c-Met Overexpression Research Articles

Advancing Lung Cancer Treatment with Combined c-Met Promoter-Driven Oncolytic Adenovirus and Rapamycin.

Lung cancer remains a formidable health challenge due to its high mortality and morbidity rates. Non-small cell lung cancer (NSCLC) constitutes approximately 85% of all lung cancer cases, with small cell lung cancer (SCLC) accounting for the remainder. Both NSCLC and SCLC cells express receptor tyrosine kinases, which may be overexpressed or mutated in lung cancer, leading to increased activation. The c-Met receptor tyrosine kinase, crucial for cell transformation and tumor growth, invasion, and metastasis, became the focus of our study. We used an E1B55KD-deleted, replication-selective oncolytic adenovirus (Ad.What), driven by the c-Met promoter, targeting lung cancer cells with c-Met overexpression, thus sparing normal cells. Previous studies have shown the enhanced antitumor efficacy of oncolytic adenoviruses when combined with chemotherapeutic agents. We explored combining rapamycin, a selective mTOR inhibitor with promising clinical trial outcomes for various cancers, with Ad.What. This combination increased infectivity by augmenting the expression of coxsackievirus and adenovirus receptors and αV integrin on cancer cells and induced autophagy. Our findings suggest that combining a c-Met promoter-driven oncolytic adenovirus with rapamycin could be an effective lung cancer treatment strategy, offering a targeted approach to exploit lung cancer cells' vulnerabilities, potentially marking a significant advancement in managing this deadly disease.

Tumour Marker Expression in Head and Neck Malignancies to Identify Potential Targets for Intraoperative Molecular Near-Infrared Imaging.

Oral and laryngeal squamous cell carcinoma (OSCC and LSCC) and papillary thyroid carcinoma (PTC) are common head and neck cancers (HNCs) typically treated surgically. Challenges in tumour delineation often lead to inadequate resection margins in OSCC and LSCC, and missed multifocality in PTC. Fluorescence imaging (FLI) using near-infrared tumour-targeting tracers may improve intraoperative identification of malignancy, facilitating precise excision. This study evaluates six potential FLI targets in OSCC, LSCC and PTC. Immunohistochemical staining was performed on OSCC (n = 20), LSCC (n = 10) and PTC (n = 10), assessing CEA, c-Met, EpCAM, EGFR, integrin αvβ6 and VEGF-α. Expression was scored (0-12) using the total immunostaining score (TIS) system, and categorized into absent (TIS 0), low (TIS 1-5), moderate (TIS 6-8) or high (TIS 9-12). Integrin αvβ6 showed significant overexpression in OSCC (TIS: 12; p < 0.001) and LSCC (TIS: 8; p = 0.002), with 80% of OSCC and 90% of LSCC exhibiting moderate-high expression. Similarly, EGFR expression was moderate-high in most OSCC (87.5%; TIS: 8) and universally high in LSCC (100%; TIS: 12). In PTC, EGFR and VEGF-α expressions were low-moderate, but significantly higher than in healthy tissue (TIS: 6; p < 0.006). This study highlights integrin αvβ6 and EGFR as viable FLI targets in OSCC and LSCC, especially integrin αvβ6 for tumour margin delineation. In PTC, despite lower expressions, the significant overexpression of VEGF-α, c-MET, and EGFR suggests their potential as FLI targets. Our findings support the development of tumour-targeted FLI tracers to improve surgical precision in HNC.

