EGFR exon 20 insertion mutations in Chinese advanced non-small cell lung cancer patients: Molecular heterogeneity and treatment outcome from nationwide real-world study

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.

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.

First-in-human phase I study of BEBT-109 in previously treated EGFR exon 20 insertion-mutated advanced non-small cell lung cancer

BACKGROUND

BEBT-109 is an oral pan-mutant-selective inhibitor of epidermal growth factor receptor (EGFR) that demonstrated promising antitumor potency in preclinical models.

METHODS

This first-in-human study was a single-arm, open-label, two-stage study. Phase Ia dose-escalation study evaluated the safety and pharmacokinetics of BEBT-109 in 11 patients with EGFR T790M-mutated advanced non-small cell lung cancer (aNSCLC). Phase Ib dose-expansion study evaluated the safety and efficacy of BEBT-109 in 18 patients with EGFR exon 20 insertion (ex20ins)-mutated treatment-refractory aNSCLC. The primary outcomes were adverse events and antitumor activity. Clinical trial registration number CTR20192575.

FINDINGS

The phase Ia study demonstrated no dose-limiting toxicity, no observation of the maximum tolerated dose, and no new safety signals with BEBT-109 in the dose range of 20-180 mg/d, suggesting that BEBT-109 had an acceptable safety profile among patients with EGFR T790M-mutated aNSCLC. Plasma pharmacokinetics of BEBT-109 showed a dose-proportional increase in the area under the curve and maximal concentration, with no significant drug accumulation. The dose-expansion study demonstrated that BEBT-109 treatment was tolerable across the three dose levels. The three most common treatment-related adverse events were diarrhea (100%; 22.2% ≥Grade 3), rash (66.7%; 5.6% ≥Grade 3), and anemia (61.1%; 0% ≥Grade 3). The objective response rate was 44.4% (8 of 18). Median progression-free survival was 8.0 months (95% confidence intervals, 1.33-14.67).

CONCLUSION

Preliminary findings showed that BEBT-109 had an acceptable safety profile and favorable antitumor activity in patients with refractory EGFR ex20ins-mutated aNSCLC.

FUNDING

National Natural Science Foundation of China.

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.

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.

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.

The state of the art of EGFR exon 20 insertions in non-small cell lung cancer: Diagnosis and future perspectives

Insertions in the epidermal growth factor receptor (EGFR) exon 20 (Ex20Ins) are the third most incident mutations in non-small cell lung cancer (NSCLC). The hypervariable nature of these driver mutations hinders their identification by traditional polymerase chain reaction (PCR)-based methods, requiring a comprehensive sequencing approach to detect all possible insertions. The prognosis of patients with EGFR Ex20Ins is similar to those with wild-type NSCLC, since no targeted drugs are approved in the first-line setting, and platinum-based chemotherapy is currently the front-line treatment. However, the new generation of drugs currently being tested in first and post-platinum settings will likely change the management of this entity. Here, we summarize the latest data on EGFR Ex20Ins molecular characteristics, patient profile, identification challenges, and emerging therapies to help lung clinicians face a growing treatment landscape.

EGFR and ERBB2 Exon 20 Insertion Mutations in Chinese Non-small Cell Lung Cancer Patients: Pathological and Molecular Characterization, and First-Line Systemic Treatment Evaluation

BACKGROUND

Data from studies looking at both EGFR and ERBB2 exon 20 insertion mutations (-20ins) in the same cohort of patients with non-small cell lung cancer (NSCLC) are limited.

OBJECTIVE

The purpose of this study was to analyze EGFR/ERBB2-20ins in all-stage NSCLC patients to reveal their histological and molecular features, and to retrospectively evaluate the results of first-line real-world systemic treatments in patients with advanced-stage disease.

PATIENTS AND METHODS

We collected 13,920 formalin-fixed paraffin-embedded NSCLC specimens. Clinicopathological features were recorded and DNA-based next-generation sequencing was performed. First-line systemic treatment data were obtained via chart review.

RESULTS

In total, 414 (2.97%) EGFR-20ins cases and 666 (4.78%) ERBB2-20ins cases were identified. Both were more common in women, non-smokers, and patients with adenocarcinoma. The incidence of EGFR/ERBB2-20ins in adenocarcinoma is inversely proportional to the degree of invasion; 77 and 26 variants were detected in EGFR-20ins and ERBB2-20ins cases, respectively. The most common concurrently mutated genes were TP53 and RB1. In invasive adenocarcinoma, lepidic components were more common in EGFR/ERBB2-20ins-alone cases than in those with other concurrent mutated genes. In EGFR-/ERBB2-20ins patients, there was no significant difference in progression-free survival (PFS) or treatment response to first-line systemic treatments in this study. There was no significant difference in PFS or treatment response among patients with different EGFR/ERBB2-20ins variants and those with or without concurrent mutated genes.

CONCLUSIONS

EGFR/ERBB2-20ins is more common in early lung adenocarcinoma. EGFR-20ins had more variants. In both cohorts, the results for first-line systemic treatments showed no significant difference.

Mobocertinib: Mechanism of action, clinical, and translational science

Epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations represent ~6%-12% of all EGFR-mutated non-small cell lung cancer (NSCLC) cases. First-, second-, and third-generation tyrosine kinase inhibitors (TKIs) have limited clinical activity against EGFR ex20ins mutations. Mobocertinib is a first-in-class oral EGFR TKI that selectively targets in-frame EGFR ex20ins mutations in NSCLC; accelerated approval in the United States was granted for the treatment of adult patients with locally advanced or metastatic NSCLC with EGFR ex20ins mutations whose disease has progressed on or after platinum-based chemotherapy. Accelerated approval was based on the results from the three-part, open-label, multicenter, pivotal phase I/II nonrandomized clinical trial (NCT02716116) that enrolled 114 patients with locally advanced or metastatic EGFR ex20ins mutation-positive NSCLC who were previously treated with platinum-based chemotherapy and received mobocertinib at the recommended dosage of 160 mg once daily. At the November 1, 2021, data cutoff date, the confirmed objective response rate per independent review committee (IRC) was 28%, median duration of response was 15.8 months, median progression-free survival per IRC was 7.3 months, and median overall survival was 20.2 months. The most common treatment-emergent adverse events were gastrointestinal- and skin-related. The phase III EXCLAIM-2 study evaluated mobocertinib versus chemotherapy as first-line therapy for locally advanced or metastatic EGFR ex20ins-positive NSCLC; however, the primary end point was not met, resulting in initiating voluntary withdrawal of mobocertinib worldwide. This mini-review article summarizes the mechanism of action, pharmacokinetic characteristics, key clinical trials, and clinical efficacy and safety data for mobocertinib.

Sunvozertinib for patients in China with platinum-pretreated locally advanced or metastatic non-small-cell lung cancer and EGFR exon 20 insertion mutation (WU-KONG6): single-arm, open-label, multicentre, phase 2 trial

BACKGROUND

Sunvozertinib is an oral, irreversible, and selective tyrosine kinase inhibitor that has a favourable safety profile and encouraging antitumour activity, as shown in phase 1 studies of patients with heavily pretreated non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion mutation (exon20ins). We aimed to assess the antitumour efficacy of sunvozertinib in patients with platinum-pretreated locally advanced or metastatic NSCLC with EGFR exon20ins.

METHODS

WU-KONG6 is a single-group, open-label, multicentre phase 2 trial of sunvozertinib monotherapy, conducted across 37 medical centres in China. We enrolled adult patients with pathologically or cytologically confirmed locally advanced or metastatic NSCLC whose tumour tissue carried an EGFR exon20ins mutation. All patients had received at least one line of previous systemic therapy, with at least one line containing platinum-based chemotherapy. The primary endpoint was objective response rate (ORR), as assessed by the independent review committee. The ORR was defined as the percentage of patients who achieved complete or partial response, confirmed by two separate assessments with at least 4-week time interval, until disease progression or initiation of any new anti-cancer therapy. Enrolled patients received sunvozertinib 300 mg once daily until meeting discontinuation criteria per the protocol. Patients who received at least one dose of treatment and were evaluable for efficacy analysis were included in the primary analysis, and all patients who received at least one dose of treatment were included in the safety analysis. This study is registered with ChinaDrugTrials.org, CTR20211009, and ClinicalTrials.gov, NCT05712902, and efficacy and safety follow-up are ongoing.

