Mertansine

Mertansine, also known as DM1, is a highly potent cytotoxic agent. It is a maytansinoid, a class of drugs derived from maytansine, a natural product originally isolated from the plant *Maytenus ovatus*. Mertansine functions by binding to tubulin, a protein essential for microtubule formation. Microtubules are crucial for cell division, and by inhibiting their assembly, mertansine arrests cancer cells in the metaphase stage of mitosis, ultimately leading to cell death.

Mertansine is not typically administered as a standalone therapy. Its primary application is as a payload in antibody-drug conjugates (ADCs). In ADCs, mertansine is chemically linked to a monoclonal antibody designed to target specific antigens expressed on the surface of cancer cells. This targeted delivery system allows the cytotoxic agent to be delivered directly to tumor cells, minimizing systemic exposure and reducing damage to healthy tissues. This approach has significantly improved the therapeutic index of potent cytotoxins.

The development of ADCs utilizing mertansine has been a key area of research in oncology. Several approved ADCs incorporate mertansine, demonstrating its efficacy in treating various cancers, including certain types of breast cancer and lymphoma. The clinical success of these ADCs highlights the importance of mertansine as a powerful therapeutic agent in the fight against cancer.