DM1

DM1 (mertansine) is a highly potent cytotoxic agent belonging to the maytansinoid class of microtubule inhibitors. It is most widely known as the payload component in antibody-drug conjugates (ADCs), such as trastuzumab emtansine (T-DM1/Kadcyla). As a derivative of maytansine, DM1 binds to tubulin at the plus ends of cellular microtubules and inhibits their polymerization, leading to mitotic arrest and apoptosis in dividing cells. In ADCs like T-DM1, DM1 is covalently linked via a stable linker (such as MCC) to an antibody that targets specific tumor antigens—most notably HER2—enabling targeted delivery of this cytotoxin directly into cancer cells after receptor-mediated internalization[2][3][5][6]. Free DM1 itself is not used clinically due to its high toxicity; it achieves clinical utility only when delivered specifically by an antibody carrier.

Other names

mertansinemaytansinoid DM1