Dynavax Technologies Corp. priced its offering of 5 million common shares at $15 per share, for expected gross proceeds of about $75 million.

The company granted the underwriters a 30-day option to buy up to 750,000 additional shares of its common stock.

The offering is expected to close on or around August 15, 2017, subject to customary closing conditions.

Cowen, RBC Capital Markets and William Blair are acting as joint book-running managers for the offering, with Cantor Fitzgerald & Co. as lead manager.

Separately, Dynavax said in an SEC filing that the U.S. Food and Drug Administration notified the company that its response to the FDA's request for additional information regarding Dynavax's proposed post-marketing study for Heplisav-B is considered a major amendment to the company's biologics license application.

Further, the Heplisav-B Prescription Drug User Fee Act date has been extended by three months to Nov. 9.