[EGFR Exon 20 Insertion Mutation: Research Status and New Treatment Strategies].

In non-small cell lung cancer (NSCLC), as an improtant oncogenic driver gene, epidermal growth factor receptor exon 20 insertion (EGFR ex20ins) has a unique protein structure and is primarily drug-resistant to traditional EGFR-tyrosine kinase inhibitors (EGFR-TKIs). In recent years, exploration of targeted therapy for EGFR ex20ins has never stopped. Firstly Mobocertinib and Amivantamab obtained approval from U.S. Food and Drug Administration (FDA) for EGFR ex20ins mutant NSCLC patients, then other drugs, such as Sunvozertinib, made breakthroughs and combination therapies also obtained gains. Multi-pronged measures are hopeful to overcome EGFR ex20ins drug resistance. As mentioned above, it's definitely important to gain deeper understanding of molecular mechanism of EGFR ex20ins and assess effect and difference between novel drugs. This review is devoted to make a summary about newest achievement so to provide valuable reference about precise therapy for patients with EGFR ex20ins.
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A phase 2 study of mobocertinib as first-line treatment in Japanese patients with non-small cell lung cancer harboring EGFR exon 20 insertion mutations.

BACKGROUND: Mobocertinib is a novel, synthetic, orally administered tyrosine kinase inhibitor that inhibits many activated forms of epidermal growth factor receptor (EGFR), including those containing exon 20 insertion (ex20ins) mutations. This study aimed to assess the efficacy of mobocertinib in Japanese patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) harboring EGFR ex20ins mutations. METHODS: This was a phase 2, open-label study. Patients with NSCLC harboring EGFR ex20ins mutations who had not had previous systemic treatment received mobocertinib 160 mg once daily. The primary endpoint was the confirmed objective response rate. A planned interim analysis was completed for the first 14 patients with a centrally confirmed EGFR ex20ins mutation, with enrollment stopped if the number of patients with an objective response was five or fewer. RESULTS: In total, 33 patients were enrolled into the study (63.6% women; median age: 66 years). At the interim analysis, the objective response rate evaluated by a central independent review committee was 28.6% (4/14, 90% confidence interval: 10.4-54.0); therefore, enrollment was stopped for futility. In the full analysis set, the objective response rate was 18.2% (6/33, 95% confidence interval: 7.0-35.5); of the six responders, one patient (3.0%) had a complete response and five patients (15.2%) had partial responses. The most common treatment-related adverse events were diarrhea, paronychia, stomatitis, and nausea. CONCLUSION: Although study enrollment was terminated early owing to futility, our results showed modest activity of mobocertinib in Japanese patients with NSCLC with EGFR ex20ins mutations with no additional safety concerns.

Molecular heterogeneity and treatment outcome of EGFR exon 20 insertion mutations in Chinese patients with advanced non-small cell lung cancer: insights from a large-scale real-world study.

INTRODUCTION: This retrospective study aimed to investigate treatment patterns and outcomes in patients with NSCLC harboring EGFR20ins in China. EGFR20ins mutations are associated with poor responses to EGFR-TKIs, and limited real-world data exist regarding the efficacy of various treatment modalities. METHODS: In this retrospective, single-center study, treatment outcomes, including PFS and ORR, were evaluated for different treatment regimens based on imaging assessments. The impact of mutation heterogeneity on treatment efficacy was also explored. RESULTS: Data from 302 patients diagnosed with NSCLC with EGFR20ins were analyzed. EGFR-TKI monotherapy demonstrated suboptimal PFS compared to platinum-based chemotherapy in the first-line setting (3.00 m vs. 6.83 m, HR = 3.674, 95%CI = 2.48-5.44, p < 0.001). Platinum plus pemetrexed plus bevacizumab combination therapy showed improved PFS and ORR compared to platinum plus pemetrexed (7.50m vs. 5.43 m, HR = 0.593, 95%CI = 0.383-0.918, p = 0.019). In later-line treatments, monotherapy with EGFR-TKIs or ICIs exhibited suboptimal efficacy. The specific EGFR20ins subtype, A763_Y764insFQEA, showed favorable responses to EGFR-TKIs in real-world settings. CONCLUSIONS: This large-scale real-world study provides valuable insights into the treatment patterns and outcomes of NSCLC patients with EGFR20ins mutations in China. These findings contribute to the understanding of EGFR20ins treatment and provide real-world benchmark for future clinical trials and drug development.

