Dynavax's HEPLISAV(TM) Hepatitis B Vaccine Maintains Full Immunogenicity at 50 Weeks in Pha...( In Difficult-to-Immunize Populati...),Health

In Difficult-to-Immunize Population, Demonstrates Superior Long-Term

Seroprotection Compared to Conventional Vaccine

BERKELEY, Calif., Sept. 19 /PRNewswire-FirstCall/ -- Dynavax Technologies Corporation (Nasdaq: DVAX) announced today that the seroprotection of HEPLISAV at 50 weeks after the first vaccination remained at 100% while the seroprotection of the comparator, GlaxoSmithKline's Engerix-B(R); vaccine declined.

The data show that after three doses, HEPLISAV provided seroprotection (anti-HBsAg antibodies greater than or equal to 10 mIU/mL) to 100% of subjects versus 68.6% for Engerix-B (p < 0.0001) as measured at 50 weeks.

These data were reported in a poster at the 47th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Chicago, IL. Primary endpoint data from this Phase 3 study in a difficult-to-immunize population of older adults were reported in November, 2006. The primary endpoint is seroprotection four weeks after the third vaccination.

According to Eduardo Martins, M.D., D.Phil., Vice President, Clinical Development, "These results demonstrate HEPLISAV's long-term superior immunogenicity over conventional hepatitis B vaccine as measured at 50 weeks. These data confirm earlier clinical studies showing that HEPLISAV has superior immunogenicity and comparable tolerability to Engerix-B. The overall results suggest that HEPLISAV elicits a faster immune response, higher rates of seroprotection and a more durable immune response than conventional vaccine."

The Phase 3 trial enrolled more than 400 seronegative subjects, 40 to 70 years of age, at study sites in Singapore, Korea and the Philippines. One group of subjects received three dos
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