49 Inhibition of AXL along with c-Met potentially halts resistance development in renal cell carcinoma

Abstract Background c-Met, a receptor tyrosine kinase (RTK), is overexpressed in renal cell carcinoma (RCC) and correlates with a decreased survival rate. Upon binding to its specific ligand, Hepatocyte Growth Factor (HGF), c-Met activates pro-tumorigenic signaling pathways. Cabozantinib (Cabo) inhibits c-Met and a few other RTKs, including AXL, and is approved for the treatment of patients with advanced-stage RCC. AXL and its ligand, GAS6, are overexpressed in RCC and are also markers of poor prognosis. The pro-tumorigenic role of AXL and its potential crosstalk with c-Met in renal cancer need to be thoroughly investigated. Methods We generated a Cabo-resistant (CaboR) cell line from wild-type Cabo-sensitive (CaboS) Caki-1 clear-cell RCC cells, and CRISPR/Cas9-mediated AXL knock-out cells (AXL-KO) from 786-O clear-cell RCC cells. Chromatin immunoprecipitation and sequencing (ChIP-seq) was performed to profile H3K27ac, a histone post-translational modification associated with active promoters and enhancers, in CaboR and CaboS cell lines. We also performed RNA sequencing (RNA-seq) on CaboR and CaboS and evaluated differentially expressed genes and enriched pathways using gene set enrichment analysis (GSEA). Transcriptional profiles of control clones and AXL-KO cells were also compared to identify the effect of AXL-KO on pro-tumorigenic signaling. We utilized an AXL-specific small molecule inhibitor, TP-0903, in combination with Cabo to validate our data. Finally, we studied how AXL silencing or inhibition may affect resistance to Cabo. Results Our findings revealed that AXL forms a complex with c-Met and may have a significant crosstalk which can be involved in therapeutic resistance. We found that prolonged treatment with c-Met inhibitors Cabo, 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. We found that silencing AXL can prevent this c-Met-inhibitors-mediated c-Met overexpression. Moreover, we found marked activation of the promoters and enhancers of several transcription factors, including ETV1, HOXA9, and FOXK1, in CaboR cells compared to CaboS cells. In the CaboR cells, genes involved in oxidative phosphorylation, progression through the division cycle, DNA replication, the NRF2 pathway, and DNA repair were upregulated, whereas genes associated with glycolysis, angiogenesis, hypoxia, and the Met pathway were downregulated (Figure 1). Finally, silencing AXL (using siRNA) or inhibiting AXL (using TP0903) in CaboR cells, induced significant apoptosis. Conclusions Together, our data suggest that CaboR cells have a distinct epigenomic and transcriptomic profile, and that targeting AXL along with c-Met inhibition can be beneficial in preventing acquired therapeutic resistance in RCC.

Prognostic Significance of EGFR, HER2, and c-Met Overexpression in Surgically Treated Patients with Adenocarcinoma of the Ampulla of Vater.

Adenocarcinoma of the ampulla of Vater (AAC) is a rare malignancy with heterogeneous tumors arising from various histologic subtypes, necessitating new therapeutic strategies. This study examines epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and c-Met expression in AAC, given their potential as druggable targets. Among 87 patients who underwent curative resection, EGFR overexpression was found in 87.4%, HER2 in 11.5%, and c-Met in 50%. EGFR overexpression was more common in the pancreatobiliary subtype (p = 0.018) and associated with a higher histologic grade (p = 0.008). HER2 did not correlate with clinicopathological features, while c-Met was more common in node-negative groups (p = 0.004) and often co-expressed with EGFR (p = 0.049). EGFR-positive patients had worse disease-free (HR = 2.89; 95% CI, 1.35-6.20; p = 0.061) and overall survival (HR = 6.89; 95% CI, 2.94-16.2; p = 0.026) than EGFR-negative patients. HER2-positive AAC showed a trend towards shorter survival, although not statistically significant, and c-Met had no impact on survival outcomes. In the context of systemic disease, survival outcomes did not vary according to EGFR, HER2, and c-Met expression, but the HER2-positive group showed a trend towards inferior progression-free survival (HR = 1.90; 95% CI, 0.56-6.41; p = 0.166). This study underscores the potential of EGFR, HER2, and c-Met as targets for personalized therapy in AAC, warranting further research to evaluate targeted treatments.

A new 1,2,3-triazole-indirubin hybrid suppresses tumor growth and pulmonary metastasis by mitigating the HGF/c-MET axis in hepatocellular carcinoma

