The mechanism of acquired resistance to irreversible EGFR tyrosine kinase inhibitor-afatinib in lung adenocarcinoma patients

GRP78 blockade overcomes acquired resistance to EGFR-tyrosine kinase inhibitors in non-small cell lung cancer

AIMS

While significant upregulation of GRP78 has been documented in lung cancer patients, its association with resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) remains underexamined. Our study aimed to elucidate the functional importance of GRP78 in acquired resistance to EGFR-TKIs in non-small cell lung cancer (NSCLC) and to evaluate its potential as a therapeutic target.

MAIN METHODS

Immunoblot analysis or flow cytometry was employed to assess several markers for endoplasmic reticulum (ER) stress and apoptosis. Ru(II) complex I and HA15, two known GRP78 inhibitors, were used to evaluate the functional role of GRP78. A Xenograft assay was performed to evaluate the in vivo anti-cancer effects of the GRP78 inhibitors.

KEY FINDINGS

We validated a significant increase in GRP78 protein levels in HCC827-GR, H1993-GR, and H1993-ER cells. The EGFR-TKI-resistant cells overexpressing GRP78 exhibited significantly higher cell proliferation rates than did their parental counterparts. Notably, GRP78 inhibition resulted in a more profound anti-proliferative and apoptotic response via heightened ER stress and subsequent reactive oxygen species (ROS) production in EGFR-TKI-resistant cell lines compared with their parental cells. In xenograft models implanted with HCC827-GR, both Ru(II) complex I and HA15 significantly suppressed tumor growth and reduced tumor weight. Additionally, we confirmed that GRP78 plays a critical role in the proliferation of H1975, an EGFR-TKI-resistant T790M-mutant cell line, relative to other NSCLC cell lines.

SIGNIFICANCE

Our findings strongly support targeting of GRP78 as a promising therapeutic strategy for NSCLC patients with acquired resistance to EGFR-TKIs.

Drug-resistant EGFR mutations promote lung cancer by stabilizing interfaces in ligand-free kinase-active EGFR oligomers

The Epidermal Growth Factor Receptor (EGFR) is frequently found to be mutated in non-small cell lung cancer. Oncogenic EGFR has been successfully targeted by tyrosine kinase inhibitors, but acquired drug resistance eventually overcomes the efficacy of these treatments. Attempts to surmount this therapeutic challenge are hindered by a poor understanding of how and why cancer mutations specifically amplify ligand-independent EGFR auto-phosphorylation signals to enhance cell survival and how this amplification is related to ligand-dependent cell proliferation. Here we show that drug-resistant EGFR mutations manipulate the assembly of ligand-free, kinase-active oligomers to promote and stabilize the assembly of oligomer-obligate active dimer sub-units and circumvent the need for ligand binding. We reveal the structure and assembly mechanisms of these ligand-free, kinase-active oligomers, uncovering oncogenic functions for hitherto orphan transmembrane and kinase interfaces, and for the ectodomain tethered conformation of EGFR. Importantly, we find that the active dimer sub-units within ligand-free oligomers are the high affinity binding sites competent to bind physiological ligand concentrations and thus drive tumor growth, revealing a link with tumor proliferation. Our findings provide a framework for future drug discovery directed at tackling oncogenic EGFR mutations by disabling oligomer-assembling interactions.

miR-204 suppresses cancer stemness and enhances osimertinib sensitivity in non-small cell lung cancer by targeting CD44

Osimertinib is an effective treatment option for patients with advanced non-small cell lung cancer (NSCLC) with EGFR activation or T790M resistance mutations; however, acquired resistance to osimertinib can still develop. This study explored novel miRNA-mRNA regulatory mechanisms that contribute to osimertinib resistance in lung cancer. We found that miR-204 expression in osimertinib-resistant lung cancer cells was markedly reduced compared to that in osimertinib-sensitive parental cells. miR-204 expression levels in cancer cells isolated from treatment-naive pleural effusions were significantly higher than those in cells with acquired resistance to osimertinib. miR-204 enhanced the sensitivity of lung cancer cells to osimertinib and suppressed spheroid formation, migration, and invasion of lung cancer cells. Increased miR-204 expression in osimertinib-resistant cells reversed resistance to osimertinib and enhanced osimertinib-induced apoptosis by upregulating BIM expression levels and activating caspases. Restoration of CD44 (the direct downstream target gene of miR-204) expression reversed the effects of miR-204 on osimertinib sensitivity, recovered cancer stem cell and mesenchymal markers, and suppressed E-cadherin expression. The study demonstrates that miR-204 reduced cancer stemness and epithelial-to-mesenchymal transition, thus overcoming osimertinib resistance in lung cancer by inhibiting the CD44 signaling pathway.

Next-generation sequencing reveals genetic heterogeneity and resistance mechanisms in patients with EGFR-mutated non-small cell lung cancer treated with afatinib

Background

Afatinib, an irreversible ErbB family inhibitor, is widely used as first-line treatment in advanced lung adenocarcinoma patients harbouring mutant epidermal growth factor receptor (EGFR). With the advancements in next-generation sequencing (NGS), comprehensive research into the clinical impact of co-occurring genetic mutations and the molecular mechanisms of acquired resistance is required for afatinib users.

Materials

From January 2010 to December 2019, we enrolled patients with advanced lung adenocarcinoma with EGFR mutations using afatinib as first-line treatment, and we retrospectively collected pre- and post-afatinib treatment specimens from these patients for NGS testing.

Results

Of the 362 enrolled patients, 73 samples (68.9%) from 56 patients successfully returned complete NGS reports. In pre-afatinib treatment specimens, the most frequent co-occurring alterations were TP53, MUC16, USH2A, SNYE1, RECQL4 and FAT1; however, they were not related to progression-free survival. Small cell lung cancer transformation, EGFR p.T790M, amplification of MET, ERBB2, KRAS, EGFR, cell cycle-regulated genes and MDM2, and PTEN alterations were identified as acquired resistance mechanisms. EGFR p.T790M (p=0.0304) and APC alterations (p=0.0311) in post-afatinib specimens were significantly associated with longer overall survival, while MET amplification was significantly associated with poor overall survival (p=0.0324). The co-occurrence of TP53 alterations was significantly associated with shorter overall survival (p=0.0298).

Conclusions

Our results show that the frequent co-occurring alterations in advanced EGFR-mutated lung adenocarcinoma did not influence the effectiveness of afatinib. EGFR p.T790M is not only the major resistance mechanism to afatinib but also related to favourable survival outcomes. MET amplification and TP53 mutations were associated with poorer overall survival.

The role of anti-EGFR therapies in EGFR-TKI-resistant advanced non-small cell lung cancer

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are the current recommended option for the first-line treatment of patients with EGFR-mutant non-small cell lung cancer (NSCLC). Resistance to first-generation TKIs led to the development of second- and third-generation TKIs with improved clinical outcomes. However, sequential administration of TKIs has led to the emergence of new EGFR resistance mutations and persistent tumor cell survival. This evidence highlights the potential role of EGFR in transducing growth signals in NSCLC tumor cells. Therefore, dual inhibition of EGFR using combinations of anti-EGFR monoclonal antibodies (mAbs) and EGFR-TKIs may offer a unique treatment strategy to suppress tumor cell growth. Several clinical studies have demonstrated the benefits of dual blockade of EGFR using anti-EGFR mAbs coupled with EGFR-TKIs in overcoming treatment resistance in patients with EGFR-mutated NSCLC. However, a single treatment option may not result in the same clinical benefits in all patients with acquired resistance. Biomarkers, including EGFR overexpression, EGFR gene copy number, EGFR and KRAS mutations, and circulating tumor DNA, have been associated with improved clinical efficacy with anti-EGFR mAbs in patients with NSCLC and acquired resistance. Further investigation of biomarkers may allow patient selection for those who could benefit from anti-EGFR mAbs in combination with EGFR-TKIs. This review summarizes findings of recent studies of anti-EGFR mAbs in combination with EGFR-TKIs for the treatment of patients with EGFR-mutated NSCLC, as well as clinical evidence for potential biomarkers towards personalized targeted medicine.

Therapeutic role of EGFR - Tyrosine kinase inhibitors in non-small cell lung cancer with leptomeningeal metastasis

Leptomeningeal metastasis (LM) is a significant complication that advances fast and has a poor prognosis for patients with advanced non-small cell lung cancer (NSCLC) who have epidermal growth factor receptor (EGFR) mutations. Current therapies for LM are inconsistent and ineffective, and established techniques such as radiation, chemotherapy, and surgery continue to fall short of potential outcomes. Nonetheless, EGFR tyrosine kinase inhibitors (TKIs) exhibit potent anti-tumor activity and hold considerable promise for NSCLC patients with EGFR mutations. Thus, assessing EGFR-TKIs effectiveness in treating these central nervous system (CNS) problems is crucial. This review integrates current literature on the intracranial efficacy of EGFR-TKIs to explore the varying impacts of approved EGFR-TKIs in LM patients and the therapeutic possibilities presented by other EGFR-TKIs in development. To delineate the optimal clinical treatment strategy, further exploration is needed regarding the optimal sequencing of EGFR-TKIs and the selection of alternative therapy options following initial treatment failure with EGFR-TKIs.

