The study achieved its primary endpoint. Heplisav is being jointly developed by Dynavax and Merck for use in adults and in patients with end stage renal disease.
This study, called Phast, evaluated a two-dose regimen of Heplisav administered at zero and one month compared to a three-dose regimen of Engerix-B administered at zero, one and six months.
The primary endpoint was the proportion of subjects who developed protective antibodies to hepatitis B after administration. In Phast, 95.1% of subjects who received two doses of Heplisav (n=1,819) developed protective antibodies to hepatitis B when measured at 12 weeks versus 81.1% of subjects who received three doses of Engerix-B (n=608) when measured at 28 weeks.
The multi-center study evaluated 2,427 subjects from 11 to 55 years of age in Canada and Germany. Results of additional analyses from this trial will be presented in the future.
As previously disclosed, the FDA has placed a clinical hold on the two investigational new drug applications for Heplisav that is still in effect. In issuing the clinical hold, the FDA requested a review of clinical and preclinical safety data for Heplisav. Additionally, the FDA requested all available information about a single case of Wegener’s granulomatosis reported in this Phase III trial.