Abstract 3434: Evaluation of TCR-engineered T cells specific for KRAS G12V mutant peptide presented by HLA-A*02:01

Abstract Adoptive cellular therapies (ACT) have had limited success in the treatment of solid tumors. Recent approvals of both Tumor Infiltrating Lymphocyte (TIL) and T cell receptor-engineered T cell (TCR-T) therapies herald the promise of autologous T cell strategies. Unfortunately, existing therapeutics face significant challenges including an existing T cell response to immunogenic tumors (TILs) or relying on targets lacking tumor dependence (TCR-T). Engineered T cell therapies utilizing TCRs specific for public oncogenic driver mutations would overcome these hurdles with the intent of driving potent durable responses. Single residue alterations in KRAS are the most frequent oncogenic driver mutations in solid tumors, with G12V arising in indications with high unmet medical need such as PDAC, CRC, and NSCLC. HLA-A*02:01 is the most frequently occurring HLA class I allele in North American and Western European populations, and thus targeting the mutant KRAS G12V peptide presented in the context of HLA-A*02:01 offers the opportunity to treat a large patient population. However, therapeutics designed to provoke immunogenic responses to the KRAS G12V peptide presented by HLA-A*02:01 have proven challenging thus far, and physical evidence of the presentation of the G12V peptide by HLA-A*02:01 has been limited. Here, we employed a non-viral knock in system to screen TCRs via delivery of a transgene cassette comprised of 1) a transgenic TCR, 2) a chimeric cytokine receptor, and 3) the CD8αβ coreceptor to the TRAC locus of human primary T cells. We show specific TCR-T activation by KRAS G12V exogenous peptides loaded into HLA-A*02:01. We also demonstrate the potent induction of functional responses by engineered T cells to endogenous HLA-A*02:01 cancer cell lines both 1) engineered to express tandem minigenes (TMGs) encoding the KRAS G12V peptide and 2) transiently transfected with mRNA to express full length KRAS G12V proteins. These data provide evidence for the processing and presentation of KRAS G12V peptides by endogenous HLA-A*02:01 and illustrate its immunogenicity. This finding is further supported by the recognition of HLA-A*02:01 cell lines endogenously harboring KRAS G12V mutations and the specificity of the engineered T cells as assessed by X-Scan analysis. Our work provides evidence for the processing and presentation of the KRAS G12V mutant peptide in the context of HLA-A*02:01 and demonstrates the feasibility of targeting this public tumor-specific neoantigen widely expressed in indications with high unmet medical need. Citation Format: Joshua Ferrell, Xingyue He, Hongjing Qu, Allison Drain, Monique Peyreau, Nicole Danek, Ping Zhu, Hubert Lam, Dongmei Xiao, Joshua Francis, Gary Shapiro, Loïc Vincent. Evaluation of TCR-engineered T cells specific for KRAS G12V mutant peptide presented by HLA-A*02:01 [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 3434.