WASHINGTON (AP) - The government unexpectedly rejected what appeared to be the most promising candidate among a class of new diet drugs, wiping out hopes for a new medication to fight obesity anytime soon.
Orexigen Therapeutics Inc. said the Food and Drug Administration is concerned about the heart side effects of its drug Contrave and will require a new study, a costly undertaking that may prove too burdensome for the small drugmaker.
The FDA's ruling marks the third rejection of a weight loss drug in recent months, raising questions about whether any new drugs in the class can be made safe enough to win approval.
The FDA has not approved a new diet pill in more than a decade.
The FDA request for an additional study suggests the agency may yet approve the drug, but makes that path much more difficult. The news led to a sell-off that wiped out nearly three-quarters of the market value of the company.
Orexigen said it is disappointed with the FDA's decision and will work with the agency to determine its next step.