Ivashchenko Andrei A, Mitkin Oleg D, Jones Jeremy C, Nikitin Alexander V, Koryakova Angela G, Karapetian Ruben N, Kravchenko Dmitry V, Mochalov Stephan V, Ryakhovskiy Alexey A, Aladinskiy Vladimir, Leneva Irina A, Falynskova Irina N, Glubokova Ekaterina A, Govorkova Elena A, Ivachtchenko Alexandre V
Chemical Diversity Research Institute, Rabochaya St. 2a, Khimki, Moscow Region 141401, Russia.
ChemDiv, 12760 High Bluff Drive, Ste. 370 San Diego, CA 92130, USA.
J Antimicrob Chemother. 2021 Mar 12;76(4):1010-1018. doi: 10.1093/jac/dkaa524.
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.
帽依赖性核酸内切酶（CEN）抑制剂巴洛沙韦酯的研发及临床应用是流感治疗领域的一项突破，但它与耐药变异体的出现有关。
设计并合成CEN抑制剂的结构类似物，评估其体外和体内的安全性、药代动力学及抗病毒效力。
基于药效团模型合成候选药物AV5124及其活性代谢物AV5116。体外评估其在血浆和微粒体中的稳定性、血浆蛋白结合率、细胞毒性及抗病毒活性。分析CD-1小鼠静脉注射或口服给药后的药代动力学。在BALB/c小鼠中检测急性毒性及对致死性A(H1N1)pdm09流感病毒攻击的保护效力。
药效团模型辅助的三维分子对接预测了AV5116的金属结合基团和庞大疏水基团与CEN结合位点（蛋白质数据库代码：6FS6）的关键超分子相互作用，这些相互作用对于高抗病毒活性至关重要。AV5116在无细胞试验中抑制流感病毒聚合酶复合物，并在纳摩尔浓度下抑制对奥司他韦敏感和耐药的甲型和乙型流感病毒的复制。值得注意的是，对于野生型（I38-WT）病毒和携带I38T聚合酶酸性（PA）替代且对巴洛沙韦酸（BXA）敏感性降低的病毒，AV5116与BXA具有同等效力或更高效力。AV5116在Madin-Darby犬肾细胞中表现出低细胞毒性且无线粒体毒性，从而产生良好的选择性指数。用20或50mg/kg AV5124治疗分别使60%和100%的动物免于死亡。
总体而言，AV5124和A5116是有前景的流感病毒CEN抑制剂，有必要作为有效的抗流感药物进一步研发。
