Preclinical Study of a Biparatopic METxMET Antibody-Drug Conjugate, REGN5093-M114, Overcomes MET-driven Acquired Resistance to EGFR TKIs in EGFR-mutant NSCLC

Purpose: MET amplification is a frequent mechanism of resistance to EGFR tyrosine kinase inhibitors (TKI) in patients with EGFR-mutated non-small cell lung cancer (NSCLC), and combined treatment with EGFR TKIs and MET TKIs has been explored as a strategy to overcome resistance. However, durable response is invariably limited by the emergence of acquired resistance. Here, we investigated the preclinical activity of REGN5093-M114, a novel antibody-drug conjugate targeting MET in MET-driven patient-derived models. Experimental Design: Patient-derived organoids, patient-derived cells, or ATCC cell lines were used to investigate the in vitro/in vivo activity of REGN5093-M114. Results: REGN5093-M114 exhibited significant antitumor efficacy compared with METTKI or unconjugated METxMET biparatopic antibody (REGN5093). Regardless of MET gene copy number, MET-overexpressed TKI-naive EGFR-mutant NSCLC cells responded to REGN5093-M114 treatment. Cell surface MET expression had the most predictive power in determining the efficacy of REGN5093-M114. REGN5093-M114 potently reduced tumor growth of EGFR-mutant NSCLC with PTEN loss or MET Y1230C mutation after progression on prior osimertinib and savolitinib treatment. Conclusions: Altogether, REGN5093-M114 is a promising candidate to overcome the challenges facing functional MET pathway blockade.