Abstract 3192: GT316: a next-generation TIL therapy identified through genome-wide CRISPR screening with promising efficacy in advanced solid tumors

Abstract Adoptive cell therapy using tumor-infiltrating lymphocytes (TILs) has demonstrated therapeutic efficacy in late-stage melanoma patients. However, expanding its applicability to other solid tumors and improving clinical outcomes remain significant challenges. To address these limitations, we developed ImmuTFinder, a genome-wide CRISPR/Cas9 screening platform designed to identify key immunoregulatory targets that enhance TIL functionality and broaden their therapeutic potential. Functional validation of over 120 top candidate targets was performed in TCR-T cells using a high-throughput 96-well array. Promising targets were further tested for combinatorial effects in TILs through in vitro assays and in vivo models. A dual knockout of GT304 and GT312, termed GT316, emerged as the most effective combination, significantly improving TIL proliferation, cytokine production, tumor eradication in CDX and PDX mouse models, and long-term persistence with reduced dependency on IL-2. Specific and highly efficient sgRNAs for these targets were selected, and a scalable manufacturing process for GT316 TILs, named KOReTIL, was developed. A first-in-human trial of GT316 demonstrated good tolerability and encouraging preliminary antitumor activity in patients with advanced solid tumors. Notably, a patient with treatment-refractory cervical cancer achieved a confirmed complete response (CR) four weeks post-infusion, with the response persisting for 50 weeks to date (RECIST 1.1). Another patient with ovarian cancer, previously treated with nine lines of systemic therapy, achieved a confirmed partial response (PR) at six weeks post-infusion, with a response lasting over 50 weeks (RECIST 1.1). Data collection on additional responses is ongoing. In summary, these findings highlight the utility of the ImmuTFinder platform for discovering novel immunoregulatory targets and demonstrate the potential of GT316 as a next-generation TIL therapy for advanced solid tumors. Citation Format: Jingwei Sun, Yao Sheng, Jingman Wang, Jiahui Jin, Zhao Xu, JIng Yu, Jing Guo, Zhongping Cheng, Pin Wang, Yarong Liu. GT316: a next-generation TIL therapy identified through genome-wide CRISPR screening with promising efficacy in advanced solid tumors [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 3192.