Activating point mutations in the MET kinase domain represent a unique molecular subset of lung cancer and other malignancies targetable with MET inhibitors.

Activating point mutations in the MET tyrosine kinase domain (TKD) are oncogenic in a subset of papillary renal cell carcinomas (PRCC). Here, using comprehensive genomic profiling among >600,000 patients, we identify activating MET TKD point mutations as putative oncogenic driver across diverse cancers, with a frequency of ~0.5%. The most common mutations in the MET TKD defined as oncogenic or likely oncogenic according to OncoKB resulted in amino acid substitutions at positions H1094, L1195, F1200, D1228, Y1230, M1250, and others. Preclinical modeling of these alterations confirmed their oncogenic potential, and also demonstrated differential patterns of sensitivity to type I and type II MET inhibitors. Two patients with metastatic lung adenocarcinoma harboring MET TKD mutations (H1094Y, F1200I) and no other known oncogenic drivers achieved confirmed partial responses to a type I MET inhibitor. Activating MET TKD mutations occur in multiple malignancies and may confer clinical sensitivity to currently available MET inhibitors.

Characterization of 164 patients with NRAS mutated non-small cell lung cancer (NSCLC).

BACKGROUND: NRAS mutations are observed in less than 1% of non-small cell lung cancer (NSCLC). Clinical data regarding this rare subset of lung cancer are scarce and response to systemic treatment such as chemotherapy or immune checkpoint inhibitors (ICI) has never been reported. METHODS: All consecutive patients with an NRAS mutated NSCLC, diagnosed between August 2014 and November 2020 in 14 French centers, were included. Clinical and molecular data were collected and reviewed from medical records. RESULTS: Out of the 164 included patients, 106 (64.6%) were men, 150 (91.5%) were current or former smokers, and 104 (63.4%) had stage IV NSCLC at diagnosis. The median age was 62 years, and the most frequent histology was adenocarcinoma (81.7%). NRAS activating mutations were mostly found in codon 61 (70%), while codon 12 and 13 alterations were observed in 16.5% and 4.9% of patients, respectively. Programmed death ligand-1 expression level <1%/1-49%/≥50% were respectively found in 30.8%/27.1%/42.1% of tumors. With a median follow-up of 12.5 months, median overall survival (OS) of stage IV patients was 15.3 months (95% CI 9.9-27.6). No significant difference in OS was found according to the type of mutation (codon 61 vs. other), HR = 1.12 (95% CI 0.65-1.95). Among stage IV patients treated with platinum-based doublet (n = 66), ICI (n = 48), or combination of both (n = 10), objective response rate, and median progression free survival were respectively 45% and 5.8 months, 35% and 6.9 months, 70% and 8.6 months. CONCLUSION: NRAS mutated NSCLC are characterized by a high frequency of smoking history and codon 61 mutations. Further studies are needed to confirm the encouraging outcome of immunotherapy in combination with chemotherapy.

Lorlatinib for advanced anaplastic lymphoma kinase-positive non-small cell lung cancer: Results of the IFCT-1803 LORLATU cohort.

