Mertansine, also called DM1, is a thiol-containing maytansinoid that for therapeutic purposes is attached to a monoclonal antibody through reaction of the thiol group with a linker structure to create an antibody-drug conjugate.

Mechanism of action

Mertansine is a tubulin inhibitor, meaning that it inhibits the assembly of microtubules by binding to tubulin (at the rhizoxin binding site).

The monoclonal antibody binds specifically to a structure (usually a protein) occurring in a tumour, thus directing mertansine into this tumour. This concept is called targeted therapy.

Uses

The following (experimental) drugs are antibody-drug conjugates (ADC) combining monoclonal antibodies with mertansine as the cytotoxic component. Mertansine is linked via 4-mercaptovaleric acid.

Effect

Mertansine is a thiol-containing derivative of maytansine that is cytotoxic to human epidermoid carcinoma KB and human breast cancer SK-BR-3 cells (IC50 = 1.10 nM for both).Formulations containing mertansine have been studied for the treatment of multiple myeloma and squamous cell carcinoma.