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EZH2 is overexpressed in multiple types of cancer and high expression level of EZH2 correlates with poor prognosis. Besides the regulation of H3K27 trimethylation, EZH2 itself regulates its downstream proteins in a PRC2- and methylation-independent way. Starting from an approved EZH2 inhibitor EPZ-6438, we used covalent drug design and medicinal chemistry approaches to discover a novel covalent EZH2 degrader 38, which forms a covalent bond with EZH2 Cys663 and showed strong biochemical activities against EZH2 WT and mutants. Compound 38 exhibited potent antiproliferation effects against both B-cell lymphoma and TNBC cell lines by reducing the levels of H3K27me3 and EZH2. The mass spectrometry, washout and competition experiments confirmed the covalent binding of 38 to EZH2. This study demonstrates that covalent EZH2 degraders could provide an opportunity for the development of promising new drug candidates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Phosphoinositol 3-kinases (PI3Ks) γ and δ are primarily expressed in leukocytes and play crucial roles in regulation of the immune system. Dual inhibition of PI3Kγ/δ has emerged as an effective approach to regulate the tumor microenvironment. Here, we report the exploration of structure-activity relationship optimization which led to the discovery of a potent PI3Kγ/δ dual inhibitor 15u (IHMT-PI3K-455). 15u exhibits strong potency in biochemical and cellular assays and it repolarizes M2 phenotype toward M1 phenotype in THP-1 and BMDM macrophages. In addition, it shows suitable in vivo properties as demonstrated through pharmacokinetic studies in rats and pharmacodynamics properties in a MC38 xenograft model., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Through a structure-based irreversible drug design approach, we have discovered a highly potent IDH1-mutant inhibitor compound 16 (IHMT-IDH1-053) (IC 50  = 4.7 nM), which displays high selectivity against IDH1 mutants over IDH1 wt and IDH2 wt/mutants. The crystal structure demonstrates that 16 binds to the IDH1 R132H protein in the allosteric pocket adjacent to the NAPDH binding pocket through a covalent bond with residue Cys269. 16 inhibits 2-hydroxyglutarate (2-HG) production in IDH1 R132H mutant transfected 293T cells (IC 50  = 28 nM). In addition, it inhibits the proliferation of HT1080 cell line and primary AML cells which both bear IDH1 R132 mutants. In vivo, 16 inhibits 2-HG level in a HT1080 xenograft mouse model. Our study suggested that 16 would be a new pharmacological tool to study IDH1 mutant-related pathology and the covalent binding mode provided a novel approach for designing irreversible IDH1 inhibitors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Colony stimulating factor 1 receptor kinase (CSF1R) plays an integral role in tumor-associated macrophage repolarization and has emerged as a novel therapeutic target for cancer immunotherapy. Most of the current CSF1R kinase inhibitors lack selectivity between CSF1R kinase and other type III growth factor receptor members. Herein, we report a potent and selective CSF1R inhibitor 18h, which displays an IC 50 value of 5.14 nM against CSF1R and achieves selectivity over other type III receptor tyrosine kinases (>38-fold). 18h inhibits the phosphorylation of CSF1R and its downstream signaling pathway in RAW264.7, THP-1, and M-NFS-60 cells. Treatment with this compound leads to alteration of the macrophage polarization in RAW264.7 macrophages in a dose-dependent manner. In vivo, 18h demonstrates acceptable pharmacokinetic profiles and suppresses the tumor growth in a mouse xenograft model inoculated with M-NFS-60 cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Due to the critical tumorigenic role of fused NTRK genes in multiple cancers, TRK kinases have attracted extensive attention as a drug discovery target. Starting from an indazole based scaffold, through the type II kinase inhibitor fragments hybrid design approach with a ring closure strategy, we discovered a novel potent type II TRK kinase inhibitor compound 34 (IHMT-TRK-284), which exhibited IC 50 values of 10.5 nM, 0.7 nM and 2.6 nM to TRKA, B, and C respectively. In addition, it displayed great selectivity profile in the kinome when tested among 468 kinases and mutants (S score (1) = 0.02 at 1 μM). Importantly, 34 could overcome drug resistant mutants including V573M and F589L in the ATP binding pocket as well as G667C/S in the DFG region. In vivo, 34 exhibited good PK profiles in different species including mice, rats, and dogs. It also displayed good in vivo antitumor efficacies in the TRKA/B/C, TRKA mutants, and KM-12-LUC cells mediated mouse models. The potent activity against clinically important TRK mutants combined with the good in vivo PK and efficacy properties of 34 indicated that it might be a new potential therapeutic candidate for TRK kinase fusion or mutants driven cancers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Starting