Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors Erlotinib Research Articles

First-line zorifertinib for EGFR-mutant non-small cell lung cancer with central nervous system metastases: The phase 3 EVEREST trial.

Zorifertinib (AZD3759), an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) with high blood-brain barrier penetration capability, demonstrated promising intracranial and systemic antitumor activity in phase 1 and 2 studies in central nervous system (CNS)-metastatic patients. In this phase 3 EVEREST trial (ClinicalTrials.gov: NCT03653546), patients with EGFR-sensitizing mutations, advanced treatment-naive non-small cell lung cancer (NSCLC), and non-irradiated symptomatic or asymptomatic CNS metastases were randomized (1:1) to zorifertinib or first-generation EGFR-TKI (gefitinib or erlotinib; control). The primary endpoint was blinded independent central review (BICR)-assessed progression-free survival (PFS) per RECIST1.1. Overall, 439 patients were randomized (zorifertinib n= 220; control n= 219). Most patients had the EGFR L858R mutation (55%) or >3 CNS lesions (54%). Median PFS was significantly longer with zorifertinib versus control (9.6 versus 6.9months; hazard ratio [HR], 0.719; 95% confidence interval [CI], 0.580-0.893; p= 0.0024). Zorifertinib significantly prolonged intracranial PFS versus control (BICR per modified RECIST1.1: HR, 0.467; 95% CI, 0.352-0.619; investigator per RANO-BM: HR, 0.627; 95% CI, 0.466-0.844). Overall survival (OS) was immature; the estimated median OS was 37.3months with zorifertinib and 31.8months with control (HR, 0.833; 95% CI, 0.524-1.283) in patients subsequently treated with third-generation EGFR-TKIs. Safety profiles were consistent with previously reported data for zorifertinib. Zorifertinib significantly improved systemic and intracranial PFS versus first-generation EGFR-TKIs; adverse events were manageable. Sequential use of zorifertinib and third-generation EGFR-TKIs showed the potential to prolong patients' survival. The results favor zorifertinib as a novel, well-validated first-line option for CNS-metastatic patients with EGFR-mutant NSCLC. This work was funded by Alpha Biopharma (Jiangsu) Co., Ltd., China.

Real-world outcomes on platinum-containing chemotherapy for EGFR-mutated advanced nonsquamous NSCLC with prior exposure to EGFR tyrosine kinase inhibitors.

Front-line therapy with an EGFR tyrosine kinase inhibitor (TKI) is the standard of care for treating patients with advanced nonsquamous NSCLC with the common sensitizing EGFR exon 19 deletion and exon 21 L858R point mutations. However, EGFR TKI resistance inevitably develops. The optimal subsequent therapy remains to be identified, although platinum-containing chemotherapy regimens are often administered. Our objectives were to describe baseline characteristics, survival, and subsequent treatment patterns for patients with advanced nonsquamous NSCLC with EGFR exon 19 deletion or L858R mutation who received a platinum-based combination regimen after front-line EGFR TKI therapy. This retrospective study used a nationwide electronic health record-derived deidentified database to select adult patients with advanced nonsquamous NSCLC, evidence of EGFR exon 19 deletion or L858R mutation, and ECOG performance status of 0-2 who initiated platinum-containing chemotherapy, with or without concomitant immunotherapy, from 1-January-2011 to 30-June-2020 following receipt of any EGFR TKI as first-line therapy or, alternatively, a first- or second-generation EGFR TKI (erlotinib, afatinib, gefitinib, dacomitinib) as first-line therapy followed by the third-generation EGFR TKI osimertinib as second-line therapy. Data cut-off was 30-June-2022. The Kaplan-Meier method was used to estimate overall survival (OS) after initiation of pemetrexed-platinum (n=119) or any platinum-based combination regimen (platinum cohort; n=311). The two cohorts included two-thirds women (65%-66%) and 57%-58% nonsmokers; median ages were 66 and 65 years in pemetrexed-platinum and platinum cohorts, respectively. Median OS was 10.3 months (95% CI, 8.1-13.9) from pemetrexed-platinum initiation and 12.4 months (95% CI, 10.2-15.2) from platinum initiation; 12-month survival rates were 48% and 51%, respectively; 260 patients (84%) had died by the end of the study. The suboptimal survival outcomes recorded in this study demonstrate the unmet need to identify more effective subsequent treatment regimens for patients with EGFR-mutated advanced nonsquamous NSCLC after EGFR TKI resistance develops.

