Sofosbuvir in combination with peginterferon alfa-2a and ribavirin for non-cirrhotic, treatment-naive patients with genotypes 1, 2, and 3 hepatitis C infection: a randomised, double-blind, phase 2 trial

Rationale for Hepatitis C Virus Treatment During Hematopoietic Stem Cell Transplant in the Era of Novel Direct-Acting Antivirals

BACKGROUND AND AIMS

Untreated hepatitis C (HCV) infection in patients undergoing hematopoietic stem cell transplantation (HSCT) can lead to worse outcomes. Traditionally, HSCT patients infected with HCV would wait until after immune reconstitution to receive HCV therapy, as the oncologic urgency of transplant would not allow time for a full preceding treatment course of HCV therapy. However, in the era of newer direct-acting antivirals (DAAs), we propose that concomitant treatment of HCV while undergoing HSCT is safe and feasible, while keeping in mind potential drug-drug interactions.

METHODS

A literature review was performed to summarize the available data on the impact of HCV on patients undergoing HSCT. Drug-drug interactions for DAA's and pertinent HSCT drugs were evaluated using Lexicomp online® and http://hep-druginteractions.org .

RESULTS

During HSCT, HCV appears to be a conditional risk factor for sinusoidal obstruction syndrome and a potential risk factor for graft versus host disease, both of which are associated with increased mortality. HCV reactivation and exacerbation may impact the use of chemotherapeutics, but available studies haven't shown impact specifically on HSCT. Limited case reports exist but demonstrate safe and effective use DAAs during HSCT. These, along with a drug-drug interaction review demonstrate agents such as sofosbuvir/velpatasvir and glecaprevir/pibrentasvir are promising DAAs for use in HSCT.

CONCLUSION

HCV infection may worsen outcomes for patients undergoing HSCT. Concomitant treatment of HCV during HSCT using newer DAAs appears feasible and may improve patient morbidity and mortality, however large-scale studies are needed to further support this practice.

Sofosbuvir Suppresses the Genome Replication of DENV1 in Human Hepatic Huh7 Cells

Dengue virus (DENV) causes dengue fever and dengue hemorrhagic fever, and DENV infection kills 20,000 people annually worldwide. Therefore, the development of anti-DENV drugs is urgently needed. Sofosbuvir (SOF) is an effective drug for HCV-related diseases, and its triphosphorylated metabolite inhibits viral RNA synthesis by the RNA-dependent RNA polymerase (RdRp) of HCV. (2'R)-2'-Deoxy-2'-fluoro-2'-methyluridine (FMeU) is the dephosphorylated metabolite produced from SOF. The effects of SOF and FMeU on DENV1 replication were analyzed using two DENV1 replicon-based methods that we previously established. First, a replicon-harboring cell assay showed that DENV1 replicon replication in human hepatic Huh7 cells was decreased by SOF but not by FMeU. Second, a transient replicon assay showed that DENV1 replicon replication in Huh7 cells was decreased by SOF; however, in hamster kidney BHK-21 cells, it was not suppressed by SOF. Additionally, the replicon replication in Huh7 and BHK-21 cells was not affected by FMeU. Moreover, we assessed the effects of SOF on infectious DENV1 production. SOF suppressed infectious DENV1 production in Huh7 cells but not in monkey kidney Vero cells. To examine the substrate recognition of the HCV and DENV1 RdRps, the complex conformation of SOF-containing DENV1 RdRp or HCV RdRp was predicted using AlphaFold 2. These results indicate that SOF may be used as a treatment for DENV1 infection.

Spectroscopic study to verify the anti-hepatitis C virus (HCV) treatment through a delivery system of the sofosbuvir drug on chitosan and pycnogenol nanoparticles surface

The target of the current study is to create a novel hybrid nanocomposite (Cs@Pyc.SOF) by combining the anti-hepatitis C virus (HCV) drug sofosbuvir with the nano antioxidant pycnogenol (Pyc) and nano biomolecules like chitosan nanoparticles (Cs NPs). The characterization procedure works to verify the creation of nanocomposite (NCP) using several different techniques. UV-Vis spectroscopy is used to measure SOF loading efficiency. The various concentrations of the SOF drug were used to determine the binding constant rate Kb, which was found to be 7.35 ± 0.95 min-1 with an 83% loading efficiency. At pH 7.4, the release rate was 80.6% after two hours and 92% after 48 h, whereas at pH 6.8, it was 29% after two hours and 94% after 48 h. After 2 and 48 h, the release rate in water was 38% and 77%, respectively. . The SRB technique for fast screening is used for the cytotoxicity test, where the investigated composites show a safety status and high viability against the examined cell line. The cytotoxicity assay of the SOF hybrid materials has been identified with cell lines like mouse normal liver cells (BNL). So, Cs@Pyc.SOF was recommended as a substitute medication for the therapy of HCV, but the results need clinical studies.

Viral Fitness, Population Complexity, Host Interactions, and Resistance to Antiviral Agents

Fitness of viruses has become a standard parameter to quantify their adaptation to a biological environment. Fitness determinations for RNA viruses (and some highly variable DNA viruses) meet with several uncertainties. Of particular interest are those that arise from mutant spectrum complexity, absence of population equilibrium, and internal interactions among components of a mutant spectrum. Here, concepts, fitness measurements, limitations, and current views on experimental viral fitness landscapes are discussed. The effect of viral fitness on resistance to antiviral agents is covered in some detail since it constitutes a widespread problem in antiviral pharmacology, and a challenge for the design of effective antiviral treatments. Recent evidence with hepatitis C virus suggests the operation of mechanisms of antiviral resistance additional to the standard selection of drug-escape mutants. The possibility that high replicative fitness may be the driver of such alternative mechanisms is considered. New broad-spectrum antiviral designs that target viral fitness may curtail the impact of drug-escape mutants in treatment failures. We consider to what extent fitness-related concepts apply to coronaviruses and how they may affect strategies for COVID-19 prevention and treatment.

SARS-CoV-2 Mutant Spectra at Different Depth Levels Reveal an Overwhelming Abundance of Low Frequency Mutations

Populations of RNA viruses are composed of complex and dynamic mixtures of variant genomes that are termed mutant spectra or mutant clouds. This applies also to SARS-CoV-2, and mutations that are detected at low frequency in an infected individual can be dominant (represented in the consensus sequence) in subsequent variants of interest or variants of concern. Here we briefly review the main conclusions of our work on mutant spectrum characterization of hepatitis C virus (HCV) and SARS-CoV-2 at the nucleotide and amino acid levels and address the following two new questions derived from previous results: (i) how is the SARS-CoV-2 mutant and deletion spectrum composition in diagnostic samples, when examined at progressively lower cut-off mutant frequency values in ultra-deep sequencing; (ii) how the frequency distribution of minority amino acid substitutions in SARS-CoV-2 compares with that of HCV sampled also from infected patients. The main conclusions are the following: (i) the number of different mutations found at low frequency in SARS-CoV-2 mutant spectra increases dramatically (50- to 100-fold) as the cut-off frequency for mutation detection is lowered from 0.5% to 0.1%, and (ii) that, contrary to HCV, SARS-CoV-2 mutant spectra exhibit a deficit of intermediate frequency amino acid substitutions. The possible origin and implications of mutant spectrum differences among RNA viruses are discussed.

Binding of GS-461203 and Its Halogen Derivatives to HCV Genotype 2a RNA Polymerase Drug Resistance Mutants

Hepatitis C Virus (HCV) is reported to develop GS-461203 resistance because of multiple mutations within the RNA-dependent RNA Polymerase (RdRp) of HCV. The lack of a high-resolution structure of these RdRp mutants in complex with GS-461203 hinders efforts to understand the drug resistance. Here we decipher the binding differences of GS-461203 in the wild type and mutated systems T179A or M289L of HCV RdRp Genotype 2a using homology modeling, molecular docking, and molecular dynamics simulation. Key residues responsible for GS-461203 binding were identified to be Arg48, Arg158, Asp318, Asp319, and Asp220, and that mutations T179A or M289L have caused conformational changes of GS-461203 in the RdRp active site. The affinities of GS-461203 were reduced in T179A system, but it became slightly stronger in the M289L system. Furthermore, we designed two new analogues of GS-461203 which encouragingly induced more stable interactions than GS-461203, and thus resulted in much better binding energies. This present study reveals how a single mutation, T179A or M289L, will modulate GS-461203 binding in HCV RdRp Genotype 2a, while introducing two novel analogues to overcome the drug resistance which may be good candidate for further experimental verification.

