Second-line treatment of EGFR T790M-negative non-small cell lung cancer patients

From osimertinib to preemptive combinations

Here, I suggest that while first-line osimertinib extends median progression-free survival (PFS) in EGFR-mutant lung cancer compared to first-generation TKIs, it reduces individual PFS in 15-20% of patients compared to first-generation TKIs. Since detecting a single resistant cell before treatment is usually impossible, osimertinib must be used in all patients as a first-line treatment, raising median PFS overall but harming some. The simplest remedy is a preemptive combination (PC) of osimertinib and gefitinib. A comprehensive PC (osimertinib, afatinib/gefitinib, and capmatinib) could dramatically increase PFS for 80% of patients compared to osimertinib alone, without harming anyone. This article also explores PCs for MET-driven lung cancer.

GW4869 Can Inhibit Epithelial-Mesenchymal Transition and Extracellular HSP90α in Gefitinib-Sensitive NSCLC Cells

Objective

GW4869 is an exosomal inhibitor. It is necessary to delay the occurrence of gefitinib resistance during non-small-cell lung cancer (NSCLC) treatment. This study aimed to investigate the anti-tumor effects of GW4869 on epithelial-mesenchymal transition (EMT) and expression of extracellular heat shock protein 90α (eHSP90α) that contributes to acquired resisitance. Our study provides a new sight into the treatment of EGFR-mutated NSCLC.

Materials and Methods

We performed western blotting to detect levels of EMT and eHSP90α. Wound healing and transwell assays were performed to evaluate the behavioral dynamics of EMT. A nude mouse model of HCC827 was established in vivo.

Results

GW4869 inhibited the expression of eHSP90α, EMT, invasion and migration abilities of HCC827 and PC9. GW4869 enhanced sensitivity to gefitinib in BALB/c nude mice bearing tumors of HCC827.

Conclusion

These studies suggest that GW4869 can inhibit EMT and extracellular HSP90α, providing new strategies for enhancing gefitinib sensitivity in NSCLC.

Epidermal Growth Factor Receptor T790M Mutation Testing in Non-Small Cell Lung Cancer: An International Collaborative Study to Assess Molecular EGFR T790M Testing in Liquid Biopsy

BACKGROUND

The detection of the EGFR T790M (T790M) mutation in non-small cell lung cancer (NSCLC) patients who progressed under treatment with first- or second-generation EGFR-tyrosine kinase inhibitors (TKIs) is important to offer a subsequent therapy with a third-generation EGFR-TKI. Liquid biopsy is a powerful tool to determine the T790M mutation status. Several liquid biopsy platforms with varying degrees of accuracy are available to test for T790M mutations, and sensitivities may differ among these methods.

METHODS

As no standard exists for the testing of T790M mutation in liquid biopsy, we performed a collaborative study to describe and compare the sensitivity of different in-house liquid biopsy platforms for the detection of the T790M mutation, EGFR exon 19 deletion (del19) and EGFR L858R mutation (L858R) across multiple participating laboratories in seven Central and Eastern European countries.

RESULTS

Of the 25 invited laboratories across Central and Eastern Europe, 21 centers participated and received 10 plasma samples spiked with cell-line DNA containing the T790M, del19, or L858R mutation in different concentrations. In-house PCR-based and NGS-based methods were used accordingly, and results were reported as in routine clinical practice. Two laboratories, which used the AmoyDx^® EGFR 29 Mutations Detection Kit (AmoyDx) with Cobas^® cfDNA Sample Preparation Kit and QX200 Droplet Digital PCR (ddPCR) with the QIAamp Circulating Nucleic Acid Kit identified all ten samples correctly. Cobas^® EGFR Mutation Test v2 (Cobas), the NGS methods, and the Idylla^TM detection method used in this study performed within the known sensitivity range of each detection method.

CONCLUSIONS

If a negative result was obtained from methods with lower sensitivity (e.g., Cobas), repeated liquid biopsy testing and/or tissue biopsy analysis should be performed whenever possible, to identify T790M-positive patients to allow them to receive the optimal second-line treatment with a third-generation EGFR TKI.

Factors associated with outcomes of second-line treatment for EGFR-mutant non-small-cell lung cancer patients after progression on first- or second-generation EGFR-tyrosine kinase inhibitor treatment

Purpose

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are standard first-line treatments for advanced EGFR-mutant non-small-cell lung cancer (NSCLC) patients. However, factors associated with outcomes after progression on first-line therapy are seldom investigated.

Materials and methods

From January 2016 to December 2020, we enrolled 242 EGFR-mutant stage IIIB-IV NSCLC patients who progressed on first- or second-generation EGFR-TKI treatments, and 206 of them receive second-line treatments after disease progression. The factors that predict the survival outcomes of different second-line treatments after disease progression were evaluated. Clinical and demographic characteristics, including metastatic sites, neutrophil-to-lymphocyte ratio (NLR) at first-line progression, and second-line treatment regimens, and whether re-biopsied after disease progression or not, were reviewed for outcome analysis.

