Selective Epidermal Growth Factor Receptor Research Articles

A Novel Network Pharmacology Strategy Based on the Universal Effectiveness-Common Mechanism of Medical Herbs Uncovers Therapeutic Targets in Traumatic Brain Injury.

Many herbs can promote neurological recovery following traumatic brain injury (TBI). There must lie a shared mechanism behind the common effectiveness. We aimed to explore the key therapeutic targets for TBI based on the common effectiveness of the medicinal plants. The TBI-effective herbs were retrieved from the literature as imputes of network pharmacology. Then, the active ingredients in at least two herbs were screened out as common components. The hub targets of all active compounds were identified through Cytohubba. Next, AutoDock vina was used to rank the common compound-hub target interactions by molecular docking. A highly scored compound-target pair was selected for in vivo validation. We enrolled sixteen TBI-effective medicinal herbs and screened out twenty-one common compounds, such as luteolin. Ten hub targets were recognized according to the topology of the protein-protein interaction network of targets, including epidermal growth factor receptor (EGFR). Molecular docking analysis suggested that luteolin could bind strongly to the active pocket of EGFR. Administration of luteolin or the selective EGFR inhibitor AZD3759 to TBI mice promoted the recovery of body weight and neurological function, reduced astrocyte activation and EGFR expression, decreased chondroitin sulfate proteoglycans deposition, and upregulated GAP43 levels in the cortex. The effects were similar to those when treated with the selective EGFR inhibitor. The common effectiveness-based, common target screening strategy suggests that inhibition of EGFR can be an effective therapy for TBI. This strategy can be applied to discover core targets and therapeutic compounds in other diseases.

Anticancer Evaluation of Novel Benzofuran-Indole Hybrids as Epidermal Growth Factor Receptor Inhibitors against Non-Small-Cell Lung Cancer Cells.

The epidermal growth factor receptor (EGFR), also known as ErbB1 and HER1, belongs to the receptor tyrosine kinase family. EGFR serves as the primary driver in non-small-cell lung cancer (NSCLC) and is a promising therapeutic target for NSCLC. In this study, we synthesized a novel chemical library based on a benzofuran-indole hybrid scaffold and identified 8aa as a potent and selective EGFR inhibitor. Interestingly, 8aa not only showed selective anticancer effects against NSCLC cell lines, PC9, and A549, but it also showed significant inhibitory effects against the double mutant L858R/T790M EGFR, which frequently occurs in NSCLC. In addition, in PC9 and A549 cells, 8aa potently blocked the EGFR signaling pathway, cell viability, and cell migration. These findings suggest that 8aa, a benzofuran-indole hybrid derivative, is a novel EGFR inhibitor that may be a potential candidate for the treatment of NSCLC patients with EGFR mutations.

Perinatal triphenyl phosphate exposure induces metabolic dysfunctions through the EGFR/ERK/AKT signaling pathway: Mechanistic in vitro and in vivo studies

Triphenyl phosphate (TPhP), a widely used organophosphate-flame retardant, is ubiquitously found in household environments and may adversely affect human health. Evidence indicates that TPhP exposure causes metabolic dysfunctions in vivo; however, the underlying mechanism of such adverse effects has not been comprehensively investigated. Herein, we utilized two in vitro models including mouse and human preadipocytes to delineate adipogenic mechanisms of TPhP. The results revealed that both mouse and human preadipocytes exposed to TPhP concentration-dependently accumulated more fat through a significant upregulation of epidermal growth factor receptor (EGFR). We demonstrated that TPhP significantly promoted adipogenesis through the activation of EGFR/ERK/AKT signaling pathway as evident by a drastic reduction in adipogenesis of preadipocytes cotreated with inhibitors of EGFR and its major effectors. Furthermore, we confirmed the mechanism of TPhP-induced metabolic dysfunctions in vivo. We observed that male mice perinatally exposed to TPhP had a significant increase in adiposity, hepatic triglycerides, insulin resistance, plasma insulin levels, hypotension, and phosphorylated EGFR in gonadal fat. Interestingly, an administration of a potent and selective EGFR inhibitor significantly ameliorated the adverse metabolic effects caused by TPhP. Our findings uncovered a potential mechanism of TPhP-induced metabolic dysfunctions and provided implications on toxic metabolic effects posed by environmental chemicals.

