Financial Assistance Agreement
with the North Carolina Biotechnology Center (the "Center"). Under this
agreement, the Center agreed to extend to the Company a line of credit up
 
                                      F-9
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                   NOTES TO FINANCIAL STATEMENTS -- CONTINUED
 
3. NOTES PAYABLE -- Continued
to $250,000 for the funding of certain research performed by the Company. This
note payable is unsecured and bears interest at 8.5% on the balance of all
outstanding principal. The note matures in March 2000, at which time principal
and accrued interest is to be repaid. At December 31, 1995, 1996 and June 30,
1997 (unaudited), the total principal and interest due were $162,218, $262,600
and $284,000, respectively.
 
     In November 1995, the Company entered into a Collaborative Funding
Assistance Agreement with the Center. Under this agreement, the Center agreed to
lend the Company up to $10,000 for the funding of certain research performed by
the Company. This note payable is unsecured and bears interest at 8.75% on the
balance of all outstanding principal. The note matures in December 2000, at
which time principal and accrued interest is to be repaid. At December 31, 1995,
1996 and June 30, 1997 (unaudited), the total principal due was $4,500, $9,000
and $10,000, respectively.
 
4. STOCKHOLDERS' EQUITY (DEFICIT)
 
     The Company has the authority to issue 121,750,000 shares of stock
consisting of 69,750,000 shares of Common Stock, par value $0.001 per share, and
52,000,000 shares of Preferred Stock, par value $0.001 per share, of which
3,000,000 shares shall be designated Series A Preferred Stock, 29,000,000 shares
shall be designated Series B Preferred Stock, and 20,000,000 shares shall be
designated Series C Preferred Stock.
 
     During 1996 and the six months ended June 30, 1997 (unaudited), loans with
an interest rate of 8% totaling $14,000 and $249,540, respectively, were issued
to employees of the Company for purchase of shares of the Company's Common
Stock. This amount has been presented as contra-equity in the statement of
stockholders' equity (deficit).
 
PREFERRED STOCK
 
  DIVIDENDS
 
     Holders of the Preferred Stock are not entitled to receive dividends,
provided however, that in the event the Company shall at any time declare or pay
a dividend on the Common Stock, other than a stock dividend, each holder of
Preferred Stock shall receive a dividend equal to the dividend that would have
been payable to such holder if the Preferred Stock had been converted into
Common Stock on the date of record for holders of the Common Stock.
 
     In the event of a merger or consolidation, holders of Preferred Stock will
have the right to redeem the shares within 15 days of receipt of such notice.
Any redeemed shares will be considered permanently retired.
 
  LIQUIDATION
 
     Upon any liquidation, dissolution, or winding up of the Company, holders of
the Preferred Stock shall be entitled, before any distribution is made upon the
Common Stock, to be paid for each share in cash an amount equal to (i) $0.67 per
share in the case of the Series A Preferred Stock, (ii) $0.50 per share in the
case of the Series B Preferred Stock or (iii) $0.60 per share in the case of
Series C Preferred Stock in addition to other considerations. If the assets to
be distributed are insufficient to permit full payment to the preferred
stockholders, then the assets of the Company shall be distributed on a pro rata
basis to each class of preferred stockholders. The value of any noncash
distribution shall be determined by an independent appraiser or securities
exchange if the item is an actively traded security.
 
                                      F-10
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                   NOTES TO FINANCIAL STATEMENTS -- CONTINUED
 
4. STOCKHOLDERS' EQUITY (DEFICIT) -- Continued
  CONVERSION
 
     Holders of Preferred Stock have the right, at any time, to convert into
such number of shares of common stock as is obtained by multiplying the number
of shares to be converted by the preferred stock's "Basic Liquidation
Preference" ($0.67 for Series A Preferred Stock, $0.50 for Series B Preferred
Stock $0.60 for Series C Preferred Stock and $0.75 for Series D Preferred Stock)
and dividing such amount by the Preferred Stock's conversion price in effect at
the time of conversion.
 
     The respective preferred stock conversion prices are as follows as of
December 31:
 
<TABLE>
<CAPTION>
                                          1994      1995      1996
<S>                                      <C>       <C>       <C>
Series A..............................   $0.670    $0.534    $0.524
Series B..............................       --     0.500     0.500
Series C..............................       --        --     0.600
</TABLE>
 
     The Preferred Stock conversion price will be reduced in the event of the
Company's issuing any shares of its Common Stock without consideration or for a
consideration per share of less than the conversion price of any series of
Preferred Stock in effect immediately prior to the time of such issue or sale,
subject to certain limitations.
 
     The Company shall at times reserve and keep available out of its authorized
Common Stock or treasury shares, such number of common shares sufficient to
cover the conversion of all outstanding Preferred Stock.
 
     The Company may at its option, require the conversion of all (but not less
than all) the shares at the time outstanding if the Company shall complete a
firm commitment underwritten public offering involving the sale of the Company's
Common Stock (i) at a price to the public of at least $10 per share
appropriately adjusted for stock splits and dividends and stock combinations,
and (ii) yielding gross proceeds to the Company of at least $20 million.
 
  VOTING
 
     Each holder of Preferred Stock shall be entitled to one vote for each share
of Common Stock which would be issuable to holder upon conversion. Each holder
of Common Stock is entitled to one vote per share. Preferred and common
stockholders shall vote together as a class.
 
  RESTRICTIONS
 
     The Company cannot, without the consent of the preferred stockholders: (i)
authorize any new classes of stock unless that class ranks junior to the
Preferred Stock, (ii) increase the authorized amount of Preferred Stock, or
(iii) authorize any obligation or security which is convertible into Preferred
Stock.
 
COMMON STOCK
 
  DIVIDENDS
 
     The holders of Common Stock shall be entitled to receive dividends as from
time to time may be declared by the Board of Directors taking into account the
rights of the preferred stockholders.
 
  LIQUIDATION
 
     After payment to the preferred stockholders as discussed above, holders of
Common Stock shall be entitled, together with the holders of Preferred Stock, to
share ratably, according to the number of shares held by them in all remaining
assets of the Company available for distribution.
 
                                      F-11
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                   NOTES TO FINANCIAL STATEMENTS -- CONTINUED
 
5. STOCK OPTION PLAN
 
     In 1993, the Company adopted a stock option plan which allows for the
issuance of non-qualified and incentive stock options. During 1996, the
Trimeris, Inc. New Stock Option Plan (the "Stock Option Plan") was implemented
that replaced the 1993 plan. Under this new Stock Option Plan, the Company may
grant non-qualified or incentive stock options for up to 852,941 shares of
Common Stock. The exercise price of each option shall not be less than the fair
market value of the Company's Common Stock on the date of grant and an option's
maximum term is ten years. All outstanding incentive stock options have been
issued at $.34. The vesting period occurs ratably over four years. All incentive
stock options which had been granted under the 1993 plan were cancelled at
inception of the new Stock Option Plan while the non-qualified stock options
remain outstanding at an exercise price of $.43. No more grants will be made
under the 1993 plan.
 
     Stock option transactions for the years ended December 31, 1994, 1995 and
1996 and the six months ended June 30, 1997 (unaudited) are as follows:
 
<TABLE>
<CAPTION>
                                                                                                          JUNE 30,
                                                                   1994         1995          1996          1997
<S>                                                              <C>          <C>          <C>           <C>
                                                                                                         (UNAUDITED)
Options outstanding at January 1..............................      27,276      141,411       166,191       482,804
Granted.......................................................     114,341       37,753       572,206       100,782
Exercised (at $.43/share).....................................        (147)      (4,755)      (28,394)     (319,540)
Cancelled.....................................................         (59)      (8,218)     (227,199)       (3,685)
Options outstanding at end of period..........................     141,411      166,191       482,804       260,361
</TABLE>
 
     The Company applies APB Opinion No. 25 and related interpretations in
accounting for its plans. Accordingly, compensation cost related to stock
options issued to employees would be recorded on the date of grant only if the
current market price of the underlying stock exceeded the exercise price. For
the period ended June 30, the Company has recorded a deferred charge of $2.0
million, representing the difference between the exercise price and the deemed
fair value of the Company's Common Stock for 347,529 shares of Common Stock and
79,959 shares subject to Common Stock Options granted in the second quarter of
1997. The deferred compensation will be amortized to expense over the period the
shares and options vest, generally four years.
 
     SFAS 123, Accounting for Stock-Based Compensation, permits entities to
recognize as expense over the vesting period the fair value of all stock-based
awards on the date of grant. Alternatively, SFAS No. 123 also allows entities to
continue to apply the provisions of APB Opinion No. 25 and provide pro forma net
income and pro forma earnings per share disclosures for employee stock option
grants as if the fair-value-based method defined in SFAS No. 123 had been
applied. The Company has elected to continue to apply the provisions of APB
Opinion No. 25. The pro forma disclosures have not been included as the fair
value of the options granted in 1996 and 1995 are immaterial. The fair value of
each option grant is estimated on the date of grant using the Black-Scholes
option pricing model with the following assumptions:
 
<TABLE>
<S>                                                                 <C>
Estimated dividend yield.........................................             0.00%
Expected stock price volatility..................................             0.00%
Risk-free interest rate..........................................        5.07-6.00%
Expected life of options.........................................         5-7 years
</TABLE>
 
6. INCOME TAXES
 
     At December 31, 1996, the Company has net operating loss carryforwards
(NOL's) for federal income tax purposes of approximately $17.4 million which
expire in varying amounts between 2009 and 2012. The Company
 
                                      F-12
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                   NOTES TO FINANCIAL STATEMENTS -- CONTINUED
 
6. INCOME TAXES -- Continued
has NOL's for state tax purposes of approximately $17.4 million which expire in
varying amounts between 1999 and 2002. Additionally, the Company has research
and development credits of $261,000 which expire in varying amounts between 2008
and 2011.
 
     The Tax Reform Act of 1986 contains provisions which limit the ability to
utilize net operating loss carryforwards in the case of certain events including
significant changes in ownership interests. If the Company's NOL's are limited,
and the Company has taxable income which exceeds the permissible yearly NOL, the
Company would incur a federal income tax liability even though NOL's would be
available in future years.
 
     The components of deferred tax assets and deferred tax liabilities as of
December 31, 1995 and 1996 and June 30, 1997 (unaudited) are as follows:
 
<TABLE>
<CAPTION>
                                                                                                         JUNE 30,
                                                                             1995           1996           1997
<S>                                                                       <C>            <C>            <C>
                                                                                                        (UNAUDITED)
Deferred tax assets:
  Tax loss carryforwards...............................................   $ 4,100,000    $ 6,823,000    $ 8,165,000
  Tax credits..........................................................       158,000        261,000        297,000
  Reserves and accruals................................................        76,000        211,000         56,000
  Start-up costs.......................................................       114,000        109,000         57,000
                                                                            4,448,000      7,404,000      8,575,000
Valuation allowance....................................................    (4,448,000)    (7,404,000)    (8,575,000)
  Net deferred asset...................................................            --             --             --
 
Deferred tax liabilities:
  Deferred tax liability...............................................            --             --             --
     Net deferred tax assets and (liability)...........................   $        --    $        --    $        --
</TABLE>
 
     The Company has established a valuation allowance against its deferred tax
assets due to the uncertainty surrounding the realization of such assets.
 
7. PROFIT SHARING PLAN
 
     The Company has adopted a 401(k) Profit Sharing Plan (the "Plan") covering
all qualified employees. The effective date of the Plan is January 1, 1994.
 
     Participants may elect a salary reduction from 1% to 10% as a contribution
to the Plan. Modifications of the salary reductions may be made annually. The
Plan permits the Company to match up to 8% of a participant's salary, but to
date, the Company has elected not to match participants' contributions.
 
     The normal retirement age shall be the later of a participant's 65th
birthday or the fifth anniversary of the first day of the Plan year in which
participation commenced. The Plan does not have an early retirement provision.
 
8. SUPPLEMENTARY CASH FLOW INFORMATION
 
     Capital lease obligations of $345,104, $330,168 and $195,179 were incurred
in 1995 and 1996 and for the six months ended June 30, 1997 (unaudited),
respectively, for leases of new furniture and equipment.
 
     During 1995, the Company exchanged notes payable to stockholders, including
accrued interest of $6.4 million for Series B Preferred Stock.
 
                                      F-13
 
<PAGE>
                                 TRIMERIS, INC.
                         (A DEVELOPMENT STAGE COMPANY)
 
                   NOTES TO FINANCIAL STATEMENTS -- CONTINUED
 
8. SUPPLEMENTARY CASH FLOW INFORMATION -- Continued
     Shares issued under the license and consulting agreements have been valued
by the Board of Directors taking into consideration the fair value of the most
recently issued preferred stock or the value of the services, whichever is more
readily determinable.
 
9. EQUITY FINANCING
 
     An initial investment of $2 million was provided by Domain Partners II,
L.P. ("Domain") and Biotechnology Investments Limited ("BIL") to fund the start
up phase of the Company.
 
     During the year ended December 31, 1995, Domain, BIL and others invested an
additional $3.9 million to fund continued operations of the Company through the
purchase of shares of Series B Preferred Stock. In addition, the Company
exchanged notes payable, including accrued interest, of $6.4 million for shares
of Series B Preferred Stock. These notes were payable to Domain and BIL and were
entered into during the years ended December 31, 1994 and 1995. A total of
20,635,564 shares were issued for a total consideration of $10.3 million.
 
     In March and October 1996, Domain, BIL, and others invested an additional
$5.3 million to fund continued operations of the Company through the purchase of
6,500,000 shares of Series B Preferred Stock and 3,333,335 shares of Series C
Preferred Stock, respectively.
 
     Common stock was issued during 1994, 1995, and 1996 through purchase by
Company personnel and also through the exercise of stock options.
 
10. CONTINGENCIES
 
     The Company is involved in certain claims and legal actions arising in the
ordinary course of business. In the opinion of management, the ultimate
disposition of these matters will not have a material adverse effect on the
financial position or results of operations of the Company.
 
11. SUBSEQUENT EVENTS
 
     (a) During the six months ended June 30, 1997 equity financing of
         approximately $12.8 million has been received from current and new
         investors.
 
     (b) The Company's Certificate of Incorporation was amended on July 11,
         1997, giving the Company the authority to issue 142,666,667 shares of
         stock consisting of 80,000,000 shares of Common Stock, par value $.001
         per share, and 62,666,667 shares of Preferred Stock, par value $0.001
         per share, of which 3,000,000 shares shall be designated Series A
         Preferred Stock, 29,000,000 shares shall be designated Series B
         Preferred Stock, 20,000,000 shares shall be designated Series C
         Preferred Stock, and 10,666,667 shares shall be designated Series D
         Preferred Stock.
 
     (c) During 1997, the Company entered into agreements for the production of
         drug material which require maximum payments of approximately $2.3
         million, subject to acceptance of the material under the terms of the
         contracts.
 
     (d) On August 26, 1997, the Board of Directors adopted, and the
         stockholders of the Company approved, the Trimeris, Inc. 1997 Employee
         Stock Purchase Plan, subject to and contingent upon the consummation of
         the Offering.
 
                                      F-14
 
<PAGE>
 
     NO DEALER, SALESPERSON OR ANY OTHER PERSON HAS BEEN AUTHORIZED TO GIVE ANY
INFORMATION OR MAKE ANY REPRESENTATION NOT CONTAINED IN THIS PROSPECTUS IN
CONNECTION WITH THE OFFER MADE BY THIS PROSPECTUS AND, IF GIVEN OR MADE, SUCH
INFORMATION OR REPRESENTATION MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED
BY THE COMPANY OR THE UNDERWRITERS. THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER
TO SELL OR A SOLICITATION OF AN OFFER TO BUY ANY OF THE SECURITIES OFFERED
HEREBY BY ANYONE IN ANY JURISDICTION IN WHICH SUCH OFFER OR SOLICITATION IS NOT
AUTHORIZED OR IN WHICH THE PERSON MAKING SUCH OFFER OR SOLICITATION IS NOT
QUALIFIED TO DO SO OR TO ANYONE TO WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER OR
SOLICITATION. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY SALE MADE
HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE ANY IMPLICATION THAT THE
INFORMATION HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO THE DATE OF THIS
PROSPECTUS OR THAT THERE HAS BEEN NO CHANGE IN THE AFFAIRS OF THE COMPANY SINCE
SUCH DATE.
 
