An update on clinical outcome data for a phase II randomized study comparing androgen deprivation therapy plus docetaxel versus androgen deprivation therapy alone in men with locally advanced/metastatic hormone sensitive prostate cancer.

259 Background: Androgen deprivation therapy has been the standard of care for advanced prostate cancer for many years. However recent studies have reported a survival benefit for upfront docetaxel chemotherapy in men with hormone sensitive prostate cancer. The GenTax trial was a single institution phase II study investigating clinical outcome and gene profiling for patients with treatment naïve prostate cancer treated with either docetaxel chemotherapy plus androgen deprivation therapy (D+ADT) or androgen deprivation therapy alone (ADT). We report on updated clinical outcome data for this trial. Methods: Patients with newly diagnosed T3/T4, PSA ≥ 50ng/ml or Gleason score ≥ 8, or metastatic disease were enrolled. Patients were randomised to ADT or D+ADT (docetaxel 75mg/m2 q21 days for 6 cycles). Data were analysed for overall survival, toxicities, time to second line treatment and number of subsequent treatments. Results: 30 patients were randomly assigned to ADT (n = 15) or D+ADT (n = 15) between 10/13/2005 and 12/02/2009. 7 patients in each arm had metastatic disease. Grade 3-4 toxicities were infrequent in D+ADT arm and were not noted in the ADT arm. There were no significant differences between treatment arms for overall survival (log rank p = 0.977) or time to second line treatment (log rank p = 0.954). Median overall survival was 98 months (95% CI 72.3 - 123.7) for ADT and 87 months (95% CI 71.5 - 102.5) for D+ADT. Median time to second line treatment was 45 months (95% CI 13.4 - 76.6) for ADT and 46 months (95% CI 13.2 – 78.8) for D+ADT. Number of subsequent treatments ranged from 0-6 (mean 2.40) for ADT-only and 0-5 (mean 2.13) for D+ADT. Conclusions: The combination of docetaxel and ADT in the hormone sensitive setting is well tolerated, as previously reported. This study was not sufficiently powered to detect statistically significant differences in survival. Patients proceeded to receive a number of subsequent lines of therapy although the order in which these were given was variable. There is a need to establish optimal sequencing of treatments in the upfront docetaxel era. Clinical trial information: 2004-004874-96.