IntroductionHepatocellular carcinoma (HCC) is a fatal cancer that is often diagnosed at the advanced stages which limits the available therapeutic options. The interaction of HGF with c-MET (a receptor tyrosine kinase) results in the activation of c-MET which subsequently triggers the PI3K/Akt/mTOR axis. Overexpression of c-MET in HCC tissues has been demonstrated to contribute to tumor progression and metastasis. ObjectivesWe aimed to synthesize triazole-indirubin conjugates, examine their growth suppressor efficacy in cell-based assays, and investigate the antitumor as well as antimetastatic activity of lead cytotoxic agent in the orthotopic mice model. MethodsA series of triazole-indirubin hybrids were synthesized and cytotoxicity, apoptogenic, and antimigratory effect of the lead compound (CRI9) was evaluated using MTT assay, cell cycle analysis, annexin-V/PI assay, TUNEL assay, and wound healing assay. The effect of CRI9 on the operation of the HGF/c-MET/PI3K/Akt/mTOR axis was examined using western blotting and transfection experiments. Acute toxicity, antitumor, and antimetastatic activity of CRI9 were examined in NCr nude mice. The expression of c-MET/PI3K/Akt/mTOR, CD31, and Ki-67 was examined using immunohistochemistry and western blotting. ResultsAmong the new compounds, CRI9 consistently displayed potent cytotoxicity against HGF-induced HCC cells. CRI9 induced apoptosis as evidenced by increased sub G1 cells, annexin-V+/PI+ cells, TUNEL+ cells, and cleavage of procaspase-3 and PARP. CRI9 inhibited HGF-induced phosphorylation of c-METY1234/1235 and subsequently suppressed the PI3K/Akt/mTOR axis. Also, depletion of c-MET or inhibition of c-MET by CRI9 resulted in suppression of the PI3K/Akt/mTOR axis. CRI9 showed no toxic effects in NCr nude mice and displayed a potent antitumor and antimetastatic effect in the orthotopic HCC mice model. CRI9 also reduced the levels of phospho-c-MET, CD31, and Ki-67 and suppressed the activation of the PI3K/Akt/mTOR axis in tumor tissues. ConclusionCRI9 has been identified as a new inhibitor of the c-MET/PI3K/Akt/mTOR axis in HCC preclinical models.

Reproducibility of c-Met Immunohistochemical Scoring (Clone SP44) for Non-Small Cell Lung Cancer Using Conventional Light Microscopy and Whole Slide Imaging.

Emerging therapies for non-small cell lung cancer targeting c-Met overexpression have recently demonstrated promising results. However, the evaluation of c-Met expression can be challenging. We aimed to study the inter and intraobserver reproducibility of c-Met expression evaluation. One hundred ten cases with non-small cell lung cancer (40 biopsies and 70 surgical specimens) were retrospectively selected in a single laboratory (LPCE) and evaluated for c-Met expression. Six pathologists (4 seniors and 2 juniors) evaluated the H-score and made a 3-tier classification of c-Met expression for all cases, using conventional light microscopy (CLM) and whole slide imaging (WSI). The interobserver reproducibility with CLM gave global Cohen Kappa coefficients (ƙ) ranging from 0.581 (95% CI: 0.364-0.771) to 0.763 (95% CI: 0.58-0.92) using the c-Met 3-tier classification and H-score, respectively. ƙ was higher for senior pathologists and biopsy samples. The interobserver reproducibility with WSI gave a global ƙ ranging from 0.543 (95% CI: 0.33-0.724) to 0.905 (95% CI: 0.618-1) using the c-Met H-score and 2-tier classification (≥25% 3+), respectively. ƙ for intraobserver reproducibility between CLM and WSI ranged from 0.713 to 0.898 for the c-Met H-score and from 0.600 to 0.779 for the c-Met 3-tier classification. We demonstrated a moderate to excellent interobserver agreement for c-Met expression with a substantial to excellent intraobserver agreement between CLM and WSI, thereby supporting the development of digital pathology. However, some factors (scoring method, type of tissue samples, and expertise level) affect reproducibility. Our findings highlight the importance of establishing a consensus definition and providing further training, particularly for inexperienced pathologists, for c-Met immunohistochemistry assessment in clinical practice.

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 .

Telisotuzumab vedotin monotherapy in patients with previously treated c-Met–overexpressing non-squamous EGFR wildtype advanced NSCLC: Primary analysis of the LUMINOSITY trial.

