Heplisav-B regulatory update

Dynavax said FDA issued a complete response letter to the company for a BLA for its Heplisav-B HBV vaccine and that it will seek a pharmaceutical or financial partner to advance the program. Dynavax said the agency is requesting information on selected adverse events and on a numerical imbalance in cardiac events in the Phase III HBV-23 trial; new analyses of the product’s integrated safety database across different time periods; and postmarketing commitments. The company said the letter does not ask for additional clinical trials or express concerns about rare, serious autoimmune events. The vaccine combines hepatitis B surface antigen (HBsAg) with a toll-like receptor 9 (TLR9) agonist.

On a conference call, Dynavax said it believes the imbalance in cardiac events in HBV-23 was due to an unexpectedly low number of events in the trial’s Engerix-B comparator arm, but declined to discuss specific cardiac events seen in the trial. The company also said FDA acknowledged in the letter that it had not completed its review of Dynavax’s responses to 25 questions the agency posed in September. The biotech speculated the agency issued the letter because its review would not be complete by the Dec. 15 PDUFA date (see BioCentury, Sept. 12)...