Viral hepatitis: Milestones, unresolved issues, and future goals

In this review the current overall knowledge on hepatitis A, B, C, D, and E will be discussed. These diseases are all characterized by liver inflammation but have significant differences in distribution, transmission routes, and outcomes. Hepatitis B virus and hepatitis C virus are transmitted by exposure to infected blood, and in addition to acute infection, they can cause chronic hepatitis, which in turn can evolve into cirrhosis. It is estimated that more than 300 million people suffer from chronic hepatitis B or C worldwide. Hepatitis D virus, which is also transmitted by blood, only affects hepatitis B virus infected people, and this dual infection results in worse liver-related outcomes. Hepatitis A and E spread via the fecal-oral route, which corresponds mainly to the ingestion of food or water contaminated with infected stools. However, in developed countries hepatitis E is predominantly a zoonosis. Although hepatitis A virus and hepatitis E virus are usually responsible for a self-limiting hepatitis, a serious, rarely fatal illness is also possible, and in immunosuppressed patients, such as organ transplant recipients, hepatitis E virus infection can become chronic. The description of goals achieved, unresolved issues, and the latest research on this topic may make it possible to speculate on future scenarios in the world of viral hepatitis.

Distribution of naturally -occurring NS5B resistance-associated substitutions in Egyptian patients with chronic Hepatitis C

Background

NS5B polymerase inhibitors represent the cornerstone of the present treatment of Hepatitis C virus infection (HCV). Naturally occurring substitution mutations to NS5B inhibitors have been recorded. The current study intended to demonstrate possible natural direct acting antiviral (DAA)—mutations of the HCV NS5B region in HCV patients in Minia governorate, Egypt.

Methods

Samples were collected from 27 treatment-naïve HCV patients and 8 non-responders. Out of 27 treatment-naïve patients, 17 NS5B sequences (amino acids 221–345) from treatment-naïve patients and one sample of non-responders were successfully amplified. Nucleotide sequences have been aligned, translated into amino acids, and compared to drug resistance mutations reported in the literature.

Results

NS5B amino acid sequence analysis ensures several novel NS5B mutations existence (more than 40 substitution mutations) that have not been previously documented to be correlated with a resistant phenotype. It was found that K304R (82.4%), E327D and P300T (76.5% each) substitutions were the most distributed in the tested samples, respectively. S282T, the major resistance mutation that induces high sofosbuvir-resistance level in addition to other reported mutations (L320F/C) and (C316Y/N) were not recognized. Q309R mutation is a ribavirin-associated resistance, which was recognized in one strain (5.9%) of genotype 1g sequences. Besides, one substitution mutation (E237G) was identified in the successfully amplified non-responder sample.

Conclusion

Our study showed various combinations of mutations in the analyzed NS5B genes which could enhance the possibility of therapy failure in patients administered regimens including multiple DAA.

Genotype 3-hepatitis C virus’ last line of defense

Chronic infection with hepatitis C virus (HCV) is one of the leading causes of liver disease globally, affecting approximately 71 million people. The majority of them are infected with genotype (GT) 1 but infections with GT3 are second in frequency. For many years, GT3 was considered to be less pathogenic compared to other GTs in the HCV family due to its favorable response to interferon (IFN)-based regimen. However, the growing evidence of a higher rate of steatosis, more rapid progression of liver fibrosis, and lower efficacy of antiviral treatment compared to infection with other HCV GTs has changed this conviction. This review presents the specifics of the course of GT3 infection and the development of therapeutic options for GT3-infected patients in the era of direct-acting antivirals (DAA). The way from a standard of care therapy with pegylated IFN-alpha (pegIFNα) and ribavirin (RBV) through a triple combination of pegIFNα + RBV and DAA to the highly potent IFN-free pangenotypic DAA regimens is discussed along with some treatment options which appeared to be dead ends. Although the implementation of highly effective pangenotypic regimens is the most recent stage of revolution in the treatment of GT3 infection, there is still room for improvement, especially in patients with liver cirrhosis and those who fail to respond to DAA therapies, particularly those containing inhibitors of HCV nonstructural protein 5A.

Prevalence and genotype distribution of hepatitis C virus in Mongolia: Systematic review and meta-analysis

OBJECTIVE

To characterize hepatitis C virus (HCV) infection epidemiology in Mongolia.

METHOD

Publications on HCV antibody (Ab) and RNA prevalence, and/or genotypes/subtypes were systematically reviewed and reported following PRISMA guidelines. Random-effects meta-analyses and age adjustments were conducted to estimate the prevalence of Mongolians exposed to HCV (pooled HCV-Ab prevalence) by time period, sex, and at-risk populations; and to estimate the prevalence of chronically-infected HCV individuals.

RESULTS

The national pooled HCV-Ab prevalence was 12.3% in 2000-2009 and 11.2% in 2013. Sex-specific pooled prevalence appeared higher among females than males (14.0% versus 6.8%). Age-specific pooled prevalence significantly increased from 3.7% among children (aged 0-10 years) to 34.1% among people aged ≥50 years (p < 0.001). Among the adult general population (low-risk population), the national age-adjusted prevalence was 8.1%. Age-adjusted chronic infection prevalence in adults was 6.0%. Among healthcare workers, pooled prevalence was 18.0%. Among patients with liver diseases, pooled prevalence was 53.7%. Among individuals engaging in risky sexual behaviors, pooled prevalence was 11.1%. The identified circulating genotypes/subtypes were 1b (58.0%), 2a (21.7%), and 1a (20.2%).

CONCLUSION

The national HCV prevalence in Mongolia appeared to be among the highest worldwide. Higher prevalence in the clinical setting indicated potential ongoing HCV iatrogenic and occupational transmission. Additionally, HCV transmission in community settings should be investigated.

Amino Acid Substitutions Associated with Treatment Failure for Hepatitis C Virus Infection

Despite the high virological response rates achieved with current directly acting antiviral agents (DAAs) against hepatitis C virus (HCV), around 2% to 5% of treated patients do not achieve a sustained viral response. The identification of amino acid substitutions associated with treatment failure requires analytical designs, such as subtype-specific ultradeep sequencing (UDS) methods, for HCV characterization and patient management. Using this procedure, we have identified six highly represented amino acid substitutions (HRSs) in NS5A and NS5B of HCV, which are not bona fide resistance-associated substitutions (RAS), from 220 patients who failed therapy. They were present frequently in basal and posttreatment virus of patients who failed different DAA-based therapies. Contrary to several RAS, HRSs belong to the acceptable subset of substitutions according to the PAM250 replacement matrix. Their mutant frequency, measured by the number of deep sequencing reads within the HCV quasispecies that encode the relevant substitutions, ranged between 90% and 100% in most cases. They also have limited predicted disruptive effects on the three-dimensional structures of the proteins harboring them. Possible mechanisms of HRS origin and dominance, as well as their potential predictive value for treatment response, are discussed.

Sofosbuvir and daclatasvir compared with standard of care in the treatment of patients admitted to hospital with moderate or severe coronavirus infection (COVID-19): a randomized controlled trial

Background

Currently no effective antiviral therapy has been found to treat COVID-19. The aim of this trial was to assess if the addition of sofosbuvir and daclatasvir improved clinical outcomes in patients with moderate or severe COVID-19.

Methods

This was an open-label, multicentre, randomized controlled clinical trial in adults with moderate or severe COVID-19 admitted to four university hospitals in Iran. Patients were randomized into a treatment arm receiving sofosbuvir and daclatasvir plus standard care, or a control arm receiving standard care alone. The primary endpoint was clinical recovery within 14 days of treatment. The study is registered with IRCT.ir under registration number IRCT20200128046294N2.

Results

Between 26 March and 26 April 2020, 66 patients were recruited and allocated to either the treatment arm (n = 33) or the control arm (n = 33). Clinical recovery within 14 days was achieved by 29/33 (88%) in the treatment arm and 22/33 (67%) in the control arm (P = 0.076). The treatment arm had a significantly shorter median duration of hospitalization [6 days (IQR 4–8)] than the control group [8 days (IQR 5–13)]; P = 0.029. Cumulative incidence of hospital discharge was significantly higher in the treatment arm versus the control (Gray’s P = 0.041). Three patients died in the treatment arm and five in the control arm. No serious adverse events were reported.

Conclusions

The addition of sofosbuvir and daclatasvir to standard care significantly reduced the duration of hospital stay compared with standard care alone. Although fewer deaths were observed in the treatment arm, this was not statistically significant. Conducting larger scale trials seems prudent.

Sofosbuvir: Really Meets the Unmet Needs for Hepatitis C Treatment?

