Prevention of Type 2 Diabetes in Subjects With Prediabetes and Metabolic Syndrome Treated With Phentermine and Topiramate Extended Release

Abstract

OBJECTIVE To evaluate over 108 weeks the effect of phentermine and topiramate extended release (PHEN/TPM ER) treatment on progression to type 2 diabetes and/or cardiometabolic disease in subjects with prediabetes and/or metabolic syndrome (MetS) at baseline. RESEARCH DESIGN AND METHODS Subanalysis of a phase 3, randomized, placebo-controlled, double-blind study of overweight/obese subjects (BMI ≥27 to ≤45 kg/m2) with two or more comorbidities. Subjects were randomized to placebo, PHEN 7.5 mg/TPM ER 46 mg (7.5/46), or PHEN 15 mg/TPM ER 92 mg (15/92) plus lifestyle modifications for 108 weeks. Percent weight loss in the intent-to-treat population using multiple imputation (ITT-MI), annualized incidence rate of progression to type 2 diabetes, and changes in glycemia, lipid parameters, blood pressure, and waist circumference were evaluated. RESULTS At baseline, 475 subjects met the criteria for prediabetes and/or MetS. After 108 weeks, subjects with prediabetes and/or MetS in the placebo, 7.5/46, and 15/92 groups experienced mean percent weight loss of 2.5, 10.9, and 12.1%, respectively (ITT-MI; P < 0.0001 vs. placebo), associated with reductions of 70.5 and 78.7% in the annualized incidence rate of type 2 diabetes for those receiving 7.5/46 and 15/92, respectively (ITT, P < 0.05), versus placebo. The ability of PHEN/TPM ER to prevent diabetes was related to degree of weight lost and was accompanied by significant improvements in cardiometabolic parameters. PHEN/TPM ER was well tolerated by this subgroup over 2 years. CONCLUSIONS PHEN/TPM ER plus lifestyle modification produced significant weight loss and markedly reduced progression to type 2 diabetes in overweight/obese patients with prediabetes and/or MetS, accompanied by improvements in multiple cardiometabolic disease risk factors.