c-Met Overexpression Research Articles

P60.12 Prevalence of c-Met overexpression (c-Met+) and Impact of Prior Lines of Treatment on c-Met Protein Expression in NSCLC

Teliso-V, an anti–c-Met antibody conjugated with monomethyl auristatin E, is currently being investigated as monotherapy in c-Met+ 2nd/3rd-line metastatic NSCLC in a phase 2 study (NCT03539536). Here we present prevalence of c-Met+ NSCLC based on histopathology and EGFR mutation status. c-Met expression change from archival (diagnostic (Dx)/post-Dx biopsy) vs fresh (tumor biopsy at time of study prescreening) is also presented for patient subsets. In this study, patients were prospectively selected for c-Met–positive expression by immunohistochemistry (central assay; SP44 antibody). Archival or fresh tumor tissue was eligible for c-Met expression testing and enrollment consideration. Per protocol, if archival tissue was c-Met negative, patients could provide fresh tumor tissue for reassessment of c-Met expression. As of December 2020, 841 patients evaluable for c-Met expression have been prescreened (Table 1). c-Met+ rates were lower in EGFR wild-type (25%) vs mutant (37%) non-squamous cohorts. Squamous histology had a 39% positivity rate. c-Met+ rates were higher in fresh vs archival tumor tissue. Similar trends were observed when EGFR wild-type and mutant cohorts were separated based on c-Met–high or –intermediate groups (Table 2). Sixteen patients (non-squamous cohorts: EGFR mutant, N=8; EGFR wild-type, N=8) initially reported c-Met–negative status based on archived tissue and submitted fresh tissue for c-Met reassessment. Tumors from EGFR mutant (50%) and wild-type (12.5%) cohorts had changes in c-Met status from negative to positive, potentially due to prior anti-EGFR or immuno-oncology/chemotherapy treatments, degradation of the epitope over time in the sample, or heterogeneity within tumor lesions.Table 1Patientsc-Met Positive, %a (n)NSQ EGFR MU24537 (90)NSQ EGFR WT44625 (122)Squamous15039 (58)aThe c-Met–positive cutoffs (by immunohistochemistry using SP44 antibody) were derived from retrospective receiver operating characteristic analysis of phase 1 (NCT02099058) Teliso-V monotherapy data. Cutoffs were established as membrane staining: non-squamous (≥25% 3+) and squamous (≥75% 1+) NSCLC. MU, mutant; NSQ, non-squamous; WT, wild-type. Open table in a new tab aThe c-Met–positive cutoffs (by immunohistochemistry using SP44 antibody) were derived from retrospective receiver operating characteristic analysis of phase 1 (NCT02099058) Teliso-V monotherapy data. Cutoffs were established as membrane staining: non-squamous (≥25% 3+) and squamous (≥75% 1+) NSCLC. MU, mutant; NSQ, non-squamous; WT, wild-type. Based on defined cutoffs, 25%–39% of NSCLC tumors were c-Met+. Consistent with prior observations, an increase in c-Met expression was observed in tumor tissue after anti-EGFR treatments. The increase in c-Met expression following immuno-oncology/chemotherapy treatments was a new observation. Additional data are needed to make conclusive remarks.

P47.03 Telisotuzumab Vedotin Monotherapy in Patients With Previously Treated c-Met+ Advanced Non-Small Cell Lung Cancer: Stage 2

Telisotuzumab vedotin (Teliso-V) is an anti-c-Met antibody conjugated with a tubulin inhibitor, monomethylauristatin E. The c-Met receptor tyrosine kinase is the cell surface receptor for hepatocyte growth factor (HGF) encoded for by the MET proto-oncogene. c-Met overexpression occurs in various solid tumors, including non-small cell lung cancer (NSCLC), and the aberrant activation of the c-Met/HGF axis contributes to tumor progression, angiogenesis, invasive growth, metastasis, and resistance to therapies. Following encouraging evidence of anti-tumor activity in a Phase 1 study (Strickler et al. J Clin Oncol 2018;36:3298–3306), a Phase 2 study was initiated to explore the safety and efficacy of Teliso-V monotherapy in 3 cohorts (based on histopathology and epidermal growth factor receptor [EGFR] mutation) and 5 subgroups (based on c-Met expression) of patients with c-Met+ advanced NSCLC (study Stage 1), followed by expansion into an appropriately selected population based on study Stage 1 results for further evaluation of safety and efficacy (study Stage 2). This Phase 2, non-randomized, single-arm, adaptive study (NCT03539536) is enrolling patients aged ≥18 years with Eastern Cooperative Oncology Group performance status ≤1 and locally advanced or metastatic c-Met+ NSCLC who have received 1–2 prior lines of therapy (including systemic chemotherapy, immunotherapy, and targeted therapy, if eligible). Based on data from study Stage 1 (Camidge et al. AACR 2021), the cohort of patients with non-squamous EGFR wild type c-Met+ NSCLC met prespecified criteria to transition to the study Stage 2 single-arm expansion cohort. Study Stage 2 enrollment commenced in February 2021 and is ongoing; up to approximately 160 patients will be enrolled in study Stage 2. c-Met status is determined centrally by immunohistochemistry. The primary endpoint is overall response rate per independent central review (based on Response Evaluation Criteria in Solid Tumors version 1.1). Secondary endpoints are duration of response, disease control rate, progression-free survival, and overall survival. Quality of life will be evaluated as an exploratory efficacy endpoint and safety and tolerability will be assessed. Pharmacokinetic and biomarker samples will also be collected for analysis. Teliso-V is administered as a 30±10 min intravenous infusion at a dose of 1.9 mg/kg every 2 weeks until disease progression or study discontinuation criteria are met. ▪▪▪ ▪▪▪

