Retrospective analysis of the efficacy and safety of eribulin therapy for metastatic breast cancer in daily practice

BACKGROUND Evidence of eribulin therapy for metastatic breast cancer (MBC) in clinical practice is not well documented. METHODS We retrospectively analyzed the safety and efficacy of eribulin in 29 MBC patients from 2011 to 2016 at Fukuoka University Hospital. RESULTS The median patient age, number of courses, total dose, and relative dose intensity were as follows: 65 years, five courses, 8.6 mg/m2 , and 75%, respectively. One patient achieved a complete response, (CR) six a partial response (PR), eight stable disease (SD) and 14 patients exhibited progressive disease. The objective response rate (ORR: CR + PR) was 24.1%, and the clinical benefit rate (CBR: CR + PR + SD) was 51.7%. The median progression-free survival was 90 days (95% confidence interval [CI] 67-126) and median overall survival was 264 days (95% CI 198-357). In patients who previously received 2-4 regimens, the ORR was 28.5% and the CBR was 57.1%. In patients who received 5-12 regimens, the ORR was 20% and the CBR was 45%. Chemotherapy was administered to 20 patients (69%) after eribulin administration, and the median overall survival rate of cases that achieved greater than a PR was 1088 days. The most frequent treatment-related grade 3/4 adverse events were neutropenia (55.2%), and febrile neutropenia (20.1%). Grade 3 peripheral neuropathy occurred in 13.8% of patients, but was not exacerbated even if present before treatment. CONCLUSION Eribulin is effective for MBC patients who have received multiple chemotherapies. Neutropenia and febrile neutropenia may develop after heavy prior therapy.