The specific patient populations who appeared to benefit from eribulin, in comparison to capecitabine, are as follows:

• Patients with more than two organs involved with metastatic breast cancer
• Patients who had not received chemotherapy for six months or longer
• Patients who had received anthracycline and/or a taxane therapies in the metastatic setting

Previous pre-specified exploratory analysis of overall survival and progression-free survival showed women with triple-negative, ER-negative, HER2-negative also had a greater relative benefit in overall survival with eribulin over capecitabine.

"These exploratory analyses suggest that other patient subgroups may benefit from eribulin and further studies are warranted," said Peter A. Kaufman, MD, associate professor of medicine at the Geisel School of Medicine at Dartmouth, and oncologist at Dartmouth-Hitchcock and Norris Cotton Cancer Center in Lebanon, N.H.

In 2010, the FDA approved eribulin for the treatment of patients with metastatic breast cancer who had previously received an anthracycline and a taxane and at least two cytotoxic chemotherapy treatment regimens for metastatic breast cancer. The FDA granted approval based on data showing a statistically significant improvement in overall survival compared with current treatments.

Kaufman and colleagues are still compiling data from the quality-of-life analysis, which according to Kaufman, will help guide their next steps in further studying eribulin in this patient population.

Clinical Trial information: NCT00337103