Epidermal growth factor receptor exon 20 insertion variants in non-small cell lung cancer patients

The relevance of the reference range for EGFR testing in non-small cell lung cancer patients

INTRODUCTION

Identifying mutations in the epidermal growth factor receptor (EGFR) gene is crucial for individualized treatment of non-small cell lung cancer (NSCLC) patients. Accordingly, several methodologies and instruments are now commercially available to detect these alterations. The aim of this study was to examine the performance of next generation sequencing (NGS) in detecting both common and uncommon EGFR gene mutations in advanced NSCLC patients.

METHODS

We retrospectively retrieved molecular data from n = 1312 advanced stage NSCLC patients tested by our NGS DNA-based panel (namely SiRe® panel) from January 2018 to December 2022. We subsequently compared the NGS results with the reference ranges of the most popular real time PCR (RT-qPCR) assays (cobas® EGFR Mutation Test v2, EasyPGX® ready EGFR, Idylla™ EGFR mutation test, and therascreen® EGFR Plus RGQ).

RESULTS

Overall, NGS detected n = 234 mutations in n = 192 (15.9 %) patients. Conversely, when these results were compared with the reference ranges of the four most common commercially available RT-qPCR assays, far fewer mutations were identified: n = 18 (9.4 %), n = 17 (8.9 %), n = 17 (8.9 %), and n = 18 (9.4 %) mutations. These results suggest that if patients were tested solely using RT-qPCR assays, a substantial proportion would have been ineligible for targeted therapies.

CONCLUSIONS

Our study highlights that NGS is able to identify a much higher number of actionable EGFR mutations than RT-qPCR approaches, thereby providing many more patients the opportunity to receive targeted EGFR treatments.

Current clinical practice and physicians' insights on Chinese patients with advanced non-small cell lung cancer habouring epidermal growth factor receptor 20 insertion mutation

BACKGROUND

The present study aimed to investigate physicians' perspectives on the diagnosis and treatment decisions for patients with non-small cell lung cancer (NSCLC) harbouring epidermal growth factor receptor (EGFR) exon 20 insertion (exon20ins) mutations in a real-world setting in China using an online questionnaire.

METHODS

This study was performed via the CAPTRA-Lung collaboration between December 9, 2022 and March 6, 2023. The questionnaire was distributed digitally to physicians around China and was comprised of three sections: basic characteristics of surveyed physicians, diagnosis and treatment status of NSCLC patients with the EGFR exon20ins-mutation, and physicians' perspectives on treatment options. Physicians who treat more than 10 patients with advanced NSCLC every month and who have treated patients with advanced EGFR exon20ins-mutant NSCLC in the past six months were involved in this study.

RESULTS

A total of 53,729 questionnaires were distributed and 390 valid ones were collected. The EGFR mutation test was performed in 80.9% and 59.9% of patients receiving first-line or second-line therapy and beyond (hereinafter "second-line")therapy, respectively. In terms of treatment options, chemotherapy plus antiangiogenic therapy was the most common treatment option (30.0% of patients in first-line settings; 25.0% of patients in second-line settings), and a certain proportion of patients received novel EGFR exon20ins-targeted agents (including tyrosine kinase inhibitors [TKIs] and bispecific antibodies) in first- or second-line settings, which accounted for 11.9% and 15.7% of all treated patients, respectively. Additionally, physicians reported the highest satisfaction score for the efficacy and safety of targeted agents. Most physicians believed that EGFR exon20ins-targeted TKIs represented the most promising treatment option (80.2% in first-line treatment and 73.3% in second-line treatment). Among several novel agents under study, sunvozertinib has received the highest recognition for efficacy and safety.

CONCLUSIONS

This study investigated the current diagnosis and treatment status and physicians' perspective, of patients with EGFR exon20ins-mutant NSCLC. The results highlight significant unmet clinical needs in this subgroup of patients. EGFR exon20ins-targeted TKIs were recognized as the most promising treatment regimen and may benefit more patients considering their awareness and acceptance of targeted therapy.

