Data Show that Benefit of Fuzeon is Maintained at 48 weeks

Roche and Trimeris announce top line details of preliminary 48 week data referred to in the Fuzeon positive opinion adopted by the EMEA today. These preliminary 48-week data combine results from the Phase III studies (TORO 1 and TORO 2) of Fuzeon (enfuvirtide) the first HIV fusion inhibitor. These longer term results build upon the positive 24 week results that were presented at the International AIDS Conference in July 2002. Fuzeon was approved by the U.S. Food and Drug Administration (FDA) last week.  Marketing authorisations for Fuzeon have also been submitted in Australia, Canada and Switzerland.

At the request of Health Authorities a preliminary analysis of the combined TORO 1 and 2 studies has been conducted at week 48 to determine the durability of response to Fuzeon. The 24 week combined analysis for these studies had previously shown a significant benefit for the Fuzeon arm versus the control arm of the study with patients twice as likely to achieve a reduction in HIV to below detection (<400 copies/ml) in the Fuzeon arm (32.7%; 216/661 patients) compared with the control arm (15.0%; 50/334 patients).

The preliminary 48 week analysis shows that for patients on the Fuzeon-containing arm who achieved a reduction in HIV to below detection (less than 400 copies/ml) by week 24, 80% maintained this response at week 48. Significantly fewer patients on the control arm achieved a reduction in HIV to below detection by week 24, and of these 68% maintained this response at week 48. Overall the proportion of all patients achieving <400 copies/ml at week 48 was significantly greater on the Fuzeon arm (30%) compared to the control arm (12%). 

�Following on from last week's US FDA approval and this week's positive opinion from the European CPMP we are very excited by these preliminary results of our analysis of the longer term benefits of Fuzeon� said Dr. David Reddy, Lifecycle Leader Fusion Inhibitors at Roche. He added �This is especially important for HIV patients who are running out of treatment options�.

�We are extremely pleased that these preliminary 48 week results appear to confirm the earlier week 24 data� said Dr. Dani Bolognesi, CEO Trimeris. �We are planning to present the full and final 48 week results at an upcoming international HIV conference. While it is possible that there may be some differences between the results presented here and the analysis of the 48 week data set that will be finalised in the coming weeks, the data we are announcing today are extremely encouraging.�

Safety Results

Fuzeon is administered as a twice-daily subcutaneous injection.  Local injection site reactions were the most frequent adverse events associated with the use of Fuzeon.  In Phase III clinical studies, 98 percent of patients had at least one local injection site reaction.  In this treatment-experienced patient population, three percent of patients discontinued treatment with Fuzeon as a result of injection site reactions.

The addition of Fuzeon to background antiretroviral therapy generally did not increase the frequency or the severity of the majority of adverse reactions.  The majority of adverse reactions were of mild or moderate intensity. Hypersensitivity reactions have occasionally been associated with Fuzeon therapy and in rare cases have recurred on re-challenge.  A preliminary analysis of longer term safety data has identified an increased rate of some bacterial infections, primarily pneumonia, in patients treated with Fuzeon.

Study Design

TORO 1 (T-20 vs. Optimised Regimen Only) and TORO 2 are randomised, open-label trials that enrolled approximately 1000 patients at 112 centres internationally. Patients in the trials were treatment-experienced and/or had documented resistance to each of the three classes of currently available antiretrovirals. In addition, each patient was required to have a HIV level of greater than 5,000 copies/mL. Patients are expected to undergo treatment for 48 weeks, with an optional 48-week treatment extension.

At entry, genotypic and phenotypic resistance testing was used to aid in the selection of an antiretroviral regimen, consisting of three to five drugs, including if appropriate, up to two newly approved or investigational drugs. After selection of the regimen, patients were randomised 2:1 to receive either the regimen in combination with Fuzeon or the regimen alone. Patients randomised to Fuzeon receive Fuzeon administered as one 90 mg subcutaneous self-injection twice-daily.

