Background：Bimagrumab is a monoclonal anti-ActRIIA/IIB antibody that targets ActRIIA and ActRIIB simultaneously. Native ActRIIA and ActRIIB are both mediators of signaling from several TGFβ superfamily members such as activins, myostatin, and GDF11. Hence, pan-blockade by Bimagrumab achieves greater effect than a monoclonal antibody against either receptor alone, i.e. monotherapy with anti-ActRIIA antibody or anti-ActRIIB antibody. Bimagrumab has been explored as a therapy for sporadic inclusion body myositis, primary sarcopenia, and muscle wasting associated with chronic obstructive pulmonary disease.
