Interferon free therapy with direct acting antivirals for HCV

Treatment of Hepatitis C Post-Liver Transplantation Could Mitigate Discard Rates of Hepatitis C-Positive Deceased Donor Livers and Expand the Donor Pool

Background

Prior to 2014, treatment for hepatitis C was limited. However, the subsequent introduction of direct acting antiviral medications (DAA) against hepatitis C led to improvements in morbidity and better medication tolerance. DAA therapy allowed for an increase in treatment rates of hepatitis C in patients on the liver transplant waiting list. With the popularization of DAA, there became a growing concern about the utility of hepatitis C-positive (HCV+) deceased liver donors, especially after treating HCV+ potential recipients on the transplant waiting list.

Methods

This is a retrospective, observational study using Mid-America Transplant Services (MTS) database from 2008 to 2017. Comparison was made before the widespread use of DAAs 2008–2013 (pre-DAA) against their common practice use 2014–2017 (post-DAA). All deceased liver donors with HCV antibody or nucleic acid positive results were evaluated.

Results

Between 2008 and 2017, 96 deceased liver donors were positive for HCV. In the pre-DAA era, 47 deceased liver donors were positive for HCV, of which 32 (68.1%) were transplanted and 15 (31.9%) were discarded. In the post-DAA era, a total of 49 HCV+ organs were identified, out of which 43 (87.8%) livers were transplanted and 6 (12.2%) were discarded. Discard rate was significantly higher in the pre-DAA population (31.9% vs. 12.2%, p = 0.026). Secondary analysis showed a distinct trend towards increased regional sharing and utilization of HCV+ donors.

Conclusion

In order to reduce discard rates of HCV+ patients, our data suggest that transplant centers could potentially delay HCV treatment in patients on the transplant waitlist.

Effect of DAA therapy in hepatitis C treatment - an impulsive control approach

In this article, we have presented a mathematical model to study the dynamics of hepatitis C virus (HCV) disease considering three populations namely the uninfected liver cells, infected liver cells, and HCV with the aim to control the disease. The model possesses two equilibria namely the disease-free steady state and the endemically infected state. There exists a threshold condition (basic reproduction number) that determines the stability of the disease-free equilibrium and the number of the endemic states. We have further introduced impulsive periodic therapy using DAA into the system and studied the efficacy of the DAA therapy for hepatitis C infected patients in terms of a threshold condition. Finally, impulse periodic dosing with varied rate and time interval is adopted for cost effective disease control for finding the proper dose and dosing interval for the control of HCV disease.

Relation Between Immunohistochemical Expression of Hippo Pathway Effectors and Chronic Hepatitis Induced Fibrosis in Egyptian Patients

OBJECTIVE

Chronic hepatitis is a global health problem especially in Egypt. Hepatic fibrosis is a common end clinical manifestation of many chronic liver diseases. Although it is a wound-healing process, excessive accumulation of fibrillary collagen leads to architectural damage, cirrhosis and liver failure. Recently, a few studies have linked Hippo pathway effectors of yes-associated protein (YAP) and its paralog transcriptional coactivator with PDZ-binding motif (TAZ) to extracellular matrix deposition and ongoing fibrosis.

MATERIAL AND METHOD

Immunohistochemical expression of YAP and TAZ were analyzed in 121 liver needle core biopsies (91 core biopsies of chronic viral hepatitis, 20 biopsies of autoimmune hepatitis and 10 normal liver cores).

RESULTS

YAP and TAZ nuclear localization was absent in all normal liver cores. Autoimmune hepatitis cases showed higher nuclear expression of both YAP and TAZ in comparison to chronic viral cases. YAP and TAZ expression were correlated with severity of hepatocyte injury together with fibrosis in chronic viral cases but these correlations were absent in AIH cases despite the pronounced increase of YAP and TAZ nuclear localization.

CONCLUSION

The correlation between Hippo effectors activation and fibrosis in chronic viral hepatitis patients emphasize their role in the development and advancement of hepatic scarring and highlight the use of both YAP and TAZ as novel targets to ameliorate liver fibrosis.

Economic consequences of the implementation of national screening program for chronic HCV infection

BACKGROUND

Chronic HCV infection is still one of the leading causes for liver morbidity and mortality worldwide. Increase in testing and diagnosis would result in early identification of people with chronic infection and would enable timely access to care and treatment, as well as prevent or delay progression of liver disease. The aim of the present study is to examine the cost and benefits of introducing ones per life testing for HCV infection among the group of 39-64 years old people who regularly go to prophylactic examinations in Bulgaria.

RESEARCH DESIGN AND METHODS

Combined cost-effectiveness and cost-benefit analysis was performed to evaluate the cost-effectiveness and net benefit of three screening approaches.

RESULTS

Screening of the birth-cohort type (aged 39-64 and born before the blood testing became available) provides benefits compared to the current practice of symptomatic testing and leads to more LYGs. Testing among this age group is efficient with an ICER below the proposed by WHO threshold of 1-3 times GDP/capita.

CONCLUSIONS

Targeted testing among adults between 39 and 64 years with anti-HCV antibody once per their life in Bulgaria could be considered as cost-effective and provides benefits both for the paying institutions and the patients.

Transplantation of HCV Viremic Livers into HCV Viremic Recipients Followed by Direct-acting Antiviral Therapy

Background and Aims: Hepatitis C virus (HCV)-infected organs are underutilized. We aimed to assess the safety and efficacy of direct-acting antiviral agents (DAAs) therapy in HCV viremic patients who are transplanted with a liver from a HCV viremic donor. Methods: We conducted a retrospective study, including patients seen from July 2015 to April 2017. HCV viremic patients transplanted with a liver from a HCV viremic donor and subsequently treated with DAAs were included. Outcomes assessed included undetectable viral load at 12 weeks after completing DAA therapy (sustained virologic response, SVR₁₂), adverse events, and interactions with immunosuppression. Results: Twenty-four HCV viremic recipients received livers from HCV viremic donors. Median age was 63 years, and the majority (79.2%) were genotype 1a. Donors and recipients were viremic at the time of transplant. Median modified model for end-stage liver disease score was 19, and median time on the waitlist was 81 days. Median time from transplant to initiation of DAA therapy was 123 days. Several DAA regimens were used and 15 (62.5%) patients did not receive ribavirin. Treatment duration ranged from 12 to 24 weeks. Twenty-three (95.8%) patients achieved SVR₁₂. Five (20.8%) patients developed adverse events; however, none required DAA discontinuation. Conclusions: DAA therapy was efficacious and well tolerated in HCV viremic recipients who underwent liver transplantation from a HCV viremic donor.

Synthesis and biological evaluation of deuterated sofosbuvir analogs as HCV NS5B inhibitors with enhanced pharmacokinetic properties

A series of deuterated sofosbuvir analogs were designed and prepared with the aim of improving their pharmacokinetic properties. The devised synthetic routes allow for site-selective deuterium incorporation with high levels of isotopic purity. As expected, the deuterated analogs (37-44) are as efficacious as sofosbuvir when tested in vitro inhibition of viral replication (replicon) assays. Compared with sofosbuvir, deuterated analog 40 displays improved in vivo pharmacokinetics profiles in rats and dogs in terms of the metabolite and the prodrug. The Cmax and area under the curve (AUC) of 40 in dogs were increased by 3.4- and 2.7-fold, respectively. Due to the enhanced pharmacokinetic properties and the great synthetic advantage of an inexpensive deuterium source (D₂ O) for 40, it was chosen for further investigation.

