Phase II Trial of Afatinib in Patients With EGFR-Mutated Solid Tumors Excluding Lung Cancer: Results From NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocol A.

PURPOSE: National Cancer Institute-Molecular Analysis for Therapy Choice (NCI-MATCH) was a multicohort phase 2 trial that assigned patients with advanced pretreated cancers to molecularly targeted therapies on the basis of tumor genomic testing. NCI-MATCH Arm A evaluated afatinib, an EGFR tyrosine kinase inhibitor (TKI) approved for advanced non-small cell lung cancer, in patients with tumors other than lung cancer harboring EGFR mutations. METHODS: Patients with advanced pretreated cancers other than lung cancer found to have selected actionable EGFR mutations were offered participation in Arm A. Previous therapy with an EGFR TKI was not allowed. Patients received afatinib 40 mg once daily continuously until disease progression or unacceptable toxicity. The primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS), 6-month PFS, and overall survival (OS). RESULTS: Seventeen patients received protocol therapy. Tumor types included glioblastoma multiforme (GBM) (13), gliosarcoma (1), adenocarcinoma not otherwise specified (NOS) (2), and adenosquamous carcinoma of the breast (1). Fifty-nine percent of patients received ≥2 lines of previous therapy. The ORR was 11.8% (90% CI, 2.1 to 32.6), with one complete response lasting 16.4 months (GBM harboring a rare exon 18 EGFR-SEPT14 fusion) and one partial response lasting 12.8 months (adenocarcinoma NOS with the classic EGFR mutation, p.Glu746_Ala750del). Three patients had stable disease. The 6-month PFS was 15% (90% CI, 0 to 30.7); the median OS was 9 months (90% CI, 4.6 to 14.0). Rash and diarrhea were the most common toxicities. CONCLUSION: Afatinib had modest activity in a cohort of patients with heavily pretreated cancer with advanced nonlung, EGFR-mutated tumors, but the trial's primary end point was not met. Further evaluation of afatinib in GBM with EGFR exon 18 fusions may be of interest.

[Afatinib Treatment for Advanced Mixed Non-small Cell Lung Cancer 
with CRISPLD2-NRG1 Fusion: A Case Report and Literature Review].

Lung cancer is the most common malignant disease and the leading cause of cancer death in China. Non-small cell lung cancer (NSCLC) accounts for over 80% of all lung cancers, and the probability of NSCLC gene mutations is high, with a wide variety of types. With the development of next-generation sequencing (NGS) detection technology, more and more patients with rare fusion gene mutations are detected. Neuregulin 1 (NRG1) gene is a rare oncogenic driver that can lead to activation of human epidermal growth factor receptor 3 (Her3/ErbB3) mediated pathway, resulting in tumor formation. In this article, we reported a case of mixed NSCLC with CRISPLD2-NRG1 fusion detected by RNA-based NGS, who responsed to Afatinib well after 1 month of treatment, and magnetic resonance imaging (MRI) showed shrinkage of intracranial lesions. Meanwhile, we also compiled previously reported NSCLC patients with NRG1 rare gene fusion mutation, in order to provide effective references for clinical diagnosis and treatment.
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Prolonged Response to Afatinib and Crizotinib in a Rare Case of EGFR-, HER2-, MET- and ROS1-Alterated Lung Adenocarcinoma.

We present the case of a 70-year-old never-smoking female patient with epidermal growth factor receptor (EGFR) p.L858R-mutated metastatic non-small cell lung cancer (NSCLC). After three months of first-line treatment with erlotinib, progression occurred and platinum/pemetrexed was initiated, followed by a response for more than two years. After the progression, the molecular testing of a vertebral metastasis revealed a ROS proto-oncogene 1 (ROS1) translocation and a human epidermal growth factor receptor 2 (HER2) p.S310F mutation, in addition to the known EGFR p.L858R mutation. Crizotinib then led to a durable response of 17 months. The molecular retesting of the tumour cells obtained from the recurrent pleural effusion revealed the absence of the ROS1 translocation, whereas the EGFR and HER2 mutations were still present. Afatinib was added to the crizotinib, and the combination treatment resulted in another durable response of more than two years. The patient died more than 7 years after the initial diagnosis of metastatic NSCLC. This case demonstrates that the repeated molecular testing of metastatic NSCLC may identify new druggable genomic alterations that can impact the patient management and improve the patient outcome.

