<DOCUMENT>
<TYPE>424B3
<SEQUENCE>1
<FILENAME>d424b3.txt
<DESCRIPTION>FINAL PROSPECTUS
<TEXT>
<PAGE>

                                              Filed Pursuant to Rule 424 (b)(3)
                                                     Registration No. 333-81708

PROSPECTUS

                               1,257,500 SHARES
                                [TRIMERIS LOGO]

                                Trimeris, Inc.

                                 COMMON STOCK

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

   This prospectus relates solely to the resale of up to an aggregate of
1,257,500 shares of common stock of Trimeris, Inc. that we sold to the selling
stockholders listed on pages 18-19 of this prospectus in a private placement
that closed on January 29, 2002. The selling stockholders may sell these shares
at market prices prevailing at the time of sale or at negotiated prices.

   We will not receive any of the proceeds from the sale of the shares being
sold by the selling stockholders. We have agreed to bear the expenses incurred
in connection with the registration of these shares. The selling stockholders
will pay or assume brokerage commissions or similar charges incurred in the
sale of these shares of common stock.

   Our common stock is traded on The Nasdaq National Market under the symbol
"TRMS." On January 25, 2002, the closing price for the common stock as reported
by Nasdaq was $37.14 per share.

Investing in our common stock involves risks. See "Risk Factors" starting on
page 7.

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

Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if
this prospectus is truthful or complete. Any representation to the contrary is
a criminal offense.

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

               The date of this prospectus is February 7, 2002.

<PAGE>

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
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             <S>                                               <C>

             Special Note Regarding Forward-Looking Statements   1

             Trimeris.........................................   3

             Risk Factors.....................................   7

             Use of Proceeds..................................  18

             Selling Stockholders.............................  18

             Plan of Distribution.............................  20

             Legal Matters....................................  22

             Experts..........................................  22

             Where You Can Find More Information..............  23
</TABLE>

<PAGE>

               SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

   Statements in this prospectus that are not historical fact are
forward-looking statements. These forward-looking statements include statements
regarding our expectations, hopes, beliefs, intentions or strategies regarding
the future and are subject to a number of known and unknown risks and
uncertainties, many of which are beyond our control. While we believe these
statements are accurate, our business is dependent on many factors, some of
which are discussed in the "Risk Factors" section of this prospectus and the
"Business" section of our Annual Report on Form 10-K, as amended.

   These factors include, but are not limited to, the following:

    .  we are a development stage company that has sustained losses since our
       inception, and expect our losses to continue and we may never develop
       any drugs that achieve commercial viability;

    .  if we cannot raise additional funds in the future, our ability to
       develop our drug candidates will suffer;

    .  terrorists attacks such as the attacks that occurred in New York and
       Washington, D.C. on September 11, 2001 and other attacks or acts of war
       may adversely affect the markets on which our common stock trades, our
       drug candidates, our financial condition and our results of operations;

    .  any additional financing we obtain may dilute our stockholders, restrict
       our operating flexibility or result in a transfer of particular rights
       to our technologies or drug candidates;

    .  if we are unable to commercialize T-20, our lead drug candidate, our
       business will be materially harmed;

    .  if our clinical trials are delayed or achieve unfavorable results, we
       may never obtain regulatory approval for our drugs or generate any
       revenue;

    .  if sufficient amounts of our drug candidates cannot be manufactured on a
       cost-effective basis or we cannot obtain the quantities of raw materials
       required to manufacture our drug candidates, our financial condition and
       results of operations will be materially and adversely affected;

    .  if Roche does not meet its contractual obligations to us, our research
       and development efforts and the regulatory approval and
       commercialization of our drug candidates could be delayed or otherwise
       materially and adversely affected;

    .  if we cannot maintain commercial manufacturing agreements with third
       parties on acceptable terms, or if these third parties do not perform as
       agreed, the commercial development of our drug candidates could be
       delayed or otherwise materially and adversely affected;

    .  our business is based on a novel technology called fusion inhibition,
       and unexpected side effects or other characteristics of this technology
       may delay or otherwise adversely affect the development, regulatory
       approval and/or commercialization of our drug candidates;

    .  even if we are successful in developing a commercially viable drug, in
       order to become profitable we will need to maintain arrangements with
       third parties for the sale, marketing and distribution of our drug
       candidates or expend significant resources to develop these capabilities;

    .  the HIV virus is likely to develop resistance to some of our drug
       candidates, which could adversely affect demand for those drug
       candidates and harm our competitive position;

    .  our stock price is highly volatile and an investor may not be able to
       sell shares of Trimeris stock at or above the price paid to acquire our
       shares;

    .  we depend on patents and proprietary rights, which may offer only
       limited protection against infringement, and if we are unable to protect
       these rights, our assets and business could be materially harmed;

    .  we are subject to extensive and complex government regulation, including
       regulation by the FDA, which can entail significant costs and could
       delay, limit or prevent commercialization of our drug candidates;

                                      1

<PAGE>

    .  we face intense competition in our efforts to develop commercially
       successful drugs in the biopharmaceutical industry and if we are unable
       to compete successfully, our business will suffer;

    .  our drugs may not achieve market acceptance;

    .  uncertainty relating to third-party reimbursement and health care reform
       measures could limit the amount we will be able to charge for our drugs
       and adversely affect our results of operations;

    .  if an accident or injury involving hazardous materials occurs, we could
       incur fines or liability, which could materially and adversely affect
       our business and our reputation;

    .  if the testing or use of our drug candidates harms people, we could face
       costly and damaging product liability claims far in excess of our
       liability and indemnification coverage;

    .  our quarterly operating results are subject to fluctuations, and if our
       operating results for a particular period deviate from the levels
       expected by securities analysts and investors, it could adversely affect
       the market price of our common stock;

    .  if we lose any of our executive management or other key employees, we
       will have difficulty replacing them, and if we cannot attract and retain
       qualified personnel on acceptable terms, the development of our drug
       candidates and our financial position may suffer; and

    .  future sales of our common stock by our existing stockholders or key
       management could adversely affect our stock price.

   Many of these factors are beyond our control and any of these and other
factors could cause actual results to differ materially from the
forward-looking statements made in this prospectus. The results of our previous
clinical trials are not necessarily indicative of the results of future
clinical trials. We undertake no obligation to release publicly the results of
any revisions to the statements contained in this prospectus to reflect events
or circumstances that occur subsequent to the date of this prospectus.

                                      2

<PAGE>

                                   TRIMERIS

   We are engaged in the discovery and development of a new class of antiviral
drug treatments called fusion inhibitors. Fusion inhibitors impair viral
fusion, a complex process by which viruses attach to and penetrate host cells.
If a virus cannot enter a host cell, the virus cannot replicate. By inhibiting
the fusion process of particular types of viruses, our drug candidates under
development offer a novel mechanism of action with the potential to treat many
serious viral diseases.

   We are a development stage company that has sustained operating losses since
our inception, and we expect these losses to continue. As of September 30,
2001, our accumulated deficit since beginning our operations in January 1993,
was approximately $167.4 million. We have invested a significant portion of our
time and financial resources in the development of T-20, our lead drug
candidate. If we are unable to commercialize T-20, our business will be
significantly harmed. In addition, we are engaged in segments of the
biopharmaceutical industry that are intensely competitive and change rapidly.

                              Our Drug Candidates

   Our most advanced drug candidates, T-20 and T-1249, are for the treatment of
human immunodeficiency virus--type I, or HIV. T-20 is our first generation
fusion inhibitor which prevents HIV from entering and infecting cells. T-1249
is our second generation fusion inhibitor for the HIV virus. T-1249 is in an
earlier stage of development than T-20 but is part of the same class of drug
treatments, fusion inhibitors. The history of HIV treatment has demonstrated
that the existence of multiple drugs within a drug treatment class allows for a
variety of drug combinations and may help improve patient treatment. We believe
that multiple types of anti-HIV fusion inhibitors may enhance HIV therapy by
providing an even broader range of treatment options than a single fusion
inhibitor would allow.

   Human pharmaceutical products, including our drug candidates, are subject to
lengthy and rigorous preclinical testing and clinical trials and other
extensive, costly and time-consuming procedures mandated by the United States
Food and Drug Administration, or FDA, and foreign regulatory authorities.
Clinical trials involve testing investigational drugs on healthy volunteers or
on infected patients under the supervision of a qualified principal
investigator. These trials typically are conducted in three sequential phases,
although the phases may overlap with one another.

    .  Phase I clinical trials involve giving an 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. This includes testing
       for dose tolerance and analyzing how the drug behaves in the body,
       including analyzing absorption, metabolism, excretion, clinical
       pharmacokinetics, or the amount of drug present in a patient's
       bloodstream, and biodistribution, or how a drug is distributed in
       tissues and organs.

    .  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.

    .  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 labeling for promotion and use.

   The results of the research and development, manufacturing analysis,
preclinical testing, clinical trials and related information are submitted to
the FDA in the form of a New Drug Application, or NDA, for approval of the
marketing and shipment of the drug.

