A phase Ib study of the highly selective MET-TKI savolitinib plus gefitinib in patients with EGFR-mutated, MET-amplified advanced non-small-cell lung cancer

Assessment of efficacy and safety of MET tyrosine kinase inhibitors in non-small-cell lung cancer patients with MET alterations

Background

While targeted therapy has become the standard treatment for certain non-small-cell lung cancer (NSCLC) patients with gene mutation positivity, there remains a lack of enough reports of the efficacy of mesenchymal-epithelial transition (MET) alterations in the real world.

Objectives

We aimed to explore the efficacy and toxicity of targeted therapy in NSCLC patients with different types of MET alterations and hope to provide more clinical medication guidance.

Design

Designed different subgroups to compare the efficacy and safety of targeted therapy in NSCLC patients with MET alterations.

Methods

We conducted analyses on the efficacy and safety of mesenchymal-epithelial transition factor-tyrosine kinase inhibitor (MET-TKI) therapy in NSCLC patients with MET alterations. Tumor response was evaluated based on the Response Evaluation Criteria in Solid Tumors version 1.1 criteria, and both progression-free survival (PFS) and overall survival were determined using the Kaplan-Meier method.

Results

Our study encompassed 116 NSCLC patients with MET alterations, including MET ex14 skipping mutation (n = 50), MET primary amplification (amp) (n = 25), and secondary amp (n = 41). Among treated patients, 34 achieved a partial response, while 52 exhibited stable disease. The overall response rate for the entire cohort was 29.31%, with a disease control rate of 74.14%. A significant difference was observed in the median PFS among patients with MET ex14 skipping mutation, MET primary amplification (amp), and secondary amp (10.4 versus 6.6 versus 4.5 months, p = 0.002). In all, 69 patients experienced drug-related adverse effects, with the most common being peripheral edema (35.34%), nausea and vomiting (21.55%), and fatigue (10.34%). In total, 29 patients (25%) encountered drug-related adverse reactions of grade 3 or higher.

Conclusion

MET-TKI therapy works better for MET ex14 skipping mutation than other types of MET gene alteration. In the two MET amplified groups, the secondary amp was less effective. This study may provide more research support for the treatment of these patients.

Molecular features and clinical outcomes of EGFR-mutated, MET-amplified non-small-cell lung cancer after resistance to dual-targeted therapy

Background

Some studies of dual-targeted therapy (DTT) targeting epidermal growth factor receptor (EGFR) and mesenchymal-epithelial transition (MET) have shown promising efficacy in non-small-cell lung cancer (NSCLC). Consequently, patient management following DTT resistance has gained significance. However, the underlying resistance mechanisms and clinical outcomes in these patients remain unclear.

Objectives

This study aimed to delineate the molecular characteristics and survival outcomes of patients with NSCLC harboring EGFR mutations and acquired MET amplification after developing resistance to DTT.

Design

We conducted a retrospective analysis of patients with NSCLC with EGFR mutations and acquired MET amplification who exhibited resistance to EGFR/MET DTT.

Methods

Next-generation sequencing (NGS) was performed on patients with available tissue samples before and/or after the development of resistance to DTT. Stratified analyses were carried out based on data sources and subsequent salvage treatments. Univariate/multivariate Cox regression models and survival analyses were employed to explore potential independent prognostic factors.

Results

The study included 77 NSCLC patients, with NGS conducted on 19 patients. We observed many resistance mechanisms, including EGFR-dependent pathways (4/19, 21.1%), MET-dependent pathways (2/19, 10.5%), EGFR/MET co-dependent pathways (2/19, 10.5%), and EGFR/MET-independent resistance mechanisms (11/19, 57.9%). Post-progression progression-free survival (pPFS) and post-progression overall survival (pOS) significantly varied among patients who received the best supportive care (BSC), targeted therapy, or chemotherapy (CT), with median pPFS of 1.5, 3.9, and 4.9 months, respectively (p = 0.003). Median pOS were 2.3, 7.7, and 9.2 months, respectively (p < 0.001). The number of treatment lines following DTT resistance and the Eastern Cooperative Oncology Group performance status emerged as the independent prognostic factors.

Conclusion

This study revealed a heterogeneous landscape of resistance mechanisms to EGFR/MET DTT, with a similar prevalence of on- and off-target mechanisms. Targeted therapy or CT, as compared to BSC, exhibited the potential to improve survival outcomes for patients with advanced NSCLC following resistance to DTT.

Functional Heterogeneity in MET Pathway Activation in PDX Models of Osimertinib-resistant EGFR-driven Lung Cancer

MET pathway activation is one of the most common mechanisms of resistance to osimertinib in EGFR-mutant non-small cell lung cancer (NSCLC). We previously demonstrated spatial and temporal heterogeneity in MET pathway activation upon osimertinib resistance in EGFR-mutant NSCLC; however, the functional relevance of these findings is unclear. Here, we generated 19 patient-derived xenografts (PDX) from 9 patients with multi-region and temporal sampling of osimertinib-resistant tumor tissue from patients with EGFR-mutant NSCLC. MET pathway activation was a putative mechanism of osimertinib resistance in 66% (n = 6/9) patients from whom PDXs were generated. Significant spatial and temporal heterogeneity in MET pathway activation was evident. Osimertinib-resistant PDXs with MET amplification by FISH (defined as MET/CEP7 ratio ≥2.0 or mean MET ≥ 6.0 copies/cell) and high-level phospho-MET, but not c-MET expression, had better responses to osimertinib and savolitinib combination than to osimertinib alone. MET polysomy tumors by FISH from both PDXs and patients had evidence of subclonal phospho-MET expression. Select MET polysomy PDX tumors with phospho-MET expression responded better to osimertinib and savolitinib combination than MET polysomy PDX tumors without phospho-MET expression. Our results suggest osimertinib and savolitinib combination is most effective for osimertinib-resistant EGFR-mutant tumors with MET pathway activation as evidenced by phospho-MET. As subclonal MET amplification may be evident in MET polysomy tumor progression, MET polysomy warrants close clinical follow-up with phospho-MET IHC in parallel with FISH diagnostic.

