A phase 3 randomized, placebo-controlled double-blind study of JNJ-56021927 in combination with a GNRH Agonist versus GNRH Agonist plus placebo in subjects with high-risk localized or locally advanced prostate cancer and treated with primary radiation therapy. The purpose of this study is to determine if JNJ-56021927 plus gonadotropin releasing hormone (GnRH) in participants with high-risk, localized or locally advanced prostate cancer receiving primary radiation therapy results in an improvement of metastasis-free survival.