Efficacy and Safety of Biweekly Regimen of Eribulin Versus a Standard Regimen for the Treatment of Locally Recurrent or Metastatic HER2-negative Breast Cancer: a Multicenter, Randomized, Open-label, Phase III Trial

Eribulin is a soft spongin-like inhibitor of mitotic microtubule dynamics in cells. From the evidence of efficacy, the STUDY 305 and STUDY 301 studies suggest that eribulin improves PFS and OS in patients with breast cancer. Eribulin has a good safety profile with a low incidence of patient-perceivable adverse effects, with myelosuppression being the main adverse effect, and neutropenia, anemia, and also fatigue being the most common adverse effects. However, serious neutropenia, may result in delayed dosing, dose reduction or discontinuation in some patients. In studies of standard regimen therapy with eribulin, grade 3-4 neutropenia occurred in approximately 45% of patients, of which approximately 25% required dose adjustment or discontinuation of therapy, which has become an urgent clinical problem in the treatment of eribulin. Therefore, a modified bi-weekly regimen of eribulin (1.4 mg/m2 intravenously on days 1 and 15 of a 28-day cycle), based on the standard regimen (1.4 mg/m2 intravenously on days 1 and 8 of a 21-day cycle), is expected to improve the safety of eribulin administration without compromising efficacy, in order to minimize dose reductions of the medication and interruptions of therapy, thereby improving patients' quality of life. There is still a lack of head-to-head studies on the efficacy and safety of the combination of eribulin standard regimen and biweekly regimen in HER2-negative advanced breast cancer, and the treatment data in the Chinese population need to be further explored. The aim of this study is to explore the efficacy and safety of eribulin biweekly regimen compared with the standard regimen in patients with locally recurrent or metastatic HER2-negative breast cancer, and to provide a clinical evidence-based basis for the optimization of eribulin treatment regimen.