Transforming Type II to Type I c-Met kinase inhibitors via combined scaffold hopping and structure-guided synthesis of new series of 1,3,4-thiadiazolo[2,3-c]-1,2,4-triazin-4-one derivatives

Novel 1,3,4-thiadiazolo[2,3-c]-1,2,4-triazin-4-one derivatives 3a-e, 4a-f and 5a-f were designed as Type I c-Met kinase inhibitors based on scaffold hopping of our previous Type II c-Met kinase lead. Target compounds were then synthesized under the guidance of molecular docking analysis to identify the potential inhibitors that fit the binding pocket of c-Met kinase in the characteristic manner as the reported Type I c-Met kinase inhibitors. All synthesized derivatives were evaluated for their c-Met kinase inhibitory activity at 10 µM concentration, where 3d, 5d and 5f displayed >80% inhibition. Further IC50 investigation of these compounds identified 5d as the most potent c-Met kinase inhibitor with IC50 value of 1.95 µM. Moreover, 5d showed selective antitumor activity against c-Met over-expressing colon HCT-116 and lung A549 adenocarcinoma cells with IC50 values of 6.18 and 10.6 µg/ml, respectively. More significantly, 5d effectively inhibited c-Met phosphorylation in the Western blot experiment. Also, 5d induced cellular apoptosis in HCT-116 cancer cells as well as cell cycle arrest with accumulation of cells in G2/M phase. Finally, kinase selectivity profiling of 5d against nine oncogenic kinases revealed its selectivity to only Tyro3 kinase (% inhibition = 80%, IC50 = 3 µM). All these experimental findings clearly demonstrate that 5d is a potential dual acting inhibitor against c-Met and Tyro3 kinases, standing out as a viable lead that deserves further investigation and development to new generation of antitumor agents.

P4-13 cMET promotes metastasis and epithelial-mesenchymal transition in colorectal carcinoma via repressing RKIP

Colorectal cancer (CRC) ranks among the most frequent malignancies globally and is associated with high metastasis incidence. Today, it is becoming more prevalent among Asian populations, especially in the Chinese. There is increasing evidence that c-mesenchymal-epithelial transition factor (cMET) plays an important role in malignant progression, and its overexpression is closely linked with poor survival and enhanced resistance to drug therapy, hence abnormal cMET is viewed as a signature event in CRC. As a metastasis suppressor, loss of raf kinase inhibitory protein (RKIP) has been reported in many of cancer types. Both of them may serve to regulate CRC initiation and progression. It is therefore necessary to address the interaction between cMET/ERK signal axis and RKIP. In this study, expression of cMET and RKIP in CRC tissues and cell lines were determined, and their crosstalk and potential biological effects were explored using. Immunofluorescence staining and Chromatin immunoprecipitation. Our results showed cMET was inversely correlated with RKIP. Both cMET upregulation and RKIP downregulation implied poor clinical outcomes. Moreover, the MAPK/ERK signal pathway was involved in the regulation of cMET and RKIP. Overexpression of cMET promoted epithelial mesenchymal transition (EMT), invasion, migration and chemoresistance of tumor cells, whereas the impact could be efficiently impeded by increased RKIP. Notably, shRNA-mediated cMET knockdown dramatically suppressed cell proliferation, although no influence of RKIP on cell growth was observed in CRC. Altogether, cMET overexpression may contribute to tumor progression by inhibiting anti-oncogene RKIP, which provides preclinical justification for targeting RKIP to treat cMET-induced metastasis in CRC.

