Crizotinib in MET-Deregulated or ROS1-Rearranged Pretreated Non–Small Cell Lung Cancer (METROS): A Phase II, Prospective, Multicenter, Two-Arms Trial

Phase 2 trial of crizotinib in Japanese patients with advanced NSCLC harboring a MET gene alteration: a Co-MET study

BACKGROUND

MET exon 14 skipping mutations occur in 3-4% and MET high amplifications occur in < 1% of patients with non-small-cell lung cancer (NSCLC). Crizotinib, a selective ATP-competitive small-molecule inhibitor of c-Met, ALK, and ROS1 tyrosine kinases, has shown activity in cancer models with various types of MET activation.

METHODS

The Co-MET study is a single-arm phase 2 trial to assess the safety and efficacy of crizotinib in MET inhibitor-naïve patients with advanced NSCLC harboring MET exon 14 skipping mutation (cohort 1) or high MET gene copy number of ≥ 7 (cohort 2). The primary endpoint was the objective response rate (ORR) per RECIST v1.1 by independent radiology review in cohort 1. The key secondary endpoints were the duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

A total of 28 patients (23 in cohort 1 and 5 in cohort 2) were enrolled between March 2018 and February 2020. The primary endpoint was met as the ORR (90% confidence interval: CI) in cohort 1 was 38.1% (20.6-58.3). Median DoR, PFS, and OS (95% CI) were 7.6 (1.9-NE), 5.7 (2.1-11.3), 9.1 (4.0-19.9) months, respectively, in cohort 1. ORR in cohort 2 was 40.0% (18.9-92.4). The safety signals were generally consistent with the known safety profile of crizotinib.

CONCLUSIONS

Crizotinib showed a clinical activity similar to that of tepotinib and capmatinib in patients with NSCLC harboring MET exon 14 skipping mutations.

CLINICAL TRIAL INFORMATION

UMIN000031623.

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.

Recording and classifying MET receptor mutations in cancers

Tyrosine kinase inhibitors (TKI) directed against MET have been recently approved to treat advanced non-small cell lung cancer (NSCLC) harbouring activating MET mutations. This success is the consequence of a long characterization of MET mutations in cancers, which we propose to outline in this review. MET, a receptor tyrosine kinase (RTK), displays in a broad panel of cancers many deregulations liable to promote tumour progression. The first MET mutation was discovered in 1997, in hereditary papillary renal cancer (HPRC), providing the first direct link between MET mutations and cancer development. As in other RTKs, these mutations are located in the kinase domain, leading in most cases to ligand-independent MET activation. In 2014, novel MET mutations were identified in several advanced cancers, including lung cancers. These mutations alter splice sites of exon 14, causing in-frame exon 14 skipping and deletion of a regulatory domain. Because these mutations are not located in the kinase domain, they are original and their mode of action has yet to be fully elucidated. Less than five years after the discovery of such mutations, the efficacy of a MET TKI was evidenced in NSCLC patients displaying MET exon 14 skipping. Yet its use led to a resistance mechanism involving acquisition of novel and already characterized MET mutations. Furthermore, novel somatic MET mutations are constantly being discovered. The challenge is no longer to identify them but to characterize them in order to predict their transforming activity and their sensitivity or resistance to MET TKIs, in order to adapt treatment.

Therapy for Stage IV Non-Small Cell Lung Cancer With Driver Alterations: ASCO Living Guideline, Version 2023.3

PURPOSE

To provide evidence-based recommendations for patients with stage IV non-small cell lung cancer with driver alterations.

METHODS

This ASCO living guideline offers continually updated recommendations based on an ongoing systematic review of randomized clinical trials (RCTs), with the latest time frame spanning February to October 2023. An Expert Panel of medical oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened. The literature search included systematic reviews, meta-analyses, and randomized controlled trials. Outcomes of interest include efficacy and safety. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

This guideline consolidates all previous updates and reflects the body of evidence informing this guideline topic. Eight new RCTs were identified in the latest search of the literature to date.

RECOMMENDATIONS

Evidence-based recommendations were updated to address first, second, and subsequent treatment options for patients based on targetable driver alterations.Additional information is available at www.asco.org/living-guidelines.

Early-Stage Non-Small Cell Lung Cancer: Prevalence of Actionable Alterations in a Monocentric Consecutive Cohort

Early-stage (ES) non-small cell lung cancer (NSCLC) is diagnosed in about 30% of cases. The preferred treatment is surgery, but a significant proportion of patients experience recurrence. Neoadjuvant and adjuvant chemotherapy has a limited clinical benefit. EGFR tyrosine kinase inhibitors and immunotherapy have recently opened new therapeutic scenarios. However, only a few data are available about the ES-NSCLC molecular landscape and the impact of oncogene addiction on therapy definition. Here, we determined the prevalence of the main lung cancer driver alterations in a monocentric consecutive cohort. Molecular analysis was performed on 1122 cases, including 368 ES and 754 advanced NSCLC. The prevalence of actionable alterations was similar between early and advanced stages. ES-NSCLC was significantly enriched for MET exon-14 skipping alterations and presented a lower prevalence of BRAF p.(V600E) mutation. PD-L1 expression levels, evaluated according to actionable alterations, were higher in advanced than early tumors harboring EGFR, KRAS, MET alterations and gene fusions. Taken together, these results confirm the value of biomarker testing in ES-NSCLC. Although approved targeted therapies for ES-NSCLC are still limited, the identification of actionable alterations could improve patients' selection for immunotherapy, favoring the enrollment in clinical trials and allowing a faster treatment start at disease recurrence.

Overall survival and central nervous system activity of crizotinib in ROS1-rearranged lung cancer-final results of the EUCROSS trial

BACKGROUND

In 2019, we reported the first efficacy and safety analysis of EUCROSS, a phase II trial investigating crizotinib in ROS1 fusion-positive lung cancer. At that time, overall survival (OS) was immature and the effect of crizotinib on intracranial disease control remained unclear. Here, we present the final analysis of OS, systemic and intracranial activity, and the impact of co-occurring aberrations.

MATERIALS AND METHODS

EUCROSS was a prospective, single-arm, phase II trial. The primary endpoint was best overall response rate (ORR) using RECIST 1.1. Secondary and exploratory endpoints were progression-free survival (PFS), OS, and efficacy in pre-defined subgroups.

RESULTS

Median OS of the intention-to-treat population (N = 34) was 54.8 months [95% confidence interval (CI) 20.3 months-not reached (NR); median follow-up 81.4 months] and median all-cause PFS of the response-evaluable population (N = 30) was 19.4 months (95% CI 10.1-32.2 months). Time on treatment was significantly correlated with OS (R = 0.82; P < 0.0001). Patients with co-occurring TP53 aberrations (28%) had a significantly shorter OS [hazard ratio (HR) 11; 95% CI 2.0-56.0; P = 0.006] and all-cause PFS (HR 4.2; 95% CI 1.2-15; P = 0.025). Patients with central nervous system (CNS) involvement at baseline (N = 6; 20%) had a numerically shorter median OS and all-cause PFS. Median intracranial PFS was 32.2 months (95% CI 23.7 months-NR) and the rate of isolated CNS progression was 24%.

CONCLUSIONS

Our final analysis proves the efficacy of crizotinib in ROS1-positive lung cancer, but also highlights the devastating impact of TP53 mutations on survival and treatment efficacy. Additionally, our data show that CNS disease control is durable and the risk of CNS progression while on crizotinib treatment is low.

