A weekly schedule of docetaxel for metastatic hormone-refractory prostate cancer

Docetaxel has proven its efficacy in the management of hormone-refractory prostate cancer (HRPC). Schedules of docetaxel administration differ. This prospective phase II study was designed to reevaluate the activity and toxicity of docetaxel administered weekly at an optimal dose to a large cohort of HRPC patients.

Sixty-four patients were treated with docetaxel 40 mg/m(2) i.v., administered weekly for 6 consecutive weeks followed by a 2-week recovery period. Three treatment cycles were planned in the absence of progression or toxicity. The principal end point was the biochemical response based on the prostate-specific antigen (PSA) level (a decline of more than 50% for at least 4 weeks). Secondary end points were objective response to measurable disease, survival and toxicity.

Toxicity was assessed in 64 patients. Toxicity was acceptable, with no toxicity-related deaths. Twenty-one percent of the patients developed grade 3-4 hematological toxicity. Sixty-four patients were evaluable for the PSA response. Forty-one patients (64%) achieved a decrease in PSA of >50%, 13 of whom had a PSA <4 ng/ml. Two out of 12 patients with measurable disease exhibited an objective response. With respect to PSA, the median progression-free survival was 29 weeks (95% confidence interval: 18-46 weeks). The global 1-year survival rate was 58%.

Weekly docetaxel at a dosage of 40 mg/m(2) is a well-tolerated treatment, which has very promising activity on the reduction of PSA in metastatic HRPC. A large phase III study is underway.