FDA Declines Approval for Contrave as Latest Weight Loss Therapy Drug


Despite a recommendation by the Endocrine and Metabolic Drugs Advisory Committee in December, the US Food and Drug Administration has denied approval for Orexigen Therapeutics and Takeda Pharmaceutical Co’s weight loss drug Contrave (naltrexone/bupropion). The agency is requesting another clinical trial due to concerns about the cardiovascular safety profile.

FDA Requests Further Studies on Cardiovascular Safety

Specifically, the FDA requested that a study be conducted “of sufficient size and duration” to demonstrate that the drug does not increase the risk of heart attack or stroke.


Contrave combines an antidepressant – bupropion, brand name Wellbutrin – and a drug used for addiction called naltrexone. In clinical studies, 35% of patients who took Contrave lost at least 5% of their body weight, a level that measures successful weight loss.

The major complications found in patients on Contrave were increased blood pressure and heart rate. Two patients were also noted to have seizures during the studies and the FDA is reviewing a case of fatal heart attack.

Orexigen has argued that the ingredients that comprise Contrave have been on the market for 20 years and have not shown any major cardiovascular-safety problems. The company had already agreed to a large post-approval study to test the risk of stroke and heart attack and proposed that limitations be set to exclude patients with high cardiovascular risk from being placed on Contrave for weight loss.

Had it been approved, Contrave would be the first new diet pill in a decade. Two other weight loss therapy drugs were rejected last year, including Lorquess (lorcaserin hydrochloride) and Qnexa (phentermine/topiramate). A previously approved diet drug, Meridia, was removed from the market last year due to cardiovascular safety concerns.