                                      3

<PAGE>

    T-20.  To date, we have tested T-20 in more than 1,000 patients, with the
longest duration of treatment exceeding approximately two years. These studies
suggest that T-20 is well-tolerated and has potent antiviral activity, as
demonstrated in the TRI-003 trial by a maximum reduction of approximately
40-fold in the number of copies of the HIV virus present in the patient's
bloodstream after 14 days of dosing with T-20. A 40-fold reduction means that
the number of copies of the HIV virus circulating in the patient's bloodstream
was reduced by 97.5%, or to 2.5% of the original number. The most common
adverse event reported in our clinical trials of T-20 has been mild to moderate
local skin irritations at the site of injection, or injection site reactions.

   We currently have two ongoing Phase III clinical trials, T20-301 and
T20-302, and one ongoing Phase II clinical trial, T20-208, evaluating T-20, for
which we have not yet collected clinically relevant data. We plan to commence
additional Phase II and/or Phase III trials for T-20 throughout 2002. T-20 has
received "fast track" designation by the FDA for the treatment of HIV. Fast
track designation is granted to products that may provide a significant
improvement in the safety or effectiveness of the treatment for a serious or
life-threatening disease, and this designation is intended to expedite the drug
development process.

   In February 2001, we presented 16 week interim data from T20-206, a 71
patient, dose comparison Phase II trial for T-20. Patients in T20-206 were
randomly separated into four treatment groups, with the control group receiving
a potent, or very strong, background regimen consisting of four different,
currently-approved anti-HIV drugs--abacavir, amprenavir, efavirenz and
ritonavir. The conventional approach to treating HIV, as represented by these
four drugs, has been to lower viral loads, or the amount of HIV virus present
in the bloodstream, by using drugs that inhibit the viral enzymes necessary for
HIV to replicate. We designed T20-206 so that patients may receive these other
currently approved drugs, in what is commonly referred to as a background
regimen, in addition to T-20. The remaining three treatment groups are
receiving various dosage levels of T-20 by twice daily injections under the
skin, along with the background regimen. At 16 weeks, the median reduction of
viral load in the patient's blood from the viral load at the beginning of the
trial, commonly referred to as baseline viral load, for all patients across the
three T-20 treatment groups was 99.9%, compared to a median reduction of 99.3%
for the control group.

   In December 2001, we presented data from T20-204, a 12 patient pediatric
Phase I/II trial for T-20. In T20-204, 12 pediatric patients were randomly
assigned to two treatment groups to receive T-20 at different dosage levels in
combination with a background regimen of other anti-HIV drugs. At 24 weeks,
this trial showed that T-20 was well-tolerated by children and that children
receiving the highest dose experienced a ten-fold reduction in viral load from
baseline viral load. A ten-fold reduction in viral load from baseline viral
load means that the number of copies of the HIV virus circulating in the
patient's bloodstream was reduced by 90%, to one-tenth of the original number.

   In June 2001, we completed enrolling patients in a multi-center Phase III
clinical trial, T20-301, in North America, Mexico and Brazil. T20-301 is a 48
week study which enrolled approximately 500 HIV-infected patients with a
planned interim analysis at 24 weeks. In this trial, patients are randomly
assigned to receive either T-20 plus an optimized background regimen of
anti-HIV drugs, or an optimized regimen of anti-HIV drugs without T-20. For
each patient, the optimized regimen is a combination of other anti-HIV drugs
individually determined for that patient based on the genotypic and phenotypic
analysis of the HIV virus in that patient's blood. A genotypic resistance
analysis involves examination of the genetic sequence of the strains of virus
present in the sample. A phenotypic resistance analysis involves an assessment
of the ability of a drug to block infection caused by strains of a virus grown
in culture. T-20 is being administered by twice daily injections under the
skin, delivering 90 milligrams of T-20 each, using the formulation tested in
our ongoing Phase II trial, T20-208. In T20-208, analysis of the highest dose
group indicated that a patient received a delivered dose of 90 milligrams of
T-20 per dose. In August 2001, we completed enrolling patients in T20-302, a
multi-center Phase III clinical trial with a protocol, or trial design, similar
to T20-301. This trial enrolled approximately 500 HIV-infected patients in
Western Europe and Australia. Data from the 24-week interim analysis of these
trials is currently expected to be available during the first half of 2002.
Based upon data from the 24-week interim analysis of these trials, we currently
expect to file an NDA for T-20 with the FDA during the second half of 2002.

                                      4

<PAGE>

   T-1249.  Our second generation fusion inhibitor for HIV is T-1249. T-1249
has demonstrated potent, or strong, HIV suppression in culture, commonly
referred to as in vitro, and is highly active against a wide range of HIV
strains in vitro, including strains resistant to T-20. HIV is prone to genetic
mutations that produce strains of HIV that are resistant to currently-approved
anti-HIV therapies. Resistance occurs because viruses make trillions of copies
of themselves and some copies will contain mutations in their genetic material.
Mutations that confer a selective advantage, such as drug resistance, will
enable mutant viruses to replicate even in the presence of an active drug. As a
result, these mutants, while initially found in low frequency, can become the
predominant strain in an infected patient undergoing drug therapy and can be
transmitted to other individuals. Generally, an HIV virus that is resistant to
one drug within a drug treatment class is likely to become resistant to the
entire drug treatment class, a phenomenon known as cross-resistance. Attempts
to reestablish suppression of HIV viral load by substituting different anti-HIV
combinations from the same drug treatment class often fail because of
cross-resistance. Studies suggest that currently, 10% to 20% of newly-infected
HIV patients are infected with a strain of HIV that is resistant to at least
one currently-approved anti-HIV drug.

   Despite the fact that T-20 and T-1249 are members of the same class of
fusion inhibitors and have a similar mechanism of action, T-1249 appears to
have a different resistance profile than T-20, meaning that types of viruses
that have demonstrated the ability to become resistant to T-20 have not
demonstrated the ability to become resistant to T-1249. In addition, T-1249 has
enhanced pharmacokinetic properties compared to T-20, which means T-1249 is
expected to remain at higher levels in the bloodstream compared to T-20. We
believe that this should permit T-1249 to be administered only once daily.
T-1249 has also received "fast track" designation by the FDA for the treatment
of HIV.

   In February 2001, we presented two week interim data from T1249-101, an
ongoing Phase I/II trial of T-1249 administered alone and not in combination
with any other anti-HIV drugs. This trial evaluates the safety and preliminary
antiviral activity of T-1249 in 72 HIV-infected adults, substantially all of
whom had previously received other anti-HIV drugs. Data from this trial suggest
that T-1249 was well-tolerated over the 14-day period and produced dose-related
decreases in HIV viral load. As a result of this data, we have amended the
trial design to continue this trial at increasing doses of T-1249.

   Analysis of this data also suggests that a daily dose of T-1249, and not
prior anti-HIV treatment experience, was the only variable that was associated
with the viral load reduction among treatment-experienced patients. The most
common adverse event reported in our clinical trial of T-1249 has been mild to
moderate local skin irritations at the site of injection, or injection site
reactions. In addition, two serious adverse events were reported in this
clinical trial of T-1249, a hypersensitivity reaction and a low white blood
cell count, or neutropenia. We are unable to determine whether T-1249 caused
some of these side effects because there were no patients in our trial for
comparison who did not receive T-1249.

                                Roche Agreement

   We have entered into an agreement with F. Hoffmann-La Roche Ltd, or Roche,
to develop and market T-20 and T-1249 worldwide. Our agreement with Roche
grants them an exclusive, worldwide license for T-20 and T-1249 and certain
other compounds. Roche may terminate its license as a whole or for a particular
country or countries in its sole discretion with advance notice. We will share
development expenses and profits for T-20 and T-1249 in the United States and
Canada equally with Roche. Outside of these two countries, Roche will fund all
development costs and pay us royalties on net sales of T-20 and T-1249 for a
specified term. In addition, Roche has agreed to pay us up to $68 million in
upfront and milestone payments, of which we have received $12 million as of the
date of this prospectus.

   We have also entered into a research agreement with Roche to discover,
develop and commercialize anti-HIV fusion inhibitor peptides. We will share
equally the worldwide research, development and commercialization expenses and
profits from the worldwide sales of anti-HIV fusion inhibitor peptides

                                      5

<PAGE>

discovered after July 1, 1999. Our agreement with Roche grants them an
exclusive, worldwide license for these peptides. Either party may terminate the
agreement as a whole or for a particular drug, country or countries in its sole
discretion with advance notice. The agreement expires in January 2003 and is
renewable thereafter on an annual basis.

   We have transferred the manufacturing process for the amounts of T-20
required in our clinical trials to four third party contract manufacturers,
including Roche. We have selected Roche's manufacturing facility to manufacture
the quantities of bulk drug substance of T-20 we will need if we are successful
in commercializing T-20, and we have selected a third party to produce the
finished drug product from such bulk drug substance.

   We are also currently pursuing research programs to develop fusion
inhibitors that target respiratory syncytial virus, commonly known as RSV.

   Our principal executive office is located at 3518 Westgate Drive, Durham,
North Carolina 27707, and our telephone number is (919) 419-6050. As used in
this prospectus, "we," "us," "our," the "Company" and "Trimeris" refer to
Trimeris, Inc.