FINDINGS

Between July 19, 2021, and May 6, 2022, 104 patients were enrolled. At data cutoff (Oct 17, 2022), the last enrolled patient had been followed up for about 6 months. Among 97 patients evaluable for efficacy analysis, 59 (61%) patients achieved tumour response, with a confirmed ORR of 61% (95% CI 50-71). All tumour responses were partial responses. Tumour responses were observed irrespective of age, sex, smoking history, EGFR exon20ins subtypes, brain metastasis at baseline, previous lines of therapy, and history of onco-immunotherapy. In total, 19 death events occurred over a median follow-up period of 7·6 months (IQR 6·1-9·4). Sunvozertinib was well tolerated at 300 mg once daily. The most common grade 3 or worse treatment-related adverse events were blood creatine phosphokinase increased (18 [17%] of 104), diarrhoea (eight [8%]), and anaemia (six [6%]). The most common serious treatment-related adverse events were interstitial lung disease (five [5%] of 104), anaemia (three [3%]), vomiting (two [2%]), nausea (two [2%]) and pneumonia (two [2%]).

INTERPRETATION

In this phase 2 study, sunvozertinib demonstrated antitumour efficacy in patients with platinum-based chemotherapy pretreated NSCLC with EGFR exon20ins, with a manageable safety profile. A multinational randomised, phase 3 study of sunvozertinib versus platinum-doublet chemotherapy in EGFR exon20ins NSCLC is ongoing (NCT05668988).

FUNDING

Dizal Pharmaceutical.

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.

Comprehensive Genomic Analysis of Patients With Non-Small-Cell Lung Cancer Using Blood-Based Circulating Tumor DNA Assay: Findings From the BFAST Database of a Single Center in Taiwan

PURPOSE

The Blood First Assay Screening Trial (BFAST) is a prospective study using next-generation sequencing (NGS) of circulating tumor DNA (ctDNA) in treatment-naïve advanced/metastatic non-small-cell lung cancer (NSCLC). We compared liquid biopsy to tissue testing and analyzed genomic alterations in Taiwanese patients with NSCLC using the BFAST database.

MATERIALS AND METHODS

A total of 269 patients underwent FoundationOne Liquid Companion Diagnostic (F1LCDx) assay at the National Taiwan University Hospital, of whom 264 underwent tissue-based genetic testing also. We analyzed the actionable mutations and the concordance between tissue-based genetic testing, which was limited to EGFR, ALK, ROS1, and BRAF, in a real-life clinical setting and blood-based NGS in the clinical trial. Additionally, we analyzed the co-occurring genomic alterations from the blood-based ctDNA assay.

RESULTS

A total of 76.2% patients showed actionable mutations. Standard tissue testing did not detect known driver alterations in about 22.7% of the patients (sensitivity, 70.24%). Liquid NGS detected additional mutations (RET, KRAS, MET, and ErbB2) in 14% of the patients, which went undetected by the standard-of-care testing. The complementary use of ctDNA NGS increased the detection rate by 42%. The F1LCDx assay had a sensitivity of 83.41%. Lower tumor and metastasis stages predicted nondetected blood-based NGS ctDNA results. Common co-occurring mutations in the blood-based NGS ctDNA assay were TP53, DNMT3A, TET2, PIK3CA, CTNNB1, and RB1. Among the patients with EGFR-mutated NSCLC, TET2 co-occurring alterations correlated with shorter progression-free survival of EGFR tyrosine kinase inhibitor treatment.

CONCLUSION

NGS ctDNA analysis in comprehensive genetic testing improves actionable mutation identification, vital for treating Asian NSCLC cases with high actionable mutation rates. Lower stages correlated with undetected blood-based NGS ctDNA assay results.

First report of furmonertinib as a first-line treatment in advanced lung adenocarcinoma patients harboring EGFR exon 20 insertion mutations after the kinase domain αC-helix: Two case reports and a literature review

RATIONALE

Many studies have shown that first- and second-generation epidermal growth factor receptor tyrosine kinase inhibitors are less effective in patients with epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations. The efficacy of third-generation epidermal growth factor receptor tyrosine kinase inhibitors is still under investigation. Although new targeted tyrosine kinase inhibitors and monoclonal antibody-based agents have made significant advances in the treatment of epidermal growth factor receptor exon 20 insertion (EGFR ex20ins) mutation, the efficacy of these novel agents is not quite satisfactory. Platinum- and pemetrexed-based chemotherapy remains the standard first-line treatment for patients harboring EGFR ex20ins mutation.

PATIENT CONCERNS

We report for the first time 2 Chinese patients diagnosed with advanced lung adenocarcinoma with EGFR ex20ins mutations after analysis of the αC-helix sequence by next-generation sequencing. Both patients were treated with furmonertinib as the first-line therapy.

INTERVENTIONS

The first case included a 38-year-old female who had an EGFR ex20ins mutation (p.S768_D770dupSVD). After 1 month of treatment with furmonertinib, her symptoms of pain and cough were significantly alleviated. She achieved a partial response according to response evaluation criteria in solid tumors.[1] The final progression-free survival was 8.13 months. The second case included a 40-year-old male who had an EGFR ex20ins mutation (p.N771_P772insVal). He had a good response to furmonertinib and exhibited stable disease according to response evaluation criteria in solid tumors with a progression-free survival of 10.90 months.

OUTCOMES

Both patients experienced significant improvement in symptoms and prolonged survival after furmonertinib was used as first-line treatment. Side effects were limited but manageable.

CONCLUSION

The present study indicates that furmonertinib may be a first-line treatment option for patients with non-small cell lung cancer harboring EGFR ex20ins mutation.

Amivantamab compared with real-world therapies in patients with advanced non-small cell lung cancer EGFR Exon 20 insertion mutations after platinum-based chemotherapy

BACKGROUND

In the single-arm CHRYSALIS trial, advanced non-small cell lung cancer patients harboring epidermal growth factor receptor (EGFR) exon 20 insertion (Exon 20ins) showed durable responses to amivantamab, an EGFR-MET bispecific antibody targeting tumors with EGFR Exon 20ins. This study compared the effectiveness of amivantamab to real-world systemic anti-cancer therapies in Japan.

PATIENTS AND METHODS

External control patients were selected by applying CHRYSALIS eligibility to Japanese patients from LC-SCRUM-Asia. External control patients were included for every qualifying line of therapy after platinum-based chemotherapy. Propensity score weighting was applied to external control patients to adjust for differences in baseline characteristics. Outcomes were compared between external control patients, and all and Asian-only CHRYSALIS patients using weighted Cox proportional hazards regression models for progression-free survival (PFS), time to next therapy (TTNT), and overall survival (OS), and generalized estimating equations with repeated measurements for overall response rate (ORR).

RESULTS

One hundred fifteen CHRYSALIS and 94 external control patients were identified. Compared to external control patients, amivantamab-treated patients had significantly longer OS (median OS 19.88 vs 14.09 months, HR [95% CI] 0.59 [0.40-0.88]), PFS (median PFS 6.74 vs 4.73 months, HR 0.59 [0.45-0.78]), TTNT (median TTNT 12.16 vs 5.09 months, HR 0.39 [0.29-0.53]), and significantly higher ORR (41.7% vs 14.1%). Analyses of amivantamab-treated Asian patients (n = 61) showed similar clinical benefits.

CONCLUSION

In the absence of clinical evidence from randomized clinical trials, this study reflects the benefit of amivantamab after platinum-based chemotherapy for advanced non-small cell lung cancer patients harboring EGFR Exon 20ins, compared to current real-world therapies.