EGFR Inhibition Overcomes Resistance to FGFR4 Inhibition and Potentiates FGFR4 Inhibitor Therapy in Hepatocellular Carcinoma

Aberrant activation of the FGF19-FGFR4 signaling pathway plays an essential role in the tumorigenesis of hepatocellular carcinoma (HCC). As such, FGFR4 inhibition has emerged as a novel therapeutic option for the treatment of HCC and has shown preliminary efficacy in recent clinical trials for patients exhibiting aberrant FGF19 expression. Resistance to kinase inhibitors is common in oncology, presenting a major challenge in the clinical treatment process. Hence, we investigated the potential mechanisms mediating and causing resistance to FGFR4 inhibition in HCC. Upon the successful establishment of a battery of cellular models developing resistance to FGFR4 inhibitors, we have identified the activation of EGFR, MAPK, and AKT signaling as the primary mechanisms mediating the acquired resistance. Combination of inhibitors against EGFR or its downstream components restored sensitivity to FGFR4 inhibitors. In parental HCC cell lines, EGF treatment also resulted in resistance to FGFR4 inhibitors. This resistance was effectively reverted by inhibitors of the EGFR signaling pathway, suggesting that EGFR activation is a potential cause of intrinsic resistance. We further confirmed the above findings in vivo in mouse xenograft tumor models. Genomic analysis of patient samples from The Cancer Genome Atlas confirmed that a segment of patients with HCC harboring FGF19 overexpression indeed exhibited increased activation of EGFR signaling. These findings conclusively indicate that both induced and innate activation of EGFR could mediate resistance to FGFR4 inhibition, suggesting that dual blockade of EGFR and FGFR4 may be a promising future therapeutic strategy for the treatment of FGF19-FGFR4 altered HCC.

Computer-Assisted Drug Discovery of a Novel Theobromine Derivative as an EGFR Protein-Targeted Apoptosis Inducer

The overexpression of the Epidermal Growth Factor Receptor (EGFR) marks it as a pivotal target in cancer treatment, with the aim of reducing its proliferation and inducing apoptosis. This study aimed at the CADD of a new apoptotic EGFR inhibitor. The natural alkaloid, theobromine, was used as a starting point to obtain a new semisynthetic (di-ortho-chloro acetamide) derivative (T-1-DOCA). Firstly, T-1-DOCA's total electron density, energy gap, reactivity indices, and electrostatic surface potential were determined by DFT calculations, Then, molecular docking studies were carried out to predict the potential of T-1-DOCA against wild and mutant EGFR proteins. T-1-DOCA's correct binding was further confirmed by molecular dynamics (MD) over 100 ns, MM-GPSA, and PLIP experiments. In vitro, T-1-DOCA showed noticeable efficacy compared to erlotinib by suppressing EGFRWT and EGFRT790M with IC50 values of 56.94 and 269.01 nM, respectively. T-1-DOCA inhibited also the proliferation of H1975 and HCT-116 malignant cell lines, exhibiting IC50 values of 14.12 and 23.39 µM, with selectivity indices of 6.8 and 4.1, respectively, indicating its anticancer potential and general safety. The apoptotic effects of T-1-DOCA were indicated by flow cytometric analysis and were further confirmed through its potential to increase the levels of BAX, Casp3, and Casp9, and decrease Bcl-2 levels. In conclusion, T-1-DOCA, a new apoptotic EGFR inhibitor, was designed and evaluated both computationally and experimentally. The results suggest that T-1-DOCA is a promising candidate for further development as an anti-cancer drug.

CT Radiomics Predict EGFR-T790M Resistance Mutation in Advanced Non-Small Cell Lung Cancer Patients After Progression on First-line EGFR-TKI

RATIONALE AND OBJECTIVES

We aim to explore the value of chest CT radiomics in predicting the epidermal growth factor receptor (EGFR)-T790M resistance mutation of advanced non-small cell lung cancer (NSCLC) patients after the failure of first-line EGFR-tyrosine kinase inhibitor (EGFR-TKI).

MATERIALS AND METHODS

A total of 211 and 135 advanced NSCLC patients with tumor tissue-based (Cohort-1) or circulating tumor DNA (ctDNA)-based (Cohort-2) EGFR-T790M testing were included, respectively. Cohort-1 was used for modeling and Cohort-2 was for models' validation. Radiomic features were extracted from tumor lesions on chest nonenhanced CT (NECT) and/or contrast-enhanced CT (CECT). We used eight feature selectors and eight classifier algorithms to establish radiomic models. Models were evaluated by area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA).

RESULTS

CT morphological manifestations of peripheral location and pleural indentation sign were associated with EGFR-T790M. For NECT, CECT, and NECT+CECT radiomic features, the feature selector and classifier algorithms of LASSO and Stepwise logistic regression, Boruta and SVM, and LASSO and SVM were chosen to develop the optimal model, respectively (AUC: 0.844, 0.811, and 0.897). All models performed well in calibration curves and DCA. Independent validation of models in Cohort-2 revealed that both NECT and CECT models individually had limited power for predicting EGFR-T790M mutation detected by ctDNA (AUC: 0.649, 0.675), while the NECT+CECT radiomic model had a satisfactory AUC (0.760).

CONCLUSION

This study proved the feasibility of using CT radiomic features to predict the EGFR-T790M resistance mutation, which could be helpful in guiding personalized therapeutic strategies.

Improving the efficacy of anti-EGFR drugs in GBM: Where we are going?

The therapies targeting mutations of driver genes in cancer have advanced into clinical trials for a variety of tumors. In glioblastoma (GBM), epidermal growth factor receptor (EGFR) is the most commonly mutated oncogene, and targeting EGFR has been widely investigated as a promising direction. However, the results of EGFR pathway inhibitors have not been satisfactory. Limited blood-brain barrier (BBB) permeability, drug resistance, and pathway compensation mechanisms contribute to the failure of anti-EGFR therapies. This review summarizes recent research advances in EGFR-targeted therapy for GBM and provides insight into the reasons for the unsatisfactory results of EGFR-targeted therapy. By combining the results of preclinical studies with those of clinical trials, we discuss that improved drug penetration across the BBB, the use of multi-target combinations, and the development of peptidomimetic drugs under the premise of precision medicine may be promising strategies to overcome drug resistance in GBM.

Ramucirumab plus erlotinib versus placebo plus erlotinib in previously untreated EGFR-mutated metastatic non-small-cell lung cancer (RELAY): exploratory analysis of next-generation sequencing results

BACKGROUND

Ramucirumab plus erlotinib (RAM + ERL) demonstrated superior progression-free survival (PFS) over placebo + ERL (PBO + ERL) in the phase III RELAY study of patients with epidermal growth factor receptor (EGFR)-mutated metastatic non-small-cell lung cancer (EGFR+ mNSCLC; NCT02411448). Next-generation sequencing (NGS) was used to identify clinically relevant alterations in circulating tumor DNA (ctDNA) and explore their impact on treatment outcomes.

PATIENTS AND METHODS

Eligible patients with EGFR+ mNSCLC were randomized 1 : 1 to ERL (150 mg/day) plus RAM (10 mg/kg)/PBO every 2 weeks. Liquid biopsies were to be prospectively collected at baseline, cycle 4 (C4), and postdiscontinuation follow-up. EGFR and co-occurring/treatment-emergent (TE) genomic alterations in ctDNA were analyzed using Guardant360 NGS platform.

RESULTS

In those with valid baseline samples, detectable activating EGFR alterations in ctDNA (aEGFR+) were associated with shorter PFS [aEGFR+: 12.7 months (n = 255) versus aEGFR-: 22.0 months (n = 131); hazard ratio (HR) = 1.87, 95% confidence interval (CI) 1.42-2.51]. Irrespective of detectable/undetectable baseline aEGFR, RAM + ERL was associated with longer PFS versus PBO + ERL [aEGFR+: median PFS (mPFS) = 15.2 versus 11.1 months, HR = 0.63, 95% CI 0.46-0.85; aEGFR-: mPFS = 22.1 versus 19.2 months, HR = 0.80, 95% CI 0.49-1.30]. Baseline alterations co-occurring with aEGFR were identified in 69 genes, most commonly TP53 (43%), EGFR (other than aEGFR; 25%), and PIK3CA (10%). PFS was longer in RAM + ERL, irrespective of baseline co-occurring alterations. Clearance of baseline aEGFR by C4 was associated with longer PFS (mPFS = 14.1 versus 7.0 months, HR = 0.481, 95% CI 0.33-0.71). RAM + ERL improved PFS outcomes, irrespective of aEGFR mutation clearance. TE gene alterations were most commonly in EGFR [T790M (29%), other (19%)] and TP53 (16%).

