Soluble c-Met Research Articles

Influential Serum Kinases (Non-sFlt-1) and Phosphatases in Preeclampsia-Systemic Review and Metanalysis.

The early identification of women with an increased risk of preeclampsia (PE) is desirable, but apart from soluble fms-like tyrosine kinase-1 (sFlt-1), few biomarkers have previously been identified as relevant for predicting preeclampsia. Since kinases and phosphatases regulate critical biological processes and previous evidence suggests a potential role of these molecules in preeclampsia, we performed this systematic review and metanalysis. The objective was to determine if there are kinases and phosphatases whose serum levels are different between women with and without PE, being relevant biomarkers of PE. We followed the recommendations of Cochrane and the Preferred Reported Items for Systematic Reviews and Metanalysis (PRISMA) to perform this study. The MESH terms preeclampsia, kinases, phosphatases, angiopoietins, soluble tyrosine protein kinase receptor (sTIE2), and cellular-mesenchymal-epithelial transition factor (c-MET) were combined to find relevant articles in the PubMed, PROSPERO, and Cochrane databases. Then, a qualitative and quantitative analysis was performed in R Studio software. From 580 abstracts identified, 37 were included in the final analysis, which comprised 24,211 pregnant women (2879 with PE and 21,332 women without PE [HP]. The pooled analysis showed that serum creatine kinase (CK) (SMD: 2.43, CI 95% 0.25-4.62) was significantly higher in PE, whereas sTIE2 and anti-angiogenic factor soluble c-Met (sMet)were significantly lower in PE than in HP (SMD: -0.23, CI95% -0.37 to -0.09; and SMD:0.24, CI95% 0.01-0.47, respectively). Adenosine monophosphate-activated protein kinase (AMPK), angiopoietin-1 (ANG-1), angiopoietin-2 (ANG-2), the ratio angiopoietin-1/angiopoietin-2, acid phosphatase, and alkaline phosphatase were not different between women with PE and HP. In summary CK, sTIE2, and c-MET are relevant biomarkers of PE. It is desirable to incorporate them into current models for PE prediction to evaluate their utility as biomarkers.

1175-P: The Alteration of Serum Level and Expression of c-MET in Gestational Diabetes Mellitus (GDM)

Objective: The aim of this study was to explore changes in serum levels and tissue expression of HGF and c-MET, and to determine how HGF/c-MET signaling contributes to the pathophysiology of GDM. Methods: A total of 44 pregnant women with normal glucose tolerance (NGT) and 32 pregnant women with GDM were studied. Blood samples were taken just before delivery, and placenta and visceral adipose tissue were taken immediately after cesarean delivery. Serum levels of HGF, soluble c-MET and insulin were measured by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of HGF and c-MET was measured in the placenta and visceral adipose tissue. In addition, we investigated pregnancy of high fat diet (HFD) mice as an animal model of GDM. The glucose tolerance test (GTT) was performed at GD 10, and measured the serum levels of Hgf and soluble c-Met at GD 16. After scarifying mice, we measured the weight and expression of mRNA of Hgf and c-Met in WAT, placenta, liver and muscle. Results: Serum soluble c-MET levels were significantly higher in the GDM group (p <0.001). In multiple logistic regression analysis, soluble serum c-MET level was strongly associated with GDM (OR 9.063, p=0.027). There were more patients with increased mRNA expression of HGF and c-MET in placenta. Interestingly, the protein expression of HGF and c-MET in maternal visceral fat tissue was significantly higher in the GDM group. In mouse study, maternal serum levels of soluble c-Met in pregnant HFD (PH) mice were higher than in non-pregnant HFD (NPH) mice and pregnant chow diet (PC) mice. Relative mRNA expression of Hgf was significantly increased in eWAT of PH than PC mice. Relative c-Met mRNA expression was significantly increased in sWAT of PH than PC mice. Conclusion: We observed the differences in serum levels and expression of HGF and c-MET between GDM and control pregnant women in human and mice model. Our results suggest that HGF/c-MET signaling may be altered in GDM, which associated with insulin resistance and pathophysiology in GDM. Disclosure H.Kim: None. J.Lee: None. Y.Jung: None. M.Lee: None. J.Kim: None. K.Joung: None. B.Ku: Speaker's Bureau; AstraZeneca, Boehringer-Ingelheim, Eli Lilly and Company, Sanofi, Novo Nordisk, LG Chem. Funding National Research Foundation of Korea (2022R1F1A1074608)

Abstract 4999: Preclinical evaluation of MCLA-129, a bispecific antibody targeting EGFR and c-MET on solid tumor cells, in comparison with amivantamab

