Case Report: Afatinib Treatment in a Patient With NSCLC Harboring a Rare EGFR Exon 20 Mutation

Bilateral keratitis associated with afatinib therapy

This case discussed a significant ocular side effect, bilateral keratitis, which could be induced by afatinib, an irreversible epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). We explored the disease progression of a 52-year-old, stage IV nasopharyngeal carcinoma male patient, who was under afatinib treatment and had experienced progressive bilateral eye dryness and tenderness on increasing afatinib from 40 mg every other day to 40 mg daily. Clinical examination noted bilateral visual acuity reduction, diffuse superficial punctate keratopathy in the right eye, and a central epithelial defect in the left eye. Seidel test results were negative for both eyes, with no corneal infiltration, lagophthalmos, anterior chamber cell precipitation, or retinal lesion. Symptoms subsequently resolved after reducing the frequency of afatinib used, along with intensive ocular hydration. In summary, this case highlighted afatinib's potential link to bilateral keratitis, and early afatinib dose adjustment with supportive medication could significantly reverse the condition.

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.

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.

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.

Emerging therapies for non-small cell lung cancer harboring EGFR exon 20 insertion mutations: narrative review

Background and Objective

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations (ex20ins) are uncommon in non-small cell lung cancer (NSCLC). These mutations are generally resistant to first-generation EGFR tyrosine kinase inhibitors, unlike common EGFR mutations, including exon 19 deletions or exon 21 L858R point mutation. The development of effective targeted therapies for NSCLC harboring EGFR ex20ins has been eagerly anticipated over the years. Recently, the therapeutic landscape of this subgroup of EGFR-mutant NSCLC patients has rapidly evolved due to the emergence of new drugs. In 2021, several novel agents, such as amivantamab and mobocertinib, have been approved by the US Food and Drug Administration for patients with advanced platinum-resistant NSCLC harboring EGFR ex20ins. In this review, we mainly focus on emerging therapies targeting NSCLC with EGFR ex20ins, as well as important ongoing clinical trials.

Methods

Searches were conducted in PubMed and supplemented with recent conference proceedings in November 30th, 2021.

Key Content and Findings

Several novel emerging therapies showed favorable safety profile and promising anti-tumor activity in NSCLC patients with EGFR ex20ins in recent several clinical trials.

Conclusions

There is still room for improvement in the treatment results of NSCLC harboring EGFR ex20ins. Future research should focus on the molecular heterogeneity in the size and location of distinct EGFR ex20ins, the mechanisms of acquired resistance to novel EGFR inhibitors, effective treatment that have good central nervous system penetrance, and the potential role of combination strategy.

Molecularly Targeted Photothermal Ablation of Epidermal Growth Factor Receptor-Expressing Cancer Cells with a Polypyrrole-Iron Oxide-Afatinib Nanocomposite

Simple Summary

In this manuscript, we describe the design and synthesis of a nanocomposite containing afatinib, polypyrrole, and iron oxide (PIA-NC) to molecularly target epidermal growth factor receptor (EGFR)-overexpressing cancer cells for photothermal conversion. In addition to physical and chemical characterization, we also showed that PIA-NC induces selective reactive oxygen species surge and apoptosis in response to sublethal near-infrared light only in EGFR-overexpressing cancer cells, not in EGFR-negative fibroblasts. The work demonstrates the feasibility of photothermal therapy with cellular precision.

