Safety of MET Tyrosine Kinase Inhibitors in Patients with MET Exon 14 Skipping Non-small Cell Lung Cancer: A Clinical Review

Uncommon MET mutational landscape in a non-small cell lung cancer patient treated with crizotinib: Case report

Background

MET exon 14 (METex14) skipping mutations are oncogenic drivers observed in approximately 3-4% of non-small cell lung cancers (NSCLC). Several distinct genetic alterations leading to METex14 have been reported but clinical significances of rare mutations are not well defined as well as outcomes of patients upon MET inhibitors (METi).

Case presentation

This report presents the case of a patient with metastatic NSCLC harboring an uncommon MET mutational landscape including notably a novel METex14 mutation (R1022L). Dramatic but transient efficacy was observed under crizotinib, due to early occurrence of acquired both on- and off-target mechanisms of resistance such as MET D1246H mutation and wild-type KRAS amplification.

Conclusion

Our case provides additional data on MET rare oncogenic variants and their sensitivity to METi. Systematic assessment of post-tyrosine kinase inhibitor tumor sample remains critical to identify on- and off-target mechanisms that may represent therapeutically targetable drivers in resistant patients.

MET exon 14 skipping mutation drives cancer progression and recurrence via activation of SMAD2 signalling

BACKGROUND

c-Met encoded by the proto-oncogene MET, also known as hepatocyte growth factor (HGF) receptor, plays a crucial role in cellular processes. MET exon 14 skipping alteration (METΔ14EX) is a newly discovered MET mutation. SMAD2 is an important downstream transcription factor in TGF-β pathway. Unfortunately, the mechanisms by which METΔ14EX leads to oncogenic transformation are scarcely understood. The relationship between METΔ14EX and SMAD2 has not been studied yet.

METHODS

We generate METΔ14EX models by CRISPR-Cas9. In vitro transwell, wound-healing, soft-agar assay, in vivo metastasis and subcutaneous recurrence assay were used to study the role of METΔ14EX in tumour progression. RNA-seq, Western blotting, co-immunoprecipitation (CO-IP) and immunofluorescent were performed to explore the interaction between c-Met and SMAD2.

RESULTS

Our results demonstrated that METΔ14EX, independent of HGF, can prolong the constitutive activation of c-Met downstream signalling pathways by impeding c-Met degradation and facilitating tumour metastasis and recurrence. Meanwhile, METΔ14EX strengthens the interaction between c-Met and SMAD2, promoting SMAD2 phosphorylation. Therapeutically, MET inhibitor crizotinib impedes METΔ14EX-mediated tumour metastasis by decreasing SMAD2 phosphorylation.

CONCLUSIONS

These data elucidated the previously unrecognised role of METΔ14EX in cancer progression via activation of SMAD2 independent of TGF-β, which helps to develop more effective therapies for such patients. METΔ14EX alteration significantly triggers tumour progression via activation of SMAD2 signalling that are involved in activating tumour invasion, metastasis and recurrence. On the left, in the MET wild-type (METWT), the juxtamembrane (JM) domain is involved in the regulation of tyrosine kinase activity, receptor degradation, and caspase cleavage. On the right, the METΔ14EX mutation leads to the loss of the juxtamembrane domain, resulting in an abnormal MET protein lacking a CBL-binding site. This causes the accumulation of truncated MET receptors followed by constitutive activation of the MET signalling pathway. Thus, the METΔ14EX-mutated protein has strong binding and phosphorylation to SMAD2, which results in the phosphorylation of a large number of SMAD2/3 proteins that combine with SMAD4 to form a complex in the nucleus, activating downstream signalling pathways, such as EMT and ECM remodelling, resulting in tumour progression and recurrence. TF transcription factor.

Profile of Capmatinib for the Treatment of Metastatic Non-Small Cell Lung Cancer (NSCLC): Patient Selection and Perspectives

Aberrant c-MET (Mesenchymal-Epithelial Transition) signaling contributes to cancer cell development, proliferation, and metastases of non-small cell lung cancer (NSCLC). MET exon 14 (METex14) skipping mutation is noted in approximately 4% of NSCLC cases and is targetable with the recently approved tyrosine kinase inhibitors capmatinib and tepotinib. Capmatinib, the focus of this review article, is a highly selective MET inhibitor approved for use in patients with METex14 mutated NSCLC. In this review, we discuss cMET as a target, the pharmacology of capmatinib, key trials of capmatinib in MET-altered lung cancer, and toxicity profile. We highlight some ongoing capmatinib clinical trials that expand their role to other subsets of patients, especially those with EGFR mutations, who develop MET alterations as a resistance pathway. We further provide our perspective on the management of METex14 NSCLC, strategies for sequencing agents, and toxicity management.