Chronic hepatitis C remains a major public health concern with a prevalence of more than 1% worldwide. Of late, with the discovery of newer drugs, chronic HCV treatment has touched new dimensions. The treatment has progressed from Interferons to Pegylated interferon (Peg IFN) based therapy, with or without ribavirin to treatment with orally active Direct Acting Antivirals (DAA) with Peg IFN and ribavirin and eventually to various combinations of DAA, without IFN. Introduction of newer DAAs has transfigured the treatment of chronic HCV. Chronic HCV patients with advanced liver disease, psychiatric condition, anemia or autoimmune diseases, not eligible for Peg IFN based therapy have a ray of hope now. Amongst all DAAs, nucleoside inhibitors have been the most promising agent. Thus the present review focuses on Sofosbuvir, one of the most effective nucleoside inhibitors; in terms of potency, resistance profile, activity against all genotypes of HCV and adverse effects. FDA approved Sofobuvir for clinical use in 2013. Chemically, it is 2'-deoxy-2'-α-fluoro-β-Cmethyluridine- 5'-triphosphate; a phosphoramidate prodrug that is activated by enzyme present in human liver. It is a highly potent inhibitor of HCV NS5B polymerase. Efficacy of the Sofosbuvir has been established in various phase 2 and phase 3 clinical trials like PROTON, ELECTRON, FUSION, POSITRON etc. Sofosbuvir has a good safety profile with few mild to moderate adverse effects. Evidence reveals that sofosbuvir has substantial impact on the treatment of HCV.

Peripheral Expression of CXCL10 Gene in Chronic Hepatitis C Patients Treated with Sofosbuvir, Daclatasvir, and Ribavirin

Hepatitis C virus (HCV) causes persistent infection and invades host's innate and adaptive immune systems. During the eradication of this pathogen, the components of immune system may cause bystander damage to host, which might be even worse than the viral pathogenesis. Thus, the therapy should not only eliminate primary virus infection but also improve the inflammatory immune responses. The breakthrough of interferon free direct acting antiviral (DAA) drugs has provided the opportunity to unravel the association of HCV with immune response. This study aimed to examine the expression level of C-X-C motif chemokine ligand 10 (CXCL10) in the Peripheral blood mononuclear cells (PBMCs) of HCV infected patients treated with DAAs + Ribavirin. In this study we analyzed the expression levels of CXCL10 mRNA in the 90 chronic HCV patients using quantitative PCR (qPCR) prior, after, and during therapy with sofosbuvir/ribavirin (SOF+RBV) and sofosbuvir/daclatasvir/ribavirin (SOF+DCV+RBV), and further, the results were analyzed relative to treatment response. Significantly elevated CXCL10 mRNA was seen in naive patients having higher viral load (P = 0.005) and those suffering from hepatocellular carcinoma (P = 0.006). HCV patients had remarkable decline in CXCL10 level after 4, 12, and 24 weeks of therapy with DAAs. An approximate one-fold decrease was observed in patients who attained sustained virological response compared to untreated patients (P < 0.0001). Comparing the 2 regimens, the reduction in peripheral CXCL10 expression was more pronounced in patients undergoing SOF+DCV+RBV therapy. The current study implicitly shows the role of CXCL10 as an indicator of disruption of host-virus equilibrium and consequent pathogenesis of HCV during successful antiviral therapy. Furthermore, the drop in CXCL10 level after HCV viral clearance might reflect the DAA-induced alleviation in the extrahepatic manifestation of this infection.

Loss to follow-up: A significant barrier in the treatment cascade with direct-acting therapies

Effectiveness of direct-acting antiviral (DAA) therapies could be influenced by patient characteristics such as comorbid conditions, which could lead to premature treatment discontinuation and/or irregular medical follow-ups. Here, we evaluate loss to follow-up and treatment effectiveness of sofosbuvir/ledipasvir ± ribavirin (SOF/LDV ± RBV), ombitasvir/paritaprevir/ritonavir + dasabuvir ± ribavirin (OBV/PTV/r + DSV ± RBV) for hepatitis C virus (HCV) genotype 1 (GT1) and sofosbuvir + ribavirin (SOF + RBV) for genotype 3 (GT3) in British Columbia Canada: The British Columbia Hepatitis Testers Cohort includes data on individuals tested for HCV since 1992, integrated with medical visit, hospitalization and prescription drug data. HCV-positive individuals who initiated DAA regimens, irrespective of treatment completion, for GT1 and GT3 until 31 December, 2017 were included. Factors associated with sustained virological response (SVR) and loss to follow-up were assessed by using multivariable logistic regression models. In total 4477 individuals initiated DAAs. The most common prescribed DAA was SOF/LDV ± RBV with SVR of 95%. The highest SVR of 99.5% was observed among OBV/PTV/r + DSV-treated patients. Overall, 453 (10.1%) individuals were lost to follow-up. Higher loss to follow-up was observed among GT1 patients treated with OBV (17.8%) and GT3 patients (15.7%). The loss to follow-up rate was significantly higher among individuals aged <60 years, those with a history of injection drug use (IDU), on opioid substitution therapy and with cirrhosis. Our findings indicate that loss to follow-up exceeds viral failure in HCV DAA therapy and its rate varies significantly by genotype and treatment regimen. Depending on the aetiology of lost to follow-up, personalized case management for those with medical complications and supporting services among IDU are needed to achieve the full benefits of effective treatments.

Viral fitness: history and relevance for viral pathogenesis and antiviral interventions

The quasispecies dynamics of viral populations (continuous generation of variant genomes and competition among them) has as one of its frequent consequences variations in overall multiplication capacity, a major component of viral fitness. This parameter has multiple implications for viral pathogenesis and viral disease control, some of them unveiled thanks to deep sequencing of viral populations. Darwinian fitness is an old concept whose quantification dates back to the early developments of population genetics. It was later applied to viruses (mainly to RNA viruses) to quantify relative multiplication capacities of individual mutant clones or complex populations. The present article reviews the fitness concept and its relevance for the understanding of the adaptive dynamics of viruses in constant and changing environments. Many studies have addressed the fitness cost of escape mutations (to antibodies, cytotoxic T cells or inhibitors) as an influence on the efficacy of antiviral interventions. Here, we summarize the evidence that the basal fitness level can be a determinant of inhibitor resistance.

Treatment outcomes of patients with chronic hepatitis C receiving sofosbuvir-based combination therapy within national hepatitis C elimination program in the country of Georgia

Background

Georgia has one of the highest HCV prevalence in the world and launched the world’s first national HCV elimination programs in 2015. Georgia set the ambitious target of diagnosing 90% of people living with HCV, treating 95% of those diagnosed and curing 95% of treated patients by 2020. We report outcomes of Sofosbuvir (SOF) based treatment regimens in patients with chronic HCV infection in Georgia.

Methods

Patients with cirrhosis, advanced liver fibrosis and severe extrahepatic manifestations were enrolled in the treatment program. Initial treatment consisted of SOF plus ribavirin (RBV) with or without pegylated interferon (INF). Sustained virologic response (SVR) was defined as undetectable HCV RNA at least 12 weeks after the end of treatment. SVR were calculated using both per-protocol and modified intent-to-treat (mITT) analysis. Results for patients who completed treatment through 31 October 2018 were analyzed.

Results

Of the 7342 patients who initiated treatment with SOF-based regimens, 5079 patients were tested for SVR. Total SVR rate was 82.1% in per-protocol analysis and 74.5% in mITT analysis. The lowest response rate was observed among genotype 1 patients (69.5%), intermediate response rate was achieved in genotype 2 patients (81.4%), while the highest response rate was among genotype 3 patients (91.8%). Overall, SOF/RBV regimens achieved lower response rates than IFN/SOF/RBV regimen (72.1% vs 91.3%, P < 0.0001).

In multivariate analysis being infected with HCV genotype 2 (RR =1.10, CI [1.05–1.15]) and genotype 3 (RR = 1.14, CI [1.11–1.18]) were associated with higher SVR. Patients with cirrhosis (RR = 0.95, CI [0.93–0.98]), receiving treatment regimens of SOF/RBV 12 weeks, SOF/RBV 20 weeks, SOF/RBV 24 weeks and SOF/RBV 48 weeks (RR = 0.85, CI [0.81–0.91]; RR = 0.86, CI [0.82–0.92]; RR = 0.88, CI [0.85–0.91] and RR = 0.92, CI [0.87–0.98], respectively) were less likely to achieve SVR.

Conclusions

Georgia’s real world experience resulted in high overall response rates given that most patients had severe liver damage. Our results provide clear evidence that SOF plus IFN and RBV for 12 weeks can be considered a treatment option for eligible patients with all three HCV genotypes. With introduction of next generation DAAs, significantly improved response rates are expected, paving the way for Georgia to achieve HCV elimination goals.

Efficacy and safety of treatment of chronic hepatitis C with sofosbuvir and ribavirin with or without peginterferon: a French prospective real-life cohort study of unselected 211 patients

INTRODUCTION

Sofosbuvir is the first directly-acting antiviral for the treatment of hepatitis C virus. First, the regimens were combinations with sofosbuvir+ribavirin (SR) or with sofosbuvir+ribavirin and pegylated-interferon α-2a (SPR) with cure rates around 90%. The aim of this study was to report the results of these combinations in 'real-life' in France.

