EFFECT OF WEIGHT LOSS INDUCED BY PHENTERMINE AND TOPIRAMATE EXTENDED-RELEASE ON ANNUAL MEDICATION COSTS IN OBESE AND OVERWEIGHT INDIVIDUALS

Wednesday, October 23, 2013
Key Ballroom Foyer (Hilton Baltimore)
Poster Board # P4-4
Applied Health Economics (AHE)

Timothy Church, MD, MPH, PhD1, Sunil Karnawat, PhD2, Vincent Wu, BS3 and Weiyu W. Liu, MHA2, (1)Pennington Biomedical Research Center, Baton Rouge, LA, (2)VIVUS, Inc., Mountain View, CA, (3)Independent Contractor, San Francisco, CA

Purpose: The economic costs of obesity extend to the management of obesity-related comorbidities, including hypertension, dyslipidemia, and type 2 diabetes mellitus (T2DM). This post hoc analysis evaluated changes in annual antihypertensive, lipid-lowering, and antidiabetic medication costs among 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 (body-mass index [BMI] ≥27 and ≤45 kg/m2) with ≥2 weight-related comorbidities randomized 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 T2DM (n=207). Annual antihypertensive, lipid-lowering, and antidiabetic medication costs were calculated at baseline and end of treatment by multiplying 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, changes in annual antihypertensive, lipid-lowering, and antidiabetic medication costs were greater with PHEN/TPM ER than with placebo (Table). For hypertension, the changes in annual medication cost vs placebo were -$109.19 and -$118.57 for 7.5/46 and 15/92, respectively; for dyslipidemia, were -$186.66 and -$179.14 for 7.5/46 and 15/92, respectively; and for T2DM, were -$125.09 and -$205.39 for 7.5/46 and 15/92, respectively. Common treatment-emergent adverse events were constipation, dry mouth, and paraesthesia.

Conclusions: PHEN/TPM ER induced significant weight loss vs placebo and was associated with reduced annual medication costs for the treatment of hypertension, dyslipidemia, and T2DM. This suggests that PHEN/TPM ER–induced weight loss may help decrease the medication cost burden of obesity by reducing the need for concomitant medications.