Current and future HCV therapy: do we still need other anti-HCV drugs?

Small molecule NS5B RdRp non-nucleoside inhibitors for the treatment of HCV infection: A medicinal chemistry perspective

Hepatitis C virus (HCV) infection has become a global health problem with enormous risks. Nonstructural protein 5B (NS5B) RNA-dependent RNA polymerase (RdRp) is a component of HCV, which can promote the formation of the viral RNA replication complex and is also an essential part of the replication complex itself. It plays a vital role in the synthesis of the positive and negative strands of HCV RNA. Therefore, the development of small-molecule inhibitors targeting NS5B RdRp is of great value for treating HCV infection-related diseases. Compared with NS5B RdRp nucleoside inhibitors, non-nucleoside inhibitors have more flexible structures, simpler mechanisms of action, and more predictable efficacy and safety of drugs in humans. Technological advances over the past decade have led to remarkable achievements in developing NS5B RdRp inhibitors. This review will summarize the non-nucleoside inhibitors targeting NS5B RdRp developed in the past decade and describe their structure optimization process and structure-activity relationship.

Quality of life, risk behaviors and depression among carriers of hepatitis C virus and human T-cell lymphotropic virus type 1: a comparative study

Human T-cell lymphotropic virus type 1 (HTLV-1) has low prevalence rates, but is endemic in some regions of the world. It is usually a chronic asymptomatic infection, but it can be associated with serious neurologic and urinary conditions. Hepatitis C virus (HCV) is broadly spread out worldwide. The majority of these infections have a chronic course that may progress to cirrhosis and hepatocellular carcinoma.

Objectives

To compare sociodemographic and mental health (risk behaviors, depression, and suicide) aspects, and quality of life among patients with HCV or HTLV-1.

Methods

Observational, comparative and cross-sectional study involving outpatients with HCV or HLTV-1 infection. Sociodemographic characteristics, risk behaviors and quality of life were assessed through the questionnaires Mini International Neuropsychiatric Interview – MINI Plus (depression and suicide) and Medical Outcomes Study 36-Item Short-Form Health Survey (quality of life). Univariate and multivariate statistical analyses (hierarchical logistic regression) were conducted.

Results

143 individuals with HCV and 113 individuals with HTLV-1 infection were included. Males were predominant in the HCV group (68.8%) and females in the HTLV-1 group (71.7%). The frequency of risk behaviors (sexual and drug use) was greater in those with HCV (p < 0.05). A past depressive episode was more common in the HTLV-1 group (p = 0.037). Quality of life was significantly worse in the physical functioning, vitality, mental health, and social functioning domains in those with HTLV-1 (p < 0.05). HTLV-1 infection remained independently associated with worse quality of life in multivariate analysis.

Conclusions

Risk behaviors are frequent among those infected with HCV. Additionally, despite HTLV-1 being considered an infection with low morbidity, issues related to mental health (depressive episode) and decreased quality of life are relevant.

Discovery of 3-Amino-2-Hydroxypropoxyisoflavone Derivatives as Potential Anti-HCV Agents

Synthesis and anti-hepatitis C virus (anti-HCV) effects of certain 3-amino-2-hydroxy-propoxy isoflavone derivatives, 6a–i, were described. The known 3-(3,4-dimethoxyphenyl)-7-(oxiran-2-ylmethoxy)-4H-chromen-4-one (5) was reacted with substituted amines to give the desired isoflavone derivatives, 6a–i. Among them, 7-{3-[(3,4-dimethoxy-phenethyl)amino]-2-hydroxypropoxy}-3-(3,4-dimethoxyphenyl)-4H-chromen-4-one (6b) was the most active, exhibiting approximately 2-fold higher anti-HCV effects than standard antiviral drug ribavirin (EC₅₀ of 6.53 vs. 13.16 μM). In addition, compound 6b was less cytotoxic than ribavirin. The selectivity index (SI) of 6b is approximately 2.6-fold higher than ribavirin. The compounds 6e, 6h, and 6i were also found to possess higher anti-HCV effects than ribavirin. Compound 6b was found to inhibit the HCV RNA expression in Ava5 cells in a dose-dependent manner; furthermore, we found that the antiviral mechanism of compounds 6b, 6e, 6h, and 6i gave rise to induction of HO-1 expression. With the HO-1 promoter-based analysis, we found compounds 6b, 6e, 6h, and 6i induced HO-1 expression through increasing Nrf-2 binding activity. Taken together, compound 6b may serve as a potential lead compound for developing novel anti-HCV agents.