                               TABLE OF CONTENTS
 
   
<TABLE>
<CAPTION>
                                                    Page
<S>                                                 <C>
Prospectus Summary...............................     3
Risk Factors.....................................     6
Use of Proceeds..................................    19
Dividend Policy..................................    19
Capitalization...................................    20
Dilution.........................................    21
Selected Financial Data..........................    22
Management's Discussion and Analysis of Financial
  Condition and Results of Operations............    23
Business.........................................    26
Management.......................................    45
Certain Transactions.............................    54
Principal Stockholders...........................    56
Description of Capital Stock.....................    58
Shares Eligible for Future Sale..................    60
Underwriting.....................................    62
Legal Matters....................................    64
Experts..........................................    64
Additional Information...........................    64
Index to Financial Statements....................   F-1
</TABLE>
    
 
    UNTIL         , 1997 (25 DAYS AFTER THE DATE OF THIS PROSPECTUS), ALL
DEALERS EFFECTING TRANSACTIONS IN THE REGISTERED SECURITIES, WHETHER OR NOT
PARTICIPATING IN THIS DISTRIBUTION, MAY BE REQUIRED TO DELIVER A PROSPECTUS.
THIS IS IN ADDITION TO THE OBLIGATION OF DEALERS TO DELIVER A PROSPECTUS WHEN
ACTING AS UNDERWRITERS AND WITH RESPECT TO THEIR UNSOLD ALLOTMENTS OR
SUBSCRIPTIONS.
 
                                2,500,000 Shares
 
                                 Trimeris, Inc.
 
                                  Common Stock
 
                                   PROSPECTUS
                                         , 1997
 
                                 UBS Securities
 
                             Montgomery Securities
 
<PAGE>
                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 13. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION

     The following table sets forth the expenses to be paid by Trimeris, Inc.
(the "Registrant" or the "Company") in connection with the issuance and
distribution of the securities being registered hereby other than underwriting
discounts and commissions.
 
<TABLE>
<S>                                                                                                        <C>
Registration Fee -- Securities and Exchange Commission..................................................   $ 12,197
Filing Fee -- National Association of Securities Dealers, Inc...........................................      4,525
Filing and Listing Fee -- Nasdaq National Market........................................................     42,177
Transfer Agent's Fee and Expenses*......................................................................      5,000
Legal Fees and Expenses*................................................................................    325,000
Printing and Engraving Expenses*........................................................................    175,000
Accounting Fees and Expenses*...........................................................................    150,000
Blue Sky Fees and Expenses (including legal fees)*......................................................     15,000
Miscellaneous*..........................................................................................     71,101
       Total............................................................................................   $800,000
</TABLE>
 
* Estimated
 
ITEM 14. INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
     Section 145 of the Delaware General Corporation Law (the "DGCL") permits
indemnification of officers and directors of the Company under certain
conditions and subject to certain limitations. Section 145 of the DGCL also
provides that a corporation has the power to purchase and maintain insurance on
behalf of its officers and directors against any liability asserted against such
person and incurred by him and her in such capacity, or arising out of his or
her status as such, whether or not the corporation would have the power to
indemnify him or her against such liability under the provisions of Section 145
of the DGCL.
 
     The Company's Third Amended and Restated Certificate of Incorporation to be
filed upon the completion of this Offering contains certain provisions permitted
under DGCL relating to the liability of directors. These provisions eliminate a
director's personal liability for monetary damages resulting from a breach of
fiduciary duty, except in certain circumstances involving certain wrongful acts,
such as (i) for any breach of the director's duty of loyalty to the Company or
its stockholders, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the DGCL, (iv) for any transaction from which the director derives an improper
personal benefit or (v) acts or omissions occurring prior to the date of these
provisions. These provisions do not limit or eliminate the rights of the Company
or any stockholder to seek equitable relief, such as an injunction or
rescission, in the event of a breach of director's fiduciary duty. These
provisions will not alter a director's liability under federal securities laws.
The Company's Third Amended and Restated Certificate of Incorporation also
contains provisions indemnifying the directors and officers of the Company to
the fullest extent permitted by DGCL.
 
     The Amended and Restated Bylaws of the Company to be effective upon the
completion of this Offering provide that the Company shall indemnify its
directors and executive officers to the fullest extent permitted by the DGCL.
The rights to indemnity thereunder continue as to a person who has ceased to be
a director, officer, employee or agent and inure to the benefit of the heirs,
executors and administrators of the person. In addition, expenses incurred by a
director or officer in defending any civil, criminal, administrative or
investigative action, suit or proceeding by reason of the fact that he or she is
or was a director or officer of the Company (or was serving at the Company's
request as a director or officer of another corporation) shall be paid by the
Company in advance of the final disposition of such action, suit or proceeding
upon receipt of an undertaking by or on behalf of such director or officer to
repay such amount if it shall ultimately be determined that he or she is not
entitled to be indemnified by the Company as authorized by the relevant section
of the DGCL.
 
                                      II-1
 
<PAGE>
     The Company intends to enter into indemnification agreements with each of
its directors and executive officers prior to the completion of the Offering.
Generally, the indemnification agreements will provide the maximum protection
available under the Third Amended and Restated Certificate of Incorporation, the
Amended and Restated Bylaws and the DGCL as it may be amended from time to time.
Under such indemnification agreements, however, an individual will not receive
indemnification for judgments, settlements or expenses if he or she is found
liable to the Company (except to the extent the court determines he or she is
fairly and reasonably entitled to indemnity for expenses), for settlements not
approved by the Company or for settlements and expenses if the settlement is not
approved by the court. The indemnification agreements provide for the Company to
advance to the individual any and all expenses (including attorneys' fees)
incurred in investigating or defending any such action, suit or proceeding.
Also, the individual must repay such advances upon a final judicial decision
that he or she is not entitled to indemnification.
 
     The Underwriting Agreement (to be filed as Exhibit 1.1 to this Registration
Statement) contains provisions by which the Underwriters have agreed, severally
and not jointly, to indemnify and hold harmless the Company, each person, if
any, who controls the Company, within the meaning of Section 15 of the
Securities Act, each director of the Company, and each officer of the Company
who signs this Registration Statement, from and against any liability caused by
any information furnished in writing by the Underwriters for use in the
Registration Statement.
 
ITEM 15. RECENT SALES OF UNREGISTERED SECURITIES
 
     Except as hereinafter set forth, there have been no securities sold by the
Registrant within the last three years which were not registered under the
Securities Act of 1933, as amended (the "Securities Act"). Amounts in this Item
15 have been adjusted to reflect the 1-for-8.5 reverse stock split of the
Registrant effected on July 11, 1997.
 
     (a) Issuances of Securities
 
          On July 1, 1997, the Registrant issued 10,589 shares of Common Stock
     to a key employee of the Registrant at a purchase price of $.43 per share.
 
          On June 27, 1997, the Registrant issued 9,047,962 shares of Series D
     Preferred Stock to certain existing stockholders and new investors at a
     purchase price of $.75 per share.
 
          On June 11, 1997, the Registrant issued an aggregate of 117,648 shares
     of Common Stock to certain executive officers and key employees of the
     Registrant at a purchase price of $.43 per share payable pursuant to the
     terms of certain promissory notes.
 
          On June 2, 1997, the Registrant issued an aggregate of 219,295 shares
     of Common Stock to certain executive officers and key employees of the
     Registrant at a purchase price of $.43 per share payable pursuant to the
     terms of certain promissory notes.
 
          In a series of closings held on October 7, 1996, January 16, 1997,
     March 27, 1997 and April 29, 1997, the Registrant issued an aggregate of
     13,317,739 shares of Series C Preferred Stock to certain existing
     stockholders and new investors at a purchase price of $.60 per share.
 
          On October 31, 1996, the Registrant issued an aggregate of 41,177
     shares of Common Stock to certain executive officers and key employees of
     the Registrant at a purchase price of $.34 per share payable pursuant to
     the terms of certain promissory notes.

          On June 25, 1996, the Registrant issued an aggregate of 14,118 shares
     of Common Stock to a former executive officer of the Registrant at a
     purchase price of $.34 per share.
 
          On January 26, 1996, the Registrant issued an aggregate of 589 shares
     of Common Stock to consultants of the Registrant at a purchase price of
     $.43 per share.
 
          On July 31, 1995, the Registrant issued a warrant to purchase up to an
     aggregate of 100,000 shares of Series B Preferred Stock (which warrant has
     been amended to provide for the purchase shares of Common Stock upon the
     completion of this Offering) at an exercise price of $0.50 per share to
     North Carolina Biotechnology Center.
 
                                      II-2
 
<PAGE>
          In a series of closings held on July 17, 1995, August 16, 1995, and
     March 22, 1996, the Registrant issued an aggregate of 27,135,564 shares of
     Series B Preferred Stock to existing stockholders and new investors at a
     purchase price of $.50 per share.

          On March 1, 1995, the Registrant issued an aggregate of 17,648 shares
     of Common Stock to certain executive officers and key employees of the
     Registrant at a purchase price of $.43 per share.
 
          On February 21, 1995, the Registrant issued 5,883 shares of Common
     Stock to an executive officer of the Registrant at a purchase price of $.43
     per share.
 
          On September 16, 1994, the Registrant sold 11,765 shares of Common
     Stock to a former executive officer at a purchase price of $.43 per share.
 
          In a series of transactions on August 24, 1993, October 26, 1994 and
     February 7, 1995, the Registrant issued warrants to purchase an aggregate
     of 381,808 shares of Series B Preferred Stock (which warrant has been
     amended to provide for the purchase of shares of Common Stock upon the
     completion of this Offering) at an exercise price of $.50 per share to its
     venture leasing partner in consideration for certain leasing arrangements.
 
   
          Since June 1994, the Registrant has issued options to certain
     employees, directors, consultants and others to purchase an aggregate of
     706,782 shares of Common Stock at a weighted average exercise price of $.44
     per share. 356,634 of such options have been exercised, 271,562 of such
     options remain outstanding at a weighted average exercise price of $.39 per
     share and 77,586 of such options have been terminated.
    
 
     (b) No underwriters were involved in connection with the sales of
securities referred to in paragraph (a) of this Item 15.
 
     (c) The shares of Series B, Series C and Series D Preferred Stock described
in paragraph (a) of this Item 15 were issued in reliance on the exemption
provided by Rule 506 of Regulation D promulgated pursuant to the Securities Act,
as well as Section 4(2) of the Securities Act. The issuances of compensatory
stock awards, stock options and the shares of Common Stock upon the exercise
thereof as described in paragraph (a) of this Item 15 were issued in reliance
upon the exemption provided by Section 3(b) of the Securities Act and Rule 701
promulgated thereunder, as well as Section 4(2) of the Securities Act. The
warrants described in paragraph (a) of this Item 15 were issued upon reliance on
exemption provided by Section 4(2) of the Securities Act. Appropriate legends
are affixed to the stock certificates and warrant certificates issued in the
aforementioned transactions.
 
ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

(a) Exhibits

   
<TABLE>
<C>       <S>
   1.1 *  Form of Underwriting Agreement.
   3.1 ** Second Restated Certificate of Incorporation of the Registrant.
   3.2    Form of Third Amended and Restated Certificate of Incorporation of the Registrant (to be filed
          with the Secretary of State of Delaware upon the completion of the Offering).
   3.3    Bylaws of the Registrant.
   3.4    Form of Amended and Restated Bylaws of the Registrant (to be adopted upon the completion of the
          Offering).
   4.1 ** Specimen certificate for shares of Common Stock.
   4.2    Description of Capital Stock (contained in the Third Amended and Restated Certificate of
          Incorporation of the Corporation of the Registrant, filed as Exhibit 3.2).
   5.1    Opinion of Hutchison & Mason PLLC with respect to the legality of the shares being registered.
  10.1    License Agreement dated February 3, 1993, between the Registrant and Duke University.
  10.2    Sublease Agreement dated November 19, 1993, by and among the Registrant, Sphinx Pharmaceuticals
          Corporation and University Place Associates and as amended by the Lease Amendment dated August
          15, 1994, and Second Agreement of Sublease dated January 16, 1995.
  10.3    Cooperation and Strategic Alliance Agreement dated April 21, 1997, between the Registrant and
          MiniMed Inc.
  10.4 *  Trimeris, Inc. New Stock Option Plan.
  10.5 ** Trimeris, Inc. Employee Stock Purchase Plan.
</TABLE>
    

                                      II-3

<PAGE>
   
<TABLE>
<C>       <S>
  10.6    Form of Promissory Notes executed by certain executive officers in favor of the Registrant, and
          related collateral documents.
  10.7    Form of Stock Restriction Agreements between the Registrant and certain executive officers.
  10.8    Form of Stock Pledge Agreement between the Registrant and certain executive officers.
  10.9    Employment Offer Letter with M. Ross Johnson dated December 15, 1994.
  10.10   Employment Offer Letter with Matthew A. Megaro dated February 23, 1995.
  10.11   Sixth Amended and Restated Registration Rights Agreement dated June 27, 1997, by and among the
          Registrant and certain stockholders of the Registrant.
  10.12   Agreement with Max N. Wallace dated July 10, 1997.
  10.13** Form of Indemnification Agreements.
  11.1    Computation of Net Income (Loss) Per Share.
  23.1    Consent of Hutchison & Mason PLLC (included in Exhibit 5.1).
  23.2 ** Consent of KPMG Peat Marwick, LLP, Independent Auditors.
  23.3 ** Consent of Pennie & Edmonds.
  24.1    Power of Attorney (included in signature page to Registration Statement).
  27      Financial Data Schedule.
</TABLE>
    

 * To be filed by amendment

** Filed herewith.

(b) Financial Statement Schedules.

All financial statement schedules have been omitted because either they are not
required, are not applicable, or the information is otherwise set forth in the
Financial Statements and Notes thereto.
 
ITEM 17. UNDERTAKINGS
 
     The undersigned Registrant hereby undertakes to provide to the Underwriters
at the closing or closings specified in the Underwriting Agreement, certificates
in such denominations and registered in such names as required by the
Underwriters to permit promt delivery to each purchaser.
 
     The undersigned Registrant hereby further undertakes that:
 
          (1) For purposes of determining any liability under the Securities Act
     of 1933, the information omitted from the form of prospectus filed as part
     of this registration statement in reliance upon Rule 430A and contained in
     a form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or
     (4) or 497(b) under the Securities Act shall be deemed to be part of this
     registration statement as of the time it was declared effective.
 
          (2) For the purpose of determining any liability under the Securities
     Act of 1933, each post-effective amendment that contains a form of
     prospectus shall be deemed to be a new registration statement relating to
     the securities offered therein, and the offering of such securities at that
     time shall be deemed to be the initial BONA FIDE offering thereof.
 
     Insofar as indemnification for liabilities arising under the Securities Act
of 1933, as amended, may be permitted to directors, officers and controlling
persons of the Registrant pursuant to the foregoing provisions, or otherwise,
the Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Securities Act of 1933, as amended, and is, therefore, unenforceable. In
the event that a claim for indemnification against such liabilities (other than
the payment by the Registrant of expenses incurred or paid by a director,
officer or controlling person of the Registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered, the Registrant will,
unless in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933, as amended, and will be governed by the final
adjudication of such issue.
 
                                      II-4
 
<PAGE>
                                   SIGNATURES
 
   
     Pursuant to the requirements of the Securities Act of 1933, as amended, the
Registrant has duly caused this Registration Statement to be signed on its
behalf by the undersigned, thereunto duly authorized, in the City of Durham,
County of Durham, State of North Carolina, on this 5th day of September, 1997.
    
 
                                            TRIMERIS, INC.
 
                                            By: /s/      M. ROSS JOHNSON
 
                                                       M. ROSS JOHNSON,
                                              PRESIDENT, CHIEF EXECUTIVE OFFICER
                                                 AND CHIEF SCIENTIFIC OFFICER
 
   
WITNESS our hands on this 5th day of September, 1997.
    
 
<TABLE>
<S>                                       <C>                             <C>
/s/           JESSE I. TREU*                                              /s/       ANDREW MCCREATH*
Jesse I. Treu, Ph.D.                                                      Andrew McCreath
Chairman of the Board of Directors                                        Director

/s/        DANI P. BOLOGNESI*                                             /s/       MATTHEW A. MEGARO
Dani P. Bolognesi, Ph.D.                                                  Matthew A. Megaro
Director                                                                  Chief Operating Officer, Chief Financial
                                                                          Officer, Executive Vice President and
                                                                          Secretary (Principal Accounting and
                                                                          Financial Officer)
 
/s/         BRIAN H. DOVEY*                                               /s/      CHARLES A. SANDERS*
Brian H. Dovey                                                            Charles A. Sanders, M.D.
Director                                                                  Director
 
/s/         M. ROSS JOHNSON
M. Ross Johnson, Ph.D.
President, Chief Executive Officer,
Chief Scientific Officer and Director
(Principal Executive Officer)
 
* Executed on behalf of these persons by
Matthew A. Megaro, duly appointed
Attorney-in-fact of each such person.

