Targeting the EGFR pathway: An alternative strategy for the treatment of tuberous sclerosis complex?

INTRODUCTION: Tuberous sclerosis complex (TSC) is caused by variants in TSC1/TSC2, leading to constitutive activation of the mammalian target of rapamycin (mTOR) complex 1. Therapy with everolimus has been approved for TSC, but variations in success are frequent. Recently, caudal late interneuron progenitor (CLIP) cells were identified as a common origin of the TSC brain pathologies such as subependymal giant cell astrocytomas (SEGA) and cortical tubers (CT). Further, targeting the epidermal growth factor receptor (EGFR) with afatinib, which is expressed in CLIP cells, reduces cell growth in cerebral TSC organoids. However, investigation of clinical patient-derived data is lacking. AIMS: Observation of EGFR expression in SEGA, CT and focal cortical dysplasia (FCD) 2B human brain specimen and investigation of whether its inhibition could be a potential therapeutic intervention for these patients. METHODS: Brain specimens of 23 SEGAs, 6 CTs, 20 FCD2Bs and 17 controls were analysed via immunohistochemistry to characterise EGFR expression, cell proliferation (via Mib1) and mTOR signalling. In a cell-based assay using primary patient-derived cells (CT n = 1, FCD2B n = 1 and SEGA n = 4), the effects of afatinib and everolimus on cell proliferation and cell viability were observed. RESULTS: EGFR overexpression was observed in histological sections of SEGA, CT and FCD2B patients. Both everolimus and afatinib decreased the proliferation and viability in primary SEGA, tuber and FCD2B cells. CONCLUSION: Our study demonstrates that EGFR suppression might be an effective alternative treatment option for SEGAs and tubers, as well as other mTOR-associated malformations of cortical development, including FCD2B.

Synthetic Routes and Clinical Application of Representative Small-Molecule EGFR Inhibitors for Cancer Therapy.

The epidermal growth factor receptor (EGFR) plays a pivotal role in cancer therapeutics, with small-molecule EGFR inhibitors emerging as significant agents in combating this disease. This review explores the synthesis and clinical utilization of EGFR inhibitors, starting with the indispensable role of EGFR in oncogenesis and emphasizing the intricate molecular aspects of the EGFR-signaling pathway. It subsequently provides information on the structural characteristics of representative small-molecule EGFR inhibitors in the clinic. The synthetic methods and associated challenges pertaining to these compounds are thoroughly examined, along with innovative strategies to overcome these obstacles. Furthermore, the review discusses the clinical applications of FDA-approved EGFR inhibitors such as erlotinib, gefitinib, afatinib, and osimertinib across various cancer types and their corresponding clinical outcomes. Additionally, it addresses the emergence of resistance mechanisms and potential counterstrategies. Taken together, this review aims to provide valuable insights for researchers, clinicians, and pharmaceutical scientists interested in comprehending the current landscape of small-molecule EGFR inhibitors.

Single cell lineage tracing reveals clonal dynamics of anti-EGFR therapy resistance in triple negative breast cancer.

BACKGROUND: Most primary Triple Negative Breast Cancers (TNBCs) show amplification of the Epidermal Growth Factor Receptor (EGFR) gene, leading to increased protein expression. However, unlike other EGFR-driven cancers, targeting this receptor in TNBC yields inconsistent therapeutic responses. METHODS: To elucidate the underlying mechanisms of this variability, we employ cellular barcoding and single-cell transcriptomics to reconstruct the subclonal dynamics of EGFR-amplified TNBC cells in response to afatinib, a tyrosine kinase inhibitor (TKI) that irreversibly inhibits EGFR. RESULTS: Integrated lineage tracing analysis revealed a rare pre-existing subpopulation of cells with distinct biological signature, including elevated expression levels of Insulin-Like Growth Factor Binding Protein 2 (IGFBP2). We show that IGFBP2 overexpression is sufficient to render TNBC cells tolerant to afatinib treatment by activating the compensatory insulin-like growth factor I receptor (IGF1-R) signalling pathway. Finally, based on reconstructed mechanisms of resistance, we employ deep learning techniques to predict the afatinib sensitivity of TNBC cells. CONCLUSIONS: Our strategy proved effective in reconstructing the complex signalling network driving EGFR-targeted therapy resistance, offering new insights for the development of individualized treatment strategies in TNBC.

