Objectives: To evaluate bicalutamide as a therapy in nearly 3000 patients with advanced prostate cancer and to determine the dose-ranging, pharmacodynamic, and pharmacokinetic properties of bicalutamide. To evaluate bicalutamide as a monotherapy or in combination with luteinizing hormone-releasing hormone analogue (LHRH-A) therapy.
Results: Bicalutamide is a potent, nonsteroidal antiandrogen with a plasma half-life consistent with a once-daily schedule. Monotherapy trials with 50 mg of bicalutamide established its intrinsic activity, as demonstrated by subjective and objective responses and decreases in PSA concentrations. In comparison with castration, 50 mg of bicalutamide monotherapy was inferior with respect to survival. In a randomized, double-blind (for antiandrogen therapy) trial, with a median follow-up of 49 weeks, 50 mg of bicalutamide plus an LHRH-A was superior (P = 0.005) to flutamide plus an LHRH-A in delaying time-to-treatment failure and was better tolerated, as was evident from a significantly (P < 0.001) lower incidence of diarrhea and fewer withdrawals for adverse events among bicalutamide-treated patients. With longer follow-up and a 34% mortality, survival was equivalent between groups. Dose-related effects of bicalutamide on serum PSA concentrations were clearly demonstrated in the clinical trial program. With a total exposure of > 2800 patient-years, bicalutamide has been shown to be a well-tolerated therapy with a low incidence of treatment-related withdrawals.
Conclusions: Bicalutamide is a new antiandrogen that offers the convenience of once-daily administration, demonstrated activity in prostate cancer, and an excellent safety profile. Because it is effective and offers better tolerability than flutamide, bicalutamide represents a valid first choice for antiandrogen therapy in combination with castration for the treatment of patients with advanced prostate cancer.