Press Release

Sep 4, 2002

Dynavax Initiates Phase II Clinical Trial of ISS Vacine for Hepatitis B - Study Focuses on Single-Injection Approach

Dynavax Initiates Phase II Clinical Trial of ISS Vacine for Hepatitis B - Study Focuses on Single-Injection Approach

Contact:
Dino Dina, M.D.
President and Chief Executive Officer
Dynavax Technologies Corporation
(510) 848-5100


Berkeley, CA, September 4, 2002 - Dynavax Technologies, a privately held biopharmaceutical company, today announced it has initiated a Phase II clinical study to evaluate the ability of its ISS (immunostimulatory DNA sequence) vaccine candidate to provide effective hepatitis B prophylaxis in patients after a single injection. The study will compare the protective immune response of patients after immunization with either Engerix-B® HBV vaccine, a commercially available hepatitis B vaccine, or recombinant hepatitis B surface antigen (rHBsAg) co-administered with Dynavax's proprietary immunostimulatory DNA sequences (1018-ISS). Infection with the hepatitis B virus (HBV) is a major global health problem, with 350 million chronically infected individuals worldwide. One third of those with chronic infection develop cirrhosis of the liver and/or liver cancer.

About Dynavax

Dynavax Technologies is a privately held biopharmaceutical company developing innovative products to treat allergy, inflammation-mediated diseases, infectious diseases and cancer. The company's lead products are based on ImmunoStimulatory DNA Sequences (ISS), short DNA sequences that enhance the ability of the immune system to fight disease and prevent inflammation. The company's two most advanced products are AIC, which has provided positive results in recently completed phase II clinical trials for the treatment of ragweed allergy, and a next-generation hepatitis B vaccine that may offer single-dose protection. The company is also investigating ISS-based treatments for cancer and asthma. In addition, Dynavax is developing an oral TNF-alpha synthesis inhibitor initially for the treatment of rheumatoid arthritis. A company profile is available at the Dynavax website, www.dynavax.com.