CONCLUSIONS

Baseline aEGFR alterations in ctDNA were associated with shorter mPFS. RAM + ERL was associated with improved PFS outcomes, irrespective of detectable/undetectable aEGFR, co-occurring baseline alterations, or aEGFR+ clearance by C4. aEGFR+ clearance by C4 was associated with improved PFS outcomes. Monitoring co-occurring alterations and aEGFR+ clearance may provide insights into mechanisms of EGFR tyrosine kinase inhibitor resistance and the patients who may benefit from intensified treatment schedules.

EGFR-TKIs plus Stereotactic Body Radiation Therapy (SBRT) for Stage IV Non-small Cell Lung Cancer (NSCLC): a prospective, multicenter, randomized, controlled phase II study

BACKGROUND

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have a significant therapeutic effect in the treatment of advanced non-small-cell lung cancer (NSCLC) with EGFR mutations. However, the acquired resistance greatly limits the survival benefit of EGFR-TKIs for EGFR-mutant NSCLC patients. We aimed to assess the efficacy and safety of stereotactic body radiotherapy (SBRT) plus EGFR-TKIs in these patients.

METHODS

In this prospective, randomized, controlled, phase 2 study, participants were recruited from 4 different hospitals in Wuhan, China. Eligible patients were histologically confirmed to have NSCLC with an EGFR-sensitive mutation (19DEL or 21L858R) and diagnosed at stage IV. Patients who had received first-line EGFR-TKIs treatment including gefitinib, erlotinib, and icotinib and achieved stable disease or partial response were enrolled after three months. Eligible participants were randomly assigned (1:1) to receive SBRT plus EGFR-TKIs or EGFR-TKIs treatment alone. In the combination-group, different tumor sites were irradiated at doses ranging from 30-50Gy in five fractions. Considering the short duration of SBRT, the TKIs were continued during the radiotherapy. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS) and safety. This study was registered at ClinicalTrials.gov, with the registration number of NCT03595644.

RESULTS

Between May 4, 2018 and Dec 20, 2019, 74 patients were screened, of whom 62 patients were enrolled and randomized. The study was closed early with 62/72 patients due to slow accrual. The enrolled patients were randomly assigned to receive SBRT plus EGFR-TKI(n=31) or EGFR-TKI alone (n=31). One patient who was randomized to the SBRT plus EGFR-TKI group refused to receive SBRT during the treatment, and, 61 patients were included the modified intention-to-treat (mITT) analysis, with 30 in the SBRT plus EGFR-TKI and 31 in the EGFR-TKI group. As of the clinical cutoff date (Feb 14, 2022), the median follow-up was 29.4 months (IQR 6.9-38.9). The median PFS of the EGFR-TKI group and SBRT combination group was 9.0 vs 17.6 months (hazard ratio [HR]=0.52, 95% confidence interval [95%CI], 0.31-0.89, P=0.016). Meanwhile, the median OS was 23.2 vs 33.6 months (HR [95%CI], 0.53(0.30-0.95); P= 0.026). There was no grade 3 or greater toxicity observed in either group, the grade 2 adverse events were 50% in the EGFR-TKIs+SBRT group while the percentage was 45.2% in the EGFR-TKIs+SBRT group.

CONCLUSIONS

The addition of SBRT significantly delayed the onset of acquired resistance to EGFR-TKIs and prolonged the PFS and OS of patients. Radiotherapy of the primary lesion alone might be superior to metastatic sites. Further confirmatory studies are needed to confirm our findings.

Monitoring of T790M in plasma ctDNA of advanced EGFR-mutant NSCLC patients on first- or second-generation tyrosine kinase inhibitors

BACKGROUND

The T790M mutation is the major resistance mechanism to first- and second-generation TKIs in EGFR-mutant NSCLC. This study aimed to investigate the utility of droplet digital PCR (ddPCR) for detection of T790M in plasma circulating tumor DNA (ctDNA), and explore its impact on prognosis.

METHODS

This prospective study enrolled 80 advanced lung adenocarcinoma patients treated with gefitinib, erlotinib, or afatinib for TKI-sensitizing mutations between 2015 and 2019. Plasma samples were collected before TKI therapy and at tri-monthly intervals thereafter. Genotyping of ctDNA for T790M was performed using a ddPCR EGFR Mutation Assay. Patients were followed up until the date of death or to the end of 2021.

RESULTS

Seventy-five of 80 patients experienced progressive disease. Fifty-three (71%) of 75 patients underwent rebiopsy, and T790M mutation was identified in 53% (28/53) of samples. Meanwhile, plasma ddPCR detected T790M mutation in 23 (43%) of 53 patients. The concordance rate of T790M between ddPCR and rebiopsy was 76%, and ddPCR identified 4 additional T790M-positive patients. Ten (45%) of 22 patients who did not receive rebiopsy tested positive for T790M by ddPCR. Serial ddPCR analysis showed the time interval from detection of plasma T790M to objective progression was 1.1 (0-4.1) months. Compared to 28 patients with rebiopsy showing T790M, the overall survival of 14 patients with T790M detected solely by ddPCR was shorter(41.3 [95% CI, 36.6-46.0] vs. 26.6 months [95% CI, 9.9-43.3], respectively).

CONCLUSION

Plasma ddPCR-based genotyping is a useful technology for detection and monitoring of the key actionable genomic alteration, namely, T790M, in patients treated with gefitinib, erlotinib, or afatinib for activating mutations, to achieve better patient care and outcome.

Absence of copy number gain of EGFR: A possible predictive marker of long-term response to afatinib

Treatment efficacy of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) is diverse even in non-small cell lung cancer (NSCLC) patients with EGFR activating mutations. Extraordinary long-term responses sustained over 3 years among NSCLC patients treated with afatinib, an EGFR-TKI, have been reported, but how to predict such long survivors has not been clarified. A multi-institutional prospective observational study, based on comprehensive genomic examination performed with next-generation sequencing of circulating tumor DNA (ctDNA), was conducted to identify potential predictive markers of long-term response to afatinib. Twenty-nine patients with advanced stage NSCLC and EGFR driver mutations detected by standard techniques were enrolled in the study. ctDNA from plasma collected before afatinib treatment was analyzed by Guardant360. ctDNA was detected in 25 of the 29 samples. Median progression-free survival was shorter in patients whose tumors had EGFR copy number gain (7.0 vs 23.0 months, p = 0.022). The impact of EGFR copy number on cell proliferation and the antitumor effect of afatinib were evaluated using genome-editing lung cancer cell lines. HCC827 with EGFR amplification was relatively resistant to afatinib at concentrations below 0.5 nM, but genome-edited derivatives of HCC827 with decreased EGFR copy number demonstrated growth inhibition with 0.1 nM afatinib. The absence of EGFR copy number gain detected in ctDNA may be a predictive marker of long-term response to afatinib. Comprehensive genomic analysis could lead to a more accurate prediction of EGFR-TKI efficacy.

Candidate mechanisms of acquired resistance to first-line osimertinib in EGFR-mutated advanced non-small cell lung cancer

Osimertinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), potently and selectively inhibits EGFR-TKI-sensitizing and EGFR T790M resistance mutations. In the Phase III FLAURA study (NCT02296125), first-line osimertinib improved outcomes vs comparator EGFR-TKIs in EGFRm advanced non-small cell lung cancer. This analysis identifies acquired resistance mechanisms to first-line osimertinib. Next-generation sequencing assesses circulating-tumor DNA from paired plasma samples (baseline and disease progression/treatment discontinuation) in patients with baseline EGFRm. No EGFR T790M-mediated acquired resistance are observed; most frequent resistance mechanisms are MET amplification (n = 17; 16%) and EGFR C797S mutations (n = 7; 6%). Future research investigating non-genetic acquired resistance mechanisms is warranted.

Analysis of acquired resistance mechanisms to osimertinib in patients with EGFR-mutated advanced non-small cell lung cancer from the AURA3 trial

Osimertinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), potently and selectively inhibits EGFR-TKI-sensitizing and EGFR T790M resistance mutations. This analysis evaluates acquired resistance mechanisms to second-line osimertinib (n = 78) in patients with EGFR T790M advanced non-small cell lung cancer (NSCLC) from AURA3 (NCT02151981), a randomized phase 3 study comparing osimertinib with chemotherapy. Plasma samples collected at baseline and disease progression/treatment discontinuation are analyzed using next-generation sequencing. Half (50%) of patients have undetectable plasma EGFR T790M at disease progression and/or treatment discontinuation. Fifteen patients (19%) have >1 resistance-related genomic alteration; MET amplification (14/78, 18%) and EGFR C797X mutation (14/78, 18%).