SIGNIFICANCE

Using a novel cohort of in vivo PDX models of MET pathway activation with acquired resistance to osimertinib in EGFR-mutant lung cancer, we demonstrate that phospho-MET may be a clinically relevant assay to guide treatment selection with osimertinib and savolitinib combination. In addition, our work shows that patients with MET polysomy tumors may have subclonal MET amplification and therefore require close follow up for the use of osimertinib and savolitinib combination.

Plasma ddPCR for the detection of MET amplification in advanced NSCLC patients: a comparative real-world study

Background

Mesenchymal-epithelial transition (MET) amplification is a crucial oncogenic driver and a resistance mechanism to epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) of non-small-cell lung cancer (NSCLC). Fluorescence in situ hybridization (FISH) is the gold standard for MET amplification detection. However, it is inapplicable when tissue samples are unavailable.

Objective

This study assessed the performance of plasma droplet digital polymerase chain reaction (ddPCR) in MET amplification detection in NSCLC patients.

Design and methods

A total of 87 NSCLC patients were enrolled, and 94 paired tissue and plasma samples were analyzed for the concordance between FISH and plasma ddPCR/tissue next-generation sequencing (NGS) in detecting MET amplification. In addition, the efficacy of patients with MET amplification using different detection methods who were treated with MET-TKIs was evaluated.

Results

Plasma ddPCR showed substantial concordance with FISH (74.1% sensitivity, 92.5% specificity, and 87.2% accuracy with a kappa value of 0.68) and outperformed tissue NGS (kappa value of 0.64) in MET amplification detection. Combined plasma ddPCR and tissue NGS showed substantial concordance with FISH (92.3% sensitivity, 89.2% specificity, and an accuracy of 90.1% with a kappa value of 0.77). The efficacy is comparable in these NSCLC patients with MET amplification detected by FISH and plasma ddPCR who were treated with MET-TKIs.

Conclusion

Plasma ddPCR is a potentially reliable method for detecting MET amplification in advanced NSCLC patients. Combined plasma ddPCR and tissue NGS might be an alternative or complementary method to MET amplification detection.

Non-small cell lung cancer with MET amplification: review of epidemiology, associated disease characteristics, testing procedures, burden, and treatments

Introduction

Mesenchymal-epidermal transition factor gene amplification (METamp) is being investigated as a therapeutic target in advanced non-small cell lung cancer (NSCLC). We reviewed the epidemiology and disease characteristics associated with primary and secondary METamp, as well as the testing procedures used to identify METamp, in advanced NSCLC. Economic and humanistic burdens, and the practice patterns and treatments under investigation for METamp were also examined.

Methods

Embase and Medline (via ProQuest), ClinicalTrials.gov, and Cochrane Controlled Register of Trials (2015-2022) were systematically searched. Conference abstracts were searched via Embase and conference proceedings websites (2020-2022). The review focused on evidence from the United States; global evidence was included for identified evidence gaps.

Results

The median rate of primary METamp in NSCLC across the references was 4.8% (n=4 studies) and of secondary METamp (epidermal growth factor receptor [EGFR]-mutant NSCLC) was 15% (n=10). Next-generation sequencing (NGS; n=12) and/or fluorescence in situ hybridization (FISH; n=11) were most frequently used in real-world studies and FISH testing most frequently used in clinical trials (n=9/10). METamp definitions varied among clinical trials using ISH/FISH testing (MET to chromosome 7 centromere ratio of ≥1.8 to ≥3.0; or gene copy number [GCN] ≥5 to ≥10) and among trials using NGS (tissue testing: GCN ≥6; liquid biopsy: MET copy number ≥2.1 to >5). Limited to no data were identified on the economic and humanistic burdens, and real-world treatment of METamp NSCLC. Promising preliminary results from trials enrolling patients with EGFR-mutated, METamp advanced NSCLC progressing on an EGFR-tyrosine kinase inhibitor (TKI) were observed with MET-TKIs (i.e., tepotinib, savolitinib, and capmatinib) in combination with EGFR-TKIs (i.e., gefitinib and osimertinib). For metastatic NSCLC and high-level METamp, monotherapy with capmatinib, crizotinib, and tepotinib are recommended in the 2022 published NSCLC NCCN Guidelines.

Conclusion

Primary METamp occurs in approximately 5% of NSCLC cases, and secondary METamp in approximately 15% of cases previously treated with an EGFR inhibitor. Variability in testing methods (including ISH/FISH and NGS) and definitions were observed. Several treatments are promising in treating METamp NSCLC. Additional studies evaluating the clinical, economic, and humanistic burdens are needed.

Chinese expert consensus on clinical practice of MET detection in non-small cell lung cancer

Mesenchymal epithelial transition (MET) factor alteration in non-small cell lung cancer (NSCLC) includes MET exon 14 skipping alteration (METex14 skipping), MET gene amplification, MET gene mutation (mainly kinase domain mutation), MET gene fusion, and MET protein overexpression. The incidence of METex14 skipping in patients with NSCLC is 0.9-4.0%. At present, drugs targeting METex14 skipping have been approved in China and other countries like Japan and USA. Patients with advanced NSCLC should undergo testing, including METex14 skipping, to screen the population with benefit from targeted therapy with MET inhibitors. The incidence of de novo MET gene amplification in NSCLC patients is 1-5%, the incidence of acquired MET gene amplification in epidermal growth factor receptor tyrosine kinase inhibitor (TKI)-resistant patients is 5-50%, and the incidence in anaplastic lymphoma kinase (ALK) TKI-resistant patients is about 13%; the incidence of MET protein overexpression in NSCLC patients is 13.7-63.7%. Several clinical trials on MET gene amplification and MET protein overexpression are ongoing, which have demonstrated their important guiding significance as biomarkers in the clinical treatment with MET inhibitors. Accurate detection of MET alterations is a prerequisite for MET inhibitor therapy. Since there are many types of MET alterations and related testing methods, as well as many problems and challenges during clinical testing, further sorting and standardization are required. Combined with clinical practice experience, literature review, and expert discussion, the writing group developed this consensus on the three main types of MET alterations (METex14 skipping, MET gene amplification, and MET protein overexpression) in order to guide the practical applications of clinical MET testing.