Afatinib or Bevacizumab in combination with Osimertinib efficiently control tumor development in orthotopic murine models of non-small lung cancer.

Lung cancer is one of the most common and deadliest cancers. Preclinical models are essential to study new therapies and combinations taking tumor genetics into account. We have established cell lines expressing the luciferase gene from lines with varied genetic backgrounds, commonly encountered in patients with pulmonary adenocarcinoma. We have characterized these lines by testing their response to multiple drugs. Thus, we have developed orthotopic preclinical mouse models of NSCLC with very high engraftment efficiency. These models allow the easy monitoring of tumor growth, particularly in response to treatment, and of tumor cells dissemination in the body. We show that concomitant treatment with osimertinib (3rd generation tyrosine kinase inhibitor targeting mutated EGFR) and bevacizumab (anti-angiogenic targeting VEGF) can have a beneficial therapeutic effect on EGFR-mutated tumors. We also show that the addition of afatinib to osimertinib-treated tumors in escape leads to tumor growth inhibition. No such effect is observed with selumetinib or simvastatin. These preclinical mouse models therefore make it possible to test innovative therapeutic combinations and are also a tool of choice for studying resistance mechanisms.

Clinical efficacy and identification of factors confer resistance to afatinib (tyrosine kinase inhibitor) in EGFR-overexpressing esophageal squamous cell carcinoma.

Epidermal growth factor receptor (EGFR) is reportedly overexpressed in most esophageal squamous cell carcinoma (ESCC) patients, but anti-EGFR treatments offer limited survival benefits. Our preclinical data showed the promising antitumor activity of afatinib in EGFR-overexpressing ESCC. This proof-of-concept, phase II trial assessed the efficacy and safety of afatinib in pretreated metastatic ESCC patients (n = 41) with EGFR overexpression (NCT03940976). The study met its primary endpoint, with a confirmed objective response rate (ORR) of 39% in 38 efficacy-evaluable patients and a median overall survival of 7.8 months, with a manageable toxicity profile. Transcriptome analysis of pretreatment tumors revealed that neurotrophic receptor tyrosine kinase 2 (NTRK2) was negatively associated with afatinib sensitivity and might serve as a predictive biomarker, irrespective of EGFR expression. Notably, knocking down or inhibiting NTRK2 sensitized ESCC cells to afatinib treatment. Our study provides novel findings on the molecular factors underlying afatinib resistance and indicates that afatinib has the potential to become an important treatment for metastatic ESCC patients.

QM/MM Simulations of Afatinib-EGFR Addition: The Role of ß-Dimethylaminomethyl Substitution.

Acrylamides are the most commonly used warheads of targeted covalent inhibitors (TCIs) directed at cysteines; however, the reaction mechanisms of acrylamides in proteins remain controversial, particularly for those involving protonated or unreactive cysteines. Using the combined semiempirical quantum mechanics (QM)/molecular mechanics (MM) free energy simulations, we investigated the reaction between afatinib, the first TCI drug for cancer treatment, and Cys797 in the EGFR kinase. Afatinib contains a ß-dimethylaminomethyl (ß-DMAM) substitution which has been shown to enhance the intrinsic reactivity and potency against EGFR for related inhibitors. Two hypothesized reaction mechanisms were tested. Our data suggest that Cys797 becomes deprotonated in the presence of afatinib, and the reaction proceeds via a classical Michael addition mechanism, with Asp800 stabilizing the ion-pair reactant state ß-DMAM+/C797- and the transition state of the nucleophilic attack. Our work elucidates an important structure-activity relationship of acrylamides in proteins.

Topical JAK inhibition ameliorates EGFR inhibitor-induced rash in rodents and humans.

