Chemotherapy-induced peripheral neuropathy in breast cancer patients treated with eribulin: interim data from a post-marketing observational study.

backgroundFew studies have examined chemotherapy-induced peripheral neuropathy (CIPN) following the administration of eribulin as first- or second-line therapy in patients with breast cancer. We therefore assessed CIPN incidence by severity and risk factors for CIPN in patients treated with eribulin for HER2-negative inoperable or recurrent breast cancer, regardless of line therapy status.

methodsThis multicenter, prospective, post-marketing observational study enrolled patients from September 2014 in Japan and followed them for 2 years. For this interim analysis, the data cut-off point was in November 2017. CIPN severity was assessed based on the Japanese version of the Common Terminology Criteria for Adverse Events, version 4.0.

resultsAmong 634 patients included in the safety analysis, 374 patients did not have existing CIPN at baseline. CIPN was observed in 105 patients (28.1%), including 67 (17.9%), 34 (9.1%), and 4 (1.1%) patients with grade 1, 2, and 3 severity, respectively. Of the 105 patients, 85.7% patients continued, 7.6% reduced, interrupted or postponed, and 6.7% discontinued eribulin. The median time (min‒max) from baseline to CIPN onset was 60 (3‒337) days. Multivariate logistic regression identified a significant association between CIPN and hemoglobin level at baseline, starting dose of eribulin, and history of radiotherapy.

conclusionsOur findings indicate that, with respect to CIPN, eribulin is well-tolerated, as approximately one-quarter of patients developed CIPN, most cases were grade 1 or 2, and the majority of patients continued eribulin after CIPN onset.