Design, synthesis and biological evaluation of structurally new 4-indolyl quinazoline derivatives as highly potent, selective and orally bioavailable EGFR inhibitors

Targeting the epidermal growth factor receptor (EGFR) has been recognized as an effective strategy for treating non-small-cell lung cancer (NSCLC). Although several representative EGFR inhibitors have been approved for clinical use, it is highly desirable to develop highly potent and selective EGFR inhibitors with novel scaffolds because of the occurrence of acquired resistance after treatment. Here we first demonstrate that the 4-indolyl quinazoline derivatives could potently inhibit EGFR in vitro and in vivo, of which YS-67 effectively and selectively inhibits EGFR[WT] (IC50 = 5.2 nM), EGFR[d746-750] (IC50 = 9.6 nM) and EGFR[L858R] (IC50 = 1.9 nM). The TREEspot™ kinase interaction map further reveals the binding selectivity toward 468 kinases. YS-67 not only potently suppresses p-EGFR and p-AKT, but also effectively inhibits proliferation of A549 (IC50 = 4.1 μM), PC-9 (IC50 = 0.5 μM) and A431 cells (IC50 = 2.1 μM). YS-67 treatment also causes colony formation inhibition, arrests cell cycle progression at G0/G1 phases and induces apoptosis. More importantly, YS-67 is well tolerated in A431 xenograft model after oral administration, showing effective tumor growth suppression and low toxicity. Collectively, YS-67 represents an underexplored scaffold for developing new EGFR inhibitors.

Epidermal growth factor receptor activation is essential for kidney fibrosis development

Fibrosis is the progressive accumulation of excess extracellular matrix and can cause organ failure. Fibrosis can affect nearly every organ including kidney and there is no specific treatment currently. Although Epidermal Growth Factor Receptor (EGFR) signaling pathway has been implicated in development of kidney fibrosis, underlying mechanisms by which EGFR itself mediates kidney fibrosis have not been elucidated. We find that EGFR expression increases in interstitial myofibroblasts in human and mouse fibrotic kidneys. Selective EGFR deletion in the fibroblast/pericyte population inhibits interstitial fibrosis in response to unilateral ureteral obstruction, ischemia or nephrotoxins. In vivo and in vitro studies and single-nucleus RNA sequencing analysis demonstrate that EGFR activation does not induce myofibroblast transformation but is necessary for the initial pericyte/fibroblast migration and proliferation prior to subsequent myofibroblast transformation by TGF-ß or other profibrotic factors. These findings may also provide insight into development of fibrosis in other organs and in other conditions.

Loss of EGF receptor polarity enables homeostatic imbalance in epithelial-cell models.

The polarized distribution of membrane proteins into apical and basolateral domains provides the basis for specialized functions of epithelial tissues. The EGF receptor (EGFR) plays important roles in embryonic development, adult-epithelial tissue homeostasis, and growth and survival of many carcinomas. Typically targeted to basolateral domains, there is also considerable evidence of EGFR sorting plasticity but very limited knowledge regarding domain-specific EGFR substrates. Here we have investigated effects of selective EGFR mistargeting because of inactive-basolateral sorting signals on epithelial-cell homeostatic responses to growth-induced stress in MDCK cell models. Aberrant EGFR localization was associated with multilayer formation, anchorage-independent growth, and upregulated expression of the intermediate filament-protein vimentin characteristically seen in cells undergoing epithelial-to-mesenchymal transition. EGFRs were selectively retained following their internalization from apical membranes, and a signaling pathway involving the signaling adaptor Gab1 protein and extracellular signal-regulated kinase ERK5 had an essential role integrating multiple responses to growth-induced stress. Our studies highlight the potential importance of cellular machinery specifying EGFR polarity in epithelial pathologies associated with homeostatic imbalance.

