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

A method for improving body composition in a subject in need thereof, the method comprising administering to the subject a composition in an amount effective to alter body composition, wherein the composition comprises an antibody or an antigen-binding fragment thereof comprising three heavy chain complementarity determining regions (CDRs) comprising amino acid sequences of SEQ ID NO:

• 1 (CDRH1), SEQ ID NO:
• 4 (CDRH2), and SEQ ID NO:
• 10 (CDRH3), and three light chain CDRs comprising amino acid sequences of SEQ ID NO:
• 12 (CDRL1), SEQ ID NO:
• 18 (CDRL2), and SEQ ID NO:
• 22 (CDRL3), as defined by the Kabat numbering system;
• or three heavy chain CDRs comprising amino acid sequences of SEQ ID NO:
• 2 (CDRH1), SEQ ID NO:
• 5 (CDRH2), and SEQ ID NO:
• 10 (CDRH3), and three light chain CDRs comprising amino acid sequences of SEQ ID NO:
• 13 (CDRL1), SEQ ID NO:
• 19 (CDRL2), and SEQ ID NO:
• 22 (CDRL3), as defined by the IMGT numbering system.