High c-Met Research Articles

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).

Telisotuzumab Vedotin Monotherapy in Patients With Previously Treated c-Met Protein-Overexpressing Advanced Nonsquamous EGFR-Wildtype Non-Small Cell Lung Cancer in the Phase II LUMINOSITY Trial.

Telisotuzumab vedotin (Teliso-V) is a c-Met-directed antibody-drug conjugate with a monomethyl auristatin E cytotoxic payload. The phase II LUMINOSITY trial (ClinicalTrials.gov identifier: NCT03539536) aimed to identify the optimal c-Met protein-overexpressing non-small cell lung cancer (NSCLC) population for treatment with Teliso-V (stage I) and expand the selected group for efficacy evaluation (stage II). Stage II enrolled patients with nonsquamous epidermal growth factor receptor (EGFR)-wildtype NSCLC. Eligible patients had locally advanced/metastatic c-Met protein-overexpressing NSCLC and ≤2 previous lines of therapy (including ≤1 line of systemic chemotherapy). c-Met protein overexpression in nonsquamous EGFR-wildtype NSCLC was defined as ≥25% tumor cells with 3+ staining (high [≥50% 3+]; intermediate [≥25%-<50%]). Teliso-V was administered at 1.9 mg/kg once every 2 weeks. The primary end point was overall response rate (ORR) by independent central review. In total, 172 patients with nonsquamous EGFR-wildtype NSCLC received Teliso-V in stages I and II. ORR was 28.6% (95% CI, 21.7 to 36.2; c-Met high, 34.6% [95% CI, 24.2 to 46.2]; c-Met intermediate, 22.9% [95% CI, 14.4 to 33.4]). The median duration of response was 8.3 months (95% CI, 5.6 to 11.3; c-Met high, 9.0 [95% CI, 4.2 to 13.0]; c-Met intermediate: 7.2 [95% CI, 5.3 to 11.5]). The median overall survival was 14.5 months (95% CI, 9.9 to 16.6; c-Met high, 14.6 [95% CI, 9.2 to 25.6]; c-Met intermediate, 14.2 [95% CI, 9.6 to 16.6]). The median progression-free survival was 5.7 months (95% CI, 4.6 to 6.9; c-Met high, 5.5 [95% CI, 4.1 to 8.3]; c-Met intermediate: 6.0 [95% CI, 4.5 to 8.1]). Most common any-grade treatment-related adverse events (AEs) were peripheral sensory neuropathy (30%), peripheral edema (16%), and fatigue (14%); the most common grade ≥3 AE was peripheral sensory neuropathy (7%). Teliso-V was associated with durable responses in c-Met protein-overexpressing nonsquamous EGFR-wildtype NSCLC, especially in those with high c-Met. AEs were generally manageable.

A phase 3 global study of telisotuzumab vedotin versus docetaxel in previously treated patients with c-Met 0verexpressing, EGFR wildtype, locally advanced/metastatic nonsquamous NSCLC (TeliMET NSCLC-01).

