T Cells Expressing CD19 Chimeric Antigen Receptors for Acute Lymphoblastic Leukaemia in Children and Young Adults: A Phase 1 Dose-Escalation Trial

Lancet. 2015 Feb 7;385(9967):517-528. doi: 10.1016/S0140-6736(14)61403-3. Epub 2014 Oct 13.

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.

Findings: 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).

Interpretation: 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.

Funding: National Institutes of Health Intramural funds and St Baldrick's Foundation.

Publication types

  • Clinical Trial, Phase I
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antigens, CD19*
  • Cell- and Tissue-Based Therapy*
  • Child
  • Child, Preschool
  • Chimera
  • Cohort Studies
  • Feasibility Studies
  • Female
  • Humans
  • Infant
  • Lymphoma, Non-Hodgkin / therapy*
  • Male
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / therapy*
  • Receptors, Antigen, T-Cell*
  • T-Lymphocytes / immunology
  • T-Lymphocytes / transplantation*
  • Treatment Outcome
  • Young Adult

Substances

  • Antigens, CD19
  • Receptors, Antigen, T-Cell

Associated data

  • ClinicalTrials.gov/NCT01593696