Neoadjuvant Targeted Therapy in Resectable NSCLC: Current and Future Perspectives

The standard of care (SoC) for medically operable patients with early-stage (stages I-IIIB) NSCLC is surgery combined with (neo)adjuvant systemic therapy for patients with stages II to IIIB disease and some stage IB or, rarely, chemoradiation (stage III disease with mediastinal lymph node metastases). Despite these treatments, metastatic recurrence is common and associated with poor survival, highlighting the need for systemic therapies that are more effective than the current SoC. After the success of targeted therapy (TT) in patients with advanced NSCLC harboring oncogenic drivers, these agents are being investigated for the perioperative (neoadjuvant and adjuvant) treatment of patients with early-stage NSCLC. Adjuvant osimertinib is the only TT approved for use in the early-stage setting, and there are no approved neoadjuvant TTs. We discuss the importance of comprehensive biomarker testing at diagnosis to identify individuals who may benefit from neoadjuvant targeted treatments and review emerging data from neoadjuvant TT trials. We also address the potential challenges for establishing neoadjuvant TTs as SoC in the early-stage setting, including the identification and validation of early response markers to guide care and accelerate drug development, and discuss safety considerations in the perioperative setting. Initial data indicate that neoadjuvant TTs are effective and well tolerated in patients with EGFR- or ALK-positive early-stage NSCLC. Data from ongoing trials will determine whether neoadjuvant targeted agents will become a new SoC for individuals with oncogene-addicted resectable NSCLC.

Savolitinib: A Promising Targeting Agent for Cancer

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

Capmatinib-Induced Liver Injury as Emerging Toxicity of MET Inhibitors in Patients With NSCLC Pretreated With Immune Checkpoint Inhibitors

Safety data on MET inhibitors in patients with advanced NSCLC harboring MET exon 14 mutation and treated with frontline immune checkpoint inhibitors (ICIs) are still limited. Here, we describe clinical characteristics, liver biopsy features, and management of liver injury of two patients with a diagnosis of MET exon 14-mutant NSCLC receiving capmatinib after ICI failure. On the basis of histologic findings and exclusion of other potential causes, a diagnosis of drug-induced liver injury (DILI) associated with portal fibrosis was made in both cases. The use of hepatoprotective drugs, in addition to oral ursodeoxycholic acid, resulted in liver blood tests normalization. To provide a global safety perspective, we queried the Food and Drug Administration Adverse Event Reporting System and detected a robust disproportionality signal. Out of the 918 total reports with capmatinib from the Food and Drug Administration Adverse Event Reporting System database, DILI was recorded in 43 cases (4.7%), mostly serious (93.0%) with hospitalization and death recorded in 25.6% and 16.3% of the cases, respectively. The median time to onset was 42 days, with discontinuation and positive dechallenge documented in 41.9% and 39.5% of the cases, respectively. Anti-programmed cell death protein-1 agents were coreported in 11 DILI cases. Only two cases of DILI out of 105 reports were found for tepotinib. Our data support a potential association between capmatinib and DILI in patients who have also been previously exposed to immunotherapy. Considering the potential implications for sequence strategy and timing of ICI and MET inhibitor, further investigation is warranted.

MET Exon 14 Skipping in NSCLC: A Systematic Literature Review of Epidemiology, Clinical Characteristics, and Outcomes

INTRODUCTION

MET exon 14 (METex14) skipping is a rare oncogenic driver in non-small-cell lung cancer (NSCLC) for which targeted therapy with MET tyrosine kinase inhibitors (TKIs) was recently approved. Given the heterogeneity in published data of METex14 skipping NSCLC, we conducted a systematic literature review to evaluate its frequency, patient characteristics, and outcomes.

METHODS

On June 13, 2022 we conducted a systematic literature review of publications and conference abstracts reporting frequency, patient characteristics, or outcomes of patients with METex14 skipping NSCLC.