Tissue or liquid rebiopsy? A prospective study for simultaneous tissue and liquid NGS after first-line EGFR inhibitor resistance in lung cancer

INTRODUCTION

According to current International Association for the Study of Lung Cancer guideline, physicians may first use plasma cell-free DNA (cfDNA) methods to identify epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-resistant mechanisms (liquid rebiopsy) for lung cancer. Tissue rebiopsy is recommended if the plasma result is negative. However, this approach has not been evaluated prospectively using next-generation sequencing (NGS).

METHODS

We prospectively enrolled patients with lung cancer with first-line EGFR-TKI resistance who underwent tissue rebiopsy. The rebiopsied tissues and cfDNA were sequenced using targeted NGS, ACTDrug®+, and ACTMonitor®Lung simultaneously. The clinicopathological characteristics and treatment outcomes were analyzed.

RESULTS

Totally, 86 patients were enrolled. Twenty-six (30%) underwent tissue biopsy but the specimens were inadequate for NGS. Among the 60 patients with paired tissue and liquid rebiopsies, two-thirds (40/60) may still be targetable. T790M mutations were found in 29, including 14 (48%) only from tissue and 5 (17%) only from cfDNA. Twenty-four of them were treated with osimertinib, and progression-free survival was longer in patients without detectable T790M in cfDNA than in patients with detectable T790M in cfDNA (p = 0.02). For the 31 T790M-negative patients, there were six with mesenchymal-epithelial transition factor (MET) amplifications, four with ERBB2 amplifications, and one with CCDC6-RET fusion. One with MET amplification and one with ERBB2 amplification responded to subsequent MET and ERBB2 targeting agents respectively.

CONCLUSIONS

NGS after EGFR-TKI resistance may detect targetable drivers besides T790M. To do either liquid or tissue NGS only could miss patients with T790M. To do tissue and liquid NGS in parallel after EGFR-TKI resistance may find more patients with targetable cancers.

Savolitinib: A Promising Targeting Agent for Cancer

Savolitinib is a highly selective small molecule inhibitor of the mesenchymal epithelial transition factor (MET) tyrosine kinase, primarily developed for the treatment of non-small cell lung cancer (NSCLC) with MET mutations. It is also being investigated as a treatment for breast, head and neck, colorectal, gastric, pancreatic, and other gastrointestinal cancers. In both preclinical and clinical studies, it has demonstrated efficacy in lung, kidney, and stomach cancers. Savolitinib is an oral anti-cancer medication taken as a 600 mg dose once daily. It can be used as a monotherapy in patients with non-small cell lung cancer with MET mutations and in combination with epidermal growth factor receptor (EGFR) inhibitors for patients who have developed resistance to them. Furthermore, savolitinib has shown positive results in gastric cancer treatment, particularly in combination with docetaxel. As a result, this review aims to validate its efficacy in NSCLC and suggests its potential application in other gastrointestinal cancers, such as pancreatic cancer, based on related research in gastric and renal cancer.

Targeting MET Amplification: Opportunities and Obstacles in Therapeutic Approaches

The MET gene plays a vital role in cellular proliferation, earning it recognition as a principal oncogene. Therapies that target MET amplification have demonstrated promising results both in preclinical models and in specific clinical cases. A significant obstacle to these therapies is the ability to distinguish between focal amplification and polysomy, a task for which simple MET copy number measurement proves insufficient. To effectively differentiate between the two, it is crucial to utilize comparative measures, including in situ hybridization (ISH) with the centromere or next generation sequencing (NGS) with adjacent genes. Despite the promising potential of MET amplification treatment, the judicious selection of patients is paramount to maximize therapeutic efficacy. The effectiveness of MET inhibitors can fluctuate depending on the extent of MET amplification. Future research must seek to establish the ideal threshold value for MET amplification, identify the most efficacious combination therapies, and innovate new targeted treatments for patients exhibiting MET amplification.

Novel systemic therapies in the management of tyrosine kinase inhibitor-pretreated patients with epidermal growth factor receptor-mutant non-small-cell lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the standard first-line option for non-small-cell lung cancer (NSCLC) harboring active EGFR mutations. The overall survival of patients with advanced NSCLC has improved dramatically with the development of comprehensive genetic profiles and targeted therapies. However, resistance inevitably occurs, leading to disease progression after approximately 10-18 months of EGFR-TKI treatment. Platinum-based chemotherapy is the standard treatment for patients who have experienced disease progression while undergoing EGFR-TKI treatment, but its efficacy is limited. The management of extensively pretreated patients with EGFR-mutant NSCLC is becoming increasingly concerning. New agents have shown encouraging efficacy in clinical trials for this patient population, including fourth-generation EGFR-TKIs, EGFR-TKIs combined with counterpart targeted drugs, and novel agents such as antibody-drug conjugates. We review current efforts to manage extensively pretreated patients with EGFR-mutant NSCLC.

Targeting MET in Non-Small Cell Lung Cancer (NSCLC): A New Old Story?

