METex14 Skipping Research Articles

Spatial profiling of METex14-altered NSCLC under tepotinib treatment: Shifting the immunosuppressive landscape

MET inhibitors have demonstrated efficacy in treating patients with non-small cell lung cancer (NSCLC) harboring METex14 skipping alterations. Advancements in spatial profiling technologies have unveiled the complex dynamics of the tumor microenvironment (TME), a crucial factor in cancer progression and therapeutic response.This study uses spatial profiling to investigate the effects of the MET inhibitor tepotinib on the TME in a case of locally advanced NSCLC with a METex14 skipping alteration. A patient with resectable stage IIIB NSCLC, unresponsive to neoadjuvant platinum-based chemotherapy, received tepotinib following the detection of a METex14 skipping alteration. Paired pre- and post-treatment biopsies were subjected to GeoMx Digital Spatial Profiling using the Cancer Transcriptome Atlas and immune-related protein panels to evaluate shifts in the immune TME.Tepotinib administration allowed for a successful lobectomy and a pathological downstaging to stage IA1. The TME was transformed from an immunosuppressive to a more permissive state, with upregulation of antigen-presenting and pro-inflammatory immune cells. Moreover, a marked decrease in immune checkpoint molecules, including PD-L1, was noted. Spatial profiling identified discrete immune-enriched clusters, indicating the role of tepotinib in modulating immune cell trafficking and function. Tepotinib appears to remodel the immune TME in a patient with METex14 skipping NSCLC, possibly increasing responsiveness to immunotherapy.Our study supports the integration of genetic profiling into the management of early and locally advanced NSCLC to guide personalized, targeted interventions. These findings underscore the need to further evaluate combinations of MET inhibitors and immunotherapies.

EP.12D.06 Real-World Cases on Efficacy and Safety of Savolitinib for Elderly Patients with NSCLC Harbouring METex14 Skipping Mutations

EP.12D.06 Real-World Cases on Efficacy and Safety of Savolitinib for Elderly Patients with NSCLC Harbouring METex14 Skipping Mutations

1382P Vebreltinib efficacy and safety in NSCLC patients with METex14 skipping mutations

1382P Vebreltinib efficacy and safety in NSCLC patients with METex14 skipping mutations

Integrating the Idylla™ System Alongside a Real-Time Polymerase Chain Reaction and Next-Generation Sequencing for Investigating Gene Fusions in Pleural Effusions from Non-Small-Cell Lung Cancer Patients: A Pilot Study.

Malignant pleural effusion (MPE) from patients with advanced non-small-cell lung cancer (NSCLC) has been proven valuable for molecular analysis; however, simultaneous detection of driver fusions in MPE is still challenging. In this study, we investigated the Idylla™ GeneFusion Panel, a stand-alone test in tissue samples, in the evaluation of ALK, ROS1, RET and MET ex14 skipping mutations in MPE and compared its performance with routine reference methods (Real-time-based and Next-generation Sequencing-NGS). The inclusion criteria for sample selection were as follows: advanced NSCLC harboring ALK, ROS1, RET fusions or MET exon-skipping alterations and the availability of MPE collected at diagnosis or disease progression. Molecular alterations have been investigated on tissue by fluorescence in situ hybridization (FISH) or Real-time PCR or NGS. For molecular profiling with the Idylla™ GeneFusion, 200 µL of MPE supernatants combined with 50 µL of RNA Later solution were loaded into the Idylla™ cartridge without cfRNA extraction. The Idylla™ GeneFusion Assay performed on MPEs was able to confirm molecular profile, previously diagnosed with conventional methods, in all cases. Our data confirm that MPE are suitable material for investigating fusion alterations. The Idylla™ GeneFusion, although indicated for investigation of tissue samples, offers the possibility of performing a molecular characterization of supernatants without undertaking the entire cfRNA extraction procedure providing a rapid and reliable strategy for the detection of actionable genetic alterations.

