Ladiratuzumab (also known as SGN-LIV1A) is an investigational antibody-drug conjugate (ADC) developed by Seagen. It consists of a humanized monoclonal antibody targeting LIV-1 (SLC39A6) linked to a potent microtubule-disrupting payload, monomethyl auristatin E (MMAE), via a protease-cleavable linker. Upon binding to LIV-1 on the cancer cell surface, the ADC is internalized, the linker is cleaved, and the cytotoxic payload is released inside the cell, leading to cell cycle arrest and apoptosis. Ladiratuzumab has been primarily investigated in clinical trials for the treatment of metastatic triple-negative breast cancer (TNBC), leveraging the high and frequent expression of LIV-1 in this aggressive disease.