Dynavax shares shoot up as hep B PhIII vaccine blasts by rival GSK

Dynavax CEO Eddie Gray

Shares of Dynavax ($DVAX) charged this morning after the biotech laid out a fresh batch of promising Phase III data for its hepatitis B vaccine Heplisav-B, which bested GlaxoSmithKline's ($GSK) rival mainstay Engerix-B and positioned the biotech to overcome big delays at the FDA and EMA.

Some analysts have been excited by repeated late-stage evidence that shows two injections of Heplisav-B can provide better protection against the virus when compared to the standard three injections of Engerix-B. And this latest round--which includes assurances on the relative safety of Heplisav-B--will likely incite fresh encouragement that Dynavax can convince regulators in a second run at an approval.

Initially, shares of Dynavax surged close to 40% this morning, but later gave up some of those gains and was ahead about 30% in early trading.

In this latest Phase III, investigators determined that Heplisav-B provided a peak seroprotection rate of 90% among diabetics, compared to 65.1% for Engerix-B. And the entire patient group getting Heplisav-B also offered a statistically higher response: 95.4% to 81.3%. The experimental hep B vaccine also outscored Engerix-B in every subpopulation, ranging from sex, body mass index, and smoking status to age groups.

The Phase III points Berkeley, CA-based Dynavax squarely at a near-term regulatory filing as the company continues a comeback following its rejection at the FDA in early 2014. The biotech mounted this new Phase III study to provide more safety data as well as fresh comparisons to the GSK rival. 

RBC's Simos Simeonidis has noted that Heplisav is a "stronger and more convenient" vaccine than Engerix-B, which should let it grab the lion's share of the $270 million U.S. hepatitis B market.

"We are delighted to report these topline results from HBV-23 and confirm our intention to resubmit the HEPLISAV-B BLA by the end of March. These results support our belief that HEPLISAV-B, if approved, could offer benefits to adults at risk for hepatitis B, particularly given that these significant differences in seroprotection were demonstrated in a controlled setting, where compliance is optimized," said Dynavax CEO Eddie Gray.

- here's the release