The third time apparently isn't the charm at Amarin (NASDAQ:AMRN). The biotech got its lipid-lowering drug, Vascepa, approved in July, which meant the exclusivity should have been listed when the Food and Drug Administration updated its Orange Book in August. It wasn't.

Ditto for September.

The October update should happen this Friday, but Amarin disclosed in an SEC filing that it doesn't expect its exclusivity status to be updated then either.

Might it come in the update in November? Amarin says it doesn't know.

This, Fools, is not how things are normally done. Exclusivities for drugs are usually listed the month after they're approved, certainly not three or more month later.

But Vascepa isn't a usual compound. The drug is a fish oil that's more pure than GlaxoSmithKline's (NYSE:GSK) Lovaza. The question is whether it's new enough to be classified as a new chemical entity, or NCE, which comes with a five-year exclusivity period, during which generics can't enter the market. There's some president for giving NCE status to purified molecules. Sanofi's (NYSE:SNY) Lovenox, a low-molecular-weight heparin, was granted NCE status even though other heparins were on the market.

Clearly this isn't a cut-and-dry case or the FDA would have already made its ruling. It's notable that the agency hasn't already decided against NCE status either, so Amarin still has a chance to sway the FDA.

Of course we're just debating Amarin's backup plan. The NCE status runs concurrent to the patents. Amarin has a patent listed in the Orange Book that expires in 2020 and is working on getting others through the patent system and eventually listed in the Orange Book as well. As long as the patents hold up in court, the NCE status is basically meaningless.

Of course, patents do get overturned in court, so a backup plan is always nice, which explains some of the downturn today, but I think the bigger issue is that investors are hoping for a sale or a marketing partnership before the scheduled launch in the first quarter of 2013. Merck (NYSE:MRK) or AstraZeneca (NYSE:AZN), which would both be great fits given their experience with cardiovascular drugs, might not be willing to move in until the NCE status is worked out.

 

Fool contributor Brian Orelli has no positions in the stocks mentioned above. The Motley Fool owns shares of AstraZeneca and GlaxoSmithKline. Motley Fool newsletter services recommend GlaxoSmithKline. 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.