Objective: To produce chimeric antigen receptor T cells (CAR-T) targeting human hepatocyte growth factor/c-Met (HGF/c-Met) protein and detect its cytotoxicity against non-small cell lung cancer (NSCLC) cells H1975 in vitro. Methods: The whole gene sequence of c-Met CAR containing c-Met single-chain fragment variable was synthesized and linked to lentiviral vector plasmid, plasmid electrophoresis was used to detect the correctness of target gene. HEK293 cells were transfected with plasmid and the concentrated solution of the virus particles was collected. c-Met CAR lentivirus was transfected into T cells to obtain second-generation c-Met CAR-T and the expression of CAR sequences was verified by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and western blot, and the positive rate and cell subtypes of c-Met CAR-T cells were detected by flow cytometry. The positive expression of c-Met protein in NSCLC cell line H1975 was verified by flow cytometry, and the negative expression of c-Met protein in ovarian cancer cell line A2780 was selected as the control. The cytotoxicity of c-Met CAR-T to H1975 was detected by lactate dehydrogenase (LDH) cytotoxicity assay at 1∶1, 5∶1, 10∶1 and 20∶1 of effector: target cell ratio (E∶T). Enzyme-linked immunosorbent assay (ELISA) was used to detect the release of cytokines such as TNF-α, IL-2 and IFN-γ from c-Met CAR-T co-cultured with H1975. Results: The size of band was consistent with that of designed c-Met CAR, suggesting that the c-Met CAR plasmid was successfully constructed. The results of gene sequencing were consistent with the original design sequence and lentivirus was successfully constructed. CAR molecules expression in T cells infected with lentivirus was detected by western blot and RT-qPCR, which showed c-Met CAR-T were successfully constructed. Flow cytometry results showed that the infection efficiency of c-Met CAR in T cells was over 38.4%, and the proportion of CD8(+) T cells was increased after lentivirus infection. The NSCLC cell line H1975 highly expressed c-Met while ovarian cancer cell line A2780 negatively expressed c-Met. LDH cytotoxicity assay indicated that the killing efficiency was positively correlated with the E∶T, and higher than that of control group, and the killing rate reached 51.12% when the E∶T was 20∶1. ELISA results showed that c-Met CAR-T cells released more IL-2, TNF-α and IFN-γ in target cell stimulation, but there was no statistical difference between c-Met CAR-T and T cells in the non-target group. Conclusions: Human NSCLC cell H1975 expresses high level of c-Met which can be used as a target for immunotherapy. CAR-T cells targeting c-Met have been successfully produced and have high killing effect on c-Met positive NSCLC cells in vitro.
目的： 制备靶向c－Met蛋白的嵌合抗原受体T细胞(CAR－T)，并检测其对人非小细胞肺癌(NSCLC)H1975细胞的体外杀伤作用。 方法： 将含c－Met抗体scFv片段的CAR序列插入慢病毒质粒中，用酶切质粒电泳，检测目的基因正确性。质粒转染工具为HEK293细胞，收集浓缩慢病毒，通过慢病毒感染的方式制备第二代c－Met CAR－T，通过实时荧光定量聚合酶链反应(qRT－PCR)、Western blot验证CAR序列的表达，采用流式细胞术检测c－Met CAR－T的阳性率、细胞亚型，流式细胞术验证NSCLC细胞H1975中c－Met蛋白的阳性表达并选择c－Met蛋白阴性表达的卵巢癌细胞A2780作为对照，采用乳酸脱氢酶(LDH)释放法检测c－Met CAR－T在效靶比为1∶1、1∶5、1∶10、1∶20时对H1975细胞的杀伤作用。酶联免疫吸附试验(ELISA)检测c－Met CAR－T在靶抗原刺激下，细胞因子白细胞介素2(IL－2)、肿瘤坏死因子α(TNF－α)和IFN－γ的释放情况。 结果： 成功合成c－Met CAR慢病毒重组质粒，酶切条带位置符合理论值。基因测序结果符合原设计序列，并成功包装慢病毒。Western blot和qRT－PCR结果显示，CAR分子存在于慢病毒感染后的T细胞中，c－Met CAR－T构建成功。c－Met CAR－T阳性率可达38.4%以上，且在慢病毒感染过后CD8(+) T细胞比例有所上调。流式细胞术验证结果显示，NSCLC细胞H1975有较强的c－Met蛋白表达，卵巢癌细胞A2780 c－Met蛋白表达阴性。LDH释放实验提示，c－Met CAR－T的抗肿瘤作用随效靶比的提升而增强，且均高于对照组，当效靶比为20∶1时杀伤率达到51.12%。ELISA检测结果显示，与对照组比较，在靶细胞刺激下c－Met CAR－T能释放出更多的IL－2、TNF－α和IFN－γ，而Non target组无此效应。 结论： c－Met在NSCLC细胞系H1975中表达，可以作为NSCLC免疫治疗的靶点；靶向c－Met的CAR－T能对c－Met阳性肺癌细胞产生较强的体外杀伤作用。.

