Abstract 244: Patient-derived organoids: A pre-clinical model to assess infection and killing capacity of viral vectors for cancer therapy

Abstract

Abstract HUB’s patient-derived organoids (PDOs) are in vitro models that preserve tissue morphology and original cellular complexity. Additionally, PDOs are compatible with (high) throughput screening methods, enabling informed decision-making early in the drug development pipeline and significantly improving the odds of positive outcomes in clinical trials. Akamis Bio has developed experimental viral vector-based tumour gene therapies that have the potential to treat a variety of solid tumours by driving the expression of immunologically active biomolecules and therapeutic proteins hampering tumour immune evasion. These vectors are based on a replication competent, chimeric group B adenovirus backbone that selectively replicates and expresses transgene payloads in tumor cells, and additionally exerts oncolytic activity. To evaluate the efficacy of such a virus-based gene delivery strategy, HUB set up a proof-of-concept study to assess the propagation capability of Akamis Bio’s viral vectors in tumour PDOs. Intact PDOs from primary pancreatic tumours were infected with several viral loads, ranging from 0.1 viral particles per cell (PPC) to 100 PPC. The viral vector encoded a GFP reporter gene to identify infected cells using fluorescence imaging. The cultures were imaged daily for 14 days, allowing the assessment of cytotoxicity and infection efficiency and dynamics. Independently of PPC, infections always started in the exterior of PDOs in a few GFP-positive cells. The gradual increase over time in GFP-signal toward the interior of PDOs suggests the high likelihood of secondary infection events. Crucially, GFP intensity was correlated with cell death in PDOs, as evidenced by morphological features detected in brightfield images. Moreover, the infection dynamics were dose-dependent, as the GFP intensity peak arose later with decreasing PPC. These results show the capacity of HUB PDOs to study the infection dynamics of Akamis viral vectors. This pre-clinical platform permits rapid and efficient screening and dose evaluation for oncolytic virotherapies. Unique access to extensive tumour PDO biobanks with characterized genomic landscapes allows best-in-class stratification of treatment response based on tumour type and genetic heterogeneity. Citation Format: Francisco Morales-Rodriguez, Maria Stella Sasso, Taya Bezhaeva, Samantha Bailey-Bucktrout, Ka Wai Lai, Foteini Gkogkou, Sylvia Boj. Patient-derived organoids: A pre-clinical model to assess infection and killing capacity of viral vectors for cancer therapy [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 244.