CRISPR/Cas9-Engineered Universal CD19/CD22 Dual-Targeted CAR-T Cell Therapy for Relapsed/Refractory B-cell Acute Lymphoblastic Leukemia

Clin Cancer Res. 2021 May 15;27(10):2764-2772. doi: 10.1158/1078-0432.CCR-20-3863. Epub 2021 Feb 24.


Purpose: Autologous chimeric antigen receptor T (CAR-T) cell therapy is an effective treatment for relapsed/refractory acute lymphoblastic leukemia (r/r ALL). However, certain characteristics of autologous CAR-T cells can delay treatment availability. Relapse caused by antigen escape after single-targeted CAR-T therapy is another issue. Therefore, we aim to develop CRISPR-edited universal off-the-shelf CD19/CD22 dual-targeted CAR-T cells as a novel therapy for r/r ALL.

Patients and methods: In this open-label dose-escalation phase I study, universal CD19/CD22-targeting CAR-T cells (CTA101) with a CRISPR/Cas9-disrupted TRAC region and CD52 gene to avoid host immune-mediated rejection were infused in patients with r/r ALL. Safety, efficacy, and CTA101 cellular kinetics were evaluated.

Results: CRISPR/Cas9 technology mediated highly efficient, high-fidelity gene editing and production of universal CAR-T cells. No gene editing-associated genotoxicity or chromosomal translocation was observed. Six patients received CTA101 infusions at doses of 1 (3 patients) and 3 (3 patients) × 106 CAR+ T cells/kg body weight. Cytokine release syndrome occurred in all patients. No dose-limiting toxicity, GvHD, neurotoxicity, or genome editing-associated adverse events have occurred to date. The complete remission (CR) rate was 83.3% on day 28 after CTA101 infusion. With a median follow-up of 4.3 months, 3 of the 5 patients who achieved CR or CR with incomplete hematologic recovery (CR/CRi) remained minimal residual disease (MRD) negative.

Conclusions: CRISPR/Cas9-engineered universal CD19/CD22 CAR-T cells exhibited a manageable safety profile and prominent antileukemia activity. Universal dual-targeted CAR-T cell therapy may offer an alternative therapy for patients with r/r ALL.

Publication types

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

MeSH terms

  • Adult
  • Antigens, CD19 / immunology*
  • CRISPR-Cas Systems*
  • Drug Resistance, Neoplasm
  • Female
  • Gene Editing
  • Genetic Engineering*
  • Humans
  • Immunotherapy, Adoptive* / methods
  • Male
  • Middle Aged
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / diagnosis
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / etiology
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / metabolism
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / therapy*
  • Receptors, Chimeric Antigen / genetics
  • Receptors, Chimeric Antigen / immunology*
  • Recurrence
  • Sialic Acid Binding Ig-like Lectin 2 / immunology*
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Treatment Outcome


  • Antigens, CD19
  • CD22 protein, human
  • Receptors, Chimeric Antigen
  • Sialic Acid Binding Ig-like Lectin 2