Poziotinib for EGFR exon 20-mutant NSCLC: Clinical efficacy, resistance mechanisms, and impact of insertion location on drug sensitivity

A real‑world study of clinical characteristics, treatment sequence and outcomes of patients with non-small cell lung cancer and EGFR exon 20 insertion mutations

OBJECTIVES

EGFR exon 20 insertion (EGFRex20ins) mutations are found in up to 4% of all patients with non-small cell lung cancer (NSCLC). These patients are often insensitive to EGFR-tyrosine kinase inhibitors (TKIs) and have worse prognosis than patients with more common EGFR mutations. In this multicenter, retrospective, real-world study, we sought to determine whether the administration of recently approved treatments that specifically target EGFRex20ins mutations could significantly improve outcomes in this patient population.

MATERIALS AND METHODS

We evaluated the clinical features of 41 patients diagnosed with NSCLC and EGFRex20ins mutations, their evolution, and response to treatments received across 7 hospitals in the Valencian Community, Spain, between 31st December 2012 and 31st December 2022.

RESULTS

32 patients (72%) developed metastatic disease, and 29 (71%) of them received oncological treatment. We found that administering a targeted therapy against EGFRex20ins mutations (amivantamab, mobocertinib and/or sunvozertinib) at some point during the course of treatment, significantly increased the median OS of metastatic patients from 8 months (95% CI 0-21.7) to 30 months (95% CI 11.1-48.8; Hazard ratio = 0.297, p = 0.02).

CONCLUSION

Our findings contribute to the evolving standard of care for this specific population and highlight the clinical benefits of targeted cancer therapies.

Efficacy and safety outcomes of emerging EGFR‑TKIs for patients with non‑small cell lung cancer with EGFR exon 20 insertion mutations: A systematic review and meta‑analysis

Lung cancer remains a leading cause of mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for ~85% of all lung cancer cases. Epidermal growth factor receptor (EGFR) exon 20 insertion mutant NSCLC is rare and associated with poor outcomes. Several novel generations (third-generation) of EGFR-tyrosine kinase inhibitors (TKIs) have been developed for the treatment of NSCLC and have shown antitumour potential. Therefore, the present study reviewed their efficacy and safety outcomes for this condition. A thorough literature searching was performed using the Cochrane Library, Web of Science, PubMed and Embase databases. Clinical trials published in English and reporting overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and treatment relevant adverse events (TRAEs) of grade ≥3 were included for further analysis. A total of 13 studies were included. All included studies reported ORRs with a pooled ORR of 0.486 [95% confidence interval (CI), 0.369-0.602]. Subgroup analysis revealed the following ORRs: 0.731 (95% CI, 0.560-0.901; I2=0%) for YK-029A; 0.608 (95% CI, 0.511-0.705; I2=0%) for sunvozertinib; 0.602 (95% CI, 0.440-0.764; I2=80.2%) for furmonertinib; 0.602 (95% CI, 0.486-0.718; I2=84.5%) for befotertinib; 0.566 (95% CI, 0.236-0.896; I2=96.3%) for amivantamab; 0.444 (95% CI, 0.215-0.674; I2=0%) for BEBT-109; and 0.256 (95% CI, 0.178-0.334; I2=75.0%) for poziotinib. The pooled DCR, median PFS and median OS were 0.843 (95% CI, 0.740-0.946), 10.11 months (95% CI, 9.58-10.64 months; I2=78.8%; P<0.001) and 23.00 months (95% CI, 20.30-25.69 months; I2=44.8; P=0.178), respectively. The pooled incidence of TRAEs of grade ≥3 was 0.458 (95% CI, 0.336-0.580; I2=96.9%; P<0.001), with the incidence of the three most reported TRAEs (diarrhoea, thrombocytopenia and anaemia) demonstrated to be 0.112 (95% CI, 0.060-0.164), 0.065 (95% CI, -0.012-0.141) and 0.040 (95% CI, 0.005-0.076), respectively. In conclusion, the emerging EGFR-TKIs for NSCLC with EGFR exon 20 insertion have a promising treatment outcome with a manageable safety profile. However, further analysis is needed when more clinical data are released.

Genetic biomarker study of sunvozertinib for clinical prognosis and prediction in NSCLC with EGFR exon 20 insertion mutation

This is a report of biomarker analysis for sunvozertinib, a leading epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) targeting EGFR exon 20 insertion mutation (exon20ins) non-small cell lung cancer (NSCLC). There is a positive correlation between positive EGFR exon20ins in plasma circulating tumor DNA (ctDNA) and advanced disease. Shorter progression-free survival and lower objective response rate (45.8% vs. 68.0%) were observed in patients with positive EGFR exon20ins compared to those with negative status. Droplet digital PCR analysis showed that the EGFR exon20ins allele in ctDNA decreased over time in 85.7% of patients, with the earliest clearance occurred after 1 week of sunvozertinib treatment. Acquired EGFR C797S is identified as a potential on-target resistance mutation to sunvozertinib. Finally, efforts are undertaken to investigate therapeutic approaches that aim to overcome the putative acquired resistance to sunvozertinib.

EGFR exon 20 insertions mutation in lung adenocarcinoma and its response by high-dose of Furmonertinib: a real-world study

BACKGROUND

LUAD patients with EGFR exon 20 insertions (ex20ins) have a poorer prognosis than those with EGFR 19del or L858R mutations. The FAVOUR study showed high-dose furmonertinib's efficacy in ex20ins patients. However, more real-world data are needed to validate these findings.

METHODS

We summarized LUAD patients who underwent NGS testing at Henan Cancer Hospital from January 1, 2020, to December 31, 2022. We then reviewed cases of patients with EGFR exon 20 insertion (ex20ins) mutations who received high-dose furmonertinib (240 mg/day) and had follow-up data. We assessed the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), time to treatment failure (TTF), overall survival (OS), and treatment-related adverse events (TRAEs).