from a bipyridine-sulfonamide scaffold, medicinal chemistry optimization leads to the discovery of a novel Plasmodium falciparum PI4K kinase (PfPI4K) inhibitor compound 15g (CHMFL-PI4K-127, IC 50 : 0.9 nM), which exhibits potent activity against 3D7 Plasmodium falciparum (P. falciparum) (EC 50 : 25.1 nM). CHMFL-PI4K-127 displays high selectivity against PfPI4K over human lipid and protein kinase. In addition, it exhibits EC 50 values of 23-47 nM against a panel of the drug-resistant strains of P. falciparum. In vivo, the inhibitor demonstrates the favorable pharmacokinetic properties in both rats and mice. Furthermore, oral administration of CHMFL-PI4K-127 exhibits the antimalaria efficacy in both blood stage (80 mg/kg) and liver stage (1 mg/kg) of Plasmodium in infected rodent model. The results suggest that CHMFL-PI4K-127 might be a new potential drug candidate for malaria., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

There is still a great demand in the clinic for the drugs which can overcome a variety of imatinib resistant ABL mutants. Starting from a type I inhibitor axitinib, which has been reported to overcome ABL-T315I mutant induced resistance, through a structure guided drug design approach and binding mode switch strategy, we have discovered a novel type II ABL inhibitor 24 (CHMFL-ABL-121), which significantly improved the inhibitory activity against ABL wt and a broad spectrum of mutants including the most prevalent imatinib-resistant gatekeeper mutant T315I. 24 exhibited IC 50 values of 2 nM and 0.2 nM against purified inactive ABL wt and T315I kinase protein respectively and inhibited the proliferation of the established CML cell lines with GI 50 at single digit nM. In cellular context, 24 strongly affected BCR-ABL mediated signaling pathways and induced apoptosis as well as arrested cell cycle at G0/G1 phase. In the in vivo study, 50 mg/kg/day dosage of 24 displayed TGI of 52% in the TEL-ABLT315I-BaF3 cell inoculated allograft mouse model without obvious toxicity., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Through a structure-guided rational drug design approach, we have discovered a highly selective inhibitor compound 40 (JSH-150), which exhibited an IC 50 of 1 nM against CDK9 kinase in the biochemical assay and achieved around 300-10000-fold selectivity over other CDK kinase family members. In addition, it also displayed high selectivity over other 468 kinases/mutants (KINOMEscan S score(1) = 0.01). Compound 40 displayed potent antiproliferative effects against melanoma, neuroblastoma, hepatoma, colon cancer, lung cancer as well as leukemia cell lines. It could dose-dependently inhibit the phosphorylation of RNA Pol II, suppress the expression of MCL-1 and c-Myc, arrest the cell cycle and induce the apoptosis in the leukemia cells. In the MV4-11 cell-inoculated xenograft mouse model, 10 mg/kg dosage of 40 could almost completely suppress the tumor progression. The high selectivity and good in vivo PK/PD profile suggested that 40 would be a good pharmacological tool to study CDK9-mediated physiology and pathology as well as a potential drug candidate for leukemia and other cancers., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

PI3Kδ, which is mainly expressed in leukocytes, plays a critical role in B-cell receptor mediated signaling pathway and has been extensively studied as a drug discovery target for B cell malignances such as AML, CLL etc. In this manuscript, we report the discovery, SAR optimization and pharmacological evaluation of a novel series of aminothiazole-pyridine containing PI3Kδ inhibitors. Among them compound 15i (CHMFL-PI3KD-317) displays an IC 50 of 6 nM against PI3Kδ in the ADP-Glo biochemical assays. It also exhibits over 10-1500 fold selectivity over other class I, II and III PIKK family isoforms. In addition, in the cellular context, 15i can selectively and potently inhibit PI3Kδ mediated phosphorylation of Akt T308 but not PI3Kα, β, γ mediated Akt phosphorylation. 15i also exhibits an excellent selectivity profile in the protein kinases including 468 kinases/mutants at the concentration of 1 μM. 15i has acceptable pharmacokinetic properties and can dose-dependently inhibit the tumor growth of AML cell line MOLM14 inoculated xenograft mouse model. The high selectivity and potency makes 15i a potential valuable addition to the current PI3Kδ armory., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Through exploration of the non-highly conserved allosteric hydrophobic pocket generated by DFG-out shifting in the inactive conformation, we discovered a highly selective type II PDGFRα kinase inhibitor 15i (CHMFL-PDGFRα-159), which exhibited strong potency against purified PDGFRα (IC 50 : 132 nM) but not structurally similar PDGFRβ, ABL, c-KIT and VEGFR2 kinases. In addition, it displayed a high selectivity profile (S score (10) = 0.02) at the concentration of 1 μM among 468 kinases/mutants in the KINOMEscan profiling. X-ray