MATERIALS AND METHODS

Main features of patients treated with SR or SPR in 24 hospitals were collected. Undetectable hepatitis C virus week 12 viral load after treatment defined sustained virological response (SVR12). Statistics were performed using StatView software for descriptive analysis and χ for the sub-groups comparisons.

RESULTS

Two hundred and eleven patients were analyzed. The average age was 56.1. One hundred and seventy-one (89%) patients had a fibrosis score of at least 3. Seventy-nine patients were infected by a genotype 1 (G1). One hundred and thirteen patients were treated with SR and 95 with SPR. In naive patients: with SPR for 12 weeks, SVR12 was 93% in G1, 100% in G3 and 83% in G4. With SR for 12 weeks, SVR12 was 100% in G2 patients (6/6). The safety of these regimens was satisfactory with only two patients who had to stop P due to severe side effects. Multivariate analysis shows a higher SVR in SPR versus SR (odds ratio = 1.28; P = 0.05) and in G2 or G3 versus others (odds ratio = 1.56; P = 0.04). Moreover, Child-Pugh score B or C (P = 0.02), platelets count under 100G/l (P = 0.05) or a past event of ascites (P = 0.04) was independently associated with less SVR.

CONCLUSION

This multicenter large study confirms the good results of SR for 12 weeks in G2 naive patients. Finally, a decompensated cirrhosis, a past event of ascites and a baseline low platelet count were strongly associated with poor response.

Interplay of Amino Acid Residues at Positions 28 and 31 in NS5A Defines Resistance Pathways in HCV GT2

Hepatitis C virus (HCV) genotype (GT) 2 represents approximately 9% of all viral infections globally. While treatment outcomes for GT2-infected patients have improved substantially with direct-acting antiviral agents (DAAs) compared to interferon-α, the presence of polymorphisms in NS5A can impact efficacy of NS5A inhibitor-containing regimens. Thus, pathways of NS5A resistance were explored in GT2 subtypes using elbasvir, an NS5A inhibitor with broad genotype activity. Resistance selection studies, resistance analysis in NS5A-inhibitor treated virologic failures, antiviral activities in replicons bearing a panel of GT2 subtype sequences and amino acid substitutions introduced by site-directed mutagenesis were performed to define determinants of inhibitor susceptibility. Elbasvir showed differential antiviral activity in replicons bearing GT2 sequences. The EC₅₀ values for replicons bearing reference NS5A sequences for GT2a and GT2b were 0.003 and 3.4 nanomolar (nM) respectively. Studies with recombinant replicons demonstrated crosstalk between amino acid positions 28 and 31. The combination of phenylalanine and methionine at positions 28 and 31 respectively, conferred the highest potency reduction for elbasvir in GT2a and GT2b. This combination was observed in failures from the C-SCAPE trial. Addition of grazoprevir, an NS3/4A protease inhibitor, to elbasvir more effectively suppressed the emergence of resistance in GT2 at modest inhibitor concentrations (3X EC₉₀). Ruzasvir, a potent, pan-genotype NS5A inhibitor successfully inhibited replicons bearing GT2 resistance-associated substitutions (RASs) at positions 28 and 31. The studies demonstrate crosstalk between amino acids at positions 28 and 31 in NS5A modulate inhibitor potency and may impact treatment outcomes in some HCV GT2-infected patients.

Sofosbuvir susceptibility of genotype 1 to 6 HCV from DAA-naïve subjects

High sequence diversity of HCV may lead to variation in susceptibility to antiviral agents amongst different genotypes and subtypes of the virus. We assessed the susceptibility to sofosbuvir of chimeric replicons carrying the full length NS5B coding region from 479 HCV infected, treatment-naïve patients, including 15 subtypes in 6 genotypes. NS5B replicon vectors with subtype 1b, subtype 4a and subtype 6a backbone were modified to support testing of patient samples. We also evaluated sofosbuvir susceptibility in a panel of 331 replicons containing engineered NS5B inhibitor resistance-associated substitutions. The mean 50% effective sofosbuvir concentration (EC₅₀) amongst different genotypes ranged from 32 (subtype 2a) to 130 nM (genotype 4); while some variation in susceptibility amongst patient isolates was observed, the 95th percentile for any genotype did not exceed 189 nM. Levels of resistance to sofosbuvir in replicons containing S282T were between 2.4 and 18 fold-change in EC₅₀; no other single NS5B resistance-associated substitution demonstrated reduced sofosbuvir susceptibility. These data suggest that S282T is the only known substitution that confers detectable resistance to sofosbuvir in vitro. Sofosbuvir displayed potent antiviral activity across a diverse range of NS5B mutants and HCV clinical isolates in multiple subtypes of genotypes 1 to 6.

Eltrombopag enables initiation and completion of pegylated interferon/ribavirin therapy in Japanese HCV-infected patients with chronic liver disease and thrombocytopenia

To investigate the efficacy of eltrombopag for the treatment of thrombocytopenia in patients with chronic hepatitis C, a phase II, single-arm, open-label study with a 9-week pre-antiviral phase was conducted, followed by a 48-week antiviral phase and a 24-week follow-up phase. The proportion of patients who achieved a platelet count threshold, the proportion of patients who maintained a platelet count >50,000/µl, sustained virological response (SVR) rates and safety parameters were evaluated. Of the 45 enrolled patients (median age, 59 years; median platelet count, 63,000/µl; 98% with Child-Pugh class A), 43 (96%) achieved the platelet count threshold during the pre-antiviral phase. A total of 13 patients (29%) experienced ≥1 adverse event (AE), of which headache and vomiting were the most common, and 41 patients (mostly receiving eltrombopag 12.5 mg or 25 mg) entered the antiviral phase, of which 36 (88%) maintained the platelet count threshold; no patient platelet count decreased below 25,000/µl. Nine patients (22%) achieved an SVR at the 24-week follow-up. Grade ≥3 AEs occurred in 25 patients (61%). A total of 8 serious AEs occurred in five patients (12%). No mortality, thromboembolic events (TEEs), or cataract progression were reported. Eltrombopag increased the platelet count in chronic hepatitis C virus-infected patients with cirrhosis and thrombocytopenia and enabled them to initiate and complete interferon-based antiviral therapy (NCT01636778; first submitted: July 05, 2012).

Genetic variants in IFIH1 and DDX58 influence hepatitis C virus clearance in Chinese Han population

AIMS

To investigate the association between two RIG-I-like receptor gene polymorphisms and hepatitis C virus (HCV) infection in Chinese Han population.

METHODS

The current study genotyped two selected SNPs (IFIH1 rs3747517 and DDX58 rs9695310) using TaqMan allelic discrimination assay to assess their association with the susceptibility and clinical outcome of HCV infection among 3065 participants (1545 non-HCV infection individuals, 568 spontaneous HCV clearance cases, and 952 persistent infection patients).

RESULTS

IFIH1 rs3747517 (dominant model: Adjusted odds ratio [OR] = 1.34, 95% confidence interval [CI] = 1.07-1.68; P = 0.009) and DDX58 rs9695310 (dominant model: Adjusted OR = 1.43, 95% CI = 1.15-1.78; P = 0.001) were associated with chronic hepatitis C (CHC). And the risk of CHC increased when people were carrying more unfavorable rs3747517-GA/AA and rs9695310-GC/CC genotypes from zero to two with the chronic rates of 56.72%, 59.38%, and 69.01%, respectively (Ptrend  < 0.001).

CONCLUSION

Genetic variations at IFIH1 rs3747517 and DDX58 rs9695310 were independent predictors of chronic hepatitis C in Chinese Han population.

Hepatitis C Treatment in Patients with Drug Addiction Is Effective or Not Effective?

Introduction

Patients with drug addiction have high risk for hepatitis C virus (HCV). Effective treatment response is essential to optimize treatment for drug abusers infected by hepatitis C virus.

Aim

The aim of this present study was to show that hepatitis C treatment in patients with drug addiction is effective like patients without drug addiction.

Material and Methods

Total amount of 57 patients with hepatitis C (25 drug abuser and 32 non-drug abuser) that referred to Shahid Motahari clinic of Shiraz were selected. All patients infected with HCV treated by combination regimens of ribavirin, sofosbuvir and interferon. Patients received sofosbuvir (400mg once a day) in combination with peg-IFN-alpha (92a180m/w›92b1/5m/kg/w) and RBV (under 75 kg 1000mg, over 75 kg 12000kg) for 12 weeks. The Kolmogorov-Smirnov test was used for testing normality. Associations between variables were analyzed using a Chi-square, Fisher exact, T student and Mann-Whitney U test.