Abstract 1958: EGFR and mTOR signaling facilitate RET-independent resistance to selective RET-TKIs

Abstract RET fusions are an oncogenic driver mutation occurring in 1-2% non-small cell lung cancer (NSCLC). Currently, RET-selective tyrosine kinase inhibitors (TKIs) selpercatinib and pralsetinib are approved for this patient population, demonstrating favorable antitumor activity and safety profiles in advanced RET fusion-positive NSCLC. However, tumors eventually become refractory to selective RET inhibitor monotherapy. We sought to identify signaling pathways which mediate RET-independent acquired resistance to RET inhibitors and effective therapeutic combinations to overcome resistance. Using LC-2/ad (CCDC6-RET) NSCLC cells, we assessed the expression and activation of critical signaling pathways at a proteomic level following RET knockdown using reverse-phase protein array. RET knockdown resulted in rapidly increased adaptive upregulation of EGFR, HER2, MET, mTOR and MEK pathway signaling; observations were confirmed by Western Blotting. To determine whether EGFR or MET signaling facilitate RET inhibitor resistance, LC-2/ad and NCCE-TH1101 (KIF5B-RET) NSCLC cells were treated with increasing concentrations of selpercatinib or pralsetinib with or without ligands for these receptors, EGF or HGF respectively, and after five days cell viability was measured by CellTiter Glo. EGFR and MET signaling promoted RET TKI resistance in both cell lines. Next, to evaluate whether blockade of EGFR or MET signaling could enhance the activity of RET inhibitors, we treated LC-2/ad and NCCE-TH1101 cells with RET TKIs alone or in combination with the EGFR TKI erlotinib or poziotinib, or the MET inhibitor SU11274. We observed an additive effect with EGFR but not MET inhibitors when combined with RET TKIs. Western blot analysis revealed that EGFR signaling could reactivate mTOR and MAPK signaling after RET TKI treatment. Therefore, we next tested whether inhibition of these downstream pathways might enhance RET TKI sensitivity. We observed that treatment of LC-2/ad and NCCE-TH1101 cells with an mTOR inhibitor (everolimus) or a MEK inhibitor (trametinib) in combination with RET TKIs increased the anti-tumor activity or RET inhibitors. Finally, we established cells with acquired resistance to selpercatinib and pralsetinib. RET TKI resistant cells did not harbor secondary RET fusion mutations but underwent epithelial to mesenchymal transition and exhibited pan-RET inhibitor resistance. Moreover, RET TKI resistant cells showed increased cell surface expression of EGFR and MET by flow cytometry. RET TKI resistant cells were sensitive to mTOR or MEK inhibitors in combination with RET TKIs. Collectively, our findings indicate that in RET-fusion positive NSCLC tumor cells, activation of bypass pathways including the EGFR, MAPK, mTOR pathways may facilitate RET inhibitor resistance and that blockade of bypass pathways may enhance the efficacy of selective RET inhibitors and overcome acquired RET TKI resistance. Citation Format: Tomohiro Takehara, Monique B. Nilsson, Ximeng Liu, Hibiki Udagawa, Naoto Morikawa, Alissa Poteete, Junqin He, Xiaoxing Yu, Thiru Arumugam, Koichi Goto, John V. Heymach. EGFR and mTOR signaling facilitate RET-independent resistance to selective RET-TKIs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1958.

A Comparative Study Evaluating the Quality of Life and Survival Outcomes in Patients Receiving Chemotherapy Versus Oral Tyrosine Kinase Inhibitor in the Third Line and Beyond Setting for Advanced NSCLC

IntroductionThe outcomes in advanced NSCLC have improved owing to the availability of more effective systemic and improved supportive care. This has increased the number of patients who seek treatment in the third line and beyond setting. We conducted this study to compare the quality of life (QoL), toxicity, and outcomes in patients receiving chemotherapy and EGFR tyrosine kinase inhibitors (TKIs) in this setting. MethodsIn this phase 3, randomized, open-label study, patients with stage III or IV NSCLC with disease progression on at least two prior lines of chemotherapy, with a life expectancy of at least 3 months, without prior EGFR TKI exposure, and stable brain metastases (if any) were included. Patients were randomized to receive chemotherapy (gemcitabine or docetaxel or paclitaxel or vinorelbine) or an EGFR TKI (erlotinib or gefitinib). The primary end point was the change in QoL at 8 to 10 weeks; the secondary outcomes were safety and overall survival (OS). Patients underwent clinical evaluation at every visit, and toxicity was assessed as per Common Terminology Criteria for Adverse Events version 4.03. A radiological tumor response assessment was done every 8 to 12 weeks from the start of therapy. The QoL was assessed using the EORTC QLQ C30 and LC13 questionnaires. The change in QoL scores was calculated as the difference between scores at baseline and scores at 8 to 10 weeks (Δ) for each QoL domain. The Mann-Whitney U test was used to compare the mean difference (Δ) for each domain. OS and progression-free survival (PFS) were determined using the Kaplan-Meier method and Cox proportional regression analysis. ResultsA total of 246 patients were enrolled in the study, with 123 in each arm. There was a male predominance with 69.1% male patients in the chemotherapy arm and 70.7% in the EGFR TKI arm. The median age of patients in the chemotherapy arm was 54 years and 55 years in the chemotherapy and EGFR TKI arms, respectively. There was no significant difference in the change in QoL at baseline and the second visit (Δ) in both arms in all domains of EORTC QLQ C30 except cognitive function (p = 0.0045) and LC13 except alopecia (0.01249). The mean Δ Global Health Status was −28 in the chemotherapy arm and −26.8 in the EGFR TKI arm; this was not statistically significant (p = 0.973). The median follow-up was 88.1 months (95% confidence interval [CI]: 39.04–137.15). On the intention-to-treat analysis, the median PFS was 3.13 months (95% CI: 2.15–4.11) in the chemotherapy arm and 2.26 months (95% CI: 2.1–2.43) in the EGFR TKI arm, with hazard ratio at 1.074 (95% CI: 0.83–1.38) (p = 0.58). There were 120 deaths in each arm. The median OS was 7.63 months (95% CI: 5.96–9.30) in the chemotherapy arm and 7.5 months in the EGFR TKI arm (95% CI: 5.85–9.14); hazard ratio at 1.033 (95% CI: 0.80–1.33) (p = 0.805). The toxicity profile was similar in both arms except for a significantly higher incidence of fatigue (p = 0.043), peripheral neuropathy (0.000), alopecia, hypokalemia (0.037), and pedal edema (0.007) in the chemotherapy arm and dry skin (p = 0.000) and skin rash (p = 0.019) in the EGFR TKI arm. ConclusionsThere was no significant difference in most QoL scales (except cognitive function and alopecia), OS, and PFS of patients with advanced NSCLC receiving an EGFR TKI as compared with chemotherapy TKI in the third-line setting. The toxicity profile is consistent with the known toxicities of the agents.

