scholarly journals In VitroActivity and Resistance Profile of Samatasvir, a Novel NS5A Replication Inhibitor of Hepatitis C Virus

2014 ◽  
Vol 58 (8) ◽  
pp. 4431-4442 ◽  
Author(s):  
J. P. Bilello ◽  
L. B. Lallos ◽  
J. F. McCarville ◽  
M. La Colla ◽  
I. Serra ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Agents ◽  
Resistance Profile ◽  
Direct Acting Antiviral ◽  
Genotype 1A ◽  
Hcv Protease ◽  
Chronic Hcv ◽  
Direct Acting

ABSTRACTThe hepatitis C virus (HCV) nonstructural 5A (NS5A) protein is a clinically validated target for drugs designed to treat chronic HCV infection. This study evaluated thein vitroactivity, selectivity, and resistance profile of a novel anti-HCV compound, samatasvir (IDX719), alone and in combination with other antiviral agents. Samatasvir was effective and selective against infectious HCV and replicons, with 50% effective concentrations (EC50s) falling within a tight range of 2 to 24 pM in genotype 1 through 5 replicons and with a 10-fold EC50shift in the presence of 40% human serum in the genotype 1b replicon. The EC90/EC50ratio was low (2.6). A 50% cytotoxic concentration (CC50) of >100 μM provided a selectivity index of >5 × 107. Resistance selection experiments (with genotype 1a replicons) and testing against replicons bearing site-directed mutations (with genotype 1a and 1b replicons) identified NS5A amino acids 28, 30, 31, 32, and 93 as potential resistance loci, suggesting that samatasvir affects NS5A function. Samatasvir demonstrated an overall additive effect when combined with interferon alfa (IFN-α), ribavirin, representative HCV protease, and nonnucleoside polymerase inhibitors or the nucleotide prodrug IDX184. Samatasvir retained full activity in the presence of HIV and hepatitis B virus (HBV) antivirals and was not cross-resistant with HCV protease, nucleotide, and nonnucleoside polymerase inhibitor classes. Thus, samatasvir is a selective low-picomolar inhibitor of HCV replicationin vitroand is a promising candidate for future combination therapies with other direct-acting antiviral drugs in HCV-infected patients.

scholarly journals In VitroandIn VivoAntiviral Activity and Resistance Profile of the Hepatitis C Virus NS3/4A Protease Inhibitor ABT-450

2014 ◽  
Vol 59 (2) ◽  
pp. 988-997 ◽  
Author(s):  
Tami Pilot-Matias ◽  
Rakesh Tripathi ◽  
Daniel Cohen ◽  
Isabelle Gaultier ◽  
Tatyana Dekhtyar ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Agents ◽  
Cross Resistance ◽  
Hcv Rna ◽  
Genotype 1 ◽  
Common Amino Acid ◽  
Direct Acting Antiviral ◽  
Genotype 1A

ABSTRACTThe development of direct-acting antiviral agents is a promising therapeutic advance in the treatment of hepatitis C virus (HCV) infection. However, rapid emergence of drug resistance can limit efficacy and lead to cross-resistance among members of the same drug class. ABT-450 is an efficacious inhibitor of HCV NS3/4A protease, with 50% effective concentration values of 1.0, 0.21, 5.3, 19, 0.09, and 0.69 nM against stable HCV replicons with NS3 protease from genotypes 1a, 1b, 2a, 3a, 4a, and 6a, respectively.In vitro, the most common amino acid variants selected by ABT-450 in genotype 1 were located in NS3 at positions 155, 156, and 168, with the D168Y variant conferring the highest level of resistance to ABT-450 in both genotype 1a and 1b replicons (219- and 337-fold, respectively). In a 3-day monotherapy study with HCV genotype 1-infected patients, ABT-450 was coadministered with ritonavir, a cytochrome P450 3A4 inhibitor shown previously to markedly increase peak, trough, and overall drug exposures of ABT-450. A mean maximum HCV RNA decline of 4.02 log10was observed at the end of the 3-day dosing period across all doses. The most common variants selected in these patients were R155K and D168V in genotype 1a and D168V in genotype 1b. However, selection of resistant variants was significantly reduced at the highest ABT-450 dose compared to lower doses. These findings were informative for the subsequent evaluation of ABT-450 in combination with additional drug classes in clinical trials in HCV-infected patients. (Study M11-602 is registered at ClinicalTrials.gov under registration no. NCT01074008.)

scholarly journals Impact of Preexisting Hepatitis C Virus Genotype 6 NS3, NS5A, and NS5B Polymorphisms on theIn VitroPotency of Direct-Acting Antiviral Agents

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Fiona McPhee ◽  
Joseph Ueland ◽  
Vincent Vellucci ◽  
Scott Bowden ◽  
William Sievert ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Agents ◽  
Virologic Response ◽  
Virus Genotype ◽  
Direct Acting Antiviral ◽  
East And Southeast Asia ◽  
Direct Acting ◽  
Ns3 Protease

