Early preclinical data on TR-291144 and TR-290999 to be presented at major HIV congress in February

Basel, Switzerland and Morrisville, N.C. (January 19, 2006) Roche and Trimeris today announced their collaboration in the co-development of two new HIV fusion inhibitor peptides. The peptides, TR-291144 and TR-290999, are being developed with the goal of achieving highly potent and durable suppression of the HIV virus while simultaneously improving convenience for patients through less frequent dosing such as once weekly administration. Data from the early pre-clinical studies evaluating TR-291144 and TR-290999 will be presented at an upcoming international HIV congress in February.

�Early studies with these new peptide fusion inhibitors have shown very promising results� said Dr Nick Cammack, Head of Virology Research, Roche. �These studies, along with our other ongoing NNRTI and CCR5 discovery programmes, demonstrate Roche�s commitment to finding new and improved approaches to fighting HIV/AIDS.�

First Fusion Inhibitor, FUZEON, continues to provide much needed hope for HIV patients facing treatment failure

FUZEON� (enfuvirtide), co-developed by Roche and Trimeris (Nasdaq: TRMS) and launched worldwide in 2003, was the first major breakthrough in the treatment of HIV since 1997.  FUZEON ushered in a completely new approach to fighting HIV by blocking the virus from entering human immune cells. It is the first and only fusion inhibitor available for the treatment of HIV.

�We are very encouraged by the prospect of co-developing the next generation of fusion inhibitor peptides with our colleagues at Roche,� said Steven D. Skolsky, CEO, Trimeris, Inc. �This is a significant milestone which further validates our peptide technology platform.�

In vitro data on peptides that are precursors to TR-291144 and TR-290999 were presented at the First Conference on Entry Inhibition of HIV in December 2005. They demonstrated significant potency and durability.

Notes to editors

For further information on FUZEON and Roche in HIV please visit: http://www.roche-hiv.com/Newsandfeatures/fuzeon.cfm

About FUZEON

Recommendations - The updated DHHS guidelines (October 6, 2005) are available online: http://aidsinfo.nih.gov/guidelines/.

The Panel on Clinical Practices for Treatment of HIV Infection convened by the US Department of Health and Human Services (DHHS) provides guidance on the management of HIV-infected patients. It also provides guidance on changing an antiretroviral therapy regimen for virologic failure, for which the latest recommendations include:

Using the treatment history and past and current resistance test results to identify active agents (preferably at least two fully active agents) to design the new regimen. A fully active agent is one likely to demonstrate antiretroviral activity on the basis of both the treatment history and susceptibility on drug-resistance testing.

Adding a drug with activity against drug-resistant virus (e.g. a potent ritonavir-boosted PI) and a drug with new mechanism of action (e.g. HIV entry inhibitor) to an optimised background antiretroviral regimen can provide significant antiretroviral activity.

Growing body of evidence, RESIST 1&2 / POWER 1&2 / TORO 1&2 - Collectively the data from all six studies, in over 2,500 patients, suggest a new paradigm in the management of triple class-experienced patients. Latest data adds to growing Body of Evidence � Latest Boosted Protease Inhibitors (lopinavir/r, tipranavir/r and the investigational agent TMC 114/r) all work better in combination with FUZEON.

RESIST Phase III tipranavir trials

• Over 24 weeks, almost double the proportion of patients who received FUZEON plus boosted tipranavir showed a 90% drop in viral load compared with patients not receiving FUZEON

POWER Phase II TMC114 dosing trials

• Preliminary data over 24 weeks in the combined TMC114 trials showed that almost double the proportion of patients who received FUZEON plus the investigational boosted PI TMC114 achieved a viral load below 50 copies/ml compared with patients not receiving FUZEON

-        A remarkable 67% of the patients receiving FUZEON plus boosted TMC114 reached an undetectable viral load (<50 copies/ml)

-        In the POWER 1 trial 63% of the patients receiving FUZEON plus boosted TMC114 reached an undetectable viral load (<50 copies/ml) compared with 56% of patients receiving TMC114 alone

-        Preliminary data in the POWER 2 trial showed that 64% of the patients receiving FUZEON plus boosted TMC114 reached an undetectable viral load (<50 copies/ml) compared with 30% of patients receiving TMC114 alone

TORO Phase III FUZEON trials

• Over 24 weeks, double the proportion of patients who received FUZEON plus boosted lopinavir achieved an undetectable viral load (<50 copies/ml) compared with patients not receiving FUZEON

About Roche

Headquartered in Basel, Switzerland, Roche is one of the world�s leading innovation-driven healthcare groups. Its core businesses are pharmaceuticals and diagnostics. Roche is number one in the global diagnostics market and is the leading supplier of pharmaceuticals for cancer and a leader in virology and transplantation. As a supplier of products and services for the prevention, diagnosis and treatment of disease, the Group contributes on a broad range of fronts to improving people�s health and quality of life. Roche employs roughly 65,000 people in 150 countries. The Group has alliances and research and development agreements with numerous partners, including majority ownership interests in Genentech and Chugai.

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; 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 11, 2005 and its periodic reports filed with the SEC.

For more information, please contact:

Katie Banks                                                                   Libby Day

Ketchum                                                                        F. Hoffmann-La Roche Ltd

Tel: +44 207 611 3619                                                    Tel: +41 616 87 02 36

Email: katie.banks@ketchum.com                                  Mob: +41 79 597 2054

Email: elisabeth.day@roche.com