Results of a phase-III study presented at the American Society of Clinical Oncology (ASCO) Annual Meeting showed that Eisai’s eribulin mesylate significantly improved median overall survival (OS) compared with Treatment of Physician’s Choice (TPC) in heavily pre-treated metastatic breast cancer patients.

These results were presented as part of an ASCO-sponsored press briefing; additional details from the study will be presented in an oral session on June 8, 2010 in East Hall D1 at Chicago's McCormick Place. The study abstract has also been selected for presentation at the 2010 Best of ASCO Meetings, which will be held in San Francisco and Boston in the United States and in several countries around the world in the months following the ASCO Annual Meeting.

The phase-III “EMBRACE” study (Eisai Metastatic Breast Cancer Study Assessing Physician’s Choice Versus Eribulin E7389) met its primary endpoint of overall survival, showing that patients who received eribulin survived a median of 2.5 months longer than patients who received TPC (overall survival of 13.12 months versus 10.65 months, respectively, p=0.04). Results from EMBRACE also showed that a secondary endpoint of overall response rate (ORR) was statistically significant. Another secondary endpoint, progression free survival (PFS), was supportive of the primary endpoint but did not reach statistical significance.

“To date, no single-agent phase-III clinical trial has demonstrated improved survival in women with heavily pre-treated metastatic breast cancer,” said Chris Twelves, lead investigator for the EMBRACE study and professor of Clinical Cancer Pharmacology and Oncology from the University of Leeds and St James’s University Hospital, Leeds, United Kingdom. “These results showed that eribulin significantly improved overall survival versus a variety of agents used in a real-world setting, which previously no single agent has shown.”

The most frequently reported adverse events (AEs) among patients treated with eribulin were asthenia, or fatigue (53.7%), neutropenia, or low white blood cell counts (51.7%), alopecia, or hair loss (44.5%) and peripheral neuropathy, or numbness and tingling in different parts of the body (34.6%). Treatment-emergent serious AEs were reported for 25 per cent of patients in the eribulin group and 25.9 percent of patients in the TPC arm.

“Women with advanced breast cancer are in critical need of new treatment options,” said Alton Kremer, global head of Clinical Development for Oncology at Eisai Inc. “In this study, eribulin has shown an improvement in survival, and if approved by health authorities, it may offer patients a new treatment option at this stage of the disease.”

Eisai was established in 1995 and is ranked among the top-20 US pharmaceutical companies (based on retail sales).