BusinessWire, Monday, January 25, 1999 at 07:36
DURHAM, N.C. (BW HealthWire) Jan. 25, 1999

First in New Class of Drugs Continues to Show Potency and Safety

Trimeris, Inc. (NASDAQ:TRMS) announced today that preliminary results from TRI-003, a Phase II clinical trial of T-20, a fusion inhibitor, will be presented at the upcoming 6th Conference on Retroviruses and Opportunistic Infections in Chicago. T-20 attacks HIV in an entirely different way than currently approved agents. InTRI-003, T-20 was well tolerated at all doses and a dose-related reduction of viral load was observed in HIV infected subjects with extensive prior antiretroviral exposure and high viral loads. Dr. Joseph Eron, a TRI-003 investigator from the University of North Carolina at Chapel Hill, will present the findings from the trial in detail during the late-breaking scientific session on February 4. "These results from TRI-003 are impressive, particularly when one considers the population that enrolled in this clinical trial is extremely difficult to treat," said Dr. Eron. "The average number of anti-HIV medications that the patients in this trial had failed was nine, including an average of 3 protease inhibitors. Additionally, the average baseline viral load of the study population, 100,000 copies/mL, represents a difficult hurdle for any drug when administered as a single agent. T-20 performed well by reducing HIV in the blood by greater than 90% in the higher dose groups without significant side effects."

In the Phase II clinical trial, T-20 was given for twenty-eight days to 78 HIV infected adults. T-20 was administered via continuous subcutaneous infusion or subcutaneous injection and was added to a stable antiretroviral regimen or administered as monotherapy. Mild to moderate local skin irritation at the site of infusion or injection was observed in most patients. However, only 3% of patients discontinued T-20 due to side effects during this trial. Preliminary pharmacokinetic analyses indicate that both continuous subcutaneous infusion and twice-daily subcutaneous injection resulted in consistent plasma concentrations of T-20, with little peak-to-trough variation throughout the dosing period. "An unexpected positive outcome from this trial was the demonstration that twice-daily injection may be a feasible method to deliver T-20 on a chronic basis," said Trimeris CEO, M. Ross Johnson, PhD. "In both twice-daily injection groups evaluated, targeted blood levels of T-20 were sustained throughout the entire dosing interval. This result expands our options for administering T-20." "There is genuine excitement in the medical community for T-20, because it is the only drug in Phase II clinical trials which works by an entirely novel mechanism of action," commented TRI-003 lead investigator Dr. Jacob Lalezari, from San Francisco. "T-20 attacks HIV before it enters the cell, and the chance for cross-resistance with current treatments is minimal. The encouraging results from this trial affirm that T-20 continues to hold promise for the growing number of HIV-infected people who are failing currently approved drugs." The complete data from TRI-003 and other Phase II trials are expected to provide a basis for initiating pivotal clinical trials during 1999.

For a more technical discussion of the TRI-003 results, call 919-419-6050, or visit Trimeris' website at HYPERLINK http://www.trimeris.com. 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 The > company's lead product candidate, T-20, which inhibits fusion of the human immunodeficiency virus (HIV) with host cells, is currently in Phase II clinical trials.

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 the company's 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 the company's 1997 Form 10K filed with the Securities and Exchange Commission on March 31, 1998, and the company's Registration Statement on Form S-1 as declared effective by the Securities and Exchange > Commission on October 6, 1997, and those discussed from time to time in Trimeris' filings with the Securities and Exchange Commission.

CONTACT: Trimeris, Inc. Burns McClellan
Matthew A. Megaro Justin Jackson (media)
Chief Financial Officer John Nugent (investors)
919/419-6050 212/213-0006