Kaufman and colleagues recently reported findings of a phase III trial comparing eribulin (Halaven) vs capecitabine in patients with advanced breast cancer who had previously received anthracycline and taxane therapy,1 and a review of their study appears in this issue of The ASCO Post. Although this large study did not achieve its primary endpoints of improvement in progression-free survival and overall survival, it is an important clinical trial that can help guide clinical practice.
This study established eribulin (a drug that is indicated in later-line therapy) as a drug that is no worse than capecitabine in an earlier line of therapy than its U.S. Food and Drug Administration label. This is valuable information for practicing oncologists who treat patients with breast cancer, because there is no preferred sequence of therapies for HER2-negative/nonamplified breast cancer. Since treatment decisions require balancing of risks and benefits, it is essential to know how therapeutics directly compare with each other. This study gives insight into how frequently used drugs in breast cancer measure up to each other from an efficacy and a toxicity perspective.
Efficacy and Toxicity
Kaufman et al randomized more than 1,000 patients with breast cancer who had received less than two regimens in the metastatic setting to treatment with eribulin or capecitabine. The study was designed for superiority of eribulin over capecitabine for both progression-free survival and overall survival.
Both arms were well balanced with respect to age, prior therapy, and burden of disease. Study therapy represented first or second line of therapy for advanced disease in 72% of patients.
The median progression-free survival was similar at 4.2 months with eribulin and 4.1 months with capecitabine. The response rates were also similar at 11%. As expected, severe (grade 3 and 4) adverse events were predictable, with hand-foot syndrome (14.5%) and diarrhea (5.3%) more prominent with capecitabine, and neutropenia (46.7%) and neuropathy (7%) more prominent with eribulin.
In my opinion, this study lends some clarity to how regimens compare and adds significantly to the available body of literature that we use to choose therapies for our patients. ■
Disclosure: Dr. Vahdat is on the speakers bureau for Eisai.
Reference
1. Kaufman PA, Awada A, Twelves C, et al: Phase III open-label randomized study of eribulin mesylate versus capecitabine in patients with locally advanced or metastatic breast cancer previously treated with an anthracycline and a taxane. J Clin Oncol 33:594-601, 2015.
Dr. Vahdat is Professor of Medicine and Director of the Breast Cancer Research Program, Weill Cornell Medical College, New York.