In-silico design, pharmacophore-based screening, and molecular docking studies reveal that benzimidazole-1,2,3-triazole hybrids as novel EGFR inhibitors targeting lung cancer

Lung cancer is a complex and heterogeneous disease, which has been associated with various molecular alterations, including the overexpression and mutations of the epidermal growth factor receptor (EGFR). In this study, designed a library of 1843 benzimidazole-1,2,3-triazole hybrids and carried out pharmacophore-based screening to identify potential EGFR inhibitors. The 164 compounds were further evaluated using molecular docking and molecular dynamics simulations to understand the binding interactions between the compounds and the receptor. In-si-lico ADME and toxicity studies were also conducted to assess the drug-likeness and safety of the identified compounds. The results of this study indicate that benzimidazole-1,2,3-triazole hybrids BENZI-0660, BENZI-0125, BENZI-0279, BENZI-0415, BENZI-0437, and BENZI-1110 exhibit dock scores of −9.7, −9.6, −9.6, −9.6, −9.6, −9.6 while referencing molecule −7.9 kcal/mol for EGFR (PDB ID: 4HJO), respectively. The molecular docking and molecular dynamics simulations revealed that the identified compounds formed stable interactions with the active site of EGFR, indicating their potential as inhibitors. The in-silico ADME and toxicity studies showed that the compounds had favorable drug-likeness properties and low toxicity, further supporting their potential as therapeutic agents. Finally, performed DFT studies on the best-selected ligands to gain further insights into their electronic properties. The findings of this study provide important insights into the potential of benzimidazole-1,2,3-triazole hybrids as promising EGFR inhibitors for the treatment of lung cancer. This research opens up a new avenue for the discovery and development of potent and selective EGFR inhibitors for the treatment of lung cancer. Communicated by Ramaswamy H. Sarma

The next generation of EGFR inhibitors: a patenting perspective of PROTACs based EGFR degraders

ABSTRACT Introduction Abnormal expression of epidermal growth factor receptor (EGFR) contributes to tumor development, especially in non-small cell lung cancer (NSCLC). Although multiple inhibitors have been developed to target diverse EGFR mutations and several have been approved, the inevitable drug resistance and side effect remain a challenge, which motivates novel strategies. Proteolysis-targeting chimeras (PROTACs) have been gaining momentum for their potential as novel therapeutics for human diseases by triggering protein degradation. To date, various potent and specific EGFR PROTACs have been discovered and some of them have entered clinical trials. Areas covered This review provides an overview of EGFR degraders in patents from 2016 to 2022. It provides an update of the discovery strategies, chemical structures, and molecular profiling of all available EGFR PROTACs. SciFinder, PubMed, Web of Science, EPO, and CNIPA databases were used for searching the literature and patents for EGFR PROTACs. Expert opinion By employing the PROTAC technology, highly potent and selective EGFR degraders based on four generation EGFR inhibitors have been developed, which offer a new strategy to target EGFR mutations and overcome the drug resistance. Despite the satisfactory result in vitro and in vivo studies, their therapeutic value awaits more rigorous preclinical testing and clinical investigation.

Cellular photo(geno)toxicity of gefitinib after biotransformation.

Gefitinib (GFT) is a selective epidermal growth factor receptor (EGFR) inhibitor clinically used for the treatment of patients with non-small cell lung cancer. Bioactivation by mainly Phase I hepatic metabolism leads to chemically reactive metabolites such as O-Demethyl gefitinib (DMT-GFT), 4-Defluoro-4-hydroxy gefitinib (DF-GFT), and O-Demorpholinopropyl gefitinib (DMOR-GFT), which display an enhanced UV-light absorption. In this context, the aim of the present study is to investigate the capability of gefitinib metabolites to induce photosensitivity disorders and to elucidate the involved mechanisms. According to the neutral red uptake (NRU) phototoxicity test, only DF-GFT metabolite can be considered non-phototoxic to cells with a photoirritation factor (PIF) close to 1. Moreover, DMOR-GFT is markedly more phototoxic than the parent drug (PIF = 48), whereas DMT-GFT is much less phototoxic (PIF = 7). Using the thiobarbituric acid reactive substances (TBARS) method as an indicator of lipid photoperoxidation, only DMOR-GFT has demonstrated the ability to photosensitize this process, resulting in a significant amount of TBARS (similar to ketoprofen, which was used as the positive control). Protein photooxidation monitored by 2,4-dinitrophenylhydrazine (DNPH) derivatization method is mainly mediated by GFT and, to a lesser extent, by DMOR-GFT; in contrast, protein oxidation associated with DMT-GFT is nearly negligible. Interestingly, the damage to cellular DNA as revealed by the comet assay, indicates that DMT-GFT has the highest photogenotoxic potential; moreover, the DNA damage induced by this metabolite is hardly repaired by the cells after a time recovery of 18h. This could ultimately result in mutagenic and carcinogenic effects. These results could aid oncologists when prescribing TKIs to cancer patients and, thus, establish the conditions of use and recommend photoprotection guidelines.

