Axitinib +/- Pembrolizumab in First Line Treatment of mPRCC

This study is testing whether adding the immunotherapy drug pembrolizumab to axitinib (a targeted anti-cancer drug) can improve treatment outcomes for people with advanced papillary renal cell carcinoma (type 2 or mixed PRCC) — a less common type of kidney cancer — compared to axitinib alone. **You may be eligible if...** - You have been diagnosed with metastatic or locally advanced type 2 or mixed papillary renal cell carcinoma, confirmed by central laboratory review - You have not had any prior systemic treatment for kidney cancer - Your cancer has at least one measurable tumor on scans - You are 18 or older in reasonably good physical health (ECOG ≤ 1) - Your blood, kidney, and liver function are within acceptable ranges **You may NOT be eligible if...** - You have received any prior systemic treatment for this kidney cancer - You have active autoimmune disease requiring systemic treatment - You are pregnant or breastfeeding - You have active brain metastases - You have significant heart or liver disease Talk to your doctor to see if this trial is right for you.