Inclusion Criteria:
* 1\. The subject or their legal representative must sign the written informed consent before enrollment.
2\. Age ≥ 8 years and ≤ 40 years, both male and female are eligible. 3. Pathologically confirmed Ewing's sarcoma, and detailed pathological reports must be provided. Pathology must be confirmed by fluorescence in situ hybridization (FISH) or next-generation sequencing (NGS) to show the presence of Ewing's sarcoma-specific FET family (including EWSR1 or FUS) gene breaks. This study does not impose special restrictions on fusion partner genes, but clear FET-non ETS fusions (such as EWSR1-WT1, EWSR1-NFATC2, EWSR1-PATZ1, etc.) do not meet the enrollment criteria.
4\. At least one measurable target lesion as judged by RECIST 1.1 criteria. 5. Failure of first-line standard treatment. First-line standard treatment includes the following drugs: doxorubicin, cyclophosphamide and/or ifosfamide. Treatment failure is defined as disease progression during adjuvant chemotherapy or within 6 months after chemotherapy. For disease progression more than 6 months after chemotherapy, the consent of the subject or their legal representative is required.
6\. ECOG score: 0-1. 7. Expected survival ≥ 3 months. 8. Recovery from previous treatment: According to NCI-CTCAE 5.0, all side effects (except alopecia) must have subsided to grade 1 or below.
9\. Normal major organ function, meeting the following criteria:
1\) Blood routine examination must meet the following criteria (no blood transfusion, no use of hematopoietic factors, and no drug correction within 14 days):
1. ANC ≥ 1.5×109/L;
2. HB ≥ 90 g/L;
3. PLT ≥ 100×109/L; 2) Biochemical examination must meet the following criteria:
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1. TBIL ≤ 1.5 ULN;
2. ALT, AST ≤ 2.5 ULN (if liver function abnormalities are due to liver metastasis, then ≤ 5 ULN);
3. Serum creatinine sCr ≤ 1.5 ULN, endogenous creatinine clearance rate ≥ 50 ml/min (Cockcroft-Gault formula); 3) Coagulation function must meet the following criteria: INR ≤ 1.5 and APTT ≤ 1.5 ULN.
10\. Women of childbearing age must have taken reliable contraceptive measures or undergone a pregnancy test (serum or urine) within one week before enrollment, with a negative result, and be willing to use appropriate contraceptive methods during the trial and for 8 weeks after the last administration of the investigational drug. For men, they must agree to use appropriate contraceptive methods during the trial and for 8 weeks after the last administration of the investigational drug or have undergone surgical sterilization.
Exclusion Criteria:
* 1\. Known hypersensitivity, anaphylaxis or intolerance to irinotecan liposome, temozolomide and vincristine or their excipients; 2. Within 2 weeks after the last systemic cytotoxic drug treatment, radiotherapy, targeted therapy or any anti-tumor drug treatment except immunotherapy; 3. Patients who have received irinotecan treatment before; 4. Other malignant tumors within the past 5 years; 5. Known symptomatic central nervous system metastases; 6. Known symptomatic brain metastases, spinal cord compression, carcinomatous meningitis, or unstable brain or leptomeningeal disease found on CT or MRI at screening; 7. Symptomatic serous cavity effusion (including pleural effusion, ascites, pericardial effusion) requiring surgical intervention; 8. Uncontrolled concomitant diseases, including but not limited to: poorly controlled hypertension, heart failure, diabetes, persistent active infection, poorly controlled active peptic ulcer, or mental disorders or social conditions that may affect the subject's compliance with the study; 9. Abnormal coagulation function (INR \> 1.5 or prothrombin time (PT) \> ULN + 4s or APTT \> 1.5 ULN), with bleeding tendency or receiving thrombolytic or anticoagulant therapy; 10. Treatment with anticoagulants or vitamin K antagonists such as warfarin, heparin or similar drugs; Note: Under the condition of INR ≤ 1.5, low-dose heparin (adult daily dose of 6,000 - 12,000 U), low-dose aspirin (daily dose ≤ 100 mg), or rivaroxaban (daily dose ≤ 10 mg) for preventive purposes is allowed; 12. History of drug abuse of psychotropic drugs and unable to quit or with mental disorders; 13. Known hereditary or acquired bleeding and thrombotic tendencies (such as hemophilia, coagulation disorders, thrombocytopenia, hypersplenism, etc.); 14. Open wounds, fractures, or poorly healing wounds; 15. Major surgery within 2 weeks; 16. Confirmed inflammatory bowel disease, intestinal obstruction or chronic diarrhea; 17. Cavity organ fistula or perforation within 6 months; 18. Active hepatitis B or C virus infection or active infection requiring antimicrobial treatment (such as the use of antibacterial drugs, antiviral drugs, antifungal drugs); 19. Participation in other interventional anti-tumor clinical trials within 4 weeks; 20. Patients who have used strong CYP3A4 inducers or strong CYP3A4 inhibitors or strong UGT1A1 inhibitors within 3 weeks before the first dose; 21. Lactation; 22. Any condition that the investigator deems may harm the patient or prevent the patient from meeting or fulfilling the study requirements.
