Compound Epidermal Growth Factor Receptor Research Articles

In silico and in vitro evaluation of novel carbothioamide-based and heterocyclic derivatives of 4-(tert-butyl)-3-methoxybenzoic acid as EGFR tyrosine kinase allosteric site inhibitors

Cancer is an elaborate sequence of disease grades that include uncontrolled cell growth and division, invasion, and metastasis. Overexpression of the epidermal growth factor receptor (EGFR) causes an abnormal signal transduction and is directly linked to cancer development. Most EGFR tyrosine kinase inhibitors (TKIs) are ATP-competitive inhibitors that frequently cause EGFR mutations or chemoresistance. Therefore, targeting the EGFR TK allosteric site has become a highly sought after cancer treatment strategy. Ten new derivatives of 4-(tert-butyl)-3-methoxybenzoic acid containing carbothioamide (compounds 3a-e), triazole (compounds 4a-d) or oxadiazole (compound 5) moieties were designed as EGFR TK allosteric site inhibitors as deduced in silico. The structures of these derivatives were characterized by chemical spectroscopic methods (ATR-FTIR, 1HNMR, 13CNMR and HRESI-MS). According to the molecular docking studies, compounds 3e and 3d showed the highest docking scores (ΔG), which was confirmed by molecular dynamic (MD) simulation studies. The synthesized derivatives, specifically compounds 3d and 3e, exhibited favorable pharmacokinetic profile. In vitro, the newly synthesized derivatives were evaluated for their cytotoxicity against A549 (lung adenocarcinoma), HepG2 (hepatocellular carcinoma), and HCT-116 (colorectal) cancer cell lines via the MTT assay, flow cytometry, RT-PCR, immunoblotting, and kinase inhibition assay. The cytotoxicity results showed that compound 3d was cytotoxic to the three tested cell lines, achieving the lowest IC50 concentration against A549 cancer cells. Compound 3d targeting EGFR tyrosine kinase caused cell cycle arrest at the G2/M phase and induction of the ER-mediated apoptosis pathway. In silico and in vitro antitumor activity findings of compound 3d demonstrated that it is a promising EGFR tyrosine kinase allosteric site inhibitor.

Real-world analysis of afatinib as a first-line treatment for patients with advanced stage non-small-cell lung cancer with uncommon EGFR mutations: a multicenter study in Vietnam.

Afatinib is indicated for advanced-stage non-small-cell lung cancer (NSCLC) with Epidermal Growth Factor Receptor (EGFR) and uncommon mutations. However, real-world studies on this topic are limited. This study aimed to evaluate afatinib as first-line therapy for locally advanced and metastatic NSCLC with uncommon EGFR mutations. A retrospective study included 92 patients with advanced NSCLC with uncommon and compound EGFR mutations, treated with afatinib as first-line therapy. Patients were followed up and evaluated every 3 months or when symptoms of progressive disease arose. The endpoints were objective response rate (ORR), time-to-treatment failure (TTF), and adverse events. The G719X EGFR mutation had the highest occurrence rate (53.3% for both monotherapy and the compound). By contrast, the compound mutation G719X-S768I was observed at a rate of 22.8%. The ORR was 75%, with 15.2% of patients achieving complete response. The overall median TTF was 13.8 months. Patients with the G719X EGFR mutation (single and compound) had a median TTF of 19.3 months, longer than that of patients with other mutations, who had a median TTF of 11.2 months. Patients with compound EGFR mutations (G719X and S768I) demonstrated a median TTF of 23.2 months compared to that of 12.3 months for other mutations. Tolerated doses of 20 or 30 mg achieved a longer median TTF of 17.1 months compared to 11.2 months with 40 mg. Median TTF differed between patients with and without brain metastasis, at 11.2 and 16.9 months, respectively. Rash (55.4%) and diarrhea (53.3%) were the most common adverse events, primarily grades 1 and 2. Other side effects occurred at a low rate. Afatinib is effective for locally advanced metastatic NSCLC with uncommon EGFR mutations. Patients with G719X, compound G719X-S768I mutations, and tolerated doses of 20 or 30 mg had a longer median TTF than those with other mutations.

