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 Amarin (AMRN -0.92%), a biopharmaceutical company focused on creating therapies to treat cardiovascular diseases, tumbled as much as 26% after the Food and Drug Administration issued a response to its request to have its special protocol assessment (SPA) reinstated for Vascepa in the ANCHOR trial.

So what: According to Amarin's press release, the Division of Metabolism and Endocrinology Products (DMEP) has denied Amarin's request to reinstate the SPA in the ANCHOR trial, ending any hope that there would be a quicker channel to expanding Vascepa's approval beyond the current indication of treating patients with extremely high triglyceride levels (at least 500 mg/DL or greater) to a larger chunk of the population that falls into the high triglyceride range (200 mg/DL through 499 mg/DL). Amarin plans to appeal the DMEP's decision.

Now what: With the FDA essentially putting its foot down for a second time, Amarin is going to have no choice but to complete its REDUCE-IT cardiovascular outcomes study if it has any hope of expanding Vascepa's indicated uses. Unfortunately, this trial is going to take years and millions of dollars to complete, so it will be a while before Amarin has any chance of realizing a sizable monetary impact from Vascepa. In the meantime, Amarin has let go of a good chunk of its workforce and may need to rein in costs even further if it hopes to complete the REDUCE-IT study. All things considered, I'd suggest keeping a safe distance from Amarin moving forward.