Neoadjuvant Zanzalintinib Plus Nivolumab in Patients With Locally Advanced and/or Inoperable Clear Cell Renal Cell Carcinoma With or Without Non-measurable Metastasis

Inclusion Criteria: 1. Written informed consent and Health Insurance Portability and Accountability Act (HIPAA) authorization for release of personal health information prior to registration. NOTE: HIPAA authorization may be included in the informed consent or obtained separately. 2. Age ≥ 18 years at the time of consent. 3. Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 1 within 30 days prior to registration. 4. Histologically confirmed (i.e., tissue from primary kidney tumor of interest) diagnosis of clear cell renal cell carcinoma with or without sarcomatoid features. NOTE: biopsy should be performed at least 5 days before the first dose of study treatment and must be completely healed before dosing. 5. Locally advanced (cT3/T4, N0-1) OR deemed surgically challenging/inoperable per surgeon discretion. Satisfying either of the criteria allows for enrollment. NOTE: Surgically challenging/inoperable per surgeon discretion is based on one or more of the following, which will be documented on the Surgical Operability and Outcomes Form and evaluated per central surgery review: * cT4 disease * N1 disease * Surgery may be significantly complex and/or significantly affect residual renal function, where neoadjuvant therapy may downsize/downstage primary tumor for maximum renal preservation, including: * IVC tumor thrombus involvement * cT1-3 tumor with pre-surgery calculated creatinine clearance \<60 mL/min per Cockcroft-Gault formula OR solitary kidney (any calculated creatinine clearance), with potential to convert from radical to partial nephrectomy * High complexity on RENAL Nephrometry Score (score ≥ 10) * Other reversible comorbidity(ies) that in the opinion of the surgeon renders the patient surgically challenging/inoperable at baseline, where neoadjuvant therapy and medical optimization may allow subsequent surgery 6. Non-measurable soft tissue metastasis with longest diameter \< 10mm or pathological lymph nodes \< 15 mm in short axis are allowed. 7. Recovery to baseline or Grade ≤ 1 severity (CTCAE v5) from adverse events (AEs) related to any prior treatments, unless AE(s) are clinically nonsignificant and/or stable on supportive therapy (eg, physiological replacement of corticosteroid). Low-grade or controlled toxicities such as alopecia, Grade ≤ 2 hypomagnesemia, Grade ≤ 2 neuropathy are permitted). 8. Adequate organ and marrow function, based upon meeting all the following laboratory criteria within 30 days before first dose of study treatment: * Platelets (Plt): ≥ 100,000 /mm3; without transfusion within 2 weeks of screening laboratory sample collection * Absolute Neutrophil Count (ANC): ≥ 1500 K/mm3; without granulocyte colony-stimulating factor support within 2 weeks of screening laboratory sample collection * Hemoglobin (Hgb): ≥ 9 g/dL; without transfusion within 2 weeks of screening laboratory sample collection * Creatinine OR Calculated creatinine clearance: ≤ 1.5 x ULN OR ≥ 40 mL/min * Urine protein-to-creatinine ratio (UPCR): ≤ 1.5 mg/mg (≤ 169.8 mg/mmol) creatinine * Total bilirubin: ≤ 1.5 × upper limit of normal (ULN); for subjects with Gilbert's disease ≤ 3 x ULN * Aspartate aminotransferase (AST): ≤ 3× ULN * Alanine aminotransferase (ALT): ≤ 3 × ULN * Alkaline Phosphatase (ALP): ≤ 3 × ULN 9. Females of childbearing potential must have a negative urine or serum pregnancy test within 48 hours of Cycle 1 Day 1. If a urine test is done and it is positive or cannot be confirmed as negative, a serum pregnancy test will be required. Female subjects are considered to be of childbearing potential unless one of the following criteria is met: permanent sterilization (hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) or documented postmenopausal status (defined as 12 months of amenorrhea in a woman \> 45 years-of-age in the absence of other biological or physiological causes. For females \< 55 years old, confirmation of menopausal status is per institutional standards. NOTE: documentation may include review of medical records, medical examination, or medical history interview by study site staff. 10. Females of childbearing potential who are sexually active with a male able to father a child must be willing to abstain from penile-vaginal intercourse or must use an effective method(s) of contraception. Males able to father a child who are sexually active with a female of childbearing potential must be willing to abstain from penile-vaginal intercourse or use an effective method(s) of contraception. 11. As determined by the enrolling physician or protocol designee, ability of the subject to understand and comply with study procedures for the entire length of the study. Exclusion Criteria: 1. Non-clear cell histology. 2. Measurable metastatic disease per RECIST 1.1 criteria and other non-measurable lesions including bone metastasis, leptomeningeal disease, lymphangitic involvement of lung or skin, pathologically confirmed-malignant ascites/pleural/pericardial effusion. 3. Prior systemic therapy, including zanzalintinib, nivolumab and other vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs)/immune checkpoint inhibitors(IOs), for the treatment of renal cell carcinoma. 4. Prior surgery and/or radiation to the primary renal cell carcinoma tumor of interest. NOTE: prior surgery and/or radiation to other areas of the kidney (i.e., prior small kidney tumor resection or radiation) is allowed if \> 4 weeks before first dose of study treatment. 5. Concomitant anticoagulation with oral anticoagulants (eg, warfarin, direct thrombin inhibitors) and platelet inhibitors (eg, clopidogrel). NOTE: For prohibited anticoagulants, subjects must have discontinued the anticoagulant within 3 days or 5 half-lives prior to first dose of study treatment, whichever is longer. Allowed anticoagulants are the following: * Prophylactic use of low-dose aspirin for cardio-protection (per l