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Bucking the market rout, shares of Amarin (AMRN - Get Report) posted a healthy increase Wednesday after a brokerage firm upgraded the heart-drug firm's stock.

Amarin rose 3.5% to $14.80 after SVB Leerink upped its rating on the biotech's stock to outperform, saying a recent double-digit decline offers investors a buying opportunity.

Amarin's stock price plunged more than 20% on Friday after the Food and Drug Administration said it would hold an advisory committee meeting to review data on the firm's anti-cholesterol drug Vascepa.

The announcement came after Amarin executives had insisted that any further review by the FDA was unlikely, clearing the way for its plans for expanded use of the drug. The agency also pushed back the timetable for approval for the drug to December from September.

Still, the biotech's strong performance so far this year -- both in its stock price and bottom line -- has kept investors on board.

Amarin last month reported a 91% surge in quarterly revenue, crossing the $100 million mark. The biotech reported net income of $6.1 million, or 2 cents a share, compared with a $30.6 million loss, or 10 cents a share, in the year-earlier period.

In a statement last week after the FDA announcement, Amarin said it would push ahead with plans to double its sales force ahead of the agency's expected approval of Vascepa's expanded use.

"We look forward to the planned advisory committee meeting as an opportunity to highlight the landmark Reduce-It data and the important role we expect Vascepa should play in the treatment of cardiovascular disease in appropriate patients," John Thero, president and chief executive of Amarin, said in a statement.