Results

Out of 25 HCV patients (43.9%) were drug addicts and 32 patients (56.1%) were non-drug addicts. Insomnia (61.4%), fatigue (63.1%) and debility (49.1%) were more common adverse effects of therapy in drug abusers and non-drug abusers. Alanine transaminase (ALT) and HCV RNA was normal in the end of therapy (EOT). White blood cell (WBC) count decreased in during two-week after starting of the treatment and then increased to normal levels at the end of treatment. Reduction of WBC count was considerable in during two-week. Hematologic result was not considerable. Reduction of hemoglobin was <10 g/dL in 9.37% of non-injecting drug addicts and <8.5 g/dL in 6.25% of injecting drug addicts. The results of this study did not demonstrated a significant relationship about sustained virologic response (SVR) between the drug abusers and non-drug abusers (P = 0.99).

Conclusions

In conclusion, patients with drug addiction can receive hepatitis C treatment on the history of their past or current drug use status. Combination therapy with sofosbuvir plus peginterferon and ribavirin can lead to high treatment response in HCV patients were drug abuser. In addition, this treatment combination was with low discontinuation rates and low adverse effects. Effective intervention in HCV patients with drug addiction to reduce injection- related risk.

Incorporating single-arm evidence into a network meta-analysis using aggregate level matching: Assessing the impact

Increasingly, single-armed evidence is included in health technology assessment submissions when companies are seeking reimbursement for new drugs. While it is recognized that randomized controlled trials provide a higher standard of evidence, these are not available for many new agents that have been granted licenses in recent years. Therefore, it is important to examine whether alternative strategies for assessing this evidence may be used. In this work, we examine approaches to incorporating single-armed evidence formally in the evaluation process. We consider matching aggregate level covariates to comparator arms or trials and including this evidence in a network meta-analysis. We consider two methods of matching: (i) we include the chosen matched arm in the data set itself as a comparator for the single-arm trial; (ii) we use the baseline odds of an event in a chosen matched trial to use as a plug-in estimator for the single-arm trial. We illustrate that the synthesis of evidence resulting from such a setup is sensitive to the between-study variability, formulation of the prior for the between-design effect, weight given to the single-arm evidence, and extent of the bias in single-armed evidence. We provide a flowchart for the process involved in such a synthesis and highlight additional sensitivity analyses that should be carried out. This work was motivated by a hepatitis C data set, where many agents have only been examined in single-arm studies. We present the results of our methods applied to this data set.

A novel, potent, and orally bioavailable thiazole HCV NS5A inhibitor for the treatment of hepatitis C virus

A medicinal chemistry program based on the small-molecule HCV NS5A inhibitor daclatasvir has led to the discovery of dimeric phenylthiazole compound 8, a novel and potent HCV NS5A inhibitor. The subsequent SAR studies and optimization revealed that the cycloalkyl amide derivatives 27a-29a exhibited superior potency against GT1b with GT1b EC₅₀ values at picomolar concentration. Interestingly, high diastereospecificity for HCV inhibition was observed in this class with the (1R,2S,1'R,2'S) diastereomer displaying the highest GT1b inhibitory activity. The best inhibitor 27a was found to be 3-fold more potent (GT1b EC₅₀ = 0.003 nM) than daclatasvir (GT1b EC₅₀ = 0.009 nM) against GT1b, and no detectable in vitro cytotoxicity was observed (CC₅₀ > 50 μM). Pharmacokinetic studies demonstrated that compound 27a had an excellent pharmacokinetic profiles with a superior oral exposure and desired bioavailability after oral administration in both rats and dogs, and therefore it was selected as a developmental candidate for the treatment of HCV infection.

Sofosbuvir-Based Regimens for Chronic Hepatitis C in a Well-Insured U.S. Population: Patient Characteristics, Treatment Adherence, Effectiveness, and Health Care Costs, 2013-2015

BACKGROUND

Chronic hepatitis C (CHC) is a leading cause of morbidity and mortality and has imposed a high health care burden in the United States. Direct-acting antiviral (DAA) regimens are well tolerated and highly effective for CHC therapy but were initially marketed at a high price. Studies of their real-world use with a nationwide population are limited.

OBJECTIVE

To examine patient characteristics, treatment adherence, effectiveness, and health care costs in a large U.S. population with commercial and Medicare supplemental insurance plans who received simeprevir (SIM), sofosbuvir (SOF), or ledipasvir/sofosbuvir (LED/SOF) during the years 2013-2015.

METHODS

Patients with at least 1 diagnosis code for CHC and at least 1 claim for SIM, SOF, or LED/SOF prescriptions were selected. The date of the first claim for SIM, SOF, or LED/SOF was defined as the index date. Analyses were stratified by 4 regimens: SOF + SIM ± ribavirin (RBV), SOF + peginterferon alpha-2a or 2b (PEG) + RBV, SOF + RBV, and LED/SOF ± RBV. Adherence was defined by the proportion of days covered (PDC) ≥ 80%. Sustained virologic response (SVR12) was defined as a hepatitis C virus (HCV) RNA load of ≤ 25 IU/mL measured at ≥ 12 weeks following the end of the days supply of the last DAA refill. Health care costs such as DAA drug costs and medical costs (inpatient costs plus outpatient costs) were described.

RESULTS

Of 10,808 CHC patients, approximately two thirds were male, and mean age was 55 years. The proportion of patients with compensated cirrhosis among each regimen ranged from 7.4% in LED/SOF ± RBV to 13.8% in SOF + SIM ± RBV, and the proportion of patients with decompensated cirrhosis ranged from 3.9% in LED/SOF ± RBV to 10.7% in SOF + SIM ± RBV. The majority of patients (89.0%) used the newer regimen LED/SOF ± RBV in 2015. Adherence rates were estimated at 80.5%, 81.5%, 85.7%, and 91.4% for SOF + SIM ± RBV (n = 1,761); SOF + PEG + RBV (n = 1,314); SOF + RBV (n = 1,994); and LED/SOF ± RBV (n = 5,739), respectively. Regimen-specific adherence predictors included sex, age group, payer type, health plan, and treatment option with RBV. Being born during 1945-1965, liver disease severity, and Charlson Comorbidity Index levels did not predict adherence in any regimen. Overall SVR12 was 92.6% in 203 patients with available HCV RNA results: 100% (41/41) in SOF + SIM ± RBV; 83.3% (25/30) in SOF + PEG + RBV; 90.6% (29/32) in SOF + RBV; and 93% (93/100) in LED/SOF ± RBV. While the drug costs for these DAA regimens were initially high, they had decreased 18.9% (P < 0.001) during 2013-2015. Medical costs decreased 9.2% (P < 0.001) 1 year after the index dates.

CONCLUSIONS

These results indicate that DAA drug costs decreased steadily during 2013-2015 and that 89% of patients on SOF-based DAA regimens took newer, lower-cost regimens with adherence rates above 80%. Available data show that SVR12 rates were close to those obtained in clinical studies. Medical costs also significantly decreased 1 year after the index dates.

DISCLOSURES

No outside funding supported this study. All authors are U.S. federal employees of the Centers for Disease Control and Prevention. The authors declare that they have no competing interests. The findings and conclusions in this research are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Fib-4 Predicts Early Hematological Adverse Events Induced by Interferon-Based Triple Therapy in Chronic Hepatitis C Virus Patients

Interferon-alpha (IFN-α)-based therapy is associated with several hematological adverse events in hepatitis C virus (HCV)-infected patients with advanced fibrosis. We performed this study to evaluate the association between Fibrosis-4 (Fib-4) index and hematological adverse events in patients with chronic HCV infection, undergoing IFN-α-based triple therapy. We included 120 HCV-infected patients, receiving triple therapy: weekly PegIFN-α, daily ribavirin (1,000-1,200 mg), and daily sofosbuvir (400 mg) for 12 weeks. We compared Fib-4 scores for patients who developed hematological adverse events at weeks 4 (w4) and w12 of treatment and w12 post-treatment versus those who did not. Treatment with the aforementioned triple regimen was associated with a sustained virological response (SVR)-12 rate of 93.9%. We found no significant associations (P > 0.05) between SVR12 rate and the degree of fibrosis or the risk of hematological adverse events. The Fib-4 score could predict patients who developed hematological adverse events (anemia, leukopenia, and neutropenia) in the first month of treatment, but not in later stages. A Fib-4 cutoff value of 3.59 had high specificity for anemia, leukopenia, and neutropenia (85.1%, 87.2%, and 88.2%, respectively), but had low sensitivity for detecting the 3 events. In conclusion, the Fib-4 score may predict early hematological adverse effects in HCV-infected patients on IFN-based triple therapy.

New Direct-Acting Antivirals for the Treatment of Patients With Hepatitis C Virus Infection: A Systematic Review of Randomized Controlled Trials

BACKGROUND

New direct-acting antiviral agents (DAAs) approved for the treatment of patients infected by Hepatitis C virus (HCV) are well tolerated and increase sustained virological response (SVR) rate. We summarize current evidence on the efficacy and safety from comparative randomized controlled trials (RCTs) of DAAs.