BACKGROUND: Anaplastic lymphoma kinase (ALK)-rearranged (ALK+) non-small cell lung cancer (NSCLC) represents a rare subset of lung cancer, with specific presentation, and multiple treatment options, including selective tyrosine kinase inhibitors (TKIs). Real-world evidence is insufficient regarding the actual real-life treatment sequences in the late line setting, and available clinical trials may not reflect real-world situation. Here, we took advantage of the French Expanded Access Program (EAP) of lorlatinib, a third-generation TKI targeting ALK and ROS1, to assess treatment sequencing, and lorlatinib efficacy and safety, in patients with ALK+ NSCLC. METHODS: All consecutive patients with advanced ALK+ NSCLC treated between October 2015 and June 2019 with lorlatinib as part of EAP were included. Data were collected and reviewed from medical records by independent research staff of the French Thoracic Cancer Intergroup. The primary endpoint was progression-free survival (PFS). RESULTS: Of the 208 patients included, 117 (56%) were female, 142 (69%) were never smokers, and 180 (87%) had stage IV NSCLC at diagnosis. The most frequent histology was adenocarcinoma (94%), and the median age was 60.9 years. At the time of lorlatinib initiation, 160 (77%) patients had brain metastases, and 125 (72%) were performance status 0/1. Lorlatinib was delivered as 2nd/3rd/4th/5th+ line in 4%/17%/30%/49% of patients. A total of 162 (78%) patients had previously been treated with chemotherapy, 194 (93%) with a first-generation ALK-TKI, 195 (94%) with a second-generation ALK-TKI. The median follow-up from lorlatinib initiation was 23.3 months. The median PFS, median overall survival (OS) from lorlatinib initiation and median OS from advanced NSCLC diagnosis were 9.9 months (95% confidence interval [CI] 6-12.3 months), 32.9 months (95% CI 18.7 months to not reached) and 97.3 months (95% CI 75.7-152.8 months), respectively. The median duration of treatment with lorlatinib was 11.8 months (95% CI 8.5-18.8 months). Overall response and disease control rate were 49% and 86%, respectively. Central nervous system objective response rate was 56%. Treatment was stopped due to toxicity in 28 patients (14%). The safety profile of lorlatinib was consistent with previously published data. CONCLUSIONS: Real-world evidence indicates that lorlatinib offers a significant clinical benefit and high intracerebral antitumour activity in heavily pretreated patients with ALK+ NSCLC. GOV IDENTIFIER: NCT03727477.

Does bevacizumab increase joint pain in patients with cancer? Results of the prospective observational BEVARTHRALGIA study.

PURPOSE: The occurrence of arthralgia and myalgia during treatment with bevacizumab (Bev) has been described but not spontaneously reported. We aimed to evaluate the frequency of arthralgia in patients treated with Bev and identify the risk factors. METHODS: In this observational prospective study, a self-administered questionnaire was distributed to patients at the initiation of Bev and at 3 and 6 months of treatment. Bev (5-15 mg/kg) was administered every 2 or 3 weeks, with or without chemotherapy. RESULTS: A total of 71 patients (42 with colorectal cancer, 22 with ovarian cancer, and 7 with lung cancer) were enrolled from January to November 2018. All patients completed the questionnaire at initiation, while only 56 (78.9%) and 36 (50.7%) patients completed the questionnaire at 3 and 6 months, respectively. The frequency of joint pain was 29.6% before Bev treatment and increased to 41.8% and 50% at 3 and 6 months, respectively, without reaching significance. The evolution of pain was significant according to the Common Terminology Criteria for Adverse Events grades (P = 0.032). No significant increase in the impact of pain on instrumental or elementary activities was observed over time. The frequency of arthralgia significantly increased at 3 months in patients with ovarian cancer versus those with colorectal cancer (odds ratio: 19.50; 95% confidence interval 4.53-83.98; P < 0.001). CONCLUSIONS: Bev­including regimens tend to be associated with a significant increase in the frequency of arthralgia in women treated for ovarian cancer. Physicians should be aware of this side effect. CLINICAL TRIAL NUMBER: NCT03455907, date of registration: March 7, 2018.

Complete and prolonged response to anti-PD1 therapy in an ALK rearranged lung adenocarcinoma.

OBJECTIVE: Immune checkpoint inhibitors (ICI) have become a major treatment in advanced non small cell lung cancer (NSCLC). However, some patients do not benefit from ICI, especially those harboring an ALK rearrangement. Here, we report a case of prolonged complete tumor response to immunotherapy in an ALK-rearranged NSCLC patient. MATERIALS AND METHODS: We verify ALK expression and rearrangement on formalin-fixed paraffin-embedded tumor samples of the patient by Immunohistochemistry and Fluorescence In Situ Hybridization analysis. The patient provided written informed consent authorizing publication of clinical case. RESULTS: We report the case of 48 years old man with a ALK-rearranged NSCLC. This patient displayed a complete response for 16 months under nivolumab therapy in third line setting after ceritinib and platin based chemotherapy. CONCLUSION: This is the first case of complete and prolonged response to ICI in ALK rearranged NSCLC. This case supports the idea that some ALK rearranged NSCLC could durably benefit from immunotherapy.

