Design, synthesis, SAR discussion, in vitro and in vivo evaluation of novel selective EGFR modulator to inhibit L858R/T790M double mutants

Modular and Diverse Synthesis of Acrylamides by Palladium-Catalyzed Hydroaminocarbonylation of Acetylene

The development of all kinds of covalent drugs had a major impact on the improvement of the human health system. Covalent binding to target proteins is achieved by so-called electrophilic warheads, which are incorporated in the respective drug molecule. In the last decade, specifically acrylamides emerged as attractive warheads in covalent drug design. Herein, a straightforward palladium-catalyzed hydroaminocarbonylation of acetylene has been developed, allowing a modular and diverse synthesis of bio-active acrylamides. This general protocol features high atom efficiency, wide functional group compatibility, high chemoselectivity and proceeds additive free under mild reaction conditions. The synthetic utility of this protocol is showcased in the synthesis of ibrutinib, osimertinib, and other bio-active compound derivatives.

Exploring the structural activity relationship of the Osimertinib: A covalent inhibitor of double mutant EGFRL858R/T790M tyrosine kinase for the treatment of Non-Small Cell Lung Cancer (NSCLC)

The USFDA granted regular approval to Osimertinib (AZD9291) on March 2017, for treating individuals with metastatic Non-Small Cell Lung Cancer having EGFR T790M mutation. Clinically, Osimertinib stands at the forefront for the treatment of patients with Non-Small Cell Lung Cancer. Osimertinib forms a covalent bond with the Cys797 residue and predominantly spares binding to WT-EGFR, thereby reducing toxicity and enabling the administration of doses that effectively inhibit T790M. However, a high percentage of patients treated with Osimertinib (AZD9291) developed a tertiary cysteine797 to serine797 (C797S) mutation in the EGFR kinase domain, rendering resistance to it. This comprehensive review sheds light on the chemistry, computational aspects, structural features, and expansive spectrum of biological activities of Osimertinib and its analogues. The in-depth exploration of these facets serves as a valuable resource for medicinal chemists, empowering them to design better Osimertinib analogues. This exhaustive study not only provides insights into improving potency but also emphasizes considerations for mutant selectivity and optimizing pharmacokinetic properties. This review acts as a guiding beacon for the strategic design and development of next-generation Osimertinib analogues.

Biological properties of pyrroloquinoline and pyrroloisoquinoline derivatives

In this review, we summarize pyrroloquinoline and pyrroloisoquinoline derivatives (PQs and PIQs) that act on a broad spectrum of biological targets and are used as bacteriostatic, antiviral, plasmodial, anticancer, antidiabetic and anticoagulant agents. Many of these compounds play important roles in the study of DNA and its interactions, the regulation of the cell cycle and programmed cell death. This review involves twenty-five types of skeletally analogical compounds bearing pyrrole and (iso)quinoline scaffolds with different mutual annelations.

FHND004 inhibits malignant proliferation of multiple myeloma by targeting PDZ-binding kinase in MAPK pathway

Inhibitors of Epidermal growth factor receptor tyrosine kinase (EGFR-TKIs) are producing impressive benefits to responsive types of cancers but challenged with drug resistances. FHND drugs are newly modified small molecule inhibitors based on the third-generation EGFR-TKI AZD9291 (Osimertinib) that are mainly for targeting the mutant-selective EGFR, particularly for the non-small cell lung cancer (NSCLC). Successful applications of EGFR-TKIs to other cancers are less certain, thus the present pre-clinical study aims to explore the anticancer effect and downstream targets of FHND in multiple myeloma (MM), which is an incurable hematological malignancy and reported to be insensitive to first/second generation EGFR-TKIs (Gefitinib/Afatinib). Cell-based assays revealed that FHND004 and FHND008 significantly inhibited MM cell proliferation and promoted apoptosis. The RNA-seq identified the involvement of the MAPK signaling pathway. The protein chip screened PDZ-binding kinase (PBK) as a potential drug target. The interaction between PBK and FHND004 was verified by molecular docking and microscale thermophoresis (MST) assay with site mutation (N124/D125). Moreover, the public clinical datasets showed high expression of PBK was associated with poor clinical outcomes. PBK overexpression evidently promoted the proliferation of two MM cell lines, whereas the FHND004 treatment significantly inhibited survival of 5TMM3VT cell-derived model mice and growth of patient-derived xenograft (PDX) tumors. The mechanistic study showed that FHND004 downregulated PBK expression, thus mediating ERK1/2 phosphorylation in the MAPK pathway. Our study not only demonstrates PBK as a promising novel target of FHND004 to inhibit MM cell proliferation, but also expands the EGFR kinase-independent direction for developing anti-myeloma therapy.

