Abstract P1-11-20: Open-Label Phase II Study of Neoadjuvant Bevacizumab Combined with FEC→Paclitaxel in Patients with Inflammatory or Locally Advanced Breast Cancer

Abstract

Abstract Background: There is strong evidence that VEGF plays an important role in the pathogenesis and progression of human breast cancer. Bevacizumab, a monoclonal antibody, specifically inhibits VEGF. The combination of first-line bevacizumab with chemotherapy significantly improved the activity in comparison to chemotherapy alone in three randomized phase III trials in metastatic breast cancer patients (pts). In early breast cancer, the FEC→Paclitaxel regimen is a highly active standard therapy. Therefore we initiated a trial to evaluate the combination of bevacizumab with this efficacious chemotherapy regimen for the treatment of stage III or inflammatory early breast cancer (LABC). Patients and Methods: The study is designed to evaluate a sequential regimen of FEC90 followed by the combination of paclitaxel and bevacizumab as neoadjuvant therapy in patients with HER2-negative locally advanced (stage III or inflammatory) breast cancer. Patients are treated with neoadjuvant FEC 600/90/600 mg/m2 q21d x 4, followed by paclitaxel 80 mg/m2 weekly x 12 combined with bevacizumab 10 mg/kg q2w x 6. Patients undergo surgery 4 weeks after completing chemotherapy. Pathologic complete response (pCR), the primary endpoint, is defined as no evidence of invasive tumor in the final surgical sample both in the breast and axilla. Secondary endpoints include objective clinical response rate (RR), disease-free interval, overall survival, rate of breast-conserving surgery, and the safety of the regimen. Results: Between Feb 2008 and Dec 2009, 54 pts (mean age of 51±7.5 years) were enrolled into the study. To date, 32 pts have completed neoadjuvant treatment and surgery and are evaluable for response. Baseline characteristics in these 32 patients were as follows: cT3/cT4b: 20 (63%) and/or cN2/cN3: 14 (43%); estrogen receptor (ER) positive: 24 (75%) and 8 (25%) triple-negative (TN), defined as ER negative, progesterone receptor-(PgR-) negative, and HER2 negative. Histological type was ductal carcinoma in 24 patients (75%), lobular carcinoma in 4 (13%), inflammatory breast cancer in 1 (3%), and other in 3 (9%). Mastectomy was performed in 22 patients (69%) and breast-conserving surgery in 10 patients (31%). After neoadjuvant treatment, 8/32 patients (25%) achieved a pCR. Conclusions: This open-label, multicenter, phase II study demonstrated that the FEC→Paclitaxel plus bevacizumab combination is a highly active neoadjuvant treatment for HER2-negative locally advanced breast cancer. A 25% of pCR in this group of pts with high tumor burden, i.e. the LABC, is oneof the most promising chemotherapeutic regimen if confirmed in the final analyis. Results for all 54 pts enrolled will be presented at the meeting. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-11-20.