(Reuters) – Orexigen Therapeutics Inc said study data showed its experimental obesity drug did not increase heart-related risks, sending its shares up 28 percent in premarket trading. The drug, Contrave, was previously denied approval by the U.S. Food and Drug Administration, which cited potential heart risks. The FDA had requested an additional trial. The company said it would resubmit its application for U.S. marketing approval for Contrave in the next few weeks, with a decision expected by June. (Reporting by Esha Dey in Bangalore; Editing by Maju Samuel)