Phase II study of capecitabine combined with gemcitabine in the treatment of androgen-independent prostate cancer previously treated with taxanes

BACKGROUND. The primary objective of the current study was to evaluate the effectiveness of capecitabine and gemcitabine in the treatment of patients with androgen-independent prostate cancer (AIPCa) who experienced disease progression after taxane therapy. The secondary objective was to evaluate the safety and tolerability of the combination of capecitabine and gemcitabine in these patients. METHODS, Patients with AIPCa, either metastatic or unresectable disease, and prior taxane therapy were eligible. Patients were treated with 800 mg/m² of capecitabine orally twice daily (1600 mg/m² per day) for 14 days, and 800 mg/m² of gemcitabine intravenously on Days 1 and 8. This regimen was repeated every 21 days. Response to therapy was determined by measuring prostate-specific antigen concentration. RESULTS. Sixteen patients participated in this study from June 2003 to January 2004. There were no responses as defined by a 50% decline in prostate-specific antigen. The study was terminated early because the response rate was not projected to exceed 30% (rejection error of 10%). Toxicities were notable: 3 patients had Grade 3 thrombocytopenia, 4 patients had Grade 3 neutropenia, and 3 patients had Grade 3 infections (according to the National Cancer Institute Common Toxicity Criteria [version 2.0]). Eight patients (50%) required dose reduction or treatment interruption. CONCLUSIONS. The combination of capecitabine and gemcitabine for the salvage treatment of patients with AIPCa was associated with significant toxicities and was ineffective for induction of disease regression.