Abstract The HGF/c-MET pathway is frequently upregulated in tumors that are resistant to EGFR tyrosine kinase inhibitors. MCLA-129 is an antibody-dependent cellular cytotoxicity (ADCC) enhanced Biclonics® that targets epidermal growth factor receptor (EGFR) and c-MET in non-small cell lung cancer (NSCLC) and other solid tumors. MCLA-129 is a potent inhibitor of tumor growth applying various mechanisms of action (MOA), including inhibition of c-MET and EGFR signaling, antibody-dependent cellular phagocytosis (ADCP) and ADCC. Here we compared the MOA of MCLA-129 with the MOA of the EGFR-c-MET bispecific antibody amivantamab. The binding of MCLA-129 to tumor cells expressing different levels of EGFR and c-MET was quantified using radiolabeled antibodies. Scatchard plot analysis showed that the affinity of MCLA-129 for both c-MET and EGFR is in the low nanomolar range. In FACS, MCLA-129 and amivantamab show similar binding to tumor cells harboring EGFR or c-MET exon14-skipping mutations. Crossblock experiments with the c-MET binding antibody onartuzumab analog showed that MCLA-129 competes for the same HGF-binding region of c-MET, which is distinct from the binding site of amivantamab according to Neijssen et al, 2021 (PMC8113745). MCLA-129 and amivantamab did not downmodulate EGFR or c-MET. ADCP was also comparable for MCLA-129 and amivantamab, as measured with monocyte-derived macrophages incubated with pHrodo-labeled target cells with readout of tumor cell phagocytosis on the Incucyte® system. In contrast, MCLA-129 displayed ADCC activity similar to or more potently than amivantamab in an ADCC reporter assay with either high affinity FcγRIII 158V-variant or low affinity 158F-variant effector cells in absence or presence of soluble EGFR and soluble c-MET. MCLA-129-induced ADCC appears to be less affected than amivantimab by the presence of soluble EGFR and soluble c-MET. In conclusion, MCLA-129 is a Biclonics® common light chain bispecific antibody with multiple MOA including inhibition of c-MET and EGFR ligand binding, ADCP and ADCC comparable or more potent than amivantamab. A phase 1/2 clinical trial of MCLA-129 in solid tumors is ongoing. These data support the further clinical development of MCLA-129 in patients with NSCLC and other solid tumors. Citation Format: David J.J. de Gorter, Alexandre Deshiere, Arjen Kramer, Martijn van Rosmalen, Franziska Mortensen, Cecile Geuijen. Preclinical evaluation of MCLA-129, a bispecific antibody targeting EGFR and c-MET on solid tumor cells, in comparison with amivantamab. [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 4999.

Analysis of Soluble Mesenchymal-Epithelial Transition Factor and Hepatocyte Growth Factor Serum Levels in Children With Autism Spectrum Disorder

Background: Hepatocyte Growth Factor (HGF) and its receptor, Mesothelial-Epithelial Transition (cMet) factor signaling, play an essential role in controlling synaptogenesis. Objectives: Because of the vital role of HGF and Met signaling in synaptogenesis and spatial learning function of the brain’s hippocampal region, we aimed to study the HGF and soluble cMet (s-cMet) serum levels in children with different stages of Autism Spectrum Disorders (ASD). Materials & Methods: A total of 189 ASD patients (mild; n=69, moderate; n=63 and severe; n=57) and 82 control were enrolled in this project. Blood samples were collected from ASD patients referred to Pediatric Neurology Clinic, 17 Shahrivar Hospital, Rasht City, Iran, and serum concentrations of s-cMet and HGF were measured by ELISA. The control children with no clinical characteristics of ASD attended routine blood tests. Results: HGF Mean±SD serum concentration in ASD patients was 239±52.02 pg/mL compared to controls which was 360.04±71.15 pg/mL (P=0.004). Also, the Mean±SD serum concentrations of HGF in mild, moderate, and severe ASD patients were 297.54±69.82, 232.81±56.41, and 189±33.25 ng/mL, respectively, compared to control, which was 360.18±57.40. Besides, the s-cMet Mean±SD serum concentrations in ASD and controls were 143.54±32.50 and 200.25±31.16 pg/mL, respectively (P=0.005). The Mean±SD serum concentrations of s-cMet in the mild, moderate, and severe ASD patients were 172.81±37.69, 129.81±45.55, and 85.18±22.95 ng/mL, respectively, as compared to the control, which was 214.54±34.17 ng/mL. Conclusion: Serum HGF and s-cMet concentration decreased in ASD patients corresponding to disease severity. Also, detecting serum HGF and s-cMet may help classify ASD.

