Resistance to MET inhibition in MET-dependent NSCLC and therapeutic activity after switching from type I to type II MET inhibitors

Responsiveness of different MET tumour alterations to type I and type II MET inhibitors

BACKGROUND

Mutations in c-MET receptor tyrosine kinase (MET) can be primary oncogenic drivers of multiple tumour types or can be acquired as mechanisms of resistance to therapy. MET tyrosine kinase inhibitors (TKIs) are classified as type I or type II inhibitors, with the former binding to the DFG-in, active conformation of MET, and the latter to the DFG-out, inactive conformation of MET. Understanding how the different classes of MET TKIs impact tumours with varied MET alterations is critical to optimising treatment for patients with MET altered cancers. Here, we characterise MET mutations identified in patients' tumours and assess responsiveness to type I and II TKIs.

METHODS

We used structural modelling, in vitro kinase and in cell-based assays to assess the response of MET mutations to type I and II TKIs. We then translated our pre-clinical findings and treated patients with MET mutant tumours with selected inhibitors.

RESULTS

We detected the emergence of four (three previously uncharacterised and one known) MET resistance mutations (METG1090A, METD1213H, METR1227K and a METY1230S) in samples from patients with multiple solid tumours, including patients who had been previously treated with type I inhibitors. In silico modelling and biochemical assays across a variety of MET alterations, including the uncharacterised METG1090A and the METY1230S substitutions, demonstrated impaired binding of type I but not of type II TKIs (i.e., cabozantinib/foretinib). Applying our pre-clinical findings, we then treated two patients (one with a non-small-cell lung cancer and one with a renal cell carcinoma) whose tumours harboured these previously uncharacterised MET alterations with cabozantinib, a type II MET TKI, and observed clinical responses.

CONCLUSIONS

Comprehensive characterisation of the sensitivity of mutations to different TKI classes in oncogenic kinases may guide clinical intervention and overcome resistance to targeted therapies in selected cases.

KEY POINTS

Kinase mutations in RTKs are primary or secondary drivers in multiple cancer types Some of these mutations confer resistance to type I but not to type II inhibitors in preclinical samples and in patients The biochemical characterization of mutations in oncogenic kinases based on their sensitivity to type I and type II inhibitors is crucial to inform clinical intervention.

Proteomic characterization of MET-amplified esophageal adenocarcinomas reveals enrichment of alternative splicing- and androgen signaling-related proteins

BACKGROUND

Esophageal adenocarcinomas (EACs) represent an evolving tumor entity with high mortality rates. MET amplification is a recurrent driver in EACs and is associated with decreased patient survival. However, the response to MET inhibitors is limited. Recent studies have identified several mechanisms that lead to resistance against MET inhibitors in different tumor entities. Nonetheless, a characterization of additional vulnerable targets beyond MET has not been conducted in MET-amplified EACs.

METHODS

In this study, we determined the MET amplification status in a cohort of more than 900 EACs using fluorescence in situ hybridization (FISH) and compared the proteomes of MET-amplified (n = 20) versus non-amplified tumors (n = 39) by mass spectrometry.

RESULTS

We identified a phenotype, present in almost all MET-amplified tumors, which shows an enrichment of alternative RNA splicing, and androgen receptor signaling proteins, as well as decreased patient survival. Additionally, our analyses revealed a negative correlation between MET expression and patient survival in MET-amplified EACs, indicating biological heterogeneity with clinical relevance despite the presence of MET amplification as the predominant oncogenic driver. Furthermore, quantitative immunohistochemical analysis of the inflammatory tumor microenvironment showed that an increased percentage of M2 macrophages is associated with lower overall survival in MET-amplified EACs.

CONCLUSIONS

Our results provide valuable insights into possible new therapeutic approaches for MET-amplified EACs for further research.

