c-MET Amplification Research Articles

Novel quinazoline-based dual EGFR/c-Met inhibitors overcoming drug resistance for the treatment of NSCLC: Design, synthesis and anti-tumor activity

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) have demonstrated the ability to impede tumor cell proliferation by suppressing EGFR expression. Nonetheless, patients undergoing treatment may acquire resistance, which may occur through an EGFR-dependent (such as T790M mutation) or an EGFR-independent (such as c-Met amplification) manner. Therefore, developing dual-target inhibitors might present a potential avenue for addressing treatment-acquired resistance in patients. Herein, we designed, synthesized, and screened several novel 4-phenoxyquinazoline derivatives, aiming to identify a potent dual EGFR/c-Met inhibitor for the treatment of NSCLC, among which H-22 emerged as the most promising candidate exhibiting significant antitumor properties. Moreover, we assessed the in vitro inhibitory effect of H-22 on EGFR kinase and c-Met kinase in five cancer cell lines. In addition, a series of functional experiments (cell cycle, apoptosis assays, in vitro/in vivo animal model, etc.) were conducted to further investigate the anti-tumor mechanisms of H-22. The present study revealed that H-22 exhibited strong antitumor activity both in vitro and in vivo. Interestingly, H-22 exhibited anti-proliferative activity (2.27–3.35 μM) similar to Afatinib against all five cancer cells, with inhibitory functions against EGFRWT, EGFRL858R/T790M, and c-Met kinases at a concentration of 64.8, 305.4 and 137.4 nM, respectively. Cell cycle analysis indicated that the antiproliferative activity of H-22 was associated with its ability to cause G2/M arrest. Furthermore, in vivo data showed that H-22 could inhibit tumor growth in our xenograft models and induce apoptosis. Collectively, our findings uncovered that H-22 is a novel dual EGFR and c-Met inhibitor and a prospective anti-tumor therapeutic drug.

Clinicopathological Features and Prognosis of Patients Newly Diagnosed With Lung Adenocarcinoma With Both EGFR Mutation and C-MET Amplification

Objective To explore the clinicopathological features and prognosis of the patients newly diagnosed with lung adenocarcinoma with both EGFR mutation and C-MET amplification.Methods The pathological sections were reviewed.EGFR mutation was detected by amplification refractory mutation system-quantitative real-time polymerase chain reaction,and C-MET amplification by fluorescence in situ hybridization.The clinicopathological features and survival data of the patients newly diagnosed with lung adenocarcinoma with both EGFR mutation and C-MET amplification were analyzed retrospectively.Results In 11 cases of EGFR mutation combined with C-MET amplification,complex glands and solid high-grade components were observed under a microscope in 10 cases except for one case with a cell block,the tissue structure of which was difficult to be evaluated.The incidence of lung adenocarcinoma in the patients with EGFR mutation combined with C-MET amplification at clinical stage Ⅳ was higher than that in the EGFR mutation or C-MET amplification group (all P<0.001),whereas the difference was not statistically significant between the EGFR mutation group and C-MET amplification group at each clinical stage (all P>0.05).There was no significant difference in the trend of survival rate between EGFR gene group and C-MET amplification group (χ2=0.042,P=0.838),while the survival of the patients with EGFR mutation combined with C-MET amplification was worse than that of the patients with EGFR mutation (χ2=246.72,P<0.001) or C-MET amplification (χ2=236.41,P<0.001).Conclusions The patients newly diagnosed with lung adenocarcinoma with EGFR mutation plus C-MET amplification demonstrate poor histological differentiation,rapid progress,and poor prognosis.The patients are often in the advanced stage when being diagnosed with cancer.Attention should be paid to this concurrent adverse driving molecular event in clinical work.With increasing availability,the inhibitors targeting C-MET may serve as an option to benefit these patients in the near future.

I-125 seeds brachytherapy combined with immunotherapy for MET amplification in non-small cell lung cancer from clinical application to related lncRNA mechanism explore: a case report.

