Familiar concerns crop up for Qnexa in briefing docs

FDA reviewers on Friday reiterated concerns about the safety of obesity product Qnexa phentermine/topiramate, including questions about its cardiovascular risk and potential for teratogenicity. The reviewers did say that treatment with the Vivus Inc. (NASDAQ:VVUS) product demonstrated significant weight loss compared to placebo after one year of treatment, and depending on dose, met one or both of the agency's efficacy criteria. The comments came in briefing documents posted ahead of Wednesday's Endocrinologic and Metabolic Drugs Advisory Committee meeting, which will be the second agency panel to discuss Qnexa.

The documents noted that at two years, patients receiving Qnexa had a larger mean increase in heart rate compared with placebo. Reviewers concluded that a long-term CV outcome trial would be the only way to determine Qnexa's effect on CV risk in an obese at-risk population. The committee will be asked whether a cardiovascular outcomes trial should be conducted pre-approval. The reviewers also said that exposure to topiramate in pregnancy is likely to be associated with a two- to five-fold increased prevalence of oral clefts in infants whose mothers receive the product during pregnancy. ...