Abstract: The present disclosure relates to antibodies specific for urokinase-type plasminogen activator (uPA). According to certain embodiments, the anti-uPA antibody specifically binds to the active form of uPA. In certain aspects, the anti-uPA antibody that specifically binds to active uPA binds specifically to the active form of human uPA (e.g., the antibody does not cross-react with active forms of uPA from non-human organisms). In certain aspects, an anti-uPA antibody of the present disclosure competes for specific binding to uPA with plasminogen activator inhibitor type 1 (PAI-1), where binding of the antibody to uPA results in internalization of a complex that includes the antibody, uPA, and urokinase-type plasminogen activator receptor (uPAR). Also provided are antibodies that specifically bind to uPA and compete for binding to uPA with a synthetic ligand of uPA. The disclosure also provides anti-uPA antibody conjugates and compositions (e.g.

Abstract: The invention relates generally to multispecific antibodies and to multispecific activatable antibodies that specifically bind to two or more different antigens or epitopes, as well as to methods of making and using these multispecific antibodies and/or multispecific activatable antibodies in a variety of therapeutic, diagnostic and prophylactic indications.

Abstract: The invention relates generally to activatable antibodies that include a masking moiety (MM), a cleavable moiety (CM), and an antibody (AB) that specifically binds to interleukin-6 receptor (IL-6R), and to methods of making and using these anti-IL-6R activatable antibodies in a variety of therapeutic, diagnostic and prophylactic indications.

Abstract: The present disclosure relates to antibodies specific for urokinase-type plasminogen activator (uPA). According to certain embodiments, the anti-uPA antibody specifically binds to the active form of uPA. In certain aspects, the anti-uPA antibody that specifically binds to active uPA binds specifically to the active form of human uPA (e.g., the antibody does not cross-react with active forms of uPA from non-human organisms). In certain aspects, an anti-uPA antibody of the present disclosure competes for specific binding to uPA with plasminogen activator inhibitor type 1 (PAI-1), where binding of the antibody to uPA results in internalization of a complex that includes the antibody, uPA, and urokinase-type plasminogen activator receptor (uPAR). Also provided are antibodies that specifically bind to uPA and compete for binding to uPA with a synthetic ligand of uPA. The disclosure also provides anti-uPA antibody conjugates and compositions (e.g.