A federal panel has voted against a new weight loss drug, putting Vivus Inc's hopes for Qnexa review in jeopardy. The company wants to approve the combination of phentermine, approved for short-term weight reduction, and topiramate, used for migraines and seizures. The FDA usually follows the advice of its advisory panels, and it is expected to make a decision on the drug in April.
The drug's potential to help obese people lose weight and keep it off is a major selling point, but the company also emphasized that Qnexa is not a miracle drug. People who take it have to continue taking the pill for life, and some studies have shown that they experience side effects including dry mouth, constipation, upper respiratory tract infections, and changes in taste and sleep patterns.
One study found that patients who took the highest dose of the drug lost 14.4% of their body weight compared with 2.1% of those who took placebos. Eighteen percent of the patients in the highest-dose group dropped out because of adverse events, compared with 10% of those taking the placebo.
The FDA has asked Vivus to prove that the drug's increased heart rate does not increase long-term risks for cardiovascular disease. It also wants more details of the two-year study and a plan for evaluating possible birth defects in babies born to women who took topiramate while pregnant. Vivus has assured investors that it will be able to meet these demands, and the company says it expects to get approval this spring.