CAR T cell therapy for children with relapsed B-cell leukemia

Inclusion Criteria:

1, age 3-18 years old (including boundary value), male and female;

2\. The patient was clinically diagnosed as relapsed/refractory B acute lymphoblastic leukemia/lymphoblastic lymphoblastic

Patients with tumors who meet one of the following conditions:

• Complete marrow response (MRD\>1%) or not achieved after at least 2 courses of standardized induction regimen chemotherapy

Complete response at the molecular level and immunology (characterized by specific molecular markers and immunophenotypes prior to treatment)

Patients, did not turn negative after treatment);

* Recurrence during chemotherapy, early recurrence after drug withdrawal (\<12 months) or late recurrence after complete remission (≥

  12 months) and did not achieve complete remission after 1 course of standard induction regimen (MRD\>1%);
* Recurrence after bone marrow transplantation;
* Simple bone marrow, simple extramedullary (testicular leukemia, central nervous system leukemia) or combined

recrudescence

3\. Lansky score ≥60;

4, the treatment related antigen test result is positive (CD19/CD20/CD22);

5\. The expected survival period from the signing date of the informed consent is more than 3 months;

6, HGB≥70g/L (blood transfusion);

7, liver and kidney function, cardiopulmonary function meet the following requirements:

1. Creatinine ≤1.5×ULN;
2. Left ventricular ejection fraction ≥50%;
3. Blood oxygen saturation \>90%;
4. Total bilirubin ≤1.5×ULN; ALT and AST≤2.5 x ULN.-

   Exclusion Criteria:
   * 1, severe cardiac insufficiency, left ventricular ejection fraction \<50%;

     2, have a history of severe lung function impairment;

     3\. Combined with other advanced malignant tumors;

     4, combined with serious infection and can not be effectively controlled;

     5, combined with serious autoimmune disease or congenital immune deficiency;

     6, active hepatitis (hepatitis B virus deoxyribonucleic acid \[HBVDNA\] or hepatitis C virus ribonucleic acid \[HCVRNA\] positive);

     7, human immunodeficiency virus (HIV) infection or known acquired immunodeficiency syndrome (AIDS), or syphilis infection;

     8\. Have a history of severe allergy to biological products (including antibiotics);

     9\. Patients with allogeneic hematopoietic stem cell transplantation still had acute graft-versus-host response (GvHD) one month after immunosuppressant discontinuation;

     10, the presence of other serious physical or mental illnesses or abnormalities in laboratory tests that may increase the risk of participating in the study or interfere with the study results, as well as patients deemed unsuitable for participation in the study by the investigator.