scholarly journals Genotypic and phenotypic analysis of variants resistant to hepatitis C virus nonstructural protein 5A replication complex inhibitor BMS-790052 in Humans: In Vitro and In Vivo Correlations

Hepatology ◽  
2011 ◽  
Vol 54 (6) ◽  
pp. 1924-1935 ◽  
Author(s):  
Robert A. Fridell ◽  
Chunfu Wang ◽  
Jin-Hua Sun ◽  
Donald R. O'Boyle ◽  
Peter Nower ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Phenotypic Analysis ◽  
Replication Complex ◽  
Nonstructural Protein 5A

scholarly journals Preclinical Profile and Clinical Efficacy of a Novel Hepatitis C Virus NS5A Inhibitor, EDP-239

2016 ◽  
Vol 60 (10) ◽  
pp. 6207-6215 ◽  
Author(s):  
Christopher M. Owens ◽  
Bradley B. Brasher ◽  
Alex Polemeropoulos ◽  
Michael H. J. Rhodin ◽  
Nicole McAllister ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Viral Rna ◽  
Controlled Clinical Trial ◽  
Genotype 1A ◽  
Pharmacokinetic Properties ◽  
Direct Acting

ABSTRACTEDP-239, a novel hepatitis C virus (HCV) inhibitor targeting nonstructural protein 5A (NS5A), has been investigatedin vitroandin vivo. EDP-239 is a potent, selective inhibitor with potency at picomolar to nanomolar concentrations against HCV genotypes 1 through 6. In the presence of human serum, the potency of EDP-239 was reduced by less than 4-fold. EDP-239 is additive to synergistic with other direct-acting antivirals (DAAs) or host-targeted antivirals (HTAs) in blocking HCV replication and suppresses the selection of resistancein vitro. Furthermore, EDP-239 retains potency against known DAA- or HTA-resistant variants, with half-maximal effective concentrations (EC50s) equivalent to those for the wild type. In a phase I, single-ascending-dose, placebo-controlled clinical trial, EDP-239 demonstrated excellent pharmacokinetic properties that supported once daily dosing. A single 100-mg dose of EDP-239 resulted in reductions in HCV genotype 1a viral RNA of >3 log10IU/ml within the first 48 h after dosing and reductions in genotype 1b viral RNA of >4-log10IU/ml within 96 h. (This study has been registered at ClinicalTrials.gov under identifier NCT01856426.)

scholarly journals Effect of Hepatitis C Virus (HCV) NS5B-Nucleolin Interaction on HCV Replication with HCV Subgenomic Replicon

2006 ◽  
Vol 80 (7) ◽  
pp. 3332-3340 ◽  
Author(s):  
Tetsuro Shimakami ◽  
Masao Honda ◽  
Takashi Kusakawa ◽  
Takayuki Murata ◽  
Kunitada Shimotohno ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Polymerase Activity ◽  
Subgenomic Replicon ◽  
Huh7 Cells ◽  
Hcv Ns5b

ABSTRACT We previously reported that nucleolin, a representative nucleolar marker, interacts with nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) through two independent regions of NS5B, amino acids 208 to 214 and 500 to 506. We also showed that truncated nucleolin that harbors the NS5B-binding region inhibited the RNA-dependent RNA polymerase activity of NS5B in vitro, suggesting that nucleolin may be involved in HCV replication. To address this question, we focused on NS5B amino acids 208 to 214. We constructed one alanine-substituted clustered mutant (CM) replicon, in which all the amino acids in this region were changed to alanine, as well as seven different point mutant (PM) replicons, each of which harbored an alanine substitution at one of the amino acids in the region. After transfection into Huh7 cells, the CM replicon and the PM replicon containing NS5B W208A could not replicate, whereas the remaining PM replicons were able to replicate. In vivo immunoprecipitation also showed that the W208 residue of NS5B was essential for its interaction with nucleolin, strongly suggesting that this interaction is essential for HCV replication. To gain further insight into the role of nucleolin in HCV replication, we utilized the small interfering RNA (siRNA) technique to investigate the knockdown effect of nucleolin on HCV replication. Cotransfection of replicon RNA and nucleolin siRNA into Huh7 cells moderately inhibited HCV replication, although suppression of nucleolin did not affect cell proliferation. Taken together, our findings strongly suggest that nucleolin is a host component that interacts with HCV NS5B and is indispensable for HCV replication.

scholarly journals Impact of a baseline polymorphism on the emergence of resistance to the hepatitis C virus nonstructural protein 5a replication complex inhibitor, BMS-790052

