Study of Nivolumab and Ipilimumab in Children and Young Adults With INI1-Negative Cancers

This research study is a Phase II clinical trial, which tests the safety and effectiveness of an investigational drug or drug combination to learn whether the drug or drug combination works in treating a specific disease. "Investigational" means that the drug combination is being studied. The names of the study drugs involved in this study are: * Nivolumab (OPDIVO) * Ipilimumab (YERYOY) This trial is studying whether nivolumab and ipilimumab work to treat INI1-negative cancers. The U.S. Food and Drug Administration (FDA) has not approved combination nivolumab and ipilimumab for the specific diseases in this study but it has been approved for other diseases. Nivolumab and ipilimumab have been tested in children to find out a safe dose of this combination.