The Usefulness of Nanotechnology in Improving the Prognosis of Lung Cancer

Lung cancer remains a major public health problem both in terms of incidence and specific mortality despite recent developments in terms of prevention, such as smoking reduction policies and clinical management advances. Better lung cancer prognosis could be achieved by early and accurate diagnosis and improved therapeutic interventions. Nanotechnology is a dynamic and fast-developing field; various medical applications have been developed and deployed, and more exist as proofs of concepts or experimental models. We aim to summarize current knowledge relevant to the use of nanotechnology in lung cancer management. Starting from the chemical structure-based classification of nanoparticles, we identify and review various practical implementations roughly organized as diagnostic or therapeutic in scope, ranging from innovative contrast agents to targeted drug carriers. Available data are presented starting with standards of practice and moving to highly experimental methods and proofs of concept; particularities, advantages, limits and future directions are explored, focusing on the potential impact on lung cancer clinical prognosis.

Treatment Strategies for Non-Small Cell Lung Cancer with Common EGFR Mutations: A Review of the History of EGFR TKIs Approval and Emerging Data

The development of targeted therapies over the past two decades has led to a dramatic change in the management of EGFR-mutant non-small cell lung cancer (NSCLC). While there are currently five approved EGFR tyrosine kinase inhibitors (TKIs) for treating EGFR-mutant NSCLC in the first-line setting, therapy selection after progression on EGFR TKIs remains complex. Multiple groups are investigating novel therapies and drug combinations to determine the optimal therapy and treatment sequence for these patients. In this review, we summarize the landmark trials and history of the approval of EGFR TKIs, their efficacy and tolerability, and the role of these therapies in patients with central nervous system metastasis. We also briefly discuss the mechanisms of resistance to EGFR TKIs, ongoing attempts to overcome resistance and improve outcomes, and finalize by offering treatment sequencing recommendations.

A real-world study of second or later-line osimertinib in patients with EGFR T790M-positive NSCLC: the final ASTRIS data

Aim: Report the final analysis from ASTRIS, the largest real-world study of second-/later-line osimertinib in advanced/metastatic EGFR T790M non-small-cell lung cancer (NSCLC). Methods: Patients with advanced/metastatic EGFR T790M NSCLC and prior EGFR-TKI treatment, received once-daily osimertinib 80 mg. Primary end point: overall survival (OS); secondary end points: progression-free survival (PFS), time-to-treatment discontinuation (TTD) and response rate. Safety was also recorded. Results: In 3014 patients, median OS: 22.8 months (21.6-23.8), median PFS: 11.1 months (11.0-12.0), median TTD: 13.5 months (12.6-13.9), and response rate: 57.3% (55.5-59.2). All end points reported with 95% CIs . Numerically longer median OS was observed in patients with baseline WHO performance status <2 versus 2 (24.0 vs 11.1 months) and those without versus with brain/leptomeningeal metastases (25.4 vs 18.0 months). No new safety signals were identified. Conclusion: Second-/later-line osimertinib demonstrated real-world clinical benefit and safety in advanced/metastatic EGFR T790M NSCLC. Clinical Trial Registration: NCT02474355 (ClinicalTrials.gov).

New Targeted Therapy for Non-Small Cell Lung Cancer

Lung cancer ranks first in cancer mortality in Korea and cancer incidence in Korean men. More than half of Korean lung cancer patients undergo chemotherapy, including adjuvant therapy. Cytotoxic agents, targeted therapy, and immune checkpoint inhibitors are used in chemotherapy according to the biopsy and genetic test results. Among chemotherapy, the one that has developed rapidly is targeted therapy. The National Comprehensive Cancer Network (NCCN) guidelines have been updated recently for targeted therapy of multiple gene mutations, and targeted therapy is used not only for chemotherapy but also for adjuvant therapy. While previously targeted therapies have been developed for common genetic mutations, recently targeted therapies have been developed to overcome uncommon mutations or drug resistance that have occurred since previous targeted therapy. Therefore, this study describes recent, rapidly developing targeted therapies.

Therapeutic strategies for EGFR-mutated non-small cell lung cancer patients with osimertinib resistance

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the preferential options for advanced non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. Osimertinib is a potent irreversible third-generation EGFR-TKI targeting EGFR mutations but has little effect on wild-type EGFR. In view of its remarkable efficacy and manageable safety, osimertinib was recommended as the standard first-line treatment for advanced or metastatic NSCLC patients with EGFR mutations. However, as the other EGFR-TKIs, osimertinib will inevitably develop acquired resistance, which limits its efficacy on the treatment of EGFR-mutated NSCLC patients. The etiology of triggering osimertinib resistance is complex including EGFR-dependent and EGFR-independent pathways, and different therapeutic strategies for the NSCLC patients with osimertinib resistance have been developed. Herein, we comprehensively summarized the resistance mechanisms of osimertinib and discuss in detail the potential therapeutic strategies for EGFR-mutated NSCLC patients suffering osimertinib resistance for the sake of the improvement of survival and further achievement of precise medicine.

Afatinib and Dacomitinib Efficacy, Safety, Progression Patterns, and Resistance Mechanisms in Patients with Non-Small Cell Lung Cancer Carrying Uncommon EGFR Mutations: A Comparative Cohort Study in China (AFANDA Study)

(1) Background: Afatinib has been approved for patients with non-small cell lung cancer (NSCLC) carrying major uncommon epidermal growth factor receptor gene (EGFR) mutations. Dacomitinib, another second-generation tyrosine kinase inhibitor, has also shown promising potential for uncommon EGFR mutations. However, no comparative study has been conducted. (2) Methods: Two cohorts were employed: the AFANDA cohort, an ambispective cohort including 121 patients with uncommon EGFR mutations admitted to two tertiary hospitals in China, and an external validation afatinib cohort (ex-AC), extracted from the Afatinib Uncommon EGFR Mutations Database (N = 1140). The AFANDA cohort was divided into an afatinib cohort (AC) and a dacomitinib cohort (DC) for internal exploration. Objective response rate (ORR), progression-free survival (PFS), and adverse events (AEs) were assessed for comparison. Progression patterns and resistance mechanisms were explored. (3) Results: In total, 286 patients with advanced NSCLC carrying uncommon EGFR mutations treated with afatinib or dacomitinib were enrolled, including 79 in the AFANDA cohort (44 in the DC, 35 in the AC) and 207 in the ex-AC. In internal exploration, the ORR of the DC was significantly higher than that of the AC (60.5 vs. 26.7%, p = 0.008), but there was no significant difference in median PFS between the DC and the AC (12.0 months vs. 10.0 months, p = 0.305). Multivariate analysis confirmed an independent favorable effect of dacomitinib on PFS (hazard ratio (HR), 1.909; p = 0.047). In external validation, multivariate analysis confirmed the independent prognostic role of dacomitinib in PFS (HR, 1.953; p = 0.029). Propensity score matching analysis confirmed the superiority of dacomitinib over afatinib in terms of PFS in both univariate and multivariate analyses. Toxicity profiling analysis suggested more G1 (p = 0.006), but fewer G3 (p = 0.036) AEs in the DC than in the AC. Progression patterns revealed that the incidence of intracranial progression in the AC was significantly higher than that in the DC (50 vs. 21.1%, p = 0.002). Drug resistance analysis indicated no significant difference in the occurrence of T790M between the AC and the DC (11.8 vs. 15.4%, p = 0.772). (4) Conclusions: Compared with afatinib, dacomitinib demonstrated a more favorable activity with manageable toxicity and different progression patterns in patients with NSCLC carrying uncommon EGFR mutations.