Alterations in the PI3K Pathway Drive Resistance to MET Inhibitors in NSCLC Harboring MET Exon 14 Skipping Mutations.

Hepatocyte growth factor receptor (MET) tyrosine kinase inhibitors (MET TKIs) have been found to have efficacy against advanced NSCLC with mutations causing MET exon 14 skipping (METex14 mutations), but primary resistance seems frequent, as response rates are lower than those for targeted TKIs of other oncogene-addicted NSCLCs. Given the known interplay between MET and phosphoinositide 3-kinases (PI3K), we hypothesized that in METex14 NSCLC, PI3K pathway alterations might contribute to primary resistance to MET TKIs. We reviewed clinical data from 65 patients with METex14 NSCLC, assessing PI3K pathway alterations by targeted next-generation sequencing (mutations) and immunohistochemistry (loss of phosphatase and tensin homolog [PTEN]). Using a cell line derived from a patient with primary resistance to a MET TKI and cell lines harboring both a METex14 mutation and a PI3K pathway alteration, we assessed sensitivity to MET TKIs used alone or with a PI3K inhibitor and investigated relevant signaling pathways. We found a phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) mutation in two of 65 samples (3%) and loss of PTEN in six of 26 samples (23%). All three of the MET TKI-treated patients with a PI3K pathway alteration had been found to have progressive disease at first assessment. Likewise, MET TKIs had no effect on the proliferation of METex14-mutated cell lines with a PI3K pathway alteration, including the PTEN-lacking patient-derived cell line. Treatment combining a MET TKI with a PI3K inhibitor caused inhibition of both PI3K and MAPK signaling and restored sensitivity to MET TKIs. PI3K pathway alterations are common in METex14 NSCLC and may confer primary resistance to MET TKIs. In preclinical models, PI3K inhibition restores sensitivity to MET TKIs.

Efficacy of Immune Checkpoint Inhibitors in Lung Sarcomatoid Carcinoma.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have improved cancer prognosis but have not been evaluated specifically in sarcomatoid carcinoma (SC), a rare lung cancer subtype with poor prognosis. As such, our study sought to retrospectively assess the efficacy of ICI in SC. METHODS: All consecutive patients with centrally confirmed SC treated using ICI as a second-line treatment or beyond between 2011 and 2017 were enrolled. Programmed death-ligand 1 (PD-L1) tumor expression was assessed using immunohistochemistry (SP263 clone) and the tumor mutational burden (TMB) with the Foundation One panel. TMB was considered high if it was greater than or equal to 10 mutations per megabase. RESULTS: Overall, 37 patients with SC were evaluated, predominantly men (73%) with a median age of 63.2 years (36.8-79.7) and who were current or former smokers (94.6%). Immunotherapy (nivolumab, 86.5% of cases) was given as a second-line treatment in 54% of the patients and as third-line treatment or beyond in 46% of the patients. The objective response rate was 40.5% and disease control rate was 64.8%, regardless of PD-L1 status. Median overall survival was 12.7 months (range: 0.3-45.7). One-third of patients exhibited early progression. The median PD-L1 expression was 70% (0-100). There was a trend toward higher PD-L1 expression in responsive diseases, with an objective response rate of 58.8% in patients with PD-L1+ and 0% in the one patient with PD-L1- (p = 0.44). The median TMB was 18 (4-39) mutations per megabase, with 87.5% of the cases displaying a high TMB. There was a trend toward higher TMB in responders versus stable or progressive diseases (p = 0.2). CONCLUSIONS: Patients with SC exhibited high response rates and prolonged overall survival under ICI treatment. These data support the prospective investigation of ICI in patients with SC who are under first-line treatment.

High MET Overexpression Does Not Predict the presence of MET exon 14 Splice Mutations in NSCLC: Results From the IFCT PREDICT.amm study.