Rare mutation-dominant compound EGFR-positive NSCLC is associated with enriched kinase domain-resided variants of uncertain significance and poor clinical outcomes

BackgroundCompound epidermal growth factor receptor (EGFR) mutations are less responsive to tyrosine kinase inhibitors (TKIs) than single EGFR mutations in non-small cell lung cancer (NSCLC). However, the detailed clinical characteristics and prognosis of various compound EGFR mutations remain to be elucidated.MethodsWe retrospectively studied the next-generation sequencing (NGS) data of treatment-naïve tumors from 1025 NSCLC patients with compound EGFR mutations, which were sub-categorized into different combinations of common mutations (19-Del and EGFR exon 21 p.L858R), rare mutations, and variants of uncertain significance (VUSs). Prognosis and drug resistance to first-line TKIs were analyzed in 174 and 95 patients, respectively.ResultsCompound EGFR mutations were enriched with EGFR exon 21 p.L858R and rare mutations, but not 19-Del (P < 0.001). The common + rare and rare + rare subtypes had fewer concurrent mutations in the PI3K pathway (P = 0.032), while the rare + rare and common + VUSs subtypes showed increased association with smoking- and temozolomide-related mutational signatures, respectively (P < 0.001). The rare mutation-dominant subtypes (rare + VUSs and rare + rare) had the worst clinical outcomes to first-line TKIs (P < 0.001), which was further confirmed using an external cohort (P = 0.0066). VUSs in the rare + VUSs subtype selectively reside in the EGFR kinase domain (P < 0.001), implying these tumors might select additional mutations to disrupt the regulation/function of the kinase domain.ConclusionsDifferent subtypes of compound EGFR mutations displayed distinct clinical features and genetic architectures, and rare mutation-dominant compound EGFR mutations were associated with enriched kinase domain-resided VUSs and poor clinical outcomes. Our findings help better understand the oncogenesis of compound EGFR mutations and forecast prognostic outcomes of personalized treatments.

First-line Afatinib in Patients With Non-small-cell Lung Cancer With Uncommon EGFR Mutations in South Korea

Non-small cell lung cancers (NSCLCs) harboring uncommon epidermal growth factor receptor (EGFR) mutations are heterogeneous and show variable prevalence and clinical responses to EGFR tyrosine kinase inhibitors. We investigated the characteristics of uncommon EGFR mutations and the clinical efficacy of afatinib in patients with NSCLC harboring uncommon EGFR mutations. In this multicenter, retrospective study, we analyzed patients with NSCLC with uncommon EGFR mutations in 16 South Korean institutes. Mutations were categorized according to their incidence: 1) major uncommon mutations (G719X and L861Q), 2) compound mutations, and 3) minor uncommon mutations (exon 20 insertion, S768I, and de novo T790M). Of 703 patients with EGFR-mutant NSCLC, 64 (9.1%) had uncommon EGFR mutations. Afatinib demonstrated activity against tumors harboring major uncommon mutations [median time of treatment (TOT): 20.3 months, 95% confidence interval (CI)=15.1-25.5; overall survival (OS): 30.6 months, 95% CI=26.3-34.8] and compound mutations (median TOT: 12.3 months, 95% CI=7.7-17.0; OS: 29.1 months, 95% CI=20.4-37.7) but not against tumors harboring minor uncommon mutations (median TOT: 3.8 months, 95% CI=1.7-6.0; OS: 8.5 months, 95% CI=5.2-11.7). The S768I mutation was present in 14 patients (1.99%). The median TOT and OS were not significantly different between S768I mutations and resistant exon 20 mutations. Afatinib is effective in patients with NSCLC harboring major uncommon and compound EGFR mutations.

Uncommon EGFR Compound Mutations in Non-Small Cell Lung Cancer (NSCLC): A Systematic Review of Available Evidence.

