Nivolumab + Ipilimumab With Immunostimulatory Embolization for Stage 4 Renal Cell Carcinoma With Unresected Primary

Inclusion Criteria: 1. Metastatic renal cell carcinoma with unresected primary tumor or with metastasis amenable to embolization. 2. No prior immune checkpoint therapy 3. Primary tumor or metastasis amenable to percutaneous embolization per review by the treating interventional oncologist · Patent feeding artery to tumor \> 2 mm diameter without macroscopic arteriovenous fistula/shunt 4. Additional metastatic site \> 1 cm assessable for response by RECIST 1.1 5. Adequate organ function by screening laboratory studies within 30 days of embolization * platelets \> 50K, correctable by transfusion * INR \< 1.5, correctable by transfusion * creatinine \< 2.0 6. ECOG performance status 0-2 7. Age ≥ 18 years 8. Have signed the current approved informed consent form and be willing and able to comply with this protocol 9. Women of childbearing potential (WOCBP) must use appropriate method(s) of contraception. WOCBP should use an adequate method to avoid pregnancy for 5 months after the last dose of study drug 10. Women of childbearing potential must have a negative serum or urine pregnancy test 11. Men who are sexually active with WOCBP must use any contraceptive method with a failure rate of less than 1% per year Men receiving nivolumab and who are sexually active with WOCBP will be instructed to adhere to contraception for a period of 7 months after the last dose Exclusion Criteria: 1. Untreated CNS metastasis 2. Autoimmune disorder; subjects are permitted to enroll if they have vitiligo, type I diabetes mellitus, residual hypothyroidism due to autoimmune condition only requiring hormone replacement, psoriasis not requiring systemic treatment 3. Immunodeficiency syndrome 4. Glucocorticoid (\> 10 mg daily prednisone equivalents) or immunosuppressant therapy 5. Active infection requiring systemic therapy 6. Any other medical or personal condition that, in the opinion of the site investigator, may potentially compromise the safety or compliance of the patient, or may preclude the patient's successful completion of the clinical trial. 7. Positive test for hepatitis B virus surface antigen (HBV sAg) or hepatitis C virus ribonucleic acid (HCV antibody) indicating acute or chronic infection 8. Contrast allergy not mitigated by usual prophylaxis