Treatment outcomes of EGFR-TKI with or without locoregional brain therapy in advanced EGFR-mutant non-small cell lung cancer patients with brain metastases.

This study aimed to evaluate the treatment outcomes of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy alone or in combination with locoregional brain therapy for advanced EGFR-mutant non-small cell lung cancer (NSCLC) patients with brain metastases. A retrospective study involving 72 advanced EGFR-mutant NSCLC patients with brain metastases at the Vietnam National Cancer Hospital were conducted. Patients were divided into 2 groups: EGFR-TKI (erlotinib) monotherapy and EGFR-TKI combined with locoregional therapy (γ knife surgery - GKS or whole-brain radiation therapy). Evaluation criteria included clinical and laboratory characteristics, central nervous system (CNS) progression time, progression-free survival (PFS), overall survival (OS), T790M mutation rate, and adverse events. Epidermal growth factor receptor tyrosine kinase inhibitor monotherapy patients had better performance status (PS), fewer CNS symptoms, and significantly fewer brain metastases (p < 0.05). Median PFS and OS were 11 and 25 months, respectively, in both groups. Patients with PS 0-1 had longer median PFS (15 months) than those with PS 2 (7 months) (p = 0.039). Exon 19 deletion patients in both groups had longer median OS (26 months) than those with L858R exon 21 (15 months) (p = 0.023). Patients with T790M mutation who received osimertinib after progression had longer median OS (41 months vs. 23 months, p = 0.0001). Median time to CNS progression was 13.9 months (48 patients). Longer time to CNS progression correlated with longer OS (R2 = 0.89). Epidermal growth factor receptor tyrosine kinase inhibitor therapy, with or without locoregional therapy, is effective for advanced EGFR-mutant NSCLC patients with brain metastases. Exon 19 deletion patients had better prognosis.

Overall Survival Benefits of First-Line Treatments for Asian Patients with Advanced Epidermal Growth Factor Receptor-Mutated NSCLC Harboring Exon 19 Deletion: A Systematic Review and Network Meta-Analysis.

Simple SummarySurvival benefits and clinical responsiveness have been exhibited by various generations of EGFR-tyrosine kinase inhibitors (TKIs) in numerous randomized-controlled trials for EGFR-mutated advanced non-small-cell lung cancer (NSCLC) over the past two decades. However, the efficacy, especially long-term overall survival (OS) for Asians harboring an exon 19 deletion (19del) in their NSCLC, remains uncertain. This systematic review and network meta-analysis evaluate the efficacy of all first-line treatments in Asian patients with advanced EGFR-mutated NSCLC harboring 19del. EGFR-TKIs and combination treatments demonstrated no OS benefits in comparison with standard chemotherapy treatments, although progression-free survival (PFS) benefits were revealed. Erlotinib plus bevacizumab, ramucirumab plus erlotinib, and osimertinib are the optimal regimens to prolong PFS for Asians with 19del. Further studies are warranted to investigate the resistance mechanisms and possible strategies for individuals harboring this common mutation.(1) Background: Randomized controlled trials (RCTs) have explored various primary treatments for individuals diagnosed as having later-stage epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer. Nevertheless, the extent to which such treatments are efficacious, particularly with regard to overall survival (OS) rates of patients from Asia with exon 19 deletion (19del), has yet to be clarified. (2) Methods: A systematic review and frequentist network meta-analysis were conducted by obtaining pertinent studies from PubMed/MEDLINE Ovid, Embase, Cochrane Library, and trial registries, as well as various other sources. RCTs in which two or multiple treatments in the primary setting for patients from Asia with EGFR 19del were compared were included. This research has been recorded in the Prospective Register of Systematic Reviews (CRD 42022320833). (3) Results: A total of 2715 patients from Asia participated in 18 trials in which 12 different treatments were administered, which included: EGFR tyrosine kinase inhibitors (TKIs) (osimertinib, dacomitinib, afatinib, erlotinib, gefitinib, and icotinib), pemetrexed-based chemotherapy, pemetrexed-free chemotherapy, and combination treatments (gefitinib plus apatinib, erlotinib plus ramucirumab, erlotinib plus bevacizumab, and gefitinib plus pemetrexed-based chemotherapy). Such treatments were not significantly beneficial in terms of OS for patients from Asia who had 19del. It was demonstrated that erlotinib plus bevacizumab, ramucirumab plus erlotinib, and osimertinib consistently yielded the greatest benefits regarding progression-free survival benefit (P-scores = 94%, 84%, and 80%, respectively). Combination treatments resulted in increased toxicity, particularly gefitinib plus apatinib and erlotinib plus bevacizumab, causing the highest prevalence of grade ≥ 3 adverse events. Icotinib and osimertinib had the fewest grade ≥ 3 adverse events. Specific treatments were associated with a wide range of toxicity levels. (4) Conclusions: In patients from Asia with 19del, both EGFR-TKIs and treatments in which therapies were combined exhibited no OS benefits in comparison with standard chemotherapy treatments. Additional research is required to study TKIs’ resistance mechanisms and possible combined approaches for individuals harboring this common mutation.