Indirect comparison of capmatinib treatment from GEOMETRY mono-1 trial to SOC in German patients with locally advanced or metastatic NSCLC harboring METex14 skipping mutations

BackgroundThis study provides comparative evidence of the selective MET inhibitor capmatinib versus standard of care (SOC) in first-line (1 L) and second-line (2 L) non-small cell lung cancer (NSCLC) patients with METex14 mutations in German routine care. MethodsSOC data were collected from German routine care via retrospective chart review. Analyses were conducted as naive and propensity score adjusted (PSA) comparisons to capmatinib-treated patients within the GEOMETRY mono-1 trial. Effectiveness endpoints included overall survival (OS), progression-free survival (PFS), overall response rate (ORR), time to CNS progression (CNSprog), and exploratory safety endpoints. ResultsThe SOC arm included 119 patients in 1 L and 46 in 2 L versus 60 patients in 1 L and 81 in 2 L treated with capmatinib, with balanced baseline characteristics after PSA. In 1 L, the naive comparison showed a significant benefit of capmatinib versus SOC for OS (median: 25.49 vs 14.59 months; HR 0.58; 95 % CI 0.39–0.87; P = 0.011), PFS (median: 12.45 vs 5.03 months; HR: 0.44; 95 % CI: 0.31–0.63; P < 0.001), and ORR (event rate: 68.3 vs 26.9 %; RR 2.54; 95 % CI 1.80–3.58; P < 0.001). In 2 L, OS, PFS, and ORR showed positive trends favoring capmatinib over SOC. Capmatinib treatment in the 1 L and 2 L led to significant benefit in CNSprog. PSA analyses showed consistent results to naive analysis. Exploratory safety endpoints indicated a manageable safety profile for capmatinib. ConclusionsThe present study demonstrates the important role of capmatinib in providing robust clinically meaningful benefit to patients with NSCLC harboring METex14 mutations and its significant role in preventing the development of brain metastases.

Landscape of gene fusions and METex14 skipping in non-small cell lung carcinoma among the Chinese population: Insights from targeted RNA sequencing.

e20041 Background: Targeted RNA Sequencing is crucial for detecting gene fusions and exon-skipping mutations in non-small cell lung carcinoma (NSCLC). This study delineates the landscape of RNA-based fusion and METex14 skipping in the Chinese NSCLC population, compares the consistency with DNA-based fusion detection, and further explores the relationship between fusion-positive cases and immune markers. Methods: We profiled 294 NSCLC tumor tissues using targeted RNA sequencing, focusing on 29 fusion genes and 6 reference genes. Of these, 229 samples were concurrently assessed for fusions using a DNA panel. Patients with gene fusions or METex14 skipping were categorized as 'FUSION-POS'. Additionally, the expression of PD-L1 was evaluated. Results: In 294 NSCLC patients, 33 types of fusions and METex14 skipping were detected from 45 patients based on RNA detection. Actionable gene fusions/METex14 skipping were present in 11.22% (33/294) of patients, with the most prevalent being ALK (4.4%), METex14 skipping (2.7%), ROS1 (1.4%), and RET (1.0%). The partners of ALK, RET and ROS1 were EML4 (n= 12)/ LCLAT1(n=1), KIF5B (n=3) /PARD3(n=1) and CD74(n=2)/LRIG3(n=1)/EZR (n=1), respectively. Notably, we also identified two patients harboring FGFR2-ATE1 fusion and CD74-NRG1 fusion, respectively. Except for MET 14skipping, ST7-MET fusion was detected in 2 patients. Comparing the consistency of actionable fusions/METex14 skipping between RNA and DNA assessments in 229 NSCLC patients, RNA detection yielded a higher number of cases (24 patients vs 15 patients, 10.5% vs 6.5%), with all 15 fusions/ METex14 skipping detected by DNA also identified by RNA. Furthermore, we observed that PD-L1 expression was significantly elevated in the FUSION-POS group within lung adenocarcinoma patients (TPS: P=0.015). Conclusions: Our findings indicate that 11.22% of Chinese LUAD patients possess actionable fusions and METex14 skipping. The detection rate of fusions/ METex14 skipping via RNA is higher than that via DNA, with RNA detection fully encompassing all fusions/ METex14 skipping identified by DNA. Meanwhile, the association between fusions and PD-L1 expression suggests potential synergies for combining targeted therapy and immunotherapy in NSCLC.

Diagnosis and treatment of non-small cell lung cancer (NSCLC) harboring MET Ex14 skipping: have we met the desired drug?

Diagnosis and treatment of non-small cell lung cancer (NSCLC) harboring MET Ex14 skipping: have we met the desired drug?