/s/       MATTHEW A. MEGARO
Matthew A. Megaro
Attorney-in-Fact
</TABLE>

<PAGE>

                  SECOND RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                                 TRIMERIS, INC.
                             Pursuant to Section 245
                        of the General Corporation Law of
                              the State of Delaware

         TRIMERIS, INC., a corporation duly organized and existing under and by
virtue of the General Corporation Law of the State of Delaware (the
"Corporation"), and which was incorporated under the name SL-1 Pharmaceuticals,
Inc. on January 7, 1993, does hereby certify as follows:

         FIRST: that the following resolutions were duly adopted by written
consent in lieu of meeting of the Board of Directors of the Corporation pursuant
to Section 141(f) of the General Corporation Law of the State of Delaware on May
28, 1997, setting forth proposed amendments to and the restatement of the
Certificate of Incorporation of the Corporation, as previously amended and
supplemented (the "Certificate of Incorporation"), in accordance with Section
245 of the General Corporation Law of the State of Delaware; determining that
the capital of the Corporation will not be decreased on account of such
amendments to and restatement of the Certificate of Incorporation; and,
declaring such amendments to and restatement of the Certificate of Incorporation
to be advisable and directing that such amendments to and restatement of the
Certificate of Incorporation be submitted to the stockholders of the Corporation
for their approval:

                  "RESOLVED, that the Certificate of Incorporation of the
         Corporation, as heretofore amended or supplemented, be amended and
         restated in its entirety to read as follows (the "Second Restated
         Certificate of Incorporation"):

                                   * * * * * *

                  Article 1.       The name of the corporation is TRIMERIS, INC.

                  Article 2. The address of the registered office of the
         corporation in the State of Delaware is 1013 Centre Road, Wilmington,
         New Castle County, Delaware 19805 and the name of the registered agent
         is Corporation Service Company.

                  Article 3. The purpose for which the corporation is organized
         is to engage in any lawful act or activity for which corporations may
         be organized under the General Corporation Law of the State of
         Delaware.

                                       1
<PAGE>

                  Article 4. The aggregate number of shares of all classes of
         stock which the Corporation shall have authority to issue is
         142,666,667 shares, consisting of 80,000,000 shares of Common Stock,
         par value $0.001 per share (herein called the "Common Stock"), and
         62,666,667 shares of Convertible Preferred Stock, par value $0.001 per
         share (herein called the "Preferred Stock"), of which 3,000,000 shares
         shall be designated Series A Convertible Preferred Stock (the "Series A
         Preferred"), 29,000,000 shares shall be designated Series B Convertible
         Preferred Stock (the "Series B Preferred"), 20,000,000 shares shall be
         designated Series C Convertible Preferred Stock (the "Series C
         Preferred"), and 10,666,667 shares shall be designated Series D
         Convertible Preferred Stock (the "Series D Preferred"). All
         cross-references in each subdivision of this Article 4 refer to other
         paragraphs in such subdivision unless otherwise indicated.

                           The following is a statement of the designations and
         the preferences, limitations and relative rights in respect of each
         class of stock of the Corporation:




                                       I.

                                 PREFERRED STOCK

                           1. Dividends. The holders of the Preferred Stock
         shall not be entitled to receive dividends, provided, however, that in
         the event the Corporation shall at any time declare or pay a dividend
         on the Common Stock (other than a dividend referred to in subparagraph
         4D(4)), it shall, simultaneously therewith and as part of such
         declaration or payment, declare and pay to each holder of Preferred
         Stock a dividend equal to the dividend which would have been payable to
         such holder if the shares of Preferred Stock held by such holder had
         been converted into Common Stock on the date of determination of
         holders of Common Stock entitled to receive such dividend.

                           2. Redemption. The shares of Preferred Stock shall be
         redeemable as follows:

                           2A. Mandatory Redemption. In case of the
         consolidation or merger of the Corporation with or into any other
         corporation (other than (i) a merger in which the Corporation is the
         surviving corporation and in which the persons who owned a majority of
         the outstanding Common Stock of the Corporation (giving effect to
         conversion of outstanding convertible securities convertible into
         Common Stock) immediately prior to the effective date of such merger
         continue to own, in substantially the same proportions, at least a
         majority of the outstanding Common Stock of the Corporation (giving
         effect to conversion of outstanding convertible securities convertible
         into Common Stock) immediately after such effective date or (ii) a
         consolidation or merger in which



                                       2
<PAGE>



         each share of Common Stock outstanding immediately before such
         consolidation or merger (including as outstanding all shares issuable
         upon conversion of outstanding Preferred Stock) shall, immediately
         after giving effect to such consolidation or merger, have a value, or
         represent a right to receive cash or other property having a value,
         determined in accordance with subparagraph 3B, equal to or greater than
         the Target Value (as hereinafter defined)), and, in the case of a sale
         of all or substantially all of the properties and assets of the
         Corporation as an entirety to any other person, the Corporation shall,
         not later than 20 days prior to the effective date of any such
         consolidation, merger or sale of properties and assets, give notice
         thereof to the holder or holders of shares of Preferred Stock, and in
         the event that within 15 days after receipt of such notice any holder
         or holders of shares of Preferred Stock shall elect, by written notice
         to the Corporation, to have any or all of its or their shares of
         Preferred Stock redeemed, the Corporation shall redeem the same (in the
         manner and with the effect provided in subparagraphs 2B through 2D
         below) not later than the effective date of such consolidation, merger
         or sale of properties and assets. Any date on which shares of Preferred
         Stock are to be redeemed by the Corporation shall be referred to as a
         "Redemption Date." As used in this subparagraph 2A, the term "Target
         Value" shall mean an amount equal to three (3) times the consideration
         per share paid for the Preferred Stock, provided that, in case the
         Corporation shall at any time subdivide its outstanding shares of
         Common Stock into a greater number of shares, the Target Value shall be
         proportionally reduced, and conversely, in case the outstanding shares
         of Common Stock of the Corporation shall be combined into a smaller
         number of shares, the Target Value shall be proportionally increased.

                           2B. Redemption Price.The Preferred Stock to be
         redeemed on a Redemption Date shall be redeemed by paying for each
         share in cash the sum of (i) its Basic Liquidation Preference (as
         defined in subparagraph 3A) plus (ii) in each case an amount equal to
         the amount by which (x) cumulative dividends on such shares from the
         respective dates of the issue thereof through the Redemption Date, at
         the rate per annum of 8% of their respective Basic Liquidation
         Preference, exceed (y) any cash dividends theretofore declared and paid
         thereon, plus (iii) an amount equal to (a) the net assets of the
         Corporation which would be available for distribution to holders of
         Common Stock after payment of the amounts described in the preceding
         clauses (i) and (ii) to holders of all outstanding shares of Preferred
         Stock (whether or not such holders shall have elected to have such
         shares redeemed) divided by (b) the number of shares of Common Stock
         which would be outstanding if all outstanding shares of Preferred Stock
         (including any such shares the holder or holders of which shall have
         elected redemption) had been converted immediately prior to the event
         giving rise to such redemption, multiplied by (c) the number of shares
         of Common Stock into which each share of Preferred Stock is then
         convertible pursuant to paragraph 4 immediately prior to the event
         giving rise to redemption, and the holders of Preferred Stock shall not
         be entitled to any



                                       3
<PAGE>


         further payment, such amount being herein sometimes referred to as the
         "Redemption Price." If on the Redemption Date the assets of the
         Corporation available for distribution to stockholders shall be
         insufficient to permit payment of the full aggregate Redemption Price
         of all Preferred Stock outstanding at the time (regardless of whether
         or not the holders thereof shall have elected redemption), then the
         holder of each share of Preferred Stock to be redeemed shall be
         entitled to receive such holder's pro rata share of such assets
         available for distribution, based on the respective Basic Liquidation
         Preferences of all shares of Preferred Stock outstanding at the time.
         If notice of any consolidation, merger or sale of all or substantially
         all of the assets of the Corporation shall have been duly given
         pursuant to subparagraph 2A, and the holder of any shares of Preferred
         Stock shall have duly elected to have such shares redeemed, as provided
         in subparagraph 2A, and if on or before such Redemption Date the funds
         necessary for redemption shall have been set aside (as set forth below)
         so as to be and continue to be available therefor, then,
         notwithstanding that any certificate for shares of Preferred Stock to
         be redeemed shall not have been surrendered for cancellation, after the
         close of business on such Redemption Date, the shares to be redeemed
         shall no longer be deemed outstanding, the dividends thereon shall
         cease to accrue, and all rights with respect to such shares shall
         forthwith after the close of business on the Redemption Date, cease,
         except only the right of the holders thereof to receive, upon
         presentation of the certificate representing shares so called for
         redemption, the Redemption Price therefor, without interest thereon.
         All funds required or permitted to be set aside for redemption of the
         Preferred Stock as provided in this subparagraph 2B shall be placed in
         an account maintained by a bank or trust company (i) organized and
         doing business under the laws of the United States of America or of any
         state, (ii) authorized under such laws to exercise trust powers, (iii)
         having a combined capital and undivided surplus of at least $50,000,000
         and (iv) subject to supervision or examination by a federal or state
         authority.

                           2C. Redeemed or Otherwise Acquired Shares to Be
         Retired. Any shares of the Preferred Stock redeemed pursuant to this
         paragraph 2 or otherwise acquired by the Corporation in any manner
         whatsoever shall be permanently retired and shall not under any
         circumstances be reissued; and the Corporation may from time to time
         take such appropriate corporate action as may be necessary to reduce
         the number of authorized shares of Preferred Stock accordingly.

                           3A. Liquidation. Upon any liquidation, dissolution or
         winding up of the Corporation, whether voluntary or involuntary, the
         holders of the shares of Preferred Stock shall be entitled, before any
         distribution or payment is made upon any Common Stock, to be paid for
         each share in cash an amount equal to (i) $0.67 per share in the case
         of the Series A Preferred or $0.50 per share in the case of the Series
         B Preferred or $0.60 per share in the



                                       4
<PAGE>


         case of Series C Preferred or $0.75 per share in case of the Series D
         Preferred (such amounts being herein called the "Basic Liquidation
         Preference" of the shares of such respective series) plus (ii) an
         amount equal to the amount by which (x) cumulative dividends (whether
         or not declared by the Board of Directors) on such shares from the
         respective dates of issue thereof through the date of such liquidation,
         dissolution or winding up, at the rate per annum of 8% of their
         respective Basic Liquidation Preference, exceed (y) any cash dividends
         theretofore declared and paid thereon, plus (iii) an amount equal to
         (a) the net assets of the Corporation which would be available for
         distribution to holders of Common Stock after payment of the amounts
         described in the preceding clauses (i) and (ii) to holders of all
         outstanding shares of Preferred Stock divided by (b) the number of
         shares of Common Stock which would be outstanding if all outstanding
         shares of Preferred Stock had been converted immediately prior to the
         effective time of such liquidation, dissolution or winding up,
         multiplied by (c) the number of shares of Common Stock into which each
         share of Preferred Stock is convertible pursuant to paragraph 4 at the
         effective time of such liquidation, dissolution or winding up, and the
         holders of Preferred Stock shall not be entitled to any further
         payment, such amounts being sometimes referred to as the "Liquidation
         Payments." If upon such liquidation, dissolution or winding up of the
         Corporation, whether voluntary or involuntary, the assets to be
         distributed among the holders of Preferred Stock shall be insufficient
         to permit payment to such holders of the full proportional amount to
         which they are respectively entitled then the entire assets of the
         Corporation to be so distributed shall be distributed among the holders
         of Preferred Stock pro rata in proportion to the respective numbers of
         shares of Preferred Stock held by such holders. Upon any such
         liquidation, dissolution or winding up of the Corporation, after the
         holders of Preferred Stock shall have been paid in full the amounts to
         which they shall be entitled, the remaining net assets of the
         Corporation may be distributed to the holders of Common Stock. Written
         notice of such liquidation, dissolution or winding up, stating a
         payment date, the amount of the Liquidation Payments and the place
         where said Liquidation Payments shall be payable shall be given by
         certified or registered mail, postage prepaid, not less than 30 days
         prior to the payment date stated therein, to the holders of record of
         Preferred Stock, such notice to be addressed to each such holder at his
         post office address as shown by the records of the Corporation. Subject
         to all provisions of paragraph 2, neither the consolidation or merger
         of the Corporation into or with any other corporation or corporations,
         nor the sale or transfer by the Corporation of all or substantially all
         its assets, shall be deemed to be a liquidation, dissolution or winding
         up of the Corporation within the meaning of the provisions of this
         paragraph 3.

                           3B. Noncash Distributions. If any of the assets of
         the Corporation are to be distributed other than in cash under
         paragraph 2 or this paragraph 3 or for any other purpose, then the
         Board of Directors shall promptly engage independent competent
         appraisers to determine the value of the



                                       5
<PAGE>


         assets to be distributed to the holders of Preferred Stock or Common
         Stock. The Corporation shall, upon receipt of such appraiser's
         valuation, give prompt written notice to each holder of shares of
         Preferred Stock and each holder of shares of Common Stock of the
         appraiser's valuation. Notwithstanding the above, any securities to be
         distributed to the stockholders shall be valued as follows:

                           (i) If traded on a securities exchange or quotations
                  system, the value shall be deemed to be the average of the
                  closing bid prices of the securities on such exchange over the
                  30-day period ending three (3) business days prior to the
                  closing;

                           (ii) If actively traded over-the-counter, the value
                  shall be deemed to be the average of the closing bid prices
                  over the 30-day period ending three (3) business days prior to
                  the closing; and

                           (iii) If there is no active public market, the value
                  shall be the fair market value thereof, as mutually determined
                  by the Corporation and the holders of not less than a majority
                  of the outstanding shares of Preferred Stock, voting as a
                  class, and a majority of the outstanding shares of Common
                  Stock, voting as a class, provided that if the Corporation and
                  the holders of a majority of the outstanding shares of
                  Preferred Stock, voting as a class, and a majority of the
                  outstanding shares of Common Stock, voting as a class, are
                  unable to reach agreement, then by independent competent
                  appraisal by an investment banker hired and paid by the
                  Corporation, but acceptable to the holders of a majority of
                  the outstanding shares of Preferred Stock, voting as a class,
                  and a majority of the outstanding shares of Common Stock,
                  voting as a class.

                           4A. Right to Convert. Subject to the terms and
         conditions of this paragraph 4, the holder of any share or shares of
         Preferred Stock shall have the right, at its option at any time prior
         to the close of business on the last full business day preceding the
         Redemption Date for any shares, to convert any such shares of Preferred
         Stock (except that upon any liquidation of the Corporation the right of
         conversion shall terminate at the close of business on the last full
         business day next preceding the date fixed for payment of the amount
         distributable on the Preferred Stock) into such number of fully paid
         and nonassessable whole shares of Common Stock as is obtained, in the
         case of the Series A Preferred, by multiplying the number of shares of
         Series A Preferred to be so converted by their Basic Liquidation
         Preference of $0.67 and dividing the result by the initial Series A
         Preferred conversion price of $0.67 per share or, if applicable, by the
         Series A Preferred conversion price as last adjusted and in effect at
         the date any share or shares of Series A preferred are surrendered for
         conversion (such price, or such price as last adjusted, being referred
         to herein as


                                       6
<PAGE>


         the "Series A Conversion Price") and, in the case of the Series B
         Preferred, by multiplying the number of shares of Series B Preferred to
         be so converted by their Basic Liquidation Preference of $0.50 and
         dividing the result by the initial Series B Preferred conversion price
         of $0.50 per share, if applicable, or by the Series B Preferred
         conversion price as last adjusted and in effect at the date any share
         or shares of Series B Preferred are surrendered for conversion (such
         price or such price as last adjusted, being referred to herein as the
         "Series B Conversion Price") and, in the case of Series C Preferred, by
         multiplying the number of shares of Series C Preferred to be so
         converted by their Basic Liquidation Preference of $0.60 and dividing
         the result by the initial Series C Preferred conversion price of $0.60
         per share, if applicable, or by the Series C Preferred conversion price
         as last adjusted and in effect at the date any share or shares of
         Series C Preferred are surrendered for conversion (such price or such
         price as last adjusted, being referred to herein as the "Series C
         Conversion Price") and, in the case of the Series D Preferred, by
         multiplying the number of shares of Series D Preferred to be so
         converted by their Basic Liquidation Preference of $0.75 and dividing
         the result by the initial Series D Preferred conversion price of $0.75
         per share or, if applicable, by the Series D Preferred conversion price
         as last adjusted and in effect at the date any share or shares of
         Series D Preferred are surrendered for conversion (such price or such
         price as last adjusted, being referred to herein as the "Series D
         Conversion Price"). Such rights of conversion shall be exercised by the
         holder thereof by giving written notice that the holder elects to
         convert a stated number of shares of Preferred Stock into Common Stock
         and by surrender of a certificate or certificates for the shares so as
         to be converted to the Corporation at its principal office (or such
         other office or agency at the Corporation as the Corporation may
         designate by notice in writing to the holder or holders of the
         Preferred Stock) at any time during its usual business hours on the
         date set forth in such notice, together with a statement of the name or
         names (with address) in which the certificate or certificates for
         shares of Common Stock shall be issued.

