Drug repurposing in KRAS G12C-mutant NSCLC: a focus on resistance mechanisms and clinical strategies

KRAS G12C-mutant non-small cell lung cancer (NSCLC) has transitioned from a therapeutically problematic disease to a precision-targetable cancer, anchored by the landmark approvals of sotorasib and adagrasib. Yet despite these advances, responses remain limited in duration and multiple mechanisms of rapid adaptive resistance emerge under inhibitor pressure. These resistance mechanisms define a therapeutic vulnerability map that can be addressed by repurposing approved agents with established safety profiles. This review emphasises the current understanding of KRAS G12C biology, integrates updated phase 3 clinical data and next-generation inhibitor pipelines through early 2026, and presents a mechanism-stratified drug repurposing framework that links validated bypass mechanisms to FDA-approved or clinically available compounds amenable to rapid combination trials. We further highlight patient-derived 3D models, multi-omics technologies, and ctDNA-guided monitoring as essential translational platforms. Finally, we propose an integrated translational roadmap that combines mechanistic insights with clinical innovation, offering new directions for precision therapy and improved patient outcomes in KRAS-driven NSCLC.