Clinical benefits of bicalutamide compared with flutamide in combined androgen blockade for patients with advanced prostatic carcinoma: final report of a double-blind, randomized, multicenter trial. Casodex Combination Study Group.

OBJECTIVES

To compare the efficacy and tolerability of bicalutamide and flutamide, each combined with luteinizing hormone-releasing hormone analogue (LHRH-A) therapy, in patients with metastatic (Stage D2) prostate cancer.

METHODS

This was a randomized, double-blind (for antiandrogen therapy), multicenter study with a two-by-two factorial design. Eight hundred thirteen patients were allocated 1:1 to bicalutamide (50 mg once daily) and flutamide (250 mg three times daily) and 2:1 to goserelin acetate (3.6 mg every 28 days) and leuprolide acetate (7.5 mg every 28 days).

RESULTS

The median times to progression and death were 97 and 180 weeks for the bicalutamide plus LHRH-A group compared with 77 and 148 weeks for the flutamide plus LHRH-A group. The hazard ratio for time to progression for bicalutamide plus LHRH-A to flutamide plus LHRH-A was 0.93 (95% confidence interval [CI] 0.79 to 1.10, P = 0.41) and that for survival time was 0.87 (95% CI 0.72 to 1.05, P = 0.15). The therapies were generally well tolerated. The most common adverse event in the two groups was hot flashes. The incidence of hematuria was significantly higher for the bicalutamide plus LHRH-A group than for the flutamide plus LHRH-A group (12% versus 6%, P = 0.007), but no patient withdrew from therapy because of hematuria. There was a significantly (26% versus 12%, P < 0.001) higher incidence of diarrhea and more withdrawals for diarrhea (25 patients versus 2) for the flutamide plus LHRH-A group relative to the bicalutamide plus LHRH-A group.

CONCLUSIONS

With a median follow-up time of 160 weeks, the combination of bicalutamide plus LHRH-A was well tolerated and had equivalent time to progression and survival compared with flutamide plus LHRH-A. Treatment with bicalutamide plus LHRH-A resulted in longer median survival than treatment with flutamide plus LHRH-A.