Chimeric antigen receptor (CAR) T-cell therapy is a promising treatment for neoplasia and autoimmune diseases. Immunocompromised mice are a common model to test the efficacy and safety of CAR T cells of human origin. Preclinical toxicity associated with human CAR T-cell products encompasses a spectrum of morphologic changes, with currently limited documentation in the scientific literature. The purpose of this retrospective study was to characterize the histopathologic features associated with human CAR T-cell administration in immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice (n = 392) submitted to 3 different academic institutions in the United States between 2017 and 2024. Lesions were categorized into xenogeneic graft-versus-host disease (xGvHD) (n = 287), aberrant proliferation of human T cells (n = 188), vascular pathologies (n = 66), on-target/off-tumor (OTOT) toxicity (n = 44), immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS) in mice previously humanized with human CD34+ hematopoietic stem cells (HSCs) (n = 21), and acute lysis syndrome (ALS) (n = 5). This study provides veterinary pathologists with descriptive guidance on the pathology associated with human CAR T-cell therapy in immunodeficient mice. Additional molecular data and detailed information related to each construct are necessary to further investigate the translatability of such liabilities to the clinical setting.
Mammone et al. (Tue,) studied this question.