ABSTRACT
A series of next in class small-molecule hepatitis C virus (HCV) NS5A inhibitors with picomolar potency containing 2-pyrrolidin-2-yl-5-{4-[4-(2-pyrrolidin-2-yl-1H-imidazol-5-yl)buta-1,3-diynyl]phenyl}-1H-imidazole cores was designed based on the SAR studies available for the reported NS5A inhibitors. Compound 13a (AV4025), with (S,S,S,S)-stereochemistry (EC50 = 3.4 ± 0.2 pM, HCV replicon genotype 1b), was dramatically more active than were the compounds with two (S)- and two (R)-chiral centers. Human serum did not significantly reduce the antiviral activity (<4-fold). Relatively favorable pharmacokinetic features and good oral bioavailability were observed during animal studies. Compound 13a was well tolerated in rodents (in mice, LD50 = 2326 mg/kg or higher), providing a relatively high therapeutic index. During safety, pharmacology and subchronic toxicity studies in rats and dogs, it was not associated with any significant pathological or clinical findings. This compound is currently being evaluated in phase I/II clinical trials for the treatment of HCV infection.
Subject(s)
Antiviral Agents/pharmacology , Drug Discovery , Hepacivirus/drug effects , Imidazoles/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/metabolism , Antiviral Agents/pharmacokinetics , Antiviral Agents/toxicity , Chlorocebus aethiops , Clinical Trials as Topic , Dogs , Female , Humans , Imidazoles/metabolism , Imidazoles/pharmacokinetics , Imidazoles/toxicity , Male , Mice , Molecular Docking Simulation , Protein Conformation , Rats , Vero Cells , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolismABSTRACT
OBJECTIVES: Development of a novel drug candidate with improved potency against influenza virus neuraminidase compared with currently available therapeutics, and high activity against oseltamivir-resistant viruses. METHODS: A number of synthetic compounds were evaluated for antiviral properties in vitro and in vivo. Three-dimensional molecular docking, assisted by a pharmacophore model, was applied to classify compounds within the series by their inhibitory potency. Compound stability in blood and in animal models was determined. Pharmacokinetic studies in dogs and rats after oral or intravenous administration were performed. RESULTS: A novel highly potent drug candidate [(3R,4R,5S)-5-[(diaminomethylene)amino]-3-(1-ethylpropoxy)-4-[(fluoroacetyl)amino]cyclohex-1-ene-1-carboxylic acid; AV5080] was synthesized and tested. AV5080 exhibited high activity against influenza virus neuraminidase in vitro, with IC(50) values of 0.03 nM and 0.07 nM against the neuraminidase of A/Duck/Minnesota/1525/1981/H5N1 and A/Perth/265/2009/H1N1 (wild-type), respectively. Notably, AV5080 was highly active against oseltamivir-resistant influenza viruses. CONCLUSIONS: Based on the results presented in this study, AV5080 is a promising novel oral drug candidate for the treatment of influenza, including oseltamivir-resistant types. Further pre-clinical development of AV5080 is warranted.
Subject(s)
Antiviral Agents/isolation & purification , Enzyme Inhibitors/isolation & purification , Neuraminidase/antagonists & inhibitors , Viral Proteins/antagonists & inhibitors , Administration, Oral , Animals , Antiviral Agents/administration & dosage , Antiviral Agents/pharmacokinetics , Antiviral Agents/pharmacology , Dogs , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/pharmacology , Female , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H1N1 Subtype/enzymology , Influenza A Virus, H5N1 Subtype/drug effects , Influenza A Virus, H5N1 Subtype/enzymology , Inhibitory Concentration 50 , Molecular Docking Simulation , RatsABSTRACT
OBJECTIVES: Development of a novel drug candidate with improved activity against influenza virus neuraminidase (NA) compared with currently available therapeutics. METHODS: Synthesized compounds were evaluated in vitro and in vivo. Three-dimensional molecular docking was successfully applied to classify compounds within the series by inhibitory potency. Stability was investigated in blood samples and in animal models. A pharmacokinetic study was performed in dogs and rats using peroral and intravenous administration. RESULTS: A novel highly potent drug candidate [(3R,4R,5S)-4-(2,2-difluoroacetylamino)-5-amino-3-(1-ethyl-propoxy)-cyclohex-1-enecarboxylic acid; AV5027] and its prodrug ethyl ester (AV5075S) were synthesized and tested. AV5027 and AV5075S exhibit picomolar activity against influenza virus NA. AV5075S inhibited NA in a model of pneumonia using mouse-adapted A/Aichi/2/68 (H3N2) virus significantly more strongly than oseltamivir phosphate. A general metabolic pathway was constructed for the parent compound based on experimental results and theoretical analyses. CONCLUSIONS: AV5075S can be reasonably regarded as a novel 'next in class' oral drug candidate for the treatment of influenza.
Subject(s)
Antiviral Agents/administration & dosage , Prodrugs/administration & dosage , Administration, Intravenous , Administration, Oral , Animals , Disease Models, Animal , Dogs , Female , Male , Mice , Orthomyxoviridae Infections/drug therapy , Orthomyxoviridae Infections/virology , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Rats, Sprague-Dawley , Treatment OutcomeABSTRACT
A medium-sized focused library of novel Oseltamivir structural analogues with promising antiviral activity was successfully synthesized using a combinatorial approach. The synthesized compounds were then thoroughly evaluated in neuraminidase- and cell-based assays. As a result, (3R,4R,5S)-4-(2,2-difluoroacetylamino)-5-amino-3-(1-ethyl-propoxy)-cyclohex-1-enecarboxylic acid (AV5027) was identified as novel Hit-compound with picomolar potency. QSAR analysis was carried out based on the obtained biological data. Computational modeling was performed using a 3D-molecular docking approach and classical regression analysis. The developed integral model demonstrated a sufficient prediction accuracy and tolerance to evaluate compounds based on their potential activity against neuraminidase (NA) at least within the scaffold. Several compounds from the series can be reasonably regarded as promising anti-influenza drug-candidates.