Efficacy of L-carnitine on ribavirin-induced hemolytic anemia in patients with hepatitis C virus infection

Background/Aims

L-carnitine not only alleviates hyperammonemia and reduces muscle cramps in patients with liver cirrhosis, but also improves anemia in patients with chronic hepatitis and renal dysfunction. This study prospectively evaluated the preventative efficacy of L-carnitine supplementation against hemolytic anemia during antiviral treatment using ribavirin in patients with hepatitis C virus (HCV)-related chronic liver disease.

Methods

A total of 41 patients with chronic hepatitis were consecutively enrolled in this study. Group A (n=22) received sofosbuvir plus ribavirin for 3 months, whereas group B (n=19) was treated with sofosbuvir, ribavirin, and L-carnitine. Hemoglobin concentration changes, the effects of antiviral treatment, and the health status of patients were analyzed using short form-8 questionnaires.

Results

A significantly smaller decrease in hemoglobin concentration was observed in group B compared to group A at every time point. Moreover, the prescribed dose intensity of ribavirin in group B was higher than that of group A, resulting in a higher ratio of sustained virological response (SVR) 24 in group B compared with group A. The physical function of patients in group B was also significantly improved compared to group A at the end of antiviral treatment.

Conclusions

L-carnitine supplementation alleviates ribavirin-induced hemolytic anemia in patients with HCV and helps relieve the physical burden of treatment with ribavirin-containing regimens. These advantages significantly increase the likelihood of achieving SVR.

Outcomes and costs of treating hepatitis C patients with second-generation direct-acting antivirals: results from the German Hepatitis C-Registry

OBJECTIVE

Chronic hepatitis C virus infection is associated with a significant health burden. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. The introduction of direct-acting antivirals (DAA) has led to an increase in sustained virologic response rates (SVR), but is accompanied by higher treatment costs. The aim of this study was to assess the outcomes and costs of treating hepatitis C virus infected patients with DAAs in clinical practice in Germany.

PATIENTS AND METHODS

Data were derived from a noninterventional study including a pharmacoeconomic subset of 2673 patients with genotypes 1 and 3 who initiated and completed treatment between February 2014 and February 2017. Sociodemographic and clinical parameters as well as resource utilization were collected using a web-based data recording system. Costs were calculated using official remuneration schemes.

RESULTS

The mean age of the patients was 54.6 years; 48% were men. 93.5% of all patients achieved an SVR. The average total treatment costs were &OV0556;67 979 (&OV0556;67 131 medication costs, &OV0556;824 ambulatory care, &OV0556;24 hospital costs). The average costs per SVR of &OV0556;72 705 were calculated. Differences in SVR and costs according to genotype, treatment regimen, treatment experience, and cirrhosis were observed. Quality-of-life data showed no or a minimal decrease during treatment.

CONCLUSION

This analysis confirms high SVR rates for newly introduced DAAs in a real-world setting. Costs per SVR estimated are comparable to first-generation DAA. Given the fact that the costs for the currently used treatment regimens have declined, it can be assumed that the costs per SVR have also decreased. Our insight into real-world outcomes and costs can serve as a basis for a comparison with the mentioned newly introduced treatment regimens.

Real-World Efficacy and Safety of Pangenotypic Direct-Acting Antivirals Against Hepatitis C Virus Infection

BACKGROUND

Advances in the development of Direct-Acting Antivirals (DAAs), particularly pangenotypic drugs, have led to a high rate of hepatitis C virus (HCV) eradication. Notably, real- world studies have confirmed the efficacy and safety of pangenotypic DAA combinations reported in registration trials. The aim of this study was to review the treatment recommendations, and the efficacy and safety data of anti-HCV pangenotypic drugs reported in registration clinical trials and in recent real-life cohort studies.

METHODS

We reviewed the efficacy and safety data of pangenotypic anti-HCV drug combinations reported in original articles and in online conference abstracts.

RESULTS

Current pangenotypic drug combinations resulted in very high rates of sustained virologic response and few adverse reactions in real-life settings. SVR12 rates in real-life studies ranged from 90-100% depending on the pangenotypic combination, the HCV genotype and the stage of liver disease. Most adverse reactions reported in real-life settings were mild in intensity and rarely led to treatment discontinuation. These results are in accordance with those of clinical trials.

CONCLUSION

Pangenotypic DAAs result in very high rates of sustained virologic responses and are well tolerated. However, they are contraindicated in patients with decompensated cirrhosis or advanced chronic kidney disease who failed previous DDA-based treatment. Further research is required to customize treatment to "unpackage" current DAA combinations and to develop generic drugs against HCV.

Hypericin inhibits hepatitis C virus replication via deacetylation and down-regulation of heme oxygenase-1

BACKGROUND

Hepatitis C virus (HCV) is a globally prevalent pathogen and a leading cause of death and morbidity. Traditional therapy with pegylated interferon-<alpha> and ribavirin has had only limited success, with some adverse effects. Direct-acting antivirals (DAAs) are effective in suppressing HCV replication, but are expensive.

PURPOSE

Hypericin has been reported to be a good antiviral agent for inhibiting HCV replication, however, little is known about its mechanisms of action. The aim of this study is to elucidate the mode of action of hypericin in Ava5 human hepatoma cell line (Huh7 derivative) harboring HCV subgenomic replicon RNA.

METHODS

To determine the non-structure protein 5A (NS5A) mRNA and NS3 protein expression levels, real-time PCR and Western blot analysis were performed, respectively. To investigate how hypericin inhibits HCV replication, 5-aza-2'-deoxycytidine (5-Aza-dC) and chidamide were used for determining histone modification. Furthermore, shRNA was applied to confirm the role of heme oxygenase (HO-1) in HCV repression.

RESULTS

Hypericin in experiment were tested and showed no cytotoxicity. Hypericin reduced HO-1 and NS5A in a time- and dose- dependent manner. Chidamide, but not 5-Aza-dc, restored hypericin-induced reduction in HCV NS3 expression and reversed HO-1 expression in Ava5 cells. LY294002 inhibited HCV replication via HO-1 down-regulation. Constitutive expressed p-AKT was not involved in hypericin-induced reduction in HCV replication. In addition, shHO-1 inhibited HCV replication.

CONCLUSION

In conclusion, hypericin inhibits HCV replication via down-regulation of HO-1 expression and deacetylation.

RIG-I-Like Receptors as Novel Targets for Pan-Antivirals and Vaccine Adjuvants Against Emerging and Re-Emerging Viral Infections

Emerging and re-emerging viruses pose a significant public health challenge around the world, among which RNA viruses are the cause of many major outbreaks of infectious diseases. As one of the early lines of defense in the human immune system, RIG-I-like receptors (RLRs) play an important role as sentinels to thwart the progression of virus infection. The activation of RLRs leads to an antiviral state in the host cells, which triggers the adaptive arm of immunity and ultimately the clearance of viral infections. Hence, RLRs are promising targets for the development of pan-antivirals and vaccine adjuvants. Here, we discuss the opportunities and challenges of developing RLR agonists into antiviral therapeutic agents and vaccine adjuvants against a broad range of viruses.

