Abstract 3307: c-Met targeting chaperone-mediated protein degrader for therapeutic intervention in NSCLC

Abstract The interaction between E3 ligases and chaperones is crucial for proteostasis, regulating more than 10% of total proteasomes and over 30% of human E3 ligases (Kevei, 2017). Chaperones also can recognize their substrates and direct them to degradation by the ubiquitin-proteasome system (UPS). Developing a targeted protein degradation (TPD) technology that utilizes these advantageous attributes of chaperones, termed chaperone-mediated protein degradation (CMPD) technology, would broaden the range of disease-causing target proteins and would efficiently degrade them by recruiting various intracellular E3 ligases through interaction with chaperones, compare to other TPD approaches. The c-mesenchymal-epithelial transition (c-MET) is recognized as primary cause of drug-resistance to EGFR inhibitors in non-small cell lung cancer (NSCLC). Herein, to degrade the c-MET, we synthesized bifunctional small molecule compound inducing c-MET and chaperones in proximity, termed CMPD-MET degrader, and evaluate it in MET-mutant NSCLC cell lines and mouse xenograft models. The efficacy and potency of CMPD-MET degrader were assessed using H596 and H1437 cells in vitro. Cell proliferation was measured using MTT assay and c-Met degradation assay was conducted, along with the examination of proteasome-dependent degradation via western blot. An in vivo H596 xenograft model gauged impact of CMPD-MET degrader via I.P. administration. In NSCLC with MET Exon 14 skipping mutation cell line H596 and H1437, treatment a OZD-MET degrader resulted inhibition of cell proliferation with IC50< 5 µM and subsequent proteasome-dependent c-MET degradation with DC50 ranging from 4-6 µM for 24h. The degradation of c-MET levels significantly induced by OZD-MET degrader, especially, the c-Met was degraded by 70.4% and 51.7% at 5 µM for 24h in H596 and H1437 cells, respectively. Also, OZ-MET degrader effectively suppressed c-MET mediated signaling and showed cleavage of PARP-1 in a dose-dependent manner. OZD-MET degrader induced selective degradation of c-MET showing at least more than about 5-fold selectivity over other chaperones-regulated client proteins.In the H596 xenograft model, OZD-MET degrader was administered in 5 dosage groups (minimum dose is 2.5 mg/kg) resulted in dramatic reduction in tumor size compared to the vehicle-treated group. Remarkably, administration of OZD-MET degrader revealed more than 90% degradation of c-Met in tumor tissues compared to the vehicle groups via western blots and fluorescence image. In contrast, c-MET inhibitor treated group showed no effect on degradation of c-MET in tumor tissues. In summary, we developed a novel c-Met targeting chaperone-mediated protein degrader, showed highly potent and selective proteasome-dependent c-MET degradation and notable inhibition of tumor size in xenograft models. These results provide a strong foundation for further evaluation in clinical trials. Citation Format: Han Jung Chae, Jisun Kim, SunHye Lee, Ho Yoo, Hyun-Kyoung Kim, Young-Jin Yu. c-Met targeting chaperone-mediated protein degrader for therapeutic intervention in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3307.