High c-Met Expression Research Articles

Targeting c-MET for Endoscopic Detection of Dysplastic Lesions Within Barrett's Esophagus Using EMI-137 Fluorescence Imaging.

Esophageal cancer (EC) carries a poor prognosis with 5-year overall survival of less than 20%. Barrett's esophagus (BE) increases the risk of esophageal adenocarcinoma (EAC). The aim of this study was to investigate the ability of EMI-137, a mesenchymal-epithelial transition factor (c-MET)-targeting optical imaging tracer, to detect dysplasia in BE. c-MET expression in human esophageal tissue was investigated using Gene Expression Omnibus (GEO) datasets, tissue microarrays and BE biopsies. EMI-137 was tested in a dual xenograft mouse model bearing OE33 (c-MET high expression) and FLO-1 (c-MET low expression) tumors. Fluorescence molecular endoscopy (FME) was performed in a mouse model of Barrett's-like metaplasia and dysplasia (L2-IL1β). Tumors and organs-of-interest were evaluated through ex vivo fluorescence imaging. MET mRNA expression analyses and c-MET immunostaining confirmed upregulation of c-MET in BE and EAC compared to normal epithelium. There was strong accumulation of EMI-137 in OE33 xenografts 3 h post injection decreasing by more than 50% on co-injection of a 10-fold molar excess of unlabeled EMI-137. The target-to background ratio (TBR) at 3 h p.i. for OE33 and FLO-1 tumors was 10.08 and 1.42, respectively. FME of L2-IL1β mice showed uptake of EMI-137 in dysplastic lesions within BE with a TBR of 1.9 in vivo, and greater than 2 in ex vivo fluorescence imaging. EMI-137 accumulates in dysplastic lesions within BE and in c-MET positive EAC. EMI-137 imaging has potential as a screening and surveillance tool for patients with BE and as a means to detecting dysplasia and EAC.

Xanthohumol overcomes osimertinib resistance via governing ubiquitination-modulated Ets-1 turnover

Non-small cell lung cancer (NSCLC) is a prevalent and fatal malignancy with a significant global impact. Recent advancements have introduced targeted therapies like tyrosine kinase inhibitors (TKIs) such as osimertinib, which have improved patient outcomes, particularly in those with EGFR mutations. Despite these advancements, acquired resistance to TKIs remains a significant challenge. Hence, one of the current research priorities is understanding the resistance mechanisms and identifying new therapeutic targets to improve therapeutic efficacy. Herein, we identified high expression of c-Met in osimertinib-resistant NSCLC cells, and depletion of c-Met significantly inhibited the proliferation of osimertinib-resistant cells and prolonged survival in mice, suggesting c-Met as an attractive therapeutic target. To identify effective anti-tumor agents targeting c-Met, we screened a compound library containing 641 natural products and found that only xanthohumol exhibited potent inhibitory effects against osimertinib-resistant NSCLC cells. Moreover, combination treatment with xanthohumol and osimertinib sensitized osimertinib-resistant NSCLC cells to osimertinib both in vitro and in vivo. Mechanistically, xanthohumol disrupted the interaction between USP9X and Ets-1, and inhibited the phosphorylation of Ets-1 at Thr38, promoting its degradation, thereby targeting the Ets-1/c-Met signaling axis and inducing intrinsic apoptosis in osimertinib-resistant NSCLC cells. Overall, the research highlights the critical role of targeting c-Met to address osimertinib resistance in NSCLC. By demonstrating the efficacy of xanthohumol in overcoming resistance and enhancing therapeutic outcomes, this study provides valuable insights and potential new strategies for improving the clinical management of NSCLC.

Design, Synthesis and Evaluation of a Novel Teoptinib Derivative as an Effective Anti-hepatocellular Carcinoma Agent.

Hepatocellular Carcinoma (HCC) is a type of liver cancer known for its poor prognosis and high mortality. Teoptinib is a highly selective MET inhibitor that has been used in the treatment of liver cancer. Although good progress has been made in clinical treatment, further improvement is still needed. In this study, a series of novel Teoptinib derivatives were synthesized and evaluated as anti-cancer agents for the treatment of liver cancer, and an oral nanodrug delivery system was also explored. A series of novel Teoptinib derivatives were synthesized, and an oral nanodrug delivery system was also explored. HPLC, high-resolution mass spectrometer and NMR were used to determine the structure and molecular formula of the synthesized compounds. Zeta potential assay was used to access the particle size distribution and zeta potential of the nanoparticles. MTT assay, cell colony formation assay, cell apoptosis inhibition assay, cell scratch assay, and the MHCC-97H xenograft model of nude mice assay were used to evaluate the in vitro and in vivo anti-tumor activity of the synthesized compounds. Compound (R)-10 showed the best antitumor activity with 0.010 μM of the IC50 value against MHCC-97H, a human liver cancer cell line with high c-Met expression. The MHCC-97H xenograft model of nude mice assay showed that nano-prodrug of compound (R)-10 exhibited good in vivo activity with 87.67% of the TGI at the dosage of 8 mg/kg. We designed and synthesized a series of c-Met inhibitors containing different side chains and chiral centers as anti-liver cancer agents. Among them, compound (R)-10 shows a promising effect as a lead molecule for further study in the treatment of liver cancer. The successful incorporation of (R)-10 into a novel oral nanodrug delivery system highlights the importance of effective drug delivery systems for enhanced therapeutic efficacy.

MYTX-011: a pH-dependent anti-cMET antibody-drug conjugate designed for enhanced payload delivery to cMET expressing tumor cells.