Rapid high performance liquid chromatography method for erlotinib quantification in vitro: Application to study the effect of resveratrol on metabolism and cellular uptake of erlotinib.

Erlotinib is a selective epidermal growth factor receptor inhibitor that is used for the treatment of non-small cell lung cancer and pancreatic cancer. Its metabolism is mainly mediated by cytochrome P450 3A (CYP 3A). Resveratrol, a natural compound found in many plants and supplements, is known to inhibit CYP3A enzyme, therefore, it may act as an inhibitor for the metabolism of erlotinib. Development of a rapid high performance liquid chromatography with photodiode array detection (HPLC-PDA) method for the quantification of erlotinib in liver microsomes and cancer cells and its application to study resveratrol effect on metabolism and cellular uptake of erlotinib. HPLC-PDA was used to develop an efficient bioanalytical method with a 2.5-min runtime preceded by a simple protein precipitation step. The method was validated according to the European Medicines Agency guidelines. Erlotinib metabolic stability and resveratrol effect on erlotinib metabolite formation were evaluated in rat liver microsomes. Furthermore, the method was used to measure the intracellular concentrations of erlotinib in cancer colorectal cells and investigating resveratrol effect on the cellular uptake of erlotinib. A rapid HPLC-PDA method was developed and validated for the first time to address potential drug interaction of erlotinib with resveratrol. Resveratrol was a strong inhibitor of erlotinib metabolism in vitro with IC50 = 4.03 μM. Resveratrol, however, had no effect on erlotinib cellular uptake after 1h incubation in human colorectal cancer cells. The study suggests that resveratrol may produce a potential herb-drug interaction with erlotinib at the metabolism level and should be investigated in patients in the clinic.

A Novel and Highly Selective Epidermal Growth Factor Receptor Inhibitor, SMUZ106, for the Treatment of Glioblastoma.

Targeting the epidermal growth factor receptor (EGFR) is one of the potential ways to treat glioblastoma (GBM). In this study, we investigate the anti-GBM tumor effects of the EGFR inhibitor SMUZ106 in both in vitro and in vivo conditions. The effects of SMUZ106 on the growth and proliferation of GBM cells were explored through MTT and clone formation experiments. Additionally, flow cytometry experiments were conducted to study the effects of SMUZ106 on the cell cycle and apoptosis of GBM cells. The inhibitory activity and selectivity of SMUZ106 to the EGFR protein were proved by Western blotting, molecular docking, and kinase spectrum screening methods. We also conducted a pharmacokinetic analysis of SMUZ106 hydrochloride following i.v. or p.o. administration to mice and assessed the acute toxicity level of SMUZ106 hydrochloride following p.o. administration to mice. Subcutaneous and orthotopic xenograft models of U87MG-EGFRvIII cells were established to assess the antitumor activity of SMUZ106 hydrochloride in vivo. SMUZ106 could inhibit the growth and proliferation of GBM cells, especially for the U87MG-EGFRvIII cells with a mean IC50 value of 4.36 μM. Western blotting analyses showed that compound SMUZ106 inhibits the level of EGFR phosphorylation in GBM cells. It was also shown that SMUZ106 targets EGFR and presents high selectivity. In vivo, the absolute bioavailability of SMUZ106 hydrochloride was 51.97%, and its LD50 exceeded 5000 mg/kg. SMUZ106 hydrochloride significantly inhibited GBM growth in vivo. Furthermore, SMUZ106 inhibited the activity of U87MG-resistant cells induced by temozolomide (TMZ) (IC50: 7.86 μM). These results suggest that SMUZ106 hydrochloride has the potential to be used as a treatment method for GBM as an EGFR inhibitor.

Design, Synthesis, and Antitumor Activity of Potent and Selective EGFR L858R/T790M Inhibitors and Identification of a Combination Therapy to Overcome Acquired Resistance in Models of Non-small-cell Lung Cancer.