Abstract LB097: MET inhibitor enhances efficacies of gemcitabine and olaparib in pancreatic cancer cells

Abstract Gemcitabine is one of the current first-line chemotherapy agents in pancreatic cancer treatment. However, the response rate of pancreatic cancer patients to gemcitabine treatment is lower than 20%. Among the potential targeted therapies for pancreatic cancer patients, PARP inhibitor (Olaparib) has been approved by the U.S. Food and Drug Administration for maintenance treatment of metastatic pancreatic adenocarcinoma patients with germline BRCA-mutation. Taking advantages of the high oxidative stress in most pancreatic cancer cells, therapeutic agents that enhance the burden of oxidative DNA damages in these cancer cells can be introduced in novel treatment strategies. Because c-MET overexpression positively correlates with poor prognosis in pancreatic cancer, and our previous studies show that oxidative stress induced-nuclear c-MET phosphorylates PARP1 to reduce oxidative DNA damages, we focused on developing novel treatment strategies by combining c-MET inhibitors (crizotinib and tivantinib) with either gemcitabine or olaparib. In this study, we found that gemcitabine induced nuclear accumulation of c-MET, and that tivantinib reduced c-MET mediated PARP1 phosphorylation in both BxPC-3 and L3.6pl pancreatic cancer cell lines. We also found that combination of tivantinib with either gemcitabine or Olaparib induced more DNA damages than the single agent treatments. Further, we demonstrated the synergistic effects of c-MET inhibitors combined with gemcitabine or Olaparib in pancreatic cancer cell lines, suggesting that combining c-MET inhibitor with PARP inhibitor or gemcitabine is a novel and rational therapeutic strategy for pancreatic cancer treatment. Citation Format: Meikuang Chen, Yuan Gao, Dihua Yu, Mien-Chie Hung. MET inhibitor enhances efficacies of gemcitabine and olaparib in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB097.

A phase Ⅰ open-label dose-escalation study of AL2846 in combination with gemcitabine in patients with locally advanced or metastatic pancreatic adenocarcinoma.

e16210 Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with a 5-year survival rate of 10%. Overexpression of c-Met is associated with the poor prognosis in patients with PDAC and it was noted that phosphorylation of c-Met is increased in gemcitabine-resistant PDAC. AL2846 is an oral c-Met inhibitor, which targets multiple receptor tyrosine kinases (RTK’s) primarily including c-Met, VEGFR1, KIT, Axl and RET. The combination of AL2846 with chemotherapy may improve the clinical efficacy of PDAC. Based on these consideration, a phase Ⅰ clinical trial was initiated to determine the maximum tolerated dose (MTD) of AL2846 in combination with gemcitabine in patients with advanced PDAC and to clarify the potential anti-tumor activity. Methods: Patients with untreated locally advanced or metastatic PDAC were enrolled to receive oral AL2846 once daily in a fasted state in combination with gemcitabine intravenous infusion over 30 min on days 1, 8, and 15 every 28 days. The starting dose level is AL2846 40 mg and gemcitabine 1000 mg/m2. Primary endpoint was the maximum tolerated dose (MTD), defined as the highest dose level at which ≤33 % of patients incurred a dose-limiting toxicity (DLT), and RP2D. Secondary endpoints included response rate (ORR), progression-free survival (PFS) and overall survival (OS). Results: As of January 1, 2021, a total of 15 patients with PDAC were enrolled and received 4 dose-levels of AL2846 (40 mg: n = 1; 60 mg: n = 6; 90 mg: n = 3; 120 mg: n = 5) treatment. DLTs occurred in 1 patient who experienced grade 3 abnormal liver function. The most common grade 3 or above drug-related adverse events were neutropenia (n = 7, 46.7%), thrombocytopenia (n = 5, 33.3%), leukopenia (n = 4, 26.7%), GGT increased (n = 4, 26.7%), hyperbilirubinemia (n = 3, 20.0%) and alkaline phosphatase increased (n = 3, 20.0%). Among the 15 patients available for efficacy evaluation, 1 patient (6.6%) achieved partial response who was at the dose levels of 90mg. There were 4 patients whose PFS was more than 5 months. Although there were no more than 2 DLT events, we chose 90 and 120 mg as the target dose for RP2D according to the dose reduction and proportion of gemcitabine. Conclusions: The RP2D of AL2846 in combination with standard dose of gemcitabine were 90 and 120 mg QD continuously. The results demonstrated that AL2846 in combination with gemcitabine was well tolerated at doses up to 120 mg. Further clinical studies about the efficacy of AL2846 in pancreatic cancer are in progress. Clinical trial information: CTR20201021.

Genomic and immunologic characterization of large-cell neuroendocrine carcinoma of the lung.