Targeting MET in NSCLC: An Ever-Expanding Territory

MET protooncogene (MET) alterations are known driver oncogenes in NSCLC. Since the identification of MET as a potential therapeutic target, extensive clinical trials have been performed. As a result, MET-targeted therapies, including MET tyrosine kinase inhibitors, monoclonal antibodies, and MET antibody-drug conjugates now play important roles in the standard treatment of MET-altered NSCLC; they have considerably improved the outcomes of patients with tumors that harbor MET oncogenic drivers. Although clinical agents are currently available and numerous other options are in development, particular challenges in the field require attention. For example, the therapeutic efficacy of each drug remains unsatisfactory, and concomitantly, the resistance mechanisms are not fully understood. Thus, there is an urgent need for optimal drug sequencing and combinations, along with a thorough understanding of treatment resistance. In this review, we describe the current landscape of pertinent clinical trials focusing on MET-targeted strategies and discuss future developmental directions in this rapidly expanding field.

Real-World Outcomes of Crizotinib in ROS1-Rearranged Advanced Non-Small-Cell Lung Cancer

Real-world data on the use and outcomes of crizotinib in ROS1-rearranged non-small-cell lung cancer (NSCLC) are limited. This study aims to analyze the real-world efficacy of crizotinib in South Korea and explore the utilization of liquid biopsies that implement next-generation sequencing (NGS) using cell-free total nucleic acids. In this prospective multicenter cohort study, 40 patients with ROS1-rearranged NSCLC, either starting or already on crizotinib, were enrolled. Patients had a median age of 61 years, with 32.5% presenting brain/central nervous system (CNS) metastases at treatment initiation. At the data cutoff, 48.0% were still in treatment; four continued with it even after disease progression due to the clinical benefits. The objective response rate was 70.0%, with a median duration of response of 27.8 months. The median progression-free survival was 24.1 months, while the median overall survival was not reached. Adverse events occurred in 90.0% of patients, primarily with elevated transaminases, yet these were mostly manageable. The NGS assay detected a CD74-ROS1 fusion in 2 of the 14 patients at treatment initiation and identified emerging mutations, such as ROS1 G2032R, ROS1 D2033N, and KRAS G12D, during disease progression. These findings confirm crizotinib's sustained clinical efficacy and safety in a real-world context, which was characterized by a higher elderly population and higher rates of brain/CNS metastases. The study highlights the clinical relevance of liquid biopsy for detecting resistance mechanisms, suggesting its value in personalized treatment strategies.

Clinical outcomes of ROS1-positive non-small cell lung cancer with limited access to ROS1-tyrosine kinase inhibitors (TKIs): experience from an Indian tertiary referral centre

Introduction

ROS1 as a driver mutation is observed in approximately 1%-2% of all non-small cell lung cancer (NSCLC). Given its rarity, we share our experience regarding ROS1-positive NSCLC including the access to ROS1 tyrosine kinase inhibitors (TKIs) in a low-middle income country like India.

Methods

It is a retrospective analysis of ROS1-positive NSCLC patients registered between January 2015 to December 2021 for demographics, treatment patterns and outcomes i.e., overall survival (OS) and progression free survival (PFS).

Results

Baseline characteristics were available for 70 patients of 78 patients positive for ROS1 by fluorescent in situ hybridisation. Median age at presentation was 52 years, 39 (55.7%) were males, most (51, 72.86%) were non-smokers and ten patients (14.3%) had poor Eastern Cooperative Oncology Group (ECOG) performance status (PS) i.e., PS >2 at presentation. A total of 67 patients receiving cancer directed therapy were analysed for survival. The first line (1L) therapies included - ROS1 TKIs in 38, chemotherapy in 20, epidermal growth factor receptor TKI in eight and chemotherapy-bevacizumab in one only. ROS1 TKI was provided to 20 patients as part of an assistance programme. The median OS for patients who received ROS1 TKI was not attained (95% CI 37.85-NA), while it was 8.11 (95% CI 6.31-NA) months for those who did not (HR-0.1673). The median PFS for the 1L ROS1 TKI compared to the no-TKI group was 27.07 (95% CI 24.28-NA) months versus 5.78 (95% CI 3.42-12) months (HR: 0.2047). Poor ECOG PS at presentation was the only independent prognosticator for survival.

Conclusion

Using ROS1 TKI improves clinical outcomes in all-comers though statistically not significant. To further improve outcomes, future trials should pay special attention to patients with poor PS and find a way to increase the current limited access to TKI.

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.

A Phase I Trial of the Dual MET Kinase/OCT-2 Inhibitor OMO-1 in Metastatic Solid Malignancies Including MET Exon 14 Mutated Lung Cancer

INTRODUCTION

Targeted therapy in non-small cell lung cancer (NSCLC) patients with mesenchymal epithelial transition (MET) exon 14 skipping mutations (METex14) and MET amplifications has improved patients' outcomes. The development of more potent MET kinase inhibitors could further benefit these patients. The aim of this trial is to determine the safety and recommended phase 2 dose (RP2D) of OMO-1 (an oral dual MET kinase/OCT-2 inhibitor) and to assess preliminary clinical efficacy in METex14-positive NSCLC and other MET-positive solid tumors.

MATERIALS AND METHODS

This was a first-in-patient, open-label, multicenter study of OMO-1 in patients with locally advanced or metastatic solid malignancies. A standard 3 + 3 dose escalation design was utilized starting at a dose level of 100 mg BID continuously. Preliminary efficacy was investigated in patients with METex14-positive NSCLC, and MET amplified NSCLC and other solid tumors (MET basket).

RESULTS

In the dose-escalation part, 24 patients were included in 5 dose levels ranging from 100 mg twice daily (BID) to 400 mg BID. Most common adverse events (≥ 20%) were nausea, fatigue, vomiting, increased blood creatinine, and headache. The RP2D was determined at 250 mg BID. In the expansion cohorts, 15 patients were included (10 in METex14-positive NSCLC cohort and 5 in MET basket cohort) and received either 200 or 250 mg BID. Eight out of the 10 patients with METex14 positive NSCLC had stable disease as the best response.

CONCLUSION

OMO-1 was tolerated at the dose of 250 mg BID and shows initial signs of MET inhibition and anti-tumor activity in METex14 mutated NSCLC patients.

Comprehensive Review of ROS1 Tyrosine Kinase Inhibitors-Classified by Structural Designs and Mutation Spectrum (Solvent Front Mutation [G2032R] and Central β-Sheet 6 [Cβ6] Mutation [L2086F])

Despite ROS1 fusion-positive NSCLC accounting for approximately 1% to 2% of NSCLC, there is a long list of ROS1 tyrosine kinase inhibitors (TKIs) being developed in addition to three approved ROS1 TKIs, crizotinib, entrectinib and repotrectinib. Here, we categorized ROS1 TKIs by their structures (cyclic versus noncyclic) and inhibitory abilities (active against solvent front mutation G2032R or central β-sheet #6 [Cβ6] mutation L2086F) and summarized their reported clinical activity in order to provide a dashboard on how to use these ROS1 TKIs in various clinical situations. In addition, the less known Cβ6 mutation ROS1 L2086F confer resistances to next-generation ROS1 TKIs (repotrectinib, taletrectinib, and potentially NVL-520) that can be overcome by cabozantinib as documented in published patient reports and potentially by certain L-shaped type I ROS1 TKIs including ceritinib and gilteritinib, which is approved as a FLT3 inhibitor for relapsed refractory FLT3+ acute myeloid leukemia but have published preclinical activites against ROS1 (and ALK). Future clinical trials should investigate cabozantinib and gilteritinib to repurpose them as ROS1 TKIs that can target ROS1 L2086F Cβ6 mutation.