RESULTS

A total of 3,571 patients underwent NGS testing, with 1,632 (45.70%) identified as having EGFR mutations, including 87 (2.44%) with exon 20 insertions (ex20ins). Follow-up data were complete for 21 ex20ins patients treated with 240 mg/d of furmonertinib. Thirteen had prior treatments, including targeted therapy, and four had received EGFR-TKI. By March 1, 2024, 18 patients progressed, and 13 died. The ORR was 52.40% (11/21), DCR was 100%, median PFS was 6.15 months, TTF was 10.78 months, and OS was 21.67 months. Among the 18 progressing patients, 11 had neurological progression, six had thoracic progression, and two had liver progression. Diarrhea was the most common adverse event, and no patients discontinued treatment due to AEs.

CONCLUSIONS

Among LUAD patients, 2.44% harbored EGFR exon 20 insertions (ex20ins), and furmonertinib at 240 mg/d demonstrated efficacy and was well-tolerated in this real-world study of LUAD patients with EGFR ex20ins mutations.

Predicting drug-gene relations via analogy tasks with word embeddings

Natural language processing is utilized in a wide range of fields, where words in text are typically transformed into feature vectors called embeddings. BioConceptVec is a specific example of embeddings tailored for biology, trained on approximately 30 million PubMed abstracts using models such as skip-gram. Generally, word embeddings are known to solve analogy tasks through simple vector arithmetic. For example, subtracting the vector for man from that of king and then adding the vector for woman yields a point that lies closer to queen in the embedding space. In this study, we demonstrate that BioConceptVec embeddings, along with our own embeddings trained on PubMed abstracts, contain information about drug-gene relations and can predict target genes from a given drug through analogy computations. We also show that categorizing drugs and genes using biological pathways improves performance. Furthermore, we illustrate that vectors derived from known relations in the past can predict unknown future relations in datasets divided by year. Despite the simplicity of implementing analogy tasks as vector additions, our approach demonstrated performance comparable to that of large language models such as GPT-4 in predicting drug-gene relations.

New advances in the treatment of EGFR exon20ins mutant advanced NSCLC

The epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations, albeit less frequent, are a clinically significant subset within the EGFR mutation landscape of non-small cell lung cancer (NSCLC), accounting for roughly 4%-12% of all EGFR-altered cases. Ranking as the third most prevalent EGFR mutation type, these ex20ins mutations trail the widely recognized EGFR exon 19 deletion (19-Del) and exon 21 L858R substitution. In advanced-stage NSCLC patients with EGFR exon 20 insertion mutations, conventional treatments such as EGFR tyrosine kinase inhibitors (TKIs), chemotherapy, and immunotherapies often yield suboptimal responses, resulting in unfavorable clinical outcomes. This unmet clinical need underscores the urgency to explore innovative targeted therapies. In the realm of precision medicine, targeted agents specifically tailored for EGFR ex20ins mutations have emerged as promising candidates. This review examines the latest research on targeted therapies for EGFR ex20ins mutations, dissecting the mechanisms of action of these agents, evaluating the results of relevant clinical trials, and integrating the evidence in a systematic manner. The aim is to uncover novel therapeutic insights and strategies to optimize the clinical management of patients with EGFR ex20ins mutation-positive NSCLC.

Landscape and clinical implications of EGFR exon 20 insertions in non-small cell lung cancer patients

Although most mutations in Epidermal Growth Factor Receptor (EGFR) found in non-small cell lung cancer (NSCLC) patients are targetable drivers, exon 20 insertions (ex20ins) represent a distinct and heterogeneous subgroup with differences in treatment outcomes and prognosis. Next Generation Sequencing (NGS) testing has played a key role in identifying ex20ins and associated co-alterations, enhancing our understanding of the complex biology within this group. Furthermore, new molecules recently developed, some of them still under investigation, are shown promising results in the clinical management of ex20ins patients. This review aims to give an update of the landscape of EGFR ex20ins, focusing on their molecular and clinical implications as well as on new treatment strategies emerging in clinical trials.

Prognostic and predictive biomarkers with therapeutic targets in nonsmall-cell lung cancer: A 2023 update on current development, evidence, and recommendation

BackgroundSince the publication of the original work in 2014, significant progress has been made in the characterization of genomic alterations that drive oncogenic addiction of nonsmall cell lung cancer (NSCLC) and how the immune system can leverage non-oncogenic pathways to modulate therapeutic outcomes. This update evaluates and validates the recent and emerging data for prognostic and predictive biomarkers with therapeutic targets in NSCLC.Data sourcesWe performed a literature search from January 2015 to October 2023 using the keywords non-small cell lung cancer, clinical practice guidelines, gene mutations, genomic assay, immune cancer therapy, circulating tumor DNA, predictive and prognostic biomarkers, and targeted therapies.Study selection and data extractionWe identified, reviewed, and evaluated relevant clinical trials, meta-analyses, seminal articles, and published clinical practice guidelines in the English language.Data synthesisRegulatory-approved targeted therapies include those somatic gene alterations of EGFR ("classic" mutations, exon 20 insertion, and rare EGFR mutations), ALK, ROS1, BRAF V600, RET, MET, NTRK, HER2, and KRAS G12C. Data for immunotherapy and circulating tumor DNA in next-generation sequencing are considered emerging, whereas the predictive role for PIK3CA gene mutation is insufficient.ConclusionsAdvances in sequencing and other genomic technologies have led to identifying novel oncogenic drivers, novel resistance mechanisms, and co-occurring mutations that characterize NSCLC, creating further therapeutic opportunities. The benefits associated with immunotherapy in the perioperative setting hold initial promise, with their long-term results awaiting.

Efficacy of EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer with EGFR exon 19 insertions: clinical-genomic, preclinical analysis through LC-SCRUM-Asia (multi-institutional genomic screening registry)

BACKGROUND

EGFR exon 19 insertions (EGFRex19ins) are rare EGFR mutations. Their clinical-genomic characteristics and outcomes with EGFR-tyrosine kinase inhibitors (TKIs) remain uncertain.

