Abstract P078: Aurora A kinase inhibition with VIC-1911 overcomes intrinsic and acquired resistance to KRASG12C inhibition in KRAS(G12C)-mutated lung cancer

Abstract Oncogenic KRAS mutation is common in non-small cell lung cancer (NSCLC) and portends poor outcome. Direct KRASG12C inhibitors have clinical activity; however, intrinsic and acquired resistance to these drugs limits their utility. Aurora A Kinase (AURKA), a mitotic cell cycle regulator, has been considered as a key druggable KRAS effector and mediates adaptive resistance to direct KRASG12C inhibitors. We found that AURKA expression correlated with poor outcome of lung cancer patients in caBIG, GEO and TCGA, and its expression was greater in KRAS-mutated NSCLC cells resistant to KRASG12C inhibitor sotorasib (AMG510) compared to normal human tracheobronchial epithelial (NHTBE), lung fibroblast, and KRAS wild-type cells. We have previously demonstrated synergistic antitumor effects for combination AURKA and WEE1 inhibition. Here, we explored a novel combination of AURKA and KRASG12C inhibition in KRAS(G12C)-mutated NSCLC cells intrinsically resistant to the KRASG12C inhibitor, along with a combination of AURKA and WEE1 inhibition in mutant KRAS(G12C) lung cancer cells with acquired resistance to the inhibitor. To overcome resistance to the KRASG12C inhibitor sotorasib, we tested combination treatment with VIC-1911, a newly synthesized selective AURKA inhibitor, with sotorasib in sotorasib-resistant human lung cancer cells. Cooperative screening, Loewe plotting, and clonogenic survival assays were performed to determine synergistic antitumor effects. In addition, we established KRAS(G12C)-mutated human lung cancer cell lines with acquired resistance to sotorasib through the means of escalated incremental dosing or sorting non-quiescent cells after drug exposure. Synergy was further confirmed with cell cycle distribution, phenotypic mitotic catastrophe on confocal microscopy, and induction of apoptosis. Interestingly, cells intrinsically resistant to sotorasib showed profound synergistic suppressive effect on cancer cell survival with addition of VIC-1911 compared to sotorasib-sensitive cells (Loewe synergy scores: NCI-H1792=16.03; HCC44=14.37; NCI-H358=1.48). Further, the combination of AURKA and WEE1 inhibition synergistically induced greater cell death in NCI-H358 lung carcinoma cells harboring acquired resistance to sotorasib, with dramatic induction of Bim. Moreover, the combination of AURKA and WEE1 inhibition resulted in a synergistic tumor control in KRAS/TP53-mutated lung cancer xenograft models. Our findings suggest AURKA activation leads to both intrinsic and acquired resistance to sotorasib in KRAS(G12C)-mutated NSCLC; therefore, addition of AURKA inhibition to sotorasib may be a promising therapeutic approach in NSCLC with intrinsic resistance to direct KRASG12C inhibitors, while the combination of AURKA and WEE1 inhibition merits exploration in acquired resistance to these agents. Citation Format: Jong Woo Lee, Sundong Kim, Cindy Yang, Barbara Burtness. Aurora A kinase inhibition with VIC-1911 overcomes intrinsic and acquired resistance to KRASG12C inhibition in KRAS(G12C)-mutated lung cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P078.