Comparison and performance of three plasma next-generation sequencing assays versus tissue testing for the detection of actionable driver mutations in advanced non-squamous non-small cell lung carcinoma.

e20018 Background: Liquid biopsy (LB) is a useful tool for the detection of actionable mutations in advanced non-squamous non-small cell lung cancer (NS-NSCLC) at progression. However, the clinical benefits of integrating both LB and tissue biopsy (TB)-based genomic profiling at diagnosis of NS-NSCLC remain uncertain. Methods: We tested three commercially available next-generation sequencing (NGS) gene panel assays in circulating cell-free DNA (cfDNA) using replicate sets of 85 LB samples from advanced NS-NSCLC patients at baseline and compared the results with matched TB for the detection of tier IA/B (AMP/ASCO/CAP classification) alterations. We used methylation testing of cfDNA to assess the tumor fraction (TF). We correlated molecular data with clinico-pathological features and follow-up data. Results: All TB-based NGS results were interpretable. 5 LB-based NGS results for one assay were not performed due to the material exhaustion. Tier IA/B gene alteration was detected by LB-based NGS and TB-based NGS in 18 to 23 (21 to 27%) patients and in 35 (41%) patients, respectively. The positive percent agreement of each LB-based NGS assay method compared with TB-based NGS assay ranged from 51% to 68%. The incremental add provided by first LB-based NGS ranged from 0 to 23% versus 25 to 45% for first TB-based NGS, depending on the LB-based NGS assay. It includes one EGFR uncommon mutation, 9 MET amplifications and 2 HER2 amplifications detected by LB-based NGS assays that were not detected by TB-based NGS. Overall agreement between the three LB-based NGS assays was 44%. Hybrid-capture based assay detects 14 MET/HER2 CNVs, two METex14 skipping mutation and two ALK fusions that were not detected by amplicon-based assay. Amplicon-based assay detects one uncommon EGFR mutation, one KRAS non-G12C and one ALK fusion that were not detected by hybrid-capture based assay. 64 LB samples were tested for cfDNA methylation. Positive predictive value and negative predictive value of the detection of TF by cfDNA methylation profiling was 90% and 92%, respectively. The only false-negative result of TF evaluation by cfDNA methylation profiling was observed for a variant with a cfDNA VAF &lt; 1%. Correlation analyses with clinicopathological data are ongoing. Conclusions: While concordance with tissue is relatively high, the incremental add provided by LB-based NGS at diagnosis of advanced NS-NSCLC compared to TB-based NGS is limited and greatly varies according to the sequencing method used. Thus, LB-based NGS at diagnosis of NSCLC can be used as a complement of TB-based NGS or as an alternative when tissue is not available.

Molecular profiling across histologies in lung cancer: Time to change WHO nomenclature?

8532 Background: Biomarker testing is essential for optimal therapeutic management of Non-Small lung Cancer (NSCLC). However, a not negligible percentage of patients (pts) is not tested in clinical practice for all the relevant actionable biomarkers. Biomarker testing is recommended in lung adenocarcinoma (LUAD), while in tumors with other histologies it is reserved when clinical features indicate a higher probability of an oncogenic driver. Histopathology report and biomarker testing are usually performed sequentially, which is time consuming and delays patient care. Herein we determined the distribution of actionable biomarkers across NSCLC histotypes and other clinic-demographic characteristics. Methods: This is an observational retrospective analysis on histologically confirmed NSCLC cases tested between 2014-2022 using FoundationOne/FoundationOneCDx assay. Histopathologies of all cases were centrally reviewed and confirmed by Board Certified Anatomic Pathologists. Results: 82,328 NSCLC pts were included. Actionable genomic alterations (GA) were found in 35.1% of the cases (Table). LUAD and adenosquamous (ASC) were more commonly associated with actionable GA (45.8% and 40.9%, respectively) as compared with sarcomatoid (29.1%), not otherwise specified (NOS) (27.6%), large cell (LCC) (21.1%), and squamous cell (LUSC) (6.5%) histologies. Sarcomatoid histology had the highest METex14 skipping mutations (muts) frequency (9.9% vs. 2.4% in LUAD). Tumor mutational burden (TMB) ≥10 Mut/Mb was associated with histology (50.9% in LCC, 40.8% in NOS, 39.1% in LUSC, and 36.3% in sarcomatoid vs. 31.2% in LUAD and 29.2% in ASC). Pts with actionable GA usually had a low TMB (80.9%). A significant correlation (p&lt;0.005) between age and actionable GA was reported for BRAF/ ERBB2 muts, ALK/RET/ROS1 rearrangements (RE), and MET amplification. EGFR actionable muts and KRASG12C were more commonly observed in females, whereas no significant correlation between sex and other GA was observed. Finally, genetic ancestry analyses revealed a strong correlation between EGFR actionable muts and South/East Asian and American ancestries, but not for other GA. Conclusions: This is the largest NSCLC dataset analyzed for biomarker distribution across histologies, age, sex and genetic ancestry. This dataset confirms sufficient enough biomarker prevalence across LUAD and ASC carcinoma to be included in WHO nomenclature for lung tumors, and provides reassurance that cases with NOS, LCC and sarcomatoid histologies must be considered for biomarker workup. [Table: see text]

