Systematic Review and Meta-analysis of CD19-Specific CAR-T Cell Therapy in Relapsed/Refractory Acute Lymphoblastic Leukemia in the Pediatric and Young Adult Population: Safety and Efficacy Outcomes

Clin Lymphoma Myeloma Leuk. 2021 Apr;21(4):e334-e347. doi: 10.1016/j.clml.2020.12.010. Epub 2020 Dec 17.


Acute lymphoblastic leukemia (ALL) typically responds better when treated with multiagent chemotherapy in the pediatric and young adolescent populations. Treatment of relapsed/refractory (RR) ALL remains a challenge. Even after stem-cell transplantation and intensive chemotherapy, the prognosis of RR-ALL remains grave. The advent of chimeric antigen receptors has demonstrated promising results in RR-ALL. Chimeric antigen receptor-modified T cells (CAR-T) and engineered T cells are used to target cancer cells. In 2017, the US Food and Drug Administration approved CD19-specific CAR-T (tisagenlecleucel) therapy for RR-B-cell ALL in patients under 25 years old. In this systematic review, we discuss the efficacy and safety of CD19-specific CAR-T therapy in RR-B-cell ALL in the pediatric and young adult population. We searched the PubMed, Embase, Web of Science, Cochrane Library, and clinical trials databases. A total of 448 patients received a CD19-specific CAR-T product, and 446 patients had evaluable data. The age range was 0 to 30 years. The incidence rate of complete remission was 82%. The cumulative incidence of relapse after CD19-specific CAR-T therapy is 36%. Similarly, the incidence rate of grade 3 or higher adverse events of neutropenia, thrombocytopenia, neurotoxicity, infections, and cytokine release syndrome were 38%, 23%, 18%, 29%, and 19%, respectively. Our subgroup analysis shows the incidence rate of minimal residual negative complete remission was 69% with the CD28z costimulatory domain, 81% with the 4-1BB domain, and 77% with fourth-generation CD19-specific CAR-T therapy.

Keywords: Childhood Acute lymphoblastic leukemia; Chimeric antigen receptors; Efficacy; Refractory; Relapse; Safety.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Adolescent
  • Antigens, CD19 / immunology
  • Child
  • Cytokine Release Syndrome / epidemiology
  • Cytokine Release Syndrome / immunology
  • Drug Resistance, Neoplasm
  • Humans
  • Immunotherapy, Adoptive / adverse effects*
  • Immunotherapy, Adoptive / methods
  • Neoplasm Recurrence, Local / immunology
  • Neoplasm Recurrence, Local / mortality
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Recurrence, Local / therapy*
  • Neurotoxicity Syndromes / epidemiology
  • Neurotoxicity Syndromes / immunology
  • Neutropenia / epidemiology
  • Neutropenia / immunology
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / immunology
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / mortality
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / pathology
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / therapy*
  • Progression-Free Survival
  • Receptors, Antigen, T-Cell / therapeutic use*
  • Receptors, Chimeric Antigen / genetics
  • Receptors, Chimeric Antigen / immunology
  • Remission Induction / methods
  • Thrombocytopenia / epidemiology
  • Thrombocytopenia / immunology
  • Young Adult


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