8535 Background: Large-cell neuroendocrine carcinoma (LCNEC) is a rare type of lung cancer with a poor prognosis. Due to its rarity, molecular characterization of LCNEC is not well elucidated. We aim to understand the genomic and immunologic landscape of LCNEC to identify molecular alterations and relevant biological pathways with potential therapeutic value. Methods: Comprehensive profiling including whole exome sequencing (WES), next-generation sequencing (NGS), whole transcriptome sequencing (WTS), and immunohistochemistry (IHC) for PD-L1 was performed (Caris Life Sciences, Phoenix, AZ). Tumor mutational burden (TMB) was calculated based on somatic nonsynonymous mutations. LCNEC was categorized as small cell lung cancer (SCLC)-like LCNEC ( TP53/ RB1 co-mutated) and non-small-cell lung cancer (NSCLC)-like LCNEC (wild type for one or both of TP53/ RB1). Molecular features of LCNEC were compared among the subgroups and with those of SCLC using the χ2 test with Benjamini & Hochberg correction. Results: A total of 467 cases of LCNEC were included. Commonly altered genes (≥ 5%) included TP53 (79.1%), RB1 (36.8%), SMARCA4 (10.4%), ARID1A (10.3%), KRAS (9.7%), KEAP1 (9.2%), KMT2D (8.7%), STK11 (8.4%), NF1 (7.1%), PTEN (6.1%), and CDKN2A (5.9%) . The prevalence of potentially actionable mutations was as follows: EGFR exon 19 deletion (0.48%), EGFR L858R (0.48%), ALK fusion (1.7%), KRAS G12C (2.9%). EGFR exon 19 deletion, EGFR L858R, and ALK fusion were exclusive to NSCLC-like LCNEC tumors. RET fusion, NTRK fusion and BRAFV600E were not detected. Copy number alterations (CNAs) were found in MYC (8.8%), ZNF703 (4.1%), FOXA1 (4.0%), FGFR1 (4.0%), ATK2 (3.9%), CCNE1 (3.7%), FGF19 (3.4%), TNFRSF14 (3.4%), and CCND1 (2.7%). Over-expression of cMET was noted in 10% and PD-L1 expression (by 22C3 pharmDx) of > 1% was noted in 21.5% of samples. WTS detected cMET exon 14 skipping mutations in 2.4% of samples. High tumor mutation burden (TMB; ≥ 10 Mut/MB) was seen in 40.6%. Among the 467 cases of LCNEC, 112 (24%) were SCLC-like LCNEC and 335 (76%) NSCLC-like LCNEC. Mutations in KRAS (12%), STK11 (11%), CDKN2A (9%), and SMARCA4 (14%) were more common in NSCLC-like LCNEC, compared with SCLC-like LCNEC (p value < 0.05). 442 cases of SCLC were compared with LCNEC tumors. SLFN11:SLFN12 fusion events, detected by WTS, were exclusively seen in SCLC and were not seen in any of the LCNEC cases. Gene expression profiles revealed that 1) B cell infiltration was higher in SCLC-like LCNEC, compared with SCLC, and 2) NK and T cell infiltration was lower, but B-cell infiltration was higher in NSCLC-like LCNEC, compared with SCLC. Conclusions: LCNEC displays a broad pattern of genomic alterations that overlap in the SCLC-like subset with the classic alterations in SCLC. The distinct genomic alterations and transcriptomic profiles present opportunities for therapeutic targeting and inform a future framework for development of therapeutics for LCNEC.

Trial in progress: A phase 1-2 multicenter, open-label, dose-escalation and dose-expansion study to evaluate the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of ABN401 in patients with advanced solid tumors.

TPS3157 Background: c-MET (hepatocyte growth factor (HGF) receptor) overexpression, either by gene amplification, or mutation is associated with oncogenic transformation in numerous malignancies including lung, gastric, skin, renal, colorectal, and pancreatic cancers. ABN401 inhibits the activation of c-MET by reversibly interfering with the binding of c-Met tyrosine kinase to adenosine triphosphate (ATP) and blocking the receptor's downstream signaling that has demonstrated efficacy in NSCLC and gastric cancer in mouse xenograft and PDx models. This clinical trial is in progress in patients with advanced cancers. Methods: ABN401 is being evaluated in an open-label, non-randomized, dose-escalation (phase 1) study in patients with advanced solid tumors, and dose-expansion (phase 2) in patients with targeted indications and c-MET biomarker expression (NCT04052971). The phase 1 explores ascending daily doses of oral ABN401 monotherapy in 21-day cycles to identify the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D). A preplanned extension (pilot expansion) study has been initiated based on predefined positive efficacy signals at intermediate doses up to 10 NSCLC patients who have c-MET alteration. Once RP2D is determined, the phase 2 expansion of up to 10-29 patients in four specific tumor-type cohorts is planned, utilizing a Simon's optimal two-stage design to evaluate the clinical activity of ABN401. ABN401-001 study began enrolling patients in August 2019 and is ongoing in Korean and Australia. Dose escalation up to cohort 4 has been completed, enrollment to cohort 5 began in November 2020. AEs are assessed according to CTCAE v5. Tumor response is determined according to RECIST 1.1 criteria and safety findings reviewed by the DRC, which will determine the RP2D and MTD. Key Phase 1 eligibility criteria include 1) histological or cytological diagnosis of melanoma or any type of carcinoma or sarcoma and 2) refractory metastatic disease, or refractory locally advanced disease not amenable to local therapy. For the extension (pilot expansion) study, patients must have NSCLC with MET exon 14 skipping, MET amplification and/or c-MET overexpression. An exploratory study is being conducted for co-development of a companion diagnostic (CDx) system including a CTC device and ddPCR kit through liquid biopsy. Clinical trial information: NCT04052971.