TPS8656 Background: Non-small cell lung cancer (NSCLC) encompasses over two-thirds of lung cancer diagnoses, most presenting as advanced disease. c-Met (MET protein) is overexpressed in NSCLC. In this study, we investigate telisotuzumab vedotin (Teliso-V), a first-in-class antibody-drug conjugate composed of a c-Met–targeting antibody (telisotuzumab) and a microtubule polymerization inhibitor (cytotoxin monomethyl auristatin E). Interim efficacy analysis of the Phase 2 LUMINOSITY study (NCT03539536) of Teliso-V monotherapy showed an objective response rate (ORR) of 37% (95% CI: 24–51) in previously treated patients (pts) with c-Met overexpressing epidermal growth factor receptor (EGFR) wildtype (WT) nonsquamous NSCLC and 52% (95% CI: 31–73) in the high c-Met overexpressing group (Camidge DR et al. J Clin Oncol. 2022;40(16_suppl):9016). Methods: This randomized, open-label, global Phase 3 study (NCT04928846) evaluates the efficacy, safety, pharmacokinetics, and pharmacodynamics of Teliso-V monotherapy compared with docetaxel in pts with locally advanced/metastatic c-Met overexpressing EGFR WT nonsquamous NSCLC who have progressed on prior therapy. Enrollment began in May 2022. To be eligible across global sites, pts must be ≥18 years old with c-Met overexpressing (ie, ≥25% tumor cells at 3+ intensity by IHC assay [anti-MET clone SP44; Roche Tissue Diagnostics]) locally advanced/metastatic EGFR WT NSCLC, with ECOG score ≤1. Pts must have progressed on at least one prior line of therapy, which can include no more than one line of prior chemotherapy, and must be naïve to c-Met–targeted antibodies and docetaxel. Target enrollment is 698 pts. Pts will be randomized 1:1 to Teliso-V (1.9 mg/kg every 2 weeks) and docetaxel (control, 75 mg/m2 every 3 weeks). Treatment continues until disease progression or discontinuation criteria are met. Co-primary endpoints are progression-free survival by independent central review and overall survival. Secondary endpoints include ORR, duration of response, and patient-reported outcomes. Safety, adverse events (AEs), drug discontinuation or dosing modification due to AEs, and tolerability will be assessed. Previously presented at the 2023 ESMO Congress, Final Publication Number: 1501TiP, Antonio Lugini et al. - Reused with permission. Clinical trial information: NCT04928846 .

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 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 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 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.

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.

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.

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.

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.

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.

Low co-expression of PD-L1 and oncogenic receptor tyrosine kinases HER2 and cMET in urothelial carcinoma is associated with discordant expression between primary and metastatic sites

Novel regimens targeting immune checkpoints and the cMET or HER2 pathways are under investigation in metastatic urothelial carcinoma (mUC) though co-expression of these molecular targets has not been defined. We sought to characterize the protein co-expression rates of PD-L1, cMET and HER2 in primary and metastatic mUC lesions and agreement rates in paired biopsies.We assessed PD-L1, cMET and HER2 protein expression by immunohistochemistry (IHC) in archival mUC samples identified from an institutional database (n = 143). Correlation of expression between primary and metastatic biopsies was performed in patients with available paired biopsies (n = 79). Protein expression levels by predefined thresholds were measured, and Cohen's kappa statistics (κ) were utilized to assess the agreement in expression between paired primary and metastatic samples.In primary tumors (n = 85), high expression of PD-L1, cMET, and HER2 was observed in 14.1%, 34.1%, and 12.9%, respectively. In metastatic samples (n = 143), high expression of PD-L1, cMET and HER2 was detected in 9.8%, 41.3%, and 9.8%, respectively. Expression agreement rates between paired specimens (n = 79) were PD-L1: 79.7% (κ = 0.09), cMET: 69.6% (κ = 0.35), HER2: 84.8% (κ = 0.17). High PD-L1/cMET co-expression was observed in only 5.1% (n = 4) of primary and 4.9% (n = 7) of metastatic specimens. High co-expression of PD-L1/HER2 occurred in 3.8% (n = 3) of primary samples and no metastatic samples. The overall co-expression agreement between paired samples was 55.7% (κ = 0.22) for PD-L1/cMET and 67.1% (κ = 0.06) for PD-L1/HER2, but agreement for high co-expression between paired samples was very low (2.5% for PD-L1/cMET and 0% for PD-L1/HER2).Tumor co-expression of high cMET or HER2 and PD-L1 is low in this cohort. Agreement of high co-expression between primary and metastatic sites is rare. Biomarker-based strategies used in selection of patients for contemporary trials testing combinations of immune checkpoint inhibitors with either cMET or HER2-targeted agents should account for discordant biomarker expression between primary and metastatic sites.

Phase 1 multicenter dose escalation and dose expansion study of antibody-drug conjugate (ADC) MYTX-011 in subjects with non-small cell lung cancer.