First-line immunotherapy in patients with mNSCLC with rare molecular alterations.

e20604 Background: Oncogene-addicted non-small cell lung cancer (NSCLC) is an heterogeneous group including different molecular alterations. Most single agent (IO) and combination immunotherapy (CT-IO) trials excluded specific oncogene-addicted NSCLCs such as ALK and EGFR; however, it is likely that other oncogene driven tumours were not tested for but included in these trials and could be actually treated with IO in clinical practice. Methods: Among 428 patients treated with IO or CT-IO as first-line treatment, 30 patients were identified to harbour rare molecular alterations (37% non-smokers, 63% former or current smokers): METex14 skipping mutation (n = 10), MET amplifications (n = 4), BRAF other than V600E mutations (n = 7), HER2 exon 20 insertions (n = 5), RET fusions (n = 2), EGFR exon 20 insertions (n = 2). We analyzed progression-free survival (PFS) and overall survival (OS) in patients harbouring these mutations who underwent first-line IO (if PD-L1≥50%; n = 23) or CT-IO (if PD-L1 &lt; 1-49% n = 2 or &lt; 1% n = 5). Results: In whole population median PFS was 5,1 months (95%CI: 2,39-11,29) and median OS 25,5 months (95%CI: 8,80-60,98); 13 patients experienced progressive disease as best response, the disease control rate (DCR) was 56,7%. Patients treated with IO (n = 22) had a mPFS of 4,7 m (95%CI: 2,13-23,48) and a mOS of 29,8 months (95%CI: 10,08-60,98); those treated with CT-IO (n = 8) had a mPFS of 5,1 m (95%CI: 2,29-6,01) and a mOS of 8,5 m (95%CI: 7,68-12,51). Among the most represented molecular alterations, MET alterations (n = 14, 3 treated with CT-IO and 11 with IO) had a mPFS of 5,1 m (95%CI: 1,67-23,90) and a mOS of 25,5 m (95%CI: 8,80-60,72). In particular METex14 skipping mutations had a mPFS of 5,1 m and a mOS of 25,5 m, while MET amplifications had a mPFS of 2,4 m and mOS of 10,3 m. BRAF nonV600E mutations (n = 7, 2 treated with CT-IO and 5 with IO) had a mPFS 5,3 m and mOS not reached. HER2 exon 20 insertions (n = 5, 2 treated with CT-IO and 3 with IO) had a similar mPFS (6,0 m) but a poorer OS outcome (8,5 m). ( Table 1) Conclusions: Our results show a limited effectiveness of both IO alone and CT-IO as first-line treatment in oncogene addicted mNSCLC, even taking into account survival outcomes of upfront CT compared to targeted agents in pivotal trials. [Table: see text]

Retrospective Analysis to Optimize the Detection of MET Exon 14 Skipping Mutations in Non-Small Cell Lung Cancer.

Our study optimized METex14 skipping mutation detection by analyzing 223 Oncomine™ Focus Assay-positive cases using Pan Lung Cancer PCR Panel and reverse transcription (RT)-PCR. Among the 11 METex14 skipping mutation-positive cases (average read counts: 1390), 2 with Oncomine™ Focus Assay read counts of 2540 and 10,177 were positive on all platforms. Those with Oncomine™ Focus Assay read counts ranging from 179 to 612 tested negative elsewhere. Specimens with low ratios (average ratio: 0.12% for nine cases) may yield false-positive results. Our results suggested that monitoring read counts and ratios and validating the results with RT-PCR are crucial to prevent false positives.