Results

The univariate analysis showed that the PFS was shorted in male patients (p =0.049), patients with ECOG performance state ≥ 2 (p =0.014), former smokers (p =0.003), patients with brain metastasis (p =0.04), second-line chemotherapy or EGFR-TKIs other than osimertinib (p =0.002), and NLR ≥5.0 (p=0.024). In addition, second-line osimertinib was associated with longer OS compared to chemotherapy and other EGFR-TKI treatment (p =0.001). In the multivariate analysis, only second-line osimertinib was an independent predictor of PFS (p =0.023). Re-biopsy after first-line treatment was associated with a trend of better OS. Patients with NLR ≥5.0 at disease progression had shorter OS than patients with NLR <5.0 (p = 0.008).

Conclusion

The benefits of osimertinib necessitate that aggressive re-biopsy after progression on first- or second-generation EGFR-TKI treatment is merited for appropriate second-line treatments to provide better outcomes for these patients.

Nanotechnology - a robust tool for fighting the challenges of drug resistance in non-small cell lung cancer

Genomic and proteomic mutation analysis is the standard of care for selecting candidates for therapies with tyrosine kinase inhibitors against the human epidermal growth factor receptor (EGFR TKI therapies) and further monitoring cancer treatment efficacy and cancer development. Acquired resistance due to various genetic aberrations is an unavoidable problem during EGFR TKI therapy, leading to the rapid exhaustion of standard molecularly targeted therapeutic options against mutant variants. Attacking multiple molecular targets within one or several signaling pathways by co-delivery of multiple agents is a viable strategy for overcoming and preventing resistance to EGFR TKIs. However, because of the difference in pharmacokinetics among agents, combined therapies may not effectively reach their targets. The obstacles regarding the simultaneous co-delivery of therapeutic agents at the site of action can be overcome using nanomedicine as a platform and nanotools as delivery agents. Precision oncology research to identify targetable biomarkers and optimize tumor homing agents, hand in hand with designing multifunctional and multistage nanocarriers that respond to the inherent heterogeneity of the tumors, may resolve the challenges of inadequate tumor localization, improve intracellular internalization, and bring advantages over conventional nanocarriers.

Successful treatment of a patient with advanced lung adenocarcinoma (EGFR-T790M and C797S cis) with lazertinib: A case report and literature review

Lazertinib has been shown to treat non-small cell lung cancer (NSCLC) patients with EGFR-T790M, Ex19del, and L858R mutations. However, there are still no studies to prove that lazertinib could be used in patients with EGFR-T790M and C797s cis mutations in NSCLC. We report a case of a patient with advanced lung adenocarcinoma with EGFR-T790M and C797s cis mutations who were treated with lazertinib and achieved satisfactory efficacy without serious side effects. And the scratch assay and colony-forming unit assay were performed using lung adenocarcinoma cells from patients, the results showed that both lazertinib and amivantamab could inhibit the proliferation and migration of lung adenocarcinoma cells to some extent, and the inhibitory effect of lazertinib was better than that of amivantamab (p < 0. 01), while the inhibitory effect of lazertinib combined with amivantamab was not statistically different from that of lazertinib alone(p>0.05). This finding suggests that lazertinib may be an effective treatment option for patients with lung adenocarcinoma presenting with EGFR-T790M and C797s cis mutations.

LncRNA AFAP1-AS1 Induces Gefitinib Resistance of Lung Adenocarcinoma Through the miR-653-5p/AGR2 Axis

Purpose

Gefitinib resistance limits the therapeutic efficacy of gefitinib to lung adenocarcinoma (LUAD). The goal of this research is to learn more about the lncRNA AFAP1-AS1 and how it functions in gefitinib-resistant LUAD cells.

Methods

RT-qPCR was performed to test the expression of AFAP1-AS1, miR-653-5p and AGR2 in LUAD tissues with acquired resistance to gefitinib or not as well as in gefitinib-resistant LUAD cells. Cell proliferation, invasion and apoptosis were measured by CCK8 assays, transwell invasion assays and flow cytometry, respectively. Luciferase reporter assay showed that miR-653-5p and AFAP1-AS1 or AGR2 interactions.

Results

In gefitinib-resistant LUAD cells and tissues, AFAP1-AS1 was overexpressed. Meanwhile, silencing AFAP1-AS1 reduced proliferation and migration while increasing apoptosis and gefitinib sensitivity. Mechanically, AFAP1-AS1 sequestered the miR-653-5p and blocked the inhibition of miR-653-5p to AGR2 and stepwise upregulated AGR2 overexpression in LUAD gefitinib resistant cells, resulting gefitinib resistance in LUAD.

