January 6, 2003

For Immediate Release

Dynavax and University of California Announce Issuance of Landmark Asthma Patent

First Patent Covering Delivery of ISS Alone to Treat Disease

BERKELEY, Calif., /PRNewswire/ -- Dynavax Technologies, a privately held biopharmaceutical company, and the Regents of the University of California today announced that the University has been granted U.S. Patent No. 6,498,148 B1 (the '148 patent), covering the use of Dynavax's ISS (immunostimulatory DNA sequences) alone to treat asthma. Dynavax is the exclusive licensee of the '148 patent, giving Dynavax a significant position in the rapidly developing field of ISS treatment of asthma.

ISS are short synthetic DNA sequences that have been shown to strengthen an insufficient immune response against foreign pathogens and cancer, and to suppress an inappropriate immune response against otherwise harmless environmental substances, known as allergens. Dynavax is developing ISS-based therapies for a wide variety of diseases, including asthma, allergy, cancer and viral infections.

"This patent provides Dynavax with exclusivity in what we consider to be the largest possible indication for ISS-based treatments -- asthma," said Dino Dina, M.D., president and chief executive officer of Dynavax. "Our inhaled ISS formulation for asthma entered human clinical trials in 2002."

The '148 patent reflects a significant breakthrough in ISS technology -- the first demonstration that ISS alone, in the absence of co-delivered antigen, could treat an immune-mediated disease like asthma. The patent, which is based on seminal work conducted by Eyal Raz, M.D. and colleagues at the University of California, covers a method for treating asthma by administering ISS molecules to a patient in the absence of asthma-stimulating antigen or polynucleotides encoding that antigen. This work was reported in the Journal of Immunology in 1998. (Broide et al., Immunostimulatory DNA Sequences Inhibit IL-5, Eosinophilic Inflammation, and Airway Hyperresponsiveness in Mice, J. Immunol. (1998) 161: 7054-7062.)

Allergic asthma is a major health problem affecting an estimated 17 million Americans and more than 100 million individuals worldwide. The prevalence and severity of asthma in the U.S. and other developed countries is increasing, causing significant impact both in terms of quality of life and in the total costs associated with the disease. Asthma is a chronic lung disease characterized by inflammation of the airways typically driven by inflammatory responses involving Th2 cells (T helper type 2 cells). Dynavax's preclinical studies have demonstrated that ISS can reprogram the immune response by reducing inflammatory Th2 responses to allergens. In numerous mouse and primate studies, ISS delivered to sensitized animals before, during or after allergen challenge were shown to inhibit airway hyper-reactivity and allergic inflammation.

About Dynavax Technologies
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 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. Dynavax is also developing an oral TNF-alpha synthesis inhibitor initially for the treatment of rheumatoid arthritis. The company has collaborations with Aventis-Pasteur, Triangle Pharmaceuticals and Stallergenes.

Andrew Gengos
Chief Financial Officer
Dynavax Technologies Corporation
(510) 848-5100

/Web site: www.dynavax.com