Integrated mutational landscape analysis of poorly differentiated high-grade neuroendocrine carcinoma of the uterine cervix.

High-grade neuroendocrine cervical cancers (NETc) are exceedingly rare, highly aggressive tumors. We analyzed 64 NETc tumor samples by whole-exome sequencing (WES). Human papillomavirus DNA was detected in 65.6% (42/64) of the tumors. Recurrent mutations were identified in PIK3CA, KMT2D/MLL2, K-RAS, ARID1A, NOTCH2, and RPL10. The top mutated genes included RB1, ARID1A, PTEN, KMT2D/MLL2, and WDFY3, a gene not yet implicated in NETc. Somatic CNV analysis identified two copy number gains (3q27.1 and 19q13.12) and five copy number losses (1p36.21/5q31.3/6p22.2/9q21.11/11p15.5). Also, gene fusions affecting the ACLY-CRHR1 and PVT1-MYC genes were identified in one of the eight samples subjected to RNA sequencing. To resolve evolutionary history, multiregion WES in NETc admixed with adenocarcinoma cells was performed (i.e., mixed-NETc). Phylogenetic analysis of mixed-NETc demonstrated that adenocarcinoma and neuroendocrine elements derive from a common precursor with mutations typical of adenocarcinomas. Over one-third (22/64) of NETc demonstrated a mutator phenotype of C > T at CpG consistent with deficiencies in MBD4, a member of the base excision repair (BER) pathway. Mutations in the PI3K/AMPK pathways were identified in 49/64 samples. We used two patient-derived-xenografts (PDX) (i.e., NET19 and NET21) to evaluate the activity of pan-HER (afatinib), PIK3CA (copanlisib), and ATR (elimusertib) inhibitors, alone and in combination. PDXs harboring alterations in the ERBB2/PI3K/AKT/mTOR/ATR pathway were sensitive to afatinib, copanlisib, and elimusertib (P < 0.001 vs. controls). However, combinations of copanlisib/afatinib and copanlisib/elimusertib were significantly more effective in controlling NETc tumor growth. These findings define the genetic landscape of NETc and suggest that a large subset of these highly lethal malignancies might benefit from existing targeted therapies.

From osimertinib to preemptive combinations.

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

Development of a Small Molecule Downmodulator for the Transcription Factor Brachyury.

Brachyury is an oncogenic transcription factor whose overexpression drives chordoma growth. The downmodulation of brachyury in chordoma cells has demonstrated therapeutic potential, however, as a transcription factor it is classically deemed "undruggable". Given that direct pharmacological intervention against brachyury has proven difficult, attempts at intervention have instead targeted upstream kinases. Recently, afatinib, an FDA-approved kinase inhibitor, has been shown to modulate brachyury levels in multiple chordoma cell lines. Herein, we use afatinib as a lead to undertake a structure-based drug design approach, aided by mass-spectrometry and X-ray crystallography, to develop DHC-156, a small molecule that more selectively binds brachyury and downmodulates it as potently as afatinib. We eliminated kinase-inhibition from this novel scaffold while demonstrating that DHC-156 induces the post-translational downmodulation of brachyury that results in an irreversible impairment of chordoma tumor cell growth. In doing so, we demonstrate the feasibility of direct brachyury modulation, which may further be developed into more potent tool compounds and therapies.

A real-world cohort study of first-line afatinib in patients with EGFR-mutant advanced non-small cell lung cancer in Vietnam.