Hepatology ◽  
2012 ◽  
Vol 55 (6) ◽  
pp. 1692-1699 ◽  
Author(s):  
Jin-Hua Sun ◽  
Donald R. O'Boyle II ◽  
Yan Zhang ◽  
Chunfu Wang ◽  
Peter Nower ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Replication Complex ◽  
Emergence Of Resistance ◽  
Nonstructural Protein 5A

scholarly journals Preclinical and Clinical Resistance Profile of EDP-239, a Novel Hepatitis C Virus NS5A Inhibitor

2016 ◽  
Vol 60 (10) ◽  
pp. 6216-6226 ◽  
Author(s):  
Christopher M. Owens ◽  
Bradley B. Brasher ◽  
Alex Polemeropoulos ◽  
Michael H. J. Rhodin ◽  
Nicole McAllister ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Nonstructural Protein ◽  
Subgenomic Replicon ◽  
Ns5a Inhibitor ◽  
Clinical Resistance ◽  
Ns5a Sequence

ABSTRACTEDP-239, a potent and selective hepatitis C virus (HCV) nonstructural protein 5A (NS5A) inhibitor developed for the treatment of HCV infection, has been investigatedin vitroandin vivo. This study sought to characterize genotypic changes in the HCV NS5A sequence of genotype 1 (GT1) replicons and to compare those changes to GT1 viral RNA mutations isolated from clinical trial patients. Resistance selection experimentsin vitrousing a subgenomic replicon identified resistance-associated mutations (RAMs) at GT1a NS5A amino acid positions 24, 28, 30, 31, and 93 that confer various degrees of resistance to EDP-239. Key RAMs were similarly identified in GT1b NS5A at amino acid positions 31 and 93. Mutations F36L in GT1a and A92V in GT1b do not confer resistance to EDP-239 individually but were found to enhance the resistance of GT1a K24R and GT1b Y93H. RAMs were identified in GT1 patients at baseline or after dosing with EDP-239 that were similar to those detectedin vitro. Baseline RAMs identified at NS5A position 93 in GT1, or positions 28 or 30 in GT1a only, correlated with a reduced treatment response. RAMs at additional positions were also detected and may have contributed to reduced EDP-239 efficacy. The most common GT1a and GT1b RAMs found to persist up to weeks 12, 24, or 48 were those at NS5A positions 28, 30, 31, 58 (GT1a only), and 93. Those RAMs persisting at the highest frequencies up to weeks 24 or 48 were L31M and Q30H/R for GT1a and L31M and Y93H for GT1b. (This study has been registered at ClinicalTrials.gov under identifier NCT01856426.)

scholarly journals Analysis of hepatitis C virus resistance to silibinin in vitro and in vivo points to a novel mechanism involving nonstructural protein 4B

Hepatology ◽  
2013 ◽  
Vol 57 (3) ◽  
pp. 953-963 ◽  
Author(s):  
Katharina Esser-Nobis ◽  
Inés Romero-Brey ◽  
Tom M. Ganten ◽  
Jérôme Gouttenoire ◽  
Christian Harak ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Resistance ◽  
Nonstructural Protein

scholarly journals The NS4A Protein of Hepatitis C Virus Promotes RNA-Coupled ATP Hydrolysis by the NS3 Helicase

2009 ◽  
Vol 83 (7) ◽  
pp. 3268-3275 ◽  
Author(s):  
Rudolf K. F. Beran ◽  
Brett D. Lindenbach ◽  
Anna Marie Pyle
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Serine Protease ◽  
Protease Activity ◽  
Rna Binding ◽  
Nonstructural Protein ◽  
Helicase Activity ◽  
Protease Domain

ABSTRACT Nonstructural protein 3 (NS3) is an essential replicative component of the hepatitis C virus (HCV) and a member of the DExH/D-box family of proteins. The C-terminal region of NS3 (NS3hel) exhibits RNA-stimulated NTPase and helicase activity, while the N-terminal serine protease domain of NS3 enhances RNA binding and unwinding by NS3hel. The nonstructural protein 4A (NS4A) binds to the NS3 protease domain and serves as an obligate cofactor for NS3 serine protease activity. Given its role in stimulating protease activity, we sought to determine whether NS4A also influences the activity of NS3hel. Here we show that NS4A enhances the ability of NS3hel to bind RNA in the presence of ATP, thereby acting as a cofactor for helicase activity. This effect is mediated by amino acids in the C-terminal acidic domain of NS4A. When these residues are mutated, one observes drastic reductions in ATP-coupled RNA binding and duplex unwinding by NS3. These same mutations are lethal in HCV replicons, thereby establishing in vitro and in vivo that NS4A plays an important role in the helicase mechanism of NS3 and its function in replication.

