Docetaxel Plus Prednisolone for the Treatment of Metastatic Hormone-refractory Prostate Cancer: A Multicenter Phase II Trial in Japan

Background Docetaxel-based chemotherapy has been shown to be effective and well tolerated by Western patients with metastatic hormone-refractory prostate cancer (HRPC). This study was undertaken to assess the feasibility of docetaxel in combination with prednisolone in Japanese patients with HRPC. Methods Patients aged 50–74 years with measurable metastatic HRPC were included in this non-comparative Phase II study. Treatment consisted of docetaxel 70 mg/m2 once every 3 weeks plus prednisolone 5 mg twice daily, for a maximum of 10 cycles. The primary endpoint was overall tumor response rate, assessed by Response Evaluation Criteria in Solid Tumors; secondary endpoints included prostate-specific antigen (PSA) response and toxicity. Results A total of 43 patients were evaluable for efficacy and toxicity. The response rate was 44.2% (90% CI, 31.2–57.8%), with partial responses in 19/43 patients. The median duration of response was 19.3 weeks. PSA responses were recorded in 44.4% of patients (95% CI, 27.9–61.9%). The most common non-hematological adverse events (of any grade) possibly related to treatment were alopecia (88.4%), anorexia (65.1%) and fatigue (53.5%). Grade 3/4 leukopenia and neutropenia occurred in 81.4 and 93.0% of patients, respectively; however, the grade 3/4 rates of febrile neutropenia (16.3%) and infection without fever (14.0%) were lower. Conclusion The combination of docetaxel and prednisolone was feasible and active in Japanese patients with HRPC, with a manageable adverse-event profile similar to that observed in Western patients.