Effectiveness of crizotinib in patients with ROS1-positive non-small-cell lung cancer: real-world evidence in Japan

Aim: Crizotinib, approved in Japan (2017) for ROS1-positive NSCLC, has limited real-world data. Materials & methods: Crizotinib monotherapy real-world effectiveness and treatment status were analyzed from claims data (June 2017-March 2021; Japanese Medical Data Vision; 58 patients tested for ROS1-NSCLC). Results: Median duration of treatment ([DoT]; primary end point), any line: 12.9 months; 22 patients on crizotinib, 23 discontinued, 13 receiving post-crizotinib treatment. 1L (n = 27) median DoT: 13.0 months (95% CI, 4.4-32.0 months); 13 patients on crizotinib; seven discontinued; seven receiving post-crizotinib treatment. 2L (n = 13) median DoT: 14.0 months (95% CI, 4.6-22.2 months); 2L+ (n = 31): nine patients on crizotinib; 16 discontinued; six receiving post-crizotinib treatment. Post-crizotinib treatments (chemotherapy, cancer immunotherapy, anti-VEGF/R) did not affect crizotinib DoT. Conclusion: Data supplement crizotinib's effectiveness in ROS1-positive NSCLC previously seen in clinical trials/real-world.

Lung Injury Induced by Crizotinib and Entrectinib in a Patient with ROS1-rearranged Non-small-cell Lung Cancer

We herein report the first case of c-ros oncogene 1 (ROS1)-rearranged advanced non-small-cell lung cancer (NSCLC) in which lung injury was induced by crizotinib and entrectinib. Crizotinib was administered as first-line chemotherapy in a woman in her early 70s with stage IV NSCLC showing ROS1 rearrangement. This resulted in the development of drug-induced organizing pneumonia, which was alleviated by discontinuing drug administration and giving corticosteroids. Following second-line chemotherapy with entrectinib, a similar lung injury was noted. In cases of crizotinib-induced lung injury, physicians must be alert for drug-induced lung injury in subsequent treatment with entrectinib.

Discovery of oncogenic ROS1 missense mutations with sensitivity to tyrosine kinase inhibitors

ROS1 is the largest receptor tyrosine kinase in the human genome. Rearrangements of the ROS1 gene result in oncogenic ROS1 kinase fusion proteins that are currently the only validated biomarkers for targeted therapy with ROS1 TKIs in patients. While numerous somatic missense mutations in ROS1 exist in the cancer genome, their impact on catalytic activity and pathogenic potential is unknown. We interrogated the AACR Genie database and identified 34 missense mutations in the ROS1 tyrosine kinase domain for further analysis. Our experiments revealed that these mutations have varying effects on ROS1 kinase function, ranging from complete loss to significantly increased catalytic activity. Notably, Asn and Gly substitutions at Asp2113 in the ROS1 kinase domain were found to be TKI-sensitive oncogenic variants in cell-based model systems. In vivo experiments showed that ROS1 D2113N induced tumor formation that was sensitive to crizotinib and lorlatinib, FDA-approved ROS1-TKIs. Collectively, these findings highlight the tumorigenic potential of specific point mutations within the ROS1 kinase domain and their potential as therapeutic targets with FDA-approved ROS1-TKIs.

MET in Non-Small-Cell Lung Cancer (NSCLC): Cross 'a Long and Winding Road' Looking for a Target

Non-Small-Cell Lung Cancer (NSCLC) can harbour different MET alterations, such as MET overexpression (MET OE), MET gene amplification (MET AMP), or MET gene mutations. Retrospective studies of surgical series of patients with MET-dysregulated NSCLC have shown worse clinical outcomes irrespective of the type of specific MET gene alteration. On the other hand, earlier attempts failed to identify the 'druggable' molecular gene driver until the discovery of MET exon 14 skipping mutations (METex14). METex14 are rare and amount to around 3% of all NSCLCs. Patients with METex14 NSCLC attain modest results when they are treated with immune checkpoint inhibitors (ICIs). New selective MET inhibitors (MET-Is) showed a long-lasting clinical benefit in patients with METex14 NSCLC and modest activity in patients with MET AMP NSCLC. Ongoing clinical trials are investigating new small molecule tyrosine kinase inhibitors, bispecific antibodies, or antibodies drug conjugate (ADCs). This review focuses on the prognostic role of MET, the summary of pivotal clinical trials of selective MET-Is with a focus on resistance mechanisms. The last section is addressed to future developments and challenges.

An Observatory for the MET Oncogene: A Guide for Targeted Therapies

The MET proto-oncogene encodes a pivotal tyrosine kinase receptor, binding the hepatocyte growth factor (HGF, also known as scatter factor, SF) and governing essential biological processes such as organogenesis, tissue repair, and angiogenesis. The pleiotropic physiological functions of MET explain its diverse role in cancer progression in a broad range of tumors; genetic/epigenetic alterations of MET drive tumor cell dissemination, metastasis, and acquired resistance to conventional and targeted therapies. Therefore, targeting MET emerged as a promising strategy, and many efforts were devoted to identifying the optimal way of hampering MET signaling. Despite encouraging results, however, the complexity of MET's functions in oncogenesis yields intriguing observations, fostering a humbler stance on our comprehension. This review explores recent discoveries concerning MET alterations in cancer, elucidating their biological repercussions, discussing therapeutic avenues, and outlining future directions. By contextualizing the research question and articulating the study's purpose, this work navigates MET biology's intricacies in cancer, offering a comprehensive perspective.

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.

Real-World Data on Combined EGFR-TKI and Crizotinib Treatment for Acquired and De Novo MET Amplification in Patients with Metastatic EGFR-Mutated NSCLC

Amplification of the mesenchymal epithelial transition (MET) gene is a mechanism of acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine-kinase-inhibitors (TKIs) in over 20% of patients with advanced EGFR-mutated (EGFRm+) non-small lung cancer (NSCLC). However, it may also occur de novo in 2-8% of EGFRm+ NSCLC cases as a potential mechanism of intrinsic resistance. These patients represent a group with unmet needs, since there is no standard therapy currently approved. Several new MET inhibitors are being investigated in clinical trials, but the results are awaited. Meanwhile, as an alternative strategy, combinations of EGFR-TKIs with the MET/ALK/ROS1-TKI Crizotinib may be used in this setting, despite this use is principally off-label. Thus, we studied five of these MET amplified cases receiving EGFR-TKI and Crizotinib doublet after progression on EGFR-TKI treatment to assess the benefits and challenges related to this combination and the possible occurrence of genomic and phenotypic co-alterations. Furthermore, we compared our cases with other real-world reports on Crizotinib/EGFR-TKI combinations, which appeared effective, especially in patients with high-level MET amplification. Yet, we observed that the co-occurrence of other genomic and phenotypical alterations may affect the response to combined EGFR-TKI and Crizotinib. Finally, given the heterogeneity of MET amplification, the diagnostic methods for assessing it may be discrepant. In this respect, we observed that for optimal detection, immunohistochemistry, fluorescence in situ hybridization, and next-generation sequencing should be used together, as these methods possess different sensitivities and complement each other in characterizing MET amplification. Additionally, we addressed the issue of managing EGFR-mutated NSCLC patients with de novo MET amplification causing primary EGFR-TKI resistance. We conclude that, while data from clinical trials with new MET inhibitors are still pending, adding Crizotinib to EGFR-TKI in NSCLC patients acquiring MET amplification at progression on EGFR-TKI monotherapy is a reasonable approach, with a progression-free survival of 3-19 months.

