British Toxicology Society Congress (BTS 2026)

Modelling immune-mediated hepatotoxicity of monoclonal antibodies using a human liver microphysiological system

Background

Immune-mediated drug-induced liver injury (iDILI) remains a major challenge in the development of biologics, including monoclonal antibodies (mAbs), due to limited human relevance of traditional animal and 2D cell-based models. Aligning with recent regulatory emphasis on new approach methodologies, this study describes the modification of the FDA‑recognised PhysioMimix® DILI assay to incorporate peripheral blood mononuclear cells (PBMCs). to address this with an immune-competent, human liver relevant MPS model. This approach aims to enhance translational relevance and improve safety profiling in drug development pipelines

Methods

Primary human hepatocytes were cultured under dynamic perfusion in Liver‑12 plates using the PhysioMimix® Core to generate three‑dimensional liver microtissues. Hepatic functionality was assessed via CYP activity, albumin, and urea production, alongside clinically relevant injury markers (ALT, AST). After four days, HLA‑matched peripheral blood mononuclear cells (PBMCs) were introduced into the circulating media and co‑cultured with the liver microtissues for a further four days to establish immune competence. Two clinically relevant monoclonal antibodies, ipilimumab (anti‑CTLA‑4) and infliximab (anti‑TNF‑α), were dosed into hepatocyte‑only and co‑culture systems for 48 hours, with samples collected at defined time points post‑dosing. Hepatotoxicity was evaluated using functional biomarkers, while immune activation and inflammatory responses were assessed by cytokine profiling.

Results

PBMC recovery and circulation within the Liver‑12 system were confirmed, demonstrating unhindered traversal of the microfluidic channels and scaffolds with 60–70% immune cell recovery. Following initiation of co‑culture, liver microtissue functionality and stable immune phenotypes were maintained over four days. In immune‑competent cultures, treatment with monoclonal antibodies resulted in clear immune‑mediated hepatotoxicity, evidenced by significant elevations in LDH and ALT/AST alongside reductions in functional biomarkers, including albumin and urea. Notably, a pronounced pro‑inflammatory cytokine response was observed exclusively following ipilimumab exposure, consistent with clinical reports of T‑cell–driven immune activation.

Conclusion

This proof-of-concept study demonstrates the utility of an immune-competent human liver microphysiological system for predicting immune-mediated hepatotoxicity of monoclonal antibodies, supporting its potential role in improving translational safety assessment.