Conclusion

AFAP1-AS1 promotes gefitinib-resistance LUAD cells through a previously unrecognized miR-653-5p/AGR2 axis, suggesting targeting AFAP1-AS1/miR-653-5p/AGR2 axis might be a promising way for LUAD intervention.

Sequential treatment in advanced non-small cell lung cancer harboring EGFR mutations

BACKGROUND

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are standard treatments for advanced EGFR-mutated non-small cell lung cancer (NSCLC) patients. Osimertinib is an effective therapy for NSCLC patients with acquired resistance due to T790M mutation after first- and second-generation EGFR-TKI treatment. This study aimed to analyze the clinical outcomes of sequential therapy following first-line EGFR-TKIs and the predictive factors of an acquired T790M mutation.

METHODS

Between January 2014 and December 2018, data from 2190 advanced NSCLC patients with common EGFR mutations (exon 19 deletion and L858R) receiving first- and second-generation EGFR-TKIs in Linkou, Kaohsiung, Chiayi and Keelung Chang Gung Memorial Hospitals were retrospectively retrieved and analyzed.

RESULTS

Until August 2021, among 1943 patients who experienced progressive disease, 526 underwent T790M mutation tests, and their T790M-positive rate was 53.6%. Exon 19 deletion mutation and progression-free survival (PFS) of >12 months were positively associated with secondary T790M mutation. Different first-line first- and second-generation EGFR-TKI therapies did not affect the appearance of acquired T790M mutations. The median overall survival (OS) was 58.3 [95% confidence interval (CI): 49.0-67.5] months among the patients with T790M mutation who received second-line osimertinib therapy compared with 31.0 (95% CI: 27.5-34.5) months among the patients without T790M mutation who received chemotherapy alone. The multivariate analysis showed that a poor performance status (score: >2), nonadenocarcinoma histology, stage IV cancer, liver metastasis, brain metastasis, PFS while on first-line EGFR-TKIs, and subsequent chemotherapy without third-generation EGFR-TKIs were significant independent unfavorable prognostic factors for OS.

CONCLUSION

This study demonstrated the efficacy of first-line EGFR-TKIs and sequential osimertinib therapy. The results of our study suggest that T790M mutation tests are important for the use of subsequent osimertinib, which yielded favorable survival outcomes.

Sequential Afatinib and Osimertinib in Asian Patients with EGFR Mutation-Positive Non-Small Cell Lung Cancer and Acquired T790M: Combined Analysis of Two Global Non-Interventional Studies

Objective

Two recent non-interventional trials, GioTag and UpSwinG, demonstrated encouraging time-to-treatment failure (TTF) and overall survival (OS) in patients with epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC) (Del19 or L858R) who received sequential afatinib/osimertinib, especially in Asians. Here, we have undertaken a combined analysis of Asian patients from both studies.

Materials and Methods

Existing medical/electronic records were identified for consecutive EGFR-tyrosine kinase inhibitor (TKI)-naïve patients who received first-line afatinib/second-line osimertinib in “real-world” practice (all T790M-positive). Patients with active brain metastases were excluded. The primary objective was TTF. OS was a key secondary objective.

Results

One hundred and sixty-eight patients were analyzed. Most patients were recruited from South Korea or Japan (52/21%). At the start of afatinib, median age (range) was 61.5 years (35–88), 58% were female, Eastern Cooperative Oncology Group Performance Status (ECOG PS) (0/1/≥2) was 29/62/9%, 17% had brain metastases, and EGFR mutation status (Del19/L858R) was 65/35%. At the start of osimertinib, ECOG PS (0/1/≥2) was 22/61/17% and 14% had brain metastases. Median TTF and OS were 30.0 months (95% CI: 24.5–32.5) and 45.2 months (95% CI: 41.7–71.1), respectively. Median OS was 63.5 months in patients with a Del19 mutation. Median OS in patients with brain metastases or ECOG PS ≥2 was 26.4 and 33.1 months, respectively.

Conclusion

Sequential afatinib/osimertinib showed encouraging activity in Asian patients with EGFR mutation-positive NSCLC and T790M-mediated acquired resistance, especially those with Del19-positive disease. Activity was observed across “real-world” patients including those with poor ECOG PS and/or brain metastases. ECOG PS and incidence of brain metastases remained stable prior to, and after, afatinib.

Ablative Radiotherapy as a Strategy to Overcome TKI Resistance in EGFR-Mutated NSCLC

Simple Summary

Most patients with EGFR-mutated NSCLC who receive treatment with targeted therapy will eventually develop resistance, meaning the therapy will lose its efficacy. Prior studies have shown a benefit to continuing to treat patients on TKI therapy despite limited progression of one or more sites of metastatic disease in EGFR-mutated NSCLC. Based on the data reviewed here, the use of radiation therapy to sites of disease progression is both efficacious and carries a low risk for side effects, with the added benefit of allowing patients to continue on TKI therapy.