Targeted dual inhibition of c-Met/VEGFR2 signalling by foretinib improves antitumour effects of nanoparticle paclitaxel in gastric cancer models.

Elevated expression of multiple growth factors and receptors including c‐Met and VEGFR has been reported in gastric adenocarcinoma (GAC) and thus provides a potentially useful therapeutic target. The therapeutic efficacy of foretinib, a c‐Met/VEGFR2 inhibitor, was determined in combination with nanoparticle paclitaxel (NPT) in GAC. Animal studies were conducted in NOD/SCID mice in subcutaneous and peritoneal dissemination xenografts. The mechanism of action was assessed by Immunohistochemical and Immunoblot analyses. In c‐Met overexpressing MKN‐45 cell‐derived xenografts, NPT and foretinib demonstrated inhibition in tumour growth, while NPT plus foretinib showed additive effects. In c‐Met low‐expressing SNU‐1 or patient‐derived xenografts, the foretinib effect was smaller, while NPT had a similar effect compared with MKN‐45, as NPT plus foretinib still exhibited an additive response. Median mice survival was markedly improved by NPT (83%), foretinib (100%) and NPT plus foretinib (230%) in peritoneal dissemination xenografts. Subcutaneous tumour analyses exhibited that foretinib increased cancer cell death and decreased cancer cell proliferation and tumour vasculature. NPT and foretinib suppressed the proliferation of GAC cells in vitro and had additive effects in combination. Further, foretinib caused a dramatic decrease in phosphorylated forms of c‐Met, ERK, AKT and p38. Foretinib led to a decrease in Bcl‐2, and an increase in p27, Bax, Bim, cleaved PARP‐1 and cleaved caspase‐3. Thus, these findings highlight the antitumour impact of simultaneous suppression of c‐Met and VEGFR2 signalling in GAC and its potential to enhance nanoparticle paclitaxel response. This therapeutic approach might lead to a clinically beneficial combination to increase GAC patients’ survival.

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.

The role of c-Met and VEGFR2 in glioblastoma resistance to bevacizumab

Dismal prognosis of glioblastoma (GBM) prompts for the identification of response predictors and therapeutic resistance mechanisms of current therapies. The authors investigated the impact of c-Met, HGF, VEGFR2 expression and microvessel density (MVD) in GBM patients submitted to second-line chemotherapy with bevacizumab. Immunohistochemical expression of c-Met, HGF, VEGFR2, and MVD was assessed in tumor specimens of GBM patients treated with bevacizumab, after progression under temozolomide. Survival analysis was evaluated according to the expression of the aforementioned biomarkers. c-Met overexpression was associated with a time-to-progression (TTP) after bevacizumab of 3 months (95% CI, 1.5–4.5) compared with a TTP of 7 months (95% CI, 4.6–9.4) in patients with low or no expression of c-Met (p = 0.05). VEGFR2 expression was associated with a TTP after bevacizumab of 3 months (95% CI, 1.8–4.2) compared with a TTP of 7 months (95% CI, 5.7–8.3) in patients with no tumoral expression of VEGFR2 (p = 0.009). Concomitant c-Met/VEGFR2 overexpression was associated with worse overall survival (13 months) compared with concomitant c-Met/VEGFR2 negative expression (19 months; p = 0.025). Our data support the hypothesis that c-Met and VEGFR2 overexpression have a role in the development of glioblastoma early resistance and might predict poorer responses to anti-angiogenic therapies.

