[Safety and efficacy of docetaxel in prostate cancer patients: based on the post-marketing surveillance in Japan].

ABSTRACT

The safety and efficacy of docetaxel in prostate cancer were evaluated based on the results of post-marketing surveillance. 149 patients were enrolled between September 2008 and May 2010. The starting dose of docetaxel was 75 mg/m² in 53 patients(36%), 70 mg/m² in 55 (37%), and ≤ 60 mg/m² in 41(28%). The median number of treatment cycles was 8 (range, 1 to 10). There was no age difference observed in the starting doses and the treatment cycles. The most common ≥ grade 3 adverse drug reactions (ADRs) were neutropenia (71%)and leukocytopenia (51%), and they occurred more frequently in patients receiving ≥ 70 mg/m². However, the multi-variate analyses revealed that ≥ grade 3 ADRs did not correlate with the starting doses. Infection-related events (≥ grade 3) and interstitial pneumonia were observed in 15% and 1% of patients, respectively. Prostate-specific-antigen (PSA) flare appeared in 19% of 95 evaluable patients at median period of 26 days from treatment initiation. It continued with median duration of 39. 5 days. PSA response rate as defined ≥ 50% level decline was 37%(95%confidence interval 27-47) in evaluable patients. It was low in patients receiving ≤ 60 mg/m² (18%). There was no notable difference between patients with initial dose of 75 and 70 mg/m². Further investigation for the longer term is warranted.