The U.S. Food and Drug Administration rejected Dynavax Technologies Corp's hepatitis B vaccine for the second time in three years, casting doubts on the drug developer's ability to bring its main drug to the market on its own.
Shares of the company, which has no drug on the market, plunged as much as 72 percent to $3.20, their lowest since late 2008.
Dynavax Chief Executive Eddie Gray said on Monday the company would meet with the FDA "as soon as possible" to discuss concerns raised by the agency in a "complete response letter".
