First-line bevacizumab and eribulin combination therapy for HER2-negative metastatic breast cancer: Efficacy and safety in the GINECO phase II ESMERALDA study

Combining bevacizumab with paclitaxel significantly improves progression-free survival (PFS) versus paclitaxel alone in HER2-negative metastatic breast cancer (MBC). Eribulin is active and tolerable in pretreated MBC. To assess whether eribulin may offer a more tolerable yet effective combination partner for bevacizumab, we evaluated a bevacizumab/eribulin combination regimen as first-line therapy for MBC. In this single-arm phase II study, patients with histologically confirmed HER2-negative MBC and no prior chemotherapy for MBC received eribulin 1.23 mg/m2 on days 1 and 8 every 3 weeks for ≥6 cycles plus bevacizumab 15 mg/kg on day 1 every 3 weeks until disease progression. The primary endpoint was non-progression rate at 1 year. Secondary endpoints included objective response rate (ORR), PFS, and safety. The median age of the 61 treated female patients was 59 years, 16% had triple-negative MBC, 30% had ≥3 metastatic sites, and 71% had received prior (neo)adjuvant chemotherapy. Patients received a median of six eribulin and nine bevacizumab cycles. The non-progression rate at 1 year was 32% (95% confidence interval [CI]: 20–43%), ORR was 47% (95% CI: 34–60%), and median PFS was 8.3 months (95% CI: 7.0–9.6 months). The only grade ≥3 clinical adverse events in >5% of patients were hypertension (39%), neutropenia (26%), thrombosis (10%), and paresthesia/dysesthesia (7%). First-line eribulin/bevacizumab combination therapy showed interesting activity in MBC with an acceptable safety profile, including a particularly low incidence of high-grade neuropathy. •A single-arm study evaluated first-line bevacizumab–eribulin for HER2-negative MBC.•The primary endpoint was non-progression rate at 1 year.•The 1-year non-progression rate was 32% (95% CI 20–43%); median PFS was 8.3 months.•Grade ≥3 clinical AEs in >10% comprised hypertension (39%) and neutropenia (26%).•Eribulin–bevacizumab showed interesting activity and acceptable safety in MBC.