Abstract 2116: Telisotuzumab vedotin (Teliso-V)-mediated c-Met internalization, endolysosomal trafficking, and potent cytotoxic activity are unaffected by MET exon-14 skipping mutation

Abstract Background: Telisotuzumab vedotin (Teliso-V) is an antibody-drug conjugate (ADC) composed of a c-Met (MET protein) antibody coupled to the microtubule inhibitor monomethyl auristatin E (MMAE). Teliso-V was granted FDA Breakthrough Therapy Designation for advanced/metastatic EGFR WT, NSQ NSCLC with high c-MET overexpression. For MMAE drug delivery, Teliso-V must first undergo receptor internalization and endolysosomal (EL) trafficking. Hepatocyte growth factor (HGF)-dependent MET EL trafficking and degradation depend on the E3 ubiquitin ligase Casitas B-lineage lymphoma (CBL). METex14 skipping and CBL-binding site mutations, which delete the binding site for CBL, occur in ~ 3% of NSCLC. The role of CBL in Teliso-V-MMAE delivery and activity was assessed in this work. Methods: WT-human c-Met, c-Met-Y1003F/N (CBL binding site mutations in MET), and c-Met-ex14∆ (47 aa deletion to mimic ex14 skipping) or CBL-L620f, G807*, and W802* (CBL inactivating mutants) were expressed in NIH3T3, Ba/F3 cells, or A549 tumor cells using retroviral transduction. Genetically modified cells were then used to define the role of CBL in c-Met surface expression, intracellular signaling, EL trafficking (using pHrodo Red-labeled Teliso-V), and Teliso-V sensitivity in 2D/3D cell cultures. Results: c-Met expression was required for Teliso-V cytotoxicity and intracellular payload delivery in all cell lines. While minimal changes in cell surface c-Met levels were observed, CBL binding mutants had increased phosphorylated c-Met in the absence of HGF, and ex14∆-MET and CBL binding site mutants showed increased sensitivity to small molecule c-Met inhibitors. Compared to WT c-Met, ex14∆ and CBL-binding mutants showed similar EL trafficking and no change in sensitivity to Teliso-V. Co-treatment with a pan-CBL inhibitor also failed to alter Teliso-V EL trafficking and anti-tumor activity. Like most ADCs, EL trafficking was dependent on a dynamin-mediated process with reduced EL trafficking by co-treatment with Dyngo4a. To further understand the role of CBL in Teliso-V sensitivity, we expressed CBL inactivating mutations in A549 tumor cells. While the L602F and W802* mutants increased spheroid size, as well as activated p-MET, there was no change in sensitivity to Teliso-V. Conclusions: Loss of CBL-binding sites on c-Met via ex14 deletion or Y1003F/N leads to increased MET-targeted TKI sensitivity and increased phospho-c-Met levels but does not impact Teliso-V sensitivity or EL trafficking. Our results indicate that Teliso-V traffics to the EL via a dynamin-mediated process. Therefore, Teliso-V delivers MMAE through a robust ADC-mediated EL-dependent mechanism that is independent of CBL, suggesting that high c-Met expression in Ex14skipping or CBL binding site mutant NSCLC patients should be further investigated for response to Teliso-V. Citation Format: Izhar Batth, Ronald Pandoy, Shamim Khaja, Dolonchampa Maji, Tamar Uziel, Athan Vasilopoulos, Peter Ansell, PK Epling-Burnette. Telisotuzumab vedotin (Teliso-V)-mediated c-Met internalization, endolysosomal trafficking, and potent cytotoxic activity are unaffected by MET exon-14 skipping mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2116.

Abstract 7408: Robust profiling of cancer-related gene fusions: Analytical validation of PANCARNA for multiple cancer types