MET Activation in Lung Cancer and Response to Targeted Therapies

The hepatocyte growth factor receptor (MET) is a receptor tyrosine kinase (RTK) that mediates the activity of a variety of downstream pathways upon its activation. These pathways regulate various physiological processes within the cell, including growth, survival, proliferation, and motility. Under normal physiological conditions, this allows MET to regulate various development and regenerative processes; however, mutations resulting in aberrant MET activity and the consequent dysregulation of downstream signaling can contribute to cellular pathophysiology. Mutations within MET have been identified in a variety of cancers and have been shown to mediate tumorigenesis by increasing RTK activity and downstream signaling. In lung cancer specifically, a number of patients have been identified as possessing MET alterations, commonly receptor amplification (METamp) or splice site mutations resulting in loss of exon 14 (METex14). Due to MET's role in mediating oncogenesis, it has become an attractive clinical target and has led to the development of various targeted therapies, including MET tyrosine kinase inhibitors (TKIs). Unfortunately, these TKIs have demonstrated limited clinical efficacy, as patients often present with either primary or acquired resistance to these therapies. Mechanisms of resistance vary but often occur through off-target or bypass mechanisms that render downstream signaling pathways insensitive to MET inhibition. This review provides an overview of the therapeutic landscape for MET-positive cancers and explores the various mechanisms that contribute to therapeutic resistance in these cases.

Anti-MET Antibody Therapies in Non-Small-Cell Lung Cancer: Current Progress and Future Directions

Background/Objectives: Non-small-cell lung cancer (NSCLC) remains a leading cause of cancer mortality globally, though advances in targeted therapies have improved treatment outcomes. The mesenchymal-epithelial transition (MET) gene plays a significant role in NSCLC, often through protein overexpression, exon 14 skipping mutations, and gene amplification, many of which arise as resistance mechanisms to other oncogenic drivers like epidermal growth factor receptor (EGFR) mutations. This review examines the development and clinical efficacy of anti-MET antibody therapies. Methods: A comprehensive literature search was conducted using major medical databases looking at key relevant studies on anti-MET antibody studies. Both authors reviewed the literature, assessed study quality, and interpreted the results from each study. Results: Amivantamab, a bispecific EGFR/MET antibody was approved to treat EGFR exon 20 insertion and now has recently been extended to target classical EGFR mutations with progression on osimertinib. Other important anti-MET targeted therapies in development include antibody drug conjugates such as telisotuzumab vedotin, REGN5093-M114, and AZD9592 and emibetuzumab, which is a humanized immunoglobulin G4 monoclonal bivalent MET antibody. Conclusions: MET plays a significant role in NSCLC and amivantamab along with other anti-MET targeted therapies play a role in directly targeting MET and addressing acquired resistance to oncogenic drivers. Future research should focus on developing novel MET antibody drugs and exploring new therapeutic combinations to enhance treatment efficacy and overcome resistance in NSCLC. Refining biomarker-driven approaches to ensure precise patient selection is also critical to optimizing treatment outcomes.

Capmatinib in MET exon 14-mutated non-small-cell lung cancer: final results from the open-label, phase 2 GEOMETRY mono-1 trial

BACKGROUND

Capmatinib has previously shown activity in treatment-naive and previously treated patients with non-small-cell lung cancer (NSCLC) and a MET exon 14-skipping mutation (METex14). Here, we report the final outcomes from the phase 2 GEOMETRY mono-1 study with an aim to provide further evidence for the activity of capmatinib.

METHODS

In this non-randomised, multi-cohort, open-label, phase 2 trial conducted in 152 centres and hospitals in 25 countries, with patients treated in 95 centres in 20 countries, eligible patients (aged ≥18 years) with MET-dysregulated, EGFR wild-type, and ALK rearrangement-negative advanced NSCLC (stage IIIB/IV) and an Eastern Cooperative Oncology Group performance status of 0 or 1 were assigned to cohorts (1a, 1b, 2, 3, 4, 5a, 5b, 6 and 7) based on their MET status (METex14 or MET amplification) and previous therapy lines. Patients received capmatinib (400 mg orally twice daily) in 21-day treatment cycles. The primary endpoint was overall response rate by blinded independent central review per Response Evaluation Criteria in Solid Tumours version 1.1 and was performed on the full analysis set (all patients who received at least one dose of capmatinib). Previous reports of this study had published interim or primary data for cohorts 1-7. Here, we report the final clinical outcomes from all METex14 cohorts (4, 5b, 6, and 7) and safety from all study cohorts (1-7). The trial is registered with ClinicalTrials.gov, NCT02414139, and has been completed.