Self-association and conformational variation of NS5A domain 1 of hepatitis C virus

Direct-acting antivirals (DAAs) targeting the non-structural 5A (NS5A) protein of the hepatitis C virus (HCV) are crucial drugs that have shown exceptional clinical success in patients. However, their mode of action (MoA) remains unclear, and drug-resistant HCV strains are rapidly emerging. It is critical to characterize the behaviour of the NS5A protein in solution, which can facilitate the development of new classes of inhibitors or improve the efficacy of the currently available DAAs. Using biophysical methods, including dynamic light scattering, size exclusion chromatography and chemical cross-linking experiments, we showed that the NS5A domain 1 from genotypes 1b and 1a of the HCV intrinsically self-associated and existed as a heterogeneous mixture in solution. Interestingly, the NS5A domain 1 from genotypes 1b and 1a exhibited different dynamic equilibria of monomers to higher-order structures. Using small-angle X-ray scattering, we studied the structural dynamics of the various states of the NS5A domain 1 in solution. We also tested the effect of daclatasvir (DCV), the most prominent DAA, on self-association of the wild and DCV-resistant mutant (Y93H) NS5A domain 1 proteins, and demonstrated that DCV induced the formation of large and irreversible protein aggregates that eventually precipitated out. This study highlights the conformational variability of the NS5A domain 1 of HCV, which may be an intrinsic structural behaviour of the HCV NS5A domain 1 in solution.

The unexpected structures of hepatitis C virus envelope proteins

Hepatitis C virus (HCV) envelope proteins are essential not only for maintaining the viral life cycle, but also for evading the host's immune response and in clinical intervention. A thorough understanding of HCV envelope proteins depends on the availability of detailed structural information. Two crystal structures of the E2 core portion and of the E2 ectodomain, and one structure of the N-terminus of E1 ectodomain have shed new light on the complexity of HCV envelope proteins. In addition, the full-length E1-E2 complex has recently been modeled. The present review focuses on these advancements, introduces the recently solved structures and their biological implications and proposes novel ideas for studying the full-length E1-E2 complex.

Prioritization for interferon-free regimens and potential drug interactions of current direct-acting anti-hepatitis C agents in routine clinical practice

BACKGROUND

We determined the proportions of patients with chronic hepatitis C (CHC) in association with possible prioritized indications for interferon-free regimens and the use of co-medications with potential drug-drug interactions (DDIs).

METHODS

Five hundred consecutive mono-infected CHC patients seen in 2015 at 5 Greek centers were included. Priorities for interferon-free regimens were based on liver disease severity, contraindication(s) for interferon and prior interferon-treatment failure. All co-medications were classified into those with no DDIs/no clear data for DDIs, potential DDIs, and contraindication due to DDI for each agent, according to the HEP Drug Interaction Checker.

RESULTS

Of the 500 patients, 1% had undergone liver transplantation, whereas 6.6% had decompensated cirrhosis, 21.8% F4, 17.1% F3, 10.4% F2, and 34.8% F0-1 fibrosis. Contraindications for interferon were present in 38.5% of non-transplant patients with compensated liver disease. The probability of contraindications/potential DDIs was greater for boceprevir/telaprevir and ombitasvir/paritaprevir/ritonavir±dasabuvir, compared to all other agents (P<0.001), and least for sofosbuvir (P<0.05). Contraindications/potential DDIs were more frequently present in patients ≥50 than <50 years old (P≤0.034), and more common in F3-4 than F0-2, and F4 than F0-3 fibrosis (P≤0.019) for all direct-acting antivirals (DAAs).

CONCLUSIONS

The expansion of the criteria for prioritization of interferon-free regimens from cirrhosis to F3 and perhaps F2 fibrosis will increase the proportion of patients with DAA access by only 10-15% and 10%, respectively. A potential for DDIs is frequently present with protease inhibitors, but also exists with other DAAs. The probability of DDIs is higher in patients with priority for DAAs, including those who have advanced liver disease and are usually of older age.

Living with Hepatitis C Virus: A Systematic Review and Narrative Synthesis of Qualitative Literature

Background and Aims. The lived experience of HCV has not been well documented in the literature. The aim of this systematic review was to understand the experiences of living with Hepatitis C Virus (HCV). Methods. Five databases were searched from inception until January 19, 2015. Studies were included if they focused on adults diagnosed with HCV; reported experience living with HCV; and described original research. Results. 46 studies were included. Studies found that participants had reduced quality of life due to physical symptoms. Due to physical symptoms and discrimination, many participants switched to part-time work or quit their jobs. Many individuals reported negative experiences with the healthcare system; themes of feeling unsupported, not having adequate information, and not feeling involved in decisions were reported. Stigma significantly impacted those living with HCV. Conclusions. Published literature indicates that those with HCV often feel stigmatized and unsupported in their care, relationships, and work environments, while simultaneously coping with physical and psychological symptoms. This synthesis points to areas where greater education, compassion, and patient-centered healthcare could improve the experience of people living with HCV.

Cost-effectiveness of screening for hepatitis C virus: a systematic review of economic evaluations

OBJECTIVES

With the developments of near-cures for hepatitis C virus (HCV), who to screen has become a high-priority policy issue in many western countries. Cost-effectiveness of screening programmes should be one consideration when developing policy. The objective of this work is to synthesise the cost-effectiveness of HCV screening programmes.

SETTING

A systematic review was completed. 5 databases were searched until May 2016 (NHSEED, MEDLINE, the HTA Health Technology Assessment Database, EMBASE, EconLit).

PARTICIPANTS

Any study reporting an economic evaluation (any type) of screening compared with opportunistic or no screening for HCV was included. Exclusion criteria were: (1) abstracts or commentaries, (2) economic evaluations of other interventions for HCV, including blood donors screening, diagnosis tests for HCV, screening for concurrent disease or medications for treatment.

PRIMARY AND SECONDARY OUTCOME MEASURES

Data extraction included type of model, target population, perspective, comparators, time horizon, discount rate, clinical inputs, cost inputs and outcome. Quality was evaluated using the Consolidated Health Economic Evaluation Reporting Standards checklist. Data are summarised using narrative synthesis by population.

RESULTS

2305 abstracts were identified with 52 undergoing full-text review. 30 papers met inclusion criteria addressing 7 populations: drug users (n=6), high risk (n=5), pregnant (n=4), prison (n=3), birth cohort (n=8), general population (n=5) and other (n=6). The majority (77%) of the studies were high quality. Drug users, birth cohort and high-risk populations were associated with cost-effectiveness ratios of under £30 000 per quality-adjusted-life-year (QALY). The remaining populations were associated with cost-effectiveness ratios that exceeded £30 000 per QALY.

CONCLUSIONS

Economic evidence for screening populations is robust. If a cost per QALY of £30 000 is considered reasonable value for money, then screening birth cohorts, drug users and high-risk populations are policy options that should be considered.

