Tazemetostat+Nivo/Ipi in INI1-Neg/SMARCA4-Def Tumors

This study is testing a combination of two immune-boosting drugs — tazemetostat and nivolumab/ipilimumab — for rare and aggressive tumors that are missing a protein called INI1 or SMARCA4. These are typically very hard-to-treat childhood and adult cancers. **You may be eligible if...** - You or your child has been diagnosed with a tumor confirmed to lack INI1 or SMARCA4 (e.g., atypical teratoid rhabdoid tumor, malignant rhabdoid tumor, kidney rhabdoid tumor, epithelioid sarcoma, chordoma, or similar) - The tumor has been assessed at diagnosis or relapse - Standard treatments have not worked or are not available **You may NOT be eligible if...** - The tumor does not have the required molecular marker (INI1-negative or SMARCA4-deficient) - You have certain other serious health conditions Talk to your doctor to see if this trial is right for you.