CBM588 Capsules in Combination With Nivolumab and Ipilimumab for the Treatment of Advanced Stage Kidney Cancer

This study is testing whether adding a probiotic capsule (CBM588, a beneficial gut bacteria supplement) to a standard immunotherapy combination (nivolumab and ipilimumab) improves outcomes for people with advanced kidney cancer. Researchers believe the gut microbiome may affect how well immunotherapy works. **You may be eligible if...** - You are 18 or older - You have been diagnosed with advanced or metastatic kidney cancer (specifically clear cell or sarcomatoid type) - You have not previously received systemic (full-body) treatment for kidney cancer - Your cancer is classified as intermediate- or poor-risk - Your blood counts and organ function meet specific healthy thresholds **You may NOT be eligible if...** - You have previously received nivolumab or ipilimumab - You eat probiotic foods (yogurt, probiotic supplements) or plan to during treatment - You have active lung inflammation, autoimmune disease (with some exceptions), or serious infections - Cancer has spread to the brain (unless already treated and stable) - You are pregnant or breastfeeding - You cannot swallow capsules or receive IV infusions Talk to your doctor to see if this trial is right for you.