BACKGROUND: This study aimed to evaluate the efficacy and side effects of first-line afatinib treatment in a real-world setting in Vietnam. METHODS: This retrospective study was conducted across nine hospitals in Vietnam. Advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients who received afatinib as first-line therapy between April 2018 and June 2022 were included, and patient medical records were reviewed. Key outcomes were overall response rate (ORR), time-to-treatment failure (TTF), and tolerability. RESULTS: A total of 343 patients on first-line afatinib were eligible for the study. EGFR exon 19 deletion (Del19) alone was detected in 46.9% of patients, L858R mutation alone in 26.3%, and other uncommon EGFR mutations, including compound mutations, in 26.8%. Patients with brain metastases at baseline were 25.4%. Patients who received 40 mg, 30 mg, and 20 mg as starting doses of afatinib were 58.6%, 39.9%, and 1.5%, respectively. The ORR was 78.1% in the overall population, 82.6% in the Del19 mutation subgroup, 73.3% in the L858R mutation subgroup, and 75.0% in the uncommon mutation subgroup (p > 0.05). The univariate and multivariate analyses indicate that the ORR increased when the starting dose was 40 mg compared to starting doses below 40 mg (83.9% vs. 74.3%, p = 0.034). The median TTF (mTTF) was 16.7 months (CI 95%: 14.8-18.5) in all patients, with a median follow-up time of 26.2 months. The mTTF was longer in patients in the common EGFR mutation subgroup (Del19/L858R) than in those in the uncommon mutation subgroup (17.5 vs. 13.8 months, p = 0.045) and in those without versus with brain metastases at baseline (17.5 vs. 15.1 months, p = 0.049). There were no significant differences in the mTTF between subgroups based on the starting dose of 40 mg and < 40 mg (16.7 vs. 16.9 months, p > 0.05). The most common treatment-related adverse events (any grade/grade ≥ 3) were diarrhea (55.4%/3.5%), rash (51.9%/3.2%), paronychia (35.3%/5.0%), and stomatitis (22.2%/1.2%). CONCLUSIONS: Afatinib demonstrated clinical effectiveness and good tolerability in Vietnamese EGFR-mutant NSCLC patients. In our real-world setting, administering a starting dose below 40 mg might result in a reduction in ORR; however, it might not have a significant impact on TTF.

Mechanism of action of adapalene for treating EGFR-TKI-induced skin disorder.

BACKGROUND: Skin disorders are the most common side effect associated with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. It is important to manage skin lesions. Adapalene has been used to treat skin lesions caused by EGFR-TKIs in some cases. The aim of this study was to investigate the functional mechanism of adapalene in erlotinib-induced skin disorder. METHODS: To analyze the effect of adapalene on skin rash, afatinib and adapalene were administered to mice. The relationship between the concentration of adapalene and skin disorders was also examined by analyzing AQP3 expression. A skin lesion model was experimentally established in human skin keratinocytes (HaCaT) by using erlotinib with TNF-α and IL-1ß. We used qRT-PCR to analyze chemokine-induced inflammation and western blotting to analyze the effects of adapalene on the NF-κB signaling pathway. Antimicrobial peptides and adhesion factors were also examined using qRT-PCR. RESULTS: Mice administered 0.01% adapalene had less skin inflammation than mice treated with afatinib alone. The expression level of AQP3 decreased in an adapalene concentration-dependent manner. The mRNA levels of proinflammatory cytokines such as CCL2 and CCL27 in HaCaT cells were significantly reduced by adapalene. The expression of an antimicrobial peptide, hBD3, was upregulated after adapalene treatment. Adhesion factors, such as E-cadherin, were significantly downregulated by EGFR-TKI and significantly upregulated by adapalene treatment. Western blot analysis suggested that erlotinib-induced phosphorylation of p65 was decreased by adapalene. CONCLUSION: We suggest that adapalene may be a possible treatment option for skin disorders induced by EGFR-TKIs.

Thromboembolic Events Associated with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors: A Pharmacovigilance Analysis of the US FDA Adverse Event Reporting System (FAERS) Database.