Effectiveness of chronic hepatitis C treatment with direct-acting antivirals in the Public Health System in Brazil

INTRODUCTION

Chronic hepatitis C virus infection is one of the major causes of cirrhosis, hepatocellular carcinoma and liver transplantation. Treatment using direct-acting antivirals has revolutionized the treatment of hepatitis C virus, increasing long-term prognosis after cure. The goal of the present study was to evaluate the effectiveness of direct-acting antivirals in a Public Health System in southern Brazil.

METHODS

A retrospective study evaluated all patients with chronic hepatitis C virus infection who underwent treatment at one center of the Public Health Department of the State of Rio Grande do Sul - Brazil, according to the Brazilian Clinical Protocol and Therapeutic Guidelines. The effectiveness was assessed in terms sustained virological response 12 weeks after the end of treatment.

RESULTS

A total of 1002 patients who were treated for chronic hepatitis C virus infection were evaluated. The mean age was 58.6 years, 557 patients (55.6%) were male and 550 (54.9%) were cirrhotic. Overall sustained virological response was observed in 936 (93.4%) patients. There was a difference in sustained virological response rate varied according to sex, 91.6% in men and 95.7% in women (p = 0.009), length of treatment in genotype 1, 92.7% with 12 weeks and 99.1 with 24 weeks (p = 0.040), and genotype, 94.7% in genotype 1, 91.7% in genotype 2, and 91.4% in genotype 3 (p = 0.047).

CONCLUSION

The treatment of chronic hepatitis C virus infection for genotypes 1, 2 or 3 with the therapeutic regimens established by the Brazilian guidelines showed high rates of SVR, even in cirrhotic patients.

Improved survival of patients with hepatocellular carcinoma and compensated hepatitis C virus-related cirrhosis who attained sustained virological response

BACKGROUND

Few studies examined the outcome of patients with hepatitis C virus (HCV)-related cirrhosis who developed hepatocellular carcinoma (HCC). The relative weight as determinant of death for cancer vs end-stage liver disease (ESLD) and the benefit of HCV eradication remain undefined. This multicentre, retrospective analysis evaluates overall survival (OS), rate of decompensation and tumour recurrence in compensated HCC patients treated with interferon (IFN) according to HCV status since HCC diagnosis.

METHODS

Two groups of patients with HCV-related cirrhosis and HCC were followed since HCC diagnosis: (i) compensated cirrhotics with prior sustained virological response (SVR) on IFN-based regimens (N=19); (ii) compensated cirrhotics without SVR (viraemic) (N=156).

RESULTS

Over a median follow-up of 3.0 years since the onset of HCC, OS was longer for HCC patients with SVR than for viraemic patients (log-rank P=.004). The 5-year OS rate was 65.9% in patients with SVR vs 31.9% in viraemic patients. Similar trends were reported for hepatic decompensation (log-rank P=.01) and tumour recurrence (log-rank P=.01). These findings were confirmed at multivariable and propensity score analysis. At propensity analysis, 0/19 compensated patients with SVR died for ESLD vs 7/19 (37%) viraemic patients (P=.004). HCC mortality was similar in the two groups.

CONCLUSIONS

Hepatocellular carcinoma patients with prior SVR and compensated cirrhosis at the time of tumour diagnosis have prolonged OS than viraemic patients. Given the lack of cirrhosis progression, no SVR patient ultimately died for ESLD while this condition appears the main cause of death among viraemic patients.

Hepatitis C Genotypes in Libya: Correlation with Patients' Characteristics, Level of Viremia, and Degree of Liver Fibrosis

OBJECTIVES

Our study sought to determine the distribution of hepatitis C virus (HCV)-genotypes among patients attending two tertiary care hospitals in Benghazi and Tripoli, Libya, and correlate this with patient's characteristics, viral load, and degree of fibrosis.

METHODS

We conducted a retrospective study of 286 HCV-RNA positive Libyan patients referred from different health care facilities in east and west Libya for specific HCV treatment. HCV genotyping was carried out by gene amplification. Liver histology was graded by Metavir score according to the stage of fibrosis.