A Systematic Review of Mesenchymal Epithelial Transition Factor (MET) and Its Impact in the Development and Treatment of Non-Small-Cell Lung Cancer

Lung cancer represents the leading cause of annual cancer-related deaths worldwide, accounting for 12.9%. The available treatment options for patients who experience disease progression remain limited. Targeted therapeutic approaches are promising but further understanding of the role of genetic alterations in tumorigenesis is imperative. The MET gene has garnered great interest in this regard. The aim of this systematic review was to analyze the findings from multiple studies to provide a comprehensive and unbiased summary of the evidence. A systematic search was conducted in the reputable scientific databases Embase and PubMed, leading to the inclusion of twenty-two articles, following the PRISMA guidelines, elucidating the biological role of MET in lung cancer and targeted therapies. The systematic review was registered in PROSPERO with registration ID: CRD42023437714. MET mutations were detected in 7.6-11.0% of cases while MET gene amplification was observed in 3.9-22.0%. Six studies showed favorable treatment outcomes utilizing MET inhibitors compared to standard treatment or placebo, with increases in PFS and OS ranging from 0.9 to 12.4 and 7.2 to 24.2 months, respectively, and one study reporting an increase in ORR by 17.3%. Furthermore, patients with a higher mutational burden may derive greater benefit from treatment with MET tyrosine kinase inhibitors (TKIs) than those with a lower mutational burden. Conversely, two studies reported no beneficial effect from adjunctive treatment with a MET targeted therapy. Given these findings, there is an urgent need to identify effective therapeutic strategies specifically targeting the MET gene in lung cancer patients.

Therapeutical Options in ROS1-Rearranged Advanced Non Small Cell Lung Cancer

ROS proto-oncogene 1 (ROS1) rearrangements occur in 0.9-2.6% of patients with non small cell lung cancer (NSCLC), conferring sensitivity to treatment with specific tyrosine-kinase inhibitors (TKI). Crizotinib, a first-generation TKI, was the first target-therapy approved for the first-line treatment of ROS1-positive NSCLC. Recently, entrectinib, a multitarget inhibitor with an anti-ROS1 activity 40 times more potent than crizotinib and better activity on the central nervous system (CNS), received approval for treatment-naive patients. After a median time-to-progression of 5.5-20 months, resistance mechanisms can occur, leading to tumor progression. Therefore, newer generation TKI with greater potency and brain penetration have been developed and are currently under investigation. This review summarizes the current knowledge on clinicopathological characteristics of ROS1-positive NSCLC and its therapeutic options.

The Development and Role of Capmatinib in the Treatment of MET-Dysregulated Non-Small Cell Lung Cancer-A Narrative Review

Non-small cell lung cancer (NSCLC) is a leading cause of death, but over the past decade, there has been tremendous progress in the field with new targeted therapies. The mesenchymal-epithelial transition factor (MET) proto-oncogene has been implicated in multiple solid tumors, including NSCLC, and dysregulation in NSCLC from MET can present most notably as MET exon 14 skipping mutation and amplification. From this, MET tyrosine kinase inhibitors (TKIs) have been developed to treat this dysregulation despite challenges with efficacy and reliable biomarkers. Capmatinib is a Type Ib MET TKI first discovered in 2011 and was FDA approved in August 2022 for advanced NSCLC with MET exon 14 skipping mutation. In this narrative review, we discuss preclinical and early-phase studies that led to the GEOMETRY mono-1 study, which showed beneficial efficacy in MET exon 14 skipping mutations, leading to FDA approval of capmatinib along with Foundation One CDx assay as its companion diagnostic assay. Current and future directions of capmatinib are focused on improving the efficacy, overcoming the resistance of capmatinib, and finding approaches for new indications of capmatinib such as acquired MET amplification from epidermal growth factor receptor (EGFR) TKI resistance. Clinical trials now involve combination therapy with capmatinib, including amivantamab, trametinib, and immunotherapy. Furthermore, new drug agents, particularly antibody-drug conjugates, are being developed to help treat patients with acquired resistance from capmatinib and other TKIs.

The acid-sensing nociceptor TRPV1 controls breast cancer progression in bone via regulating HGF secretion from sensory neurons

Cancers showing excessive innervation of sensory neurons (SN) in their microenvironments are associated with poor outcomes due to promoted growth, increased tumor recurrence, metastasis, and cancer pain, suggesting SNs play a regulatory role in cancer aggressiveness. Using a preclinical model in which mouse 4T1 breast cancer (BC) cells were injected into the bone marrow of tibiae, we found 4T1 BC cells aggressively colonized bone with bone destruction and subsequently spread to the lung. Of note, 4T1 BC colonization induced the acidic tumor microenvironment in bone in which SNs showed increased innervation and excitation with elevated expression of the acid-sensing nociceptor transient receptor potential vanilloid-1 (TRPV1), eliciting bone pain (BP) assessed by mechanical hypersensitivity. Further, these excited SNs produced increased hepatocyte growth factor (HGF). Importantly, the administration of synthetic and natural TRPV1 antagonists and genetic deletion of TRPV1 decreased HGF production in SNs and inhibited 4T1 BC colonization in bone, pulmonary metastasis from bone, and BP induction. Our results suggest the TRPV1 of SNs promotes BC colonization in bone and lung metastasis via up-regulating HGF production in SNs. The SN TRPV1 may be a novel therapeutic target for BC growing in the acidic bone microenvironment and for BP.

Efficacy, safety and pharmacokinetics of Unecritinib (TQ-B3101) for patients with ROS1 positive advanced non-small cell lung cancer: a Phase I/II Trial

This phase I/II trial characterized the tolerability, safety, and antitumor activities of unecritinib, a novel derivative of crizotinib and a multi-tyrosine kinase inhibitor targeting ROS1, ALK, and c-MET, in advanced tumors and ROS1 inhibitor-naive advanced or metastatic non-small cell lung cancer (NSCLC) harboring ROS1 rearrangements. Eligible patients received unecritinib 100, 200, and 300 mg QD, and 200, 250, 300, and 350 mg BID in a 3 + 3 design during dose escalation and 300 and 350 mg BID during expansion. Phase II trial patients received unecritinib 300 mg BID in continuous 28-day cycles until disease progression or unacceptable toxicity. The primary endpoint was the objective response rate (ORR) per independent review committee (IRC). Key secondary endpoints included intracranial ORR and safety. The ORR of 36 efficacy evaluable patients in the phase I trial was 63.9% (95% CI 46.2%, 79.2%). In the phase II trial, 111 eligible patients in the main study cohort received unecritinib. The ORR per IRC was 80.2% (95% CI 71.5%, 87.1%) and the median progression-free survival (PFS) per IRC was 16.5 months (95% CI 10.2, 27.0). Additionally, 46.9% of the patients who received recommended phase II dose of 300 mg BID experienced grade 3 or higher treatment-related adverse events. Treatment-related ocular disorders and neurotoxicity occurred in 28.1% and 34.4% of patients, respectively, but none was grade 3 or higher. Unecritinib is efficacious and safe for ROS1 inhibitor-naive patients with ROS1-positive advanced NSCLC, particularly patients with brain metastases at baseline, strongly supporting that unecritinib should become one of the standards of care for ROS1-positive NSCLC.ClinicalTrials.gov identifier: NCT03019276 and NCT03972189.