Liquid Biopsy: A Multi-Parametric Analysis of Mutation Status, Circulating Tumor Cells and Inflammatory Markers in EGFR-Mutated NSCLC

The liquid biopsy has the potential to improve patient care in the diagnostic and therapeutic setting in non-small cell lung cancer (NSCLC). Consented patients with epidermal growth factor receptor (EGFR) positive disease (n = 21) were stratified into two cohorts: those currently receiving EGFR tyrosine kinase inhibitor (TKI) therapy (n = 9) and newly diagnosed EGFR TKI treatment-naïve patients (n = 12). Plasma genotyping of cell-free DNA was carried out using the FDA-approved cobas® EGFR mutation test v2 and compared to next generation sequencing (NGS) cfDNA panels. Circulating tumor cell (CTC) numbers were correlated with treatment response and EGFR exon 20 p.T790M. The prognostic significance of the neutrophil to lymphocyte ratio (NLR) and lactate dehydrogenase (LDH) was also investigated. Patients in cohort 1 with an EGFR exon 20 p.T790M mutation progressed more rapidly than those with an EGFR sensitizing mutation, while patients in cohort 2 had a significantly longer progression-free survival (p = 0.04). EGFR exon 20 p.T790M was detected by liquid biopsy prior to disease progression indicated by computed tomography (CT) imaging. The cobas® EGFR mutation test detected a significantly greater number of exon 20 p.T790M mutations (p = 0.05). High NLR and derived neutrophil to lymphocyte ratio (dNLR) were associated with shorter time to progression and worse survival outcomes (p < 0.05). High LDH levels were significantly associated with shorter time to disease progression (p = 0.03). These data support the use of liquid biopsy for monitoring EGFR mutations and inflammatory markers as prognostic indicators in NSCLC.

Engaging innate immunity for targeting the epidermal growth factor receptor: Therapeutic options leveraging innate immunity versus adaptive immunity versus inhibition of signaling

The epidermal growth factor receptor (EGFR) is a key player in the normal tissue physiology and the pathology of cancer. Therapeutic approaches have now been developed to target oncogenic genetic aberrations of EGFR, found in a subset of tumors, and to take advantage of overexpression of EGFR in tumors. The development of small-molecule inhibitors and anti-EGFR antibodies targeting EGFR activation have resulted in effective but limited treatment options for patients with mutated or wild-type EGFR-expressing cancers, while therapeutic approaches that deploy effectors of the adaptive or innate immune system are still undergoing development. This review discusses EGFR-targeting therapies acting through distinct molecular mechanisms to destroy EGFR-expressing cancer cells. The focus is on the successes and limitations of therapies targeting the activation of EGFR versus those that exploit the cytotoxic T cells and innate immune cells to target EGFR-expressing cancer cells. Moreover, we discuss alternative approaches that may have the potential to overcome limitations of current therapies; in particular the innate cell engagers are discussed. Furthermore, this review highlights the potential to combine innate cell engagers with immunotherapies, to maximize their effectiveness, or with unspecific cell therapies, to convert them into tumor-specific agents.

Association between EGFR gene mutant protein expression and T790M mutation after first-generation EGFR-TKI treatment resistance: a retrospective, single-arm clinical study

Background

Epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) is an important treatment for lung adenocarcinoma patients with EGFR gene mutations. The purpose of this study was to review the efficacy of first-generation EGFR-TKIs and the incidence of T790M after first-generation TKI resistance in stage IV lung adenocarcinoma patients with positive EGFR gene mutation expression associated with EGFR mutant protein.

Methods

Tumor tissues were collected from stage IV lung adenocarcinoma patients with EGFR gene mutation who received first-generation EGFR-TKI targeted therapy. Patients were followed up through outpatient and inpatient systems. Immunohistochemistry was used to detect the expression of corresponding EGFR mutant protein in tumor tissues. The incidence of T790M mutation after first-generation TKI resistance and the correlation between the mutant protein and progression-free survival (PFS) after first-generation TKI treatment were investigated.

Results

T790M mutation rates were 37.93% (11/29) and 42.50% (17/40) in the EGFR mutation groups, respectively, after first-generation TKI treatment for drug resistance. In patients with exon 19 deletion, T790M mutations were found in 63.64% (7/11) of patients with positive protein expression and 22.22% (4/18) of patients with negative protein expression (P=0.026; χ²=4.974). The mutation rate of T790M after drug resistance in patients with L858R mutation was 53.57% (15/28) and 16.67% (2/12) in the protein expression-positive and negative groups, respectively (χ²=4.682, P=0.030). The variations were statistically significant.

Conclusions

After resistance to the first-generation EGFR-TKI treatment, the occurrence of T790M mutation may be related to the expression of EGFR mutant protein in patients with EGFR gene mutation.

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.

Development and externally validate MRI-based nomogram to assess EGFR and T790M mutations in patients with metastatic lung adenocarcinoma

OBJECTIVES

This study aims to explore values of multi-parametric MRI-based radiomics for detecting the epidermal growth factor receptor (EGFR) mutation and resistance (T790M) mutation in lung adenocarcinoma (LA) patients with spinal metastasis.

METHODS

This study enrolled a group of 160 LA patients from our hospital (between Jan. 2017 and Feb. 2021) to build a primary cohort. An external cohort was developed with 32 patients from another hospital (between Jan. 2017 and Jan. 2021). All patients underwent spinal MRI (including T1-weighted (T1W) and T2-weighted fat-suppressed (T2FS)) scans. Radiomics features were extracted from the metastasis for each patient and selected to develop radiomics signatures (RSs) for detecting the EGFR and T790M mutations. The clinical-radiomics nomogram models were constructed with RSs and important clinical parameters. The receiver operating characteristics (ROC) curve was used to evaluate the predication capabilities of each model. Calibration and decision curve analyses (DCA) were constructed to verify the performance of the models.

RESULTS

For detecting the EGFR and T790M mutation, the developed RSs comprised 9 and 4 most important features, respectively. The constructed nomogram models incorporating RSs and smoking status showed favorite prediction efficacy, with AUCs of 0.849 (Sen = 0.685, Spe = 0.885), 0.828 (Sen = 0.964, Spe = 0.692), and 0.778 (Sen = 0.611, Spe = 0.929) in the training, internal validation, and external validation sets for detecting the EGFR mutation, respectively, and with AUCs of 0.0.842 (Sen = 0.750, Spe = 0.867), 0.823 (Sen = 0.667, Spe = 0.938), and 0.800 (Sen = 0.875, Spe = 0.800) in the training, internal validation, and external validation sets for detecting the T790M mutation, respectively.

CONCLUSIONS

Radiomics features from the spinal metastasis were predictive on both EGFR and T790M mutations. The constructed nomogram models can be potentially considered as new markers to guild treatment management in LA patients with spinal metastasis.

KEY POINTS

• To our knowledge, this study was the first approach to detect the EGFR T790M mutation based on spinal metastasis in patients with lung adenocarcinoma. • We identified 13 MRI features that were strongly associated with the EGFR T790M mutation. • The proposed nomogram models can be considered as potential new markers for detecting EGFR and T790M mutations based on spinal metastasis.

A randomized phase II study of docetaxel or pemetrexed with or without the continuation of gefitinib after disease progression in elderly patients with non-small cell lung cancer harboring EGFR mutations (JMTO LC12-01)

BACKGROUND

Gefitinib (G) is a recommended molecular-targeted agent for elderly patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). Docetaxel (Doc) and pemetrexed (Pem) have similar efficacies, and either is often used as the sole agent during treatment. The efficacy of continuing G after progressive disease (PD) develops has been reported. It remains unclear whether the continuation of G in combination with a single cytotoxic agent beyond PD is beneficial for elderly patients. Here, we conducted a randomized phase II study to assess the efficacy and safety of cytotoxic chemotherapy with G for elderly patients with progressive EGFR-mutant NSCLC.

METHODS

Elderly patients with EGFR-mutant NSCLC with PD previously treated with G were enrolled. Patients received Pem 500 mg/m or Doc 60 mg/m every 21 days and were randomly assigned to receive chemotherapy with 250 mg G (G+ Doc/Pem arm) or without G (Doc/Pem arm) until further disease progression or unacceptable toxicity.

RESULTS

This trial was terminated early owing to slow accrual. A group of 22 patients underwent analysis. The primary endpoint, progression-free survival (PFS), was significantly longer in the G + Doc/Pem arm (median: 1.6 months vs. 5.6 months, hazard ratio = 0.40, 95% CI: 0.16-0.99, p = 0.0391). Adverse events ≥ grade 3 were more frequent in the G + Doc/Pem arm (45.5% vs. 90.9%, p = 0.032).

CONCLUSIONS

Patients on G and Pem or Doc beyond PD showed a longer PFS than those on single-agent chemotherapy; however, it was associated with increased toxicity.

Membrane Repairing Capability of Non-Small Cell Lung Cancer Cells Is Regulated by Drug Resistance and Epithelial-Mesenchymal-Transition

The plasma membrane separates the interior of the cells from the extracellular fluid and protects the cell from disruptive external factors. Therefore, the self-repairing capability of the membrane is crucial for cells to maintain homeostasis and survive in a hostile environment. Here, we found that micron-sized membrane pores induced by cylindrical atomic force microscope probe puncture resealed significantly (~1.3-1.5 times) faster in drug-resistant non-small cell lung cancer (NSCLC) cell lines than in their drug-sensitive counterparts. Interestingly, we found that such enhanced membrane repairing ability was due to the overexpression of annexin in drug-resistant NSCLC cells. In addition, a further ~50% reduction in membrane resealing time (i.e., from ~23 s to ~13 s) was observed through the epithelial-mesenchymal-transition, highlighting the superior viability and potential of highly aggressive tumor cells using membrane resealing as an indicator for assessing the drug-resistivity and pathological state of cancer.

