Abstract KRAS mutations are frequently found in various types of cancers with an overall mutation frequency of 19.3%. G12C mutation of KRAS (KRASG12C) represents 11.4% of all KRAS mutations in cancer. Targeting KRAS mutations as a cancer treatment strategy has long been investigated for over 30 years already but still remains unconquered field. XNW14010 is a highly selective KRASG12C inhibitor that is rationally designed from AMG510, another proven covalent inhibitor of KRASG12C with potential antineoplastic activity. Compared to AMG510, XNW14010 demonstrated a better pharmaceutical potential and a better safety profile. XNW14010 does not have an axial chiral center shown in AMG510, thus the production cost of this agent could be vastly reduced. The in vitro efficacy of XNW14010 was tested in a variety of cancer cell lines with either wild type KRAS or different mutant KRAS, including lung cancer, colorectal cancer, and pancreatic cancer. The result shows that XNW14010 potently inhibits the activity of KRASG12C, but not wild type KRAS or KRAS bearing other mutations. Specifically, in a pancreatic cancer cell line MIA PaCa-2, which bears KRASG12C, the IC50 of XNW14010 is 26 nM. Furthermore, XNW14010 demonstrated a much less plasma protein binding (PPB) than AMG510 (50.4% versus 93.2%, respectively), suggesting much great potential to penetrating into tumor tissue for XNW14010 compared to AMG510. XNW14010 exhibited comparable or superior pharmacokinetic characteristics compared to AMG510 after oral administration in animal studies. More interestingly, XNW14010 has an improved brain penetration capability. The brain/plasma ratio of XNW14010 exposure is two folds as high as that of AMG510 and the Cmax of XNW14010 in brain tissue is also much higher. XNW14010 had a wider therapeutic window and good tolerance compared to AMG510, both in mouse and dog models, suggesting potentially better safety profile in humans. We also compared the antineoplastic activity of XNW14010 with that of AMG510 in vivo in Xenograft mouse models including lung cancer, colorectal cancer, and pancreatic cancer. The results demonstrated that XNW14010 has comparable antineoplastic activities to AMG510 when administered at the same doses. In pancreatic cancer, the total growth inhibition (TGI) is 90% when administered at the dose of 10 mg/kg QD. Given the better PPB, superior brain penetrating capacity, and similar antineoplastic activitie of XNW14010 compared to AMG510 in non-clinical studies, XNW14010 is expected to be a potent therapeutic candidate in treating cancers bearing KRASG12C, including pancreatic cancer. Citation Format: Yonghan Hu, Xin Li, Bin Huang, Liang Kong, Meijie Le, Yan Li, Cungang Liu, Xiaojun Liu, Bin Qian, Jing Qiang, Qifeng Shi, Wengui Wang, Yuchuan Wu, Zhenwei Wu, Linfeng Xu, Jinfeng Zhao. XNW14010:A highly selective KRASG12C inhibitor with potent efficacy in animal model of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A071.