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.

Real-world treatment patterns and survival of patients with ROS1 rearranged stage IV non-squamous NSCLC in the Netherlands

INTRODUCTION

Rearrangement of c-ros oncogene 1 (ROS1) is a rare gene alteration in patients with stage IV non-squamous non-small cell lung cancer (NSCLC). Molecular testing for ROS1 is recommended to enable primary treatment with tyrosine kinase inhibitors (TKI). Aim of this study was to describe real-world treatment patterns and survival for patients with ROS1 in the Netherlands.

METHODS

All non-squamous NSCLC stage IV patients, diagnosed 2015-2019, were identified from the population-based Netherlands Cancer Registry (N = 19,871). For patients with ROS1 rearrangements (ROS1+ ) who received first line TKI, additional information about progression and second-line treatment was retrieved by active follow-up. Overall survival (OS) and progression-free survival (PFS) were calculated using Kaplan-Meier estimators.

RESULTS

A total of 67 patients (0.43%) were diagnosed with a ROS1+ NSCLC. Systemic treatment was administered in 75% which was most often TKI (n = 34) followed by chemotherapy (n = 14). Two-year OS for patients receiving upfront TKI versus other systemic treatment was 53% (95% CI 35-68) and 50% (95% CI 25-71), respectively. For patients receiving TKI, median OS was 24.3 months. Survival was inferior in case of brain metastasis (BM) at diagnosis (5.2 months). One in five patients receiving TKI as a first line treatment had BM at diagnosis, of the remaining 22 another 9 developed BM during follow up. PFS was also inferior for patients with BM at diagnosis with a median PFS of 4.3 months versus 9.0 without BM.

CONCLUSION

In this real-world population of ROS1+ NSCLC patients, only half received primary treatment with TKI. Overall survival and PFS during TKI were disappointing, mainly related to brain metastasis. TKI treatment with agents that have intra-cranial activity may be beneficial in this patient population and our results confirm the importance of performing an MRI of the brain as part of the standard diagnostic work up in patients with ROS1+ NSCLC.

SYK-mediated epithelial cell state is associated with response to c-Met inhibitors in c-Met-overexpressing lung cancer

Genomic MET amplification and exon 14 skipping are currently clinically recognized biomarkers for stratifying subsets of non-small cell lung cancer (NSCLC) patients according to the predicted response to c-Met inhibitors (c-Metis), yet the overall clinical benefit of this strategy is quite limited. Notably, c-Met protein overexpression, which occurs in approximately 20-25% of NSCLC patients, has not yet been clearly defined as a clinically useful biomarker. An optimized strategy for accurately classifying patients with c-Met overexpression for decision-making regarding c-Meti treatment is lacking. Herein, we found that SYK regulates the plasticity of cells in an epithelial state and is associated with their sensitivity to c-Metis both in vitro and in vivo in PDX models with c-Met overexpression regardless of MET gene status. Furthermore, TGF-β1 treatment resulted in SYK transcriptional downregulation, increased Sp1-mediated transcription of FRA1, and restored the mesenchymal state, which conferred resistance to c-Metis. Clinically, a subpopulation of NSCLC patients with c-Met overexpression coupled with SYK overexpression exhibited a high response rate of 73.3% and longer progression-free survival with c-Meti treatment than other patients. SYK negativity coupled with TGF-β1 positivity conferred de novo and acquired resistance. In summary, SYK regulates cell plasticity toward a therapy-sensitive epithelial cell state. Furthermore, our findings showed that SYK overexpression can aid in precisely stratifying NSCLC patients with c-Met overexpression regardless of MET alterations and expand the population predicted to benefit from c-Met-targeted therapy.

Survival outcomes and prognostic factors of lung cancer patients with the MET exon 14 skipping mutation: A single-center real-world study

Introduction

The MET exon 14 skipping (METex14) mutation is an important oncogenic driver in lung cancer. We performed a retrospective analysis of clinical data from lung cancer patients with the METex14 mutation to analyze their survival outcomes and associated prognostic factors.

Methods

A one-step reverse transcription-polymerase chain reaction to examine the presence of the METex14 mutation was performed using RNA samples from 1374 lung cancer patients with no detected EGFR and ALK mutations. Pathological features and immunohistochemistry (IHC) results for c-MET were analyzed in patients with METex14-positive tumors.

Results

METex14 was identified in 69 patients with lung cancer, including 53 adenocarcinoma (ADC) and 16 non-ADC patients. In comparison with patients without the METex14 mutation, lung cancer patients harboring the METex14 mutation were generally elderly individuals, never-smokers, and had poor performance scores. A higher frequency of METex14 mutations was detected in pulmonary sarcomatoid carcinoma (PSC) patients (24.3%, n = 9/37). However, stage IV PSC patients with or without the METex14 mutations showed similarly poor overall survival (OS) (p = 0.429). For all 36 METex14-positive lung ADCs, multivariate analysis showed several poor prognostic factors, including strong c-MET IHC staining (p = 0.006), initial brain metastasis (p = 0.005), and administration of only supportive care (p &lt; 0.001). After excluding seven patients who received only supportive care, we further analyzed 29 stage IV lung ADC patients with METex14 mutations who received anti-cancer treatment. Multivariate analysis showed that pemetrexed treatment (p = 0.003), lung radiotherapy (p = 0.020), initial brain metastasis (p = 0.005), and strong c-MET IHC staining (p = 0.012) were independent prognostic factors for OS in these patients.

Conclusions

A higher frequency of METex14 mutations was detected in PSC patients. Stage IV PSC patients with or without the METex14 mutations had similarly poor overall survival. Pemetrexed-based chemotherapy, strong c-MET ICH staining, initial brain metastasis, and lung radiotherapy, may help predict survival outcomes in patients with advanced lung ADCs harboring the METex14 mutation.

Crizotinib efficacy and safety in patients with advanced NSCLC harboring MET alterations: A real-life data of Turkish Oncology Group

Crizotinib is a multikinase inhibitor, effective in non-small cell lung cancer (NSCLC) harboring mesenchymal-epidermal transition (MET) alterations. Although small prospective studies showed efficacy and safety of crizotinib in NSCLC with MET alterations, there is limited real-life data. Aim of this study is to investigate real-life efficacy and safety of crizotinib in patients with advanced NSCLC harboring MET alterations. This was a retrospective, multicenter (17 centers) study of Turkish Oncology Group. Patients' demographic, histological data, treatment, response rates, survival outcomes, and toxicity data were collected. Outcomes were presented for the study population and compared between MET alteration types. Total of 62 patients were included with a median age of 58.5 (range, 26-78). Major histological type was adenocarcinoma, and 3 patients (4.8%) had sarcomatoid component. The most common MET analyzing method was next generation sequencing (90.3%). MET amplification and mutation frequencies were 53.2% (n = 33) and 46.8% (n = 29), respectively. Overall response rate and disease control rate were 56.5% and 74.2% in whole study population, respectively. Median progression free survival (PFS) was 7.2 months (95% confidence interval [CI]: 3.8-10.5), and median overall survival (OS) was 18.7 months (95% CI: 13.7-23.7), regardless of treatment line. Median PFS was 6.1 months (95% CI: 5.6-6.4) for patients with MET amplification, whereas 14.3 months (95% CI: 6.7-21.7) for patients with MET mutation (P = .217). Median PFS was significantly longer in patients who have never smoked (P = .040), have good performance score (P < .001), and responded to the treatment (P < .001). OS was significantly longer in patients with MET mutation (25.6 months, 95% CI: 15.9-35.3) compared to the patients with MET amplification (11.0 months; 95% CI: 5.2-16.8) (P = .049). In never-smokers, median OS was longer than smoker patients (25.6 months [95% CI: 11.8-39.3] vs 16.5 months [95% CI: 9.3-23.6]; P = .049). The most common adverse effects were fatigue (50%), peripheral edema (21%), nausea (29%) and diarrhea (19.4%). Grade 3 or 4 adverse effects were observed in 6.5% of the patients. This real-life data confirms efficacy and safety of crizotinib in the treatment of advanced NSCLC harboring MET alteration.