Structural dynamics and kinase inhibitory activity of three generations of tyrosine kinase inhibitors against wild-type, L858R/T790M, and L858R/T790M/C797S forms of EGFR

Mutations in the tyrosine kinase domain of epidermal growth factor receptor (EGFR), including L858R/T790M double and L858R/T790M/C797S triple mutations, are major causes of acquired resistance towards EGFR targeted drugs. In this work, a combination of comprehensive molecular modeling and in vitro kinase inhibition assay was used to unravel the mutational effects of EGFR on the susceptibility of three generations of EGFR tyrosine kinase inhibitors (erlotinib, gefitinib, afatinib, dacomitinib, and osimertinib) in comparison with the wild-type EGFR. The binding affinity of all studied inhibitors towards the double and triple EGFR mutations was in good agreement with the experimental data, ranked in the order of osimertinib > afatinib > dacomitinib > erlotinib > gefitinib. Three hot-spot residues at the hinge region (M790, M793, and C797) were involved in the binding of osimertinib and afatinib, enhancing their inhibitory activity towards mutated EGFRs. Both double and triple EGFR mutations causing erlotinib and gefitinib resistance are mainly caused by the low number of H-bond occupations, the low number of surrounding atoms, and the high number of water molecules accessible to the enzyme active site. According to principal component analysis, the molecular complexation of osimertinib against the two mutated EGFRs was in a closed conformation, whereas that against wild-type EGFR was in an open conformation, resulting in drug resistance. This work paves the way for further design of the novel EGFR inhibitors to overcome drug resistance mechanisms.

Overall Survival Benefits of First-Line Treatments for Asian Patients With Advanced EGFR-Mutated NSCLC Harboring L858R Mutation: A Systematic Review and Network Meta-Analysis

IntroductionRandomized controlled trials have investigated different first-line treatments for patients with advanced EGFR-mutated NSCLC. Nevertheless, their efficacy, in particular, the long-term overall survival (OS) benefit in Asian patients with L858R mutation, remains unclear. MethodsWe performed a systematic review and frequentist network meta-analysis by retrieving relevant literature from PubMed/MEDLINE, Ovid, EMBASE, Cochrane Library, trial registries, and other sources. We included randomized controlled trials comparing two or more treatments in the first-line setting for Asian patients with L858R mutation. This study was registered in the Prospective Register of Systematic Reviews (CRD 42022295897). ResultsThere were a total of 18 trials that involved 1852 Asian patients and 12 treatments, including the following: EGFR tyrosine kinase inhibitors (TKIs) (osimertinib, dacomitinib, afatinib, erlotinib, gefitinib, and icotinib), pemetrexed-based chemotherapy, pemetrexed-free chemotherapy, and combination treatments (gefitinib plus apatinib, erlotinib plus ramucirumab, erlotinib plus bevacizumab and gefitinib plus pemetrexed-based chemotherapy). Asian patients with L858R mutation had no significant OS benefits from all these treatments. Gefitinib plus pemetrexed-based chemotherapy, dacomitinib, osimertinib, and erlotinib plus bevacizumab were found to be consistent in yielding the best progression-free survival benefit (p scores = 93%, 79%, 77%, and 70%). Combination treatments caused more toxicity, especially erlotinib plus bevacizumab and gefitinib plus pemetrexed-based chemotherapy, resulting in the greatest incidence of grade greater than or equal to 3 adverse events. ConclusionsIn Asian patients harboring L858R mutation, EGFR TKIs and combination treatments had no OS benefit when compared with conventional chemotherapies. Further studies are warranted to investigate the resistance mechanism with TKIs and potential combination strategies in patients with this common but less favorable mutation.

Inhibition of epidermal growth factor receptor suppresses parathyroid hormone-related protein expression in tumours and ameliorates cancer-associated cachexia.

