FDA panel backs Heplisav-B, wants rigorous postmarketing study

Dynavax Technologies Corp. (NASDAQ:DVAX) jumped $7.45 (81%) to $16.70 in after-hours trading on Friday after FDA's Vaccines and Related Biological Products Advisory Committee voted 12 to one, with three abstentions, that available safety data support the use of the company's HBV vaccine Heplisav-B in adults. The committee also stressed the importance of a well-designed postmarketing study to assess observed imbalances in cardiovascular events. Heplisav-B's PDUFA date is Aug. 10.

The reviewers were concerned with imbalances in the incidence of myocardial infarction (MI) in the Phase III HBV-23 trial, in which 19 patients treated with Heplisav-B had an MI vs. three patients treated in the trial's Engerix-B comparator arm. However, several panel members said safety should be considered on a risk/benefit scale, emphasizing Heplisav-B’s superior efficacy over current options and the high public health need. One member suggested that the FDA label include a warning or alert for patients with increased CV risk factors...