ABSTRACTHCV genotype 6 (GT-6) is found predominantly in East and Southeast Asia. Clinical studies have focused on patients infected with hepatitis C virus (HCV) GT-6a, where high sustained virologic response (SVR) rates to direct-acting antivirals (DAAs) have been achieved. However, GT-6 is highly diverse, with 29 reported subtypes. We explored the diversity of GT-6 polymorphisms at residues associated with DAA resistance, their impact on DAAin vitropotency when evaluated in a GT-6a consensus replicon, and their association with specific GT-6 subtypes. GT-6 sequences from 25 patient-derived samples and 105 sequences from the U.S. HCV database were compared, and substitutions at resistance-associated residue positions were phenotyped against different DAAs. Preexisting resistance-associated substitutions (RASs) to NS3 protease (A156V and D168E) and NS5B nucleotide (L159F and S282C) inhibitors were rare (<4%). Preexisting RASs to NS5A inhibitors were common, especially at L28 (A/F/G/M/T/V) and R30 (E/N/S).In vitrosusceptibilities of NS5A-L28A and -L28T were dramatically reduced against all tested NS5A drugs (90% effective concentration [EC90] range, 119 to 2,032 nM) compared with susceptibilities against a GT-6a consensus replicon (EC90range, 0.1 to 19 nM). These L28 RASs preexisted in combination with R30S (EC90[L28A-R30S] of ≥720 nM or EC90[L28T-R30S] of ≥128 nM against tested DAAs) or as L28T-L31I (EC90[tested DAAs] of >5,000 nM) and were detected in evaluated GT-6b and -6f sequences. NS5A-L28A-R30A, observed in GT-6r, did not replicate. In conclusion, HCV GT-6b, GT-6f, and GT-6r sequences harbored highly resistant RASs to all evaluated NS5A drugs. Therefore, monitoring SVR in patients infected with these GT-6 subtypes treated with NS5A drug-containing regimens is suggested to confirm any association between noted NS5A polymorphisms and treatment failure.

scholarly journals Safety and efficacy of direct-acting antiviral drugs in the treatment of chronic hepatitis C virus infection in patients with thalassemia: a prospective study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elsayed Ghoneem ◽  
Ahmed Saleh ◽  
Shahira Aly El-Etreby ◽  
Metwaly Ibrahim Mortada ◽  
Mayada A. Ghannam ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Agents ◽  
Virologic Response ◽  
Direct Acting Antiviral ◽  
Significant Difference ◽  
Before And After ◽  
Chronic Hcv ◽  
Direct Acting ◽  
A Prospective Study

Abstract Background Hepatitis C virus (HCV) infection is a major cause of liver-related morbidity and mortality among thalassemic patients. Direct-acting antiviral agents (DAAs) are highly effective and well-tolerated by chronic HCV patients. Results The mean age of our patients was 29 years. Sustained virologic response (SVR) at 12 and 24 weeks was achieved in all patients (100%). The most common side effects were fatigue (18%), anemia (13.63%), and headache (4.5%). There was no statistically significant difference in the hemoglobin level before and after treatment (p = 0.48). There was a significant improvement in serum bilirubin and mean ALT levels after treatment compared to baseline data (p < 0.0005 each). Conclusions DAAs, namely, sofosbuvir plus daclatasvir or sofosbuvir plus ledipasvir, are effective and well-tolerated regimens in thalassemic patients with chronic HCV.

scholarly journals In Vitro Antiviral Profile of Ruzasvir, a Potent and Pangenotype Inhibitor of Hepatitis C Virus NS5A

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Ernest Asante-Appiah ◽  
Rong Liu ◽  
Stephanie Curry ◽  
Patricia McMonagle ◽  
Sony Agrawal ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Activity ◽  
De Novo ◽  
Antiviral Agents ◽  
Cross Resistance ◽  
Hcv Rna ◽  
Direct Acting Antiviral ◽  
Direct Acting

ABSTRACT Inhibition of NS5A has emerged as an attractive strategy to intervene in hepatitis C virus (HCV) replication. Ruzasvir (formerly MK-8408) was developed as a novel NS5A inhibitor to improve upon the potency and barrier to resistance of early compounds. Ruzasvir inhibited HCV RNA replication with 50% effective concentrations (EC50s) of 1 to 4 pM in Huh7 or Huh7.5 cells bearing replicons for HCV genotype 1 (GT1) to GT7. The antiviral activity was modestly (10-fold) reduced in the presence of 40% normal human serum. The picomolar potency in replicon cells extended to sequences of clinical isolates available in public databases that were synthesized and tested as replicons. In GT1a, ruzasvir inhibited common NS5A resistance-associated substitutions (RASs), with the exception of M28G. De novo resistance selection studies identified pathways with certain amino acid substitutions at residues 28, 30, 31, and 93 across genotypes. Substitutions at position 93 were more common in GT1 to -4, while changes at position 31 emerged frequently in GT5 and -6. With the exception of GT4, the reintroduction of selected RASs conferred a ≥100-fold potency reduction in the antiviral activity of ruzasvir. Common RASs from other classes of direct-acting antiviral agents (DAAs) did not confer cross-resistance to ruzasvir. The interaction of ruzasvir with an NS3/4A protease inhibitor (grazoprevir) and an NS5B polymerase prodrug (uprifosbuvir) was additive to synergistic, with no evidence of antagonism or cytotoxicity. The antiviral profile of ruzasvir supported its further evaluation in human trials in combination with grazoprevir and uprifosbuvir.

