Phase II study of capecitabine in patients with fluorouracil-resistant metastatic colorectal carcinoma.

Purpose: Capecitabine is an oral fluoropyrimidine converted to fluourouracil (FU) preferentially in tumor tissue. It has proven clinical activity against colorectal cancer when used as first-line therapy. The objectives of this study were to assess the safety and efficacy of capecitabine in patients with metastatic colorectal carcinoma who progressed despite previous FU therapy.

Patients And Methods: According to the group sequential analysis design of this study, accrual would stop if no responses were observed in the first 20 patients treated. If one or more objective responses were confirmed, the trial would be expanded. Patients received capecitabine 1,250 mg/m(2) twice a day for 14 days, every 3 weeks. Tumor lesions were assessed every 6 weeks, and patients were followed for survival every 3 months after completing treatment.

Results: Twenty-three patients were enrolled onto the study; 22 fulfilled all the eligibility criteria. No objective responses were observed among the 22 eligible patients; 11 patients (50%) had stable disease for a median duration of 141 days (range, 88-289 days). The Kaplan-Meier estimate of median time to disease progression was 64 days (95% CI, 41 to 134 days). The median survival time estimate was 389 days (95% CI, 267 to 637 days). The most frequent treatment-related adverse events were hand-foot syndrome, diarrhea, and nausea or vomiting. There were no grade 4 toxicities and no treatment-related deaths.

Conclusion: Single-agent capecitabine in patients with metastatic colorectal carcinoma refractory to FU showed no objective responses and clinical benefit that was, at best, modest. The use of capecitabine in combination with other treatments in this patient population is under investigation.