103 Background: Approximately 25% of patients (pts) with non-squamous (NSQ) EGFR wildtype (WT) NSCLC have c-Met protein overexpression (Ansell et al. 2022 CRUK), which is associated with a poor prognosis (Liang, Wang. Onco Targets Ther. 2020). Telisotuzumab vedotin (Teliso-V) is a c-Met–directed antibody-drug conjugate comprising the mAb telisotuzumab and the microtubule polymerization inhibitor monomethyl auristatin E. The phase 2 LUMINOSITY trial (NCT03539536) aimed to identify the c-Met–overexpressing (OE) NSCLC population best suited to Teliso-V and expand selected group(s) for further evaluation of efficacy. We report on the primary analysis for pts with c-Met OE NSQ EGFRWT NSCLC. Methods: This phase 2, non-randomized, multicenter study enrolled pts with locally advanced/metastatic c-Met OE NSCLC, ≤2 prior lines of therapy (chemotherapy [CTx] + immunotherapy [IO] or sequential CTx + IO), and ≤1 line of chemotherapy. c-Met OE (Ventana MET [SP44] clinical trial assay [CTA]) was defined as ≥25% tumor cells with 3+ staining (high: ≥50% 3+; intermediate [int]: 25 to &lt;50% 3+). Teliso-V was dosed at 1.9 mg/kg IV Q2W. Primary endpoint was overall response rate (ORR) by independent central review per RECIST v1.1. Results: 172 pts with NSQ EGFR WT NSCLC received ≥1 dose of Teliso-V and comprised the safety population; 161 (c-Met high, 78; c-Met int, 83) were included in baseline and efficacy analyses. Median age was 64 yrs (range 33–83), 69% were male, and 70% had ECOG PS 1. 97.5% had prior platinum and 82.0% had prior immune checkpoint inhibitor. Efficacy data are presented in Table below. ORR was 34.6% (c-Met high), 22.9% (c-Met int), 28.6% (overall). Median DOR was 9.0 mo (c-Met high), 7.2 mo (c-Met int), 8.3 mo (overall). Most common any-grade treatment-related AEs (TRAEs) were peripheral sensory neuropathy (30%), peripheral edema (16%), and fatigue (14%). Grade 5 TRAEs occurred in 2 pts (interstitial lung disease, respiratory failure). Conclusions: Teliso-V has shown compelling and durable responses in pts with c-Met OE NSQ EGFR WT NSCLC, especially in pts with c-Met high. Teliso-V had an acceptable safety profile that was clinically manageable, which is consistent with previous data. Clinical trial information: NCT03539536 . [Table: see text]

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 &lt; 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 &gt; 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]

Phase 1b study evaluating the efficacy and safety of ABBV-400, a c-Met–targeting antibody-drug conjugate, in select advanced solid tumor indications.

TPS3162 Background: c-Met (MET protein) is commonly overexpressed in a number of tumors, including hepatocellular carcinoma (HCC), pancreatic ductal adenocarcinoma (PDAC), biliary tract cancers (BTC), esophageal squamous cell carcinoma (ESCC), breast cancer (BC), and head and neck squamous cell carcinoma (HNSCC). Patients with c-Met–overexpressing tumors represent an underserved population, with the need for more effective c-Met–targeting therapies to become available. ABBV-400 is an antibody-drug conjugate, consisting of the c-Met–targeting antibody telisotuzumab conjugated to a potent topoisomerase 1 inhibitor payload. Initial results from the ongoing first-in-human study (NCT05029882) of ABBV-400 in patients with advanced solid tumors indicate a tolerable safety profile, with a maximum tolerated dose of 3 mg/kg once every 3 weeks (Q3W), and promising antitumor activity, with an overall response rate of 24.4% (1). Herein, we describe a signal-seeking study evaluating ABBV-400 treatment in patients with select solid tumors. Methods: Multicenter, open-label, phase 1 signal-seeking study(NCT06084481). Eligible patients (≥18 years) have confirmed locally advanced/metastatic disease measurable per RECIST v1.1 and Eastern Cooperative Oncology Group performance status ≤1. Approximately 220 patients are planned for enrollment across 7 cohorts (HCC, n=40; PDAC, n=40; BTC, n=20; ESCC, n=40; triple-negative BC, n=20; hormone receptor-positive/HER2-negative BC, n=20; HNSCC, n=40). The primary objectives are to assess efficacy and safety/tolerability of ABBV-400 in each tumor indication. Secondary objectives include the evaluation of pharmacokinetics (PK) and immunogenicity of ABBV-400. Pharmacodynamic (PD) and biomarker analyses are exploratory endpoints. Patients receive intravenous ABBV-400 at 3 mg/kg Q3W until disease progression, intolerable toxicity, or any other per-protocol discontinuation criteria. c-Met expression will be assessed retrospectively by immunohistochemistry. The maximum treatment duration is 2 years. Tumor assessments are performed at screening and every 6 weeks from the first dose of study drug, with objective response rate as primary efficacy endpoint and duration of response, clinical benefit rate, progression-free survival, and overall survival as secondary efficacy endpoints. Safety evaluations include adverse events monitoring (graded according to the NCI CTCAE, v5.0), physical examinations, vital sign measurements, ECG variables, and clinical laboratory testing. Blood samples for PK, PD, and biomarker analysis are collected at designated time points throughout the study. Enrollment started in November 2023. As of 19 January 2024, 24 patients have been enrolled. 1. Sharma et al. JCO 2023;41[16 suppl]:3015. Clinical trial information: NCT06084481 .