RESULTS

HCV genotypes 1, 2, 3, and 4 were found in 24.1%, 10.8%, 3.4%, and 61.5% of the patients, respectively. Genotype 4 was detected more frequently in patients from east Libya (Benghazi) compared to west Libya (Tripoli) (75.9% vs. 41.6%, p = 0.245). Genotype 1 was more frequent in patients from west Libya compared to east Libya (34.1% vs. 16.8%, p = 0.657). There was a significant correlation between HCV genotype distribution and viral load. Patients with genotype 4 exhibited a higher degree of liver fibrosis (p < 0.001).

CONCLUSIONS

HCV genotype 4 is the predominant genotype in Libya followed by genotype 1. However, as we go from the east to the west of the country, genotype 1 increases. Genotype 4 was associated with higher level of viremia and higher stage of liver fibrosis. It is important to note that both genotypes 1 and 4 are associated with a poor response to pegylated interferon and ribavirin combination therapy. The findings emphasize the need to develop improved strategies in Libya for the successful treatment of HCV infection with novel newly available antiviral drugs.

Hepatitis C virus infection

Hepatitis C virus (HCV) is a hepatotropic RNA virus that causes progressive liver damage, which might result in liver cirrhosis and hepatocellular carcinoma. Globally, between 64 and 103 million people are chronically infected. Major risk factors for this blood-borne virus infection are unsafe injection drug use and unsterile medical procedures (iatrogenic infections) in countries with high HCV prevalence. Diagnostic procedures include serum HCV antibody testing, HCV RNA measurement, viral genotype and subtype determination and, lately, assessment of resistance-associated substitutions. Various direct-acting antiviral agents (DAAs) have become available, which target three proteins involved in crucial steps of the HCV life cycle: the NS3/4A protease, the NS5A protein and the RNA-dependent RNA polymerase NS5B protein. Combination of two or three of these DAAs can cure (defined as a sustained virological response 12 weeks after treatment) HCV infection in >90% of patients, including populations that have been difficult to treat in the past. As long as a prophylactic vaccine is not available, the HCV pandemic has to be controlled by treatment-as-prevention strategies, effective screening programmes and global access to treatment.

Incremental cost-effectiveness pharmacoeconomic assessment of hepatitis C virus therapy: an approach for less wealthy members of the common market

AIM

To develop a new method of health-economic analysis based on a marginal approach.

METHODS

We tested the research hypothesis that a detailed comparative a priori incremental cost-effectiveness analysis provides the necessary input for budget impact analysis about the proper order of introduction of new therapies, and thus maximizes the cost-effectiveness bounded by the total budget constraint. For the analysis we chose a combination therapy for the treatment of hepatitis C virus (HCV) genotype 1 (GT1) infection, which was approved by the European Medicine Agency in 2015. We used the incremental cost-effective approach to assess the increase in the percentage of patients achieving sustained virological response (SVR) and the expenditure per additional SVR modulated by the new therapy's market entrance dynamics. Patient subpopulations were differentiated by their response to previous treatment, presence of cirrhosis, and HCV GT1 subtype. Final parameters were estimated by Monte Carlo simulations.

RESULTS

The new combination therapy had high efficacy, shorter duration, and was better tolerated than alternative interventions. The research hypothesis was confirmed: gradual introduction of the new therapy on the market, based on a priori incremental cost-effectiveness analysis, would result in average increase in successfully treated patients by 20%-40%, while additional costs would approximately be between 8%-40%, ie, ?21000-52000 per additional patient achieving SVR.

CONCLUSION

We showed the new combination therapy to be cost-effective for certain patient subpopulations, especially for experienced cirrhotic HCV GT1 patients. Results of the analysis are in agreement with the latest recommendations for HCV patients' treatment in Croatia. This economic evaluation could serve as a starting point for negotiations between pharmaceutical industry and insurance companies.