INTRODUCTION: MET proto-oncogene (MET) exon 14 splice site (METex14) mutations were recently described in NSCLC and has been reported to correlate with efficacy of MET tyrosine kinase inhibitors. High diversity of these alterations makes them hard to detect by DNA sequencing in clinical practice. Because METex14 mutations induce increased stabilization of the MET receptor, it is anticipated that these mutations are associated with MET overexpression. We aim to determine whether NSCLC with high MET overexpression could define a subset of patients with a high rate of METex14 mutations. METHODS: From The French Cooperative Thoracic Intergroup PREDICT.amm cohort of 843 consecutive patients with a treatment-naive advanced NSCLC who were eligible for a first-line therapy, 108 NSCLC samples with high MET overexpression defined by an immunochemistry score 3+ were tested for METex14 mutations using fragment length analysis combined with optimized targeted next-generation sequencing. MET copy number analysis was also derived from the sequencing data. RESULTS: METex14 mutations were detected in two patients (2.2%) who also displayed a TP53 mutation and a PIK3CA mutation, respectively. An MET gene copy number increase was observed in seven additional patients (7.7%). Next-generation sequencing analysis revealed inactivating mutations in TP53 (52.7%) and PTEN (1.1%), and oncogenic mutations in KRAS (28.6%), EGFR (7.7%), PIK3CA (4.4%), BRAF (4.4%), NRAS (2.2%), GNAS (1.1%), and IDH1 (1.1%). CONCLUSIONS: The rate of METex14 mutations in NSCLC with high MET overexpression was similar to that found in unselected NSCLC. Moreover, we observed a high frequency of driver alterations in other oncogenes. Consequently these findings do not support the use of MET immunohistochemistry as a surrogate marker for METex14 mutations.

Relevance of Detection of Mechanisms of Resistance to ALK Inhibitors in ALK-Rearranged NSCLC in Routine Practice.

BACKGROUND: Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) have shown efficacy in the treatment of ALK-rearranged non-small-cell lung cancer (NSCLC), but the disease eventually progresses in all patients. In many cases, resistance to ALK TKIs arises through ALK mutations. Although clinical and biological data suggest variations in TKI efficacy according to the mechanism of resistance, ALK mutations are still rarely investigated in routine practice. MATERIALS AND METHODS: We performed a retrospective multicentric study with an aim to determine the frequency and clinical relevance of ALK alterations detected using targeted next-generation sequencing in patients with advanced ALK-rearranged NSCLC after progression during an ALK TKI treatment. Data on clinical, pathological, and molecular characteristics and patient outcomes were collected. RESULTS: We identified 23 patients with advanced ALK-rearranged NSCLC who, between January 2012 and May 2017, had undergone at least 1 repeat biopsy at progression during an ALK TKI treatment. A resistance mechanism was identified in 9 of the 23 patients (39%). The anomalies involved included 9 ALK mutations in 8 patients and one ALK amplification. The ALK mutation rate was 15% after failure of a first ALK TKI and 33% after failure of 2 ALK TKI treatments. Five of 7 patients who received a different ALK TKI after detection of an ALK mutation achieved an objective response. All of the patients who received a TKI presumed to act on the detected ALK mutant achieved disease control. CONCLUSION: Targeted next-generation sequencing is suitable for detecting ALK resistance mutations in ALK-rearranged NSCLC patients in routine practice. It might help select the best treatment at the time of disease progression during treatment with an ALK TKI.

MET amplification increases the metastatic spread of EGFR-mutated NSCLC.