FINDINGS

Of 373 treated patients enrolled from June 11, 2015, to March 12, 2020, 160 (97 [61%] female) patients had METex14 NSCLC and were enrolled in four cohorts: 60 treatment-naive (cohorts 5b and 7) and 100 previously treated (cohorts 4 and 6). The overall median study follow-up was 46·4 months (IQR 41·8-65·4) for the treatment-naïve patients and 66·9 months (56·7-73·9) for previously treated patients, respectively. Overall responses were recorded in 41 (68%; 95% CI 55·0-79·7) of 60 treatment-naive patients and 44 (44%; 95% CI 34·1-54·3) of 100 previously treated patients. In all 373 treated patients, the most common treatment-related adverse events were peripheral oedema (n=174; 47%), nausea (n=130; 35%), increased blood creatinine (n=78; 21%), and vomiting (n=74; 20%). Grade 3-4 serious adverse events occurred in 164 (44%) patients, dyspnoea being the most common (18 patients [5%]). Treatment-related deaths occurred in four (1%) patients (one each of cardiac arrest, hepatitis, organising pneumonia, and pneumonitis). No new safety signals were reported.

INTERPRETATION

These long-term results support METex14 as a targetable oncogenic driver in NSCLC and add to the evidence supporting capmatinib as a targeted treatment option for treatment-naive and previously treated patients with METex14 NSCLC.

FUNDING

Novartis Pharmaceuticals.

Response to Crizotinib After Entrectinib Resistance in ROS1-Rearranged, MET-Amplified Lung Adenocarcinoma

Crizotinib successfully overcomes MET amplification in ROS1-rearranged NSCLC after entrectinib failure.

Therapeutic advances of targeting receptor tyrosine kinases in cancer

Receptor tyrosine kinases (RTKs), a category of transmembrane receptors, have gained significant clinical attention in oncology due to their central role in cancer pathogenesis. Genetic alterations, including mutations, amplifications, and overexpression of certain RTKs, are critical in creating environments conducive to tumor development. Following their discovery, extensive research has revealed how RTK dysregulation contributes to oncogenesis, with many cancer subtypes showing dependency on aberrant RTK signaling for their proliferation, survival and progression. These findings paved the way for targeted therapies that aim to inhibit crucial biological pathways in cancer. As a result, RTKs have emerged as primary targets in anticancer therapeutic development. Over the past two decades, this has led to the synthesis and clinical validation of numerous small molecule tyrosine kinase inhibitors (TKIs), now effectively utilized in treating various cancer types. In this manuscript we aim to provide a comprehensive understanding of the RTKs in the context of cancer. We explored the various alterations and overexpression of specific receptors across different malignancies, with special attention dedicated to the examination of current RTK inhibitors, highlighting their role as potential targeted therapies. By integrating the latest research findings and clinical evidence, we seek to elucidate the pivotal role of RTKs in cancer biology and the therapeutic efficacy of RTK inhibition with promising treatment outcomes.

Case report: Acquired resistance to crizotinib from a MET Y1230H mutation in a patient with non-small cell lung cancer and KIF5B-MET fusion

Background

The c-met proto-oncogene (MET) serves as a significant primary oncogenic driver in non-small cell lung cancer (NSCLC) and has the potential to fuse with other genes, such as KIF5B, although it occurs infrequently. Only a limited number of reported cases have examined the clinical efficacy of crizotinib in patients with KIF5B-MET gene fusion, with no known data regarding acquired resistance to crizotinib and its potential mechanisms. In this report, we present the clinical progression of a female patient diagnosed with NSCLC and harboring a KIF5B-MET gene fusion.

Case description

The patient initially exhibited partial response to first-line crizotinib treatment, albeit for a short duration and with limited efficacy. Subsequent disease progression revealed the emergence of a secondary MET mutation, specifically MET Y1230H, leading to acquired resistance to crizotinib.

Conclusion

The reporting of this case is imperative for informing clinical practice, given the uncommon occurrence of NSCLC with MET fusion, displaying responsiveness to MET tyrosine kinase inhibitor therapy, as well as the emergence of the secondary Y1230H alteration as a potential resistance mechanism.