                                 Recent Events

   In December 2001, we signed an agreement with ConjuChem, which for a certain
period, provides us with the exclusive right to negotiate terms and conditions
of a worldwide right and license to ConjuChem's Drug Affinity Complex (DAC/TM/)
technology to create long lasting DAC/TM/ compounds targeted for the treatment
of HIV infection.

   In November 2001, we announced with Roche the beginning of site selection
and patient enrollment in the United States for T20-305, an open-label study of
T-20 in combination with oral anti-HIV drugs. We expect to conduct the study at
various sites in North America, Europe, Brazil and Australia. This study,
running in parallel with two ongoing, controlled Phase III clinical trials,
will initially enroll a total of 450 adults around the world. The planned start
of this study is the first quarter of 2002 and is contingent upon securing
adequate drug supply.

   In August 2001, Kevin Tang, formerly a managing director and the head of
Life Sciences research group at Deutsche Banc Alex. Brown, was elected to our
board of directors.

   In August 2001, we entered into an agreement with Array BioPharma, Inc. to
discover small molecule fusion inhibitors of HIV and RSV.

                                      6

<PAGE>

                                 RISK FACTORS

   You should carefully consider the risks described below before making an
investment decision. If any of the following risks occur, our business,
financial condition and results of operations could be materially and adversely
affected. As a result, the market price of our common stock could decline, and
you may lose all or part of your investment.

We are a development stage company that has sustained operating losses since
our inception, and we expect these losses to continue. We may never develop any
drugs that achieve commercial viability.

   As of September 30, 2001, our accumulated deficit since beginning our
operations in January 1993 was approximately $167.4 million. We had net losses
of approximately $19.7 million in 1998, approximately $22.2 million in 1999,
approximately $50.9 million in 2000 and approximately $45.2 million in the
first nine months ended September 30, 2001. Since inception, we have spent our
funds on our drug development efforts, relating primarily to the development of
T-20 and T-1249. We expect that we will incur substantial losses for the
foreseeable future and that these losses will increase significantly as we
expand our research and development, preclinical testing, clinical trial and
regulatory approval efforts and begin anticipated commercialization of T-20. We
have not yet generated any revenues from product sales or royalties. We may not
ever be able to generate any product revenues or royalties or become profitable
if we do generate any revenues or royalties.

If we cannot raise additional funds in the future, our ability to develop our
drug candidates will suffer.

   The private placement of common stock that we completed in January 2002,
raised net proceeds of approximately $41 million. Barring unforeseen
developments, we anticipate that our existing capital resources will fund our
capital requirements through the end of 2002. Because we do not expect to have
an approved and marketable drug generating revenues at that time, we will
require substantial additional funds after that time. If we do not obtain such
financing, we will be required to delay, scale back or eliminate some of our
planned preclinical testing, clinical trials, research and development programs
and pre-marketing activities. We anticipate that our expenditures will increase
as a result of the ongoing costs of our Phase III clinical trials, which are
generally larger and more expensive than the Phase I and Phase II clinical
trials we have conducted to date, the anticipated preparation and submission of
an NDA to the FDA following receipt of data from our Phase III clinical trials,
and the costs of pre-marketing activities that will need to be undertaken in
anticipation of the commercialization of T-20. During the year ended December
31, 2000, we used net cash of approximately $24.8 million for operations,
including research and development, and net cash of approximately $52.2 million
for investing activities. During the nine months ended September 30, 2001, we
used net cash of approximately $46.1 million for operations, including research
and development, and net cash of approximately $5.7 million for investing
activities.

   We have financed our activities primarily through public offerings and
private placements of our common stock and we expect to continue to rely
primarily on sales of our equity securities to finance our activities for the
foreseeable future. We may have difficulty raising funds by selling equity in
the future. Our access to capital could be limited if we do not achieve
continued progress in our research and development programs and our preclinical
testing and clinical trials, and could be limited by overall market conditions.
The public capital markets in which our common stock trades have been highly
volatile and the general ability of companies to obtain additional equity
financing, which was significantly more difficult in 2001 compared to 2000, is
expected to remain difficult in 2002.

Terrorists attacks such as the attacks that occurred in New York and
Washington, D.C. on September 11, 2001 and other attacks or acts of war may
adversely affect the markets on which our common stock trades, our drug
candidates, our financial condition and our results of operations.

   On September 11, 2001, the United States was the target of terrorist attacks
of unprecedented scope. These attacks have caused major instability in the U.S.
and other financial markets. There could be further acts of terrorism in the
United States or elsewhere that could have a similar impact. Leaders of the
U.S. government

                                      7

<PAGE>

have announced their intention to actively pursue and take military and other
action against those behind the September 11, 2001 attacks and to initiate
broader action against global terrorism. Armed hostilities or further acts of
terrorism would cause further instability in financial markets and could
directly impact our drug candidates, our financial condition and our results of
operations.

Any additional financing we obtain may result in dilution to our stockholders,
restrictions on our operating flexibility, or the transfer of particular rights
to technologies or drug candidates.

   Although we have no specific plans to raise additional funds at the current
time, we may raise additional funds in the future through equity or debt
financings. If we raise funds by selling equity, we may dilute our
stockholders' interest in us. Any debt financings may contain restrictive terms
that would limit our operating flexibility. Additionally or alternatively, we
may have to obtain funds through arrangements with collaborative partners.
These partners may require us to relinquish rights to our technologies or drug
candidates. Any of these forms of financing could materially and adversely
affect our business and financial condition.

If we are unable to commercialize T-20, our lead drug candidate, our business
will be materially harmed.

   We have invested a significant portion of our time and financial resources
since our inception in the development of T-20. T-20 is our lead drug candidate
and is our only drug candidate for which we have completed Phase II clinical
trials and initiated Phase III clinical trials as of the date of this
prospectus. Our other drug candidate in clinical trials, T-1249, is at an
earlier stage of clinical trial development. We anticipate that for the
foreseeable future, our ability to generate revenues and profits, if any, will
depend solely on the successful commercialization of T-20. Commercialization of
T-20 will require success in our clinical trials, regulatory approval and the
ability to have sufficient commercial quantities of T-20 manufactured on a
cost-effective basis with the requisite quality. We cannot assure you that we
will be able to commercialize T-20 or any other drug candidate.

If our clinical trials are delayed or achieve unfavorable results, we may never
obtain regulatory approval for our drugs or generate any revenues.

   In order to obtain the regulatory approvals necessary to sell a drug
candidate commercially, we must demonstrate to the FDA and other applicable
United States and foreign regulatory authorities that the drug candidate is
safe and effective for use in humans for each target indication. We attempt to
demonstrate this through a lengthy and complex process of preclinical testing
and clinical trials, which typically takes a number of years. Delays or
unanticipated increases in costs of clinical development, or failure to obtain
regulatory approval or market acceptance for any of our drug candidates, could
materially and adversely affect our financial condition and operating results.

   We have not yet submitted any of our drug candidates to the FDA or any other
regulatory authority for approval of commercialization. To date:

    .  we have completed initial preclinical testing of T-20 and T-1249;

    .  we have completed collecting clinically relevant data with respect to
       two Phase I/II clinical trials of T-20 and three Phase II clinical
       trials of T-20;

    .  we are continuing one Phase II clinical trial of T-20 from which we
       currently anticipate completing the collection of clinically relevant
       data in 2002;

    .  we are continuing a Phase I/II clinical trial of T-1249, from which we
       have collected interim clinically relevant data and anticipate the
       collection of additional clinically relevant data in 2002; and

    .  we have completed enrollment in two Phase III clinical trials for T-20,
       one in the United States and one internationally, and we currently
       anticipate collecting clinically relevant data from these clinical
       trials in the first half of 2002 sufficient to support submission of an
       NDA for T-20 to the FDA in the second half of 2002.

                                      8

<PAGE>

   Because these clinical trials to date have been limited to a relatively
small number of patients, we cannot assure you that the results of these early
clinical trials will support further clinical trials of T-20 or T-1249. We may
not be able to demonstrate that potential drug candidates that appeared
promising in preclinical testing and early clinical trials will be safe or
effective in advanced clinical trials that involve larger numbers of patients.
We also cannot assure you that the results of the clinical trials we have
conducted and still intend to conduct will support our applications for
regulatory approval. In particular, if the results of the Phase III trials we
are currently conducting for T-20 do not demonstrate the safety and
effectiveness of T-20 to the satisfaction of the FDA or foreign regulatory
authorities, we will be unable to commercialize T-20. Even if we obtain
regulatory approval for T-20, the results of these Phase III trials may
indicate that T-20 is less safe or effective than expected, and any such
approval may limit the indicated uses for which T-20 may be marketed.

   We may be required to redesign, delay or cancel our preclinical testing and
clinical trials for some or all of the following reasons, any of which may
adversely affect our results of operations:

    .  unanticipated, adverse or ambiguous results from our preclinical testing
       or clinical trials;

    .  change in the focus of our collaborative partner, Roche;

    .  undesirable side effects that delay or extend the trials;

    .  our inability to locate, recruit and qualify a sufficient number of
       patients for our trials;

    .  difficulties in manufacturing sufficient quantities at the requisite
       quality of the particular drug candidate or any other components needed
       for our preclinical testing or clinical trials;

    .  regulatory delays or other regulatory actions;

    .  change in the focus of our development efforts; and

    .  reevaluation of our clinical development strategy.