Clinical Utility of a New Automated Hepatitis C Virus Core Antigen Assay for Prediction of Treatment Response in Patients with Chronic Hepatitis C

Hepatitis C virus core antigen (HCV Ag) is a recently developed marker of hepatitis C virus (HCV) infection. We investigated the clinical utility of the new HCV Ag assay for prediction of treatment response in HCV infection. We analyzed serum from 92 patients with HCV infection who had been treated with pegylated interferon and ribavirin. HCV Ag levels were determined at baseline in all enrolled patients and at week 4 in 15 patients. Baseline HCV Ag levels showed good correlations with HCV RNA (r = 0.79, P < 0.001). Mean HCV Ag levels at baseline were significantly lower in patients with a sustained virologic response (SVR) than in those with a non SVR (relapse plus non responder) based on HCV RNA analysis (2.8 log₁₀fmol/L vs. 3.27 log₁₀fmol/L, P = 0.023). Monitoring of the viral kinetics by determination of HCV RNA and HCV Ag levels resulted in similarly shaped curves. Patients with undetectable HCV Ag levels at week 4 had a 92.3% probability of achieving SVR based on HCV RNA assay results. The HCV Ag assay may be used as a supplement for predicting treatment response in HCV infection, but not as an alternative to the HCV RNA assay.

The safety of daclatasvir for the treatment of hepatitis C

INTRODUCTION

The direct acting antiviral daclatasvir is an NS5A replication inhibitor active against the entire range of hepatitis C virus genotypes. It is a key step in establishing the goal of an all-oral, ribavirin-free, pan-genotypic regimen against hepatitis C.

AREAS COVERED

We review current literature including published abstracts and manuscripts. Evidence was obtained through PubMed/Medline search using listed keywords and through review of published abstracts.

EXPERT OPINION

Daclatasvir introduces a degree of pangenotypic potency currently lacking in other NS5A agents. Emerging literature suggests that daclatasvir in combination with other DAAs will represent a promising option in this difficult to treat populations including posttransplant, genotype 3 and HIV patients.

Global prevalence of pre-existing HCV variants resistant to direct-acting antiviral agents (DAAs): mining the GenBank HCV genome data

Direct-acting antiviral agents (DAAs) against hepatitis C virus (HCV) proteins open a whole new era for anti-HCV therapy, but DAA resistance associated variants (RAVs) could jeopardize the effectiveness of DAAs. We reported the global prevalence of DAA RAVs using published GenBank data. 58.7% of sequences (854/1455) harbored at least one dominant resistance variant and the highest RAV frequency occurred in Asia (74.1%), followed by Africa (71.9%), America (53.5%) and Europe (51.4%). The highest RAV frequency was observed in genotype (GT) 6 sequences (99%), followed by GT2 (87.9%), GT4 (85.5%), GT1a (56%), GT3 (50.0%) and GT1b (34.3%). Furthermore, 40.0% and 29.6% of sequences were detected RAVs of non-structural (NS) 5A inhibitors and NS3 protease inhibitors, respectively. However, RAVs to NS5B nucleo(t)ide inhibitor (NI) and NI-based combinations were uncommon (<4% of sequences). As expected, combinations of multiple RAVs to the IFN-free regimens recommended by current guidelines were rarely detected (0.2%-2.0%). Our results showed that the overall global prevalence of DAA RAVs was high irrespective of geography or genotype. However, the NI-based multi-DAA regimens had a low RAV prevalence, suggesting that these regimens are the most promising strategies for cure of the long-term HCV infection.

Analysis of peripheral blood dendritic cells as a non-invasive tool in the follow-up of patients with chronic hepatitis C

Hepatitis C virus (HCV) has a high propensity to establish chronic infections. Failure of HCV-infected individuals to activate effective antiviral immune responses is at least in part related to HCV-induced impairment of dendritic cells (DCs) that play a central role in activating T cell responses. Although the impact of HCV on DC phenotype and function is likely to be more prominent in the liver, major HCV-induced alterations are detectable in peripheral blood DCs (pbDCs) that represent the most accessible source of DCs. These alterations include numerical reduction, impaired production of inflammatory cytokines and increased production of immunosuppressive IL10. These changes in DCs are relevant to our understanding the immune mechanisms underlying the propensity of HCV to establish persistent infection. Importantly, the non-invasive accessibility of pbDCs renders the analysis of these cells a convenient procedure that can be serially repeated in patient follow-up. Accordingly, the study of pbDCs in HCV-infected patients during conventional treatment with pegylated interferon and ribavirin indicated that restoration of normal plasmacytoid DC count may represent an additional mechanism contributing to the efficacy of the dual therapy. It also identified the pre-treatment levels of plasmacytoid DCs and IL10 as putative predictors of response to therapy. Treatment of chronic HCV infection is changing, as new generation direct-acting antiviral agents will soon be available for use in interferon-free therapeutic strategies. The phenotypic and functional analysis of pbDCs in this novel therapeutic setting will provide a valuable tool for investigating mechanisms underlying treatment efficacy and for identifying predictors of treatment response.

Chronic hepatitis C: This and the new era of treatment

Over the last years it has started a real revolution in the treatment of chronic hepatitis C. This occurred for the availability of direct-acting antiviral agents that allow to reach sustained virologic response in approximately 90% of cases. In the near future further progress will be achieved with the use of pan-genotypic drugs with high efficacy but without side effects.

IFN-λ Inhibits MiR-122 Transcription through a Stat3-HNF4α Inflammatory Feedback Loop in an IFN-α Resistant HCV Cell Culture System

BACKGROUND

HCV replication in persistently infected cell culture remains resistant to IFN-α/RBV combination treatment, whereas IFN-λ1 induces viral clearance. The antiviral mechanisms by which IFN-λ1 induces sustained HCV clearance have not been determined.

AIM

To investigate the mechanisms by which IFN-λ clears HCV replication in an HCV cell culture model.

METHODS

IFN-α sensitive (S3-GFP) and resistant (R4-GFP) cells were treated with equivalent concentrations of either IFN-α or IFN-λ. The relative antiviral effects of IFN-α and IFN-λ1 were compared by measuring the HCV replication, quantification of HCV-GFP expression by flow cytometry, and viral RNA levels by real time RT-PCR. Activation of Jak-Stat signaling, interferon stimulated gene (ISG) expression, and miRNA-122 transcription in S3-GFP and R4-GFP cells were examined.

RESULTS

We have shown that IFN-λ1 induces HCV clearance in IFN-α resistant and sensitive replicon cell lines in a dose dependent manner through Jak-Stat signaling, and induces STAT 1 and STAT 2 activation, ISRE-luciferase promoter activation and ISG expression. Stat 3 activation is also involved in IFN-λ1 induced antiviral activity in HCV cell culture. IFN-λ1 induced Stat 3 phosphorylation reduces the expression of hepatocyte nuclear factor 4 alpha (HNF4α) through miR-24 in R4-GFP cells. Reduced expression of HNF4α is associated with decreased expression of miR-122 resulting in an anti-HCV effect. Northern blot analysis confirms that IFN-λ1 reduces miR-122 levels in R4-GFP cells. Our results indicate that IFN-λ1 activates the Stat 3-HNF4α feedback inflammatory loop to inhibit miR-122 transcription in HCV cell culture.

CONCLUSIONS

In addition to the classical Jak-Stat antiviral signaling pathway, IFN-λ1 inhibits HCV replication through the suppression of miRNA-122 transcription via an inflammatory Stat 3-HNF4α feedback loop. Inflammatory feedback circuits activated by IFNs during chronic inflammation expose non-responders to the risk of hepatocellular carcinoma.

Daclatasvir + asunaprevir: first global approval

The combination of daclatasvir + asunaprevir [Daklinza(®) + Sunvepra(®) (Japan)], two direct-acting antiviral agents, has been developed by Bristol-Myers Squibb for the treatment of patients with chronic hepatitis C virus (HCV) genotype 1 infections, including those with compensated cirrhosis. Daclatasvir + asunaprevir has received its first global approval in this indication in Japan. Daclatasvir + asunaprevir is the first all-oral, interferon- and ribavirin-free regimen for this indication. This article summarizes the milestones in the development of daclatasvir + asunaprevir leading to this first approval for the treatment of chronic HCV genotype 1 infections.

