What: Shares of Anacor Pharmaceuticals (UNKNOWN:ANAC.DL) rose by over 40% today on heavy volume after the company released positive top-line results from two pivotal late-stage trials for crisaborole topical ointment as a treatment for mild-to-moderate atopic dermatitis, or eczema, in children and adults. Based on these results, the company plans on filing a New Drug Application with the U.S. Food and Drug Administration in the first half of 2016. 

Per the press release, the non-steroidal ointment crisaborole showed response rates of 32.8% and 31.4% across the two studies, which were both significantly better than response rates for patients in the control group. Response rates were defined as a two grade improvement from baseline on the Investigator's Static Global Assessment at day 29. Anacor also noted in its press release that this experimental eczema treatment was generally well-tolerated, with no treatment-related serious adverse events popping up in either trial. 

So what: If approved, crisaborole has the potential to become a first line treatment for this widespread skin condition that reportedly affects around 25 million Americans. Depending on pricing, Anacor could thus have its first blockbuster drug in hand, and give the company two commercially available products. Last year, Anacor received approval from the FDA for the topical solution Kerydin as a treatment for toenail fungus. This product is currently licensed out to Sandoz.  

Now what: While these pivotal trial results bode well for the ointment's regulatory fate, investors should keep in mind that Anacor's stock has probably baked in a lot of this news at this point, and therefore might not be worth buying after this latest jump. After all, Anacor's shares have now risen by over 800% in the last 52-weeks alone, and the company's remaining clinical pipeline is years away from producing another late-stage candidate capable of moving the needle, so to speak.