New Therapeutic Options for Chemotherapy-Resistant Metastatic Breast CancerTe Epothilones

When taxanes were introduced as anticancer agents some 20 years ago, their broad spectrum of activity was striking and engendered renewed hope for cancer patients. However, they were not without their problems, including a susceptibility to drug resistance caused by the drug efflux pump protein, P-glycoprotein. The epothilones are a new class of chemotherapeutic agents that have a mechanism of action similar enough to the taxanes to retain their broad spectrum of activity, but different enough to escape the multidrug resistance caused by P-glycoprotein. These properties are especially promising for patients with metastatic breast cancer who have run out of therapeutic options as a result of multidrug resistance.