Anacor Pharmaceuticals (UNKNOWN:ANAC.DL) announced today that its onychomycosis drug tavaborole successfully met both its primary and secondary endpoints in its first phase 3 trial. Rather than celebrate this news, however, investors saw shares drop around 20% today. Why did this happen?Could the fall have something to do with a rival drug that Valeant Pharmaceuticals (NYSE:BHC) is seeking FDA approval for? In this video, health care analyst Max Macaluso breaks down this news.

Max Macaluso, Ph.D. has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not 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.