Abstract

Near-infrared–photothermal therapy (NIR-PTT) is a potential modality for cancer treatment. Directing photothermal effects specifically to cancer cells may enhance the therapeutic index for the best treatment outcome. While epithelial growth factor receptor (EGFR) is commonly overexpressed/genetically altered in human malignancy, it remains unknown whether targeting EGFR with tyrosine kinase inhibitor (TKI)-conjugated nanoparticles may direct NIR-PTT to cancers with cellular precision. In the present study, we tested this possibility through the fabrication of a polypyrrole–iron oxide–afatinib nanocomposite (PIA-NC). In the PIA-NC, a biocompatible and photothermally conductive polymer (polypyrrole) was conjugated to a TKI (afatinib) that binds to overexpressed wild-type EGFR without overt cytotoxicity. A Fenton catalyst (iron oxide) was further encapsulated in the NC to drive the intracellular ROS surge upon heat activation. Diverse physical and chemical characterization experiments were conducted. Particle internalization, cytotoxicity, ROS production, and apoptosis in EGFR-positive and -negative cell lines were investigated in the presence and absence of NIR. We found that the PIA-NCs were stable with a size of 243 nm and a zeta potential of +35 mV. These PIA-NCs were readily internalized close to the cell membrane by all types of cells used in the study. The Fourier transform infrared spectra showed 3295 cm⁻¹ peaks; substantial O–H stretching was seen, with significant C=C stretching at 1637 cm⁻¹; and a modest appearance of C–O–H bending at 1444 cm⁻¹ confirmed the chemical conjugation of afatinib but not iron oxide to the NC. At a NIR-PTT energy level that has a minimal cytotoxic effect, PIA-NC significantly sensitizes EGFR-overexpressing A549 lung cancer cells to NIR-PTT-induced cytotoxicity at a rate of 70%, but in EGFR-negative 3T3 fibroblasts the rate was 30%. Within 1 min of NIR-PTT, a surge of intracellular ROS was found in PIA-NC-treated A549 cells. This was followed by early induction of cellular apoptosis for 54 ± 0.081% of A549 cells. The number of viable cells was less than a quarter of a percent. Viability levels of A549 cells that had been treated with NIR or PIA were only 50 ± 0.216% and 80 ± 0.216%, respectively. Only 10 ± 0.816% of NIH3T3 cells had undergone necrosis, meaning that 90 ± 0.124% were alive. Viability levels were 65 ± 0.081% and 81 ± 0.2%, respectively, when only NIR and PIA were used. PIA binding was effective against A549 cells but not against NIH3T3 cells. The outcome revealed that higher levels of NC + NIR exposure caused cancer cells to produce more ROS. In summary, our findings proved that a molecularly targeted NC provides an orchestrated platform for cancer cell-specific delivery of NIR-PTT. The geometric proximity design indicates a novel approach to minimizing the off-target biological effects of NIR-PTT. The potential of PIA-NC to be further developed into real-world application warrants further investigation.

Amivantamab in the Treatment of Metastatic NSCLC: Patient Selection and Special Considerations

Amivantamab is a bispecific antibody that recognizes epidermal growth factor receptor (EGFR) and MET proto-oncogene (MET). In May 2021, the Food and Drug Administration gave an accelerated approval of amivantamab for the treatment of non-small cell lung cancer (NSCLC) patients with EGFR exon 20 insertions (Exon20ins) who progressed after platinum-based chemotherapy. Amivantamab prevents ligand binding to EGFR and MET and the dimerization of the receptors suppressing the downstream signal transduction. Moreover, amivantamab determines antibody dependent cellular cytotoxicity and down regulation of cell surface proteins through internalization of the receptor and trogocytosis. Preliminary results of the Phase I/IB CHRYSALIS trial demonstrated an objective response rate of 40% with a median duration of response of 11.1 months (95% CI 9.6-not reached) in 81 patients treated with amivantamab with pretreated NSCLC with Exon20ins EGFR mutations. In a different cohort of the CHRYSALIS trial, patients with Ex19del and L858R EGFR mutations were enrolled after progression on osimertinib. 121 and 45 patients received amivantamab or a combination with lazertinib, a third-generation tyrosine kinase inhibitor, respectively. The objective response rate was 19% and 36% in patients treated with amivantamab alone or in combination with lazertinib, with a median progression-free survival of 6.9 (95% CI: 3.2-5.3) and 11.1 (95% CI: 3.7-9.5) months, respectively. All 20 patients with Ex19del and L858R EGFR mutations who received amivantamab and lazertinib as their first line treatment achieved an objective response. Amivantamab is currently under evaluation in Phase III clinical trials for the first line treatment of NSCLCs with Exon20ins EGFR mutations in combination with chemotherapy (PAPILLON), for the first line therapy of Ex19del and L858R mutated NSCLCs in combination with lazertinib (MARIPOSA) and in combination with chemotherapy and lazertinib in NSCLCs who progressed on osimertinib (MARIPOSA-2).

Treatment outcome of atypical EGFR mutations in the German National Network Genomic Medicine Lung Cancer (nNGM)

BACKGROUND

Atypical EGFR mutations occur in 10-30% of NSCLC patients with EGFR mutations and their sensitivity to classical EGFR-tyrosine kinase inhibitors (TKI) is highly heterogeneous. Patients harboring one group of uncommon, recurrent EGFR mutations (G719X, S768I, L861Q) respond to EGFR-TKI. Exon 20 insertions are mostly insensitive to EGFR-TKI but display sensitivity to exon 20 inhibitors. Clinical outcome data of patients with very rare point and compound mutations upon systemic treatments are still sparse to date.