Hepatitis C

Hepatitis C virus (HCV) infection is a major health problem worldwide. The effects of chronic infection include cirrhosis, end-stage liver disease, and hepatocellular carcinoma. As a result of shared routes of transmission, co-infection with HIV is a substantial problem, and individuals infected with both viruses have poorer outcomes than do peers infected with one virus. No effective vaccine exists, although persistent HCV infection is potentially curable. The standard of care has been subcutaneous interferon alfa and oral ribavirin for 24-72 weeks. This treatment results in a sustained virological response in around 50% of individuals, and is complicated by clinically significant adverse events. In the past 10 years, advances in HCV cell culture have enabled an improved understanding of HCV virology, which has led to development of many new direct-acting antiviral drugs that target key components of virus replication. These direct-acting drugs allow for simplified and shortened treatments for HCV that can be given as oral regimens with increased tolerability and efficacy than interferon and ribavirin. Remaining obstacles include access to appropriate care and treatment, and development of a vaccine.

The use of marine-derived bioactive compounds as potential hepatoprotective agents

The marine environment may be explored as a rich source for novel drugs. A number of marine-derived compounds have been isolated and identified, and their therapeutic effects and pharmacological profiles are characterized. In the present review, we highlight the recent studies using marine compounds as potential hepatoprotective agents for the treatment of liver fibrotic diseases and discuss the proposed mechanisms of their activities. In addition, we discuss the significance of similar studies in Oman, where the rich marine life provides a potential for the isolation of novel natural, bioactive products that display therapeutic effects on liver diseases.

Sofosbuvir, a New Nucleotide Analogue, for the Treatment of Chronic Hepatitis C Infection

Objective: To evaluate the clinical role of sofosbuvir (Solvadi) in the treatment of hepatitis C virus (HCV). Data Sources: A MEDLINE, EMBASE, and Cochrane search indexed from January 2000 to July 2014 was performed using the search terms GS-7977 and sofosbuvir. Study Selection and Data Extraction: Studies including humans subjects, published in English, and assessing efficacy and safety of sofosbuvir in management of chronic HCV were evaluated. Data Synthesis: Sofosbuvir, a nucleotide analogue NS5B polymerase inhibitor, competes with nucleotides within the hepatocytes resulting in chain termination and inhibition of RNA replication. Trials evaluating the efficacy of sofosbuvir combination therapy have demonstrated significant advantage in sustained virologic response (SVR) over previous therapies. Genotype 1, 4, 5, and 6 patients treated with peginterferon-α, ribavirin, and sofosbuvir for 12 weeks achieved SVR rates of 90%. Twelve-week peginterferon-free regimens have resulted in SVR rates of 90% in genotype 2 patients, whereas genotype 3 patients required 24 weeks of therapy to achieve similar results. Favorable SVR rates were also seen in previously difficult-to-treat patient populations including cirrhosis, HIV coinfection, and treatment-experienced. Sofosbuvir appears to be well tolerated and relatively safe, avoiding severe adverse drug reactions, laboratory abnormalities, and resistance issues associated with traditional HCV therapies. The biggest limitation of sofosbuvir is the high cost associated with therapy. Conclusions: Sofosbuvir is a safe and effective treatment option for patients infected with genotypes 1 to 6 HCV including previously difficult-to-treat populations. The shorter duration, oral route, minimal side effects, and decreased resistance potential makes it a welcome addition to the treatment of chronic HCV.

Treatment for hepatocellular carcinoma in Japan over the last three decades: Our experience and published work review

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related mortality worldwide. In the last few decades, there has been a marked increase in therapeutic options for HCC and epidemiological characteristics at HCC diagnosis have also significantly changed. With these changes and advances in medical technology and surveillance program for detecting earlier stage HCC, survival in patients with HCC has significantly improved. Especially, patients with liver cirrhosis are at high risk of HCC development, and regular surveillance could enable early detection of HCC and curative therapy, with potentially improved clinical outcome. However, unfortunately, only 20% of HCC patients are amenable to curative therapy (liver transplantation, surgical resection or ablative therapies). Locoregional therapies such as radiofrequency ablation, percutaneous ethanol injection, microwave coagulation therapy and transcatheter arterial chemoembolization play a key role in the management of unresectable HCC. Currently, molecular-targeted agents such as sorafenib have emerged as a promising therapy for advanced HCC. The choice of the treatment modality depends on the size of the tumor, tumor location, anatomical considerations, number of tumors present and liver function. Furthermore, new promising therapies such as gene therapy and immunotherapy for HCC have emerged. Approaches to the HCC diagnosis and adequate management for patients with HCC are improving survival. Herein, we review changes of epidemiological characteristics, prognosis and therapies for HCC and refer to current knowledge for this malignancy based on our experience of approximately 4000 HCC cases over the last three decades.

Synthesis and evaluation of NS5A inhibitors containing diverse heteroaromatic cores

Inhibitors of the HCV NS5A nonstructural protein are showing promising clinical potential in the treatment of hepatitis C when used in combination with other direct-acting antiviral agents. Current NS5A clinical candidates such as daclatasvir, ledipasvir, and ombitasvir share a common pharmacophore that features a pair of (S)-methoxycarbonylvaline capped pyrrolidines linked to various cores by amides, imidazoles and/or benzimidazoles. In this Letter, we describe the evaluation of NS5A inhibitors which contain alternative heteroaromatic replacements for these amide mimetics. The SAR knowledge gleaned in the optimization of scaffolds containing benzoxazoles was parlayed toward the identification of potent NS5A inhibitors containing other heteroaromatic replacements such as indoles and imidazopyridines.

Impact of IL28B on the treatment decision in naïve and experienced patients with genotype 1 and 4 chronic hepatitis C in real-life clinical practice: a prospective multicenter cohort

BACKGROUND

The impact of the IL28B genotype on the real-life treatment decisions for patients infected with the hepatitis C virus (HCV) is unknown.

OBJECTIVE

To prospectively analyze the impact of IL28B genotype in HCV genotype 1 (G1)- or 4 (G4)-infected patients using buccal epithelial cell samples in real-life clinical practices.

PATIENTS AND METHODS

From October 2011 to March 2013, 1007 CHC patients were included among 127 French clinical centers.

RESULTS

The IL28B CC, CT, and TT genotype distribution was 252 (25%), 576 (57%), and 177 (18%), respectively. The treatment decisions were recorded and matched with the initial intentions for 433 patients. Multivariate analysis on intention to start treatment showed that patients with HCV G4 were less likely to be intended to be treated than HCV G1 patients (odds ratio [OR]=0.43 [95% CI 0.19-0.97], P=0.04); similarly HIV-HCV coinfected patients were less likely to be intended to be treated than HCV monoinfected patients (OR=0.20 [0.09-0.41], P<.0001); conversely, F3-F4 patients were more likely to be intended to be treated than F0-F2 patients (OR=2.24 [1.29-3.89], P=0.004). Multivariate analysis on final decision to treat showed that Patients with F3-F4 were more likely to be treated than others (OR=2.06 [1.26-3.38], P=0.004). Conversely, although P-values are not significant, patients recruited in public hospitals tended to be less treated (OR=0.65 [0.40-1.04], P=0.069), similarly to HIV-HCV coinfected patients (OR=0.55 [0.28-1.11], P=0.095).

