ChemDiv (United States)

Abstract Background Lung cancer is the most common cause of cancer death globally, with non-small cell lung cancer representing 87% of the cases. Activating mutations in the kinase domain of EGFR (epidermal growth factor receptor) are a key driver in a subset of NSCLC, accounting for up to 50% of newly diagnosed lung adenocarcinoma in Asian patients and 15-20% in Western countries. The most common EGFR mutations are deletions in exon 19 and the L858R point mutation in exon 21. While multiple generations of EGFR inhibitors have effectively targeted these alterations there remains a critical challenge to target additional mutations like C797S and atypical variants such as exon 20 insertions. There is a clear need for a reversible, broad-spectrum EGFR inhibitor to address this gap. We describe herein, ZE77-0273, a novel, reversible, panEGFR inhibitor that wild-type–sparing of EGFR, with potent in vitro and in vivo activity. Methods ZE77-0273 was developed using a rational structure-guided, approach that incorporated AI-enabled modeling, virtual screening, and medicinal chemistry optimization from Expert Systems. The compound’s potency was evaluated against mutant EGFR kinases in biochemical assays, and its cytotoxicity assessed in engineered and patient-derived cell lines. Pharmacokinetic (PK) properties were characterized in rodents and dogs. Antitumor efficacy was tested in an EGFR-driven patient-derived xenograft (PDX) model in mice. Results ZE77-0273 exhibited sub-nanomolar inhibition of EGFR mutants in vitro, including atypical or PACC mutations, such as L792H/C797S/L858R (0.4 nM), L718Q (0.8 nM), G719C (0.4 nM), S768I (0.04 nM). Cell-based assays showed potent cytotoxicity in Ba/F3 and Rat1 cells expressing various EGFR mutations, including C797S triple mutants (EGFR L861Q 3.3 nM, EGFR (G719S) 43 nM, EGFR (T790M/L858R/C797S) 17 nM), compared to 100 nM for wild type EGFR. ZE77-0273 demonstrated strong oral bioavailability with preferential to lung and brain penetration. In patient-derived NSCLC cells harboring EGFR exon 20 insertions, CC50 values were 44 nM and 60 nM. In vivo, ZE77-0273 induced tumor regression in a PDX model, with durable tumor control across multiple dosing regimens. Conclusions ZE77-0273 is a promising, AI-designed, reversible pan-EGFR inhibitor with broad activity across classical, atypical, and resistance EGFR mutations. Its favorable PK profile, preclinical efficacy, and broad mutational coverage support its advancement toward clinical development in EGFR-mutant NSCLC. Citation Format: Alexander Khvat, Ruben Karapetian, Alexey Rjahovskiy, Elena Bulanova, Vladislav Parchinsky, Nikolay Savchuk, Amy Burd, Iain Dukes. A Novel, wild-type sparing pan-EGFR Inhibitor (ZE77-0273) with Broad Activity Against Resistance Mutations in EGFR-Mutant NSCLC [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2025 Oct 22-26; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2025;24(10 Suppl):Abstract nr B068.

Clade 2.3.4.4b highly pathogenic avian influenza (HPAI) A(H5N1) viruses that are responsible for devastating outbreaks in birds and mammals pose a potential threat to public health. Here, we evaluated their susceptibility to influenza antivirals. Of 1,015 sequences of HPAI A(H5N1) viruses collected in the United States during 2022, eight viruses (∼0.8%) had a molecular marker of drug resistance to an FDA-approved antiviral: three adamantane-resistant (M2-V27A), four oseltamivir-resistant (NA-H275Y), and one baloxavir-resistant (PA-I38T). Additionally, 31 viruses contained mutations that may reduce susceptibility to inhibitors of neuraminidase (NA) (n = 20) or cap-dependent endonuclease (CEN) (n = 11). A panel of 22 representative viruses was tested phenotypically. Overall, clade 2.3.4.4b A(H5N1) viruses lacking recognized resistance mutations were susceptible to FDA-approved antivirals. Oseltamivir was least potent at inhibiting NA activity, while the investigational NA inhibitor AV5080 was most potent, including against NA mutants. A novel NA substitution T438N conferred 12-fold reduced inhibition by zanamivir, and in combination with the known marker N295S, synergistically affected susceptibility to all five NA inhibitors. In cell culture-based assays HINT and IRINA, the PA-I38T virus displayed 75- to 108-fold and 37- to 78-fold reduced susceptibility to CEN inhibitors, baloxavir and the investigational AV5116, respectively. Viruses with PA-I38M or PA-A37T showed 5- to 10-fold reduced susceptibilities. As HPAI A(H5N1) viruses continue to circulate and evolve, close monitoring of drug susceptibility is needed for risk assessment and to inform decisions regarding antiviral stockpiling.