Hepatocyte growth factor and soluble cMet levels in plasma are prognostic biomarkers of mortality in patients with severe acute kidney injury.

BackgroundHepatocyte growth factor (HGF)/cMet pathway is necessary for repair and regeneration following acute kidney injury (AKI). We evaluated the clinical potential of plasma HGF and soluble cMet as prognostic biomarkers for severe AKI requiring continuous renal replacement therapy (CRRT).MethodsOne hundred thirty-six patients with severe AKI who participated in the VENUS (volume management under body composition monitoring in critically ill patients on CRRT) trial between 2017 and 2019 were enrolled in this study. We investigated associations between plasma HGF and cMet concentrations and all-cause mortality.ResultsPlasma HGF and soluble cMet levels were positively correlated. Patients were divided into three groups based on their HGF and soluble cMet concentrations. The day D 0, D2, and D7 highest concentration HGF groups had significantly higher in-hospital mortality after adjusting for sex, body mass index, Acute Physiology and Chronic Health Evaluation II, and age-adjusted Charlson comorbidity index score, especially on D7 (hazard ratio, 4.26; 95% confidence interval, 1.71–10.62; p = 0.002). D7 soluble cMet level was also associated with mortality. Receiver operating characteristic curve analysis indicated that D7 HGF and soluble cMet levels were best at predicting mortality. Addition of plasma HGF and soluble cMet to conventional prognostic indices significantly improved the predictive value for mortality on D7. However, plasma HGF and soluble cMet were not associated with fluid status.ConclusionPlasma HGF and soluble cMet levels were significant predictors of the outcomes of severe AKI patients undergoing CRRT. There was no correlation between plasma HGF and soluble cMet levels and fluid balance.

Overexpression of Hepatocyte growth factor and its soluble receptor (s-cMet) in the serum of patients with different grades of meningioma

ObjectivesMeningiomas are the most common primary intracranial tumor. Hepatocyte growth factor (HGF) and its receptor, cMet, were shown to be involved in meningioma. This study was aimed to determine the concentration of HGF and soluble cMet (s-cMet) in the serum of patients with different grades of meningioma. MethodsNinety serum samples from different grades of meningioma patients (42 cases of grade I, 28 grade II, 20 grade III) and 51 controls were included in this study. The serum total protein concentration (TPC) was measured by a Bio-Rad protein assay and serum concentration of HGF and s-cMet by enzyme linked immunosorbent assay (ELISA). ResultsNo significant change in the serum TPC of patients was seen as compared to controls. We also showed that serum HGF and s-cMet concentration in meningioma patients was higher than in controls. The results showed that starting from grades I to III meningioma, a significant increase in HGF and s-cMet serum concentration was observed (HGF; 380 ± 57.69, 430.27 ± 48.72, 596.36 ± 104.49 pg/ml, respectively, as compared to controls which was 327.72 ± 49.68 pg/ml and for s-cMet was 274.45 ± 45.05, 314.81 ± 38.71, 433.54 ± 51.81 ng/ml, respectively, as compared to controls which was 213.72 ± 29.13 ng/ml). The results showed that a high concentration of HGF and s-cMet is associated with advanced grades of meningioma. ConclusionIt is concluded that HGF and s-cMet serum levels increased in meningioma patients and their concentration was significantly higher in more advanced grades of the disease. It is also suggested that HGF/s-cMet might be involved in the progression of meningioma.

The levels of soluble cMET ectodomain in the blood of patients with ovarian cancer are an independent prognostic biomarker.

The tyrosine kinase mesenchymal–epithelial transition (cMET) is typically overexpressed in up to 75% of patients with ovarian cancer, and cMET overexpression has been associated with poor prognosis. The proteolytic release of the soluble cMET (sMET) ectodomain by metalloproteases, a process called ectodomain shedding, reflects the malignant potential of tumour cells. sMET can be detected in the human circulation and has been proposed as biomarker in several cancers. However, the clinical relevance of sMET in ovarian cancer as blood‐based biomarker is unknown and was therefore investigated in this study. sMET levels were determined by enzyme‐linked immunosorbent assay in a set of 432 serum samples from 85 healthy controls and 86 patients with ovarian cancer (87% FIGO III/IV). Samples were collected at primary diagnosis, at four longitudinal follow‐up time points during the course of treatment and at disease recurrence. Although there was no significant difference between median sMET levels at primary diagnosis of ovarian cancer vs. healthy controls, increased sMET levels at primary diagnosis were an independent predictor of shorter PFS (HR = 0.354, 95% CI: 0.130–0.968, P = 0.043) and shorter OS (HR = 0.217, 95% CI: 0.064–0.734, P = 0.014). In the follow‐up samples, sMET levels were prognostically most informative after the first three cycles of chemotherapy, with high sMET levels being an independent predictor of shorter PFS (HR = 0.245, 95% CI: 0.100–0.602, P = 0.002). This is the first study to suggest that sMET levels in the blood can be used as an independent prognostic biomarker for ovarian cancer. Patients at high risk of recurrence and with poor prognosis, as identified based on sMET levels in the blood, could potentially benefit from cMET‐directed therapies or other targeted regimes, such as PARP inhibitors or immunotherapy.

