TRIMERIS/HOFFMAN LA ROCHE PROGRESS WITH HIV FUSION INHIBITORS.

A member of a new class of anti-HIV drugs, called fusion inhibitors is demonstrating its ability to suppress viral replication and remain well-tolerated in patients in an ongoing Phase II clinical trial. The investigational drug T-20, being developed through the collaboration of Trimeris, Inc., and Hoffmann-La-Roche, is the first member of a class of compounds known as fusion inhibitors. A second-generation fusion inhibitor, T-1249, is currently being evaluated in Phase I clinical studies. T-20 and T-1249 are the only fusion inhibitors currently in clinical development.

Fusion inhibitors work specifically on the virus to prevent it from fusing with the cell. Because they target a unique part of the viral lifecycle, T-20 and T-1249 are not expected to be cross-resistant to existing anti-HIV drugs.

"Developing regimens that include anti-HIV drugs designed to attack the virus in new ways is one of the most pressing unmet medical needs in HIV therapeutics today," said Dr. David Ho, director of the Aaron Diamond Center for AIDS Research. "As many as 40 percent of HIV/AIDS patients have failed multiple treatment regimens or have developed resistance to existing options, and while AIDS-related deaths have declined, the number of people living with HIV continues to grow. Fusion inhibitors may very well be the first new class of anti-HIV drugs since the introduction of protease inhibitors in 1995."

Thirty-two week results from an ongoing Phase II clinical study of T-20 (T20-205) are demonstrating consistent trends in tolerability and a decline in plasma viral load as was observed with initial 16-week data, announced in September 1999 at the 39th Interscience Conference on Antimicrobial Agents and Chemotherapy. New data from this study suggest a substantial CD4 cell increase in addition to the observed viral load decline. The open label single-arm study is evaluating T-20 in combination with other antiretrovirals in 71 HIV-positive adults who had received T-20 during earlier trials.

"Based on the encouraging results we're seeing, we have recently extended this trial to allow these advanced patients to continue using T-20 beyond 48 weeks," said Dr. Sam Hopkins, senior vice president of medical affairs at Trimeris. "When administered on a chronic basis, as a twice-daily subcutaneous injection, T-20 appears to be well-tolerated."

Trimeris and Roche also report that accrual is nearly complete in two additional ongoing studies involving their fusion inhibitors: a Phase II study (T20-206) evaluating the safety and dosing of T-20 in NNRTI-naive, protease inhibitor-experienced patients, and a Phase I study of T-1249 (T1249-101), assessing the safety, pharmacokinetics and tolerability of this compound.

In clinical studies, the most common adverse events observed with T-20 were mild to moderate in severity. The most frequent adverse events include injection site reaction, headache, nausea, fever, increased energy levels, asthenia, diarrhea, and dizziness, although a causal relationship to T-20 cannot be established for some of these results.

In addition to clinical advances, Trimeris and Roche are making progress on the manufacturing of T-20 and T-1249. The companies are announcing the successful transfer of methods to the Roche Colorado manufacturing facility for the production of large-scale clinical batches. In July 1999, Trimeris and Roche signed an agreement for the full-scale clinical testing and development of T-20 and T-1249.

Both T-20 and T-1249 have received fast-track designation by the U.S. Food and Drug Administration (FDA) for the treatment of HIV-infected individuals. Fast-track is granted to expedite the development of products that may provide a significant improvement in the safety or effectiveness of the treatment for a serious or life-threatening disease. T-20 and T-1249 will be investigated to meet a growing need for new anti-HIV therapies for the mounting number of patients who have failed or developed resistance to current medications.

This new class of anti-HIV drugs known as fusion inhibitors belongs to a broader category of investigational drugs known as "entry inhibitors." Entry inhibitors work in various ways to block HIV before it takes over the cell, either on the virus itself or on the cell. The entry inhibitor category includes the fusion inhibitor class, as well as two other classes: attachment inhibitors and co-receptor inhibitors. The fusion inhibitors, led by T-20, are the furthest along in development in the entry inhibitor category.

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 II 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 clinical testing.

For more information on Trimeris, Inc., visit the company's web site at www.trimeris.com.

About Hoffmann-La Roche Inc.

Hoffmann-La Roche Inc. (Roche), based in Nutley, N.J., is the U.S. prescription drug unit of the Roche Group, a leading research-based health care enterprise that ranks among the world's leaders in pharmaceuticals, diagnostics, vitamins, and fragrances and flavors. Roche discovers, develops, manufactures and markets numerous important prescription drugs that enhance people's health, well-being and quality of life. Among the company's areas of therapeutic interest are: virology, including HIV/AIDS and hepatitis C; infectious diseases, including influenza; cardiology; neurology; oncology; transplantation; dermatology; and metabolic diseases including obesity and diabetes.

For more information, call 919/419-6050.