Combination of Trastuzumab and Vinorelbine in Metastatic Breast Cancer

Background: Since the clinical introduction of trastuzumab (Herceptin®) for metastatic breast cancers that overexpress human epidermal growth factor receptor 2 (HER2), this anticancer agent has played an important role in breast cancer treatment. We examined the effects of trastuzumab and vinorelbine (Navelbine®) as a second- or third-line therapy in 24 patients whose HER2-positive tumors did not respond to or relapsed after administration of trastuzumab alone or in combination with taxane. Methods: Trastuzumab was administered at 2 mg/kg (loading dose 4 mg/kg) once weekly and vinorelbine at 25 mg/m2 once weekly. The median treatment duration was 118.5 days (range, 22–351 days). Results: The response rate was 42% (95% confidence interval (CI): 22%–63%). The adverse events of NCI-CTC grade 3 or above consisted of neutropenia in three patients; other adverse events, including vasculitis, generalized fatigue, anemia and thrombocytopenia, were grade 1 or 2. All adverse events were reversible after treatment withdrawal and were easily manageable. Conclusion: A combination of trastuzumab and vinorelbine can be safely administered on an outpatient basis, and is useful in the treatment of patients with HER2-overexpressing metastatic breast cancer.