Phase I Study of Ficlatuzumab and Cetuximab in Cetuximab-Resistant, Recurrent/Metastatic Head and Neck Cancer.

Cetuximab, an anti-EGFR monoclonal antibody (mAb), is approved for advanced head and neck squamous cell carcinoma (HNSCC) but benefits a minority. An established tumor-intrinsic resistance mechanism is cross-talk between the EGFR and hepatocyte growth factor (HGF)/cMet pathways. Dual pathway inhibition may overcome cetuximab resistance. This Phase I study evaluated the combination of cetuximab and ficlatuzumab, an anti-HGF mAb, in patients with recurrent/metastatic HNSCC. The primary objective was to establish the recommended Phase II dose (RP2D). Secondary objectives included overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Mechanistic tumor-intrinsic and immune biomarkers were explored. Thirteen patients enrolled with no dose-limiting toxicities observed at any dose tier. Three evaluable patients were treated at Tier 1 and nine at Tier 2, which was determined to be the RP2D (cetuximab 500 mg/m2 and ficlatuzumab 20 mg/kg every 2 weeks). Median PFS and OS were 5.4 (90% CI = 1.9–11.4) and 8.9 (90% CI = 2.7–15.2) months, respectively, with a confirmed ORR of 2 of 12 (17%; 90% CI = 6–40%). High circulating soluble cMet levels correlated with poor survival. An increase in peripheral T cells, particularly the CD8+ subset, was associated with treatment response whereas progression was associated with expansion of a distinct myeloid population. This well-tolerated combination demonstrated promising activity in cetuximab-resistant, advanced HNSCC.

Randomized, phase II study of ficlatuzumab with or without cetuximab in patients with pan-refractory, recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

TPS6594 Background: Patients with pan-refractory R/M HNSCC, with clinical resistance to cytotoxic therapy, anti-EGFR molecular targeting, and immunotherapy, have poor survival. An established tumor-intrinsic resistance mechanism to cetuximab, an anti-EGFR IgG1 monoclonal antibody (mAb), is activation of the hepatocyte growth factor (HGF)/cMet pathway, which converges with the EGFR network at both the PI3K/Akt and MAPK nodes allowing for reciprocal compensation. Moreover, over-expression of HGF in the tumor microenvironment is immunosuppressive. Convergent data suggest that HGF/cMet pathway inhibition concurrent with EGFR blockade may overcome cetuximab resistance. We previously reported a Phase I study of ficlatuzumab, a humanized anti-HGF IgG1 mAb, with cetuximab in cetuximab-resistant R/M HNSCC. The combination showed promising safety, overall response rate (ORR) and progression-free survival (PFS). Preliminary biomarker analyses showed that high circulating cMet was associated with poor PFS whereas serum Veristrat, a proteomic classifier associated with worse prognosis in the setting of anti-EGFR monotherapy, was not. An increase in total peripheral T cells, particularly the CD8+ subset, was associated with treatment response while progression was associated with expansion of a unique myeloid population. We designed a follow-on randomized phase II trial evaluating ficlatuzumab with or without cetuximab in pan-refractory, R/M HNSCC with signaling and immune correlatives. Methods: This is a multicenter phase II trial with a randomized, non-comparative, two-arm design (ficlatuzumab 20 mg/kg with or without cetuximab 500 mg/m2 every 2 weeks) in patients with pan-refractory R/M HNSCC. Key eligibility criteria include: R/M HNSCC; cetuximab resistance (progression during or within 6 months of cetuximab-radiation or palliative cetuximab); platinum resistance; prior exposure to anti-PD1 mAb; ECOG 0-1; consent to baseline research biopsy. The primary objective is to evaluate the efficacy of each arm as measured by PFS. To test the hypothesis that either regimen improves historical PFS from 2 to 3.33 months requires 66 eligible patients. Key secondary endpoints are ORR and survival. Mechanistic biomarkers include tumor HGF/cMet pathway activation, tumor and peripheral immune profiles, soluble cMet, and serum Veristrat. Thirty-five of 66 subjects have enrolled at 6 centers. A Bayesian continuous monitoring rule for futility has not been triggered for either arm. Clinical trial information: NCT03422536 .