Cabozantinib, a Promising Therapeutic Strategy for Resistant Head and Neck Squamous Cell Carcinoma Patients

Local or metastatic relapses following surgery, radiotherapy and chemotherapy (cisplatin) are the leading causes of death of patients with head and neck squamous cell carcinoma (HNSCC). In the current study, we showed that acquired resistance to radiotherapy and cisplatin of HNSCC cells and patients depends on overexpression of c-MET and AXL. Cabozantinib, a VEGFR, c-MET and AXL inhibitor, decreased migration, invasion and proliferation, and induced mitotic catastrophe and apoptotic cell death of naive and radiotherapy- and cisplatin-resistant HNSCC cells.Cabozantinib inhibited the growth of experimental HNSCC in mice by inhibiting tumor cell proliferation and angiogenesis. Cabozantinib inhibited the growth and the metastatic spread of experimental HNSCC in zebrafish. The efficacy of cabozantinib on experimental models of HNSCC was further confirmed on viable sections of surgically removed specimens of human HNSCC. These results suggest that cabozantinib is highly relevant for the treatment of HNSCC patients following relapses on radiotherapy and cisplatin.

C-Met/MAPK pathway promotes the malignant progression of residual hepatocellular carcinoma cells after insufficient radiofrequency ablation.

Radiofrequency ablation (RFA) is popularly used in the treatment of hepatocellular carcinoma (HCC). However, the accelerated malignant progression of residual HCC cells after RFA is the main obstacle for the application of this technology in HCC treatment. In the present study, HepG2 cells, an established human HCC cell line, experienced repeatedly with heat treatment, survived cells, HepG2-H cells, were used to simulate residual HCC cells after RFA. The abilities of proliferation, colony formation, and migration were compared between HepG2 and HepG2-H cells. Then, RNA sequencing was used to explore the difference in genes expression between two groups of cells. Subsequently, the level of c-Met, one of membranous receptors of MAPK signal pathway, was measured by RT-qPCR and western blot; the effect of c-Met inhibition on the malignant progression of HepG2-H cells was evaluated. The results showed that HepG2-H cells exhibited higher abilities in the proliferation, colony formation, and migration than that of HepG2 cells. Moreover, differentially expressed genes between two groups of cells were prominently enriched in MAPK signal pathway. The level of c-Met in HepG2-H cells was significantly higher than that in HepG2 cells, and the inhibition in the activity of c-Met could repress the malignant behaviors of HepG2-H cells. These results indicated that the accelerated malignant progression of residual HCC cells after RFA can be partly attributed to the overexpression of c-Met and the activation of MAPK signal pathway. Therefore, we proposed that RFA followed by c-Met inhibitor intake maybe is a better treatment protocol for HCC.

CMET promotes metastasis and epithelial-mesenchymal transition in colorectal carcinoma by repressing RKIP.

Increasing evidence indicates that c-mesenchymal-epithelial transition factor (cMET) plays an important role in the malignant progression of colorectal cancer (CRC). However, the underlying mechanism is not fully understood. As a metastasis suppressor, raf kinase inhibitory protein (RKIP) loss has been reported in many cancer types. In this study, the expression levels of cMET and RKIP in CRC tissues and cell lines were determined, and their crosstalk and potential biological effects were explored in vitro and in vivo. Our results showed that cMET was inversely correlated with RKIP. Both cMET upregulation and RKIP downregulation indicated poor clinical outcomes. Moreover, the MAPK/ERK signaling pathway was implicated in the regulation of cMET and RKIP. Overexpression of cMET promoted tumor cell epithelial-mesenchymal transition, invasion, migration, and chemoresistance, whereas the effects could be efficiently inhibited by increased RKIP. Notably, small hairpin RNA-mediated cMET knockdown dramatically suppressed cell proliferation, although no RKIP-induced influence on cell growth was observed in CRC. Altogether, cMET overexpression may contribute to tumor progression by inhibiting the antioncogene RKIP, providing preclinical justification for targeting RKIP to treat cMET-induced metastasis of CRC.

Overexpression of metastasis-associated in colon cancer 1 in retinoblastoma.

