bimagrumab bimagrumab bimagrumab (bym338) is a human monoclonal antibody developed by novartis to treat pathological muscle loss and weakness. on august 20, 2013, it was announced that bimagrumab had received a breakthrough therapy designation for sporadic inclusion body myositis (sibm) by the us food and drug administration. bimagrumabmonoclonal antibodytype?sourcehumantargetacvr2bclinical dataother namesbym338atc codenoneidentifierscas number1356922-05-8chemspidernoneuniin15sw1div8keggd10620 ychemical and physical dataformulac6306h9732n1684o1990s46molar mass142451.78 g·mol−1 in 2014, bimagrumab entered phase ii development, with some research indicating clinical effects. novartis planned to apply in 2016 for fda approval to treat sibm patients with bimagrumab. in april 2016, novartis announced that bimagrumab had failed a phase iib/iii study for sporadic inclusion body myositis. in january 2021, a new study confirmed that treatment with bimagrumab is safe and effective for treating excess adiposity and metabolic disturbances of adult patients with obesity and type 2 diabetes.