Exosomal MicroRNAs Derived From Umbilical Mesenchymal Stem Cells Inhibit Hepatitis C Virus Infection

: Hepatitis C virus (HCV) is a significant global public health problem, causing more than 350,000 deaths every year. Although the development of direct-acting antivirals has improved the sustained virological response rate in HCV patients, novel anti-HCV agents with higher efficacy as well as better tolerance and cheaper production costs are still urgently needed. Cell-based therapy, especially its unique and strong paracrine ability to transfer information to other cells via extracellular vesicles such as exosomes, has become one of the most popular therapeutic methods in recent years. In our study, exosomes secreted from umbilical mesenchymal stem cells (uMSCs), which are widely used in regenerative medicine, inhibited HCV infection in vitro, especially viral replication, with low cell toxicity. Our analysis revealed that microRNAs (miRNAs) from uMSC-derived exosomes (uMSC-Exo) had their unique expression profiles, and these functional miRNAs, mainly represented by let-7f, miR-145, miR-199a, and miR-221 released from uMSC-Exo, largely contributed to the suppression of HCV RNA replication. These four miRNAs possessed binding sites in HCV RNA as demonstrated by the target prediction algorithm. In addition, uMSC-Exo therapy showed synergistic effect when combined with U.S. Food and Drug Administration-approved interferon-α or telaprevir, enhancing their anti-HCV ability and thus improving the clinical significance of these regenerative substances for future application as optimal adjuvants of anti-HCV therapy.

SIGNIFICANCE

This work reported, for the first time, the identification of stem cell-derived exosomes of antiviral activity. Umbilical mesenchymal stem cell-secreted exosomes inhibited hepatitis C virus infection through transporting a mixture of microRNAs complementing the viral genomes to the host cells. This finding provides insights and prospects for physiologically secreted substances for antiviral therapy.

Emerging biological agents for hepatitis C

INTRODUCTION

New direct-acting antiviral agents have changed the landscape of treatment of chronic HCV infection. Despite current treatments are well tolerated with a high rate of sustained virological response (SVR), some medical needs remain. Nowadays there are a large number of approved medications for the treatment of HCV infection; nevertheless, new studies are conducted to find new agents and new combinations.

AREAS COVERED

A literature research of new antiviral compounds indicated for the treatment of HCV infection was achieved by an online search of medication undergoing development on Pubmed and clinicalTrials.gov clinical trials registry. We considered phase I/II studies and some randomized Phase III trials.

EXPERT OPINION

More knowledge about impact of HCV eradication on disease progression and more confidence regarding drug-drug interaction are needed. Furthermore, each treatment should be individualized targeting the patients needs with the aim not only to obtain viral suppression but also to stop progression of liver disease and HCV related conditions, and to improve patient health status.

Molecular characterization of Hepatitis C virus 3a in Peshawar

Background

The purpose of this study was to explore molecular epidemiology of HCV genotype 3a in Peshawar based on sequencing and phylogenetic analysis of Core region of HCV genome.

Methods

Chronically infected Hepatitis C virus infected patients enrolled under the Prime Minister Hepatitis C control program at three Tertiary care units of Peshawar [Khyber Teaching Hospital Peshawar, Lady Reading Hospital Peshawar, Hayat Abad Medical Complex Peshawar] were included in this cross sectional observational study. Qualitative detection of HCV and HCV genotyping was carried out by a modified reverse transcription-polymerase chain reaction (RT-PCR) and type specific genotyping assay. The Core gene of HCV genotype 3a was amplified, cloned and sequenced. The sequences obtained were used for phylogenetic analysis using MEGA 6 software.

Results

Among the 422 (82.75 %) PCR positive samples, 192 (45.5 %) were identified as having HCV genotype 3a infection. HCV Core gene sequencing was carried out randomly for the characterization of HCV 3a. Nucleotide sequence analysis of the obtained viral genomic sequences based on partial HCV 3a Core gene sequences with reference sequences from different countries showed that our sequences clustered with some local and regional sequences with high bootstrap values.

Conclusion

HCV 3a is highly prevalent in Peshawar, Pakistan and its phylogenetics based on Core gene sequences indicate the prevalence of different lineages of HCV 3a in Peshawar which may have consequences for disease management strategies causing more economic pressure on the impoverished population due to possible antiviral resistance.

