BEDMINSTER, NJ ( TheStreet) -- More market exclusivity woes for Amarin ( AMRN) and its prescription fish oil pill Vascepa. I was speaking with an institutional investor last week who made money on Amarin when Vascepa was still in clinical development and known as AMR101. He's been out of Amarin for awhile but was taking another look with the stock trading near a 16-month low. While digging into the controversy over Amarin's inability to win five years of marketing exclusivity for Vascepa as a New Chemical Entity (NCE), it dawned on him that FDA had also refused (so far) to grant the drug three years of market exclusivity as a New Molecular Entity (NME.) NME exclusivity is supposed to be the consolation prize awarded by FDA to new drugs refused the preferred NCE status. But not in this case. If you look at the FDA Orange Book, Vascepa is listed as having "no unexpired exclusivity." No NCE. No NME. By now, most people believe FDA is unwilling to grant NCE status to Vascepa because its active moiety, or active ingredient, is the same as GlaxoSmithKline's ( GSK) Lovaza. But my investor source believes FDA is also refusing to grant Vascepa three years of marketing exclusivity as an NME because Vascepa is approved for the same indication -- triglyceride reduction in patients with very high ( >500mg/dl) hypertriglyceridemia -- previously awarded to Lovaza. (These are the patients who encompassed Amarin's "Marine" phase III trial.) FDA could grant Vascepa NME status and three years of marketing exclusivity for the larger, mixed dyslipidemia "Anchor" indication. Lovaza is not approved for these patients so there is no overlap. But here's where Amarin runs into big trouble even if Vascepa wins three years of marketing exclusivity for the "Anchor" indication. The absence of NME exclusivity for the "Marine" patients makes it easier for generic versions of Vascepa to reach the market. And if a generic Vascepa is approved -- assuming a label for "Marine" very high triglyceride patients only -- doctors (with the encouragement of insurance companies) will be able to prescribe the less expensive generic for all patients, including the mixed dyslipidemia "Anchor" patients.