Barcelona, Spain, July 9 � The majority of patients taking the novel investigational fusion inhibitor T-20 have reported that the drug�s subcutaneous self-injections do not disrupt their daily activities. Over 500 patients were surveyed in two ongoing international phase III studies. After 8 weeks of therapy, 65% reported that T-20 was either �very easy� (27%) or �easy� (38%) to use. To assess whether taking the drug impacted their daily routines, patients were asked if twice daily self-injections influenced familiar routines of work, sleep, recreation, social life, travel, intimacy, and privacy. This will be welcome news to those patients who have developed resistance to most of the currently available drugs and will be considering optimising their therapy and using T-20.

Unlike existing AIDS drugs which work once the HIV virus has entered the human cell, T-20 works in a completely new way in that it blocks HIV from entering CD4 cells of the immune system.

The addition of T-20 on top of conventional optimised therapy is expected to become a key treatment component helping physicians optimise therapy in previously treated HIV patients, as it helps the body�s immune cells (CD4 cells) from further depletion by facilitating the reduction of the amount of HIV virus in the blood that can destroy these cells.

"We are pleased that patients who are used to taking numerous tablets every day find T-20 acceptable," reported Dr. David Reddy, Disease Area Head, HIV/AIDS, Roche. "We had hoped that the injectable formulation would not pose a major problem as millions of people with Type 1 diabetes give themselves up to 6 daily injections of insulin and still lead very active lifestyles. These results confirm that once people get used to giving themselves injections, it becomes part of their daily routine."

While almost all (98%) patients on the T-20 arms of both TORO 1 and TORO 2 phase III studies experienced injection site reactions at 24 weeks, no more than 3.3% of patients in either study discontinued the treatment due to these reactions.

A second study presented today by American researchers confirmed the levels of T-20 in the blood remained in the same range when HIV patients self-injected themselves in the stomach, thigh or arm. Daily injections of any drug in the same part of the body can sometimes cause build-up of scar tissue and fatty deposits. So, as with insulin injections, patients who may eventually take T-20 should try to change or rotate daily injection sites to help minimise discomfort.

Dr Calvin Cohen � a leading investigator in the US T-20 phase III trial reports, "As T-20 cannot be taken orally as it would be destroyed by digestive enzymes in the gut, it is essential that patients are able to adhere to the daily injection routine. As with any injection we always encourage patients to rotate the site to avoid overuse of any one area. Consequently, reports from patients are very positive with more than 90% saying it is something they can do, something they can live with, so it�s great news all round that a similar amount of T-20 will reach the system from a variety of injection sites."

These findings build on earlier results released at the 1^st International AIDS society Conference in Buenos Aires last year where 98% of patients who completed one year of T-20 therapy said that they would choose to continue on this drug. Phase III studies have shown T-20 to have potent antiviral activity against viruses resistant to existing classes of antiretrovirals and to be well tolerated.

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.

Optimised background therapy consists of an individually chosen anti-HIV drug combination selected from currently available drugs. The TORO studies demonstrate a significant additional reduction in HIV when T-20 is used with optimised background therapy, compared to an optimised background therapy alone.

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.

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.

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.