BackgroundLung cancer is the primary cause of cancer deaths worldwide. Activation of epidermal growth factor receptor (EGFR) leads to lung cancer progression and poor prognosis while involuntary weight loss remains a major problem. Tumour‐derived parathyroid hormone‐related protein (PTHrP) emerged as a potential mediator of cachexia. Here, we investigated the modulatory role of EGFR signalling in PTHrP (encoded by Pthlh) gene expression and the impact of this relationship on cancer cachexia.MethodsGlobal gene expression profiles of Lewis lung carcinoma (LLC) cells were analysed. Pthlh mRNA levels were measured by qRT‐PCR in LLC cells treated with EGFR ligands and tyrosine kinase inhibitors (TKIs). LLC tumour‐bearing mice received EGFR TKI erlotinib for 7 days via intraperitoneal injection or oral gavage. Tumour Pthlh mRNA, weight of fat/muscle tissue, and grip strength were assessed. RNA‐seq data from The Cancer Genome Atlas and gene expression analysis tools were used to characterize expression profiles of PTHLH and EGFR along with correlation analysis of PTHLH with EGFR and transforming growth factor alpha (TGFA) in human lung cancer and head and neck squamous carcinoma (HNSC). Survival of lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) patients with EGFR gene alterations was analysed in regard to PTHLH expression.ResultsExpression of EGFR ligands, EGFR itself, and PTHrP co‐clusters in LLC cells. Activation of EGFR signalling with its ligands significantly increases (3.8‐fold, P < 0.0005) while EGFR TKIs significantly decrease (90%, P < 0.0005) Pthlh mRNA levels in LLC cells. Pthlh mRNA drops 65–75% (P < 0.0005) in tumours upon treatment of LLC tumour‐bearing mice with erlotinib while their muscle mass and grip strength increase (9.2% P < 0.05, 23% P < 0.005, respectively) compared with tumour‐bearing control mice. PTHLH is overexpressed in tumours of LUSC (45.8‐fold, P < 0.05) and HNSC (17.5‐fold, P < 0.05) compared with normal tissue. PTHLH expression correlates with EGFR and its ligand TGFA in both cancers (LUSC: n = 745, R = 0.32, P < 0.0001 and R = 0.51, P < 0.0001; HNSC: n = 545, R = 0.34, P < 0.001 and R = 0.50, P < 0.001, respectively). High PTHLH mRNA associates with poor overall survival in LUAD patients with activating EGFR mutations (n = 40, log‐rank test, P = 0.0451).ConclusionsEpidermal growth factor receptor signalling regulates expression of cachexia mediator PTHrP. EGFR inhibition reduces PTHrP expression in LLC tumours and ameliorates cachexia in LLC tumour‐bearing mice.

Adverse Event Profiles of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Adenocarcinoma Lung Patients in North Sumatera Population

BACKGROUND: In early 2000, a new targeted therapy was introduced and appeared to be a medical revolution due to the great emergence of procedural treatments in lung cancers. This new target therapy has been developed recently, which is also accompanied by the development of molecular markers as medical guidance. AIM: This study aims to assess the side effect of the usage of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) on lung adenocarcinoma patients in North Sumatera. METHODS: This study was a descriptive analysis study with consecutive sampling. Data was collected from the medical records of 50 pulmonary adenocarcinoma patients who have been treated by EGFR-TKI erlotinib and gefitinib. The statistical analysis was performed through SPSS software. RESULTS: From this study, the majority of subjects were in the age range of 50–60 years old (24%), had no smoking history (52%), and were in Stage IVA (62%) at the time of diagnosis. Allele-specific polymerase chain reaction was performed and showed that exon 19 was found as the commonest mutations (62%). After using the first generation of EGFR-TKI including erlotinib and gefitinib, the majority of subjects experienced Grade I toxicities (46%) involved skin (acneiform). CONCLUSION: The most common adverse event that is occurred in the cases was in skin disorders (72% of cases), which is particularly indicated by acne rash (46% of cases). The degree of toxicity during the medications was populously on degree 1 (46% of cases).

Risk Stratification Using a Novel Nomogram for 2190 EGFR-Mutant NSCLC Patients Receiving the First or Second Generation EGFR-TKI.

Simple SummaryNo comprehensive and simple prognostic model based on pretreatment factors exists for patients with epidermal growth factor receptor mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC) undergoing EGFR-tyrosine kinase inhibitors (EGFR-TKIs). A total of 11 independent prognostic factors were identified by multivariate analysis, including performance status, morphology, mutation, stage, EGFR-TKIs, and metastasis to liver, brain, bone, pleura, adrenal gland, and distant lymph nodes. We established a nomogram based on independent pretreatment factors and used it to stratify EGFRm+ NSCLC patients undergoing EGFR-TKI treatment into five different risk groups for survival using recursive partitioning analysis. The performance of this nomogram was good and feasible, providing clinicians and patients with additional information for evaluating therapeutic options.Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the standard treatment for EGFR mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC). This study aimed to create a novel nomogram to help physicians suggest the optimal treatment for patients with EGFRm+ NSCLC. Records of 2190 patients with EGFRm+ NSCLC cancer who were treated with EGFR-TKIs (including gefitinib, erlotinib, and afatinib) at the branches of a hospital group between 2011 and 2018 were retrospectively reviewed. Their clinicopathological characteristics, clinical tumor response, progression-free survival (PFS), and overall survival (OS) data were collected. Univariate and multivariate analyses were performed to identify potential prognostic factors to create a nomogram for risk stratification. Univariate analysis identified 14 prognostic factors, and multivariate analysis confirmed the pretreatment independent factors, including Eastern Cooperative Oncology Group performance status, morphology, mutation, stage, EGFR-TKIs (gefitinib, erlotinib, or afatinib), and metastasis to liver, brain, bone, pleura, adrenal gland, and distant lymph nodes. Based on these factors, a novel nomogram was created and used to stratify the patients into five different risk groups for PFS and OS using recursive partitioning analysis. This risk stratification can provide additional information to clinicians and patients when determining the optimal therapeutic options for EGFRm+ NSCLC.