Compound epidermal growth factor receptor (EGFR) mutations represent a heterogeneous subgroup of non-small cell lung cancer (NSCLC) patients with uncommon EGFR mutations. We conducted a systematic review to investigate the available data on this patients’ subgroup. Overall, we found a high heterogeneity in the incidence of compound mutations (4–26% of total EGFR mutant cases), which is dependent on the different testing methods adopted and the specific mutations considered. In addition, the relative incidence of distinct compound subclasses identified is reported with extreme variability in different studies. Preclinical and clinical data, excluding de novo EGFR exon 20 p.T790M compound mutations, show good responses with EGFR tyrosine kinase inhibitors (TKIs) (combined common mutations: response rate (RR) ≥ 75% with either first- or second-generation TKIs; combined common plus uncommon: RR 40–80% and 100% with first-generation TKIs and afatinib, respectively; combined uncommon: RR 20–70%, ~80% and ~75% with first-generation TKIs, afatinib and osimertinib, respectively). Overall, data are consistent in supporting the use of EGFR TKIs in treating compound EGFR mutations, taking into account different sensitivity profile of accompanying EGFR mutations for selecting the most adequate EGFR TKI for individual patients.

Uncommon single and compound EGFR mutations: clinical outcomes of a heterogeneous subgroup of NSCLC

Molecular characterization of non-small-cell lung cancer (NSCLC) is essential to define the correct therapeutic algorithm in metastatic disease. Approximately 90% of epidermal growth factor receptor (EGFR) mutations are usually associated with sensitivity to EGFR tyrosine kinase inhibitors (TKIs). The remaining 10% defines a small, extremely heterogeneous subgroup of mutations, with a varied profile of sensitivity and response to target therapies.This retrospective observational study includes 47 patients affected by metastatic NSCLC harboring uncommon EGFR mutations (single or compound mutation). Patients were treated with EGFR-targeting TKIs or platinum-based chemotherapy as first-line treatment.Median OS resulted longer in the compound mutation group when compared to single rare mutations (33.6 vs 12 months; P = 0.473); a similar result was observed for PFS (16 vs 7.6 months; P = 0.281), although statistical significance was not reached. ORR, PFS and OS resulted similar for patients treated with first-line EGFR TKIs or chemotherapy. No difference in terms of PFS and OS was found according to the TKI administered.Compound mutations seem to be a good prognostic indicator for OS; they are also predictive of response to 1st and 2nd generation EGFR TKIs, as well as exon 19 insertions and mutations in codon 719 of exon 18. For mutations in exon 18 (not in codon 719) and exon 20 insertions, chemotherapy seems the most effective available option. The addition of immunotherapy to chemotherapy could change this approach in the next future.

Icotinib, an effective treatment option for patients with lung adenocarcinoma harboring compound EGFR L858R and A871G mutation.

Compound epidermal growth factor receptor (EGFR) mutations are defined as double or multiple independent mutations of the EGFR tyrosine kinase domain (TKD), in which an EGFR-tyrosine kinase inhibitor (TKI)-sensitizing mutation is identified together with a mutation of unclarified clinical significance. Lung adenocarcinoma with compound EGFR mutation shows poor clinical response to EGFR-TKIs. Kobayashi et al. reported a non-small-cell lung cancer (NSCLC) patient whose tumor had EGFR exon21 L858R/A871G mutation presented rapid disease progression to erlotinib. However, in this case, we present an EGFR exon21 L858R/A871G mutation patient exerted significant benefit to icotinib, another first-generation EGFR-TKI, indicating that different EGFR-TKIs have diversiform sensitive sites and therapeutic effects, consistent mutation sites might achieve heterogeneous benefits from different EGFR-TKIs. Our case report provides promising EGFR-TKI for clinical treatment with EGFR exon21 L858R/A871G mutation in NSCLC. More dedicated efforts are needed to clarify their biologic effects on disease course and drug responsiveness.