Integration of liquid biopsy and pharmacogenomics for precision therapy of EGFR mutant and resistant lung cancers

The advent of molecular profiling has revolutionized the treatment of lung cancer by comprehensively delineating the genomic landscape of the epidermal growth factor receptor (EGFR) gene. Drug resistance caused by EGFR mutations and genetic polymorphisms of drug metabolizing enzymes and transporters impedes effective treatment of EGFR mutant and resistant lung cancer. This review appraises current literature, opportunities, and challenges associated with liquid biopsy and pharmacogenomic (PGx) testing as precision therapy tools in the management of EGFR mutant and resistant lung cancers. Liquid biopsy could play a potential role in selection of precise tyrosine kinase inhibitor (TKI) therapies during different phases of lung cancer treatment. This selection will be based on the driver EGFR mutational status, as well as monitoring the development of potential EGFR mutations arising during or after TKIs treatment, since some of these new mutations may be druggable targets for alternative TKIs. Several studies have identified the utility of liquid biopsy in the identification of EGFR driver and acquired resistance with good sensitivities for various blood-based biomarkers. With a plethora of sequencing technologies and platforms available currently, further evaluations using randomized controlled trials (RCTs) in multicentric, multiethnic and larger patient cohorts could enable optimization of liquid-based assays for the detection of EGFR mutations, and support testing of CYP450 enzymes and drug transporter polymorphisms to guide precise dosing of EGFR TKIs.

Treatment patterns, testing practices, and outcomes in the pre-FLAURA era for patients with EGFR mutation-positive advanced NSCLC: a retrospective chart review (REFLECT)

Introduction:

For epidermal growth factor receptor mutation-positive (EGFRm) non-small-cell lung cancer (NSCLC), EGFR-tyrosine kinase inhibitors (EGFR-TKIs) are the preferred first-line (1 L) treatment in the advanced setting. Osimertinib, a third-generation EGFR-TKI, received full approval in 2017 for second-line (2 L) treatment of EGFR T790M-positive NSCLC. The REFLECT study characterizes real-world treatment/testing patterns, attrition rates, and outcomes in patients with EGFRm advanced NSCLC treated with 1 L first-/second-generation (1G/2G) EGFR-TKIs before 1 L osimertinib approval.

Methods:

Retrospective chart review (NCT04031898) of European/Israeli adults with EGFRm unresectable locally advanced/metastatic NSCLC, initiating 1 L 1G/2G EGFR-TKIs 01/01/15–30/06/18 (index date).

Results:

In 896 patients (median follow-up of 21.5 months), the most frequently initiated 1 L EGFR-TKI was afatinib (45%). Disease progression was reported in 81%, including 10% (86/896) who died at 1 L. By the end of study, most patients discontinued 1 L (85%), of whom 33% did not receive 2 L therapy. From index, median 1 L real-world progression-free survival was 13.0 (95% confidence interval (CI): 12.3–14.1) months; median overall survival (OS) was 26.2 (95% CI: 23.6–28.4) months. 71% of patients with 1 L progression were tested for T790M; 58% were positive. Of those with T790M, 95% received osimertinib in 2 L or later. Central nervous system (CNS) metastases were recorded in 22% at index, and 15% developed CNS metastases during treatment (median time from index 13.5 months). Median OS was 19.4 months (95% CI: 17.1–22.1) in patients with CNS metastases at index, 24.8 months (95% CIs not available) with CNS metastases diagnosed during treatment, and 30.3 months (95% CI: 27.1, 33.8) with no CNS metastases recorded.

Conclusion:

REFLECT is a large real-world study describing treatment patterns prior to 1 L osimertinib availability for EGFRm advanced NSCLC. Given the attrition rates highlighted in the study and the impact of CNS progression on outcomes, offering a 1 L EGFR-TKI with CNS penetration may improve patient outcomes in this treatment setting.

Biomarker subset analysis of a phase IIIb, open-label study of afatinib in EGFR tyrosine kinase inhibitor-naive patients with EGFRm+ non-small-cell lung cancer

Aim: To explore the relationship between mutations in cfDNA and response to afatinib. Patients & methods: In total, 64 patients from one Chinese site with locally advanced/metastatic EGFRm+ non-small-cell lung cancer, who received afatinib 40 mg once daily, were included. Results: Overall, 33 (82.5%) patients became EGFRm- by visit 3; median progression-free survival was longer in these patients vs those who did not (11.0 vs 5.5 months). Progression-free survival was shorter in 42 (45.2%) patients with non-EGFR co-mutations at baseline vs those without (8.1 vs 12.5 months). Neither difference was significant. Conclusion: Afatinib provided clinical benefit for patients with EGFRm+ non-small-cell lung cancer across all subgroups. EGFRm status assessment in plasma cfDNA is a useful method of monitoring treatment.

Heterogeneity among tumors with acquired resistance to EGFR tyrosine kinase inhibitors harboring EGFR ‐T790M mutation in non‐small cell lung cancer cells

EGFR‐T790M mutation is a major mechanism underlying acquired resistance to first‐ and second‐generation EGFR tyrosine kinase inhibitors (EGFR‐TKIs) in lung cancer with mutated EGFR. However, differences in the biological characteristics of T790M tumors based on treatment regimens with each generation of EGFR‐TKI are not fully understood. We established cell lines with acquired resistance harboring EGFR‐T790M mutation derived from xenograft tumors treated with each generation of EGFR‐TKI and examined their biological characteristics with respect to third‐generation EGFR‐TKI osimertinib sensitivity. Second‐generation EGFR‐TKI dacomitinib‐resistant cells with T790M‐exhibited higher sensitivity to osimertinib than first‐generation EGFR‐TKI gefitinib‐resistant cells with T790M via inhibition of AKT and ERK signaling and promotion of apoptosis. Furthermore, gefitinib‐resistant cells showed enhanced intratumor heterogeneity accompanied by genomic instability and activation of alternative resistance mechanisms compared with dacomitinib‐resistant cells; this suggests that the maintenance of EGFR dependency after acquiring resistance might depend on the type of EGFR‐TKI. Our results demonstrate that the progression of tumor heterogeneity via both genetic and non‐genetic mechanisms might affect osimertinib sensitivity in tumors with acquired resistance harboring EGFR‐T790M mutation.

Discovery of potent antiproliferative agents from selected oxygen heterocycles as EGFR tyrosine kinase inhibitors from the U.S. National Cancer Institute database by in silico screening and bioactivity evaluation

A similarity search was conducted on the U.S. Enhanced National Cancer Institute Database Browser 2.2 to find structures related to 1,5-dihydroxy-9H-xanthen-9-one, a previously established EGFR-TK inhibitor. Compounds were virtually screened and selected for bioactivity testing revealed 5 candidates, mostly displayed stronger antiproliferative activities than erlotinib with IC₅₀ values between 0.95 and 17.71 μM against overexpressed EGFR-TK cancer cell lines: A431 and HeLa. NSC107228 displayed the strongest antiproliferative effects with IC₅₀ values of 2.84 and 0.95 μM against A431 and HeLa cancer cell lines, respectively. Three compounds, NSC81111, NSC381467 and NSC114126 inhibited EGFR-TK with IC₅₀ values between 0.15 and 30.18 nM. NSC81111 was the best inhibitor with IC₅₀ = 0.15 nM. Molecular docking analysis of the 3 compounds predicted hydrogen bonding and hydrophobic interactions with key residues were important for the bioactivities observed. Furthermore, calculations of the physicochemical properties suggest the compounds are drug-like and are potentially active orally.

Efficacy of Prophylactic Traditional Chinese Medicine on Skin Toxicity of Afatinib in EGFR Mutation-Positive Advanced Lung Adenocarcinoma: A Single-Center, Prospective, Double-Blinded, Randomized-Controlled Pilot Trial

OBJECTIVES

To evaluate the efficacy of prophylactic traditional Chinese medicine (TCM) on skin toxicities in patients with advanced lung adenocarcinoma treated with first-line epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in a randomized-controlled trial (RCT).

MATERIALS AND METHODS

This pilot study was a prospective, single-center, double-blinded RCT. The study enrolled patients with a new diagnosis of locally advanced and metastatic lung adenocarcinoma harboring EGFR mutations who were treated with first-line afatinib from July 1, 2016 to December 31, 2017. Thirty patients who met the inclusion and exclusion criteria were assigned to the TCM and placebo groups with simple randomization. TCM and placebo were initiated at the same time as afatinib and were administered for 3 months. The survival of each subject was followed until 3 years.