Mesenchymal-epithelial transition factor amplification correlates with adverse pathological features and poor clinical outcome in colorectal cancer.

Colorectal cancer (CRC) is the third most common cancer and the second most common cause of cancer-related mortality worldwide. Mesenchymal-epithelial transition factor (MET) gene participates in multiple tumor biology and shows clinical potential for pharmacological manipulation in tumor treatment. MET amplification has been reported in CRC, but data are very limited. Investigating pathological values of MET in CRC may provide new therapeutic and genetic screening options in future clinical practice. To determine the pathological significance of MET amplification in CRC and to propose a feasible screening strategy. A number of 205 newly diagnosed CRC patients undergoing surgical resection without any preoperative therapy at Shenzhen Cancer Hospital of Chinese Academy of Medical Sciences were recruited. All patients were without RAS/RAF mutation or microsatellite instability-high. MET amplification and c-MET protein expression were analyzed using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), respectively. Correlations between MET aberration and pathological features were detected using the chi-squared test. Progression free survival (PFS) during the two-year follow-up was detected using the Kaplan-Meier method and log rank test. The results of MET FISH and IHC were compared using one-way ANOVA. Polysomy-induced MET amplification was observed in 14.4% of cases, and focal MET amplification was not detected. Polysomy-induced MET amplification was associated with a higher frequency of lymph node metastasis (LNM) (P < 0.001) and higher tumor budding grade (P = 0.02). In the survival analysis, significant difference was detected between patients with amplified- and non-amplified MET in a two-year follow-up after the first diagnosis (P = 0.001). C-MET scores of 0, 1+, 2+, and 3+ were observed in 1.4%, 24.9%, 54.7%, and 19.0% of tumors, respectively. C-MET overexpression correlated with higher frequency of LNM (P = 0.002), but no significant difference of PFS was detected between patients with different protein levels. In terms of concordance between MET FISH and IHC results, MET copy number showed no difference in c-MET IHC 0/1+ (3.35 ± 0.18), 2+ (3.29 ± 0.11) and 3+ (3.58 ± 0.22) cohorts, and the MET-to-CEP7 ratio showed no difference in three groups (1.09 ± 0.02, 1.10 ± 0.01, and 1.09 ± 0.03). In CRC, focal MET amplification was a rare event. Polysomy-induced MET amplification correlated with adverse pathological characteristics and poor prognosis. IHC was a poor screening tool for MET amplification.

Abstract LB025: CKD-703, a novel antibody-drug conjugate targeting cMET with an enhanced therapeutic index in solid tumors