Advances in linker payload technology and target selection have been at the forefront of recent improvements in antibody-drug conjugate (ADC) design, leading to several approvals over the last decade. In contrast, the potential of novel ADC technologies to enhance payload delivery to tumors is relatively underexplored. We demonstrate that incorporation of pH-dependent binding in the antibody component of a cMET targeting ADC (MYTX-011) can overcome the requirement for high cMET expression on tumors, an innovation that has the potential to benefit a broader population of patients with lower cMET levels. MYTX-011 drove four-fold higher net internalization than a non-pH engineered parent ADC in non-small cell lung cancer (NSCLC) cells and showed increased cytotoxicity against a panel of cell lines from various solid tumors. A single dose of MYTX-011 showed at least three-fold higher efficacy than a benchmark ADC in mouse xenograft models of NSCLC ranging from low to high cMET expression. Moreover, MYTX-011 showed improved pharmacokinetics over parent and benchmark ADCs. In a repeat dose toxicology study, MYTX-011 exhibited a toxicity profile similar to other MMAE-based ADCs. These results highlight the potential of MYTX-011 for treating a broader range of NSCLC patients with cMET expression than other cMET targeting ADCs. A first in human study is ongoing to determine the safety, tolerability, and preliminary efficacy of MYTX-011 in patients with NSCLC (NCT05652868).

First-in-human study of ABBV-400, a novel c-Met–targeting antibody-drug conjugate, in advanced solid tumors: Results in colorectal cancer.

3515 Background: c-Met (MET protein) is frequently overexpressed in several advanced solid tumors including colorectal cancer (CRC). There are no approved therapies specific for c-Met–overexpressing tumors in CRC. The antibody-drug conjugate ABBV-400 comprises c-Met–targeting antibody telisotuzumab conjugated to a novel topoisomerase 1 inhibitor payload. A phase 1 study of ABBV-400 was initiated for adults with advanced solid tumors and progression on standard therapies (NCT05029882); results from dose escalation (ESC) at doses 1.6–6.0 mg/kg once every 3 weeks (Q3W) were previously presented and showed preliminary efficacy (Sharma et al. ASCO 2023. Abstract 3015). We present data from dose ESC and expansion (EXP) cohorts in CRC. Methods: During EXP, patients (pts) with CRC were randomized to receive ABBV-400 at 1.6, 2.4, or 3.0 mg/kg Q3W. Primary objectives were to evaluate the safety, tolerability, pharmacokinetics, preliminary efficacy, and the recommended phase 2 dose of ABBV-400. Results: As of Oct 2023, 122 pts (ESC: 29; EXP: 93) were included. Median age: 56 years; 65 (53%) males. Median prior treatments was 4. Follow-up was longer in ESC vs EXP (14.8 vs 3.8 months). Seventy-eight (64%) pts had a grade (G)≥3 treatment-emergent adverse event (TEAE); 41% had a serious TEAE. Most frequent hematologic TEAEs were anemia (52%; G≥3: 30%), neutropenia (37%; G≥3: 25%), leukopenia (25%; G≥3: 12%), and thrombocytopenia (23%; G≥3: 12%); nonhematologic TEAEs were nausea (57%, G≥3: 3%), fatigue (43%; G≥3: 2%), and vomiting (39%, G≥3: 4%). G≥3 diarrhea was < 1%. Unadjudicated interstitial lung disease/pneumonitis rate was 7% (G≥3: 2%). Treatment-related AEs leading to discontinuation occurred in 11 (9%) pts. Preliminary efficacy outcomes are shown in the Table. The majority of tissues expressed c-Met. In pts with higher c-Met expression, an increased ORR of > 30% was observed at efficacious doses (≥2.4 mg/kg). Activity was also seen at lower c-Met expression levels (10–15% ORR). Conclusions: ABBV-400 at 2.4 and 3.0 mg/kg Q3W has a tolerable and manageable safety profile, with promising antitumor activity. Long-term tolerability appears improved at 2.4 relative to 3.0 mg/kg, with higher relative dose intensity and generally lower TEAEs. The study is also evaluating ABBV-400 with bevacizumab in pts with CRC. Clinical trial information: NCT05029882 . [Table: see text]

Abstract LB043: VBC101-F11: An innovative EGFR/cMet bispecific antibody drug conjugate (ADC) targeting key oncogenic drivers in solid tumors

