1034P - Preclinical development of genetically modified tumor-infiltrating lymphocytes using biopsy samples from liver cancer patients

Background

Tumor Infiltrating Lymphocytes (TILs) are a group of heterogeneous lymphocytes residing in tumor tissues, among which are various T cell clones with specificity towards tumor or viral antigens. TIL therapy has been successfully approved for melanoma treatment with high-dose interleukin-2 (IL-2). However, the accessibility of the TILs, heterogeneity of T cell clones, and toxicity of IL-2 infusion restrict its application to treating other solid tumors. Here, we expanded and genetically modified TILs derived from liver cancer biopsies. These engineered TILs showed improved proliferation and enhanced anti-tumor potential towards various tumor cell lines and primary liver cancer cells without IL-2.

Methods

TILs isolated from fresh or cryopreserved biopsy samples were stimulated with anti-CD3/CD28 antibodies, transduced with lentiviral vector, and further expanded ex vivo with γ-irradiated feeder cells and cytokines for 26-30 days and cryopreserved. Phenotypic analyses were performed by flow cytometry. IFN-γ ELISA, RTCA Xcelligence, and IncuCyte were used to analyze the in vitro TIL activation and cytotoxicity. Anti-tumor efficacy was further evaluated in patient-derived organoids (PDO) and immunocompromised xenograft models.

Results

Up to 10¹¹ TILs were harvested after ex vivo expansion. Compared to conventional TIL culture, the percentage of central memory CD8⁺ T cells increased by 5.5±2.7 folds with <5% expression of exhaustion markers PD-1 and CTLA-4. TILs were further modified to express membrane-bound interleukins and mitochondrial homeostasis regulators to sustain their in vivo proliferation and long-term anti-tumor efficacy. These engineered TILs demonstrated potent killing efficacy towards multiple liver cancer cell lines and autologous primary tumor cells or PDO. Moreover, engineered TILs could accumulate to the tumor lesion and inhibit tumor growth without toxicity in an immunocompromised murine model.

Conclusions

Engineered TILs derived from liver tumor biopsies showed robust proliferation and anti-tumor potential, supporting its clinical development for liver cancer treatment.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Biosyngen Pte Ltd.

Funding

Biosyngen Pte Ltd.

Disclosure

M. Liu, X. Zhang, D. Han, J.P. Thiery: Financial Interests, Personal, Full or part-time Employment: Biosyngen Pte Ltd.