Phentermine/Topiramate for the Treatment of Adolescent Obesity

Antiobesity medication may be useful for the treatment of pediatric obesity, yet few safe and effective options exist. We evaluated phentermine/topiramate (PHEN/TPM) for weight management in adolescents with obesity.

This 56-week, randomized, double-blind trial enrolled adolescents 12 to less than 17 years of age with obesity. Participants were randomly assigned 1:1:2 to receive either placebo (n=56), mid-dose PHEN/TPM (7.5 mg/46 mg; n=54), or top-dose PHEN/TPM (15 mg/92 mg; n=113), respectively. All participants received lifestyle therapy. The primary end point was mean percent change in body-mass index (BMI) from randomization to week 56.

Participants had a mean (±SD) age of 14.0±1.4 years and a mean (±SD) BMI of 37.8±7.1 kg/m²; 54.3% were female. The primary end point of percent change in BMI at week 56 showed differences from placebo of -10.44 percentage points (95% CI, -13.89 to -6.99; P<0.001) and -8.11 percentage points (95% CI, -11.92 to -4.31; P<0.001) for the top and mid doses of PHEN/TPM, respectively. Differences from placebo in percent change in triglycerides nominally favored PHEN/TPM (mid dose, -21%; 95% CI, -40 to -2; and top dose, -21%; 95% CI, -38 to -4), as did differences in percent change in high-density lipoprotein cholesterol (HDL-C) (mid dose, 10%; 95% CI, 3 to 18; and top dose, 9%; 95% CI, 2 to 15). The incidence of participants reporting at least one adverse event was 51.8%, 37.0%, and 52.2% in the placebo, mid-dose, and top-dose groups, respectively. Serious adverse events were reported for two participants in the top-dose group.

PHEN/TPM at both the mid and top doses offered a statistically significant reduction in BMI and favorably impacted triglyceride and HDL-C levels in adolescents with obesity. (Funded by VIVUS LLC, with project support provided by Covance LLC; ClinicalTrials.gov number, NCT03922945.).