Dynavax Technologies Corp. saw its stock gain 24 percent on the hope of a regulatory pathway for hepatitis B vaccine Heplisav, which has been on clinical hold since last March.
Shares of the Berkeley, Calif.-based company (NASDAQ:DVAX) rose 15 cents to close at 77 cents on Monday.
Heplisav combines HBV surface antigen with Dynavax's immunostimulatory sequence (ISS) technology, which is designed to stimulate an innate immune response by targeting Toll-like receptor 9. The drug was in a Phase II trial for HBV prevention in end-stage renal disease (ESRD) patients and a Phase III trial for HBV prevention in healthy adults when the FDA hit the brakes after a patient began showing symptoms of vasculitis. (See BioWorld Today, March 19, 2008.)
The clinical hold halted progress with the ESRD trial and held up consistency studies needed to support a biologics license application in healthy adults.
Yet patient treatment in the Phase III healthy adult trial was completed before the hold, and data released in August showed that the vaccine met its primary endpoint of inducing a noninferior antibody response (95 percent) compared to GlaxoSmithKline plc's marketed hepatitis B vaccine, Engerix-B (81.1 percent). (See BioWorld Today, Aug. 7, 2008.)
Dynavax and partner Merck & Co. Inc. submitted a complete response to the FDA, hoping to see the clinical hold lifted. But the agency responded that the balance of risk vs. potential benefit no longer favored continued clinical evaluation of Heplisav in healthy adults. Shares of Dynavax plummeted 80 percent, and Merck bailed out of its partnership. (See BioWorld Today, Dec. 22, 2008.)
Now the FDA has requested additional clinical and safety information about Heplisav that Dynavax believes may create a development path for the product in both ESRD and healthy adults.
Dynavax's vice president and chief business officer, Michael Ostrach, told BioWorld Today that the company met with the FDA in January and had the opportunity to present a thorough safety analysis as well as complete data from its Phase III trial. That may have led them to change their assessment of the risk-benefit, he said.
Now, the agency is looking for "a bit more commentary on a few more patients," Ostrach said - although he added that the information does not have to do with the vasculitis case and that the agency appeared satisfied on that front.
Ostrach said Dynavax has the data requested and just needs to write them up, which should allow for submission to the FDA "in the near future."
Dynavax continues to work with European and Canadian regulatory authorities on a development path as well.
The company previously predicted that it would have $65 million in cash, equivalents and marketable securities at the end of 2008 - enough to last more than two years.