Advanced non-small cell lung cancer (NSCLC) with MET amplification primarily relies on MET inhibitors for treatment, but once resistance occurs, the available treatment options are limited and the prognosis is typically poor. A 57-year-old man with advanced NSCLC and C-MET amplification was initially treated with crizotinib but developed progressive disease. After the antirotinib treatment, he achieved a partial response for a year. Genetic testing showed high PD-L1 expression, and he was treated with pembrolizumab and chemotherapy for 3months, with partial response. Maintenance therapy with pembrolizumab and local I-125 seeds brachytherapy (ISB) was given after the lung lesion progressed but other lesions remained stable. The therapy resulted in significant resolution of the right upper lung lesion. It demonstrates the effectiveness of ISB-ICI combination in treating MET amplification advanced NSCLC. Ongoing research and treatment innovation are important in managing advanced NSCLC with complex genetic aberrations. To explore the candidate mechanism of ISB therapy response, we download public genetic data and conduct different expression Lncrnas analysis and pathway analysis to discover radiotherapy related sensitive or resistance lncRNAs and pathways, we found that AL654754.1 is a key lncRNA with radiotherapy response, and it also include in classical p53 and Wnt signaling pathway. Overall, the clinical case reports, combined with the exploration of underlying mechanisms, provide positive guidance for the precise treatment of lung cancer.

Droplet digital PCR as an alternative method for detecting MET amplification in patients with non-small cell lung cancer.

e15107 Background: Mesenchymal-epithelial transition (MET) amplification is associated with resistance to epidermal growth factor receptor tyrosine kinase inhibitors in lung cancer patients and poor prognosis. Fluorescence in situ hybridization (FISH) is the most commonly used method for detecting MET amplification but is not possible in cases where tissue samples are unavailable. Here, we evaluated the utility of droplet digital PCR (ddPCR) in detecting MET amplification in non-small cell lung cancer (NSCLC) patients. Methods: We evaluated a c-Met: EFTUD ddPCR assay of the c-Met gene and using EFTUD as the reference gene to determine c-Met amplification in plasma cfDNA samples from 80 advanced NSCLC patients. A total of 84 plasma samples were collected for MET amplification detection using ddPCR. Paired tissue samples using FISH were to evaluate the correlation between the MET-ddPCR ratio and MET FISH. Results were correlated with clinical findings. Results: We found that ddPCR had an 88.1% concordance rate with FISH in detecting MET CNG, with an area under the curve (AUC) of 0.84. Eleven patients were positive for MET amplification by FISH prior to MET inhibitor treatment, and these patients had a partial response rate (PR) of 45.5% and a median progression-free survival (PFS) of 12.1 months. However, MET amplification identified by ddPCR failed to distinguish significant clinical outcomes. The PR rate and median PFS for ddPCR-positive vs. negative patients were 57.1% vs. 50.0% and 12.1 months vs. 2.1 months (P = 0.276). Conclusions: Our results suggest that ddPCR is a reliable alternative to detect MET amplification in plasma cfDNA samples. Met status determined in cfDNA may have potential as a predictive factor for PFS after c-Met inhibitor therapy.

UNcommon EGFR Mutations: International Case Series on Efficacy of Osimertinib in Real-Life Practice in First-LiNe Setting (UNICORN)

IntroductionApproximately 10% of EGFR mutations (EGFRmuts) are uncommon (ucEGFRmuts). We aimed to collect real-world data about osimertinib for patients with ucEGFRmuts. MethodsThis is a multicenter, retrospective study of ucEGFRmut (exon 20 insertions excluded) metastatic NSCLC treated with osimertinib as first EGFR inhibitor. The Response Evaluation Criteria in Solid Tumors and response assessment in neuro-oncology brain metastases brain objective response rate (ORR) were evaluated by the investigators. Median progression-free survival (mPFS), median overall survival, and median duration of response (mDOR) were calculated from osimertinib initiation. Mutations found at resistance were collected. ResultsA total of 60 patients were included (22 centers, nine countries), with median age of 64 years, 75% females, and 83% Caucasian. The largest subgroups were G719X (30%), L861Q (20%), and de novo Thr790Met (T790M) (15%). The ORR was 61%, mPFS 9.5 months, mDOR 17.4 months, and median overall survival 24.5 months. Regarding patients with no concurrent common mutations or T790M (group A, n = 44), ORR was 60%, mPFS 8.6 months, and mDOR 11 months. For G719X, ORR was 47%, mPFS 8.8 months, and mDOR 9.1 months. For L861Q, ORR was 80%, mPFS 16 months, and mDOR 16 months. For de novo T790M, ORR was 44%, mPFS 12.7 months, and mDOR 46.2 months. Compound EGFRmut including common mutations had better outcome compared with only ucEGFRmut. For 13 patients with a response assessment in neuro-oncology brain metastases–evaluable brain metastases, brain ORR was 46%. For 14 patients, rebiopsy results were analyzed: four patients with additional EGFR mutation (C797S, D585Y, E709K), three with new TP53 mutation, one with c-Met amplification, one with PIK3CA mutation, and one with neuroendocrine transformation. ConclusionsOsimertinib was found to have an activity in ucEGFRmut with a high rate of disease control systemically and intracranially. Several resistance mechanisms were identified. This report comprises, to the best of our knowledge, the largest data set of its kind.