Current status of molecular diagnostics for lung cancer

The management of lung cancer (LC) requires the analysis of a diverse spectrum of molecular targets, including kinase activating mutations in EGFR, ERBB2 (HER2), BRAF and MET oncogenes, KRAS G12C substitutions, and ALK, ROS1, RET and NTRK1-3 gene fusions. Administration of immune checkpoint inhibitors (ICIs) is based on the immunohistochemical (IHC) analysis of PD-L1 expression and determination of tumor mutation burden (TMB). Clinical characteristics of the patients, particularly age, gender and smoking history, significantly influence the probability of finding the above targets: for example, LC in young patients is characterized by high frequency of kinase gene rearrangements, while heavy smokers often have KRAS G12C mutations and/or high TMB. Proper selection of first-line therapy influences overall treatment outcomes, therefore, the majority of these tests need to be completed within no more than 10 working days. Activating events in MAPK signaling pathway are mutually exclusive, hence, fast single-gene testing remains an option for some laboratories. RNA next-generation sequencing (NGS) is capable of detecting the entire repertoire of druggable gene alterations, therefore it is gradually becoming a dominating technology in LC molecular diagnosis.

Research for accurate auxiliary diagnosis of lung cancer based on intracellular fluorescent fingerprint information

The distinctions in pathological types and genetic subtypes of lung cancer have a direct impact on the choice of treatment choices and clinical prognosis in clinical practice. This study used pathological histological sections of surgically removed or biopsied tumor tissue from 36 patients. Based on a small sample size, millions of spectral data points were extracted to investigate the feasibility of employing intracellular fluorescent fingerprint information to diagnose the pathological types and mutational status of lung cancer. The intracellular fluorescent fingerprint information revealed the EGFR gene mutation characteristics in lung cancer, and the area under the curve (AUC) value for the optimal model was 0.98. For the classification of lung cancer pathological types, the macro average AUC value for the ensemble-learning model was 0.97. Our research contributes new idea for pathological diagnosis of lung cancer and offers a quick, easy, and accurate auxiliary diagnostic approach.

Improving the turnaround time of molecular profiling for advanced non-small cell lung cancer: Outcome of a new algorithm integrating multiple approaches

BACKGROUND

Molecular tumor profiling to identify oncogenic drivers and actionable mutations has a profound impact on how lung cancer is treated. Especially in the subgroup of non-small cell lung cancer (NSCLC), molecular testing for certain mutations is crucial in daily clinical practice and is recommended by international guidelines. To date, a standardized approach to identify druggable genetic alterations are lacking. We have developed and implemented a new diagnostic algorithm to harmonize the molecular testing of NSCLC.

PATIENTS AND METHODS

In this retrospective analysis, we reviewed 119 patients diagnosed with NSCLC at the University Hospital Zurich. Tumor samples were analyzed using our standardized diagnostic algorithm: After the histological diagnosis was made, tissue samples were further analyzed by immunohistochemical stainings as well as the real-time PCR test Idylla™. Extracted DNA was further utilized for comprehensive genomic profiling (FoundationOne®CDx, F1CDx).

RESULTS

Out of the 119 patients were included in this study, 100 patients were diagnosed with non-squamous NSCLC (nsqNSCLC) and 19 with squamous NSCLC (sqNSCLC). The samples from the nsqNSCLC patients underwent testing by Idylla™ and were evaluated by immunohistochemistry (IHC). F1CDx analysis was run on 67 samples and 46 potentially actionable genomic alterations were detected. Ten patients received the indicated targeted treatment. The median time to test results was 4 days for the Idylla test, 5 days for IHC and 13 days for the F1CDx.

CONCLUSION

In patients with NSCLC, the implementation of a standardized molecular testing algorithm provided information on predictive markers for NSCLC within a few working days. The implementation of broader genomic profiling led to the identification of actionable targets, which would otherwise not have been discovered.