Epidermal growth factor receptor (EGFR) is one of the most studied drug targets for the treatment of non-small-cell lung cancer (NSCLC). Here, we report the identification, structure optimization, and structure-activity relationship studies of quinazoline derivatives as novel selective EGFR L858R/T790M inhibitors. The most promising compound, 28f, exhibited strong inhibitory activity against EGFR L858R/T790M (IC50 = 3.5 nM) and greater than 368-fold selectivity over EGFR WT (IC50 = 1290 nM), a 6.7-fold improvement over osimertinib. Furthermore, 28f effectively inhibited downstream signaling pathways and induced apoptosis in mutant cells. In the H1975 xenograft in vivo model, 28f exhibited a good tumor suppressive effect. Furthermore, the combination of 28f with the ACK1 inhibitor dasatinib produced synergistic antiproliferative efficacy with 28f in 28f-resistant cells and in vivo. In conclusion,28f could become a candidate drug for the treatment of NSCLC, and the combination of 28f and dasatinib is expected to overcome EGFR resistance.

A Potential Boron Neutron Capture Therapy Agent Selectively Suppresses High-Grade Glioma: In Vitro and in Vivo Exploration.

Glioblastoma (GBM), as the most central nervous system (CNS) intractable disease, has spoiled millions of lives due to its high mortality. Even though several efforts have been made, the existing treatments have had limited success. In this sense, we studied a lead compound, the boron-rich selective epidermal growth factor receptor (EGFR)-inhibitor hybrid 1, as a potential drug for GBM treatment. For this end, we analyzed the in vitro activity of hybrid 1 in a glioma/primary astrocytes coculture, studying cellular death types triggered by treatment with this compound and its cellular localizations. Additionally, hybrid 1 concentrated boron in glioma cells selectively and more effectively than the boron neutron capture therapy (BNCT)-clinical agent 10B-l-boronophenylalanine and thus displayed a better in vitro-BNCT effect. This encouraged us to analyze hybrid 1 in vivo. Therefore, immunosuppressed mice bearing U87 MG human GBM were treated with both 1 and 1 encapsulated in a modified liposome (recognized by brain-blood barrier peptide transporters), and we observed a potent in vivo per se antitumor activity (tumor size decrease and animal survival increase). These data demonstrate that 1 could be a promising new targeted therapy for GBM.

Development and validation of an LC-MS/MS method for simultaneous determination of SH-1028, an irreversible third-generation EGFR TKI, and two of its metabolites in human plasma: application in clinical pharmacokinetics

SH-1028 is a novel, potent, and highly selective epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) developed for the treatment of T790M Mutation-positive non-small cell lung cancer (NSCLC). The objective was to develop an LC-MS/MS method for the simultaneous determination of SH-1028 and its metabolites, Imp2 and Imp3, in human plasma. The plasma samples were extracted through protein precipitation with acetonitrile on wet ice conditions. A rapid, sensitive, and specific method was developed and successfully applied to evaluate the pharmacokinetic (PK) properties of SH-1028 in patients with advanced NSCLC following single and multiple doses of SH-1028 (60 mg). After single-dose administration, the C max of SH-1028, Imp2, and Imp3 was 11.2, 50.2, and 7.99 ng/mL, respectively. The mean AUC0–24 h was 138, 602, and 76.7 h*ng/mL, respectively. And the terminal half-life time was 19.9, 14.4, and 26.1 h, respectively. After multiple-dose administration, SH-1028 exhibited a slight accumulation, with a mean accumulation ratio (R AUC) of 2.00. The study assessed the PK properties of SH-1028 following single and multiple doses in patients with advanced NSCLC and would provide meaningful information for the further development of SH-1028.

Discovery of HCD3514 as a potent EGFR inhibitor against C797S mutation in vitro and in vivo.

