Preliminary results of the Prostacox phase II trial in hormonal refractory prostate cancer

To assess in a phase II open multicentre study the efficacy and tolerance of docetaxel administered every 14 days combined with celecoxib, in patients with hormone-refractory prostate cancer (HRPC), and to test the hypothesis that this therapeutic combination would improve overall survival.

In all, 48 patients were included with a mean age of 70.4 years and Gleason score of 7.5, all had a satisfactory Karnofsky performance-status score of 92% and a metastatic bone site was measurable in 77%. The mean delay between initial diagnosis and docetaxel administration was 45 months, with a median PSA level increase of 54.8 ng/mL. The therapeutic schedule was: docetaxel (50 mg/m(2)) administered every 14 days (one cycle of two injections at 2 week intervals (Day 1 = Day 28) with a total of six cycles) and simultaneously a daily oral fixed dose of celecoxib (800 mg).

In all, 237 cycles of docetaxel were administered with a dose reduction in 23 patients at the beginning of a cycle (day 1) and 36 in the middle of a cycle (day 14). The haematological toxicity included anaemia grade 1-2 (78%) and only 10% neutropenia grade 3-4. However, there was only a 15% improvement of pain intensity. The response rate for the total PSA level was 45.5 (30.4-61.1)%, the mean time to progression was 9.3 months and the tumour-response rate was 26.3%. In all, 75% of patients had an overall survival of >14.6 months.

Our results confirm the usefulness of docetaxel for HRPC treatment and show a significant reduction of haematological toxicity with bi-weekly docetaxel administration combined with celecoxib.