MET alterations in advanced non-small cell lung cancer

Precision medicine has helped identify several tumor molecular aberrations to be treated with targeted therapies. These therapies showed substantial improvement in efficacy without excessive toxicity in patients with specific oncogenic drivers with advanced cancers. In metastatic lung cancers, the implementation of broad platforms for molecular tumor sequencing has helped oncology providers identify oncogenic drivers linked with better outcomes when treated upfront with targeted therapies. Mesenchymal-epithelial transition factor (MET) alterations are present in up to 60% of non-small cell lung cancer and are associated with a poor prognosis. Capmatinib and tepotinib are currently the only two approved targeted therapies by the U.S. Food and Drug Administration (FDA) for patients with MET exon 14 skipping mutation. Several agents are being developed to tackle an unmet need in patients with MET alterations. Some of these agents are being used in combination with EGFR targeted therapy to mitigate resistance to EGFR inhibitor. These agents are poised to provide new hope for these patients.

KIF20B and MET, hub genes of DIAPHs, predict poor prognosis and promote pancreatic cancer progression

BACKGROUND

The DIAPHs (DIAPH1, DIAPH2, and DIAPH3) are members of the diaphanous subfamily of the formin family. KIF20B and MET, hub genes of DIAPHs, play crucial roles in cytoskeletal remodeling, cell migration, and adhesion. However, their combined prognostic and treatment value in pancreatic adenocarcinoma (PC) warrants further investigation.

METHODS

Multiomics analysis tools were used to comprehensively assess the genomic expression and prognostic value of KIF20B and MET in PC. Immune cell infiltration, functional enrichment, single-cell RNA-seq (scRNA) analysis, potential therapeutic drugs, and nomograms were established and analyzed. CCK-8 levels, transwell assay, Co-IP assay, mass spectrometry, and western blotting were performed to assess the role of KIF20B and MET as modulators of β-catenin and Lactate Dehydrogenase A (LDHA) in vitro. Xenograft tumor models were used to evaluate the anti-tumor effects in vivo.

RESULTS

DIAPHs, KIF20B, and MET were overexpressed and functioned as poor prognostic markers of PC. Immunoinfiltration analysis revealed that pDC and NK cells were enriched with low expression levels of KIF20B and MET, whereas Th2 cells were enriched with high expression levels of these two genes. The copy number variations (CNVs) in KIF20B and MET were positively correlated with B cell and CD4 + T cell infiltration. Immunological checkpoints NT5E and CD44 were positively correlated with KIF20B and MET expression. Moreover, the nomogram constructed based on KIF20B and MET demonstrated predictive value for overall survival. scRNA-Seq analysis indicated that KIF20B and MET were enriched in endothelial, malignant, B, T, and CD8 + T cells, which correlated with glycolysis and the epithelial-mesenchymal transition (EMT). The interactions of KIF20B and MET with β-catenin and LDHA were verified by Co-IP assay and mass spectrometry. Knockdown of KIF20B and MET downregulates β-catenin and LDHA in vitro. Furthermore, dual knockdown of KIF20B and MET exhibited a synergistic suppressive effect on PC progression in vitro and in vivo.

CONCLUSION

DIAPHs, KIF20B, and MET are promising candidates for the prognosis and treatment of PC. More importantly, downregulation of KIF20B and MET inhibited pancreatic cancer progression by regulating LDHA and EMT.

MET Fusions in NSCLC: Clinicopathologic Features and Response to MET Inhibition

INTRODUCTION

MET fusions have been described only rarely in NSCLC. Thus, data on patient characteristics and treatment response are limited. We here report histopathologic data, patient demographics, and treatment outcome including response to MET tyrosine kinase inhibitor (TKI) therapy in MET fusion-positive NSCLC.

METHODS

Patients with NSCLC and MET fusions were identified mostly by RNA sequencing within the routine molecular screening program of the national Network Genomic Medicine, Germany.

RESULTS

We describe a cohort of nine patients harboring MET fusions. Among these nine patients, two patients had been reported earlier. The overall frequency was 0.29% (95% confidence interval: 0.15-0.55). The tumors were exclusively adenocarcinoma. The cohort was heterogeneous in terms of age, sex, or smoking status. We saw five different fusion partner genes (KIF5B, TRIM4, ST7, PRKAR2B, and CAPZA2) and several different breakpoints. Four patients were treated with a MET TKI leading to two partial responses, one stable disease, and one progressive disease. One patient had a BRAF V600E mutation as acquired resistance mechanism.