Tumor immune microenvironment of NSCLC with EGFR exon 20 insertions may predict efficacy of first-line ICI-combined regimen.

OBJECTIVES: Non-small cell lung cancer (NSCLC) patients with exon 20 insertion mutations (ex20ins) of the epidermal growth factor receptor (EGFR) were resistant to monotherapy of immune checkpoint inhibitor (ICI). However, recent reports have shown that the combination of ICI and chemotherapy (ICI-combined regimen) exhibited certain efficacy for NSCLC with EGFR ex20ins. The mechanisms behind this phenomenon have not been thoroughly clarified. Hence, we conducted this study tofind correlations between the tumor immune microenvironment of EGFR ex20ins and the efficacy of ICI-combined regimen. METHODS: We performed single-cell transcriptome sequencing and multiplex immunofluorescence staining (mIF) to investigate the immune microenvironment of NSCLC patients with EGFR ex20ins, L858R, and EGFR wild-type. We analyzed 15 treatment-naïve NSCLC samples utilizing single-cell RNA sequencing (scRNA-seq). Another 30 cases of EGFR L858R and 4 cases of wild-type were recruited to compare the immune microenvironment with that of EGFR ex20ins (28 cases) by mIF. RESULTS: We observed that cell components, function and interactions varied between EGFR ex20ins, L858R, and wild-type NSCLC.We discovered similar T cell and CD8+ T cell distributions among groups but found noninferior or even better T cell activation in ex20ins patients. Infiltrating CD8+ FOXP3- T cells were significantly lower in the tumor region of EGFR ex20ins compared to wild-type. T cells from the ex20ins group had a greater tendency to promote cancer cell inflammation and epithelial-mesenchymal transition (EMT) compared to wild-type group. For macrophages, there were more M2-like macrophages in ex20ins patients. M1-like macrophages in ex20ins group produced fewer antitumor cytokines than in other groups. CONCLUSIONS: The immune microenvironment of EGFR ex20ins is more suppressive than that of L858R and wild-type, suggesting that ICI monotherapy may not be sufficient for these patients. ICI-combined regimen might be a treatment option for EGFR ex20ins due to tumor-promoting inflammation and noninferior T cell functions in the immune microenvironment.

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.

A phase II study of osimertinib in patients with NSCLC harboring EGFR exon 20 insertion: A multicenter trial of the Korean Cancer Study Group (LU17-19).

BACKGROUND: Epidermal growth factor receptor (EGFR) exon 20 insertions account for up to 10% of all EGFR mutations. Clinical outcomes in patients receiving approved EGFR exon 20 insertion-specific inhibitors have been variable. Although osimertinib has demonstrated antitumor activity in clinical trials, its clinical efficacy and translational potential remain to be determined in non-small cell lung carcinoma (NSCLC) with EGFR exon 20 insertion. METHODS: In this multicenter phase II study, patients with advanced NSCLC harboring EGFR exon 20 insertions for whom the standard chemotherapy failed received 80 mg osimertinib once daily. The primary endpoint was the investigator-assessed objective response rate (ORR) as defined by Response Evaluation Criteria in Solid Tumors version 1.1. The secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety profile. RESULTS: Among 15 patients enrolled at stage 1, the best response was most commonly disease stabilization (73.3 %), which did not meet the stage 1 threshold (objective response ≥ 2/15). As of data cutoff, two patients remained on the treatment. The median PFS and OS were 3.8 (95 % confidence interval [CI] = 1.7-5.5) months and 6.5 (95 % CI = 3.9-not reached) months, respectively. Adverse events (≥grade 3) were anemia, hypercalcemia, and pneumonia (13.3 % each), and asthenia, femur fracture, increased alkaline phosphate, hyperkalemia, bone pain, and azotemia (6.7 % each). Pre-existing EGFR C797S mutation detected in plasma limited the efficacy of osimertinib. CONCLUSION: Osimertinib at 80 mg once daily had limited efficacy and mostly showed disease stabilization with an acceptable safety profile in advanced NSCLC harboring EGFR exon 20 insertions. CLINICALTRIALS: govIdentifier: NCT03414814.