PATIENTS AND METHODS

In this retrospective, multi-center study of the national Network Genomic Medicine (nNGM) in Germany, 856 NSCLC cases with atypical EGFR mutations including co-occuring mutations were reported from 12 centers. Clinical follow-up data after treatment with different EGFR-TKI, chemotherapy and immune checkpoint inhibitors were available from 260 patients. Response to treatment was analyzed in three major groups: (1) uncommon mutations (G719X, S7681, L861Q and combinations), (2) exon 20 insertions and (3) very rare EGFR mutations (very rare single point mutations, compound mutations, exon 18 deletions, exon 19 insertions).

RESULTS

Our study comprises the largest thus far reported real-world cohort of very rare EGFR single point and compound mutations treated with different systemic treatments. We validated higher efficacy of EGFR-TKI in comparison to chemotherapy in group 1 (uncommon), while most exon 20 insertions (group 2) were not EGFR-TKI responsive. In addition, we found TKI sensitivity of very rare point mutations (group 3) and of complex EGFR mutations containing exon 19 deletions or L858R mutations independent of the combination partner. Notably, treatment responses in group 3 (very rare) were highly heterogeneous. Co-occurring TP53 mutations exerted a non-significant trend for a detrimental effect on outcome in EGFR-TKI treated patients in groups 2 and 3 but not in group 1.

CONCLUSIONS

Based on our findings we propose a novel nNGM classification of uncommon EGFR mutations.

Budget Impact di afatinib per il trattamento in prima linea del Non Small Cell Lung Cancer (NSCLC) con mutazioni non comuni EGFR

Background:

The current clinical practice for patients affected by Non-Small Cell Lung Cancer (NSCLC) with uncommon mutation is based on afatinib and osimertinib, second and third generation of Tyrosine Kinase Inhibitor (TKI) respectively. For uncommon EGFR mutations, it is still unclear which EGFR TKI is most effective, since there are few dedicated prospective studies and Next Generation Sequencing (NGS) techniques trace an increasingly large and sometimes little-known population of EGFR mutations.

Objective:

To determine the economic impact associated to afatinib and osimertinib, a Budget Impact model considering a 3-year time horizon with two scenarios was developed: a first scenario, called AS IS, based on treatment with afatinib and osimertinib according to a distribution of market shares as emerged from clinical practice; a second suitable scenario, called TO BE, based on reviewed literature data, assuming for each year a 10%, 15% and 20% increase in afatinib use, respectively.

Methods:

Budget Impact analysis was conducted using a dynamic cohort model, in which the annual number of patients with NSCLC and uncommon mutations was equally distributed over 12 months. Progression-free survival (PFS) data for afatinib and osimertinib were extrapolated up to 36 months from published Kaplan Meier curves, and then the number of patients was estimated for each treatment.

Results:

The increase of 10% in afatinib use allowed a saving of drug acquisition costs for the Italian NHS, over the 3-year time horizon, of –€ 622,432. The univariate sensitivity analysis shows the market share of osimertinib to be the parameter significantly affecting the results achieved in the base case.

Conclusions:

The potential increase in the use of afatinib in patients with NSCLC and uncommon mutations leads to lower drug acquisition costs, lower Budget Impact and a saving of money for the Italian NHS.

Case Report: Osimertinib Followed by Osimertinib Plus Bevacizumab, Personalized Treatment Strategy for a Lung Cancer Patient With a Novel EGFR Exon 20 Insertion D770_N771insGT and Multiple Brain Metastases

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) are the standard of care for non–small cell lung cancer (NSCLC) patients with EGFR exon 19 deletion and L858R mutations. However, no EGFR TKI has been approved for NSCLC patients harboring insertion mutations in EGFR exon 20 (EGFRex20ins), a subgroup of uncommon EGFR mutations resistant to first-generation EGFR TKIs. This unmet clinical challenge is further complicated by disease progression due to brain metastases (BMs), which limits the use of EGFR TKIs with low intracranial activity. Osimertinib, a third-generation EGFR TKI with high CNS activity, has demonstrated superior efficacy as a first-line treatment for EGFR-mutant NSCLC with or without BM. The VEGF pathway is a key mediator of cancer metastasis and resistance to EGFR TKIs. Accumulating evidence has demonstrated that the addition of anti-VEGF agents to EGFR TKIs provides an alternative treatment option for the clinical management of EGFR-mutant NSCLC. We herein report an NSCLC case with a novel EGFRex20ins mutation D770_N771insGT and multiple brain metastases who briefly responded to first-line osimertinib treatment and subsequently achieved prolonged disease control with osimertinib plus bevacizumab as second-line treatment. Our case suggests that osimertinib in combination with bevacizumab may be an effective option for NSCLC patients with specific EGFRex20ins mutations and brain metastases.

