Antiviral therapy with nucleotide polymerase inhibitors for chronic hepatitis C

Regulation of NS5B Polymerase Activity of Hepatitis C Virus by Target Specific Phytotherapeutics: An In-Silico Molecular Dynamics Approach

Chronic hepatitis caused by the hepatitis C virus (HCV) is closely linked with the advancement of liver disease. The research hypothesis suggests that the NS5B enzyme (non-structural 5B protein) of HCV plays a pivotal role in facilitating viral replication within host cells. Hence, the objective of the present investigation is to identify the binding interactions between the structurally diverse phytotherapeutics and those of the catalytic residue of the target NS5B polymerase protein. Results of our docking simulations reveal that compounds such as arjunolic acid, sesamin, arjungenin, astragalin, piperic acid, piperidine, piperine, acalyphin, adhatodine, amyrin, anisotine, apigenin, cuminaldehyde, and curcumin exhibit a maximum of three interactions with the catalytic residues (Asp 220, Asp 318, and Asp 319) present on the Hepatitis C virus NS5B polymerase of HCV. Molecular dynamic simulation, particularly focusing on the best binding lead compound, arjunolic acid (-8.78 kcal/mol), was further extensively analyzed using RMSD, RMSF, Rg, and SASA techniques. The results of the MD simulation confirm that the NS5B-arjunolic acid complex becomes increasingly stable from 20 to 100 ns. The orientation of both arjunolic acid and sofosbuvir triphosphate (standard) within the active site was investigated through DCCM, PCA, and FEL analysis, indicating highly stable interactions of the lead arjunolic acid with the catalytic region of the NS5B enzyme. The findings of our current investigation suggest that bioactive therapeutics like arjunolic acid could serve as promising candidates for limiting the NS5B polymerase activity of the hepatitis C virus, offering hope for the future of HCV treatment.

Cardiac effects of direct anti-viral treatment in type II diabetic patients with hepatitis C infection

BACKGROUND

The link between diabetes mellitus and chronic hepatitis C infection remains well established. It is estimated that up to one third of chronic hepatitis C patients have type II diabetes mellitus. Hepatitis C virus infection is one of the main global health burdens. Sofosbuvir and Daclatasvir are used as effective antiviral inhibitors of hepatitis C virus. The cardiovascular effects of those drugs are not well studied. We used electrocardiography and echocardiography with global longitudinal strain assessment by speckle tracking to detect their effect on cardiac function.

METHODS AND RESULTS

One hundred diabetic patients with hepatitis C infection were included in the study. Abdominal ultrasound and laboratory work up were carried out for all participants. Left ventricular systolic and diastolic function were assessed by 2D-echocardiography and global longitudinal strain, before and 3 months after treatment. Results showed significant decrease in global longitudinal strain 3 months after therapy (-21 ± 4 vs. -18 ± 7; P < 0.001) but other echocardiographic findings showed no significant changes.

CONCLUSIONS

Sofosbuvir and Daclatasvir were associated with early left ventricular systolic dysfunction as assessed by global longitudinal strain in diabetic patients. More deterioration in left ventricular systolic function was detected among those with Child-Pough class B. Further long-term follow-up may be required.

Discovery of New Zika Protease and Polymerase Inhibitors through the Open Science Collaboration Project OpenZika

