New Treatment Guidelines Support Use of FUZEON(R) to Achieve Undetectable HIV in Treatment-Experienced Patients.

TORONTO -- Newly updated HIV/AIDS treatment guidelines, issued by the International AIDS Society-USA and published in this week's edition of the Journal of the American Medical Association, support important changes for the management of treatment-experienced patients. They recommend for the first time that the goal of therapy in heavily treatment-experienced patients should be to achieve undetectable levels of HIV (less than 50 copies/mL), and highlight the results from several pivotal studies with newer anti-HIV treatments, such as darunavir and tipranavir, in which concomitant use of FUZEON was associated with a significantly greater likelihood of achieving this result. FUZEON, the first and only fusion inhibitor available for the treatment of HIV, was co-developed by Roche and Trimeris (Nasdaq: TRMS). The revised IAS-USA guidelines were released in a news conference at the XVI International AIDS Conference, being held this week in Toronto.

"Maintaining undetectable viral load is the best way to achieve long-term treatment success in HIV," said Dr. Julio S.G. Montaner, president-elect of the International AIDS Society and a member of the IAS-USA panel that drafted the updated guidelines. "Today using FUZEON with darunavir or tipranavir, we have the right drugs to help us achieve this goal for treatment-experienced patients. The new IAS-USA guidelines clearly support this approach."

Detectable HIV can lead to drug resistance, and recent research shows 66 percent of HIV patients in the U.S. have detectable viral levels. In order to combat these rates of resistance and improve the chances of reaching undetectable - which has been shown to improve clinical outcomes - the newly-issued guidelines recognize that patients need the full potency of at least two fully active drugs, such as FUZEON and a newer boosted protease inhibitor. Prior to the simultaneous availability of these drugs which retain activity against drug-resistant virus, achieving undetectable in a significant number of heavily treatment-experienced patients was not possible.

"This concept of the significance of getting HIV to under 50 copies/mL is not complicated. If viral load is over 50 copies/mL, resistance can develop, leading to a deterioration in immune function and eventually resulting in disease progression," said Jules Levin, founder and Executive Director, National AIDS Treatment Advocacy Project (NATAP). "Now that the IAS-USA guidelines have been updated, doctors must aim for an undetectable viral load if they have the drugs available - none of us should be complacent."

Facts About FUZEON

Administered via one 90 mg injection twice-daily, FUZEON is the first and only fusion inhibitor for the treatment of HIV. Unlike other HIV drugs that work after HIV has entered the human immune cell, FUZEON works outside the CD4 cell, blocking HIV from entering the cell. For this reason, FUZEON is effective in treatment-experienced patients who have developed resistance to other anti-HIV drugs, though patients may still develop resistance to FUZEON. FUZEON was granted accelerated approval by the U.S. Food and Drug Administration (FDA) in March 2003 on the basis of 24-week data, and was granted traditional (full) approval on Oct. 15, 2004 on the basis of long-term 48-week data.

Injection Site Reactions (ISRs): ISRs are the most common adverse events associated with FUZEON. ISRs occurred in 98% of patients studied and 4% discontinued FUZEON due to ISRs. Signs/symptoms may include pain and discomfort, hardened skin, redness, bumps, itching and swelling. Eleven percent of patients had local reactions that required analgesics or limited usual activities.

Pneumonia: An increased rate of bacterial pneumonia was observed in subjects treated with FUZEON in the Phase III clinical trials compared to the control arm. It is unclear if the increased incidence of pneumonia is related to FUZEON use. Patients with HIV infection should be carefully monitored for signs and symptoms of pneumonia. Risk factors for pneumonia included low initial CD4 cell count, high initial viral load, intravenous drug use, smoking and a prior history of lung disease.

Hypersensitivity Reactions: Systemic hypersensitivity reactions have been associated with FUZEON therapy and may recur on rechallenge. Hypersensitivity reactions have included individually and in combination: rash, fever, nausea and vomiting, chills, rigors, hypotension and elevated serum liver transaminases. Other adverse events that may be immune mediated and have been reported in subjects receiving FUZEON include primary immune complex reaction, respiratory distress, glomerulonephritis and Guillain-Barre syndrome.

Other Adverse Events: The events most frequently reported in patients receiving FUZEON plus an optimized background regimen were diarrhea (32%), nausea (23%) and fatigue (20%). These events were seen at a lower incidence in patients taking a FUZEON-based regimen compared to those receiving an optimized background regimen without FUZEON when taking into account the uneven number of patients in each arm and the length of time they are in that arm. As measured in number per 100 patient years, the incidence was: diarrhea (38 per 100 patient-years in subjects receiving FUZEON-based regimens vs. 73 per 100 patient-years in patients who did not receive FUZEON), nausea (27 vs. 50, respectively) and fatigue (24 vs. 38, respectively).

Roche in HIV

Roche is at the forefront of efforts to combat HIV infection and AIDS, committed for more than 15 years to groundbreaking research and development of new drugs and diagnostic technology. The objective is to provide tailored treatment solutions and an improved standard of care worldwide for those people living with HIV.

Roche and Trimeris are working together to discover, develop and commercialize the next generation of HIV fusion inhibitors.

About Roche

Hoffmann-La Roche Inc. (Roche), based in Nutley, N.J., is the U.S. pharmaceuticals headquarters of the Roche Group, one of the world's leading research-oriented healthcare groups with core businesses in pharmaceuticals and diagnostics. For more than 100 years, the Roche Group has been committed to developing innovative products and services that address prevention, diagnosis and treatment of diseases, thus enhancing people's health and quality of life. An employer of choice, in 2005, Roche was named one of Fortune magazine's Best Companies to Work For in America, ranked as the No. 3 Best Company to Work For in NJ (NJ Biz magazine), the No. 1 Company to Sell For (Selling Power) and one of AARP's Top Companies for Older Workers. For additional information about the U.S. pharmaceuticals business, visit our websites: http://www.rocheusa.com or www.roche.us.

About Trimeris, Inc.

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, approved in the U.S., Canada and European Union, is the first in a new class of anti-HIV drugs called fusion inhibitors. Trimeris is developing FUZEON and future generations of peptide fusion inhibitors in collaboration with F. Hoffmann-La Roche Ltd. For more information about Trimeris, please visit the company's Web site at http://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; we are dependent on third parties for the sale, marketing and distribution of our drug candidates; 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 10-K filed with the Securities and Exchange Commission on March 10, 2006 and its periodic reports filed with the SEC.