Acute osimertinib exposure induces electrocardiac changes by synchronously inhibiting the currents of cardiac ion channels

Introduction: As the third generation of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), osimertinib has demonstrated more significant cardiotoxicity than previous generations of EGFR-TKIs. Investigating the mechanism of osimertinib cardiotoxicity can provide a reference for a comprehensive understanding of osimertinib-induced cardiotoxicity and the safety of the usage of this drug in clinical practice. Methods: Multichannel electrical mapping with synchronous ECG recording was used to investigate the effects of varying osimertinib concentrations on electrophysiological indicators in isolated Langendorff-perfused hearts of guinea pigs. Additionally, a whole-cell patch clamp was used to detect the impact of osimertinib on the currents of hERG channels transfected into HEK293 cells and the Nav1.5 channel transfected into Chinese hamster ovary cells and acute isolated ventricular myocytes from SD rats. Results: Acute exposure to varying osimertinib concentrations produced prolongation in the PR interval, QT interval, and QRS complex in isolated hearts of guinea pigs. Meanwhile, this exposure could concentration-dependently increase the conduction time in the left atrium, left ventricle, and atrioventricular without affecting the left ventricle conduction velocity. Osimertinib inhibited the hERG channel in a concentration-dependent manner, with an IC50 of 2.21 ± 1.29 μM. Osimertinib also inhibited the Nav1.5 channel in a concentration-dependent manner, with IC50 values in the absence of inactivation, 20% inactivation, and 50% inactivation of 15.58 ± 0.83 μM, 3.24 ± 0.09 μM, and 2.03 ± 0.57 μM, respectively. Osimertinib slightly inhibited the currents of L-type Ca2+ channels in a concentration-dependent manner in acutely isolated rat ventricular myocytes. Discussion: Osimertinib could prolong the QT interval; PR interval; QRS complex; left atrium, left ventricle, and atrioventricular conduction time in isolated guinea pig hearts. Furthermore, osimertinib could block the hERG, Nav1.5, and L-type Ca2+ channels in concentration-dependent manners. Therefore, these findings might be the leading cause of the cardiotoxicity effects, such as QT prolongation and decreased left ventricular ejection fraction.

Synthesis and Evaluation of 2-Amine-4-oxyphosaniline Pyrimidine Derivatives as EGFR L858R/T790M/C797S Mutant Inhibitors

Epidermal growth factor receptor (EGFR) C797S mutation leads to Osimertinib drug resistance by disturbing the covalent biding of Michael acceptor group to the Cys797 residue in the ATP biding cleft. In this manuscript, a class of 2-amine-4-oxyphosaniline pyrimidine derivatives were designed, synthesized and evaluated as new noncovalent reversible EGFR inhibitors against L858R/T790M/C797S (CTL) triple mutant. The kinases inhibitiory activity evaluation showed that four compounds exhibited significant inhibitory activities against CTL (IC₅₀ < 30 nM). In particularly, the most promising compound 7a showed excellent enzymatic inhibitory activity against CTL with IC₅₀ value of 9.9 nM, which was more potent than control compound Osimertinib. Moreover, cell proliferation assays indicated that 7a effectively inhibited H1975-EGFR L858R/T790M/C797S with IC₅₀ value of 0.33 µM. Furthermore, compound 7a displayed good metabolic stabilities in human, rat and mouse liver microsomes, and the putative biding mode of compound 7a with ATP was revealed by molecular docking study. These findings strongly indicated that compound 7a was a promising L858R/T790M/C797S mutant EGFR inhibitor.

Pyrrole-based EGFR inhibitors for the treatment of NCSLC: Binding modes and SARs investigations

The treatment of advanced non-small cell lung cancer (NSCLC) has made substantial progress due to the rapid development of small molecule targeted therapy, with dramatically prolonged survival. As an effective drug for the treatment of NSCLC, epidermal growth factor receptor (EGFR) inhibitors are currently experiencing issues like severe adverse events and drug resistance. It is urgent to develop novel types of EGFR inhibitors to overcome the abovementioned limitations. Pyrrole always works well as a probe for the creation of novel medication candidates for hard-to-treat conditions like lung cancer. Although the design, synthesis, and biological assays of pyrrole derivatives have been reported, their inhibitory actions against the receptor tyrosine kinase (RTK) EGFR have not been in-depthly studied. This review highlights the small molecule EGFR inhibitors containing pyrrole heterocyclic pharmacophores in recent years, and the research on their mechanism, biological activity, and structure-activity relationship (SAR).

