Sustained remissions with CD19-specific chimeric antigen receptor (CAR)-modified T cells in children with relapsed/refractory ALL.

Abstract

3011Background: Targeted immunotherapy with chimeric antigen receptor (CAR)-modified T cells can produce potent anti-tumor responses. We previously reported complete remissions (CR) and prolonged persistence in children and adults with relapsed/refractory (r/r) acute lymphoblastic leukemia (ALL) treated with CD19-specific CART cells (CTL019). We now report on outcomes and longer follow-up of 59 children with r/r ALL. Methods: T cells collected from the patient were transduced with a lentiviral vector encoding a CAR composed of anti-CD19 scFv, CD3z, and 4-1BB domains, activated/expanded ex vivo with anti-CD3/CD28 beads, and then infused at a dose of 107 to 108cells/kg with a transduction efficiency of 2.3-45%. 54/59 patients received lymphodepleting chemotherapy the week prior to cell infusion. Results: Of 59 patients aged 20mo-24y with CD19+ ALL, 44 had detectable disease prior to CTL019 cell infusion, while 15 were MRD-. 39 were treated for relapse after prior stem cell transplant (SCT). 15 patients had ...