Clinical Question

Is lorcaserin (Belviq) a safe and effective aid for weight loss in obese patients?

Bottom Line

Lorcaserin, 10 mg twice daily, helps some patients lose 10% or more of their body weight (number needed to treat [NNT] = 10) and appears to be safe in terms of cardiovascular events. (Level of Evidence = 1b)

Synopsis

Although lorcaserin has been approved for treatment of obesity by the U.S. Food and Drug Administration, they required a postmarketing randomized trial to assure cardiovascular safety. In this study, patients (N = 12,000) with a body mass index (BMI) of 27 kg per m² or higher who had heart disease or multiple cardiovascular risk factors were randomized to receive lorcaserin, 10 mg twice daily, or matching placebo. All patients had access to a study nurse by phone. The groups were balanced at the start of the study, with a mean age of 64 years and a mean BMI of 35 kg per m²; 90% were hypertensive and 57% had diabetes mellitus. Approximately one-third of patients in each group stopped taking the study drug or placebo during the median 3.3-year follow-up period. Lorcaserin had a modest effect on weight. Patients who took the drug lost a mean of 2.8 kg (6.2 lb) more than those who took the placebo. More patients in the lorcaserin group lost at least 10% of their body weight (14.6% vs. 4.8%; P < .001; NNT = 10). There was no difference in the likelihood of cardiovascular events between the two groups (6.1% for lorcaserin vs. 6.2% for placebo). There was also no difference in serious adverse events between groups. Patients randomized to receive lorcaserin were more likely to experience an adverse event that led to the discontinuation of the drug (7.2% vs. 3.7%; P < .05; number needed to treat to harm = 29), mostly dizziness, fatigue, and headache. The overall rates of these events were low, with absolute risk increases of only 0.4% to 1.1%.

Study design: Randomized controlled trial (double-blinded)

Funding source: Industry

Allocation: Uncertain

Setting: Outpatient (any)

Reference: Bohula EA, Wiviott SD, McGuire DK, et al.; CAMELLIA–TIMI 61 Steering Committee and Investigators. Cardiovascular safety of lorcaserin in over-weight or obese patients. N Engl J Med. 2018;379(12):1107–1117.

Editor's Note: On February 13, 2020, the U.S. Food and Drug Administration (FDA) requested that the manufacturer of Belviq (lorcaserin) voluntarily withdraw this drug from the market because a safety clinical trial showed an increased occurrence of cancer that outweighed any potential weight loss benefits. See the FDA Drug Safety Communication (https://www.fda.gov/drugs/ drug-safety-and-availability/fda-requests-withdrawal-weight-loss-drug-belviq-belviq-xr-lorcaserin-market). 

Dr. Ebell is deputy editor for evidence-based medicine for AFP and cofounder and editor-in-chief of Essential Evidence Plus, published by Wiley-Blackwell.