   In addition, due to uncertainties inherent in the clinical development
process, we may underestimate the costs and/or length of time associated with
clinical development of T-20 or T-1249.

If sufficient amounts of our drug candidates cannot be manufactured on a
cost-effective basis or we cannot obtain the quantities of raw materials
required to manufacture our drug candidates, our financial condition and
results of operations will be materially and adversely affected.

   T-20 and T-1249 are peptide-based therapeutics, which are drug treatments
made from long chains of proteins called peptides, which in turn are composed
of molecular building blocks called amino acids. T-20 is a large peptide
composed of a precise 36 amino acid sequence. Large peptides are difficult and
expensive to manufacture because the process of creating commercial quantities
of a large peptide is lengthy and complicated. For example, we believe that,
using traditional peptide synthesis methods, the process of creating a
commercial quantity of T-20 could take more than a year, although to our
knowledge no one has attempted to create such a quantity of peptides using
traditional peptide synthesis methods. The novel process we and our third-party
manufacturers are currently using to manufacture T-20 and intend to use to
manufacture T-1249 requires approximately five months to complete and is
extremely complicated, requiring over 100 separate, precisely controlled
chemical reactions. As a result of this novel and complex manufacturing
process, we may encounter unexpected difficulties or expense in manufacturing
T-20 and T-1249. We may not be able to manufacture T-20 or T-1249 on a
large-scale or cost-effective basis, or develop an alternate, more efficient
manufacturing method for T-20, T-1249 or any future peptide drug candidates.
Commercial production of T-20 and T-1249 will also require raw materials,
including highly specialized amino acids, in amounts substantially greater than
those required at our current stage of development. We may not be able to
obtain these materials in sufficient quantities, quality or on a cost-effective
basis to support the commercial manufacture of T-20 or T-1249.

                                      9

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   In addition, the FDA must approve the facilities that will be used to
manufacture commercial quantities of T-20 and T-1249 before commencement of
commercial sales. Moreover, although we are in the process of developing
alternate manufacturing plans in the event our intended manufacturing plan
generates insufficient supplies of T-20 and T-1249, we do not have an alternate
manufacturing plan in place at this time and it would take a significant amount
of time to arrange for alternative sources of supply. We do not have insurance
to cover any shortages or other problems in the manufacturing of our drug
candidates. If we are unable to manufacture sufficient amounts of T-20 or
T-1249 on a cost-effective basis, obtain the necessary quantities of raw
materials or obtain the required FDA approvals, our financial condition and
results of operations will be materially and adversely affected.

If Roche does not meet its contractual obligations to us, our research and
development efforts and the regulatory approval and commercialization of our
drug candidates could be delayed or otherwise materially and adversely affected.

   As described in more detail in the section of this prospectus titled
"Trimeris," we have entered into an agreement with Roche to develop and market
T-20 and T-1249 worldwide, manufacture clinical and commercial quantities of
T-20 and help conduct our clinical trials of T-20 and T-1249. In addition to
sharing with us the development expenses and profits for T-20 and T-1249 in the
United States and Canada and paying us royalties on net sales of T-20 and
T-1249 outside of those countries, Roche has agreed to pay us up to $68 million
in upfront and milestone payments, of which we have received $12 million as of
the date of this prospectus. In addition, we have entered into a research
agreement with Roche to discover, develop and commercialize anti-HIV fusion
inhibitor peptides. Our reliance on Roche in connection with these activities
poses a number of risks, including the following:

    .  Roche has the right to terminate our development and license agreement,
       including its marketing provisions, or the research agreement, in each
       case as a whole or with respect to any particular country or countries,
       at any time and from time to time in its sole discretion, even though we
       have a joint management committee consisting of members of Roche and
       Trimeris that oversees the strategy for our collaboration and research;

    .  Roche may not devote sufficient resources to the research, development
       or marketing of our drugs;

    .  Roche may not devote sufficient resources to manufacture T-20 in
       commercial quantities on a cost-effective basis and with the requisite
       quality;

    .  disagreements with Roche could lead to delays in or termination of the
       research, development or commercialization of our drugs, or result in
       litigation or arbitration;

    .  Roche may choose to devote fewer resources to the research, development
       and marketing of our drugs than it does to drugs of its own development,
       or may choose to compete with us by seeking, on its own or in
       collaboration with our competitors, alternate means of developing drug
       therapies for the diseases we have targeted; and

    .  disputes may arise in the future with respect to the ownership of rights
       to technology developed with Roche.

   If any of the foregoing occurs or if Roche otherwise fails to fulfill any of
its obligations to us in accordance with our agreements, our research and
development efforts and clinical trials, and the regulatory approval and
commercialization of our drug candidates, could be delayed or otherwise
materially and adversely affected.

   We also may rely from time to time on the services of other third parties in
connection with our research and development and clinical trial activities,
including contract research organizations, manufacturers who produce clinical
amounts of our drug candidates, licensors, collaborators and others. The
failure of any of these persons to perform their obligations as agreed may also
delay and otherwise adversely affect our research and development, clinical
trial activities and regulatory approval of our drug candidates.

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If we cannot maintain commercial manufacturing arrangements with third parties
on acceptable terms, or if these third parties do not perform as agreed, the
commercial development of our drug candidates could be delayed or otherwise
materially and adversely affected.

   We have selected Roche to manufacture commercial quantities of the bulk drug
substance of T-20 in the event that we successfully commercialize T-20, and
together with Roche, we have selected another third party to produce the
finished drug product from such bulk drug substance. The manufacture of
pharmaceutical products requires significant expertise and capital investment.
Third-party manufacturers of pharmaceutical products often encounter
difficulties in scaling up production, including problems involving production
yields, quality control and assurance, shortage of qualified personnel,
compliance with FDA regulations, production costs, and development of advanced
manufacturing techniques and process controls. Our third-party manufacturers,
including Roche, may not perform as agreed or may not remain in the contract
manufacturing business for the time required to successfully produce and market
our drug candidates. The number of third-party manufacturers with the expertise
and facilities to manufacture bulk drug substance of T-20 on a commercial
scale, using the manufacturing method described above, is extremely limited. We
also intend to have additional third-party manufacturers produce the finished
drug product from the bulk drug substance of T-20, by employing a process
involving lyophilization, or freeze-drying. A limited number of third-party
manufacturers have the capability to produce a finished drug product on a
commercial scale through a process involving lyophilization. If our third-party
manufacturers, including Roche, fail to deliver the required commercial
quantities of bulk drug substance or finished drug product on a timely basis
and at commercially reasonable prices, and we fail to promptly find one or more
replacement manufacturers or develop our own manufacturing capabilities at a
substantially equivalent cost and on a timely basis, the commercial development
of our drug candidates could be delayed or otherwise materially and adversely
affected.

Our business is based on a novel technology called fusion inhibition, and
unexpected side effects or other characteristics of this technology may delay
or otherwise adversely affect the development, regulatory approval and/or
commercialization of our drug candidates.

   The technology platform underlying our drug development program is novel
because it is designed to discover drug candidates that treat viral infection
by preventing the virus from fusing to and entering host cells that viruses use
to reproduce themselves. The conventional approach to treating HIV, as
represented by all currently-marketed anti-HIV drugs, is to inhibit specific
viral enzymes that are necessary for HIV to replicate. We are not aware of any
other approved anti-HIV pharmaceutical products that target the inhibition of
viral fusion. As a result, existing preclinical and clinical data on the safety
and efficacy of this technology are very limited. Although the most common
adverse side effect reported with respect to T-20 to date has been mild to
moderate local skin irritations at the site of injection, or injection site
reactions, we may discover other unacceptable side effects during or after
preclinical and clinical testing of our drug candidates, including side effects
that may only become apparent after long-term exposure. We may also encounter
technological challenges relating to these technologies and applications in our
research and development programs that we may not be able to resolve. Any such
unexpected side effects or technological challenges may delay or otherwise
adversely affect the development, regulatory approval and/or commercialization
of our drug candidates.

Even if we are successful in developing a commercially viable drug, in order to
become profitable we will need to maintain arrangements with third parties for
the sale, marketing and distribution of our drug candidates or expend
significant resources to develop these capabilities.

   We have no experience in sales, marketing or distribution of
pharmaceuticals. To the extent we successfully commercialize T-20 and/or
T-1249, we currently plan to rely on Roche for the sales, marketing and
distribution of these drug candidates, in accordance with the marketing terms
contained in our development and license agreement with Roche. Roche may
terminate this agreement at any time with advance notice. If Roche failed to
market our drug candidates adequately and we were unable to reach agreement
with one or more other marketing partners, we would be required to develop
internal sales, marketing and distribution capabilities. We may not be able to
establish cost-effective sales, marketing or distribution capabilities or make
arrangements with third

                                      11

<PAGE>

parties to perform these activities on acceptable terms on a timely basis, if
at all. This would have a material adverse effect on our business, financial
condition, results of operations and the market price of our stock.

   Any sales, marketing or distribution arrangements we establish with other
parties, including our agreement with Roche, may give those parties significant
control over important aspects of the commercialization of our drugs, including:

    .  market identification;

    .  marketing methods;

    .  pricing;

    .  drug positioning;

    .  composition of sales force; and

    .  promotional activities.

