Background: Non-clear cell renal cell carcinomas (nccRCC) are a heterogeneous group of tumors accounting for approximately 25% of RCC patients (pts.). Since most clinical trials focus on clear-cell RCC (ccRCC) only, data on treatment strategies for nccRCC are limited. The combination of Nivolumab and Ipilimumab (IO/IO) has recently been approved for treatment in RCC showing a significant improvement in overall response rate (ORR), progression free (PFS), and overall survival (OS) in intermediate and high-risk pts. compared to sunitinib in a phase-III trial. Furthermore retrospective analysis in nccRCC patients have shown promising results for IO/IO as well in these entities. Methods: In this prospective randomized phase-II multicenter European trial adults with advanced or metastatic nccRCC without prior systemic therapy are eligible. Other key inclusion criteria include: available tumor tissue, Karnofsky > 70% and measurable disease per RECIST 1.1. All histological diagnoses are reviewed by a central pathologist. The study plans to randomize ~306 pts. stratified for papillary or non-papillary non-clear cell histology and by the International Metastatic RCC Database Consortium (IMDC) risk score. Pts. will be randomized 1:1 to either i) Nivolumab 3mg/kg intravenously (IV) plus Ipilimumab 1mg/kg IV every 3 weeks for 4 doses followed by Nivolumab fixed dose 240mg IV every 2 weeks or ii) standard of care therapy according to the approved schedule. Treatment will be discontinued in case of unacceptable toxicity or withdrawal of informed consent. Pts may continue treatment beyond progression, if clinical benefit is achieved and treatment is well tolerated. Primary endpoint is the OS rate at 12 months. Secondary endpoints include OS rate at 6 and 18 months, median OS, PFS, ORR and quality of life. The trial is in progress and 122 patients (78 pts with papillary, 37 pts with non-papillary histology) have been enrolled until now. Clinical trial information: NCT03075423.