Poor Efficacy of Immune Checkpoint Inhibitors Plus Chemotherapy in Lung Cancer Patients with EGFR/ERBB2 Exon 20 Insertion

BACKGROUND

EGFR and ERBB2 exon 20 insertion (Ex20ins) account for a small fraction of patients with EGFR mutations. The efficacy of immune checkpoint inhibitors (ICIs) for these patients was still controversial.

METHODS

This retrospective study enrolled lung cancer patients harboring either EGFR or ERBB2 Ex20ins mutations. All the patients were treated with platinum-based chemotherapy plus ICIs, or platinum-based chemotherapy. The demographic features and clinical outcome of each patient were reviewed and analyzed.

RESULTS

When treated with immunochemotherapy, patients with EGFR/ERBB2 Ex20ins mutations (n = 31) had poor PFS compared with those without EGFR mutations (n = 141, 5.0 mon and 11.2 mon, p < 0.001). When compared with those with EGFR classic mutations who received immunotherapy as the salvage therapy (n = 24), these patients with EGFR/ERBB2 Ex20ins mutations had similar PFS (5.0 mon and 4.1 mon, p = 0.625), ORR (37.5% vs. 48.4%), and DCR (70.8% vs. 77.4%). In the patients with EGFR/ERBB2 Ex20ins mutations, the PFS of those treated with chemotherapy (n = 54) and those treated with immunochemotherapy (n = 31) was 6.5 mon vs. 5.0 mon (p = 0.066). In the EGFR Ex20ins subgroup, the PFS of addition of bevacizumab to chemotherapy (n = 20) and chemotherapy alone (n = 16) was 8.8 mon and 5.2 mon, respectively (p = 0.082) or immunochemotherapy (n = 15, 8.8 mon and 5.0 mon, p = 0.097). Similarly, in the ERBB2 subgroup, the combination of bevacizumab and chemotherapy achieved a numerically longer PFS over chemotherapy alone (9.1 mon and 4.5 mon, p = 0.253), but there was no statistical significance.

CONCLUSIONS

This study showed that platinum-based chemotherapy plus ICIs had limited efficiency compared to platinum-based chemotherapy for patients with EGFR/ERBB2 Ex20ins. Chemotherapy plus bevacizumab may be a potential scheme for these patients.

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.

Real-World Response and Outcomes in Patients With NSCLC With EGFR Exon 20 Insertion Mutations

Introduction

This study describes treatment patterns and outcomes in patients with NSCLC with EGFR exon 20 insertions (EGFRex20ins) in the United States.

Methods

The Flatiron Health electronic health record database was used to select three cohorts among patients diagnosed with NSCLC with EGFRex20ins (January 1, 2011-February 29, 2020): (1) first-line (1L) or patients receiving 1L therapy after documented EGFRex20ins; (2) second or later-line (≥2L) or patients receiving ≥2L therapy after documented EGFRex20ins; and (3) ≥2L postplatinum trial-aligned, or ≥2L patients previously treated with platinum chemotherapy whose baseline characteristics aligned with key eligibility criteria (initiating new treatment after documented EGFRex20ins and ≥1 previous treatment excluding mobocertinib or amivantamab) of the mobocertinib trial NCT02716116. Real-world end points were confirmed overall response rate, overall survival, and progression-free survival.

Results

Of 237 patients with EGFRex20ins-mutated NSCLC, 129 and 114 patients were included in the 1L and ≥2L cohorts, respectively. In 1L patients, platinum chemotherapy plus nonplatinum chemotherapy (31.0%) and EGFR tyrosine kinase inhibitors (28.7%) were the most common regimens. In ≥2L patients, immuno-oncology monotherapy (28.1%) and EGFR tyrosine kinase inhibitors (17.5%) were the most common index treatments. For any 1L, ≥2L, and ≥2L postplatinum trial-aligned patients, the confirmed overall response rate was 18.6%, 9.6%, and 14.0%, respectively; the median overall survival was 17.0, 13.6, and 11.5 months; the median progression-free survival was 5.2, 3.7, and 3.3 months, respectively.

Conclusions

The outcomes for patients with NSCLC with EGFRex20ins were poor. This real-world study provides a benchmark on treatment outcomes in this patient population and highlights the unmet need for improved therapeutic options.

Characteristics, treatment patterns, and clinical outcomes in patients with advanced non-small cell lung cancer harboring EGFR exon 20 insertions

PURPOSE

Epidermal growth factor receptor (EGFR) exon 20 insertions (ex20ins) are associated with poor prognosis and resistance to traditional therapies in patients with non-small cell lung cancer (NSCLC). We aimed to elucidate the characteristics and treatment patterns to improve outcomes among this population in Taiwan.

METHODS

Patients with advanced or recurrent NSCLC harboring EGFR ex20ins from 2011 to 2021 were reviewed. The treatment groups were classified as platinum-based chemotherapy (PtC), EGFR tyrosine kinase inhibitor (TKI), and others. The response to therapy, objective response rate (ORR), disease control rate (DCR), overall survival (OS), progression-free survival (PFS), and factors associated with survival were analyzed.

RESULTS

Among the 71 patients, most were never-smoking males with stage IVB adenocarcinoma. The most common first-line (1L) regimen was PtC, followed by TKI. The most common second-line (2L) regimen was TKI. The median PFS of 1L treatment was 5.03 months, and the median OS was 18.43 months. Compared with that of TKI, 1L PtC use was associated with a higher ORR (26.3% vs. 9.1%) and DCR (60.5% vs. 18.2%) and a longer PFS (5.37 vs. 3.13 months, p = 0.044). PFS was also significantly longer in the 2L PtC group than in the 2L TKI group (4.73 vs. 2.25 months, p = 0.047). No patients receiving an immune checkpoint inhibitor-based regimen exhibited a therapeutic response.

CONCLUSION

This study demonstrated the heterogeneous clinical characteristics and treatment pattern of NSCLC patients with EGFR ex20ins, underscoring the need for more effective therapies for this distinct molecular subtype.

Comparison of efficacy and safety of second- and third-generation TKIs for non-small-cell lung cancer with uncommon EGFR mutations

BACKGROUND

The efficacy of definite for non-small-cell lung cancer (NSCLC) with uncommon epidermal growth factor receptor (EGFR) mutations has been preliminarily demonstrated. However, there is a paucity of data with which to compare the efficacy and safety of second- and third-generation TKIs in patients with NSCLC carrying uncommon EGFR mutations.

METHODS

We compared the efficacy and safety of second- and third-generation TKIs in all NSCLC patients in whom next-generation sequencing confirmed uncommon EGFR mutations, including G719X, S768I, and L861Q. The parameters analyzed included the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). The rate of treatment-related adverse events (AEs) reflected the safety of these TKIs.

RESULTS

Eighty-four NSCLC patients with uncommon EGFR mutations were enrolled between April 2016 and May 2022 at Zhejiang Cancer Hospital, including 63 treated with second-generation TKIs and 21 treated with third-generation TKIs. The ORR for all patients receiving TKIs was 47.6%, and the DCR was 86.9%. The median PFS for NSCLC patients with uncommon EGFR mutations receiving TKIs was 11.9 months and OS was 30.6 months. There was no significant difference in PFS after treatment with second- or third-generation TKIs (13.3 vs. 11.0 months, respectively, P = 0.910) or in OS (30.6 vs. 24.6 months, respectively P = 0.623). The third-generation TKIs showed no severe toxicity.

CONCLUSIONS

The efficacy of second- and third-generation TKIs for NSCLC with uncommon EGFR mutations does not differ, and so can be used to treat NSCLC patients with these mutations.

A real-world study of the efficacy and safety of furmonertinib for patients with non-small cell lung cancer with EGFR exon 20 insertion mutations

BACKGROUND

Furmonertinib is a novel third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). A phase Ib study (FAVOUR, NCT04858958) initially demonstrated the efficacy of furmonertinib in non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion (ex20ins). This study aimed to investigate the real-world efficacy and safety of furmonertinib in patients with advanced NSCLC with EGFR ex20ins.