Management and Treatment of Non-small Cell Lung Cancer with MET Alteration and Mechanisms of Resistance

OPINION STATEMENT

MET-driven tumors are a heterogenous group of non-small cell lung cancers (NSCLC) with activating mutations. Pathologic activation of MET can be achieved with increased number of gene copies overexpression, or decreased protein degradation through several mechanisms, including mutations, amplifications, or fusions. Besides its role as primary driver, MET activation might also mediate resistance to kinase inhibitors in NSCLC with various other actionable alterations. While checkpoint inhibitors have modest efficacy in MET-driven tumors, several approaches of targeted blockade are available. Among them the most promising are small tyrosine kinase inhibitors, antibody-drug conjugates, and bispecific antibodies. Unfortunately, resistance is virtually inevitable. Resistance to small kinase inhibitors might be mediated by kinase domain mutations or activation of shunting cascades. Various resistance mechanisms might be present in one patient, making it overcoming an unresolved problem.

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.

Meeting an un-MET need: Targeting MET in non-small cell lung cancer

The MET pathway can be activated by MET exon 14 skipping mutations, gene amplification, or overexpression. Mutations within this pathway carry a poor prognosis for patients with non-small cell lung cancer (NSCLC). MET exon 14 skipping mutations occur in 3-4% of patients with NSCLC, while MET amplifications are found in 1-6% of patients. The most effective method for detection of MET amplification is fluorescent in situ hybridization (FISH) and of MET exon 14 skipping mutations is RNA-based next generation sequencing (NGS). Immunohistochemistry (IHC) is an alternative method of diagnosis but is not as reliable. Early studies of MET tyrosine kinase inhibitors (TKIs) demonstrated limited clinical benefit. However, newer selective MET TKIs, such as capmatinib and tepotinib, have improved efficacy. Both drugs have an acceptable safety profile with the most common treatment-related adverse event being peripheral edema. One of the most frequent resistance mechanisms to EGFR inhibition with osimertinib is MET amplification. There is interest in combining EGFR inhibition plus MET inhibition in an attempt to target this resistance mechanism. Additional ways of targeting MET alterations are currently under investigation, including the bi-specific antibody amivantamab. Additional research is needed to further understand resistance mechanisms to MET inhibition. There is limited research into the efficacy of immune checkpoint inhibition for MET-altered NSCLC, though some data suggests decreased efficacy compared with wild-type patients and increased toxicity associated with the combination of immunotherapy and MET TKIs. Future directions for research will include combination clinical trials and understanding rational combinations for MET alterations.

Molecular Characteristics of Radon Associated Lung Cancer Highlights MET Alterations

Simple Summary

Lung cancer (LC) is the leading cause of cancer death worldwide. After smoking, one of the most prominent risk factors for LC development is radon (Rn) exposure. In our study we analysed and compared the genetic landscape of LC patients from a Rn exposed village with local matched non-exposed patients. Within the concordant genetic landscape, an increase in genetic MET proto-oncogene, receptor tyrosine kinase (MET) alteration in the Rn-exposed cohort was monitored, underlining the importance of routine MET testing and potential to enable a more effective treatment for this specific subgroup.

Abstract

Effective targeted treatment strategies resulted from molecular profiling of lung cancer with distinct prevalent mutation profiles in smokers and non-smokers. Although Rn is the second most important risk factor, data for Rn-dependent driver events are limited. Therefore, a Rn-exposed cohort of lung cancer patients was screened for oncogenic drivers and their survival and genetic profiles were compared with data of the average regional population. Genetic alterations were analysed in 20 Rn-exposed and 22 histologically matched non-Rn exposed LC patients using targeted Next generation sequencing (NGS) and Fluorescence In Situ Hybridization (FISH). Sufficient material and sample quality could be obtained in 14/27 non-exposed versus 17/22 Rn-exposed LC samples. Survival was analysed in comparison to a histologically and stage-matched regional non-exposed lung cancer cohort (n = 51) for hypothesis generating. Median overall survivals were 83.02 months in the Rn-exposed and 38.7 months in the non-exposed lung cancer cohort (p = 0.22). Genetic alterations of both patient cohorts were in high concordance, except for an increase in MET alterations and a decrease in TP53 mutations in the Rn-exposed patients in this small hypothesis generating study.

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.

Management of Peripheral Edema in Patients with MET Exon 14-Mutated Non-small Cell Lung Cancer Treated with Small Molecule MET Inhibitors

Small molecule mesenchymal-epithelial transition (MET) inhibitors, such as crizotinib, capmatinib, and tepotinib, are treatment options for metastatic non-small cell lung cancer (NSCLC) in adult patients whose tumors have a mutation that leads to MET exon 14 skipping. In clinical trials, these MET inhibitors were associated with a high incidence of peripheral edema, although this was generally mild-to-moderate in severity. There is limited information about the mechanism involved in MET inhibitor-induced peripheral edema. Perturbation of hepatocyte growth factor (HGF)/MET signaling may disrupt the permeability balance in the vascular endothelium and thus promote edema development. Another potential mechanism is through effects on renal function, although this is unlikely to be the primary mechanism. Because edema is common in cancer patients and may not necessarily be caused by the cancer treatment, or other conditions that have similar symptoms to peripheral edema, a thorough assessment is required to ascertain the underlying cause. Before starting MET-inhibitor therapy, patients should be educated about the possibility of developing peripheral edema. Patient limb volume should be measured before initiating treatment, to aid assessment if symptoms develop. Since the exact mechanism of MET inhibitor-induced edema is unknown, management is empiric, with common approaches including compression stockings, specific exercises, massage, limb elevation, and/or diuretic treatment. Although not usually required, discontinuation of MET inhibitor treatment generally resolves peripheral edema. Early diagnosis and management, as well as patient information and education, are vital to decrease the clinical burden associated with edema, and to reinforce capmatinib treatment adherence.

Liquid biopsy and non-small cell lung cancer: are we looking at the tip of the iceberg?

The possibility to analyse the tumour genetic material shed in the blood is undoubtedly one of the main achievements of translational research in the latest years. In the modern clinical management of advanced non-small cell lung cancer, molecular characterisation plays an essential role. In parallel, immunotherapy is widely employed, but reliable predictive markers are not available yet. Liquid biopsy has the potential to face the two issues and to increase its role in advanced NSCLC in the next future. The aim of this review is to summarise the main clinical applications of liquid biopsy in advanced non-small cell lung cancer, underlining both its potential and limitations from a clinically driven perspective.

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.