Abstract In our pursuit of advancing cancer therapeutics, we introduce CKD-703, a groundbreaking cMET-targeting antibody drug conjugate (ADC) designed to strategically address the challenges posed by cMET overexpression and alteration in various solid tumors. Recognizing the pivotal role of tolerability and efficacy in shaping the therapeutic landscape of ADC, CKD-703 represents a significant advancement, aiming to widen the therapeutic index of cMET-targeted therapies. As we develop CKD-703, an innovative cMET-targeting ADC, we acknowledge the oncogenic potential of cMET alterations, particularly in non-small cell lung cancer (NSCLC), and the prevalent elevation of cMET across various cancers. Antibody drug conjugates targeting cMET (cMET-ADCs) have shown its therapeutic potential in treating cMET positive tumors, irrespective of their dependency on cMET signaling. Clinical success, however, has often been limited to NSCLC patients with the highest cMET levels. In light of this, CKD-703 is crafted to not only improve tolerability but also enhance efficacy, thereby broadening its application to a diverse patient population, including those with moderate cMET expression. To develop a novel cMET-ADC, Chong Kun Dang leverages Synaffix's ADC platform technology, incorporating glycan remodeling to achieve site-specific conjugation of the linker-payload to the antibody and ensuring a homogeneous drug-antibody ratio. These unique characteristics enhance CKD-703's stability in the bloodstream, minimizing the concentration of liberated free payload and significantly improving tolerability. The uniform DAR of CKD-703 contributes to improved pharmacokinetics, ensuring a consistent and sustained therapeutic effect. In comparison to benchmark antibodies, CKD-703 exhibits superior binding affinity to cMET and efficient internalization, resulting in enhanced therapeutic efficacy. This is evidenced in preclinical experiments which performed in several animal models that can mimic the complexities of cMET positive tumors with varying expression levels. The GLP toxicity studies of CKD-703 are ongoing. In conclusion, CKD-703 is a novel cMET-targeting ADC designed to overcome the limitations observed in existing cMET-ADCs in clinical trials as well as significantly improve tolerability and efficacy. By strategically addressing challenges associated with moderate cMET expression levels, CKD-703 emerges as a promising therapeutic candidate, aiming to broaden the therapeutic index in cMET-overexpressing solid tumors. This study highlights the importance of tailored approaches to diverse patient populations in advancing the development of CKD-703 in the pursuit of precision cancer therapies. Citation Format: Kwanwoo Lee, Sue-Youn Kim, Hye-Jin Hong, Eunjeong Park, Jungok Park, Seong-Ho Hong, Daekwon Bae, Nina Ha, Sohn-Ji Yeon, Inchang Hwang, Semi Kim, Yoonseok Lee, Ju-Hee Lee. CKD-703, a novel antibody-drug conjugate targeting cMET with an enhanced therapeutic index 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 LB025.

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 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.

Rational Design of PARP1/c-Met Dual Inhibitors for Overcoming PARP1 Inhibitor Resistance Induced by c-Met Overexpression.

The emergence of resistance to PARP1 inhibitors poses a current therapeutic challenge, necessitating the development of novel strategies to overcome this obstacle. The present study describes the design and synthesis of a series of small molecules that target both PARP1 and c-Met. Among them, compound 16 is identified as a highly potent dual inhibitor, exhibiting excellent inhibitory activities against PARP1 (IC50 = 3.3 nM) and c-Met (IC50 = 32.2 nM), as well as demonstrating good antiproliferative effects on HR-proficient cancer cell lines and those resistant to PARP1 inhibitors. Importantly, compound 16 demonstrates superior antitumor potency compared to the PARP1 inhibitor Olaparib and the c-Met inhibitor Crizotinib, either alone or in combination, in MDA-MB-231 and HCT116OR xenograft models. These findings highlight the potential of PARP1/c-Met dual inhibitors for expanding the indications of PARP1 inhibitors and overcoming tumor cells' resistance to them.

C-MET-positive circulating tumor cells and cell-free DNA as independent prognostic factors in hormone receptor-positive/HER2-negative metastatic breast cancer

BackgroundEndocrine therapy resistance in hormone receptor-positive/HER2-negative (HR+/HER2−) breast cancer (BC) is a significant clinical challenge that poses several unmet needs in the management of the disease. This study aimed to investigate the prognostic value of c-MET-positive circulating tumor cells (cMET+ CTCs), ESR1/PIK3CA mutations, and cell-free DNA (cfDNA) concentrations in patients with hormone receptor-positive (HR+) metastatic breast cancer (mBC).MethodsNinety-seven patients with HR+ mBC were prospectively enrolled during standard treatment at Samsung Medical Center. CTCs were isolated from blood using GenoCTC® and EpCAM or c-MET CTC isolation kits. PIK3CA and ESR1 hotspot mutations were analyzed using droplet digital PCR. CfDNA concentrations were calculated using internal control copies from the ESR1 mutation test. Immunocytochemistry was performed to compare c-MET overexpression between primary and metastatic sites.ResultsThe proportion of c-MET overexpression was significantly higher in metastatic sites than in primary sites (p = 0.00002). Survival analysis showed that c-MET+ CTC, cfDNA concentration, and ESR1 mutations were significantly associated with poor prognosis (p = 0.0026, 0.0021, and 0.0064, respectively) in HR+/HER2− mBC. By contrast, EpCAM-positive CTC (EpCAM+ CTC) and PIK3CA mutations were not associated with progression-free survival (PFS) in HR+/HER2− mBC. Multivariate analyses revealed that c-MET+ CTCs and cfDNA concentration were independent predictors of PFS in HR+/HER2− mBC.ConclusionsMonitoring c-MET+ CTC, rather than assessing c-MET expression in the primary BC site, could provide valuable information for predicting disease progression, as c-MET expression can change during treatment. The c-MET+ CTC count and cfDNA concentration could provide complementary information on disease progression in HR+ /HER2− mBC, highlighting the importance of integrated liquid biopsy.

