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/m(2) 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.