BACKGROUND: Studies have found that c-Met plays a critical role in the progression of solid tumors. This study aimed to investigate the expression of c-Met in gastric cancer (GC) and its correlation with preoperative serum tumor markers and prognosis, in order to provide a more theoretical basis for targeting c-Met in the treatment of GC.
METHODS: Ninety-seven patients who underwent curative gastrectomy in our hospital from December 2013 to September 2015 were included in this study. The tissue microarray was constructed by paraffin-embedded tumor tissue of enrolled patients, including 97 GC points and 83 paracancerous points. Then, it was used for c-Met immunohistochemical staining, followed by an immunological H-score. The clinical baseline data and 5-year survival of patients with low and high c-Met expression were compared. Besides, the correlation between the expression of c-Met in tumor tissues and preoperative serum tumor markers was investigated. Finally, multivariate Cox regression analysis was used to explore the survival risk factors of patients.
RESULTS: c-Met has a high expression rate in GC tissues 64.95% (63/97). The expression of c-Met was significantly different in different clinicopathological stages (p < 0.05); the high expression group also had a higher M stage and clinicopathological stage of GC. The correlation test between the c-Met H-score and CA125 was statistically significant (p = 0.004), indicating a positive correlation. Furthermore, high c-Met expression correlated with poor overall survival (OS) for 5 years (p = 0.005). It was also found that the high expression of c-Met in stage I-II patients was correlative with poor OS for 5 years (p = 0.026), while stage III-IV patients had no statistical significance (p > 0.05). Multivariate Cox regression analysis showed that c-Met might be an independent risk factor for survival 5 years after surgery.
CONCLUSIONS: This study found that the high expression of c-Met in GC tissues was associated with poor 5-year OS in GC patients and was an independent risk factor for 5-year survival after curative gastrectomy. The expression of c-Met in GC tissues was also positively correlated with preoperative serum CA125.

Bevacizumab improves survival outcomes in women diagnosed with epithelial ovarian cancer (EOC). Pre-clinical data showed that the c-MET/VEGFR-2 heterocomplex negates VEGF inhibition through activation of c-MET signalling, leading to a more invasive and metastatic phenotype. We evaluated the clinical significance of c-MET and VEGFR-2 co-localisation and its association with VEGF pathway-related single nucleotide polymorphisms (SNPs) in women participating in the phase 3 trial, ICON7 (ClinicalTrials.gov identifier: NCT00262847).
Patients had FIGO stage I-IIA grade 3/poorly differentiated or clear cell carcinoma or stage IIB-IV epithelial ovarian, primary peritoneal or fallopian tube cancer. Immunofluorescence staining for co-localised c-MET and VEGFR-2 on tissue microarrays and genotyping of germline DNA from peripheral blood leukocytes for VEGFA and VEGFR-2 SNPs was performed. The significance of these biomarkers was assessed against survival.
Tissue microarrays from 178 women underwent immunofluorescence staining. Multivariable analysis showed that greater c-MET/VEGFR-2 co-localisation predicted worse OS in patients treated with bevacizumab after adjusting for FIGO stage and debulking surgery outcome (hazard ratio [HR] 1.034, 95% confidence interval [95%CI] 1.010-1.059). Women in the c-MET/VEGFR-2HIGH group treated with bevacizumab demonstrated significantly reduced OS (39.3 versus > 60 months; HR 2.00, 95%CI 1.08-3.72). Germline DNA from 449 women underwent genotyping. In the bevacizumab group, those women with the VEGFR-2 rs2305945 G/G variant had a trend towards shorter PFS compared with G/T or T/T variants (18.3 versus 23.0 months; HR 0.74, 95%CI 0.53-1.03).
In bevacizumab-treated women diagnosed with EOC, high c-MET/VEGFR-2 co-localisation on tumour tissue and the VEGFR-2 rs2305945 G/G variant, which may be biologically related, were associated with worse survival outcomes.

