Abstract 3993: High-throughput screening of clinically relevant patient-derived 3D cultures to inform on the efficacy of antibody drug conjugate payloads in 10 distinct cancer indications

Abstract High-throughput screening (HTS) enables rapid evaluation of the efficacy of anticancer agents alone and in combinations across diverse cell-based tumor models. However, the successful translation of these findings to clinical settings necessitates the use of tumor models with high biological fidelity. By integrating tumor cell heterogeneity and three-dimensional morphological features, patient-derived 3D cultures offer enhanced in vivo relevance compared to traditional tumor cell lines grown as monolayers. Nevertheless, the growth of these cultures within an extracellular matrix material and the use of complex media formulations represent challenges for culture scale-up and automated drug screening methods. To address these challenges, we leveraged our well-characterized Patient Derived Xenograft (PDX) bank and Champions TumorGraft3D platform (CTG3D), comprising over 165 well-characterized models, to develop an HTS solution. This platform is highly representative of the patient population and enables users to evaluate the activity of test agents in (i) expandable and ex vivo amen-able 3D models from indications such as Colorectal and Non-Small Cell Lung Cancer (NSCLC); as well as in (ii) models freshly derived from PDXs, which present more heterogeneous and indication-specific material such as Prostate and Glioblastoma Multiforme (GBM). Champions Oncology’s PDX-derived 3D platform (CTG3D) models are low passage and preserve the molecular and phenotypic signatures of parental PDX and hence original patient-derived material maximizing translatability and minimizing clonal drift. Here, we present work that supports the translation of our assays to a 384-well plate-based high-throughput format, using models representing more than 15 cancer indications. These models were evaluated for their recovery from cryopreservation, reproducible growth, and assay performance metrics in a miniaturized 384-well format using CellTiter-Glo® 3D luciferase assay-viability endpoint. PDX-derived and patient-derived 3D cultures from varied indications were screened with a library of agents used as Antibody-Drug-Conjugates (ADC) payloads. Over 4 days, our 3D cultures were exposed to eight concentrations of each drug in a 1/2-log dilution series. Assay performance metrics (such as Z’ and S:N ratio) and pharmacological data demonstrated the robust performance of this organoid screening platform. Future initiatives will focus on developing additional PDX-derived 3D culture panels to expand our high-throughput screening (HTS) capabilities. Citation Format: Annamaria Rapisarda, Kayin Chan, Mara Gilardi, Stefano Cairo, BanuPriya Sridharan. High-throughput screening of clinically relevant patient-derived 3D cultures to inform on the efficacy of antibody drug conjugate payloads in 10 distinct cancer indications [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 3993.