Abstract EGFR and cMet are two classic growth factor receptors frequently co-expressed in solid tumors at significantly high levels, while only limited to moderate expression in normal tissues. Beyond their co-expression patten, the aberrant or over expression in their pathway are implicated in oncogenesis. Notably, MET pathway activation either through increased cMet expression or its ligand, is often associated with resistance to EGFR tyrosine kinase inhibitors (TKI). Therefore, the interplay between EGFR and cMet, coupled with their differential expression in tumors versus normal tissue substantiates the rationale for a bispecific approach that targets both receptors to enhance tumor specificity. VBC101-F11 is a bispecific anti-EGFR/cMet ADC engineered to deliver clinically validated cytotoxic agents to tumor cells with a drug-to antibody ratio (DAR) of 4. This innovative design distinguishes VBC101-F11 from other EGFR/cMet-targeting agents on the market or in clinical trials (ABBV399 or AZD9592), optimizing both efficacy and safety. 1. VBC101-F11 features a low-affinity EGFR arm coupled with a high-affinity cMet arm. Incorporating the low-affinity EGFR arm enhances binding avidity and internalization, resulting in a superior cytotoxicity with a 5-fold improvement in IC50 compared to ABBV-399 (targeting cMet only). This nuanced EGFR arm design ensures a reduction in EGFR-related off-target toxicity in normal tissues. 2. The biparatopic design in cMet arm further underscores our strategic rationale by demonstrating a synergistic effect in terms of binding, internalization, and functional blocking with a 10-fold improvement in EC50 compared to the monospecific parental antibodies that target a single epitope. This ensures VBC101-F11’s maximized efficacy in tumor cells. 3. VBC101-F11’s innovative nanobody-based format sets our molecule apart. Living imaging data in mouse model reveals that VBC101-F11 (90kD) achieves superior tumor penetration and accumulation from 1 hour to over 90 hours surpassing the mAb ABBV399 and bispecific antibody AZD9592, both at 150kD. 4. VBC101-F11 has demonstrated outstanding molecular developability in stress tests, particularly in human and non-human primate (NHP) plasma, where both the antibody component and the entire ADC molecule exhibit remarkable stability, positioning VBC101-F11 as a viable candidate for future Chemistry, Manufacturing, and Controls (CMC) development. 5. In in vivo CDX models using various lung cancer cell lines, VBC101-F11 equipped with MMAE warhead displayed a marked superiority in tumor growth inhibition (TGI of 60% vs. 17%) at a single dose of 3mg/kg compared to MMAE conjugating ADC ABBV-399. Further payload exploration, such as DNA replication inhibitor, has also yielded promising results, with VBC101-F11-new payload showing comparable efficacy to the same class ADC AZD9592 in models with low EGFR and high cMet expression (100% TGI) and in those with moderate EGFR/cMet expression (~ 60% TGI). In summary, VBC101-F11, with unique design and distinguished attributes, has demonstrated its remarkable potential in the landscape of anti-EGFR/cMet therapies. The encouraging efficacy observed in preclinical models supports the molecule’s advancement into clinical development, positioning it as a best-in-class bispecific ADC for treating tumors in patients. Citation Format: Wei (Vivian) Wang, Jing Li, Lin Ma, Man Xu, Qun Yin. VBC101-F11: An innovative EGFR/cMet bispecific antibody drug conjugate (ADC) targeting key oncogenic drivers in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB043.

Abstract 4555: c-Met/AXL crosstalk in mediating therapeutic resistance in renal cell carcinoma

Abstract Receptor Tyrosine Kinase (RTK), c-Met, is overexpressed in renal cancer and correlates with a decreased survival rate. Upon binding with its specific ligand, Hepatocyte Growth Factor (HGF), c-Met activates pro-tumorigenic signaling. c-Met/RTK inhibitors are used for the treatment of advanced renal cell carcinoma (RCC). However, acquired therapeutic resistance is a major clinical problem and the underlying mechanisms are largely unknown. Hence, novel therapeutic targets are needed to overcome the clinical hurdles; and the RTK, AXL, can be a potential target. AXL is overexpressed and a poor prognostic marker in RCC. AXL overexpression drives wide-ranging processes, including epithelial-to-mesenchymal transition (EMT), tumor angiogenesis, and resistance to chemotherapeutics. Cabozantinib (XL184/Cabo), is approved for advanced-stage RCC and can inhibit c-Met and VEGFR2 activation (including AXL and a few other RTKs); however, it is not a specific/potent inhibitor of AXL. Hence, inhibiting c-Met alone may not be sufficient when AXL remains active. Therefore, the pro-tumorigenic role of AXL and its cross-talk with c-Met in renal cancer need to be thoroughly investigated. We compared the expression of c-Met and AXL in TCGA and found significantly high expression of both c-Met and AXL in primary renal tumor tissues compared to normal tissues. Our data showed that AXL forms a complex with c-Met and may have a significant cross-talk which can be involved in therapeutic resistance. We have also found that prolonged treatment of c-Met inhibitor Cabo, (including Crizotinib and PF-4217903) induced c-Met and AXL overexpression in RCC cells. Interestingly, c-Met inhibitor(s)-induced overexpressed c-Met can also be increasingly phosphorylated (at low concentrations) in the presence of HGF, which may cause enhanced downstream tumor-promoting signaling. To understand the role of AXL in tumor-promoting pathways and therapeutic resistance, we have generated CRISPR/Cas9-mediated AXL knock-out cells (AXL-KO) and found that silencing AXL can prevent c-Met-inhibitor(s)-mediated c-Met overexpression. Furthermore, to identify the effect of AXL-KO on pro-tumorigenic signaling, transcriptional profiles of control clones and AXL-KO cells were compared. The gene set enrichment analysis (GSEA) showed that genes involved in ‘EMT’, ‘Hypoxia’, and ‘K-Ras’ signaling pathways were significantly downregulated. We have also utilized an AXL-specific small molecule inhibitor, TP-0903, in combination with Cabo and validated our data. We have also generated a Cabo-resistant cell line (Caki-1) and found high expression of c-Met and AXL in these cells. Furthermore, either silencing of AXL (using siRNA) or inhibiting AXL (using TP0903) induced significant apoptosis in these Cabo-resistant cells. Together, our data suggest that inhibition of AXL along with c-Met can be beneficial in preventing acquired therapeutic resistance in RCC. Citation Format: Akash Sabarwal, Laxminarayan Rawat, Johannes Wedel, Murugabaskar Balan, Gwo-Shu Mary Lee, Toni K. Choueiri, Soumitro Pal. c-Met/AXL crosstalk in mediating therapeutic resistance in renal cell carcinoma [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 4555.

