Epidermal Growth Factor Receptor L858R Research Articles

Spheroids Generated from Malignant Pleural Effusion as a Tool to Predict the Response of Non-Small Cell Lung Cancer to Treatment.

Spheroids generated by tumor cells collected from malignant pleural effusion (MPE) were shown to retain the characteristics of the original tumors. This ex vivo model might be used to predict the response of non-small cell lung cancer (NSCLC) to anticancer treatments. The characteristics, epidermal growth factor receptor (EGFR) mutation status, and clinical response to EGFR-TKIs treatment of enrolled patients were recorded. The viability of the spheroids generated from MPE of enrolled patients were evaluated by visualization of the formazan product of the MTT assay. Spheroids were generated from 14 patients with NSCLC-related MPE. Patients with EGFR L861Q, L858R, or Exon 19 deletion all received EGFR-TKIs, and five of these seven patients responded to treatment. The viability of the spheroids generated from MPE of these five patients who responded to EGFR-TKIs treatment was significantly reduced after gefitinib treatment. On the other hand, gefitinib treatment did not reduce the viability of the spheroids generated from MPE of patients with EGFR wild type, Exon 20 insertion, or patients with sensitive EGFR mutation but did not respond to EGFR-TKIs treatment. Multicellular spheroids generated from NSCLC-related MPE might be used to predict the response of NSCLC to treatment.

Abstract LB056: IBI334, a novel ADCC-enhanced B7-H3/EGFR bispecific antibody, demonstrated potent pre-clinical efficacy in solid tumors

Abstract Many solid tumors, such as colorectal cancer (CRC) and lung cancer, are dependent on epidermal growth factor receptor (EGFR) pathway for tumor growth. Antibodies that inhibit EGFR signaling, such as Cetuximab, show clinical efficacy but are associated with on-target toxicities that potentially limit the drug efficacy. To enhance the EGFR signaling inhibition and reduce on-target toxicities, we performed bioinformatics analysis for EGFR/TAA co-expression. We found that B7-H3, a member of the B7 family of immune checkpoint proteins, is broadly expressed in many solid tumors and their expression correlates with EGFR expression in multiple cancers, including lung cancer, head and neck cancer, pancreatic cancer and esophageal cancer. Using Innovent’s proprietary Innobody platform, we developed a bispecific antibody, IBI334, against B7-H3 and EGFR. IBI334 has an EGFR arm for signal blockage and is coupled with a fine-tuned B7-H3 arm with optimal affinity and binding domain. With the aid of B7-H3, IBI334 showed enhanced EGFR signal inhibition than Zalutumumab (EGFR mAb) and Amivantamab (c-met/EGFR bsAb). In addition, IBI334 is afucosylated to enhance its antibody-mediated cell cytotoxicity (ADCC) effects as compared to wild type antibody. IBI334 showed significantly better in vivo efficacy than Amivantamab in NCI-H358 (bronchioalveolar carcinoma with KRAS-G12C mutation), NCI-H292 (lymph node metastasis of a pulmonary mucoepidermoid carcinoma), SK-MES1 (lung cancer) and SK-MES1-LTC (lung cancer with EGFR L858R, T790M and C797S mutations) xenograft models and comparable efficacy in NCI-H322-EGFRexon20ins (lung cancer) model. Cetuximab, an EGFR monoclonal antibody, had high on-target toxicity with 50% early mortalities in cynomolgus monkeys at 120/75 mg/kg/week. With the careful design of B7-H3/EGFR bispecific antibody, IBI334 ameliorated the on-target toxicities and showed only slight hardening of the skin at the injection site at 120 mg/kg/week. As a result, IBI334 has a large therapeutic window of >200 folds. In conclusion, IBI334 is a potent B7-H3/EGFR bispecific antibody with broad application in many EGFR-driven solid tumors. The large therapeutic window enables safe and effective cancer treatment at high exposure levels. Citation Format: Jian Guan, Shuaixiang Zhou, Weiwei Wu, Tianyu Zhu, Lei Cao, Ming Wu, Ninghuan Li, Fenggen Fu, Zhengguan Liao, Shuming Lin, Zeyu Liu, Mengjia Zhu, Nana Luo, Ying Zhang, Tiong Sun Chia, Bingliang Chen, Kaijie He. IBI334, a novel ADCC-enhanced B7-H3/EGFR bispecific antibody, demonstrated potent pre-clinical efficacy in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB056.

Abstract CT152: FURTHER: A global study to evaluate furmonertinib in patients with EGFR mutant NSCLC including uncommon EGFR mutations