BACKGROUND AND OBJECTIVES: Although thromboembolic events (TEEs) have been reported with the use of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), their association remains largely unknown. In this study, we aimed to provide a comprehensive review of TEEs associated with EGFR-TKIs. METHODS: We collected EGFR-TKIs (gefitinib, erlotinib, afatinib, and osimertinib) adverse reaction reports from 2015 Q1 to 2023 Q1 from the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. Disproportionality analysis was conducted to identify thromboembolic adverse events associated with EGFR-TKIs by comparing them with the overall FAERS database according to the reporting odds ratio (ROR). Associated factors were explored using univariate logistic regression. RESULTS: We identified 1068 reports of TEEs associated with EGFR-TKIs (1.24% accounts for all TEEs). Affected patients were females (49.72%) and those older than 65 years (41.20%). The reported TEE case fatality was 30.24%. The median time to onset (TTO) of all cases was 39 days [interquartile range (IQR) 11-161], and the median TTO of fatalities [31 days (IQR 10-116)] was significantly shorter than that of non-fatal cases [46 days (IQR 12-186)]. CONCLUSION: This study yielded three key findings. Firstly, EGFR-TKIs seem to exhibit prothrombotic effects, elevating the risk of TEEs. Secondly, the clinical outcomes of TEEs associated with EGFR-TKIs were poor. Thirdly, most TEEs occurred within the initial 3 months, and fatal cases occurred earlier than non-fatal cases.

Afatinib treatment of severe respiratory failure due to malignant lymphangitis in a dialysis patient with squamous cell carcinoma of the lung.

Patients on dialysis have limited treatment options for advanced lung cancer because some chemotherapeutic agents are unavailable due to renal dysfunction. A man in his 70s on peritoneal dialysis presented with persistent fever refractory to antibiotics for 2 weeks. Subsequent whole-body CT showed a 5 cm diameter mass in the right lower lobe of the lung with right-sided pleural effusion and osteolytic metastasis of the right iliac bone. The patient was diagnosed with squamous cell carcinoma (cT3N2M1b, stage IVB) harbouring the p.Gly719Ala point mutation on exon 18 of the epidermal growth factor receptor. The patient developed severe respiratory failure due to malignant lymphangitis after a bronchoscopy. He received 30 mg/day of afatinib, resulting in tumour shrinkage and recovery from respiratory failure. We advocate for aggressive screening of driver oncogenes in patients with lung cancer on dialysis, including those with squamous cell lung cancer.

The difference between dacomitinib and afatinib in effectiveness and safety in first-line treatment of patients with advanced EGFR-mutant non-small cell lung cancer: a real-world observational study.

OBJECTIVES: The irreversible epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) afatinib and dacomitinib are approved for first-line treatment of EGFR mutation-positive non-small cell lung cancer (NSCLC). We aimed to compare the efficacy and safety of afatinib and dacomitinib in this setting. MATERIALS AND METHODS: Between September 2020 and March 2023, we retrospectively recruited patients diagnosed with advanced-stage EGFR-mutant NSCLC who were treated with first-line irreversible EGFR-TKIs. The enrolled patients were assigned to two groups based on whether they received afatinib or dacomitinib. RESULTS: A total of 101 patients were enrolled in the study (70 to afatinib and 31 to dacomitinib). The partial response rates (PR) for first-line treatment with afatinib and dacomitinib were 85.7 and 80.6% (p = 0.522). The median progression-free survival (PFS) (18.9 vs. 16.3 months, p = 0.975) and time to treatment failure (TTF) (22.7 vs. 15.9 months, p = 0.324) in patients with afatinib and dacomitinib treatment were similar. There was no significant difference observed in the median PFS (16.1 vs. 18.9 months, p = 0.361) and TTF (32.5 vs. 19.6 months, p = 0.182) between patients receiving the standard dose and those receiving the reduced dose. In terms of side effects, the incidence of diarrhea was higher in the afatinib group (75.8% vs. 35.5%, p < 0.001), while the incidence of paronychia was higher in the dacomitinib group (58.1% vs. 31.4%, p = 0.004). The PFS (17.6 vs. 24.9 months, p = 0.663) and TTF (21.3 vs. 25.1 months, p = 0.152) were similar between patients younger than 75 years and those older than 75 years. CONCLUSION: This study showed that afatinib and dacomitinib had similar effectiveness and safety profiles. However, they have slightly different side effects. Afatinib and dacomitinib can be safely administered to patients across different age groups with appropriate dose reductions.