Clinical Impact of Rare and Compound Mutations of Epidermal Growth Factor Receptor in Patients With Non–Small-Cell Lung Cancer

BackgroundStandard therapy of advanced non–small-cell lung cancer harboring an activating mutation in the epidermal growth factor receptor (EGFR) gene is treatment with tyrosine kinase inhibitors (TKI). However, for rare and compound mutations of the EGFR gene, the clinical evidence of TKI therapy is still unclear. Patients and MethodsA total of 2906 lung cancer samples were analyzed for EGFR mutations during routine analysis between 2010 and 2017. The samples have been investigated by Sanger sequencing and since 2014 by next-generation sequencing. ResultsWe detected EGFR mutations in 408 specimens (14%). Among these, we found 41 samples with rare and 22 with compound mutations. In these 63 samples, 56 different rare EGFR mutations occurred. Information about the clinical outcome was available for 37. Among those with rare mutations, only one patient harboring the mutation p.G874D had disease that responded to first-generation TKI therapy. In contrast, the disease of all patients with compound mutations responded to first- or second-generation TKI therapy. Furthermore, we collected data on clinical relevance regarding TKI therapy from different databases and from an additional literature search, and only found data for 36 of the 56 detected rare mutations. ConclusionInformation about the clinical outcome of patients with rare and compound EGFR mutations remains limited. At present, second- and third-generation TKIs are available, which may represent new treatment strategies for these patients. Therefore, it is becoming increasingly important to maintain databases concerning rare EGFR mutations.

First-generation EGFR tyrosine kinase inhibitor therapy in 106 patients with compound EGFR-mutated lung cancer: a single institution\u2019s clinical practice experience

BackgroundThe antitumour efficacy of tyrosine kinase inhibitors (TKIs) in lung cancer patients with compound epidermal growth factor receptor (EGFR) mutations has not been resolved. Our study summarizes a single institutional experience of first-generation TKI therapy for lung cancers with compound EGFR mutations.MethodsA total of 106 consecutive patients with tumours bearing compound EGFR mutations were identified between January 2012 and May 2016; all patients received first-generation TKI therapy. Deletions in exon 19 and the L858R point mutation in exon 21 were considered common mutations; T790M was considered separately because of its association with TKIs resistances. Any other mutation was defined as a rare mutation. Patients were divided as follows: double common mutations (group A); common plus T790M mutations (group B); common plus rare mutations (group C); double rare mutations (group D); and rare plus T790M mutations (group E). A separate group of 115 consecutive patients with a single common mutation was created for comparative analysis (group F).ResultsThe frequency of patients with compound EGFR was 2.9% (114/3925) and their response rate to first-generation TKIs was 50.9%, which was not significantly different from group F (67.0%, P = 0.088). The progression-free survival (PFS) of the 106 patients receiving TKI therapy was worse than that of group F (median, 9.1 vs. 13.0 months, respectively; P < 0.001). The PFS of the compound mutation group was shorter than that of the single common mutation group (median, 10.1 months in group A, P = 0.240; 9.1 months in group B, P < 0.001; 9.6 months in group C, P = 0.010; 6.5 months in group D, P = 0.048; 5.4 months in group E, P = 0.017). Patients with a co-occurring mutation in exon 20 (excluding T790M) exhibited significantly worse PFS than the patients with other compound mutations or with a single common mutation (median, 6.5 vs. 9.1 vs. 13.0 months, respectively, P = 0.002).ConclusionsThere was significant heterogeneity among the compound EGFR mutations and their response to first-generation TKIs. Individualized treatment in clinical practice should be considered for each case.

