A placebo-controlled pilot study of the novel opioid receptor antagonist ALKS-33 in binge eating disorder

Objective: To assess preliminarily the effectiveness of a novel opioid antagonist, ALKS-33, in binge eating disorder (BED). Method: In this randomized, placebo-controlled, flexible dose, proof-of-concept trial, 62 outpatients with BED and obesity received ALKS-33 (N = 26) or placebo (N = 36) for 6 weeks. Outcome measures of binge eating, body weight, and eating pathology were assessed. Results: A large decrease in binge eating episode frequency was observed following both ALKS-33 and placebo treatment. There was no significant difference between treatment groups in binge eating episode frequency or any other measure of binge eating, body weight, or eating pathology. Discussion: In this preliminary proof-of-concept study in BED, ALKS-33 did not separate from placebo. Although a failed trial cannot be excluded, the finding is consistent with earlier observations in bulimia nervosa with other opioid antagonists and suggests ALKS-33, at least when administered daily for 6 weeks, may not be efficacious for BED.