Fibroblast growth factor receptor 3 overexpression mediates ALK inhibitor resistance in ALK-rearranged non-small cell lung cancer.

The rearrangement of anaplastic lymphoma kinase (ALK) occurs in 3%-5% of patients with non-small cell lung cancer (NSCLC) and confers sensitivity to ALK-tyrosine kinase inhibitors (TKIs). For the treatment of patients with ALK-rearranged NSCLC, various additional ALK-TKIs have been developed. Ceritinib is a second-generation ALK-TKI and has shown great efficacy in the treatment of patients with both newly diagnosed and crizotinib (a first-generation ALK-TKI)-refractory ALK-rearranged NSCLC. However, tumors can also develop ceritinib resistance. This may result from secondary ALK mutations, but other mechanisms responsible for this have not been fully elucidated. In this study, we explored the mechanisms of ceritinib resistance by establishing ceritinib-resistant, echinoderm microtubule-associated protein-like 4 (EML4)-ALK-positive H3122 cells and ceritinib-resistant patient-derived cells. We identified a mechanism of ceritinib resistance induced by bypass signals that is mediated by the overexpression and activation of fibroblast growth factor receptor 3 (FGFR3). FGFR3 knockdown by small hairpin RNA or treatment with FGFR inhibitors was found to resensitize the resistant cells to ceritinib in vitro and in vivo. FGFR ligands from either human serum or fetal bovine serum were able to activate FGFR3 and induce ceritinib resistance. A detailed analysis of ceritinib-resistant patient-derived specimens confirmed that tyrosine-protein kinase Met (cMET) amplification induces ceritinib resistance. Amplified cMET counteractivated EGFR and/or Her3 and induced ceritinib resistance. These results reveal multiple ceritinib resistance mechanisms and suggest that ceritinib resistance might be overcome by identifying precise resistance mechanisms.

L718Q/V mutation in exon 18 of EGFR mediates resistance to osimertinib: clinical features and treatment

Osimertinib, a mutant-specific third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is emerging as the preferred first-line of treatment for EGFR-mutant lung cancer. However, osimertinib resistance inevitably develops among patients treated with the drug. The modal resistance mechanisms of osimertinib include the occurrence of epithelial transition factor (c-MET) amplification and C797S mutation, whereas rare mutations are presented as case reports. Recently, the L718Q/V mutation in exon 18 of EGFR has been reported to contribute to one of the possible mechanisms of resistance. The clinical features and subsequent treatment strategies for this mutation require further research. This study retrospectively enrolled NSCLC patients with the L718Q/V mutation from 2017 to 2021 at the Cancer Hospital of the University of the Chinese Academy of Sciences (Zhejiang Cancer Hospital), as well as additional patients with the same mutation from PubMed literature, to summarize the clinical features of the mutation. The association between the detection of L718Q/V and resistance to osimertinib, as well as impacts on the therapeutic process and outcome, was analyzed. We included a total of two patients diagnosed at Zhejiang Cancer Hospital and twelve patients from the literature. Of the fourteen total patients, 64.3% were male and 35.7% were female. The average age of the group was 60.2 years (range 45–72). A history of tobacco use was common among the group. In all of the cases we considered, the L718Q/V mutation was secondary to the L858R mutation. The second-generation TKI afatinib was found to provide a high disease control rate (DCR) (85.7%, 6/7) and relatively low objective response rate (ORR) (42/9%, 3/7). The median progression free survival (mPFS) for this treatment reached 2 months (1–6 months). The patients failed to benefit from chemotherapy combined with immunotherapy or other TKI medications. Due to the limited number of cases considered in this study, future studies should explore drugs that more precisely target the L718Q/V mutation of EGFR exon 18.

Abstract LB538: Characterization of GB263T, a tri-specific antibody against EGFR/cMET/cMET for NSCLC

