Arena Pharmaceuticals' drug to treat obesity was approved by U.S. health regulators on Wednesday, making it the first weight-loss drug to win clearance in 13 years.

Arena's drug lorcaserin, which will be sold under the brand name Belviq, was one of three experimental new weight-loss drugs seeking Food and Drug Administration approval after initial rejections by the agency.

The company's shares were halted ahead of the announcement.

Vivus and Orexigen Therapeutics are also hoping to bring their medicines to market.