Fuzeon supply and access

There is a significant and growing need for new antiretrovirals that are active against strains of HIV that are resistant to the currently available medications. As Fuzeon represents the first new class of HIV therapy to be introduced since 1996, there is likely to be a considerable demand for the drug which may exceed initial supplies.  In view of the potential for demand to exceed supply, Roche and Trimeris will carefully manage available drug to ensure that people who initiate therapy have uninterrupted supply. Increased access to Fuzeon will be in step with increased supply output.

---

Notes to editors

Film footage is available for broadcast journalists from The NewsMarket  at www.thenewsmarket.com. Video is compressed in MPEG2 and is available for download to your FTP server.

Resistance to HIV drugs

It is estimated that in a single untreated person the virus can mutate to form around a billion new and potentially different versions of HIV every day. The incidence of drug resistant HIV among already treated patients is increasing at a disturbing rate. It was recently reported in one study that up to 78 percent of patients in North America are infected with a strain of the virus that has developed resistance to one or more anti-HIV drug.

Roche in HIV

Roche is at the forefront of efforts to combat HIV infection and AIDS, committed since 1986 to groundbreaking research and development of innovative new drugs and diagnostic technology. Saquinavir was the first Protease Inhibitor (PI) and was first introduced by Roche in 1995 in the US.

As a consequence of Roche's continuous research and development, the combination of boosted saquinavir with ritonavir (1000/100 mg twice daily) has shown encouraging results in the MaxCmin 1 trial with high efficacy and an excellent safety and tolerability profile. Saquinavir/r was approved in the EU in August 2002. Viracept (nelfinavir), a leading  PI is supplied by Roche outside the US and Canada. In first-line HIV therapy, Viracept delivers consistent long-term efficacy and safety. When used first line, Viracept also allows the subsequent use of both NNRTIs and other PIs for most patients due to its unique resistance pattern. Fuzeon and T-1249 are being co-developed by Roche and Trimeris.

Roche is a committed partner of the Accelerating Access Initiative to increase access to HIV care in sub-Saharan Africa and the world's Least Developed Countries. For more information on Roche policy and pricing of HIV protease inhibitors for these regions and research in HIV, visit www.roche-hiv.com.

About Roche

Headquartered in Basel, Switzerland, Roche is one of the world's leading research-oriented healthcare groups in the fields of pharmaceuticals and diagnostics. Roche's innovative products and services address prevention, diagnosis and treatment of diseases, thus enhancing people's well being and quality of life.

All trademarks used or mentioned in this release are legally protected.

About Trimeris

Trimeris, Inc. (Nasdaq: TRMS) is a biopharmaceutical company engaged in the discovery, development and commercialization of novel therapeutic agents for the treatment of viral disease.  The core technology platform of fusion inhibition is based on blocking viral entry into host cells.  FUZEON�, just approved by the FDA, is the first in a new class of anti-HIV drugs called fusion inhibitors.  A Marketing Authorisation Application (MAA) has also been submitted for FUZEON in the European Union.  Trimeris� second fusion inhibitor product candidate, T-1249, has received fast track status from the FDA and is in Phase I/II clinical testing.  Trimeris is developing FUZEON and T-1249 in collaboration with F. Hoffmann-La Roche Ltd.  For more information about Trimeris, please visit the company�s website at www.trimeris.com.

Trimeris Safe Harbor Statement
This document and any attachments may contain forward-looking information about the Company�s financial results and business prospects that involve substantial risks and uncertainties.  These statements can be identified by the fact that they use words such as �expect,� �project,� �intend,� �plan,� �believe� and other words and terms of similar meaning.  Among the factors that could cause actual results to differ materially are the following:  there is uncertainty regarding the success of research and development activities, regulatory authorizations and product commercializations; the results of our previous clinical trials are not necessarily indicative of future clinical trials; and, our drug candidates are based upon novel technology, are difficult and expensive to manufacture and may cause unexpected side effects.  For a detailed description of these factors, see Trimeris� Form S-3 filed with the Securities and Exchange Commission on September 27, 2002 and its periodic reports filed with the SEC.