Azintuxizumab is a humanized monoclonal antibody typically of the IgG1\kappa isotype, although IgG1 variants are also referenced, indicating its primary role is functional blockade with minimized Fc effector function in its native form. However, its main clinical application is as the antibody component (targeting moiety) of the Antibody-Drug Conjugate (ADC) known as Azintuxizumab vedotin (ABBV-838). In this ADC format, the antibody is linked to a potent cytotoxic payload, usually monomethyl auristatin E (MMAE). Azintuxizumab's role is to bind specifically to its target on malignant cells, allowing the entire ADC complex to be internalized. Once inside the cell, the cytotoxic drug is released, leading to the destruction of the cancer cell. It has been primarily investigated for the treatment of relapsed/refractory multiple myeloma (RRMM).