Abstract 1907: MYTX-011: A pH-dependent anti-cMET ADC with increased payload delivery in vivo and potent activity against cMET-expressing tumors of various epithelial origins

Abstract cMET is an oncogenic receptor tyrosine kinase overexpressed in multiple types of solid tumors, including non-small cell lung cancer (NSCLC), gastric, head and neck, liver cancer and others. Several cMET-directed therapies including antibody-drug conjugates (ADCs) have been developed that may benefit a subset of patients with tumors that have high cMET expression, MET amplification, or dependency on cMET signaling. MYTX-011 is an investigational, pH-sensitive, vcMMAE-based ADC that is designed to potentially benefit not only patients whose tumors express high levels of cMET, but also a broader set of patients whose tumors express low to moderate levels of cMET. MYTX-011 is engineered to rapidly dissociate from cMET only at the acidic pH of endolysosomes. We have previously demonstrated that MYTX-011 drives increased internalization and cytotoxicity in tumor cells expressing moderate cMET levels compared to a matched parent non-pH sensitive ADC. MYTX-011 also demonstrated markedly superior efficacy in NSCLC xenografts with moderate cMET expression as compared to either the parent ADC or benchmark ADCs representing clinical-stage anti-cMET ADCs with vcMMAE and maytansinoid payloads. MYTX-011 was efficacious in NSCLC PDX models with moderate cMET expression of adenocarcinoma/squamous histology and in heterogeneous cMET-expressing EGFR mutant models. In these studies, we demonstrate that MYTX-011 exerts enhanced efficacy by delivering increased levels of payload to cMET+ tumors compared to the parent ADC. MYTX-011 treatment induced significantly increased levels of phospho-histone H3 (pHH3), a pharmacodynamic marker of MMAE cytotoxicity, in moderate cMET expressing NCI-H1975 NSCLC xenograft tumors compared to the parent ADC. Further, increased levels of free MMAE were detected in tumors from mice treated with MYTX-011 compared to a matched dose of the parent ADC, indicating that the pH dependent binding engineered into MYTX-011 translated to increased payload delivery to tumors in vivo. To explore the potential efficacy of MYTX-011 in other cMET-expressing tumor types, we tested the activity of MYTX-011 in a panel of cell lines derived from gastric and head and neck cancers. MYTX-011 demonstrated increased cMET-dependent cytotoxicity compared to the parent ADC. MYTX-011 was also highly active in cMET+ xenograft models derived from gastric (non-MET amplified), esophageal, and head and neck cancers. Together, these findings highlight the potential of MYTX-011 as a therapeutic candidate for treating a broader range of cMET-expressing malignancies. Citation Format: Deepak Kanojia, William Comb, William Israelsen, Federico Colombo, Lin Nie, Nimish Gera, Thomas Chittenden, Brian Fiske. MYTX-011: A pH-dependent anti-cMET ADC with increased payload delivery in vivo and potent activity against cMET-expressing tumors of various epithelial origins [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 1907.

Abstract 5939: Enhancing nab-paclitaxel chemotherapy response in gastric cancer preclinical models through Inhibition of the HGF/c-Met pathway with merestinib

Abstract Background: Current treatments for primary metastatic or recurrent gastric adenocarcinoma (GAC) primarily involve combination chemotherapy, but the median survival time remains under a year. Nab-paclitaxel has displayed significant antitumor activity in preclinical GAC studies. GAC often exhibits overexpression of various growth factors and their receptors, which play a critical role in its pathophysiology. Aberrant activation of the HGF/c-Met pathway has been reported in up to 50% of GAC patients. We investigated the therapeutic potential of merestinib, a novel inhibitor targeting c-Met, along with Axl and DDR1/2 pathways, in combination with nab-paclitaxel in GAC preclinical models. Methods: Animal survival studies were conducted using peritoneal dissemination xenografts in NOD/SCID mice implanted with MKN-45 cells. Tumor growth was assessed in subcutaneous xenografts using MKN-45 and SNU-1 cells in NOD/SCID mice. IHC analyses were performed to evaluate tumor cell proliferation and microvessel density. In vitro cell proliferation and protein expression were assessed using the WST-1 assay and Western blot analysis, respectively. Results: Animal survival significantly improved with nab-paclitaxel (118%) and merestinib (41%) individually. The combination of merestinib with nab-paclitaxel (153%) resulted in further increased animal survival. In MKN-45 xenografts with high c-Met expression, a substantial reduction in tumor growth was observed with nab-paclitaxel and merestinib, showing a synergistic response. The net change in tumor size in the control, nab-paclitaxel, merestinib, and combination groups was 503 mm3, 115 mm3, 91 mm3, and -9.7 mm3 (tumor regression). In low c-Met expressing SNU-1 xenografts, the effect of merestinib and nab-paclitaxel was less pronounced compared to MKN-45 xenografts. The net change in tumor size in the control, nab-paclitaxel, merestinib, and combination groups was 219 mm3, 105 mm3, 131 mm3, and 57 mm3. Tumor cell proliferation and microvessel density corroborated the tumor growth study results. Nab-paclitaxel and merestinib reduced in vitro cell proliferation, with an additive effect in combination. The reduction in cell proliferation by nab-paclitaxel (10 nM), merestinib (100 nM), and their combination was 87%, 82%, and 94% in MKN-45, 59%, 50%, and 82% in SNU-1, and 53%, 19%, and 66% in gastric fibroblasts. In MKN-45 cells, merestinib increased the expression of pro-apoptotic proteins and decreased the expression of phospho-c-Met, phospho-EGFR, phospho-IGF-1R, phospho-ERK, and phospho-AKT. Conclusion:Merestinib has strong antitumor activity in GAC, especially when administered with nab-paclitaxel, demonstrating a synergistic effect. These results provide compelling evidence for the potential clinical relevance of this combination therapy in improving the survival of GAC patients. Citation Format: Quinn Kaurich, Jennifer Huang, Sazzad Hassan, Urs von Holzen, Niranjan Awasthi. Enhancing nab-paclitaxel chemotherapy response in gastric cancer preclinical models through Inhibition of the HGF/c-Met pathway with merestinib [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 5939.

