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 Cytokinetics (NASDAQ:CYTK), a clinical-stage biopharmaceutical company focused on developing therapies that alter muscle function to treat serious diseases and disorders, collapsed by as much as 62% after announcing disappointing top-line results from its BENEFIT-ALS midstage study involving tirasemtiv.

So what: According to the before-the-bell press release, tirasemtiv did not meet its primary efficacy endpoint of delivering a mean change from baseline in the ALS functional rating scale. Secondary endpoints, which analyzed respiratory function and other skeletal functions weren't conclusive, either. Per Robert Blum, CEO of Cytokinetics, "Once we have fully evaluated the data from BENEFIT-ALS, we expect to determine whether there is a potential development path forward for tirasemtiv for the potential treatment of ALS and what may be the appropriate next steps."

Now what: There's probably no way to sugarcoat this, so I'm just going to say it: Without hitting its primary endpoint and having mixed secondary endpoints results there's little chance that tirasemtiv moves forward as a Lou Gehrig's disease treatment. Is today's move lower justified? I believe so considering that it only has a handful of clinical studies currently ongoing. Pretty much Cytokinetics' entire value now rests on acute heart failure prevention therapy omecamtiv mecarbil which is currently in phase 2b studies and being tested in both oral and IV formats with collaborative partner Amgen. Yet even this ongoing study isn't without its drama. In September the two companies reported mid-stage top-line data for omecamtiv mecarbil and noted that it failed to meet its primary endpoint of helping patients breathe better. With all of these question marks I'd suggest even risk-seeking investors should avoid Cytokinetics for the time being.

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.

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