Resistance mechanisms of EGFR tyrosine kinase inhibitors, in EGFR exon 20 insertion-mutant lung cancer.

BACKGROUND: Mobocertinib, an EGFR exon 20 insertion (Ex20ins)-specific tyrosine kinase inhibitor has been used for treatment of advanced/metastatic EGFR Ex20ins-mutant non-small cell lung cancer (NSCLC). However, resistance mechanisms to EGFR Ex20ins-specific inhibitors and the efficacy of subsequent amivantamab treatment is unknown. METHODS: To investigate resistance mechanisms, tissue and cfDNA samples were collected before treatment initiation and upon development of resistance from NSCLC patients with EGFR Ex20ins mutations received mobocertinib, poziotinib, and amivantamab treatments. Genetic alterations were analyzed using whole-genome and targeted sequencing, and in vitro resistant cell lines were generated for validation. RESULTS: EGFR amplification (n = 6, including 2 broad copy number gain) and EGFR secondary mutation (n = 3) were observed at the resistance of mobocertinib. One patient had both EGFR secondary mutation and high EGFR focal amplification. In vitro models harboring EGFR alterations were constructed to validate resistance mechanisms and identify overcoming strategies to resistance. Acquired EGFR-dependent alterations were found to mediate resistance to mobocertinib in patients and in vitro models. Furthermore, two of six patients who received sequential amivantamab followed by an EGFR tyrosine kinase inhibitor had MET amplification and showed partial response. CONCLUSIONS: Our study revealed EGFR-dependent and -independent mechanisms of mobocertinib resistance in patients with advanced EGFR Ex20ins-mutant NSCLC.

Cost-effectiveness analysis of amivantamab plus chemotherapy for non-small cell lung cancer patients with epidermal growth factor receptor exon 20 insertions in the United States.

BACKGROUND: Although amivantamab has shown clinical benefits for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) exon 20 insertions, its cost-effectiveness requires further investigation. AIM: To evaluate the cost-effectiveness of amivantamab plus chemotherapy for the treatment of NSCLC patients with EGFR exon 20 insertions from the United States payer perspective. METHOD: A partitioned survival model was developed based on the data from the PAPILLON trial. Costs were derived from the pricing files of Medicare and Medicaid Services and published literature, and utility values were derived from previous studies. A 3% annual discount rate was applied to both costs and outcomes. The primary outcome was the incremental cost-effectiveness ratio (ICER). One-way sensitivity analysis, probabilistic sensitivity analysis and scenario analysis, were conducted to test the model stability. RESULTS: Amivantamab plus chemotherapy yielded an additional 1.12 quality-adjusted life years (QALYs) while increasing costs by $483,769.50 relative to the chemotherapy regimen, leading to an ICER of $432,401.16/QALY. The combination of amivantamab with chemotherapy was not cost effective at a threshold of $150,000/QALY. In the scenario analysis, the results showed that the ICERs were $263,680.69/QALY and $418,416.35/QALY when different utility values and 10-year time horizons were adopted, respectively. For PSA, the probability that amivantamab plus chemotherapy would be cost-effective was 0% if the willingness-to-pay (WTP) threshold was $150,000/QALY. CONCLUSION: Amivantamab plus chemotherapy is unlikely to be a cost-effective option for NSCLC patients with EGFR exon 20 insertions. Reducing the cost of amivantamab may produce favorable economic outcomes.