   We may not be able to control the amount or timing of resources that Roche
or any third party may devote to our drugs.

The HIV virus is likely to develop resistance to some of our drug candidates,
which could adversely affect demand for those drug candidates and harm our
competitive position.

   As discussed in the section of this prospectus titled "Trimeris," HIV is
prone to genetic mutations that can produce strains of HIV resistant to
particular drug treatments. HIV has developed resistance, in varying degrees,
to each of the currently approved anti-HIV drug treatments. As a result,
combination therapy, or the prescribed use of three or more anti-HIV drugs, has
become the preferred method of treatment for HIV-infected patients, because in
combination these drugs may prove effective against strains of the HIV virus
that have become resistant to one or more drugs in the combination. In the
clinical trials we have conducted to date, the HIV virus has demonstrated the
ability to develop resistance to T-20, as it has with respect to all other
currently-marketed anti-HIV drugs. If the HIV virus in a short time period
develops resistance to any of our drug candidates when used in combination
therapy, it would adversely affect demand for those drug candidates and harm
our competitive position.

Our stock price is highly volatile, and you may not be able to sell our shares
at or above the price you pay to acquire our shares.

   Our stock price has fluctuated substantially since our initial public
offering in October 1997. The equity securities of many companies, including
equity securities of many other biotechnology and pharmaceutical companies,
have experienced extreme fluctuations in trading price and volume in recent
months. Often, these fluctuations are unrelated to the companies' operating
performance. Our common stock may not trade at the same levels as other
biotechnology or pharmaceutical stocks, and biotechnology and pharmaceutical
stocks in general may not sustain their current market prices. Any or all of
the following could cause the market price of our common stock to fluctuate
significantly after this offering:

    .  changes in financial estimates or investment recommendations for us or
       our industry by securities analysts;

    .  failure to meet clinical expectations of securities analysts or
       investors;

    .  quarterly variations in our operating results, especially operating
       results that fall short of analysts' or investors' expectations in any
       given period;

    .  market conditions in the biotechnology or pharmaceutical market or in
       the economy as a whole;

    .  announcements by us or our competitors of new products, services,
       acquisitions, FDA actions, or strategic relationships;

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<PAGE>

    .  departures of key personnel;

    .  changes in business or regulatory conditions;

    .  the trading volume of our common stock; and

    .  terrorist attacks, other attacks or acts of war that affect the markets
       on which our common stock trades, our drug candidates, our financial
       condition and our results of operations.

We depend on patents and proprietary rights, which may offer only limited
protection against infringement. If we are unable to protect our patents and
proprietary rights, our assets and business could be materially harmed.

   Our success depends in part on our ability and the ability of our licensors
to obtain, maintain and enforce patents and other proprietary rights for our
drugs and technologies. Patent law relating to the scope of claims in the
biotechnology field in which we operate is still evolving and surrounded by a
great deal of uncertainty. Accordingly, we cannot assure you that our pending
patent applications will result in issued patents. Because U.S. patent
applications may be maintained in secrecy until a patent issues or is otherwise
published, we cannot assure you that others have not filed patent applications
for technology covered by our pending applications or that we were the first to
invent the technology.

   Other companies, universities and research institutions have or may obtain
patents and patent applications that could limit our ability to use,
manufacture, market or sell our drug candidates or impair our competitive
position. As a result, we may have to obtain licenses from other parties before
we could continue using, manufacturing, marketing or selling our potential
drugs. Those licenses may not be available on commercially acceptable terms, if
at all. If we do not obtain required licenses, we may not be able to market our
potential drugs at all or we may encounter significant delays in drug
development while we redesign potentially infringing drugs or methods.

   In addition, although we own or exclusively license 20 issued United States
patents, 21 pending United States patent applications, and corresponding
foreign patents and patent applications, including issued patents and patent
applications relating to T-20 and T-1249, the issuance of a patent is not
conclusive as to its validity or enforceability, and third parties may
challenge the validity or enforceability of our patents. We cannot assure you
how much protection, if any, our patents will provide if we attempt to enforce
them and/or if the patents are challenged in court or in other proceedings. It
is possible that a competitor may successfully challenge our patents or that
challenges will result in limitations of their coverage. In addition, the cost
of litigation to uphold the validity of patents can be substantial. If we are
unsuccessful in such litigation, third parties may be able to use our patented
technologies without paying licensing fees or royalties to us.

   Moreover, competitors may infringe our patents or successfully avoid them
through design innovation. To prevent infringement or unauthorized use, we may
need to file infringement claims, which are expensive and time-consuming. In
addition, in an infringement proceeding, a court may decide that a patent of
ours is not valid or enforceable or may refuse to stop the other party from
using the technology at issue on the grounds that its technology is not covered
by our patents. Policing unauthorized use of our intellectual property is
difficult, and we cannot assure you that we will be able to prevent
misappropriation of our proprietary rights, particularly in countries where the
laws may not protect such rights as fully as in the United States.

   Recently, several generic drug-makers in countries such as India have
offered to sell HIV drugs currently protected under United States patents to
patients in Africa at prices significantly below those offered by the drugs'
patent holders in other countries. There is a risk that these drugs produced by
the generic drug-makers could be illegally imported into the United States and
other countries at prices below those charged by the drugs' patent holders. If
any of these actions occur with respect to our drugs, it could limit the amount
we could charge for our drugs.

   In addition to our patented technology, we also rely on unpatented
technology, trade secrets and confidential information. We may not be able to
effectively protect our rights to this technology or information. Other parties
may independently develop substantially equivalent information and techniques
or otherwise gain access to or

                                      13

<PAGE>

disclose our technology. We require each of our employees, consultants and
corporate partners to execute a confidentiality agreement at the commencement
of an employment, consulting or collaborative relationship with us. However,
these agreements may not provide effective protection of our technology or
information or, in the event of unauthorized use or disclosure, they may not
provide adequate remedies.

   The occurrence of any of these risks could have a material adverse effect on
our business, financial condition, results of operations and market price of
our stock.

We are subject to extensive and complex government regulation, including
regulation by the FDA, which can entail significant costs and could delay,
limit or prevent commercialization of our drug candidates.

   Our research and development activities, and the testing, development,
manufacturing and commercialization of our drug candidates are subject to
regulation by numerous governmental authorities in the United States and, to
the extent that we may be engaged in activities outside of the United States,
in other countries. In addition to proving to these authorities the safety and
efficacy of our drug candidates through the clinical trial process, we must
also prove that we and our clinical testing and manufacturing partners maintain
good laboratory, clinical and manufacturing practices. In addition, the Federal
Food, Drug and Cosmetic Act, the Public Health Service Act and other domestic
and foreign statutes and regulations govern or affect the testing, manufacture,
safety, labeling, storage, record keeping, approval, advertising and promotion
of substances such as our drug candidates, as well as safe working conditions
and the experimental use of animals. Noncompliance with applicable requirements
can result in criminal prosecution and fines, recall or seizure of drugs, total
or partial suspension of production, refusal of the government to approve
product license applications, prohibitions or limitations on the commercial
sale of drugs or refusal to allow us to enter into supply contracts. The FDA
also has the authority to revoke product licenses and establishment licenses
that it has previously granted. In addition, if compliance with these
regulations proves more costly than anticipated, our financial condition and
results of operations could be materially and adversely affected. We do not
separately track as an accounting item the amounts we spend to comply with
regulatory requirements, but the majority of our activities and expenditures to
date, including our preclinical and clinical trial activities and expenditures,
have been undertaken directly or indirectly in order to comply with applicable
governmental regulations. Although it is impossible to predict with any degree
of certainty the outcome of the regulatory approval process for our drugs, we
believe that we currently are in compliance with applicable statutes, rules and
regulations governing our research and development activities.

   A number of reasons, including those set forth below, may delay our
regulatory submissions or cause us to cancel plans to submit proposed drug
candidates for approval:

    .  unanticipated preclinical testing or clinical trial reports;

    .  changes in regulations, or the adoption of new regulations;

    .  unanticipated enforcement of existing regulations;

    .  unexpected technological developments; and

    .  developments by our competitors.

We face intense competition in our efforts to develop commercially successful
drugs in the biopharmaceutical industry. If we are unable to compete
successfully, our business will suffer.

   We are engaged in segments of the biopharmaceutical industry, including the
treatment of HIV, that are intensely competitive and change rapidly. We expect
that new developments in the areas in which we are conducting our research and
development will continue at a rapid pace in both industry and academia.

                                      14

<PAGE>

   If we successfully develop our drug candidates and gain regulatory approval
for those drugs, they will compete with numerous existing therapies, as well as
a significant number of drugs that are currently under development and will
become available in the future for the treatment of HIV. For example:

    .  At least 17 anti-HIV drugs are currently approved in the United States
       for the treatment of HIV, including drugs produced by GlaxoSmithKline,
       DuPont Pharmaceuticals, Merck, Roche and Abbott Laboratories. None of
       these currently-approved drugs are viral fusion inhibitors.

    .  We believe that other companies may be currently engaged in research
       efforts to develop viral fusion inhibitors. To our knowledge, none of
       these potentially competing drug candidates have entered human clinical
       trials.