RESULTS

We included 139 studies reporting frequency or patient characteristics (350,997 patients), and 39 studies reporting clinical outcomes (3989 patients). Median METex14 skipping frequency was 2.0% in unselected patients with NSCLC, with minimal geographic variation. Median frequency was 2.4% in adenocarcinoma or nonsquamous subgroups, 12.0% in sarcomatoid, and 1.3% in squamous histology. Patients with METex14 skipping NSCLC were more likely to be elderly, have adenocarcinoma histology; there was no marked sex or smoking status distribution. In first line of treatment, median objective response rate ranged from 50.7% to 68.8% with targeted therapies (both values correspond to MET TKIs), was 33.3% with immunotherapy, and ranged from 23.1% to 27.0% with chemotherapy.

CONCLUSIONS

Patients with METex14 skipping are more likely to have certain characteristics, but no patient subgroup can be ruled out; thus, it is crucial to test all patients with NSCLC to identify suitable candidates for MET inhibitor therapy. MET TKIs appeared to result in higher efficacy outcomes, although no direct comparison with chemotherapy or immunotherapy regimens was found.

The Preclinical Pharmacology of Tepotinib-A Highly Selective MET Inhibitor with Activity in Tumors Harboring MET Alterations

The mesenchymal-epithelial transition factor (MET) proto-oncogene encodes the MET receptor tyrosine kinase. MET aberrations drive tumorigenesis in several cancer types through a variety of molecular mechanisms, including MET mutations, gene amplification, rearrangement, and overexpression. Therefore, MET is a therapeutic target and the selective type Ib MET inhibitor, tepotinib, was designed to potently inhibit MET kinase activity. In vitro, tepotinib inhibits MET in a concentration-dependent manner irrespective of the mode of MET activation, and in vivo, tepotinib exhibits marked, dose-dependent antitumor activity in MET-dependent tumor models of various cancer indications. Tepotinib penetrates the blood-brain barrier and demonstrates strong antitumor activity in subcutaneous and orthotopic brain metastasis models, in-line with clinical activity observed in patients. MET amplification is an established mechanism of resistance to EGFR tyrosine kinase inhibitors (TKI), and preclinical studies show that tepotinib in combination with EGFR TKIs can overcome this resistance. Tepotinib is currently approved for the treatment of adult patients with advanced or metastatic non-small cell lung cancer harboring MET exon 14 skipping alterations. This review focuses on the pharmacology of tepotinib in preclinical cancer models harboring MET alterations and demonstrates that strong adherence to the principles of the Pharmacological Audit Trail may result in a successful discovery and development of a precision medicine.

Consensus Recommendations for the Diagnosis, Biomarker Testing, and Clinical Management of Advanced or Metastatic Non-small Cell Lung Cancer With Mesenchymal-Epithelial Transition Exon 14 Skipping Mutations in the Middle East, Africa, and Russia

Mesenchymal-epithelial transition exon 14 (METex14) skipping mutations occur in about 3%-4% of patients with non-small cell lung cancer (NSCLC). This is an aggressive subtype associated with poor prognosis. METex14 skipping is a potentially targetable mutation. Targeted therapy is a promising treatment modality for patients with advanced/metastatic METex14-mutant NSCLC. Performing systematic molecular testing to detect the driver mutation is essential for initiating targeted therapy. However, there is a lack of guidelines on molecular testing for assessing the eligibility of patients for targeted therapy. Therefore, a multidisciplinary panel consisting of experts from the Middle East, Africa, and Russia convened via a virtual advisory board meeting to provide their insights on various molecular testing techniques for the diagnosis of METex14 skipping mutation, management of patients with targeted therapies, and developing consensus recommendations for improving the processes. The expert panel emphasized performing molecular testing and liquid biopsy before treatment initiation and tissue re-biopsy for patients with failed molecular testing. Liquid biopsy was recommended as complementary to tissue biopsy for disease monitoring and prognosis. Selective MET inhibitors were recommended as the first and subsequent lines of therapy. These consensus recommendations will facilitate the management of METex14 skipping NSCLC in routine practice and warrant optimum outcomes for these patients.

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 Outcomes of MET Exon14 Skipping in Non-small Cell Lung Cancer: GFPC 03-18 Study

BACKGROUND

MET-targeted tyrosine kinase inhibitors (TKIs) demonstrated efficacy in advanced non-small cell lung cancer (aNSCLC) with MET exon14 skipping mutations (METexon14); yet, data on the management of these patients in clinical practice is sparse.