Abstract Background: Furmonertinib (AST2818) is an oral, highly brain-penetrant, and broadly active mutation-selective epidermal growth factor receptor (EGFR) inhibitor engineered for broad activity and selectivity across EGFR mutations (mts) (Musib et al., NACLC 2022). Furmonertinib is approved in China for first-line advanced NSCLC with EGFR Ex19del or L858R mts based on the positive Phase 3 study (FURLONG) versus gefitinib. Furmonertinib has also demonstrated promising interim efficacy and safety in patients (pts) with NSCLC with EGFR exon 20 insertion (ex20ins) mts with a confirmed overall response rate (ORR) of 78.6% (n=28) by blinded independent central review (BICR) with a preliminary median duration of response (DoR) of 15.2 months in the front-line setting (FAVOUR study; see Han et al., WCLC 2023). Furmonertinib recently obtained FDA Breakthrough Therapy Designation for the treatment of pts with advanced NSCLC with EGFR ex20ins mts. P-loop and αC-helix Compressing (PACC) mts represent another subset of uncommon EGFR mts (Robichaux et al., 2021) that are similar to ex20ins mts in narrowing the drug-binding pocket; including G719X, S768I, E709X, L747X, V774M. Preclinical data indicating that furmonertinib is potent in models harboring EGFR PACC mts will be presented at this meeting (Nilsson et al., Abstract #4174). Developing efficacious, well-tolerated, and CNS-penetrant medicines for NSCLC pts with EGFR ex20ins mts and PACC mts remains an unmet need. Methods: FURTHER (FURMO-002) is the first global trial evaluating furmonertinib in NSCLC pts with EGFR and HER2 mts in North America, Europe, and the Asia-Pacific. FURTHER is a phase 1b, open-label, multicenter study in which pts will be treated orally with furmonertinib daily. For Stage 1 dose-escalation, the primary endpoint is incidence and severity of adverse events, including dose limiting toxicities and has been completed. For Stage 2 dose expansion, approximately 120 pts will be enrolled across 4 expansion cohorts. Stage 2 Cohorts 1-3 dose expansion cohorts will enroll pts with previously treated, locally advanced or metastatic NSCLC pts with either EGFR ex20ins mts, HER2 ex20ins mts, or EGFR activating mts, respectively. Cohorts 1-3 allow enrollment of pts with prior EGFR or HER2-directed therapy. Stage 2 Cohort 4 will enroll EGFR TKI-naïve NSCLC pts with EGFR PACC mts. Key inclusion criteria include documented EGFR or HER2 mts by local testing and measurable disease per RECIST v1.1. Stage 2 primary endpoint is ORR using RECIST v1.1. Key secondary endpoints include progression-free survival and overall survival. Stage 2 enrollment is ongoing. Clinical trial information: NCT05364073. Citation Format: Xiuning Le, Alexander Spira, Shirish Gadgeel, Yan Yu, Yanqiu Zhao, Ying Cheng, Jonathan Riess, Oscar Juan-Vidal, Bo Gao, Kiyotaka Yoh, Martin Forster, Satoru Kitazono, Hidetoshi Hayashi, David Planchard, Yong Jiang, Jack Huang, Nichole Baio, Marcin Kowanetz, Shirley Wang, William Leung, Jerry Y. Hsu, Jie Wang. FURTHER: A global study to evaluate furmonertinib in patients with EGFR mutant NSCLC including uncommon EGFR mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT152.

Abstract 4365: Mechanistic effects of N361 glycosylation in epidermal growth factor receptor protein

Abstract Glycosylation is a tightly regulated post-translational modification where structured sugar groups are added to protein amino acid backbones, most commonly on asparagine for N-glycosylation. The glycosylation-regulating metabolic enzyme uridine diphosphate-glucose pyrophosphorylase 2 (UGP2) is required in oncogene-transformed cancer cells, but not in normal cells. UGP2 heavily regulates glycosylation of epidermal growth factor receptor (EGFR) at asparagine 361 (N361), a key site near the ligand binding domain. EGFR is a transmembrane tyrosine kinase receptor that promotes cell proliferation via growth cascades. Mutations and amplifications in EGFR account for a significant fraction of non-small cell lung carcinomas and breast adenocarcinoma, with L858R being the most common oncogenic hotspot. Other glycosylation sites on EGFR have been implicated in ligand binding, dimerization, and phosphorylation of downstream targets. Molecular dynamic simulations suggested that N361 may be important for dimerization or ligand binding. However, the functional relevance of how glycosylation of EGFR at N361 impacts EGFR protein and cellular behaviors remains unclear. To determine the functional relevance of glycosylation at N361, we created glycosylation-defective EGFR N361A mutant, with or without an additional oncogenic EGFR L858R mutant. We expressed these constructs in MCF10A and 293T cells, which do not have pre-existing activation of this pathway. Immunofluorescence and flow cytometry showed that the mutants were each well expressed at the cell membrane. Proximity ligation assays measuring dimerization of EGFR in cells showed that EGFR N361A greatly increased dimerization relative to wildtype controls. Loss of glycosylation of EGFR N361 impacted cell viability when grown in dose courses of its high affinity ligand EGF or lower affinity ligand amphiregulin. Furthermore, EGFR N361A desensitized cells expressing the oncogenic EGFR L858R to inhibitors targeting the extracellular domain, possibly because the mutation alters the antibody binding interface. N361A sensitized EGFR L858R to inhibitors targeting the cytoplasmic domain of EGFR. These findings help us understand the intricate relationship between EGFR and N-glycosylation, reinforcing the critical functional relevance of post-translational modifications on oncogenes. Citation Format: Dennis Lam, Ariel N. Liberchuk, Brandon Arroyo, Andrew L. Wolfe. Mechanistic effects of N361 glycosylation in epidermal growth factor receptor protein [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4365.

