Amarin supporters were quick to defend Vascepa Wednesday night, with some taking to Twitter to argue the negative findings from the fish oil supplement study had no bearing on Vascepa because it contains more fish oil manufactured at a higher purity.

Amarin executives will likely make the same argument if/when they're asked to comment on the Italian study during tonight's conference call.

But in the Italian study, daily use of the fish oil supplement resulted in a statistically significant reduction in triglycerides, a type of fat found in the blood believed to have a negative effect on heart health. This is exactly what Vascepa does and is the basis for the pill's approval last year.

Yet now we have another study showing fish oil's role in lowering triglyceride levels, which is only a laboratory measurement, doesn't help patients avoid heart disease or reduce heart-related deaths, not even a little bit.

The evidence against fish oil's benefits is growing, and Amarin will have hard time explaining why Vascepa, even at a higher dose, should perform any better.

-- Reported by Adam Feuerstein in Boston.

Follow Adam Feuerstein on Twitter.
Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.

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