BACKGROUND: Five to 20% of metastatic EGFR-mutated non-small cell lung cancers (NSCLC) develop acquired resistance to EGFR tyrosine kinase inhibitors (EGFR-TKI) through MET amplification. The effects of MET amplification on tumor and patient phenotype remain unknown. METHODS: We investigated,in vitro and in vivo, the impact of MET amplification on the biological properties of the HCC827 cell line, derived from an EGFR-mutated NSCLC. We further evaluated the time to new metastases after EGFR-TKI progression in EGFR-mutated NSCLC, exhibiting MET amplification or high MET overexpression. RESULTS: MET amplification significantly enhanced proliferation, anchorage independent growth, anoikis resistance, migration, and induced an epithelial to mesenchymal transition. In vivo, MET amplification significantly increased the tumor growth and metastatic spread. Treatment with a MET-TKI reversed this aggressive phenotype. We found that EGFR-mutated NSCLC patients exhibiting MET amplification on a re-biopsy, performed after EGFR-TKI progression, displayed a shorter time to new metastases after EGFR-TKI progression than patients with high MET overexpression but no MET amplification. CONCLUSION: MET amplification increases metastatic spread even in the context of an already pre-existing strong driver mutation such as EGFR mutation. These results prompt development of therapeutic strategies aiming at preventing emergence of MET amplification.

Optimization of Routine Testing for MET Exon 14 Splice Site Mutations in NSCLC Patients.

INTRODUCTION: Genomic alterations affecting splice sites of MNNG HOS transforming gene (MET) exon 14 were recently identified in NSCLC patients. Objective responses to MET tyrosine kinase inhibitors have been reported in these patients. Thus, detection of MET exon 14 splice site mutations represents a major challenge. So far, most of these alterations were found by full-exome sequencing or large capture-based next-generation sequencing (NGS) panels, which are not suitable for routine diagnosis. METHODS: Aiming to provide a molecular testing method applicable in routine practice, we first developed a fragment-length analysis for detecting deletions in introns flanking MET exon 14. Second, we designed an optimized targeted NGS panel called CLAPv1, covering the MET exon 14 and flanking regions in addition to the main molecular targets usually covered in genomic testing. In patients with MET exon 14 mutations, MET gene amplification, gene copy number and MET receptor expression were also determined. RESULTS: Among 1514 formalin-fixed paraffin-embedded NSCLC samples, nonoptimized NGS allowed detection of MET exon 14 mutations in only 0.3% of the patients, and fragment length analysis detected deletions in 1.1% of the patients. Combined, the optimized CLAPv1 panel and fragment-length analysis implemented for routine molecular testing revealed MET exon 14 alterations in 2.2% of 365 additional NSCLC patients. MET gene amplification or high gene copy number was observed in 6 of 30 patients (20%) harboring MET exon 14 mutations. CONCLUSIONS: These results show that optimized targeted NGS and fragment-length analysis improve detection of MET alterations in routine practice.

The multiple paths towards MET receptor addiction in cancer.

Targeted therapies against receptor tyrosine kinases (RTKs) are currently used with success on a small proportion of patients displaying clear oncogene activation. Lung cancers with a mutated EGFR provide a good illustration. The efficacy of targeted treatments relies on oncogene addiction, a situation in which the growth or survival of the cancer cells depends on a single deregulated oncogene. MET, a member of the RTK family, is a promising target because it displays many deregulations in a broad panel of cancers. Although clinical trials having evaluated MET inhibitors in large populations have yielded disappointing results, many recent case reports suggest that MET inhibition may be effective in a subset of patients with unambiguous MET activation and thus, most probably, oncogene addiction. Interestingly, preclinical studies have revealed a particularity of MET addiction: it can arise through several mechanisms, and the mechanism involved can differ according to the cancer type. The present review describes the different mechanisms of MET addiction and their consequences for diagnosis and therapeutic strategies. Although in each cancer type MET addiction affects a restricted number of patients, pooling of these patients across all cancer types yields a targetable population liable to benefit from addiction-targeting therapies.

Outcome of EGFR-mutated NSCLC patients with MET-driven resistance to EGFR tyrosine kinase inhibitors.