Effect on the adherence to concomitant medications after initiation of treatment with direct-acting antiviral agents against hepatitis C virus

2020 ◽  
Vol 43 (8) ◽  
pp. 418-425
Author(s):  
Maria Isabel Guzman Ramos ◽  
Mercedes Manzano-García ◽  
M. de las Aguas Robustillo-Cortés ◽  
Juan Antonio Pineda ◽  
Ramón Morillo-Verdugo
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Agents ◽  
Direct Acting Antiviral ◽  
Concomitant Medications ◽  
Direct Acting ◽  
Direct Acting Antiviral Agents

scholarly journals Computer-aided identification of a series of novel ligands showing high potency as hepatitis C virus NS3/4A protease inhibitors

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Stephen Ejeh ◽  
Adamu Uzairu ◽  
Gideon Adamu Shallangwa ◽  
Stephen E. Abechi
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Binding Energy ◽  
Protease Inhibitor ◽  
Protease Inhibitors ◽  
Antiviral Agents ◽  
High Potency ◽  
Direct Acting Antiviral ◽  
Direct Acting ◽  
Direct Acting Antiviral Agents

Abstract Background Hepatitis C virus (HCV) is a global medical condition that causes several life-threatening chronic diseases in the liver. The conventional interferon-free treatment regimens are currently in use by a blend of direct-acting antiviral agents (DAAs) aiming at the viral NS3 protease. However, major concerns may be the issue of DAA-resistant HCV strains and the limited availability to the DAAs due to their high price. Due to this crisis, the developments of a new molecule with high potency as an NS3/4A protease inhibitor of the hepatitis-C virus remain a high priority for medical research. This study aimed to use in-silico methods to identify high potent molecule as an NS3/4A protease inhibitor and investigating the binding energy of the identified molecule in comparison with approved direct-acting antiviral agents (Telaprevir, Simeprevir, and Voxilaprevir) through molecular docking. Results The model obtained by in-silico method have the following statistical records, coefficient of determination (r2) of 0.7704, cross-validation (q2LOO = 0.6914); external test set (r2(pred) = 0.7049) and Y-randomization assessment (cR2p = 0.7025). The results from the model were used to identify 12 new potential human HCV NS3/4A protease inhibitors, and it was observed that the identified molecule is well-fixed when docked with the receptor and was found to have the lowest binding energy of − 10.7, compared to approved direct-acting antiviral agents (Telaprevir, Simeprevir, and Voxilaprevir) with − 9.5, − 10.0, − 10.5 binding energy, respectively. Conclusion The binding affinity (− 10.7) of the newly identified molecule docked with 3D structures of HCV NS3/4a protease/helicase (PDB ID: 4A92) was found to be better than that of Telaprevir, Simeprevir, and Voxilaprevir (approved direct-acting antiviral agents) which are − 9.5, − 10.0, and − 10.5, respectively. Hence, a novel molecule was identified showing high potency as HCV NS3/4a protease inhibitors.

scholarly journals Hepatitis C virus vaccine development: old challenges and new opportunities

2015 ◽  
Vol 2 (3) ◽  
pp. 285-295 ◽  
Author(s):  
Dapeng Li ◽  
Zhong Huang ◽  
Jin Zhong
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Chronic Hepatitis C ◽  
Vaccine Development ◽  
Rna Virus ◽  
Antiviral Agents ◽  
Resistance Mutations ◽  
Direct Acting Antiviral ◽  
Direct Acting

Abstract Hepatitis C virus (HCV), an enveloped positive-sense single-stranded RNA virus, can cause chronic and end-stage liver diseases. Approximately 185 million people worldwide are infected with HCV. Tremendous progress has been achieved in the therapeutics of chronic hepatitis C thanks to the development of direct-acting antiviral agents (DAAs), but the worldwide use of these highly effective DAAs is limited due to their high treatment cost. In addition, drug-resistance mutations remain a potential problem as DAAs are becoming a standard therapy for chronic hepatitis C. Unfortunately, no vaccine is available for preventing new HCV infection. Therefore, HCV still imposes a big threat to human public health, and the worldwide eradication of HCV is critically dependent on an effective HCV vaccine. In this review, we summarize recent progresses on HCV vaccine development and present our views on the rationale and strategy to develop an effective HCV vaccine.

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