Simultaneous quantitative detection of afatinib, erlotinib, gefitinib, icotinib, osimertinib and their metabolites in plasma samples of patients with non-small cell lung cancer using liquid chromatography-tandem mass spectrometry

Background and aimsAs numerous studies have reported the concentration-exposure relationships of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), therapeutic drug monitoring is a promising approach in lung cancer treatment, aiming to avoid treatment failure or toxicity. A new method for the simultaneous analysis of five EGFR-TKIs (afatinib, erlotinib, gefitinib, icotinib and osimertinib) and their metabolites in human plasma samples was developed and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Materials and methodsAfatinib-d6, erlotinib-d6, OSI-420-d4, gefitinib-d6 and osimertinib-C13,d3 were used as internal standards (ISs). The samples were prepared by liquid-liquid extraction using tert-butyl methyl ether. Chromatographic separation was undertaken on an XBridge C18 column using a linear gradient elution. LC-MS/MS was conducted in positive ionization mode with multiple reaction monitoring. ResultsThe proposed method showed satisfactory results in terms of linearity, sensitivity, specificity, precision (intra- and inter-day coefficients of variation ranged from 1.1 to 13.9%), and accuracy (from 93.3 to 111.1%). The IS-normalized matrix factors were below 15%. The sensitivity and linearity were highly appropriate for the expected concentrations according to the analysis of samples from non-small cell lung caner (NSCLC) patients who received EGFR-TKIs. ConclusionsThe proposed method showed an acceptable reproducibility, high sensitivity and selectivity, and low matrix effects. This method could be significant for monitoring plasma concentrations of the mentioned EGFR-TKIs in NSCLC patients, aiming to improve the efficacy and safety of targeted therapies.

An Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of Afatinib, Alectinib, Ceritinib, Crizotinib, Dacomitinib, Erlotinib, Gefitinib, and Osimertinib in Human Serum.

Routine therapeutic drug monitoring is a promising approach for the rational use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) inhibitors. The purpose of this study was to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of 5 EGFR-TKIs (afatinib, dacomitinib, erlotinib, gefitinib, and osimertinib) and 3 ALK inhibitors (alectinib, ceritinib, and crizotinib). A 100-mL aliquot of serum was diluted with 100 μL of 1% aqueous ammonia containing internal standards and then purified using the supported liquid extraction method. LC-MS/MS was conducted in positive ionization mode, and the method was validated according to published guidelines. Calibration curves were linear across concentration ranges examined. The intra- and interassay accuracies were 90.7%-110.7% and 94.7%-107.6%, respectively. All intra- and interassay imprecision values were ≤10.1%. The EGFR-TKIs and ALK inhibitors examined in this study, except osimertinib, which could be stored on ice for at least 5 hours, were stable at room temperature for 3 hours. For the internal standard-normalized matrix factors, the mean recovery and percent coefficient of variation values ranged between 54%-112% and 1.7%-11.7%, respectively. This method successfully determined serum concentrations of afatinib, alectinib, erlotinib, gefitinib, and osimertinib in clinical samples. Serum levels of kinase inhibitors consistently reflected those reported in previous studies. An LC-MS/MS method suitable for the simultaneous determination of 5 EGFR-TKIs and 3 ALK inhibitors in serum was developed and validated. The newly developed method enabled the determination of 5 of 8 target drugs examined in clinical samples. However, a large number of clinical samples need to be analyzed to verify the usefulness of the method.

KCa channel blockers increase effectiveness of the EGF receptor TK inhibitor erlotinib in non-small cell lung cancer cells (A549)

Non-small cell lung cancer (NSCLC) has a poor prognosis with a 5 year survival rate of only ~ 10%. Important driver mutations underlying NSCLC affect the epidermal growth factor receptor (EGFR) causing the constitutive activation of its tyrosine kinase domain. There are efficient EGFR tyrosine kinase inhibitors (TKIs), but patients develop inevitably a resistance against these drugs. On the other hand, KCa3.1 channels contribute to NSCLC progression so that elevated KCa3.1 expression is a strong predictor of poor NSCLC patient prognosis. The present study tests whether blocking KCa3.1 channels increases the sensitivity of NSCLC cells towards the EGFR TKI erlotinib and overcomes drug resistance. mRNA expression of KCa3.1 channels in erlotinib-sensitive and -resistant NSCLC cells was analysed in datasets from Gene expression omnibus (GEO) and ArrayExpress. We assessed proliferation and migration of NSCLC cells. These (live cell-imaging) experiments were complemented by patch clamp experiments and Western blot analyses. We identified three out of four datasets comparing erlotinib-sensitive and -resistant NSCLC cells which revealed an altered expression of KCa3.1 mRNA in erlotinib-resistant NSCLC cells. Therefore, we evaluated the combined effect of erlotinib and the KCa3.1 channel inhibition with sencapoc. Erlotinib elicits a dose-dependent inhibition of migration and proliferation of NSCLC cells. The simultaneous application of the KCa3.1 channel blocker senicapoc increases the sensitivity towards a low dose of erlotinib (300 nmol/L) which by itself has no effect on migration and proliferation. Partial erlotinib resistance can be overcome by KCa3.1 channel blockade. The sensitivity towards erlotinib as well as the potentiating effect of KCa3.1 blockade is further increased by mimicking hypoxia. Our results suggest that KCa3.1 channel blockade may constitute a therapeutic concept for treating NSCLC and overcome EGFR TKI resistance. We propose that this is due to complementary mechanisms of action of both blockers.