A lung adenocarcinoma patient with co-mutations of MET and EGFR exon20 insertion responded to crizotinib

Background

Targeted therapy has revolutionized the treatment of patients with malignancies harboring mutations in driver genes and has brought a favorable survival benefit to the population with actionable oncogenic mutations. In recent years, the MET exon14 skipping mutation has been recognized as a potentially promising therapeutic target in non-small cell lung cancer (NSCLC). These changes are mutually exclusive with molecular drivers such as EGFR, KRAS, HER-2, BRAF, ALK and ROS1. The prevalence rate of coexisting MET exon 14 mutations and EGFR sensitive mutations (L858R, exon 19 deletions) in Chinese population was reported to be 0.2% (3/1590). However, the coexistence of MET exon 14 mutations with EGFR exon 20 insertion mutations has never been reported and the management of this subtype is not identified.

Case presentation

A 69-year-old male with a right lung adenocarcinoma (T4N2M0, IIIB) was confirmed to be positive for MET exon 14 skipping (c.3028_3028+1delGGinsTT, 44.4%), MET amplification (copy number 4.4), and EGFR exon 20 insertion (p. N771_H773dup, 22.1%) mutations. After the progression of one cycle of chemotherapy (Pemetrexed 0.8 g d1), the patient was subsequently accepted treatment with Crizotinib (250 mg twice a day) and achieved an important clinical remission for six months until the development of brain metastases. Then, he was submitted to a cycle of anti-programmed cell death-1 (PD-1) therapy after failure of Crizotinib and eventually acquired resistance despite of the high expression of programmed death ligand-1 (PD-L1) and tumor mutational burden (TMB) status.

Conclusion

This case report provides treatment strategies for epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs)-untreated lung adenocarcinoma patients simultaneously carrying MET alterations and EGFR exon 20 insertion mutations. In addition, the signatures of PD-L1 or TMB expression were not the candidate for predicting the efficacy of immunotherapy in this context.

NSCLC as the Paradigm of Precision Medicine at Its Finest: The Rise of New Druggable Molecular Targets for Advanced Disease

Standard treatment for advanced non-small cell lung cancer (NSCLC) historically consisted of systemic cytotoxic chemotherapy until the early 2000s, when precision medicine led to a revolutionary change in the therapeutic scenario. The identification of oncogenic driver mutations in EGFR, ALK and ROS1 rearrangements identified a subset of patients who largely benefit from targeted agents. However, since the proportion of patients with druggable alterations represents a minority, the discovery of new potential driver mutations is still an urgent clinical need. We provide a comprehensive review of the emerging molecular targets in NSCLC and their applications in the advanced setting.

ROS1-positive non-small cell lung cancer (NSCLC): Biology, Diagnostics, Therapeutics and Resistance

ROS1 is a proto-oncogene encoding a receptor tyrosine protein kinase (RTK), homologous to the v - Ros sequence of University of Manchester tumours virus 2(UR2) sarcoma virus, whose ligands are still being investigated. ROS1 fusion genes have been identified in various types of tumours. As an oncoprotein, it promotes cell proliferation, activation and cell cycle progression by activating downstream signalling pathways, accelerating the development and progression of non-small cell lung cancer (NSCLC). Studies have demonstrated that ROS1 inhibitors are effective in patients with ROS1-positive NSCLC and are used for first-line clinical treatment. These small molecule inhibitors provide a rational therapeutic option for the treatment of ROS1-positive patients. Inevitably, ROS1 inhibitor resistance mutations occur, leading to tumours recurrence or progression. Here, we comprehensively review the identified biological properties and Differential subcellular localization of ROS1 fusion oncoprotein promotes tumours progression. We summarize recently completed and ongoing clinical trials of the classic and new ROS1 inhibitors. More importantly, we classify the complex evolving tumours cell resistance mechanisms. This review contributes to our understanding of the biological properties of ROS1 and current therapeutic advances and resistant tumours cells, and the future directions to develop ROS1 inhibitors with durable effects.

Complete and durable response to crizotinib in a patient with malignant pleural mesothelioma harboring CD74-ROS1 fusion

Malignant pleural mesothelioma (MPM) is a rare and deadly malignancy with an extremely poor prognosis. The median overall survival (OS) of this disease is 12-18 months. However, the oncogenic driver mutations of MPM are rarely understood, and the targeted therapy for it is still under investigation. In this report, we describe a case of MPM with CD74-ROS1 fusion who obtains complete and durable response after receiving crizotinib. By the time of submission, the progression-free survival (PFS) with crizotinib has been 6.0 years, and the patient has survived for 7.6 years. Currently, he is still in complete remission (CR). To the best of our knowledge, this case represents the first report of CD74-ROS1 fusion identified in MPM. Meanwhile, it is also the first report of complete and long-term response to crizotinib in a patient with MPM positive for CD74-ROS1 fusion. This case report might contribute to the tumorigenesis and targeted therapy of this deadly disease.

MET∆14 promotes a ligand-dependent, AKT-driven invasive growth

MET is an oncogene encoding the tyrosine kinase receptor for hepatocyte growth factor (HGF). Upon ligand binding, MET activates multiple signal transducers, including PI3K/AKT, STAT3, and MAPK. When mutated or amplified, MET becomes a "driver" for the onset and progression of cancer. The most frequent mutations in the MET gene affect the splicing sites of exon 14, leading to the deletion of the receptor's juxtamembrane domain (MET∆14). It is currently believed that, as in gene amplification, MET∆14 kinase is constitutively active. Our analysis of MET in carcinoma cell lines showed that MET∆14 strictly depends on HGF for kinase activation. Compared with wt MET, ∆14 is sensitive to lower HGF concentrations, with more sustained kinase response. Using three different models, we have demonstrated that MET∆14 activation leads to robust phosphorylation of AKT, leading to a distinctive transcriptomic signature. Functional studies revealed that ∆14 activation is predominantly responsible for enhanced protection from apoptosis and cellular migration. Thus, the unique HGF-dependent ∆14 oncogenic activity suggests consideration of HGF in the tumour microenvironment to select patients for clinical trials.

Detection of MET amplification by droplet digital PCR in peripheral blood samples of non-small cell lung cancer

PURPOSE

Mesenchymal-epithelial transition (MET) amplification is one of the mechanisms accounting for the resistance of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in lung cancer patients, as well as the poor prognosis. Fluorescence in situ hybridization (FISH) is the most widely used method for MET amplification detection. However, it is inapplicable when tissue samples were unavailable. Herein, we assessed the value of droplet digital PCR (ddPCR) in MET copy number gain (CNG) detection in non-small cell lung cancer (NSCLC) patients treated with EGFR-TKIs.

MATERIALS AND METHODS

A total of 103 cancer tissues and the paired peripheral blood samples from NSCLC patients were collected for MET CNG detection using ddPCR. In parallel, MET amplification in tissue samples was verified by FISH. Also, the relationships between MET CNG and EGFR T790M, as well as the EGFR-TKI resistance were also evaluated using Chi-square or Fisher's exact tests.

RESULT

The concordance rate of ddPCR and FISH in detecting MET CNG in tissue samples was 100% (102/102), and it was 94.17% (97/103) for ddPCR method in detecting the MET CNG among peripheral blood and tissue samples. No statistical difference was observed between MET amplification and EGFR T790M (p = 0.65), while MET amplification rate was significantly increased in patients with resistance to third generations of EGFR-TKIs as compared with patients with resistance to first/second EGFR-TKIs (p < 0.05).

CONCLUSIONS

ddPCR is an alternative method to detect MET CNG in both tissues and peripheral blood samples, which is of worthy in clinical promotion.

