Afatinib in Untreated Stage IIIB/IV Lung Adenocarcinoma with Major Uncommon Epidermal Growth Factor Receptor (EGFR) Mutations (G719X/L861Q/S768I): A Multicenter Observational Study in Taiwan.

Real-world clinical experience with afatinib as a treatment for advanced lung adenocarcinoma harboring uncommon epidermal growth factor receptor (EGFR) mutations (G719X, L861Q and S768I) has rarely been reported. We aimed to perform a retrospective multicenter study to analyze afatinib therapy in untreated advanced lung adenocarcinoma harboring uncommon EGFR mutations. Between May 2014 and June 2021, the data of 90 stage IIIB/IV lung adenocarcinoma patients with uncommon EGFR mutations (G719X/L861Q/S768I) treated with first-line afatinib from the cancer center database of Linkou, Tucheng, and Kaohsiung Chang Gung Memorial Hospitals were retrospectively retrieved and analyzed. Afatinib had an objective response rate (ORR) of 63.3% and a disease control rate (DCR) of 86.7%. The median progression-free survival (PFS) with first-line afatinib therapy was 17.3 months (95% confidence interval (CI), 12.07-22.53), and the median overall survival (OS) was 28.5 months (95% CI, 20.22-36.77) in all study patients. In the multivariate analysis, poor performance (Eastern Cooperative Oncology Group performance status (ECOG PS) ≥ 2) and brain and liver metastases were independent predictors of unfavorable PFS. The G719X mutation (alone+compound) was an independent predictor of favorable PFS (hazard ratio (HR) = 0.578; 95% CI, 0.355-0.941; P = 0.027). Most afatinib-related adverse events (AEs) were limited to grades 1 and 2 and were manageable. First-line afatinib therapy is effective and safe for advanced lung adenocarcinoma harboring uncommon EGFR mutations. The G719X mutation was an independent factor associated with a favorable outcome. Poor performance (ECOG PS ≥ 2), brain metastasis, and liver metastasis were predictive factors of shorter PFS with first-line afatinib therapy.

Hsu PC ，Lee SH ，Chiu LC ，Lee CS ，Wu CE ，Kuo SC ，Ju JS ，Huang AC ，Li SH ，Ko HW ，Yang CT ，Wang CC ... -  《-》

Epidermal growth factor receptor tyrosine kinase inhibitors for non-small cell lung cancer harboring uncommon EGFR mutations: Real-world data from Taiwan.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the standard treatment for patients with non-small cell lung cancer (NSCLC) harboring EGFR mutations. This study aimed to evaluate the efficacy of EGFR-TKIs and prognostic factors for patients with NSCLC harboring uncommon EGFR mutations, which account for 10% of EGFR mutations. A total of 230 treatment-naive patients with NSCLC harboring uncommon EGFR mutations treated with first-line EGFR-TKIs between 2011 and 2018 at four hospitals (belonging to four institutions, Linkou, Kaohsiung, Keelung, and Chiayi, of the Chang Gung Memorial Hospital) in Taiwan were retrospectively reviewed. Their clinicopathological characteristics, adverse events (AEs), objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were collected. Univariate and multivariate analyses were performed to identify potential prognostic factors for PFS. Overall, patients who received afatinib (n = 62) had better PFS (median: 6.4 vs. 5.9 months, p = 0.022) and OS (median: 13.4 vs. 13.0 months, p = 0.008) than those who received gefitinib/erlotinib (n = 124), although no significant differences were observed for ORR (46.8% vs. 35.5%, p = 0.137) or DCR (59.7% vs. 58.9%, p = 0.916). Patients who received afatinib showed significantly higher ORR (58.3% vs. 31.3%, p = 0.027) but not DCR compared with gefitinib/erlotinib for major uncommon mutations. Afatinib trended toward better PFS and OS for major uncommon mutations and compound mutations. No EGFR-TKIs were effective for most NSCLC patients with exon 20 insertions. Performance status, metastasis of the liver and pleura, and dose reduction were independent prognostic factors for PFS. Afatinib demonstrated better survival outcomes than gefitinib/erlotinib for NSCLC patients harboring major EGFR uncommon mutations and compound mutations. Performance status and metastatic sites may be useful for predicting PFS for major uncommon mutations and compound mutations.

Chang JW ，Huang CY ，Fang YF ，Chang CF ，Yang CT ，Kuo CS ，Hsu PC ，Wu CE ... -  《-》

Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Treatment Response in Advanced Lung Adenocarcinomas with G719X/L861Q/S768I Mutations.

Chiu CH ，Yang CT ，Shih JY ，Huang MS ，Su WC ，Lai RS ，Wang CC ，Hsiao SH ，Lin YC ，Ho CL ，Hsia TC ，Wu MF ，Lai CL ，Lee KY ，Lin CB ，Yu-Wung Yeh D ，Chuang CY ，Chang FK ，Tsai CM ，Perng RP ，Chih-Hsin Yang J ... -  《-》

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.

Kim MH ，Choi CM ，Lee SY ，Park CK ，Chang YS ，Lee KY ，Kim SJ ，Yang SH ，Ryu JS ，Lee JE ，Lee SY ，Park CK ，Lee SH ，Jang SH ，Yoon SH ，Jang TW ... -  《-》

Efficacy and potential resistance mechanisms of afatinib in advanced non-small cell lung cancer patients with EGFR G719X/L861Q/S768I.

Afatinib is the only currently approved EGFR-tyrosine kinase inhibitors for advanced non-small cell lung cancer (NSCLC) patients with EGFR G719X/L861Q/S768I. However, there are limited real-world data concerning the benefits and resistance mechanisms of afatinib in patients with these nonclassical mutations. To fill this gap, the present study was conducted. All NSCLC patients treated with afatinib were screened, and patients with EGFR G719X/L861Q/S768I were enrolled into the analysis. Either tumor tissue or blood specimens were detected by the commercial next-generation sequencing (NGS) panels or amplification-refractory mutation system (ARMS)-polymerase chain reaction (PCR) to figure out the mutation genotype. A total of 106 advanced NSCLC patients with EGFR G719X/L861Q/S768I received afatinib treatment. The benefits of afatinib exhibited heterogeneity in different mutation genotypes. Notably, at baseline, NGS testing was performed in 59 patients, and TP53 was the most frequently coexisting mutation. Patients with TP53 mutations obtained fewer survival benefits than those with TP53 wild-type. A total of 68 patients ultimately experienced progression, and 27 patients received NGS testing to clarify the potential resistance mechanisms. EGFR-T790M, CDK4 amplification, FGFR1 amplification, PIK3CA, MET amplification, RET fusions, HER2, and BRAF mutations were identified in three (11.1%), three (11.1%), three (11.1%), three (11.1%), three (11.1%), one (3.7%), one (3.7%), and one (3.7%) of the cases, respectively. Five patients underwent ARMS-PCR testing for detecting EGFR-T790M mutation, and only one patient was T790M-positive. The present study elucidated the differential benefits of afatinib within different mutation genotypes and first revealed the spectrum of potential resistance mechanisms in patients with EGFR G719X/L861Q/S768I. The results of this study may provide practical clinical information that can guide optimal treatment in this setting.

Pang LL ，Gan JD ，Tan JR ，Huang YH ，Liao J ，Liang WT ，Deng PB ，Fang WF ... -  《-》