FDA approved Vivus’ once-daily Qsymia™ (phentermine and topiramate extended-release) capsules as an aid to weight loss in conjunction with a calorie-reduced diet and increased physical activity. The single capsule combination therapy is indicated for use in obese patients with an initial body mass index (BMI) of at least 30, or overweight patients (BMI 27 or greater) who have at least one weight-related comorbidity, such as hypertension, type 2 diabetes, or high cholesterol.
Approval of the drug was based on data from two year-long Phase III studies. The placebo-controlled Equip trial evaluated Qsymia in severely obese patients, and the placebo-controlled Conquer study included overweight and obese patients with at least two weight-related comorbidities. Data from Equip showed that patients given Qsymia achieved an average weight loss of 10.9%, compared with 1.6% for those receiving placebo. Qsymia-treated patients in the Conquer trial achieved an average weight loss of up to 9.8% (7.8% for those receiving a lower dose), compared with a weight loss of 1.2% for placebo-treated patients.
FDA clearance of the drug comes with a risk evaluation and mitigation strategy to inform users and prescribers of the risks of orofacial clefts developing in infants exposed to Qsymia during the first trimester of pregnancy. Vivus is also charged with carrying out postmarketing studies to assess the long-term effects of Qsymia therapy on major adverse cardiovascular events in overweight and obese patients with confirmed cardiovascular disease, as well as safety and efficacy studies in obese pediatric and adolescent subjects, and assessments of drug utilization and pregnancy exposure, and effects on renal function.