Eribulin as Treatment for Metastatic Breast Cancer

Sarah S. Mougalian, MD:So there are a variety of agents used in the treatment of metastatic breast cancer that target the microtubules, either in the polymerization of the microtubules in creating the mitotic spindle, or in de-polymerization resulting in the formation of 2 daughter cells from the cancer cell.

The agents, the epothilones and the taxanes, tend to inhibit the de-polymerization; whereas eribulin and vinorelbine tend to inhibit polymerization. I absolutely take into consideration the mechanism of action, but, importantly, I also have to take into consideration the other medical comorbidities that patients may have. The primary toxicities of these agents tend to include neuropathy, alopecia, fatigue, some cytopenias; but neuropathy can be one of those quality-of-life affecting adverse effects. So in any patient with a pre-existing neuropathy, I tend to steer away from some of these agents.

Eribulin is a microtubule inhibitor that is approved in the United States for treatment of metastatic breast cancer after 2 prior lines of treatment in patients who have received a prior taxane and a prior anthracycline. This approval was based on 2 randomized clinical trials. The first was EMBRACE, for which patients who had received 2 to 5 prior lines of therapy were randomized either to receive eribulin or treating physician’s choice. And in that study, there was an improvement in overall survival in those patients receiving eribulin.

This study was followed up by Study 301, for which women with 0 to 2 prior lines of therapy in the metastatic setting were treated either with eribulin or capecitabine. In this study, there was no difference in overall survival. But based on the EMBRACE trial, eribulin received its FDA approval.

I use eribulin a lot in my practice. I tend to follow the FDA guidelines. However, in women who have had a lot of prior therapy, for example in the neoadjuvant or adjuvant setting, if they’ve received an anthracycline and a taxane, I might use it earlier. I might use it in the first-line. Or I might use it in the second-line setting. Of course, this is a very patient-specific decision.

Transcript edited for clarity.