Vudalimab (XmAb20717) in Combination With Standard of Care Treatment in Patients With Metastatic Castration Sensitive Prostate Cancer

Inclusion Criteria: * Age \>= 18 years * Histologically confirmed adenocarcinoma of the prostate with metastatic disease * Castration-sensitive status: either not have been treated with androgen deprivation therapy (ADT) (hormone therapy) or not on ADT at the time of progression * Participants can have received up to 3 months of ADT with luteinizing hormone-releasing hormone (LHRH) agonists or antagonists or orchiectomy with or without concurrent first-generation antiandrogens prior to enrollment, with no radiographic evidence of disease progression or rising prostate-specific antigen (PSA) prior to enrollment * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 (Karnofsky \>= 60%) * Life expectancy \> 12 weeks as determined by the investigator * Hemoglobin \>= 9.0 g/dl (within 28 days of cycle 1 day 1) (no transfusions allowed within 7 days of Cycle 1 Day 1 to meet entry criteria) * White blood cell (WBC) \>= 2000/uL (within 28 days of cycle 1 day 1) (after at least 7 days without growth factor support or transfusion) * Absolute neutrophil count (ANC) \>= 1,500/mcL (within 28 days of cycle 1 day 1) (after at least 7 days without growth factor support or transfusion) * Platelets \>= 100,000/mcL (within 28 days of cycle 1 day 1) (no transfusions allowed within 7 days of cycle 1 day 1 to meet entry criteria) * Prothrombin time (PT)/ partial thromboplastin time (PTT) =\< 1.5 x upper limit of normal (ULN) (within 28 days of cycle 1 day 1) * Total bilirubin =\<…