Influence of Different Therapies on EGFR Mutants by Circulating Cell-free DNA of Lung Adenocarcinoma and Prognosis

背景与目的表皮生长因子受体（epidermal growth factor receptor, EGFR）基因突变与肺腺癌患者TKI靶向治疗疗效和预后密切相关，常规组织分析其突变状态有诸多局限。本研究旨在探讨非小细胞肺癌（non-small cell lung cancer, NSCLC）患者血液循环游离DNA（cell-free DNA, cfDNA）检测EGFR基因突变在治疗前、传统化疗以及靶向治疗后的表达差异。分析血液cfDNA是否能准确检测EGFR基因突变并监测耐药基因T790M的变化，以及TKI在靶向治疗患者中的预后价值。方法应用ARMS（amplification refractory mutation system）法检测107例（50例治疗前、29例传统化疗和28例靶向治疗）肺癌患者配对血液和肿瘤组织样本的EGFR基因突变并比较其表达差异；计算检测的一致性、敏感性和特异性；分析血检对靶向治疗患者的预后价值。结果血浆cfDNA检测EGFR总突变率在107例肺癌患者中为56%（60例），而配对肿瘤组织样本检出率为77.6%（83例）。一一配对比较发现两者总体一致率为68.2%。血检的敏感性是72.3%，特异性为100%。依据治疗状态分组后发现治疗前组患者血液和肿瘤组织样本的检测一致率最高（74%, 37/50），而靶向组一致率最低（57.1%, 16/28），提示靶向治疗改变血浆cfDNA中EGFR基因状态。具体分析靶向组不一致病例发现50%新检出含T790M的双突变，提示靶向治疗后耐药基因出现。生存分析证实血检含T790M双突变组的无进展生存期（progression-free survival, PFS）和总生存期（overall survival, OS）均显著低于无T790M突变组。结论应用ARMS法检测血液循环游离DNA（circulating cell-free DNA, cfDNA）的EGFR基因突变是一种特异性高、敏感性好的检测方法。适用于治疗前晚期肺癌患者的EGFR基因突变状态检测。同时，适用于靶向治疗后监测T790M耐药突变状态及预测患者预后。

High proportion of rare and compound epidermal growth factor receptor mutations in an Australian population of non-squamous non-small-cell lung cancer.

Epidermal growth factor receptor (EGFR) mutation positivity in primary non-small-cell lung cancer (NSCLC) may confer increased sensitivity to EGFR tyrosine kinase inhibitor (TKI) therapy with improved progression-free survival over EGFR wild-type tumours. Some mutation subtypes may not confer such TKI sensitivity. The incidence of rare and compound subtypes in the Australian lung cancer population is not fully defined. The aim of the study was to audit the incidence of EGFR mutation in serial cases of primary non-squamous NSCLC presenting to two multidisciplinary team meetings in metropolitan Sydney for incidence, type of mutation and phenotypic association with mutation positivity. Serially presenting cases of primary non-squamous NSCLC were tested for EGFR mutation. The cases presented to either of two multidisciplinary team meetings in metropolitan Sydney and were referred for EGFR mutation testing on the basis of non-squamous NSCLC histopathology. Samples from the two sites were analysed for EGFR mutation at one of three different laboratories, each using a slightly different assay. Data on phenotypic characteristics, smoking history and clinicopathological features of the tumour were collected. There is a relatively high incidence of EGFR mutation in non-squamous NSCLC in a series of patients drawn from two metropolitan multidisciplinary team meetings in Sydney at a rate of 23.8%. A high proportion of rare and compound EGFR mutations were identified (6/32 mutation positive cases, 18.8%). The incidence of EGFR mutation may be higher in Australian populations than in other populations of predominantly European origin. Rare and compound EGFR mutations may occur and may have implications for treatment that differ from classically activating mutations.

