A Study of CNCT19 Treatment in Children and Adolescent r/r ALL Patients(Pediatric)

Key Inclusion Criteria:

1. Signed written informed consent prior to any study procedures (patient and/or parentor legal guardian)

2. Age 3 to 18. Weight ≥10kg

3. Relapsed or refractory acute lymphoblastic leukemia (ALL).

4. Documentation of CD19 tumor expression demonstrated in bone marrow or peripheralblood within 3 months before screening.

5. Bone marrow with ≥ 5% lymphoblasts by morphologic assessment at screening.

6. Karnofsky (age ≥ 16 years) performance status ≥ 70 or Lansky (age < 16 years)performance status ≥ 50 at screening

7. Organ function requirements: All patients must have adequate renal and liverfunctions

Key Exclusion Criteria:

1. Active Central Nervous System (CNS) involvement by malignancy.

2. Isolated extra-medullary disease relapse.

3. Patients with Burkitt's lymphoma/leukemia, mixed phenotypic acute leukemia andChronic Myelogenous Leukemia in Blast Crisis

4. History of concomitant genetic syndrome

5. Patients with acute graft-versus-host disease (GVHD) or moderate-to-severe chronicGVHD within 4 weeks before screening.

6. Active systemic autoimmune disease

7. Known infection with human immunodeficiency virus (HIV) or chronic infection withhepatitis B virus (HbsAg positive) or hepatitis C virus (anti-HCV positive).

8. Patients with active infections at screening.

9. Patients who received specified chemotherapy before CNCT19 infusion

10. Radiotherapy before CNCT19 infusion: Non-CNS site of radiation completed < 4 weeks prior to CNCT19 Infusion; CNS directedradiation completed < 8 weeks prior to CNCT19 infusion.

11. Donor lymphocyte infusion (DLI) must be stopped > 6 week prior to CNCT19 infusion.

12. Has had treatment with any prior CAR-T therapy.

13. Life expectancy < 3 months.