Cambridge, MA, April 3, 2002 - Therion Biologics has expanded its Board of Directors with the appointments of Peter R. Wolfe, M.D., Partner and Director of Research at Pacific Oaks Medical Group, and Trudie Resch, Partner of CDP Sofinov. These additions strengthen Therion's Board by bringing to the company Dr. Wolfe's clinical expertise and Ms. Resch's financing and biotechnology investment experience. Ms. Resch replaces Luc E. J. Mareng�re as CDP Sofinov's representative on Therion's Board.

"We are privileged to have attracted such industry knowledge to our Board of Directors. Both Peter and Trudie will be instrumental in guiding Therion's progress as the company focuses on late stage clinical development and product commercialization," said Mark Leuchtenberger, President and Chief Executive Officer of Therion. "Based on their strong track record in the biopharmaceutical industry, they will provide invaluable insight and expertise as Therion continues to build a deep and broad pipeline of cancer vaccine products."

Therion's vaccine product portfolio is led by two programs in colorectal and prostate cancer. Clinical trials with lead vaccines in these areas have demonstrated that the products are both safe and well tolerated in all patients treated to date. Recent studies of Therion's pox virus-based CEA vaccines, which target colorectal cancers, have shown improved immune responses against CEA-bearing tumors and significant increases in patient survival. In Therion's prostate cancer program, patients enrolled in recent clinical studies have exhibited PSA stabilization when treated with the company's PROSTVAC� vaccine. Such maintenance of PSA levels is considered an important first sign of disease control. Therion's prostate cancer vaccine is projected to enter Phase III clinical trials in 2003.

Dr. Wolfe has conducted extensive clinical research as a Partner and Director of Research at Pacific Oaks Medical Group. His primary responsibilities have included working with major pharmaceutical firms to develop and execute clinical research trials in antiviral therapeutics for the treatment of HIV and hepatitis B and C. While at Pacific Oaks, he has established partnerships with Merck, GlaxoSmithKline, Roche and Pfizer to evaluate clinically a number of new antiviral compounds. In addition, Dr. Wolfe is a member of the Human Subjects Protection Committee of Century City Hospital, Los Angeles and is on staff at Cedar-Sinai Medical Center. He also serves on a number of scientific and medical advisory boards. Dr. Wolfe received his M.D. from the University of Pittsburgh and completed his residency in internal medicine and an infectious disease fellowship at UCLA-affiliated programs.

Ms. Resch brings over 15 years of marketing and business development experience to promote the growth and development of early stage biotechnology companies. At CDP Sofinov, a leading Canadian venture capital firm, Ms. Resch's work focuses primarily on mezzanine investments and private financings of public firms. She has played a key role in a number of investments in companies such as Cubist and Corvas. Before joining the CDP Sofinov team, she worked for the Biotechnology Research Institute (NRC), where she took part in developing research partnerships with several Canadian biotechnology companies that have since become major industry players. Ms. Resch holds a MBA from McGill University and a Bachelor of Biochemistry from Concordia University.

About Therion Biologics
Therion Biologics Corporation is focused on the development of therapeutic vaccines for cancer and preventive vaccines for AIDS. Therion's most advanced product, PROSTVAC-VF�, is currently in Phase II studies for prostate cancer. Under the terms of a strategic collaboration with Aventis Pasteur, a second product, ALVAC-CEA/B7.1, will move into pivotal clinical trials in the next two years for colorectal cancer. The company also has a broad pipeline of vaccines in early clinical development for treatment of major cancers, including breast cancer, melanoma and other solid tumors. In addition to Aventis, Therion's partners include the National Cancer Institute and a network of leading clinical institutions around the world. Therion is headquartered in Cambridge, Massachusetts.