Abstract 1962: PH009-1, a highly potent, selective and brain-penetrable fourth-generation EGFR-TKI that overcome classic and resistant EGFR mutations in NSCLC

Abstract Background: Epidermal growth factor receptor (EGFR) inhibitors, especially 3rd Gen inhibitor such as osimertinib (Osi), have become the first line therapy for non-small cell lung cancer (NSCLC) patients with EGFR activating mutations. However, treatments with 3rd Gen EGFR inhibitors lead to occurrence of acquired C797S mutation in 10-24% of patients. Though studies showed that double mutations 19Del/C797S (DC) and L858R/C797S (LC) could be inhibited by 1st Gen EGFR TKIs, appearance of triple mutations 19Del/T790M/C797S (DTC) and L858R/T790M/C797S (LTC) always leads to treatment failure. In recent years, 4th Gen EGFR inhibitors have been developed such as BLU-945 and PH009-1. PH009-1 had been reported on AACR annual meeting 2023. Methods: Cell activity and selectivity were determined in engineered Ba/F3 cell lines carrying EGFR wild type (WT, stimulated with EGF), 19Del (D), L858R (L), 19Del/T790M (DT), L858R/T790M (LT), DC, LC, DTC and LTC. The in vivo anti-tumor efficacy and PK-PD studies were performed in cell or patient derived xenograft (CDX or PDX) cancer models (HCC827, D; Ba/F3, LC; PDX, DTC). Brain penetration capability was tested in mice orally treated with PH009-1 for 7 days. Systemic safety of PH009-1 was evaluated in 28-day repeated dosing toxicity studies in rats and dogs following GLP guidelines. Results: PH009-1 displayed potent anti-proliferation activity against Ba/F3 cells harboring EGFR mutations (L, D, LC, DC, LT, DT, LTC, DTC) with IC50 of 2.4, 1.3, 5.2, 1.2, 1.1, 1.5, 2.8, 1.9 nM, respectively, but had very weak effect on EGFR WT Ba/F3 cells (IC50, 1135 nM), suggesting excellent potency and selectivity. In contrast, though BLU-945 potently inhibited DT, LT, DTC, LTC with IC50 less than 5 nM, but its activities on L, D, LC, DC were not strong with IC50 of 31.6, 81.2, 46.2, and 52.0 nM. In in vivo efficacy studies, PH009-1 at a dose of 20 mg/kg BID led to potent inhibition on tumor growth and EGFR phosphorylation, and tumor regression was observed at higher doses in all tested models. In HCC827 model with 19Del (first line therapy setting), mice were treated for more than 200 days, and one tumor relapsed in BLU-945 group but not in PH009-1 or Osi group. Also, deaths were observed in Osi group, but not with PH009-1. After treated mice with PH009-1 at efficacious dose for 7 days, concentrations in cerebrospinal fluids (CSF) at 0-8 h post final dose were more than enough (≥1.5 fold) to cover IC80 on all tested mutations. In GLP toxicity studies, no unexpected toxicity was observed. In dogs. the highest tested dose was determined as highest non-severely toxic dose (HNSTD) and based on high plasma exposure, wide safety margin was confirmed with PH009-1. Conclusion: Our data suggested that PH009-1 overcome T790M/C797S resistant mutations, and also have potential to become a potent and safe approach for first line therapy of NSCLC with EGFR mutations. Citation Format: Feng Gao, Jing Wang, Bin Liu, Yongyong Wu, Liandong Jing, Pengzhi Zhang, Yu Gao, Zhizhong Li, Yongqi Guo. PH009-1, a highly potent, selective and brain-penetrable fourth-generation EGFR-TKI that overcome classic and resistant EGFR mutations in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1962.

Abstract 5774: Are 19del and L858R really not the same disease entities

Abstract IntroductionThe similarities and differences between the two subtypes of common epidermal growth factor receptor (EGFR) mutations have been recognized by clinicians, but actual treatment strategies remain unchanged. The L858R mutation can be explained by the pharmacological conformational plasticity of the receptor protein and other co-occurring mutations, which may be subtypes of EGFR mutations or non-EGFR mutations, and differences in downstream signaling pathways. As long as we know that molecular differences lead to biological differences, it is a challenge for all of us that our treatment strategies must changeWe investigated the RWD, conformational structure and RNA expression profile about two types of common mutations in the mEGFR+ NSCLC patients.MethodWe collected the medical information for stage I-IIIA mEGFR+ NSCLC patients and explored the conformational structure by crystalized radiologic technique. And we performed RNA expression assay using multiplex IF and High-through-output Profiling. ResultOverall, the static structures of wild type (WT), L858R, and 19del (ΔL747-E749) EGFR did not show any significant differences. However, the difference in the static structure between WT-19del and L858R-19del was subtly greater than that of WT-L858R. In addition, further analyses demonstrated no significant structural differences in the phosphorylation sites. However, it should be noted that proteins do not exist as static structures in vivo, and they have a dynamic, flexible structure that changes over time, i.e., plasticity of proteins. Therefore, we investigated the X-ray B-factor value, which is an indicator of flexibility, dynamics, and plasticity of proteins. As expected, the loop or disordered regions mainly shows higher B-factor values, which indicates an active structure, highly changeable and dynamic. Together, the three types of the EGFR protein manifest wholly similar B-factor values, while several local regions present appreciably distinct B-factors. Physical properties such as the dynamic structure may affect intermolecular recognition of EGFR proteins and their function Recent biochemical and biophysical evidence suggests that oncogenic mutations have an impact on the conformational dynamics of enzymesConclusionIn conclusion, our results suggest that Patients with 19del and L858R mutations demonstrated a different clinical course. It is necessary to consider the dynamic structural characteristics and functional differences of EGFR membrane proteins. Citation Format: Yunseok Heo, Joo Ri Kim, Yeoun Eun Sung, Seoree Kim, Chan Kwon Jung, Jeong-Oh Kim, Jeong-yeon Shin, Guk Jin Lee, Sang hoon Chun, Seong Hyeon Bu, Young Ho Lee, Jin Hyoung Kang. Are 19del and L858R really not the same disease entities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5774.