METHODS

We retrospectively examined patients with advanced NSCLC with EGFR ex20ins having complete follow-up data, who were treated with furmonertinib from April 14, 2021, to March 15, 2022, at our institution and multiple hospitals in China. Objective response rate (ORR), disease control rate (DCR), 6-month progression-free survival (PFS) rates and treatment related adverse events (TRAEs) were assessed.

RESULTS

This study included 53 patients with advanced NSCLC with EGFR ex20ins. A767_V769dup (28.3%) and S768_D770dup (11.3%) are the major variants. The ORR and DCR were 37.7% (20/53) and 92.5% (49/53), respectively. The 6-month PFS rate was 69.4% (95% CI 53.7-85.1%). The ORR of patients in the 240 mg once-daily dosage group was higher (42.9%) than that of patients in the 80 mg once-daily (25.0%) and 160 mg once-daily (39.5%) groups, but with no statistically significant difference (P = 0.816). The ORR of furmonertinib is not dependent on insertion location (P = 0.893). Patients with central nervous system (CNS) metastases at baseline responded similarly to those without CNS metastases (ORR: 33.3% vs. 40.6%, P = 0.773). The most common AEs were diarrhea (26.4%) and rash (26.4%). No grade ≥ 3 TRAEs were observed. No statistically significant difference was observed in the incidence of TRAEs between dosage groups (P = 0.271).

CONCLUSIONS

Furmonertinib has shown encouraging antitumor activity and CNS activity in patients with advanced NSCLC with EGFR ex20ins. Moreover, furmonertinib had a good safety profile and no dose-dependent toxicity.

Discovery of YK-029A, a novel mutant EGFR inhibitor targeting both T790 M and exon 20 insertion mutations, as a treatment for NSCLC

Although traditional EGFR-TKIs have advanced the treatment landscape of NSCLC with sensitive driver mutations (del19 or L858R), some NSCLC patients with EGFR exon 20 insertion mutations have been left with few effective therapies. The development of novel TKIs is still in progress. Herein, we describe the structure-guided design of a novel selective and orally bioavailable inhibitor, YK-029A, which could overcome both the T790 M mutations and exon 20 insertion of EGFR. YK-029A inhibited EGFR signaling, suppressed sensitive mutations and ex20ins of EGFR-driven cell proliferation, and was largely effective with oral administration in vivo. Furthermore, YK-029A exhibited significant antitumor activity in EGFRex20ins-driven patients-derived xenograft (PDX) models, preventing tumor progression or causing tumor regression at well-tolerated dosages. Based on the outcomes of preclinical efficacy and safety studies, YK-029A will enter phase Ⅲ clinical trials for the treatment of EGFRex20ins NSCLC.

Afatinib for the Treatment of NSCLC with Uncommon EGFR Mutations: A Narrative Review

Afatinib, the world's first irreversible ErbB family (containing four different cancer cell epidermal growth factor receptors, including EGFR, HER2, ErbB3, and ErbB4) inhibitor, is a second-generation oral epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). It can be used as a first-line treatment for locally advanced or metastatic non-small-cell lung cancer (NSCLC) with an EGFR-sensitive mutation or for patients with locally advanced or metastatic squamous lung cancer whose disease progresses during or after platinum-containing chemotherapy. Currently, with the use of third-generation EGFR-TKIs, afatinib is no longer clinically indicated as the first choice for patients with NSCLC who have EGFR-sensitive mutations. However, afatinib showed a considerable inhibitory effect in NSCLC patients with uncommon EGFR mutations (G719X, S768I, and L861Q) according to a combined post hoc analysis of the LUX-Lung2/3/6 trials. With the development of genetic testing technology, the detection rate of uncommon EGFR mutations is increasing. The aim of this paper is to describe in detail the sensitivity of rare EGFR mutations to afatinib and to provide information and a reference for those suffering from advanced NSCLC who have uncommon EGFR mutations.

EGFR and ERBB2 exon 20 insertion/duplication in advanced non-small cell lung cancer: genomic profiling and clinicopathologic features

Background

Exon 20 (ex20) in-frame insertions or duplications (ins/dup) in epidermal growth factor receptor (EGFR) and its analog erb-b2 receptor tyrosine kinase 2 (ERBB2) are each detected in 1.5% of non-small cell lung cancer (NSCLC). Unlike EGFR p.L858R or ex19 deletions, ex20 ins/dup is associated with de novo resistance to classic EGFR inhibitors, lack of response to immune checkpoint inhibitors, and poor prognosis. US Food and Drug Administration has approved mobocertinib and amivantamab for targeting tumors with this aberration, but the number of comprehensive studies on ex20 ins/dup NSCLC is limited. We identified 18 cases of NSCLCs with EGFR/ERBB2 ex20 ins/dup and correlated the findings with clinical and morphologic information including programed death-ligand 1 (PD-L1) expression.

Methods

A total of 536 NSCLC cases tested at our institution between 2014 and 2023 were reviewed. A custom-designed 214-gene next-generation sequencing panel was used for detecting DNA variants, and the FusionPlex CTL panel (ArcherDx) was used for the detection of fusion transcripts from formalin-fixed, paraffin-embedded tissue. Immunohistochemistry (IHC)for PD-L1 was performed using 22C3 or E1L3N clones.

Results

Nine EGFR and nine ERBB2 ex20 ins/dup variants were identified from an equal number of men and women, 14 were non- or light smokers, and 15 had stage IV disease. All 18 cases were adenocarcinomas. Seven of the 11 cases with available primary tumors had acinar predominant pattern, two had lepidic predominant pattern, and the remainder had papillary (one case) and mucinous (one case) patterns. Ex20 ins/dup variants were heterogenous in-frame one to four amino acids spanning A767-V774 in EGFR and Y772-P780 in ERBB2 and were clustered in the loop following the C-helix and α C-helix. Twelve cases (67%) had co-existing TP53 variants. Copy number variation in CDK4 amplification was identified in one case. No fusion or microsatellite instability was identified in any case. PD-L1 was positive in two cases, low positive in four cases, and negative in 11 cases.

Conclusions

NSCLCs harboring EGFR/ERBB2 ex20 ins/dup are rare and tend to be acinar predominant, negative for PD-L1, more frequent in non- or light smokers, and mutually exclusive with other driver mutations in NSCLC. The correlation of different EGFR/ERBB2 ex20 ins/dup variants and co-existing mutations with response to targeted therapy and the possibility of developing resistant mutations after mobocertinib treatment warrants further investigation.

Comparative Effectiveness of Mobocertinib and Standard of Care in Patients with NSCLC with EGFR Exon 20 Insertion Mutations: An Indirect Comparison

INTRODUCTION

Mobocertinib is a novel, first-in-class, irreversible, oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) designed to selectively target in-frame EGFR exon 20 insertions (ex20ins). Comparative effectiveness data for mobocertinib versus real-world treatments are lacking in this rare population. This study compared data for mobocertinib reported in a Phase I/II single-arm clinical trial with an external control group consisting of patients who received available treatment in the real-world setting in the United States (US).

MATERIALS AND METHODS

The mobocertinib group included platinum-pretreated patients with advanced EGFR ex20ins non-small cell lung cancer (NSCLC) receiving mobocertinib 160 mg QD in an ongoing, single-arm, phase 1/2 clinical trial (NCT02716116; n = 114). The real-world data (RWD) group included platinum-pretreated patients with advanced EGFR ex20ins-mutant NSCLC from the Flatiron Health database (n = 50). Inverse probability treatment weighting based on the propensity score method controlled for potential confounding between groups. Confirmed overall response rate (cORR), progression-free survival (PFS), and overall survival (OS) were compared between groups.

RESULTS

After weighting, baseline characteristics were balanced. Patients in the RWD group received EGFR TKI (20 %), immuno-oncology therapy (40 %), or any regimens containing chemotherapy (40 %) in the second- or later-line setting. In the mobocertinib and RWD groups, respectively, cORR was 35.1 % and 11.9 % (odds ratio: 3.75 [95 % confidence interval (CI): 2.05, 6.89]); median PFS was 7.3 and 3.3 months (hazard ratio [HR]: 0.57 [95 % CI: 0.36, 0.90]); and median OS was 24.0 and 12.4 months (HR: 0.53 [95 % CI: 0.33, 0.83]) after weighting.

