MONOTHERAPY WITH NILUTAMIDE, A PURE NONSTEROIDAL ANTIANDROGEN, IN UNTREATED PATIENTS WITH METASTATIC CARCINOMA OF THE PROSTATE

A total of 26 previously untreated patients with metastatic carcinoma of the prostate received the pure nonsteroidal antiandrogen nilutamide as a single agent. Objective response rate was 38.5 +/- 18.7% (95% confidence interval). Median progression-free survival and median survival were 9 and 23 months, respectively. Of 13 patients with progression on antiandrogen 5 showed an additional objective response to a second-line endocrine treatment. The drug was generally well tolerated, except for 2 patients who discontinued treatment because of moderate gastrointestinal symptoms. Approximately a third of the patients complained of decreased adaptation to darkness. An electroretinogram and dark adaptation test revealed the presence of functional damage and visual complaints reversed in all patients on cessation of therapy. The other most frequent side effects were slight nausea (26.9% of the patients) and alcohol intolerance (19.2%). A nonsignificant increase in testosterone levels was shown within 1 month of treatment, after which the levels remained stable. Approximately half of the sexually active men claimed maintenance of libido and sexual potency during treatment. A slightly significant increase in hemoglobin was observed during the long term, suggesting the occurrence of a trophic effect by androgens on erythropoiesis. The results indicate that nilutamide as a single agent has an acceptable toxicity and a moderate activity, and may maintain sexual interest in a discrete number of cases. Whether monotherapy with nonsteroidal antiandrogens offers a valid option in the palliation of advanced disease remains to be seen in comparative prospective trials.