Interleukin-1β Induces Tissue Factor Expression in A549 Cells via EGFR-Dependent and -Independent Mechanisms

Tissue factor (TF) plays an important role in the progression and angiogenesis of tumor cells. The present study investigated the mechanism of interleukin-1β (IL-1β)-induced TF expression in A549 lung cancer cells. Based on mRNA and protein analyses, including appropriate inhibitor experiments, IL-1β was shown to induce TF expression in a time-dependent manner, mediated by IL-1 receptor-dependent phosphorylation of the mitogen-activated protein kinases (MAPK) p38, p42/44 and c-jun N-terminal kinase (JNK), as well as the Src kinase and the epidermal growth factor receptor (EGFR). Thereby, inhibition of EGFR transactivation by the Src inhibitor PP1 or direct EGFR inhibition by the EGFR tyrosine kinase inhibitor (TKI) erlotinib led to a reduction of IL-1β-induced TF expression and to a suppression of p42/44 MAPK and EGFR activation, while IL-1β-induced p38 MAPK and JNK activation remained unchanged. A knockdown of EGFR by siRNA was associated with decreased IL-1β-mediated p42/44 MAPK activation, which was no longer inhibitable by erlotinib. Concentration-dependent inhibition of IL-1β-induced TF expression was also observed in the presence of gefitinib and afatinib, two other EGFR TKIs. In summary, our results suggest that IL-1β leads to increased TF formation in lung cancer cells via both Src/EGFR/p42/44 MAPK-dependent and EGFR-independent signaling pathways, with the latter mediated via p38 MAPK and JNK.

Toxicity profile of epidermal growth factor receptor tyrosine kinase inhibitors for patients with lung cancer: A systematic review and network meta-analysis.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are treatments commonly used for lung cancer. The toxicity profile including toxicity incidence, severity, and spectrum (involving various specific adverse events) of each EGFR-TKI are of particular clinical interest and importance. Data from phase II and III randomized controlled trials comparing treatments among EGFR-TKIs (osimertinib, dacomitinib, afatinib, erlotinib, gefitinib, and icotinib) and chemotherapy for lung cancer were synthesized with Bayesian network meta-analysis. The primary outcome was systemic all-grade and grade ≥3 adverse events. The secondary outcome was specific all-grade adverse events including those of the skin, gastrointestinal tract, lung, etc. 40 trials randomizing 13,352 patients were included. Generally greater toxicity for dacomitinib and afatinib, and safety for icotinib were suggested. Furthermore, we found individual EGFR-TKIs had different toxicity spectrums. These findings provide a compelling safety reference for the individualized use of EGFR-TKIs for patients with lung cancer.

Identifying advanced stage NSCLC patients who benefit from afatinib therapy using 18F-afatinib PET/CT imaging

ObjectivesNon-small cell lung cancer (NSCLC) tumors harboring common (exon19del, L858R) and uncommon (e.g. G719X, L861Q) activating epidermal growth factor receptor (EGFR) mutations are best treated with EGFR tyrosine kinase inhibitors (TKI) such as the first-generation EGFR TKI erlotinib, second-generation afatinib or third-generation osimertinib. However, identifying these patients through biopsy is not always possible. Therefore, our aim was to evaluate whether 18F-afatinib PET/CT could identify patients with common and uncommon EGFR mutations. Furthermore, we evaluated the relation between tumor 18F-afatinib uptake and response to afatinib therapy. Materials and methods18F-afatinib PET/CT was performed in 12 patients: 6 EGFR wild type (WT), 3 EGFR common and 3 EGFR uncommon mutations. Tumor uptake of 18F-afatinib was quantified using TBR_WB60−90 (tumor-to-whole blood activity ratio 60−90 min post-injection) for each tumor. Response was quantified per lesion using percentage of change (PC): [(response measurement (RM)–baseline measurement (BM))/BM]×100. Statistical analyses were performed using t-tests, correlation plots and sensitivity/specificity analysis. ResultsTwenty-one tumors were identified. Injected dose was 348 ± 31 MBq. Group differences were significant between WT versus EGFR (common and uncommon) activating mutations (p = 0.03). There was no significant difference between EGFR common versus uncommon mutations (p = 0.94). A TBR_WB60−90 cut-off value of 6 showed the best relationship with response with a sensitivity of 70 %, a specificity of 100 % and a positive predictive value of 100 %. Conclusion18F-afatinib uptake was higher in tumors with EGFR mutations (common and uncommon) compared to WT. Furthermore, a TBR_WB60−90 cut-off of 6 was found to best predict response to therapy. 18F-afatinib PET/CT could provide a means to identify EGFR mutation positive patients who benefit from afatinib therapy.