Osimertinib (AZD9291), a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI), has significantly improved the survival of non-small cell lung cancer (NSCLC) patients with EGFRT790M mutation, the major mechanism of acquired resistance to first-generation EGFR TKI. However, resistance to AZD9291 arises eventually and EGFRC797S mutation was reported to be a major resistance mechanism. Thus, it is highly valuable to develop novel EGFR fourth-generation inhibitors targeting C797S mutation to override the acquired resistance. In this study, we identified HCD3514 as a novel EGFR fourth-generation inhibitors targeting C797S triple mutation. It strongly inhibited EGFRL858R/T790M/C797S and EGFR19del/T790M/C797S mutations with IC50 values of 1.0 and 2.0 nM, respectively. HCD3514 dose-dependently inhibited the activation of EGFR in both engineered BaF3 cells and tumor cells harboring EGFRC797S triple mutant and thus effectively suppressed the proliferation of the cells. Moreover, HCD3514 caused a dose-dependent increase of apoptosis in C797S triple mutant cells accompanied by increased levels of cleaved caspase-3 and cleaved PARP. Furthermore, HCD3514 induced tumor growth inhibition in EGFR19del/T790M/C797S xenograft model as a single oral agent by decreasing the activation of EGFR. In addition to EGFRC797S triple mutations, HCD3514 also potently and selectively inhibited EGFRT790M double mutations (L858R/T790M and 19del/T790M). Collectively, HCD3514 is a highly selective and potent EGFR inhibitor against EGFRC797S triple mutations as well as EGFRT790M double mutations and is confirmed potently anti-tumor activity in preclinical models.

Epidermal growth factor receptor mediates the basolateral uptake of phosphorothioate-modified antisense oligonucleotides in the kidney

Antisense oligonucleotides (ASOs) are highly biologically stable and specific therapeutic molecules that interfere with mRNA transcription and as a result effectively reduce the expression of a protein of interest. ASOs have low drug clearance and are retained in tissues. This is particularly evident in the kidneys where they accumulate in the renal proximal tubules. Receptor-mediated endocytosis (RME) plays a role in ASO uptake, however the membrane receptors facilitating the process and the full mechanism behind these transport and subsequent renal retention is still poorly understood. In the present study we employ a proximal tubule-on-a-chip (PTOC) that recapitulates the highly polarized nature of the renal epithelium and can discriminate between basal and apical uptake processes. The PTOC was used to determine the impact of cellular polarization in ASO uptake in the kidney and elucidate which receptors predominantly facilitated uptake. In the PTOC the uptake occurred predominantly from the basolateral side and was extensively inhibited using the selective epidermal growth factor receptor (EGFR) antagonist cetuximab. These results demonstrate that ASO uptake in a physiologically relevant model is predominately mediated by the EGFR and takes place from the basolateral side of the proximal tubules. In comparison to the 2D culture, PTOC could differentiate between distinct ASO uptake routes mediated by either Megalin or EGFR, which proper membrane expression is highly dependent on cellular polarity. Our results highlight the limitations of renal 2D models and demonstrate how an organ on a chip model can fill the physiological gap and is a powerful tool to study ASO, which have intricate transport mechanisms that ultimately impact both their efficacy and safety. • Continuously perfused proximal tubule-on-a-chip model recreates a highly polarized renal epithelium. • Uptake of antisense-oligonucleotides occurs from the basolateral side of the renal proximal tubules. • EGFR drives antisense-oligonucleotide uptake in our proximal tubule-on-a-chip model, an effect not observed in 2D culture.

EP05.02-008 Phase II Trial of Neoadjuvant Icotinib Plus Chemotherapy for Stage II-IIIB EGFR-mutant Non-small-Cell Lung Cancer

Icotinib is a novel and selective epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKI) for oral usage. Adjuvant therapy with icotinib has been confirmed to be associated with the improvement of DFS among patients with EGFR-mutant non-small-cell lung cancer (NSCLC) in several studies. However, the clinical benefit of neoadjuvant icotinib combined with chemotherapy for EGFR-mutant NSCLC remains unknown. This is the first trial evaluating the efficacy and safety of icotinib plus chemotherapy as neoadjuvant therapy for patients with stage II-IIIB EGFR-mutant NSCLC.

Abstract 5457: QLH11811, a selective 4th-generation EGFR inhibitor for osimertinib-resistant EGFR-mutant NSCLC

