Dynavax, Johns Hopkins University, and NIH-Sponsored Immune Tolerance Network Present New Positive Data from Phase II Study of Ragweed Immunotherapy Product (AIC) Results Suggest Extended Benefits of Therapy

DENVER, March 11 /PRNewswire/ -- A single course of Dynavax's proprietary anti-allergy immunotherapy known as AIC appears to provide extended protection against ragweed allergy, according to Phase II clinical data presented here at the 60th annual meeting of the American Academy of Allergy, Asthma and Immunology (AAAAI). According to the study, AIC administration prior to the 2001 allergy season resulted in reduced allergy symptoms and other clinical markers of the allergic response through the following 2002 ragweed season, indicating a long-lasting effect of the drug. The study results were reported by Peter Creticos, M.D. of the Johns Hopkins University, Dynavax Technologies Corporation, and the National Institutes of Health (NIH)-Sponsored Immune Tolerance Network. Johns Hopkins University's Peter Creticos, M.D., the principal investigator for the trial, presented data indicating that a single course of ISS-enhanced ragweed allergy immunotherapy retained activity throughout more than one allergy season. Consistent with study results reported last year for the 2001 ragweed season, this subsequent Phase II clinical trial showed that individuals who received AIC therapy prior to the 2001 ragweed season had substantially lower hay fever nasal allergy symptoms and used less allergy medication during the 2002 peak ragweed season, compared to individuals who received placebo. Other measures, such as quality of life scores and daily symptom diaries, also indicated fewer allergy symptoms among study participants. The observer-blinded, placebo-controlled Phase II study evaluated adult volunteers who had a history of fall seasonal allergic rhinitis and exhibited skin test reactions to ragweed pollen. These patients, immunized prior to the 2001 ragweed season, were followed for allergy symptoms, medication use and immune response throughout the 2001 and 2002 ragweed seasons without additional interventions. Results for the 2001 ragweed season were reported last year. "These results demonstrate one of the most important advantages of ISS therapy -- its potential to reprogram a faulty immune response and thus produce long-lasting effects," stated Dino Dina, M.D., Dynavax's president and chief executive officer. AIC consists of the major ragweed allergen, Amb a 1, linked to Dynavax's proprietary 1018 immunostimulatory DNA sequence (ISS). ISS, unique short immunostimulatory sequences of single-stranded DNA, are the foundation technology for Dynavax's proprietary drug development platform. AIC is an example of an ISS linked to a known allergen for presentation to the immune system at the same time. Together with the Immune Tolerance Network, the researchers are investigating the potential mechanisms for AIC's extended activity using a number of biological and genetic techniques. "This is an important finding, that a short course of therapy can have a lasting, positive effect on the patient's response to allergens," said ITN Director Dr. Jeffrey A. Bluestone. "We are looking forward to additional data from this study that will further reveal the exact mechanisms that have contributed to this effect." The Phase II trial was sponsored and coordinated by the Immune Tolerance Network (ITN) in collaboration with Johns Hopkins University and Dynavax. ITN is an international collaborative clinical research program aimed at accelerating the clinical use of tolerance therapeutics for islet, kidney and liver transplantation, autoimmune disease, and allergy and asthma. Led by over 100 world leaders in the clinical and basic science of immunology, the ITN is funded by a contract from the National Institute of Allergy and Infectious Diseases, the National Institute of Diabetes, Digestive and Kidney Disease, and the Juvenile Diabetes Research Foundation. The program is headquartered at the University of California, San Francisco. Allergic rhinitis, or hay fever, is the fifth most prevalent chronic disease in the U.S., affecting more than 40 million people and resulting in an estimated 9.2 million physician visits each year. The majority of allergic individuals suffer seasonal symptoms in response to airborne pollens produced by weeds,grasses, and trees. In the U.S., ragweed is reported as the most prominent among the seasonal allergens, affecting an estimated 20 to 30 million people. AIC is the first in a series of ISS-allergen conjugate products that Dynavax plans to develop for the treatment of allergic rhinitis caused by seasonal and perennial allergens.

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 Sequences (ISS), short DNA sequences that enhance the ability of the immune system to fight disease and prevent inflammation. Dynavax's two most advanced products include an ISS-based next-generation vaccine for the prevention of hepatitis B, currently in pivotal Phase II clinical trials, and AIC, now in late Phase II clinical testing for the treatment of ragweed allergy. Dynavax also has an oral TNF-alpha synthesis inhibitor in preclinical development for rheumatoid arthritis. A company profile is available at the Dynavax website, www.dynavax.com. Dr. Creticos is a paid consultant to Dynavax Technologies. Another member of the Johns Hopkins University Division of Clinical Immunology is a paid consultant and owns equity in the company.

SOURCE Dynavax Technologies Corporation -0- 03/11/2003
CONTACT: Dino Dina, M.D., President and Chief Executive Officer of Dynavax Technologies Corporation, +1-510-848-5100, or
Jeffrey B. Matthews,
Ph.D., Director of Communications of Immune Tolerance Network,
+1-604-253-4990, or
jmatthews@immunetolerance.org/ /Web site: http://www.dynavax.com /