    .  Several companies, including Progenics Pharmaceuticals, Pfizer and
       Aronex Pharmaceuticals, are in early stage human clinical trials with
       anti-HIV drug candidates that target viral processes different from
       those targeted by currently approved anti-HIV drugs, and different from
       the viral fusion process that our drug candidates target.

   We expect to face intense and increasing competition in the future as these
new drugs enter the market and advanced technologies become available. Even if
we are able to successfully develop T-20 or T-1249 and either drug candidate
receives regulatory approval, we cannot assure you that existing or new drugs
for the treatment of HIV developed by our competitors will not be more
effective, less expensive or more effectively marketed and sold, than T-20,
T-1249 or any other drug treatment for HIV that we may develop.

   Many of our competitors have significantly greater financial, technical,
human and other resources than we do. Smaller companies may also prove to be
significant competitors, particularly through collaborative arrangements with
large pharmaceutical and biotechnology companies. For example, Progenics
Pharmaceuticals has entered into a collaborative agreement with Roche for the
development of its anti-HIV technology platform. Furthermore, academic
institutions, governmental agencies and other public and private research
organizations are becoming increasingly aware of the value of their inventions
and are more actively seeking to commercialize the technology they have
developed.

Our drugs may not achieve market acceptance.

   T-20 and T-1249 are peptides and are delivered once or twice daily by
injection under the skin. All of the currently approved drug treatments for HIV
are delivered orally. Even if T-20 or T-1249 receives regulatory approval,
patients and physicians may not readily accept daily injections of an anti-HIV
drug treatment, which would limit their acceptance in the market.

   Peptides are also expensive to manufacture, which could result in prices for
T-20 and T-1249 that are above prices of currently approved anti-HIV drug
treatments. Even if T-20 or T-1249 receives regulatory approval, physicians may
not readily prescribe T-20 or T-1249, due to cost-benefit considerations when
compared with other anti-HIV drug treatments. In addition, higher prices could
also limit our ability to receive reimbursement coverage for our drugs from
third-party payors, such as private or government insurance programs.

Uncertainty relating to third-party reimbursement and health care reform
measures could limit the amount we will be able to charge for our drugs and
adversely affect our results of operations.

   In the United States and elsewhere, sales of prescription drugs depend, in
part, on the consumer's ability to obtain reimbursement for the cost of the
drugs from third-party payors, such as private and government insurance
programs. 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. Because of the high cost
of the treatment of HIV, many state legislatures are also reassessing
reimbursement policies for this therapy. If third-party payor reimbursements
for any drugs we commercialize are not available or are not available at a
level that will allow us or our potential collaborative partners to sell these
drugs on a competitive basis, our results of operations will be materially and
adversely affected. In addition, an increasing emphasis in

                                      15

<PAGE>

the United States on the reduction of the overall costs of health care through
managed care has increased and will continue to increase the pressure to reduce
the prices of pharmaceutical products. The announcement and/or adoption of
these types of proposals or efforts could also materially and adversely affect
our business, since the amount of revenues that we may potentially be able to
generate in the future for any products we may commercialize could affect an
investor's decision to invest in us, the amount of funds we decide to spend now
on our development and clinical trial efforts, and/or our decision to seek
regulatory approval for certain product candidates.

   Recently, several major pharmaceutical companies have offered to sell their
anti-HIV drugs at or below cost to certain countries in Africa, which could
adversely affect the reimbursement climate, and the prices that may be charged,
for HIV medications in the United States and the rest of the world. Third-party
payors could exert pressure for price reductions in the United States and the
rest of the world based on these offers to Africa. This price pressure could
limit the amount that we would be able to charge for our drugs.

If an accident or injury involving hazardous materials occurs, we could incur
fines or liability, which could materially and adversely affect our business
and our reputation.

   In our drug development programs, we use hazardous materials, including
chemicals, radioactive compounds and infectious disease agents, such as viruses
and HIV-infected blood. We believe that our handling and disposal of these
materials comply with the standards prescribed by state and federal
regulations, but we cannot completely eliminate the risk of contamination or
injury from these materials. If there were such a contamination, injury or
other accident, we could be held liable for any damages or penalized with
fines. Although our general liability insurance coverage may cover some of
these liabilities, the amount of the liability and fines could exceed our
resources. We currently maintain general liability insurance coverage in the
amount of approximately $1 million per occurrence and $2 million in the
aggregate.

If the testing or use of our drug candidates harms people, we could face costly
and damaging product liability claims far in excess of our liability and
indemnification coverage.

   Our business exposes us to potential product liability risks that are
inherent in the testing, manufacturing and marketing of pharmaceutical
products, such as undesirable side effects or injury during clinical trials. In
addition, the use in our clinical trials of drugs that we or our potential
collaborators may develop and the subsequent sale of these drugs by us or our
potential collaborators may cause us to bear a portion of product liability
risks relating to these drugs.

   We have obtained an advanced medical technology policy which includes
limited product liability insurance coverage for our clinical trials in the
amount of $5 million per occurrence and $5 million in the aggregate. However,
insurance coverage is becoming increasingly expensive and we may not be able to
maintain insurance coverage at a reasonable cost or in sufficient amounts to
protect us against potential liabilities. We intend to expand our insurance
coverage to include the sale of commercial products if we obtain marketing
approval for drug candidates in development, but we cannot assure you that we
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 our potential liabilities. Furthermore, our collaborators or
licensees may not be willing to indemnify us against these types of liabilities
and may not themselves 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, or indemnification payments, that may be
obtained by us could have a material adverse effect on our financial condition.

Our quarterly operating results are subject to fluctuations. If our operating
results for a particular period deviate from the levels expected by securities
analysts and investors, it could adversely affect the market price of our
common stock.

   Our operating results are likely to fluctuate over time, due to a number of
factors, many of which are outside of our control. Some of these factors
include:

    .  the status and progress of our collaborative agreement with Roche;

    .  the status of our research and development activities;

                                      16

<PAGE>

    .  the progress of our drug candidates through preclinical testing and
       clinical trials;

    .  the timing of regulatory actions;

    .  our ability to establish manufacturing, sales, marketing and
       distribution capabilities, either internally or through relationships
       with third parties;

    .  technological and other changes in the competitive landscape;

    .  changes in our existing or future research and development relationships
       and strategic alliances; and

    .  the commercial viability of our drug candidates.

   As a result, we believe that comparing financial results for one period
against another period is not necessarily meaningful, and you should not rely
on our results of operations in prior periods as an indication of our future
performance. If our results of operations for a period deviate from the levels
expected by securities analysts and investors, it could adversely affect the
market price of our common stock.

If we lose any of our executive management or other key employees, we will have
difficulty replacing them. If we cannot attract and retain qualified personnel
on acceptable terms, the development of our drug candidates and our financial
position may suffer.

   Because our business is very science-oriented and relies considerably on
individual skill and experience in the research, development and testing of our
drug candidates, we depend heavily on members of our senior management and
scientific staff, including Dani P. Bolognesi, Ph.D., our Chief Executive
Officer and Chief Scientific Officer. We have entered into employment
agreements with Dr. Bolognesi, M. Nixon Ellis, Ph.D., our Executive Vice
President and Chief Business Officer, and Robert R. Bonczek, our Chief
Financial Officer and General Counsel. Unless earlier terminated in accordance
with their terms, our employment agreements with each of Dr. Bolognesi, Dr.
Ellis and Mr. Bonczek, respectively, automatically renew for a one or two year
period at the end of the initial term of employment in each agreement. We have
also entered into employment agreements with a few of our other key employees,
but as a general matter we do not enter into employment agreements with our
officers or employees.

   Future recruitment and retention of management personnel and qualified
scientific personnel is also critical to our success. We cannot assure you that
we will successfully attract and retain sufficient numbers of qualified
personnel on acceptable terms given the competition among biotechnology,
pharmaceutical and health care companies, universities and non-profit research
institutions for experienced management personnel and scientists. If we cannot
attract and retain a sufficient number of qualified personnel or if a
significant number of our key employees depart, our drug development efforts
and the timing and success of our clinical trials may be materially and
adversely affected. Even if we do hire and retain a sufficient number of
qualified employees, the expense necessary to compensate them may adversely
affect our operating results. In addition, we rely on scientific advisors and
other consultants to assist us in formulating our research and development
strategy. These consultants are employed by other parties and may have
commitments to, or advisory or consulting agreements with, other entities,
which may limit their availability to us.

Future sales of common stock by our existing stockholders or key management
could adversely affect our stock price.

   As of January 29, 2002, approximately 18,672,000 shares of our common stock
were outstanding. Once the registration statement of which this prospectus is a
part becomes effective, approximately 18,449,000 of the currently outstanding
shares will be freely transferable without restriction or further registration
under the Securities Act. The remainder of our outstanding shares are
"restricted securities" which may be sold subject to the applicable limitations
of Rule 144. In addition, as of January 29, 2002, options, warrants and other
convertible securities convertible or exercisable into approximately 2,619,000
shares of common stock were outstanding and we had reserved an additional
984,000 shares of common stock under our stock option plans and employee stock
purchase plan. The market price of our common stock could decline as a result
of sales by our existing stockholders or key management of shares of common
stock in the market, or the perception that these sales could occur. A
reduction in the price of our common stock could reduce the value of your
investment in us and impair our ability to raise capital through the sale of
additional equity securities.

