Abstract 5342: Evaluation of autologous and allogeneic T cell-based therapies in ex-vivo and in-vivo xenograft tumor models

Abstract

Abstract The field of adoptive T cell-based immunotherapy, including tumor-infiltrating lymphocytes (TILs), T cell receptor (TCR) & Chimeric antigen receptor (CAR) - T cells, has undergone unprecedented growth, specifically later in delivering effective and durable clinical response. Notable success with CAR-T cells is limited to hematological malignancies while clinical gains with solid tumors is still a challenge. Solid tumors’ heterogenous target expression and loss, T cell status and metabolic fitness, T cell trafficking into the tumor, and the hostile immunosuppressive tumor microenvironment (TME) have hampered T cell efficacy in the patients. There is a lack of clinically relevant solid tumor models for the translation of T cell-based therapies into the clinic. We report the development of translational ex-vivo and in-vivo platforms for evaluating cell line-derived and patient-derived xenografts (CDX and PDX) models (BarneyOI™️ model), validated with hCD3 T-cells, autologous TILs and/or allogeneic 3rd generation CAR-T cells (scFv(HER2)-CD28-4-1BB-CD3zeta CAR-T). Anti-hPDL1 but not anti-hPD1 significantly enhanced hCD3 T-cell and autologous TIL-mediated killing of tumor cells in an ex-vivo co-culture assay using Incucyte-based live cell imaging. Also, a dose-dependent killing of HER-2 expressing CDX (A549 & Colo205) and PDX was observed with HER-2 targeting CAR-T cells in an ex-vivo co-culture assay. This was in concordance with the activation, effector function, and differentiation status of the CAR-T cells, immune phenotype by Cytek aurora spectral flow cytometry. Further, to imitate the patient population and the effect of solid TME, HER-2 targeting CAR-T cells were assessed for their in-vivo efficacy and immune response differences in the subcutaneous and orthotopically implanted HER-2 expressing PDX in immunodeficient NOG mice. Our findings highlight the importance of testing T cell-based immune therapies in the appropriate translational tumor models with better certainty of clinical outcome. Citation Format: Sherry Liu, Jasmine Borroel, Carmen Sunico, Emily Eastwood, Bridget Corcoran, Bianca Carapia, Jantzen Sperry, Jonathan Nakashima, Rajeev Shrimali. Evaluation of autologous and allogeneic T cell-based therapies in ex-vivo and in-vivo xenograft tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5342.