scholarly journals Activity of a Potent Hepatitis C Virus Polymerase Inhibitor in the Chimpanzee Model

2007 ◽  
Vol 51 (12) ◽  
pp. 4290-4296 ◽  
Author(s):  
Chih-Ming Chen ◽  
Yupeng He ◽  
Liangjun Lu ◽  
Hock Ben Lim ◽  
Rakesh L. Tripathi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Viral Load ◽  
Hepatitis C ◽  
Half Life ◽  
Nonstructural Protein ◽  
Hcv Rna ◽  
Antiviral Efficacy ◽  
Genotype 1A ◽  
Genotype 1B ◽  
Infected Chimpanzee

ABSTRACT A-837093 is a potent and specific nonnucleoside inhibitor of the hepatitis C virus (HCV) nonstructural protein 5B (NS5B) RNA-dependent RNA polymerase. It possesses nanomolar potencies in both enzymatic and replicon-based cell culture assays. In rats and dogs this compound demonstrated an oral plasma half-life of greater than 7 h, and its bioavailability was >60%. In monkeys it had a half-life of 1.9 h and 15% bioavailability. Its antiviral efficacy was evaluated in two chimpanzees infected with HCV in a proof-of-concept study. The design included oral dosing of 30 mg per kg of body weight twice a day for 14 days, followed by a 14-day posttreatment observation. Maximum viral load reductions of 1.4 and 2.5 log10 copies RNA/ml for genotype 1a- and 1b-infected chimpanzees, respectively, were observed within 2 days after the initiation of treatment. After this initial drop in the viral load, a rebound of plasma HCV RNA was observed in the genotype 1b-infected chimpanzee, while the genotype 1a-infected chimpanzee experienced a partial rebound that lasted throughout the treatment period. Clonal analysis of NS5B gene sequences derived from the plasma of A-837093-treated chimpanzees revealed the presence of several mutations associated with resistance to A-837093, including Y448H, G554D, and D559G in the genotype 1a-infected chimpanzee and C316Y and G554D in the genotype 1b-infected chimpanzee. The identification of resistance-associated mutations in both chimpanzees is consistent with the findings of in vitro selection studies, in which many of the same mutations were selected. These findings validate the antiviral efficacy and resistance development of benzothiadiazine HCV polymerase inhibitors in vivo.

scholarly journals Adaptive Mutations Producing Efficient Replication of Genotype 1a Hepatitis C Virus RNA in Normal Huh7 Cells

2004 ◽  
Vol 78 (15) ◽  
pp. 7904-7915 ◽  
Author(s):  
MinKyung Yi ◽  
Stanley M. Lemon
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Host Cell ◽  
Nonstructural Protein ◽  
Northern Analysis ◽  
Adaptive Mutations ◽  
Amino Terminal ◽  
Genotype 1A ◽  
Genotype 1B ◽  
Huh7 Cells

ABSTRACT Despite recent successes in generating subgenomic RNA replicons derived from genotype 1b strains of hepatitis C virus (HCV) that replicate efficiently in cultured cells, it has proven difficult to generate efficiently replicating RNAs from any other genotype of HCV. This includes genotype 1a, even though it is closely related to genotype 1b. We show here that an important restriction to replication of the genotype 1a H77c strain RNA in normal Huh7 cells resides within the amino-terminal 75 residues of the NS3 protease. We identified adaptive mutations located within this NS3 domain and within NS4A, in close proximity to the essential protease cofactor sequence, that act cooperative to substantially enhance the replication of this genotype 1a RNA in Huh7 cells. These and additional adaptive mutations, identified through a series of iterative transfections and the selection of G418-resistant cell clones, form two groups associating with distinct nonstructural protein domains: the NS3/4A protease and NS5A. A combination of mutations from both groups led to robust replication of otherwise unmodified H77c genomic RNA that was readily detectable by northern analysis within 4 days of transfection into Huh7 cells. We speculate that these adaptive mutations favorably influence assembly of the replicase complex with host cell-specific proteins, or alternatively promote interactions of NS3/4A and/or NS5A with cellular proteins involved in host cell antiviral defenses.

