An Efficacy and Safety Study of JNJ-56021927 (Apalutamide) in High-risk Prostate Cancer Subjects Receiving Primary Radiation Therapy: ATLAS

The purpose of this study is to determine if apalutamide plus gonadotropin releasing hormone (GnRH) agonist in participants with high-risk, localized or locally advanced prostate cancer receiving primary radiation therapy (RT) results in an improvement of metastasis-free survival (MFS) based on conventional imaging assessed by blinded independent central review (BICR).

Inclusion Criteria: * Age \>= 18 years * Indicated and planned to receive primary radiation therapy for prostate cancer * Histologically confirmed adenocarcinoma of an intact prostate, and 1 of the following at diagnosis: 1) Gleason score \>=8 and \>=cT2c, 2) Gleason score 7, PSA \>=20 nanogram per milliliters (ng/mL), and \>=cT2c * Charlson index (CCI) \3 months prior to randomization * Bilateral orchiectomy * History of pelvic radiation * Prior systemic (example \[e.g.\], chemotherapy) or local (e.g. radical prostatectomy, cryotherapy) treatment for prostate cancer * History of seizure or any condition that may predispose to seizure (including, but not limited to prior stroke, transient ischemic attack or loss of consciousness \