Phase II Study of Vinorelbine Plus Ifosfamide in Patients with Taxane-resistant Metastatic Breast Cancer

Purpose: The patients with metastatic breast cancer are routinely exposed to taxane and anthracycline as neoadjuvant, adjuvant, and palliative chemotherapeutic agents. This study was designed to evaluate the efficacy and safety of using a vinorelbine and ifosfamide (VI) combination treatment in patients with taxane-resistant metastatic breast cancer. Methods: We evaluated the use of a VI regimen (25 mg/m2 vinorelbine administered on days 1 and 8 plus 2,000 2 ifosfamide administered on day 1-3 every 3 weeks) for breast cancer patients who evidenced tumor progression after palliative taxane treatment. Results: Overall, 35 patients were enrolled in this study: Their median age was 50 years (range, 38-72 years). The overall response rate was 40.0% (14 patients; 95% confidence interval [CI], 23-57%). The median time to progression was 4.5 months (95% CI, 3.55.4 months). The median overall survival was 18.3 months (95% CI, 12.9-23.6 months). In the 190 cycle of treatment, the incidence of grade ≥3 neutropenia, anemia, and thrombocytopenia was 29.3%, 4.2%, and 2.0%, respectively. Neutropenic fever was noted in 6 cycles (3.1%). The non-hematological toxicities were not severe: grade 1 or 2 vomiting was observed in 22.8% of the patients. Conclusion: Our results suggest that the use of vinorelbine and ifosfamide (VI) combination chemotherapy appears to be effective and it showed an acceptable toxicity profile in the patients with taxane-resistant metastatic breast cancer.