Gemcitabine and nab-paclitaxel combined with afatinib in metastatic pancreatic cancer - Results of a phase 1b clinical trial.

PURPOSE: The combination of gemcitabine/nab-paclitaxel is an established standard treatment in the first-line treatment of metastatic ductal adenocarcinoma of the pancreas (mPDAC). Afatinib, an oral second-generation pan ErbB family tyrosine kinase inhibitor, has shown promising pre-clinical signs in the treatment of pancreatic cancer. The aim of this phase 1b trial was to determine the maximum tolerated dose (MTD) of afatinib in combination with gemcitabine/nab-paclitaxel in patients with mPDAC. METHODS: Treatment naïve patients (≥18 years) with histologically proven mPDAC and good performance status (ECOG 0/1) were enrolled to receive gemcitabine/nab-paclitaxel in combination with afatinib. Treatment was continued until disease progression, or unacceptable toxicity. The primary endpoint MTD was determined using a 3 + 3 design. Treatment started at dose level 0 with intravenous gemcitabine/nab-paclitaxel 1000 mg/m2 / 125 mg/m2 (day 1, 8, 15 of a 28-day cycle) + oral afatinib 30 mg daily. At dose level + 1 afatinib was increased to 40 mg. Secondary endpoints included safety parameters and exploratory endpoints evaluated treatment efficacy. RESULTS: Twelve patients were included in this trial, and 11 patients were treated and analysed in the safety and full analysis set (FAS). At dose level 0 the first three patients did not experience a dose-limiting toxicity (DLT). At dose leve (DL) + 1 two patients experienced a DLT. Accordingly, enrolment continued at DL 0 with three more patients, of which one experienced DLT (skin rash ≥ CTCAE grade 3). Seven patients (63.6%) experienced at least one treatment-emergent serious adverse event (TESAE), with four patients (36.4%) experiencing TESAEs grade 3-5 related to the study medication. In the FAS, the objective response rate (ORR) was 36.4%, median progression-free survival (PFS) was 3.5 months and median overall survival in nine evaluable patients was 7.5 months. CONCLUSIONS: In this phase 1b clinical trial, the MTD of gemcitabine/nab-paclitaxel (1000 mg/m2 / 125 mg/m2) and afatinib (30 mg) was established. In a cohort of 11 patients, the combination showed an acceptable safety profile.

Real-world outcomes associated with afatinib use in patients with solid tumors harboring NRG1 gene fusions.

OBJECTIVES: Neuregulin-1 (NRG1) fusions may drive oncogenesis via constitutive activation of ErbB signaling. Hence, NRG1 fusion-driven tumors may be susceptible to ErbB-targeted therapy. Afatinib (irreversible pan-ErbB inhibitor) has demonstrated activity in individual patients with NRG1 fusion-positive solid tumors. This study collected real-world data on demographics, clinical characteristics, and clinical outcomes in this patient population. MATERIALS AND METHODS: In this retrospective, multicenter, non-comparative cohort study, physicians in the US-based Cardinal Health Oncology Provider Extended Network collected data from medical records of patients with NRG1 fusion-positive solid tumors who received afatinib (afatinib cohort) or other systemic therapies (non-afatinib cohort) in any therapy line. Objectives included demographics, clinical characteristics, and outcomes (overall response rate [ORR], progression-free survival [PFS], and overall survival [OS]). RESULTS: Patients (N = 110) with a variety of solid tumor types were included; 72 received afatinib, 38 other therapies. In the afatinib cohort, 70.8 % of patients received afatinib as second-line treatment and Eastern Cooperative Oncology Group performance status (ECOG PS) was 2-4 in 69.4 % at baseline. In the non-afatinib cohort, 94.7 % of patients received systemic therapy as first-line treatment and ECOG PS was 2-4 in 31.6 % at baseline. In the afatinib cohort, ORR was 37.5 % overall (43.8 % when received as first-line therapy); median PFS and OS were 5.5 and 7.2 months, respectively. In the non-afatinib cohort, ORR was 76.3 %; median PFS and OS were 12.9 and 22.6 months, respectively. CONCLUSION: This study provides real-world data on the characteristics of patients with NRG1 fusion-positive solid tumors treated with afatinib or other therapies; durable responses were observed in both groups. However, there were imbalances between the cohorts, and the study was not designed to compare outcomes. Further prospective/retrospective trials are required.

