By Michael Fitzhugh
Vivus (VVUS) shares soared February 23 following news that a U.S. Food and Drug Administration advisory committee recommended the agency approve the company’s experimental obesity drug, Qnexa. The Mountain View, California-based company’s shares rose nearly 78% following a 20-to-2 vote in the Endocrinologic and Metabolic Drugs Advisory Committee supporting the safety and efficacy of Qnexa as a treatment for obesity in adults.
The FDA is not bound by the recommendations of its advisory committees. Although it generally follows the direction of the experts it recruits for the panels, obesity drugs pose a special quandary. An effective drug could help manage America’s obesity crisis, but the FDA is likely to be cautious. The infamous “fen-phen”—pulled from the market in 1997—left a lasting impact on the agency.
The committee vote is a substantial victory for Vivus, which has struggled to bring Qnexa to market. The low-dose combination of phentermine and topiramate is designed to decrease appetite and increase satiety. Although the drug has proved effective in clinical trials, it raised red flags when Vivus first sought FDA approval. In October 2010, the FDA told the company it wanted a comprehensive assessment of the drug’s potential to cause birth defects and asked for a detailed plan and strategy to evaluate and mitigate the potential risks of birth defects in women of childbearing age who take the drug to lose weight.
Vivus resubmitted its new drug Application for Qnexa in October 2011 and will now await an FDA decision, anticipated on or before the agency-determined April 17 PDUFA date. Between now and then, the FDA will decide how to address what the committee identified as a need for more cardiovascular safety data on Qnexa, either by way of a post-marketing trial, which Vivus has already suggested, or by means of a pre-market trial. Either way, the agency will be putting a lot of thought into the market for obesity therapies. The agency is holding a meeting March 28 and 29 to discuss the role of cardiovascular assessment in the pre-approval and post-approval settings for drugs and biologics developed for the treatment of obesity.