BACKGROUND: Telisotuzumab vedotin (Teliso-V) is an anti-c-Met-directed antibody-drug conjugate that has exhibited antitumor activity as monotherapy in NSCLC. Its potential activity combined with programmed cell death protein-1 inhibitors has not been previously evaluated.
METHODS: In a phase 1b study (NCT02099058), adult patients (≥18 y) with advanced NSCLC received combination therapy with Teliso-V (1.6, 1.9, or 2.2 mg/kg, every 2 wk) plus nivolumab (3 mg/kg, 240 mg, or per locally approved label). The primary objective was to assess safety and tolerability; secondary objectives included the evaluation of antitumor activity.
RESULTS: As of January 2020, a total of 37 patients received treatment with Teliso-V (safety population) in combination with nivolumab; 27 patients (efficacy population) were c-Met immunohistochemistry-positive. Programmed death-ligand 1 (PD-L1) status was evaluated in the efficacy population (PD-L1-positive [PD-L1+]: n = 15; PD-L1-negative [PD-L1-]: n = 9; PD-L1-unknown: n = 3). The median age was 67 years and 74% (20 of 27) of patients were naive to immune checkpoint inhibitors. The most common any-grade treatment-related adverse events were fatigue (27%) and peripheral sensory neuropathy (19%). The pharmacokinetic profile of Teliso-V plus nivolumab was similar to Teliso-V monotherapy. The objective response rate was 7.4%, with two patients (PD-L1+, c-Met immunohistochemistry H-score 190, n = 1; PD-L1-, c-Met H-score 290, n = 1) having a confirmed partial response. Overall median progression-free survival was 7.2 months (PD-L1+: 7.2 mo; PD-L1-: 4.5 mo; PD-L1-unknown: not reached).
CONCLUSIONS: Combination therapy with Teliso-V plus nivolumab was well tolerated in patients with c-Met+ NSCLC with limited antitumor activity.

BACKGROUND: Hepatocyte growth factor (HGF) binds to the c-mesenchymal-epithelial transition (C-MET) receptor and activates downstream signaling pathways, playing an essential role in the development of various cancers. Given the role of this signaling pathway, the primary therapeutic direction focuses on identifying and designing HGF inhibitors, antagonists and other molecules to block the binding of HGF to C-MET, thereby limiting the abnormal state of other downstream genes.
METHODS: This study focuses on the analysis of immune-related genes and corresponding immune functions that are significantly associated with the HGF/c-MET pathway using transcriptome data from 11 solid tumors.
RESULTS: We systematically analyzed 11 different cancers, including expression correlation, immune infiltration, tumor diagnosis and survival prognosis from HGF/c-MET pathway and immune regulation, two biological mechanisms having received extensive attention in cancer analysis.
CONCLUSIONS: We found that the HGF/c-MET pathway affected the tumor microenvironment mainly by interfering with expression levels of other genes. Immune infiltration is another critical factor involved in changes to the tumor microenvironment. The downstream immune-related genes activated by the HGF/c-MET pathway regulate immune-related pathways, which in turn affect the degree of infiltration of immune cells. Immune infiltration is significantly associated with cancer development and prognosis.