Abstract

Tyrosine kinase inhibitor (TKI) therapy is the recommended first-line treatment for metastatic non-small-cell lung cancer (NSCLC) positive for epidermal growth factor receptor (EGFR) gene mutation. However, most individuals treated with TKI therapy for EGFR-mutant NSCLC will develop tumor resistance to TKI therapy. Therapeutic strategies to overcome TKI resistance are the topic of several ongoing clinical trials. One potential strategy, which has been explored in numerous trials, is the treatment of progressive sites of disease with stereotactic body radiation treatment (SBRT) or stereotactic radiosurgery (SRS). We sought to review the literature pertaining to the use of local ablative radiation therapy in the setting of acquired resistance to TKI therapy and to discuss stereotactic radiation therapy as a strategy to overcome TKI resistance.

Consensus Recommendations to Optimize Testing for New Targetable Alterations in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) has historically been associated with a poor prognosis and low 5-year survival, but the use of targeted therapies in NSCLC has improved patient outcomes over the past 10 years. The pace of development of new targeted therapies is accelerating, with the associated need for molecular testing of new targetable alterations. As the complexity of biomarker testing in NSCLC increases, there is a need for guidance on how to manage the fluid standard-of-care in NSCLC, identify pragmatic molecular testing requirements, and optimize result reporting. An expert multidisciplinary working group with representation from medical oncology, pathology, and clinical genetics convened via virtual meetings to create consensus recommendations for testing of new targetable alterations in NSCLC. The importance of accurate and timely testing of all targetable alterations to optimize disease management using targeted therapies was emphasized by the working group. Therefore, the panel of experts recommends that all targetable alterations be tested reflexively at NSCLC diagnosis as part of a comprehensive panel, using methods that can detect all relevant targetable alterations. In addition, comprehensive biomarker testing should be performed at the request of the treating clinician upon development of resistance to targeted therapy. The expert multidisciplinary working group also made recommendations for reporting to improve clarity and ease of interpretation of results by treating clinicians and to accommodate the rapid evolution in clinical actionability of these alterations. Molecular testing of all targetable alterations in NSCLC is the key for treatment decision-making and access to new therapies. These consensus recommendations are intended as a guide to further optimize molecular testing of new targetable alterations.

Optimizing Patient Outcomes Through Sequential EGFR TKI Treatment in Asian Patients With EGFR Mutation-Positive NSCLC

Patients from Asia with non-small-cell lung cancer (NSCLC) often have mutations in the epidermal growth factor receptor (EGFR) gene. While an increasing number of EGFR tyrosine kinase inhibitors (TKIs) are now available for patients with EGFR mutation-positive NSCLC, most patients inevitably develop resistance to the treatment. Evidence from clinical studies suggests that treatment outcomes and resistance mechanisms vary depending on the choice of TKI therapy in the first-line setting. Hence, it is important to develop optimal treatment sequencing strategies that can provide maximum survival benefit for the patient. In this review we present clinical evidence in Asian patients with NSCLC for various EGFR TKIs, with the goal of supporting the optimization of treatment sequencing.

Detection of MET amplification by droplet digital PCR in peripheral blood samples of non-small cell lung cancer

PURPOSE

Mesenchymal-epithelial transition (MET) amplification is one of the mechanisms accounting for the resistance of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in lung cancer patients, as well as the poor prognosis. Fluorescence in situ hybridization (FISH) is the most widely used method for MET amplification detection. However, it is inapplicable when tissue samples were unavailable. Herein, we assessed the value of droplet digital PCR (ddPCR) in MET copy number gain (CNG) detection in non-small cell lung cancer (NSCLC) patients treated with EGFR-TKIs.

MATERIALS AND METHODS

A total of 103 cancer tissues and the paired peripheral blood samples from NSCLC patients were collected for MET CNG detection using ddPCR. In parallel, MET amplification in tissue samples was verified by FISH. Also, the relationships between MET CNG and EGFR T790M, as well as the EGFR-TKI resistance were also evaluated using Chi-square or Fisher's exact tests.

RESULT

The concordance rate of ddPCR and FISH in detecting MET CNG in tissue samples was 100% (102/102), and it was 94.17% (97/103) for ddPCR method in detecting the MET CNG among peripheral blood and tissue samples. No statistical difference was observed between MET amplification and EGFR T790M (p = 0.65), while MET amplification rate was significantly increased in patients with resistance to third generations of EGFR-TKIs as compared with patients with resistance to first/second EGFR-TKIs (p < 0.05).