In recent years, we have seen the development and approval for clinical use of an increasing number of therapeutic agents against actionable oncogenic drivers in metastatic non-small cell lung cancer (NSCLC). Among them, selective inhibitors, including tyrosine kinase inhibitors (TKIs) and monoclonal antibodies targeting the mesenchymal-epithelial transition (MET) receptor, have been studied in patients with advanced NSCLC with MET deregulation, primarily due to exon 14 skipping mutations or MET amplification. Some MET TKIs, including capmatinib and tepotinib, have proven to be highly effective in this molecularly defined subgroup of patients and are already approved for clinical use. Other similar agents are being tested in early-stage clinical trials with promising antitumor activity. The purpose of this review is to provide an overview of MET signaling pathways, MET oncogenic alterations primarily focusing on exon 14 skipping mutations, and the laboratory techniques used to detect MET alterations. Furthermore, we will summarize the currently available clinical data and ongoing studies on MET inhibitors, as well as the mechanisms of resistance to MET TKIs and new potential strategies, including combinatorial approaches, to improve the clinical outcomes of MET exon 14-altered NSCLC patients.

The Role of MET in Resistance to EGFR Inhibition in NSCLC: A Review of Mechanisms and Treatment Implications

Utilizing targeted therapy against activating mutations has opened a new era of treatment paradigms for patients with advanced non-small cell lung cancer (NSCLC). For patients with epidermal growth factor (EGFR)-mutated cancers, EGFR inhibitors, including the third-generation tyrosine kinase inhibitor (TKI) osimertinib, significantly prolong progression-free survival and overall survival, and are the current standard of care. However, progression after EGFR inhibition invariably occurs, and further study has helped elucidate mechanisms of resistance. Abnormalities in the mesenchymal-epithelial transition (MET) oncogenic pathway have been implicated as common alterations after progression, with MET amplification as one of the most frequent mechanisms. Multiple drugs with inhibitory activity against MET, including TKIs, antibodies, and antibody-drug conjugates, have been developed and studied in advanced NSCLC. Combining MET and EGFR is a promising treatment strategy for patients found to have a MET-driven resistance mechanism. Combination TKI therapy and EGFR-MET bispecific antibodies have shown promising anti-tumor activity in early clinical trials. Future study including ongoing large-scale trials of combination EGFR-MET inhibition will help clarify if targeting this mechanism behind EGFR resistance will have meaningful clinical benefit for patients with advanced EGFR-mutated NSCLC.

Receptor tyrosine kinase inhibitors in cancer

Targeted therapy is a new cancer treatment approach, involving drugs that particularly target specific proteins in cancer cells, such as receptor tyrosine kinases (RTKs) which are involved in promoting growth and proliferation, Therefore inhibiting these proteins could impede cancer progression. An understanding of RTKs and the relevant signaling cascades, has enabled the development of many targeted drug therapies employing RTK inhibitors (RTKIs) some of which have entered clinical application. Here we discuss RTK structures, activation mechanisms and functions. Moreover, we cover the potential effects of combination drug therapy (including chemotherapy or immunotherapy agents with one RTKI or multiple RTKIs) especially for drug resistant cancers.

MET kinase inhibitor reverses resistance to entrectinib induced by hepatocyte growth factor in tumors with NTRK1 or ROS1 rearrangements

BACKGROUND

Entrectinib is an effective drug for treating solid tumors with NTRK gene rearrangement and non-small cell lung cancer (NSCLC) with ROS1 gene rearrangement. However, its efficacy is limited by tolerance and acquired resistance, the mechanisms of which are not fully understood. The growth factors produced by the tumor microenvironment, including hepatocyte growth factor (HGF) produced by tumor-associated fibroblasts, critically affect the sensitivity to targeted drugs.

METHODS

We investigated whether growth factors that can be produced by the microenvironment affect sensitivity of NTRK1-rearranged colon cancer KM12SM cells and ROS1-rearranged NSCLC HCC78 cells to entrectinib both in vitro and in vivo.

RESULTS

Among the growth factors assessed, HGF most potently induced entrectinib resistance in KM12SM and HCC78 cells by activating its receptor MET. HGF-induced entrectinib resistance was reversed by the active-HGF-specific macrocyclic peptide HiP-8 and the MET kinase inhibitor capmatinib in vitro. In addition, HGF-producing fibroblasts promoted entrectinib resistance in vitro (culture model) and in vivo (subcutaneous tumor model). The use of capmatinib circumvented entrectinib resistance in a subcutaneous tumor model inoculated with KM12SM and HGF-producing fibroblasts.

CONCLUSION

Our findings suggest that growth factors in the tumor microenvironment, such as HGF, may induce resistance to entrectinib in tumors with NTRK1 or ROS1 rearrangements. Our results further suggest that optimally co-administering inhibitors of resistance-inducing growth factors may maximize the therapeutic efficacy of entrectinib.

MET alterations in advanced non-small cell lung cancer

Targeting the MET pathway in advanced NSCLC has been of particular interest due to its role as both a primary oncogenic driver and secondary oncogenic driver of acquired resistance. Activation of the MET pathway can occur through several mechanisms, which can complicate the diagnostic and treatment approach. Recently, several MET-directed therapies have been developed with promising results. In this narrative review, we summarize the biology and mechanism of MET as a clinically relevant driver mutation, distinct MET alterations including diagnostic challenges, significance in the setting of acquired resistance, and novel treatment strategies in advanced NSCLC.

MET Amplification as a Resistance Driver to TKI Therapies in Lung Cancer: Clinical Challenges and Opportunities

Targeted therapy has emerged as an important pillar for the standard of care in oncogene-driven non-small cell lung cancer (NSCLC), which significantly improved outcomes of patients whose tumors harbor oncogenic driver mutations. However, tumors eventually develop resistance to targeted drugs, and mechanisms of resistance can be diverse. MET amplification has been proven to be a driver of resistance to tyrosine kinase inhibitor (TKI)-treated advanced NSCLC with its activation of EGFR, ALK, RET, and ROS-1 alterations. The combined therapy of MET-TKIs and EGFR-TKIs has shown outstanding clinical efficacy in EGFR-mutated NSCLC with secondary MET amplification-mediated resistance in a series of clinical trials. In this review, we aimed to clarify the underlying mechanisms of MET amplification-mediated resistance to tyrosine kinase inhibitors, discuss the ways and challenges in the detection and diagnosis of MET amplifications in patients with metastatic NSCLC, and summarize the recently published clinical data as well as ongoing trials of new combination strategies to overcome MET amplification-mediated TKI resistance.