METHODS

We systematically searched MEDLINE, Embase, Scopus, CENTRAL, and Lilacs as well as a list of reference literature. We included RCTs comparing DAAs with placebo or active control and reporting response rates and adverse events according to antiviral regimens. Risk ratios (RRs) were pooled as appropriate. We assessed the risk of bias of included studies and graded the quality of evidence according to the GRADE method.

RESULTS

We included 28 RCTs, enrolling more than 7000 patients. The quality of evidence was generally low. Twelve-week treatment with DAAs in naïve patients significantly increased SVR12 and SVR24 compared with placebo (RR 1.4, 95% CI 1.3-1.6; RR 1.5, 95% CI 1.4-1.6, respectively). This means that for every 1000 patients, 240 or 260 more patients experienced SVR12 or SVR24 if treated with any DAAs. We could not find RCTs assessing progression of liver disease or development of hepatocellular carcinoma. DAAs were not associated with higher incidence of serious adverse events or discontinuation due to adverse events.

CONCLUSIONS

This systematic review confirms that new DAAs are more effective in inducing SVR than placebo. Outside clinical trials, in real word, HCV cure with DAA regimens occurs in less than 90% of patients, so further comparative evaluations are needed to establish their long-term effects.

Overview of Direct-Acting Antiviral Drugs and Drug Resistance of Hepatitis C Virus

The advent of direct-acting antivirals (DAAs) has brought about a sudden renaissance in the treatment of chronic hepatitis C virus (HCV) infection with SVR rates now routinely >90%. However, due to the error-prone nature of the HCV RNA polymerase, resistance-associated substitutions (RASs) to DAAs may be present at baseline and can result in a significant effect on treatment outcomes and hamper the achievement of sustained virologic response. By further understanding the patterns and nature of these RASs, it is anticipated that the incidence of treatment failure will continue to decrease in frequency with the development of drug regimens with increasing potency, barrier to resistance, and genotypic efficacy. This review summarizes our current knowledge of RASs associated with HCV infection as well as the clinical effect of RASs on treatment with currently available DAA regimens.

Use of Ribavirin for Hepatitis C Treatment in the Modern Direct-acting Antiviral Era

Ribavirin, once a staple of hepatitis C treatment, has significant drawbacks, including treatment-limiting side effects, the requirement for intensive laboratory monitoring, the need for frequent dose adjustments, and teratogenicity. These factors make it difficult to escalate ribavirin-based HCV treatment to most infected patients globally. Most studies have shown comparable response rates between ribavirin-inclusive and ribavirin-sparing regimens in uncomplicated patient populations. However, ribavirin is still used in the management of patients who have failed previous therapy as well as those with decompensated liver disease. In this review, we explore the evidence supporting the use of ribavirin in the current climate of hepatitis C treatment with oral combination direct-acting antiviral agents.

Structural and functional analysis of the roles of the HCV 5' NCR miR122-dependent long-range association and SLVI in genome translation and replication

The hepatitis C virus RNA genome possesses a variety of conserved structural elements, in both coding and non-coding regions, that are important for viral replication. These elements are known or predicted to modulate key life cycle events, such as translation and genome replication, some involving conformational changes induced by long-range RNA–RNA interactions. One such element is SLVI, a stem-loop (SL) structure located towards the 5′ end of the core protein-coding region. This element forms an alternative RNA–RNA interaction with complementary sequences in the 5′ untranslated regions that are independently involved in the binding of the cellular microRNA 122 (miR122). The switch between ‘open’ and ‘closed’ structures involving SLVI has previously been proposed to modulate translation, with lower translation efficiency associated with the ‘closed’ conformation. In the current study, we have used selective 2′-hydroxyl acylation analysed by primer extension to validate this RNA–RNA interaction in the absence and presence of miR122. We show that the long-range association (LRA) only forms in the absence of miR122, or otherwise requires the blocking of miR122 binding combined with substantial disruption of SLVI. Using site-directed mutations introduced to promote open or closed conformations of the LRA we demonstrate no correlation between the conformation and the translation phenotype. In addition, we observed no influence on virus replication compared to unmodified genomes. The presence of SLVI is well-documented to suppress translation, but these studies demonstrate that this is not due to its contribution to the LRA. We conclude that, although there are roles for SLVI in translation, the LRA is not a riboswitch regulating the translation and replication phenotypes of the virus.

Current Status of Direct Acting Antiviral Agents against Hepatitis C Virus Infection in Pakistan

In Pakistan, the burden of the hepatitis C virus (HCV) infection is the second highest in the world with the development of chronic hepatitis. Interferon-based combination therapy with ribavirin was the only available treatment until a few years back, with severe side-effects and high failure rates against different genotypes of HCV. Interferon-free all-oral direct-acting antiviral agents (DAAs) approved by the FDA have revolutionized the HCV therapeutic landscape due to their efficiency in targeting different genotypes in different categories of patients, including treatment naïve, treatment failure and relapsing patients, as well as patients with compensated and decompensated cirrhosis. The availability and use of these DAAs is limited in the developing world. Sofosbuvir (SOF), a uridine nucleotide analogue and inhibitor of HCV encoded NS5B polymerase, is now a widely available and in-use DAA in Pakistan; whereas daclatasvir was recently added in the list. According to the documented results, there is hope that this disease can be effectively cured in Pakistan, although a few concerns still remain. The aim of this article is to review the effectiveness of DAAs and the current status of this treatment against HCV genotype 3 infection in Pakistan; various factors associated with SVR; its limitations as an effective treatment regime; and future implications.

Quasispecies dynamics and clinical significance of hepatitis C virus (HCV) antiviral resistance

Hepatitis C virus (HCV) follows quasispecies dynamics in infected hosts and this influences its biology, how the virus diversifies into several genotypes and many subtypes, and how viral populations respond to antiviral therapies. Despite current antiviral combinations being able to cure a great percentage of HCV-infected patients, the presence of resistance-associated substitutions (RASs) diminishes the success of antiviral therapies, which is a main concern in the re-treatment of patients treated with direct-acting antiviral agents. Current methodologies such as ultra deep sequencing are ideal tools to obtain a detailed representation of the mutant spectrum composition circulating in infected patients. Such knowledge should allow optimisation of rescue treatments. A new mechanism of antiviral resistance not based on the selection of RASs but on high viral fitness is discussed.

Analysis of Host and Viral-Related Factors Associated to Direct Acting Antiviral Response in Hepatitis C Virus Patients

Hepatitis C virus (HCV) signifies an important health issue as it is a globally prevalent pathogen and poses a great threat to human health. Direct antiviral therapy became a landmark in treatment against chronic HCV infection as they have proven to increase sustained virological response (SVR) rate, provide shortened and simplified regimens. This study aimed to evaluate efficacy of Sofosbuvir and classify factors of treatment success and their function in therapy continuation decision. We studied host and viral factors in 310 patients who received Sofosbuvir (DAA) at a dose of 400 mg daily along with ribavirin 10 mg/kg body weight for 24 weeks and followed by 12 weeks after completion of treatment. A total of 302 patients (97.42%) showed end-of-treatment response. However, 8 patients (2.58%) were virological nonresponders and 286 patients (94.70%) achieved SVR. Among 310 HCV positive, the percentage of viral genotype 3-infected patients was 89.6%, whereas only 10.32% were affected by HCV genotype 1. Multivariable analysis showed that baseline HCV RNA (≤8 × 10⁶ IU/mL vs. >8 × 10⁶ IU/mL) [95% confidence interval (CI), odds ratio (OR) 3.0, 2.0 to 8.4; p = 0.004], age (<50 vs. ≥50 years) (95% CI, OR 1.9, 3.0 to 10.1; p = 0.03), liver texture (normal liver vs. coarse) are related to virological response. None of the patients included in the study has S282T substitution in NS5b of HCV. No significant difference in response was observed in patients with different genotypes of rs12979860. Liver texture, age, and viral load are predictors of SVR. In this real-life data no substitution of S282T in NS5b was observed related to failure of therapy. Oral Sofosbuvir generally has a high tolerance and can effortlessly beat the safety concerns of past regimens.

Hepatitis C virus genotype 3: clinical features, current and emerging viral inhibitors, future challenges

Hepatitis C virus (HCV) represents a global burden on healthcare that affects over 150 million people worldwide. In the past, HCV genotype 3 was considered difficult to treat relative to other genotypes. Genotype 3 has been associated with a higher rate of complications, including fatty liver disease, fibrosis, hepatocellular carcinoma and mortality. However, with the advent of first- and second-generation direct-acting antivirals, genotype 3 can be treated effectively. Additionally, these new drugs are well tolerated by patients and have significantly fewer side effects compared to ribavirin and interferon-based regimens. However, while great strides have been made in overcoming biological barriers, our next challenge lies in overcoming economic and financial obstacles if we are to eradicate HCV genotype 3. Herein, we review the clinical features associated with HCV genotype 3, current and emerging treatment regimens, and challenges associated with treatment.

