This is a phase II clinical study to evaluate the safety and efficacy of CAR-T-19 injection in the treatment of CD19-positive relapsed/refractory B-cell acute lymphoblastic leukemia.
Voluntary participation in clinical trial, The Participants or his legal guardian is fully understands this clinical trial and signs the Informed Consent Form (ICF); Willing to follow and be able to complete all trial procedures.
Age≤25 years old at the time of screening, regardless of gender.
Bone marrow examination confirmed the diagnosis of B-ALL, and meet one of the following conditions： Relapsed B-ALL：1）Relapse within 12 months of the first remission；2）Recurrence occurring again more than 12 months after the first remission,, relapsed or not responded after first-line/multi-line salvage chemotherapy；3) Experienced two or more bone marrow recurrences; 4） recurrence after autologous or allogeneic hematopoietic stem cell transplantation； Refractory B-ALL：1）failed to achieve complete remission after 2 cycles of standard induction chemotherapy.
Ph+ALL patients are eligible：1）Relapsed or refractory after receiving at least two Tyrosine kinase inhibitors (TKI) treatments；If Ph+ALL patients with t315i mutation are resistant to first- and second-generation TKIs, in the absence of effective TKI therapy, patients are not required to receive at least two TKIs；2）cannot tolerate TKI treatment；3）Presence of contraindications to TKI therapy.
Isolated extra-medullary disease relapse .
Participants with genetic syndromes, Patients with Down Syndrome will not be excluded.
Participants with Burkitt's lymphoma/leukemia.
Participants with active central nervous system disease.