Abstract 1941: AXL activation promotes adaptive resistance to KRAS-G12C inhibitors in KRAS-G12C-mutated non-small cell lung cancer

Abstract Background: KRAS is the most frequent targetable oncogene in non-small cell lung cancer (NSCLC). Recently, novel KRAS inhibitor have been clinically developed for treatment of KRAS G12C-mutated NSCLC patients. However, it is difficult to achieve complete remission of tumor. Therefore, the optimal combined therapeutic intervention with KRAS G12C inhibitors has a potentially crucial role in the clinical outcomes of patients. In this study, we focused on the mechanisms underlying adaptive resistance to KRAS G12C inhibitors and therapeutic strategies required to overcome them. Methods: We used KRAS G12C-mutated NSCLC cell lines to evaluate the adaptive response to KRAS G12C inhibitors in vitro and in vivo. We also investigated the correlation between AXL expression in pre-treated tumors and clinical outcomes with sotorasib for KRAS G12C-mutated NSCLC patients. Results: We revealed that AXL signaling leads to the adaptive resistance to KRAS G12C inhibitors in KRAS-G12C mutated NSCLC, activation of which is induced by GAS6 production via transcriptional coactivator YAP. AXL inhibition reduced the viability of AXL-overexpressing KRAS G12C-mutated lung cancer cells by enhancing KRAS G12C inhibition-induced apoptosis. In xenograft models of AXL-overexpressing KRAS G12C-mutated lung cancer treated with KRAS G12C inhibitors, initial combination therapy with AXL inhibitor markedly delayed tumor regrowth compared with KRAS G12C inhibitor alone or the combination after acquired resistance to KRAS G12C inhibitor. AXL was highly expressed in clinical specimens of KRAS G12C-mutated lung cancers and its high expression was associated with a low treatment response to sotorasib. Conclusions: These results indicated pivotal roles for AXL activation and its inhibition in the intrinsic resistance to KRAS G12C inhibitor. Citation Format: Kenji Morimoto, Tadaaki Yamada, Soichi Hirai, Yuki Katayama, Kei Kunimasa, Takaaki Sasaki, Makoto Nishida, Satoshi Watanabe, Shinsuke Shiotsu, Hisanori Uehara, Koichi Takayama. AXL activation promotes adaptive resistance to KRAS-G12C inhibitors in KRAS-G12C-mutated non-small cell lung cancer abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 1941.