Development of cell-based functional assays to predict CAR T cell potency and persistence

ASGCT 2025 -- Cytokine secretion assays are used to predict the effectiveness of adoptive cell therapy products by assessing factors like IFNγ, TNFα and IL-2. However, these assays are limited as they lack direct functional information on target cell status and cannot predict the long-term persistence of the therapy. To address these limitations, we developed functional and phenotypic assays using the AVATAR platform (Xcellbio). By manufacturing CD19 CAR T cells under hypoxic and hyperbaric conditions to mimic the tumor microenvironment (TME), we observed an increased stem-like phenotype, enhanced tumor killing capacity and improved long-term serial killing activity. Our data suggest these assays can help accurately predict the potency and persistence of adoptive cell therapy products and can be applied in all phases of development.