BACKGROUND: Crizotinib is a tyrosine kinase inhibitor (TKI) effective in ALK/ROS-1/c-MET positive non-small cell lung cancer (NSCLC) patients. Bevacizumab is an antiangiogenic monoclonal antibody, and improves clinical benefit of NSCLC in combination with EGFR-TKIs or chemotherapy. However, the efficacy and safety of crizotinib plus bevacizumab in treating naive ALK/ROS-1/c-MET positive NSCLC patients have not been studied.
METHODS: In this open-label, single-arm, prospective observational study, locally advanced or metastatic ALK rearrangement/ROS-1 fusion/c-MET amplification NSCLC patients were treated with crizotinib (250 mg orally twice daily) and bevacizumab (7.5 mg/kg intravenous every three weeks) until disease progression or intolerant toxicity or death. Primary end point was progressive free survival (PFS), secondary end points were duration of response (DOR), overall response rate (ORR), disease control rate (DCR) and safety. Patients receiving ≥1 cycle of treatment were evaluated.
RESULTS: Fourteen patients were eligible for analyzing between June 2016 and October 2017. There were 12 patients with ALK rearrangement, 1 patient with ROS-1 fusion, and 1 patient with c-MET amplification. The median follow-up time was 42.8 months. The median PFS and DOR of the patients with ALK rearrangement were 13.9 and 14.8 months respectively. Of the 12 patients, 7 gained partial response, 5 gained stable disease. The ORR and DCR were 58.3% and 100%. The PFS were 12.9 months and 1.9 months for patient with ROS-1 fusion or c-MET amplification. The most two common treatment-related adverse events were fatigue (28.6%) and rash (21.4%). 3 patients discontinued therapy because of liver damage or hemoptysis.
CONCLUSIONS: This study demonstrated that crizotinib plus bevacizumab showed benefit in treating naive ALK rearrangement NSCLC patients, and the toxicity was relatively tolerant. Our results suggested that crizotinib plus bevacizumab might be a promising treatment strategy in ALK/ROS-1/c-MET positive NSCLC patients.

Telisotuzumab vedotin (formerly ABBV-399) is an antibody-drug conjugate targeting c-Met-overexpressing tumor cells, irrespective of MET gene amplification status. Safety, pharmacokinetics, and preliminary efficacy of telisotuzumab vedotin were evaluated outside of Japan. This phase 1 open-label study evaluated the safety, tolerability, pharmacokinetics, and preliminary antitumor activity of telisotuzumab vedotin in Japanese patients with advanced solid tumors. Telisotuzumab vedotin was administered intravenously at either 2.4 mg/kg (n = 3) or 2.7 mg/kg (n = 6) every 3 weeks, following a 3 + 3 design. Maximum tolerated dose was not reached on the basis of the study design; no dose-limiting toxicity events were observed. The most common treatment-emergent adverse events related to telisotuzumab vedotin were peripheral sensory neuropathy (44%), and nausea, decreased appetite, and decreased white blood cell count (33% each). Most frequent grade ≥3 treatment-emergent adverse events, irrespective of relationship to telisotuzumab vedotin, were decreased neutrophil count and hypoalbuminemia, reported in two patients (22%) each. Systemic exposure of telisotuzumab vedotin at both dose levels was approximately dose proportional. Pharmacokinetic profile in Japanese patients was similar to that previously reported in non-Japanese patients. Two (22%) patients achieved a partial response, six (67%) had stable disease, one (11%) had progressive disease. Overall disease control rate was 89% (eight of nine patients; 95% confidence interval: 51.8%-99.7%]). Median progression-free survival was 7.1 months (95% confidence interval: 1.2-10.4). In conclusion, telisotuzumab vedotin demonstrated a manageable safety profile, with antitumor activity in Japanese patients with advanced solid tumors; the recommended phase 2 dose was confirmed as 2.7 mg/kg every 3 weeks. ClinicalTrials.gov registration number: NCT03311477.