METHODS

We evaluated the clinical-genomic characteristics and outcomes of EGFR-TKIs for EGFRex19ins in the multi-institutional prospective lung cancer genomic screening project (LC-SCRUM-Asia). We also studied preclinical Ba/F3 models expressing EGFR-K745_E746insIPVAIK (Ba/F3-IPVAIK) to investigate their sensitivity to 1st-, 2nd-, 3rd-generation, and EGFR exon 20 insertion-active TKIs.

RESULTS

In LC-SCRUM-Asia, 16,204 NSCLC patients were enrolled from March 2015 to December 2023. EGFRex19ins were detected in 13 samples (0.1 % of NSCLC). The median age was 72 years (range, 38-80); most patients were female (77 %), had adenocarcinoma (92 %), and were never-smokers (62 %). Twelve patients (93 %) had EGFR-K745_E746insIPVAIK, while one (7 %) had EGFR-K745_E746insVPVAIK. The most frequent co-mutation was TP53 (62 %); no patients had other driver alterations. Six patients (46 %) tested positive for EGFR exon 19 deletions with PCR-based Cobas EGFR test, likely due to cross-reactivity arising from sequence homology. Twelve patients received EGFR-TKIs; five (42 %) experienced partial response. In the preclinical study, Ba/F3-IPVAIK showed the highest sensitivity to 2nd-generation EGFR-TKIs compared to other EGFR-TKIs. Structural studies supported these consistent results. When broken down by EGFR-TKI generations, response rates for 1st-, 2nd-, and 3rd-generation TKIs were 50 % (1/2), 80 % (4/5), and 0 % (0/5), respectively. The median PFS for 1st-, 2nd-, and 3rd-generation TKIs were 8.7 (95 % CI, 7.4-NR), 14.7 (95 % CI, 8.0-NR), and 4.4 (95 % CI, 3.4-NR) months, respectively.

CONCLUSION

Our preclinical, structural, and clinical findings indicate 2nd-generation EGFR-TKIs are more effective for EGFRex19ins compared to other TKIs.

Resistance Mutation Profiles Associated with Current Treatments for Epidermal Growth Factor Receptor-Mutated Non-Small-Cell Lung Cancer in the United States: A Systematic Literature Review

Treatment resistance due to gene alterations remains a challenge for patients with EGFR-mutated advanced or metastatic non-small-cell lung cancer (a/mNSCLC). A systematic literature review (SLR) was conducted to describe resistance mutation profiles and their impact on clinical outcomes in adults with a/mNSCLC in the United States (US). A comprehensive search of MEDLINE and Embase (2018-August 2022) identified 2986 records. Among 45 included studies, osimertinib was the most commonly reported treatment (osimertinib alone: 15 studies; as one of the treatment options: 18 studies), followed by other tyrosine kinase inhibitors (TKIs; 5 studies) and non-TKIs (1 study). For first-line (1L) and second-line (2L) osimertinib, the most frequent EGFR-dependent resistance mechanisms were T790M loss (1L: 15.4%; 2L: 20.5-49%) and C797X mutation (1L: 2.9-12.5%; 2L: 1.4-22%). EGFR-independent mechanisms included MET amplification (1L: 0.6-66%; 2L: 7.2-19%), TP53 mutation (1L: 29.2-33.3%), and CCNE1 amplification (1L: 7.9%; 2L: 10.3%). For patients receiving osimertinib, EGFR T790M mutation loss, EGFR/MET/HER2 amplification, RET fusion, and PIK3CA mutation were associated with worse progression-free survival. Resistance mechanisms resulting from current NSCLC treatments in the US are complex, underscoring the need to address such heterogeneous resistance profiles and improve outcomes for patients with EGFR-mutated a/mNSCLC.

Novel strategies for rare oncogenic drivers in non-small-cell lung cancer: An update from the 2024 Annual ESMO meeting

Across the landscape of oncogene-addicted non-small-cell lung cancer (NSCLC), various tyrosine kinase inhibitors (TKIs) have been introduced in the last twenty years. During the 2024 Annual ESMO meeting new therapeutic options were presented for EGFR exon 20 insertion mutation, ALK fusion and ROS1 fusion positive advanced stage NSCLC. For EGFR exon 20 insertion mutation positive NSCLC, results from REZILIENT-1, a single arm phase II study with zipalertinib, were presented, showing an objective response rate (ORR) of 50% in patients that were pretreated with amivantamab, and 25% in patients pretreated with amivantamab and an EGFR exon 20 insertion-directed TKI. The vast majority of these patients also received platinum-doublet chemotherapy. For ALK, results from ALKOVE-1, a single arm phase I/II study with NVL-655, a next generation ALK TKI, were presented. The ORR was 35 % in patients pretreated with ≥ 2 ALK TKIs including lorlatinib and 57 % in patients pretreated with ≥ 1 ALK TKI, excluding lorlatinib. The median number of prior anticancer therapies was 3. Intracranial responses were seen in lorlatinib naïve- and lorlatinib pretreated patients and toxicity was manageable. In addition, results of the first-line randomized phase III INSPIRE study were presented, in which iruplinalkib, an ALK and ROS1 selective TKI, is being evaluated versus crizotinib. Iruplinalkib showed a superior median PFS (36.8 versus 14.55 months for crizotinib), but no difference in 36-month overall survival (OS) rate. Finally, results from ARROS-1, a single arm phase I/II study with zidesamtinib, a ROS1 selective and TRK-sparing TKI, were presented. An ORR of 73% was obtained in patients that were pretreated with crizotinib and an ORR of 38% in patients pretreated with repotrectinib. In this review, we will discuss the relevant study results presented at ESMO 2024 for these three genomic drivers and hypothesize on their respective place in the sequence of treatment options.

