NEW YORK (AP) -- Shares of Amarin Corp. fell 4 percent in aftermarket trading on Wednesday after the biopharmaceutical company said regulators have delayed a decision related to its bid to gain approval for wider uses for its Vascepa fish-oil pill.
The stock's pullback followed a 16 percent surge in the regular trading session.
The drug Vascepa is a prescription-strength form of an omega-3 fatty acid. It is Amarin's only product and it was approved last year for a relatively narrow use in patients with unusually high triglyceride levels.
Amarin believes the drug can be used safely by patients with high triglyceride levels and heart disease that are already taking a statin drug to help control their cholesterol.
Amarin had asked the Food and Drug Administration to reinstate a special protocol assessment, which is an agreement between the company and the agency over the design of research.
FDA advisers voted 9-2 against recommending broader use two months ago, sending company shares plunging 74 percent in October. A majority of panelists said that while Vascepa significantly lowers fat levels, it is unclear whether that actually translates into fewer heart attacks. The panel said the FDA should delay a decision on expanded use until Amarin completes a study of patient heart attack rates.
The drug maker has said that it believes FDA advisers would have recommended a broader use for the drug if the special protocol assessment had been in place.
Previously the FDA had said it would make a decision by Jan. 15. Now there is no date for a decision, the company said, but added that it does not expect the delay to be "significant."
Shares fell 14 cents to $2.26 percent in aftermarket trading, after closing the regular session up 33 cents to $2.40 in regular trading.