Systematic review and meta-analysis: real-world effectiveness of direct-acting antiviral therapies in chronic hepatitis C genotype 3 in Asia

BACKGROUND

Genotype 3 (GT3) is a common chronic hepatitis C (CHC) genotype in Asia. Direct-acting antiviral (DAA) regimens have high cure rates, but real-world results are limited for Asia.

AIM

To determine the real-world effectiveness of DAAs for patients with CHC GT3 in Asia.

METHODS

A systematic search was performed in PubMed (including MEDLINE), Embase, and selected international meeting abstract repositories. Eligible studies were postmarketing observational studies from Asia with the primary outcome of sustained virological response 12 weeks after completion of treatment (SVR12).

RESULTS

A total of 15 studies with 4230 patients yielded a pooled SVR12 of 92.7%. High heterogeneity (I2=93.2%, P<0.0001) was noted. In subgroup analyses, patients with cirrhosis had 10.9% lower SVR12 than non-cirrhotic patients (88.6% vs 98.9%; P<0.0001) and contributed 69.5% of the heterogeneity. Prior treatment failure did not reduce the pooled SVR12 (treatment-naïve: 94.6%, 95% CI 91.3% to 96.7% vs treatment-experienced: 94.0%, 95% CI 77.5% to 98.6%; P=0.89). Twenty-four weeks of sofosbuvir+ribavirin dual therapy was the most commonly used regimen which led to similar SVR12 (OR=1.1, P=0.73) but lower adverse event rate than 12 weeks of sofosbuvir+ribavirin+pegylated interferon triple therapy.

CONCLUSION

Sofosbuvir+ribavirin for 24 weeks is the most widely used and generally well-tolerated DAA therapy in Asia. However, its effectiveness is not optimal in GT3 patients with cirrhosis.

The Mexican consensus on the treatment of hepatitis C

The aim of the Mexican Consensus on the Treatment of HepatitisC was to develop clinical practice guidelines applicable to Mexico. The expert opinion of specialists in the following areas was taken into account: gastroenterology, infectious diseases, and hepatology. A search of the medical literature was carried out on the MEDLINE, EMBASE, and CENTRAL databases through keywords related to hepatitisC treatment. The quality of evidence was subsequently evaluated using the GRADE system and the consensus statements were formulated. The statements were then voted upon, using the modified Delphi system, and reviewed and corrected by a panel of 34 voting participants. Finally, the level of agreement was classified for each statement. The present guidelines provide recommendations with an emphasis on the new direct-acting antivirals, to facilitate their use in clinical practice. Each case must be individualized according to the comorbidities involved and patient management must always be multidisciplinary.

Serious Adverse Events with Sofosbuvir Combined with Interferon and Ribavirin: Real-Life Egyptian Experience

Viral hepatitis is a serious problem worldwide that was under-recognized till recently. The prevalence of chronic hepatitis C virus (HCV) is estimated to be 180 million people worldwide. Treatment of chronic HCV using combined pegylated interferon and ribavirin (PEG/RIBA) has long been the standard of care with modest response. In our study, we will report the real-life experience of serious adverse events (SAEs) that were reported by the National Committee for Control of Viral Hepatitis (NCCVH, Cairo, Egypt) program while treating chronic HCV using the triple therapy, sofosbuvir combined with pegylated interferon and ribavirin (PEG/RIBA/SOF), which led to premature discontinuation of treatment. This retrospective analysis included a total of 6,989 chronic HCV patients who were treated by the NCCVH. They received the triple antiviral therapy in 26 treatment centers in Egypt using PEG/RIBA/SOF for 12 weeks. Among 6,989 patients who were treated in 26 treatment centers related to NCCVH, 406 cases (5.9%) reported SAEs and prematurely stopped their treatment. Triple therapy PEG/RIBA/SOF was an important intermediate milestone between interferon-based therapy and the interferon-free all-oral direct acting antiviral agents (DAAs). Results of this study were the leading cause of discontinuation of interferon-based therapy and introduction of interferon-free all-oral treatment protocols, incorporating DAAs from different classes as soon as they gain approval.

Revisiting policy on chronic HCV treatment under the Thai Universal Health Coverage: An economic evaluation and budget impact analysis

Thailand is encountering challenges to introduce the high-cost sofosbuvir for chronic hepatitis C treatment as part of the Universal Health Care's benefit package. This study was conducted in respond to policy demand from the Thai government to assess the value for money and budget impact of introducing sofosbuvir-based regimens in the tax-based health insurance scheme. The Markov model was constructed to assess costs and benefits of the four treatment options that include: (i) current practice-peginterferon alfa (PEG) and ribavirin (RBV) for 24 weeks in genotype 3 and 48 weeks for other genotypes; (ii) Sofosbuvir plus peginterferon alfa and ribavirin (SOF+PEG-RBV) for 12 weeks; (iii) Sofosbuvir and daclatasvir (SOF+DCV) for 12 weeks; (iv) Sofosbuvir and ledipasvir (SOF+LDV) for 12 weeks for non-3 genotypes and SOF+PEG-RBV for 12 weeks for genotype 3 infection. Given that policy options (ii) and (iii) are for pan-genotypic infection, the cost of genotype testing was applied only for policy options (i) and (iv). Results reveal that all sofosbuvir-based regimens had greater quality adjusted life years (QALY) gains compared with the current treatment, therefore associated with lower lifetime costs and more favourable health outcomes. Additionally, among the three regimens of sofosbuvir, SOF+PEG-RBV for genotype 3 and SOF+LDV for non-3 genotype are the most cost-effective treatment option with the threshold of 160,000 THB per QALY gained. The results of this study had been used in policy discussion which resulted in the recent inclusion of SOF+PEG-RBV for genotype 3 and SOF+LDV for non-3 genotype in the Thailand's benefit package.

Trend of estimated glomerular filtration rate during ombistasvir/paritaprevir/ritonavir plus dasabuvir ± ribavirin in HIV/HCV co-infected patients

The renal function is a key-issue in HIV/HCV co-infected patients, nevertheless, it has not established so far whether HCV treatment with new direct acting agents could impact on estimated glomerular filtration rate (eGFR) variations. In the present work, we examined the real-life data on renal function that have been prospectively collected in the SIMIT compassionate-use program of ombitasvir/paritaprevir/ritonavir plus dasabuvir (OBV/PTV/r + DSV) in 144 HIV/HCV genotype 1 co-infected patients. The population was 74% male, 30.5% in CDC stage C, with median age of 52 years (48.0-56.5) and median liver stiffness of 7.8 kPa (6.7-9.2). Median baseline eGFR was 102.0 (90.8-108.1), changing to 99.8 (83.5-104.8) at the end of treatment (EoT), and 100.0 (87.3-105.6) 12 weeks after the EoT (FU12), p<0.0001. No patient had grade 3-4 increase of creatinine. At EoT 60/144 (41.7%) patients had ≥ 5% reduction in their eGFR, confirmed at FU12 in 39/60 (65.0%) cases. Longer duration of HCV infection (cut-off 12.9 years), lower HCV-RNA viral load (cut-off 1,970,160 IU/ml) and lower platelet count (cut-off 167,000 x106/L) were significantly associated with eGFR decline at logistic analysis (adjOR 2.9, 95%CI 1.0-8.8, p = 0.05; adjOR 3.5, 95%CI 1.2-10.4, p = 0.02; adjOR 2.8, 95%CI 1.1-6.8, p = 0.03, respectively). After repeating the analysis throughout a mixed model, a higher eGFR decline was highlighted in patients concomitantly treated with tenofovir (p = 0.0001), ribavirin (p = 0.0001), or integrase inhibitors (p <0.0001), with longer duration of HIV (p = 0.0002) and HCV infection (p = 0.035), lower baseline HCV RNA (p <0.0001), previous HCV treatment (p<0.0001), and older age (p<0.0001). In conclusion, our study confirms a good renal safety profile of OBV/PTV/r + DSV treatment in HIV/HCV patients, and the median decline of 2 ml/min in eGFR, albeit statistically significant, is of doubtful clinical significance. The role of aging, concomitant therapies and duration of HIV/HCV infection needs to be further investigated.

Efficacy of sofosbuvir plus ribavirin in treatment-naive patients with genotype-1 and -3 HCV infection: results from a Russian Phase IIIb study

BACKGROUND

In this Phase IIIb study, we evaluated the efficacy and safety of the oral nucleotide analogue inhibitor sofosbuvir plus ribavirin, with special attention given to viral resistance, in Russian patients with HCV genotype-1 or -3.

