Investigators reveal eribulin may be an effective agent for previously treated metastatic breast cancer, presented at the 39th Annual Miami Breast Cancer Conference. 

“The treatment landscape for mBC has been rapidly evolving over the past few years with FDA approvals of multiple new therapies, including, for example, several immune checkpoint inhibitors and antibody-drug conjugates. Eribulin is a unique chemotherapeutic agent that is FDA approved and widely used in the treatment of mBC in both the USA and worldwide. There has previously been very little data on the efficacy of eribulin in patients with mBC who have been previously treated with either of these classes of medications," explained senior author Peter A. Kaufman, MD, University of Vermont in Burlington, alongside fellow investigators.

Researchers utilized electronic health record data for 91 patients with mBC, predominantly comprised of triple-negative breast cancer (TNBC; 74.7%). Noting a median follow-up of 11.7 months from eribulin initiation, 63.7% of patients were vital with median OD unreached. The estimated 1-year OS rate was 77.8% (95% CI, 67.3%-85.3%). Aditionally, the estimated 1-year PFS rate was 62%; the 2-year PFS rate from the time of eribulin initiation was 41.9%. The analysis included 53 patients treated with prior atezolizumab and 38 who had received sacituzumab govitecan-hziy. 

“Although this is a real-world analysis with data obtained from a medical chart review-with the limitations of these types of studies and the other limitations of this study design-we find these results to be quite intriguing and warrant further study,” Dr Kaufman continued.

Moreover, in 75.8% of cases, eribulin was administered as a second-line therapy. The agent was administered in the third line for 13.2% of patients and fourth line in 11.0% of individuals. At the time of the analysis, 36.3% of patients continued to received treatment with eribulin. For those who remained on treatment, the median treatment duration was 12.2 months. Patients who discontinued eribulin discontinued treatment after a median duration of 5.1 months.

“What was reported in this medical chart review was that approximately 75% of overall patients were receiving eribulin in the second-line setting, and approximately 25% were receiving eribulin in the third-line or later setting, which we found somewhat surprising. Nonetheless, we believe our findings to be quite intriguing.”

In conclusion, eribulin yields promising 2-year overall survival (OS) rates among pretreated patients with metastatic breast cancer (MBC), and may be an effective agent for patients with pretreated patients with mBC.