Clinical Study of ssCART-19 Cells in Patients With CD19 Positive Relapsed or Refractory Acute Lymphoblastic Leukemia

Inclusion Criteria:

1. Relapsed or refractory acute lymphoblastic leukemia (ALL):(1)Any Relaps after firstremission OR (2)Any BM relapse after allogeneic SCT and must be ≥ 3 months from SCT atthe time of ssCART-19 infusion OR (3)failed to reach CR after 2 cycles of inductionchemotherapy regimen OR (4)Patients with Ph+ ALL are eligible if they are intolerantto or have failed two lines of TKI therapy, or if TKI therapy is contraindicated
2. CD19 tumor expression demonstrated in bone marrow or peripheral blood by flowcytometry
3. Bone marrow with ≥ 5% lymphoblasts by morphologic assessment
4. Adequate organ function defined as:(1)left ventricular ejection fraction ≥ 50% byechocardiogram；(2)creatinine ≤ 1.6mg/dl；(3)ALT and AST≤3 times the ULN for age, totalbilirubin ≤ 2.0mg/dl；(4)Must have a minimum level of pulmonary reserve defined as ≤Grade 1 dyspnea and pulse oxygenation > 91% on room air
5. Informed consent is signed by the subject
6. Age 18 to 65
7. Fertility of men, to ensure that sexual partners can effectively contraception; Womenwith fertility use effective contraceptive measures and agree to use contraceptivemeasures throughout the study period
8. Qualified T cell amplification
9. Eastern cooperative oncology group (ECOG) performance status of 0 to 1
10. Vascular conditions for apheresis
11. The estimated survival time is more than 3 months

Exclusion Criteria:

1. Isolated extra-medullary disease relapse
2. Combined with other malignant tumors
3. Has had treatment with any prior anti-CD19/anti-CD3 therapy, or any other antiCD19therapy
4. Has had immunosuppressants or hormones within 2 weeks before signing informed consent,or plan to use immunosuppressants or hormones after signing informed consent
5. Patients complying with any of hepatitis B surface antigen (HBsAg) and/or hepatitis Be antigen (HBeAg) positive, hepatitis B e antibody (HBe-Ab) and/or hepatitis B coreantibody (HBc-Ab) positive and HBV-DNA copies being more than the lower limit ofdetection, hepatitis C antibody (HCV-Ab) positive, anti-treponemia pallidum antibody (TP-Ab) positive, EBV-DNA, and CMV-DNA copies being more than the lower limit ofdetection
6. Has uncontrolled bacteria, fungi, viruses, mycoplasma or other types of infections
7. Infected with HIV, syphilis or COVID-19
8. Has a history of severe immediate hypersensitivity to aminoglycosides
9. Has past or present CNS diseases, such as epilepsy, cerebrovascularischemia/hemorrhage, dementia, cerebellar diseases or any CNS-related autoimmunediseases
10. Has undergone cardiac angioplasty or stent implantation within 12 months beforesigning informed consent, or having a history of myocardial infarction, unstableangina pectoris or other clinically significant heart diseases
11. With primary immunodeficiency
12. Has had severe immediate hypersensitivity reaction to any drug to be used in thisstudy
13. Has had treat with live vaccine within 6 weeks prior to screening
14. Pregnant or lactating women
15. Has active autoimmune diseases
16. Has active acute or chronic graft-versus-host disease (GVHD) before signing informedconsent
17. Patient has an investigational medicinal product within 3 months before signinginformed consent
18. Patients with other conditions making the patients unsuitable for receiving celltherapy as judged by the investigator