Genomic Profiling Of Resistant Tumor Samples Following Progression On Egf816, A Third Generation, Mutant-Selective Egfr Tyrosine Kinase Inhibitor (Tki), In Advanced Non-Small Cell Lung Cancer (Nsclc).

11506Background: Up to 60% of patients (pts) with NSCLC harboring an activating EGFR mutation (mut) and treated with a 1st generation EGFR TKI develop a secondary gatekeeper T790M mut. EGF816 is an irreversible EGFR TKI that is highly potent against activating mut (L858R, ex19del) and T790M mut, while sparing wild-type EGFR. As previously reported, in a Phase I dose escalation study, the overall response rate to EGF816 in pts with advanced EGFR T790M mut NSCLC was 47% and the disease control rate was 87%. However, pts ultimately develop disease progression. Tumor biopsies were obtained from pts who had progressed on EGF816 to identify mechanisms of resistance. Methods: Pts with NSCLC with locally or centrally confirmed T790M status were enrolled in this multicenter, dose escalation study to determine the safety, tolerability and antitumor activity of EGF816 (NCT02108964). EGF816 was administered at 7 dose levels ranging from of 75-350 mg QD. Following disease progression, a tumor sample was obtained and w...