Maitansine (INN), or maytansine (USAN), is a cytotoxic agent.

It inhibits the assembly of microtubules by binding to tubulin at the rhizoxin binding site.

[2] It is a macrolide of the ansamycin type and can be isolated from plants of the genus Maytenus.

[3][4] Some are being investigated as the cytotoxic component of antibody-drug conjugates for cancer treatment,[5] and the antibody-drug conjugate trastuzumab emtansine is an approved drug for the treatment of certain kinds of breast cancer in the EU and in the US.

[6][7] Examples of maytansinoids are: This antineoplastic or immunomodulatory drug article is a stub.