Safety profiling of CAR-T cells using an organotypic human tissue platform

Machado, A.; Birsen, G.; Rajnpreht, I.; Furtado Peter, I.; Colell, S.; Marzal, B.; Fredon, M.; Ziegler-Martin, K.; Martinez Bedoya, D.; Fumagalli, M.; Vimeux, L.; Davanture, S.; Melchiore, F.; Thomas, A.; Collet, M.; Fremand, X.; Burroni, B.; Laugel, B.; Lupo-Mansuet, A.; Prieto, M.; Damotte, D.; Le Doussal, J.-M.; Luu, M.; Dutoit, V.; Garnache-Ottou, F.; Guedan, S.; Migliorini, D.; Donnadieu, E.

doi:10.64898/2026.07.25.740527

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bioRxiv · 10.64898/2026.07.25.740527

Safety profiling of CAR-T cells using an organotypic human tissue platform

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Abstract

CAR-T-cell-associated on-target off-tumor (OTOT) toxicity represents a major safety concern, as recognition of target antigens on healthy tissues can trigger severe and potentially life-threatening complications. Predicting OTOT toxicity remains a challenge because current preclinical models fail to capture the complexity of native human tissues. Here, we developed a human organotypic tissue platform that enables functional assessment of CAR-T-cell activity in intact human tissues across organ-specific and inflammatory contexts. Using a panel of clinically relevant CAR-T-cell products with known OTOT toxicities, we demonstrate that the platform faithfully recapitulates clinically observed tissue-specific toxicity profiles. CAR-T cells targeting EGFR, HER2, and mesothelin induced inflammatory and cytotoxic responses in healthy human lung tissue, whereas CD19 CAR-T cells remained inactive. We further show that OTOT toxicity cannot be reliably predicted from antigen abundance alone but instead results from the integration of multiple target-dependent determinants, including CAR affinity, inflammatory context, antigen accessibility, and effector-cell dose. The platform also enables quantitative assessment of inflammatory and cytotoxic responses and supports evaluation of pharmacological and CAR design-based strategies to mitigate toxicity. Together, this work establishes the first human organotypic platform for functional modeling of CAR-T-cell-associated OTOT toxicity, providing a clinically relevant framework for preclinical safety evaluation and the rational development of safer engineered cell therapies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC="FIGDIR/small/740527v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@12c8addorg.highwire.dtl.DTLVardef@150d392org.highwire.dtl.DTLVardef@17218f7org.highwire.dtl.DTLVardef@1c54078_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Machado, A., Birsen, G., Rajnpreht, I., Furtado Peter, I., Colell, S., Marzal, B., Fredon, M., Ziegler-Martin, K., Martinez Bedoya, D., Fumagalli, M., Vimeux, L., Davanture, S., Melchiore, F., Thomas, A., Collet, M., Fremand, X., Burroni, B., Laugel, B., Lupo-Mansuet, A., Prieto, M., Damotte, D., Le Doussal, J.-M., Luu, M., Dutoit, V., Garnache-Ottou, F., Guedan, S., Migliorini, D., Donnadieu, E.. 2026-07-28. Safety profiling of CAR-T cells using an organotypic human tissue platform. https://doi.org/10.64898/2026.07.25.740527

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