Abstract 2116: Telisotuzumab vedotin (Teliso-V)-mediated c-Met internalization, endolysosomal trafficking, and potent cytotoxic activity are unaffected by MET exon-14 skipping mutation

Abstract Background: Telisotuzumab vedotin (Teliso-V) is an antibody-drug conjugate (ADC) composed of a c-Met (MET protein) antibody coupled to the microtubule inhibitor monomethyl auristatin E (MMAE). Teliso-V was granted FDA Breakthrough Therapy Designation for advanced/metastatic EGFR WT, NSQ NSCLC with high c-MET overexpression. For MMAE drug delivery, Teliso-V must first undergo receptor internalization and endolysosomal (EL) trafficking. Hepatocyte growth factor (HGF)-dependent MET EL trafficking and degradation depend on the E3 ubiquitin ligase Casitas B-lineage lymphoma (CBL). METex14 skipping and CBL-binding site mutations, which delete the binding site for CBL, occur in ~ 3% of NSCLC. The role of CBL in Teliso-V-MMAE delivery and activity was assessed in this work. Methods: WT-human c-Met, c-Met-Y1003F/N (CBL binding site mutations in MET), and c-Met-ex14∆ (47 aa deletion to mimic ex14 skipping) or CBL-L620f, G807*, and W802* (CBL inactivating mutants) were expressed in NIH3T3, Ba/F3 cells, or A549 tumor cells using retroviral transduction. Genetically modified cells were then used to define the role of CBL in c-Met surface expression, intracellular signaling, EL trafficking (using pHrodo Red-labeled Teliso-V), and Teliso-V sensitivity in 2D/3D cell cultures. Results: c-Met expression was required for Teliso-V cytotoxicity and intracellular payload delivery in all cell lines. While minimal changes in cell surface c-Met levels were observed, CBL binding mutants had increased phosphorylated c-Met in the absence of HGF, and ex14∆-MET and CBL binding site mutants showed increased sensitivity to small molecule c-Met inhibitors. Compared to WT c-Met, ex14∆ and CBL-binding mutants showed similar EL trafficking and no change in sensitivity to Teliso-V. Co-treatment with a pan-CBL inhibitor also failed to alter Teliso-V EL trafficking and anti-tumor activity. Like most ADCs, EL trafficking was dependent on a dynamin-mediated process with reduced EL trafficking by co-treatment with Dyngo4a. To further understand the role of CBL in Teliso-V sensitivity, we expressed CBL inactivating mutations in A549 tumor cells. While the L602F and W802* mutants increased spheroid size, as well as activated p-MET, there was no change in sensitivity to Teliso-V. Conclusions: Loss of CBL-binding sites on c-Met via ex14 deletion or Y1003F/N leads to increased MET-targeted TKI sensitivity and increased phospho-c-Met levels but does not impact Teliso-V sensitivity or EL trafficking. Our results indicate that Teliso-V traffics to the EL via a dynamin-mediated process. Therefore, Teliso-V delivers MMAE through a robust ADC-mediated EL-dependent mechanism that is independent of CBL, suggesting that high c-Met expression in Ex14skipping or CBL binding site mutant NSCLC patients should be further investigated for response to Teliso-V. Citation Format: Izhar Batth, Ronald Pandoy, Shamim Khaja, Dolonchampa Maji, Tamar Uziel, Athan Vasilopoulos, Peter Ansell, PK Epling-Burnette. Telisotuzumab vedotin (Teliso-V)-mediated c-Met internalization, endolysosomal trafficking, and potent cytotoxic activity are unaffected by MET exon-14 skipping mutation [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 2116.

Abstract 2615: Preclinical development of a next generation antibody drug conjugate (ADC) targeting cMET for treatment of solid tumors

