Qnexa phentermine/topiramate regulatory update

FDA's Endocrinologic and Metabolic Drugs Advisory Committee voted 20-2 that the benefit-risk profile for Qnexa from Vivus supports approval to treat obesity. The panel agreed the efficacy of the fixed-dose combination of phentermine and topiramate in the Phase III program outweighed potential cardiovascular and teratogenic risks. Qnexa has an April 17 PDUFA date.

In the Phase III program, Qnexa led to a mean weight loss from baseline of up to 11% but was associated with a heart rate increase of up to 1.6 beats per minute over placebo. Patients on placebo had a mean weight loss of up to 1.8%. Panel members felt that due to the substantial improvement in weight loss, a cardiovascular outcomes trial could be conducted post-approval to characterize Qnexa's potential risks. The committee was also concerned about the increased rate of oral clefts seen in retrospective studies for the topiramate component of Qnexa, but panel members felt Vivus' proposed REMS would be sufficient to mitigate the risk. ...