Amarin (AMRN -0.53%) has been a roller coaster of a stock since the launch of its fish oil drug Vascepa. The drug competes with GlaxoSmithKline's fish oil Lovaza, but while Glaxo's drug is often used off label in patients with moderately high triglyceride levels, Amarin hasn't made much in roads into that population.

To get the drug approved for the expanded indication, the biotech signed a special protocol assessment with the Food and Drug Administration, agreeing to run an efficacy study with a surrogate endpoint -- lowering triglyceride levels -- and to substantially enroll an outcomes study measuring cardiac events, such as heart attacks and strokes.

Despite Amarin living up to its end of the bargain -- Vascepa looked even better that GlaxoSmithKline's Lovaza in terms of triglyceride and cholesterol levels -- the FDA decided it really wanted to see the outcomes data, citing data from trials testing Merck's (MRK 0.10%) Cordaptive and AbbVie's Tricor, triglyceride-lowering drugs that work under a different mechanism of action. Both Merck's and AbbVie's drugs lowered triglyceride levels, but failed to improve outcomes.

In the video that follows, Max Macaluso, the Fool's health care bureau chief, and Fool contributor Brian Orelli discuss the biotech's latest predicament.