Antibodies directed against actriia and actriib

Abstract

This description relates to antibodies and antibody fragments specific for ActRIIA and ActRIIB. The antibodies are enhanced versions of bimagrumab. The antibodies of the present invention have improved affinity for ActRIIA, resulting in enhanced in vitro potency and efficacy, an improved PK and PD profile, and greater stability, making the antibodies suitable for subcutaneous administration. Optionally, they carry Fc modifications, which make the antibodies safe for prolonged treatment.