Epidermal Growth Factor Receptor Inhibitors for Lung Cancer and the Risk of Keratitis.

Importance: Epidermal growth factor receptor inhibitors (EGFRis) have been reported to be associated with cutaneous and ocular side effects; however, there is limited evidence of an association between EGFRi treatment and keratitis. Objective: To determine the association between EGFRi treatment and agents and the risk of new-onset keratitis among patients with lung cancer. Design, Setting, and Participants: This US population-based cohort study examined TriNetX data of patients with lung cancer treated with or without EGFRis between May 1, 2003, and October 30, 2023. Exposures: Treatment with EGFRis, including the first-generation agents gefitinib and erlotinib, the second-generation agent afatinib, and the third-generation agent osimertinib. Main Outcomes and Measures: The risk of new-onset keratitis among patients with lung cancer receiving EGFRi treatment was determined using logistic and Cox proportional hazards regression. Results: Among 1 388 108 patients with lung cancer, 22 225 received EGFRis (mean [SD] age, 69.7 [10.6] years; 62.8% females and 37.2% males). Patients treated with EGFRis had a higher risk of keratitis than nonexposed patients (hazard ratio [HR], 1.520; 95% CI, 1.339-1.725). Subtypes of EGFRi-associated keratitis included keratoconjunctivitis (HR, 1.367; 95% CI, 1.158-1.615), superficial keratitis (HR, 1.635; 95% CI, 1.306-2.047), and corneal ulcer (HR, 2.132; 95% CI, 1.515-3.002). Patients taking afatinib had a higher risk of keratitis (HR, 2.229; 95% CI, 1.480-3.356). Conclusions and Relevance: These findings suggest that patients with lung cancer treated with EGFRis may have an increased risk of new-onset keratitis, especially with the second-generation EGFRi afatinib, supporting the need for prompt diagnosis and management of EGFRi-associated ocular issues to prevent serious complications or treatment disruptions.

Differential efficacy of tyrosine kinase inhibitors according to the types of EGFR mutations and agents in non-small cell lung cancer: a real-world study.

BACKGROUND: Both first and second-generation EGFR-TKIs are recommended in advanced NSCLC with common EGFR mutations. However, there are few data on the difference in efficacy of EGFR-TKIs based on the type of EGFR mutation and agents. METHODS: This retrospective real-world study evaluated the outcomes and clinicopathologic characteristics, including the type of EGFR mutations, of 237 advanced NSCLC patients treated with first- or second-generation (afatinib) EGFR-TKIs as first-line therapy. RESULTS: The median progression-free survival (PFS) and overall survival (OS) of all patients were 11 months (M) and 25M, respectively. In the univariate analysis, patients with exon 19 deletion (del) (n=130) had significantly longer median OS compared to those with other mutations (L858R: 84, others: 23) (30 vs. 22 M, p=0.047), without a difference in PFS (p=0.138). Patients treated with afatinib (n=60) showed significantly longer median OS compared to those treated with first-generation TKIs (gefitinib: 159, erlotinib: 18) (30 vs. 23 M, p=0.037), without a difference in PFS (p=0.179). In patients with exon 19 del, there was no significant difference in median PFS (p=0.868) or OS (p=0.361) between patients treated with afatinib and those treated with first-generation TKIs, while significantly better PFS (p=0.042) and trend in OS (p=0.069) were observed in patients receiving afatinib in other mutations. Exon 19 del was independently associated with favorable OS (p=0.028), while age >70 years (p=0.017), ECOG performance status ≥2 (p=0.001), primary metastatic disease (p=0.007), and synchronous brain metastasis (p=0.026) were independent prognostic factors of poor OS. CONCLUSIONS: The EGFR exon 19 del was associated with favorable OS in advanced NSCLC patients receiving first-line EGFR-TKIs. Moreover, in patients with exon 19 del, first-generation TKIs seem to be a reasonable treatment option if osimertinib is unavailable.

