Locaserin, marketed as Belviq and Belviq XR, was a prescription medication approved for the chronic management of weight. It was intended for adults with obesity (Body Mass Index (BMI) of 30 or greater), or those overweight (BMI of 27 or greater) with at least one weight-related medical condition. These conditions included high blood pressure, type 2 diabetes, or high cholesterol. The drug was used alongside a reduced-calorie diet and an exercise plan.
How Locaserin Influenced Weight Loss
Locaserin influenced weight loss by targeting a specific biological pathway in the brain. It acted as a selective serotonin 2C (5-HT2C) receptor agonist, activating these receptors primarily in the central nervous system, especially the hypothalamus.
Stimulating these receptors promoted the release of alpha-melanocyte-stimulating hormone (alpha-MSH) from neurons. This hormone then acted on other receptors, increasing feelings of fullness and reducing appetite. This mechanism aimed to decrease food consumption and calorie intake.
Reasons for Locaserin’s Market Withdrawal
The U.S. Food and Drug Administration (FDA) requested the voluntary withdrawal of locaserin (Belviq and Belviq XR) from the U.S. market in February 2020. This action stemmed from safety concerns identified in a large, five-year clinical trial (CAMELLIA-TIMI 61) involving approximately 12,000 patients. The FDA initially required this trial to assess the drug’s cardiovascular safety.
During the trial, an increased occurrence of cancer was observed in patients taking locaserin compared to those receiving a placebo. Specifically, 7.7% of patients in the locaserin group were diagnosed with cancer, while 7.1% in the placebo group developed cancer. This difference, though seemingly small, was considered statistically significant by the FDA. Cancers reported more frequently in the locaserin group included pancreatic, colorectal, and lung cancer.
Based on these findings, the FDA determined that locaserin’s potential risks outweighed its benefits. Although the exact cause of the increased cancer risk was not definitively concluded, the agency deemed it necessary to remove the drug from the market. Eisai Inc., the manufacturer, complied with the FDA’s request.
Current Status and Alternative Weight Management Strategies
Locaserin is no longer available for prescription in any market following its withdrawal in 2020. For individuals seeking weight management solutions, several evidence-based approaches are recommended. These strategies often combine lifestyle modifications, and in some cases, other FDA-approved medications or surgical interventions.
Lifestyle modifications are the foundation of effective weight management. These include individualized dietary changes focused on reducing calorie intake, while ensuring sufficient protein, vitamins, and minerals. Increased physical activity is also recommended, with adults encouraged to engage in 30-60 minutes of moderate-intensity aerobic exercise at least five days per week, totaling at least 150 minutes weekly. Behavioral strategies like self-monitoring, goal setting, and stress management can further support these efforts.
For some individuals, lifestyle changes alone may not be sufficient. Healthcare professionals may consider other FDA-approved weight-loss medications, including orlistat, phentermine-topiramate, naltrexone-bupropion, liraglutide, semaglutide, and tirzepatide. These medications work through various mechanisms, such as reducing fat absorption, decreasing appetite, or increasing feelings of fullness.
Bariatric surgery may be an option for individuals with severe obesity (BMI of 40 or higher), or a BMI of 35 or higher with weight-related health issues. Surgical procedures, such as sleeve gastrectomy and gastric bypass, can lead to substantial and sustained weight loss. Consulting with healthcare professionals for personalized advice is recommended to determine the most appropriate weight management strategy.