Abstract 1226: Advancing CAR-T cell therapies using Nilogen’s ex vivo 3D tumoroid platform

Abstract Background: Advancing CAR-T cell therapies for solid tumors remain a significant challenge due to the complexities of the tumor microenvironment, which impacts therapeutic efficacy, operational mechanisms, and biomarker discovery. Existing preclinical models, including patient-derived xenografts and traditional organoids, often fail to replicate the physiological and immunological intricacies of solid tumors and require extensive time for establishment. Nilogen's ex vivo 3D tumoroid platform overcomes these limitations by preserving the tumor-immune microenvironment and extracellular matrix (ECM) observed in patient tumors. This platform enables robust therapeutic evaluation in a physiologically relevant context. Renal cell carcinoma (RCC), which constitutes 3% of adult cancers, has seen an increasing focus on immunotherapies and combination regimens. CD70, a highly expressed antigen in RCC, represents a promising target for CAR-T cell therapy, currently in phase I clinical trials. However, patient-specific variability in CD70 expression highlights the need for models like tumoroids to capture this heterogeneity for robust assessment of CAR-T efficacy in a patient-specific manner. Methods: This study assessed the performance and functionality of second-generation anti-CD70 CAR-T cell therapy in RCC tumoroids. We explored the impact of immune checkpoint inhibitor combination therapy on CAR-T cell function. Key evaluations included tumor cell apoptosis (measured through time-lapse imaging), T cell activation (monitored using CD69, CD25, 4-1BB, and OX40 expression), T cell exhaustion (monitored using PD-1, LAG-3, and Tim-3 expression), and inflammatory secretome focusing on Th1/Th2 cytokines. In addition, we explored the impact of immune checkpoint inhibitor combination therapy on CAR-T cell functional efficacy. Results: In tumoroids derived from 13 RCC patients, CD70 CAR-T cell therapy showed variable tumor-killing efficacy, with approximately 50% of samples exhibiting a positive response. Activated CAR-T cells displayed expected activation markers upon CD70 recognition and co-expressed exhaustion markers in both responders and non-responders. Cytokine profiling and the evaluation of combination therapies provided further insights into additional opportunities for optimizing CAR-T cell therapeutic performance. Conclusions: Nilogen’s tumoroid platform provides a physiologically relevant system to evaluate CAR-T cell functionality in solid tumors, enabling the assessment of patient-specific variability in response to therapy. These findings underscore the potential of tumoroids to refine and accelerate the development of CAR-T therapies, which, in turn, enhances their clinical success, particularly for RCC and other solid tumors. Citation Format: Vanessa Garrido, Jared Ehrhart, Rikhia Chakraborty. Advancing CAR-T cell therapies using Nilogen’s ex vivo 3D tumoroid platform [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 1226.