Umbilical cord blood T cells can be isolated and enriched by CD62L selection for use in ‘off the shelf’ chimeric antigen receptor T-cell therapies to widen transplant options

Abstract

Umbilical cord blood (UCB) T cells exhibit distinct naïve ontogenetic profiles and may be an attractive source of starting cells for the production of chimeric antigen receptor (CAR) T cells. Pre-selection of UCB-T cells on the basis of CD62L expression was investigated as part of a machine-based manufacturing process, incorporating lentiviral transduction, CRISPR- Cas9 editing, T-cell expansion, and depletion of residual TCRαβ T cells. This provided stringent mitigation against the risk of graft-versus-host disease (GvHD), and was combined with simultaneous knockout of CD52 to enable persistence of edited T cells in combination with preparative lymphodepletion using alemtuzumab. Under compliant manufacturing conditions, two cell banks were generated with high levels of CAR19 expression and minimal carriage of TCRαβ T cells. Sufficient cells were cryopreserved in dose-banded aliquots at the end of each campaign to treat dozens of potential recipients. Molecular characterization captured vector integration sites and CRISPR editing signatures, and functional studies, including in vivo potency studies in humanized mice, confirmed anti-leukemic activity comparable to peripheral blood-derived universal CAR19 T cells. Machine manufactured UCB-derived T-cell banks offer an alternative to autologous cell therapies and could help widen access to CAR T cells.