Drug Pipelineline Series: Phase III, 27 Nov - 4 Dec, 2006

Dynavax's HEPLISAV™ Hepatitis B Vaccine Shows Statistically Significant Results in Phase 3 Trial

Dynavax Technologies Corporation announced statistically significant results from the primary endpoint analysis of a Phase 3 trial comparing HEPLISAV, its hepatitis B virus (HBV) vaccine, to GlaxoSmithKline's Engerix-B® vaccine in a difficult-to-immunize population of older adults. The primary endpoint is seroprotection four weeks after the third immunization.

The data show that after three doses, HEPLISAV provided seroprotection to 100% of subjects versus 73.1% for Engerix-B (p < 0.0001). The greatest difference in seroprotection after three doses was seen in subjects 56 to 70 years of age where HEPLISAV provided 100% seroprotection and Engerix-B provided 56.1%. Data for the entire study population show that after two doses, HEPLISAV provided 98.5% seroprotection versus Engerix-B's 25%. Furthermore, HEPLISAV provided a level of immunity as measured by geometric mean concentrations of anti-HBsAg antibodies 18.5 times higher than Engerix-B four weeks after the third dose.
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 doses of Dynavax's HBV vaccine; the other group received three doses of Engerix-B.