[Standard of care of EGFR mutated metastatic NSCLC in first treatment and beyond progression]

Among the oncogenic alterations of non-small cell lung cancer (NSCLC), the EGFR gene mutation is observed in 15% of patients in France, particularly among non-smokers and women. Treatment mainly relies on tyrosine kinase inhibitors (TKIs) targeting EGFR. In first-line metastatic treatment, osimertinib, a third-generation TKI, has become the standard, improving progression-free survival (PFS) and overall survival (OS) compared to first- or second-generation TKIs. The combination of TKI/chemotherapy (osimertinib/carboplatine-pemetrexed) and TKI/bispecific antibodies (e.g., amivantamab/lazertinib) are alternatives under evaluation, with benefits in PFS but increased toxicity. In case of progression under first- or second-generation TKIs, the most common resistance is the T790M mutation, which can be targeted by osimertinib. For other resistances, platinum-based chemotherapy remains an option. Amivantamab combined with chemotherapy has shown an improvement in PFS in the second line and has early access in France. Other emerging approaches include conjugated antibodies (patritumab deruxtecan, datopotamab deruxtecan) and next-generation TKIs. In the future, personalized treatment based on the molecular profile and early response to TKIs could optimize management, particularly by integrating predictive markers such as EGFR clearance under treatment.

A patent review of small molecular inhibitors targeting EGFR exon 20 insertion (Ex20ins) (2019-present)

INTRODUCTION

Mutations in epidermal growth factor receptor (EGFR) kinase domain consistently activate downstream signaling pathways, such as the PI3K/AKT/mTOR and RAS/RAF/MEK, thereby promoting tumor growth. Although the majority of non-small cell lung cancer (NSCLC) patients harboring EGFR mutations are sensitive to existing EGFR tyrosine kinase inhibitors (EGFR-TKIs), there remains an unmet clinical need for effective therapies targeting EGFR Ex20ins mutations, making direct targeting EGFR Ex20ins mutations a promising therapeutic strategy.

AREAS COVERED

This review covers the progress of clinical studies targeting EGFR Ex20ins inhibitors and summarizes recent (1 January 2019 - 30 April 2024) patents disclosing EGFR Ex20ins inhibitors available in the Espacenet and CAS SciFinder databases.

EXPERT OPINION

An increasing number of EGFR Ex20ins inhibitors are being developed and reported. Existing inhibitors are focused on enhancing the efficacy of EGFR Ex20ins inhibitors and addressing the challenge of targeted resistance by optimizing the second - or third-generation EGFR inhibitors and developing innovative skeleton molecules. Moreover, the development of targeted protein degraders, allosteric inhibitors, and combination therapies provide additional approaches to address EGFR Ex20ins mutations. However, bypass resistance, selectivity, and drug sensitivity still pose challenges in this field.

Patient-derived xenograft model in cancer: establishment and applications

The patient-derived xenograft (PDX) model is a crucial in vivo model extensively employed in cancer research that has been shown to maintain the genomic characteristics and pathological structure of patients across various subtypes, metastatic, and diverse treatment histories. Various treatment strategies utilized in PDX models can offer valuable insights into the mechanisms of tumor progression, drug resistance, and the development of novel therapies. This review provides a comprehensive overview of the establishment and applications of PDX models. We present an overview of the history and current status of PDX models, elucidate the diverse construction methodologies employed for different tumors, and conduct a comparative analysis to highlight the distinct advantages and limitations of this model in relation to other in vivo models. The applications are elucidated in the domain of comprehending the mechanisms underlying tumor development and cancer therapy, which highlights broad applications in the fields of chemotherapy, targeted therapy, delivery systems, combination therapy, antibody-drug conjugates and radiotherapy. Furthermore, the combination of the PDX model with multiomics and single-cell analyses for cancer research has also been emphasized. The application of the PDX model in clinical treatment and personalized medicine is additionally emphasized.

The changing treatment landscape of EGFR-mutant non-small-cell lung cancer

The discovery of the association between EGFR mutations and the efficacy of EGFR tyrosine-kinase inhibitors (TKIs) has revolutionized the treatment paradigm for patients with non-small-cell lung cancer (NSCLC). Currently, third-generation EGFR TKIs, which are often characterized by potent central nervous system penetrance, are the standard-of-care first-line treatment for advanced-stage EGFR-mutant NSCLC. Rational combinations of third-generation EGFR TKIs with anti-angiogenic drugs, chemotherapy, the EGFR-MET bispecific antibody amivantamab or local tumour ablation are being investigated as strategies to delay drug resistance and increase clinical benefit. Furthermore, EGFR TKIs are being evaluated in patients with early stage or locally advanced EGFR-mutant NSCLC, with the ambitious aim of achieving cancer cure. Despite the inevitable challenge of acquired resistance, emerging treatments such as new TKIs, antibody-drug conjugates, new immunotherapeutic approaches and targeted protein degraders have shown considerable promise in patients with progression of EGFR-mutant NSCLC on or after treatment with EGFR TKIs. In this Review, we describe the current first-line treatment options for EGFR-mutant NSCLC, provide an overview of the mechanisms of acquired resistance to third-generation EGFR TKIs and explore novel promising treatment strategies. We also highlight potential avenues for future research that are aimed at improving the survival outcomes of patients with this disease.

The combination of immune checkpoint inhibitor and chemotherapy may be efficacious for advanced non-small cell lung cancer with near-loop insertions of EGFR exon 20: A retrospective analysis

