Study of Abiraterone Acetate or Enzalutamide, Atezolizumab, GnRH Analog and Radiation Therapy in Men With Newly Diagnosed Hormone-sensitive Prostate Cancer

Inclusion Criteria: * Willing and able to provide or have a legally authorized representative to provide written informed consent and HIPAA authorization for the release of personal health information. A signed informed consent must be obtained before screening procedures are performed. NOTE: HIPAA authorization may be either included in the informed consent or obtained separately. * Males 18 years of age and above * Untreated metastatic (M1a/b/c) hormone-sensitive prostate cancer documented by positive bone scan or metastatic lesion on CT or MRI; untreated is defined as having never received surgical, radiotherapeutic, or systemic therapy to the prostate for cancer for their prostate cancer. Note, 10 subjects who have had prior hormonal therapy (GnRH analog +/- first-generation anti-androgen such a bicalutamide) started up to 3 months prior to signing consent to the trial will be permitted to enroll onto the study if they have demonstrated a decline in PSA. Anti-androgens must be stopped prior to Cycle 1. Note: patients who have started bicalutamide (Casodex) with or without a GnRH analog must stop prior to being registered on trial * Biopsy-proven adenocarcinoma of the prostate * Eligible for SBRT per institutional guidelines * ECOG status of 0 or 1 * Normal organ function with acceptable initial laboratory values within 14 days of treatment start: ANC ≥ 1,500 /µl Lymphocyte count ≥ 0.5 x 109/L (500/µL) Albumin ≥ 3.5 g/dL Hemoglobin ≥ 9 g/dL Platelet count ≥ 100,000 …