Lorcaserin plus lifestyle modification for weight loss maintenance: Rationale and design for a randomized controlled trial

Background/aims: Few studies have examined the efficacy of recently approved medications for chronic weight management in facilitating the maintenance of lost weight. This paper provides an overview of the design and rationale for a trial investigating whether lorcaserin, when combined with behavioral weight loss maintenance sessions (WLM), will facilitate the maintenance of losses of >= 5% of initial weight. Methods: In this two-phase trial, participants with obesity will enroll in a 14-week run-in diet program consisting of weekly group lifestyle modification sessions and a 1000-1200 kcal/d meal replacement diet. Participants who complete this weight induction phase and lose at least 5% of initial weight will then be randomized to 52 weeks of WLM plus lorcaserin or WLM plus placebo. We hypothesize that at 52 weeks post randomization, participants assigned to WLM plus lorcaserin will achieve significantly better maintenance of the prior 5% weight loss. Results: We will recruit 182 adults with obesity to participate in the diet run-in, 136 of whom (75%) are expected to become eligible for the randomized controlled trial. Co-primary outcomes include the percentage of participants who maintain a loss of at least 5% of initial weight at week 52 and change in weight (kg) from randomization to week 52. Conclusions: This two-phase design will allow us to determine the potential efficacy of chronic weight management using lorcaserin for maintaining initial losses of at least 5% body weight, induced by the use of a structured meal-replacement diet. This combined approach holds promise of achieving larger long-term weight losses.