Testing the Investigational Medication Pembrolizumab After Kidney Removal for Patients With Non-Clear Cell Renal Cell Carcinoma

Inclusion Criteria: * Patient must be ≥ 18 years of age * Patient must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 * Patient must have histologically confirmed non-clear cell renal cell carcinoma (nccRCC) with ≥ pT3Nx or pTanyN+ or pTanyNanyM1 with no evidence of disease (NED) per the American Joint Committee on Cancer (AJCC) 8th edition * Patient must not have renal medullary carcinoma * Patient must have had a partial or radical nephrectomy. In the case of patients with M1 NED status, a complete resection of the metastatic lesion(s) (metastasectomy) must have been completed at the time of nephrectomy or within 1 year after nephrectomy * Positive margins are allowed as long as no gross disease * Patient must not have residual thrombus post nephrectomy in the vena renalis or vena cava * Patient must be randomized ≤ 16 weeks after nephrectomy and/or \< 16 weeks after metastasectomy * Patient must have undergone imaging of chest, abdomen and pelvis with a CT or MRI after nephrectomy/metastasectomy and within 42 days prior to randomization documenting there is no evidence of liver, bone, or brain metastases * Patient must not have received any prior anti-PD-1/PD-L1 or CTLA-4 agents * Patient must not have received any prior radiotherapy for nccRCC * Patient must not have received prior systemic treatment for nccRCC (except nephrectomy or metastasectomy). Patient must not have received prior immune checkpoint inhibitor agents for other cancers …