Abstract The impact of examining gene fusion presence in cancer patients is often overlooked, and as such, no well-established workflow currently exists for robust profiling of tumor samples in this area. We established a targeted RNA sequencing panel (PANCARNA) for investigating gene fusions across multiple cancer types and performed analytical validation to confirm performance. Furthermore, we report on the applicability of using targeted RNA sequencing for the purposes of gene expression profiling. This panel covers 117 genes associated with solid tumors. Thirty-nine FFPE samples with gene fusion status validated using an orthogonal method were used to evaluate analytical performance. Of the 39 standard samples, 33 samples were positive for gene translocation events and 6 were negative controls. Samples were collected from across 10 cancer types. To examine the robustness of the panel, 12 samples with known fusions were selected to undergo testing. Each sample was tested in triplicate across two experimental batches. Seraseq Fusion RNA Mix V4 (SeraCare, Cat. 0710-0497) standard samples were used to test the limit of detection for PANCARNA. Additionally, we explored a cohort of 22 samples with over expressed genes and 4 samples without overexpressed genes to test the expression profiling capabilities of PANCARNA and compared the results to immunohistochemistry stains. Of the 39 samples tested using the orthogonal method and targeted RNA-Seq, 38 were found to have concordant fusion calls in both methods (Positive percent agreement = 97.0%, 32/33; Negative percent agreement = 100%, 6/6; Overall percent agreement = 97.4%, 38/39). In reproducibility studies, the assay produced consistent intrarun and interrun results in all samples (Repeatability = 100%, 12/12; Reproducibility = 100%, 12/12). The limit of detection for multiple fusions of interest, such as EML4-ALK, CD74-ROS1, TPM3-NTRK1, and SLC34A2-BRAF, is found to be 0.5-1 copies per ng of RNA. ETV6-NTRK1 can be reliably detected at 2-4 copies per ng of RNA. MET ex14 skipping events can also be detected in a few as 1-2 copies per ng of RNA. To validate the capability of PANCARNA to quantify gene expression, we tested 26 samples with known gene expression levels for three genes of interest (ERBB2, EGFR, MET). ERBB2, EGFR and MET amplification detection through PANCARNA was found to have a high concordance to IHC results (Sensitivity = 96.2%, 100%, 94.7%, respectively). In conclusion, PANCARNA demonstrated highly accurate and sensitive detection of clinically relevant gene fusions. This assay produces reliable results when detecting fusions and offers high concordance to results obtained through IHC/FISH, indicating that targeted RNA seq analysis can assist with profiling gene fusion events in a clinical setting. Citation Format: Haimeng Tang, Hua Bao, Rui Liu, Shuyu Wu, Sisi Liu, Xue Wu, Yang Shao. Robust profiling of cancer-related gene fusions: Analytical validation of PANCARNA for multiple cancer types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7408.

Chinese expert consensus on clinical practice of MET detection in non-small cell lung cancer.

Mesenchymal epithelial transition (MET) factor alteration in non-small cell lung cancer (NSCLC) includes MET exon 14 skipping alteration (METex14 skipping), MET gene amplification, MET gene mutation (mainly kinase domain mutation), MET gene fusion, and MET protein overexpression. The incidence of METex14 skipping in patients with NSCLC is 0.9-4.0%. At present, drugs targeting METex14 skipping have been approved in China and other countries like Japan and USA. Patients with advanced NSCLC should undergo testing, including METex14 skipping, to screen the population with benefit from targeted therapy with MET inhibitors. The incidence of de novo MET gene amplification in NSCLC patients is 1-5%, the incidence of acquired MET gene amplification in epidermal growth factor receptor tyrosine kinase inhibitor (TKI)-resistant patients is 5-50%, and the incidence in anaplastic lymphoma kinase (ALK) TKI-resistant patients is about 13%; the incidence of MET protein overexpression in NSCLC patients is 13.7-63.7%. Several clinical trials on MET gene amplification and MET protein overexpression are ongoing, which have demonstrated their important guiding significance as biomarkers in the clinical treatment with MET inhibitors. Accurate detection of MET alterations is a prerequisite for MET inhibitor therapy. Since there are many types of MET alterations and related testing methods, as well as many problems and challenges during clinical testing, further sorting and standardization are required. Combined with clinical practice experience, literature review, and expert discussion, the writing group developed this consensus on the three main types of MET alterations (METex14 skipping, MET gene amplification, and MET protein overexpression) in order to guide the practical applications of clinical MET testing.

Abstract B124: MYTX-011 is a highly internalized ADC with anti-tumor activity across a spectrum of NSCLC preclinical models with various levels of cMET expression