CONCLUSIONS

ddPCR is an alternative method to detect MET CNG in both tissues and peripheral blood samples, which is of worthy in clinical promotion.

HER2-Altered Non-Small Cell Lung Cancer: Biology, Clinicopathologic Features, and Emerging Therapies

Multiple oncogenic molecular alterations have been discovered that serve as potential drug targets in non-small cell lung cancer (NSCLC). While the pathogenic and pharmacological features of common targets in NSCLC have been widely investigated, those of uncommon targets are still needed to be clarified. Human epidermal growth factor receptor 2 (HER2, ERBB2)-altered tumors represent a highly heterogeneous group of diseases, which consists of three distinct situations including mutation, amplification and overexpression. Compared with breast and gastric cancer, previous studies have shown modest and variable results of anti-HER2 treatments in lung cancers with HER2 aberrations, thus effective therapies in these patients represent an unmet medical need. By far, encouraging efforts towards novel treatment strategies have been made to improve the clinical outcomes of these patients. In this review, we describe the biological and clinicopathological characteristics of HER2 alterations and systematically sum up recent studies on emerging therapies for this subset of patients.

Loss of KMT5C Promotes EGFR Inhibitor Resistance in NSCLC via LINC01510-Mediated Upregulation of MET

EGFR inhibitors (EGFRi) are standard-of-care treatments administered to patients with non-small cell lung cancer (NSCLC) that harbor EGFR alterations. However, development of resistance posttreatment remains a major challenge. Multiple mechanisms can promote survival of EGFRi-treated NSCLC cells, including secondary mutations in EGFR and activation of bypass tracks that circumvent the requirement for EGFR signaling. Nevertheless, the mechanisms involved in bypass signaling activation are understudied and require further elucidation. In this study, we identify that loss of an epigenetic factor, lysine methyltransferase 5C (KMT5C), drives resistance of NSCLC to multiple EGFRis, including erlotinib, gefitinib, afatinib, and osimertinib. KMT5C catalyzed trimethylation of histone H4 lysine 20 (H4K20), a modification required for gene repression and maintenance of heterochromatin. Loss of KMT5C led to upregulation of an oncogenic long noncoding RNA, LINC01510, that promoted transcription of the oncogene MET, a component of a major bypass mechanism involved in EGFRi resistance. These findings underscore the loss of KMT5C as a critical event in driving EGFRi resistance by promoting a LINC01510/MET axis, providing mechanistic insights that could help improve NSCLC treatment.

SIGNIFICANCE

Dysregulation of the epigenetic modifier KMT5C can drive MET-mediated EGFRi resistance, implicating KMT5C loss as a putative biomarker of resistance and H4K20 methylation as a potential target in EGFRi-resistant lung cancer.

Licochalcone A Promotes the Ubiquitination of c-Met to Abrogate Gefitinib Resistance

Met proto-oncogene (MET) amplification and tyrosine-protein kinase Met (c-Met) overexpression confer gefitinib resistance in non-small cell lung cancer (NSCLC). The natural product Licochalcone A (Lico A) exhibits a broad range of inhibitory effects against various tumors. However, the effects of Lico A on c-Met signaling and gefitinib resistance in NSCLC remain unclear. In the present study, Lico A efficiently overcame gefitinib-acquired resistance in NSCLC cells by suppressing c-Met signaling. Lico A decreased cell viability and colony formation dose-dependently and impaired in vivo tumorigenesis of gefitinib-resistant HCC827 and PC-9 cells. Furthermore, Lico A induced intrinsic apoptosis and upregulated the protein expression levels of cleaved poly (ADP-ribose) polymerase and cleaved caspase 3. Lico A promoted the interaction between c-Met and E3 ligase c-Casitas B-lineage lymphoma (Cbl), which enhanced c-Cbl-mediated c-Met ubiquitination and degradation. Depletion of c-Cbl compromised Lico A-induced c-Met ubiquitination and its inhibitory efficacy in gefitinib-resistant NSCLC cells. Taken together, the results suggest that Lico A is a promising antitumor agent that might be used to overcome c-Met overexpression-mediated gefitinib resistance in NSCLC cells.

