Eribulin for the treatment of metastatic breast cancer: an update on its safety and efficacy.

Breast cancer remains a leading cause of cancer-related death internationally. Treatment approaches for metastatic breast cancer have evolved in recent years; however chemotherapy remains a core component for the majority of patients. Agents such as anthracyclines and taxanes have been extensively studied and form standard treatment. Eribulin mesylate is a novel synthetic microtubule-directed chemotherapy, based on a naturally-occurring compound. Through phase I studies, eribulin was found to be tolerable and activity was seen in patients with metastatic breast cancer. Phase II studies in metastatic breast cancer further demonstrated its efficacy, with responses and survival which compare favorably with other studied chemotherapy agents. The phase III EMBRACE study showed superior survival for patients treated with eribulin compared with those who received a physician's choice control. This led to its approval for use in many countries in this setting. Its toxicity profile is well established and manageable for the most part, with the commonest reported toxicities being alopecia, fatigue, neutropenia and peripheral neuropathy. A second reported phase III study comparing eribulin to capecitabine failed to show an improvement in survival in pretreated patients. This article reviews the clinical pharmacology and mechanism of action of eribulin, and summarizes the results of the major preclinical and clinical studies of eribulin in metastatic breast cancer.