The current landscape, advancements, and prospects in the treatment of patients with EGFR exon 20 insertion mutations warrant scientific elucidation.

Epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations are the third most prevalent mutation in non-small cell lung cancer (NSCLC), following the 19del and L858R mutations. The unique nature of the EGFR ex20ins mutation poses challenges for the effectiveness of first- and second-generation EGFR tyrosine kinase inhibitors (TKIs). As a result, chemotherapy remains the primary and more effective treatment approach. However, with advancements in time and technology, numerous experimental studies have revealed the potential of novel drugs and therapies to have stronger inhibitory effects on EGFR ex20ins mutations. In this comprehensive review, we provide an overview of the current treatment landscape, recent advancements, and the prospects for patients with advanced NSCLC characterized by EGFR ex20ins mutations.

Comprehensive analysis of next generation sequencing and ARMS-PCR for detecting EGFR exon 20 insertion (ex20ins) mutations in Chinese non-small cell lung cancer patients.

Background: Amivantamab (JNJ-372) and mobocertinib (TAK-788) have been reported to have favorable therapeutic effect for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations. Thus, accurate detection of EGFR ex20ins mutations is crucial for subsequent individualized therapy. The aim of this study was to compare the two common methods of next generation sequencing (NGS) and amplification refractory mutation system polymerase chain reaction (ARMS-PCR) for detecting EGFR ex20ins mutations in Chinese NSCLC patients. Methods: We retrospectively analyzed EGFR mutations, especially for ex20ins, in 3,606 NSCLC patients detected by NGS and 1,785 patients by ARMS. Results: Among the 3,606 NGS patients, a total of 2,077 EGFR mutations and 95 EGFR ex20ins were identified, accounting for 57.6% and 2.6%, respectively. While 48.4% of EGFR mutations and 1.1% of ex20ins were detected in 1,785 ARMS patients, which were significantly lower than those of NGS (P<0.01). Thirty-four unique ex20ins variants were identified by NGS, and eight of them was reported for the first time. However, ARMS was designed to detect only several known EGFR ex20ins variants, and even did not include the most common variants in Chinese NSCLC patients. Conclusions: NGS is more advantageous and strongly recommended for the detection of EGFR ex20ins mutations. Considering the fast and cost-effective ARMS detection method, it is suggested that the primers design should be updated according to the characteristics of EGFR ex20ins mutations in Chinese NSCLC patients.

Natural History and Real-World Treatment Outcomes for Patients With NSCLC Having EGFR Exon 20 Insertion Mutation: An International Association for the Study of Lung Cancer-American Society of Clinical Oncology CancerLinQ Study.

Introduction: EGFR exon 20 insertion (ex20ins) mutations account for approximately 10% of EGFR mutations in lung adenocarcinoma. Patients with ex20ins mutation do not respond to standard EGFR tyrosine kinase inhibitor therapy. In this work, we analyzed the characteristics, treatment patterns, and outcomes in this subgroup of patients with NSCLC. Methods: The American Society of Clinical Oncology CancerLinQ Discovery data set was queried to identify patients with initial diagnosis of NSCLC between the years 1995 and 2018 and with EGFR ex20ins mutations. Data were extracted on patient demographics, tumor characteristics, treatments, and outcomes, and compared using chi-square and analysis of variance. Kaplan-Meier curves were generated to compare overall survival with log-rank tests. All analyses were performed using Python 3.6 (Python Software Foundation). Results: A total of 357 patients were eligible. Patient characteristics include a median age of 68 years comprising female sex of 54%, White race of 63%, and Black race of 9%. Approximately 62% of total patients had stage 4 disease, and 30% of all patients had brain metastasis. There were 54% of patients who were treated with chemotherapy and 15% with immune checkpoint inhibitors (ICIs). In patients with brain metastasis, 16% were treated with ICI, 18% with targeted therapy, and 59% with chemotherapy. The median survival of the entire group was 23.8 months. Among patients with stage 4 disease (n = 222): 51% were women, 64% were white, 37% had brain metastasis, 18% were treated with ICI, 14% had targeted therapy, and 60% were treated with chemotherapy. Stage 4 patients treated with targeted therapy had better survival compared with those who did not receive targeted therapy (20.6 versus 16.1 mo, p = 0.02). Univariate and multivariate analyses suggested favorable outcomes for patients treated with immunotherapy. Conclusions: EGFR ex20ins mutation represents a unique subset of NSCLC; it is associated with a higher propensity for brain metastases and a relatively modest overall survival. Novel treatment approaches are urgently needed to improve patient outcomes.