Discovery of mobocertinib, a new irreversible tyrosine kinase inhibitor indicated for the treatment of non-small-cell lung cancer harboring EGFR exon 20 insertion mutations

Epidermal growth factor receptor (EGFR) is essential for normal cellular functions. Mutations of EGFR's kinase domain can cause dysregulation leading to non-small cell lung cancer (NSCLC). Exon 20 insertion (ex20ins) mutations in EGFR are one of the leading contributors to oncogenesis and confer insensitivity to most available therapeutics. Mobocertinib is a novel tyrosine kinase inhibitor (TKI) recently approved by the US FDA as a first-in-class small molecule therapeutic for EGFR ex20ins-positive NSCLC. When compared to osimertinib, a TKI indicated for the treatment of EGFR T790M-positive NSCLC, mobocertinib differs only by the presence of an additional C5-carboxylate isopropyl ester group on the middle pyrimidine core. Together with the acrylamide side chain that is responsible for irreversible inhibition, this additional C5-substituent affords mobocertinib high anticancer potency and specificity to EGFR ex20ins-positive lung cancer that is resistant to other EGFR TKIs. This review article provides an overview of the discovery of mobocertinib from osimertinib including their structure-activity relationships, mechanisms of action, preclinical pharmacology, pharmacokinetics, and clinical applications. The discovery and use of mobocertinib and other EGFR TKIs demonstrate the power of structure-based drug design and promising therapeutic outcomes of using precision medicine approaches in the management of molecularly defined tumors. Graphical abstract.

Pyrimidine derivatives as EGFR tyrosine kinase inhibitors in NSCLC: - A comprehensive review

EGFR positive NSCLC due to primary mutation (EGFR DEL19 & L858R) has been recognized as a crucial mediator of tumor progression. This led to the development and approval of EGFR tyrosine kinase inhibitors which addresses EGFR mediated NSCLC but fail to show potency after initial months of therapy due to acquired resistance (EGFR T790M, EGFR C797S). Extensive research allowed identification of drugs for EGFR positive NSCLC, wherein the majority of compounds have a pyrimidine substructure offering marked therapeutic benefits compared to chemotherapy. This current review outlines the diverse pyrimidine derivatives with amino-linked and fused pyrimidine scaffolds such as furo-pyrimidine, pyrimido-pyrimidine, thieno-pyrimidine, highlighting pyrimidine EGFR TK inhibitors reported in research emphasizing structural aspects, design approaches, inhibition potential. selectivity profile towards mutant EGFR conveyed through biological evaluation studies. Furthermore, mentioning the in-silico interaction profile of synthesized compounds for evaluating the binding affinity with key amino acids. The epilogue of review focuses on the recent research that drives forward to aid in the discovery and development of substituted amino and fused scaffolds of pyrimidine that can counteract the mutations and effectively manage EGFR positive NSCLC.

Fused pyrrolo-pyridines and pyrrolo-(iso)quinoline as anticancer agents

This work emphasizes the synthesis strategies and antiproliferative related properties of fused pyrrolo-pyridine (including indolizine and azaindoles) and pyrrolo-(iso)quinoline derivatives recently reported in literature.

Design, synthesis and biological evaluation of aminopyrimidine derivatives bearing a 4,5,6,7-tetrahydrothieno [3,2-c]pyridine as potent EGFR inhibitors

To resolve the problem of drug resistance caused by epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer, we used the principle of collocation to design and synthesize a series of aminopyrimidine derivatives with 4,5,6,7-tetrahydrothieno [3,2-c]pyridine side chains (according to the binding mode of AZD9291 to EGFR^T790M) for use as EGFR^L858R/T790M kinase inhibitors. The most promising compound A12, a non-covalently bound reversible inhibitor, showed excellent kinase inhibitory activity against EGFR^L858R/T790M, with an IC₅₀ value of 4.0 nM and more than 42-fold selectivity for EGFR^WT (IC₅₀ = 170.0 nM). Moreover, compound A12 showed strong anti-proliferative activity against H1975 cells, with IC₅₀ value of 0.086 μΜ. Additionally, the effective inhibition of cell migration and the promotion of apoptosis by A12 verified its mechanism of action, as a selective inhibitor of EGFR^L858R/T790M.