LncRNA AFAP1-AS1 Induces Gefitinib Resistance of Lung Adenocarcinoma Through the miR-653-5p/AGR2 Axis

Purpose

Gefitinib resistance limits the therapeutic efficacy of gefitinib to lung adenocarcinoma (LUAD). The goal of this research is to learn more about the lncRNA AFAP1-AS1 and how it functions in gefitinib-resistant LUAD cells.

Methods

RT-qPCR was performed to test the expression of AFAP1-AS1, miR-653-5p and AGR2 in LUAD tissues with acquired resistance to gefitinib or not as well as in gefitinib-resistant LUAD cells. Cell proliferation, invasion and apoptosis were measured by CCK8 assays, transwell invasion assays and flow cytometry, respectively. Luciferase reporter assay showed that miR-653-5p and AFAP1-AS1 or AGR2 interactions.

Results

In gefitinib-resistant LUAD cells and tissues, AFAP1-AS1 was overexpressed. Meanwhile, silencing AFAP1-AS1 reduced proliferation and migration while increasing apoptosis and gefitinib sensitivity. Mechanically, AFAP1-AS1 sequestered the miR-653-5p and blocked the inhibition of miR-653-5p to AGR2 and stepwise upregulated AGR2 overexpression in LUAD gefitinib resistant cells, resulting gefitinib resistance in LUAD.

Conclusion

AFAP1-AS1 promotes gefitinib-resistance LUAD cells through a previously unrecognized miR-653-5p/AGR2 axis, suggesting targeting AFAP1-AS1/miR-653-5p/AGR2 axis might be a promising way for LUAD intervention.

Landscape of Savolitinib Development for the Treatment of Non-Small Cell Lung Cancer with MET Alteration-A Narrative Review

Non-small cell lung cancer (NSCLC) is increasingly being treated with targeted therapies. Savolitinib (Orpathys^®) is highly selective mesenchymal epithelial transition (MET)-tyrosine kinase inhibitor (TKI), which is conditionally approved in China for advanced NSCLC with MET exon 14 skipping mutations (METex14). This article summarizes the clinical development of savolitinib, as a monotherapy in NSCLC with METex14 mutation and in combination with epidermal growth factor receptor (EGFR) inhibitor in post EGFR-TKI resistance NSCLC due to MET-based acquired resistance. Preclinical models demonstrated anti-tumor activities in MET-driven cancer cell line and xenograft tumor models. The Phase Ia/Ib study established an optimized, recommended phase II dose in Chinese NSCLC patients, while TATTON study of savolitinib plus osimertinib in patients with EGFR mutant, MET-amplified and TKI-progressed NSCLC showed beneficial efficacy with acceptable safety profile. In a pivotal phase II study, Chinese patients with pulmonary sarcomatoid carcinoma, brain metastasis and other NSCLC subtype positive for METex14 mutation showed notable responses and acceptable safety profile with savolitinib. Currently, results from ongoing clinical trials are eagerly anticipated to confirm the efficacious and safety benefits of savolitinib as monotherapy and in combination with EGFR-TKI in acquired resistance setting in advanced NSCLC and its subtypes with MET alterations.

Asian Thoracic Oncology Research Group (ATORG) Expert Consensus Statement on MET Alterations in NSCLC: Diagnostic and Therapeutic Considerations

Non-small cell lung cancer (NSCLC) is a heterogeneous disease, with many oncogenic driver mutations, including de novo mutations in the Mesenchymal Epithelial Transition (MET) gene (specifically in Exon 14 [ex14]), that lead to tumourigenesis. Acquired alterations in the MET gene, specifically MET amplification is also associated with the development of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) resistance in patients with EGFR-mutant NSCLC. Although MET has become an actionable biomarker with the availability of MET-specific inhibitors in selected countries, there is differential accessibility to diagnostic platforms and targeted therapies across countries in Asia-Pacific (APAC). The Asian Thoracic Oncology Research Group (ATORG), an interdisciplinary group of experts from Australia, Hong Kong, Japan, Korea, Mainland China, Malaysia, the Philippines, Singapore, Taiwan, Thailand and Vietnam, discussed testing for MET alterations and considerations for using MET-specific inhibitors at a consensus meeting in January 2022, and in subsequent offline consultation. Consensus recommendations are provided by the ATORG group to address the unmet need for standardised approaches to diagnosing MET alterations in NSCLC and for using these therapies. MET inhibitors may be considered for first-line or second or subsequent lines of treatment for patients with advanced and metastatic NSCLC harbouring MET ex14 skipping mutations; MET ex14 testing is preferred within multi-gene panels for detecting targetable driver mutations in NSCLC. For patients with EGFR-mutant NSCLC and MET amplification leading to EGFR TKI resistance, enrolment in combination trials of EGFR TKIs and MET inhibitors is encouraged.