scholarly journals Biochemical Characterization of the Active Anti-Hepatitis C Virus Metabolites of 2,6-Diaminopurine Ribonucleoside Prodrug Compared to Sofosbuvir and BMS-986094

2016 ◽  
Vol 60 (8) ◽  
pp. 4659-4669 ◽  
Author(s):  
Maryam Ehteshami ◽  
Sijia Tao ◽  
Tugba Ozturk ◽  
Longhu Zhou ◽  
Jong Hyun Cho ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Biochemical Characterization ◽  
Nonstructural Protein ◽  
Nucleoside Triphosphate ◽  
Hcv Rna ◽  
Mitochondrial Rna ◽  
Active Metabolites

ABSTRACTRibonucleoside analog inhibitors (rNAI) target the hepatitis C virus (HCV) RNA-dependent RNA polymerase nonstructural protein 5B (NS5B) and cause RNA chain termination. Here, we expand our studies on β-d-2′-C-methyl-2,6-diaminopurine-ribonucleotide (DAPN) phosphoramidate prodrug 1 (PD1) as a novel investigational inhibitor of HCV. DAPN-PD1 is metabolized intracellularly into two distinct bioactive nucleoside triphosphate (TP) analogs. The first metabolite, 2′-C-methyl-GTP, is a well-characterized inhibitor of NS5B polymerase, whereas the second metabolite, 2′-C-methyl-DAPN-TP, behaves as an adenosine base analog.In vitroassays suggest that both metabolites are inhibitors of NS5B-mediated RNA polymerization. Additional factors, such as rNAI-TP incorporation efficiencies, intracellular rNAI-TP levels, and competition with natural ribonucleotides, were examined in order to further characterize the potential role of each nucleotide metabolitein vivo. Finally, we found that although both 2′-C-methyl-GTP and 2′-C-methyl-DAPN-TP were weak substrates for human mitochondrial RNA (mtRNA) polymerase (POLRMT)in vitro, DAPN-PD1 did not cause off-target inhibition of mtRNA transcription in Huh-7 cells. In contrast, administration of BMS-986094, which also generates 2′-C-methyl-GTP and previously has been associated with toxicity in humans, caused detectable inhibition of mtRNA transcription. Metabolism of BMS-986094 in Huh-7 cells leads to 87-fold higher levels of intracellular 2′-C-methyl-GTP than DAPN-PD1. Collectively, our data characterize DAPN-PD1 as a novel and potent antiviral agent that combines the delivery of two active metabolites.

scholarly journals Persistence of Resistant Variants in Hepatitis C Virus-Infected Patients Treated with the NS5A Replication Complex Inhibitor Daclatasvir

2013 ◽  
Vol 57 (5) ◽  
pp. 2054-2065 ◽  
Author(s):  
Chunfu Wang ◽  
Jin-Hua Sun ◽  
Donald R. O'Boyle ◽  
Peter Nower ◽  
Lourdes Valera ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Viral Fitness ◽  
Viral Rna ◽  
Wild Type Virus ◽  
Replication Complex ◽  
Resistance Patterns

ABSTRACTDaclatasvir (DCV; BMS-790052) is a hepatitis C virus (HCV) NS5A replication complex inhibitor (RCI) with picomolar to low nanomolar potency and broad genotypic coveragein vitro. Viral RNA declines have been observed in the clinic for both alpha interferon-ribavirin (IFN-α–RBV) and IFN-RBV-free regimens that include DCV. Follow-up specimens (up to 6 months) from selected subjects treated with DCV in 14-day monotherapy studies were analyzed for genotype and phenotype. Variants were detected by clonal sequencing in specimens from baseline and were readily detected by population sequencing following viral RNA breakthrough and posttreatment. The major amino acid substitutions generating resistancein vivowere at residues M28, Q30, L31, and Y93 for genotype 1a (GT-1a) and L31 and Y93 for GT-1b, similar to the resistance substitutions observed with thein vitroreplicon system. The primary difference in the resistance patterns observedin vitroandin vivowas the increased complexity of linked variant combinations observed in clinical specimens. Changes in the percentage of individual variants were observed during follow-up; however, the overall percentage of variants in the total population persisted up to 6 months. Our results suggest that during the 14-day monotherapy, most wild-type virus was eradicated by DCV. After the end of DCV treatment, viral fitness, rather than DCV resistance, probably determines which viral variants emerge as dominant in populations.

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