ObjectiveThe sensitivity of immune checkpoint inhibitors (ICIs) as monotherapy is low in non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) exon 20 insertion mutations (ex20ins). This study aims at investigating the effectiveness of the combination of ICI and chemotherapy (ICI-combined regimen) in a real-world population of NSCLC patients harboring near-loop insertions of EGFR exon 20.MethodsWe conducted a retrospective study of advanced NSCLC with EGFR ex20ins from April 2016 to March 2021 at Guangdong Provincial People's Hospital, Southern Medical University, China. A total of 126 cases of EGFR ex20ins were screened from 1610 patients with advanced NSCLC harboring EGFR mutations and 62 cases were further analyzed for different therapeutic efficacy.ResultsThe first-line ICI-combined regimen showed marked efficacy for near-loop insertions of EGFR exon 20, with an ORR of 71.4% and a mPFS of 11.5 months, compared to ORRs of 12.5% for traditional targeted therapy (P = .003) and 18.8% for chemotherapy (P = .013). The first-line mPFS of traditional EGFR-TKIs and chemotherapy were only 5.6 and 5.8 months, respectively. Similar results were observed for any-line therapy of ICI-combined regimen, with an ORR of 80%. The median progression-free survival (PFS) of any-line therapy of ICI-combined regimen was 11.5 months, which were significantly longer than that of traditional targeted therapy (4.5 months, P = .026) and chemotherapy (5.0 months, P = .013).ConclusionsICI-combined regimen may be superior compared to targeted therapy and chemotherapy for advanced NSCLC with near-loop insertions of EGFR exon 20. Further exploration is warranted to confirm the efficacy of ICI-combined regimen.

RAS signaling in carcinogenesis, cancer therapy and resistance mechanisms

Variants in the RAS family (HRAS, NRAS and KRAS) are among the most common mutations found in cancer. About 19% patients with cancer harbor RAS mutations, which are typically associated with poor clinical outcomes. Over the past four decades, KRAS has long been considered an undruggable target due to the absence of suitable small-molecule binding sites within its mutant isoforms. However, recent advancements in drug design have made RAS-targeting therapies viable, particularly with the approval of direct KRASG12C inhibitors, such as sotorasib and adagrasib, for treating non-small cell lung cancer (NSCLC) with KRASG12C mutations. Other KRAS-mutant inhibitors targeting KRASG12D are currently being developed for use in the clinic, particularly for treating highly refractory malignancies like pancreatic cancer. Herein, we provide an overview of RAS signaling, further detailing the roles of the RAS signaling pathway in carcinogenesis. This includes a summary of RAS mutations in human cancers and an emphasis on therapeutic approaches, as well as de novo, acquired, and adaptive resistance in various malignancies.

Unraveling the future: Innovative design strategies and emerging challenges in HER2-targeted tyrosine kinase inhibitors for cancer therapy

Human epidermal growth factor receptor 2 (HER2) is a transmembrane receptor-like protein with tyrosine kinase activity that plays a vital role in processes such as cell proliferation, differentiation, and angiogenesis. The degree of malignancy of different cancers, notably breast cancer, is strongly associated with HER2 amplification, overexpression, and mutation. Currently, widely used clinical HER2 tyrosine kinase inhibitors (TKIs), such as lapatinib and neratinib, have several drawbacks, including susceptibility to drug resistance caused by HER2 mutations and adverse effects from insufficient HER2 selectivity. To address these issues, it is essential to create innovative HER2 TKIs with enhanced safety, effectiveness against mutations, and high selectivity. Typically, SPH5030 has advanced to phase I clinical trials for its strong suppression of four HER2 mutations. This review discusses the latest research progress in HER2 TKIs, with a focus on the structural optimization process and structure-activity relationship analysis. In particular, this study highlights promising design strategies to address these challenges, providing insightful information and inspiration for future development in this field.

Molecular landscape of ERBB2 alterations in 3000 advanced NSCLC patients

ERBB2 (HER2) represents a newly recognized actionable oncogenic driver in non-small cell lung cancer (NSCLC), with approved targeted therapy available. Understanding the landscape of ERBB2 alterations and co-occurring mutations is essential for guiding treatment decisions. We conducted an analysis involving 3000 NSCLC patients with all types of ERBB2 alterations, drawn from two extensive retrospective cohorts: 1281 from Geneplus (Chinese) and 1719 from Guardant360 (the United States, US). The incidence of all types of ERBB2 alterations was found to be 5.6% in the Chinese group and 5.2% in the US group. In both cohorts, among oncogenic alterations of ERBB2, exon 20 insertion Y772_A775dupYVMA was the most frequent alteration (58% vs 41.6% in the Chinese vs the US), followed by G776delinsVC/LC/VV/IC (10.7% vs 9.7%), and S310X (10.5% vs 15.4%). EGFR ex20 insertions were identified in the A767-V774 region, whereas ERBB2 ex20 insertions were observed in the Y772-P780 region. Notably, EGFR ex20 insertions exhibited greater insertion diversity. Clinical characteristics of EGFR and ERBB2 ex20 NSCLC were similar, characterized by low tumor mutation burden (TMB), a predominant never-smoker population, and a majority of lung adenocarcinoma cases.

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.

Mechanisms of resistance to tyrosine kinase inhibitor-targeted therapy and overcoming strategies

Tyrosine kinase inhibitor (TKI)-targeted therapy has revolutionized cancer treatment by selectively blocking specific signaling pathways crucial for tumor growth, offering improved outcomes with fewer side effects compared with conventional chemotherapy. However, despite their initial effectiveness, resistance to TKIs remains a significant challenge in clinical practice. Understanding the mechanisms underlying TKI resistance is paramount for improving patient outcomes and developing more effective treatment strategies. In this review, we explored various mechanisms contributing to TKI resistance, including on-target mechanisms and off-target mechanisms, as well as changes in the tumor histology and tumor microenvironment (intrinsic mechanisms). Additionally, we summarized current therapeutic approaches aiming at circumventing TKI resistance, including the development of next-generation TKIs and combination therapies. We also discussed emerging strategies such as the use of dual-targeted antibodies and PROteolysis Targeting Chimeras. Furthermore, we explored future directions in TKI-targeted therapy, including the methods for detecting and monitoring drug resistance during treatment, identification of novel targets, exploration of dual-acting kinase inhibitors, application of nanotechnologies in targeted therapy, and so on. Overall, this review provides a comprehensive overview of the challenges and opportunities in TKI-targeted therapy, aiming to advance our understanding of resistance mechanisms and guide the development of more effective therapeutic approaches in cancer treatment.

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.

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.