Regulation of Chloride Channels by Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor-Induced α-Defensin 5.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are used to treat non-small cell lung cancer with EGFR mutations. However, first-generation erlotinib and second-generation afatinib often cause diarrhea, which may develop because of the association between EGFR-TKIs and the chloride channel or abnormalities in the intestinal microbiota due to disruption of the intestinal immune system. As reports on the effects of EGFR-TKIs on intestinal immunity are lacking, we aimed to determine whether the intestinal immune system is involved in the molecular effects of EGFR-TKIs on chloride channels using Caco-2 cells. Initially, we evaluated the association of chloride channels with α-defensin 5 (DEFA5), a marker of intestinal immunity. Erlotinib and afatinib significantly increased the extracellularly secreted DEFA5 level and autophagy-related 16-like 1 and X-box binding protein 1 transcript levels, indicative of enhanced granule exocytosis. Conversely, intracellular DEFA5 and Toll-like receptor 4 protein expression and tumor necrosis factor-α transcript levels decreased significantly, suggesting that Toll-like receptor 4 suppression repressed DEFA5 production. Furthermore, among the chloride channels, DEFA5 was found to significantly increase the transcript levels of cystic fibrosis transmembrane conductance regulators. These results indicate that DEFA5 plays a significant role in the mechanism of chloride channel-mediated diarrhea induced by EGFR-TKIs. Therefore, we successfully elucidated the potential host action of DEFA5 in cancer therapy for the first time.

Covalent inhibition of epidermal growth factor receptor using a long-lived iridium(III)-afatinib probe.

The overexpression and overactivation of epidermal growth factor receptor (EGFR) are frequently observed in human cancers, including squamous cell carcinoma and adenocarcinoma. In this study, a covalent EGFR probe was developed by conjugating afatinib to an iridium(III) scaffold. Complex 1 showed enhanced luminescence in living epidermoid squamous carcinoma A431 cells compared to other cell lines, via engaging EGFR as confirmed via CETSA and knockdown experiments. Moreover, complex 1 inhibited downstream targets of EGFR in cellulo with repression persisting after removal of the complex, indicating an irreversible mode of inhibition. Finally, complex 1 showed potent antiproliferative activity against A431 cells with comparable potency to afatinib alone. To our knowledge, complex 1 is the first EGFR covalent inhibitor based on an iridium scaffold reported in the literature, with the potential to be further explored as a theranostic agent in the future.

Factors associated with prolonged progression-free survival of patients treated with first-line afatinib for advanced epidermal growth factor receptor-mutated non-small cell lung cancer.