Recent advances in understanding hepatitis C

The past decade has seen tremendous progress in understanding hepatitis C virus (HCV) biology and its related disease, hepatitis C. Major advances in characterizing viral replication have led to the development of direct-acting anti-viral therapies that have considerably improved patient treatment outcome and can even cure chronic infection. However, the high cost of these treatments, their low barrier to viral resistance, and their inability to prevent HCV-induced liver cancer, along with the absence of an effective HCV vaccine, all underscore the need for continued efforts to understand the biology of this virus. Moreover, beyond informing therapies, enhanced knowledge of HCV biology is itself extremely valuable for understanding the biology of related viruses, such as dengue virus, which is becoming a growing global health concern. Major advances have been realized over the last few years in HCV biology and pathogenesis, such as the discovery of the envelope glycoprotein E2 core structure, the generation of the first mouse model with inheritable susceptibility to HCV, and the characterization of virus-host interactions that regulate viral replication or innate immunity. Here, we review the recent findings that have significantly advanced our understanding of HCV and highlight the major challenges that remain.

TM6SF2 rs58542926 is not associated with steatosis and fibrosis in large cohort of patients with genotype 1 chronic hepatitis C

BACKGROUND & AIMS

We tested the putative association of the rs58542926 variant of TM6SF2, a recently described genetic determinant of nonalcoholic fatty liver disease, with steatosis and fibrosis in genotype 1(G1) chronic hepatitis C(CHC) patients.

METHODS

A total of 694 consecutively biopsied Caucasian G1 CHC patients were genotyped for TM6SF2 rs58542926, IL28B rs12979860 and PNPLA3 rs738409. Steatosis was classified as absent (<5%), mild-moderate(5-29%) and severe(≥30%), Fibrosis was considered severe if=F3-F4.

RESULTS

Carriers of TM6SF2 rs58542926 (6.3% of patients) exhibited lower serum levels of cholesterol (P = 0.04) and triglycerides (P = 0.01), but a similar distribution of steatosis severity (P = 0.63), compared to noncarriers. Prevalence and severity of steatosis were reduced in IL28B C allele carriers (P = 0.005) and elevated in PNPLA3 G allele carriers (P < 0.001). After adjustment for age, gender, body mass index and homoeostasis model assessment score, steatosis severity was independently associated with IL28B rs12979860 (odds ratio [OR] 0.69, 95% confidence interval [CI] 0.55-0.86, P = 0.001) and PNPLA3 rs738409 (OR 1.84, 95% CI 1.46-2.83, P < 0.001), but not TM6SF2 rs58542926 (OR 1.48, 95% CI 0.82-2.69, P = 0.19). Variants of TM6SF2 (30.9% vs. 25%, P = 0.40), IL28B and PNPLA3 were not directly associated with fibrosis severity, although variants of IL28B and PNPLA3 promoted steatosis (OR 1.36, 95% CI 1.06-1.75, P = 0.01) that in turn is associated with severe fibrosis.

CONCLUSIONS

In G1 CHC patients, TM6SF2 rs58542926 does not affect the histological severity of liver damage. However, IL28B rs12979860 and PNPLA3 rs738409 modify steatosis.

[Chronic hepatitis C in Russia: current challenges and prospects]

This paper evaluates the impact of different medical care strategies for chronic hepatitis C patients in relation to its prevalence, frequency of adverse outcomes and mortality rate.

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.

Antiviral Therapy

Antiviral therapy is one of the most exciting aspects of virology, since it has successfully employed basic science to generate very effective treatments for serious viral infections. Table 1 lists selected examples of those human viral diseases for which there are established antiviral drugs. Therapy for human immunodeficiency virus (HIV) infection has demonstrated that the potential impact antivirals can have on a lethal, chronic infection with lifesaving therapy administered to more than 12 million individuals by 2015. This dramatic advance is about to be recapitulated for the treatment of hepatitis C virus (HCV) infection. The development of new antiviral drugs is very much a work in progress, with active drug discovery programs for filoviruses, coronaviruses, dengue, and others.