Drug development and evidence for lung cancer targeted therapy in Eastern Asia

The development of targeted drugs in the Eastern Asia region is going through a flourishing stage. With the continuous advancement of technology and medical research, biotechnology companies and research institutions in the region have made significant progress in cancer field. The Eastern Asian region not only actively participates in clinical trials, but is also committed to developing personalized medical plans to meet the diverse genotypes and phenotypes of patients. The governments and enterprises are increasingly valuing innovation, strengthening international cooperation, and promoting drug development. This paper summarizes the development of genetic testing technology, targeted drugs approval, ongoing promising clinical trials in the field of lung cancer and the important progress made by governments in the Eastern Asian region, and proposed key factors that will contribute to the promising future prospects in the region. The targeted drug market in the Eastern Asian region is expected to drive the medical field forward.

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.

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.

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.

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.

Non-small cell lung cancer: an update on emerging EGFR-targeted therapies

INTRODUCTION

Current research in EGFR-mutated NSCLC focuses on the management of drug resistance and uncommon mutations, as well as on the opportunity to extend targeted therapies' field of action to earlier stages of disease.

AREAS COVERED

We conducted a review analyzing literature from the PubMed database with the aim to describe the current state of art in the management of EGFR-mutated NSCLC, but also to explore new strategies under investigation. To this purpose, we collected recruiting phase II-III trials registered on Clinicaltrials.govand conducted on EGFR-mutated NSCLC both in early and advanced stage.

EXPERT OPINION

With this review, we want to provide an exhaustive overview of current and new potential treatments in EGFR-mutated NSCLC, with emphasis on the most promising newly investigated strategies, such as association therapies in the first-line setting involving EGFR-TKIs and chemotherapy (FLAURA2) or drugs targeting different driver pathways (MARIPOSA). We also aimed at unearthing challenges to achieve in this field, specifically the need to fully exploit already available compounds while developing new ones, the management of new emerging toxicities and the necessity to improve our biological understanding of the disease to design trials with a solid scientific rationale and to allow treatment personalization such in case of uncommon 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.

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.

Novel therapeutic strategies for rare mutations in non-small cell lung cancer

Lung cancer is still the leading cause of cancer-related mortality. Over the past two decades, the management of non-small cell lung cancer (NSCLC) has undergone a significant revolution. Since the first identification of activating mutations in the epidermal growth factor receptor (EGFR) gene in 2004, several genetic aberrations, such as anaplastic lymphoma kinase rearrangements (ALK), neurotrophic tropomyosin receptor kinase (NTRK) and hepatocyte growth factor receptor (MET), have been found. With the development of gene sequencing technology, the development of targeted drugs for rare mutations, such as multikinase inhibitors, has provided new strategies for treating lung cancer patients with rare mutations. Patients who harbor this type of oncologic driver might acquire a greater survival benefit from the use of targeted therapy than from the use of chemotherapy and immunotherapy. To date, more new agents and regimens can achieve satisfactory results in patients with NSCLC. In this review, we focus on recent advances and highlight the new approval of molecular targeted therapy for NSCLC patients with rare oncologic drivers.

Predictive value of PD-L1 and TMB for short-term efficacy prognosis in non-small cell lung cancer and construction of prediction models

Objective

To investigate the correlation between programmed death ligand 1(PD-L1), tumor mutation burden (TMB) and the short-term efficacy and clinical characteristics of anti-PD-1 immune checkpoint inhibitor combination chemotherapy in NSCLC patients. The efficacy of the prediction model was evaluated.

Methods

A total of 220 NSCLC patients receiving first-line treatment with anti-PD-1 immune checkpoint inhibitor combined with chemotherapy were retrospectively collected. The primary endpoint was short-term efficacy ORR. The correlation between short-term efficacy, PD-L1, TMB, and clinical characteristics using χ2 test or t-test was evaluated. Screen the independent prognostic factors using univariate and multivariate logistic regression analyses, and construct a nomogram prediction model using the "rms" package in R software. Using receiver operating characteristic (ROC) curve analysis to evaluate the independent Prognostic factors and the prediction model. Using decision curve analysis (DCA) to verify the superiority of the prediction model.

Results

The mean values of PD-L1, TMB, neutrophils, lymphocytes, neutrophil-to-lymphocyte ratio, and albumin were the highest in the ORR group, PD-L1 expression and TMB correlated with epidermal growth factor receptor expression. Multivariate analyses showed that PD-L1, TMB, and neutrophil were independent prognostic factors for ORR. The area under the ROC curve (AUC) values of the ROC constructed based on these three indicators were 0.7104, 0.7139, and 0.7131, respectively. The AUC value under the ROC of the nomogram model was 0.813. The DCA of the model showed that all three indicators used together to build the prediction model of the net return were higher than those of the single indicator prediction model.

Conclusion

PD-L1, TMB, and neutrophils are independent prognostic factors for short-term efficacy. The nomogram prediction model constructed using these three indicators can further improve predictive efficacy of ICIs in patients with NSCLC.

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.

Current management of uncommon EGFR mutations in non-small cell lung cancer

Epidermal growth factor receptor (EGFR) mutations are frequently implicated in non-small cell lung cancer (NSCLC). Though these typically involve exon 19 in-frame deletions or L858R mutations in exon 21, uncommon EGFR mutations comprise 10-15 % of all EGFR mutations. These most frequently include G719X mutations in exon 18, L861Q mutations in exon 21, S768I mutations in exon 20, and in-frame insertions and/or duplications in exon 20. It is crucial to understand these distinct variants and their specific responses to active treatment options to optimize care. In this review, we discuss these uncommon mutations in depth and dissect the current literature regarding their treatment outcomes and subsequent evidence-based management guidelines.