TPS9147 Background: cMET is a receptor tyrosine kinase and proto-oncogene whose activity is upregulated across a wide range of cancers. In NSCLC, expression of cMET is upregulated by DNA amplification (2% to 5%), exon 14 skipping mutations (2% to 4%), and overexpression (30% to 60%). In NSCLC, cMET upregulation has also been demonstrated to be a resistance mechanism for several approved EGFR-targeted kinase inhibitors, and this may limit their effectiveness. Despite the approval of MET tyrosine kinase inhibitors, almost half of patients do not respond to these inhibitors and resistance is inevitable. MYTX-011 is an ADC incorporating the clinically validated vcMMAE linker-payload conjugated to a novel, pH-dependent anti-cMET antibody. In preclinical studies, MYTX-011, compared to a surrogate of an advanced clinical stage cMET ADC, showed markedly higher ( &gt; 3 fold) internalization and increased cytotoxicity in cMET+ tumor cells in vitro, which translates to greater (≥3 fold) efficacy in high or moderate c-Met+ xenograft models in vivo. PK and toxicity studies revealed that MYTX-011 exhibited favorable PK characteristics, and a toxicity profile similar to previously described MMAE-based ADCs. Methods: MYTX-011-01 (ClinicalTrials.gov Identifier: NCT05652868) is a first-in-human Phase 1 dose escalation and dose expansion study. MYTX-011 will be administered intravenously every 21 days for a maximum of 2 years. Part 1 (dose escalation) will assess the safety and tolerability of MYTX-011 in patients with advanced NSCLC and identify the recommended Phase 2 dose (RP2D). Part 2 (dose expansion) will include subjects with NSCLC with cMET overexpression or MET amplification/exon 14 skipping mutations. In Part 1, subjects will be enrolled to evaluate the safety of escalating doses of MYTX-011 as a single-agent and to establish the RP2D and/or MTD. The dose escalation scheme is based on a 3-subject cohort minimum Bayesian Optimal Interval (BOIN) design. The RP2D will be selected as a biologically active dose at or below the MTD (or the highest dose tested if an MTD is not identified during the study) and will be informed by safety, tolerability, pharmacokinetic data, and preliminary anti-tumor activity of MYTX-011 based on RECIST 1.1. Part 2 of the study will be initiated once the RP2D has been determined and will enroll subjects into different cohorts based on cMET IHC positivity cutoff and/or presence of MET genetic alterations ( MET amplification or exon 14 skipping). All cohorts are defined to explore preliminary antitumor activity in populations with different thresholds of cMET positivity that were selected based on data for cMET expression and efficacy observed with MYTX-011 in preclinical models, published data for responses to cMET targeting agents, and on the prevalence of subject tumors with different expression levels. Enrollment in the MYTX-011-01 study is ongoing. Clinical trial information: NCT05652868 .

Abstract 540: c-MET mutations sensitize to antibody-drug conjugate telisotuzumab vedotin through efficient internalization and rapid intracellular drug delivery