Abstract cMET (mesenchymal-epithelial transition factor), which belongs to the MET family, is a type of receptor tyrosine kinase that is expressed on the surfaces of various epithelial cells. The elevation of cMET can promote the development and progression of multiple cancers. cMET- ADCs have shown promising clinical activity with highest cMET levels, indicating tumor cMET levels may be limited for efficacy. YL211, a novel cMET-ADC was developed by leveraging on MediLink’s tumor microenvironment activable linker-payload platform (TMALIN platform), which could release the payload both in the tumor cell and in the tumor microenvironment. YL211 is comprised of an anti-cMET humanized monoclonal antibody conjugated to a novel topoisomerase 1 inhibitor via a protease-cleavable linker. The novel linker-payload and site-specific conjugation of YL211 results in a homogeneous product with a DAR (Drug-to-Antibody Ratio) of 8. Furthermore, the advancement in linker-payload design has facilitated the development of more hydrophilic ADCs, which exhibit minimal impact on the antibody's characteristics while being less prone to aggregation and showcasing lower systematic clearance. Along with release of the payload in the tumor microenvironment extracellularly, upon binding to cMET on tumor cell surfaces, the antigen-ADC complexes are internalized to lysosomal vesicles and subsequently release the toxic payload. The cytotoxic features drive cell cycle arrest, apoptosis, elevation of PARP/caspase 7 expression, as well as cell death and bystander effect. These findings translated in vivo where YL211 showed superior efficacy in causing tumor regressions and good tolerability in both cell lines and patient-derived xenograft (CDX and PDX) mouse models with both low to high cMET expression levels (H358, CR5088, ect.). The in vivo pharmacokinetics in monkeys showed that YL211 is highly stable with less than 0.1% (molar ratio) payload released in circulation. GLP safety evaluations demonstrated good safety profiles and no off-target toxicity in monkeys. These non-clinical data suggest the stability of the linker in circulation as well as efficient release of the payload in tumors with improved therapeutic window. Taken together, preclinical data suggest that YL211 could be a promising treatment strategy for cMET positive cancer patients. Citation Format: Liang Xiao, Wei Lian, Shuai Song, Qigang Liu, Qing Zong, Sasha Stann, Jiaqiang Cai, Tongtong Xue. Preclinical development of a next generation antibody drug conjugate (ADC) targeting cMET for treatment of solid tumors [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 2615.

PHA-665752's Antigrowth and Proapoptotic Effects on HSC-3 Human Oral Cancer Cells.

c-Met is a tyrosine-kinase receptor, and its aberrant activation plays critical roles in tumorigenesis, invasion, and metastatic spread in many human tumors. PHA-665752 (PHA) is an inhibitor of c-Met and has antitumor effects on many hematological malignancies and solid cancers. However, the activation and expression of c-Met and its role and the antitumor effect of PHA on human oral squamous cell carcinoma (OSCC) cells remain unclear. Here, we investigated the activation and expression of c-Met and the effects of PHA on the growth of a highly tumorigenic HSC-3 human OSCC cell line with high c-Met phosphorylation and expression. Of note, c-Met was highly expressed and phosphorylated on Y1234/1235 in HSC-3 cells, and PHA treatment significantly suppressed the growth and induced apoptosis of these cells. Moreover, PHA that inhibited the phosphorylation (activation) of c-Met further caused the reduced phosphorylation and expression levels of Src, protein kinase B (PKB), mammalian target of rapamycin (mTtor), and myeloid cell leukemia-1 (Mcl-1) in HSC-3 cells. In addition, the antiangiogenic property of PHA in HSC-3 cells was shown, as evidenced by the drug's suppressive effect on the expression of hypoxia-inducible factor-1α (HIF-1α), a critical tumor angiogenic transcription factor. Importantly, genetic ablation of c-Met caused the reduced growth of HSC-3 cells and decreased Src phosphorylation and HIF-1α expression. Together, these results demonstrate that c-Met is highly activated in HSC-3 human oral cancer cells, and PHA exhibits strong antigrowth, proapoptotic, and antiangiogenic effects on these cells, which are mediated through regulation of the phosphorylation and expression of multiple targets, including c-Met, Src, PKB, mTOR, Mcl-1, and HIF-1α.

HER3 overexpression: a predictive marker for poor prognosis in advanced ALK-positive non-small cell lung cancer treated with ALK inhibitors.

Anaplastic lymphoma kinase (ALK)-targeted tyrosine kinase inhibitors (TKIs) improve patient survival; however, some patients develop ALK-TKI resistance with unidentified mechanisms. We investigated ErbB family and c-MET expression in patients with ALK-positive non-small cell lung cancer (NSCLC) to understand their roles in the ALK-TKI response. We studied 72 patients with advanced ALK-positive NSCLC with EML4-ALK fusion variant subtyping and immunostaining for c-MET, EGFR, HER2, and HER3 on tissue specimens both pre- (primary) and post-treatment (secondary) with ALK-TKI. We investigated the association of their expression with survival outcomes and assessed the effectiveness of combining ALK and EGFR inhibitors in ALK-positive NSCLC cell lines stimulated with the HER3-specific ligand HRG1. High expression of c-MET, EGFR, HER2, and HER3 was observed in 4.9%, 18.0%, 1.6%, and 25.8% of primary tumors, respectively, and 18.5%, 37.0%, 10.7%, and 35.7% of secondary tumors, respectively. HER3 overexpression in primary tumors showed inferior survival (P=0.132). In the subgroup with EML4-ALK variant 1/2 (V1/V2), HER3 overexpression was significantly associated with inferior survival in both primary and secondary tumors (P=0.022 and P=0.004, respectively). Combination treatment with lorlatinib and erlotinib significantly reduced HRG1-induced activation of RTK signaling in ALK-positive NSCLC cells. HER3 overexpression has potential as a prognostic marker in ALK-positive NSCLCs, including ALK-TKI naïve and treated cases, especially those with EML4-ALK V1/V2. Assessing HER3 expression may be crucial for treatment planning and outcome prediction in these patients.