The role of antiangiogenic monoclonal antibodies combined to EGFR-TKIs in the treatment of advanced non-small cell lung cancer with activating EGFR mutations: acquired resistance mechanisms and strategies to overcome them

As of today, only two antiangiogenic monoclonal antibodies plus epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) combinations are FDA and EMA-approved and are recommended by American Society of Clinical Oncology, European Society for Medical Oncology, and National Comprehensive Cancer Network for the first-line treatment of EGFR+ advanced non-small cell lung cancer patients: erlotinib plus bevacizumab and erlotinib plus ramucirumab. However, all treated patients eventually become unresponsive to such drugs, due to several different acquired resistance mechanisms, mainly represented by T790M substitutions and MET amplifications. While osimertinib treatment in T790M+ patients still represents the only approved treatment, MET-TKIs will likely change this status quo in the near future. In fact, existing clinical data strongly support a role for MET-TKI-based combinations in EGFR+ MET-amplified patients, possibly revolutionizing our current treatment algorithm. Chemotherapy plus immunotherapy plus antiangiogenic therapy combinations could also represent another useful addition.

MET-Induced CD73 Restrains STING-Mediated Immunogenicity of EGFR-Mutant Lung Cancer

Immunotherapy has shown limited efficacy in patients with EGFR-mutated lung cancer. Efforts to enhance the immunogenicity of EGFR-mutated lung cancer have been unsuccessful to date. Here, we discover that MET amplification, the most common mechanism of resistance to third-generation EGFR tyrosine kinase inhibitors (TKI), activates tumor cell STING, an emerging determinant of cancer immunogenicity (1). However, STING activation was restrained by ectonucleosidase CD73, which is induced in MET-amplified, EGFR-TKI-resistant cells. Systematic genomic analyses and cell line studies confirmed upregulation of CD73 in MET-amplified and MET-activated lung cancer contexts, which depends on coinduction of FOSL1. Pemetrexed (PEM), which is commonly used following EGFR-TKI treatment failure, was identified as an effective potentiator of STING-dependent TBK1-IRF3-STAT1 signaling in MET-amplified, EGFR-TKI-resistant cells. However, PEM treatment also induced adenosine production, which inhibited T-cell responsiveness. In an allogenic humanized mouse model, CD73 deletion enhanced immunogenicity of MET-amplified, EGFR-TKI-resistant cells, and PEM treatment promoted robust responses regardless of CD73 status. Using a physiologic antigen recognition model, inactivation of CD73 significantly increased antigen-specific CD8+ T-cell immunogenicity following PEM treatment. These data reveal that combined PEM and CD73 inhibition can co-opt tumor cell STING induction in TKI-resistant EGFR-mutated lung cancers and promote immunogenicity.

SIGNIFICANCE

MET amplification upregulates CD73 to suppress tumor cell STING induction and T-cell responsiveness in TKI-resistant, EGFR-mutated lung cancer, identifying a strategy to enhance immunogenicity and improve treatment.

MET-targeted therapies for the treatment of non-small-cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Dysregulation of the mesenchymal epithelial transition (MET) pathway contributes to poor clinical outcomes in patients with non-small cell lung cancer (NSCLC). Numerous clinical trials are currently investigating several therapies based on modulation of the MET pathway.

OBJECTIVES

This study aimed to systematically evaluate the activity and safety of MET inhibitors in patients with NSCLC.

METHODS

We searched PubMed, Embase, and the Cochrane Library from inception to June 02, 2022. The objective response rate (ORR) and disease control rate (DCR) were extracted as the main outcomes and pooled using the weighted mean proportion with fixed- or random-effects models in cases of significant heterogeneity (I 2>50%). Safety analysis was performed based on adverse events reported in all studies.

RESULTS

Eleven studies (882 patients) were included in the meta-analysis. The pooled ORR was 28.1% (95% confidence interval [CI], 0.223-0.354), while the pooled DCR was 69.1% (95% CI, 0.631-0.756). ORRs were higher for tepotinib (44.7% [95% CI, 0.365-0.530]) and savolitinib (42.9% [95% CI, 0.311-0.553]) than for other types of MET inhibitors. Patients with NSCLC with exon 14 skipping exhibited higher ORRs (39.3% (95% CI, 0.296-0.522)) and DCRs (77.8% (95% CI, 0.714-0.847)) than those with MET protein overexpression or amplification. Intracranial response rate and intracranial disease control rates were 40.1% (95% CI, 0.289-0.556) and 95.4% (95% CI, 0.892-0.100), respectively. Adverse events were mild (grade 1 to 2) in 87.2% of patients. Common adverse events above grade 3 included lower extremity edema (3.5% [95% CI, 0.027-0.044]), alanine aminotransferase (ALT) elevation (2.4% [95% CI, 0.014-0.033]), and lipase elevation (2.2% [95% CI, 0.016-0.031]).

CONCLUSION

MET inhibitors, which exhibited a satisfactory safety profile in the current study, may become a new standard of care for addressing MET dysregulation in patients with advanced or metastatic NSCLC, and even in those with brain metastases, particularly tepotinib, savolitinib and capmatinib. Further randomized trials are required to establish standard predictive biomarkers for MET therapies and to compare the effects of different MET inhibitors in NSCLC with MET dysregulation.

MET alterations in NSCLC—Current Perspectives and Future Challenges

Targeted therapies have revolutionized the treatment and improved the outcome for oncogene-driven NSCLC and an increasing number of oncogenic driver therapies have become available. For MET-dysregulated NSCLC (especially MET exon 14 skipping mutations and MET-amplifications, which is one of the most common bypass mechanisms of resistance in oncogene-addicted NSCLC), several anti-MET-targeted therapies have been approved recently (MET exon 14 skipping mutation) and multiple others are in development. In this narrative review, we summarize the role of MET as an oncogenic driver in NSCLC, discuss the different testing methods for exon 14 skipping mutations, gene amplification, and protein overexpression, and review the existing data and ongoing clinical trials regarding targeted therapies in MET-altered NSCLC. As immunotherapy with or without chemotherapy has become the standard of care for advanced NSCLC, immunotherapy data for MET-dysregulated NSCLC are put into perspective. Finally, we discuss future challenges in this rapidly evolving landscape.

