Gemcitabine and Vinorelbine Combination Chemotherapy in Taxane-Pretreated Patients with Metastatic Breast Cancer: A Phase II Study of the Kinki Multidisciplinary Breast Oncology Group (KMBOG) 1015.

BACKGROUND: This phase II study was conducted to evaluate the efficacy and safety of the chemotherapy combination of gemcitabine and vinorelbine in taxane-pretreated Japanese metastatic breast cancer patients. METHODS: In this multicenter, phase II, single-arm study, patients with recurrent or metastatic HER2-negative breast cancer were administered gemcitabine (1,200 mg/m2) and vinorelbine (25 mg/m2) intravenously on days 1 and 8 every 3 weeks. The primary endpoint was the objective response rate, and other endpoints included progression-free survival, overall survival, and safety. RESULTS: A total of 42 patients were enrolled in this study. The objective response rate and clinical benefit rate were 24 and 43%, respectively. The median progression-free survival was 4.0 months. The median overall survival was 11.1 months. Grade 3/4 neutropenia was the most common hematologic toxicity, occurring in 22 patients (54%). Nonhematologic toxicity was moderate and transient, with fatigue (48%) being the most common condition and no severe adverse event reported. CONCLUSION: The combination of gemcitabine and vinorelbine is an effective and tolerable regimen for HER2-negative, taxane-pretreated, metastatic breast cancer patients in Japan.