An Fc-engineered CD19 antibody eradicates MRD in patient-derived -rearranged acute lymphoblastic leukemia xenografts.

Antibody therapy constitutes a major advance in the treatment of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). To evaluate the efficacy and the mechanisms of action of CD19 monoclonal antibody therapy in pediatric BCP-ALL, we tested an Fc-engineered CD19 antibody carrying the S239D/I332E mutation for improved effector cell recruitment (CD19-DE). Patient-derived xenografts (PDX) of pediatric mixed-lineage leukemia gene ()-rearranged ALL were established in NOD.