Knockdown of the DJ-1 (PARK7) gene sensitizes pancreatic cancer to erlotinib inhibition

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib, in combination with gemcitabine, has been shown to be a promising therapy in the treatment of pancreatic cancer. Our previous study showed that DJ-1 promotes invasion and metastasis of pancreatic cancer cells by activating SRC/extracellular signal-regulated kinase (ERK)/uPA. The aim of this study was to evaluate whether knockdown of DJ-1 expression can sensitize pancreatic cancer cells to erlotinib treatment. Knockdown of DJ-1 expression accelerated erlotinib-induced cell apoptosis and improved the inhibitory effect of erlotinib on pancreatic cancer cell proliferation (for the BxPC-3, PANC-1, and MiaPACa-2 cell lines, regardless of KRAS mutation status) in vitro and in xenograft tumor growth in vivo. Knockdown of DJ-1 decreased K-RAS expression, membrane translocation, and activity in BxPC-3 cells. Knockdown of DJ-1 also decreased K-RAS, H-RAS, and N-RAS expression in PANC-1 and MiaPACa-2 cells. Knockdown of DJ-1 synergistically inhibited AKT and ERK1/2 phosphorylation with erlotinib in pancreatic cancer cells. These findings indicate that DJ-1 may activate the RAS pathway, reinforcing erlotinib drug resistance. Therefore, blocking DJ-1 in combination with the EGFR tyrosine kinase inhibitor erlotinib may be an attractive therapeutic target in pancreatic cancer.

DDRE-28. EGFR INHIBITION DOWNREGULATES MGMT AND SENSITIZES GBM CELLS TO TMZ

Abstract Glioblastoma (GBM) is a highly malignant type of adult brain tumor with a poor prognosis. Temozolomide (TMZ), a DNA alkylating agent, has been widely used as an effective first-line chemotherapeutic agent for the treatment of GBM patients. The efficacy of TMZ in GBM depends on the absence of the DNA repair protein MGMT which reverses the DNA damage induced by TMZ. The MGMT promoter is hypermethylated in about 45% of GBMs, resulting in lack of MGMT expression and increased responsiveness to TMZ. TMZ is less effective in MGMT unmethylated GBMs. We propose that EGFR inhibition downregulates MGMT and sensitizes glioma cells to TMZ and a combination of pretreatment with erlotinib followed by TMZ could be a useful therapeutic approach in MGMT expressing GBMs. As our experimental model we used multiple MGMT unmethylated lines from the Mayo Clinic patient derived xenografts (PDXs) panel. Our data demonstrate that exposure of cells to EGFR tyrosine kinase inhibitor erlotinib for 48h results in downregulation of MGMT at the mRNA and protein level. Additionally, EGFR inhibition activates the AP-1 transcription factor and overexpression of AP-1 components Fos and Jun results in decreased MGMT expression in TMZ resistant PDXs, suggesting that AP-1 acts as a transcriptional repressor of MGMT. We further identified that the mice implanted with TMZ resistant PDXs pretreated with afatinib followed by TMZ treatment survived longer compared to those treated with TMZ alone. Thus, the use of EGFR inhibition may enhance the sensitivity of MGMT unmethylated GBMs to TMZ.

Mechanism of intrinsic resistance of lung squamous cell carcinoma to epithelial growth factor receptor-tyrosine kinase inhibitors revealed by high-throughput RNA interference screening.

Although targeted therapy has achieved a great breakthrough in the treatment of lung adenocarcinoma, there are still no effective targeted drugs for lung squamous cell carcinoma (SqCC). In addition, as immunotherapy can only prolong the overall survival (OS) of lung SqCC by ≤5 months, chemotherapy and radiotherapy are still the main types of therapy for advanced SqCC. The expression level of epithelial growth factor receptor (EGFR) in patients with lung SqCC is higher compared with those with adenocarcinoma, but the former group is intrinsically resistant to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Therefore, if the drug resistance in patients with lung SqCC could be reversed, the majority of patients may benefit from EGFR-TKIs. In the present study, the high-throughput RNA interference technology was used to screen the genes involved in the EGFR-TKI erlotinib resistance of lung SqCCs, and integrin-linked kinase (ILK) was identified to be the most effective. The role of ILK in erlotinib resistance was further studied in cell lines, and the expression of ILK was analyzed in patients with SqCC and adenocarcinoma. Finally, the mechanism of ILK in EGFR-TKIs resistance was analyzed using Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO) and ingenuity pathway analysis (IPA). The results demonstrated that the ILK gene knockdown could overcome erlotinib resistance by inhibiting cell proliferation, inducing apoptosis and blocking the cell cycle at the G2/M phase. The expression of ILK in patients with SqCC was significantly higher compared with those with adenocarcinoma with sensitizing EGFR mutations. In addition, the cell cycle pathway ‘G2/M DNA damage and checkpoint regulation’ was identified to be significantly inhibited by ILK knockdown in IPA, KEGG and GO analysis. The results of the present study may improve the understanding of EGFR-TKI resistance in lung SqCCs, thus promoting the development of potential targeted therapies for lung SqCCs.