IDUA and Ewing sarcoma: SOC was defined as treatment routinely used in a tumor type or treatment reported to have proven clinical activity, for example, irinotecan (IRN) or temozolomide (TMZ) for relapsed Ewing’s sarcoma (EWS) and FLAG-Ida (fludarabine, cytarabine, idarubicin, granulocyte-colony stimulating factor) for relapsed acute leukemia.