CONCLUSION

Our study showed that the IL28B genotype is used for the management of HCV-infected patients. In the context of future treatments, IL28B genotyping may remain useful if it can be used to develop individualized treatment strategies, identifying patients who can be successfully treated with shorter, simpler, or cheaper regimens.

Specific serotonin reuptake inhibitors prevent interferon-α-induced depression in patients with hepatitis C: a meta-analysis

BACKGROUND & AIMS

Interferon-α (IFN-α)-induced depression is a major complication to treatment of chronic hepatitis C virus (HCV) infection. Specific serotonin reuptake inhibitors (SSRIs) can be used to treat depression, but it is not clear whether they can prevent depression in patients receiving IFN therapy for chronic HCV infection.

METHODS

We performed a meta-analysis by searching the Cochrane Library, PubMed, and EMBASE databases through 2013 for published results from randomized, placebo-controlled trials evaluating the utility of SSRIs in preventing IFN-induced depression in HCV patients. We analyzed data from 7 studies with a total of 662 patients. The incidence of IFN-induced major depression and depression severity were defined as primary outcomes. Sustained virologic response, completion of antiviral therapy, and tolerability were considered secondary outcomes.

RESULTS

A meta-analysis of IFN-induced major depression revealed that prophylactic SSRIs reduced the risk of depression, compared with placebo (relative risk [RR], 0.56; 95% confidence interval [CI], 0.37-0.84; P = .005). Proportions of patients achieving a sustained virologic response (RR, 1.02; 95% CI, 0.79-1.32; P = .87) and completing antiviral therapy (RR, 0.98; 95% CI, 0.66-1.44; P = .91) were similar between patients given SSRIs and controls. Prophylactic SSRIs were tolerated in patients with HCV during treatment.

CONCLUSIONS

On the basis of a meta-analysis of 7 randomized controlled trials, prophylactic administration of SSRIs to patients with HCV significantly lowered the incidence of IFN-induced major depression, compared with placebo, and the SSRIs were well tolerated.

Modelling the impact of improving screening and treatment of chronic hepatitis C virus infection on future hepatocellular carcinoma rates and liver-related mortality

Background

The societal, clinical and economic burden imposed by the complications of chronic hepatitis C virus (HCV) infection - including cirrhosis and hepatocellular carcinoma (HCC) - is expected to increase over the coming decades. However, new therapies may improve sustained virological response (SVR) rates and shorten treatment duration. This study aimed to estimate the future burden of HCV-related disease in England if current management strategies remain the same and the impact of increasing diagnosis and treatment of HCV as new therapies become available.

Methods

A previously published model was adapted for England using published literature and government reports, and validated through an iterative process of three meetings of HCV experts. The impact of increasing diagnosis and treatment of HCV as new therapies become available was modelled and compared to the base-case scenario of continuing current management strategies. To assess the ‘best case’ clinical benefit of new therapies, the number of patients treated was increased by a total of 115% by 2018.

Results

In the base-case scenario, total viraemic (HCV RNA-positive) cases of HCV in England will decrease from 144,000 in 2013 to 76,300 in 2030. However, due to the slow progression of chronic HCV, the number of individuals with cirrhosis, decompensated cirrhosis and HCC will continue to increase over this period. The model suggests that the ‘best case’ substantially reduces HCV-related hepatic disease and HCV-related liver mortality by 2020 compared to the base-case scenario. The number of HCV-related HCC cases would decrease 50% by 2020 and the number progressing from infection to decompensated cirrhosis would decline by 65%. Therefore, compared to projections of current practices, increasing treatment numbers by 115% by 2018 would reduce HCV-related mortality by 50% by 2020.

Conclusions

This analysis suggests that with current treatment practices the number of patients developing HCV-related cirrhosis, decompensated cirrhosis and HCC will increase substantially, with HCV-related liver deaths likely to double by 2030. However, increasing diagnosis and treatment rates could optimise the reduction in the burden of disease produced by the new therapies, potentially halving HCV-related liver mortality and HCV-related HCC by 2020.

Genetic variants at the IFNL3 locus and their association with hepatitis C virus infections reveal novel insights into host-virus interactions

Human genetic variation plays a critical role in both spontaneous clearance of and response to interferon (IFN)-based therapies against hepatitis C virus (HCV) as shown by the success of recent genome-wide association studies (GWAS). Several GWAS and later validation studies have shown that single nucleotide polymorphisms (SNPs) at the IFNL3 (formerly IL28B) locus on chromosome 19 are involved in eliminating HCV in human patients. No doubt that this information is helping clinicians worldwide in making better clinical decisions in anti-HCV therapy, but the biological mechanisms involving the SNPs leading to differential responses to therapy and spontaneous clearance of HCV remain elusive. Recent reports including the discovery of a novel IFN (IFN-λ4) gene at the IFNL3 locus and in vitro functional studies implicating 2 SNPs as causal variants lead to novel conclusions and perhaps to new directions in research. An attempt is made in this review to summarize the major findings of the GWAS, the efforts involved in the discovery of causal SNPs; and to explain the biological basis for spontaneous clearance and response to treatment in HCV infections.

Sofosbuvir

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. A drug class review is now published monthly with The Formulary Monograph Service. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service, call The Formulary at 800-322-4349. The May 2014 monograph topics are droxidopa, elosulfase alfa, vorapaxar, ramucirumab, and pimavanserin. The DUE/MUE is on droxidopa.

Update on hepatitis C virus resistance to direct-acting antiviral agents

Resistance to direct-acting antiviral (DAA) agents against hepatitis C virus (HCV) infection is driven by the selection of mutations at different positions in the NS3 protease, NS5B polymerase and NS5A proteins. With the exception of NS5B nucleos(t)ide inhibitors, most DAAs possess a low genetic barrier to resistance, with significant cross-resistance between compounds belonging to the same family. However, a specific mutation profile is associated with each agent or drug class and varies depending on the genotype/subtype (e.g., genotype 1b showed higher rates of sustained virological response (SVR) and a higher genetic barrier for resistance than genotype 1a). Moreover, some resistance mutations exist as natural polymorphisms in certain genotypes/subtypes at frequencies that require baseline drug resistance testing before recommending certain antivirals. For example, the polymorphism Q80K is frequently found among genotype 1a (19-48%) and is associated with resistance to simeprevir. Similarly, L31M and Y93H, key resistance mutations to NS5A inhibitors, are frequently found (6-12%) among NS5A genotype 1 sequences. In particular, the presence of these polymorphisms may be of relevance in poorly interferon-responsive patients (i.e., null responders and non-CC IL28B) under DAA-based therapies in combination with pegylated interferon-α plus ribavirin. The relevance of pre-existing resistance mutations for responses to interferon-free DAA therapies is unclear for most regimens and requires further study.