RESULTS

There were 36 patients with newly diagnosed lung adenocarcinoma during the study period. After the exclusion of 6 patients, the remaining 30 patients were assigned to the TCM (n = 14) and placebo (n = 16) groups comprising the intention-to-treat population. The time to first skin toxicity was 22.3 days in the TCM group and 17.6 days in the placebo group (P = .510) in the per-protocol population. The analysis of the present pilot study results determined that the difference in time to first skin toxicity between the 2 groups would reach statistical significance with a sample size of 237 based on a power of 0.8. There were significant differences in certain subscales of quality of life between the TCM and placebo groups; however, there was no significant difference in progression-free survival or overall survival between the 2 groups.

CONCLUSIONS

Integrative TCM may prolong the time to first skin toxicity in patients with advanced lung adenocarcinoma treated with first-line afatinib. Prophylactic TCM could delay skin toxicity of any grade and reduce the incidence of grade 3 skin toxicity. Future large-scale RCTs are warranted to validate these findings.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05204758. Registered on 24 Jan 2022.

NOTCH alteration in EGFR-mutated lung adenocarcinoma leads to histological small-cell carcinoma transformation under EGFR-TKI treatment

BACKGROUND

Molecular targeted therapy has been developed as an innovative treatment for metastatic cancer. Epidermal growth factor receptor (EGFR) mutation is one of the most important and frequent oncogenic drivers in non-small-cell lung cancer, and EGFR-tyrosine kinase inhibitors are indispensable drugs for mutation-positive patients. Currently, the acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is a problem, the mechanism of which has not been elucidated. The histological transformation from original adenocarcinoma to small-cell carcinoma is rare; however, it has been detected in many cases after EGFR-TKI treatment. This study aimed to evaluate mutational status in two different histological types and further elucidate the molecular pathogenesis.

METHODS

Three patients with EGFR-mutant lung cancer who underwent a histological transformation to small-cell carcinoma after growth factor receptor-TKI treatment were enrolled in this study. Two samples per patient were collected from histologically different lesions, and DNA samples were extracted from formalin-fixed, paraffin-embedded tumor tissues. The paired samples were subjected to next-generation sequencing of 160 cancer-related genes. Based on the sequencing results, the expression levels of related proteins were validated using reverse-transferase polymerase chain reaction and immunohistochemical staining.

RESULTS

The following five variants were common among the three cases: MTOR, JAK1, NOTCH2, CSF1R, and MAP2K2. The former four variants were additive to small-cell carcinoma, and the last variant was lost. Both TP53 and Rb1 alterations were detected in adenocarcinoma. Notch2 expression was negative in small-cell carcinoma in both reverse-transcriptase polymerase chain reaction analysis and immunohistochemical staining. ASCL1 expression increased after histological transformation detected using both methods in one case, only these samples were evaluable.

CONCLUSIONS

Notch and ASCL1 signaling are the master regulators of neuroendocrine differentiation in small-cell lung carcinoma. Our results suggest that the Notch-ASCL1 axis may also play an essential role in the transformation of small-cell carcinoma under TP53 and RB1 inactivation.

Comparing survival and treatment response of patients with acquired T790M mutation second-line osimertinib versus sequential treatment of chemotherapy followed by osimertinib: A real-world study

Purpose

To investigate the survival benefit with first/second generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) and osimertinib in different treatment sequences.

Methods

We retrospectively screened 3807 patients diagnosed with cancer between 2013 and 2019 at Kaohsiung Chang Gung Memorial Hospital. In total, 76 patients with EGFR T790M mutation who received osimertinib after re‐biopsy or liquid biopsy were enrolled for the analysis.

Results

The median progression‐free survival (PFS), median overall survival (OS), and median OS2 of the 76 patients were 11.93, 66.53, and 29.57 months, respectively. A significant difference was observed in the disease control rate between those who received osimertinib treatment after chemotherapy (group A) and those who received osimertinib immediately following EGFR‐TKI therapy (group B) (34 [94.4%] vs. 31 [77.5%], p = 0.036). In addition, chronic obstructive pulmonary disease tended to be a poor prognostic factor for PFS and OS.

Conclusion

This real‐world analysis revealed that previous chemotherapy could affect the treatment outcomes of patients with non‐small cell lung cancer treated with osimertinib. Osimertinib treatment following first/second generation EGFR‐TKI treatment or chemotherapy resulted in improved survival benefit.

Serial Plasma Cell-Free Circulating Tumor DNA Tests Identify Genomic Alterations for Early Prediction of Osimertinib Treatment Outcome in EGFR T790M-Positive NSCLC

Introduction

Recent advances in the detection of genomic DNA from plasma samples allow us to follow tumor DNA shedding in plasma during systemic treatment. Osimertinib is the standard of care for patients with NSCLC with acquired EGFR T790M mutations. We assessed changes in serial plasma cell-free circulating tumor DNA (ctDNA) genomic alterations to predict osimertinib efficacy.

Methods

We prospectively collected plasma from patients having EGFR-mutated advanced NSCLC previously treated with EGFR tyrosine kinase inhibitor therapy and with acquired EGFR T790M mutation detected by standard methods. Plasma samples were collected before starting osimertinib treatment, 4 weeks after osimertinib treatment, and on progression. ctDNA was analyzed using the Guardant360 assay.

Results

A total of 15 eligible patients received osimertinib. Before starting treatment, EGFR-activating mutations were detected in the ctDNA of all patients, and EGFR T790M was detected in 93% of the cases. Osimertinib treatment was associated with an objective response rate of 53% and a median progression-free survival of 7.3 months. A total of 12 of the 15 patients had undetectable plasma T790M and decreased activating mutation allelic frequency (AF) at week 4. None of the 12 patients had disease progression within 16 weeks. For the remaining three patients, with detectable plasma T790M (n = 2) or increased activating mutation AF (n = 1) at week 4, two had progressive disease within 16 weeks (p = 0.03).

Conclusions

In patients with EGFR-mutated advanced NSCLC, persistent EGFR T790M or increasing activating mutation AF as detected in ctDNA 4 weeks after the start of osimertinib treatment may predict disease progression within 16 weeks.

An Observational Study to Assess the Molecular Epidemiology and Direct Medical Costs of Epidermal Growth Factor Receptor (EGFR) Mutations in Patients with Advanced EGFR Mutation-Positive Non-Small Cell Lung Cancer Treated with Afatinib in Real-World Clinical Settings in Greece

Purpose

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the preferred first-line option for patients with advanced, EGFR-mutant non-small cell lung cancer (NSCLC). Afatinib, a second-generation irreversible EGFR-TKI, has been extensively used in Greece in this setting; however, real-world data regarding molecular epidemiology and financial implications of afatinib use are lacking.

Materials and Methods

This was an observational, non-interventional, multicenter, retrospective cohort study, based on real-world data collected from the medical charts/records of patients treated with afatinib between 15/03/2015 and 25/06/2020 and were recorded on a web-based data capture system. Cox models were used to assess the prognostic significance of clinicopathological parameters with respect to clinical outcomes of interest. Cost analysis was conducted from a public third-payer perspective, and only direct medical costs reimbursed by the payer were considered.

Results

A total of 59 patients were treated with afatinib for their EGFR mutation-positive advanced NSCLC; the median age was 61 years (range: 37-91). Performance status was zero in 61%, and brain metastases were present in 13.6%. Forty-four patients (74.6%) had a deletion in exon 19 only, while nine (15.3%) had a mutation in exon 21, 8 of them in L858R and one in L861Q. At a median follow-up of 41.8 months (95% CI 35.9-51.4), the median PFS was 14.3 months (95% CI 12.2-16.4), and the median OS was 29 months (95% CI 25.6-33.4). Corresponding values for patients with deletion 19 only were 14.3 months (95% CI 11.5-18.5) and 28.1 months (95% CI 21.1-32.6), respectively. The mean expenditure for the treatment of each patient equals €25,333.68; with €21,865.06 being attributed to drug acquisition costs, €3325.35 to monitoring costs and €143.27 to adverse event treatment-related costs.

Conclusion

Long-term data in the real-world setting in Greece confirm activity, tolerability and cost-effectiveness of afatinib as first-line treatment of patients with advanced EGFR-mutant NSCLC.

Clinical Trial Registration

Clinicaltrials.gov NCT04640870.

Outcomes of salvage lung resections in advanced EGFR-mutant lung adenocarcinomas under EGFR TKIs

Background

Studies regarding the outcomes of salvage lung resections of epidermal growth factor receptor (EGFR)‐mutant advanced lung adenocarcinomas (ALAs) following treatment with EGFR tyrosine kinase inhibitors (TKIs) are limited, hence the objective of this study was to investigate such outcomes.