Soluble cMet levels in urine are a significant prognostic biomarker for diabetic nephropathy

Hepatocyte growth factor and its receptor cMet activate biological pathways necessary for repair and regeneration following kidney injury. Here, we evaluated the clinical role of urinary cMet as a prognostic biomarker in diabetic nephropathy (DN). A total of 218 patients with DN were enrolled in this study. We examined the association of urine cMet levels and long-term outcomes in patients with DN. The levels of urinary cMet were higher in patients with decreased renal function than in patients with relatively preserved renal function (5.25 ± 9.62 ng/ml versus 1.86 ± 4.77 ng/ml, P = 0.001). A fully adjusted model revealed that a urinary cMet cutoff of 2.9 ng/mL was associated with a hazard ratio for end-stage renal disease of 2.33 (95% confidence interval 1.19–4.57, P = 0.014). The addition of urinary cMet to serum creatinine and proteinuria provided the highest net reclassification improvement. We found that in primary cultured human glomerular endothelial cells, TGFβ treatment induced fibrosis, and the protein expression levels of collagen I, collagen IV, fibronectin, and αSMA were decreased after administration of an agonistic cMet antibody. In conclusion, elevated levels of urinary cMet at the time of initial diagnosis could predict renal outcomes in patients with DN.

Soluble c-Met Levels Correlated With Tissue c-Met Protein Expression in Patients With Advanced Non–Small-Cell Lung Cancer

BackgroundImmunohistochemistry (IHC) and fluorescent in situ hybridization are reliable methods for identifying c-Met protein expression or c-Met gene amplification. However, each technique requires a high-quality tissue sample, which might not be available. The aim of the present study was to investigate the correlation between the soluble c-Met level and tissue c-Met protein expression and the relationship between these markers and patient prognosis. Materials and MethodsIn 198 patients with advanced non–small-cell lung cancer, tumor tissue c-Met expression was determined using IHC according to the H score criteria. Positivity was defined as ≥ 50% of cells with strong staining (IHC 3+). The concentration of c-Met protein in paired plasma samples was measured using a human soluble c-Met quantitative enzyme-linked immunosorbent assay kit, and the predictive value was determined using receiver operating characteristic curve analysis. ResultsOf the 198 patients, 140 (70.7%) had tissue c-Met− findings and 58 (29.3%) tissue c-Met+ findings. Receiver operating characteristic curve analysis showed 67.2% specificity and 65.0% sensitivity for predicting tissue c-Met positivity at a plasma c-Met cutoff of 766 ng/mL. The correlation between the soluble c-Met level and tissue c-Met protein expression was significant (Pearson's r = 0.309; P < .001). Patients with high soluble c-Met levels (> 766 ng/mL) had poorer overall survival than patients with low soluble c-Met levels (9.5 vs. 22.2 months; P < .001). Multivariate analyses demonstrated the same result (hazard ratio, 2.15; 95% confidence interval, 1.334-3.446; P = .002). ConclusionA significant correlation was found between the plasma soluble c-Met levels and tissue c-Met protein expression in patients with advanced non–small-cell lung cancer. A high level of soluble c-Met was associated with a poor prognosis.

Plasma dynamic monitoring of soluble c-Met level for EGFR-TKI treatment in advanced non-small cell lung cancer.

BackgroundThe activation of c-Met has been associated with both primary and acquired resistance to EGFR-TKI therapy in NSCLC patients. Thus, c-Met status during EGFR-TKI therapy should receive much attention.ResultsForty-nine patients were selected as training cohort and 52 cases as validation cohort. With disease progression, IHC results showed that 37 (75.5%) of the patients were tissue c-Met-negative, and 12 (24.5%) were tissue c-Met-positive. There was a statistically significant difference in the dynamic change in soluble c-Met between the tissue c-Met-negative and c-Met-positive groups (P = 0.002). Patients with a baseline soluble c-Met level >766 ng/ml showed inferior median progression-free survival (PFS; 10.2 vs. 14.0 months; P = 0.003) after EGFR-TKI treatment. Multivariate Cox proportional hazards model analyses demonstrated that the soluble c-Met level was an independent prognostic factor for PFS after EGFR-TKI treatment (P = 0.009; hazard ratio: 3.583; 95% confidence interval: 1.379-9.312). In the validation cohort, patients with soluble c-Met levels >766 ng/ml were also determined to have significant short median PFS after EGFR-TKI treatment (6.8 vs. 14.5 months, P < 0.001).Patients and MethodsWe retrospectively investigated the dynamic change in the soluble c-Met level in plasma and its relationship with clinical outcomes of EGFR-TKI therapy in advanced NSCLC. Immunohistochemistry (IHC) was used to assess the expression of c-Met in the resistant tissue. Plasma c-Met levels were assayed in duplicate using a human soluble c-Met quantitative enzyme-linked immunosorbent assay (ELISA) kit.ConclusionsQuantitatively determining the soluble c-Met level in plasma by ELISA might provide a non-invasive and sensitive method to predict EGFR-TKI prognosis.