OBJECTIVE

The aim of this study was to describe the management of METexon14 aNSCLC patients.

PATIENTS AND METHODS

This real-life, retrospective study analyzed the management of METexon14 aNSCLC. The primary endpoint was the median overall survival (mOS). Secondary endpoints were to assess investigator-progression-free survival (PFS) and mOS in different subgroups: patients treated with (a) crizotinib, regardless of treatment line; (b) anti-MET TKIs (crizotinib, tepotinib, capmatinib); and (c) immunotherapy.

RESULTS

A total of 118 patients were included between December 2015 and January 1, 2020 in 13 centers. Median age was 73 years, 62.7% were female, 83.9% had adenocarcinoma, 92.4% at stage IV, and 27% had more than three metastatic sites. The majority of the patients (106, 89.8%) received at least one systemic treatment; 73% received at least one anti-MET TKI: crizotinib (68.6%), tepotinib (16%), capmatinib (10%). Only 10% received two anti-MET TKIs in their treatment sequences. With a median follow-up of 16 months (95% CI 13.6-29.7), mOS was 27.1 months (95% CI 18-31.4). There was no significant difference between mOS of patients treated and never treated with crizotinib, 19.7 (95% CI 13.6-29.7) and 28 (95% CI 16.4-NR) months, respectively (p = 0.16); mOS of the TKI cohort and of the TKI-naïve patient cohort were 27.1 (95% CI 18-29.7) and 35.6 (95% CI 8.6-NR) months respectively, with no significant difference (p = 0.7).

CONCLUSIONS

In this real-life study, there was no evidence of benefit in mOS with anti-MET TKIs.

Patient-reported outcomes in capmatinib-treated patients with METex14-mutated advanced NSCLC: Results from the GEOMETRY mono-1 study

INTRODUCTION

Capmatinib, a MET inhibitor, showed substantial antitumour activity with manageable side effects in patients with MET exon 14 (METex14)-mutated advanced non-small cell lung cancer (aNSCLC) in the GEOMETRY mono-1 study. We report patient-reported outcomes (PROs) from this study.

METHODS

Enrolled treatment-naïve (1L) or pre-treated (2L⁺) patients with aNSCLC with a METex14-skipping mutation received 400 mg capmatinib twice daily during 21-day treatment cycles. PROs were collected at baseline and every six weeks thereafter using EORTC QLQ-C30 global health status/quality of life (GHS/QoL), QLQ-LC13 symptoms, and EQ-5D-5L visual analogue scale (VAS) questionnaires.

RESULTS

As of 6 January 2020, 27/28 1L and 65/69 2L⁺ patients had completed PROs at baseline; compliance rates remained >70%. Cough improved early, with meaningful improvements (≥10-point change from baseline) observed throughout cycles (mean change from baseline [SD] by week 7: 1L -13.0 [39.9], 2L⁺ -8.2 [28.4]; week 43: 1L -28.2 [26.7], 2L⁺ -10.5 [27.3]). QoL, assessed by GHS/QoL and VAS, improved by week 7 in 1L and 2L⁺ patients, with improvements generally sustained over time. Median time to definitive deterioration (TTDD) in GHS/QoL was 16.6 months (95% CI: 9.7, not estimable [NE]) in 1L and 12.4 months (95% CI: 4.2, 19.4) in 2L⁺ patients. Median TTDD for dyspnoea was 19.4 months (95% CI: 12.4, NE) and 22.1 months (95% CI: 9.9, NE) for 1L and 2L⁺ patients, respectively, and NE for cough and chest pain.

CONCLUSIONS

Capmatinib was associated with clinically meaningful improvements in cough and preserved QoL, further supporting its use in patients with METex14-mutated aNSCLC.

TRIAL REGISTRATION

ClinicalTrials.gov registry number: NCT02414139.

