A panel of experts advising the US Food and Drug Administration voted Thursday against approving for sale a new obesity treatment called Qnexa, citing safety risks.
The FDA is not required to follow the recommendation of the expert panel on endocrinological and metabolic drugs, but generally accepts its findings.
Qnexa, made by California-based biotech firm Vivus, is the first obesity drug submitted to the FDA in a decade.
While a high percentage of Americans are overweight or obese, there are few medical treatments, and those on the market can have side effects including increased heart problems and intestinal gas.
Leland Wilson, chief executive officer at Vivus, said the company was still optimistic it would win final approval for Qnexa.
"We are disappointed with the advisory committee's vote," he said in a statement.
"While the final vote was close, and we are encouraged that the committee recognized the efficacy demonstrated in the Qnexa clinical trials, we will work closely with the FDA leading up to our October 28, 2010 (decision) date to address the labeling and safety questions raised during today's proceedings. We remain committed to patients living with obesity and weight-related disease."
Qnexa combines two existing drugs, the appetite suppressant phentermine and topiramate, an anti-convulsant that can be used in conjunction with other drugs for weight loss.