CONCLUSIONS

MET fusions are very rare oncogenic driver events in NSCLC and predominantly seem in adenocarcinomas. They are heterogeneous in terms of fusion partners and breakpoints. Patients with MET fusion can benefit from MET TKI therapy.

Nanomedicine Combats Drug Resistance in Lung Cancer

Lung cancer is the second most prevalent cancer and the leading cause of cancer-related death worldwide. Surgery, chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy are currently available as treatment methods. However, drug resistance is a significant factor in the failure of lung cancer treatments. Novel therapeutics have been exploited to address complicated resistance mechanisms of lung cancer and the advancement of nanomedicine is extremely promising in terms of overcoming drug resistance. Nanomedicine equipped with multifunctional and tunable physiochemical properties in alignment with tumor genetic profiles can achieve precise, safe, and effective treatment while minimizing or eradicating drug resistance in cancer. Here, this work reviews the discovered resistance mechanisms for lung cancer chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy, and outlines novel strategies for the development of nanomedicine against drug resistance. This work focuses on engineering design, customized delivery, current challenges, and clinical translation of nanomedicine in the application of resistant lung cancer.

Advances and challenges in the treatment of lung cancer

Lung cancer accounts for a relatively high proportion of malignant tumors. As the most prevalent type of lung cancer, non-small cell lung cancer (NSCLC) is characterized by high morbidity and mortality. Presently, the arsenal of treatment strategies encompasses surgical resection, chemotherapy, targeted therapy and radiotherapy. However, despite these options, the prognosis remains distressingly poor with a low 5-year survival rate. Therefore, it is urgent to pursue a paradigm shift in treatment methodologies. In recent years, the advent of sophisticated biotechnologies and interdisciplinary integration has provided innovative approaches for the treatment of lung cancer. This article reviews the cutting-edge developments in the nano drug delivery system, molecular targeted treatment system, photothermal treatment strategy, and immunotherapy for lung cancer. Overall, by systematically summarizing and critically analyzing the latest progress and current challenges in these treatment strategies of lung cancer, we aim to provide a theoretical basis for the development of novel drugs for lung cancer treatment, and thus improve the therapeutic outcomes for lung cancer patients.

Lorlatinib and capmatinib in a ROS1-rearranged NSCLC with MET-driven resistance: tumor response and evolution

Acquired drug resistance remains a major problem across oncogene-addicted cancers. Elucidation of mechanisms of resistance can inform rational treatment strategies for patients relapsing on targeted therapies while offering insights into tumor evolution. Here, we report acquired MET amplification as a resistance driver in a ROS1-rearranged lung adenocarcinoma after sequential treatment with ROS1 inhibitors. Subsequent combination therapy with lorlatinib plus capmatinib, a MET-selective inhibitor, induced intracranial and extracranial tumor response. At relapse, sequencing of the resistant tumor revealed a MET D1246N mutation and loss of MET amplification. We performed integrated molecular analyses of serial tumor and plasma samples, unveiling dynamic alterations in the ROS1 fusion driver and MET bypass axis at genomic and protein levels and the emergence of polyclonal resistance. This case illustrates the complexity of longitudinal tumor evolution with sequential targeted therapies, highlighting challenges embedded in the current precision oncology paradigm and the importance of developing approaches that prevent resistance.

Clinicopathologic and molecular characteristics of small-scale ROS1-mutant non-small cell lung cancer (NSCLC) patients

BACKGROUND

ROS1 fusions are well treatable aberrations in NSCLC. Besides solvent-front mutations (SFM) in resistance to targeted therapy, small-scale ROS1 mutations are largely unknown. We exploratively analyzed the clinical and molecular characteristics of small-scale ROS1 mutations in NSCLC patients without activating ROS1 fusions or SFMs.

METHODS

Next-generation sequencing was performed on tissue samples from NSCLC patients within the Network Genomic Medicine. Patients with ROS1 fusions and SFMs were excluded. We analyzed clinical characteristics of patients harboring small-scale ROS1-mutations, ROS1- and co-occurring mutations, and their response to systemic therapy.