DISCUSSION

Mobocertinib showed substantially improved outcomes versus an external control group using available therapies in platinum-pretreated patients with EGFR ex20ins-mutant NSCLC. In the absence of comparative evidence from randomized trials, these findings help elucidate potential benefits of mobocertinib in this rare population.

Advances in the management of non-small-cell lung cancer harbouring EGFR exon 20 insertion mutations

Epidermal growth factor receptor (EGFR) mutation is one of the key oncogenic mutations in non-small-cell lung cancer with adenocarcinoma histology. Exon 19 deletions and exon 21 L858R substitutions account for 90%, while EGFR exon 20 insertions constitute 4-10% of EGFR mutations and are the third most prevalent activating EGFR mutations. EGFR exon 20 insertions are associated with decreased sensitivity to EGFR tyrosine kinase inhibitors and, until recently, effective targeted therapy against these tumours remained an unmet clinical need and chemotherapy was the only treatment of choice available. The approval of amivantamab and mobocertinib for patients who have progressed after chemotherapy represents an important step forward in the management of these patients. Here in this review, we summarize the epidemiology, structure and the tumour microenvironment of EGFR exon 20 insertion and also review the systemic treatments, including targeted therapies and ongoing clinical trials in EGFR exon 20 insertion mutations, as well as detection methods for EGFR exon 20 insertion. Lastly, resistant mechanisms and future directions are addressed.

Structure-Guided Strategies of Targeted Therapies for Patients with EGFR-Mutant Non-Small Cell Lung Cancer

Oncogenic mutations within the EGFR kinase domain are well-established driver mutations in non-small cell lung cancer (NSCLC). Small-molecule tyrosine kinase inhibitors (TKIs) specifically targeting these mutations have improved treatment outcomes for patients with this subtype of NSCLC. The selectivity of these targeted agents is based on the location of the mutations within the exons of the EGFR gene, and grouping mutations based on structural similarities has proved a useful tool for conceptualizing the heterogeneity of TKI response. Structure-based analysis of EGFR mutations has influenced TKI development, and improved structural understanding will inform continued therapeutic development and further improve patient outcomes. In this review, we summarize recent progress on targeted therapy strategies for patients with EGFR-mutant NSCLC based on structure and function analysis.

Targeting exon 20 insertion mutations in lung cancer

PURPOSE OF REVIEW

The application of tyrosine kinase inhibitor (TKI) has successfully changed the standard of care in epidermal growth factor receptor ( EGFR ) positive non-small cell lung cancer. However, clinical survivals for patients with EGFR exon 20 insertions have failed to improve over the long period and the mutation appeared resistant to EGFR -TKIs. This overview focused on the current treatment strategies, summarized the emerging regimens for patients with EGFR exon 20 insertions, and demonstrated historical challenges and future development.

RECENT FINDING

Current clinical trials suggested that several regimens selectively-targeted EGFR exon 20 insertions presented potent antitumor activity, like mobocertinib and the bispecific anti- EGFR-MET monoclonal antibody amivantamab and were approved by Food and Drug Administration (FDA) in patients progressed beyond first-line treatment. Novel treatments, including DZD9008, CLN-081, revealed modest clinical efficacy as well and clinical trials are underway, which may lead to improvement of survival outcomes.

SUMMARY

Recent clinical evidence indicates that targeted therapies could improve survival benefits to some extent. More efforts on drug development are underway to bring higher response rates both extracranial and intracranial, sustained clinical remission, and better survival benefits.

Review of novel and supplemental approvals of the targeted cancer drugs by the Food and Drug Administration in 2021

OBJECTIVE

This review aims to present the most recent results from clinical trials of targeted cancer drugs that led to the Food and Drug Administration approval in 2021 and reflect the changing treatment landscape of solid malignancies.

DATA SOURCES

Novel approvals and supplemental approvals in 2021 were retrieved from the official web page of the Food and Drug Administration (Drugs@FDA). This review did not include approvals for generics, biosimilars, imaging, and diagnostics agents.

DATA SUMMARY

This review included 10 novel drugs approved for 11 indications and 10 already-approved drugs approved for 21 indications by the Food and Drug Administration in 2021. Novel approvals mainly were related to treating an orphan disease. In addition, one-third of the supplemental approvals were given for neoadjuvant or adjuvant treatment, while the number of indications for each tumor site was as follows: gastrointestinal (7), genitourinary (5), skin (3), lung (2), breast (2), thyroid (1), and cervix (1).

CONCLUSIONS

Targeted cancer treatments are gaining more importance than ever in treating malignant diseases. As the approval of targeted cancer drugs provides a possibility for patients and this trend is expected to continue in the future, it remains vital for healthcare providers to stay up-to-date with newer therapeutic options.

Characterization and management of adverse events observed with mobocertinib (TAK-788) treatment for EGFR exon 20 insertion-positive non-small cell lung cancer

BACKGROUND

Mobocertinib has demonstrated durable clinical benefit in platinum-pretreated patients (PPP) with epidermal growth factor receptor exon 20 insertion-positive non-small cell lung cancer (NSCLC).

RESEARCH DESIGN AND METHODS

Pooled safety analysis of two studies included patients with NSCLC (N = 257) treated with the recommended phase 2 dose (RP2D) of mobocertinib (160 mg once daily). We report overall safety (treatment-emergent adverse events [TEAEs]) in the RP2D population; characterization of GI and skin-related events in 114 PPP from a phase 1/2 study (NCT02716116); and clinical activity in PPP with and without dose reductions due to TEAEs.

RESULTS

In the RP2D population (N = 257), the most common TEAEs were diarrhea (93%), nausea (47%), rash (38%), and vomiting (37%). In PPP (N = 114), median times to diarrhea onset and resolution were 5 and 2 days, respectively. Median times to onset and resolution of skin-related events were 9 and 78 days, respectively. Among PPP with (n = 29) or without (n = 85) dose reductions due to TEAEs, overall response rates were 21% and 31% and median durations of response were 5.7 and 17.5 months, respectively.

CONCLUSIONS

GI and skin-related events are common with mobocertinib; minimizing dose reductions with proactive management may improve clinical outcomes.

TRIAL REGISTRATION

NCT02716116; NCT03807778.

EGFR exon 20 insertion variants A763_Y764insFQEA and D770delinsGY confer favorable sensitivity to currently approved EGFR-specific tyrosine kinase inhibitors

Background: The EGFR exon 20 insertions (ex20ins) D770_N771insSVD and V769_D770insASV are most frequent in non-small-cell lung cancer (NSCLC) and are associated with intrinsic resistance to currently approved EGFR tyrosine kinase inhibitors (TKIs). A763_Y764insFQEA and D770delinsGY, respectively, account for 3%-8% and 2.0%-4.8% of EGFR ex20ins in NSCLC and are associated with a more favorable response to EGFR-specific TKIs as per case reports. The aim of this study was to elucidate the molecular structures of these mutants and their binding affinities to diverse EGFR TKIs and compare the clinical outcomes in NSCLC patients harboring these mutations. Methods: A real-world cohort study was conducted to evaluate and compare the clinical outcomes of EGFR TKIs among NSCLC patients with different EGFR ex20ins mutants in response to EGFR TKIs. The structures of A763_Y764insFQEA and D770delinsGY were also analyzed and drug binding simulations were performed. Results: With a median follow-up of 24.0 months, the first-line objective response rate (ORR), disease control rate (DCR), and median progression-free survival (PFS) were, respectively, 0 (0/16), 50.0% (8/16), and 2.07 months (95%CI, 0-6.25) in patients harboring D770_N771insSVD and V769_D770insASV variants and 33.3% (4/12), 83.3% (10/12), and 9.97 months (95%CI, 4.75-15.19) in patients with A763_Y764insFQEA and D770delinsGY variants. There was a significant difference between the PFS of these two subgroups (median, 9.97 vs.2.07 months, HR = 0.33, 95%CI, 0.13-0.85, p = 0.02). Similarly, the PFS was significantly longer after second-line treatment with EGFR TKIs in patients harboring A763_Y764insFQEA and D770delinsGY compared to those with other insertions (median, 6.77 vs.2.23 months, HR = 0.14, p < 0.001). Computational simulations indicated that A763_Y764insFQEA and D770delinsGY mutants were structurally similar to wild-type EGFR. In contrast, the C-helix and phosphate-binding loop of D770_N771insSVD and V769_D770insASV had shifted into the drug-binding pocket, resulting in significant steric hindrance and a lack of affinity for the currently approved EGFR inhibitors. Conclusion: NSCLC patients harboring A763_Y764insFQEA and D770delinsGY insertions of EGFR are responsive to the currently approved EGFR TKIs as opposed to patients with the D770_N771insSVD and V769_D770insASV variants. Therefore, A763_Y764insFQEA and D770delinsGY should be classified as active mutations among heterogeneous EGFR ex20ins subtypes and the carriers can be treated with the suitable EGFR TKIs.

