Multicenter phase II study of capecitabine in paclitaxel-refractory metastatic breast cancer

Capecitabine is a novel, oral, selectively tumor-activated fluoropyrimidine carbamate. This large multicenter phase II trial tested the efficacy and safety of twice-daily oral capecitabine at 2,510 mg/m2/d given for 2 weeks followed by a 1-week rest period and repeated in 3-week cycles, in patients with paclitaxel-refractory metastatic breast cancer.

Patients were to have received at least two but not more than three prior chemotherapeutic regimens, one of which had to have contained paclitaxel given for metastatic disease. One hundred sixty-three patients were entered onto the study at 25 centers, and 162 patients received capecitabine. One hundred thirty-five patients had bidimensionally measurable disease, and 27 patients had assessable disease.

The overall response rate was 20% (95% confidence interval, 14% to 28%). All responding patients were resistant to or had failed paclitaxel, and all had received an anthracycline. Three complete responses were seen, with complete response durations of 106, 109, and 194+ days. Median duration of response was 8.1 months, median survival time was 12.8 months, and the median time to disease progression was 93 days. The most common treatment-related adverse events were hand-foot syndrome, diarrhea, nausea, vomiting, and fatigue. Diarrhea (14%) and hand-foot syndrome (10%) were the only treatment-related adverse events that occurred with grade 3 or 4 intensity in more than 10% of patients.

Capecitabine is an active drug in the treatment of paclitaxel-refractory metastatic breast cancer. It has a favorable toxicity profile with the added advantage of being an oral drug administered at home.