Frequency, underdiagnosis, and heterogeneity of epidermal growth factor receptor exon 20 insertion mutations using real-world genomic datasets

Comprehensive genomic profiling in multiple cancer types: A comparative analysis of the National Biobank Consortium of Taiwan and clinical practice cohorts

BACKGROUND

This retrospective study analyzed tumor tissue profiling data to assess the potential of comprehensive genomic profiling (CGP) for patient care across diverse solid tumors.

MATERIAL AND METHODS

Patients with newly diagnosed or recurrent stage IIIB or IV lung adenocarcinoma with a null immunophenotype and esophageal, gastric, pancreatic, or bile duct cancer between January 2020 and July 2023 at two medical centers in Taiwan were included. One cohort was a part of the National Biobank Consortium of Taiwan project, whereas the other consisted of patients undergoing routine clinical practice. Tumor samples were subjected to CGP using FoundationOne®CDx, with therapeutic implications determined using OncoKB classification.

RESULTS

FoundationOne®CDx testing of 574 patients was successful in 456 (79.4%) patients. Clinically actionable genomic alterations were detected in 21.1% (96/456) of the patients, including 17.5%, 2.9%, and 0.7% of patients with evidence levels 1, 2, and 3, respectively. Lung adenocarcinoma accounted for the largest proportion of samples with at least one actionable gene alteration (63.2%), followed by bile duct (26.9%), gastric (17.6%), esophageal (4.0%), and pancreatic (3.1%) cancers. Based on CGP results, 43 patients (9.4%) received matched targeted therapy. The median overall survival of patients who received matched therapy or not was 26.1 months (95% confidence interval (CI), 16.7-35.5 months) and 10.6 months (95% CI, 8.1-13.1 months; hazard ratio, 0.28, 95% CI, 0.14-0.55, p < 0.001), respectively.

CONCLUSIONS

This study provides comprehensive insights into the genomic profiles of diverse cancers in Taiwan, highlighting the crucial role of CGP in identifying actionable genomic alterations and guiding effective therapeutic strategies in real-world practice.

Benefits of NGS in Advanced Lung Adenocarcinoma Vary by Populations and Timing of Examination

Despite the widespread application of next-generation sequencing (NGS) in advanced lung adenocarcinoma, its impact on survival and the optimal timing for the examination remain uncertain. This cohort study included advanced lung adenocarcinoma patients who underwent NGS testing. We categorized patients into four groups: Group 1: treatment-naïve, upfront NGS; Group 2: Treatment-naïve, exclusionary EGFR/ALK/ROS1; Group 3: post-treatment, no known EGFR/ALK/ROS1; Group 4: known driver mutation and post-TKI treatment. A total of 424 patients were included. There were 128, 126, 90, and 80 patients in Groups 1, 2, 3, and 4, respectively. In Groups 1, 2, 3, and 4, targetable mutations were identified in 76.6%, 49.2%, 41.1%, and 33.3% of the patients, respectively (p < 0.001). Mutation-targeted treatments were applied in 68.0%, 15.1%, 27.8%, and 22.5% of the patients, respectively (p < 0.001). In the overall population, patients receiving mutation-targeted treatments exhibited significantly longer overall survival (OS) (aHR 0.54 [95% CI 0.37-0.79], p = 0.001). The most profound benefit was seen in the Group 1 patients (not reached vs. 40.4 months, p = 0.028). The median OS of patients with mutation-targeted treatments was also significantly longer among Group 2 patients. The median post-NGS survival of patients receiving mutation-targeted treatments was numerically longer in Group 3 and Group 4 patients. In conclusion, mutation-targeted therapy is associated with a favorable outcome. However, the opportunities of NGS-directed treatment and the survival benefits of mutation-targeted treatment were various among different populations.

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.

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.

Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of YK-029A in Treatment-Naive Patients With Advanced NSCLC Harboring EGFR Exon 20 Insertion Mutations: A Phase 1 Trial

INTRODUCTION

Treatment options for treatment-naive patients with advanced NSCLC harboring EGFR exon 20 insertion (ex20ins) mutations are limited. This study evaluated the safety, tolerability, and pharmacokinetics of YK-029A, a third-generation EGFR tyrosine kinase inhibitor, and the preliminary efficacy of YK-029A in treatment-naive patients with EGFR ex20ins mutation.