Epidermal growth factor receptor inhibitors (EGFRis) are used to treat many cancers, but their use is complicated by the development of a skin rash that may be severe, limiting their use and adversely affecting patient quality of life. Most studies of EGFRi-induced rash have focused on the fully developed stage of this skin disorder, and early pathological changes remain unclear. We analyzed high-throughput transcriptome sequencing of skin samples from rats exposed to the EGFRi afatinib and identified that keratinocyte activation is an early pathological alteration in EGFRi-induced rash. Mechanistically, the induction of S100 calcium-binding protein A9 (S100A9) occurred before skin barrier disruption and led to keratinocyte activation, resulting in expression of specific cytokines, chemokines, and surface molecules such as interleukin 6 (Il6) and C-C motif chemokine ligand 2 (CCL2) to recruit and activate monocytes through activation of the Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathway, further recruiting more immune cells. Topical JAK inhibition suppressed the recruitment of immune cells and ameliorated the severity of skin rash in afatinib-treated rats and mice with epidermal deletion of EGFR, while having no effect on EGFRi efficacy in tumor-bearing mice. In a pilot clinical trial (NCT05120362), 11 patients with EGFRi-induced rash were treated with delgocitinib ointment, resulting in improvement in rash severity by at least one grade in 10 of them according to the MASCC EGFR inhibitor skin toxicity tool (MESTT) criteria. These findings provide a better understanding of the early pathophysiology of EGFRi-induced rash and suggest a strategy to manage this condition.

Unfavorable response to capmatinib for MET exon14 skipping after first-line osimertinib in a patient with EGFR-mutated lung adenocarcinoma: A case report and literature review.

MET exon14 skipping mutations (METex14s) are rarely reported as a potential resistance mechanism to EGFR tyrosine kinase inhibitors (TKIs). The efficacy of targeted therapy against METex14s emerging after osimertinib resistance is uncertain. Herein, we report a case of EGFR-mutated metastatic lung adenocarcinoma in which METex14 was detected in a re-biopsy upon first-line osimertinib resistance. The patient received capmatinib monotherapy as third-line therapy, which was ineffective, followed by an exceptional response to salvage therapy with afatinib. This report highlights the heterogeneity of EGFR-TKI resistance and that targeting rare resistance mechanisms remains challenging.

The ASCENT Trial: a phase 2 study of induction and consolidation afatinib and chemoradiation with or without surgery in stage III EGFR-mutant NSCLC.

BACKGROUND: The role of tyrosine kinase inhibitors (TKIs) in early-stage and metastatic oncogene-driven non-small cell lung cancer (NSCLC) is established, but it remains unknown how best to integrate TKIs with concurrent chemoradiotherapy (cCRT) in locally advanced disease. The phase 2 ASCENT trial assessed the efficacy and safety of afatinib and cCRT with or without surgery in locally advanced epidermal growth factor receptor (EGFR)-mutant NSCLC. PATIENTS AND METHODS: Adults ≥18 years with histologically confirmed stage III (AJCC 7th edition) NSCLC with activating EGFR mutations were enrolled at Mass General and Dana-Farber/Brigham Cancer Centers, Boston, Massachusetts. Patients received induction afatinib 40 mg daily for 2 months, then cisplatin 75 mg/m2 and pemetrexed 500 mg/m2 IV every 3 weeks during RT (definitive or neoadjuvant dosing). Patients with resectable disease underwent surgery. All patients were offered consolidation afatinib for 2 years. The primary endpoint was the objective response rate (ORR) to induction TKI. Secondary endpoints were safety, conversion to operability, progression-free survival (PFS), and overall survival (OS). Analyses were performed on the intention-to-treat population. RESULTS: Nineteen patients (median age 56 years; 74% female) were enrolled. ORR to induction afatinib was 63%. Seventeen patients received cCRT; 2/9 previously unresectable became resectable. Ten underwent surgery; 6 had a major or complete pathological response. Thirteen received consolidation afatinib. With a median follow-up of 5.0 years, median PFS and OS were 2.6 (95% CI, 1.4-3.1) and 5.8 years (2.9-NR), respectively. Sixteen recurred or died; 6 recurrences were isolated to CNS. The median time to progression after stopping consolidation TKI was 2.9 months (95% CI, 1.1-7.2). Four developed grade 2 pneumonitis. There were no treatment-related deaths. CONCLUSION: We explored the efficacy of combining TKI with cCRT in oncogene-driven NSCLC. Induction TKI did not compromise subsequent receipt of multimodality therapy. PFS was promising, but the prevalence of CNS-only recurrences and rapid progression after TKI discontinuation speak to unmet needs in measuring and eradicating micrometastatic disease.

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.

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.

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.

Co-occurring EGFR p.E709X Mutation Mediates Primary Resistance to the Third-Generation EGFR-TKIs in EGFR p.G719X-Mutant Patients with Advanced NSCLC.