Methods

A total of 29 patients with EGFR‐mutant ALA who underwent salvage surgery after EGFR‐TKI treatment from October 2013 through January 2019 were enrolled. The patients were divided into two groups according to the surgical indications. Their perioperative parameters and surgical outcomes, including progression‐free survival (PFS) and overall survival (OS), were then analyzed.

Results

The initial stages of the patients were stage IIIB (seven patients), IVA (17 patients), and IVB (five patients). Their surgical indications included residual tumor (25 patients) and progressive disease (PD) (four patients). They all underwent surgery via minimally invasive approaches and the median follow‐up was 33.9 months. Within that follow‐up duration, the median PFS after surgery was 36.4 months, and the median OS was still not reached. There were no significant differences in PFS or OS according to the different EGFR‐TKIs used, the different durations of EGFR‐TKI treatment before surgery, or the different surgical indications. However, the patients presenting with pleural seeding before EGFR‐TKI treatment had significantly poorer PFS and OS than the other patients (P < 0.001).

Conclusions

Salvage surgery following EGFR‐TKI treatment of ALAs is a safe procedure with acceptable intra‐ and postoperative results. However, studies involving more cases and longer follow‐up periods are needed to clarify its benefits.

Key points

Salvage surgery following EGFR‐TKI treatment of ALAs is a safe procedure with acceptable intra‐ and postoperative results.

Our results support the use of surgery following treatment with EGFR‐TKIs such as afatinib in advanced lung cancer.

The role of molecular heterogeneity targeting resistance mechanisms to lung cancer therapies

Introduction: The treatment scenario of lung cancer is rapidly evolving through time. In parallel, growing evidence is accumulating on different mechanisms of treatment resistance. Inter- and intra-tumor heterogeneity define the spatial and temporal tumor clonal evolution, that is at the basis of tumor progression and resistance to anticancer treatments.Areas covered: This review summarizes the available evidence on molecular heterogeneity in lung cancer, from diagnosis to the occurrence of treatment resistance. The application of novel molecular diagnostic methods to detect molecular heterogeneity, and the implications of understanding heterogeneity for drug development strategies are discussed, with focus on clinical relevance and impact on patients' survival.Expert opinion: The current knowledge of molecular heterogeneity allows to identify different molecular subgroups of patients within the same conventional tumor type. Deeper understanding of heterogeneity determinants and the possibility to comprehensively investigate tumor molecular patterns will lead to the development of personalized treatment approaches, with the final goal to overcome resistance and prolong survival in lung cancer patients.

An open-label expanded access program of afatinib in EGFR tyrosine kinase inhibitor-naïve patients with locally advanced or metastatic non-small cell lung cancer harboring EGFR mutations

BACKGROUND

Afatinib is approved globally for EGFR-TKI treatment-naïve patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). In this Korean expanded access program, we evaluated its 'real-world' safety and efficacy.

METHODS

EGFR-TKI treatment-naïve patients with EGFR mutation-positive NSCLC received afatinib 40 mg/day until disease progression or other withdrawal criteria. Dose reductions were permitted for adverse events (AEs). The primary endpoint was the number of patients with AEs (CTCAE version 3.0). Other endpoints included progression-free survival (PFS), overall response rate (ORR), duration of response (DOR), and changes in investigator-assessed cancer-related symptoms.

RESULTS

Eighty-eight patients received afatinib, including 27 (31%) with brain metastases and 16 (18%) with uncommon EGFR mutations. Median PFS was 17.0 months (95% confidence interval [CI] 12.9-23.3 months). Grade 3 treatment-related AEs (TRAEs) were reported in 51 (58%) patients; the most common were diarrhea (22%) and rash/acne (20%). No grade > 3 TRAEs were reported. AEs leading to dose reduction occurred in 49 (56%) patients. Treatment discontinuation due to TRAEs occurred in 4 (5%) patients. ORR was 81% overall, 89% in patients with brain metastases, and 55% in patients with uncommon mutations (excluding T790M/exon 20 insertions). Median DOR was 15.1 months (95% CI 12.4-21.4 months). Cancer-related symptoms were improved/unchanged/worsened in 34-66%/36-66%/0-3% of patients over the first year.

CONCLUSIONS

No unexpected safety signals for afatinib were observed. AEs were manageable; the treatment discontinuation rate was low. Afatinib showed encouraging efficacy in a broad patient population including those with brain metastases or tumors harboring uncommon EGFR mutations.

TRIALS REGISTRATION

ClinicalTrials.gov NCT01931306 ; 29/08/2013.

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.

A Real-World, Observational, Prospective Study to Assess the Molecular Epidemiology of Epidermal Growth Factor Receptor (EGFR) Mutations upon Progression on or after First-Line Therapy with a First- or Second-Generation EGFR Tyrosine Kinase Inhibitor in EGFR Mutation-Positive Locally Advanced or Metastatic Non-Small Cell Lung Cancer: The 'LUNGFUL' Study

Simple Summary

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer cases, with few patients carrying driver mutations in the gene encoding for epidermal growth factor receptor (EGFR). Advances in translational research have established EGFR tyrosine kinase inhibitors (TKIs) as the standard first-line therapy for NSCLC patients with activating EGFR mutations. The aim of our observational study was to assess the frequency of T790M acquired resistance and predictors of its presence, in patients with EGFR-mutated locally advanced or metastatic NSCLC who have progressed in the first-line EGFR-TKI treatment setting with first- or second-generation TKIs and have undergone molecular testing in tissue and/or plasma biopsy. The study highlights the challenges of performing tissue re-biopsy in routine care settings, which can lead to patients considered non-eligible for certain therapies from which they can benefit, and merits further actions from the healthcare community, in order to establish re-biopsy as a standard procedure.

Abstract

Background: Real-world data on the molecular epidemiology of EGFR resistance mutations at or after progression with first- or second-generation EGFR-TKIs in patients with advanced NSCLC are lacking. Methods: This ongoing observational study was carried out by 23 hospital-based physicians in Greece. The decision to perform cobas^®EGFR Mutation Test v2 in tissue and/or plasma at disease progression was made before enrollment. For patients with negative/inconclusive T790M plasma-based results, tissue re-biopsy could be performed. Results: Ninety-six (96) eligible patients were consecutively enrolled (median age: 67.8 years) between July-2017 and September-2019. Of the patients, 98% were tested upon progression using plasma and 2% using tissue/cytology biopsy. The T790M mutation was detected in 16.0% of liquid biopsies. Tissue re-biopsy was performed in 22.8% of patients with a T790M-negative plasma result. In total, the T790M positivity rate was 21.9%, not differing between patients on first- or second-generation EGFR-TKI. Higher (≥2) ECOG performance status and longer (≥10 months) time to disease progression following EGFR-TKI treatment initiation were associated with T790M positivity. Conclusions: Results from plasma/tissue-cytology samples in a real-world setting, yielded a T790M positivity rate lower than previous reports. Fewer than one in four patients with negative plasma-based testing underwent tissue re-biopsy, indicating the challenges in routine care settings.

Celastrol acts synergistically with afatinib to suppress non-small cell lung cancer cell proliferation by inducing paraptosis

Non-small cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is intrinsic resistance to EGFR-tyrosine kinase inhibitors (TKIs), such as afatinib. Celastrol, a natural compound with antitumor activity, was reported to induce paraptosis in cancer cells. In this study, intrinsic EGFR-TKI-resistant NSCLC cell lines H23 (EGFR wild-type and KRAS mutation) and H292 (EGFR wild-type and overexpression) were used to test whether celastrol could overcome primary afatinib resistance through paraptosis induction. The synergistic effect of celastrol and afatinib on survival inhibition of the NSCLC cells was evaluated by CCK-8 assay and isobologram analysis. The paraptosis and its modulation were assessed by light and electron microscopy, Western blot analysis, and immunofluorescence. Xenografts models were established to investigate the inhibitory effect of celastrol plus afatinib on the growth of the NSCLC tumors in vivo. Results showed that celastrol acted synergistically with afatinib to suppress the survival of H23 and H292 cells by inducing paraptosis characterized by extensive cytoplasmic vacuolation. This process was independent of apoptosis and not associated with autophagy induction. Afatinib plus celastrol-induced cytoplasmic vacuolation was preceded by endoplasmic reticulum stress and unfolded protein response. Accumulation of intracellular reactive oxygen species and mitochondrial Ca2+ overload may be initiating factors of celastrol/afatinib-induced paraptosis and subsequent cell death. Furthermore, Celastrol and afatinib synergistically suppressed the growth of H23 cell xenograft tumors in vivo. The data indicate that a combination of afatinib and celastrol may be a promising therapeutic strategy to surmount intrinsic afatinib resistance in NSCLC cells.