More than one million women worldwide are diagnosed with breast cancer every year. For those diagnosed with metastatic breast cancer, the 5-year survival rates are low as, ultimately, patients develop tumors that become refractory to treatment. In clinical trials, eribulin mesylate (E7389) - a novel nontaxane microtubule dynamics inhibitor - demonstrated efficacy in patients with various solid tumors, in particular, those with heavily pretreated metastatic breast cancer. The Eisai Metastatic Breast Cancer Study Assessing Physician's Choice Versus E7389 (EMBRACE) study observed a significant increase in overall survival with eribulin compared with treatment of physician's choice (median: 13.1 vs 10.6 months, respectively). Based on these results, eribulin recently received approval by the US FDA for the treatment of patients with metastatic breast cancer who have received at least two prior chemotherapeutic regimens including an anthracyline and a taxane. In addition, eribulin has a manageable tolerability profile, requires no premedication and has shorter infusion times than most other microtubule-targeted agents.