                           4B. Issuance of Certificates; Time Conversion
         Effected. Promptly after the receipt of the written notice referred to
         in subparagraph 4A and surrender of the certificate or certificates for
         the share or shares of the Preferred Stock to be converted, the
         Corporation shall issue and deliver, or cause to be issued and
         delivered, to the holder, registered in such name or names as such
         holder may direct, a certificate or certificates for the number of
         whole shares of Common Stock issuable upon the conversion of such share
         or shares of Preferred Stock. To the extent permitted by law, such
         conversion shall be deemed to have been affected, and the Series A,
         Series B, Series C or Series D Conversion Price, as the case may be,
         shall be determined, as of the close of business on the date on which
         such written notice shall have been received by the Corporation and the
         certificate or certificates for such share or shares shall have been
         surrendered as aforesaid, and at such time the rights of the holder of
         such share or shares of Preferred Stock shall cease, and the person



                                       7
<PAGE>

         or persons in whose name or names any certificate or certificates for
         shares of Common Stock shall be issuable upon such conversion shall be
         deemed to have become the holder or holders of record of the shares
         represented thereby.

                           4C. Fractional Shares; Dividends; Partial Conversion.
         No fractional shares shall be issued upon conversion of the Preferred
         Stock into Common Stock and no payment or adjustment shall be made upon
         any conversion on account of any cash dividends on the Common Stock
         issued upon such conversion. At the time of each conversion, the
         Corporation shall pay in cash an amount equal to all dividends declared
         and unpaid on the shares surrendered for conversion to the date upon
         which such conversion is deemed to take place as provided in
         subparagraph 4B. In case the number of shares of Preferred Stock
         represented by the certificate or certificates surrendered pursuant to
         subparagraph 4A exceeds the number of shares converted, the Corporation
         shall, upon such conversion, execute and deliver to the holder thereof,
         at the expense of the Corporation, a new certificate or certificates
         for the number of shares of Preferred Stock represented by the
         certificate or certificates surrendered which are not to be converted.
         If any fractional interest in a share of Common Stock would, except for
         the provisions of the first sentence of this subparagraph 4C, be
         deliverable upon any such conversion, the Corporation, in lieu of
         delivering the fractional share thereof, shall pay to the holder
         surrendering the Preferred Stock for conversion an amount in cash equal
         to the current market price of such fractional interest as determined
         in good faith by the Board of Directors of the Corporation.

                           4D. Adjustment of Price Upon Issuance of Common
         Shares. Except as provided in subparagraph 4F hereof, if and whenever
         the Corporation shall issue or sell, or is in accordance with
         subparagraphs 4D(1) through 4D(7) deemed to have issued or sold, any
         shares of its Common Stock without consideration or for a consideration
         per share less than the Conversion Price of any series of Preferred
         Stock in effect immediately prior to the time of such issue or sale,
         then, forthwith upon such issue or sale, the Conversion Price of such
         series of Preferred Stock shall be reduced concurrently with such issue
         or sale, to a price (calculated to the nearest cent) determined by
         dividing (i) an amount equal to the sum of (x) the number of shares of
         Common Stock outstanding immediately prior to such issue or sale
         (including as outstanding all shares of Common Stock issuable
         immediately prior to the time of such issue or sale upon conversion of
         outstanding Series B Preferred, Series C Preferred and Series D
         Preferred, in the case of adjustment of the Series A Conversion Price,
         or including as outstanding all shares of Common Stock issuable
         immediately prior to the time of such issue or sale upon conversion of
         outstanding Series A Preferred, Series C Preferred and Series D
         Preferred, in the case of adjustment of the Series B Conversion Price,
         or including as outstanding all shares of Common Stock issuable
         immediately prior to the time of such issue or sale upon conversion of
         outstanding Series A Preferred, Series B Preferred and Series D



                                       8
<PAGE>


         Preferred, in the case of adjustment of the Series C Conversion Price,
         or including as outstanding all shares of Common Stock issuable
         immediately prior to the time of such issue or sale upon conversion of
         outstanding Series A Preferred, Series B Preferred and Series C
         Preferred, in the case of adjustment of the Series D Conversion Price)
         multiplied by the then existing applicable Conversion Price, and (y)
         the consideration, if any, received by the Corporation upon such issue
         or sale, by (ii) the total number of shares of Common Stock outstanding
         immediately after such issue or sale (including as outstanding all
         shares of Common Stock issuable immediately prior to the time of such
         issue or sale upon conversion of outstanding Series B Preferred, Series
         C Preferred and Series D Preferred, in the case of adjustment of the
         Series A Conversion Price, or including as outstanding all shares of
         Common Stock issuable immediately prior to the time of such issue or
         sale upon conversion of outstanding Series A Preferred, Series C
         Preferred and Series D Preferred, in the case of adjustment of the
         Series B Conversion Price or including as outstanding all shares of
         Common Stock issuable immediately prior to the time of such issue or
         sale upon conversion of outstanding Series A Preferred, Series B
         Preferred and Series D Preferred in the case of adjustment of the
         Series C Conversion Price, or including as outstanding all shares of
         Common Stock issuable immediately prior to the time of such issue or
         sale upon conversion of outstanding Series A Preferred, Series B
         Preferred and Series C Preferred, in the case of adjustment of the
         Series D Conversion Price). In the event that the Corporation shall
         issue and sell, or is in accordance with subparagraphs 4D(1) through
         4D(7) deemed to have issued or sold, Series B Preferred, Series C
         Preferred or Series D Preferred in separate transactions, the
         adjustment to the Series A Conversion Price resulting from the issuance
         of the Series B Preferred, Series C Preferred or Series D Preferred, as
         the case may be, shall be calculated as if all outstanding shares of
         Series B Preferred, Series C Preferred, or Series D Preferred
         (including any shares deemed to be outstanding pursuant to subparagraph
         4D(1) to 4D(7)) had been issued and sold in a single transaction at the
         time of the last issuance and sale of Series B Preferred, Series C
         Preferred, or Series D Preferred, as the case may be. In the event that
         the Corporation shall issue and sell, or is in accordance with
         subparagraphs 4D(1) through 4D(7) deemed to have issued or sold, Series
         A Preferred, Series C Preferred or Series D Preferred in separate
         transactions, the adjustment to the Series B Conversion Price resulting
         from the issuance of the Series A Preferred, Series C Preferred or
         Series D Preferred, as the case may be, shall be calculated as if all
         outstanding shares of Series A Preferred, Series C Preferred, or Series
         D Preferred (including any shares deemed to be outstanding pursuant to
         subparagraph 4D(1) to 4D(7)) had been issued and sold in a single
         transaction at the time of the last issuance and sale of Series A
         Preferred, Series C Preferred, or Series D Preferred, as the case may
         be. In the event that the Corporation shall issue and sell, or is in
         accordance with subparagraphs 4D(1) through 4D(7) deemed to have issued
         or sold, Series A Preferred, Series B Preferred or Series D Preferred
         in separate transactions, the adjustment to the Series C Conversion


                                       9
<PAGE>


         Price resulting from the issuance of the Series A Preferred, Series B
         Preferred or Series D Preferred, as the case may be, shall be
         calculated as if all outstanding shares of Series A Preferred, Series B
         Preferred, or Series D Preferred (including any shares deemed to be
         outstanding pursuant to subparagraph 4D(1) to 4D(7)) had been issued
         and sold in a single transaction at the time of the last issuance and
         sale of Series A Preferred, Series B Preferred, or Series D Preferred,
         as the case may be. In the event that the Corporation shall issue and
         sell, or is in accordance with subparagraphs 4D(1) through 4D(7) deemed
         to have issued or sold, Series A Preferred, Series B Preferred or
         Series C Preferred in separate transactions, the adjustment to the
         Series D Conversion Price resulting from the issuance of the Series A
         Preferred, Series B Preferred or Series C Preferred, as the case may
         be, shall be calculated as if all outstanding shares of Series A
         Preferred, Series B Preferred, or Series C Preferred (including any
         shares deemed to be outstanding pursuant to subparagraph 4D(1) to
         4D(7)) had been issued and sold in a single transaction at the time of
         the last issuance and sale of Series A Preferred, Series B Preferred,
         or Series C Preferred, as the case may be.

                           No adjustment of any Conversion Price, however, shall
         be made in an amount less than $0.01 per share, and any such lesser
         adjustment shall be carried forward and shall be made at the time and
         together with the next subsequent adjustment which together with any
         adjustments so carried forward shall amount to $0.01 per share or more.

                           For purposes of this subparagraph 4D, the following
         subparagraphs 4D(1) to 4D(7) shall also be applicable.

                           4D(1). Issuance of Rights or Options. In case at any
         time the Corporation shall in any manner grant (whether directly or by
         assumption in a merger or otherwise) any rights to subscribe for or to
         purchase, or any options for the purchase of, Common Stock or any stock
         or securities convertible into or exchangeable for Common Stock (such
         rights or options being herein called "Options" and such convertible or
         exchangeable stock or securities being herein called "Convertible
         Securities") whether or not such Options or the right to convert or
         exchange any such Convertible Securities are immediately exercisable,
         and the price per share for which Common Stock is issuable upon the
         exercise of such Options or upon conversion or exchange of such
         Convertible Securities (determined by dividing (i) the total amount, if
         any, received or receivable by the Corporation as consideration for the
         granting of such Options, plus the minimum aggregate amount of
         additional consideration payable to the Corporation upon the exercise
         of all such Options, plus, in the case of such Options which relate to
         Convertible Securities, the minimum aggregate amount of additional
         consideration, if any, payable upon the issue or sale of such

         convertible Securities and upon the conversion or exchange thereof, by
         (ii) the total maximum number of shares of Common Stock issuable upon

         the 



                                       10
<PAGE>


         exercise of such Options or upon the conversion or exchange of all
         such Convertible Securities issuable upon the exercise of such Options)
         shall be less than the applicable Conversion Price in effect
         immediately prior to the time of the granting of such Options, then the
         total maximum number of shares of Common Stock issuable upon the
         exercise of such Options or upon conversion or exchange of the total
         maximum amount of such Convertible Securities issuable upon the
         exercise of such Options shall be deemed to have been issued for such
         price per share as of the date of the granting of such Options and
         thereafter shall be deemed to be outstanding. Except as otherwise
         provided in subparagraph 4D(3), no adjustment of the Series A, Series
         B, Series C or Series D Conversion Prices shall be made upon the actual
         issue of such Common Stock or of such Convertible Securities upon
         exercise of such Options or upon the actual issue of such Common Stock
         upon conversion or exchange of such Convertible Securities.

                           4D(2). Issuance of Convertible Securities.In case the
         Corporation shall in any manner issue (whether directly or by
         assumption, in a merger or otherwise) or sell any Convertible
         Securities, whether or not the rights to exchange or convert thereunder
         are immediately exercisable, and the price per share for which Common
         Stock is issuable upon such conversion or exchange (determined by
         dividing (i) the total amount received or receivable by the Corporation
         as consideration for the issue or sale of such Convertible Securities,
         plus the minimum aggregate amount of additional consideration, if any,
         payable to the Corporation upon the conversion or exchange thereof, by
         (ii) the total maximum number of shares of Common Stock issuable upon
         the conversion or exchange of all such Convertible Securities) shall be
         less than the applicable Conversion Price in effect immediately prior
         to the time of such issue or sale, then the total maximum number of
         shares of Common Stock issuable upon conversion or exchange of all such
         Convertible Securities shall be deemed to have been issued for such
         price per share as of the date of the issue or sale of such Convertible
         Securities and thereafter shall be deemed to be outstanding, provided
         that (a) except as otherwise provided in subparagraph 4D(3) below, no
         adjustment of the Series A, Series B, Series C or Series D Conversion
         Prices shall be made upon the actual issue of such Common Stock upon
         conversion or exchange of such Convertible Securities, and (b) if any
         such issue or sale of such Convertible Securities is made upon exercise
         of any option to purchase any such Convertible Securities for which
         adjustments of the Conversion Price have been or are to be made
         pursuant to other provisions of this subparagraph 4D, no further
         adjustment of the Series A, Series B, Series C or Series D Conversion
         Prices shall be made by reason of such issue or sale.

                           4D(3). Change in Option Price or Conversion Rate.
         Upon the happening of any of the following events, namely, if the
         purchase price provided for in any Option referred to in subparagraph
         4D(1), the additional consideration, if any, payable upon the
         conversion or exchange of any


                                       11
<PAGE>


         Convertible Securities referred to in subparagraph 4D(1) or 4D(2), or
         the rate at which any Convertible Securities referred to in
         subparagraph 4D(1) or 4D(2) are convertible into or exchangeable for
         Common Stock shall change at any time (other than under or by reason of
         provisions designed to protect against dilution), the Series A, Series
         B, Series C or Series D Conversion Prices in effect at the time of such
         event shall forthwith be readjusted to the Series A, Series B, Series C
         or Series D Conversion Prices which would have been in effect at such
         time had such Options or Convertible Securities still outstanding
         provided for such changed purchase price, additional consideration or
         conversion rate, as the case may be, at the time initially granted,
         issued or sold; and on the expiration of any such Option or the
         termination of any such right to convert or exchange such Convertible
         Securities, the Series A, Series B, Series C or Series D Conversion
         Prices then in effect hereunder shall forthwith be increased to the
         Conversion Prices which would have been in effect at the time of such
         expiration or termination had such option or Convertible Securities, to
         the extent outstanding immediately prior to such expiration or
         termination, never been issued, and the Common Stock issuable
         thereunder shall no longer be deemed to be outstanding. If the purchase
         price provided for in any such Option referred to in subparagraph 4D(1)
         or the rate at which any Convertible Securities referred to in
         subparagraph 4D(1) or 4D(2) convertible into or exchangeable for Common
         Stock shall be reduced at any time under or by reason of provisions
         with respect thereto designed to protect against dilution, then, in
         case of the delivery of the Common Stock upon the exercise of any such
         Option or upon conversion or exchange of any such Convertible
         Securities, the Conversion Prices then in effect hereunder shall
         forthwith be adjusted to such respective amount as would have been
         obtained had such option or Convertible Securities never been issued as
         to such Common Stock and had adjustments been made upon the issuance of
         the shares of Common Stock delivered as aforesaid, but only if as a
         result of such adjustment the Series A, Series B, Series C or Series D
         Conversion Prices then in effect hereunder is thereby reduced.

                           4D(4). Stock Dividends. In case the Corporation shall
         declare a dividend or make any other distribution upon any stock of the
         Corporation payable in Common Stock, Options or Convertible Securities,
         any Common Stock, Options or Convertible Securities, as the case may
         be, issuable in payment of such dividend or distribution shall be
         deemed to have been issued or sold without consideration.

                           4D(5). Consideration for Stock. In case any shares of
         Common Stock, Options or Convertible Securities shall be issued or sold
         for cash, the consideration received therefor shall be deemed to be the
         amount received by the Corporation therefor, without deduction
         therefrom of any expenses incurred or any underwriting commissions or
         concessions paid or allowed by the Corporation in connection therewith.
         The amount of consideration deemed to be received by the Corporation
         pursuant to the foregoing provisions of this



                                       12
<PAGE>
<PAGE>

         subparagraph 4D(5) upon any issuance and/or sale of shares of Common
         Stock, Options or Convertible Securities, pursuant to an established
         compensation plan of the Corporation, to directors, officers or
         employees of the Corporation in connection with their employment shall
         be increased by the amount of any tax benefit realized by the
         Corporation as a result of such issuance and/or sale, the amount of
         such tax benefit being the amount by which the Federal and/or state
         income or other tax liability of the Corporation shall be reduced in
         such year by reason of any deduction or credit in respect of such
         issuance and/or sale. In case any Options shall be issued in connection
         with the issue and sale of other securities of the Corporation,
         together comprising one integral transaction in which no specific
         consideration is allocated to such Options by the parties thereto, such
         Options shall be deemed to have been issued without consideration.

                           4D(6). Record Date. In case the Corporation shall
         take a record of the holders of its Common Stock for the purpose of
         entitling them (i) to receive a dividend or other distribution payable
         in Common Stock, Options or Convertible Securities, or (ii) to
         subscribe for or purchase Common Stock, Options or Convertible
         Securities, then such record date shall be deemed to be the date of the
         issue or sale of the shares of Common Stock deemed to have been issued
         or sold upon the declaration of such dividend or the making of such
         other distribution or the date of the granting of such right of
         subscription or purchase, as the case may be.