Successful natural interferon-β plus ribavirin therapy in a chronic hepatitis C patient after discontinuation of interferon-α treatment due to arrhythmia and interstitial pneumonia

A 71-year-old female patient with hepatitis C virus genotype 1 had previously discontinued interferon (IFN)-α plus ribavirin therapy, pegylated IFN-α (pegIFN-α) monotherapy, and natural IFN-α monotherapy because of arrhythmia, interstitial pneumonia, and severe neurovegetative symptoms. She subsequently completed 72 weeks of natural IFN-β plus ribavirin therapy without remarkable adverse effects and achieved a sustained viral response, suggesting differences in the pharmacological properties and biological effects of IFN-α and IFN-β. Thus, natural IFN-β plus ribavirin therapy may be a treatment option for patients with poor tolerance to IFN-α or pegIFN-α treatments.

Reduction of microRNA 122 expression in IFNL3 CT/TT carriers and during progression of fibrosis in patients with chronic hepatitis C

The microRNA miR-122 is highly expressed in the liver and stimulates hepatitis C virus (HCV) replication in vitro. IFNL3 (lambda-3 interferon gene) polymorphisms and the expression of miR-122 have been associated with sustained virological response (SVR) to treatment with pegylated interferon plus ribavirin in patients with chronic hepatitis C (CHC). We investigated, in vivo, the relationship between miR-122 expression, IFNL3 polymorphism, fibrosis, and response to PEG-IFN plus ribavirin. Pretreatment liver biopsy specimens and serum samples from 133 patients with CHC were included. Sixty-six patients achieved SVR, and 64 failed to respond to the treatment (43 nonresponders [NR] and 21 relapsers [RR]). All stages of fibrosis were represented, with 39, 50, 23, and 19 patients, respectively, having Metavir scores of F1, F2, F3, and F4. miR-122 expression was assessed by real-time quantitative PCR (RT-qPCR) and IFNL3 rs12979860 by direct sequencing. Hepatic miR-122 expression was higher in patients with the IFNL3 CC genotype than in those with the IFNL3 CT or TT genotype, in all patients (P = 0.025), and in NRs plus RRs (P = 0.013). Increased hepatic miR-122 was more strongly associated with complete early virological response (cEVR) (P = 0.003) than with SVR (P = 0.016). In multivariate analysis, increased hepatic miR-122 was only associated with the IFNL3 CC genotype. miR-122 was decreased in patients with advanced fibrosis (Metavir scores of F3 and F4) compared to its levels in patients with mild and moderate fibrosis (F1 and F2) (P = 0.01). Serum and hepatic expression of miR-122 were not associated. The association between miR-122 and IFNL3 was stronger than the association between miR-122 and response to treatment. miR-122 may play a role in the early viral decline that is dependent on IFNL3 and the innate immune response.

IMPORTANCE

miR-122 plays a crucial role during HCV infection. Moreover, it was reported that miR-122 binding within the HCV genome stimulates its replication. Moreover, miR-122 is highly expressed within hepatocytes, where it regulates many cellular pathways. A reduction of miR-122 expression has been suggested to be associated with responsiveness to IFN-based therapy in patients with chronic hepatitis C. Several independent genome-wide association studies reported a strong association between IFNL3 polymorphism and responsiveness to IFN-based therapy. We report here a strong association between the expression of miR-122 and IFNL3 polymorphism that is independent of the response to the treatment. Our data suggest that modification of miR-122 expression may play an important role in the molecular mechanism associated with IFNL3 polymorphism. Moreover, we report a reduction of miR-122 at more advanced stages of fibrosis in patients with chronic hepatitis C.

Discovery and development of hepatitis C virus NS5A replication complex inhibitors

Lead inhibitors that target the function of the hepatitis C virus (HCV) nonstructural 5A (NS5A) protein have been identified by phenotypic screening campaigns using HCV subgenomic replicons. The demonstration of antiviral activity in HCV-infected subjects by the HCV NS5A replication complex inhibitor (RCI) daclatasvir (1) spawned considerable interest in this mechanistic approach. In this Perspective, we summarize the medicinal chemistry studies that led to the discovery of 1 and other chemotypes for which resistance maps to the NS5A protein and provide synopses of the profiles of many of the compounds currently in clinical trials. We also summarize what is currently known about the NS5A protein and the studies using NS5A RCIs and labeled analogues that are helping to illuminate aspects of both protein function and inhibitor interaction. We conclude with a synopsis of the results of notable clinical trials with HCV NS5A RCIs.

Second-wave IFN-based triple therapy for HCV genotype 1 infection: simeprevir, faldaprevir and sofosbuvir

With the approval of second-wave direct-acting antivirals simeprevir, sofosbuvir and faldaprevir in 2014-2015, for genotype 1 hepatitis C, patients and doctors will have more treatment options. During a first period, these treatments will still be used with peginterferon and ribavirin. The second wave of IFN-based triple therapy will have benefits and risk. These treatments have the following advantages: higher efficacy with more patient candidates for a shorten treatment duration (12-24 weeks, instead of 48 weeks). These new treatments appear to have a better safety profile than first generation, with no additional increase in anaemia over peginterferon/ribavirin. Then, these treatments are to take for patients with a decrease in pill burden (these three direct-acting antivirals are given orally one pill a day). Simeprevir and sofosbuvir may be approved in the US and Europe, in 2014, at the time this manuscript will be released. Approval of faldaprevir will follow. These direct-acting antivirals with many others will hopefully be combined in future interferon-free regimens. The goal of this review to summarize the results and safety of simeprevir, faldaprevir and sofosbuvir, to advise physicians and to inform patients on the benefits and risks of these second-wave IFN-based regimens for HCV genotype infection.

Is there still a role for PEG IFN+RBV therapy in patients with HCV genotype 1?

Boceprevir and telaprevir-based triple therapy is now the standard of care for the treatment of genotype 1 patients. However, dual therapy with pegylated interferon and ribavirin should be discussed in treatment-naïve patients with good predictors of response. A recent published trial has shown in non-cirrhotic patients with low viral load at baseline, similar efficacy of a 24-week course of dual therapy vs a 24-week course of boceprevir-based triple therapy in case of rapid virological response. Accordingly, addition of protease inhibitor should be discussed after 4 weeks of dual therapy in this easy-to-treat population.

How to optimize current treatment of genotype 2 hepatitis C virus infection

The standard of care (SOC) for hepatitis C virus (HCV) genotype 2 is pegylated interferon (PEG-IFN) plus ribavirin (RBV). Even though most patients can be cured with this therapy after 24 weeks, tailoring treatment can improve its safety and efficacy in special populations. Thus, shortening treatment together with a weight-based RBV dosing approach has been considered satisfactory in patients with positive predictors of response. With the development of the direct antiviral agents (DAAs), shorter, better tolerated and more efficient treatments for HCV genotype 2 will become available, including interferon-free regimens. Until these new treatments are released, the decision to treat patients with HCV genotype 2 with currently approved drugs or to wait for future options must be made, taking into account the stage of fibrosis.

HCV F1/F2 patients: treat now or continue to wait

The treatment of chronic HCV is evolving rapidly. In 2014, three new oral antiviral agents, simeprevir, faldeprevir and sofosbuvir will become available for patients with HCV genotype 1. These agents have far less side effects than the first generation protease inhibitors telaprevir and boceprevir. Treatment will therefore be easier for patients to tolerate but still require peginterferon and ribavirin (PEGINF/RBV). The first IFN free therapy, sofosbuvir (SOF) and ribavirin (RBV), will also become available in 2014. This treatment is highly effective for patients with HCV genotype 2. However, SVR rates with SOF/RBV appear to be similar to that achieved with PEGINF/RBV in patients with HCV genotype 3. The first IFN-free all oral antiviral therapy combination for patients with HCV genotype 1 may be available late in 2014 or early 2015. The factors which should be considered when deciding whether to treat a patient with HCV now or to delay treatment until IFN free therapies are available is discussed.

