• Age 2-21 (at the time of diagnosis), no gender limit.

• After biopsy or surgery, the first postoperative pathological diagnosis is medulloblastoma.

• The recurrence of the tumor is confirmed by MRI, that is, the diameter of the lesion on the enhanced MRI image is ≥1cm, and ≥2 slices (slice spacing 5mm) are visible; or after another biopsy or surgery, the pathological diagnosis is medulloblastoma.

• The time interval from the last radiotherapy is ≥4 weeks.

• The time interval from the last chemotherapy is ≥4 weeks, and the patients have fully recovered from the acute toxicity of the last treatment. If you receive nitrosourea chemotherapeutics before enrollment, the interval between enrollment and the last chemotherapy is ≥6 weeks.

• The interval between the last biopsy or surgery is ≥2 weeks.

• KPS score ≥50 (patient\> 12 years old), or Lansky score ≥ 50 (patient ≤ 12 years old).

• If the patient is taking glucocorticoid therapy, the hormone dosage has stabilized or decreased for at least 1 week before the baseline MRI.

• The expected survival time is ≥12 weeks.

⁃ The main organ functions are normal, and there is no serious blood, heart, lung, liver, kidney dysfunction and immune deficiency diseases. The laboratory inspection meets the following requirements:

‣ (1) Routine blood examination, which must be met (no blood transfusion within 14 days):

• HGB≥100g/L;

• WBC≥3.0×109/L; NEUT≥1.5×109/L;

• PLT ≥100×109/L; (2) The biochemical inspection shall meet the following standards:

‣ a. BIL≤1.5 times the upper limit of normal (ULN); b. ALT and AST≤2.0×ULN; c. Serum Cr≤1.5×ULN or endogenous creatinine clearance ≥50ml/min (Cockcroft-Gault formula); (3) Occult blood in stool (-); (4) Urine routine is normal, or urine protein \<(++), or 24-hour urine protein \<1.0 g; 11. The ECG shows that the heart rate is in the normal range (55-100 beats/min), the QT interval is normal or slightly prolonged (QTc\<480ms), the T wave is normal or low, and the ST segment is normal or non-specific changes.

‣ 12\. The coagulation function is normal, without active bleeding and thrombosis.

• International standardized ratio INR≤1.5×ULN;

• Partial thromboplastin time APTT≤1.5×ULN;

• Prothrombin time PT≤1.5ULN. 13. Female patients of childbearing age must undergo a negative pregnancy test (serum or urine) within 7 days before enrollment, and voluntarily use appropriate methods of contraception during the observation period and within 8 weeks after the last administration; male patients of childbearing age should agree to During the observation period and within 8 weeks after the last administration, use appropriate methods of contraception.

• 14\. Patients voluntarily provide 25-30 slices of tumor tissue after the last biopsy or surgery.

• 15\. The patient has normal swallowing function and can swallow capsules. 16. The patient voluntarily joined the study and signed an informed consent form (ICF).

• 17\. Those who are expected to have good compliance can follow up the efficacy and adverse reactions as required by the plan.