crystal structure of 15i in complex with PDGFRα revealed a distinct binding feature in the allosteric hydrophobic pocket which might help to expand the diversity of type II kinase inhibitors. Compound 15i potently inhibited the proliferation of PDGFRα driving Chronic Eosinophilic Leukemia (CEL) cell line EOL-1 through strong blockage of PDGFRα mediated signaling pathways, arresting cell cycle progression, and induction of apoptosis. Furthermore, compound 15i effectively suppressed the EOL-1 tumor progression in the xenograft model and increased the survival rate in the engraftment tumor model., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Recently, more and more concomitant EGFR mutations and ALK rearrangement are observed from the clinic, which still lacks effective single-agent therapy. Starting from ALK inhibitor 14 (TAE684), we have developed a highly potent EGFR/ALK dual kinase inhibitor compound 18 (CHMFL-ALK/EGFR-050), which potently inhibited EGFR L858R, del 19 and T790M mutants as well as EML4-ALK, R1275Q, L1196M, F1174L and C1156Y mutants biochemically. Compound 18 significantly inhibited the proliferation of EGFR mutant and EML4-ALK driven NSCLC cell lines. In the cellular context it strongly affected EGFR and ALK mediated signaling pathways, induced apoptosis and arrested cell cycle at G0/G1 phase. In the in vivo studies, 18 significantly suppressed the tumor growth in H1975 cell inoculated xenograft model (40 mg/kg/d, TGI: 99%) and H3122 cell inoculated xenograft model (40 mg/kg/d, TGI: 78%). Compound 18 might be a potential drug candidate for EGFR- or ALK-individual as well as concomitant EGFR/ALK NSCLC., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Through a structure-based drug design approach, a tricyclic benzonaphthyridinone pharmacophore was used as a starting point for carrying out detailed medicinal structure-activity relationhip (SAR) studies geared toward characterization of a panel of proposed BTK inhibitors, including 6 (QL-X-138), 7 (BMX-IN-1) and 8 (QL47). These studies led to the discovery of the novel potent irreversible BTK inhibitor, compound 18 (CHMFL-BTK-11). Kinetic analysis of compound 18 revealed an irreversible binding efficacy (k inact /K i ) of 0.01 μM -1 s -1 . Compound 18 potently inhibited BTK kinase Y223 auto-phosphorylation (EC 50  < 100 nM), arrested cell cycle in G0/G1 phase, and induced apoptosis in Ramos, MOLM13 and Pfeiffer cells. We believe these features would make 18 a good pharmacological tool for studying BTK-related pathologies., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Currently there are several irreversible BTK inhibitors targeting Cys481 residue under preclinical or clinical development. However, most of these inhibitors also targeted other kinases such as BMX, JAK3, and EGFR that bear the highly similar active cysteine residues. Through a structure-based drug design approach, we discovered a highly potent (IC 50 : 7 nM) irreversible BTK inhibitor compound 9 (CHMFL-BTK-01), which displayed a high selectivity profile in KINOMEscan (S score (35) = 0.00) among 468 kinases/mutants at the concentration of 1 μM. Compound 9 completely abolished BMX, JAK3 and EGFR's activity. Both X-ray crystal structure and cysteine-serine mutation mediated rescue experiment confirmed 9's irreversible binding mode. 9 also potently inhibited BTK Y223 auto-phosphorylation (EC 50 : <30 nM), arrested cell cycle in G0/G1 phase and induced apoptosis in U2932 and Pfeiffer cells. We believe these features would make 9 a good pharmacological tool to study the BTK related pathology., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1) have shown to be promising in clinical trials against cancer and other diseases, and lots of efforts have been put into the development of organic compounds as more potent PARP-1 inhibitors. Here we describe a strategy to conveniently obtain metal-based PARP-1 inhibitors with enhanced biological activities by conjugating platinum moiety with an original inhibitor, e.g., benzonaphthyridone. Based on the structure-activity relationship analysis of PARP-1 inhibitors, three platinated PARP-1 inhibitors were designed, and the complexes were synthesized and characterized. Complex 3 presented significantly enhanced cytotoxicity against a panel of human cancer cells and a 10-fold increased inhibitory effect against recombinant PARP-1 compared with the original PARP-1 inhibitor. Complex 3 was as cytotoxic as cisplatin and its spectrum of anticancer activity was identical to that of cisplatin. The complex was able to enter into cancer cells efficiently, bind to DNA well, and block cell cycle at G₂/M phase, indicating that complex 3 is an effective anticancer agent with a distinct mechanism of action. Our study implies that the conjugation of platinum with PARP-1 inhibitors could be a valid strategy to obtain more potent anticancer agents with improved biological activities., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)