Amarin Sinks to Five-Month Low After Losing Ruling on Heart Drug

Amarin Corp. fell to the lowest since March after it lost its bid to revive patents on the heart medicine Vascepa, its only product, a decision that opens the door to generic competition for the drug.

The U.S. Court of Appeals for the Federal Circuit in Washington affirmed a trial court ruling that invalidated six patents on Vascepa. The decision, made without a formal opinion, came just one day after the court heard arguments in the case.

Amarin closed down 9.5% in New York trading of 47 million shares, seven times the daily average. The stock has shed more than ...