Landscape of C-MET overexpression in non-small cell lung cancer: a large-scale study of clinicomolecular features and prognosis based on Chinese data.

Real-world data on C-MET protein overexpression in non-small cell lung cancer (NSCLC) patients, particularly among the Asian Chinese population, are limited. This study aimed to evaluate the clinicomolecular characteristics and prognosis of C-MET overexpression in Chinese NSCLC patients, focusing on those with positive C-MET overexpression (immunohistochemistry (IHC) 3+). A retrospective and observational study. Data were collected from NSCLC patients diagnosed at the First Affiliated Hospital of Guangzhou Medical University between November 2006 and April 2021. We identified C-MET overexpression using IHC and C-MET overexpression positivity was defined as IHC 3+ with ⩾50% tumor cells. Additionally, patient genotypes were collected for subgroup analysis. Data from 9785 NSCLC patients were collected. C-MET (-) accounted for 5% (503/9785), C-MET (+) for 27% (2654/9785), C-MET (++) for 36% (3464/9785), and C-MET (+++) for 32% (3164/9785). Genetic testing was available for 4326 patients. Wild-type was observed in 37% (1591 cases), with epidermal growth factor receptor (EGFR) abnormalities being the most common at 49% (2127 cases). Positive C-MET overexpression correlated significantly with women (p < 0.001), early-stage (p = 0.003), adenocarcinoma (p < 0.001), and driver mutations (p < 0.001). Patients with anaplastic lymphoma kinase (ALK) alterations had a higher occurrence of C-MET overexpression positivity (57.1%). Positive C-MET overexpression was significantly associated with EGFR (p < 0.001), ALK (p < 0.001), and KRAS alterations (p = 0.024). Compared to C-MET overexpression (IHC 0), C-MET overexpression (IHC 2+) (hazard ratio (HR) = 0.455, p < 0.001) and C-MET overexpression (IHC 3+) (HR = 0.569, p < 0.001) were correlated with better overall survival in overall NSCLC patients, especially for C-MET overexpression (IHC 2+). Our study elucidates the clinicomolecular characteristics and prognosis of C-MET overexpression in NSCLC patients, particularly those with positive C-MET overexpression (IHC 3+). This provides insight into the prevalence of C-MET overexpression in Chinese NSCLC patients and offers a basis for considering C-MET overexpression as a prognostic and predictive marker in NSCLC.

Up-regulation by overexpression of c-MET in fibroblastic foci of usual interstitial pneumonia.

Usual interstitial pneumonia (UIP) is the radiologic and histologic hallmark of idiopathic pulmonary fibrosis (IPF) and the commonest histologic pattern of other progressive fibrosing interstitial lung diseases (e.g., fibrotic hypersensitivity pneumonia). Analogous to lung cancer, activation of epithelial-to-mesenchymal transition (EMT) is one of the main molecular pathways recently identified by transcriptomic studies in IPF. Fibroblastic foci (FF) are considered the active/trigger component of UIP pattern. The proto-oncogene C-MET is a key gene among molecules promoting EMT against which several inhibitors are currently available or promising in ongoing studies on lung cancer. Twenty surgical cases of diffuse fibrosing interstitial lung diseases (fILD) with UIP pattern and FF-rich (17 IPF and 3 patients with fibrotic hypersensitivity pneumonia, fHP) were retrospectively selected. FF were manually microdissected and analysed for c-MET gene alterations (FISH amplification and gene hot-spot mutations Sanger sequencing) and tested with a c-MET companion diagnostic antibody (clone SP44 metmab) by immunohistochemistry. FF are characterized by upregulation of c-MET as shown by overexpression of the protein in 80% of cases, while no gene amplification by FISH or mutations were detected. C-MET upregulation of FF was observed either in IPF and fHP, with a tropism for the epithelial cell component only. Upregulation of c-MET in FF of ILD with UIP pattern further confirms the key role of the proto-oncogene c-MET in its pathogenesis, possibly representing an interesting and easily-detectable molecular target for selective therapy using specific inhibitors in future clinical trials, similar to lung cancer. It is reasonable to speculate that molecular alterations in FF can also be detected in FF by transbronchial cryobiopsy.