Targeted Therapies for EGFR Exon 20 Insertion Mutation in Non-Small-Cell Lung Cancer.

Non-small-cell lung cancer (NSCLC) frequently harbors mutations in the epidermal growth factor receptor (EGFR), with exon 20 insertions comprising 1-10% of these mutations. EGFR exon 20 insertions are less responsive to conventional tyrosine kinase inhibitors (TKIs), leading to the development of targeted agents. This review explores key therapeutic agents, such as Amivantamab, Mobocertinib, Poziotinib, Zipalertinib, and Sunvozertinib, which have shown promise in treating NSCLC with EGFR exon 20 insertions. Amivantamab, a bispecific antibody-targeting EGFR and c-MET, demonstrates significant efficacy, particularly when combined with chemotherapy. Mobocertinib, a TKI, selectively targets EGFR exon 20 mutations but faces limitations in efficacy. Poziotinib, another oral TKI, shows mixed results due to mutation-specific responses. Zipalertinib and Sunvozertinib have emerged as potent TKIs with promising clinical data. Despite these advances, challenges in overcoming resistance mutations and improving central nervous system penetration remain. Future research should focus on optimizing first-line combination therapies and enhancing diagnostic strategies for comprehensive mutation profiling.

Amivantamab: A Novel Advance in the Treatment of Non-small Cell Lung Cancer.

Amivantamab is a fully human bispecific monoclonal antibody indicated for treating patients with specifically large cell lung cancer. Its dosage is based on the patient's initial body weight and is administered via intravenous infusion after dilution. Therefore, this drug is given as a strategy due to the great need for a molecule targeting epidermal growth factor receptor (EGFR) and the mesenchymal-epithelial transition factor (MET), as acquired resistance to tyrosine kinase inhibitors (TKIs) was observed in the treatment of large cell lung cancer. This article encompasses a review of the benefits of amivantamab for patients with non-small cell lung cancer (NSCLC). This drug is the first therapy directed against this specific mutation, and unlike others, it could bind to two genetic receptors, whereas antibodies, in general, are directed toward a single receptor.

Evaluating the Clinical Characteristics and Prognosis of Advanced Non-Small Cell Lung Cancer with Exon 20 Insertions.

BACKGROUND: Epidermal growth factor receptor exon 20 insertion (EGFR ex20ins), an uncommon mutation in non-small cell lung cancer (NSCLC), can induce poor patient response to EGFR tyrosine kinase inhibitors (EGFR-TKI). However, the clinical features and prognosis of patients with EGFR ex20ins are not clearly understood. This study investigated the clinical characteristics and prognosis of advanced NSCLC patients with EGFR ex20ins. METHODS: Advanced NSCLC patients treated at Fujian Cancer Hospital were consecutively recruited from June 1, 2014 to December 20, 2021 and retrospectively examined. EGFR ex20ins was identified by polymerase chain reaction (PCR) or next-generation sequencing (NGS). The clinical characteristics, treatment methods, and patient outcomes were retrieved from the hospital database. The progression-free survival (PFS)  and overall survival (OS) were assessed by Kaplan-Meier analysis. RESULTS: Fourteen mutation subtypes of EGFR ex20ins were identified in the 24 enrolled patients, with EGFR ex20ins mutation more prevalent in non-smoking women. A763_Y764insFQEA and A767_V769dup (12.5% for both) were the most common mutation subtypes. Notably, no significant differences in PFS and OS were found between the first-line targeted therapy group [PFS: 257 days, 95% confidence interval (CI): 116-397 days; OS: not reached] and chemotherapy-based combination therapy group (PFS: 182 days, 95% CI: 156-207 days; OS: 998 days, 95% CI: 674-1321 days). TP53 mutation was the commonest concomitant mutation (62%), followed by EGFR amplification (25%). Chemotherapy combined with immunotherapy improved the prognosis of patients with high PD-L1 expression. CONCLUSION: For NSCLC patients with EGFR ex20ins, limited therapeutic benefits can be gleaned from either EGFR-TKIs or chemotherapy-based combination therapy.