Metastasis-associated in colon cancer 1 (MACC1), one of the prognostic markers for colonic and other tumours was noted to be overexpressed in retinoblastoma (Rb) Y79 cancer stem cells. This prompted us to evaluate its expression in primary Rb tumour and serum samples with clinicopathologic correlation. The interacting partner, c-MET was also evaluated in primary tumour tissues to explore the activation of MACC1 signaling. This study was done following institutional review board approval from participating institutes. Semiquantitative gene expression for MACC1 was evaluated using formalin-fixed paraffin-embedded sections and unfixed tumour samples from primary Rb cases (n = 44). Immunolocalization for MACC1 was assessed in primary Rb tumours (n = 22), bone marrow aspirates with metastasis (n = 3), and c-MET expression was also assessed in Rb tumours (n = 17). Serum MACC1 levels were analysed using enzyme-linked immunosorbent assay in samples collected from Rb patients undergoing enucleation (n = 31), Rb patients with proven clinical metastasis (n = 3), and compared to appropriate controls. Clinicopathologic correlation of MACC1 expression was analysed using the medical records with specific reference to histologic risk factors (HRF) for metastasis and differentiation. High expression of MACC1 gene was noted in all the tumour samples (n = 44), more so in cases with versus without HRF (p < 0.0001). In cases with HRF, MACC1 and c-MET showed diffuse nuclear and cytoplasmic staining whereas it was predominantly cytoplasmic in cases without HRF. Mean immunoreactivity score of MACC1 and c-MET tissue immunolocalization revealed that cases with HRF showed significantly higher expression compared to cases without HRF (p < 0.05). Unlike the findings in colonic tumours, serum levels of MACC1 were lower in patients compared to normal controls. Overexpression of MACC1 and c-MET in retinoblastoma tissues, specifically those with risk factors for metastasis, suggests its role in proliferation and possibly in invasion. However, the current data do not support it to be a clinical prognostic marker in retinoblastoma tumours. The inverse serum expression is an intriguing finding, which warrants further studies especially in retinoblastoma.

HGF/c-Met Axis: The Advanced Development in Digestive System Cancer.

Numerous studies have indicated that abnormal activation of the HGF/c-Met signaling pathway can lead to cell proliferation, invasiveness, and metastasis of cancers of the digestive system. Moreover, overexpression of c-Met has been implicated in poor prognosis of patients with these forms of cancer, suggesting the possibility for HGF/c-Met axis as a potential therapeutic target. Despite the large number of clinical and preclinical trials worldwide, no significant positive success in the use of anti-HGF/c-Met treatments on cancers of the digestive system has been achieved. In this review, we summarize advanced development of clinical research on HGF/c-Met antibody and small-molecule c-Met inhibitors of cancers of the digestive system and provide a possible direction for future research.

SIX4 promotes hepatocellular carcinoma metastasis through upregulating YAP1 and c-MET.

Metastasis is the main reason for high mortality in hepatocellular carcinoma (HCC) patients and the molecular mechanism remains unclear. Therefore, it is important to elucidate the mechanism underlying HCC metastasis. Here, we report a novel role of SIX homeobox 4 (SIX4), one of the SIX gene family, in promoting HCC metastasis. The elevated expression of SIX4 was positively correlated with loss of tumor encapsulation, microvascular invasion, higher TNM stage, and poor prognosis in human HCC. SIX4 expression was an independent and significant risk factor for the recurrence and survival in HCC patients. Upregulation of SIX4 promoted HCC invasion and metastasis, whereas downregulation of SIX4 decreased HCC invasion and metastasis. SIX4 transactivated Yes1 associated transcriptional regulator (YAP1) and MET proto-oncogene, receptor tyrosine kinase (MET) expression through directly binding to their promoters. Knockdown of YAP1 and c-MET inhibited SIX4-medicated HCC metastasis, while the stable overexpression of YAP1 and c-MET reversed the decreased metastasis induced by SIX4 knockdown. Hepatocyte growth factor (HGF), the specific ligand of c-MET, upregulated SIX4 expression through ERK/NF-κB pathway. Knockdown of SIX4 significantly decreased HGF-enhanced HCC metastasis. In human HCC tissues, SIX4 expression was positively correlated with nuclear YAP1, c-MET and HGF expression. Patients with positive coexpression of SIX4/ nuclear YAP1, SIX4/c-MET or HGF/SIX4 had the poorest prognosis. Moreover, the combination treatment of YAP1 inhibitor Verteporfin and c-MET inhibitor Capmatinib significantly suppressed SIX4-mediated HCC metastasis. In conclusion, SIX4 is a prognostic biomarker in HCC patients and targeting the HGF-SIX4-c-MET positive feedback loop may provide a promising strategy for the treatment of SIX4-driven HCC metastasis.

Protein overexpression of c-MET has a significant impact on survival in patients with uterine cervical adenocarcinoma

Protein overexpression of c-MET has a significant impact on survival in patients with uterine cervical adenocarcinoma

1414TiP Evaluating telisotuzumab vedotin in combination with osimertinib in patients with advanced non-small cell lung cancer: A phase I/Ib study cohort