Hepatitis C genotype 4: The past, present, and future

Hepatitis C virus (HCV) genotype (GT) 4 represents 12%-15% (15-18 million) of total global HCV infection. It is prevalent in Northern and Equatorial Africa and the Middle East, and is also present in some countries in Europe. GT-4 (and subtype 4a in particular) dominates the HCV epidemic in Egypt. In underdeveloped countries, risk factors associated with HCV infection may be due to unsafe medical practices or other factors such as familial transmission, mother's HCV status, or illiteracy. HCV prevention and control programs should include health education, increased community awareness towards the disease, controlling infection distribution in health-care centers, proper sterilization of medical and dental instruments, and ensuring safe supply of blood and blood-products. Response rates to a 48-wk combined pegylated-interferon (PEG-IFN) and ribavirin (RBV) treatment range from 40%-69%, and HCV-GT-4 has been considered better than GT-1 but worse than GT-2 and GT-3 in treatment with PEG-IFN/RBV. However, with the introduction of the HCV-GT-1 effective protease inhibitors boceprevir and telaprevir in 2011, HCV-GT-4 became the "most difficult (GT) to treat". Recently, the direct-acting antivirals (DAAs) with pan- genotypic activities simeprevir, sofosbuvir, and daclatasvir have been recommended in triple regimens with PEG-IFN/RBV for the treatment of HCV-GT-4. An IFN-free regimen will be available for treatment of all genotypes of HCV in the near future. To date, several DAAs have been developed and are currently being evaluated in various combinations in clinical trials. As new regimens and new agents are being approved by the Food and Drug Administration, we can expect the guidelines for HCV treatment to be changed. The availability of shorter, simpler, and more tolerable treatment regimens can reduce the morbidity and mortality associated with HCV infection. With such a large number of therapeutic agents available, we can end up with a range of choices that we can select from to treat patients.

Clinical impact of alcohol-related cirrhosis in the next decade: estimates based on current epidemiological trends in the United States

BACKGROUND

Identifying changes in the epidemiology of liver disease is critical for establishing healthcare priorities and allocating resources to develop therapies. The projected contribution of different etiologies toward development of cirrhosis in the United States was estimated based on current publications on epidemiological data and advances in therapy. Given the heterogeneity of published reports and the different perceptions that are not always reconcilable, a critical overview rather than a formal meta-analysis of the existing data and projections for the next decade was performed.

METHODS

Data from the World Health Organization Global Status Report on Alcohol and Health of 2014, Scientific Registry of Transplant Recipients from 1999 to 2012, National Institute on Alcohol Abuse and Alcoholism, and the Centers for Disease Control and Prevention were inquired to determine future changes in the epidemiology of liver disease.

RESULTS

Alcohol consumption has increased over the past 60 years. In 2010, transplant-related costs for liver recipients were the highest for hepatitis C (~$124 million) followed by alcohol-related cirrhosis (~$86 million). We anticipate a significant reduction in incidence cirrhosis due to causes other than alcohol because of the availability of high efficiency antiviral agents for hepatitis C, universal and effective vaccination for hepatitis B, relative stabilization of the obesity trends in the United States, and novel, potentially effective therapies for nonalcoholic steatohepatitis. The proportion of alcohol-related liver disease is therefore likely to increase in both the population as a whole and the liver transplant wait list.

CONCLUSIONS

Alcohol-related cirrhosis and alcohol-related liver disorders will be the major cause of liver disease in the coming decades. There is an urgent need to allocate resources aimed toward understanding the pathogenesis of the disease and its complications so that effective therapies can be developed.

Overtreating versus undertreating: what is the optimized treatment duration in HCV?

The prospect of global eradication of HCV is foreseeable with IFN-free direct-acting antiviral (DAA) combination therapies. DAAs boasts 12-week sustained virologic response rates (SVR)-12 that exceed 90%. Despite the 90% and above SVR-12 achieved with DAAs, challenges regarding how to select the optimal treatment regimen remain. One of the biggest challenges is how to actualize the benefits without under- or over-treating HCV-infected individuals. Truncated therapy should be less expensive, but may unnecessarily increase the risk of relapse. The risk of overtreatment includes costs and exposure to adverse effects of the medication. Here, we provide our perspective on selection of the optimized treatment duration in HCV to minimize either over- or under-treating HCV infection.

New treatment strategies for hepatitis C infection

Hepatitis C infection can lead to cirrhosis and hepatocellular carcinoma and it is an important cause of mortality and morbidity. Achieving a sustained virological response has been the major aim for decades. Interferon treatment was the primarily developed therapy against the infection. Addition of the guanosine analog ribavirin to stop viral RNA synthesis increased the response rates as well as the adverse effects of the treatment. The increasing demands for alternative regimens led to the development of direct-acting antivirals (DAAs). The approval of sofosbuvir and simeprevir signaled a new era of antiviral treatment for hepatitis C infection. Although the majority of studies have been performed with DAAs in combination with interferon and resulted in a decrease in treatment duration and increase in response rates, the response rates achieved with interferon-free regimens provided hope for patients ineligible for therapy with interferon. Most DAA studies are in phase II leading to phase III. In the near future more DAAs are expected to be approved. The main disadvantage of the therapy remains the cost of the drugs. Here, we focus on new treatment strategies for hepatitis C infection as well as agents targeting hepatitis C virus replication that are in clinical development.