Prevalence, Treatment Patterns, and Outcomes of Individuals with EGFR Positive Metastatic Non-Small Cell Lung Cancer in a Canadian Real-World Setting: A Comparison of Exon 19 Deletion, L858R, and Exon 20 Insertion EGFR Mutation Carriers

Real-world evidence surrounding EGFR positive NSCLC patients in Canada is limited. Administrative databases in Alberta, Canada were used to evaluate EGFR testing and mutation prevalence in de novo metastatic NSCLC, as well as the characteristics, treatment patterns, and outcomes of individuals with Exon 19, L858R and Exon20ins mutations. Between 2013-2019, 2974 individuals underwent EGFR testing, of which 451 (15.2%) were EGFR positive. Among EGFR positive individuals, 221 (49.0%) had an Exon 19 mutation, 159 (35.3%) had an L858R mutation, and 18 (4%) had an Exon20ins mutation. The proportion of individuals who initiated 1L systemic therapy was 89.1% for Exon19, 85.5% for L858R, and 72.2% for Exon20ins carriers. The primary front-line systemic therapy was gefitinib or afatinib monotherapy for individuals with Exon 19 (93.4%) and L858R (94.1%) mutations versus platinum combination therapy for individuals with Exon20ins mutations (61.5%). The Exon20ins cohort had worse median overall survival from initiation of 1L systemic therapy (10.5 months [95% CI: 8.0-not estimable]) than the Exon19 (20.6 months [95% CI: 18.4-24.9]), and L858R cohorts (19.1 months [95% CI: 14.5-23.1]). These findings highlight that Exon20ins mutations represent a rare subset of NSCLC in which treatment options are limited and survival outcomes are worse relative to individuals with more common types of EGFR mutations.

Optimizing diagnosis and treatment of EGFR exon 20 insertions mutant NSCLC

The Epidermal growth factor receptor (EGFR) exon (ex) 20 insertions (ins) has been considered as an "undruggable target" for a long time, with platinum-pemetrexed combination recommended as upfront standard treatment for newly diagnosed advanced non-small cell lung cancer (NSCLC) patients. Recent preliminary data from early phase clinical trials have demonstrated that pharmacological inhibition of EGFRex20ins is possible, offering new treatment opportunities to 1-2% of advanced NSCLC patients harboring such hard-to-treat molecular alteration. Among the different drugs under clinical investigation, both amivantamab and mobocertinib have received regulatory approval in the United States, by the Food and Drugs Administration (FDA), while amivantamab has been recently approved also in Europe, for the clinical treatment of advanced NSCLC patients harboring EGFRex20ins who failed at least one prior line of systemic therapy, representing a major breakthrough in lung cancer treatment over the last year. With novel effective targeted options on the horizon, there is a renewed interest on optimizing the molecular screening of advanced NSCLC, and next-generation sequencing (NGS)-based genotyping is currently considered the gold standard approach to profile advanced NSCLC patients, as recommended by international guidelines. Herein we provide an updated overview of the most recent findings and upcoming challenges regarding both molecular detection and therapeutic management of EGFR ex20ins mutant advanced NSCLC patients.

EGFR signaling pathway as therapeutic target in human cancers

Epidermal Growth Factor Receptor (EGFR) enacts major roles in the maintenance of epithelial tissues. However, when EGFR signaling is altered, it becomes the grand orchestrator of epithelial transformation, and hence one of the most world-wide studied tyrosine kinase receptors involved in neoplasia, in several tissues. In the last decades, EGFR-targeted therapies shaped the new era of precision-oncology. Despite major advances, the dream of converting solid tumors into a chronic disease is still unfulfilled, and long-term remission eludes us. Studies investigating the function of this protein in solid malignancies have revealed numerous ways how tumor cells dysregulate EGFR function. Starting from preclinical models (cell lines, organoids, murine models) and validating in clinical specimens, EGFR-related oncogenic pathways, mechanisms of resistance, and novel avenues to inhibit tumor growth and metastatic spread enriching the therapeutic portfolios, were identified. Focusing on non-small cell lung cancer (NSCLC), where EGFR mutations are major players in the adenocarcinoma subtype, we will go over the most relevant discoveries that led us to understand EGFR and beyond, and highlight how they revolutionized cancer treatment by expanding the therapeutic arsenal at our disposal.