EGFR-TKIs have limited efficacy in NSCLC patients with EGFR ex20ins. Combining chemotherapy with immunotherapy may represent a promising treatment approach for individuals with positive ex20ins and high PD-L1 expression.

A phase 1 study to assess the absolute bioavailability, mass balance, pharmacokinetics, metabolism, and excretion of [14C]-mobocertinib, an oral inhibitor of EGFR exon 20 insertion mutations, in healthy participants.

Mobocertinib (TAK-788) is a first-in-class oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that received accelerated approval for the treatment of patients with non-small cell lung cancer with EGFR exon 20 insertion mutations previously treated with platinum-based chemotherapy. This phase 1, 2-period, study was conducted to assess the absolute bioavailability of mobocertinib (Period 1), as well as mass balance, pharmacokinetics, metabolism, and excretion of [14C]-mobocertinib (Period 2) in healthy adult males. In Period 1, participants received a single oral capsule dose of 160 mg mobocertinib, followed by a 15-minute intravenous infusion of 50 µg (~ 2 µCi) [14C]-mobocertinib administered from 3.75 to 4 h after the capsule dose. In Period 2, a single oral dose of 160 mg (~ 100 µCi) [14C]-mobocertinib was administered as an oral solution. The geometric mean absolute bioavailability of mobocertinib was determined to be 36.7%. After oral administration of [14C]-mobocertinib, mobocertinib and its active metabolites, AP32960 and AP32914, were minor components in plasma, accounting for only 0.275% of total plasma radioactivity as the majority of mobocertinib-related material was covalently bound to plasma proteins. The geometric mean percentage of the administered radioactive dose recovered in the urine and feces was 3.57% and 76.0%, respectively. Only 0.39% of the oral dose of [14C]-mobocertinib was recovered in the urine as mobocertinib; thus, indicating that renal excretion of unchanged drug was a very minor pathway of elimination. In both treatment periods, mobocertinib was generally safe and well-tolerated as all adverse events were Grade 1 in severity. (Trial registration number ClinicalTrials.gov NCT03811834. Registration date January 22, 2019).

Dacomitinib exhibits promising activity against the rare HER2 exon 20 insertion M774delinsWLV in lung cancer: A case report and literature review.

A775_G776insYVMA, the typical and predominant HER2 exon 20 insertion variant in non-small cell lung cancer, exhibits relative insensitivity to covalent HER2-targeted tyrosine kinase inhibitors. However, other less common insertions have shown better responses to HER2-targeted inhibitors. M774delinsWLV is a rare HER2 exon 20 insertion subtype and its clinical sensitivity to HER2-targeted inhibitors remains unclear. Furthermore, there is a lack of current studies to elucidate its structure and predict its sensitivity to HER2-targeted tyrosine kinase inhibitors. Herein, we presented a case of non-small cell lung cancer harboring M774delinsWLV who derived favorable response and significant survival benefit from HER2-targeted tyrosine kinase inhibitors. A 60-year-old male with metastatic lung adenocarcinoma carrying M774delinsWLV received pyrotinib monotherapy as first-line treatment. After rapid disease progression at three months, sequential combination therapy with pyrotinib and bevacizumab yielded promising antitumor activity and sustained progression-free survival benefits for nearly a year. Subsequent dacomitinib monotherapy displayed significant activity against this uncommon insertion, resulting in a rapid decrease in tumor markers and partial response, along with progression-free survival of one year. The molecular simulation revealed no significant differences in the overall protein structure and binding pocket region between M774delinsWLV and the HER2 wild type. Drug binding dynamics simulation indicated that dacomitinib exhibited the most potent binding activity compared to afatinib, pyrotinib and poziotinib. Conclusively, dacomitinib exhibited promising efficacy against the rare HER2 exon 20 insertion M774delinsWLV. Extensive investigation is needed to elucidate the effects of HER2-targeted tyrosine kinase inhibitors on non-small cell lung cancer with different HER2 insertion subtypes.

