What happened

Dynavax Technologies Corporation (DVAX -1.82%) stock jumped a whopping 81.6% in after-hours trading Friday because of a favorable 12-to-1 advisory committee vote for its experimental hepatitis-B vaccine, Heplisav-B. This panel of independent experts was charged with assessing the vaccine's safety profile for the U.S. Food and Drug Administration, which they deemed sufficient to warrant approval. As the FDA only rarely goes against the advice of its advisory committees, Dynavax appears to be a near lock to gain its first regulatory approval, and finally transition into a commercial-stage company.  

Miniature rocket taking flight from a person's hand.

Image source: Getty Images.

So what

The outcome of this critical vote was in serious doubt after the FDA released its briefing documents last Wednesday. Specifically, the agency pointed out that patients receiving Heplisav-B exhibited a higher rate of serious adverse effects in its latest phase 3 trial, compared with those receiving GlaxoSmthKline's Engerix-B. Although the data was far from conclusive, this safety concern was enough to cause Dynavax's shares to nosedive by double digits. 

Now what

The FDA is expected to hand down a regulatory decision for Heplisav-B by Aug. 10. If approved, this vaccine has the potential to become the new standard of care for hepatitis-B in adults, which should translate into peak sales in the neighborhood of $700 million per year.

As vaccine-makers are highly coveted because of the commercial longevity of their products, Dynavax has a real shot at eventually garnering a top-notch premium in the area of something along the lines of 5 times Heplisav-B's peak sales, assuming approval. In other words, this quantum leap in Dynavax's valuation may only be just the beginning of a long-tailed growth trend for the company.

So while there's still some regulatory risk on the table, and commercial launches rarely go according to plan, this small-cap biotech stock could prove to be a tremendous growth vehicle.