Abstract Background: The EGFR tyrosine kinase inhibitors (TKIs) have been effectively used for non-small cell lung cancer (NSCLC) driven by EGFR mutations. However, patients eventually develop drug resistance via various mechanisms such as secondary EGFR mutations and activation of alternative pathways. The cMET amplification is one of the resistant mechanisms. Amivantamab, a bispecific antibody to EGFR/c-Met has shown that concurrent inhibition of EGFR and c-Met can overcome resistance of EGFR-TKIs and improve patient outcomes. Thus, amivantamab has been approved for the treatment of advanced NSCLC patients with EGFR exon20ins mutations in the US. GB263T is a novel EGFR/cMET/cMET tri-specific antibody with enhanced ADCC function. The current study has demonstrated GB263T exhibited robust anti-tumor activity by in vitro and in vivo studies. Methods: GB263T has been extensively characterized. The binding/blocking activities were analyzed by SPR and ELISA. The protein levels and phosphorylation of EGFR/cMET were detected by Western Blot. Internalization ability was evaluated by confocal microscope. ADCC function was tested by Jurkat-CD16A-NFAT-Luc reporter system. Various CDX and PDX models were used to evaluate the in vivo efficacy in tumor inhibition. Results: GB263T showed high affinity binding to EGFR and cMET, with robust blocking activity. Moreover, GB263T induced receptor internalization and EGFR/cMET phosphorylation in NSCLC cell lines. GB263T dose-dependently inhibited the proliferation of cells containing EGFR exon 20 insertion mutations and C797S mutations. In addition, potent ADCC function against NSCLC cell lines was observed. Significant in vivo anti-tumor efficacy was demonstrated by multiple tumor models of EGFR exon 20 insertion, EGFR C797S mutation, cMET amplification, and cMET exon 14 skipping mutation. Conclusions: GB263T is a novel tri-specific antibody that exhibited robust anti-tumor activity. The preclinical data indicate that GB263T has great potential to become an effective therapeutics in the treatment of NSCLC. Citation Format: Qinglin Du, Wengang Zeng, Xueyan Yang, Liwen Liang, Xueqin Li, Yan Li, Yiqi Cao, Zongjun Xia, Jing Zhang, Qian Ding, Shuhua Han. Characterization of GB263T, a tri-specific antibody against EGFR/cMET/cMET for NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB538.

Crizotinib in MET Exon 14-Mutated or MET-Amplified in Advanced Disease Non-Small Cell Lung Cancer: A Retrospective, Single Institution Experience

Introduction: Non-small cell lung cancer (NSCLC) accounts for most lung cancers and is a leading cause of cancer-related deaths in the USA. Alterations in c-MET, a tyrosine kinase receptor, have been involved in many cases of NSCLC progression and metastasis. Crizotinib and other tyrosine kinase inhibitors (TKIs) have been used in NSCLC treatment with limited success. Methods: In this retrospective observational study, we analyzed data from patients diagnosed with lung cancer at Soroka University Medical Center between January 2015 and January 2020. We investigated patient characteristics, including disease-associated mutation type and median survival in response to different TKI treatments. Results: A total of 780 patients with lung cancer were included in the study, 134 of whom had small cell lung cancer and 646 had NSCLC. Of the NSCLC patients, 403 were diagnosed with advanced or metastatic disease, and 374 underwent molecular testing. We identified 16 patients with either c-MET mutations or amplifications who were treated with crizotinib. Of these patients, 7 expressed a c-MET exon 14 skipping mutation while the remaining 9 patients expressed c-MET amplification. Among the patients with a c-MET exon 14 skip mutation, the overall survival was 22.8 months and the median progression-free survival (PFS) on crizotinib treatment was 12.4 months. Of the patients with c-MET amplification, the median overall survival was 5.4 months and the median PFS with crizotinib treatment was 2.6 months. Discussion and Conclusions: We analyzed the data of a series of cases describing patients diagnosed with different stages of NSCLC, having either a c-MET exon 14 skipping mutation or an amplification mutation, and treated with various TKIs, including crizotinib. We investigated the characteristics of these patient groups in accordance with mutation types and compared median survival between patient groups. Crizotinib was found to be an optimal treatment for NSCLC harboring c-MET exon 14 skipping mutations.

Uncommon EGFR mutations on osimertinib, real-life data (UNICORN study): Updated results, brain efficacy, and resistance mechanisms.