METHODS

This multicenter, dose-escalation, and dose-expansion phase 1 clinical trial enrolled patients with NSCLC harboring EGFR mutations. During the dose-escalation phase, YK-029A was orally administered using the traditional 3+3 principle at 50, 100, 150, 200, and 250 mg/d. In the dose-expansion phase, treatment-naive patients with EGFR ex20ins mutations were enrolled and administered YK-029A 200 mg/d. The primary end point was safety and tolerability.

RESULTS

The safety analysis included 108 patients. No dose-limiting toxicity was observed, and the maximum tolerated dose was not reached. The most common treatment-emergent adverse events were anemia (50.9%), diarrhea (49.1%), and rash (34.3%). There was minimal drug accumulation after multiple doses. A total of 28 treatment-naive patients with EGFR ex20ins mutations were enrolled in the dose-expansion and 26 were included in the efficacy analysis. According to the independent review committee evaluation, the objective response rate was 73.1% (95% confidence interval: 52.21%-88.43%), and the disease control rate was 92.3% (95% confidence interval: 74.87%-99.05%).

CONCLUSIONS

YK-029A was found to have manageable safety and be tolerable in patients with NSCLC harboring EGFR mutations and have promising antitumor activity in untreated patients with EGFR ex20ins mutations.

Navigating challenges in EGFR exon 20 insertions: The PAPILLON trial unravels the promise of amivantamab-chemotherapy

The PAPILLON trial showed that adding amivantamab to carboplatin-pemetrexed for advanced non-small cell lung cancer (NSCLC) patients with EGFR exon 20 insertion mutations is more effective than chemotherapy. Although safety concerns may arise, this study highlights the need for alternative therapeutic strategies beyond chemotherapy for this subtype of NSCLC.

Amivantamab plus Chemotherapy in NSCLC with EGFR Exon 20 Insertions

BACKGROUND

Amivantamab has been approved for the treatment of patients with advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 20 insertions who have had disease progression during or after platinum-based chemotherapy. Phase 1 data showed the safety and antitumor activity of amivantamab plus carboplatin-pemetrexed (chemotherapy). Additional data on this combination therapy are needed.

METHODS

In this phase 3, international, randomized trial, we assigned in a 1:1 ratio patients with advanced NSCLC with EGFR exon 20 insertions who had not received previous systemic therapy to receive intravenous amivantamab plus chemotherapy (amivantamab-chemotherapy) or chemotherapy alone. The primary outcome was progression-free survival according to blinded independent central review. Patients in the chemotherapy group who had disease progression were allowed to cross over to receive amivantamab monotherapy.

RESULTS

A total of 308 patients underwent randomization (153 to receive amivantamab-chemotherapy and 155 to receive chemotherapy alone). Progression-free survival was significantly longer in the amivantamab-chemotherapy group than in the chemotherapy group (median, 11.4 months and 6.7 months, respectively; hazard ratio for disease progression or death, 0.40; 95% confidence interval [CI], 0.30 to 0.53; P<0.001). At 18 months, progression-free survival was reported in 31% of the patients in the amivantamab-chemotherapy group and in 3% in the chemotherapy group; a complete or partial response at data cutoff was reported in 73% and 47%, respectively (rate ratio, 1.50; 95% CI, 1.32 to 1.68; P<0.001). In the interim overall survival analysis (33% maturity), the hazard ratio for death for amivantamab-chemotherapy as compared with chemotherapy was 0.67 (95% CI, 0.42 to 1.09; P = 0.11). The predominant adverse events associated with amivantamab-chemotherapy were reversible hematologic and EGFR-related toxic effects; 7% of patients discontinued amivantamab owing to adverse reactions.

CONCLUSIONS

The use of amivantamab-chemotherapy resulted in superior efficacy as compared with chemotherapy alone as first-line treatment of patients with advanced NSCLC with EGFR exon 20 insertions. (Funded by Janssen Research and Development; PAPILLON ClinicalTrials.gov number, NCT04538664.).

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.

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.