Which class of chemotherapy drugs primarily works on the M phase of the cell cycle?

The class of chemotherapy drugs that primarily operates during the M phase of the cell cycle includes Vinca alkaloids and Taxanes. This phase is characterized by the process of mitosis, where the cell divides to produce two daughter cells.

Vinca alkaloids, such as Vincristine and Vinblastine, inhibit microtubule formation, which is essential for the proper separation of chromosomes during cell division. By disrupting this process, they effectively halt mitosis, thus preventing cancer cells from replicating.

On the other hand, Taxanes, such as Paclitaxel and Docetaxel, stabilize microtubules and prevent them from disassembling, which also interferes with normal mitotic progression. This stabilization leads to cell cycle arrest, specifically during the M phase, thereby contributing to the cytotoxic effects observed in rapidly dividing cancer cells.

Together, both Vinca alkaloids and Taxanes are critical in targeting cells in the M phase, making them effective options in chemotherapy regimens for various cancers.