Immunohistochemical characteristics and potential therapeutic regimens of hepatoid adenocarcinoma of the stomach: a study of 139 cases.

Hepatoid adenocarcinoma of stomach (HAS) is a special subtype of gastric cancer with poor prognosis. Immunohistochemical analysis could provide important clues for the treatment of HAS. A total of 159 patients were diagnosed as HAS and 139 were enrolled in this study. Statistical differences were determined using relative test methods and survival analyses were performed by the Kaplan-Meier method to find survival differences. All tumors in this study were negative for Epstein-Barr virus-encoded small RNAs (EBERs) and almost all showed no loss of mismatch repair (MMR) proteins and were positive for alpha fetoprotein (AFP or spalt like transcription factor 4 (SALL4). About half of the tumors had a positive programmed death-ligand 1 combined positive score (CPS) and 17.3% were positive for human epidermal growth factor receptor 2 (HER2). In addition, there was a relatively high proportion of cmet expression. We also found that HAS patients with recurrent disease treated by emerging therapy had a better survival than those treated with traditional chemotherapy (p = 0.002, median recurrence-to-death survival: 23 months versus 6 months); HAS patients who received anti-HER2 therapy or harbored MMR deficiency had favorable prognosis. Overall, high proportions of MMR protein proficiency, positivity for AFP or SALL4, overexpression of HER2, CPS and cmet, as well as negative EBER findings, are distinctive characteristics of HAS patients. While negative EBER and MMR proficiency indicate molecular features of HAS, positivity for AFP or SALL4 could aid in the diagnosis of HAS. In addition, HAS patients could benefit from anti-HER2 therapy, immunotherapy, and anti-angiogenesis therapy.

Suppression of TNBC metastasis by doxazosin, a novel dual inhibitor of c-MET/EGFR

BackgroundTriple-negative breast cancer (TNBC) is characterized by aggressive growth and a high propensity for recurrence and metastasis. Simultaneous overexpression of c-MET and EGFR in TNBC is associated with worse clinicopathological features and unfavorable outcomes. Although the development of new c-MET inhibitors and the emergence of 3rd-generation EGFR inhibitors represent promising treatment options, the high costs involved limit the accessibility of these drugs. In the present study, we sought to investigate the therapeutic potential of doxazosin (DOXA), a generic drug for benign prostate hyperplasia, in targeting TNBC.MethodsThe effect of DOXA on TNBC cell lines in vitro was evaluated in terms of cell viability, apoptosis, c-MET/EGFR signaling pathway, molecular docking studies and impact on cancer stem cell (CSC)-like properties. An in vivo metastatic model with CSCs was used to evaluate the efficacy of DOXA.ResultsDOXA exhibits notable anti-proliferative effects on TNBC cells by inducing apoptosis via caspase activation. Molecular docking studies revealed the direct interaction of DOXA with the tyrosine kinase domains of c-MET and EGFR. Consequently, DOXA disrupts important survival pathways including AKT, MEK/ERK, and JAK/STAT3, while suppressing CSC-like characteristics including CD44high/CD24low subpopulations, aldehyde dehydrogenase 1 (ALDH1) activity and formation of mammospheres. DOXA administration was found to suppress tumor growth, intra- and peri-tumoral angiogenesis and distant metastasis in an orthotopic allograft model with CSC-enriched populations. Furthermore, no toxic effects of DOXA were observed in hepatic or renal function.ConclusionsOur findings highlight the potential of DOXA as a therapeutic option for metastatic TNBC, warranting further investigation.