Lung-MAP S1400K was designed to evaluate the response to telisotuzumab vedotin, an antibody-drug conjugate targeting c-MET, in patients with c-MET-positive squamous cell carcinoma (SCC).
Patients with previously treated SCC with c-MET-positive tumors (H score ≥ 150, Ventana SP44 assay) were enrolled into 2 cohorts: Cohort 1 (immune checkpoint inhibitor-naive) and Cohort 2 (immune checkpoint inhibitor refractory). Telisotuzumab vedotin 2.7 mg/kg was administered intravenously every 3 weeks until disease progression or unacceptable toxicity. Response assessments were performed every 6 weeks. The primary endpoint was response by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Secondary endpoints included progression-free survival, overall survival, response within cohort, duration of response, and toxicities. Interim analysis was planned after 20 evaluable patients, with ≥ 3 responses needed to continue enrollment.
Forty-nine patients (14% of screened patients) were assigned to S1400K, 28 patients enrolled (15 in Cohort 1 and 13 in Cohort 2), and 23 were eligible. S1400K closed on December 21, 2018 owing to lack of efficacy. Two responses (response rate of 9%; 95% confidence interval, 0%-20%) were reported in cohort 1 (1 complete and 1 unconfirmed partial response), whereas 10 patients had stable disease, with a disease control rate of 52%. The median overall and progression-free survival was 5.6 and 2.4 months, respectively. There were 3 grade 5 events (2 pneumonitis, in Cohort 2, and 1 bronchopulmonary hemorrhage, in Cohort 1).
Telisotuzumab vedotin failed to meet the pre-specified response needed to justify continuing enrollment to S1400K. Pneumonitis was an unanticipated toxicity observed in patients with SCC.

Gastric cancer is a heterogeneous tumor that underlying molecular mechanisms are largely unclear. This study aimed to elucidate the expression level of HGF-c-MET in gastric cancer patients and to investigate the prognostic and diagnostic value of HGF-c-MET. In silico analysis of the TCGA and GEO database found that HGF and c-MET mRNA expression are significantly higher in gastric cancer tissues than those in peritumor tissues. Both higher mRNA expression of HGF and c-MET were associated with a poorer prognosis. c-MET expression was modulated by methylation in the promoter regions. HGF was positively correlated with CD8+ T cell, CD4+ T cell, macrophage, neutrophil and dendritic cell. Furthermore, functional enrichment analysis and protein-protein interaction networks further shown that HGF-c-MET and related proteins mainly participated in growth factor receptor binding, protein tyrosine kinase activity and signaling receptor binding. Finally, outcome of GSEA analysis showed 13 shared KEGG pathways enriched in high expressed group of HGF and c-MET.

A previous randomized phase 2 study of hepatocellular carcinoma revealed that the c-Met inhibitor tivantinib as second-line treatment significantly prolonged progression-free survival in a subpopulation whose tumor samples highly expressed c-Met (MET-high). Accordingly, this phase 3 study was conducted to evaluate the efficacy of tivantinib as a second-line treatment for Japanese patients with MET-high hepatocellular carcinoma. This randomized, double-blind, placebo-controlled study was conducted at 60 centers in Japan. Hepatocellular carcinoma patients with one prior sorafenib treatment and those with MET-high tumor samples were eligible for inclusion. Registered patients were randomly assigned to either the tivantinib or placebo group at a 2:1 ratio and were treated with twice-a-day oral tivantinib (120 mg bid) or placebo until the discontinuation criteria were met. The primary endpoint was progression-free survival while the secondary endpoints included overall survival and safety. Between January 2014 and June 2016, 386 patients provided consent, and 195 patients were randomized to the tivantinib (n = 134) or placebo (n = 61) group. Median progression-free survival was 2.8 (95% confidence interval: 2.7-2.9) and 2.3 (1.5-2.8) mo in the tivantinib and placebo groups, respectively (hazard ratio = 0.74, 95% confidence interval: 0.52-1.04, P = .082). Median overall survival was 10.3 (95% confidence interval: 8.1-11.6) and 8.5 (6.2-11.4) mo in the tivantinib and placebo group, respectively (hazard ratio = 0.82, 95% confidence interval: 0.58-1.15). The most common tivantinib-related grade ≥3 adverse events were neutropenia (31.6%), leukocytopenia (24.8%), and anemia (12.0%). This study did not confirm the significant efficacy of tivantinib as a second-line treatment for Japanese patients with MET-high hepatocellular carcinoma. (NCT02029157).