Lorcaserin, marketed as Belviq, was a prescription medication for chronic weight management in adults. The U.S. Food and Drug Administration (FDA) withdrew it from the market due to new safety information.
Mechanism of Action
Lorcaserin functioned by targeting specific receptors in the brain to influence appetite. It was a selective agonist of the serotonin 2C (5-HT2C) receptor. By activating these receptors, lorcaserin aimed to decrease food consumption and promote a feeling of fullness.
The 5-HT2C receptors are predominantly found in the hypothalamus, a brain region that regulates hunger and satiety. Lorcaserin stimulated these receptors on pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus. This stimulation led to the release of alpha-melanocyte-stimulating hormone (alpha-MSH), which then acted on melanocortin-4 receptors, ultimately suppressing appetite.
Clinical Use and Prescription Guidelines
Lorcaserin was approved for chronic weight management in adults. The FDA’s original guidelines indicated its use for individuals with an initial body mass index (BMI) of 30 kg/m² or greater.
It was also approved for adults with a BMI of 27 kg/m² or greater who had at least one weight-related comorbid condition, such as hypertension, dyslipidemia, or type 2 diabetes mellitus. The medication was always an adjunct to a reduced-calorie diet and increased physical activity, not a standalone solution.
Withdrawal From the Market
The FDA requested the voluntary withdrawal of lorcaserin (Belviq and Belviq XR) from the U.S. market on February 13, 2020. This decision stemmed from findings of the CAMELLIA-TIMI 61 trial, a post-market clinical safety study. This large, randomized, double-blind, placebo-controlled trial involved approximately 12,000 adults over five years, initially designed to evaluate cardiovascular safety.
During the trial, a statistically significant increased occurrence of cancer was observed in patients taking lorcaserin. The FDA’s review indicated that 7.7% of patients treated with lorcaserin were diagnosed with cancer, compared to 7.1% in the placebo group. Several types of cancers were reported more frequently in the lorcaserin group, including pancreatic, colorectal, and lung cancers.
The FDA concluded that lorcaserin’s potential risks, particularly the increased cancer risk, outweighed its benefits for weight loss. Although the manufacturer, Eisai Inc., stated their interpretation of the data differed, they complied with the FDA’s request to withdraw the drug.
FDA Recommendations and Patient Guidance
Following the withdrawal, the FDA issued guidance for patients and healthcare professionals. Patients taking lorcaserin were advised to stop immediately. No special cancer screening was recommended beyond standard age-appropriate screenings for those who had previously taken the drug.
Patients were encouraged to consult their healthcare professionals to discuss alternative weight management strategies. For disposal of unused lorcaserin, the FDA recommended using a drug take-back location. If unavailable, patients could mix pills with an unappealing substance like dirt or used coffee grounds, place the mixture in a sealed plastic bag, and discard it in household trash. Healthcare professionals were instructed to stop prescribing and dispensing lorcaserin and to inform patients of the increased cancer risk, discussing discontinuation and alternative options.