9109 Background: About 10% of EGFR mutations (EGFRm) are ‘uncommon mutations’ (ucEGFRm). osimertinib is a 3rd generation EGFRi, active against common EGFRm. We aimed to collect real-world data about systemic and brain response and resistance mechanisms to osimertinib for ucEGFRm patients. Methods: This is a multi-center, retrospective study of ucEGFRm mNSCLC treated with osimertinib as first EGFRi. RECIST and RANO-BM response was evaluated by investigators. Progression free survival (PFS), overall survival (OS) and duration of response (DOR) were calculated from initiation of osimertinib. Mutations found at resistance were collected. Results: 62 patients (pts) were identified in 22 centers from 9 countries. Median age was 64 (35-91) years, 74% females, 84% Caucasian, never/former/current smokers were 48%/39%/11% respectively, ECOG PS was 0-1/2/3-4 in 84%/10%/5%. Histology was adenocarcinoma in 97%. The largest subgroups were G719X, de novo T790M and L861Q (Table). Compound EGFR mutations were found in 27 pts (44%), TP53 mutations in 21 pts (34%). In 17 cases (27%), compound mutations included the common L858R/deletion19 and/or de novo T790M. Most frequent metastatic sites were lung/bone/brain in 45%/44%/39%. Most frequent toxicities were gastrointestinal (32 pts, 52%) and skin (24 pts, 39%); 8 pts had grade 3-4 AEs. No grade 5 AE occurred. 3 pts had AEs leading to discontinuation. RECIST response (RR) was available for 53 pts, CR - 4 (8%), PR - 27 (51%), SD - 17 (32%), and PD - 5 (9%). Median DOR (mDOR) was 17.4 months (95% CI 9.1-NA). mPFS was 9.5 months (95% CI 8.5–17.4). mOS was 24.5 months (95% CI 17.4-35.1). See Table for efficacy in the major subgroups. 24 pts (39%) had brain metastasis at presentation, for 12 pts a brain response by RANO-BM was available with 25%/25%/33%/17% CR/PR/SD/PD. For 14 pts, rebiopsy mutation analysis at progression on osimertinib was available: 3 pts with an additional EGFR mutation (C797S,D585Y, E709K), 3 pts with a new TP53 mutation, 1 with c-Met amplification and 1 pt with transformation to neuroendocrine carcinoma. Conclusions: Osimertinib demonstrated activity in ucEGFRm with 91% disease control rate and encouraging PFS and DOR. Brain response was seen in 50% of cases. Several resistance mechanisms were identified. This report comprises, to the best of our knowledge, the largest dataset of osimertinib as the first EGFRi for ucEGFRm presented so far. [Table: see text]

The Impact of Comprehensive Genomic Profiling (CGP) on the Decision-Making Process in the Treatment of ALK-Rearranged Advanced Non-Small Cell Lung Cancer (aNSCLC) After Failure of 2nd/3rd-Generation ALK Tyrosine Kinase Inhibitors (TKIs)

BackgroundThe use of CGP in guiding treatment decisions in aNSCLC with acquired resistance to ALK TKIs is questionable.MethodsWe prospectively assessed the impact of CGP on the decision-making process in ALK-rearranged aNSCLC patients following progression on 2nd/3rd-generation ALK TKIs. Physician’s choice of the most recommended next-line systemic treatment (NLST) was captured before and after receival of CGP results; the percentage of cases in which the NLST recommendation has changed was assessed along with the CGP turnaround time (TAT). Patients were divided into groups: patients in whom the NLST was initiated after (group 1) and before (group 2) receival of the CGP results. Time-to-treatment discontinuation (TTD) and overall survival (OS) with NLST were compared between the groups.ResultsIn 20 eligible patients (median [m]age 63 years [range, 40-89], females 75%, adenocarcinoma 100%, failure of alectinib 90%, FoundationOne Liquid CDx 80%), CGP has altered NLST recommendation in 30% of cases. CGP findings were as follows: ALK mutations 30% (l1171X 10%, G1202R, L1196M, G1269A, G1202R+l1171N+E1210K 5% each), CDKN2A/B mutation/loss 10%, c-met amplification 5%. CGP mTAT was 2.9 weeks [IQR, 2.4-4.4]. mTTD was 11.3 months (95% CI, 2.1-not reached [NR]) and 5.4 months (95% CI, 2.0-NR) in groups 1 and 2, respectively (p-0.34). mOS was 13.2 months (95% CI, 2.9-NR) and 13.0 months (95% CI, 6.0-NR) in groups 1 and 2, respectively (p-0.86).ConclusionCGP has a significant impact on the decision-making process in ALK-rearranged aNSCLC following progression on 2nd/3rd-generation ALK TKIs.

Phase Ia/Ib Study of the Selective MET Inhibitor, Savolitinib, in Patients with Advanced Solid Tumors: Safety, Efficacy, and Biomarkers.