Acquired resistance to third-generation epidermal growth factor receptor (EGFR) inhibitors (eg, osimertinib) may result in MET gene amplification and/or c-MET protein overexpression. Telisotuzumab vedotin (ABBV-399; teliso-v), an anti–c-MET antibody-drug conjugate that can both disrupt c-MET signaling and deliver a cytotoxic payload into tumor cells, has shown antitumor activity in a phase 1/1b trial (NCT02099058) in patients (pts) with non-small cell lung cancer (NSCLC) with c-MET overexpression. Here we describe the teliso-v plus osimertinib cohort (arm E) of this trial. Arm E of this phase 1/1b open-label study evaluates safety, pharmacokinetics, and preliminary efficacy of teliso-v, administered intravenously once every 2 weeks, in combination with oral osimertinib (80 mg once a day) in pts with metastatic NSCLC whose disease progressed on osimertinib. Pts must have documented osimertinib-sensitive EGFR mutations, and c-MET overexpression (defined by central immunohistochemistry test) in tumor tissue obtained post-osimertinib progression. Arm E consists of safety lead-in (SLP; n=3–6), safety evaluation (SEP; n=3–12), and expansion (n=3–12) phases. Teliso-v will first be evaluated at 1.6 mg/kg and escalated to 1.9 mg/kg on the basis of safety signals in SLP and SEP phases. Radiographic tumor assessments will continue until disease progression, start of a new anticancer therapy, death, or consent withdrawal. Response evaluation will be based on Response Evaluation Criteria in Solid Tumors version 1.1. Planned enrollment is 3–24 pts; to date, 3 pts are enrolled. NCT02099058. Medical writing support was provided by Mary L. Smith, PhD, CMPP, from Aptitude Health, Atlanta, GA, and funded by AbbVie. AbbVie.

Abstract 3046: Anti-tumor efficacy of CKD-702 in EGFR TKI-resistant patient-derived xenograft model

Abstract Background: c-MET is co-expressed with EGFR in approximately 70% of EGFR mutant-positive tumors. In addition, c-Met amplification was found in 10-20% of lung cancer patients with acquired tolerance to EGFR TKI, and c-Met overexpression was found in 14-69% of patients receiving EGFR TKI. CKD-702, a double antibody, is designed to simultaneously block both EGFR and c-MET expression. Purpose: We evaluated the anti-tumor efficacy of CKD-702 with PDX model derived from lung adenocarcinoma patients. Methods: We constructed the PDX model by transplanting surgical tissue from lung adenocarcinoma patient into NOD/SCID mice after the approval of research protocol in Seoul St. Mary's Hospital IRB. We confirmed the co-existence of activating EGFR mutation and c-MET amplification with PNAclamp and FISH methods. We also checked overexpression of EGFR and c-MET protein by immunohistochemistry. Results: The characteristics of tumor tissue transplanted for PDX model were: 1) Korean, lung cancer with EGFR TKI chemotherapy failure confirmed c-MET amplification (&amp;gt; 5 copies) and overexpression (IHC score 3+), 19del Positive EGFR mutation, 2) European lung adenocarcinoma, c-MET amplification (&amp;gt; 2.5 copy) and overexpression (IHC score 3+) were confirmed, and L858R EGFR mutation positive tumor tumor confirmed. The anti-cancer efficacy of CKD-702 was reduced by more than 80% compared to the tumor size of the control group regardless of the concentration. In the CKD-702 20mg/kg group, there was no significant difference in the change in the overall tumor size until the time of disappearing or ending during drug administration. The %TGI was 93.6 and 97.5 according to the concentration of CKD-702, and the % TGD was 118.5 and 311.8, respectively. CKD-702 has a significantly higher tumor growth inhibitory effect regardless of the concentration, but the tumor growth retardation effect is 2.6 times different depending on the concentration. % TGI of CKD-702 20mg / kg group was similar to Hu8c4 group or Hu8c4 + Vectibix group. However, % TGD was 1.4 times higher than Hu8c4 group efficacy and 3.1 times higher than Hu8c4 + Vectibix group% TGD. Even after the completion of drug administration, tumor still remained at 47 days and 67 days in the CKD-702 10 mg/kg and 20 mg/kg groups, respectively. Although c-MET protein expression decreased during the administration of CKD-702, it was confirmed that c-MET protein expression increased again in tumor tissue at the time of tumor growth. Although the tumor size was rather large (605.6 ~ 816.2mm3), CKD-702 showed twice the tumor growth inhibition effect (% TGI: 32.8 vs. 68.1) and the tumor growth delay effect was 4.4 times higher depending on the drug concentration (% TGI: 2.8 vs 12.3). Conclusion: Our data showed that CKD-702 have effective anti-tumor activity in EGFR TKI-resistant PDX model harboring both activating EGFR mutation and c-MET overexpression. Citation Format: Jung-Young Shin, Min-Young Kim, Mi-Ran Lee, Jeong-Oh Kim, Eun-Ju Jeon, Ji Hye Choi, Soon-Ki Hong, Kyu-Jin Park, Jin Hyoung Kang. Anti-tumor efficacy of CKD-702 in EGFR TKI-resistant patient-derived xenograft model [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3046.