The antibody-drug conjugate (ADC) is a combination of a cytotoxic agent and monoclonal antibodies (mAbs) through a stable specialized chemical linker. After ADC binds to the target antigen, the conjugate is internalized and toxin is released, leading to the death of a target cell. Lorvotuzumab mertansine, indatuximab ravtansine, and milatuzumab-doxorubicin are currently under clinical development for use in multiple myeloma (MM). Preliminary data from recent studies indicate that these agents induce responses in patients with relapsed and/or refractory MM and have an acceptable safety profile.