PTP-PEST Regulated Membranous/Cytoplasmic Translocation of p120ctn in the Lung Cancer Resistance to Tyrosine Kinase Inhibitor

Our previous studies indicate that resistance induction using first-generation tyrosine kinase inhibitors (TKIs) in lung cancer is accompanied with p120-catenin (p120ctn) cytoplasmic translocation from the membrane. However, the molecular mechanism underlying p120ctn intracytoplasmic translocation has not yet been reported. We performed immunohistochemistry to detect the correlation of p120ctn distribution with protein tyrosine phosphatase non-receptor type 12 (PTP-PEST) and p120ctn Y335 phosphorylation levels in non-small cell lung cancer (NSCLC) patients. After resistance induction using first-generation TKIs in lung cancer cells, Western blotting and substrate trapping were used to assess PTP-PEST expression and its influence on p120ctn Y335 phosphorylation, as well as the role of p120ctn Y335 phosphorylation on the association of p120ctn with E-cadherin and p120ctn membrane/cytoplasm translocation. In 197 samples collected from NSCLC patients, cytoplasmic p120ctn and enhanced p120ctn Y335 phosphorylation were associated with decreased PTP-PEST. After resistance induction using gefitinib, decreased PTP-PEST expression was accompanied by enhanced phosphorylation of p120ctn Y335 and p120ctn translocated to the cytoplasm. In gefitinib-resistant cells, PTP-PEST overexpression restrained p120ctn Y335 phosphorylation and restored membrane p120ctn expression. PTP-PEST enhanced the interaction of p120ctn with E-cadherin and elevated p120ctn membrane expression. However, increased p120ctn-Y335F mutant had no effect on p120ctn interaction with E-cadherin and membrane/cytoplasm translocation compared with the control group. In conclusion, resistance to first-generation TKIs inhibited PTP-PEST expression, which promoted p120ctn-Y335 phosphorylation and reduced the interaction of p120ctn with E-cadherin, resulting in p120ctn cytoplasmic translocation.

Epithelial-mesenchymal transition and H2O2 signaling - a driver of disease progression and a vulnerability in cancers

Mutation-selective drugs constitute a great advancement in personalized anticancer treatment with increased quality of life and overall survival in cancers. However, the high adaptability and evasiveness of cancers can lead to disease progression and the development of drug resistance, which cause recurrence and metastasis. A common characteristic in advanced neoplastic cancers is the epithelial-mesenchymal transition (EMT) which is strongly interconnected with H₂O₂ signaling, increased motility and invasiveness. H₂O₂ relays its signal through the installation of oxidative posttranslational modifications on cysteines. The increased H₂O₂ levels that are associated with an EMT confer a heightened sensitivity towards the induction of ferroptosis as a recently discovered vulnerability.

Overall Treatment Strategy for Patients With Metastatic NSCLC With Activating EGFR Mutations

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) are standard of care in the first-line (1L) setting for patients with metastatic non-small cell lung cancer (mNSCLC) with activating EGFR mutations. EGFR-activating mutations are a predictive factor for response to EGFR-TKIs. Meta-analyses have shown that patients with exon 21_L858R mutations exhibit reduced sensitivity to EGFR-TKIs, resulting in inferior patient outcomes compared to those with exon 19 deletion mutations, with worse overall survival, progression-free survival, objective response, and disease control rates. Clinical activity observed with 1L therapy with first-generation (1G), second-generation (2G), and third-generation (3G) EGFR-TKIs is not permanent, and resistance inevitably develops in all cases, supporting the importance of overall treatment planning. The introduction of the 3G EGFR-TKI, osimertinib, provides an opportunity to overcome T790M-mediated resistance to 1G, and 2G EGFR-TKIs. Additionally, with the use of osimertinib, fewer T790M mutations are being detected as T790M is not a reported resistance mechanism to 3G EGFR-TKIs. However, there are currently no approved targeted therapies after 3G EGFR-TKIs. In order to further improve patient outcomes, there is a need to explore additional options for the overall treatment strategy for patients, including 1L and beyond. Combination of vascular endothelial growth factor (VEGF) inhibitors and EGFR-TKIs or chemotherapy and EGFR-TKIs may be a potential therapeutic approach in the 1L setting. This review discusses current treatment options for mNSCLC with activating EGFR mutations based on tumor, patient, and treatment characteristics and how an overall treatment plan may be developed.

Sequential afatinib and osimertinib in patients with EGFR mutation-positive NSCLC and acquired T790M: A global non-interventional study (UpSwinG)

BACKGROUND

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are standard of care for EGFR mutation-positive non-small cell lung cancer (NSCLC). However, optimal sequence of treatment has yet to be defined. Overall survival (OS) is influenced by the availability/use of subsequent therapy after first-line treatment. Emergence of T790M is the main mechanism of resistance to afatinib and second-line osimertinib could be a treatment option in this instance.

METHODS

In this non-interventional, global study (NCT04179890), existing medical/electronic records were identified for consecutive EGFR TKI-naïve patients with EGFR mutation-positive NSCLC (Del19 or L858R) treated with first-line afatinib and second-line osimertinib in regular clinical practice (n = 191; all T790M-positive). The primary objective was time to treatment failure (TTF). Key secondary objectives were OS and objective response rate (ORR).

