2. PSA ≥ 4.0 ng/mL. 3. Testosterone level ≤ 100 ng/dL. 4. More than 1 month of prior hormone exposure or hormone exposure within 30 days of enrollment (up to 1 month of prior LHRH agonist and/or anti-androgen therapy as neoadjuvant therapy prior to prostatectomy is allowed). Prior enzalutamide, apalutamide, ketoconazole, abiraterone, or TAK700 prohibited. Prior antiandrogen therapy (including but not limited to bicalutamide, flutamide, nilutamide, enzalutamide, and apalutamide) and prior estrogen therapy are not allowed. All investigational agents are prohibited within 30 days of enrollment.