NKp30 isoforms in patients with chronic hepatitis C virus infection

Natural killer (NK) cells play an important role in virus infection, their action being regulated by several activating and inhibitory receptors. The NKp30 activating receptor and its isoforms have recently emerged as important determinants of efficient NK cell responses. We determined the relative proportions of NKp30 isoforms in patients with chronic hepatitis C virus (HCV) infection and healthy donors (HD). NK cell function (degranulation and cytokine production) and correlations with clinical parameters were assessed following unsupervised hierarchical clustering of patients according to isoform expression. NKp30 receptor expression on NK cells and all isoforms were reduced in HCV-infected patients. Patients were clustered into two groups: the HCV-1 group had similar isoform expression to the HD group, whereas the HCV-2 group had lower expression. The latter showed a better functional activity, and a higher proportion of the activating a isoform and of the NKp30 isoform a/c ratio compared with the HCV-1 cluster. There was a positive correlation between the activating a isoform and liver stiffness and an inverse relationship between the immunosuppressive c isoform and the fibrosis 4 score, suggesting a potentially important role of NKp30 isoforms in influencing liver damage and ensuing fibrosis.

Systematic review with meta-analysis: comparison between therapeutic regimens for paediatric chronic hepatitis C

BACKGROUND

To decide when and how to treat children with chronic hepatitis C is an ongoing debate.

AIM

To compare the outcomes of therapy for children with chronic hepatitis C.

METHODS

An electronic database assessed clinical trials with sustained virological response rates specified by genotype. The data were extracted according to the therapeutic regimen; interferonα±ribavirin and pegylated interferonα±ribavirin.

RESULTS

The search sourced 23 peer-reviewed articles which enrolled 934 cases, aged 2-19 years. Sustained virological response rates were significantly higher with the addition of ribavirin to either interferonα or pegylated nterferonα vs. their monotherapies for genotypes 1,2&3 with crude and weighted estimates. The weighted estimate indicated higher sustained virological response rates for those treated with pegylated interferonα+ribavirin vs. interferonα+ribavirin for genotype 1 (50% vs. 40%) and genotypes 2&3 (90% vs. 84%), (odds ratio 1.5, 95% confidence interval 1.2-1.8, and 1.8, 1.2-2.9 respectively). Cases with genotype 4 treated with pegylated interferonα+ribavirin had a lower sustained virological response (41%) vs. genotype 1 (1.4, 1.2-1.8), and vs. genotypes 2&3 (13.5, 10.3-17.9). Some adverse events were significantly higher among cases treated with pegylated interferonα+ribavirin vs. interferonα+ribavirin.

CONCLUSIONS

Despite the superiority of pegylated interferonα+ribavirin to interferonα+ribavirin for the treatment of chronic hepatitis C among children, the significant higher adverse events along with the modest outcome for genotypes 1&4 render that regimen a suboptimal therapy. These data indicated the need for the future comparison with clinical trials of direct anti-viral drugs for children with chronic hepatitis C.

Outcomes, costs and cost-effectiveness of treating hepatitis C with direct acting antivirals

Hepatitis C is a global public health burden. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. Introduction of different direct acting antivirals targeting the hepatitis C proteins has considerably increased rates of sustained viral response. First active substances introduced in 2011 were NS3/4A protease inhibitors telaprevir and boceprevir. In 2013/2014 the second generation of direct acting antivirals sofosbuvir, simeprevir, daclatasvir, ledipasvir and 3D therapy containing ombitasvir/paritaprevir/ritonavir and dasabuvir followed. This review focuses on treatment outcomes and costs of introduced direct acting antivirals. We provide an overview on SVR-rates in clinical trials and clinical practice, treatment costs in different countries as well as results of cost-effectiveness analyses for different treatment strategies.