Treating HCV in HIV 2013: on the cusp of change

Treating hepatitis C virus (HCV) in HIV/HCV co-infected patients is a challenge. Even if the benefits of achieving a sustained virological response are clear, the rates achieved with the combination of pegylated-interferon and ribavirin are disappointing. The addition of direct acting antiviral agents (DAAs) to the treatment of hepatitis C is revolutionizing the treatment of HCV in mono-infected patients. Even if there have not been any agents approved for the treatment of co-infected patients, many studies specifically designed for this population are ongoing. This article reviews available data on the use of DAAs in co-infected patients and the challenges associated with these new drugs.

Management of HCV patients with cirrhosis with direct acting antivirals

In recent years, several studies have clearly shown that sustained virological response (SVR) achieved by interferon-based therapies may delay or reduce the risk of hepatocellular carcinoma, liver decompensation and all-causes of mortality in all categories of patients with HCV-related cirrhosis, a condition characterized by a wide heterogeneity of clinical features, especially in patients with compensated disease. Unfortunately, the advanced fibrosis stage has been shown to be associated with poor SVR rates and poor tolerance with Peg-interferon and ribavirin. Therefore, on the basis of its risk/efficacy evaluation, most patients are considered to be ineligible for antiviral therapy with these molecules. Recently, improvement in the knowledge of the HCV life-cycle, has resulted in the rapid development of many direct-acting antivirals (DAAs). Two first generation DAAs, boceprevir (BOC) and telaprevir (TVR), have been approved, and more than 40 new small molecules are still in development. However, only a few individuals with compensated cirrhosis were included in the phase III studies assessing the safety and efficacy of BOC or TVR in naïve and chronic hepatitis C genotype 1 patients in whom treatment had failed, and patients with either decompensation or end-stage liver disease were excluded. Therefore, the information available in these patients, which have shown significantly lower SVR compared with patients with mild to moderate fibrosis, are not fully reliable. In addition, in real practice, some studies that have not yet been fully published have shown that triple therapy with these two molecules was associated with low SVR and high serious adverse events (SAEs).

Discovery and preclinical characterization of the cyclopropylindolobenzazepine BMS-791325, a potent allosteric inhibitor of the hepatitis C virus NS5B polymerase

Described herein are structure-activity relationship studies that resulted in the optimization of the activity of members of a class of cyclopropyl-fused indolobenzazepine HCV NS5B polymerase inhibitors. Subsequent iterations of analogue design and syntheses successfully addressed off-target activities, most notably human pregnane X receptor (hPXR) transactivation, and led to significant improvements in the physicochemical properties of lead compounds. Those analogues exhibiting improved solubility and membrane permeability were shown to have notably enhanced pharmacokinetic profiles. Additionally, a series of alkyl bridged piperazine carboxamides was identified as being of particular interest, and from which the compound BMS-791325 (2) was found to have distinguishing antiviral, safety, and pharmacokinetic properties that resulted in its selection for clinical evaluation.

Long-term follow-up of hepatitis C infection in a large cohort of patients with inherited bleeding disorders

BACKGROUND & AIMS

Patients with inherited bleeding disorders are an interesting group to study the long-term course of chronic hepatitis C virus (HCV) infection, because of their uniform mode of infection and reliable follow-up. Our aim was to assess the long-term occurrence of adverse liver-related events in these patients.

METHODS

The occurrence and determinants of end-stage liver disease (ESLD) were assessed using retrospective data of 863 HCV infected patients with inherited bleeding disorders from the Netherlands and the UK.

RESULTS

Median follow-up since HCV infection was 31 years, while 30% of patients had >35 follow-up years. Nineteen percent of patients spontaneously cleared the virus and 81% developed chronic HCV infection. Of the 700 patients with chronic HCV, 90 (13%) developed ESLD. Hepatocellular carcinoma (HCC) was diagnosed in 3% of patients with chronic HCV, 41% of which occurred in the last six years. Determinants of ESLD development were age at infection (hazard ratio (HR) 1.09 per year increase), HIV co-infection (HR 10.85), history of alcohol abuse (HR 4.34) and successful antiviral treatment (HR 0.14). Of the 487 patients who were still alive at the end of follow-up, 49% did not undergo optimal conventional antiviral treatment.

CONCLUSIONS

After over 30 years of HCV infection, ESLD occurred in a significant proportion of patients with inherited bleeding disorders. HCC appears to be an increasing problem. There is a significant potential for both conventional and new antiviral treatment regimens to try and limit ESLD occurrence in the future.

Treatment decisions and contemporary versus pending treatments for hepatitis C

The primary aim of antiviral therapy for chronic hepatitis C (CHC) is the prevention of progressive disease. A response to interferon (IFN) treatment is associated with an improvement in all-cause mortality and liver-related mortality from hepatitis C. Unless contraindicated, patients with CHC are thus potential candidates for treatment. Improved response rates are observed in patients with HCV genotype 1 infection treated with first-generation protease inhibitors. However, treatment with current first-generation protease inhibitors and IFN is complex and can result in appreciable adverse effects. The advent of potent, pan-genotypic all-oral direct-acting antiviral (DAA) regimens necessitates a critical examination of the immediate application of PEG-IFN, ribavirin and DAA regimens in patients with CHC. Current guidelines and position statements do not make clear recommendations, and are behind the emerging data. Some aspects of the conundrums facing physicians and patients are summarized in this Review. Cirrhosis presents an immediate threat of disease, and ideally treatment should be targeted at those patients who have advancing or advanced disease; unfortunately, a disparity exists, as response rates are reduced in patients with cirrhosis and the risks of adverse events are increased. On balance, patients with mild disease could consider deferring treatment.

Sofosbuvir for the treatment of hepatitis C virus

INTRODUCTION

The current treatment for hepatitis C virus (HCV) genotype 1 chronic infection is the addition of direct-acting antivirals (DAAs) with a protease inhibitor (telaprevir or boceprevir) to the pegylated interferon (PEG-IFN) and ribavirin (RBV) regimen. In 2014, sofosbuvir, simeprevir and faldaprevir may be available, each in combination with PEG-IFN/RBV triple therapy. All the HCV enzymes are essential for HCV replication, and are potential drug discovery targets. Therefore, DAAs with different viral targets, including NS3 protease inhibitors, nucleoside/nucleotide analogue and nonnucleoside inhibitors of the RNA-dependent RNA polymerase, and NS5A replication complex inhibitors are under development.

AREAS COVERED

Interestingly, several IFN-free Phase III trials are ongoing with promising results. Among DAAs, sofosbuvir is a potent HCV-specific nucleotide analog (chain terminator). The aim of this article is to review sofosbuvir data, in particular Phase III trials.

EXPERT OPINION

Sofosbuvir has a high barrier to resistance with no virologic breakthrough to date. It has a pan-genotypic activity (even though lower rates of response for genotype 3). So far, no safety signal in preclinical/clinical studies has been observed with this compound. It is given orally, once daily, without food effect. Sofosbuvir will first be available in association with PEG-IFN/RBV. Sofosbuvir appears to be a key compound and a backbone for future IFN free treatment regimen.