San Diego drugmaker Orexigen Therapeutics Inc. bought the U.S. rights to its flagship obesity drug from co-developer Takeda Pharmaceuticals and said it would enlist Valeant Pharmaceuticals International to sell the pill in Europe.

Orexigen said it would pay Takeda $60 million to buy the U.S. rights to the drug, sold as Contrave in the U.S. and as Mysimba in the European Union. The agreement with Valeant includes 12 European Union countries and several non-EU countries.

Orexigen and Japan's Takeda co-developed the drug, approved by the U.S. Food and Drug Administration in September 2014. However, the relationship between the two companies became strained in May following the early termination of a heart-risk study of the drug. The study was halted after an unauthorized release of trial data by Orexigen compromised its integrity, according to the Cleveland Clinic, which conducted the trial. Takeda launched a formal dispute shortly after, asking Orexigen to pay the entire cost of a new cardiovascular study. However, the two companies announced later in the year that they had resolved all disputes.

Takeda will continue to sell the drug in the U.S. during a six-month transition period, Orexigen said on Tuesday.