Emergence of Preexisting MET Y1230C Mutation as a Resistance Mechanism to Crizotinib in NSCLC with MET Exon 14 Skipping

Emergence of the preexisting MET Y1230C likely confers resistance to crizotinib in this case of METex14-positive NSCLC. Existence of pretreatment MET Y1230C may eventually modulate the response of METex14-positive NSCLC to type I MET tyrosine kinase inhibitors. Noninvasive plasma-based ctDNA assays can provide a convenient method to detect resistance mutations in patients with previously known driver mutations.