Medicines Co. shares jumped after a U.S. appeals court agreed to rehear a case in which the patent on the drugmaker’s top-selling product was invalidated.

The U.S. Court of Appeals for the Federal Circuit in Washington vacated its opinion from July 2 and reinstated Medicines Co.’s appeal. The company is seeking to protect Angiomax, its anti-clotting drug, in a lawsuit against Pfizer Inc.’s Hospira unit.

Shares of the company, which develops medication for acute and intensive conditions, rose 6.5 percent to $40.99 at 1:23 p.m. in New York, after rising to $42.85 earlier, the highest intraday price since September.

Medicines Co. sued Hospira in July on charges that its rival’s generic version of Angiomax violated patent rights. The drug is projected to bring in $245 million in sales for Medicines Co. this year.

Before it's here, it's on the Bloomberg Terminal. LEARN MORE