                           4D(7). Treasury Shares. The number of shares of
         Common Stock outstanding at any given time shall not include shares
         owned or held by or for the account of the Corporation, and any
         disposition of any such shares (other than by cancellation) shall be
         considered an issue or sale of Common Stock for the purposes of this
         subparagraph 4D.

                           4E. Subdivision or Combination of Stock. In case the
         Corporation shall at any time subdivide its outstanding shares of
         Common Stock into a greater number of shares, the Series A, Series B,
         Series C or Series D Conversion Prices in effect immediately prior to
         such subdivision shall be proportionately reduced, and conversely, in
         case the outstanding shares of Common Stock of the Corporation shall be
         combined into a smaller number of Shares, the Series A, Series B,
         Series C or Series D Conversion Prices in effect immediately prior to
         such combination shall be proportionately increased.

                           4F. Certain Issues of Common Shares Excepted.
         Anything herein to the contrary notwithstanding, the Corporation shall
         not be required to make any adjustment of the Series A, Series B,
         Series C or Series D Conversion Prices (i) in the case of the issuance
         of shares of Common Stock (or stock options to purchase such shares of
         Common Stock) to employees, officers or directors of or consultants to
         the Corporation pursuant to arrangements authorized and



                                       13
<PAGE>
<PAGE>

         approved by the Board of Directors of the Corporation, if and to the
         extent that the aggregate number of such shares so issued or reserved
         for issuance upon exercise of such options from and after February 6,
         1993 does not exceed 9,121,163, or (ii) in the case of the issuance of
         shares of Common Stock upon the conversion of any issued and
         outstanding Preferred Stock or upon the exercise of any Options (as
         defined in subparagraph 4D(1)) or conversion of Convertible Securities
         (as defined in subparagraph 4D(1)) outstanding as of June 30, 1997.

                           4G. Reorganization or Reclassification. If any
         capital reorganization or reclassification of the capital stock of the
         Corporation shall be effected in such a way that holders of Common
         Stock shall be entitled to receive stock, securities or assets with
         respect to or in exchange for Common Stock, then, as a condition of
         such reorganization or reclassification, lawful and adequate provisions
         (in form satisfactory to the holders of at least a majority of the
         outstanding shares of Preferred Stock) shall be made whereby each
         holder of a share or shares of Preferred Stock shall thereafter have
         the right to receive, upon the basis and upon the terms and conditions
         specified herein and in lieu of the shares of Common Stock of the
         Corporation immediately theretofore receivable upon the conversion of
         such share or shares of the Preferred Stock, such shares of stock,
         securities or assets as may be issued or payable with respect to or in
         exchange for a number of outstanding shares of such Common Stock equal
         to the number of shares of such stock immediately theretofore so
         receivable had such reorganization or reclassification not taken place,
         and in any such case appropriate provision shall be made with respect
         to the rights and interests of such holder to the end that the
         provisions hereof (including without limitation provisions for
         adjustment of the Conversion Prices) shall thereafter be applicable, as
         nearly as may be, in relation to any shares of stock, securities or
         assets thereafter deliverable upon the exercise of such conversion
         rights (including an immediate adjustment, by reason of such
         reorganization or reclassification, of the Conversion Prices to the
         value for the Common Stock reflected by the terms of such consolidation
         or merger if the value so reflected is less than the applicable
         Conversion Price(s) in effect immediately prior to such consolidation
         or merger). In the event of a merger or consolidation of the
         Corporation as a result of which a greater or lesser number of shares
         of common stock of the surviving corporation are issuable to holders of
         Common Stock of the Corporation outstanding immediately prior to such
         merger or consolidation, the Conversion Prices in effect immediately
         prior to such merger or consolidation shall be adjusted in the same
         manner as though there were a subdivision or combination of the
         outstanding shares of Common Stock of the Corporation. The Corporation
         will not effect any such reorganization or reclassification, unless
         prior to the consummation thereof, the successor corporation (if other
         than the Corporation) resulting from such consolidation or merger or
         the corporation purchasing such assets shall assume by written
         instrument (in form reasonably satisfactory to the holders of at least
         a majority of the shares of Preferred Stock at the time outstanding)
         executed and mailed or



                                       14
<PAGE>
<PAGE>

         delivered to each holder of shares of Preferred Stock at the last
         address of such holder appearing on the books of the Corporation, the
         obligation to deliver to such holder such shares of stock, securities
         or assets as, in accordance with the foregoing provisions, such holder
         may be entitled to receive.

                           4H. Notice of Adjustment. Upon any adjustment of the
         Series A, Series B, Series C or Series D Conversion Price, then and in
         each such case, the Corporation shall give written notice thereof, by
         first-class mail, postage prepaid, addressed to each holder of shares
         of Preferred Stock at the address of such holder as shown on the books
         of the Corporation, which notice shall state the applicable Conversion
         Price resulting from such adjustment, setting forth in reasonable
         detail the method of calculation and the facts upon which such
         calculation is based.

                           4I.      Other Notices.  In case at any time:

                           (1) the Corporation shall declare any dividend upon
                  its Common Stock payable in cash or stock or make any other
                  distribution to the holders of its Common Stock;

                           (2) the Corporation shall offer for subscription pro
                  rata to the holders of its Common Stock any additional shares
                  of stock of any class or other rights;

                           (3) there shall be any capital reorganization or
                  reclassification of the capital stock of the Corporation, or a
                  consolidation or merger of the Corporation with, or a sale of
                  all or substantially all its assets to, another corporation;
                  or

                           (4) there shall be a voluntary or involuntary
                  dissolution, liquidation or winding up of the Corporation;

         then, in any one or more of said cases, the Corporation shall give, by
         first-class mail, postage prepaid, addressed to each holder of any
         shares of Preferred Stock at the address of such holder as shown on the
         books of the Corporation, (a) at least 20 days prior written notice of
         the date on which the books of the Corporation shall close or a record
         shall be taken for such dividend, distribution or subscription rights
         or for determining rights to vote in respect of any such
         reorganization, reclassification, consolidation, merger, sale,
         dissolution, liquidation or winding up, and (b) in the case of any such
         reorganization, reclassification, consolidation, merger, sale,
         dissolution, liquidation or winding up, at least 20 days' prior written
         notice of the date when the same shall take place. Such notice in
         accordance with the foregoing clause (a) shall also specify, in the
         case of any such dividend, distribution or subscription rights, the
         date on which the holders of Common Stock shall be entitled thereto,
         and such



                                       15
<PAGE>
<PAGE>

         notice in accordance with the foregoing clause (b) shall also specify
         the date on which the holders of Common Stock shall be entitled to
         exchange their Common Stock for securities or other property
         deliverable upon such reorganization, reclassification, consolidation,
         merger, sale, dissolution, liquidation or winding up, as the case may
         be.

                           4J. Stock to Be Reserved. The Corporation will at all
         times reserve and keep available out of its authorized Common Stock or
         its treasury shares, solely for the purpose of issue upon the
         conversion of the Preferred Stock as herein provided, such number of
         shares of Common Stock as shall then be issuable upon the conversion of
         all outstanding shares of Preferred Stock. The Corporation covenants
         that all shares of Common Stock which shall be so issued shall be duly
         and validly issued and fully paid and nonassessable and free from all
         taxes, liens and charges with respect to the issue thereof, and without
         limiting the generality of the foregoing, the Corporation covenants
         that it will from time to time take all such action as may be requisite
         to assure that the par value per share of the Common Stock is at all
         times equal to or less than the effective applicable Conversion Prices.
         The Corporation will take all such action as may be necessary to assure
         that such shares of Common Stock may be so issued without violation of
         any applicable law or regulation, or of any requirements of any
         national securities exchange or quotation system upon which the Common
         Stock of the Corporation may be listed or quoted. The Corporation will
         not take any action which results in any adjustment of the applicable
         Conversion Prices if the total number of shares of Common Stock issued
         and issuable after such action upon conversion of the Preferred Stock
         would exceed the total number of shares of Common Stock then authorized
         by the Corporation's Second Restated Certificate of Incorporation.

                           4K. No Reissuance of Preferred Stock. Shares of
         Preferred Stock which are converted into shares of Common Stock as
         provided herein shall not be reissued.

                           4L. Issue Tax. The issuance of certificates for
         shares of Common Stock upon conversion of the Preferred Stock shall be
         made without charge to the holders thereof for any issuance tax in
         respect thereof, provided that the Corporation shall not be required to
         pay any tax which may be payable in respect of any transfer involved in
         the issuance and delivery of any certificate in a name other than that
         of the holder of the Preferred Stock which is being converted.

                           4M. Closing of Books. The Corporation will at no time
         close its transfer books against the transfer of any Preferred Stock or
         of any shares of Common Stock issued or issuable upon the conversion of
         any shares of Preferred Stock in any manner which interferes with the
         timely conversion of such Preferred Stock.


                                       16
<PAGE>
<PAGE>

                           4N. Definition of Common Stock. As used in this
         paragraph 4, the term "Common Stock" shall mean and include the
         Corporation's authorized Common Stock, $0.001 par value as constituted
         on the effective date of this Second Restated Certificate of
         Incorporation and shall also include any capital stock of any class of
         the Corporation thereafter authorized which shall not be limited to a
         fixed sum or percentage of par value in respect of the rights of the
         holders thereof to participate in dividends or in the distribution of
         assets upon voluntary or involuntary liquidation, dissolution or
         winding up of the Corporation; provided that the shares of Common Stock
         receivable upon conversion of shares of the Preferred Stock of the
         Corporation, or, in case of any reorganization or reclassification of
         the outstanding shares thereof, the stock, securities or assets
         provided for in subparagraph 4G, shall include only shares designated
         as Common Stock of the Corporation on the effective date of this Second
         Restated Certificate of Incorporation.

                           4O. No Impairment. The Corporation will not through
         any reorganization, recapitalization, transfer of assets,
         consolidation, merger, dissolution, issue or sale of securities or any
         other voluntary action, avoid or seek to avoid the observation or
         performance of any of the terms to be observed or performed hereunder
         by the Corporation, but will at all times in good faith assist in the
         carrying out of all of the provisions of this paragraph 4 and in the
         taking of all such action as may be necessary or appropriate in order
         to protect the conversion rights of the holders of Preferred Stock
         against impairment. This provision shall not restrict the Corporation's
         right to amend its Certificate of Incorporation with the requisite
         stockholder consent.

                           5. Voting Rights. Except as otherwise provided by law
         and this Second Restated Certificate of Incorporation, the holders of
         Common Stock and Preferred Stock shall vote together as a class on all
         matters to be voted on by the stockholders of the Corporation on the
         following bases: (1) each holder of Preferred Stock shall be entitled
         to one vote for each share of Common Stock which would be issuable to
         such holder upon the conversion of all the shares of Preferred Stock so
         held on the record date for the determination of stockholders entitled
         to vote and (2) each holder of Common Stock shall be entitled to one
         vote per share.

                           6. Restrictions. At any time when shares of Preferred
         Stock are outstanding, except where the vote or written consent of the
         holders of a greater number of shares of the Corporation is required by
         law or by this Second Restated Certificate of Incorporation and in
         addition to any other vote required by law, without the prior consent
         of the holders of a majority of the outstanding shares of each series
         of Preferred Stock, given in person or by proxy, either in writing or
         at a special meeting called for that purpose, at which



                                       17
<PAGE>
<PAGE>

         meeting the holders of the shares of such Preferred Stock shall vote
         separately as a series.

                           6A. The Corporation will not create or authorize the
         creation of any additional class of shares of stock or other equity
         security, including any other security or debt instrument convertible
         into or exercisable for any such equity security, or increase the
         authorized amount of the Preferred Stock or increase the authorized
         amount of any additional class of shares of stock unless the same ranks
         junior to the Preferred Stock as to the distribution of assets on the
         liquidation, dissolution or winding up of the Corporation or redemption
         of shares, or create or authorize any obligation or security
         convertible into shares of Preferred Stock or into shares of any other
         class of stock unless the same ranks junior to the Preferred Stock as
         to the distribution of assets on the liquidation, dissolution or
         winding up of the Corporation or redemption of shares, whether any such
         creation or authorization or increase shall be by means of amendment of
         the Corporation's Second Restated Certificate of Incorporation or by
         merger, consolidation or otherwise;

                           6B. The Corporation will not amend, alter or repeal
         its Second Restated Certificate of Incorporation or Bylaws in any
         manner so as to adversely affect the respective relative rights and
         preferences of the Preferred Stock or adversely affect the Preferred
         Stock or the holders thereof in any manner.

                           6C. The Corporation will not effect any sale or
         liquidation of all or substantially all of the Corporation's assets, or
         affect any merger, consolidation or reorganization other than a merger
         or consolidation with a wholly-owned subsidiary.

                           6D. The Corporation will not affect any
         reclassification, reverse stock split, combination of any class of
         capital stock or other recapitalization.

                           6E.      The Corporation shall not:

                           (1)      engage in any spin-out, distribution or sale
                                    of any business unit of the Corporation;

                           (2)      enter into any transactions with affiliates
                                    of the Corporation except on arms-length
                                    terms approved by a majority of the
                                    disinterested members of the Corporation's
                                    Board of Directors; or

                           (3)      redeem or repurchase any outstanding Common
                                    Stock of the Corporation except for
                                    repurchases of unvested or restricted shares
                                    of Common Stock at cost from


                                       18
<PAGE>


                                    employees, consultants or members of the
                                    Board of Directors pursuant to repurchase
                                    options of the Corporation.


                                       II.
                                  COMMON STOCK

                           1. Dividends. The holders of shares of Common Stock
         shall be entitled to receive such dividends as from time to time may be
         declared by the Board of Directors of the Corporation, subject to the
         provisions of subdivision I of this Article 4 with respect to the
         rights of holders of the Preferred Stock.

                           2. Liquidation. In the event of any liquidation,
         dissolution or winding up of the Corporation, whether voluntary or
         involuntary, after payment shall have been made to holders of Preferred
         Stock of the full amounts to which they shall respectively be entitled
         prior to the making of any distribution to the holders of Common Stock
         as stated and expressed herein or as may be stated and expressed
         pursuant hereto, the holders of Common Stock shall be entitled,
         together with the holders of the Preferred Stock as provided in
         paragraph 3 of subdivision I of this Article 4, to share ratably
         according to the number of shares of Common Stock held by them in all
         remaining assets of the Corporation available for distribution to its
         stockholders.

                           3. Voting. Except as otherwise provided by law,
         voting rights shall be governed by paragraph 5 of subdivision I of this
         Article 4.

                  Article 5. The number of Directors of the corporation may be
         fixed by the Bylaws.

                  Article 6. The Board of Directors of the corporation shall
         have the power to adopt, amend or repeal the Bylaws of the corporation.

                  Article 7. Elections of directors may be, but shall not be
         required to be, by written ballot.

                  Article 8. No director of the corporation shall have personal
         liability arising out of an action whether by or in the right of the
         Corporation or otherwise for monetary damages for breach of fiduciary
         duty as a director; provided, however, that the foregoing shall not
         limit or eliminate the liability of a director (i) for any breach of
         the director's duty of loyalty to the Corporation or its stockholders,
         (ii) for acts or omissions not in good faith or which involve
         intentional misconduct or a knowing violation of law, (iii) under
         Section 174 of the General Corporation Law of the State of Delaware or
         any successor provision,



                                       19
<PAGE>

         (iv) for any transaction from which such director derived an improper
         personal benefit, or (v) acts or omissions occurring prior to the date
         of the effectiveness of this provision.

                  Furthermore, notwithstanding the foregoing provision, in the
         event that the General Corporation Law of the State of Delaware is
         amended or enacted to permit further limitation of elimination of the
         personal liability of the director, the personal liability for the
         corporation's directors shall be limited or eliminated to the fullest
         extent permitted by the applicable law.

                  This provision shall not affect any provision permitted under
         the General Corporation Law of the State of Delaware in the Second
         Restated Certificate of Incorporation, Bylaws or contract or resolution
         of the corporation indemnifying or agreeing to indemnify a director
         against personal liability. Any repeal or modification of this
         provision shall not adversely affect any limitation hereunder on the
         personal liability of the director with respect to acts or omissions
         occurring prior to such repeal or modification.


                  RESOLVED FURTHER, that the Board of Directors determines that
         the capital of the Corporation will not be decreased on account of the
         foregoing Second Restated Certificate of Incorporation, declares the
         foregoing Second Restated Certificate of Incorporation to be advisable
         and directs that such Second Restated Certificate of Incorporation be
         submitted to the stockholders of the Corporation for their approval
         pursuant to Section 242 of the General Corporation Law of the State of
         Delaware."