BACKGROUND: This study aimed to investigate the factors associated with prolonged progression-free survival (PFS) (>36 months) of advanced non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations treated with first-line afatinib. METHODS: We performed a retrospective analysis of data of patients with advanced EGFR-mutated NSCLC receiving first-line afatinib at two tertiary care referral centers, Linkou and Kaohsiung Chang Gung Memorial Hospital, in Taiwan between June 2014 and April 2022. RESULTS: The data of 546 treatment-naïve EGFR-mutated advanced NSCLC patients were analyzed. Median PFS and overall survival were 14.5 months and 27.2 months, respectively. The PFS of 462 patients (84.6%) was less than 36 months and of 84 patients (15.4%) was more than 36 months. The PFS > 36 months group had a significantly higher percentage of patients with uncommon mutations (p = 0.002). The PFS ≤36 months group had significantly higher incidences of bone, liver, and adrenal metastases (all p < 0.05) and a higher rate of multiple distant metastases. Multivariate logistic regression analysis showed that liver metastasis was negatively and independently associated with prolonged PFS (adjusted odds ratio = 0.246 [95% CI: 0.067-0.908], p = 0.035). The median overall survival of the PFS >36 months group was 46.0 months and that of the PFS ≤36 months group was 22.9 months (log-rank test, p < 0.001). CONCLUSIONS: We found that EGFR-mutated NSCLC patients receiving first-line afatinib were prone to shorter PFS if they had distant organ metastasis, especially liver metastasis.

Effectiveness and safety of afatinib, gefitinib, and erlotinib for treatment-naïve elderly patients with epidermal growth factor receptor-mutated advanced non-small-cell lung cancer: a multi-institute retrospective study.

BACKGROUND: In real-world practice, most patients with lung cancer are diagnosed when they are aged ≥65 years. However, clinical trials tend to lack data for the elderly population. Therefore, we aimed to describe the effectiveness and safety of afatinib, gefitinib, and erlotinib for elderly patients with epidermal growth factor receptor (EGFR)-mutated advanced non-small-cell lung cancer (NSCLC). METHODS: Treatment-naïve patients with EGFR-mutated advanced NSCLC were enrolled at many hospitals in Taiwan. Patient characteristics and the effectiveness and safety of afatinib, gefitinib, and erlotinib were compared. RESULTS: This study enrolled 1,343 treatment-naïve patients with EGFR-mutated advanced NSCLC, of whom 554 were aged <65 years, 383 were aged 65-74 years, 323 were aged 75-84 years, and 83 were aged ≥85 years. For elderly patients, afatinib was more effective, with a median progression-free survival (PFS) of 14.7 months and overall survival (OS) of 22.2 months, than gefitinib (9.9 months and 17.7 months, respectively) and erlotinib (10.8 months and 18.5 months, respectively; PFS: p = 0.003; OS: p = 0.026). However, grade ≥3 adverse events, including skin toxicities, paronychia, mucositis, and diarrhea, were more frequently experienced by patients receiving afatinib than those receiving gefitinib or erlotinib. CONCLUSIONS: This large retrospective study provides real-world evidence of the effectiveness and safety of EGFR-TKIs for elderly patients with EGFR-mutated advanced NSCLC, a population that is often underrepresented in clinical trials and real-world evidence. Afatinib was more effective as a first-line treatment than gefitinib or erlotinib for elderly patients with EGFR-mutated advanced NSCLC.

Ligand and structure based hierarchical virtual screening cascade for finding novel epidermal growth factor receptor inhibitors.

The epidermal growth factor receptor (EGFR) tyrosine kinase plays an important role in tumor formation and growth by mediating cell growth and other physiological processes. Therefore, EGFR is a promising target for the treatment of cancer. In this work, we combined ligand-based and structure-based virtual screening methods to identify novel EGFR inhibitors from a library of more than 103 thousand compounds. We first obtained hundreds of compounds with similar physiochemical properties through 3D molecular shape and electrostatic similarity screening with potent inhibitors AEE788 and Afatinib as queries. Next, we identified compounds with strong binding affinities to the EGFR pocket through molecular docking, which makes good use of the structure information of the receptor. After molecular scaffold analysis, our bioassay confirmed 13 compounds with EGFR inhibitory activity and three compounds had IC50 values below 1000 nM. In addition, we collected 5371 EGFR inhibitors from online databases, and clustered them into 7 groups by K-means method using their ECFP4 fingerprints as input. Each cluster had typical molecular fragments and corresponding activity characteristics, which could guide the design of EGFR inhibitors, and we concluded that the fragments from some of the hits are indicated in the highly active scaffolds.