Purpose: Medication costs represent a significant portion of the economic burden of obesity, with greater costs associated with higher body-mass index (BMI). This post hoc analysis evaluated changes in annual medications costs for antihypertensive, lipid-lowering, and antidiabetic medications across baseline BMI categories in obese and overweight subjects receiving placebo or phentermine and topiramate extended-release (PHEN/TPM ER) in the CONQUER study.
Methods: CONQUER was a double-blind, placebo-controlled, Phase 3 trial of 2487 obese and overweight subjects (BMI ≥27 and ≤45 kg/m2) with ≥2 weight-related comorbidities randomly assigned to placebo (n=994), PHEN 7.5 mg/TPM ER 46 mg (7.5/46; n=498), or PHEN 15 mg/TPM ER 92 mg (15/92; n=995) plus lifestyle modifications for 56 weeks. Subjects included in this post hoc analysis completed ≥12 weeks of therapy and received medications at baseline or endpoint for the treatment of ≥1 of the following comorbidities: hypertension (n=830), dyslipidemia (n=340), or type 2 diabetes mellitus (T2DM) (n=207). Subjects were stratified by baseline BMI (kg/m2; <30, ≥30-<35, ≥35-<40, ≥40). Annual antihypertensive, lipid-lowering, and antidiabetic medication costs were calculated at baseline and end of treatment by multiplying the unit cost (Medi-Span's PriceRx database) by number of doses per day and by 365.
Results: Most subjects were female (70%) and Caucasian (86%); mean weight was 103.1±17.9 kg and mean BMI was 36.6±4.5 kg/m2. At end of treatment, least-squares mean percent weight loss was significantly greater in subjects receiving PHEN/TPM ER vs placebo in all subgroups (P<.001, all comparisons). At end of treatment, subjects receiving PHEN/TPM ER had greater reductions in annual antihypertensive, lipid-lowering, and antidiabetic medication costs than those receiving placebo (all baseline BMI categories except change in lipid-lowering medication cost in subjects with BMI ≥40 receiving the 15/92 dose; Table). For example, in subjects with a baseline BMI ≥35-<40, the change in annual medication cost vs placebo for hypertension, dyslipidemia, and T2DM treatment were -$176.40, -$235.68, and -$227.72, respectively for the 7.5/46 dose, and -$127.13, -$432.01, and -$178.78 for the 15/92 dose. Common treatment-emergent adverse events were constipation, dry mouth, and paraesthesia.
Conclusions: PHEN/TPM ER induced significant weight loss vs placebo in obese and overweight individuals, resulting in reductions in annual medication costs for the treatment of hypertension, dyslipidemia, and T2DM across all BMI ranges vs placebo.