Abstract Background: Telisotuzumab vedotin (Teliso-V) is an antibody-drug conjugate (ADC) composed of the c-MET antibody ABT-700 and the microtubule inhibitor monomethyl auristatin E (MMAE). Patients with EGFR wildtype (WT) nonsquamous non-small cell lung cancer with high c-MET expression had an overall response rate of 54% with Teliso-V. In addition to overexpression and amplification, genetic alterations in c-MET, such as exon 14 deletion (ex14del) and missense mutations in the tyrosine kinase domain (TKD), contribute to its constitutive activation. The efficacy of Teliso-V in context of these genomic backgrounds is currently unknown. Methods: Recombinant retroviruses were used to express WT-c-MET, c-MET-TKD (D1228H/V/N and Y1230C/H mutations), c-MET-Y1003F/N (CBL E3 ubiquitin ligase binding site mutation), and c-MET-ex14del (47 aa juxtamembrane deletion) mutants in NIH3T3 and Ba/F3 cells. c-MET surface expression, intracellular signaling, ADC internalization and endolysosomal (EL) trafficking (using pHrodo Red-labeled Teliso-V), intracellular MMAE by LC/MS, and Teliso-V sensitivity were studied in 2D/3D cell cultures. Full-length c-MET protein structures were created with the ColabFold program and molecular dynamics simulation software (with/without artificial lipid bilayer) was used to predict the mechanistic basis for differential function. Results: c-MET expression was required for Teliso-V cytotoxicity and intracellular payload delivery in all cell lines. Compared with WT-c-MET, various mutants showed oncogene-driven transformation evident by elevated levels of phosphorylated c-MET/AKT, cytokine-independent colony formation, oncogene-driven proliferation, and tyrosine kinase inhibitor (TKI) resistance. Interestingly, c-MET-TKD-expressing cells were the most sensitive to Teliso-V, which was associated with faster ADC internalization and EL trafficking. An AI-generated protein model and associated molecular dynamics simulation demonstrated that all oncogenic TKD variants tested stabilized the c-MET-plexin-semaphorin-integrin domain (R592-L614), known for its ability to position the extracellular ligand-binding (ELB) site for optimal activation. Conclusions: c-MET-TKD mutations induced TKI resistance and enhanced MMAE delivery in association with robust ADC internalization and EL trafficking. Previous studies have shown that the HER2 ADC fam-trastuzumab deruxtecan-nxki was highly effective in cell lines and patients with ERBB2 kinase domain-mutant lung cancer via a similar mechanism, raising the possibility that this may be a general phenomenon across receptor tyrosine kinase-targeting ADCs. c-MET-TKD mutations are predicted to stabilize the ELB conformation to activate enhanced oncogenic signaling that may contribute to rapid endocytosis-mediated drug delivery. Citation Format: Izhar S. Batth, Bijay S. Jaiswal, Dolonchampa Maji, Robert Sparks, William Glauser, Tamar Uziel, D. Ross Camidge, Athan Vasilopoulos, Peter Ansell, PK Epling-Burnette. c-MET mutations sensitize to antibody-drug conjugate telisotuzumab vedotin through efficient internalization and rapid intracellular drug delivery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 540.

Co-expression of PD-L1 and oncogenic receptor tyrosine kinases HER2 and cMET is low in metastatic urothelial carcinoma.

533 Background: Activation of HER2 and cMET signaling has been implicated in the pathogenesis of urothelial carcinoma subsets, and the use of anti-PD-(L)1 agents is well established in this disease. Novel therapeutic combinations targeting both immune checkpoints and the cMET or HER2 pathways are currently under investigation in metastatic urothelial carcinoma (mUC). Co-expression of these molecular targets has not been characterized in mUC. We hypothesized that the rate of PD-L1 co-expression with cMET and HER2 may be low. Therefore, we sought to define tumor protein co-expression of PD-L1, HER2 and cMET in a cohort of mUC patients. Methods: Patients with mUC were identified from an institutional database. FFPE tumor specimens from metastatic sites and available paired primary tumors underwent immunohistochemical staining for PD-L1 (SP-142), cMET, and HER2 expression. High expression was defined using the following thresholds: PD-L1: &gt;=5% of infiltrated immune cells; cMET: &gt;=50% of tumor cells; HER2: score=3+ (complete membrane staining that is intense and &gt;10% of tumor cells). Simple and Weighted Cohen’s kappa Statistics (κ) were utilized to assess the agreement in expression and co-expression between paired primary and metastatic samples. Cohen’s interpretation of the κ results is provided. Results: Specimens from 143 mUC patients were analyzed, including 79 with available paired primary tumors. In primary tumors (N=79), high expression of PD-L1, cMET, and HER2 was observed in 15.2%, 34.2%, and 12.7%, respectively. In metastatic samples (N=143), high expression of PD-L1, cMET and HER2 was detected in 9.8%, 41.3%, and 9.8%, respectively. Expression agreement rates between primary and metastatic specimens (n=79) were PD-L1: 79.7% (κ=0.09, slight agreement), cMET: 69.6% (κ=0.35, fair agreement), HER2: 84.8% (κ=0.17, slight agreement) and were driven by high prevalence of low expression. High PD-L1/cMET co-expression was observed in only 5.1% (n = 4) of primary and 4.9% (n =7) of metastatic specimens. High co-expression of PD-L1/HER2 occurred in only 3.8% (n=3) of primary samples and in no metastatic samples. The overall co-expression agreement rate between paired primary and metastatic samples was 55.7% (κ = 0.22, fair agreement) for PD-L1/cMET and 67.1% (κ = 0.06, slight agreement) for PD-L1/HER2. Importantly, however, agreements rates for high co-expression between primary and metastatic samples were very low (2.5% for PD-L1/cMET and 0% for PD-L1/HER2). Conclusions: Tumor co-expression of high cMET or HER2 and PD-L1 is low in this cohort of metastatic urothelial carcinoma patients. Furthermore, agreement of high co-expression between primary and metastatic sites is rare. These results suggest that investigational strategies combining immune checkpoint inhibition with either cMET or HER2 targeted agents in mUC may have limited synergistic activity.