The development and clinical implementation of the cap-dependent endonuclease (CEN) inhibitor baloxavir marboxil was a breakthrough in influenza therapy, but it was associated with the emergence of drug-resistant variants. To design and synthesize structural analogues of CEN inhibitors and evaluate their safety, pharmacokinetics and antiviral potency in vitro and in vivo. The drug candidate AV5124 and its active metabolite AV5116 were synthesized based on pharmacophore modelling. Stability in plasma and microsomes, plasma protein binding, cytotoxicity and antiviral activities were assessed in vitro. Pharmacokinetics after IV or oral administration were analysed in CD-1 mice. Acute toxicity and protective efficacy against lethal A(H1N1)pdm09 influenza virus challenge were examined in BALB/c mice. Pharmacophore model-assisted, 3D molecular docking predicted key supramolecular interactions of the metal-binding group and bulky hydrophobic group of AV5116 with the CEN binding site (Protein Data Bank code: 6FS6) that are essential for high antiviral activity. AV5116 inhibited influenza virus polymerase complexes in cell-free assays and replication of oseltamivir-susceptible and -resistant influenza A and B viruses at nanomolar concentrations. Notably, AV5116 was equipotent or more potent than baloxavir acid (BXA) against WT (I38-WT) viruses and viruses with reduced BXA susceptibility carrying an I38T polymerase acidic (PA) substitution. AV5116 exhibited low cytotoxicity in Madin-Darby canine kidney cells and lacked mitochondrial toxicity, resulting in favourable selective indices. Treatment with 20 or 50 mg/kg AV5124 prevented death in 60% and 100% of animals, respectively. Overall, AV5124 and A5116 are promising inhibitors of the influenza virus CEN and warrant further development as potent anti-influenza agents.

Фокусированная библиотека гетероциклических соединений, включающих фрагмент 2-аминометил-1H-бензимидазола (1 – 19), 2-аминометилиндола (20 – 83), бензофуран-2-илметиламина (84 – 92) и 2-пиперазин-1-илметилбензоксазола (93), была проскринирована на антивирусную активность в отношении вируса гепатита C (HCV) in vitro. Представлены схемы химического синтеза и данные по антивирусной активности/цитотоксичности ряда соединений. Вещества, включающие фрагмент бензоксазола-2-илметиламина, в подавляющем большинстве являлись микромолярными ингибиторами на модели клеточной линии гепатомы человека Huh7.3, зараженной HCV in vitro, но оказались неактивными на модели РНК-репликона HCV. Исключение составил 9-метил-N (6)-(3-нитрофенил)-2,3,4,9-тетрагидро-1H-карбазол-1,6-диамин (67), проявивший наномолярную антивирусную активность на обеих моделях. Наиболее активными и селективными были (пиперазин-1-ил)-[(1H-индол-2-илметил)пиперидин-4-ил]-кетоны (EC50 0,31 – 2,2 μM, CC50 10,2 – 110 μM), и 2-(1,2,3a,4,5,6-гексагидропиразино[3,2,1-ол]- карбазол-3-ил)ацетамид (EC50 = (1,69 ± 0,5) μM, CC50 = (114 ± 42) μM). Два наиболее селективных ингибитора 28 (TI50 = 52) и 77 (TI50 = 68) были выбраны для дальнейших доклинических исследований.

New 3-(arylsulfonyl)-2-(methylthio)pyrazolo[1,5-a]pyrimidines with a substituent amino group in the 7 position were synthesized and their 5-HT6 antagonist activity was studied. The transition from 7-amino and 7-dimethylamino derivatives to 7-aminoalkyl derivatives was found to lead to a significant decrease in activity; a similar pattern was seen on substitution of the methyl group in position 5 by a phenyl or thiophen-2-yl substituent. The most active (at the picomolar level) compounds were 5-methyl-2-(methylthio)-3-(phenylsulfonyl) pyrazolo[1,5-a]pyrimidin-7-amine and N,N,5,6-tetramethyl-2-(methylthio)-3-(phenylsulfonyl)pyrazolo-[1,5-a]pyrimidin-7-amine (K i = 700 pM). The first member of the hydrogenated pyrazolo[1,5-a]pteridine class –5,6,9-trimethyl-2-(methylthio)-3-(phenylsulfonyl)-6,7,8,9-tetrahydropyrazolo[1,5-a]pteridine (K i = 14.4 nM) was synthesized. These relationships between structure and 5-HT6 antagonist activity support the adequacy of our pharmacophore model, such that it can be used for the further search for new highly effective 5-HT6 antagonists.