title: T cells expressing CD19 chimeric antigen receptors for acute lymphoblastic leukaemia in children and young adults: a phase 1 dose-escalation trial.
abstract: BACKGROUND
  Chimeric antigen receptor (CAR) modified T cells targeting CD19 have shown activity in case series of patients with acute and chronic lymphocytic leukaemia and B-cell lymphomas, but feasibility, toxicity, and response rates of consecutively enrolled patients treated with a consistent regimen and assessed on an intention-to-treat basis have not been reported. We aimed to define feasibility, toxicity, maximum tolerated dose, response rate, and biological correlates of response in children and young adults with refractory B-cell malignancies treated with CD19-CAR T cells.
  
  
  METHODS
  This phase 1, dose-escalation trial consecutively enrolled children and young adults (aged 1-30 years) with relapsed or refractory acute lymphoblastic leukaemia or non-Hodgkin lymphoma. Autologous T cells were engineered via an 11-day manufacturing process to express a CD19-CAR incorporating an anti-CD19 single-chain variable fragment plus TCR zeta and CD28 signalling domains. All patients received fludarabine and cyclophosphamide before a single infusion of CD19-CAR T cells. Using a standard 3 + 3 design to establish the maximum tolerated dose, patients received either 1 × 10(6) CAR-transduced T cells per kg (dose 1), 3 × 10(6) CAR-transduced T cells per kg (dose 2), or the entire CAR T-cell product if sufficient numbers of cells to meet the assigned dose were not generated. After the dose-escalation phase, an expansion cohort was treated at the maximum tolerated dose. The trial is registered with ClinicalTrials.gov, number NCT01593696.
  
  
  RESULTS
  Between July 2, 2012, and June 20, 2014, 21 patients (including eight who had previously undergone allogeneic haematopoietic stem-cell transplantation) were enrolled and infused with CD19-CAR T cells. 19 received the prescribed dose of CD19-CAR T cells, whereas the assigned dose concentration could not be generated for two patients (90% feasible). All patients enrolled were assessed for response. The maximum tolerated dose was defined as 1 × 10(6) CD19-CAR T cells per kg. All toxicities were fully reversible, with the most severe being grade 4 cytokine release syndrome that occurred in three (14%) of 21 patients (95% CI 3·0-36·3). The most common non-haematological grade 3 adverse events were fever (nine [43%] of 21 patients), hypokalaemia (nine [43%] of 21 patients), fever and neutropenia (eight [38%] of 21 patients), and cytokine release syndrome (three [14%) of 21 patients).
  
  
  CONCLUSIONS
  CD19-CAR T cell therapy is feasible, safe, and mediates potent anti-leukaemic activity in children and young adults with chemotherapy-resistant B-precursor acute lymphoblastic leukaemia. All toxicities were reversible and prolonged B-cell aplasia did not occur.
  
  
  BACKGROUND
  National Institutes of Health Intramural funds and St Baldrick's Foundation.
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Lee
authors.affiliation: Experimental Transplantation and Immunology Branch, Bethesda, MD, USA.
authors.forename: James N
authors.initials: JN
authors.lastname: Kochenderfer
authors.affiliation: Laboratory of Pathology, Bethesda, MD, USA.
authors.forename: Maryalice
authors.initials: M
authors.lastname: Stetler-Stevenson
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Yongzhi K
authors.initials: YK
authors.lastname: Cui
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Cindy
authors.initials: C
authors.lastname: Delbrook
authors.affiliation: Surgery Branch, Bethesda, MD, USA.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Feldman
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Fry
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Rimas
authors.initials: R
authors.lastname: Orentas
authors.affiliation: Cell Processing Section, Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Marianna
authors.initials: M
authors.lastname: Sabatino
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Nirali N
authors.initials: NN
authors.lastname: Shah
authors.affiliation: Biostatistics and Data Management Section, Office of the Clinical Director, National Cancer Institute, Bethesda, MD, USA.
authors.forename: Seth M
authors.initials: SM
authors.lastname: Steinberg
authors.affiliation: Cell Processing Section, Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Dave
authors.initials: D
authors.lastname: Stroncek
authors.affiliation: National Institutes of Health Medical Student Training Program, The University of Nevada School of Medicine, Reno, NV, USA.
authors.forename: Nick
authors.initials: N
authors.lastname: Tschernia
authors.affiliation: Laboratory of Pathology, Bethesda, MD, USA.
authors.forename: Constance
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Surgery Branch, Bethesda, MD, USA.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Rosenberg
authors.affiliation: Children's Center for Cancer and Blood Diseases, Division of Hematology, Oncology and Blood and Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Wayne
authors.affiliation: Pediatric Oncology Branch, Bethesda, MD, USA. Electronic address: mackallc@mail.nih.gov.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Mackall
mesh_terms: D000293:Adolescent; D000328:Adult; D018941:Antigens, CD19; D064987:Cell- and Tissue-Based Therapy; D002648:Child; D002675:Child, Preschool; D002678:Chimera; D015331:Cohort Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007223:Infant; D008228:Lymphoma, Non-Hodgkin / Q000628:therapy*; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000628:therapy*; D011948:Receptors, Antigen, T-Cell; D013601:T-Lymphocytes / Q000276:immunology / Q000637:transplantation*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018941:Antigens, CD19; D011948:Receptors, Antigen, T-Cell