MET overexpression correlated with prognosis of EGFR-mutant treatment‑naïve advanced lung adenocarcinoma: a real‑world retrospective study.

About 50-60% treatment-naïve advanced non-small-cell lung cancers were coexistence of epidermal growth factor receptor (EGFR) and mesenchymal epithelial transition (MET) overexpression. However, few studies demonstrated the prognostic value of MET protein expression in untreated EGFR-mutant lung adenocarcinoma (LUAD). A total of 235 EGFR-mutant untreated advanced LUAD patients were retrospectively enrolled. MET expression was determined using immunohistochemistry, and MET positivity was defined as 2 + or 3 + using the METmab scoring algorithm. Progression-free survival (PFS) and overall survival (OS) were analysed according to MET expression status. Independent factors predicting prognosis were identified using multivariate Cox regression analyses. Of the 235 patients, 113 (48.1%) harboured exon 19 deletion (19_del), 103 (43.8%) had exon 21 L858R mutations, and 19 (8.1%) had other mutation types, including exon 21 L861Q, exon 18 G719A/C, exon 20 S768I, and L858R/19_del double mutations. MET-positive expression was observed in 192 (81.7%) cases. There was no significant difference in baseline clinicopathological characteristics between MET positivity and MET negativity groups. Patients were stratified by different EGFR mutation subtypes. MET-positive patients in the L858R mutation subgroup had markedly shorter PFS and OS than MET-negative patients (median PFS: 13 versus 27.5months, p < 0.001; median OS: 29 versus not reached, p = 0.008), but no significant difference was observed in the 19_del subgroup. Multivariate Cox regression analyses indicated that MET positivity was an independent predictor for poor PFS and OS in L858R subgroup (PFS: HR = 3.059, 95% CI 1.552-6.029, p = 0.001; OS: HR = 3.511, 95% CI 1.346-9.160, p = 0.010). Additionally, an inferior survival outcome of MET positivity was observed in the L858R mutation subgroup when treated with EGFR-tyrosine kinase inhibitor (TKI) monotherapy as the first-line regimen (median PFS: 13 versus 36.5months, p < 0.001; median OS: 29 versus not reached, p = 0.012) but not with EGFR-TKI plus platinum doublet chemotherapy. MET positive expression was an independent predictor of poor outcomes in untreated EGFR L858R mutation advanced LUAD patients treated with first-line EGFR-TKI monotherapy.

Genetic mutation profiling reveals biomarkers for targeted therapy efficacy and prognosis in non-small cell lung cancer

IntroductionThe genetic heterogeneity of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations may affect clinical responses and outcomes to EGFR tyrosine kinase inhibitors (EGFR-TKIs). This study aims to investigate the genomic factors that influence the efficacy and clinical outcomes of first-line, second-line and third-line treatments in NSCLC and explore the heterogeneity of resistance mechanisms. Materials and methodsThis real-world study comprised 65 patients with EGFR mutant NSCLC. Molecular alterations were detected using a customized DNA panel before and after administering targeted therapy. The efficacy and prognosis of each treatment line were evaluated. ResultsIn first-generation EGFR-TKIs treatment, gefitinib showed favorable efficacy compared to icotinib and erlotinib, particularly in patients with EGFR L858R mutations. The resistance mechanisms to first-generation EGFR-TKIs varied among different EGFR mutation cohorts and different first-generation EGFR-TKIs. In second-line EGFR-TKIs treatment, EPH receptor A3 (EPHA3), IKAROS family zinc finger 1 (IKZF1), p21 (RAC1) activated kinase 5 (PAK5), DNA polymerase epsilon, catalytic subunit (POLE), RAD21 cohesin complex component (RAD21) and RNA binding motif protein 10 (RBM10) mutations were markedly associated with poorer progression-free survival (PFS). Notably, EPHA3, IKZF1 and RBM10 were identified as independent predictors of PFS. The mechanisms of osimertinib resistance exhibited heterogeneity, with a higher proportion of non-EGFR-dependent resistant mutations. In third-line treatments, the combination of osimertinib and anlotinib demonstrated superior efficacy compared to other regimens. Glutamate ionotropic receptor NMDA type subunit 2A (GRIN2A) mutation was an independent risk indicator of shorter OS following third-line treatments. ConclusionsComprehending the tumor evolution in NSCLC is advantageous for assessing the efficacy and prognosis at each stage of treatment, providing valuable insights to guide personalized treatment decisions for patients.

PER-CRISPR/Cas14a system-based electrochemical biosensor for the detection of ctDNA EGFR L858R.

The detection of epidermal growth factor receptor (EGFR) mutation L858R in circulating tumor DNA (ctDNA) is beneficial for the clinical diagnosis and personalized therapy of non-small cell lung cancer (NSCLC). Herein, for the first time, the combination of the primer exchange reaction (PER) and clustered regularly interspaced short palindromic repeats (CRISPR) and its associated nucleases (Cas) 14a was used in electrochemical biosensor construction for the detection of ctDNA EGFR L858R. EGFR L858R, as the target, induced the isothermal amplification of the PER reaction, and then the CRISPR/Cas14a system was activated; subsequently, the substrate ssDNA-MB was cleaved and the electron on the surface of the gold electrode transferred, resulting in the fluctuation of the electrochemical redox signal on the electrode surface, whereas the electrochemical signal will be stable when EGFR L858R is absent. Therefore, the concentration of EGFR L858R can be quantified by electrochemical signal analysis. The low detection limit is 0.34 fM and the dynamic detection range is from 1 fM to 1 μM in this work. The PER-CRISPR/Cas14a electrochemical biosensor greatly improved the analytical sensitivity. In addition, this platform also exhibited excellent specificity, reproducibility, stability and good recovery. This study provides an efficient and novel strategy for the detection of ctDNA EGFR L858R, which has great potential for application in the diagnosis and treatment of NSCLC.

