June 24 , 2004

Dynavax Completes Phase I Immunization in Pediatric Ragweed Allergy Trial


BERKELEY, Calif., June 24 /PRNewswire-FirstCall/ -- Dynavax Technologies Corporation (Nasdaq: DVAX), a biopharmaceutical company focused on the discovery, development, and commercialization of innovative products to treat and prevent allergies, infectious diseases and chronic inflammatory diseases, today reported the successful completion of immunizations in a Phase I pediatric trial of its ragweed allergy immunotherapy product candidate, AIC. Only relatively minor and transitory local reactions at the injection site were reported, and no dose adjustments were necessary.

"The local reactions and adverse experience of AIC in this young population appeared to be even milder than those observed in the adult population, where the product has already been shown to be quite safe and well tolerated," said Dino Dina, M.D, President and Chief Executive Officer of Dynavax Technologies.

"The excellent tolerability of AIC thus far in the pediatric age group provides us with the ability to evaluate AIC in a larger segment of the target ragweed allergic population. Equally important, we believe these findings could permit us to explore early interventions with AIC in ragweed allergic individuals prior to the onset of severe symptoms and the development of asthma, with the goal of preventing the evolution of the disease into significant health and life-style compromising conditions. We hope in the future to test AIC therapy as a way to prevent the onset of severe allergic disease their serious sequelae such as chronic sinusitis and asthma," Dr. Dina added.

The pediatric trial is being conducted in 24 children between the ages of 9 and 17 with known ragweed allergy, as documented by medical history and a strongly positive skin test to ragweed allergen. Subjects were subdivided into three cohorts, with each cohort receiving gradually increasing doses of AIC.     The pediatric trial is part of Dynavax's larger AIC ragweed program being conducted in collaboration with Dynavax's partner, UCB Pharma.  The AIC program includes an ongoing Phase II/III study in adults, with a blinded interim analysis to be made in late 2004 to assess safety and the appropriateness of commencing a one-year Phase III trial in early 2005.

About UCB Pharma     UCB Pharma is one of Europe's leading pharmaceutical companies. It is active in all the world's major markets, specializing in the fields of allergy and respiratory diseases and in treatments for disorders of the central nervous system.  Among products developed by UCB Pharma are XYZAL(R) (levocetirizine), a novel antihistamine; ZYRTEC(R) (cetirizine hydrochloride), the world's most widely used second-generation antihistamine; and KEPPRA(R) (levetiracetam), a novel adjunctive therapy for the treatment of partial onset seizures associated with epilepsy.  ZYRTEC(R) is a registered trademark of Pfizer, which markets ZYRTEC(R) in the U.S. under an agreement with UCB.  With over 6,500 employees and operating in over 100 countries, UCB Pharma's global headquarters are in Brussels, Belgium.  In 2003 it achieved a consolidated turnover of euro 1,463 million.


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.

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

Note: This press release contains "forward looking statements" within the meaning of the federal securities laws. These forward-looking statements include without limitation, statements relating to the potential success of product development, subsequent regulatory approvals and potential product sales. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date of this release. Dynavax undertakes no obligation to update publicly any forward-looking statements to reflect new information, events or circumstances after the date of this release except as required by law.