scholarly journals Class III Phosphatidylinositol 4-Kinase Alpha and Beta Are Novel Host Factor Regulators of Hepatitis C Virus Replication

2009 ◽  
Vol 83 (19) ◽  
pp. 10058-10074 ◽  
Author(s):  
Jason Borawski ◽  
Philip Troke ◽  
Xiaoling Puyang ◽  
Veronica Gibaja ◽  
ShanChaun Zhao ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Infectious Virus ◽  
Host Factor ◽  
Hcv Rna ◽  
Class Iii ◽  
Genotype 1A ◽  
Genotype 1B ◽  
Novel Host ◽  
Phosphatidylinositol 4

ABSTRACT Host factor pathways are known to be essential for hepatitis C virus (HCV) infection and replication in human liver cells. To search for novel host factor proteins required for HCV replication, we screened a subgenomic genotype 1b replicon cell line (Luc-1b) with a kinome and druggable collection of 20,779 siRNAs. We identified and validated several enzymes required for HCV replication, including class III phosphatidylinositol 4-kinases (PI4KA and PI4KB), carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD), and mevalonate (diphospho) decarboxylase. Knockdown of PI4KA could inhibit the replication and/or HCV RNA levels of the two subgenomic genotype 1b clones (SG-1b and Luc-1b), two subgenomic genotype 1a clones (SG-1a and Luc-1a), JFH-1 genotype 2a infectious virus (JFH1-2a), and the genomic genotype 1a (FL-1a) replicon. In contrast, PI4KB knockdown inhibited replication and/or HCV RNA levels of Luc-1b, SG-1b, and Luc-1a replicons. The small molecule inhibitor, PIK93, was found to block subgenomic genotype 1b (Luc-1b), subgenomic genotype 1a (Luc-1a), and genomic genotype 2a (JFH1-2a) infectious virus replication in the nanomolar range. PIK93 was characterized by using quantitative chemical proteomics and in vitro biochemical assays to demonstrate PIK93 is a bone fide PI4KA and PI4KB inhibitor. Our data demonstrate that genetic or pharmacological modulation of PI4KA and PI4KB inhibits multiple genotypes of HCV and represents a novel druggable class of therapeutic targets for HCV infection.

Sustained Negativity for HCV-RNA over 24 or More Months by Long-Term Interferon Therapy Correlates with Eradication of HCV in Patients with Hepatitis C Virus Genotype 1b and High Viral Load

Intervirology ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Yasuji Arase ◽  
Fumitaka Suzuki ◽  
Akihito Tsubota ◽  
Yoshiyuki Suzuki ◽  
Satoshi Saitoh ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Viral Load ◽  
Hepatitis C ◽  
Interferon Therapy ◽  
High Viral Load ◽  
Hcv Rna ◽  
Virus Genotype ◽  
Genotype 1B

scholarly journals Resistance Analysis of the Hepatitis C Virus NS3 Protease Inhibitor Asunaprevir

2012 ◽  
Vol 56 (7) ◽  
pp. 3670-3681 ◽  
Author(s):  
Fiona McPhee ◽  
Jacques Friborg ◽  
Steven Levine ◽  
Chaoqun Chen ◽  
Paul Falk ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protease Inhibitor ◽  
Clinical Studies ◽  
Replication Capacity ◽  
Replication Complex ◽  
Hcv Genotype ◽  
Genotype 1A ◽  
Genotype 1B ◽  
Ns3 Protease

