Eribulin mesylate in patients with locally advanced unresectable or metastatic breast cancer: results and implications of the clinical trials

Eribulin mesylate is a novel nontaxane microtubule inhibitor, approved by the US FDA and EMA for the treatment of patients with metastatic breast cancer (MBC). This approval was based upon a pivotal Phase III trial where eribulin demonstrated a survival benefit compared with treatment of physician's choice in MBC patients who received at least two regimens in the metastatic setting. However, a subsequent Phase III study failed to demonstrate superiority of eribulin over capecitabine, in MBC patients who had received two or less regimens in the advanced setting. A pooled analysis of these two studies confirmed the survival benefit of eribulin compared with control. We will review the pivotal early-phase data and Phase III trials of eribulin, describe the role of eribulin for MBC, and summarize future directions in the development of this agent for both metastatic and early-stage breast cancer.