MscI restriction enzyme cooperating recombinase-aided isothermal amplification for the ultrasensitive and rapid detection of low-abundance EGFR mutations on microfluidic chip

The detection of low-abundance mutation genes of the epidermal growth factor receptor (EGFR) exon 21 (EGFR L858R) plays a crucial role in the diagnosis of non-small cell lung cancer (NSCLC), as it enables early cancer detection and facilitates the development of treatment strategies. A detection platform was developed by combining the MscI restriction enzyme with the recombinase-aided isothermal amplification (RAA) technique (MRE-RAA). During the RAA process, “TGG^CCA” site of the wild-type genes was cleaved by the MscI restriction enzyme, while only the low-abundance mutation genes underwent amplification. Notably, when the RAA product was combined with CRISPR-Cas system, the sensitivity of detecting the EGFR L858R mutation increased by up to 1000-fold for addition of the MscI restriction enzyme. This achievement marked the first instance of attaining an analytical sensitivity of 0.001%. Furthermore, a disk-shaped microfluidic chip was developed to automate pretreatment while concurrently analyzing four blood samples. The microfluidic features of the chip include DNA extraction, MRE-RAA, and CRISPR-based detection. The fluorescence signal is employed for detection in the microfluidic chip, which is visible to the naked eye upon exposure to blue light irradiation. Furthermore, this platform has the capability to facilitate early diagnosis for various types of cancer by enabling high-sensitivity detection of low-abundance mutation genes.

Brain metastasis, EGFR mutation subtype and generation of EGFR-TKI jointly influence the treatment outcome of patient with EGFR-mutant NSCLC

Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation is brain metastasis (BM)-prone. We determined the impact of this hallmark, along with EGFR subtype and generation of tyrosine kinase inhibitor (TKI) treatment, on patients’ outcome. 553 metastatic EGFR-mutant NSCLC patients received front-line EGFR-TKI treatment. Progression-free survival (PFS), overall survival (OS) and secondary T790M rate were analysed. BM was observed in 211 (38.2%) patients. BM (HR 1.20 [95% CI 0.99–1.48]; p = 0.053), ECOG PS 0–1 (HR 0.71 [95% CI 0.54–0.93]; p = 0.014) and afatinib treatment (HR 0.81 [95% CI 0.66–0.99]; p = 0.045) were associated with PFS. Afatinib-treated patients without BM demonstrated a significantly longer PFS (16.3 months) compared to afatinib-treated patients with BM (13.7 months) and to gefitinib/erlotinib-treated patients with (11.1 months) or without BM (14.2 months; p < 0.001). CNS-only progression trended higher in afatinib-treated patients. ECOG PS 0–1 (HR 0.41 [95% CI 0.31–0.56]; p < 0.001) and EGFR L858R mutation (HR 1.46 [95% CI 1.13–1.88]; p = 0.003), but not BM, were the predictors for OS. BM (OR 2.02 [95% CI 1.02–4.08]; p = 0.040), afatinib treatment (OR 0.26 [95% CI 0.12–0.50]; p < 0.001) and EGFR L858R mutation (OR 0.55 [95% CI 0.28–1.05]; p = 0.070) were associated with secondary T790M rate. In BM patients, gefitinib/erlotinib-treated ones with 19 deletion mutation and afatinib-treated ones with L858R mutation had the highest and the lowest T790M rate (94.4% vs. 27.3%, p < 0.001), respectively. BM and generation of EGFR-TKI jointly impact PFS and secondary T790M rate in patients with EGFR-mutant NSCLC, whereas OS was mainly associated with EGFR subtype.

Tissue and Plasma-Based Highly Sensitive Blocker Displacement Amplicon Nanopore Sequencing for EGFR Mutations in Lung Cancer.

The epidermal growth factor receptor (EGFR) mutation is a widely prevalent oncogene driver in non-small cell lung cancer (NSCLC) in East Asia. The detection of EGFR mutations is a standard biomarker test performed routinely in patients with NSCLC for the selection of targeted therapy. Here, our objective was to develop a portable new technique for detecting EGFR (19Del, T790M, and L858R) mutations based on Nanopore sequencing. The assay employed a blocker displacement amplification (BDA)-based polymerase chain reaction (PCR) technique combined with Nanopore sequencing to detect EGFR mutations. Mutant and wild-type EGFR clones were generated from DNA from H1650 (19Del heterozygous) and H1975 (T790M and L858R heterozygous) lung cancer cell lines. Then, they were mixed to assess the performance of this technique for detecting low variant allele frequencies (VAFs). Subsequently, formalin-fixed, paraffin-embedded (FFPE) tissue and cell-free DNA (cfDNA) from patients with NSCLC were used for clinical validation. The assay can detect low VAF at 0.5% mutant mixed in wild-type EGFR. Using FFPE DNA, the concordance rates of EGFR 19Del, T790M, and L858R mutations between our method and Cobas real-time PCR were 98.46%, 100%, and 100%, respectively. For cfDNA, the concordance rates of EGFR 19Del, T790M, and L858R mutations between our method and droplet digital PCR were 94.74%, 100%, and 100%, respectively. The BDA amplicon Nanopore sequencing is a highly accurate and sensitive method for the detection of EGFR mutations in clinical specimens.