         SECOND: that the Second Restated Certificate of Incorporation effected
by this certificate was duly authorized by written consent of the holders of a
majority of the issued and outstanding shares of each class and series of the
capital stock of the Corporation on June 9, 1997, after first having been
declared advisable by the Board of Directors of the Corporation, all in
accordance with the provisions of Section 242 of the General Corporation Law of
the State of Delaware.

         THIRD: that the capital of the Corporation will not be reduced under,
or by reason of, the foregoing Second Restated Certificate of Incorporation of
the Corporation.


                                       20
<PAGE>


         IN WITNESS WHEREOF, the Corporation has caused its corporate seal to be
hereunto affixed and this certificate to be signed by M. Ross Johnson, its
President, who hereby acknowledges under penalties of perjury that the facts
herein stated are true and that this certificate is his act and deed, and
attested by Max N. Wallace, its Secretary, this 25th day of June, 1997.

                            TRIMERIS, INC.
[CORPORATE SEAL]
                            By:      /s/  Matthew A. Megaro
                            Matthew A. Megaro
                            Vice President of Business Development,
                            Chief Operating Officer, and Chief Financial Officer
ATTEST:

By:      /s/  Gloria E. Ivey
         Gloria E. Ivey, Secretary



                                       21


<PAGE>


                            CERTIFICATE OF AMENDMENT
                                       OF
                  SECOND RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                                 TRIMERIS, INC.

                             PURSUANT TO SECTION 242
                           OF THE GENERAL CORPORATION
                          LAW OF THE STATE OF DELAWARE

                  TRIMERIS, INC., a corporation organized and existing under the
laws of the State of Delaware (the "Corporation"), hereby certifies as follows:

                  FIRST: That Article 4 of the Second Restated Certificate of
Incorporation of the Corporation is amended by deleting the first paragraph
thereof in its entirety and inserting the following in lieu thereof:

                           "Article 4. The aggregate number of shares of all
                  classes of stock which the Corporation shall have authority to
                  issue is 142,666,667 shares, consisting of 80,000,000 shares
                  of Common Stock, par value $0.001 per share (herein called the
                  "Common Stock"), and 62,666,667 shares of Convertible
                  Preferred Stock, par value $0.001 per share (herein called the
                  "Preferred Stock"), of which 3,000,000 shares shall be
                  designated Series A Convertible Preferred Stock (the "Series A
                  Preferred"), 29,000,000 shares shall be designated Series B
                  Convertible Preferred Stock (the "Series B Preferred"),
                  20,000,000 shares shall be designated Series C Convertible
                  Preferred Stock (the "Series C Preferred"), and 10,666,667
                  shares shall be designated Series D Convertible Preferred
                  Stock (the "Series D Preferred"). All cross-references in each
                  subdivision of this Article 4 refer to other paragraphs in
                  such subdivision unless otherwise indicated

                           Each eight and one-half (8.5) shares of the
                  Corporation's Common Stock, par value $.0001 per share issued
                  and outstanding as of the date this Certificate of Amendment
                  is filed shall be converted and reclassified into one (1)
                  share of the Corporation's Common Stock, par value $.0001 per
                  share, so that each share of the Corporation's Common Stock
                  issued and outstanding is hereby converted and reclassified.
                  No fractional interests resulting from such conversion shall
                  be issued, but in lieu thereof, the Corporation will round the
                  number of shares of Common Stock issuable to each holder of
                  Common Stock up to the nearest whole share of Common Stock."
<PAGE>

                  SECOND: that the foregoing amendment of the Second Restated
Certificate of Incorporation of the Corporation was duly authorized by written
consent of the stockholders of the Corporation on July 10, 1997, after first
having been declared advisable by the Board of Directors of the Corporation, all
in accordance with the provisions of Section 242 of the General Corporation Law
of the State of Delaware.

                  IN WITNESS WHEREOF, the Corporation has caused its corporate
seal to be hereunto affixed and this Certificate to be signed by M. Ross
Johnson, its President, and attested by Gloria E. Ivey, its Assistant Secretary,
this 11th day of July, 1997.

                                                  TRIMERIS, INC.
[CORPORATE SEAL]

                                                   By /s/  M. Ross Johnson
ATTEST:                                               M. Ross Johnson, President

By /s/  Gloria E. Ivey
      Gloria E. Ivey, Assistant Secretary


<PAGE>



        CERTIFICATE OF CORRECTION FILED TO CORRECT A CERTAIN ERROR IN THE
  CERTIFICATE OF AMENDMENT OF SECOND RESTATED CERTIFICATE OF INCORPORATION OF
    TRIMERIS, INC. FILED IN THE OFFICE OF THE SECRETARY OF STATE OF DELAWARE
                                ON JULY 11, 1997

         Trimeris, Inc., a corporation organized and existing under and by
virtue of the General Corporation Law of the State of Delaware, does hereby
certify:

         1. The name of the corporation is Trimeris, Inc.

         2. The Certificate of Amendment of Second Restated Certificate of
Incorporation filed by the Secretary of State of Delaware on July 11, 1997 (the
"Certificate of Amendment"), requires correction as permitted by Section 103 of
the General Corporation Law of the State of Delaware.

         3. The inaccuracy or defect of the Certificate of Amendment to be
corrected is the par value per share as stated in the first sentence of the
second paragraph of Article 4 of the Certificate of Amendment, which amount was
incorrectly stated as $.0001.

         4. The first sentence of the second paragraph of Article 4 of the
Certificate of Amendment is hereby corrected to read as follows:

                           "Each eight and one-half (8.5) shares of the
         Corporation's Common Stock, par value $0.001 per share issued and
         outstanding as of the date this Certificate of Amendment is filed shall
         be converted and reclassified into one (1) share of the Corporation's
         Common Stock, par value $0.001 per share, so that each share of the
         Corporation's Common Stock issued and outstanding is hereby converted
         and reclassified."

         IN WITNESS WHEREOF, this Certificate of Correction of the Certificate
of Amendment of Second Restated Certificate of Incorporation as filed on July
11, 1997 has been signed by the President and the Assistant Secretary of the
Corporation this 22nd day of August, 1997.


                                     /s/  M. Ross Johnson
                                     M. Ross Johnson
                                     President

                                     /s/  Gloria Ivey
                                     Gloria Ivey
         [CORPORATE SEAL]            Assistant Secretary


<PAGE>



        CERTIFICATE OF CORRECTION FILED TO CORRECT CERTAIN ERRORS IN THE
                SECOND RESTATED CERTIFICATE OF INCORPORATION OF
             TRIMERIS, INC. FILED IN THE OFFICE OF THE SECRETARY OF
                       STATE OF DELAWARE ON JUNE 25, 1997

         Trimeris, Inc., a corporation organized and existing under and by
virtue of the General Corporation Law of the State of Delaware, does hereby
certify:

         1. The name of the corporation is Trimeris, Inc.

         2. The Second Restated Certificate of Incorporation filed by the
Secretary of State of Delaware on June 25, 1997 (the "Certificate of
Incorporation"), requires correction as permitted by Section 103 of the General
Corporation Law of the State of Delaware.

         3. The inaccuracies or defects of the Certificate of Incorporation to
be corrected pertain to the names and titles of the signatories in the closing
paragraph and the title of the signatory in the attestation, which names and
titles were incorrectly stated.

         4. The closing paragraph of the Certificate of Incorporation is hereby
corrected to read as follows:

                           "IN WITNESS WHEREOF, the Corporation has caused its
         corporate seal to be hereunto affixed and this certificate to be signed
         by Matthew A. Megaro, its Vice President of Business Development, Chief
         Operating Officer, and Chief Financial Officer who hereby acknowledges
         under penalties of perjury that the facts herein stated are true and
         that this certificate is his act and deed, and attested by Gloria E.
         Ivey, its Assistant Secretary, this 25th day of June, 1997."

         5. The title of the signatory in the attestation should be changed from
"Secretary" to "Assistant Secretary".

         IN WITNESS WHEREOF, this Certificate of Correction of the Second
Restated Certificate of Incorporation as filed on June 25, 1997 has been signed
by the President and the Assistant Secretary of the Corporation this 22nd day of
August, 1997.


                                            /s/  M. Ross Johnson
                                            M. Ross Johnson
                                            President

                                            /s/  Gloria Ivey
                                            Gloria Ivey
         [CORPORATE SEAL]                   Assistant Secretary








                                     (logo)
NUMBER                            TRIMERIS, INC.               SHARES

T


INCORPORATED UNDER THE LAWS                                    SEE REVERSE FOR 
 OF THE STATE OF DELAWARE                                    CERTAIN DEFINITIONS
                                                              CUSIP 896263 10 0

THIS IS TO CERTIFY THAT







IS THE OWNER OF 


FULLY-PAID AND NON-ASSESSABLE SHARES OF THE COMMON STOCK OF THE PAR VALUE OF
ONE-TENTH OF ONE CENT ($0.001) EACH OF TRIMERIS, INC.



(the following text is overprinted on the paragraph below) CERTIFICATE OF STOCK
(hereinafter called the "Corporation") transferable on the books of 
the Corporation by said owner in person or by duly authorized attorney; 
upon surrender of this certificate properly endorsed. This certificate is 
not valid unless countersigned by the Transfer Agent. Witness, the 
facsimile seal of the Corporation and the facsimile signatures of 
its duly authorized officers.



Dated:


/s/ Matthew A. Megaro           Trimeris, Inc.            /s/ M. Ross Johnson
                                  Corporate
                                    SEAL
CHIEF FINANCIAL OFFICER             1993                   PRESIDENT AND CHIEF
    AND SECRETARY                 DELAWARE                  EXECUTIVE OFFICER


(c) SECURITY COLUMBIAN UNITED STATES BANKNOTE COMPANY 1980



(the following text appears rotated 90 degrees on the right side of page)

COUNTERSIGNED:                 WACHOVIA BANK, N.A.
                               (WINSTON-SALEM, NC)
BY:                                                           TRANSFER AGENT

                                                            AUTHORIZED SIGNATURE


                                      
<PAGE>

                                 TRIMERIS, INC.

The Corporation shall furnish without charge to each stockholder who so
requests the powers, designations, preferences and relative, participating,
optional or other special rights of each class of stock or series thereof and
the qualifications, limitations or restrictions of such preferences and/or
rights.

     The following abbreviations, when used in the inscription on the face of
this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:


TEN COM -as tenants in common         UNIF GIFT MIN ACT-______ CUSTODIAN_______
TEN ENT -as tenants by the entireties                    (Cust)         (Minor)
JT  TEN -as joint tenants with right of          under Uniform Gifts to Minors
         survivorship and not as tenants         Act________________________
         in common                                         (State)

    Additional abbreviations may also be used though not in the above list.


For value received, ______________ hereby sell, assign and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER
 IDENTIFYING NUMBER OF ASSIGNEE


- --------------------------------------------------------------------------------
   (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
- ----------------------------------------------------------------------   shares
of the capital stock represented by the within Certificate, and do hereby
irrevocably constitute and appoint

- ------------------------------------------------------------------- Attorney to
transfer the said stock on the books of the within named Corporation with full
power of substitution in the premises.


Dated
      -------------------------
Signature(s) Guaranteed:                            ----------------------------
                                                             Signature(s)

- -------------------------------------          ---------------------------------
THE SIGNATURE(S) SHOULD BE GUARANTEED          NOTICE: THE SIGNATURE(S) ON THIS
BY AN ELIGIBLE GUARANTOR INSTITUTION,          ASSIGNMENT MUST CORRESPOND WITH
AS DEFINED IN RULE 17 Ad-15 UNDER THE          THE NAME(S) AS WRITTEN UPON THE
SECURITIES AND EXCHANGE ACT OF 1934,           FACE OF THE CERTIFICATE, IN EVERY
AND AMENDED.                                   PARTICULAR, WITHOUT ALTERATION OR
                                               ENLARGEMENT, OR ANY CHANGE
                                               WHATEVER.






                                 TRIMERIS, INC.
                       1997 EMPLOYEE STOCK PURCHASE PLAN


PURPOSE                 The Trimeris, Inc. Employee Stock Purchase Plan (the
                        "ESPP" or the "Plan") provides employees of Trimeris,
                        Inc. (the "Company") and selected Company Subsidiaries
                        with an opportunity to become owners of the Company
                        through the purchase of shares of the Company's common
                        stock (the "Common Stock"). The Company intends this
                        Plan to qualify as an employee stock purchase plan
                        under Section 423 of the Internal Revenue Code of
                        1986, as amended (the "Code"), and its terms should
                        be construed accordingly.

ELIGIBILITY             An Employee whom the Company or an Eligible
                        Subsidiary has employed continuously for one year as
                        of the first day of an Offering Period is eligible to
                        participate in the ESPP for that Offering Period;
                        provided, however, that an Employee may not make a
                        purchase under the ESPP if such purchase would result
                        in the Employee's owning Common Stock possessing 5% or
                        more of the total combined voting power or value of the
                        Company's outstanding stock. For purposes of
                        determining an individual's amount of stock ownership,
                        any options to acquire shares of Company Common Stock
                        are counted as shares of stock, and the attribution
                        rules of Section 424(d) of the Code apply.

                        Employee means any person employed as a common law
                        employee of the Company or an Eligible Subsidiary.
                        Employee excludes anyone who, with respect to any
                        particular period of time, was not treated initially
                        on the payroll records as a common law employee.

ADMINISTRATOR           The Compensation Committee of the Board of Directors
                        of the Company, or such other committee as the Board
                        designates (the "Committee"), will administer the ESPP.
                        The Committee is vested with full authority and
                        discretion to make, administer, and interpret such
                        rules and regulations as it deems necessary to
                        administer the ESPP (including rules and regulations
                        deemed necessary in order to comply with the
                        requirements of Section 423 of the Code). Any
                        determination or action of the Committee in connection
                        with the administration or interpretation of the ESPP
                        shall be final and binding upon each Employee,
                        Participant and all persons claiming under or through
                        any Employee or Participant.

- -------------------------------------------------------------------------------
                                     Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 1 of 11

<PAGE>
<PAGE>

                        Without shareholder consent and without regard to
                        whether the actions might adversely affect
                        Participants, the Compensation Committee (or the
                        Board) may change the Offering Periods, limit or
                        increase the frequency and/or number of changes in the
                        amount withheld during an Offering Period, establish
                        the exchange ratio applicable to amounts withheld in
                        a currency other than U.S. dollars, permit payroll
                        withholding in excess of the amount the Participant
                        designated to adjust for delays or mistakes in the
                        Company's processing of properly completed withholding
                        elections, establish reasonable waiting and adjustment
                        periods and/or accounting and crediting procedures
                        to ensure that amounts applied toward the purchase of
                        Common Stock for each Participant properly correspond
                        with amounts withheld from the Participant's
                        Compensation, and establish such other limitations or
                        procedures as it determines in its sole discretion
                        advisable and consistent with the Plan.

OFFERING                Offering Periods are successive and overlapping 24
PERIOD                  month periods beginning on the first Trading Day on or
                        after December 1 and June 1 of each year and ending
                        on the last Trading Day in the 24 month period, but
                        the first period will run from [the effective date of
                        the initial public offering for the Common Stock]
                        through May 31, 1999. The Board may change the
                        duration of Offering Periods (including their
                        beginning dates) with respect to future offerings
                        without shareholder approval if the change is
                        announced at least five days before the scheduled
                        beginning of the first Offering Period for which
                        the change is effective.

PARTICIPATION           An eligible Employee may become a "Participant" for
                        an Offering Period by completing an authorization
                        notice and delivering it to the Committee through
                        the Company's Human Resources Department within a
                        reasonable period of time before the first day of such
                        Offering Period. The Committee will send to each
                        new Employee who satisfies the rules in Eligibility
                        above a notice advising the Employee of his right to
                        participate in the ESPP for the following Offering
                        Period. All Participants receiving options under the
                        ESPP will have the same rights and privileges.

METHOD                  A Participant may contribute to the ESPP through
OF PAYMENT              payroll deductions, as follows:

                        The Participant must elect on an authorization notice
                        to have deductions made from his Compensation for
                        each payroll period during the Offering Period at a
                        rate of at least 1% but not more than 10% of his
                        Compensation. Compensation under the Plan means an
                        Employee's


- -------------------------------------------------------------------------------
                                     Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 2 of 11

<PAGE>
<PAGE>


                        regular compensation, including overtime, bonuses, and
                        commissions, from the Company or an Eligible Subsidiary
                        paid during an Offering Period.

                        All payroll deductions will be credited to the
                        Participant's account under the ESPP. No interest or
                        earnings will accrue on any payroll deductions credited
                        to such accounts.