Current status and breakthroughs in treating advanced non-small cell lung cancer with EGFR exon 20 insertion mutations.

Recently, targeted therapy and immunotherapy have emerged as effective treatment options for non-small cell lung cancer (NSCLC). This progress has been facilitated by the rapid development of diagnostic and therapeutic technologies and the continuous research and development of new drugs, leading to a new era in precision medicine for NSCLC. This is a breakthrough for patients with common mutations in the human epidermal growth factor receptor (EGFR) gene in NSCLC. Consequently, the use of targeted drugs has significantly improved survival. Nevertheless, certain rare genetic mutations are referred to as EGFR exon 20 insertion (ex20ins) mutations, which differ in structure from conventional EGFR gene mutations, namely, exon 19 deletion mutations (19-Del) and exon 21 point mutations. Owing to their distinct structural characteristics, patients harboring these EGFR ex20ins mutations are unresponsive to traditional tyrosine kinase inhibitor (TKI) therapy. This particular group of patients did not fall within the scope of their applicability. However, the activating A763_Y764insFQEA mutation elicits a more pronounced response than mutations in the near and far regions of the C-helix immediately following it and should, therefore, be treated differently. Currently, there is a lack of effective treatments for EGFR ex20ins mutations NSCLC. The efficacy of chemotherapy has been relatively favorable, whereas the effectiveness of immunotherapy remains ambiguous owing to inadequate clinical data. In addition, the efficacy of the first- and second-generation targeted drugs remains limited. However, third-generation and novel targeted drugs have proven to be effective. Although novel EGFR-TKIs are expected to treat EGFR ex20ins mutations in patients with NSCLC, they face many challenges. The main focus of this review is on emerging therapies that target NSCLC with EGFR ex20ins and highlight major ongoing clinical trials while also providing an overview of the associated challenges and research advancements in this area.

Detection of EGFR exon 20 insertion mutations in non-small cell lung cancer: implications for consistent nomenclature in precision medicine.

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations (E20ins) are the third most frequent mutations observed in non-small cell lung cancer, accounting for approximately 1-10% of all EGFR mutations. In the era of precision medicine and targeted therapies, consistent naming of genetic alterations is crucial to avoid confusion and errors. However, the annotation of EGFR E20ins mutations has been inconsistent, leading to confusion in the scientific literature and product documentation. In this study, our primary objective was to investigate the usage of different annotation related to EGFR E20ins in independent studies. Additionally, we assessed the distribution of EGFR E20ins mutations and estimated the detection coverage expected from each available EGFR E20ins detection assay. A total of 1,418 EGFR E20ins mutations were collected from six studies (FoundationInsights, Geneseeq Technology Inc, mobocertinib phase I/II trial, poziotinib phase II trial, sunvozertinib phase I trial, and Samsung Medical Center) and reorganised according to Human Genome Variation Society (HGVS) nomenclature. Our analysis revealed that the majority of EGFR E20ins mutations requiring correction were 'insertion' or 'deletion-insertion', which should be appropriately designated as 'duplication'. Additionally, duplicated variants were reported using different annotations in each study, and furthermore, even identical variant sequences were annotated differently within the same study. In all six studies, p.A767_V769dup and p.S768_D770dup were the most frequently observed EGFR E20ins. The Oncomine Dx Target Test showed the highest patient coverage at 77.2%, followed by the Droplex EGFR Mutation Test v2 with a patient coverage of 70.5% for EGFR E20ins patients. To ensure comprehensive coverage in real-world settings, it is essential to standardise the annotations for each variant, for example using the HGVS nomenclature. The accurate classification and analysis of drug responsiveness in EGFR E20ins necessitate consideration of the nomenclature, particularly with respect to the locations where the actual mutations occur.