Osimertinib tolerance in a patient with Stevens Johnson syndrome during osimertinib therapy after treatment with pembrolizumab

BackgroundOsimertinib has emerged as an important tool in the treatment of non-small cell lung cancers (NSCLC) with certain activating mutations of epidermal growth factor receptor (EGFR). However, Osimertinib may cause adverse effects, including severe cutaneous adverse reactions (SCARs) such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The risk of certain adverse effects may be increased in the setting of recent use of immune checkpoint inhibitor (ICI) therapy, although it is unclear whether recent use of ICI therapy is a risk factor for Osimertinib-induced SJS specifically.Case presentationWe present a patient with EGFR L858R mutation-positive metastatic NSCLC who developed Osimertinib-induced SJS after recent administration of eight cycles of a pembrolizumab-containing chemotherapy regimen. Osimertinib, which was the best treatment targeting his lung cancer, was avoided due to history of SJS. Four years later, because of unresponsiveness or side effects of alternative treatments, he underwent Osimertinib challenge and tolerated it.ConclusionThis case highlights the importance of multi-disciplinary care and supports the hypothesis that the risk of SJS to Osimertinib is significantly higher in the context of recent administration of ICI therapy and, patients may tolerate Osimertinib after certain time has elapsed after the last dose of ICI.

Do patient characteristics affect EGFR tyrosine kinase inhibitor treatment outcomes? A network meta-analysis of real-world survival outcomes of East Asian patients with advanced non-small cell lung cancer treated with first-line EGFR-TKIs.

Despite the well-established efficacies of tyrosine kinase inhibitors (TKIs) in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), there is limited real-world evidence comparing their effectiveness according to patients' clinical characteristics. This network meta-analysis (NMA) compared survival outcomes among first-line EGFR-TKIs in different subgroups of East Asian patients with advanced NSCLC. This NMA included real-world observational studies reporting outcomes with TKIs in patients aged >65 years, with baseline brain metastasis, with different Eastern Cooperative Oncology Group (ECOG) statuses, or with different common EGFR mutation types. In patients with the EGFR L858R mutation, afatinib resulted in significantly longer progression-free survival (PFS) than erlotinib (hazard ratio [HR]: 0.59, 95% confidence interval [CI]: 0.46-0.75) and gefitinib (HR: 0.41, 95% CI: 0.32-0.53). Similarly, in patients with the EGFR Del19 mutation, afatinib and erlotinib resulted in significantly longer PFS than gefitinib (HR: 0.48 with 95% CI: 0.33-0.71 and HR: 0.54 with 95% CI: 0.36-0.80, respectively). Moreover, afatinib resulted in significantly longer PFS than gefitinib in patients with brain metastasis (HR: 0.53, 95% CI: 0.33-0.87) or ECOG status 0-1 (HR: 0.37, 95% CI: 0.23-0.59). This NMA suggests that afatinib results in similar PFS to erlotinib and superior PFS than gefitinib in patients with Del19 mutant NSCLC, aged ≥65 years, with ECOG scores of 0-1, and with baseline brain metastasis.

Expression of EGFR-mutant proteins and genomic evolution in EGFR-mutant transformed small cell lung cancer.

The transformation of epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (LUAD) into small cell lung cancer (SCLC) accounts for 3-14% of the resistance mechanism to EGFR tyrosine kinase inhibitors (TKIs). At present, there is no relevant research to explore the dynamic expression of EGFR-mutant proteins and genomic evolution in EGFR-mutant transformed SCLC/neuroendocrine carcinoma (NEC). Genetic analysis and protein level analysis by next-generation sequencing (NGS), Whole-exome sequencing (WES) and immunohistochemistry were performed to explore expression of EGFR-mutant proteins and genomic evolution in EGFR-mutant transformed SCLC. The research used three patient-derived organoids (PDOs) to explore the efficacy of combo [chemotherapy (chemo) plus TKI or bevacizumab] treatment. According to the subsequent treatment regimens after SCLC/NEC transformation, 35 patients were divided into chemo (n=21) and combo (n=14) groups. EGFR L858R and EGFR E746-750 del protein expression by immunohistochemistry was 80.0% (4/5) and 100% (6/6), respectively (P=0.455) in initially-transformed tissues. Meanwhile, EGFR-mutant proteins were expressed in 85.7% (6/7) of dynamic rebiopsy tissues or effusion samples after the first transformation. Then, by the pathway enrichment analysis of tissue and plasma NGS, the EGFR-related pathways were still activated after SCLC/NEC transformation. Moreover, WES analysis revealed that transformed SCLC shared a common clonal origin from the baseline LUAD. The drug sensitivity of three PDOs demonstrated potent anti-cancer activity of EGFR-TKIs plus chemo, compared with chemo or TKI alone. There were significant differences in objective response rate (ORR) between the combo and chemo groups [42.9 % vs. 4.8%, P=0.010, 95% confidence interval (CI): 1.5-145.2]. Furthermore, the median post-transformation progression-free survival (pPFS) was significantly prolonged in the combo group, with 5.4 (95% CI: 3.4-7.4) versus 3.5 (95% CI: 2.7-4.3, P=0.012) months. EGFR 19del or L858R-mutant proteins could be constantly expressed, and EGFR pathway still existed in EGFR-mutant transformed SCLC/NEC with a common clonal origin from the baseline LUAD. Taking together, these molecular characteristics potentially favored clinical efficacy in transformed SCLC/NEC treated with the combo regimen.