Non-small Cell Lung Cancer with EGFR or HER2 Exon 20 Insertion Mutations: Diagnosis and Treatment Options

Molecular testing is performed upon diagnosis of non-small cell lung cancer (NSCLC) because of the large success of targeted therapies for oncogenic mutations. Epidermal growth factor receptor (EGFR) mutations are the most commonly identified mutation in NSCLC, and EGFR exon 20 insertion mutations (exon20ins) are the third most common mutation in EGFR following EGFR exon 19 deletions and exon 21 L858R mutations. EGFR exon20ins have regularly demonstrated resistance to classical EGFR inhibition. Two treatments-mobocertinib and amivantamab-have recently been the first drugs to be approved by the US Food and Drug Administration (FDA) for treatment of lung cancers with these mutations following platinum-based therapy. Research surrounding these two drugs demonstrates strong efficacy, but with an intense array of side effects. Another targetable driver mutation is the human epidermal growth factor receptor 2 (HER2) exon20ins, representing approximately 2-3% of NSCLC patients. This mutation has been heavily studied in vitro as well as clinically, and trastuzumab deruxtecan was just recently granted accelerated FDA approval based on the high efficacy demonstrated in the Destiny-Lung01 study. However, similar to their EGFR counterparts, HER2 inhibitors also have evidence of toxicity in clinical studies. In this paper, we discuss the limited response of EGFR and HER2 exon20ins to a wide range of standard treatment regimens, such as platinum-based chemotherapy and classic EGFR tyrosine kinase inhibitors, as well as immunotherapy. We also review recently approved and upcoming targeted therapeutic options, considering what research is presently being done regarding efficacy and the reduction of side effects, as well as the agents' risks and benefits for incorporation into an approved treatment regimen.

Real-world clinical treatment outcomes in Chinese non-small cell lung cancer with EGFR exon 20 insertion mutations

Background

EGFR exon 20 insertions (EGFR ex20ins) constitute a heterogeneous subset of EGFR-activating alterations. However, the effectiveness of standard therapy in patients with EGFR ex20ins remains poor.

Methods

In our study, we retrospectively collected next-generation sequencing (NGS) data from 7,831 Chinese NSCLC patients and analyzed the relationship between EGFR ex20ins variations and medical records.

Results

Our data showed that EGFR ex20ins account for up to 3.5% of all EGFR mutation non-small-cell lung cancer (NSCLC) patients and 1.6% of all NSCLC patients in China. Thirty-eight different variants of EGFR ex20ins were identified in 129 NSCLC patients. We observed that the patients with EGFR ex20ins may benefit from the anti-angiogenesis agents significantly (P = 0.027). In the EGFR ex20ins near-loop group, patients who received second-/third-generation EGFR-TKI therapy treatment as first-line treatment had a longer median progression-free survival (PFS) than those who initiated treatment with first-generation EGFR-TKI or chemotherapy. Patients with co-mutations of EGFR ex20ins near-loop and TP53 tended to have a shorter OS in second-/third-generation EGFR-TKI therapy (P = 0.039). Additionally, median PFS was significantly longer in patients harboring EGFR ex20ins far-loop variants who received chemotherapy as a first-line setting (P = 0.037).

Conclusions

Overall survival was significantly longer in EGFR ex20ins patients with anti-angiogenesis agents. For the choice of first-line strategy, NSCLC with EGFR ex20ins near-loop variants may benefit from second-/third-generation EGFR-TKI, while patients harboring EGFR ex20ins far-loop variants might have better outcomes from chemotherapy. TP53 could serve as a potential predictive marker in poor prognosis for EGFR ex20ins near-loop patients.

Case Report: A good response to furmonertinib second-line treatment of an advanced lung adenocarcinoma patient with a rare EGFR exon 20 N771_P772insH mutation: A case report and literature review

Background: Lung adenocarcinoma with the classical EGFR 19 deletion and exon 21 L858R point mutations has exhibited good responses to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. However, the sensitivity of uncommon EGFR exon 20 insertion mutation to third-generation EGFR-TKIs has not been determined. Although emerging targeted therapies for EGFR exon 20 insertion mutation have been reported in recent years, such patients still have a poorer prognosis than those with typical or wild-type EGFR mutations.

Case summary: Here, we report the case of a 57-year-old man with advanced non-small cell lung cancer (NSCLC) with a rare EGFR exon 20 N771_P772insH mutation. The patient was treated with furmonertinib as second-line therapy. Although his pleural effusion was more than before that during treatment, various examination results showed that the pleural effusion was closely related to hypoproteinemia; thus, local progression was not considered. His cough was significantly alleviated, and the dose was well tolerated. The patient was evaluated for a remarkable progression-free survival (PFS) of 10.0 months, a duration of response (DOR) of 8.0 months, and an overall survival (OS) of 22.0 months, which had not previously been achieved.

Conclusion: The present study indicated that furmonertinib might be a good treatment option for first-line progressive NSCLC patients with EGFR exon 20 insertion mutation.

Non-small cell lung cancer with EGFR exon 20 insertion mutation: a systematic literature review and meta-analysis of patient outcomes

INTRODUCTION

EGFR exon 20 insertion mutation-positive non-small cell lung cancer (NSCLC) is rare, has a poor prognosis, and outcomes are not fully established. We describe and evaluate outcomes from real-world and clinical evidence in these patients.

METHODS

A systematic literature review (SLR) identified interventional and real-world evidence (RWE) studies reporting clinical outcomes for EGFR exon 20 insertion mutation-positive NSCLC. Meta-analyses were conducted by line of therapy to synthesize pooled survival and response outcomes across RWE. Published evidence from interventional studies was summarized individually.

RESULTS

The SLR identified 23 RWE and 19 original interventional studies. In the meta-analysis of RWE, pooled response and survival outcomes were low for first-line EGFR-tyrosine kinase inhibitors (TKIs) and immuno-oncology (IO) agents. First-line chemotherapy resulted in a pooled ORR 25.7%, pooled PFS 5.6 months, and pooled OS 18.3 months. Pooled outcomes were further reduced in second or later lines (≥2 L): pooled ORR was 5.0%, 3.3%, and 13.9%; pooled PFS was 2.1 months, 2.3 months, and 4.4 months; and pooled OS was 14.1 months, 8.8 months, and 17.1 months (not a pooled result) for EGFR-TKIs, IO agents, and chemotherapy, respectively. Interventional studies reported outcomes for TKIs (mobocertinib, poziotinib, osimertinib, afatinib, CLN-081, DZD9008), a monoclonal antibody (amivantamab), and a heat shock protein 90 inhibitor (luminespib). While there is limited RWE for the recently approved agents mobocertinib and amivantamab, which specifically target exon 20 insertion mutations, interventional evidence supports their potential as effective treatment options.

CONCLUSIONS

Conventional treatments used in patients with EGFR exon 20 insertion mutation-positive NSCLC have limited efficacy, though chemotherapy appeared to be associated with better response and survival outcomes than non-exon 20 targeting EGFR-TKIs and IO agents. This supports the need to identify EGFR exon 20 insertion mutations as the availability of new targeted treatments may offer additional therapeutic options to these patients.

