Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of biopharmaceutical company Dynavax Technologies (Nasdaq: DVAX) spiked as much as 14% today after a favorable meeting with the FDA regarding its hepatitis-B experimental treatment Heplisav.

So what: Today's meeting with the FDA, a Pre-Biologics License Application meeting, outlined an OK from the FDA for Dynavax to expand the age range of its Heplisav BLA from 40 and older to persons ages 18 to 70. Dynavax also plans to file a supplemental BLA with an indication for patients with chronic kidney disease once the initial BLA is approved.

Now what: Dynavax's near-term results solely rest on the acceptance or failure of Heplisav as a treatment for hep-B. Based on its stage 3 clinical trial results, Heplisav showed noticeable strengths over other drugs currently on the market. Now all that's left for Dynavax to do is adjust its BLA to the new age range indicated. Shareholders have every right to be bullish, but with no drugs currently being marketed, keep those expectations tempered until we have a decision on Heplisav.

Craving more input? Start by adding Dynavax to your free and personalized watchlist so you can keep track of the latest news with the company.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.