Effects of concurrent TP53 mutations on the efficacy and prognosis of targeted therapy for advanced EGFR mutant lung adenocarcinoma

BackgroundHow concurrent TP53 mutations affect targeted therapy of advanced Epidermal Growth Factor Receptor (EGFR) mutant lung adenocarcinoma remains controversial, particularly the deep classification of TP53 mutations. MethodsThis study retrospectively analyzed the clinical data of advanced EGFR mutant lung adenocarcinoma patients treated with EGFR-tyrosine kinase inhibitors (TKIs) in the First Affiliated Hospital of Soochow University. The survival rates were compared using Log-rank tests. Potential prognostic factors were identified using multivariate Cox hazard regression models. ResultsTotal 156 advanced lung adenocarcinoma patients treated with EGFR-TKIs were included in this study. Multivariate analysis showed that male [hazard rate (HR): 1.537, 95% confidence interval (CI): 1.055–2.240, P = 0.025], brain metastasis (HR: 1.707, 95%CI: 1.086–2.682, P = 0.020) and concurrent TP53 mutations (HR: 1.569, 95%CI: 1.051–2.341, P = 0.028) were independent negative predictors of progression-free survival (PFS). EGFR L858R mutations (HR: 2.475, 95%CI: 1.443–4.248, p = 0.001), smoking history (HR: 2.530, 95%CI: 1.352–4.733, P = 0.004) and concurrent TP53 mutations (HR: 2.326, 95%CI: 1.283–4.218, P = 0.005) were associated with worse survival. Further analysis revealed that mutations in TP53 exons 4, 5 and 8 (P<0.05), missense mutations (P = 0.006) and nondisruptive mutations (P<0.001) were associated with shorter PFS, whereas mutations in TP53 exons 5 and 7 (P<0.05), missense mutations and non-missense mutations (P = 0.006; P = 0.007), disruptive mutations and nondisruptive mutations (P = 0.013; P = 0.013) were all associated with poorer survival times. In addition, the PFS and overall survival (OS) of nondisruptive mutations in exon 7 were worse than those in other exons (P = 0.041; P<0.001). ConclusionsConcurrent TP53 mutations conferred worse EGFR-TKIs efficacy and prognosis in advanced EGFR mutant lung adenocarcinoma and the effects of different TP53 mutation types were heterogeneous.

Effect of bevacizumab plus double dose icotinib on advanced non-small cell lung cancer with EGFR L858R mutation.

e21020 Background: Double-dose icotinib has been proven effective and well tolerated for advanced NSCLC patients with the Epidermal Growth Factor Receptor (EGFR) L858R mutation. For the same patients, the excellent efficacy of bevacizumab combined with erlotinib has been proven in previous studies. In this study, we would investigate the efficacy of the combined therapy bevacizumab and double-dose icotinib for advanced NSCLC patients with EGFR L858R mutation. Methods: 35 patients diagnosed from September 2, 2021 to September 28, 2022 were enrolled in this study and 5 patients were excluded for analysis due to missing efficacy evaluation data. All patients were treated with intravenous bevacizumab (15mg / kg) combined with oral double-dose icotinib (250mg, tid). The primary endpoint was progression-free survival (PFS), and the secondary endpoints were safety, efficacy, and overall survival (OS). Results: Among the 35 patients, 12 were male and 23 were female. The median age at diagnosis was 66. Eight patients were diagnosed with brain metastases. All of the patients have EGFR L858R mutation, and 14 patients were with other coexisting mutations. To the data of December 31, 2022, the median follow-up time was 10 months (range: 3 to 18 months). For 30 patients with complete efficacy evaluation data, 20 patients achieved partial responses (PR), 9 patients had stable disease (SD), and 1 patient developed progress disease (PD). The objective response rate (ORR) was 66.7%, the disease control rate (DCR) was 96.7%, and the median PFS was 14.8 months. For adverse reaction evaluation, the grade 3 adverse events were albuminuria (n = 1) and hepatotoxicity (n = 1). Other adverse events were grade 1-2, mainly oral mucositis, rash, diarrhea and hypertension. Conclusions: The combination of bevacizumab with double-dose icotinib is an effective and relatively safe treatment for advanced NSCLC patients with EGFR L858R mutation. Further exploration will provide more evidence for this type of treatment. Clinical trial information: NCT05263947 .

Aumolertinib with chemotherapy or alone compared with osimertinib in patients with EGFR-mutant non–small-cell lung cancer (TREBLE).

