This is an open, single-arm, clinical study to evaluate efficacy and safety of anti CD22 CAR-T cell in the treatment of recurrent or refractory B-ALL

The CARs consist of an anti-CD22 single-chain variable fragment（scFv）, a portion of the human CD137（4-1BB） molecule, and the intracellular component of the human CD3ζ molecule. Prior to CAR-T cell infusion, the patients will be subjected to preconditioning treatment. After CAR-T cell infusion, the patients will be evaluated for adverse reactions and efficacy.

The Main research objectives:

To evaluate the safety and efficacy of CD22CAR-T in patients with recurrent or refractory B-ALL

The Secondary research objectives:

To investigate the cytokinetic characteristics of CD22CAR-T in patients with recurrent or refractory B-ALL

Inclusion Criteria:

1. Patients with relapsed and refractory acute B-lymphoblastic leukemia who have any of the following:

   1. B-ALL patients with relapse (including bone marrow morphological relapse 1 and minimal residual relapse 2) after remission by chemotherapy or autologous stem cell transplantation;
   2. Primary B-ALL patients who can not be completely relieved by more than two times of repeated chemotherapy;
   3. High risk primary B-ALL patients who have not been relieved but are not suitable for re intensive therapy after 1-2 times of chemotherapy;

2. Flow cytometry (FCM) showed CD 22 positive in bone marrow or peripheral blood;

3. There should be at least one assessable lesion in B-ALL patients with simple extramedullary recurrence;

4. The activity state score of the Eastern Cooperative Oncology Group (ECOG) was less than or equal to 2;

5. The estimated survival time is more than 3 months;

6. Need to sign informed consent.

Exclusion Criteria:

1. Serious cardiac insufficiency；
2. Has a history of severe pulmonary function damaging;
3. Other malignant tumors;
4. Serious infection or persistent infection and can not be effectively controlled；
5. Merging severe autoimmune diseases or immunodeficiency disease;
6. Patients with active hepatitis (HBV DNA or HCV RNA positive);
7. Patients with HIV infection or syphilis infection;
8. Has a history of serious allergies on Biological products (including antibiotics);
9. Being pregnant and lactating or having pregnancy within 12 months;
10. Any situations that the researchers believe will increase the risks for the subject or affect the results of the study（including a history of serious mental illness, substance abuse and addiction）