Abstract Background: The 3rd-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI), like osimertinib, provide marked clinical benefit for EGFR-mutant non-small cell lung cancer (NSCLC) patients with extended overall survival vs former EGFR TKIs (e.g., gefitinib). Approximate 10%-24% of NSCLC patients acquired C797S mutation when treated with osimertinib. Unfortunately, limited treatments are available for patients after osimertinib resistance. QLH11811 is a new generation EGFR TKI designed to target the EGFR with ex19del/L858R/T790M/C797S mutations. Here, we disclosed its preclinical data to support its clinical development in EGFR-mutant NSCLC. Methods: The inhibitory activity of QLH11811 on mutated and wild-type EGFR was tested in engineered cell lines and patient-derived organoid (PDO). The in vivo antitumor activity of QLH11811 was evaluated in the patient-derived xenograft (PDX) model with cis EGFR ex19del/T790M/C797S triple mutations, and the H1975 (cis EGFR L858R/T790M/C797S and cis EGFR ex19del/T790M/C797S), PC-9 (EGFR ex19del), and Ba/F3 (EGFR ex19del/C797S) cell line-derived xenograft (CDX) models. The pharmacokinetic (PK) profile was investigated in animals, and the human PK profile was projected using allometric scaling method. Results: QLH11811 displayed potent anti-proliferation activity against Ba/F3 (EGFR ex19del/T790M/C797S, L858R/T790M/C797S, ex19del/C797S, or L858R/C797S), PC-9 (EGFR ex19del/T790M/C797S), H1975 (EGFR L858R/T790M/C797S, L858R/T790M), H3255 (L858R) and HCC827 (ex19del) with IC50 of 2.6, 3.1, 2.4, 4.1, 51, 50, 27, 21, and 11 nM, respectively. QLH11811 also showed excellent selectivity when compared the above values with its IC50 against Ba/F3 (EGFR wild-type, 61 nM) and A431 (EGFR wild-type, 440nM). QLH11811 demonstrated excellent inhibitory activities against seven osimertinib-resistant PDO models. Daily oral QLH11811 significantly inhibited tumor growth at all doses tested (P <0.001) in the PDX model, the H1975, PC-9, and Ba/F3 CDX models. QLH11811 had good PK profile in mice, rats, dogs, and monkeys, with the absolute bioavailability at 71%, 29%, 80% and 42%. The human PK parameters were obtained by allometric scaling method, and the efficacious dose in human was projected to 103 mg, daily. Conclusion: The in vitro and in vivo preclinical data demonstrated QLH11811 is a highly potent and selective 4th-generation EGFR TKI with activity against the osimertinib-resistant NSCLC with EGFR C797S mutation. The preclinical PK data supported the efficacious dose of QLH11811 in human would be 103 mg. Citation Format: Shansong Zheng, Wei Deng, Qingmei Zheng, Yingying Yang, Na Li, Tan Pang, Xueying Feng, Simon Taylor, Lina Ma, Yaqiong Wu, Ziwei Zhao. QLH11811, a selective 4th-generation EGFR inhibitor for osimertinib-resistant EGFR-mutant NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5457.

Abstract 5461: H002: A wide spectrum, highly selective fourth-generation EGFR inhibitor overcoming resistance harboring C797S mutation in NSCLC

Abstract BACKGROUND: Resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is a major challenge in non-small cell lung cancer (NSCLC) treatment. EGFR activating mutations, such as exon 19 deletions (Del19) and L858R substitution, have been reported in 10-50% of patients with NSCLC. Although these patients respond well to early generations of TKIs, acquired resistance by mechanisms such as T790M mutation compromises their efficacy. Recently, the C797S mutation in combination with Del19 or L858R, and with T790M, has emerged as one of the most common mechanisms underlying on-target resistance to a third generation EGFR TKI, osimertinib. We are developing a fourth-generation EGFR inhibitor, H002, with a wide spectrum and high selectivity to address the growing unmet needs in NSCLC patients harboring C797S mutation. METHODS: H002’s selectivity was assessed by KINOMEscan against more than 400 human kinases. A panel of 44 kinases was further evaluated to enable early identification of off-target effect. In vitro and in vivo anti-tumor efficacy was determined in drug-resistant mutant cell lines, CDX and PDX models. Single mutants (Del or L858R), double mutants (Del/T790M or L858R/T790M) and triple mutants (Del/T790M/C797S or L858R/T790M/C797S) as well as wild type EGFR were assessed. Drug metabolism and pharmacokinetic (DMPK) properties were further assessed. H002’s safety profile was evaluated in rats and beagle dogs, and by hERG potassium channel assay. Acute toxicity, and repeated dose GLP toxicity studies were also conducted in IND-enabling studies. RESULTS: High kinase selectivity and very low off-target effects were demonstrated by kinome-wide profiling and safety screening. H002 was highly active against all forementioned single, double or triple EGFR mutants (IC50 < 5 nM), and highly selective against wild type EGFR. H002 also exhibited potent anti-tumor effects in a dose-dependent manner in various CDX and PDX models. Excellent PK properties were observed in rats and beagle dogs with bioavailability over 70%. H002 was shown to cross the blood-brain barrier post i.g. administration in rats. No adverse effects of respiratory, cardiovascular and central nervous system were observed in safety studies. Repeated-dose toxicity studies only showed EGFR-related adverse reactions, such as gastrointestinal and liver toxicity, with high safety margin over 10-folds. CONCLUSION: H002 has been demonstrated as a promising next generation EGFR inhibitor, with high selectivity, a wide spectrum and potent anti-tumor activity against various EGFR activating mutations, favorable DMPK and safety profiles. It will be further developed as a fourth-generation EGFR inhibitor to overcome drug resistance in NSCLC. Citation Format: Wei Huang, Lin Zhu, Xiaoe Yan, Xin Huang, Jia Hao, Shan Li, Xiangyu Li, Zhiming Chen, Yunchuan Jia, Haibo Li, Jianming Zhang, Xianming Deng, Caihong Yun. H002: A wide spectrum, highly selective fourth-generation EGFR inhibitor overcoming resistance harboring C797S mutation in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5461.

