The primary endpoint is seroprotection four weeks after the third immunization. Data for the entire study population show that after two doses, Heplisav provided 98.5% seroprotection versus Engerix-B’s 25%.
“This has the potential to drive an important change in the way people are immunized against hepatitis B,” said Dino Dina, president and CEO of Dynavax.
In December 2005, Dynavax reported the results of a smaller phase II/III trial in older adults measuring the superiority of Heplisav compared to Engerix-B relative to the primary endpoint of seroprotection. Seroprotection was 100% in the Heplisav-treated group compared to 90.5% in the Engerix-B treated group. The study also showed that subjects treated with Heplisav experienced more durable seroprotection.
Dynavax plans to pursue approval of a two-dose regimen and expects to initiate phase III trials before the year-end, comparing the two-dose regimen against Engerix-B in patients from 11 to 55 years of age. These trials are expected to be completed in 2008.
Dynavax indicates that as a result of its acquisition of Rhein Biotech in April 2006, the company has secured manufacturing capabilities in Germany for producing both clinical and commercial quantities of the vaccine.