Multicenter phase II study of oral capecitabine (Xeloda®) in patients with metastatic breast cancer relapsing after treatment with a taxane-containing therapy

Background: Capecitabine is a rationally designed oral, tumor-activated fluoropyrimidine carbamate with high activity in metastatic breast cancer. This multicenter phase II study was designed to evaluate further the efficacy and safety of capecitabine in patients with metastatic breast cancer previously treated with a taxane-containing regimen. Patients and methods: All patients had to have documented progression after paclitaxel- or docetaxel-containing chemotherapy. Treatment comprised 3-week cycles of oral capecitabine 1250 mg/m(2) twice-daily for 14 days followed by a 7-day rest period. Results: One hundred and thirty-six patients were enrolled. Disease stabilization occurred in 63 patients (46%) and the overall response rate was 15% (95% confidence interval 10% to 23%), providing an overall tumor control rate of 62%. Median time to progression was 3.5 months, median duration of response was 7.5 months and median overall survival was 10.1 months. Capecitabine was generally well-tolerated: most treatment-related adverse events were grade 1/2 in intensity; grade 3/4 treatment-related adverse events were hand-foot syndrome (13%), diarrhea (8%), vomiting (4%) and nausea (3%). There were no treatment-related deaths. Conclusions: This study confirms that capecitabine achieves a high tumor control rate in heavily pretreated patients with metastatic breast cancer. Due to its favorable safety profile and convenient oral administration, capecitabine can be given as an outpatient therapy. Capecitabine should be considered the reference treatment in this setting based on consistently high efficacy and good tolerability.