Case Report: Two Patients With EGFR Exon 20 Insertion Mutanted Non-Small Cell Lung Cancer Precision Treatment Using Patient-Derived Xenografts in Zebrafish Embryos

Background

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations are uncommon EGFR mutations and generally resistant to first- and second-generation EGFR-tyrosine kinase inhibitors (TKIs). In precision oncology, treatment regimens are tested for improving the clinical outcomes. Zebrafish embryo tumor transplant models are used in cancer research.

Methods

We report two Chinese females who were diagnosed with stage IV lung adenocarcinoma and shown to harbor EGFR exon 20 insertion mutations by next-generation sequencing (NGS). Then, we established lung cancer patient-derived xenografts using a zebrafish model. The tumor cells were isolated from the patient. For case one, tumor cells were collected from lymph node biopsy, while the tumor cells were obtained from the pleural effusion. Zebrafish were inoculated with tumor cells and placed in the culture medium containing the third-generation EGFR-TKI, osimertinib. Fluorescence microscope photographs were used to record the red fluorescence area, which represented the proliferation and migration of tumor cells in the zebrafish.

Results

Case one was diagnosed with lung adenocarcinoma (cT4N3M1b, stage IVB) and had an EGFR exon 20 mutation (p. N771delinsHH [abundance 14.08%]). Tumor cell proliferation and migration were significantly reduced in the osimertinib group compared with the control group. The patient received first-line osimertinib (160 mg). According to RECIST v1.1, she achieved a partial response. Case two had stage IVA lung adenocarcinoma with a pleural effusion. The pleural effusion sample was selected to obtain tumor cells for injection, and the zebrafish lung cancer model was established. The proliferation of tumor cells in the osimertinib group was significantly reduced compared to the control group. The migration of tumor cells was not significantly reduced compared to the control group. The patient also received first-line osimertinib (160 mg). The lung lesions were stable, but the pleural effusion was poorly controlled.

Conclusion

Our study demonstrates the applicability of a zebrafish embryos model as an innovative platform to targeted drug testing. More precise methods are needed to select treatment options in the future.

Optimizing diagnosis and treatment of EGFR exon 20 insertions mutant NSCLC

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

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

We report a phase II study of 50 advanced non-small cell lung cancer (NSCLC) patients with point mutations or insertions in EGFR exon 20 treated with poziotinib (NCT03066206). The study achieved its primary endpoint, with confirmed objective response rates (ORRs) of 32% and 31% by investigator and blinded independent review, respectively, with a median progression-free survival of 5.5 months. Using preclinical studies, in silico modeling, and molecular dynamics simulations, we found that poziotinib sensitivity was highly dependent on the insertion location, with near-loop insertions (amino acids A767 to P772) being more sensitive than far-loop insertions, an observation confirmed clinically with ORRs of 46% and 0% observed in near versus far-loop, respectively (p = 0.0015). Putative mechanisms of acquired resistance included EGFR T790M, MET amplifications, and epithelial-to-mesenchymal transition (EMT). Our data demonstrate that poziotinib is active in EGFR exon 20-mutant NSCLC, although this activity is influenced by insertion location.

Sunvozertinib, a Selective EGFR Inhibitor for Previously Treated Non-Small Cell Lung Cancer with EGFR Exon 20 Insertion Mutations

Epidermal growth factor receptor exon 20 insertion mutations (EGFRexon20ins) are detected in approximately 2% of patients with non-small cell lung cancer (NSCLC). Due to a lack of effective therapy, the prognosis of these patients is typically poor. Sunvozertinib (DZD9008) was designed as an oral, potent, irreversible, and selective EGFR tyrosine kinase inhibitor, showing activity against EGFRexon20ins and other mutations. In both cell lines and xenograft models, sunvozertinib shows potent antitumor activity. In the two ongoing phase I clinical studies, sunvozertinib was tolerated up to 400 mg once daily. The most common drug-related adverse events included diarrhea and skin rash. Antitumor efficacy was observed at the doses of 100 mg and above in patients with EGFRexon20ins NSCLC across different subtypes, with prior amivantamab treatment as well as with baseline brain metastasis. The median duration of response has not been reached.

SIGNIFICANCE

We report the discovery and early clinical development of sunvozertinib, a potential treatment option for the unmet medical need of EGFRexon20ins NSCLC. This article is highlighted in the In This Issue feature, p. 1599.

Population pharmacokinetics of mobocertinib in healthy volunteers and patients with non-small cell lung cancer

Mobocertinib is an oral tyrosine kinase inhibitor approved for treatment of patients with locally advanced or metastatic non‐small cell lung cancer (mNSCLC) with epidermal growth factor receptor gene (EGFR) exon 20 insertion mutations whose disease has progressed on or after platinum‐based chemotherapy. This population pharmacokinetic (PK) analysis describes the PK of mobocertinib and its active metabolites, AP32960, and AP32914, using data from two phase I studies in healthy volunteers (n = 110) and two phase I/II studies in patients with mNSCLC (n = 317), including the pivotal phase I/II study. The plasma PK of mobocertinib, AP32960, and AP32914 were well‐characterized by a joint semimechanistic model that included two compartments for mobocertinib with absorption via three transit compartments, two compartments for AP32960, and one compartment for AP32914. The observed time‐dependency in PK was described by an enzyme compartment with drug and metabolite concentration‐dependent stimulation of enzyme production, resulting in the enzyme increasing the apparent clearance of mobocertinib, AP32960, and AP32914. Effects of healthy volunteer status (vs. patients with mNSCLC) on apparent oral clearance of all three moieties and on apparent central volume of distribution for mobocertinib were included as structural covariates in the final model. No clinically meaningful differences in mobocertinib PK were observed based on age (18–86 years), race, sex, body weight (37.3–132 kg), mild‐to‐moderate renal impairment (estimated glomerular filtration rate 30–89 ml/min/1.73 m² by modification of diet in renal disease equation), or mild‐to‐moderate hepatic impairment, suggesting that no dose adjustment is required based on these covariates in patients with mNSCLC.

First-line immunotherapy or angiogenesis inhibitor combined with chemotherapy for advanced non-small cell lung cancer with EGFR exon 20 insertions: Real-world evidence from China

BACKGROUND

Currently, survival benefit of immunotherapy in advanced non-small cell lung cancer (NSCLC) with EGFR exon 20 insertions (ex20ins) is controversial, though it generally indicates poor response and activity. Compared with standard chemotherapy in combination with bevacizumab, first-line chemotherapy plus immune checkpoint inhibitor (ICI) in advanced NSCLC with EGFR ex20ins remains elusive and lacks real-world evidence.

PATIENTS AND METHODS

A retrospective real-world study was conducted to evaluate clinical outcomes of chemotherapy alone (C), chemotherapy plus ICI (C + I), or chemotherapy plus angiogenesis inhibitors (C + A) as first-line strategies for advanced NSCLC patients with EGFR ex20ins. Investigator-assessed response and survival outcomes were compared between subgroups. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was conducted to reveal concomitant alterations and explore the molecular landscape of ex20ins.

RESULTS

A total of 164 patients were screened, identifying 35 kinds of ex20ins, and 122 cases treated with C, C + I, and C + A were finally included in the first-line analysis. C + A achieved much better objective response rate (ORR, 38.1% vs. 18.2%) and significant progression-free survival (PFS) benefit compared with C (median, 7.73 vs.5.93 months, HR = 0.60, 95% CI: 0.40-0.90, p = 0.014), and it showed similar ORR (38.1% vs. 40.0%), but higher disease control rate (DCR, 96.8% vs. 80.0%) and numerically longer median PFS (7.73 vs. 6.53 months, HR = 0.83, 95% CI: 0.44-1.56, p = 0.30) than C + I. There was no PFS difference between C + I and C, despite of PD-L1 expression or tumor mutational burden. KEGG analysis revealed concomitant upregulation of PI3K/AKT signaling might mediate intrinsic resistance to ICI in ex20ins.

