Phase II study of the pure non-steroidal antiandrogen nilutamide in prostatic cancer. Italian Prostatic Cancer Project (PONCAP).

The activity of the pure non-steroidal antiandrogen nilutamide as a single agent was evaluated in 44 patients with metastatic carcinoma of the prostate. Objective (partial) response rates (95% confidence limits) were 38.5 (18.7)% in 26 previously untreated patients and 5.5 (11%) in 18 patients progressing on primary androgen suppressive procedures. The most frequent side-effects were decreased adaptation to darkness (29.5%), slight nausea (31.8%) and alcohol intolerance (18.2%). In addition, treatment was discontinued in 3 patients because of gastrointestinal symptoms. A non-significant increase in testosterone levels was shown in the untreated group during the first month of treatment, after which the levels remained stable. About half of the sexually active men claimed the maintenance of libido and sexual potency during treatment. Although our study confirms a significant incidence of visual disturbances, the activity data coupled with the ability of maintaining sexual interest suggest that single therapy with non-steroidal antiandrogens may deserve comparison to conventional endocrine treatment in controlled trials.