Second of two pivotal studies also meets primary endpoint; EU and US registration packages to be filed as planned

Roche and Trimeris Inc today announce positive 24 week results from the second pivotal Phase III study of T-20 (TORO 2), just four weeks after reporting similarly positive 24-week results from the first Phase III study of T-20 (TORO 1). Together, these studies will form the basis of the submission to regulatory authorities. T-20 is the furthest in clinical development of a new class of investigational anti-HIV drugs known as “fusion inhibitors”. Unlike existing AIDS drugs which work once the HIV virus has entered the host cell, T-20 has a novel mode of action in that it blocks HIV from entering and infecting human cells.

The results from the TORO 2 study show that T-20 administered in combination with an optimised antiretroviral treatment regimen provides a significant additional decrease in the amount of virus in the blood as compared to an optimised antiretroviral treatment regimen alone. TORO 2 was conducted in 504 HIV infected patients in Europe and Australia who were treatment-experienced and/or had documented resistance to each of the three classes of currently available anti-HIV drugs.

“This is the second large study demonstrating that T-20 provides a significant antiviral benefit for people living with drug resistant HIV" said William M. Burns, Head of Pharmaceuticals, Roche. "The excellent results from the TORO 2 study confirm and build upon the results of the first pivotal Phase III study TORO 1. Taken together, these data represent a significant milestone in our commitment to deliver new treatment options for treatment experienced patients, particularly those living in the shadow of drug-resistant HIV".

At baseline, patients had a median HIV RNA level of over 5 log₁₀ copies/mL and extensive prior exposure to multiple anti-HIV drugs. At 24 weeks, patients who received T-20 as part of their combination regimen achieved a mean reduction in HIV levels of 1.43 log₁₀ copies/mL compared to a mean of 0.65 log₁₀ copies/mL for those who were randomised to the control arm, calculated in accordance with the study protocol. The primary efficacy endpoint for the study, the difference in the magnitude of decrease in HIV between the two arms at 24 weeks, was 0.78 log₁₀ copies/mL and was statistically significant (p < 0.0001). Roche and Trimeris expect to present these data in detail at scientific conferences in the next several months.

“The positive results from TORO 2 are both clinically and statistically significant. It is remarkable that both TORO studies consistently demonstrate the substantial treatment effect of T-20 across a diverse, treatment-experienced patient population from a number of countries. The Roche and Trimeris collaboration plan to proceed with filing registration packages for T-20 in the EU and US as planned early in the second half of this year.“ said Dr. Dani Bolognesi, Chief Executive Officer, Trimeris. “This important milestone brings T-20, the first member of a new class of antiretrovirals, yet another step closer to patients in need.”

Safety Results
Through 24 weeks, as in TORO 1, overall clinical adverse events aside from injection site reactions were similar between T-20 and control groups. Other adverse events (>10%) occurring more frequently in the T-20 group were headache, fever, and asthenia. It was not possible to establish a causal relationship between these other adverse events and T-20. Grade 3 laboratory abnormalities were more frequent in the T-20 group, and Grade 4 laboratory abnormalities were more frequent in the control group. In TORO 2, discontinuation at 24 weeks was 17% in the T-20 group and 5% in the control group. Patients experiencing virological failure in the control group could switch to a T-20 regimen and not discontinue the study. While most patients on the T-20 arm experienced injection site reactions, only 3% of patients discontinued the study as a consequence.

Early Access to T-20
In November 2001, Roche and Trimeris announced the initiation of the T-20 open-label safety study (T20-305) to provide T-20 to 450 patients around the world. The study is ongoing and is being conducted in Australia, Brazil, Europe and North America. Roche and Trimeris are committed to starting early access programmes in the second half of this year when increased drug supply is expected to be available. Activities to build up the production capacity are on schedule.

Notes to editors
Study Design
TORO 2 (T-20 vs. Optimized Regimen Only), previously known as T20-302, and TORO 1 (previously known as T20-301) are randomized, open-label trials that enrolled approximately 1,000 patients at 112 centers worldwide. TORO 2 is being conducted in Australia, Belgium, France, Germany, Italy, The Netherlands, Spain, Sweden, Switzerland and the United Kingdom, TORO 1 is being conducted in North America and Brazil. 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 plasma HIV-RNA 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 randomized 2:1 to receive either the regimen in combination with T-20 or the regimen alone. Patients randomized to T-20 receive T-20 administered as one 90 mg subcutaneous self-injection twice-daily.

Meeting the Growing Need For a New Class of HIV Drugs
One of the biggest challenges facing people living with HIV is resistance to currently available therapies. Thirty to fifty percent of patients are infected with a strain of the virus that has developed resistance to one or more antiretrovirals, thereby reducing the treatment options available to them. Roche and Trimeris are committed to discovering and developing treatments for patients in need of new options and expect to invest approximately half a billion U.S. dollars to bring fusion inhibitors to people living with HIV/AIDS.

Long-Term Commitment to HIV Research and Development
Roche and Trimeris are working together to mobilize the considerable resources required to support the rapid development of T-20, the first member of a new class of investigational anti-HIV drugs known as fusion inhibitors. T-20, currently in Phase III clinical trials, is the furthest along in clinical development in the entry inhibitor class. T-1249, a second generation fusion inhibitor being developed by Roche and Trimeris, is in Phase I/II clinical trials. Unlike existing AIDS drugs that work inside the cell and target viral enzymes involved in the replication of the virus, T-20 inhibits fusion of HIV with host cells before the virus enters the cell and begins its replication process. In June 2001, Roche and Trimeris announced a joint research agreement to identify and develop additional HIV fusion inhibitor peptides.

T-20 has fast track designation from the FDA in the U.S. for the treatment of HIV-infected individuals. Fast track is granted to facilitate the development and expedite the review of applications for drugs that are intended to treat serious or life-threatening disease and that demonstrate the potential to address an unmet medical need.

About Trimeris, Inc.
Trimeris is a development stage, biopharmaceutical company engaged in the discovery and development of novel therapeutic agents that block viral infection by inhibiting viral fusion with host cells. Trimeris' lead product candidate, T-20, which inhibits fusion of the human immunodeficiency virus (HIV) with host cells, is currently in Phase III clinical trials and has received fast track designation from the FDA. Trimeris' second fusion inhibitor product candidate, T-1249, which also inhibits HIV fusion, has received fast track designation from the FDA and is in Phase I/II clinical testing. For more information on Trimeris, Inc., visit the company's Web site at www.trimeris.com

Trimeris Safe Harbor Statement
Note: Except for any historical information presented herein, matters presented in this release are forward-looking statements that involve risks and uncertainties. The results of Trimeris' previous clinical trials are not necessarily indicative of future clinical trials, and future results could differ materially from the results presented herein. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in the "Risk Factors" section included in Trimeris' Form 10-K for the year ended December 31, 2001 filed with the Securities and Exchange Commission on March 25, 2002.

About Roche
Headquartered in Basel, Switzerland, Roche is one of the world’s leading research-oriented healthcare groups in the fields of pharmaceuticals, diagnostics and vitamins. Roche’s innovative products and services address needs for the prevention, diagnosis and treatment of disease, thus enhancing people’s well-being and quality of life. For more information on Roche and its commitment to research in HIV, visit the: roche-hiv.com website.
All trademarks used or mentioned in this release are legally protected.

For further information:

Alexander Watson, Ketchum Telephone: + 44 20 7611 3663 Email: [email protected]

Maria Vigneau, Roche Telephone: + 41 61 688 9291 Email: [email protected]