The relationship between early weight loss and weight loss maintenance with naltrexone-bupropion therapy

BACKGROUND: Extended-release (ER) naltrexone/bupropion (NB) was associated with greater weight loss than placebo in four randomized, 56-week trials. The association of NB with longer-term maintenance of weight loss remains unknown. METHODS: We conducted a post-hoc analysis of four phase III, randomized, double-blind, placebo-controlled, 56-week studies (COR-I, COR-II, COR-BMOD, and COR-DM), the placebo-controlled cardiovascular outcomes trial LIGHT (208 weeks), and the randomized, open-label trial IGNITE (78 weeks). Included subjects were treated with NB 32 mg/360 mg or placebo, with baseline, week 16, and final time point data. The primary outcome was Kaplan-Meier-estimated weight loss maintenance in each study for up to 204 weeks. FINDINGS: Our analysis included data from 10,198 particpants (NB=5412; placebo=4786). Proportions of patients with ≥5% or ≥10% weight loss maintenance were numerically higher for NB vs. placebo in all studies and time points. Differences were statistically significant for ≥5% weight loss maintenance in COR-BMOD and COR-I/-II at weeks 52 and 56 and the LIGHT study at weeks 52, 104, and 208. For ≥10% weight loss maintenance, differences were statistically significant in COR-I/COR-II at weeks 52 and 56. INTERPRETATION: These data suggest that NB could be used as part of long-term, comprehensive weight loss and weight loss maintenance strategies. FUNDING: Orexigen Therapeutics, Inc. and Bausch Health Canada.