Belantamab mafodotin binds BCMA on target cells, is internalized, and releases MMAF, which binds beta-tubulin (vinca site) to inhibit microtubule polymerization, causing G2/M arrest and apoptosis; afucosylated Fc also enhances ADCC against BCMA+ cells. Tubulin is the intracellular payload target, not the ADC targeting antigen.