235P - Phase II trial evaluating the combination of eribulin (E)+ bevacizumab (BEV) as first line chemotherapy in patients with metastatic Her2-negative breast cancer (MBC): a GINECO group study

Abstract

Phase III combination of chemotherapy with BEV versus chemotherapy alone in first line MBC showed a benefit in favour of the combination in terms of PFS. Moreover, paclitaxel + BEV is a standard of care in Europe, and the main toxicity is sensory neuropathy (23.5 % of grade >= 3). The efficacy of E is well established in MBC pre-treated with taxanes and anthracyclines with a favourable safety profile. Therefore, our group initiated a study to assess the efficacy and safety of E + BEV combination in first-line MBC. In this prospective, open-label, phase II study, patients with histologically confirmed HER2-negative MBC received as initial chemotherapy E every 3 weeks 1.23 mg/m2 on day 1 and day 8 for 6 cycles or more with BEV 15 mg/kg on day 1, until progression. The primary end point was non-progression rate at 1 year. Secondary end points were progression free survival (PFS) and safety. Of the 62 patients enrolled, 61 received the treatment. Median age was 59, 16% were triple negative, 30% had 3 metastatic sites or more. 71% of patients received prior chemotherapy, as adjuvant or neo-adjuvant treatment and 36% received hormonotherapy for MBC before enrolment. Median number of E cycles was 6 and 9 for BEV. The non-progression rate at 1 year was 32% (95% CI: 20%-43%), overall response rate (ORR) was 46%, and PFS was 8.3 months (95%CI: 7-9.6 months). Grade 3 or 4 neutropenia was observed in 26% patients only. Grade 3 HTA and thrombosis were observed in 39% and 8% of patients respectively. Grade 3 or 4 neuropathy occurred in 11% of patients. Other non-haematological adverse events were mild in severity. This trial shows that E plus BEV has antitumor activity similar to paclitaxel plus BEV as first line chemotherapy in MBC, with an acceptable safety profile, notably a lower rate of neuropathy than expected with paclitaxel. This combination might be beneficial for patients with HER2-negative MBC what should be confirmed by further comparative study.