The safety and feasibility of preoperative induction therapy of Savolitinib in non-small cell lung cancer patients with MET exon 14 skipping mutation

PURPOSE

Neoadjuvant therapy followed by surgical resection is one of the preferred treatment option for locally advanced non-small cell lung cancer (NSCLC). For patients with mesenchymal-epithelial transition (MET) factor exon 14 skipping (METex14) mutations, the use of MET-tyrosine kinase inhibitors (TKIs) showed high efficiency and reduced toxicity compared with first-line standard chemotherapy. However, it is unknown whether preoperative induction targeted therapy of MET-TKIs is feasible and safe.

METHODS

Here, we reported 3 cases of locally advanced unresectable NSCLC with METex14 mutations receiving induction therapy of MET-TKI savolitinib as first-line therapy or second-line therapy when they experienced disease progression after preoperative chemotherapy.

RESULTS

All these 3 patients achieved significant tumor size shrinkage and their unresectable tumors became resectable after the treatment of savolitinib. No serious adverse events were observed during the treatment. They recovered well postoperatively, and no significant events were identified.

CONCLUSIONS

Preoperative induction treatment with MET-TKI savolitinib showed its safety and effectiveness and may be an alternative option for neoadjuvant therapy for NSCLC patients with METex14 mutations.

Comprehensive analysis of MET mutations in NSCLC patients in a real-world setting

Background:

Aberrant mesenchymal–epithelial transition/hepatocyte growth factor (MET/HGF) regulation presented in a wide variety of human cancers. MET exon 14 skipping, copy number gain (CNG), and kinase domain mutations/arrangements were associated with increased MET activity, and considered to be oncogenic drivers of non-small cell lung cancers (NSCLCs).

Methods:

We retrospectively analyzed 564 patients with MET alterations. MET alterations were classified into structural mutations or small mutations. MET CNG, exon 14 skipping, gain of function (GOF) mutations, and kinase domain rearrangement were defined as actionable mutations.

Results:

Six hundred thirty-two MET mutations were identified including 199 CNG, 117 exon 14 skipping, 12 GOF mutations, and 2 actionable fusions. Higher percentage of MET structural alterations (CNG + fusion) were detected in advanced NSCLC patients. Moreover, MET CNG was enriched while exon 14 skipping was rare in epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI)-treated advanced NSCLC patients. Ten of the 12 MET GOF mutations were also in EGFR-TKI-treated patients. Fifteen (68.1%) of the 22 patients treated with crizotinib or savolitinib had a partial response. Interestingly, one patient had a great response to savolitinib with a novel MET exon 14 skipping mutation identified after failure of immune-checkpoint inhibitor.

Conclusions:

Half of the MET alterations were actionable mutations. MET CNG, exon 14 skipping and GOF mutations had different distribution in different clinical scenario but all defined a molecular subgroup of NSCLCs for which MET inhibition was active.

Targeting molecular alterations in non-small-cell lung cancer: what's next?

In recent years, major advances have been achieved in our understanding of non-small-cell lung cancer (NSCLC) with oncogenic driver alterations and in the specific treatment of these with tyrosine kinase inhibitors. Currently, state-of-the-art management of patients with NSCLC (particularly adenocarcinoma or non-adenocarcinoma but with mild tobacco exposure) consists of the determination of EGFR, ALK, ROS1 and BRAF status, as they have US FDA and EMA approved targeted therapies. The increase in molecular knowledge of NSCLC and the development of drugs against other targets has settled new therapeutic indications. In this review we have incorporated the development around MET, KRAS and NTRK in the diagnosis of NSCLC given the therapeutic potential that they represent, as well as the drugs approved for these indications.

Clinical outcomes of EGFR+/METamp+ vs. EGFR+/METamp- untreated patients with advanced non-small cell lung cancer

BACKGROUND

MET dysregulation has been implicated in the development of primary and secondary resistance to EGFR tyrosine kinase inhibitor (TKI) therapy. However, the clinicopathological characteristics and outcomes of patients harboring EGFR-sensitive mutations and de novo MET amplifications still need to be explored.

METHODS

A total of 54 patients from our hospital with non-small cell lung cancer harboring EGFR-sensitive mutations and/or de novo MET amplifications were included in this study. Survival rates were estimated by the Kaplan-Meier method with log-rank statistics. Lung cancer organoids (LCOs) were generated from patient-derived malignant pleural effusion to perform drug sensitivity assays.

RESULTS

Fifty-four patients with the appropriate clinicopathological characteristics were enrolled. MET FISH was performed in 40 patients who were stratified accordingly into two groups: EGFR+/METamp- (n = 22) and EGFR+/METamp + (n = 18). Survival rates for EGFR+/METamp- and EGFR+/METamp + patients respectively, were as follows: the median progression-free survival (PFS) was 12.1 and 1.9 months (p<0.001); the median post-progression overall survival (pOS) was 25.6 and 11.6 months (p = 0.023); the median overall survival (OS) was 33.2 and 12.7 months (p = 0.013). Drug testing conducted in LCOs derived from malignant pleural effusion from EGFR+/METamp + patients showed that dual targeted therapy was more effective than TKI monotherapy.

CONCLUSION

EGFR+/METamp + patients treated with first-line TKI monotherapy had poor clinical outcomes. Dual targeted therapy showed potent anticancer activity in the LCO drug testing assay, suggesting that it is a promising first-line treatment for EGFR+/METamp + patients. Randomized controlled trials are needed to further validate these results.