                                      17

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                                USE OF PROCEEDS

   We will not receive any of the proceeds from the sale of the shares by the
selling stockholders.

                             SELLING STOCKHOLDERS

   We are registering the shares covered by this prospectus on behalf of the
selling stockholders named in the table below. We issued all of the shares
covered by this prospectus to the selling stockholders in a private placement
transaction. We are registering the shares to permit the selling stockholders
and their pledgees, donees, transferees or other successors-in-interest that
receive their shares from a selling stockholder as a gift, partnership
distribution or other non-sale related transfer after the date of this
prospectus to resell the shares.

   The following table sets forth information known to us with respect to
beneficial ownership of our common stock as of January 29, 2002 by each selling
stockholder. The number of shares in the column "Number of Shares Being
Offered" represents all of the shares that each selling stockholder may offer
under this prospectus. The following table assumes that the selling
stockholders sell all of the shares registered for sale under this prospectus.
The selling stockholders may sell some, all or none of their shares. We do not
know how long the selling stockholders will hold the shares before selling them
and we currently have no agreements, arrangements or understandings with any of
the selling stockholders regarding the sale of any of the shares. Except as set
forth in the footnotes below, none of the selling stockholders has had a
material relationship with us or any of our predecessors or affiliates in the
past three years.

   In the following table, we have determined the number and percentage of
shares beneficially owned in accordance with Rule 13d-3 of the Securities
Exchange Act of 1934, as amended, and this information does not necessarily
indicate beneficial ownership for any other purpose. In determining the number
of shares beneficially owned by a person and the percentage ownership of that
person, we include any shares as to which the individual has sole or shared
voting power or investment power, as well as any shares of common stock subject
to options, warrants or other derivative securities held by that person that
are currently exercisable or exercisable within 60 days after January 29, 2002.
We do not consider these shares underlying options, warrants and other
derivative securities outstanding in computing the percentage ownership of any
other person, however. To our knowledge, the persons named in the table below
have sole voting and investment power with respect to all shares of common
stock shown as beneficially owned by them, subject to community property laws
where applicable and except as otherwise indicated in the footnotes below. The
percentages of shares owned in the following table are based on 18,672,184
shares of our common stock outstanding, giving effect to the sale of 1,257,500
shares to the selling stockholders in the private placement.

                                      18

<PAGE>


<TABLE>
<CAPTION>
                                                  Shares Beneficially Owned                  Shares Beneficially Owned
                                                      Prior to Offering                           After Offering
                                                  ------------------------  Number of Shares -------------------------
Name                                                 Number        Percent   Being Offered      Number        Percent
----                                                -------        -------  ----------------   -------       -------
<S>                                               <C>              <C>      <C>              <C>             <C>
Acqua Wellington Opportunity I Limited...........  75,000              *         75,000            0           --
Argus Healthcare Offshore........................ 122,769              *         21,900      100,869           *
Argus Healthcare Partners, LP....................  44,213              *          8,100       36,113           *
Baker Biotech Fund I, LP (1)..................... 550,885            3.0%        50,000      500,885          2.7%
Baker Biotech Fund II, LP (1).................... 600,915            3.2%       450,000      150,915           *
Bermuda Trust Co. Ltd. As Trustee for Tang Family
 Trust (TFT 74)..................................  18,500              *         18,500            0           --
Bermuda Trust (New Zealand) as Trustee for
 Oscar L. Tang Family Trust (UC 4300)............  15,000              *         15,000            0           --
E. Gary Cook (2).................................  29,888              *          1,000       28,888           *
M. Nixon Ellis (3)...............................  67,383              *          5,000       62,383           *
Lawrence & Company, Inc.......................... 206,000            1.1%        50,000      156,000           *
Jeffrey M. Lipton (4)............................ 210,022            1.1%         1,500      208,522          1.1%
Merlin BioMed Int'l Ltd..........................  50,000              *         50,000            0           --
Merlin BioMed, L.P...............................  25,000              *         25,000            0           --
Narragansett I, LP...............................  23,250              *         23,250            0           --
Narragansett Offshore Ltd........................  51,750              *         51,750            0           --
Putnam OTC and Emerging Growth Fund.............. 260,800            1.4%       185,600       75,200           *
Putnam Emerging Opportunities Portfolio..........   4,600              *          4,600            0           --
Putnam VT OTC and Emerging Growth................  13,700              *          9,600        4,100           *
Putnam Equity Fund 2000..........................     626              *            200          426           *
Raytheon Co. Master Trust........................  34,600              *         34,600            0           --
Raytheon Combined DB/DC Master Trust.............  15,400              *         15,400            0           --
SF Capital Partners Ltd..........................  70,000              *         70,000            0           --
Kevin Tang (5)...................................  22,500              *         10,000       12,500           --
The Tang Fund....................................   6,500              *          6,500            0           --
UBS O'Connor LLC F/B/O O'Connor PIPES
 Corporate Strategies Ltd........................  37,500              *         37,500            0           --
UBS O'Connor LLC F/B/O UBS Global Equity
 Arbitrage Master Ltd............................  37,500              *         37,500            0           --
</TABLE>
--------
*  Represents less than one percent.
(1) Based upon Schedule 13G filed with the SEC on December 10, 2001 and
    subsequent SEC filings as of December 31, 2001, this number does not
    include 2,684,900 shares beneficially owned by entities affiliated with
    Baker Biotech Fund I, L.P. and Baker Biotech Fund II, L.P.
(2) Dr. Cook has been a director of Trimeris since February 2000. Includes
    26,388 shares that Dr. Cook may acquire pursuant to stock options
    exerciseable within 60 days after January 29, 2002. Includes the following
    shares as to which Dr. Cook disclaims beneficial ownership: 1,500 shares
    beneficially owned by Brenda Cook, Dr. Cook's spouse.
(3) Dr. Ellis was named Executive Vice President and Chief Business Officer in
    March 2000. Includes 55,570 shares that Dr. Ellis may acquire pursuant to
    stock options exercisable within 60 days after January 29, 2002. Includes
    the following shares as to which Dr. Ellis disclaims beneficial ownership,
    except to the extent of his pecuniary interest therein: 3,500 shares
    beneficially owned by a Charitable Remainder Trust, for which Dr. Ellis is
    the sole trustee and the beneficiary until his death.
(4) Mr. Lipton has been a director of Trimeris since June 1998 and has been
    Chairman of the Board since June 1999. Includes 57,500 shares that Mr.
    Lipton may acquire pursuant to stock options exercisable within 60 days
    after January 29, 2002. Includes the following shares as to which Mr.
    Lipton disclaims beneficial ownership: 7,890 shares beneficially owned by
    Shelley Lipton, Mr. Lipton's spouse, 270 shares beneficially owned by
    Caroline Dickens, Mr. Lipton's niece who shares Mr. Lipton's house and 380
    shares beneficially owned by Caroline Dickens Trust, for which Caroline
    Dickens, Mr. Lipton's niece who shares Mr. Lipton's house, is the sole
    beneficiary and Shelley Lipton, Mr. Lipton's spouse, is the sole trustee.
(5) Mr. Tang has been a director of Trimeris since August 2001.

                                      19

<PAGE>

                             PLAN OF DISTRIBUTION

   The selling stockholders may sell the shares from time to time. The selling
stockholders will act independently of us in making decisions regarding the
timing, manner and size of each sale. The sales may be made on the Nasdaq
National Market, one or more exchanges, in the over-the-counter market or
otherwise, at prices and at terms then prevailing or at prices related to the
then current market price, or in privately negotiated transactions. The selling
stockholders may effect these transactions by selling the shares to or through
broker-dealers. The selling stockholders may sell their shares in one or more
of, or a combination of:

    .  a block trade in which the broker-dealer will attempt to sell the shares
       as agent but may position and resell a portion of the block as principal
       to facilitate the transaction,

    .  purchases by a broker-dealer as principal and resale by a broker-dealer
       for its account under this prospectus,

    .  an exchange distribution in accordance with the rules of an exchange,

    .  ordinary brokerage transactions and transactions in which the broker
       solicits purchasers,

    .  put or call option transactions relating to the shares or through short
       sales of shares, and

    .  privately negotiated transactions.

   To the extent required, this prospectus may be amended or supplemented from
time to time to describe a specific plan of distribution. If the plan of
distribution involves an arrangement with a broker-dealer for the sale of
shares through a block trade, special offering, exchange distribution or
secondary distribution or a purchase by a broker or dealer, the amendment or
supplement will disclose:

    .  the name of each selling stockholder and of the participating
       broker-dealer(s),

    .  the number of shares involved,

    .  the price at which the shares were sold,

    .  the commissions paid or discounts or concessions allowed to the
       broker-dealer(s), where applicable,

    .  that a broker-dealer(s) did not conduct any investigation to verify the
       information set out or incorporated by reference in this prospectus, and

    .  other facts material to the transaction.

