FDA approves Qsymia for chronic weight management in adolescents 12 and older

The FDA has approved Qsymia (phentermine and topiramate extended-release capsules) for chronic weight management in patients aged 12 and older who are obese, defined as a body mass index (BMI) at the 95th percentile or higher when standardized for age and sex ^[1]. The drug is intended for use alongside a reduced-calorie diet and increased physical activity, and the approval was granted to Vivus, LLC ^[1].

The decision adds a pediatric indication to a drug first approved in July 2012 for adults with an initial BMI of 30 or higher, or 27 or higher with at least one weight-related condition such as hypertension, type 2 diabetes or dyslipidemia ^[1]. The FDA said adolescent obesity has increased over the past 50 years, with 21% of U.S. adolescents — about 1 in 5 — now considered obese, and that many obese children are likely to become obese adults ^[1]. The agency describes lifestyle modification as first-line therapy, with medication considered when lifestyle changes do not reach weight-loss goals ^[1].

What the trial showed

The pediatric evidence comes from a 56-week, double-blind, placebo-controlled study of 223 people aged 12 to under 17 with a BMI at the 95th percentile or higher for their age and sex, who had not been able to lose weight or maintain weight loss through changes to their eating and exercise habits ^[1]. Participants were randomly assigned to take Qsymia 7.5 mg/46 mg (54 people), Qsymia 15 mg/92 mg (113 people) or placebo (56 people) once daily after a titration period, and all were counseled on reducing calories and increasing physical activity ^[1].

At the end of the study, participants on the lower dose had lost an average of 4.8% of their BMI and those on the higher dose an average of 7.1%, while those taking placebo gained an average of 3.3% of their BMI ^[1]. The study reports group averages, not how any single adolescent responded.

Safety requirements and warnings

Qsymia can cause fetal harm if taken during pregnancy, including an increased risk of oral clefts (cleft lip and cleft palate) ^[1]. The FDA says patients who can become pregnant should have a negative pregnancy test before starting treatment, test monthly while taking it, and use effective contraception ^[1]. Because of the birth-defect risk, the drug is available only through a restricted program called the Qsymia Risk Evaluation and Mitigation Strategy (REMS) ^[1].

Other listed warnings include increased heart rate; suicidal behavior and ideation, with patients monitored for mood changes, depression or suicidal thoughts and treatment stopped if those symptoms develop; and slowing of linear growth, with growth monitored in adolescents taking Qsymia ^[1]. The label also cites acute myopia, secondary angle-closure glaucoma and visual problems; mood and sleep disorders; cognitive impairment; metabolic acidosis; and decreased kidney function ^[1].

The most common adverse reactions reported in the pediatric trial were depression, dizziness, joint pain, fever, flu and ankle sprain ^[1]. In adults, the most common reactions are a pins-and-needles sensation, dizziness, an altered or impaired sense of taste, insomnia, constipation and dry mouth ^[1].

Why it matters for patients

For families of adolescents with obesity, this approval creates a labeled prescription option for an age group that previously had no FDA-approved chronic weight management medicine. The FDA frames medication as a step after lifestyle changes fail to reach weight-loss goals, not a replacement for diet and activity ^[1].

Practical consequences follow from the safety rules. Starting Qsymia in this age group involves pregnancy testing and contraception for patients who can become pregnant, enrollment in a restricted distribution program, and growth monitoring during treatment ^[1]. The authorization covers standard review and does not come with a commitment to further studies disclosed in the approval notice ^[1].

What is not yet known

The effect of Qsymia on heart disease or death related to heart disease has not been established ^[1]. The drug has also not been proven to treat weight loss in combination with other products, such as prescription drugs, over-the-counter drugs and herbal preparations ^[1]. Whether the average BMI changes seen over 56 weeks persist after treatment stops, and how the drug compares with other weight management options in adolescents, has not been reported ^[1].