The Zika virus (ZIKV) is a neurotropic arbovirus considered a global threat to public health. Although there have been several efforts in drug discovery projects for ZIKV in recent years, there are still no antiviral drugs approved to date. Here, we describe the results of a global collaborative crowdsourced open science project, the OpenZika project, from IBM's World Community Grid (WCG), which integrates different computational and experimental strategies for advancing a drug candidate for ZIKV. Initially, molecular docking protocols were developed to identify potential inhibitors of ZIKV NS5 RNA-dependent RNA polymerase (NS5 RdRp), NS3 protease (NS2B-NS3pro), and NS3 helicase (NS3hel). Then, a machine learning (ML) model was built to distinguish active vs inactive compounds for the cytoprotective effect against ZIKV infection. We performed three independent target-based virtual screening campaigns (NS5 RdRp, NS2B-NS3pro, and NS3hel), followed by predictions by the ML model and other filters, and prioritized a total of 61 compounds for further testing in enzymatic and phenotypic assays. This yielded five non-nucleoside compounds which showed inhibitory activity against ZIKV NS5 RdRp in enzymatic assays (IC50 range from 0.61 to 17 μM). Two compounds thermally destabilized NS3hel and showed binding affinity in the micromolar range (Kd range from 9 to 35 μM). Moreover, the compounds LabMol-301 inhibited both NS5 RdRp and NS2B-NS3pro (IC50 of 0.8 and 7.4 μM, respectively) and LabMol-212 thermally destabilized the ZIKV NS3hel (Kd of 35 μM). Both also protected cells from death induced by ZIKV infection in in vitro cell-based assays. However, while eight compounds (including LabMol-301 and LabMol-212) showed a cytoprotective effect and prevented ZIKV-induced cell death, agreeing with our ML model for prediction of this cytoprotective effect, no compound showed a direct antiviral effect against ZIKV. Thus, the new scaffolds discovered here are promising hits for future structural optimization and for advancing the discovery of further drug candidates for ZIKV. Furthermore, this work has demonstrated the importance of the integration of computational and experimental approaches, as well as the potential of large-scale collaborative networks to advance drug discovery projects for neglected diseases and emerging viruses, despite the lack of available direct antiviral activity and cytoprotective effect data, that reflects on the assertiveness of the computational predictions. The importance of these efforts rests with the need to be prepared for future viral epidemic and pandemic outbreaks.

Hepatitis C virus infection and anaesthesia practice: A narrative review

This paper reviews the natural and treated history of hepatitis C virus infection, the interactions between current therapies and anaesthesia medications, and the implications of occupational exposure and infection to anaesthetists in light of significant changes in treatment. In the past decade, the introduction of new direct acting antiviral medications has seen high cure rates with a sustained viral response across all virus genotypes. These medications are well tolerated with minimal side-effects. Should a patient on these medications require anaesthesia, there are few clinically significant interactions with commonly used anaesthesia medications, and minimal perioperative investigations are required, although delaying elective surgery until after the completion of treatment regimens should be considered to maximise treatment success. As anaesthetists may practise exposure-prone procedures, regular screening for hepatitis C virus infection remains recommended to enable both patient protection and treatment of the anaesthetist prior to the development of any long-term complications of hepatitis C virus infection. Similarly, early diagnosis and treatment of occupationally acquired hepatitis C virus infection after body fluid exposure is associated with high cure rates with minimal risk of long-term liver damage. Although hepatitis C virus infection remains a significant public health issue in Australia and New Zealand, improvements in outcomes as a result of new treatment regimens have allowed the World Health Organization to target the elimination of hepatitis C virus infection as a public health threat by 2030, and public health strategies are being implemented to achieve this goal.

Synthesis and evaluation of 2'-dihalo ribonucleotide prodrugs with activity against hepatitis C virus

Hepatitis C virus (HCV) nucleoside inhibitors have been a key focus of nearly 2 decades of HCV drug research due to a high barrier to drug resistance and pan-genotypic activity profile provided by molecules in this drug class. Our investigations focused on several potent 2'-halogenated uridine-based HCV polymerase inhibitors, resulting in the discovery of novel 2'-deoxy-2'-dihalo-uridine analogs that are potent inhibitors in replicon assays for all genotypes. Further studies to improve in vivo performance of these nucleoside inhibitors identified aminoisobutyric acid ethyl ester (AIBEE) phosphoramidate prodrugs 18a and 18c, which provide high levels of the active triphosphate in dog liver. AIBEE prodrug 18c was compared with sofosbuvir (1) by co-dosing both compounds by oral administration in dog (5 mg/kg each) and measuring liver concentrations of the active triphosphate metabolite at both 4 and 24 h post dosing. In this study, 18c provided liver triphosphate concentrations that were 6-fold higher than sofosbuvir (1) at both biopsy time points, suggesting that 18c could be a highly effective agent for treating HCV infected patients in the clinic.

