Abstract B036: A novel functional precision oncology ex vivo culture platform: E-slice with intact TME for immunotherapy and other cancer therapy response measurements from human tumors

Abstract The need for personalized medicine in oncology is widely accepted but translating this important concept into clinical practice has been challenging. Recognizing the inherent limitations of sequencing base, inference methods for predicting anti-cancer treatment responses, functional assays (e.g., organoids and PDX models) have been developed; however, these approaches also have significant limitations including high cost and time required to establish the models, low “take rates”, and destruction of the native tumor microenvironment (TME). To overcome these challenges, EMPIRI developed a proprietary novel 3D ex vivo tumor culture method from patient samples called E-slices that enables rapid, personalized drug sensitivity testing in a clinically actionable time frame. E-slice is a faithful model of individual cancer patient’s tumor, including the TME. It is a proprietary 3D tissue culture platform that is generated by making thin sections of intact, fresh tumor tissues from each cancer patient. Importantly, the E-slice method has been shown to accurately predict individual patient treatment responses to chemotherapies and targeted therapies in two small retrospective clinical studies. In addition, because E-slices retain tumor-infiltrating immune cells and spatial topography of all cell types in their native TME, E-slices sustain immune cell survival and cellular phenotypes, enabling immunotherapy response measurements and biomarker discoveries ex vivo. Specifically for immunotherapy response measurements, key differentiators of the E-slice platform from other ex vivo systems are: 1) E-slice is generated from fresh patient tumor tissues with tumor-trained and -resident immune cells and not artificially introduced PBMCs used in most other systems; 2) E-slices are cultured serum-free, chemically defined medium that does not artificially activate or suppress the immune system; 3) E-slice has been validated by single-cell RNA-sequencing to maintain immune cells in their native state up to 8 days ex vivo; 4) E-slices can be used to detect secreted protein and metabolic biomarkers in the conditioned media pre- and post-treatment for biomarker discovery; and 5) E-slice can measure human-specific immunotherapy responses ex vivo in 8 days. In summary, we present a novel ex vivo 3D human tumor tissue culture platform that faithfully replicates and retains each patient tumor’s TME and can enhance immunotherapy development pipelines and clinical deployment. Citation Format: Viridiana Leyva-Aranda, Jose Maldonado, Thomas D Gallup, Dave Gallup, Kyuson Yun. A novel functional precision oncology ex vivo culture platform: E-slice with intact TME for immunotherapy and other cancer therapy response measurements from human tumors [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Functional and Genomic Precision Medicine in Cancer: Different Perspectives, Common Goals; 2025 Mar 11-13; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2025;85(5 Suppl):Abstract nr B036.