Savolitinib has shown good tolerability and preliminary efficacy, but efficacy biomarkers require investigation. The main purpose of this study was to confirm in Chinese patients the recommended phase II dose (RP2D) of savolitinib and to explore overall benefit in tumors bearing c-Met aberration. This was an open-label, multi-center, 2-part phase I study. A starting dose of 600 mg QD was initiated in the escalation phase, utilizing a 3+3 design with repeated QD and BID dosing. In the dose expansion phase, we enrolled patients with gastric cancer and non-small cell lung cancer (NSCLC) with documented c-met aberration into 5 cohorts to further explore biomarkers. c-Met overexpression and amplification were assessed by immunohistochemistry and FISH, respectively. The safety analysis set included 85 patients. Only one dose-limiting toxicity (grade 3 fatigue) was reported in the 600 mg BID dosing group. The most frequent treatment-related adverse events were nausea (29.4%), vomiting (27.1%), and peripheral edema (21.2%). Notably, in gastric cancer, response was only observed in patients with MET amplification (copy number 9.7-18.4), with an objective response rate of 35.7% and a disease control rate of 64.3%. For patients with NSCLC bearing a MET exon 14 skipping mutation, obvious target lesion shrinkage was observed in 2 of 4 patients, although PR was not achieved. The RP2D of savolitinib was established as 600 mg QD or 500 mg BID in Chinese patients. The promising response observed in patients with gastric cancer with c-met amplification and NSCLC with MET exon 14 skipping mutation warrants further investigation. NCT0198555.

Early On-Treatment Prediction of the Mechanisms of Acquired Resistance to EGFR Tyrosine Kinase Inhibitors.

Simple SummaryEGFR T790M-positive clones expand in treated by EGFR inhibitors. C-MET amplified clones expand in HCC827 lung cancer cells treated by EGFR inhibitors. Early on-treatment kinetics of the resistance-related gene predict the resistance mechanism.Background: Prediction of resistance mechanisms for epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) remains challenging. Thus, we investigated whether resistant cancer cells that expand shortly after EGFR-TKI treatment would eventually cause the resistant phenotype. Methods: We generated two EGFR-mutant lung cancer cell lines resistant to gefitinib (PC9GR and HCC827GR). The parent cell lines were exposed to short-term treatment with gefitinib or paclitaxel and then were assessed for EGFR T790M mutation and C-MET expression. These experiments were repeated in vivo and in clinically relevant patient-derived cell (PDC) models. For validation in clinical cases, we measured these gene alterations in plasma circulating tumor DNA (ctDNA) before and 8 weeks after starting EGFR-TKIs in four patients with EGFR-mutant lung cancer. Results: T790M mutation was only detected in the PC9GR cells, whereas C-MET amplification was detected in the HCC827GR cells. The T790M mutation level significantly increased in PC9 cells after short-term treatment with gefitinib but not in the paclitaxel. C-MET mRNA expression was only significantly increased in gefitinib-treated HCC827 cells. We confirmed that the C-MET copy number in HCC827 cells that survived after short-term gefitinib treatment was significantly higher than that in dead HCC827 cells. These findings were reproduced in the in vivo and PDC models. An early on-treatment increase in the plasma ctDNA level of these gene alterations was correlated with the corresponding resistance mechanism to EGFR-TKIs, a finding that was confirmed in post-treatment tumor tissues. Conclusions: Early on-treatment kinetics in resistance-related gene alterations may predict the final mechanism of EGFR-TKI resistance.

An updated patent review of small-molecule c-Met kinase inhibitors (2018-present)

Introduction c-Met tyrosine kinase receptor is a high-affinity ligand of hepatocyte growth factor (HGF). c-Met is widely expressed in a variety of normal human tissues, but it exhibits abnormally high expression, amplification or mutation in tumor tissues such as lung cancer, gastric cancer, and breast cancer. Therefore, the use of c-Met as a target can achieve the inhibition of a series of abnormal physiological processes such as tumourigenesis, development and metastasis. A number of small molecule tyrosine kinase inhibitors targeting c-Met have been successfully marketed. Areas covered This article reviews recent advances in patented c-Met small molecule inhibitors and their inhibitory activity against various cancer cells from 2018 to date. Expert opinion To date, small molecule inhibitors targeting c-Met have demonstrated impressive therapeutic efficacy in the clinical setting. Most recent patents have focused on addressing the direction of c-Met amplification and overexpression. Despite the great success in the development of selective c-Met inhibitors, the effects of bypass secretion and mutagenesis have led to a need for new c-Met small molecule inhibitors that are safe, efficient, selective and less toxic with novel structures and effective against other targets.

Efficacy and Safety of Combination Treatment With Apatinib and Osimertinib After Osimertinib Resistance in Epidermal Growth Factor Receptor-Mutant Non-small Cell Lung Carcinoma-A Retrospective Analysis of a Multicenter Clinical Study.