Abstract cMET overexpression occurs in non-small cell lung cancer (NSCLC) and antibody-drug conjugates targeting cMET (cMET-ADCs) have been developed to treat cMET+ NSCLC tumors irrespective of dependency on cMET signaling. cMET-ADCs have shown promising clinical activity, but largely in a subset of NSCLC patients whose tumors express the highest cMET levels. MYTX-011, an investigational, pH-sensitive ADC incorporating the clinically validated vcMMAE linker-payload, was specifically designed to potentially benefit a broader population of patients including those whose tumors express lower cMET levels. We’ve previously demonstrated that pH-sensitive cMET binding of MYTX-011 drives higher internalization in cMET+ tumor cells, and greater cytotoxicity against a panel of cMET+ cancer cell lines in vitro. MYTX-011 also shows superior efficacy in NSCLC xenograft models with high or moderate cMET expression levels when compared to the matched non-pH-sensitive Parent ADC or a Benchmark ADC generated by hinge conjugation of a clinical stage anti-cMET ADC antibody to vcMMAE. Here we demonstrate that the MYTX-011 monoclonal antibody, which is engineered to selectively and rapidly lose affinity at the acidic pH of endolysosomes, rapidly internalizes and accumulates in cells expressing moderate cMET levels compared to the matched parent antibody. MYTX-011 in vitro cytotoxicity correlated with cMET expression levels and conferred sensitivity to cells that were otherwise insensitive to ADCs generated with the parent or Benchmark antibodies. Importantly, cells that were only sensitive to MYTX-011, but not matched controls, expressed low and moderate levels of cMET. Furthermore, MYTX-011 was active against the low cMET-expressing NCI-H2122 xenograft model in vivo whereas the Benchmark ADC was inactive. In the moderate cMET-expressing NCI-H1975 xenograft model, MYTX-011 was more active than both the Benchmark ADC and a second benchmark ADC generated by hinge conjugation of a clinical stage biparatopic anti-cMET ADC antibody to a maytansinoid linker/toxin. MYTX-011 activity was further evaluated against a panel of NSCLC patient derived xenograft (PDX) models with relevant histology, cMET expression, and genetic profiles. MYTX-011 was highly active in cMET+ squamous and adenocarcinoma PDX, EGFR WT and mutant PDX, in a PDX model with MET ex14 skipping mutation, and in PDX with heterogenous cMET expression. Together, these findings highlight the potential of MYTX-011 as a therapeutic candidate for treating a broader range of cMET+ NSCLC malignancies than other cMET-ADCs. Citation Format: William C Comb, Deepak Kanojia, Federico Colombo, Vijay Ramesh, Nimish Gera, Thomas Chittenden, Brian Fiske. MYTX-011 is a highly internalized ADC with anti-tumor activity across a spectrum of NSCLC preclinical models with various levels of cMET expression [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B124.

C-Met immunohistochemistry as reflex test at diagnosis for non-small cell lung cancer: a real-world experience from a monocentric case series

AimsRecent clinical trials have shown promising results with drugs targeting the hepatocyte growth factor receptor (c-Met) for advanced non-small cell lung cancers overexpressing c-Met. We assessed reflex testing of c-Met...

Comparison of molecular testing rates and biomarker positivity by histology among patients (pts) with stage IV non-small cell lung cancer (NSCLC): A quality initiative by Integra Connect PrecisionQ.

582 Background: National Comprehensive Cancer Network guidelines for NSCLC recommend biomarker testing for EGFR, ALK, ROS1, BRAF, NTRK1/2/3, METex14 skipping, KRAS, RET, and ERBB2 (HER2) in advanced or metastatic NSCLC regardless of histology. We sought to understand the testing rates for these markers among pts with a squamous (S) histology compared to pts with a non-squamous (NS) histology, while also assessing positivity rates among pts based on histology by the respective biomarkers for pts with stage IV NSCLC. Methods: We used the Integra Connect PrecisionQ real-world de-identified database of over 2 million cancer pts across 500 sites of care to assess testing rates and biomarker positivity rates based on histology among adult NSCLC patients. We included 3,889 Stage IV NSCLC pts, where we conducted chart reviews, investigating testing rates across each of the biomarkers based on patient histology (group 1). In addition, we evaluated 6,303 stage IV NSCLC pts, regardless of whether we conducted chart reviews, to assess rates of positivity among the respective biomarkers (group 2). Pts included in the analysis were diagnosed on or after 1/1/2019. We assessed rates of biomarker testing in group 1 and biomarker positivity (irrespective of the type of mutation) in group 2 stratified by histology. Descriptive analyses were used and proportions were compared using a two-tailed two-sample z-test. Results: Among the Group 1 stage IV pts in the comparison of tested vs. not-testedbased on histology (N= 3889), the average age was 72.9 (median = 75), 49% were female, 81.6% were NS. We found the testing rates among S pts (N=714) vs. NS (N=3175) as follows: EGFR-S 76% vs. EGFR-NS 92%, ALK-S 77% vs. ALK-NS 92%, BRAF-S 75% vs. BRAF-NS 87%, KRAS-S 71% vs. KRAS-NS 81%, MET-S 72% vs. MET-NS 80%, RET-S 72% vs. RET-NS 79%, ROS1-S 72% vs. ROS1-NS 79%, ERBB2-S 69% vs. ERBB2-NS 76%, and NTRK-S 62% vs. NTRK-NS 68%. All comparisons were statistically significant at P &lt; .01. Among the Group 2 stage IV pts who were tested(N = 6303), the average age was 72.6 (median = 73), 50.8% were female, 86.0% were NS. We found the positivity rates among S pts vs. NS pts as follows: EGFR-S 7.5% (N = 827) vs. EGFR-NS 19.5% (N = 4650), ALK -S 1.3% (N =837) vs. ALK-NS 3.6% (N = 5099), BRAF-S 2.8% (N = 742) vs. BRAF-NS 6.0% (N = 4399), KRAS-S 10.4% (N = 694) vs. KRAS-NS 31.1% (N=3763), MET-S 4.3 (N=645) vs. MET-NS 7.5% (N = 3537), RET-S 0.5% (N = 635) vs. RET-NS 1.4% (N= 3397), ROS1-S 0.6% (N = 629) vs. ROS1-NS 1.4% (N = 3346), ERBB2-S 2.2% (N = 504) vs. ERBB2-NS 3.8% (N = 2510), and NTRK-S 1.0% (N = 486) vs. NTRK-NS 1.5% (N = 2444). Conclusions: Our results indicate a need to increase biomarker testing among pts with S histology to be equivalent to those who were tested with a NS histology, as biomarker positivity rates present in pts with S histology warrant a molecular evaluation regardless of histology.

