Bicalutamide in the treatment of advanced prostatic carcinoma: a phase II multicenter trial.

OBJECTIVE

The safety, efficacy, and pharmacokinetics of the nonsteroidal antiandrogen bicalutamide were investigated in a Phase II trial in 150 patients with metastatic prostate cancer.

METHODS

Patients took bicalutamide, 50 mg daily, in an open-label multicenter North American trial.

RESULTS

The objective response rate (modified European Organization 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 respond. Breast pain and gynecomastia occurred in 76% and 60% of patients, respectively. Gastrointestinal toxicity was very infrequent (diarrhea, 5%) The mean drug plasma concentration was 8528 (+/- 2928) ng/mL.

CONCLUSIONS

Bicalutamide, 50 mg daily, was well tolerated and has efficacy 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 doses as monotherapy.