206P - Bevacizumab plus dose-dense neoadjuvant FEC followed by docetaxel chemotherapy in patients with HER2-negative breast cancer: a multicentre, phase 2 study by the Hellenic Oncology Research Group

Abstract

Addition of bevacizumab to standard chemotherapy in the neoadjuvant setting improves the proportion of patients with HER2-negative breast cancer who achieve pathological complete response. We aimed to assess the addition of bevacizumab to dose-dense neoadjuvant chemotherapy. We enrolled women with operable HER2-negative breast cancer (T1c-T4 and N0-3). Patients underwent treatment every 2 weeks (with pegfilgrastim support) of fluorouracil (500 mg/m2), epirubicin (75 mg/m2), cyclophosphamide (500 mg/m2), and bevacizumab (10 mg/kg) for 4 cycles followed by docetaxel (75 mg/m2) and bevacizumab for 4 cycles. After surgery, patients received adjuvant radiotherapy, and hormone therapy (if indicated). The primary endpoint was pathological complete response in breast and the axilla, and safety of the combination. A two-stage trial design was planned with 15 and 33 patients to enroll, respectively. The trial was terminated early due to slow accrual and follow-up is ongoing. Between Oct, 2011, and Apr, 2015, we enrolled 34 patients, of whom 3 didn't undergo surgery, leaving 31 patients in the primary endpoint analysis. After neoadjuvant therapy, 5 (16.1%) of 31 patients achieved a pathological complete response according to centralized review. No patient discontinued treatment due to adverse events. The most frequent grade 3–4 toxicities were neutropenia (23.5%), nausea and vomiting (5,8%), and febrile neutropenia (2,9%). Only one patient developed grade III bevacizumab-related toxicity (hypertention). One patient died of pneumonia after cycle 8 and before surgery, which was thought to be unrelated to bevacizumab. After 25,2 months of median follow-up (range: 2,3-43,3) five patients experienced a disease relapse (16,1%). Our results seem to indicate that the addition of bevacizumab to dose-dense neoadjuvant chemotherapy with FEC and docetaxel, although safe and feasible, does not provide clinical benefit to patients with non-metastatic HER2-negative breast cancer. Translational research to identify patients who might benefit from bevacizumab is needed.