Abstract 4703: Automated 42 PDX 3D in vitro tumor models of the TME screen immuno-oncology and targeted compounds and biologics for antitumor effects and MOA

Abstract High throughput screening has been widely utilized for its efficiency in testing novel therapeutic agents. However, the conventional screening using 2D culture of cancer cell lines lacks the biological complexity of the tumor microenvironment or the immune compartment which limits their application in testing immune-oncology therapies. Particularly with the passing of the FDA Modernization Act 2.0, it is critical to create more biologically relevant 3D in vitro models that can be used to reduce, refine and ultimately replace preclinical animal models. Here we have developed a highly automated 3D high throughput screening platform comprised of 42 patient-derived xenograft models in coculture with fibroblasts in engineered extracellular matrix hydrogels that resemble tumor stromal microenvironment. The PDX models cover a diverse range of tumor and histological types including NSCLC, CRC, gastric, TNBC, RCC, bladder, ovarian, melanoma, pancreatic, and others. Moreover, PBMCs or other immune cells can be incorporated into the system for evaluating immuno-oncology drugs. The panel has been tested against chemotherapy drug cisplatin and the immunotherapy biologic, Solitomab, an EpCAM/CD3 bispecific antibody. The endpoint analyses for antitumor effects include the dose response of tumor size and tumor cell death percentage based on high content imaging analysis. In addition, immune cells and supernatant in the IO assay can be recovered from the wells and used for flow cytometry profiling and cytokine assays. In summary, the novel 42-PDX panel described here offers a unique and powerful tool for rapidly generating preclinical data and a better understanding the drug activity at the pharmacology stages, opening the door for faster and more human relevant drug discovery for cancer patients. Citation Format: Bin Xue, Christopher Harrod, Long Le, Julia Schüler, Kolin C. Hribar. Automated 42 PDX 3D in vitro tumor models of the TME screen immuno-oncology and targeted compounds and biologics for antitumor effects and MOA [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 4703.