BICALUTAMIDE IN THE TREATMENT OF ADVANCED PROSTATIC-CARCINOMA - A PHASE-II MULTICENTER TRIAL

Objectives. The safety, efficacy, and pharmacokinetics of the nonstero idal antiandrogen bicalutamide were investigated in a Phase II trial i n 150 patients with metastatic prostate cancer. Methods. Patients took bicalutamide, 50 mg daily, in an open-label multicenter North America n trial. Results. The objective response rate (modified European Organ ization on Research and Treatment of Cancer [EORTC] criteria) was 70% (57% partial, 13% stable); 59 (39%) of 150 patients had either a >90% decrease in prostate-specific antigen (PSA) levels or a decline to <4 ng/mL. Extent of disease on the bone scan was a significant predictor of response. Patients with <6 metastatic lesions were more likely to r espond. Breast pain and gynecomastia occurred in 76% and 60% of patien ts, respectively. Gastrointestinal toxicity was very infrequent (diarr hea, 5%) The mean drug plasma concentration was 8528 (+/-2928) ng/mL. Conclusions. Bicalutamide, 50 mg daily, was well tolerated and has eff icacy in metastatic prostate cancer. The percentage of men who had >90 % decline in PSA levels is less than observed with surgical or medical castration and has led to trials using this antiandrogen at higher do ses as monotherapy.