Bimagrumab for body fat reduction and maintenance/increase of lean mass: systematic review with semaglutide as comparator

Obesity is a global epidemic that compromises health and quality of life, and understanding how therapies affect body composition is essential. This review compares semaglutide and bimagrumab in adults with overweight or obesity, highlighting that semaglutide, although effective in promoting weight loss and reducing cardiovascular events, may cause significant loss of lean mass (up to 40% of total weight lost), which negatively impacts metabolism and functional capacity. In contrast, bimagrumab, an activin type II receptor, blocking monoclonal antibody - reduces more than 20% of body fat while simultaneously increasing lean mass by 3.5–5.3%, improving mobility and quality of life, especially in patients with type 2 diabetes and risk of sarcopenia. Both drugs present moderate and generally well-tolerated toxicity, but the review emphasizes the need to combine pharmacotherapy with resistance exercise to protect muscle mass, particularly when using semaglutide, and identifies bimagrumab as the most promising option for preserving and increasing lean mass.