Synthetic Routes and Clinical Application of Representative Small-Molecule EGFR Inhibitors for Cancer Therapy

The epidermal growth factor receptor (EGFR) plays a pivotal role in cancer therapeutics, with small-molecule EGFR inhibitors emerging as significant agents in combating this disease. This review explores the synthesis and clinical utilization of EGFR inhibitors, starting with the indispensable role of EGFR in oncogenesis and emphasizing the intricate molecular aspects of the EGFR-signaling pathway. It subsequently provides information on the structural characteristics of representative small-molecule EGFR inhibitors in the clinic. The synthetic methods and associated challenges pertaining to these compounds are thoroughly examined, along with innovative strategies to overcome these obstacles. Furthermore, the review discusses the clinical applications of FDA-approved EGFR inhibitors such as erlotinib, gefitinib, afatinib, and osimertinib across various cancer types and their corresponding clinical outcomes. Additionally, it addresses the emergence of resistance mechanisms and potential counterstrategies. Taken together, this review aims to provide valuable insights for researchers, clinicians, and pharmaceutical scientists interested in comprehending the current landscape of small-molecule EGFR inhibitors.

Advances in the Diagnosis and Treatment of Advanced Non-Small-Cell Lung Cancer With EGFR Exon 20 Insertion Mutation

The discovery of epidermal growth factor receptor (EGFR) mutations has greatly changed the clinical outlook for patients with advanced non-small-cell lung cancer (NSCLC). Unlike the most common EGFR mutations, such as exon 19 deletion (del19) and exon 21 L858R point mutation, EGFR exon 20 insertion mutation (EGFR ex20ins) is a rare mutation of EGFR. Due to its structural specificity, it exhibits primary resistance to traditional epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), leading to poor overall survival prognosis for patients. In recent years, there has been continuous progress in the development of new drugs targeting EGFR ex20ins, bringing new hope for the treatment of this patient population. In this regard, we conducted a systematic review of the molecular characteristics, diagnostic advances, and treatment status of EGFR ex20ins. We summarized the latest data on relevant drug development and clinical research, aiming to provide reference for clinical diagnosis, treatment, and drug development.

Prognostic and predictive biomarkers in non-small cell lung carcinoma

Lung cancer is the most common cause of cancer-related deaths globally, with the highest mortality rates among both men and women. Most lung cancers are diagnosed at late stages, necessitating systemic therapy. Modern clinical management of lung cancer relies heavily upon application of biomarkers, which guide the selection of systemic treatment. Here, we provide an overview of currently approved and emerging biomarkers of non-small cell lung cancer (NSCLC), including EGFR, ALK, ROS1, RET, NTRK1-3, KRAS, BRAF, MET, ERBB2/HER2, NRG1, PD-L1, TROP2, and CEACAM5. For practical purposes, we divide these biomarkers into genomic and protein markers, based on the tested substrate. We review the biology and epidemiology of the genomic and proteomic biomarkers, discuss optimal diagnostic assays for their detection, and highlight their contribution to the contemporary clinical management of NSCLC.

Developments in predictive biomarker testing and targeted therapy in advanced stage non-small cell lung cancer and their application across European countries

In the past two decades, the treatment of metastatic non-small cell lung cancer (NSCLC), has undergone significant changes due to the introduction of targeted therapies and immunotherapy. These advancements have led to the need for predictive molecular tests to identify patients eligible for targeted therapy. This review provides an overview of the development and current application of targeted therapies and predictive biomarker testing in European patients with advanced stage NSCLC. Using data from eleven European countries, we conclude that recommendations for predictive testing are incorporated in national guidelines across Europe, although there are differences in their comprehensiveness. Moreover, the availability of recently EMA-approved targeted therapies varies between European countries. Unfortunately, routine assessment of national/regional molecular testing rates is limited. As a result, it remains uncertain which proportion of patients with metastatic NSCLC in Europe receive adequate predictive biomarker testing. Lastly, Molecular Tumor Boards (MTBs) for discussion of molecular test results are widely implemented, but national guidelines for their composition and functioning are lacking. The establishment of MTB guidelines can provide a framework for interpreting rare or complex mutations, facilitating appropriate treatment decision-making, and ensuring quality control.

Furmonertinib for EGFR-mutant advanced non-small cell lung cancer: a glittering diamond in the rough of EGFR-TKI

The third-generation EGFR-TKIs, such as osimertinib, aumolertinib, and furmonertinib, have been recommended as the preferred treatment for EGFR-mutant advanced non-small cell lung cancer (NSCLC). Among them, furmonertinib shows several advantages in terms of clinical efficacy. Firstly, compared to osimertinib and aumolertinib, furmonertinib was the first EGFR-TKI with median progression-free survival (mPFS) of over 20.0 m (20.8 m) for advanced NSCLC with classical EGFR-mutations. Furthermore, furmonertinib achieved a mPFS of 18.1 m in advanced NSCLC with unfavorable prognostic factors, such as the 21 L858R mutation and central nervous system (CNS) metastasis, which is unrivalled by osimertinib. Secondly, furmonertinib is the only FDA-approved EGFR-TKI for breakthrough therapy in newly-diagnosed advanced NSCLC with EGFR ex20ins mutation. Thirdly, the relatively longer mPFS of 20.8 m was observed in furmonertinib compared to osimertinib and aumolertinib (15.2 m and 15.3 m) in EGFR-mutant advanced NSCLC with CNS metastases. More importantly, the efficacy of furmonertinib increases within the dose range of 80-240 mg per day. Finally, furmonertinib can be an optional treatment for advanced NSCLC patients who develop resistance to osimertinib or aumolertinib. In conclusion, furmonertinib may be a glittering star in the field of EGFR-TKI, which requires further exploration and expansion.

New Directions for Advanced Targeting Strategies of EGFR Signaling in Cancer

Epidermal growth factor (EGF)-EGF receptor (EGFR) signaling studies paved the way for a basic understanding of growth factor and oncogene signaling pathways and the development of tyrosine kinase inhibitors (TKIs). Due to resistance mutations and the activation of alternative pathways when cancer cells escape TKIs, highly diverse cell populations form in recurrent tumors through mechanisms that have not yet been fully elucidated. In this review, we summarize recent advances in EGFR basic research on signaling networks and intracellular trafficking that may clarify the novel mechanisms of inhibitor resistance, discuss recent clinical developments in EGFR-targeted cancer therapy, and offer novel strategies for cancer drug development.