Clinical outcomes in patients with non-small cell lung cancer harboring EGFR Exon20 in-frame insertions in the near-loop and far-loop: Results from LC-SCRUM-Asia.

OBJECTIVES: In this study, we explored the clinical outcomes of non-small cell lung cancer (NSCLC) patients with EGFR Exon20 in-frame insertions (Exon20ins), and the impact of the location of Exon20ins on these clinical outcomes. MATERIALS AND METHODS: The efficacies of current systemic therapies in NSCLC patients harboring Exon20ins were investigated using a large-scale clinico-genomic database of LC-SCRUM-Asia, and compared with that of amivantamab in the CHRYSALIS trial. RESULTS: Of the 11,397 patients enrolled in LC-SCRUM-Asia, Exon20ins were detected in 189 patients (1.7 %). Treatment with classical EGFR tyrosine-kinase inhibitors (classical TKIs) was associated with a significantly shorter progression-free survival (PFS) in NSCLC patients with Exon20ins as compared with Exon19 deletions and L858R. Post platinum-based chemotherapy, classical TKIs and immune checkpoint inhibitors (ICIs) were associated with a shorter PFS than with docetaxel in patients with Exon20ins (HR [95 % CI]; TKIs vs docetaxel, 2.16 [1.35-3.46]; ICIs vs docetaxel, 1.49 [1.21-1.84]). Patients treated with amivantamab in the CHRYSALIS trial showed a risk reduction in PFS and overall survival as compared with LC-SCRUM-Asia patients treated with docetaxel, classical TKIs, or ICIs. Among the 189 patients, Exon20ins were classified as near-loop or far-loop insertions in 115 (61 %) and 56 (30 %) patients, respectively. Treatment with osimertinib was associated with a longer PFS in patients with Exon20ins in near-loop as compared with far-loop (median, 5.6 vs. 2.0 months; HR [95 % CI], 0.22 [0.07-0.64]). CONCLUSIONS: After platinum-based chemotherapy, classical TKIs and ICIs are less effective in NSCLC patients with Exon20ins, and amivantamab may be a promising targeted therapy. There is a possibility that the location of Exon20ins has an impact on the efficacy of TKIs.

A study of high dose furmonertinib in EGFR exon 20 insertion mutation-positive advanced non-small cell lung cancer.

Background: The epidermal growth factor receptor (EGFR) ex20ins mutation, as a rare subtype of mutation, has gradually attracted attention. Its heterogeneity is high, its prognosis is extremely poor, and the efficacy of existing traditional treatment plans is limited. In this study, we aimed to evaluate efficacy of high dose furmonertinib as a first-line treatment for EGFR ex20ins-positive NSCLC. Methods: This is a retrospective, multi-center, non-interventional study. From May 2021 to March 2023, 9 NSCLC patients with EGFR ex20ins were enrolled. Efficacy and safety of 160 mg furmonertinib were evaluated. Objective response rate (ORR), disease control rate (DCR), median progression-free survival (PFS) and treatment related adverse events (TRAEs) were assessed. Results: Of the evaluated patients, six patients experienced partial remission (PR), two patients experienced stable disease (SD) and one patient experienced progress disease (PD). Data indicated 66.7% ORR and 88.9% DCR. The median progression free survival (PFS) was 7.2 months (95% CI: 6.616 - 7.784). Besides, a longgest PFS with 18 months was found in one patient with p.H773_V774insGTNPH mutation. No ≥ level 3 adverse events have been found. Conclusions: The study proved the potential efficacy of 160mg furmonertinib in patients with advanced NSCLC with EGFR ex20ins. Meanwhile, 160mg furmonertinib had a good safety profile.