Abstract B124: MYTX-011 is a highly internalized ADC with anti-tumor activity across a spectrum of NSCLC preclinical models with various levels of cMET expression

Abstract cMET overexpression occurs in non-small cell lung cancer (NSCLC) and antibody-drug conjugates targeting cMET (cMET-ADCs) have been developed to treat cMET+ NSCLC tumors irrespective of dependency on cMET signaling. cMET-ADCs have shown promising clinical activity, but largely in a subset of NSCLC patients whose tumors express the highest cMET levels. MYTX-011, an investigational, pH-sensitive ADC incorporating the clinically validated vcMMAE linker-payload, was specifically designed to potentially benefit a broader population of patients including those whose tumors express lower cMET levels. We’ve previously demonstrated that pH-sensitive cMET binding of MYTX-011 drives higher internalization in cMET+ tumor cells, and greater cytotoxicity against a panel of cMET+ cancer cell lines in vitro. MYTX-011 also shows superior efficacy in NSCLC xenograft models with high or moderate cMET expression levels when compared to the matched non-pH-sensitive Parent ADC or a Benchmark ADC generated by hinge conjugation of a clinical stage anti-cMET ADC antibody to vcMMAE. Here we demonstrate that the MYTX-011 monoclonal antibody, which is engineered to selectively and rapidly lose affinity at the acidic pH of endolysosomes, rapidly internalizes and accumulates in cells expressing moderate cMET levels compared to the matched parent antibody. MYTX-011 in vitro cytotoxicity correlated with cMET expression levels and conferred sensitivity to cells that were otherwise insensitive to ADCs generated with the parent or Benchmark antibodies. Importantly, cells that were only sensitive to MYTX-011, but not matched controls, expressed low and moderate levels of cMET. Furthermore, MYTX-011 was active against the low cMET-expressing NCI-H2122 xenograft model in vivo whereas the Benchmark ADC was inactive. In the moderate cMET-expressing NCI-H1975 xenograft model, MYTX-011 was more active than both the Benchmark ADC and a second benchmark ADC generated by hinge conjugation of a clinical stage biparatopic anti-cMET ADC antibody to a maytansinoid linker/toxin. MYTX-011 activity was further evaluated against a panel of NSCLC patient derived xenograft (PDX) models with relevant histology, cMET expression, and genetic profiles. MYTX-011 was highly active in cMET+ squamous and adenocarcinoma PDX, EGFR WT and mutant PDX, in a PDX model with MET ex14 skipping mutation, and in PDX with heterogenous cMET expression. Together, these findings highlight the potential of MYTX-011 as a therapeutic candidate for treating a broader range of cMET+ NSCLC malignancies than other cMET-ADCs. Citation Format: William C Comb, Deepak Kanojia, Federico Colombo, Vijay Ramesh, Nimish Gera, Thomas Chittenden, Brian Fiske. MYTX-011 is a highly internalized ADC with anti-tumor activity across a spectrum of NSCLC preclinical models with various levels of cMET expression [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B124.

C-Met immunohistochemistry as reflex test at diagnosis for non-small cell lung cancer: a real-world experience from a monocentric case series

AimsRecent clinical trials have shown promising results with drugs targeting the hepatocyte growth factor receptor (c-Met) for advanced non-small cell lung cancers overexpressing c-Met. We assessed reflex testing of c-Met...

Discovery of novel cMET-targeting antibody Fab drug conjugates as potential treatment for solid tumors with highly expressed cMET

ABSTRACT Background Solid tumors are becoming prevalent affecting both old and young populations. Numerous solid tumors are associated with high cMET expression. The complexity of solid tumors combined with the highly interconnected nature of the cMET/HGF pathway with other cellular pathways make the pursuit of finding an effective treatment extremely challenging. The current standard of care for these malignancies is mostly small molecule-based chemotherapy. Antibody-based therapeutics as well as antibody drug conjugates are promising emerging classes against cMET-overexpressing solid tumors. Research design and methods In this study, we described the design, synthesis, in vitro and in vivo characterization of cMET-targeting Fab drug conjugates (FDCs) as an alternative therapeutic strategy. The format is comprised of a Fab conjugated to a potent cytotoxic drug via a cleavable linker employing lysine-based and cysteine-based conjugation chemistries. Results We found that the FDCs have potent anti-tumor efficacies in cancer cells with elevated overexpression of cMET. Moreover, they demonstrated a remarkable anti-tumor effect in a human gastric xenograft mouse model. Conclusions The FDC format has the potential to overcome some of the challenges presented by the other classes of therapeutics. This study highlights the promise of antibody fragment-based drug conjugate formats for the treatment of solid tumors.

HGF/C-Met Expression in Epithelial Ovarian Carcinogenesis and Its Potential as Molecular Targeted Therapy

Background: The Mesenchymal-Epithelial Transition factor (C-Met) is a tyrosine kinase receptor (TKR) that binds to a ligand called Hepatocyte Growth Factor (HGF). Recent studies conducted on patients with epithelial ovarian cancer (EOC) reported that high expression of C-Met was associated with poorer clinicopathological grading and outcomes. Therefore, this study aimed to further explore the downstream pathway specifically activated when the HGF/C-Met complex was formed, the interplay between C-Met and other molecules, as well as the impact on EOC when these interactions were inhibited through designated molecular targeted therapy.Methods: The search strategy using the PubMed search engine (https://pubmed.ncbi.nlm.nih.gov/) was conducted on September 21, 2022, with the keywords: “HGF/C-Met and ovarian cancer”. The search resulted in 261 articles, and they were filtered by “published in the last five years,” which yielded 67 articles. These articles then underwent further screening, resulting in 40 articles for analysis. A systematic literature review was conducted to improve the quality of this study. Approximately 150 articles were thoroughly examined and organized using a reference manager, then 15 with the greatest impact and clinical relevance to this study were selected. Results: The HGF/C-Met complex was found to stimulate signaling pathways linked to the growth of epithelial cells and also caused the phosphorylation of tyrosine residues on other tyrosine receptors. The activation of C-Met affected the downstream pathways involving molecules associated with cell proliferation and survival, such as epidermal growth factor receptor (EGFR), p53, and KRAS. C-Met can be combined with other tyrosine kinase inhibitors in chemotherapy to enhance the initiation of cell death (apoptosis) in cancer cells.Conclusions: The HGF/C-Met mediated a signaling cascade that played an essential role in the tumorigenesis of ovarian carcinoma and had the potential to be a targeted molecular therapy in EOC

Near-Infrared Imaging of Colonic Adenomas In Vivo Using Orthotopic Human Organoids for Early Cancer Detection.

