Co-occurring Alterations in the RAS-MAPK Pathway Limit Response to MET Inhibitor Treatment in MET Exon 14 Skipping Mutation-Positive Lung Cancer.

Abstract

Although patients with advanced-stage non-small cell lung cancers (NSCLC) harboring <i>MET</i> exon 14 skipping mutations (<i>MET</i>ex14) often benefit from MET tyrosine kinase inhibitor (TKI) treatment, clinical benefit is limited by primary and acquired drug resistance. The molecular basis for this resistance remains incompletely understood. Targeted sequencing analysis was performed on cell-free circulating tumor DNA obtained from 289 patients with advanced-stage <i>MET</i>ex14-mutated NSCLC. Prominent co-occurring RAS-MAPK pathway gene alterations (e.g., in <i>KRAS, NF1</i>) were detected in NSCLCs with <i>MET</i>ex14 skipping alterations as compared with <i>EGFR</i>-mutated NSCLCs. There was an association between decreased MET TKI treatment response and RAS-MAPK pathway co-occurring alterations. In a preclinical model expressing a canonical <i>MET</i>ex14 mutation, KRAS overexpression or NF1 downregulation hyperactivated MAPK signaling to promote MET TKI resistance. This resistance was overcome by cotreatment with crizotinib and the MEK inhibitor trametinib. Our study provides a genomic landscape of co-occurring alterations in advanced-stage <i>MET</i>ex14-mutated NSCLC and suggests a potential combination therapy strategy targeting MAPK pathway signaling to enhance clinical outcomes.