Transient asymptomatic pulmonary opacities in a patient with MET exon 14 skipping non-small cell lung cancer: A case report

Mesenchymal epithelial transition factor receptor (MET) tyrosine kinase inhibitors (MET-TKIs) have been approved for the treatment of non-small cell lung cancers with MET exon 14 skipping mutations. Transient asymptomatic pulmonary opacities (TAPOs) associated with epidermal growth factor receptor (EGFR)-TKIs have been reported. Here, we report a case wherein ground-glass opacities (GGOs) appeared during the course of treatment with tepotinib, a MET-TKI, but spontaneously resolved with drug withdrawal, after which treatment was resumed with a reduced dose. Although there have been no reports of TAPOs with MET-TKIs, the clinical and imaging findings of this case were consistent with TAPOs. For TAPOs occurring because of MET-TKI, the drug can be continued under careful observation even if GGOs appear.

Differences in Sustained Cellular Effects of MET inhibitors Are Driven by Prolonged Target Engagement and Lysosomal Retention

Intracellular distribution of drug compounds is dependent on physicochemical characteristics and may have a significant bearing on the extent of target occupancy and, ultimately, drug efficacy. We assessed differences in the physicochemical profiles of MET inhibitors capmatinib, crizotinib, savolitinib, and tepotinib and their effects on cell viability and MET phosphorylation under steady-state and washout conditions (to mimic an open organic system) in a human lung cancer cell line. To examine the differences of the underlying molecular mechanisms at the receptor level, we investigated the residence time at the kinase domain and the cellular target engagement. We found that the ranking of the drugs for cell viability was different under steady-state and washout conditions and that under washout conditions, tepotinib displayed the most potent inhibition of phosphorylated MET. Postwashout effects were correlated with the partitioning of the drug into acidic subcellular compartments such as lysosomes, and the tested MET inhibitors were grouped according to their ability to access lysosomes (crizotinib and tepotinib) or not (capmatinib and savolitinib). Reversible lysosomal retention may represent a valuable intracellular storage mechanism for MET inhibitors, enabling prolonged receptor occupancy in dynamic, open-physiologic systems and may act as a local drug reservoir. The use of washout conditions to simulate open systems and investigate intracellular drug distribution is a useful characterization step that deserves further investigation. SIGNIFICANCE STATEMENT: Generally, determination of potency and receptor occupancy is performed under steady-state conditions. In vivo conditions are more complex due to concentration differences between compartments and equilibrium processes. Experiments under steady state cannot explore effects such as sustained target inhibition. This study has shown that differences between MET inhibitors are observable by applying washout conditions to in vitro assays. This important finding applies to most compound classes and may inspire readers to rethink their assay designs in the future.

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

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

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.

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.

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.

Safety of Tepotinib in Patients with MET Exon 14 Skipping NSCLC and Recommendations for Management

INTRODUCTION

The MET inhibitor tepotinib demonstrated durable clinical activity in patients with advanced MET exon 14 (METex14) skipping NSCLC. We report detailed analyses of adverse events of clinical interest (AECIs) in VISION, including edema, a class effect of MET inhibitors.

PATIENTS AND METHODS

Incidence, management, and time to first onset/resolution were analyzed for all-cause AECIs, according to composite categories (edema, hypoalbuminemia, creatinine increase, and ALT/AST increase) or individual preferred terms (pleural effusion, nausea, diarrhea, and vomiting), for patients with METex14 skipping NSCLC in the phase II VISION trial.

RESULTS

Of 255 patients analyzed (median age: 72 years), edema, the most common AECI, was reported in 69.8% (grade 3, 9.4%; grade 4, 0%). Median time to first edema onset was 7.9 weeks (range: 0.1-58.3). Edema was manageable with supportive measures, dose reduction (18.8%), and/or treatment interruption (23.1%), and rarely prompted discontinuation (4.3%). Other AECIs were also manageable and predominantly mild/moderate: hypoalbuminemia, 23.9% (grade 3, 5.5%); pleural effusion, 13.3% (grade ≥ 3, 5.1%); creatinine increase, 25.9% (grade 3, 0.4%); nausea, 26.7% (grade 3, 0.8%), diarrhea, 26.3% (grade 3, 0.4%), vomiting 12.9% (grade 3, 1.2%), and ALT/AST increase, 12.2% (grade ≥ 3, 3.1%). GI AEs typically occurred early and resolved in the first weeks.

CONCLUSION

Tepotinib was well tolerated in the largest trial of a MET inhibitor in METex14 skipping NSCLC. The most frequent AEs were largely mild/moderate and manageable with supportive measures and/or dose reduction/interruption, and caused few withdrawals in this elderly population.