IXABEPILONE

12.1 Mechanism of Action Ixabepilone is a semi-synthetic analog of epothilone B. Ixabepilone binds directly to β-tubulin subunits on microtubules, leading to suppression of microtubule dynamics. Ixabepilone suppresses the dynamic instability of αβ-II and αβ-III microtubules. Ixabepilone possesses low in vitro susceptibility to multiple tumor resistance mechanisms including efflux transporters, such as MRP-1 and P-glycoprotein (P-gp). Ixabepilone blocks cells in the mitotic phase of the cell division cycle, leading to cell death.

Contraindications

• • 4 CONTRAINDICATIONS IXEMPRA is contraindicated in patients who have: a neutrophil count <1500 cells/mm 3 or a platelet count <100
• • 000 cells/mm 3 [see Warnings and Precautions ( 5.2 )]. a history of severe hypersensitivity to agents containing Cremophor ® EL or its derivatives (e.g.