Study of CD19-directed Allogeneic Memory T-cell Therapy for Relapsed/Refractory CD19+ Leukemia

This is a Phase I clinical study evaluating the safety and maximum tolerated dose of a novel CAR T-cell product: allogeneic memory (CD45RA- negative) T-cells expressing a CD19-specific CAR 41BBz (CD19-CAR.CD45RA- negative T-cells) for the treatment of patients ≤ 21 years old with relapsed and/ or refractory CD19-positive leukemia. Primary Objective To determine the maximum tolerated dose (MTD) and characterize the safety profile and dose-limiting toxicities (DLTs) of treatment with allogeneic CD19-CAR.CD45RA-negative T-cells in pediatric, adolescent and young adult patients ≤ 21 years of age, with relapsed and/or refractory CD19-positive leukemia. Secondary Objectives * To evaluate the anti-leukemic activity of allogeneic CD19-CAR.CD45RA-negative T-cells. * To determine rates and severity of graft-versus-host-disease (GVHD) after treatment with allogeneic CD19-CAR.CD45RA-negative T-cells. Exploratory Objectives * To study the expansion, persistence and phenotype of allogeneic CD19-CAR.CD45RA-negative T-cells. * To characterize the cytokine profile in the peripheral blood and CSF after treatment with allogeneic CD19-CAR.CD45RA-negative T-cells. * To assess whether allogeneic CD19-CAR.CD45RA-negative T-cells acquire functional versus exhaustion-associated epigenetic programs. * To determine immune reconstitution post treatment, and the clonal structure and endogenous repertoire of allogeneic CD19-CAR.CD45RA-negative T-cells and relate inferred specificity to CAR response profiles. * To characterize incidence and mechanisms of relapse post-therapy with allogeneic CD19-CAR.CD45RA-negative T-cells.