RESULTS

At the start of afatinib treatment, median age (range) was 62 years (34-88). Fifty-five percent of patients were female and 67% were Asian. ECOG PS (0/1/≥2) was 31%/57%/12%. Fourteen percent of patients had brain metastases. At the start of osimertinib treatment, ECOG PS (0/1/≥2) was 25%/61%/14% and 14% had brain metastases (rising to 29% at the end of osimertinib treatment). The source of biopsy material (solid/liquid) was 86%/3% at the start of afatinib and 54%/33% at start of osimertinib. Mutations were mainly detected with PCR methods. Overall, median TTF was 27.7 months (95% CI: 24.0-30.2) and median OS was 36.5 months (95% CI: 32.9-41.8). ORR with afatinib and osimertinib was 74% and 45%. TTF, OS and ORR were generally consistent across subgroups.

CONCLUSION

Sequential afatinib and osimertinib demonstrated encouraging activity in patients with EGFR mutation-positive NSCLC and acquired T790M. Activity was observed across all subgroups, including patients with poor ECOG PS or brain metastases. ECOG PS and incidence of brain metastases remained stable prior to, and after, afatinib treatment.

Real-world implementation of sequential targeted therapies for EGFR-mutated lung cancer

Background:

Epidermal growth factor receptor-mutated (EGFR⁺) non-small-cell lung cancer (NSCLC) patients failing tyrosine kinase inhibitors (TKI) can benefit from next-line targeted therapies, but implementation is challenging.

Methods:

EGFR⁺ NSCLC patients treated with first/second-generation (1G/2G) TKI at our institution with a last follow-up after osimertinib approval (February 2016), were analyzed retrospectively, and the results compared with published data under osimertinib.

Results:

A total of 207 patients received erlotinib (37%), gefitinib (16%) or afatinib (47%). The median age was 66 years, with a predominance of female (70%), never/light-smokers (69%). T790M testing was performed in 174/202 progressive cases (86%), positive in 93/174 (53%), and followed by osimertinib in 87/93 (94%). Among the 135 deceased patients, 94 (70%) received subsequent systemic treatment (43% chemotherapy, 39% osimertinib), while 30% died without, either before (4%) or after progression, due to rapid clinical deterioration (22%), patient refusal of further therapy (2%), or severe competing illness (2%). Lack of subsequent treatment was significantly (4.5x, p < 0.001) associated with lack of T790M testing, whose most frequent cause (in approximately 50% of cases) was also rapid clinical decline. Among the 127 consecutive patients with failure of 1G/2G TKI started after November 2015, 47 (37%) received osimertinib, with a median overall survival of 36 months versus 24 and 21 months for patients with alternative and no subsequent therapies (p = 0.003).

Conclusion:

Osimertinib after 1G/2G TKI failure prolongs survival, but approximately 15% and 30% of patients forego molecular retesting and subsequent treatment, respectively, mainly due to rapid clinical deterioration. This is an important remediable obstacle to sequential TKI treatment for EGFR⁺ NSCLC. It pertains also to other actionable resistance mechanisms emerging under 1G/2G inhibitors or osimertinib, whose rate for lack of next-line therapy is similar (approximately 35% in the FLAURA/AURA3 trials), and highlights the need for closer monitoring alongside broader profiling of TKI-treated EGFR⁺ NSCLC in the future.

Identification of microRNAs that promote erlotinib resistance in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related deaths, demanding improvement in current treatment modalities to reduce the mortality rates. Lung cancer is divided into two major classes with non-small cell lung cancer representing ~84% of lung cancer cases. One strategy widely used to treat non-small cell lung cancer patients includes targeting the epidermal growth factor receptor (EGFR) using EGFR-inhibitors, such as erlotinib, gefitinib, and afatinib. However, most patients develop resistance to EGFR-inhibitors within a year post-treatment. Although some mechanisms that drive resistance to EGFR-inhibitors have been identified, there are many cases in which the mechanisms are unknown. Thus, in this study, we examined the role of microRNAs in driving EGFR-inhibitor resistance. As mediators of critical pro-growth pathways, microRNAs are severely dysregulated in multiple diseases, including non-small cell lung cancer where microRNA dysregulation also contributes to drug resistance. In this work, through screening of 2019 mature microRNAs, multiple microRNAs were identified that drive EGFR-inhibitor resistance in non-small cell lung cancer cell lines, including miR-432-5p.

EGFR tyrosine kinase inhibitors for EGFR mutation-positive non-small-cell lung cancer: outcomes in Asian populations

Few data are available that have compared outcomes with different EGFR tyrosine kinase inhibitors (TKIs) specifically in Asian patients with EGFR mutation-positive non-small-cell lung cancer. In this narrative review, we have collated available data from prospective studies that have assessed first-, second- and third-generation EGFR TKIs in Asian populations, including subanalyses in individual countries (China and Japan). These data indicate that outcomes with first- and second-generation TKIs are broadly similar in Asian and non-Asian populations. However, while the third-generation EGFR TKI, osimertinib, confers significant overall survival benefit over erlotinib/gefitinib in non-Asians, this is not apparent in Asians, particularly in countries like Japan with well-resourced healthcare. Head-to-head comparisons of second- and third-generation EGFR TKIs, with OS as a primary end point, should be considered in Asia.

