Detection of MET exon 14 skipping mutations in non-small cell lung cancer: overview and community perspective

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

Novartis Pharmaceuticals.

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.

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.

Savolitinib versus crizotinib for treating MET positive non-small cell lung cancer

BACKGROUND

The c-MET protein, encoded by the mesenchymal-epithelial transition factor (MET) gene, can regulate cell proliferation, migration and invasion. Studies have shown that it is one of the essential driver genes for non-small cell lung cancer (NSCLC). Currently, several clinical studies have carried out objective assessments on the efficacy and safety of different types of MET tyrosine kinase inhibitors (TKIs). However, direct cross-sectional comparisons between different agents are still not available.

METHODS

Our study was a single-center retrospective clinical study, which collected the data from MET positive NSCLC patients treated with MET TKIs at the Lung Cancer Center of Peking Union Medical College Hospital. We explored the efficacy and safety of crizotinib versus savolitinib in patients with METex14 skipping and MET amplification, separately.

RESULTS

Patients with METex14 skipping (median PFS = 10.7 months) had a better clinical response to MET TKIs than MET amplification patients (median PFS = 4.1 months). In the METex14 skipping subgroup, savolitinib did not show better survival benefit with significance than crizotinib (p > 0.05). In the MET amplification subgroup, savolitinib (median PFS = 7.1 months) demonstrated a better progression-free survival benefit than crizotinib (median PFS = 1.4 months), p = 0.05. The most common adverse effects of both MET TKIs were peripheral edema (41.2%), gastrointestinal reactions (23.5%), and liver injury (14.7%). The incidence rate of peripheral edema was higher in savolitinib than crizotinib.

CONCLUSION

In METex14 skipping NSCLC patients, the efficacy of savolitinib and crizotinib did not show significant difference. In MET amplification patients, savolitinib showed better efficacy than crizotinib.

Robust Performance of the Novel Research-Use-Only Idylla GeneFusion Assay Using a Diverse Set of Pathological Samples with a Proposed 1-Day Workflow for Advanced NSCLC Evaluation

A range of different techniques are available for predictive biomarker testing for non-small-cell lung cancer (NSCLC) clinical management. International guidelines suggest next-generation sequencing (NGS) as the preferred procedure, but other reverse transcriptase-polymerase chain reaction (RT-PCR)-based methods are rapidly evolving. In this study, we evaluated the reliability and accuracy of the Idylla^TM GeneFusion assay, a rapid and fully automated platform able to simultaneously detect ALK, ROS1, RET and NTRK1/2/3 and MET ex14 skipping mutations and compared its performance with routine reference methods. The cohort included thirty-seven NSCLCs plus two parotid gland carcinomas, previously characterized for the above alterations through either IHC, FISH, RT-PCR or NGS. In 36 of 39 cases, the Idylla GeneFusion assay and the reference methods were concordant (overall agreement: 92.3%). Tumor sections stored at room temperature for up to 60 days and 17 cases older than 2 years were successfully characterized. Our results suggest that the Idylla GeneFusion assay is a reliable tool to define gene fusion status and may be a valuable stand-alone diagnostic test when time efficiency is needed or NGS is not feasible.

MET Signaling Pathways, Resistance Mechanisms, and Opportunities for Target Therapies

The MET gene, known as MET proto-oncogene receptor tyrosine kinase, was first identified to induce tumor cell migration, invasion, and proliferation/survival through canonical RAS-CDC42-PAK-Rho kinase, RAS-MAPK, PI3K-AKT-mTOR, and β-catenin signaling pathways, and its driver mutations, such as MET gene amplification (METamp) and the exon 14 skipping alterations (METex14), activate cell transformation, cancer progression, and worse patient prognosis, principally in lung cancer through the overactivation of their own oncogenic and MET parallel signaling pathways. Because of this, MET driver alterations have become of interest in lung adenocarcinomas since the FDA approval of target therapies for METamp and METex14 in 2020. However, after using MET target therapies, tumor cells develop adaptative changes, favoring tumor resistance to drugs, the main current challenge to precision medicine. Here, we review a link between the resistance mechanism and MET signaling pathways, which is not only limited to MET. The resistance impacts MET parallel tyrosine kinase receptors and signals shared hubs. Therefore, this information could be relevant in the patient's mutational profile evaluation before the first target therapy prescription and follow-up to reduce the risk of drug resistance. However, to develop a resistance mechanism to a MET inhibitor, patients must have access to the drugs. For instance, none of the FDA approved MET inhibitors are registered as such in Chile and other developing countries. Constant cross-feeding between basic and clinical research will thus be required to meet future challenges imposed by the acquired resistance to targeted therapies.

MET alterations in advanced pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is a rare subset of NSCLC that accounts for about 0.5-1% of all primary lung carcinoma, and its malignant biological behavior is more aggressive than other pathological types of lung cancer. Recent studies have reported a variety of gene mutations associated with the occurrence, development and treatment of PSC, especially the mesenchymal-epithelial transition (MET) proto-oncogene alterations, including the exon 14 (METex14) skipping mutations as well as the amplification and overexpression of MET gene, which are associated with molecularly targeted therapy for PSC. METex14 skipping mutation is the most common and well-studied mutation type, occurring in about 22-31.8% of PSC patients, while the prevalence of MET amplification is reported as 4.8-13.6% and MET ovexpression is about 20.2%. Molecular pathology tests, including IHC and NGS, are valuable in determining the prognosis of patients with PSC and helping to determine the treatment. The existing clinical data have confirmed the efficacy of MET-TKI in PSC patients with MET alteration, among which the clinical study of Savolitinib has enrolled the largest proportion of PSC patients and achieved relatively good efficacy, but more clinical researches are still needed. The multi-disciplinary team may maximize the optimal treatment options for patients with the advanced PSC.

Consensus Recommendations to Optimize Testing for New Targetable Alterations in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) has historically been associated with a poor prognosis and low 5-year survival, but the use of targeted therapies in NSCLC has improved patient outcomes over the past 10 years. The pace of development of new targeted therapies is accelerating, with the associated need for molecular testing of new targetable alterations. As the complexity of biomarker testing in NSCLC increases, there is a need for guidance on how to manage the fluid standard-of-care in NSCLC, identify pragmatic molecular testing requirements, and optimize result reporting. An expert multidisciplinary working group with representation from medical oncology, pathology, and clinical genetics convened via virtual meetings to create consensus recommendations for testing of new targetable alterations in NSCLC. The importance of accurate and timely testing of all targetable alterations to optimize disease management using targeted therapies was emphasized by the working group. Therefore, the panel of experts recommends that all targetable alterations be tested reflexively at NSCLC diagnosis as part of a comprehensive panel, using methods that can detect all relevant targetable alterations. In addition, comprehensive biomarker testing should be performed at the request of the treating clinician upon development of resistance to targeted therapy. The expert multidisciplinary working group also made recommendations for reporting to improve clarity and ease of interpretation of results by treating clinicians and to accommodate the rapid evolution in clinical actionability of these alterations. Molecular testing of all targetable alterations in NSCLC is the key for treatment decision-making and access to new therapies. These consensus recommendations are intended as a guide to further optimize molecular testing of new targetable alterations.