   From time to time, a selling stockholder may transfer, pledge, donate or
assign its shares of common stock to lenders or others and each of such persons
will be deemed to be a "selling stockholder" for purposes of this prospectus.
The number of shares of common stock beneficially owned by the selling
stockholder will decrease as and when it takes such actions. The plan of
distribution for the selling stockholders' shares of common stock sold under
this prospectus will otherwise remain unchanged, except that the transferees,
pledgees, donees or other successors will be selling stockholders hereunder.
Upon being notified by a selling stockholder that a donee, pledgee, transferee
or assignee intends to sell more than 500 shares, we will file a supplement to
this prospectus.

   The selling stockholders may enter into hedging transactions with
broker-dealers in connection with distributions of the shares or otherwise. In
these transactions, broker-dealers may engage in short sales of the shares in
the course of hedging the positions they assume with selling stockholders. The
selling stockholders also may sell shares short and redeliver the shares to
close out short positions. The selling stockholders may enter into option or
other transactions with broker-dealers which require the delivery to the
broker-dealer of the shares. The broker-dealer may then resell or otherwise
transfer the shares under this prospectus. The selling stockholders also may
loan or pledge the shares to a broker-dealer. The broker-dealer may sell the
loaned shares, or upon a default the broker-dealer may sell the pledged shares
under this prospectus.

                                      20

<PAGE>

   In effecting sales, broker-dealers engaged by the selling stockholders may
arrange for other broker-dealers to participate in the resales. Broker-dealers
or agents may receive compensation in the form of commissions, discounts or
concessions from selling stockholders. Broker-dealers or agents may also
receive compensation from the purchasers of the shares for whom they act as
agents or to whom they sell as principals, or both. Compensation as to a
particular broker-dealer might be in excess of customary commissions and will
be in amounts to be negotiated in connection with the sale. Broker-dealers or
agents and any other participating broker-dealers or the selling stockholders
may be deemed to be "underwriters" within the meaning of Section 2(11) of the
Securities Act of 1933, as amended, in connection with sales of the shares.
Accordingly, any commission, discount or concession received by them and any
profit on the resale of the shares purchased by them may be deemed to be
underwriting discounts or commissions under the Securities Act. Because selling
stockholders may be deemed to be "underwriters" within the meaning of Section
2(11) of the Securities Act, the selling stockholders will be subject to the
prospectus delivery requirements of the Securities Act. In addition, any
securities covered by this prospectus that qualify for sale under Rule 144
promulgated under the Securities Act may be sold under Rule 144 rather than
under this prospectus. The selling stockholders have advised that they have not
entered into any agreements, understandings or arrangements with any
underwriters or broker-dealers regarding the sale of their securities. There is
no underwriter or coordinating broker acting in connection with the proposed
sale of shares by the selling stockholders.

   The shares will be sold only through registered or licensed brokers or
dealers if required under applicable state securities laws. In addition, in
some states the shares may not be sold unless they have been registered or
qualified for sale in the applicable state or an exemption from the
registration or qualification requirement is available and is complied with.

   Under applicable rules and regulations under the Securities Exchange Act of
1934, as amended, any person engaged in the distribution of the shares may not
simultaneously engage in market making activities with respect to our common
stock for a period of two business days prior to the commencement of the
distribution. In addition, each selling stockholder will be subject to
applicable provisions of the Exchange Act and the associated rules and
regulations under the Exchange Act, including Regulation M, which provisions
may limit the timing of purchases and sales of shares of our common stock by
the selling stockholders. We will make copies of this prospectus available to
the selling stockholders and have informed them of the need to deliver copies
of this prospectus to purchasers at or prior to the time of any sale of the
shares.

   We will bear all costs, expenses and fees in connection with the
registration of the shares. The selling stockholders will bear all commissions
and discounts, if any, attributable to the sales of the shares. The selling
stockholders may agree to indemnify any broker-dealer or agent that
participates in transactions involving sales of the shares against specific
liabilities, including liabilities arising under the Securities Act. The
selling stockholders have agreed to indemnify specific persons, including
broker-dealers and agents, against specific liabilities in connection with the
offering of the shares, including liabilities arising under the Securities Act.
We have agreed to indemnify the selling stockholders against specified
liabilities, including specified liabilities under the Securities Act. We have
agreed to maintain the effectiveness of this registration statement until the
date on which the shares may be resold by non-affiliates of Trimeris without
registration by reason of Rule 144(k) under the Securities Act or any other
rule of similar effect. The selling stockholders may sell all, some or none of
the shares offered by this prospectus.

                                      21

<PAGE>

                                 LEGAL MATTERS

   The validity of the shares of common stock offered will be passed upon for
us by Wilmer, Cutler & Pickering, Washington D.C. A partner of Wilmer, Cutler &
Pickering beneficially owns 9,804 shares of our common stock.

                                    EXPERTS

   The financial statements of Trimeris, Inc. as of December 31, 1999 and 2000
and for each of the years in the three-year period ended December 31, 2000 and
for the cumulative period from the date of inception to December 31, 2000 have
been incorporated by reference herein and in the registration statement in
reliance upon the report of KPMG LLP, independent certified public accountants,
incorporated by reference herein, and upon the authority of KPMG LLP as experts
in accounting and auditing.

   As discussed in Note 1 to the financial statements, in 2000 the Company
restated its 1998 statements of operations, stockholders' equity, and cash
flows, and its 1999 financial statements.

                                      22

<PAGE>

                      WHERE YOU CAN FIND MORE INFORMATION

   We have filed a registration statement on Form S-3 with the SEC in
connection with this offering. In addition, we file annual, quarterly and
special reports, proxy statements and other information with the SEC under the
Exchange Act. You may read and copy this information at the following locations
of the SEC:

   Public Reference Room   North East Regional Office  Midwest Regional Office
  450 Fifth Street, N.W.         233 Broadway          500 West Madison Street
         Room 1024         New York, New York 10279          Suite 1400
  Washington, D.C. 20549                               Chicago, Illinois 60661

   You may also obtain copies of this information by mail from the Public
Reference Section of the SEC, 450 Fifth Street, N.W., Room 1024, Washington, DC
20549, at prescribed rates.

   The SEC also maintains a web site that contains reports, proxy statements
and other information about issuers, like Trimeris, who file electronically
with the SEC. The address of that site is www.sec.gov.

   This prospectus is part of the registration statement and does not contain
all of the information included in the registration statement. Whenever a
reference is made in this prospectus to any contract or other document of
Trimeris, the reference may not be complete and you should refer to the
exhibits that are a part of the registration statement for a copy of the
contract or document.

   The SEC allows us to "incorporate by reference" information into this
prospectus, which means that we can disclose important information to you by
referring you to another document filed separately with the SEC. The
information incorporated by reference is deemed to be part of this prospectus,
except for any information superseded by information contained directly in this
prospectus. This prospectus incorporates by reference the documents set forth
below that we have previously filed with the SEC. These documents contain
important information about Trimeris and its finances.

<TABLE>
<CAPTION>
       TRIMERIS SEC FILINGS (File No. 0-23155)                            PERIOD
----------------------------------------------------- -----------------------------------------------
<C>                                                   <S>
Annual Report on Forms 10-K and 10-K/A                Fiscal year ended December 31, 2000
Quarterly Reports on Form 10-Q                        Quarterly periods ended March 31, June 30 and
                                                      September 30, 2001
Current Reports on Form 8-K                           Filed on May 8, 2001, May 11, 2001, January 24,
                                                      2002 and January 30, 2002
The description of Trimeris common stock as set forth
  in its Registration Statement on Form 8-A           Filed on October 1, 1997
</TABLE>

   All reports and other documents subsequently filed by us pursuant to
Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this
prospectus and prior to the termination of the offering shall be deemed to be
incorporated by reference in this prospectus and to be a part of this
prospectus from the date of filing of such reports and documents. In addition,
all documents filed by us pursuant to Sections 13(a), 13(c), 14 or 15(d) of the
Exchange Act after the date of the initial registration statement and prior to
the effectiveness of the registration statement shall be deemed to be
incorporated herein by reference. Any statement contained in any document
incorporated or deemed to be incorporated by reference herein shall be deemed
to be modified or superseded for purposes of this prospectus to the extent that
a statement contained in this prospectus or in any other subsequently filed
document which also is or is deemed to be incorporated by reference in this
prospectus modifies or supersedes such statement. Any statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this prospectus.

   We will provide without charge to each person to whom this prospectus is
delivered, upon written or oral request a copy of any or all of the foregoing
documents incorporated by reference in this prospectus, except for exhibits to
these documents, unless the exhibits are specifically incorporated by reference
into any such document. You should direct your requests for such documents to:
Investor Relations at Trimeris, Inc., 3518 Westgate Drive, Suite 300, Durham,
North Carolina 27707 or by telephone at (919) 419-6050.

                                      23

<PAGE>

   We have not authorized any dealer, salesperson or other person to give any
information or represent anything not contained in this prospectus. You must
not rely on any unauthorized information. If anyone provides you with different
or inconsistent information, you should not rely on it. This prospectus does
not offer to sell any shares in any jurisdiction where it is unlawful. The
information in this prospectus is current as of the date shown on the cover
page.

                               1,257,500 SHARES


[LOGO] TRIMERIS

                                Trimeris, Inc.

                                 COMMON STOCK


                                --------------
                                  PROSPECTUS
                                --------------


                               February 7, 2002

</TEXT>
</DOCUMENT>