Emerging Systemic Treatment Perspectives on Brain Metastases: Moving Toward a Better Outlook for Patients

The diagnosis of brain metastases has historically been a dreaded, end-stage complication of systemic disease. Additionally, with the increasing effectiveness of systemic therapies that prolong life expectancy and improved imaging tools, the incidence of intracranial progression is becoming more common. Within this context, there has been increasing attention directed at understanding the molecular underpinnings of intracranial progression. Exploring the unique features of brain metastases compared with their extracranial counterparts to identify aberrant signaling pathways, which can be targeted pharmacologically, may help lead to new treatments for this patient population. Additionally, critical discoveries outside the sphere of the central nervous system are increasingly being applied to brain metastases with the emergence of immune checkpoint inhibition, becoming a prevalent treatment option for patients with brain metastases across multiple histologies. As novel treatment strategies are considered, they require thoughtful incorporation of agents that can cross the blood-brain barrier and can synergize with pre-existing agents through rational combinations. Lastly, as clinicians and scientists continue to understand key molecular features of these tumors, they will continue to influence the treatment algorithms that are developing for the management of these patients. Due to the complexity of treatment decisions for patients with brain metastases, an emerging tool is the utilization of multidisciplinary brain metastasis tumor boards to ensure optimal treatment decisions are made and that patients are provided access to applicable clinical trials. Looking to the future, the collective effort to understand the various tumor-intrinsic and tumor-extrinsic factors that promote central nervous system seeding and propagation will have the potential to change the clinical trajectory for these patients.

Biomarker guided treatment in oncogene-driven advanced non-small cell lung cancer in older adults: A Young International Society of Geriatric Oncology Report

Lung cancer remains the leading cause of cancer-related deaths worldwide, with most patients diagnosed at an advanced age. The treatment of non-small cell lung cancer (NSCLC) has been revolutionized with the introduction of molecular guided therapy. Despites the challenges when considering treatment of older adults, they are still systematically underrepresented in registrational trials. This review aims to summarize the existing evidence on treatment of older patients with lung cancer with a targetable driver mutation or alteration (EGFR, ALK, ROS, BRAF^V600E, MET, RET, KRAS^G12C and NTRK), and consider the evidence from a geriatric oncology perspective. Early generation EGFR-tyrosine kinase inhibitors (TKIs). TKIs are fairly well-studied in older adults and have been shown to be safe and efficient. However, older adult-specific data regarding the standard-of-care first-line agent osimertinib are lacking. Erlotinib, dacomitinib, and afatinib may be more toxic than other EGFR-TKIs. Next generation ALK-TKIs are preferred over crizotinib due to increased efficacy, as demonstrated in phase III trials. Alectinib seems to be safer than crizotinib, while brigatinib is associated with increased toxicity. Lorlatinib overcomes most resistance mutations, but data regarding this agent have only recently emerged. Regarding ROS1-fusion positive NSCLC, crizotinib is an option in older adults, while entrectinib is similarly effective but shows increased neurotoxicity. In BRAF^V600E-mutant NSCLC, the combination darbafenib/tramectinib is effective, but no safety data for older adults exist. MET alterations can be targeted with capmatinib and tepotinib, and registrational trials included primarily older patients, due to the association of this alteration with advanced age. For RET-rearranged-NSCLC selpercatinib and pralsetinib are approved, and no differences in safety or efficacy between older and younger patients were shown. KRAS^G12C mutations, which are more frequent in older adults, became recently druggable with sotorasib, and advanced age does not seem to affect safety or efficacy. In NTRK-fusion positive tumors, larotrectinib and entrectinib have tumor agnostic approval, however, not enough data on older patients are available. Based on currently available data, molecularly-guided therapy for most alterations is safe and efficacious in older adults with oncogene-driven advanced NSCLC. However, for many TKIs, older adult-specific data are lacking, and should be subject of future prospective evaluations.

Companion Diagnostics and Predictive Biomarkers for MET-Targeted Therapy in NSCLC

Simple Summary

MET is a receptor tyrosine kinase encoded by the MET proto-oncogene that has a significant role in cancer cell progression. Several drugs targeting MET are under development for the treatment of different cancers, including non-small-cell lung cancer (NSCLC). However, until now, relatively few of these drugs have shown sufficient clinical activity and obtained regulatory approval. One of the reasons for this could be the lack of effective biomarkers to select the right patients for treatment. In a number of clinical trials, different biomarkers have been studied, but so far, MET exon 14 skipping mutation is the only one that has shown sufficient predictive properties. Another interesting biomarker is MET amplification detected by fluorescence in situ hybridization (FISH), which has shown promising results in the treatment of patients with NSCLC. Future clinical research will show whether MET amplification by FISH is an effective predictive biomarker for MET-targeted therapy.

Abstract

Dysregulation of the MET tyrosine kinase receptor is a known oncogenic driver, and multiple genetic alterations can lead to a clinically relevant oncogenesis. Currently, a number of drugs targeting MET are under development as potential therapeutics for different cancer indications, including non-small cell lung cancer (NSCLC). However, relatively few of these drugs have shown sufficient clinical activity and obtained regulatory approval. One of the reasons for this could be the lack of effective predictive biomarkers to select the right patient populations for treatment. So far, capmatinib is the only MET-targeted drug approved with a companion diagnostic (CDx) assay, which is indicated for the treatment of metastatic NSCLC in patients having a mutation resulting in MET exon 14 skipping. An alternative predictive biomarker for MET therapy is MET amplification, which has been identified as a resistance mechanism in patients with EGFR-mutated NSCLC. Results obtained from different clinical trials seem to indicate that the MET/CEP7 ratio detected by FISH possesses the best predictive properties, likely because this method excludes MET amplification caused by polysomy. In this article, the concept of CDx assays will be discussed, with a focus on the currently FDA-approved MET targeted therapies for the treatment of NSCLC.

The Relationship Between Short-Term Surrogate Endpoint Indicators and mPFS and mOS in Clinical Trials of Malignant Tumors: A Case Study of Approved Molecular Targeted Drugs for Non-Small-Cell Lung Cancer in China

Objective: Due to the initiation of the priority review program in China, many antitumor drugs have been approved for marketing based on phase II clinical trials and short-term surrogate endpoint indicators. This study used approved targeted drugs for the treatment of non-small-cell lung cancer (NSCLC) in China as an example to evaluate the association between short-term surrogate endpoints [objective response rate (ORR) and disease control rate (DCR)] and median progression-free survival (mPFS) and median overall survival (mOS).

Methods: Five databases, i.e., MEDLINE, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched, for phase II or phase III clinical trials of all molecular targeted drugs that have been marketed in China for the treatment of NSCLC. After screening the literature and extracting information, both univariate and multivariate linear regression were performed on the short-term surrogate indicators and mPFS and mOS to explore the relationship.

Results: A total of 63 studies were included (25 studies with only ORR, DCR, and mPFS and 39 studies with ORR, DCR, mPFS, and mOS). In terms of the targeted drugs for the treatment of NSCLC, in addition to the good but not excellent linear relationship between DCR and mOS (0.4 < R²_adj = 0.5653 < 0.6), all other short-term surrogate endpoint indicators had excellent linear relationships with mPFS and mOS (R²_adj≥0.6), while mPFS and mOS had the most excellent linear relationships (R²_adj = 0.8036).

Conclusion: For targeted drugs for the treatment of NSCLC, short-term surrogate endpoint indicators such as ORR and DCR may be reliable surrogate indicators for mPFS and mOS. However, whether short-term surrogate endpoint indicators can be used to predict final endpoints remains to be verified.