RecruitingPhase 2Drug trialClinical Study in Adult and Young Adult Patients With Advanced Desmoplastic Small Round Cell Tumor (DSRCT) ISG-TULIPSPatients participating in this study have DSRCT that has spread locally or to other parts of the body and can no longer be surgically removed without causing significant harm. Treatment will continue until the tumor progresses further, severe side effects occur, or either patient or investigator decision. In addition, patients may participate in an optional biological study. The study will analyze the tumor's genes and the molecules related to them. By studying genes and their products, the investigators can better understand the behavior of the tumor and how the body responds to therapies.