A One-Year Randomized Trial of Lorcaserin for Weight Loss in Obese and Overweight Adults: The BLOSSOM Trial

<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Context:</jats:title> <jats:p>Lorcaserin is a novel selective agonist of the serotonin 2C receptor.</jats:p> </jats:sec> <jats:sec> <jats:title>Objective:</jats:title> <jats:p>Our objective was to evaluate the effects of lorcaserin on body weight, cardiovascular risk factors, and safety in obese and overweight patients.</jats:p> </jats:sec> <jats:sec> <jats:title>Design and Setting:</jats:title> <jats:p>This randomized, placebo-controlled, double-blind, parallel arm trial took place at 97 U.S. research centers.</jats:p> </jats:sec> <jats:sec> <jats:title>Patients:</jats:title> <jats:p>Patients included 4008 patients, aged 18–65 yr, with a body mass index between 30 and 45 kg/m2 or between 27 and 29.9 kg/m2 with an obesity-related comorbid condition.</jats:p> </jats:sec> <jats:sec> <jats:title>Interventions:</jats:title> <jats:p>Patients were randomly assigned in a 2:1:2 ratio to receive lorcaserin 10 mg twice daily (BID), lorcaserin 10 mg once daily (QD), or placebo. All patients received diet and exercise counseling.</jats:p> </jats:sec> <jats:sec> <jats:title>Main Outcome Measures:</jats:title> <jats:p>The ordered primary endpoints were proportion of patients achieving at least 5% reduction in body weight, mean change in body weight, and proportion of patients achieving at least 10% reduction in body weight at 1 yr. Serial echocardiograms monitored heart valve function.</jats:p> </jats:sec> <jats:sec> <jats:title>Results:</jats:title> <jats:p>Significantly more patients treated with lorcaserin 10 mg BID and QD lost at least 5% of baseline body weight (47.2 and 40.2%, respectively) as compared with placebo (25.0%, P &lt; 0.001 vs. lorcaserin BID). Least squares mean (95% confidence interval) weight loss with lorcaserin BID and QD was 5.8% (5.5–6.2%) and 4.7% (4.3–5.2%), respectively, compared with 2.8% (2.5–3.2%) with placebo (P &lt; 0.001 vs. lorcaserin BID; least squares mean difference, 3.0%). Weight loss of at least 10% was achieved by 22.6 and 17.4% of patients receiving lorcaserin 10 mg BID and QD, respectively, and 9.7% of patients in the placebo group (P &lt; 0.001 vs. lorcaserin BID). Headache, nausea, and dizziness were the most common lorcaserin-related adverse events. U.S. Food and Drug Administration-defined echocardiographic valvulopathy occurred in 2.0% of patients on placebo and 2.0% on lorcaserin 10 mg BID.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions:</jats:title> <jats:p>Lorcaserin administered in conjunction with a lifestyle modification program was associated with dose-dependent weight loss that was significantly greater than with placebo.</jats:p> </jats:sec>