Methods for inhibiting myostatin activation by administering anti-pro/latent myostatin antibodies

A method for preparing a pharmaceutical composition comprising selecting an antibody or antigen-binding fragment thereof that specifically binds to pro/latent myostatin and formulating the antibody or antigen-binding fragment thereof in an amount suitable for administration with a pharmaceutically acceptable carrier to a subject in need of improved body composition,

• wherein the antibody or antigen-binding fragment thereof has been selected by:
• (i) providing a panel of candidate antibodies or antigen-binding fragments thereof;
• (ii) performing a binding assay on each of the candidate antibodies or antigen-binding fragments thereof to detect specific binding to pro/latent myostatin and not to mature myostatin or another member of the transforming growth factor Beta (TGFβ) family;
• thereby identifying one or more candidate anti-pro/latent myostatin antibodies or antigen-binding fragments thereof that specifically bind to pro/latent myostatin and not to mature myostatin or another member of the TGFβ family;
• (iii) performing a functional assay with each of the one or more candidate anti-pro/latent myostatin antibodies or antigen-binding fragments thereof to detect inhibition of myostatin signaling;
• and
• thereby identifying one or more candidate anti-pro/latent myostatin antibodies or antigen-binding fragments thereof that inhibit myostatin signaling;
• and wherein the improved body composition comprises a decrease in a ratio of adipose-to-muscle tissue.