A phase I/II single arm study, Safety and Efficacy assessment of the CD19 CAR T cell on pediatric patients with relapsing or refractory B cell acute lymphoblastic leukemia (r/r B-ALL)

Inclusion criteria:

boys or girls 2-18 years old Relapsing or refractory CD19+ B-ALL Disease in bone marrow (Blast > 5 percent) Able to withstand the apheresis process to produce a research product as determined by the researcher Life expectancy more than 12 weeks as determined by the researcher Lansky score (<16 yeras) or Karnofsky score (>16 years) more than 50 percent At least 7 days have passed since the last chemotherapy, excluding maintenance chemotherapy At least 7 days have passed since the last treatment with corticosteroids At least 3 days have passed since using a tyrosine kinase inhibitor (TKI) The patient or the patient's guardian/legal representative should sign the informed consent form for this study. Having potential donor for stem cell transplantation

Exclusion criteria:

Presence of active malignancy other than the disease under study Presence of chloroma and leukemic infiltration on MRI, or patients with significant neurologic symptoms (unless alternative therapies lead to neurologic stabilization) History or presence of any CNS disorder, such as seizure disorder, cerebrovascular ischemia/hemorrhage, dementia, cerebellar disease, any autoimmune disease with CNS involvement, posterior reversible encephalopathy syndrome (PRES), or cerebral edema Presence of active GVHD (acute GVHD grade 2-4 or chronic extensive), or receiving immunosuppressive therapy to treat or prevent GVHD within 4 weeks before entering the study Radiation therapy within 14 days from the time of enrollment in the study History of Anti-CD19 or Anti-CD20 therapy Donor Lymphocyte Infusion (DLI) or other cellular therapies within 30 days prior to enrollment in the study Acute severe active infection Hepatic dysfunction Renal dysfunction Cardiac dysfunction

Target sample size: 10