Idiopathic pulmonary fibrosis is a progressive lung disease with a median survival of three to five years after diagnosis and limited treatment options. Conventional mouse models cannot replicate the human immune environment, making them unsuitable for evaluating human-specific antibody therapies and cell therapies. Non-human primate studies, while more predictive, face significant ethical, financial, and supply constraints.

To address this unmet need, Preclina developed two humanized mouse models of pulmonary fibrosis: one engrafted with peripheral blood mononuclear cells (PBMCs) and one with hematopoietic stem cells (HSCs). In the PBMC-based model, human T cells accounted for 79.9% ± 9.7% of CD45+ cells, but the model was limited by high GvHD incidence. The HSC-based model demonstrated stable multilineage engraftment — T cells at 20.1% ± 28.3% and B cells at 56.8% ± 25.4% — with no GvHD, and consistent fibrotic pathology including inflammatory infiltration, fibroblast activation, and collagen deposition.

Treatment with nintedanib, an approved anti-fibrotic agent, significantly reduced inflammation and fibrosis scores in both models, confirming preclinical predictive validity consistent with known clinical outcomes. The findings are published in Scientific Reports (doi: 10.1038/s41598-025-18370-7).

"This model eliminates GvHD — the core technical barrier that has prevented PBMC-based humanized models from being used reliably in fibrosis research — while maintaining a fully functional human immune system," said Young Mo Kang, Ph.D., CEO of Preclina. "As regulators increasingly recognize human-relevant testing methods under frameworks such as the FDA Modernization Act 2.0, this platform offers a practical, primate-free alternative for sponsors developing biologics and cell therapies targeting IPF."

An international patent application covering the model and its production method was filed in February 2026 under the Patent Cooperation Treaty (PCT/KR2026/002572), with national phase entries planned in the United States, Japan, the European Union, and China. A related patent application for a humanized mouse model of inflammatory bowel disease was filed in parallel.