A drug used to treat prostate cancer that has spread to other parts of the body. It is used in patients who have had surgery to remove the testicles (orchiectomy). Nilandron binds to proteins called androgen receptors, which are found in some prostate cancer cells, and keeps androgens (male hormones) from binding to the receptors. This blocks the ability of androgens to cause prostate cancer cells to grow. Nilandron is a type of antiandrogen. Also called nilutamide.