PURPOSE: The current National Comprehensive Cancer Network (NCCN) guidelines recommend afatinib or osimertinib as the preferred first-line treatment strategy for patients with advanced NSCLC harboring EGFR p.G719X mutation. However, in the absence of head-to-head trials comparing afatinib with osimertinib in EGFR p.G719X-mutant patients, it is unclear which regimen is the preferred treatment option. EXPERIMENTAL DESIGN: A large cohort of 4,228 treatment-naïve patients with lung cancer who underwent targeted next-generation sequencing (NGS) testing was screened for EGFR p.G719X mutation. A multicenter cohort involving 68 EGFR p.G719X-mutant patients with advanced NSCLC and NGS profiling was retrospectively enrolled to evaluate clinical responses to afatinib (n = 37) and the third-generation EGFR-TKIs (n = 31). Ba/F3 cells stably expressing the EGFR p.G719A mutation were created to investigate the response to EGFR-TKIs in vitro. RESULTS: Concurrent EGFR p.E709X mutations, being the most frequent co-occurring EGFR mutation in EGFR p.G719X-mutant NSCLC (∼30%), exerted a detrimental effect on outcomes in patients treated with third-generation EGFR-TKI [G719X/E709X vs. G719X; objective response rate (ORR): 0.00% vs. 47.62%, P < 0.001; mPFS: 7.18 vs. 14.2 months, P = 0.04, respectively]. Conversely, no significant difference was found in the treatment efficacy of afatinib between EGFR p.G719X/E709X and EGFR p.G719X patients (G719X/E709X vs. G719X; ORR: 71.43% vs. 56.67%, P = 0.99; mPFS: 14.7 vs. 15.8 months, P = 0.69, respectively). In vitro experiments elucidated a resistant drug sensitivity and poor inhibition of EGFR phosphorylation in Ba/F3 cells expressing EGFR p.G719A/E709K mutation upon the third-generation EGFR-TKI treatment. CONCLUSIONS: Co-occurring EGFR p.E709X mutation mediated primary resistance to the third-generation EGFR-TKIs in EGFR p.G719X-mutant patients but remained sensitive to afatinib. A personalized treatment strategy should be undertaken based on the coexisting EGFR p.E709X mutation status.

Deleterious association between proton pump inhibitor and protein kinase inhibitor exposure and survival for patients with lung cancer: A nationwide cohort study.

INTRODUCTION: Previous studies have identified an interaction between protein kinase inhibitors (PKIs) and proton pump inhibitors (PPIs) in patients with lung cancer. This type of interaction may reduce the efficacy of PKIs. However, the effect of PKI-PPI interaction on patient mortality remains controversial. This study set out to determine the impact of PKI-PPI interaction on overall survival for lung cancer patients. MATERIALS AND METHODS: This study was conducted using data from the French National Health Care Database from January 1, 2011 to December 31, 2021. We identified patients with: (i) an age equal to or greater than 18 years; (ii) lung cancer; and (iii) at least one reimbursement for one of the following drugs: erlotinib, gefitinib, afatinib and osimertinib. Patients were followed-up between the first date of PKI reimbursement and either December 31, 2021 or if they died, the date on which death occurred. The cumulative exposure to PPI duration during PKI treatment was calculated as the ratio between the number of concomitant exposure days to PKI and PPI and the number of exposure days to PKI. A survival analysis using a Cox proportional hazards model was then performed to assess the risk of death following exposure to a PKI-PPI interaction. RESULTS: 34,048 patients received at least one reimbursement for PKIs of interest in our study: 26,133 (76.8 %) were exposed to erlotinib; 3,142 (9.2 %) to gefitinib; 1,417 (4.2 %) to afatinib; and 3,356 (9.9 %) to osimertinib. Patients with concomitant exposure to PKI-PPI interaction during 20 % or more of the PKI treatment period demonstrated an increased risk of death (HR, 1.60 [95 % CI, 1.57-1.64]) compared to other patients. When this cut-off varied from 10 % to 80 %, the estimated HR ranged from 1.46 [95 % CI, 1.43-1.50] to 2.19 [95 % CI, 2.12-2.25]. DISCUSSION/CONCLUSION: In our study, an elevated risk of death was observed in patients exposed to PKI-PPI interaction. Finally, we were able to identify a dose-dependent effect for this interaction. This deleterious effect of osimertinib and PPI was revealed for the first time in real life conditions.

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.

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.

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.