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What happened

Shares in Dynavax Technologies Corp. (DVAX 0.71%) are surging by 26.6% at 3 p.m. EDT following reassurances by management that the Food and Drug Administration is still on track to issue an approval decision on its hepatitis B vaccine in mid-December. 

So what

Dynavax Technologies' Heplisav-B stumbled last week when the FDA decided to cancel a key advisory committee meeting previously scheduled for Nov. 16 to discuss the vaccine's pros and cons. The decision to cancel the review was made in order to give the FDA additional time to communicate with the company regarding questions about Heplisav-B and to review any responses to those questions.

The FDA's cancellation caused a sharp sell-off in Dynavax Technologies' shares as investors worried that the agency wouldn't be able to make good on its previously announced decision date of Dec. 15. The FDA had already postponed its decision on Heplisav-B by three months earlier this year.

To assuage fears, management issued a statement earlier today that conversations between the company and the FDA leave it thinking that the current decision date can be met by regulators. Management also said that the FDA plans to address remaining questions on Heplisav-B "via the normal process" and that the company is prepared to address questions quickly "to enable the FDA to complete its review as soon as possible."

Now what

Heplisav-B could potentially improve hepatitis B vaccination adherence because it's dosed just twice over one month, rather than three times over six months like the leading hepatitis C vaccination, Engerix-B. However, questions regarding Heplisav-B's role in autoimmune disorders sidelined the Heplisav-B's prior FDA filing for approval in 2013 and that makes an approval anything but a slam dunk.

Overall, Dynavax Technologies is confident it can deliver whatever the FDA needs quickly enough to prevent another delay. However, investors should remember that obstacles can and often do pop up, so there's no guarantee that this will go as management plans. Heplisav-B's better dosing profile makes this company intriguing, but I'm going to focus on other investment ideas until the FDA review is complete.