CD19 hsCAR-T for Refractory/Relapsed CD19+ B-ALL Patients

Inclusion Criteria: 1. Subjects with refractory/relapse B-cell ALL with no available curative treatment options (such as autologous or allogeneic SCT); 2. Subjects previously treated with B cell-directed engineered cell therapy are eligible if they meet the following criteria: 1. relapsed and/or MRD-positive after prior cell therapy; 2. partial response to prior cell therapy; 3. Clinical and laboratory data are available; 3. Documented CD19 expression after previous B cell-directed therapies; 4. Aged 1 to 75 years; 5. KPS\>40； 6. At least 2 weeks or 5 drug half-lives, whichever is shorter must have elapsed since any prior systemic therapy at the time the subject is planned for leukapheresis, except for systemic inhibitory/stimulatory immune checkpoint therapy; 7. Women of childbearing potential must have a urine pregnancy test taken and proven negative prior to the treatment. All patients agree to use reliable methods of contraception during the trial period and throughout the last follow-up visit; 8. Subjects with relapsed disease after prior allogeneic SCT (myeloablative or non-myeloablative) will be eligible if the patients do not present with active GVHD and are not undergoing immunosuppressive regimes; 9. Patients with CNS3 (WCB ≥5/mL in CSF with presence of lymphoblasts) disease will be eligible if the CNS disease is responsive to therapy; 10. Participation in the clinical trials should be voluntary with signed informed consent. Exclusion Criteria: 1. Patients with hypervolemia (white blood cell count\> 50 x 10\^9 / L) or rapidly progressive disease that in the estimation of the investigators and sponsors would compromise the patient's ability to complete the study; 2. History of melanoma skin cancer or other primary tumors (eg, cervical cancer, bladder cancer, breast cancer) (except for those with 3 years or longer of cure); 3. Patients with fungal, bacterial, viral, or other uncontrollable infections or infections requiring Level 4 isolation (UTI or inoculation assays may be performed if necessary); 4. Patients with positive results for HIV, HBV, HCV tests; 5. With CNS disorders such as cerebrovascular ischemia/hemorrhage, dementia, cerebellar disease, or autoimmune disease with CNS involvement; 6. History of myocardial infarction, cardiac angioplasty or stenting, unstable angina, or other clinically significant cardiac diseases within 12 months of enrollment, or with cardiac atrial or cardiac ventricular lymphoma; 7. Patients that are receiving anticoagulant therapy or have ever coagulation disorders; 8. Any medical condition that in the judgment of the sponsors/investigators is likely to interfere with assessment of safety or efficacy of study; 9. History of severe immediate hypersensitivity reaction to any of the agents used in this study; 10. Female patients who are pregnant or breastfeeding; 11. Feasibility assessment during screening demonstrates \<30% transduction of target lymphocytes, or insufficient expansion (\< 5-fold) in response to CD3/CD28 co-stimulation; 12. Patients with any uncontrolled diseases that are unsuitable for enrollment; 13. CNS3 disease that is progressive on therapy, or with CNS parenchymal lesions that might increase the risk of CNS toxicity; 14. Any situation that is considered to potentially increase the risk of the subject or interfere with the outcome of the study; 15. Patients who have been enrolled in other clinical studies.