Abstract 6104: Comparative evaluation of CAR-expressing T-, NK-, NKT-cells and macrophages in an immunocompetent mouse glioma model

Abstract While chimeric antigen receptor (CAR) T-cells are promising, there is a rapidly growing interest in developing other CAR-expressing immune cells. However, to date, no reported studies evaluated these cells side-by-side in immune-competent glioma models. We developed a novel transgenic mouse strain with all hematopoietic cells expressing EGFRvIII-targeting CAR, allowing for rigorous evaluations of CAR-NK, CAR-NKT, and CAR-macrophages compared to CAR-T-cells in a syngeneic mouse SB28-EGFRVIII glioma model. CAR-NK and CAR-NKT-cells demonstrated anti-tumor effects comparable to CAR-T-cells in vitro. A single intratumoral administration of CAR-T and CAR-NKT-cells in combination mediated superior therapeutic efficacy compared to CAR-T-cells or CAR-NKT-cells alone. A single intravenous infusion of CAR-NK-cells following lymphodepletion failed to mediate significant anti-glioma effects associated with inferior persistence to CAR-T cells. Additionally, intratumoral injection of CAR-NK-cells did not confer therapeutic benefit. Contrary to previous reports using human macrophages, CAR-macrophages did not demonstrate enhanced antigen-presentation activity against glioma cells compared to non-CAR macrophages. Intratumorally administered CAR-macrophages failed to demonstrate local persistence or anti-tumor effects in vivo. These data provide a valuable basis as to which CAR-expressing immune cells can mediate effective anti-glioma response in an immuno-competent glioma environment. Our data also suggest that a combination of CAR-T and CAR-NKT-cells may represent a promising therapeutic strategy. Citation Format: Payal B. Watchmaker, Ryusuke Hatae, Akane Yamamichi, Keith Kyewalabye, Kaori Okada, Su Phyu, Yitzhar Goretsky, Jeffrey Haegelin, Psalm Pineo Cavanaugh, Marco Gallus, Lan Phung, Tiffany Chen, Hayou Long, Pavlina Chuntova, David H. Raulet, Masaki Terabe, Hideho Okada. Comparative evaluation of CAR-expressing T-, NK-, NKT-cells and macrophages in an immunocompetent mouse glioma model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6104.