A Study of Sasanlimab, Palbociclib and Axitinib in Metastatic Renal Cell Carcinoma

Inclusion Criteria: * Histologically or cytologically confirmed unresectable advanced or metastatic renal cell carcinoma with a clear cell component or translocation renal cell carcinoma. Patients with clear cell carcinoma and sarcomatoid histology are eligible. * a. For tRCC please refer to the following for eligibility definitions: * i. TFE3 (Xp11.2) translocation RCC: confirmed by IHC; however, FISH should be utilized if IHC is not optimal (ie, conclusive) or unavailable. * ii. TFEB rearranged RCC: confirmed by FISH; TFEB amplified tumors are excluded. * b. A formalin-fixed, paraffin-embedded (FFPE) tumor tissue block from a de novo tumor biopsy obtained during screening will be required (biopsied tumor lesion should not be a RECIST target lesion). Alternatively, a recently obtained archival FFPE tumor tissue block (not cut slides from a primary or metastatic tumor resection or biopsy) can be provided if the following criteria are met: * i. The biopsy or resection was performed within 1 year of registration AND * ii. The patient has not received any intervening systemic anti-cancer treatment from the time the tissue was obtained and registration onto the current study. If an FFPE tissue block cannot be provided as per documented regulations then 15 unstained slides (10 minimum) will be acceptable * c. Availability of an archival FFPE tumor tissue block from primary diagnosis specimen (if available and not provided per above). If an FFPE tissue block cannot be provided as per documented regulations, then 15 unstained slides (10 minimum) will be acceptable. * Measurable disease as per RECIST 1.1. See Section 11 for the evaluation of measurable disease. * Age ≥ 18 years. * ECOG performance status ≤2 (Karnofsky ≥60%, see Appendix A). * Normal organ and marrow function as defined below: * a. Absolute neutrophil count ≥1.5×109/L * b. Platelets ≥100×109/L * c. Hemoglobin ≥9g/dL (RBC transfusions allowed) * d. Total bilirubin ≤ 1.5 × institutional upper limit of normal (ULN) with the following exception: patients with known Gilbert disease should have a total serum bilirubin ≤ 3 x ULN * e. AST(SGOT)/ALT(SGPT) ≤1.5 × ULN * f. Creatinine clearance ≥30 mL/min according to the CKD-EPI equation. (APPENDIX C) * g. Urine protein \<1+ by urinalysis; If ≥1+ protein or otherwise suggestive of any proteinuria above a trace amount (per local institutional standards), a random urine protein and creatinine ratio (UPCR) should be collected. A 24-hour urine collection can also be utilized for direct measurement. When multiple modalities are used, the 24-hour urine measurement takes precedence over the random UPCR; refer to section 6.2 for further guidance. * Women of child-bearing potential and men must agree to use adequate contraception (intrauterine device or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. If condoms are used as a barrier method, a spermicidal agent should be added as a double barrier protection. A negative pregnancy serum test should be obtained within 7 days of therapy initiation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she must discontinue treatment immediately. Data on fetal outcome and breast-feeding are to be collected for regulatory reporting and drug safety evaluation. Participants treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 90 days after completion of sasanlimab, axitinib and palbociclib administration. * Ability to swallow oral medications. * Ability to understand and willingness to sign a written informed consent document. Exclusion Criteria: * Treatment with the following prior therapies: * a. Prior systemic therapy for advanced or metastatic RCC. * b. Prior adjuvant or neoadjuvant therapy for RCC if disease progression or relapse has occurred within 12 months of last dose of such therapy. Treatment with an immune checkpoint inhibitor in the adjuvant setting is allowed providing more than 12 months have elapsed since last dose or completion of therapy. * c. Prior treatment with any immunotherapeutic agent (IL-2, IFN-α, anti-PD(L)-1, anti-CTLA-4, or any other antibody or drug targeting T-cell co-stimulation or immune checkpoint pathways). * d. Prior therapy with axitinib or other therapies targeting VEGF pathway in the metastatic setting (adjuvant therapy is allowed). e. Prior therapy with any CDK4/6 inhibitor. * Participants with untreated brain metastases. Participants with metastatic CNS tumors may participate in this trial, if the participant is ≥ 4 weeks from therapy completion (incl. radiation and/or surgery), is clinically stable at the time of study entry and is not receiving corticosteroid therapy \>10 mg/day prednisone equivalents. A repeat MRI or CT brain to show stability is required. * Wide field radiation therapy ≤ 2 weeks prior to treatment start. Prior palliative radiotherapy to metastatic non-target lesion(s) is permitted if completed at least 48hrs prior to patient registration. * Untreated deep vein thrombosis or pulmonary embolism, or event of deep vein thrombosis or pulmonary embolism within 2 weeks of treatment start. Patient should be on at least 1 week of anticoagulation before C1D1. * Major surgery/surgical procedures within the past 4 weeks prior to registration. * The patient has serious and/or uncontrolled preexisting medical condition(s) that, in the judgment of the investigator, would preclude participation in this study (for example, interstitial lung disease - also see 3.2.22, severe dyspnea at rest or requiring oxygen therapy, severe renal impairment \[e.g. estimated creatinine clearance \<30ml/min\], history of major surgical resection involving the stomach or small bowel, or preexisting Crohn's disease or ulcerative colitis or a preexisting chronic c