Second-line therapy with first- or second-generation tyrosine kinase inhibitors in EGFR-mutated non-small cell lung cancer patients with T790M-negative or unidentified mutation

Background

T790M mutation causes resistance to tyrosine kinase inhibitors (TKIs) in approximately 49% of patients with epidermal growth receptor‐mutant non‐small cell lung cancer (NSCLC). The cause of resistance in the remaining half of the cases is a minor mutation or unknown. Here, we conducted a retrospective study of epidermal growth receptor‐mutant NSCLC patients with T790M‐negative or an unidentified mutation to appraise the therapeutic response to first‐ or second‐generation tyrosine kinase inhibitors as a second‐line treatment.

Methods

The study included 39 patients treated in our institution from April 2012 through March 2020 with second‐line tyrosine kinase inhibitors or chemotherapy after completing a first‐line therapy with tyrosine kinase inhibitors.

Results

The patients were allocated to two groups: chemotherapy (n = 28) and a tyrosine kinase inhibitor (n = 11) groups. The median progression‐free survival (PFS) was 5.4 months in the chemotherapy group and 3.4 months in the tyrosine kinase inhibitor group (p‐value = 0.36), while the median overall survival (OS) was 16.1 months in the chemotherapy group and 12.8 months in the tyrosine kinase inhibitor group (p‐ value = 0.20). This study showed no significant difference in PFS and OS between the chemotherapy and tyrosine kinase inhibitor groups.

Conclusions

These observations suggest that first‐ and second‐generation tyrosine kinase inhibitors are not recommended for second‐line treatment in epidermal growth factor receptor‐mutated NSCLC patients with T790M‐negative mutation who have received tyrosine kinase inhibitors as first‐line treatment.

Afatinib for the first-line treatment of EGFR mutation-positive NSCLC in China: a review of clinical data

Mutations in the EGFR gene are particularly prevalent among Chinese patients with non-small-cell lung carcinoma. Six EGFR tyrosine kinase inhibitors are approved for the first-line treatment of EGFR mutation-positive non-small-cell lung carcinoma in China, which poses questions about which agent is most suitable for a particular patient. In this article, we review available clinical trial and real-world data with afatinib in Chinese patients. We assess its efficacy and safety in key patient subgroups such as those with uncommon mutations or brain metastases. We also consider possible subsequent therapies following afatinib. Encouragingly, available data suggest that sequential afatinib and osimertinib confer prolonged overall time to failure of almost 4 years in Asian patients, and represents a viable option in this setting.

Post-Progression Survival in Secondary EGFR T790M-Mutated Non-Small-Cell Lung Cancer Patients With and Without Osimertinib After Failure of a Previous EGFR TKI

BACKGROUND

Osimertinib is effective in non-small-cell lung cancer (NSCLC) with an acquired epidermal growth factor receptor (EGFR) T790M mutation, the most common resistance mechanism to first- and second-generation EGFR tyrosine kinase inhibitors (TKIs).

OBJECTIVES

We aimed to evaluate survival outcome of patients with EGFR-mutant NSCLC who have progressed on previous EGFR TKI therapy.

PATIENTS AND METHODS

Advanced NSCLC patients with EGFR mutation after acquired resistance to first- or second-generation EGFR TKI who received tumor rebiopsy after EGFR TKI failure from 1 January 2012 to 31 December 2017 were reviewed. Patient clinical characteristics, T790M mutation status, and post-progression survival (PPS) were recorded by chart review.

RESULTS

We included 240 patients and the percentage of secondary T790M mutations in first time tissue rebiopsy was 52.9%. 38 of the initial T790M-negative patients received second rebiopsies and 14 (36.8%) of these were T790M positive. The duration between first and second rebiopsy tended to be longer in patients who had T790M mutation in the second biopsy (11.5 vs. 6.9 months, p = 0.043). After EGFR TKI failure, the median PPS of patients who had the T790M mutation and history of osimertinib use was 42.6 months (95% CI 34.6-50.5), compared to 18.0 (95% CI 9.6-26.4) months in T790M-positive patients without a history of osimertinib use, and 18.8 (95% CI 9.3-28.4) months in patients with no T790M mutation (p < 0.0001). Multivariate analysis showed that history of osimertinib use was correlated with improved survival.

CONCLUSIONS

These data further emphasize that osimertinib should be a standard of care in patients with pretreated EGFR T790M-positive NSCLC.