Cabozantinib and Atezolizumab for the Treatment of Metastatic Castration-Resistant Prostate Cancer

Inclusion Criteria: * Male subject aged \>= 18 years * Histologically or cytologically confirmed prostatic adenocarcinoma without small cell histology * Metastatic disease progression after continuous androgen deprivation therapy for hormone sensitive state * Patient must have non-measurable disease outside the pelvis (above aortic bifurcation) per RECIST 1.1 criteria. Non-measurable disease can be bone lesions and/or extraskeletal disease * Disease progression on or after at least one prior novel hormonal therapy (NHT) (defined as second-generation antiandrogen therapies that include but are not limited to abiraterone acetate, enzalutamide, apalutamide, darolutamide) * Eastern Cooperative Oncology Group (ECOG) performance Status =\< 2 * Effective castration with serum testosterone levels =\< 0.5 ng/mL (=\<1.7 nmol/L) * Tumor tissue available (archival or recent tumor biopsy). If no tumor tissue is available, patients can be enrolled after approval from Principal Investigator. * Absolute neutrophil count (ANC) \>= 1500/mm\^3 without granulocyte colony-stimulating factor support * White blood cell count \>= 2500/uL * Lymphocyte count \>= 0.5 x 10\^9/L (500/uL) * Platelet count \>= 100,000/mm\^3 without transfusion in the 2 weeks prior to cycle 1 day 1 (C1D1) * Hemoglobin \>= 9 g/dL * Serum albumin \>= 2.5 g/dl * For patients not receiving therapeutic anticoagulation: prothrombin time (PT)/International normalized ratio (INR) or partial thromboplastin time (PTT) test \< 1.5 x …