Abstract LB233: Targeting ENO1 to tilt the immunometabolic balance in the tumor microenvironment of KRAS-mutated colorectal cancer to improve therapeutic efficacy

Abstract KRAS mutations occur in about 40% of colorectal cancer (CRC) cases, driving tumor progression, metabolic reprogramming, and immune suppression. While adagrasib is approved for KRAS G12C-mutated CRC (about 3% of cases), effective therapies for the more common KRAS G12D and G12V mutations remain unavailable. Oncogenic KRAS signaling promotes upregulation of glycolytic enzymes like enolase 1 (ENO1), leading to lactate-driven immunosuppression and therapy resistance. Beyond its metabolic role, ENO1 externalizes to the cell surface, functioning as a plasminogen receptor that facilitates tumor migration and invasion. This study evaluates whether targeting surface ENO1, a mediator of KRAS-driven metabolic reprogramming and tumor invasion, could enhance radiotherapy efficacy by remodeling the tumor microenvironment (TME). Surface ENO1 expression in CRC tumor samples was assessed via immunohistochemistry (IHC) and correlated with KRAS mutation status and patient outcomes. ENO1 antibody (HuL001), which completed a phase I safety trial (NCT04540770), was evaluated alone or in combination with radiotherapy in a syngeneic KRAS-mutated (G12D) CRC mouse model. Tumor tissues were analyzed using transcriptomic and immune profiling. We found ENO1 was significantly upregulated in tumor tissues from early relapsed or metastatic CRC patients and correlated with KRAS mutations and poorer survival outcomes. Combining HuL001 with radiotherapy significantly enhanced tumor regression in KRAS-mutated CRC models compared to either radiotherapy or HuL001 treatment. Mechanistic studies showed that HuL001 downregulated glycolysis-related genes, reduced lactate secretion by suppressing MCT4 expression, reprogrammed macrophages toward an M1-favored phenotype, and increased CD8+ T-cell infiltration. These effects collectively suggest that ENO1 antibody is able to remodel the immunosuppressive TME and improve the therapeutic response of radiotherapy. This is the first study to demonstrate that targeting ENO1 can simultaneously overcome the immunosuppressive TME and enhance radiotherapy efficacy in KRAS-mutated CRC. These findings support further clinical evaluation of this immunometabolic strategy, with a phase I/II trial underway to assess HuL001’s therapeutic potential. Citation Format: Maisie Huang, Hsin-Yu Chang, Ta-Tung Yuan, K.S. Clifford Chao, William Tzu-Liang Chen, Tao-Wei Ke, Ji-An Liang, Wei-Ze Hong, Kevin Chih-Yang Huang. Targeting ENO1 to tilt the immunometabolic balance in the tumor microenvironment of KRAS-mutated colorectal cancer to improve therapeutic efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr LB233.