                        Payroll deductions will begin on the first payday
                        coinciding with or following the first day of each
                        Offering Period and will end with the last payday
                        preceding or coinciding with the end of that Offering
                        Period, unless the Participant sooner withdraws as
                        authorized under Withdrawals below.

                        A Participant may not alter the rate of payroll
                        deductions during the Offering Period.

                        The Company may use the consideration it receives for
                        general corporate purposes.

GRANTING OF             On the first day of each Offering Period, a Participant
OPTIONS                 will receive options to purchase on each Exercise Date
                        during the Offering Period a number of shares of
                        Common Stock with funds withheld from his Compensation.
                        Such number of shares will be determined at the end of
                        the Purchase Period according to the following
                        procedure:

                                Step 1--Determine the amount the Company
                                withheld from Compensation since the later of
                                the beginning of the Offering Period or the
                                preceding Exercise Date;

                                Step 2--Determine the amount that represents
                                85% of the lower of Fair Market Value of a
                                share of Common Stock on the (I) first day of
                                the Offering Period, or (II) the Exercise Date;
                                and

                                Step 3--Divide the amount determined in Step 1
                                by the amount determined in Step 2 and round
                                down the quotient to the nearest whole number.

        FAIR MARKET     The Fair Market Value of a share of Common Stock for
        VALUE           purposes of the Plan as of each date described in
                        Step 2 will be determined as follows:

- -------------------------------------------------------------------------------
                                     Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 3 of 11

<PAGE>
<PAGE>

                                 if the Common Stock is traded on a national
                                 securities exchange, the closing sale price on
                                 that date;

                                 if the Common Stock is not traded on any such
                                 exchange, the closing sale price as reported
                                 by the National Association of Securities
                                 Dealers, Inc. Automated Quotation System
                                 ("Nasdaq") for such date;

                                 if no such closing sale price information is
                                 available, the average of the closing bid and
                                 asked prices as reported by Nasdaq for such
                                 date;

                                 if there are no such closing bid and asked
                                 prices, the average of the closing bid and
                                 asked prices as reported by any other
                                 commercial service for such date; or

                                 if there is no established market for the
                                 Common Stock, the value as determined in
                                 good faith by the Board.

                        A Trading Day is a day on which the national stock
                        exchanges and Nasdaq are open for trading.

                        No Participant shall receive options:

                                 if, immediately after the grant, that
                                 Participant would own shares, or hold
                                 outstanding options to purchase shares, or
                                 both, possessing 5% or more of the total
                                 combined voting power or value of all classes
                                 of shares of the Company or any Subsidiaries;
                                 or

                                 that permit the Participant to purchase
                                 shares under all employee stock purchase
                                 plans of the Company and any Subsidiary with a
                                 Fair Market Value (determined at the time the
                                 options are granted) that exceeds $25,000 in
                                 any calendar year.

EXERCISE                Unless a Participant effects a timely withdrawal
OF OPTION               pursuant to the Withdrawal paragraph below, his option
AND PURCHASE            for the purchase of shares of Common Stock during
PERIODS                 an Offering Period will be automatically exercised
                        as of each Exercise Date for the purchase of the
                        maximum number of full shares that the sum of the
                        payroll deductions credited to the Participant's
                        account during the Purchase Period ending on that
                        Exercise Date can purchase pursuant to the formula
                        specified in Granting of


- -------------------------------------------------------------------------------
                                     Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 4 of 11

<PAGE>
<PAGE>


                        Options.


        Exercise Date   The Exercise Date is the last Trading Day of a given
                        Purchase Period.

        Purchase        The Purchase Period is the approximately six-month
        Period          period beginning after an Exercise Date and ending
                        with the next Exercise Date, except that the first
                        Purchase Period of any Offering Period will begin on
                        the first day of the Offering Period and end with the
                        next Exercise Date and that the initial Purchase Period
                        will run from [the effective date of the initial public
                        offering for the Common Stock] through May 31, 1999

                        Any payroll deductions credited to a Participant's
                        account during the Offering Period that are not used
                        for the purchase of shares will be treated as follows:

                                If the Participant has elected to withdraw
                                from the ESPP as of the end of the Offering
                                Period, the Company will deliver the amount of
                                the payroll deductions to the Participant.

                                The amount of any other excess payroll
                                deductions will be applied to the purchase of
                                shares in the immediately succeeding Offering
                                Period.

DELIVERY OF             As soon as administratively feasible after the options
COMMON                  are used to purchase Common Stock, the Company will
STOCK                   deliver to each Participant or, in the alternative, to
                        a custodian that the Committee designates, the shares
                        of Common Stock the Participant purchased upon
                        the exercise of the option. If shares are delivered
                        to a custodian, the Participant may elect at any time
                        thereafter to take possession of the shares or to 
                        have the Committee deliver the shares to any brokerage
                        firm. The Committee may, in its discretion, establish
                        a program for cashless sales of Common Stock received
                        under the ESPP.


SUBSEQUENT              A Participant will be deemed to have elected to
OFFERINGS               participate in each subsequent Offering Period
                        following his initial election to participate in the
                        ESPP, unless the Participant files a written withdrawal
                        notice with the Human Resources Department at least ten
                        days before the beginning of the Offering Period as of
                        which the Participant desires to withdraw from the ESPP.


WITHDRAWAL              A Participant may withdraw all, but not less than all,
FROM THE                payroll deductions
PLAN

<PAGE>
<PAGE>

- ------------------------------------------------------------------------------
                                Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 5 of 11

                        credited to his account for an Offering Period before
                        the end of such Offering Period by delivering a written
                        notice to the Human Resources Department on behalf of
                        the Committee at least thirty days before the end of
                        such Offering Period. A Participant who for any
                        reason, including retirement, termination of
                        employment, or death, ceases to be an Employee before
                        the last day of any Offering Period will be deemed to
                        have withdrawn from the ESPP as of the date of such
                        cessation.

                        Upon the withdrawal of a Participant from the ESPP
                        under the terms of Subparagraph (b) above, his
                        outstanding options under the ESPP will immediately
                        terminate.

                        If a Participant withdraws from the ESPP for any
                        reason, the Company will pay to the Participant all
                        payroll deductions credited to his account or, in the
                        event of death, to the persons designated as provided
                        in Designation of Beneficiary, as soon as
                        administratively feasible after the date of such
                        withdrawal and no further deductions will be made
                        from the Participant's Compensation.


                        A Participant who has elected to withdraw from the ESPP
                        may resume participation in the same manner and pursuant
                        to the same rules as any Employee making an initial
                        election to participate in the ESPP, i.e., he may elect
                        to participate in the next following Offering Period so
                        long as he files the authorization form by the deadline
                        for that Offering Period. Any Participant who is
                        subject to Section 16 of the Securities Exchange Act
                        of 1934, as amended (the "Exchange Act"), and who
                        withdraws from the ESPP for any reason will only be
                        permitted to resume participation in a manner that
                        will permit transactions under the ESPP to continue
                        to be exempt within the meaning of Rule 16b-3, as
                        issued under the Exchange Act.


STOCK SUBJECT           The shares of Common Stock that the Company will sell
TO PLAN                 to Participants under the ESPP will be shares of
                        authorized but unissued Common Stock. The maximum
                        number of shares made available for sale under the
                        ESPP will be _____ (subject to the provisions in
                        Adjustments upon Changes in Capital Stock). If the
                        total number of shares for which options are to be
                        exercised in a Purchase Period exceeds the number of
                        shares then available under the ESPP, the Company will
                        make, so far as is practicable, a pro rata allocation
                        of the shares available.

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

                        Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 6 of 11

<PAGE>
<PAGE>
                        A Participant will have no interest in shares covered by
                        his option until the Participant exercises the option.

                        Shares that a Participant purchases under the ESPP will
                        be registered in the name of the Participant or, at the
                        Participant's election, in street name.

                        The Company will not issue fractional shares pursuant to
                        the ESPP, but the Administrator may, in its discretion,
                        direct the Company to make a cash payment in lieu of
                        fractional shares.

[REPORTS                Individual accounts will be maintained for each
                        Participant. Statements of account will be given to
                        Participants at least annually, and those statements
                        will set forth the amount of payroll deductions, the
                        exercise price, the number of shares purchased, and the
                        remaining cash balance, if any.]

ADJUSTMENTS             Subject to any required action by the Company (which it
UPON CHANGES            shall promptly take) or its stockholders, and subject to
IN CAPITAL STOCK        the provisions of applicable corporate law, if, during
                        an Offering Period,

                                the outstanding shares of Common Stock increase
                                or decrease or change into or are exchanged for
                                a different number or kind of security by reason
                                of any recapitalization, reclassification, stock
                                split, reverse stock split, combination of
                                shares, exchange of shares, stock dividend, or
                                other distribution payable in capital stock, or

                                some other increase or decrease in such Common
                                Stock occurs without the Company's receiving
                                consideration,

                        the Administrator will make a proportionate and
                        appropriate adjustment in the number of shares of Common
                        Stock underlying the options, so that the proportionate
                        interest of the Participant immediately following such
                        event will, to the extent practicable, be the same as
                        immediately before such event. Any such adjustment to
                        the options will not change the total price with respect
                        to shares of Common Stock underlying the Participant's
                        election but will include a corresponding proportionate
                        adjustment in the price of the Common Stock, to the
                        extent consistent with Section 424 of the Code.

                        The Administrator will make a commensurate change to
                        the maximum

- -------------------------------------------------------------------------------
                                      Trimeris 1997 Employee Stock Purchase Plan
                                                                    Page 7 of 11
<PAGE>
<PAGE>

                        number and kind of shares provided in the Stock Subject
                        to Plan section.

                        Any issue by the Company of any class of preferred
                        stock, or securities convertible into shares of common
                        or preferred stock of any class, will not affect, and no
                        adjustment by reason thereof will be made with respect
                        to, the number of shares of Common Stock subject to any
                        options or the price to be paid for stock except as this
                        Adjustments section specifically provides. The grant of
                        an option under the Plan will not affect in any way the
                        right or power of the Company to make adjustments,
                        reclassifications, reorganizations or changes of its
                        capital or business structure, or to merge or to
                        consolidate, or to dissolve, liquidate, sell, or
                        transfer all or any part of its business or assets.

Substantial             Upon a Substantial Corporate Change, the Plan and the
Corporate               offering will terminate unless provision is made in
Change                  writing in connection with such transaction for

                                the assumption or continuation of outstanding
                                elections, or

                                the substitution for such options or grants of
                                any options or grants covering the stock or
                                securities of a successor employer corporation,
                                or a parent or subsidiary of such successor,
                                with appropriate adjustments as to the number
                                and kind of shares of stock and prices, in which
                                event the options will continue in the manner
                                and under the terms so provided.

                        If an option would otherwise terminate pursuant to the
                        preceding sentence, the optionee will have the right, at
                        such time before the consummation of the transaction
                        causing such termination as the Board reasonably
                        designates, to exercise any unexercised portions of the
                        option. [However, the Board may determine that allowing
                        such exercise before the end of the Offering Period will
                        not occur if the election would render unavailable
                        "pooling of interest" accounting for any reorganization,
                        merger, or consolidation of the Company.]

                        A Substantial Corporate Change means the

                                dissolution or liquidation of the Company,

                                merger, consolidation, or reorganization of the
                                Company with one or more corporations in which
                                the Company is not the surviving

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                                      Trimeris 1997 Employee Stock Purchase Plan
                                                                    Page 8 of 11
<PAGE>
<PAGE>

                        corporation,

                        the sale of substantially all of the assets of the
                        Company to another corporation, or

                        any transaction (including a merger or reorganization in
                        which the Company survives) approved by the Board that
                        results in any person or entity (other than any
                        affiliate of the Company as defined in Rule 144(a)(l)
                        under the Securities Act) owning 100% of the combined
                        voting power of all classes of stock of the Company.

DESIGNATION OF          A Participant may file with the Committee a written
BENEFICIARY             designation of a beneficiary who is to receive any
                        payroll deductions credited to the Participant's account
                        under the ESPP or any shares of Common Stock owed to the
                        Participant under the ESPP if the Participant dies. A
                        Participant may change a beneficiary at any time by
                        filing a notice in writing with the Human Resources
                        Department on behalf of the Committee.

                        Upon the death of a Participant and upon receipt by the
                        Committee of proof of the identity and existence of the
                        Participant's designated beneficiary, the Company shall
                        deliver such cash or shares, or both, to the
                        beneficiary. If a Participant dies and is not survived
                        by a beneficiary that the Participant designated in
                        accordance with the immediate preceding paragraph, the
                        Company will deliver such cash or shares, or both, to
                        the personal representative of the estate of the
                        deceased Participant. If, to the knowledge of the
                        Committee, no personal representative has been appointed
                        within 90 days following the date of the Participant's
                        death, the Committee, in its discretion, may direct the
                        Company to deliver such cash or shares, or both, to the
                        surviving spouse of the deceased Participant, or to any
                        one or more dependents or relatives of the deceased
                        Participant, or if no spouse, dependent or relative is
                        known to the Committee, then to such other person as the
                        Committee may designate.

                        No designated beneficiary may acquire any interest in
                        such cash or shares before the death of the Participant.

SUBSIDIARY              Employees of Company Subsidiaries will be entitled to
EMPLOYEES               participate in the ESPP, except as otherwise designated
                        by the Board of Directors or the Committee.




- -------------------------------------------------------------------------------
                                      Trimeris 1997 Employee Stock Purchase Plan
                                                                    Page 9 of 11

<PAGE>
<PAGE>

                        Eligible Subsidiary means each of the Company's
                        Subsidiaries (if any), except as the Board otherwise
                        specifies. Subsidiary means any corporation (other than
                        the Company) in an unbroken chain of corporations
                        beginning with the Company if, at the time an option is
                        granted to a Participant under the ESPP, each of the
                        corporations (other than the last corporation in the
                        unbroken chain) owns stock possessing 50% or more of the
                        total combined voting power of all classes of stock in
                        one of the other corporations in such chain.


TRANSFERS,              A participant may not assign, pledge, or otherwise
ASSIGNMENTS             dispose of payroll deductions credited to the
AND PLEDGES             Participant's account or any rights to exercise an
                        option or to receive shares of Common Stock under the
                        ESPP other than by will or the laws of descent and
                        distribution or pursuant to a qualified domestic
                        relations order, as defined in the Employee Retirement
                        Income Security Act. Any other attempted assignment,
                        pledge, or other disposition will be without effect,
                        except that the Company may treat such act as an
                        election to withdraw under the Withdrawal section.

AMENDMENT OR            The Board of Directors of the Company may at any time
TERMINATION             terminate or amend the ESPP. Any amendment of the ESPP
OF PLAN                 that (i) materially increases the benefits to
                        Participants, (ii) materially increases the number of
                        securities that may be issued under the ESPP, or (iii)
                        materially modifies the eligibility requirements for
                        participation in the ESPP must be approved by the
                        shareholders of the Company to take effect. The Company
                        shall refund to each Participant the amount of payroll
                        deductions credited to his account as of the date of
                        termination as soon as administratively feasible
                        following the effective date of the termination.

NOTICES                 All notices or other communications by a Participant to
                        the Committee or the Company shall be deemed to have
                        been duly given when the Human Resources Department or
                        the Secretary of the Company receives them or when any
                        other person the Company designates receives the notice
                        or other communication in the form the Company
                        specifies.

GENERAL ASSETS          Any amounts the Company invests or otherwise sets aside
                        or segregates to satisfy its obligations under this ESPP
                        will be solely the Company's property (except as
                        otherwise required by Federal or state wage laws), and
                        the optionee's claim against the Company under the ESPP,
                        if any, will be only as a general creditor. The optionee
                        will have no right, title, or interest whatever in or to
                        any investments that the Company may make to aid it in
                        meeting its obligations under the ESPP. Nothing

- -------------------------------------------------------------------------------
                                      Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 10 of 11
<PAGE>
<PAGE>
                        contained in the ESPP, and no action taken pursuant to
                        its provisions, will create or be construed to create an
                        implied or constructive trust of any kind or a fiduciary
                        relationship between the Company and any Employee,
                        Participant, former Employee, former Participant, or any
                        beneficiary.

PRIVILEGES OF           No Participant and no beneficiary or other person
STOCK OWNERSHIP         claiming under or through such Participant will have any
                        right, title, or interest in or to any shares of Common
                        Stock allocated or reserved under the Plan execpt as to
                        such shares of Common Stock, if any, that have been
                        issued to such Participant.

