Safety and Efficacy of Lorcaserin: A Combined Analysis of the BLOOM and BLOSSOM Trials

BACKGROUND: Lorcaserin, a novel selective 5-HT2C receptor agonist, is approved by the US Food and Drug Administration (FDA) for weight management in combination with lifestyle modification for adults with obesity and adults with overweight and ≥ 1 weight-related comorbid condition. The safety and effectiveness of lorcaserin in adult patients without type 2 diabetes mellitus was established based on 2 phase III clinical trials of similar design: Behavioral Modification and Lorcaserin for Overweight and Obesity Management (BLOOM) and Behavioral Modification and Lorcaserin Second Study for Obesity Management (BLOSSOM). This report presents a prespecified analysis of pooled data from these trials. METHODS: Co-primary end points in this analysis include the proportion of patients with a reduction in baseline body weight of ≥ 5% and ≥ 10%, and a change in weight from baseline. Key secondary end points include changes from baseline values in lipid parameters, quality-of-life measures, glycemic indicators, and vital signs. RESULTS: At week 52, more than twice as many lorcaserin-treated patients achieved a weight loss of ≥ 5% compared with placebo (lorcaserin, 47.1%; placebo, 22.6%), and lorcaserin-treated patients lost significantly more body weight (lorcaserin, -5.8%; placebo, -2.5%). A significantly greater proportion of lorcaserin-treated patients achieved a weight loss of ≥ 10% (lorcaserin, 22.4%; placebo, 8.7%). There were statistically significant improvements in lipid parameters, glycemic indicators, quality-of-life measures, and vital signs in the lorcaserin group compared with placebo. The most common adverse events associated with lorcaserin treatment were headache, upper respiratory tract infection, and nasopharyngitis. Lorcaserin-treated patients had a rate of FDA-defined valvulopathy similar to placebo. CONCLUSIONS: This pooled analysis of the phase III BLOOM and BLOSSOM trials shows that lorcaserin 10 mg twice daily, in combination with diet and exercise, is safe and tolerable, and is associated with statistically significant weight loss and clinically relevant improvements in cardiometabolic parameters.