Background: Several mechanisms of acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutated NSCLC have been described including the T790M mutation and MET amplification. Whereas T790M mutation confers prolonged survival and sensitivity to 3rd generation TKIs, data are lacking on clinical features and outcome of MET-driven resistant EGFR-mutated NSCLC patients. Methods: Patients with metastatic EGFR-mutated NSCLC displaying high MET overexpression or MET amplification, detected on a biopsy performed after progression on EGFR TKI, were identified in 15 centers. Clinical and molecular data were retrospectively collected. Results: Forty two patients were included. The median overall survival (OS), and the median post EGFR TKI progression overall survival (PPOS) were 36.2 months [95%CI 27.3-66.5] and 18.5 months [95%CI 10.6-27.4] respectively. Nineteen out of 36 tumors tested for MET FISH had MET amplification. A T790M mutation was found in 11/41 (26.8%) patients. T790M-positive patients had a better OS than T790M-negative patients (p=0.0224). Nineteen patients received a MET TKI. Objective response was reported in 1 out of 12 evaluable patients treated with a MET inhibitor as a single agent and in 1 of 2 patients treated with a combination of MET and EGFR TKIs. Conclusion: MET-driven resistance to EGFR TKI defines a specific pattern of resistance characterized by low objective response rate to MET inhibitors given alone and overlapping with T790M mutations. Further studies are warranted to define adequate therapeutic strategies for MET-driven resistance to EGFR TKI.

Exon 14 Deleted MET Receptor as a New Biomarker and Target in Cancers.

Inhibitors of the receptor tyrosine kinase (RTK) MET have been ineffective at treating cancer, possibly because of lack of knowledge that would allow selection of tumors likely to respond to this treatment. In contrast, specific epidermal growth factor receptor (EGFR) inhibitors have been used successfully against lung tumors displaying activating mutations in the kinase domain of EGFR. Recent publications describe a set of mutations causing MET exon 14 skipping, and importantly, several case reports describe objective responses to MET-targeting tyrosine kinase inhibitors in patients with such mutations. These observations suggest a novel therapeutic strategy for fighting cancer, especially in the lung. Exon 14 encodes the MET juxtamembrane domain targeted by mechanisms that negatively regulate receptor stability and activity. In this review, we describe the molecular mechanisms leading first to exon 14 skipping and then to activation of the MET receptor and how this process differs from that triggered by classical RTK-activating mutations in the kinase domain. We detail the clinical characteristics of patients carrying these mutations and the sensitivity of their tumors to MET inhibitors. Lastly, we discuss future challenges related to MET mutations in cancers, including patient screening and anticipating resistance to MET inhibitors.

Defect in recruiting effector memory CD8+ T-cells in malignant pleural effusions compared to normal pleural fluid.

BACKGROUND: Malignant pleural effusions (MPE) are a common and fatal complication in cancers including lung or breast cancers, or malignant pleural mesothelioma (MPM). MPE animal models and immunotherapy trials in MPM patients previously suggested defects of the cellular immunity in MPE. However only few observational studies of the immune response were done in MPM patients, using questionable control groups (transudate…). METHODS: We compared T cell populations evaluated by flow cytometry from blood and pleural effusion of untreated patients with MPM (n = 58), pleural metastasis of adenocarcinoma (n = 30) or with benign pleural lesions associated with asbestos exposure (n = 23). Blood and pleural fluid were also obtained from healthy subjects, providing normal values for T cell populations. RESULTS: Blood CD4+ or CD8+ T cells percentages were similar in all groups of patients or healthy subjects. Whereas pleural fluid from healthy controls contained mainly CD8+ T cells, benign or malignant pleural effusions included mainly CD4+ T cells. Effector memory T cells were the main T cell subpopulation in pleural fluid from healthy subjects. In contrast, there was a striking and selective recruitment of central memory CD4+ T cells in MPE, but not of effector cells CD8+ T cells or NK cells in the pleural fluid as one would expect in order to obtain an efficient immune response. CONCLUSIONS: Comparing for the first time MPE to pleural fluid from healthy subjects, we found a local defect in recruiting effector CD8+ T cells, which may be involved in the escape of tumor cells from immune response. Further studies are needed to characterize which subtypes of effector CD8+ T cells are involved, opening prospects for cell therapy in MPE and MPM.