Observational study of clinical outcomes of eribulin mesylate in metastatic breast cancer after cyclin-dependent kinase 4/6 inhibitor therapy.

Abstract

Aim: To examine the effectiveness of eribulin mesylate for metastatic breast cancer post cyclin-dependent kinase inhibitor(CDKi) 4/6 therapy. Materials & methods: US community oncologists reviewed charts of patients who had received eribulin from 3 February 2015 to 31 December 2017after prior CDKi 4/6therapy and detailed their clinical/treatment history, clinical outcomes (lesion measurements, progression, death) and toxicity. Results: Four patient cohorts were created according to eribulin line of therapy: second line, third line, per US label and fourth line with objective response rates/clinical benefit rates of 42.2%/58.7%, 26.1%/42.3%, 26.7%/54.1% and 17.9%/46.4%, respectively.Median progression-free survival/6-month progression-free survival(79.5% of all patients censored)by cohort was: 9.7months/77.3%, 10.3months/71.3%, not reached/70.4% and 4.0months/0.0%, respectively. Overall occurrence of neutropenia=23.5%, febrile neutropenia=1.3%, peripheral neuropathy=10.1% and diarrhea=11.1%. Conclusion: Clinical outcome and adverse event rates were similar to those in clinical trials and other observational studies. Longer follow-up is required to confirm these findings.