Data supports safety of Dynavax hepatitis B vaccine: USFDA panel

Available data supports the safety of Dynavax Technologies Corp's experimental hepatitis B vaccine when administered to adults, a panel of expert advisers to the U.S. Food and Drug Administration said on Friday.

Much of the panel discussion focused on the need for Dynavax to carefully track patient outcomes due to concerns about safety of the vaccine, which has been rejected twice before by the regulatory agency.

The advisory committee voted 12 to 1, including one emailed vote and three abstentions, that data supports the safety of the vaccine, Heplisav-B, for adults 18 years and older. A prior panel voted 13 to 1 that clinical trial data supports the vaccine's effectiveness, Dynavax said.

FDA staffers, in a review released earlier this week, said the experimental hepatitis B vaccine is effective, but that there were more deaths and serious heart problems in patients given the vaccine than in those who took a rival product.

The FDA is not bound to follow the advice of its advisory panels but typically does so.

If the FDA approves the vaccine, peak sales could reach $650 million a year, according to Katherine Xu, an analyst at William Blair. She said Heplisav could become the standard of care since it has an easier dosing schedule than GlaxoSmithKline Plc's Engerix-B.

In its past rejections of Heplisav-B, the FDA cited unresolved safety concerns. The second rejection, in November, sent Dynavax's shares plunging roughly 70 percent to a year low of $3.20. They have since bounced back, closing at $9.25 on Thursday.

The new review of Heplisav-B comes before the FDA at an opportune time. Recent legislation requires the agency to find ways of speeding new products to the market and President Donald Trump has described the agency's approval process as "slow and burdensome."

Heplisav-B is designed to enhance the body's immune response to the hepatitis B virus, which can lead to cirrhosis of the liver, cancer and death. There is no cure. The virus is spread through sexual contact, sharing of needles, accidental needle sticks, and from mother to child during pregnancy.

The FDA is expected to make its decision next month.