CONCLUSION

First-line chemotherapy plus angiogenesis inhibitors might yield more survival benefits than chemotherapy alone for NSCLC with EGFR ex20ins, whereas, it suggests that chemotherapy in combination with ICI might not obtain a better survival benefit for this subset of patients. Activation of PI3K/AKT signaling might mediate intrinsic immunosuppression in NSCLC with EGFR ex20ins.

EGFR exon 20 insertion mutations in advanced non-small-cell lung cancer: current status and perspectives

Platinum-based chemotherapy was previously the first-choice treatment for lung cancer. The discovery of epidermal growth factor receptor (EGFR) gene mutations and the development of EGFR tyrosine kinase inhibitors (TKIs) marked the beginning of the targeted therapy era for non-small-cell lung cancer (NSCLC). Thirty percent of NSCLC patients carry EGFR gene mutations. For these advanced NSCLC patients, EGFR-TKIs are currently preferred for their superior activity and survival benefits over platinum-based chemotherapy. However, therapeutic efficacy is quite different in patients with EGFR exon 20 insertion (ex20ins) mutations versus common mutations. Patients with ex20ins mutations are insensitive to EGFR-TKIs and have poor prognosis. Some drugs targeting EGFR ex20ins mutations have been approved. Here, we systematically reviewed the recent clinical research of and treatments used for EGFR ex20ins mutations, summarized the latest data on emerging therapies, and discussed future prospects and treatments.

Targeting Acquired and Intrinsic Resistance Mechanisms in Epidermal Growth Factor Receptor Mutant Non-Small-Cell Lung Cancer

Over the past 2 decades, rapid advances in molecular profiling and the development of targeted therapies have dramatically improved the clinical course of advanced non-small-cell lung cancer (NSCLC). Mutations in the epidermal growth factor receptor (EGFR) gene are found in about a third of patients with advanced NSCLC, and the approval of first-generation EGFR targeted kinase inhibitors significantly improved survival when compared with platinum-based doublet chemotherapy (PBC), the previous standard of care. Inevitably, selective pressure from first-generation EGFR inhibitors led to acquired resistance mechanisms, such as the T790M mutation. The advent of third-generation EGFR inhibitors (e.g., osimertinib) successfully overcame the T790M resistance mechanism, and osimertinib subsequently became the first-line therapy for EGFR mutant NSCLC. Currently, research in EGFR mutant NSCLC is primarily focused on targeting resistance mechanisms to osimertinib. Over the past several years, many important acquired and intrinsic mechanisms of resistance to osimertinib have been identified. Acquired resistance mechanisms include C797X, mesenchymal epithelial transition factor (MET) amplification, HER2/HER3 amplification, phosphoinositide 3-kinase (PI3K) pathway mutations, RAS/mitogen-activated protein kinase (MAPK) pathway mutations, cell-cycle gene alterations, oncogenic fusions, and histologic transformations. An important intrinsic resistance mechanism to osimertinib is the EGFR exon 20 insertion mutation, which is sensitive to the newly Food and Drug Administration (FDA)-approved tyrosine kinase inhibitor mobocertinib and the EGFR/MET bispecific antibody amivantamab. This review article aims to (1) summarize the advances in the treatment of EGFR mutant NSCLC, (2) delineate known resistance mechanisms to the current first-line therapy, osimertinib, and (3) describe the development of targeted drugs that aim to overcome these resistance mechanisms.

EGFR exon 20 Insertion NSCLC and Response to Platinum-Based Chemotherapy

INTRODUCTION

In classical EGFR mutant non-small-cell lung cancer (NSCLC), EGFR tyrosine kinase inhibitor (TKI) therapy yields better outcomes than platinum-based chemotherapy. However, EGFR exon 20 insertion (ex20ins) NSCLC is relatively resistant to currently available EGFR TKIs. Though platinum-based chemotherapy is the frontline standard of care for EGFR ex20ins NSCLC, its efficacy is not fully described.

STUDY DESIGN

A retrospective, single-center, case series METHODS: Patients were identified through an electronic research database at a single institution and included if they had advanced EGFR ex20ins NSCLC, received platinum-based chemotherapy for metastatic disease, and had scans evaluable for response. Each patient's demographics, tumor characteristics, and clinical course were recorded. Treatment response was evaluated using RECIST v1.1 criteria, and the PFS was calculated by the Kaplan-Meier method.

RESULTS

Among 27 patients identified with EGFR ex20ins NSCLC at our institution, 18 (67%) received platinum-based chemotherapy for metastatic disease and had scans evaluable for response. These patients received platinum-based chemotherapy in the first-line (N = 17, 94%) and second-line settings (N = 1, 6%). The objective response rate (ORR) to platinum-based chemotherapy was 39% (7 of 18 patients; 95% confidence interval [CI] 16-61). The median PFS with platinum-based chemotherapy was 7.1 months (95% CI, 6.3 -13.7), and the median overall survival was 3.2 years (95% CI, 1.92 - NR).

CONCLUSIONS

The efficacy of platinum-based chemotherapy in EGFR ex20ins NSCLC is similar to that expected for TKI sensitive EGFR mutant NSCLC. Novel agents designed to specifically target ex20ins mutant EGFR should additionally improve outcomes.

Clinical outcomes of advanced non-small cell lung cancer patients harboring distinct subtypes of EGFR mutations and receiving first-line tyrosine kinase inhibitors: brain metastasis and de novo T790M matters

Background

The clinical features, survival outcomes and patterns of treatment failure of advanced non-small cell lung cancer (NSCLC) patients harboring distinct subtypes of EGFR mutations and receiving first-line EGFR tyrosine kinases inhibitor (TKIs) are not fully understood.

Methods

Consecutive metastatic EGFR-mutant NSCLC patients receiving first-line EGFR-TKIs from October 2010 to March 2020 were enrolled and classified into two main groups based on the EGFR mutation subtypes: common mutation (L858R or exon 19 deletion), uncommon mutation (other EGFR mutations).

Results

Of the 1081 patients included, 74 (6.8%) harbored uncommon mutations. The baseline characteristics were generally balanced between the two groups, except that bone metastasis developed less frequently in patients with uncommon mutations (p = 0.02). No significant difference of survival outcomes was found between the two groups, except that among patients with baseline brain metastasis, the intracranial time to progression was significantly shorter in patients with uncommon mutations. Nine of the 17 patients with de novo T790M mutation received Osimertinib, whose overall survival tended to be longer than the remaining 8 patients without Osimertinib treatment (p = 0.08). The patterns of treatment failure were generally consistent between the two groups, except which patients with uncommon mutations had a higher risk developing progressive disease in the brain.

Conclusion

First-line EGFR-TKIs seemed to be less effective in controlling and preventing brain metastasis in patients with uncommon EGFR mutations and Osimertinib was associated with promising efficacy in patients with de novo T790M mutation, which warranted further validation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09245-5.

Case Report: Partial Response Following Nivolumab Plus Docetaxel in a Patient With EGFR Exon 20 Deletion/Insertion (p.N771delinsGF) Mutant Lung Adenocarcinoma Transdifferentiated From Squamous Cell Carcinoma

The histological transformation from lung squamous cell carcinoma (LUSC) to lung adenocarcinoma (LUAD) and p. N771delinsGF mutations in EGFR exon 20 (ex20) are exceedingly rare in non–small cell lung carcinoma (NSCLC). EGFR ex20 mutations are insensitive to EGFR tyrosine kinase inhibitors in NSCLC. Here, we present a 76-year-old male smoker harboring LUAD with a novel p. N771delinsGF deletion/insertion mutation in EGFR ex20 transdifferentiating from advanced LUSC after chemoradiotherapy. The patient presented reduced hydrothorax and relieved tightness with the treatment of nivolumab plus docetaxel and carboplatin after the failure of second-line chemotherapy. The case highlights the importance of rebiopsy and molecular retesting after the progression of lung cancer and supports the idea that the combination of immune checkpoint blockade and chemotherapy may be an attractive option for patients with EGFR ex20 mutations associated with LUSC–LUAD transformation.