Bi-weekly eribulin therapy for metastatic breast cancer: a multicenter phase II prospective study (JUST-STUDY)

This study aimed to investigate whether schedule modification is safe and effective in patients intolerant to the standard eribulin dose and schedule.

Patients with metastatic breast cancer (MBC) treated with both anthracycline and taxane and ≤ 3 prior regimens of chemotherapy for MBC received eribulin at the standard dose and schedule (1.4 mg/m² on days 1 and 8 of a 21-day cycle) in the first cycle; change of dosing schedule (1.4 mg/m² on days 1 and 15 of a 28-day cycle) was determined by change in neutrophil count, platelet count, aspartate aminotransferase, alanine aminotransferase, total bilirubin, serum creatinine, and non-hematological toxicity on day 8 of the first cycle or day 1 of the second cycle. Clinical benefit rate (CBR; primary endpoint), time to treatment failure (TTF), overall survival (OS), and safety were evaluated.

Of the 88 patients who were enrolled and received standard eribulin therapy in the first cycle, 42 patients were moved to the bi-weekly therapy group and 40 continued standard therapy. In the bi-weekly and standard therapy groups, mean relative dose intensity was 62.7 and 90.9%, CBR was 31.0 and 25.0%, median TTF was 81.5 and 75 days, and OS was 523 and 412 days, respectively. Neither group reported severe adverse events.

This is the first study to show that a bi-weekly eribulin schedule is tolerable and has comparable efficacy in patients intolerant to the standard eribulin schedule.

University Hospital Medical Information Network (UMIN) Center (ID: UMIN 000008491).