Sleeping Beauty-engineered CAR T cells achieve antileukemic activity without severe toxicities

J Clin Invest. 2020 Nov 2;130(11):6021-6033. doi: 10.1172/JCI138473.


BACKGROUNDChimeric antigen receptor (CAR) T cell immunotherapy has resulted in complete remission (CR) and durable response in highly refractory patients. However, logistical complexity and high costs of manufacturing autologous viral products limit CAR T cell availability.METHODSWe report the early results of a phase I/II trial in B cell acute lymphoblastic leukemia (B-ALL) patients relapsed after allogeneic hematopoietic stem cell transplantation (HSCT) using donor-derived CD19 CAR T cells generated with the Sleeping Beauty (SB) transposon and differentiated into cytokine-induced killer (CIK) cells.RESULTSThe cellular product was produced successfully for all patients from the donor peripheral blood (PB) and consisted mostly of CD3+ lymphocytes with 43% CAR expression. Four pediatric and 9 adult patients were infused with a single dose of CAR T cells. Toxicities reported were 2 grade I and 1 grade II cytokine-release syndrome (CRS) cases at the highest dose in the absence of graft-versus-host disease (GVHD), neurotoxicity, or dose-limiting toxicities. Six out of 7 patients receiving the highest doses achieved CR and CR with incomplete blood count recovery (CRi) at day 28. Five out of 6 patients in CR were also minimal residual disease negative (MRD-). Robust expansion was achieved in the majority of the patients. CAR T cells were measurable by transgene copy PCR up to 10 months. Integration site analysis showed a positive safety profile and highly polyclonal repertoire in vitro and at early time points after infusion.CONCLUSIONSB-engineered CAR T cells expand and persist in pediatric and adult B-ALL patients relapsed after HSCT. Antileukemic activity was achieved without severe toxicities.TRIAL NCT03389035.FUNDINGThis study was supported by grants from the Fondazione AIRC per la Ricerca sul Cancro (AIRC); Cancer Research UK (CRUK); the Fundación Científica de la Asociación Española Contra el Cáncer (FC AECC); Ministero Della Salute; Fondazione Regionale per la Ricerca Biomedica (FRRB).

Keywords: Cancer gene therapy; Clinical Trials; Hematology; Immunotherapy; Leukemias.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Allografts
  • Child
  • Child, Preschool
  • Female
  • Hematopoietic Stem Cell Transplantation*
  • Humans
  • Immunotherapy, Adoptive*
  • Infant
  • Male
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / genetics
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / immunology
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / therapy*

Associated data