Currently, there are limited treatment options for patients who developed resistance to osimertinib, a third-generation epidermal growth factor receptor (EGFR) inhibitor. Resistance to EGFR inhibitors is frequently associated with enhanced vascular endothelial growth factor (VEGF) levels. This multicenter, retrospective study aimed to evaluate the efficacy of the combination treatment with apatinib and osimertinib in 39 patients with EGFR-mutant non-small cell lung carcinoma (NSCLC) who developed osimertinib resistance. The patients received the combination of oral apatinib 250 mg qd and osimertinib 80 mg qd. The efficacy was evaluated after the first month then every 2 months thereafter. The primary endpoint was progression-free survival (PFS). The overall response rate (ORR) and the disease control rate (DCR) of the combination of apatinib and osimertinib was 12.8% (5/39) and 79.5% (31/39), respectively. The median PFS was 4 months [95% confidence interval (CI): 3.5–4.5 months]. Fourteen patients were administered with at least 6 months of combination therapy, and 11 of them remained on treatment programs. The 6-month PFS rate was 38%. Nine patients underwent biopsies after failing osimertinib treatment, and five of six patients with TP53 mutations had PFS of less than 3 months. The spectrum of resistance to osimertinib mechanisms included c-mesenchymal-epithelial transition factor (c-Met) amplification, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gain-of-function mutation, phosphatase and tensin homolog (PTEN) loss-of-function mutation, Erb-B2 receptor tyrosine kinase 2 (ERBB2) amplification, and insulin-like growth factor 1 receptor (IGF1R) mutation. The most common adverse events were hypertension (30.7%, 12/39), diarrhea (15.4%, 6/39), and proteinuria (12.8%, 5/39). The combination of apatinib and osimertinib improved the ORR and the DCR of patients with osimertinib-refractory EGFR-positive NSCLC, thus making it a reasonable treatment choice after the development of osimertinib resistance.

Crizotinib for c-MET-amplified advanced NSCLC: a single-center experience.

Lung cancer is the most common cause of cancer-related death in the world. Changes in the treatment of metastatic lung cancer in recent years have made targetable mutations gain importance. MET alteration is one of these driver mutations and crizotinib is a tyrosine kinase inhibitor used in therapy. In our study, data of patients with c-MET amplification who received crizotinib treatment between July 2017 and November 2020 in the Medical Oncology Clinic of Bakırköy Dr. Sadi Konuk Training and Research Hospital were retrospectively analyzed. c-MET scanning was performed by the fluorescent in situ hybridization method by using Cytotest MET/CCP7 probe kit by evaluating 100 tumor cells and the threshold value for positivity was accepted as above 20%. Eight of 28 patients who received crizotinib treatment had c-MET amplification. Seven of these patients were male and one was female. Progression-free survival and overall survival in these eight patients were 9.4 and 10.9 months, respectively, and objective response rate was 50%. Grade 4 nausea was observed in only one patient; there was no grade 4-5 toxicity and no patient discontinued the drug due to toxicity. Crizotinib is an effective treatment option other than cytotoxic chemotherapy in the limited number of patients with MET amplification in the stage 4 lung adenocarcinoma subgroup. It is important to investigate this amplification, which can be detected especially in smoking patients in the appropriate patient group, and to use appropriate tyrosine kinase inhibitors in treatment.

Molecular mechanism and pharmacokinetics of flavonoids in the treatment of resistant EGF receptor‐mutated non‐small‐cell lung cancer: A narrative review

Here, we review the molecular mechanism and pharmacokinetics of flavonoids in the treatment of resistant EGF receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) and particularly the possible mechanism(s) of delicaflavone, a biflavonoid extracted from Selaginella doederleinii Hieron. EGFR TK inhibitors (EGFR-TKI) are ubiquitously used in the treatment of NSCLC bearing EGFR mutations. However, patients treated with EGFR-TKI inevitably and continuously develop resistance. In laboratory studies, flavonoids, as potential adjuvants for cancer chemotherapy, exhibited anti-cancer properties such as inhibition of chemoresistance by interference with ABC transporters-induced drug efflux, curbing of c-MET amplification, or reversal of T790M mutation-mediated resistance. The current review aims at summarizing the association between the anti-cancer potentials of flavonoids and their possible regulatory roles in certain types of mutation that could trigger EGFR-TKI resistance in NSCLC. Potential practical applications of these phytochemicals, as well as the relevant pharmacokinetics, are also discussed.