154P Plasma dynamic monitoring of soluble c-Met level for EGFR-TKI treatment in advanced non-small cell lung cancer

Background: The activation of c-Met has been associated with both primary and acquired resistance to EGFR-TKI therapy in NSCLC patients. Thus, c-Met status during EGFR-TKI therapy should receive much attention. Results: Forty-nine patients were selected as training cohort and 52 cases as validation cohort. With disease progression, IHC results showed that 37 (75.5%) of the patients were tissue c-Met-negative, and 12 (24.5%) were tissue c-Met-positive. There was a statistically significant difference in the dynamic change in soluble c-Met between the tissue c-Met-negative and c-Met-positive groups (P = 0.002). Patients with a baseline soluble c-Met level >766 ng/ml showed inferior median progressionfree survival (PFS; 10.2 vs. 14.0 months; P = 0.003) after EGFR-TKI treatment. Multivariate Cox proportional hazards model analyses demonstrated that the soluble c-Met level was an independent prognostic factor for PFS after EGFR-TKI treatment (P = 0.009; hazard ratio: 3.583; 95% confidence interval: 1.379-9.312). In the validation cohort, patients with soluble c-Met levels >766 ng/ml were also determined to have significant short median PFS after EGFR-TKI treatment (6.8 vs. 14.5 months, P <

34P Predicting tissue c-Met status using plasma soluble c-Met levels in patients with advanced NSCLC

34P Predicting tissue c-Met status using plasma soluble c-Met levels in patients with advanced NSCLC

Potential Role of Soluble c-Met as a New Candidate Biomarker of Metastatic Uveal Melanoma.

Conventional melanoma serum biomarkers (S100 and lactate dehydrogenase [LDH]) perform poorly in patients with uveal melanoma, and the search for new biomarkers is needed. A high expression of the oncoprotein c-Met in primary uveal melanoma is associated with metastatic progression, and c-Met is released as a soluble ectodomain through ADAM10- and ADAM17-mediated cleavage, suggesting a possible role as biomarker. To determine the potential role of soluble c-Met (sc-Met) as a biomarker of uveal melanoma progression in comparison with S100 and LDH. Soluble c-Met was studied in the conditioned medium of 9 uveal melanoma cell lines and in the blood serum samples of 24 mice with uveal melanoma xenografts, 57 patients with uveal melanoma (17 patients whose tumors metastasized and 40 patients whose tumors did not metastasize), and 37 healthy donors. We collected blood samples for as long as 5 years after treatment of the primary tumor. The concentration of sc-Met was measured using enzyme-linked immunosorbent assays, and the receiver operating characteristic curve was used to evaluate sensitivity and specificity in the identification of metastatic uveal melanoma. The study began on May 2, 2011, and the last samples were collected in January 2015. Levels of sc-Met in uveal melanoma cell cultures and in the blood serum samples of xenotransplanted mice, of healthy donors, and of patients with uveal melanoma during follow-up. The conditioned medium of uveal melanoma cell lines and the blood serum samples of mice with uveal melanoma xenografts contained significant levels of sc-Met. Patients with metastatic disease had significantly higher serum levels of sc-Met (median level, 590 ng/mL [range, 246-12,856 ng/mL]) than did patients without metastatic disease (median level, 296 ng/mL [range, 201-469 ng/mL]) (P < .001) and healthy donors (median level, 285 ng/mL [range, 65-463 ng/mL]) (P < .001). Analysis of receiver operating characteristic curves for sc-Met levels in patients with nonmetastatic uveal melanoma vs patients with metastatic uveal melanoma yielded an area under the curve of 0.82 (95% CI, 0.68-0.95) (P < .001), which was superior to the areas under the curve achieved with S100 or LDH markers. Patients with progressive metastatic disease showed further increases in sc-Met level, whereas stable patients did not. The present pilot study suggests that sc-Met should be further exploited as a biomarker for monitoring of uveal melanoma.