RESULTS

Of 10,396 patients analyzed, 101 (1.0%) patients harbored small-scale ROS1 mutations. Most patients were male (73.3%) and smokers (96.6%). Nearly half of the patients presented with squamous-cell carcinoma (SqCC, 40.4%). Most mutations were transversions (50.5%), and 66% were in the kinase domain. Besides TP53 mutations (65.3%), KRAS (22.8%), EGFR (5.9%), PIK3CA (9.9%) and FGFR1-4 mutations (8.9%) co-occurred. In 10 (9.9%) patients, ROS1 mutation was the only aberration detected. Median overall survival (mOS) differed significantly in patients with or without KRAS co-mutations (9.7 vs 21.5 months, p = 0.02) and in patients treated with or without immune-checkpoint blockade (ICB) during treatment (21.5 vs 4.4 months, p = 0.003).

CONCLUSION

The cohort's clinical characteristics contrasted ROS1-fused cohorts. Co-occurrence of KRAS mutations led to shortened survival and patients benefited from ICB. Our data does not support the idea of ROS1 small-scale mutations as strong oncogenic drivers in NSCLC, but rather as relevant bystanders altering the efficacy of treatment approaches.

The Combined Therapy of Cabozantinib, Crizotinib, and Osimertinib in a Lung Cancer Patient with Acquired MET Amplification and Resistance Mutations

EGFR-mutant lung cancers develop a wide range of potential resistance alterations under therapy with the third-generation EGFR tyrosine kinase inhibitor osimertinib. MET amplification ranks among the most common acquired resistance alterations and is currently being investigated as a therapeutic target in several studies. Nevertheless, targeted therapy of MET might similarly result in acquired resistance by point mutations in MET, which further expands therapeutic and diagnostic challenges. Here, we report a 50-year-old male patient with EGFR-mutant lung adenocarcinoma and stepwise acquired resistance by a focal amplification of MET followed by D1246N (D1228N), D1246H (D1228H), and L1213V (L1195V) point mutations in MET, all detected by NGS. The patient successfully responded to the combined and sequential treatment of osimertinib, osimertinib/crizotinib, and third-line osimertinib/cabozantinib. This case highlights the importance of well-designed, sequential molecular diagnostic analyses and the personalized treatment of patients with acquired resistance.

Targeting MET: Discovery of Small Molecule Inhibitors as Non-Small Cell Lung Cancer Therapy

MET has been considered as a promising drug target for the treatment of MET-dependent diseases, particularly non-small cell lung cancer (NSCLC). Small molecule MET inhibitors with mainly three types of binding modes (Ia/Ib, II, and III) have been developed. In this Review, we provide an overview of the structural features, activation mechanism, and dysregulation pathway of MET and summarize progress on the development and discovery strategies utilized for MET inhibitors as well as mechanisms of acquired resistance to current approved inhibitors. The insights will accelerate discovery of new generation MET inhibitors to overcome clinical acquired resistance.

Design, synthesis and biological evaluation of 4-(4-aminophenoxy)picolinamide derivatives as potential antitumor agents

Cancer is a leading cause of death in humans. Molecular targeted therapy for cancer has become a research hotspot as it is associated with low toxicity and high efficiency. In this study, a total of 36 derivatives of 4-(4-aminophenoxy)pyridinamide were designed and synthesized, based on the analysis of the binding patterns of cabozantinib and BMS-777607 to MET protein. Most target compounds exhibited moderate to excellent antiproliferative activity against three different cell lines (A549, HeLa and MCF-7). A total of 7 compounds had stronger inhibitory activities than cabozantinib, and the IC₅₀ value of the most promising compound 46 was 0.26 μM against the A549 cells, which was 2.4 times more active than that of cabozantinib. The structure-activity relationship of the target compounds was analyzed and summarized, and the action mechanism was discussed. The acridine orange (AO) staining assay and cell cycle apoptosis revealed that compound 46 dose-dependently induced apoptosis of A549 cells, and blocked the cells mainly in G0/G1 phase. The IC₅₀ value of compound 46 on c-Met kinase was 46.5 nM. Further docking studies and molecular dynamics simulations signaled that compound 46 formed four key hydrogen bonds to c-Met kinase, and these key amino acids played a major role in binding free energy. In addition, compound 46 also showed good pharmacokinetic characteristics in rats. In conclusion, compound 46 is a promising antitumor agent.