Engineering c-Met-CAR NK-92 cells as a promising therapeutic candidate for lung adenocarcinoma

Mesenchymal-epithelial transition factor (C-Met) has been acknowledged as a significant therapeutic target for treating lung adenocarcinoma (LUAD). However, the potential application of chimeric antigen receptors (CAR)-modified natural killer (NK) cells targeting c-Met in LUAD is rarely explored. In this study, bioinformatic databases were searched and a tissue microarray (TMA) was enrolled to investigate expression status and prognostic role of c-Met in LUAD. Then, four types of c-Met-CAR structures were designed and prepared. The engineering CAR-NK cells containing c-Met-CARs were transfected, verified and characterized. The tumor-inhibitory role of c-Met-CAR-NK cells was finally evaluated in vitro and in vivo. The results demonstrated that c-Met expression elevated and confirmed that high c-Met expression was significantly associated with unfavorable prognosis in LUAD. Then, C-Met-CAR-NK cells were successfully constructed and DAP10 designed in CAR structure was a favorable stimulator for NK cell activation. CCN4 containing DAP10 co-stimulator exhibited the strongest cytotoxicity compared with other CAR-NK cells. Furthermore, CCN4 cells also exerted the prominent tumor-inhibitory effect on xenograft tumor growth. Collectively, this study suggests that DAP10 is a potent stimulator in CAR structure for NK cell activation, and CCN4-based immunotherapy may represent a promising strategy for the treatment of c-Met-positive LUAD.

Expression of c-MET in Estrogen Receptor Positive and HER2 Negative Resected Breast Cancer Correlated with a Poor Prognosis.

Introduction: The mesenchymal-epithelial transition factor (c-MET) receptor is overexpressed in about 14−54% of invasive breast cancers, but its prognostic value in clinical practice is still unclear. Methods: In order to investigate the relationship between c-MET expression levels and prognosis, we retrospectively reviewed the clinical features and outcomes of 105 women with estrogen receptor positive HER2 negative (ER+/HER2-) resected breast cancer. We used the Kaplan Meier method to estimate Disease Free Survival (DFS) and Breast Cancer Specific Survival (BCSS) in the subgroups of patients with high (≥50%) and low (<50%) c-MET expression. Univariate and multivariate Cox proportional regression models were performed to assess the prognostic impact of clinicopathological parameters for DFS an BCSS. Results: High c-MET values significantly correlated with tumor size, high Ki67 and low (<20%) progesterone receptor expression. At a median follow up of 60 months, patients with high c-MET tumor had significantly worse (p = 0.00026) and BCSS (p = 0.0013). Univariate analysis showed a significant association between large tumor size, elevated Ki67, c-MET values and increased risk of recurrence or death. The multivariate COX regression model showed that tumor size and high c-MET expression were independent predictors of DFS (p = 0.019 and p = 0.022). Moreover, large tumor size was associated with significantly higher risk of cancer related death at multivariate analysis (p = 0.017), while a trend towards a poorer survival was registered in the high c-MET levels cohort (p = 0.084). Conclusions: In our series, high c-MET expression correlated with poor survival outcomes. Further studies are warranted to validate the clinical relevance and applicability of c-MET as a prognostic factor in ER+/HER2- early BC.