Abstract CT309: Rapid evaluation of a novel small molecule cMet tyrosine kinase inhibitor in healthy subjects

Abstract Inhibiting cMet has potential therapeutic value in oncology. The Janssen WAVE Early Development unit, a team focused on efficient proof-of-concept evaluations, sought to rapidly assess the safety, pharmacokinetics, and pharmacodynamics of a novel, highly selective small molecule cMet TK inhibitor with a favorable preclinical safety profile. We conducted a placebo-controlled, randomized, double blind single ascending dose and multiple dose trial in 84 healthy males at Quotient Clinical LTD (UK). The trial design was adaptive in several respects: to expedite determination of an optimal formulation and to maintain sufficient systemic exposure to sustain target inhibition. In the single ascending dose phase, doses ranged from 6-350 mg, with early transition from a solution to capsule formulation at 18 mg. Two multiple dose cohorts received 60 mg twice daily for 7 days (inter-dose intervals of 4.5 and 12 hours). Target engagement biomarkers were plasma hepatocyte growth factor and soluble cMet. Evaluation of renal safety was of particular interest. Clinical evaluation, including both single ascending and multiple dose phases, was completed in only 6 months. All doses were safe and well tolerated. Pharmacokinetic analysis revealed dose-proportional increases in exposure. Dose escalation was limited by concentrations of a major metabolite that approached the ceiling established in preclinical toxicology studies. Renal toxicity was not identified. Initial evaluation of this oncology drug in healthy subjects offered the advantages of rapid trial enrollment and completion, robust placebo comparison data, absence of concomitant illness or laboratory abnormalities, rapid dose escalation in a carefully-monitored, controlled setting, a thorough preliminary safety evaluation, and reduced costs. This approach, enabled by the acceptable preclinical safety profile of the compound, efficiently produced high quality clinical safety and pharmacokinetic data to support compound progression decisions. Citation Format: A Dawn Millington, Sandra R. Chaplan, Zuleima Aguilar, Dennis M. Fisher, Jo Collier, Marielena Mata, Geert Mannens, Nico Goyvaerts, Vijay Peddareddigari, Chris Takimoto. Rapid evaluation of a novel small molecule cMet tyrosine kinase inhibitor in healthy subjects. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT309. doi:10.1158/1538-7445.AM2015-CT309

Soluble c-Met is a reliable and sensitive marker to detect c-Met expression level in lung cancer.

c-Met has been demonstrated as an attractive target in lung cancer therapy. Current studies showed that detection of c-Met status in tumor is critical in Met-targeted therapy. However not all patients are suitable for tissue sample collection. It is important to discover novel surrogate markers to detect c-Met status. In the study, soluble c-Met (s-Met) in plasma from 146 Chinese lung cancer patients and 40 disease-free volunteers was measured by enzyme-linked immunosorbent. In parallel, expression of c-Met in those tumors was also assessed by immunohistochemistry. Results showed that, in 146 lung cancer patients, 93 were c-Met expression positive and 74 of 93 were overexpressed. In c-Met-overexpressed patients, plasma s-Met was significantly increased. And further studies showed that plasma s-Met linearly correlated with c-Met expression in tumor. After tumor was removed in Met-overexpressed patients via resection, plasma s-Met significantly decreased to basal level. In addition, plasma s-Met showed to be poorly correlated with tumor size in Met-overexpressed patients. These results demonstrated that plasma s-Met is a sensitive and reliable marker to detect c-Met overexpression in lung cancers, and it is independent of tumor volume.

ADAM10 correlates with uveal melanoma metastasis and promotes in vitro invasion.

Uveal melanoma (UM) is a rare ocular tumor that may lead to deadly metastases in 50% of patients. A disintegrin and metalloproteinase (ADAM)10, ADAM17, and the HGF-receptor c-Met support invasiveness in different tumors. Here, we report that high ADAM10, MET, and, to a lesser extent, ADAM17 gene expression correlates with poor progression-free survival in UM patients (hazard ratio 2.7, 2.6, and 1.9, respectively). About 60% of primary UM expresses c-Met and/or ADAM10 proteins. Four UM cell lines display high levels of ADAM10 and ADAM17, which constitutively cleave c-Met, inducing the release of soluble c-Met. ADAM10/17 pharmacological inhibition or gene silencing reduces c-Met shedding, but has limited impact on surface c-Met, which is overexpressed. Importantly, ADAM10 silencing inhibits UM cell invasion driven by FCS or HGF, while ADAM17 silencing has a limited effect. Altogether our data indicate that ADAM10 has a pro-invasive role and may contribute to UM progression.