Compound EGFR Mutations and Response to EGFR Tyrosine Kinase Inhibitors

Non-small-cell lung cancers (NSCLCs) containing EGFR mutations are exquisitely sensitive to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). This is the case of the most common EGFR mutations affecting exon 18 (G719X), 19 (inframe deletions), and 21 (L858R and L861Q). However, the frequency of compound (i.e., double or complex) EGFR mutations-where an EGFR TKI sensitizing or other mutation is identified together with a mutation of unknown clinical significance-and their pattern of response/resistance to EGFR TKIs are less well described. We analyzed the EGFR mutation pattern of 79 cases of NSCLC harboring EGFR mutations and compiled the genotype-response data for patients with NSCLCs with compound EGFR mutations treated with EGFR TKIs. Of the 79 EGFR-mutated tumors identified, 11 (14%) had compound mutations. Most involved the EGFR TKI-sensitizing G719X (n = 3, plus S768I or E709A), L858R (n = 4, plus L747V, R776H, T790M, or A871G), L861Q (n = 1, plus E709V), and delL747_T751 (n = 1, plus R776H). Eight patients received an EGFR TKI: three cases with G719X plus another mutation had partial responses (PRs) to erlotinib; of three cases with L858R plus another mutation, two displayed PRs and one (with EGFR-L858R+A871G) progressive disease (PD) to erlotinib; one NSCLC with EGFR-L861Q+E709A and one with delL747_T751+R776S had PRs to EGFR TKIs. Compound EGFR mutations comprised 14% of all mutations identified during routine sequencing of exons 18-21 of EGFR in our cohort. Most patients with an EGFR TKI-sensitizing mutation (G719X, exon 19 deletion, L858R, and L861Q) in addition to an atypical mutation responded to EGFR TKIs. Reporting of the genotype-response pattern of NSCLCs with EGFR compound and other rare mutations, and the addition of this information to searchable databases, will be helpful to select the appropriate therapy for EGFR-mutated NSCLC.

Abstract 1973: Targeting activated alleles of EGFR derived from glioma and lung cancer: Correlating kinase active-site occupancy with efficacy

Abstract Introduction: The Epidermal Growth Factor Receptor (EGFR) features prominently in malignant glioma (MG), yet attempts to exploit this target in patients with MG have been somewhat disappointing. Unlike the highly sensitizing kinase site alleles of EGFR derived from patients with non-small cell lung cancer (NSCLCA), mutationally activated alleles of EGFR derived from patients with MG respond poorly to the currently available reversible clinical EGFR inhibitors. We hypothesize that the anti-tumor effects of EGFR inhibitors in MG-associated alleles of EGFR require more efficient blockade to achieve anti-tumor responses, in comparison with NSCLCA-associated alleles of EGFR, and that thisincreased efficiency can be achieved using irreversible inhibitors. Methods: We generated glioma and fibroblast cell lines that expressed wild-type or tumor-associated alleles of EGFR derived either from MG (EGFRvIII) or NSCLCA (L858R or del 747-753). Using an EGFR affinity probe (an irreversible EGFR inhibitor tethered to a flourophore), we quantified occupancy of the kinase active site in response to erotinib, a clinical reversible inhibitor of EGFR, correlating occupancy with proliferation and apoptosis. Next, we repeated these measurements using the tool compound and irreversible EGFR inhibitor PD-168394. Results: Using the affinity probe in pulse-chase experiments, we quantified active site occupancy of EGFR int response to increasing doses of inhibitors. In cells expressing MG-derived alleles, irreversible EGFR inhibitors were significantly more potent than reversible agents in abrogating signaling downstream of EGFR and in decreasing viability. Using the affinity probe, we found that irreversible inhibitors showed nearly complete occupancy of the active site, whereas treatment with reversible EGFR inhibitors resulted in only partial occupancy. Cells containing NSCLCA-derived EGFR alleles showed similar signaling and growth responses to both reversible and EGFR inhibitors, despite a large difference in EGFR kinase site occupancy with the two types of inhibitors. Flow cytometry studies correlating kinase site occupancy with downstream signaling in individual cells will also be presented. Conclusions: Activated alleles of EGFR derived from MG require significantly higher levels of kinase site blockade to achieve an anti-proliferative threshold, as compared with activated alleles derived from NSCLCA. This higher degree of kinase site blockade can be achieved using irreversible inhibitors of EGFR. These studies support the initiation of clinical trials using irreversible inhibitors of EGFR in MG. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1973.