Colorectal cancer is a leading cause of cancer-related morbidity and mortality worldwide. Premalignant lesions that are flat and subtle in morphology are often missed in conventional colonoscopies. Patient-derived adenoma colonoids with high and low cMet expression and normal colonoids were implanted orthotopically in the colon of immunocompromised mice to serve as a preclinical model system. A peptide specific for cMet was labeled with IRDye800, a near-infrared (NIR) fluorophore. This peptide was administered intravenously, and in vivo imaging was performed using a small animal fluorescence endoscope. Quantified intensities showed a peak target-to-background ratio at ~1 h after intravenous peptide injection, and the signal cleared by ~24 h. The peptide was stable in serum with a half-life of 3.6 h. Co-staining of adenoma and normal colonoids showed a high correlation between peptide and anti-cMet antibody. A human-specific cytokeratin stain verified the presence of human tissues implanted among surrounding normal mouse colonic mucosa. Peptide biodistribution was consistent with rapid renal clearance. No signs of acute toxicity were found on either animal necropsy or serum hematology and chemistries. Human colonoids provide a clinically relevant preclinical model to evaluate the specific uptake of a NIR peptide to detect premalignant colonic lesions in vivo.

Efficacy and safety of immunotherapy combined with single-agent chemotherapy as second- or later-line therapy for metastatic non-small cell lung cancer.

This study sought to assess the efficacy and safety of immunotherapy combined with single-agent chemotherapy as a second- or later-line setting for metastatic non-small cell lung cancer (NSCLC) and to provide clinical evidence for this treatment regimen. The predictive value of extracellular vesicle (EV) membrane proteins was explored in patients who underwent this treatment. Clinical data from patients diagnosed with metastatic NSCLC who received immunotherapy plus single-agent chemotherapy as a second- or later-line setting were retrospectively collected between March 2019 and January 2022. A total of 30 patients met the inclusion criteria, and all were pathologically confirmed to have NSCLC. Short-term efficacy, progression-free survival (PFS), EV markers for response prediction, and adverse events were assessed. Efficacy data were available for all 30 patients and included a partial response in 5 patients, stable disease in 18 patients, and disease progression in 7 patients. The objective response rate was 16.7%, the disease control rate was 76.7%, and the median PFS was 3.2 months. Univariate analysis showed that PFS was not associated with sex, age, smoking status, treatment lines, prior use of immunotherapy, or prior use of antiangiogenic drugs. The EV membrane proteins MET proto-oncogene, receptor tyrosine kinase (c-MET), epidermal growth factor receptor (EGFR), and vascular endothelial growth factor receptor 2 (VEGFR2) at baseline were associated with poor prognosis and correlated with the efficacy of immunotherapy plus chemotherapy. According to the receiver operating characteristics and Kaplan-Meier curve analyses, patients with high c-MET, EGFR, and VEGFR2 expression at baseline had significantly shorter PFS than those with low expression. In addition, VEGFR2 expression was increased after combined immunotherapy in responders, which was decreased in non-responders. The most common grade 2 or higher adverse events were neutropenia, gastrointestinal reactions, and thyroid dysfunction, all of which were tolerated. Immunotherapy plus single-agent chemotherapy as a second- or later-line treatment is safe, effective, and tolerable for metastatic NSCLC. EV markers can be used as predictive markers of efficacy in patients with metastatic NSCLC treated with immunotherapy plus chemotherapy to help monitor treatment efficacy and guide treatment decisions.

α-Fetoprotein contributes to the malignant biological properties of AFP-producing gastric cancer.

This study aimed to investigate whether α-fetoprotein (AFP) could affect the malignant behavior of AFP-producing gastric cancer (AFP-GC) and to explore the relationship between AFP and mesenchymal-epithelial transition factor (c-Met) in AFP-GC. In this study, 23 patients with AFP-GC (AFP[+]) and 18 patients with common gastric cancer (AFP[-]) were evaluated for the c-Met expression using immunohistochemical analysis. The AFP-GC cell line, GCIY, was used. The AFP endoribonuclease-prepared small interfering RNA (siRNA) and eukaryotic AFP overexpression vector were used to increase/knockdown the expression of AFP. Afterward, the c-Met expression was evaluated by polymerase chain reaction and western blot. The proliferation, migration, and invasion of GCIY cells were estimated before and after the AFP overexpression/knockdown. The c-Met expression in both groups was the same (p > 0.05), and AFP[+] group had a higher positive incidence of the c-Met expression than the AFP[-] group (p < 0.01). Furthermore, the c-Met expression frequency was decreased by AFP knockdown and increased by AFP overexpression (p < 0.01). The cell counting kit-8 cell proliferation assay, cell invasion, and migration assays confirmed that the AFP could affect the malignant biological behavior of AFP-GC. These findings suggest that AFP contributes to the malignant biological properties of AFP-GC and the high expression of c-Met in AFP-GC.