This is a single center, open label, single arm, dose escalation study to explore the safety, tolerability, and pharmacokinetic / pharmacodynamic profile of CD19-Directed Allogeneic Chimeric Antigen Receptor T- cell (alloCART-19) in pediatric patients with relapsed or refractory B-cell acute lymphoblastic leukemia. The study will also assess the preliminary efficacy of CD19-Directed Allogeneic Chimeric Antigen Receptor T- cell (alloCART-19). For this exploratory clinical trial, approximately 3-6 patients will be enrolled. During dose escalation, at least one evaluable patient will be enrolled at each dose level. Once DLT is reached, 1 to 3 additional patients will be enrolled at the dose level below DLT, which has been tested and determined to be safe in the trial, to evaluate the optimal safe and therapeutic dose to be approved by the investigator and sponsor.
The purpose of this study is to evaluate the safety and tolerability of CD19-Directed Allogeneic Chimeric Antigen Receptor T- cell (alloCART-19)therapy in pediatric patients with relapsed/refractory acute lymphoblastic leukemia（ALL）.