Therapeutic exploration of uncommon EGFR exon 20 insertion mutations in advanced non-small cell lung cancer: breaking through brambles and thorns

BACKGROUND

EGFR exon 20 insertion (EGFR ex20ins) mutations account for about 10-12% of all EGFR-mutated tumors, which are usually associated with primary drug resistance to conventional EGFR-TKI therapy and worse survival outcomes, and are currently a major problem for clinicians in clinical management. In recent years, with the rapid improvement of sequencing technology and careful review of clinical data, investigators have gained a deeper understanding and clearer cognition of the clinicopathological features and molecular mechanisms of these EGFR ex20ins mutations.

PURPOSE

The aim of this study was to systemically review the molecular structure and clinical characteristics of EGFR ex20ins mutations, and focus on summarizing the latest data of emerging therapies (including novel small-molecule EGFR-TKI drugs, specific monoclonal antibodies, novel drugs targeting other mechanisms, and immunotherapy) for those patients.

CONCLUSION

Advances in overcoming these systemic challenges have greatly accelerated the development of new drugs targeting EGFR ex20ins, and are committed to designing more rational combination therapies to overcome or delay the emergence of drug resistance, ultimately improve the prognosis of such uncommon mutant populations.

Clinical characteristics of advanced non-small cell lung cancer patients with EGFR exon 20 insertions

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations (Exon20ins) account for 4–12% of all EGFR mutations in non-small cell lung cancer (NSCLC) patients. Data on the differences in clinical characteristics between patients with Exon20ins and major mutations (M-mut) such as exon 19 deletion and L858R are limited. We retrospectively reviewed advanced NSCLC patients with EGFR mutations, who were treated with systemic therapy between January 2011 and December 2019. We identified 23 patients with Exon20ins and 534 patients with M-mut. In Exon20ins patients, the median age was 60 (range 27–88) years, and females and never-smokers were predominant. Clinical characteristics were similar in the two groups. In Exon20ins patients, 17 patients received platinum doublet as first-line therapy, and the overall response rate (ORR) and median progression-free survival (mPFS) were 11.8% and 8.9 months. Additionally, seven patients received conventional EGFR-tyrosine kinase inhibitors (TKIs), and eight patients anti-PD-1 antibodies in any-line therapy. ORR and mPFS of EGFR-TKIs and anti-PD-1 antibodies were 0%, 2.2 months and 25%, 3.1 months, respectively. Overall survival was significantly shorter in Exon20ins patients than in M-mut patients (29.3 vs. 43.4 months, p = 0.04). The clinical outcomes in Exon20ins patients were not satisfactory compared to M-mut patients.

Targeting EGFR Exon 20 Insertions in Non-Small Cell Lung Cancer: Recent Advances and Clinical Updates

Approximately 10% of EGFR-activating mutations occur as in-frame insertion mutations in exon 20 of the EGFR kinase domain (EGFR ins20). EGFR ins20 mutations have not demonstrated the same sensitivity to early generations of EGFR tyrosine kinase inhibitors (TKI) as canonical activating EGFR mutations such as del19 and L858R. Development of effective therapies for this subset of patients has been challenging, but recent years have seen more rapid progress in these efforts. In this review, we describe the molecular and clinicopathologic features of EGFR ins20 mutations and summarize recent data on emerging therapies for patients with this subtype of EGFR-mutant non-small cell lung cancer (NSCLC). SIGNIFICANCE: When activating mutations in EGFR were first discovered in lung cancer, the lack of sensitivity of tumors harboring EGFR ins20 mutations to early-generation EGFR TKIs resulted in this subset of EGFR-mutant tumors being initially classified as an untargetable or intrinsically resistant subpopulation. In addition, the diversity of mutations within EGFR exon 20 and resultant challenges identifying them on routine clinical genotyping tests led to underestimation of their frequency. However, recent scientific progress in targeting EGFR ins20 mutations as well as more effective identification of this clinical cohort has enhanced our ability to develop effective therapies for patients with this subtype of EGFR-mutant NSCLC.