ABSTRACTAsunaprevir (BMS-650032) is a potent hepatitis C virus (HCV) NS3 protease inhibitor demonstrating efficacy in alfa interferon-sparing, direct-acting antiviral dual-combination regimens (together with the NS5A replication complex inhibitor daclatasvir) in patients chronically infected with HCV genotype 1b. Here, we describe a comprehensivein vitrogenotypic and phenotypic analysis of asunaprevir-associated resistance against genotypes 1a and 1b using HCV replicons and patient samples obtained from clinical studies of short-term asunaprevir monotherapy. During genotype 1a resistance selection using HCV replicons, the primary NS3 protease substitutions identified were R155K, D168G, and I170T, which conferred low- to moderate-level asunaprevir resistance (5- to 21-fold) in transient-transfection susceptibility assays. For genotype 1b, a higher level of asunaprevir-associated resistance was observed at the same selection pressures, ranging from 170- to 400-fold relative to the wild-type control. The primary NS3 protease substitutions identified occurred predominantly at amino acid residue D168 (D168A/G/H/V/Y) and were associated with high-level asunaprevir resistance (16- to 280-fold) and impaired replication capacity. In asunaprevir single-ascending-dose and 3-day multiple-ascending-dose studies in HCV genotype 1a- or 1b-infected patients, the predominant pre-existing NS3 baseline polymorphism was NS3-Q80K. This substitution impacted initial virologic response rates in a single-ascending-dose study, but its effects after multiple doses were more ambiguous. Interestingly, for patient NS3 protease sequences containing Q80 and those containing K80, susceptibilities to asunaprevir were comparable when tested in an enzyme assay. No resistance-associated variants emerged in these clinical studies that significantly impacted susceptibility to asunaprevir. Importantly, asunaprevir-resistant replicons remained susceptible to an NS5A replication complex inhibitor, consistent with a role for asunaprevir in combination therapies.

scholarly journals Hepatitis C Virus Clearance after Discontinuation of Pegylated Interferon Alpha-2a Monotherapy in a Child

2012 ◽  
Vol 2012 ◽  
pp. 1-4
Author(s):  
Takeshi Endo ◽  
Koichi Ito ◽  
Tokio Sugiura ◽  
Kenji Goto
Keyword(s):  
Hepatitis C Virus ◽  
Viral Load ◽  
Hepatitis C ◽  
Antiviral Therapy ◽  
Interferon Alpha ◽  
Antiviral Treatment ◽  
Pegylated Interferon ◽  
Hcv Rna ◽  
Pegylated Interferon Alpha ◽  
Present Patient

The present patient was a 4-year-old boy. His hepatitis C virus genotype was 2a, and his viral load was high (1400,000 U/mL). The pretreatment liver biopsy revealed no fibrosis or malignancy and mild chronic hepatitis; his Knodell's histological activity (HAI) score was 4. Single nucleotide polymorphism of IL28B (rs8099917) was major type. The patient began antiviral treatment with pegylated interferon alpha 2a (90 μg/week). At week 9, serum HCV RNA became undetectable, with a sensitivity of 50 copies/mL. Antiviral treatment was discontinued at week 11 because the ALT level increased to 610 U/L. After discontinuation of therapy, the patient’s serum HCV RNA status became positive again. The serum viral load increased to 100,000 U/mL. During this period, he had been observed without medication. Sixteen months after stopping treatment, serum HCV became undetectable. Over a 4-year period, HCV RNA became negative and his anti-HCV antibody titer gradually decreased. In conclusion, though antiviral therapy resulted in failure or incomplete therapy, a reduced viral load resulted in viral clearance in the present patient. Interleukin 28B genotype might have association with the clearance of hepatitis C virus after discontinuation of antiviral therapy.

scholarly journals Short-Term Monotherapy with IDX184, a Liver-Targeted Nucleotide Polymerase Inhibitor, in Patients with Chronic Hepatitis C Virus Infection

2012 ◽  
Vol 56 (12) ◽  
pp. 6372-6378 ◽  
Author(s):  
Jacob Lalezari ◽  
David Asmuth ◽  
Arnaldo Casiró ◽  
Hugo Vargas ◽  
Shannon Lawrence ◽  
...  
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Viral Load ◽  
Hepatitis C ◽  
Adverse Events ◽  
Antiviral Activity ◽  
Chronic Hepatitis C ◽  
Hcv Rna ◽  
Plasma Exposure ◽  
Chronic Hepatitis C Virus