INSIGHT 2: a phase II study of tepotinib plus osimertinib in MET-amplified NSCLC and first-line osimertinib resistance

MET amplification (METamp), a mechanism of acquired resistance to EGFR tyrosine kinase inhibitors, occurs in up to 30% of patients with non-small-cell lung cancer (NSCLC) progressing on first-line osimertinib. Combining osimertinib with a MET inhibitor, such as tepotinib, an oral, highly selective, potent MET tyrosine kinase inhibitor, may overcome METamp-driven resistance. INSIGHT 2 (NCT03940703), an international, open-label, multicenter phase II trial, assesses tepotinib plus osimertinib in patients with advanced/metastatic EGFR-mutant NSCLC and acquired resistance to first-line osimertinib and METamp, determined centrally by fluorescence in situ hybridization (gene copy number ≥5 and/or MET/CEP7 ≥2) at time of progression. Patients will receive tepotinib 500 mg (450 mg active moiety) plus osimertinib 80 mg once-a-day. The primary end point is objective response, and secondary end points include duration of response, progression-free survival, overall survival and safety. Trial registration number: NCT03940703 (clinicaltrials.gov).

Systemic Therapy for Oligoprogression in Patients with Metastatic NSCLC Harboring Activating EGFR Mutations

After a variable period of activity of the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment, patients with advanced non-small cell lung cancer (NSCLC) harboring EGFR mutations develop resistance to these TKIs. In some cases, an oligoprogression is diagnosed, and its management is still controversial. The oligoprogression represents an intermediate stage of metastatic NSCLC between localized and widely disseminated disease, and is characterized by a limited number and/or sites of metastases in which a disease progression appears, together with a more indolent tumor biology. Currently, the management of oligoprogressed NSCLC involves local treatment, including radiotherapy and/or surgery, to control the progressive lesions. Systemic therapy should also be a potential approach to boost the activity of EGFR-TKIs. However, considering the lack of large trials addressing this topic, the optimal therapeutic strategies remain undefined and should be evaluated on an individualized basis. In this paper, we review the most relevant scientific evidence of continuing the systemic therapy with the same EGFR-TKI for the management of patients with NSCLC harboring EGFR mutations and oligoprogressed to first-line EGFR-TKIs, also discussing the controversies and potential future directions.

Molecular characterization and clinical outcomes in EGFR-mutant de novo MET-overexpressed advanced non-small-cell lung cancer

Background

Approximately 2%-8% of non-small-cell lung cancer (NSCLC) harbors concurrent epidermal growth factor receptor (EGFR) sensitizing mutation and mesenchymal–epithelial transition factor (MET) amplification prior to EGFR-tyrosine kinase inhibitor (EGFR-TKI) therapy. This study aimed to investigate the optimal first-line therapeutic options for patients with concurrent EGFR-mutant, MET-overexpressed/amplified advanced NSCLC.

Methods

A total of 104 treatment-naïve patients with EGFR-mutant de novo MET-overexpressed advanced NSCLC were identified using immunohistochemistry and stratified to four groups according to treatment regimen: EGFR-TKI monotherapy (n = 48), EGFR-TKI combined with either crizotinib (n = 9) or chemotherapy (n = 12), and chemotherapy (n = 35). A subpopulation of 28 patients was also tested with next-generation sequencing (NGS). Objective response rate (ORR) and progression-free survival (PFS) outcomes were analyzed according to treatment strategies and molecular features.

Results

All the patients (n = 104) achieved ORR of 36.5% and median PFS (mPFS) of 7.0 months. Baseline clinicopathologic characteristics were similar among the four treatment groups. Compared with chemotherapy, EGFR-TKI monotherapy or EGFR-TKI combination therapy achieved significantly higher ORR (P < 0.001) and longer mPFS (P = 0.003). No ORR or PFS difference was observed between EGFR-TKI monotherapy and combination therapy. In the NGS-identified population (n = 28), patients who received EGFR-TKI plus crizotinib (n = 9) achieved similar ORR (88.9% versus 57.9%, P = 0.195) and mPFS (9.0 versus 8.5 months, hazard ratio 1.10, 95% confidence interval 0.43-2.55, P = 0.45) than those who received EGFR-TKI monotherapy (n = 19), regardless of MET copy number status. Grade 3/4 rashes were significantly more among patients who received EGFR-TKI plus crizotinib (P = 0.026).

Conclusions

Our findings provided clinical evidence that patients with concurrent EGFR sensitizing mutation and de novo MET amplification/overexpression could benefit from first-line EGFR-TKI monotherapy.

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Concomitant EGFR sensitizing mutation and MET overexpression/amplification were detected in 2.6% of lung cancer patients.

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EGFR-TKI monotherapy elicited a higher response rate and longer PFS than chemotherapy.

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EGFR-TKI with or without crizotinib elicited comparable PFS regardless of MET copy number.

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EGFR-TKI monotherapy achieved lower number of grade 3/4 adverse events than EGFR-TKI plus crizotinib.

Case Report: Sequential Combination Targeted Therapy With Type I and II MET Inhibitors in a Metastatic EGFR-Mutated, MET-Amplified NSCLC Patient With Acquired MET Y1230H Mutation

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the standard of care for advanced non-small-cell lung cancer (NSCLC) patients. However, most patients will eventually develop resistance. For EGFR-TKI resistance mediated by MET amplification, the combination of EGFR and MET TKIs has shown promising results in early clinical trials. However, acquired resistance to MET inhibitors forms a formidable challenge to this dual blockade approach. Here, we presented an NSCLC patient with EGFR exon 19 deletion (ex19del) who was resistant to first-line erlotinib treatment but responded to chemotherapy. Given the finding of MET overexpression/amplification after disease progression, the patient received gefitinib plus crizotinib with a partial response. Her disease progressed again, and molecular testing revealed a novel MET Y1230H mutation and a PD-L1 TPS score of 75%. She received a salvage regime consisting of gefitinib, cabozantinib, and pembrolizumab with a partial response. Since we now know that EGFR ex19del NSCLC patients generally do not respond to PD-1 blockade therapy, this response is more likely the contribution from gefitinib plus cabozantinib. Therefore, sequential use of type I and II MET inhibitors in EGFR/MET dual blockade may be an effective therapeutic option for EGFR-mutant, MET-amplified NSCLC.