Synthesis of 7-Chloroquinoline Derivatives Using Mixed Lithium-Magnesium Reagents

We have prepared a library of functionalized quinolines through the magnesiation of 7-chloroquinolines under mild conditions, employing both batch and continuous flow conditions. The preparation involved the generation of mixed lithium-magnesium intermediates, which were reacted with different electrophiles. Mixed lithium-zinc reagents allowed the synthesis of halogenated and arylated derivatives. Some of the synthesized 4-carbinol quinolines have shown interesting antiproliferative properties, their hydroxyl group being a suitable amino group bioisostere. We also report a two-step approach for optically active derivatives.

Pyrimidine-based EGFR TK inhibitors in targeted cancer therapy

Despite significant improvements of new treatment options, cancer continues to represent as one of the most common and fatal disease. The EGFR signaling pathway is considered as a significant approach in targeted therapy of cancers. Blocking the EGFR-driven pathway by inhibiting the intracellular tyrosine kinase domain of EGFR have shown considerable improvement in cancer therapy. In an effort to identify EGFR tyrosine kinase inhibitors (TKI), several small molecules especially pyrimidine containing derivatives have been designed by applying molecular simulation and evaluated the emergence of epigenetic mutation and resistance problems restricted the long-term effectiveness of such medication and explained the need for further investigations in this field. In recent years, the studies have been focused on genetic alterations on EGFR tyrosine kinase domain, which led to the design and synthesis of more selective and effective inhibitors. Herein, we give an overview of the importance and status of EGFR inhibitors in cancer therapy. In addition, we provide an update of the recent advances in design, discovery and development of novel pyrimidine containing compounds as promising selective EGFR TK inhibitors.

Cyclizations and fragmentations in the alkylation of 6-chloro-5-hydroxy-4-aminopyrimidines with aminoalkyl chlorides

Substituted aminopyrimidines are an important class of compounds, in part because they frequently show biological activity. Facile synthesis of polysubstituted aminopyrimidines is highly desirable for the synthesis of screening libraries. We describe a route to 4,6-diamino-5-alkoxypyrimidines via a SNAr-alkylation-SNAr sequence from readily available 4,6-dichloro-5-methoxypyrimidine, which allows the synthesis of such compounds with regiochemical control. The extension of this approach to alkylating agents bearing amino substituents led to unexpected and, in some cases, unprecedented products resulting from intramolecular SNAr cyclization and subsequent fragmentation.

In-silico activity prediction and docking studies of some 2, 9-disubstituted 8-phenylthio/phenylsulfinyl-9h-purine derivatives as Anti-proliferative agents

In-silico activity prediction was performed to predict new inhibitory activities of 2, 9-disubstituted 8-phenylthio/phenylsulfinyl-9h-purine derivatives as anti-proliferative agents using QSAR technique. The anti-proliferative agents were optimized using Density Functional Theory (DFT) method utilizing the B3LYP/6-31G* level of theory. Genetic Function Algorithm (GFA) was used to build the QSAR models. Out of the models built, the best one was selected and reported because of its fitness statistically with the following assessment parameters: R²_trng = 0.919035, R²_adj = 0.893733, Q²_cv = 0.866475, R²_test = 0.636217, and LOF = 0.215884. The selected model was further subjected to other assessment such as VIF, Y-scrambling test, applicability domain and found to be statistically significant. The binding mode of some selected 2, 9-disubstituted 8-phenylthio/phenylsulfinyl-9H-purine (ligands) in the active site of EGFR-tyrosine kinase (EGFR-TK) (receptor) was studied via Molecular docking. Molecule 22 was identified to have the highest binding energy (-10.4 kcal/mol) among the other selected ligands which it might be as a result of hydrogen interactions formed with MET793 (2.48599 Å, 2.04522 Å) & THR854 (3.76616 Å) amino acid residues and hydrophobic/other interactions with amino acid residues (LEU718, LEU844, MET766, VAL726, ALA743, LYS745 and MET790) in the active site of EGFR-tyrosine kinase (EGFR-TK). The drug-likeness of these selected anti-proliferative agents were predicted via the pharmacokinetics profile of the molecules utilizing SWISS ADME. The anti-proliferative agents were found to be orally safe by not having more than 1 violation of the Lipinski's rule of five. This research proposed a way for designing potent anti-proliferative agents against their target enzyme.

Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives

The Pd-catalyzed C–H bond functionalization of lilolidine was investigated. The use of a palladium-diphosphine catalyst associated to acetate bases in DMA was found to promote the regioselective arylation at α-position of the nitrogen atom of lilolidine with a wide variety of aryl bromides. From these α-arylated lilolidines, a second arylation at the β-position gives the access to α,β-diarylated lilolidines containing two different aryl groups. The one pot access to α,β-diarylated lilolidines with two identical aryl groups is also possible by using a larger amount of aryl bromide. The synthesis of 5,6-dihydrodibenzo[a,c]pyrido[3,2,1-jk]carbazoles from lilolidine via three successive direct arylations is also described. Therefore, this methodology provides a straightforward access to several lilolidine derivatives from commercially available compounds via one, two or three C–H bond functionalization steps allowing to tune their biological properties.

HFIP-Promoted Bischler Indole Synthesis under Microwave Irradiation

1,1,1,3,3,3-Hexafluoropropan-2-ol (HFIP) was found to be effective for the Bischler indole synthesis under microwave irradiation in the absence of a metal catalyst. Under the catalysis of HFIP, a wide range of α-amino arylacetones were successfully transformed into indole derivatives with moderate to good yields.

An in Vitro Assay of hERG K + Channel Potency for a New EGFR Inhibitor FHND004

FHND004 is a newly synthesized epidermal growth factor receptor (EGFR) inhibitor for the treatment of non-small cell lung cancer (NSCLC). The aim of the present study was to investigate the impacts of FHND004 on human ether-à-go-go-related gene (hERG) K⁺ channels and the molecular mechanisms underlying of its action. Whole-cell patch clamp recording was performed on wild type (WT), mutant hERG channels heterologously expressed in human embryonic kidney (HEK) 293 cells or I_Kr endogenously expressed in HL-1 cells, respectively. FHND004 inhibited hERG K⁺ currents in a concentration-dependent manner with IC₅₀ values of 8.46 ± 0.33 μM in HEK293 cells and 7.52 ± 1.27 μM in HL-1 cells, respectively. However, the inhibitory potency of FHND004 on hERG channels was significantly less than its precursor AZD9291. FHND004-induced inhibition was state-dependent with a preference within open state, but did not alter other kinetics including activation, inactivation, and recovery from inactivation or deactivation. In addition, FHND004 exhibited more potent inhibitory effects on WT/A422T and WT/H562P-hERG, two known long QT syndrome (LQTS) associated KCNH2 mutations, than WT alone. Mutations of the residues at pore regions (F656C, Y652A, S624A, and F557L) in hERG channels attenuated block effects of FHND004. Taken together, our results demonstrate the evidence that FHND004 is a less potent hERG blocker than its precursor AZD9291. There is, however, a need for caution in the potential use of FHND004 for treating NSCLC patients, especially in those with other concurrent triggering factors.

Investigating mutation-specific biological activities of small molecules using quantitative structure-activity relationship for epidermal growth factor receptor in cancer

Epidermal Growth Factor Receptor (EGFR) is a potential drug target in cancer therapy. Missense mutations play major roles in influencing the protein function, leading to abnormal cell proliferation and tumorigenesis. A number of EGFR inhibitor molecules targeting ATP binding domain were developed for the past two decades. Unfortunately, they become inactive due to resistance caused by new mutations in patients, and previous studies have also reported noticeable differences in inhibitor binding to distinct known driver mutants as well. Hence, there is a high demand for identification of EGFR mutation-specific inhibitors. In our present study, we derived a set of anti-cancer compounds with biological activities against eight typical EGFR known driver mutations and developed quantitative structure-activity relationship (QSAR) models for each separately. The compounds are grouped based on their functional scaffolds, which enhanced the correlation between compound features and respective biological activities. The models for different mutants performed well with a correlation coefficient, (r) in the range of 0.72-0.91 on jack-knife test. Further, we analyzed the selected features in different models and observed that hydrogen bond and aromaticity-related features play important roles in predicting the biological activity of a compound. This analysis is complimented with docking studies, which showed the binding patterns and interactions of ligands with EGFR mutants that could influence their activities.