Ixabepilone: Antimitotic drug microtubule-stabilizing agent epothilone

Ixabepilone (BMS-247550, Ixempra™) is an analogue of epothilone B that exerts antitumor activity by stabilizing microtubules. The epothilones were originally isolated from a fermentation of a myxobacteria, Sorangium cellulosum, and later synthesized. These natural products were shown to bind to tubulin, stabilize microtubules and induce mitotic arrest at the G2/M transition, resulting in potent anticancer activity, especially against taxane-resistant tumors. Ixabepilone was recently approved by the FDA as monotherapy for resistant or refractory metastatic or locally advanced breast cancer. Phase III clinical development for the treatment of breast cancer continues, as well as earlier clinical trials for many other types of solid tumors and hematological malignancies.