ABSTRACTIDX184 is a liver-targeted prodrug of 2′-methylguanosine (2′-MeG) monophosphate. This study investigated the safety, tolerability, antiviral activity, and pharmacokinetics of IDX184 as a single agent in treatment-naïve patients with genotype-1 chronic hepatitis C virus (HCV) infection. Forty-one patients with baseline HCV RNA ≥ 5 log10IU/ml, alanine aminotransferase (ALT) ≤ 2.5× the upper limit of normal, and compensated liver disease were dosed. Sequential cohorts of 10 patients, randomized 8:2 (active:placebo), received 25, 50, 75, and 100 mg of IDX184 once daily for 3 days, with a 14-day follow-up. There were no safety-related treatment discontinuations or serious adverse events. The adverse events and laboratory abnormalities observed for IDX184- and placebo-treated patients were similar. At the end of the 3-day treatment period, changes from baseline in HCV RNA levels (means ± standard deviations) were −0.5 ± 0.6, −0.7 ± 0.2, −0.6 ± 0.3, and −0.7 ± 0.5 log10for the 25-, 50-, 75-, and 100-mg doses, respectively, while viral load remained unchanged for the pooled placebo patients (−0.05 ± 0.3 log10). Patients with genotype-1a and patients with genotype-1b responded similarly. Serum ALT levels decreased, especially at daily doses ≥ 75 mg. During the posttreatment period, plasma viremia and serum aminotransferase levels returned to near pretreatment levels. No resistance mutations associated with IDX184 were detected. Plasma exposure of IDX184 and its nucleoside metabolite 2′-MeG was dose related and low. Changes in plasma viral load correlated with plasma exposure of 2′-MeG. In conclusion, the results from this proof-of-concept study show that small doses of the liver-targeted prodrug IDX184 were able to deliver significant antiviral activity and support further clinical evaluation of the drug candidate.

Viral Dynamics and Pharmacokinetics in Combined Interferon Alfa-2b and Ribavirin Therapy for Patients Infected with Hepatitis C Virus of Genotype 1b and High Pretreatment Viral Load

Intervirology ◽  
2002 ◽  
Vol 45 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Akihito Tsubota ◽  
Norio Akuta ◽  
Fumitaka Suzuki ◽  
Yoshiyuki Suzuki ◽  
Takashi Someya ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Viral Load ◽  
Hepatitis C ◽  
Interferon Alfa ◽  
Viral Dynamics ◽  
Genotype 1B

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 Preclinical Profile of VX-950, a Potent, Selective, and Orally Bioavailable Inhibitor of Hepatitis C Virus NS3-4A Serine Protease

2006 ◽  
Vol 50 (3) ◽  
pp. 899-909 ◽  
Author(s):  
Robert B. Perni ◽  
Susan J. Almquist ◽  
Randal A. Byrn ◽  
Gurudatt Chandorkar ◽  
Pravin R. Chaturvedi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Serine Protease ◽  
Enzyme Inhibitor ◽  
Pharmacokinetic Profile ◽  
Hcv Rna ◽  
High Exposure ◽  
Genotype 1A ◽  
Hcv Protease ◽  
Orally Bioavailable

ABSTRACT VX-950 is a potent, selective, peptidomimetic inhibitor of the hepatitis C virus (HCV) NS3-4A serine protease, and it demonstrated excellent antiviral activity both in genotype 1b HCV replicon cells (50% inhibitory concentration [IC50] = 354 nM) and in human fetal hepatocytes infected with genotype 1a HCV-positive patient sera (IC50 = 280 nM). VX-950 forms a covalent but reversible complex with the genotype 1a HCV NS3-4A protease in a slow-on, slow-off process with a steady-state inhibition constant (Ki *) of 7 nM. Dissociation of the covalent enzyme-inhibitor complex of VX-950 and genotype 1a HCV protease has a half-life of almost an hour. A >4-log10 reduction in the HCV RNA levels was observed after a 2-week incubation of replicon cells with VX-950, with no rebound of viral RNA observed after withdrawal of the inhibitor. In several animal species, VX-950 exhibits a favorable pharmacokinetic profile with high exposure in the liver. In a recently developed HCV protease mouse model, VX-950 showed excellent inhibition of HCV NS3-4A protease activity in the liver. Therefore, the overall preclinical profile of VX-950 supports its candidacy as a novel oral therapy against hepatitis C.

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