This clinical trial focuses on treating patients with Ewing Sarcoma that has either come back after treatment or did not respond to initial treatment. The study tests several chemotherapy medications including gemcitabine, docetaxel, irinotecan, temozolomide, topotecan, carboplatin, cyclophosphamide, ifosfamide, etoposide, and lenvatinib. The purpose is to determine which treatment combination works best in terms of effectiveness and side effects.

The treatment involves different combinations of these medications given either through an intravenous infusion into a vein or as oral capsules taken by mouth. Some medications are given daily while others are administered on specific days during treatment cycles that typically last several weeks. The total treatment duration may continue for up to 104 weeks depending on how well the treatment works.

Throughout the study, doctors will monitor the size of tumors using imaging scans to check if the treatment is working. They will also track any side effects and how long patients stay in the hospital. The study measures how long patients live without their disease getting worse and their overall survival time. Additionally, patients’ quality of life will be evaluated during the treatment period.