A comparative study of RTK gene status between primary tumors, lymph-node metastases, and Krukenberg tumors

Krukenberg tumor (KT) refers to a rare ovarian tumor that has metastasized from a primary site. Patients with KTs have a poorer prognosis and worse survival. Thus far, little is known about the frequency of receptor tyrosine kinase (RTK) gene amplification and the concordance of gene amplification between primary tumors, lymph-node metastases, and KTs. Herein, 50 paired samples, including primary cancers, metastatic lymph nodes, and KTs were collected, and RTK gene amplification was tested by fluorescence in situ hybridization (FISH). There were four cases positive for human epidermal growth factor receptor type 2 (HER2) amplification, all of which showed conversion of HER2 status between different lesions. Of the two cases with c-mesenchymal–epithelial transition (c-MET) amplification, the primary tumors and lymph nodes were negative while the right involved ovaries were positive. Inconsistent fibroblast growth factor receptor 2 (FGFR2) status in different lesions was observed in three of the six FGFR2-amplified cases. Co-amplification of RTK genes was identified in only one patient for primary cancer and two for KTs. Collectively, there were 46, 48, 50, and 44 cases negative for HER2, c-MET, EGFR, and FGFR2 amplification in all lesions, respectively. There was no significant difference in overall survival between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin. In conclusion, the positive rate of RTK gene amplification in KTs was low. Intratumoral heterogeneity was frequent in KTs with RTK gene amplification. A mutually exclusive pattern of RTK gene amplification was dominant in primary cancers, lymph-node metastases, and KTs. There was no survival difference between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin.

EGFR mutation is positively correlated with C-Met protein expression: a study of 446 resected lung adenocarcinoma.

BackgroundEpidermal growth factor receptor (EGFR) mutation and mesenchymal-epithelial transition factor (C-Met) amplification are known factors for primary resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in advanced primary lung adenocarcinoma. However, little is known about the relationship between high expression of C-Met protein and primary EGFR mutation. This research aims to investigate the correlation between EGFR mutation and C-Met protein expression in resected primary lung adenocarcinoma.MethodsFour hundred and forty-six surgically resected lung adenocarcinoma between 2013–2015 were collected for EGFR mutation analysis by real-time PCR (RT-PCR) and C-Met protein expression by immunohistochemistry (IHC). The relationship between the two biomarkers and clinicopathological features were analyzed.ResultsThe positive rate of EGFR mutation and C-Met protein expression were 66.4% (296/446) and 96.4% (430/446). EGFR mutation was significantly higher in female, mild to moderate differentiation, lepidic, acinar and papillary histological subtypes (P<0.05). C-Met expression was more prominent in female than male (201 vs. 123, 45.07% vs. 27.57%). EGFR mutation was found positively correlated with C-Met protein expression (P<0.05).ConclusionsEGFR mutation and C-Met protein expression are prone to have a female predominance, and are positively correlated with each other in surgically resected lung adenocarcinoma specimens. This finding may be beneficial in explaining some of the resistance mechanisms of EGFR-mutated cases, which is worth further study.

Molecular profiling of afatinib-resistant non-small cell lung cancer cells in vivo derived from mice

Non-small-cell lung cancer (NSCLC) is a leading cause of cancer-related death worldwide. NSCLC patients with overexpressed or mutated epidermal growth factor receptor (EGFR) related to disease progression are treated with EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Acquired drug resistance after TKI treatments has been a major focus for development of NSCLC therapies. This study aimed to establish afatinib-resistant cell lines from which afatinib resistance-associated genes are identified and the underlying mechanisms of multiple-TKI resistance in NSCLC can be further investigated. Nude mice bearing subcutaneous NSCLC HCC827 tumors were administered with afatinib at different dose intensities (5–100 mg/kg). We established three HCC827 sublines resistant to afatinib (IC50 > 1 μM) with cross-resistance to gefitinib (IC50 > 5 μM). cDNA microarray revealed several of these sublines shared 27 up- and 13 down-regulated genes. The mRNA expression of selective novel genes — such as transmembrane 4 L six family member 19 (TM4SF19), suppressor of cytokine signaling 2 (SOCS2), and quinolinate phosphoribosyltransferase (QPRT) — are responsive to afatinib treatments only at high concentrations. Furthermore, c-MET amplification and activations of a subset of tyrosine kinase receptors were observed in all three resistant cells. PHA665752, a c-MET inhibitor, remarkably increased the sensitivity of these resistant cells to afatinib (IC50 = 12–123 nM). We established afatinib-resistant lung cancer cell lines and here report genes associated with afatinib resistance in human NSCLC. These cell lines and the identified genes serve as useful investigational tools, prognostic biomarkers of TKI therapies, and promising molecule targets for development of human NSCLC therapeutics.