Integrating Epothilones into the Treatment of Patients with Metastatic Breast Cancer: Clinical Perspectives on Incorporating Recent Data in the Practice Setting

The introduction of modern chemotherapy agents, including the taxanes, has improved the prognosis of women with metastatic breast cancer (MBC). Ultimately, however, inevitable intrinsic or acquired resistance to chemotherapy limits treatment options. The epothilones, a novel class of microtubule-stabilizing agents that have incomplete cross-resistance with taxanes and are less susceptible to common mechanisms of resistance, have demonstrated activity in breast cancer. Ixabepilone, the best studied epothilone to date, has been approved for use as a single agent or in combination with capecitabine in anthracycline- and taxane-pretreated or refractory MBC. Ixabepilone is relatively well tolerated, with the most common side effects being peripheral neuropathy and neutropenia. Other epothilones such as KOS-862, patupilone, ZK-EPO, BMS-310705, and KOS-1584 are being evaluated as therapy for patients with breast cancer, with promising preliminary data. Ongoing research alms to define and optimize the efficacy of the epothilones in an attempt to improve the quality of life and overall survival of individuals with breast cancer.