LIMITATIONS ON          Notwithstanding any other provisions of the ESPP, no
LIABILITY               individual acting as a director, employee, or agent of
                        the Company shall be liable to any Employee,
                        Participant, former Employee, former Participant, or any
                        spouse or beneficiary for any claim, loss, liability, or
                        expense incurred in connection with the ESPP, nor shall
                        such individual be personally liable because of any
                        contract or other instrument he executes in such other
                        capacity. The Company will indemnify and hold harmless
                        each director, employee, or agent of the Company to whom
                        any duty or power relating to the administration or
                        interpretation of the ESPP has been or will be
                        delegated, against any cost or expense (including
                        attorneys' fees) or liability (including any sum paid in
                        settlement of a claim with the Trimeris Board's
                        approval) arising out of any act or omission to act
                        concerning this ESPP unless arising out of such person's
                        own fraud or bad faith.

NO EMPLOYMENT           Nothing contained in this Plan constitutes an employment
CONTRACT                contract between the Company or an Eligible Subsidiary
                        and any Employee. The ESPP does not give an Employee any
                        right to be retained in the Company's employ, nor does
                        it enlarge or diminish the Company's right to terminate
                        the Employee's employment.

DURATION OF ESPP        Unless the Board extends the Plan's term, no Offering
                        Period will begin after the tenth anniversary of its
                        initial approval by the Board.

APPLICABLE LAW          The laws of the State of North Carolina (other than its
                        choice of law provisions) govern the ESPP and its
                        interpretation.

APPROVAL OF             The ESPP must be submitted to the shareholders of the
SHAREHOLDERS            Company for their approval within 12 months after the
                        Board of Directors of the Company adopts the ESPP. The
                        adoption of the ESPP is conditioned upon the approval of
                        the shareholders of the Company, and failure to receive
                        their approval will render the ESPP and any outstanding
                        options thereunder void and of no effect.

- -------------------------------------------------------------------------------
                                      Trimeris 1997 Employee Stock Purchase Plan
                                                                   Page 11 of 11







                               INDEMNITY AGREEMENT

         THIS AGREEMENT is made and entered into as of July 2, 1997 by and
between Trimeris, Inc., a Delaware corporation (the "Corporation"), and
____________________ ("Indemnitee").

                                    RECITALS

         WHEREAS, Indemnitee, a member of the Board of Directors and/or an
officer of the Corporation, performs a valuable service in such capacity for the
Corporation; and

         WHEREAS, in order to induce Indemnitee to continue to serve as a
Director and/or an officer of the Corporation, the Corporation has determined
and agreed to enter into this Agreement with Indemnitee.

         NOW, THEREFORE, in consideration of Indemnitee's continued service as a
Director/and or an officer after the date hereof, the parties hereto agree as
follows:

         1. SERVICES TO THE CORPORATION. Indemnitee will serve, at the will of
the Corporation under separate contract, if any such contract exists, as an
officer and/or Director of the Corporation, or as a director, officer or other
fiduciary of an affiliate of the Corporation (including any employee benefit
plan of the Corporation) faithfully and to the best of his ability so long as he
is duly elected and qualified in accordance with the Certificate of
Incorporation and the Bylaws, as amended or amended and restated from time to
time, of the Corporation or of such affiliate (the "Organizational Documents");
provided, however, that Indemnitee may at any time and for any reason resign
from such position or any other position (subject to any contractual obligation
that Indemnitee may have assumed apart from this Agreement) and that the
Corporation or any affiliate shall have no obligation under this Agreement to
continue Indemnitee in such position or any other position.

         2. INDEMNITY OF INDEMNITEE. The Corporation hereby agrees to hold
harmless and indemnify Indemnitee to the fullest extent authorized or permitted
by the Organizational Documents and the Delaware General Corporation Law, as
amended (the "Code"), as the same may be amended from time to time (but only to
the extent that any such amendment permits the Corporation to provide broader
indemnification rights than the Organizational Documents or the Code permitted
prior to adoption of such amendment).

         3. ADDITIONAL INDEMNITY. In addition to and not in limitation of the
indemnification otherwise provided for herein, and subject only to the
Organizational Documents, the Code, any other applicable law and the exclusions
set forth in Section 4 hereof, the Corporation hereby further agrees to hold
harmless and indemnify Indemnitee:


                                       1
<PAGE>
<PAGE>

         (a) against any and all expenses (including attorneys' fees), witness
fees, damages, judgments, fines and amounts paid in settlement and any other
amounts that Indemnitee becomes legally obligated to pay because of any claim or
claims made against or by him in connection with any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, arbitral,
administrative or investigative (including an action by or in the right of the
Corporation), to which Indemnitee is, was or at any time becomes a party, or is
threatened to be made a party, by the reason of the fact that Indemnitee is, was
or at any time becomes a director, officer, employee or other agent of the
Corporation or is or was serving or at any time serves at the written request of
the Corporation as a director, officer, employee or other agent of another
corporation, partnership, joint venture, trust, employee benefit plan or other
enterprise; and

         (b)      otherwise to the fullest extent as may be provided to

Indemnitee by the Corporation under the Code and the Organizational Documents.

         4. LIMITATIONS ON ADDITIONAL INDEMNITY. No indemnity pursuant to
Section 3 hereof shall be paid by the Corporation:

         (a) on account of any claim against Indemnitee for an accounting of
profits made from the purchase or sale by Indemnitee of securities of the
Corporation, pursuant to the provisions of Section 16(b) of the Securities
Exchange Act of 1934 and amendments thereto or similar provisions of any
federal, state or local statutory law; or

         (b) for which payment has actually been made to Indemnitee under a
valid and collectible insurance policy or under a valid and enforceable
indemnity clause, bylaw or agreement, except in respect of any excess beyond
payment under such insurance, clause, bylaw or agreement; or

         (c) in connection with any proceeding (or part thereof) brought or made
by Indemnitee against the Corporation, unless (i) such indemnification is
expressly required to be made by law, or (ii) the proceeding is initiated
pursuant to Section 9 hereof; or

         (d) on account of Indemnitee's conduct which is finally adjudged to
have been knowingly fraudulent or deliberately dishonest, or to constitute
willful misconduct.

         5. CONTINUATION OF INDEMNITY. All agreements and obligations of the
Corporation contained herein shall continue during the period Indemnitee is a
director, officer, employee or other agent of the Corporation (or is or was
serving at the written request of the Corporation as a director, officer,
employee or other agent of another corporation, partnership, joint venture,
trust, employee benefit plan or other enterprise) and shall continue thereafter
so long as Indemnitee shall be subject to any possible claim or threatened,
pending or complete action, suit or proceeding, whether civil, criminal,
arbitral, administrative or investigative, by reason of the fact that Indemnitee
was serving in the capacity referred to herein.

                                       2
<PAGE>
<PAGE>

         6. PARTIAL INDEMNIFICATION. Indemnitee shall be entitled under this
Agreement to indemnification by the Corporation for a portion of the expenses
(including attorneys' fees), witness fees, damages, judgments, fines and amount
paid in settlement and any other amounts that Indemnitee becomes legally
obligated to pay in connection with any action, suit or proceeding referred to
in Section 4 hereof even if not entitled hereunder to indemnification for the
total amount thereof, and the Corporation shall indemnify Indemnitee for the
portion thereof to which Indemnitee is entitled.

         7. NOTIFICATION AND DEFENSE OF CLAIM. Not later than thirty (30) days
after receipt by Indemnitee of notice of the commencement of any action, suit or
proceeding, Indemnitee will, if a claim in respect thereof is to be made against
the Corporation under this Agreement, notify the Corporation of the commencement
thereof; but the omission so to notify the Corporation will not relieve it from
any liability except to the extent that the failure to notify shall prejudice
the Corporation and will not relieve it from any liability which it may have to
Indemnitee otherwise than under this Agreement. With respect to any such action,
suit or proceeding as to which Indemnitee notifies the Corporation of the
commencement thereof:

         (a) The Corporation will be entitled to participate therein at its own
expense;

         (b) Except as otherwise provided below, the Corporation may, at its
option and jointly with any other indemnifying party similarly notified and
electing to assume such defense, assume the defense thereof, with counsel
reasonably satisfactory to Indemnitee. After notice from the Corporation to
Indemnitee of its election to assume the defense thereof, the Corporation will
not be liable to Indemnitee under this Agreement for any legal or other expenses
subsequently incurred by Indemnitee in connection with the defense thereof
except for reasonable costs of investigation or otherwise as provided below.
Indemnitee shall have the right to employ separate counsel in such action, suit
or proceeding but the fees and expenses of such counsel incurred after notice
from the Corporation of its assumption of the defense thereof shall be at the
expense of Indemnitee unless (i) the employment of counsel by Indemnitee has
been authorized by the Corporation, (ii) Indemnitee shall have reasonably
concluded that there may be a conflict of interest between the Corporation and
Indemnitee in the conduct of the defense of such action or (iii) the Corporation
shall not in fact have employed counsel to assume the defense of such action, in
each of which cases the fees and expenses of Indemnitee's separate counsel shall
be at the expense of the Corporation. The Corporation shall not be entitled to
assume the defense of any action, suit or proceeding brought by or on behalf of
the Corporation or as to which Indemnitee shall have made the conclusion
provided for in clause (ii) above;

         (c) The Corporation shall not be liable to indemnify Indemnitee under
this Agreement for any amounts paid in settlement of any action or claim
effected without its written consent, which shall not be unreasonably withheld.
The Corporation shall be permitted to settle any action except that it shall not
settle any action or claim in any manner which would impose any penalty or
limitation on Indemnitee without

                                       3
<PAGE>
<PAGE>

Indemnitee's written consent, which may be given or withheld in 
Indemnitee's sole discretion;

         (d) If there is a Change in Control (defined below) of the Corporation,
then with respect to all matters thereafter arising concerning the rights of
Indemnitee to indemnity, expense payments and/or advances under this Agreement
or any other agreement or the Organizational Documents now or hereafter in
effect, the Corporation shall seek and follow legal advice only from Independent
Legal Counsel (defined below) selected by Indemnitee and approved by the
Corporation (which approval shall not be unreasonably withheld). Such counsel,
among other things, shall render its written opinion to the Corporation and
Indemnitee as to whether and to what extent Indemnitee would be permitted to be
indemnified under applicable law. The Corporation shall pay the reasonable fees
of such Independent Legal Counsel.

         (e) For the purpose of this Section, a "Change in Control" shall be
deemed to have occurred if (i) during any period of two consecutive years,
individuals who at the beginning of such period constitute the Board of
Directors of the Corporation and any new director whose election by the Board of
Directors or nomination for election by the Corporation's stockholders was
approved by a vote of at least two-thirds (2/3) of the directors still in office
who either were directors at the beginning of the period or whose election or
nomination for election was previously so approved, cease for any reason to
constitute a majority thereof, (ii) the stockholders of the Corporation approve
a merger or consolidation of the Corporation with any other corporation, other
than a merger or consolidation that would result in the voting securities of the
Corporation outstanding immediately prior thereto continuing to represent
(either by remaining outstanding or by being converted into voting securities of
the surviving entity) at least 80% of the total voting power represented by the
voting securities of the Corporation or such surviving entity outstanding
immediately after such merger or consolidation, or (iii) the stockholders or the
Corporation approve a plan of complete liquidation of the Corporation or an
agreement for the sale or disposition by the Corporation of (in one transaction
or a series of transactions) all or substantially all of the Corporation's
assets; and

         (f) For purposes of this Section, "Independent Legal Counsel" shall be
defined as an attorney or firm of attorneys, selected in accordance with this
Section, who have not otherwise performed services for the Corporation or
Indemnitee within the last five years (other than with respect to matters
concerning the rights of Indemnitee under this Agreement, or of other directors,
officers, employees or other agents under similar indemnity agreements).

         8. EXPENSES. The Corporation shall advance, prior to the final
disposition of any proceeding, promptly following request thereof, all expenses
incurred by Indemnitee in connection with such proceeding upon receipt of an
undertaking by or on behalf of Indemnitee to repay said amounts if it shall be
determined ultimately that


                                       4
<PAGE>
<PAGE>

Indemnitee is not entitled to be indemnified under the provisions of this 
Agreement, the Organizational Documents, the Code or otherwise.

         9. ENFORCEMENT. Any right to indemnification or advances granted by
this Agreement to Indemnitee shall be enforceable by or on behalf of Indemnitee
in any court of competent jurisdiction if (i) the claim for indemnification or
advances is denied, in whole or in part, or (ii) no disposition of such claim is
made within ninety (90) days of request therefor. Indemnitee in such enforcement
action, if successful in whole or in part, shall be entitled to be paid also the
expenses of prosecuting his claim. It shall be a defense to any action for which
a claim for indemnification is made under Section 3 hereof (other than an action
brought to enforce a claim for expenses pursuant to Section 8 hereof, provided
that the required undertaking has been tendered to the Corporation) that
Indemnitee is not entitled to indemnification because of the limitations set
forth in Section 4 hereof.

         10. SUBROGATION. In the event of payment under this Agreement, the
Corporation shall be subrogated to the extent of such payment to all of the
rights of recovery of Indemnitee, who shall execute all documents required and
shall do all acts that may be necessary to secure such rights and to enable the
Corporation effectively to bring suit to enforce such rights.

         11. NON-EXCLUSIVITY OF RIGHTS. The right conferred on Indemnitee by
this Agreement shall not be exclusive of any other right which Indemnitee may
have or hereafter acquire under any statute, provision of the Organizational
Documents, agreement, vote of stockholders or directors, or otherwise, both as
to action in his official capacity and as to action in another capacity while
holding office.

         12.      SURVIVAL RIGHTS.

         (a) The rights conferred on Indemnitee by this Agreement shall continue
after Indemnitee has ceased to be a director, officer, employee or other agent
of the Corporation or to serve at the request of the Corporation as a director,
officer, employee or other agent of another corporation, partnership, joint
venture, trust, employee benefit plan or other enterprise and shall inure to the
benefit of Indemnitee's heirs, executors and administrators.

         (b) The Corporation shall require any successor (whether direct or
indirect, by purchase, merger, consolidation or otherwise) to all or
substantially all of the business or assets of the Corporation, expressly to
assume and agree to perform this Agreement in the same manner and to the same
extent that the Corporation would be required to perform if no such succession
has taken place.

         13. SEPARABILITY. Each of the provisions of this Agreement is a
separate and distinct agreement and independent of the others, so that if any
provision hereof shall be held to be invalid for any reason, such invalidity or
unenforceablility shall


                                       5
<PAGE>
<PAGE>

not affect the validity or enforceability of the other provisions hereof.

Furthermore, if this Agreement shall be invalidated in its entirety on any

ground, then the Corporation shall nevertheless indemnify Indemnitee to the

fullest extent provided by the Organizational Documents, the Code or any other

applicable law.

         14. GOVERNING LAW. This Agreement shall be interpreted and enforced in
accordance with the laws of the State of Delaware.

         15. AMENDMENT AND TERMINATION. No amendment, modification, termination
or cancellation of this Agreement shall be effective unless in writing signed by
both parties hereto.

         16. COUNTERPARTS. This Agreement may be executed in one or more
counterparts, each of which shall for all purposes be deemed to be original but
all of which together shall constitute but one and the same Agreement.

         17. HEADINGS. The headings of the sections of this Agreement are
inserted for convenience only and shall not be deemed to constitute part of this
Agreement or to affect the construction hereof.

         18. NOTICES. All notices, requests, demands and other communications
hereunder shall be in writing and shall be deemed to have been duly given (i)
upon delivery if delivered by hand to the party to whom such communication was
directed or (ii) upon the third business day after the date on which such
communication was mailed if mailed by certified mail with postage prepaid
addressed as follows or to such other address as a party may hereafter designate
by notice given pursuant hereto:

         (a) If to Indemnitee, at the address indicated on the signature page
hereof.

         (b)  If the Corporation, to:
                  Trimeris, Inc.
                  4727 University Drive
                  Durham, North Carolina  27707

         IN WITNESS WHEROF, the parties hereto have executed this Agreement as
of the date first above written.

                                     TRIMERIS, INC.


                                     By: __________________________
                                                   Name:
                                                  Title:

                                       6

<PAGE>



                                        INDEMNITEE


                                        ------------------------------
                                        Print Indemnitee's name and address:

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

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

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

                                       7
<PAGE>




                                                                    EXHIBIT 23.2

                         INDEPENDENT AUDITORS' CONSENT

The Board of Directors
Trimeris, Inc.:

     We consent to the use of our report included herein and to the reference to
our firm under the heading "Experts" in the prospectus.

   
                                         /s/       KPMG PEAT MARWICK LLP

Raleigh, North Carolina
September 5, 1997
    





                                                                    EXHIBIT 23.3

                               CONSENT OF COUNSEL

   
     The undersigned hereby consents to the use of our name and the statement
with respect to us appearing under the heading "Experts" in Amendment No. 2 to
the Registration Statement on Form S-1 of of Trimeris, Inc.
    

                                         /s/       PENNIE & EDMONDS LLP

                                                  PENNIE & EDMONDS LLP

   
New York, New York
September 5, 1997
    



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