Monomethyl auristatin F (MMAF) is a synthetic antineoplastic agent. It is part of the approved drug belantamab mafodotin in multiple myeloma and some experimental anti-cancer antibody-drug conjugates such as vorsetuzumab mafodotin and SGN-CD19A. In International Nonproprietary Names for MMAF-antibody-conjugates, the name mafodotin refers to MMAF plus its attachment structure to the antibody.