Incidence of peripheral neuropathy associated with eribulin mesylate versus vinorelbine in patients with metastatic breast cancer: sub-group analysis of a randomized phase III study.

BACKGROUND Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most significant neurologic complications of chemotherapy, impacting patient's behavior and quality of life. CIPN is mostly sensory, with rare incidences of autonomic dysfunction and other neuropathy. METHODS We conducted a single-center sub-group analysis of patients with metastatic breast cancer enrolled in a phase III study (NCT02225470) set up to compare eribulin mesylate (1.4 mg/m2 on days 1 and 8 every 21 days) with vinorelbine (25 mg/m2 on days 1, 8, and 15 every 21 days). The analysis investigated incidence of peripheral neuropathy, time to onset of neuropathy, and safety. RESULTS Our analysis included 110 women with a mean age of 50.7 (SD = 10.9). The median accumulated dose of eribulin was 11.2 mg/m2 and 125.0 mg/m2 for vinorelbine. Among patients in the eribulin group, a performance status (ECOG PS) of 2 was correlated with peripheral sensory neuropathy (p = 0.015), and accumulated eribulin dose (≥ 10 mg/m2) was associated with all neuropathy and peripheral sensory neuropathy (p = 0.003 and p = 0.007, respectively). In the vinorelbine group, patient age (≥ 65 years) was positively associated with all neuropathy (p = 0.043). The time to onset of neuropathy appeared to be longer for eribulin versus vinorelbine (35.3 vs. 34.6 weeks; p = 0.046), with a significantly higher incidence of autonomic neuropathy at weeks 2 and 10 observed among patients receiving vinorelbine (p = 0.008 and p = 0.043, respectively). CONCLUSION Vinorelbine is associated with a higher incidence of autonomic neuropathy than eribulin in patients with metastatic breast cancer. Furthermore, the onset of neurotoxicity appears to occur earlier with vinorelbine than eribulin.