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.

Targeting EGFR Exon 20 Insertion Mutations in Non-small-Cell Lung Cancer: Changes in Treatment Strategies are Coming

Epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations are the third most frequent EGFR mutation type, following only exon 19 deletions and exon 21 L858R point mutations. EGFR ex20ins mutations are found in approximately 4%-12% of all EGFR-positive non-small cell lung cancers (NSCLCs). Unlike classical EGFR mutations, EGFR ex20ins mutations display remarkable subtype diversity and heterogeneity. Patients harboring these mutations generally have an inferior prognosis because of insensitivity to conventional treatment approaches such as immunotherapy, chemotherapy, and targeted therapy. Consequently, there remains a significant unmet medical need for efficacious treatments. Recently, amivantamab and sunvozertinib have demonstrated notable efficacy as first-line treatments, and several other promising novel targeted drugs are also challenging the status quo of traditional first-line platinum-based chemotherapy regimens. These developments are anticipated to further improve survival outcomes for NSCLC patients with EGFR ex20ins mutations. Hence, this review summarizes the epidemiology, molecular attributes, detection methodologies, and therapeutic advancements for EGFR ex20ins mutations in NSCLC, and briefly discusses the mechanisms of drug resistance.

The Impact of On-Target Resistance Mediated by EGFR-T790M or EGFR-C797S on EGFR Exon 20 Insertion Mutation Active Tyrosine Kinase Inhibitors

Introduction

Mechanisms of resistance to EGFR exon 20 insertion mutation active inhibitors have not been extensively studied in either robust preclinical models or patient-derived rebiopsy specimens. We sought to characterize on-target resistance mutations identified in EGFR exon 20 insertion-mutated lung cancers treated with mobocertinib or poziotinib and evaluate whether these mutations would or would not have cross-resistance to next-generation inhibitors zipalertinib, furmonertinib, and sunvozertinib.

Methods

We identified mechanisms of resistance to EGFR exon 20 insertion mutation active inhibitors and then used preclinical models of EGFR exon 20 insertion mutations (A767_V769dupASV, D770_N771insSVD, V773_C774insH) plus common EGFR mutants to probe inhibitors in the absence/presence of EGFR-T790M or EGFR-C797S.

Results

Mobocertinib had a favorable therapeutic window in relation to EGFR wild type for EGFR exon 20 insertion mutants, but the addition of EGFR-T790M or EGFR-C797S negated the observed window. Zipalertinib had a favorable therapeutic window for cells driven by EGFR-A767_V769dupASV or EGFR-D770_N771insSVD in the presence or absence of EGFR-T790M. Furmonertinib and sunvozertinib had the most favorable therapeutic windows in the presence or absence of EGFR-T790M in all cells tested. EGFR-C797S in cis to all EGFR mutations evaluated generated dependent cells that were resistant to the covalent EGFR tyrosine kinase inhibitors mobocertinib, zipalertinib, furmonertinib, sunvozertinib, poziotinib, and osimertinib.

Conclusions

This report highlights that poziotinib and mobocertinib are susceptible to on-target resistance mediated by EGFR-T790M or -C797S in the background of the most prevalent EGFR exon 20 insertion mutations. Furmonertinib, sunvozertinib, and to a less extent zipalertinib can overcome EGFR-T790M compound mutants, whereas EGFR-C797S leads to covalent inhibitor cross-resistance-robust data that support the limitations of mobocertinib and should further spawn the development of next-generation covalent and reversible EGFR exon 20 insertion mutation active inhibitors with favorable therapeutic windows that are less vulnerable to on-target resistance.

Epidemiological characteristics and therapeutic advances of EGFR exon 20 insertion mutations in non-small cell lung cancer

The third most prevalent type of epidermal growth factor receptor (EGFR) mutation, EGFR exon 20 insertions (EGFRex20ins), involves 2%-12% of all cases of EGFR-positive non-small cell lung cancer (NSCLC). Approximately 90% of the mutations occur within the loop structure region, and the most frequently reported subtypes are A767_V769dup and S768_D770dup, which together account for almost 50% of instances. Apart from the unique subtype of A763_Y764insFQEA, NSCLCs with EGFRex20ins are resistant to approved EGFR tyrosine kinase inhibitors (TKIs) and are also insensitive to chemotherapy or immunotherapy. A new modality of treatment for NSCLC patients with EGFRx20ins has been established with the approval of mobocertinib and amivantamab. There are also numerous novel targeted treatments for NSCLC with EGFRex20ins in development, which are anticipated to improve this patient population's survival even further. This review provides a reference for the clinical management of these patients by summarizing the most recent epidemiological, and clinicopathological characteristics, diagnostic techniques, and therapeutic advances of EGFRex20ins in NSCLC.

A comprehensive overview of the heterogeneity of EGFR exon 20 variants in NSCLC and (pre)clinical activity to currently available treatments

Activating EGFR mutations are commonly observed in non-small cell lung cancer (NSCLC). About 4-10 % of all activating epidermal growth factor receptor (EGFR) mutations are heterogenous in-frame deletion and/or insertion mutations clustering within exon 20 (EGFRex20+). NSCLC patients with EGFRex20+ mutations are treated as a single disease entity, irrespective of the type and location of the mutation. Here, we provide a comprehensive assessment of the literature reporting both in vitro and clinical drug sensitivity across different EGFRex20+ mutations. The activating A763_Y764insFQEA mutation has a better tumor response in comparison with mutations in the near- and far regions directly following the C-helix and should therefore be treated differently. For other EGFRex20+ mutations marked differences in treatment responses have been reported indicating the need for a classification beyond the exon-based classification. A further classification can be achieved using a structure-function modeling approach and experimental data using patient-derived cell lines. The detailed overview of TKI responses for each EGFRex20+ mutation can assist treating physicians to select the most optimal drug for individual NSCLC patients.