METHODS

Treatment-naive patients with and without compensated cirrhosis were randomized (1:1) to receive 16 or 24 weeks of once-daily sofosbuvir 400 mg plus twice-daily oral ribavirin 1,000 or 1,200 mg/day. The primary efficacy end point was the proportion of patients with sustained viral response 12 weeks after the end of treatment (SVR12). Viral resistance testing was performed by deep sequencing on all baseline samples and for patients who experienced virological failure.

RESULTS

SVR12 rates for patients with genotype-1 HCV were 50% and 76% for those in the 16-week and 24-week groups, respectively, and for patients with genotype-3 HCV, SVR12 rates were 87% and 90% for patients in the 16-week and 24-weeks groups, respectively. Genotype-1 patients with the L159F resistance-associated variant who received 16 weeks of treatment had lower SVR12 rates than those without, but in patients who received 24 weeks of treatment, response rates were similar in those with and without L159F (80% versus 74%). Sofosbuvir plus ribavirin was well tolerated with no deaths, adverse event-related study drug discontinuations, or grade 3 or 4 adverse events, and few grade 3 or 4 laboratory abnormalities.

CONCLUSIONS

Sofosbuvir plus ribavirin for 16 or 24 weeks was associated with a high SVR rate in patients with HCV genotype-3. Among HCV genotype-1b patients, the presence of the L159F variant at baseline was associated with a lower SVR rate in those treated for 16 weeks but not in those treated for 24 weeks. Sofosbuvir plus ribavirin was safe and well tolerated regardless of treatment duration. Clinicaltrials.gov number NCT01896193.

A case of a patient infected with a hepatitis C virus genotype 3a multidrug resistant variant in Pakistan

BACKGROUND

Approximately 10 million people in Pakistan are infected with the hepatitis C virus (HCV). Most patients develop chronic hepatitis, with rare cases of spontaneous clearance. However, little is known about multidrug resistant viral variants in Pakistan.

FINDINGS

This case study describes a 47-year-old male diagnosed with chronic HCV genotype 3a infection in 2003. After an initial diagnosis of viral infection, the patient remained treatment naïve for 5 years. He received two therapy cycles of interferon (IFN) plus ribavirin (RBV) in 2007 and 2010, however, he was non-responsive to the therapy. The patient then received an additional two treatment cycles of pegylated IFN α-2b plus RBV (in 2011 and 2013); he was still non-responsive. In 2016, the patient underwent sofosbuvir plus RBV combination therapy, however, the sustained virological response was still not achieved. The host genetic factor was found to be heterozygous guanine and thymine (GT) and cytosine and thymine (CT) genotypes of rs8099917 and rs12979860 polymorphism of IL28B, respectively. Phylogenetic analysis suggests that the resistant variant belong to an out-group and may require triple therapy.

CONCLUSIONS

This is the first case that reports on a HCV-infected individual who was a non-responder to multiple IFN therapies in Pakistan. Further studies are needed to understand multidrug-resistant HCV variants in the Pakistani population.

Consequence of HIV and HCV co-infection on host immune response, persistence and current treatment options

Hepatitis C virus (HCV) is a common opportunistic pathogen especially among Human immunodeficiency virus (HIV) infected patients. Due to incongruous studies, the pathological effect of HCV on HIV induced disease are still not fully understood. While some studies have showed no effect of HCV on HIV infection, others reported a defined role of HCV in aggravating the rates of AIDS-related illnesses and mortality. The explanation of such variances may be due to the host immune response, viral genotypes, sub-type and quasi-species distribution. The factors that complicate the management of HIV/HCV patients are: (1) reduced HCV antibody production, (2) drug interactions, (3) liver disease and (4) different epidemiologic characteristics. However, it is abundantly clear that the morbidity and mortality caused by HCV have increased since the introduction of highly active antiretroviral therapy (HAART) against HIV. In this review, the consequence of HIV/HCV co-infection on host immune response, viral replication, disease progression, mortality and morbidity, viral load, persistence and current treatment options have been discussed. Based on the clinical studies, it is necessary to evaluate the effect of HCV therapy on HIV progression and to provide a fully active HCV treatment for patients receiving HIV treatment. In conclusion, it is recommended to provide fully active HAART therapy in combination with a known HCV therapy.

Pegylated interferon alpha 2a for the treatment of hepatitis C virus infection

INTRODUCTION

Treatments for hepatitis C virus (HCV) infection have advanced rapidly in the last decade. Pegylated interferon alpha 2a (PEG-IFN alpha 2a) alone, in combination with ribavirin and with or without direct acting antivirals (DAAs) is modestly effective in the treatment of chronic HCV infection. Areas covered: The review describes the chemistry, pharmacokinetic and pharmacodynamic properties, clinical efficacy, safety and drug-drug interaction profiles of PEG-IFN alpha 2a. Expert opinion: Despite the availability of DAAs and its formidable toxicity profile, PEG-IFN alpha 2a retains a role for the treatment of acute HCV and chronic HCV infection in resource limited settings and for end-stage renal disease patients and others who cannot access DAAs or are DAA-ineligible. Knowledge of pharmacogenetic profiles which favor successful treatment outcomes with IFN-based therapies may allow for selection of best candidates for the regimen.

Flavonoids from Pterogyne nitens Inhibit Hepatitis C Virus Entry

Hepatitis C virus (HCV) is one of the leading causes of liver diseases and transplantation worldwide. The current available therapy for HCV infection is based on interferon-α, ribavirin and the new direct-acting antivirals (DAAs), such as NS3 protease and NS5B polymerase inhibitors. However, the high costs of drug design, severe side effects and HCV resistance presented by the existing treatments demonstrate the need for developing more efficient anti-HCV agents. This study aimed to evaluate the antiviral effects of sorbifolin (1) and pedalitin (2), two flavonoids from Pterogyne nitens on the HCV replication cycle. These compounds were investigated for their anti-HCV activities using genotype 2a JFH-1 subgenomic replicons and infectious virus systems. Flavonoids 1 and 2 inhibited virus entry up to 45.0% and 78.7% respectively at non-cytotoxic concentrations. The mechanism of the flavonoid 2 block to virus entry was demonstrated to be by both the direct action on virus particles and the interference on the host cells. Alternatively, the flavonoid 1 activity was restricted to its virucidal effect. Additionally, no inhibitory effects on HCV replication and release were observed by treating cells with these flavonoids. These data are the first description of 1 and 2 possessing in vitro anti-HCV activity.

The 5BSL3.2 Functional RNA Domain Connects Distant Regions in the Hepatitis C Virus Genome

Viral genomes are complexly folded entities that carry all the information required for the infective cycle. The nucleotide sequence of the RNA virus genome encodes proteins and functional information contained in discrete, highly conserved structural units. These so-called functional RNA domains play essential roles in the progression of infection, which requires their preservation from one generation to the next. Numerous functional RNA domains exist in the genome of the hepatitis C virus (HCV). Among them, the 5BSL3.2 domain in the cis-acting replication element (CRE) at the 3' end of the viral open reading frame has become of particular interest given its role in HCV RNA replication and as a regulator of viral protein synthesis. These functionalities are achieved via the establishment of a complex network of long-distance RNA-RNA contacts involving (at least as known to date) the highly conserved 3'X tail, the apical loop of domain IIId in the internal ribosome entry site, and/or the so-called Alt region upstream of the CRE. Changing contacts promotes the execution of different stages of the viral cycle. The 5BSL3.2 domain thus operates at the core of a system that governs the progression of HCV infection. This review summarizes our knowledge of the long-range RNA-RNA interaction network in the HCV genome, with special attention paid to the structural and functional consequences derived from the establishment of different contacts. The potential implications of such interactions in switching between the different stages of the viral cycle are discussed.

Sofosbuvir (SOF) Suppresses Ledipasvir (LDV)-resistant Mutants during SOF/LDV Combination Therapy against Genotype 1b Hepatitis C Virus (HCV)

Our objective was to identify drug interactions between ledipasvir (LDV) and sofosbuvir (SOF) against a genotype 1b replicon to determine optimal exposures for each agent that will maximize antiviral activity against susceptible and drug-resistant subpopulations. LDV and SOF were evaluated using a fully factorial experimental design in the BelloCell system. Replicon levels and drug-resistant variants were quantified at various times post-therapy for 14 days and a high-dimensional mathematical model was fit to the data. Mutations associated with SOF resistance were not detected; but LDV-resistant mutants were selected and mutant subpopulations increased as exposure intensity increased. Combination therapy was additive for the total replicon population and the LDV-resistant population, but a threshold concentration of 100 ng/ml of SOF must be attained to suppress LDV-resistant subpopulations. These novel findings hold important implications for not only improving therapeutic outcomes, but also maximizing the clinical utility of LDV and SOF combination regimens.