Bevacizumab in Combination with Modified FOLFOX6 in Heavily Pretreated Patients with HER2/Neu-Negative Metastatic Breast Cancer: A Phase II Clinical Trial

BACKGROUND: Bevacizumab combined with modified FOLFOX6 is a standard regimen for colorectal cancer. The present study was to determine the efficacy and safety of bevacizumab-modified FOLFOX6 regimen in heavily pretreated patients with human epidermal growth factor receptor 2 (HER2/neu)-negative MBC. METHODS: Bevacizumab, 5 mg/kg every two weeks or 7.5 mg/kg every three weeks, was administered with modified FOLFOX6 (oxaliplatin 85 mg/m(2), leucovorin 400 mg/m(2), 5-FU 400 mg/m(2) on day 1, followed by 5-FU 2400 mg/m(2) intravenous infusion over 46 hours every 2 weeks) to patients who failed at least 1 chemotherapy regimen in the metastatic setting. The primary objective was progression free survival (PFS). Secondary objectives included objective response rate (ORR), clinical benefit rate (CBR), overall survival (OS), safety, and the change of tumor size and Eastern Cooperative Oncology Group (ECOG) performance status. RESULTS: 69 patients were enrolled. The median PFS was 6.8 months (95% CI, 5.0 to 8.5 months), ORR was 50.0% and median OS was 10.5 months (95% CI, 7.9 to 13.1 months). Patients showing objective responses had a 4.2-month median PFS gain and 5.7-month median OS gain compared with those who did not (P < 0.05). Grade 3 or 4 adverse events occurring in more than one patient were neutropenia (53/69, 76.8%), leukopenia (36/69, 52.2%), thrombocytopenia (13/69, 18.8%), anemia (3/69, 4.3%) and hypertension (3/69, 4.3%). CONCLUSIONS: Adding bevacizumab to modified FOLFOX6 does have significant anti-tumor activity and good safety profile in heavily pretreated HER2/neu-negative MBC patients. Further trials are required to confirm whether the high ORR can translate into a long-term PFS and even OS benefit. TRIAL REGISTRATION: www.clinicaltrials.gov NCT01658033