Shares of Amarin ($AMRN) took a hit overnight after the company filed papers noting that the FDA had yet to decide whether its industrial-strength fish oil product Vascepa warranted approval as a new chemical entity, a classification that carries 5 years of marketing exclusivity with it. The lengthy delay on the NCE ruling caused considerable hooting on Twitter as analysts like Adam Feuerstein at TheStreet concluded that Amarin is likely to wind up without the NCE stamp, leaving the company with only three years of exclusivity and a quick onslaught of generic competition. Amarin shares are down 5% this morning. Story