TPS9153 Background: Aumolertinib is a novel third-generation (3G) epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). Safety and efficacy of aumolertinib have been demonstrated in patients with EGFR-mutated locally advanced or metastatic (LA/m) NSCLC. (Lu, 2021; Lu, 2022) A phase 3 study in these patients in the first-line setting showed a significant improvement in progression-free survival (PFS) for aumolertinib vs gefitinib (median 19.3 months versus 9.9 months; P &lt; 0.0001). Aumolertinib was generally well-tolerated. (Lu, 2022) Aumolertinib is approved in China for patients with LA/m NSCLC who have an EGFR T790M resistance mutation upon disease progression and for treatment naïve patients with EGFR-mutated NSCLC. Studies evaluating first-generation EGFR-TKI + chemotherapy (chemo) showed improved PFS in select patient populations. (Hosomi, 2019) It is unclear if the addition of chemo to a 3G EGFR-TKI will improve PFS in patients with EGFR-mutated LA/m NSCLC. As the addition of chemo to a 3G EGFR-TKI may prove warranted, there is a need to understand the relative efficacy and safety in the diversity of patients encountered in routine clinical practice. (Tanaka, 2021). Methods: This is a randomized, multi-regional, phase 3 clinical trial comparing aumolertinib + chemo or aumolertinib monotherapy with osimertinib monotherapy. Patients are eligible if they have stage IIIB, IVA, or IVB NSCLC; harbor ex19del or L858R EGFR mutations alone or with other EGFR mutations; and have an ECOG PS of ≤2. Patients are ineligible if they received prior systemic therapy for mNSCLC or are a candidate for curative intent therapy. Eligible patients will be randomized 2:2:1 and stratified by mutation status (ex19del or L858R), ECOG PS (0 vs 1/2), and race (White vs Asian vs other races combined). Anticipated enrollment is 500 patients; 200 to receive aumolertinib + chemo (110 mg PO QD aumolertinib + investigator's choice chemo), 200 to receive osimertinib (80 mg PO QD), and 100 to receive aumolertinib (110 mg PO QD). The primary endpoint is PFS, by blinded independent review committee (BICR) per RECIST 1.1, for aumolertinib + chemo vs osimertinib. Overall survival (OS) is a key secondary endpoint for aumolertinib + chemo vs osimertinib. Additional efficacy endpoints will be assessed for aumolertinib + chemo vs osimertinib and aumolertinib vs osimertinib, as well as safety and patient reported outcomes. Exploratory endpoints include characterizing mechanisms of acquired resistance across all arms, CNS efficacy, and exposure-response relationship. Enrollment began in July 2022. The study is currently recruiting and will include approximately 200 sites globally. The study design will provide a power of 80% at a 2-sided Type I error of 0.05 for the primary endpoint. If the primary endpoint is statistically significant, a sequential test method will be used to evaluate OS. Clinical trial information: NCT05493501 .

Osimertinib combined with bevacizumab as the first-line treatment in non-small cell lung cancer patients with brain metastasis harboring epidermal growth factor receptor mutations.

The efficacy and safety of osimertinib combined with bevacizumab in non-small cell lung cancer (NSCLC) patients with brain metastasis harboring epidermal growth factor receptor (EGFR) mutations have not been fully studied. Treatment-naïve NSCLC patients with brain metastasis harboring EGFR-activating mutations were treated with osimertinib 80 mg oral daily and bevacizumab 15 mg/kg intravenously on day 1, repeated every 21 days, until disease progression, intolerable toxicity, or death. The primary endpoint was the median progression-free survival (mPFS), and the secondary endpoints were the median overall survival (mOS), response rates, and toxicities. This study has been registered in ClinicalTrials.gov (NCT05104281) and is ongoing. A total of 52 Chinese patients were enrolled, of whom 17 harbored EGFR 19 del and 35 harbored EGFR L858R mutation. The objective response rate (ORR) was 75.0% and the disease control rate (DCR) was 96.2%; the mPFS was 17.0 months (95% CI: 11.46-22.54), while the mOS was not reached. The mPFS was 20.0 months (95% CI: 14.56-25.44) and was 17.0 months (95% CI: 13.28-20.72) for patients harboring EGFR 19 del and EGFR L858R mutation (p = 0.844), respectively. The intracranial ORR was 82.7%, and the intracranial mPFS was 22.0 months (95% CI: 2.92-41.08).The main adverse events were mild-to-moderate hand-foot syndrome, diarrhea, hypertension, and proteinuria. Three patients developed grade III proteinuria, while five patients developed grade III hypertension; they permanently discontinued bevacizumab treatment. Osimertinib combined with bevacizumab shows promising results in EGFR-mutated NSCLC patients with brain metastasis, and the side effects are tolerable.

Precision immunointerception of EGFR-driven tumorigenesis for lung cancer prevention.

Epidermal growth factor receptor (EGFR) mutations occur in about 50% of lung adenocarcinomas in Asia and about 15% in the US. EGFR mutation-specific inhibitors have been developed and made significant contributions to controlling EGFR mutated non-small cell lung cancer. However, resistance frequently develops within 1 to 2 years due to acquired mutations. No effective approaches that target mutant EGFR have been developed to treat relapse following tyrosine kinase inhibitor (TKI) treatment. Vaccination against mutant EGFR is one area of active exploration. In this study, we identified immunogenic epitopes for the common EGFR mutations in humans and formulated a multi-peptide vaccine (Emut Vax) targeting the EGFR L858R, T790M, and Del19 mutations. The efficacy of the Emut Vax was evaluated in both syngeneic and genetic engineered EGFR mutation-driven murine lung tumor models with prophylactic settings, where the vaccinations were given before the onset of the tumor induction. The multi-peptide Emut Vax effectively prevented the onset of EGFR mutation-driven lung tumorigenesis in both syngeneic and genetically engineered mouse models (GEMMs). Flow cytometry and single-cell RNA sequencing were conducted to investigate the impact of Emut Vax on immune modulation. Emut Vax significantly enhanced Th1 responses in the tumor microenvironment and decreased suppressive Tregs to enhance anti-tumor efficacy. Our results show that multi-peptide Emut Vax is effective in preventing common EGFR mutation-driven lung tumorigenesis, and the vaccine elicits broad immune responses that are not limited to anti-tumor Th1 response.