Incretin therapies based on GLP-1 receptor agonism aid in the loss of weight in obesity, but a relevant part of this loss (25%-40%) is attributed to loss of lean muscle mass, which raises the risk of sarcopenia. Keros Therapeutics Inc. has presented data on RKER-065, a novel modified ActRII-Fc ligand trap that inhibits myostatin and activins and promotes muscle formation.