Purpose: MET amplification is a common resistance mechanism to EGFR inhibition in EGFR-mutant non-small cell lung cancer (NSCLC). Several trials showed encouraging results with combined EGFR and MET inhibition (EGFRi/METi). However, MET amplification has been inconsistently defined and frequently included both polysomy and true amplification.
Methods: This is a multicenter, real-world analysis in patients with disease progression on EGFR inhibition and MET copy number gain (CNG), defined as either true amplification (MET to centromere of chromosome 7 ratio [MET-CEP7] ≥ 2) or polysomy (gene copy number ≥ 5, MET-CEP7 < 2).
Results: A total of 43 patients with MET CNG were included, 42 of whom were detected by FISH. Twenty-three, 7, and 14 received EGFRi/METi, METi, and SoC, respectively. Patients in the EGFRi/METi cohort exhibited a superior real-world clinical benefit rate, defined as stable disease or better, of 82% (95% confidence interval [CI], 60-95) compared to METi (29%, 4-71) and SoC (50%, 23-77). Median real-world progression-free survival was longer with EGFRi/METi with 9.8 vs. 4.3 months with METi (hazard ratio [HR], 0.19, 95% CI, 0.06-0.57) and 3.7 months with SoC (0.41, 0.18-0.91), respectively. Overall survival was numerically improved. Interaction analysis with treatment and type of CNG (amplification vs. polysomy) suggests that differences were exclusively driven by MET-amplified patients receiving EGFRi/METi (HR for OS, 0.09, 0.01-0.54).
Conclusion: In this real-world study, EGFRi/METi showed clinical benefit over METi and SoC. Future studies should focus on the differential impact of the type of MET CNG with a focus on true MET amplification as predictor of response.
Keywords: EGFR resistance; MET amplification; MET copy number gain; Progression-free survival; Retrospective.
Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.