Abstract 5477: Compound A, a fourth-generation allosteric inhibitor, a potent and highly selective EGFR with L858R activating and C797S resistance mutations for the treatment of NSCLC

Abstract The L858R activating mutation in Epidermal Growth Factor Receptor (EGFR) accounts for approximately 40% of EGFR-mutant non-small cell lung cancer (NSCLC). These patients receive targeted therapy targeting EGFR mutation. To date all approved EGFR tyrosine kinase inhibitors (TKIs) are ATP competitive inhibitors, inevitably lead to drug resistance and to disease progress. Osimertinib is a third-generation EGFR TKI that selectively inhibits both EGFR TKI-sensitizing (L858R) mutation and T790M mutation that confers acquired resistance to first- and second-generation EGFR-TKIs. The patients develop secondary resistance L858R/C797S and L858R/T790M/C797S to this treatment in some cases. There have been strong unmet needs for specific therapies targeting C797S resistance mutations. Additionally, toxicities caused by inhibition of wild-type (WT) EGFR are frequently reported with the first-generation inhibitors (e.g. Gefitinib and Erlotinib). Our Compound A is a highly mutant-selective fourth-generation allosteric inhibitor that targets L858 activating mutations and without affecting EGFR WT that compares favorably with all ATP competitive inhibitors, indicating that it might avoid potential toxicities from targeting EGFR WT. Compound A has a single-digit nanomolar potency against L858R activating mutation and those harboring T790M and C797S resistance mutations. Oral administration of Compound A to tumor-bearing mice showed significant antitumor activity as a single-agent at well-tolerated doses via inhibiting EGFR pathway in the engineered osimertinib-resistance EGFRL858R/T790M/C797S and EGFRL858R/C797S CDX models. Furthermore, Compound A demonstrated excellent efficacy in EGFRL858R/T790M CDX model as a single-agent. Collectively, Compound A has a robust potency against L858R activating mutations including T790M, C797S, and T790M/C797S that cause acquired resistance to ATP competitive EGFR TKIs in vitro and in vivo. Based on the preclinical data, Compound A is a potent, orally available, and mutant-selective fourth-generation allosteric inhibitor of EGFR with L858R activating mutations for the treatment of NSCLC, suggesting that it might have the potential to demonstrate activity in the first line and resistance settings as a single agent. The pre-clinical data described here supports the clinical development of Compound A in NSCLC patients with L858R activating mutations of EGFR. Citation Format: Yeji Byeon, Seung Hee Jung, Daseul Yoon, Seock Yong Kang, Jiyeon Park, Hyeim Jo, Seong-Il Choi, Somyi Park, Seung-chul Lee, Yang Hun Tae, Tae Min Kim, Sung-Yup Cho, Soyeon Kim, Donghyun Ko, Dong-Kyu Kim, Dong-Wan Kim. Compound A, a fourth-generation allosteric inhibitor, a potent and highly selective EGFR with L858R activating and C797S resistance mutations for the treatment of NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5477.