Abstract 4863: IOV-5001, autologous tumor-infiltrating lymphocytes (TIL) armored with inducible membrane-tethered IL-12, shows enhanced antitumor efficacy with an improved cellular state

Abstract Introduction: Autologous tumor-infiltrating lymphocytes (TIL) engineered to secrete IL-12 have shown robust clinical efficacy in metastatic melanoma. However, systemic toxicity from elevated circulating IL-12 has limited its application. IOV-5001 is a next-generation TIL therapy engineered to inducibly express membrane-tethered IL-12 (TeIL12) upon antigen engagement, restricting IL-12 activity to the tumor microenvironment. This study evaluated the antitumor efficacy and molecular phenotype of IOV-5001. Methods: TIL were derived from solid tumor tissues, cultured, and transduced with a lentiviral vector encoding inducible TeIL12 bicistronically with a growth factor. Antitumor activity of IOV-5001 was tested in vitro via a tumor antigen-directed TCR killing assay or against autologous patient-derived endometrial cancer organoid (PDO), and/or tumor digests. Transcriptional profiling (bulk and single-cell) was used to characterize the molecular features of IOV-5001. Results: IOV-5001 TIL were successfully generated and effectively expressed TeIL12 upon T cell receptor (TCR) engagement. The expression of TeIL12, soluble IL-12, and IFN-gamma was lacking in the absence of stimulation, indicating that the activity of IOV-5001 TIL is dependent on TCR engagement. IOV-5001 demonstrated superior killing and effector cytokine production compared with unmodified TIL in a tumor antigen-directed TCR killing assay and against autologous tumor, irrespective of aldesleukin support. The antitumor activity was further enhanced when IOV-5001 was expanded in an optimized media. Analysis of bulk gene expression profiling revealed transcriptional profiles for IOV-5001 characterized by upregulation of genes involved in cell cycle, telomere maintenance, mitochondrial metabolism, IL-12, and TCR signaling. Downregulated genes exhibited an enrichment for IL-10 and IL-5 signaling, and prostanoid/eicosanoid ligand binding receptors. Single-cell analysis confirmed these patterns were enriched within tethered cytokine-positive TIL. Furthermore, single-cell analysis of preREP cells demonstrated that proportions of putative tumor-reactive CD8 T cells were similar in IOV-5001 TIL among tethered cytokine-positive and -negative TIL, indicating unbiased transduction. Conclusions: These findings demonstrate that IOV-5001 with inducible and membrane-tethered IL-12 confers superior antitumor activity compared with unmodified TIL. The enhanced molecular and functional characteristics highlight IOV-5001 as a promising product for enhancing TIL efficacy in solid tumors. Citation Format: Patrick Innamarato, Joe Dean, Mohammed Alkhouli, Marcus Machin, Nathan Gilbert, Sadie Johnson, Gerard Sapena, Nino Mtchedlidze, Behzad Damirchi, Robyn Oldham, Andrew Yuhas, Judy Fang, Jamie Blauvelt, Shari Pilon-Thomas, Rongsu Qi, Hequn Yin, Sean Hall. IOV-5001, autologous tumor-infiltrating lymphocytes (TIL) armored with inducible membrane-tethered IL-12, shows enhanced antitumor efficacy with an improved cellular state [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 4863.