Biophysical and structural characterization of the impacts of MET phosphorylation on tepotinib binding

The receptor tyrosine kinase MET is activated by hepatocyte growth factor binding, followed by phosphorylation of the intracellular kinase domain (KD) mainly within the activation loop (A-loop) on Y1234 and Y1235. Dysregulation of MET can lead to both tumor growth and metastatic progression of cancer cells. Tepotinib is a highly selective, potent type Ib MET inhibitor and approved for treatment of non-small cell lung cancer harboring METex14 skipping alterations. Tepotinib binds to the ATP site of unphosphorylated MET with critical π-stacking contacts to Y1230 of the A-loop, resulting in a high residence time. In our study, we combined protein crystallography, biophysical methods (surface plasmon resonance, differential scanning fluorimetry), and mass spectrometry to clarify the impacts of A-loop conformation on tepotinib binding using different recombinant MET KD protein variants. We solved the first crystal structures of MET mutants Y1235D, Y1234E/1235E, and F1200I in complex with tepotinib. Our biophysical and structural data indicated a linkage between reduced residence times for tepotinib and modulation of A-loop conformation either by mutation (Y1235D), by affecting the overall Y1234/Y1235 phosphorylation status (L1195V and F1200I) or by disturbing critical π-stacking interactions with tepotinib (Y1230C). We corroborated these data with target engagement studies by fluorescence cross-correlation spectroscopy using KD constructs in cell lysates or full-length receptors from solubilized cellular membranes as WT or activated mutants (Y1235D and Y1234E/1235E). Collectively, our results provide further insight into the MET A-loop structural determinants that affect the binding of the selective inhibitor tepotinib.

60P Establishment and characterization of a novel lung adenocarcinoma cell line HX-JCJ harboring MET ex14 skipping mutation

60P Establishment and characterization of a novel lung adenocarcinoma cell line HX-JCJ harboring MET ex14 skipping mutation

Path Less Traveled: Targeting Rare Driver Oncogenes in Non-Small-Cell Lung Cancer.

Over the past decade, tremendous efforts have been made in the development of targeted agents in non-small-cell lung cancer (NSCLC) with nonsquamous histology. Pivotal studies have used next-generation sequencing to select the patient population harboring oncogenic driver alterations that are targetable with targeted therapies. As treatment paradigm rapidly evolves for patients with rare oncogene-driven NSCLC, updated comprehensive overview of diagnostic approach and treatment options is paramount in clinical settings. In this review article, we discuss the epidemiology, molecular testing, and landmark clinical trials addressing the targeted agents for ROS1 rearrangement, METex14 skipping mutation, EGFR exon 20 insertion, KRAS G12C mutation, HER2 mutation, RET fusion, NTRK fusion, and BRAF mutations.