Soluble c-Met expression in the peritoneal fluid and serum of patients with different stages of endometriosis

Hepatocyte growth factor (HGF), also known as scatter factor, and its receptor c-Met have been shown to be implicated in endometriosis. HGF acts as a mitogen, motogen, and morphogen on endometrial epithelial cells. The expression of c-Met on human endometrial cells has been reported. Many proteins are proteolytically released from the surface by a process known as ectodomain shedding. The aim of this study was to determine the levels of soluble c-Met (s-cMet) in the peritoneal fluid (PF) and serum samples of patients with different stages of endometriosis. 39 PF and serum samples from normal healthy and 130 samples from different stages of patients with endometriosis (33 cases of stage I, 38 stage II, 30 stage III and 29 stage IV) were included in this study. Total protein concentration (TPC) and the level of s-cMet in the PF and serum were determined by Bio-Rad protein assay based on the Bradford dye procedure and enzyme-linked immunosorbent assay, respectively. No significant change in the TPC was seen in the serum and PF of patients with endometriosis when compared with normal controls. Results obtained demonstrated that all PF and serum samples presented s-cMet expression, whereas, starting from stages I to IV endometriosis, a significant increase of s-cMet expression was observed as compared to controls. The results of this study show that a high expression of s-cMet is correlated with advanced stages of endometriosis. It is also concluded that the detection of serum and PF s-cMet may be useful in classifying endometriosis.

Abstract LB-316: The anti-c-Met Nanobody®, a novel and promising anti-cancer therapeutic.

Abstract The hepatocyte growth factor (HGF) and its receptor, c-Met, are implicated in many human cancers to promote tumor proliferation, migration, invasion and angiogenesis. Dysregulation of the HGF/c-Met pathway is known to correlate with poor prognosis. In recent years, multiple anti-cancer agents have been developed interfering at different levels in the HGF/c-Met pathway. Here, we investigated the in vitro and in vivo efficacy of a novel Nanobody effectively antagonizing c-Met. Nanobodies are therapeutic proteins based on the smallest functional fragments of heavy chain antibodies, naturally occurring in Camelidae. The Nanobody platform allows designing modular drugs, including multivalent, biparatopic and bifunctional molecules. The anti-c-Met Nanobody is a bispecific Nanobody that comprises two building blocks, one targeting c-Met and one binding human serum albumin for half-life extension purposes. In vitro characterization revealed that the Nanobody is able to specifically and completely inhibit HGF/c-Met interaction with high potency in an ELISA-based assay. In addition, the anti-c-Met Nanobody was able to completely block the HGF-dependent c-Met-phosphorylation in the A549 non-small cell lung cancer cell line. Importantly, no agonistic activity was observed in absence of HGF, as the Nanobody was designed to have a monovalent interaction with c-Met. Next, the in vivo effect was translated towards a potent in vivo effect. The anti-tumor efficacy of the anti-c-Met Nanobody was assessed in xenograft mouse models in which autocrine U87MG (HGF+, c-Met+) glioblastoma cells, or autocrine KP4 (HGF+, c-Met+) pancreatic carcinoma cells were subcutaneously injected. In the U87MG xenograft model, Nanobody treatment (10 mg/kg i.p 3x/week) resulted in significant tumor growth inhibition compared to vehicle and sustained tumor growth suppression after cessation of the treatment. Treatment with the anti-c-Met Nanobody in the KP4 xenograft model (10 mg/kg i.p 3x/week) led to a significant tumor growth inhibition and even tumor regression. In the latter model, serum levels of soluble c-Met, IL-8 and HGF were shown to be significantly reduced upon Nanobody treatment, which could make these markers attractive as potential translational pharmacodynamics biomarkers. Furthermore, the ratio of tyrosine phosphorylated c-Met over total c-Met levels was significantly lower in KP4 tumors treated with Nanobody versus vehicle. It could be postulated based on literature data that the anti-c-Met Nanobody, by possessing an anti-albumin Nanobody building block, has the potential to show superior tumor penetration than c-Met targeting antibodies. Hence, the anti-c-Met Nanobody might be a valuable novel biological for the treatment of cancer driven by HGF-c-Met signaling. Citation Format: Tinneke Denayer, Thomas Stöhr, Gerald Beste, Ann Brige, Cedric Ververken, Josefin-Beate Holz. The anti-c-Met Nanobody®, a novel and promising anti-cancer therapeutic. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-316. doi:10.1158/1538-7445.AM2013-LB-316