Abstract A068: Multi-omics validated KRASi-resistant cell lines for combination and sequential drug treatment discovery

Abstract

Despite the transformative efficacy of KRAS inhibitors in KRAS-mutant malignancies, intrinsic refractoriness and adaptive resistance markedly impair durable treatment responses. Preclinical models that recapitulate the molecular heterogeneity and evolutionary features of clinical resistance are therefore essential for rationally developing and validating combinatorial and sequential strategies to overcome KRAS inhibitor resistance. 1) Generation of KRAS inhibitor-resistant cell lines: More than 10 KRAS inhibitor-resistant cell lines were established through prolonged exposure of KRAS-mutant cancer cells to clinically approved KRAS inhibitors, as well as emerging agents. 2) Exploration of resistance mechanism: Integrated multi-omics analyses, including transcriptomic and proteomic profiling, were performed to delineate the molecular determinants of resistance and to predict candidate synergistic combination partners.3) High-throughput combination screening: More than 3000 drug combinations (including KRAS inhibitors, targeted agents against bypass pathways, DDR inhibitors, et al) were tested using a customized resistant cell panel to identify. 4) Mechanistic validation: Key signaling pathways (e.g., MAPK, PI3K-AKT, DDR) were interrogated via Western blot and phospho-protein arrays to confirm the functional relevance of predicted resistance mechanisms and combination efficacy. Multi-omic profiling of these resistant cell lines revealed diverse mechanisms of resistance, including activation of bypass pathways, KRAS isoform switching, and metabolic reprogramming. Using this well-characterized cell panel, we systematically screened combinatorial and sequential therapeutic strategies and identified multiple actionable regimens that restored cellular sensitivity to KRAS-targeted agents. Further in vivo therapeutic efficacy evaluation using xenograft models is currently ongoing to validate the translational potential of these lead regimens. We have established a fully characterized, multi-omic-profiled panel of KRAS inhibitor-resistant cell lines that provides a physiologically relevant and mechanistically annotated platform for discovering novel therapeutic strategies. This resource accelerates the evaluation of drug efficacy across diverse resistance contexts and KRAS mutation subtypes. The seamless integration of in vitro screening with ongoing in vivo model development creates a translational pipeline for advancing next-generation regimens aimed at overcoming KRAS inhibitor resistance Liuxian Meng, Ying Bi, Xinuo Zhang, Xuemei Jin, Guangyue Gong, Zhengtai Li, Tiejun Bing. Multi-omics validated KRASi-resistant cell lines for combination and sequential drug treatment discovery [abstract]. In: Proceedings of AACR Drug Discovery and Development (AACR D3) Conference; 2026 Jul 21-24; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(14_Suppl):Abstract nr A068.