Therapeutics: Myostatin (MSTN; GDF8)

In vitro and mouse studies suggest MSTN inhibitors could help treat RA. Synovial membrane levels of MSTN were higher in samples from RA patients and in a mouse model of RA than in healthy controls. In osteoclast precursors from mouse bone marrow-derived macrophages, MSTN increased receptor activator of NF-κB ligand (RANKL; TNFSF11)-induced osteoclast formation compared with no treatment. In mouse models of RA, MSTN knockout or an anti-MSTN antibody decreased arthritis severity and joint damage and increased grip strength compared with normal MSTN expression or a control antibody, respectively. Next steps could include testing the antibody in additional RA models...