Management of HCV patients in cases of direct-acting antiviral failure

Introduction: Over 70 million people are infected with hepatitis C virus (HCV), increasing the risk of cirrhosis and hepatocellular carcinoma. Areas covered: Since the approval of the first interferon-free direct-acting antiviral (DAA) therapy in 2011, a number of DAAs have been approved, and HCV is now considered curable. Until recently, however, there were no clear guidelines on how to re-treat patients who fail DAA therapy. Current protease inhibitors (PIs) are generally unaffected by earlier resistance-associated variants (RAVs), but many NS5A inhibitors continue to have overlapping resistance profiles, and NS5A RAVs can persist even in the absence of DAAs. Expert opinion: Fortunately, RAVs affecting NS5B polymerase inhibitors are rare, making sofosbuvir a safe choice as the backbone of re-treatment therapies. Recent re-treatment guidelines that take into account genotype, fibrosis, treatment history, and RAV suggest that >90% of patients with prior treatment failures can be successfully re-treated with sofosbuvir/velpatasvir, sofosbuvir/velpatasvir/voxilaprevir or glecaprevir/pibrentasvir.

Safety and Effectiveness of Ledipasvir and Sofosbuvir, With or Without Ribavirin, in Treatment-Experienced Patients With Genotype 1 Hepatitis C Virus Infection and Cirrhosis

BACKGROUND & AIMS

We aimed to evaluate the safety and effectiveness of 12 or 24 weeks treatment with ledipasvir and sofosbuvir, with or without ribavirin, in treatment-experienced patients with hepatitis C virus (HCV) genotype 1 infection and cirrhosis in routine clinical practice. Patients were followed in a multi-center, prospective, observational cohort study (HCV-TARGET).

METHODS

We collected data from 667 treatment-experienced adults with chronic genotype 1 HCV infection who began treatment with ledipasvir and sofosbuvir, with or without ribavirin, from 2011 through September 15, 2016, according to the regional standards of care, at academic (n = 39) and community (n = 18) centers in the United States, Canada, Germany, and Israel. Information was collected from medical records and abstracted into a unique centralized data core. Independent monitors systematically reviewed data entries for completeness and accuracy. Demographic, clinical, adverse event, and virologic data were collected every 12 weeks during treatment and during the follow-up period. The primary efficacy endpoint was sustained virologic response, defined as a level of HCV RNA below the lower limit of quantification or undetectable at a minimum 64 days after the end of treatment (SVR12). The per-protocol population (n = 610) was restricted to patients who completed 12 or 24 weeks of treatment (±2 weeks) and had final virologic outcomes available.

RESULTS

The per-protocol analysis revealed that 579 patients (93.8%) achieved an SVR12, including 50/51 patients who received ledipasvir and sofosbuvir for 12 weeks (98%), 384/408 patients who received ledipasvir and sofosbuvir for 24 weeks (94.1%), 68/70 patients who received ledipasvir and sofosbuvir with ribavirin for 12 weeks (97.1%), and 57/60 patients who received ledipasvir and sofosbuvir with ribavirin for 24 weeks (95%). On multivariate analysis, neither treatment duration nor the addition of ribavirin was associated with SVR12. Compensated cirrhosis (odds ratio [OR] compared to decompensated cirrhosis, 2.41; 95% CI, 1.16-5.02), albumin ≥ 3.5 g/dL (OR, 3.15; 95% CI 1.46-6.80), or total bilirubin ≤ 1.2 mg/dL (OR 3.34; 95% CI, 1.59-7.00) were associated with SVR12.

CONCLUSIONS

In an analysis of safety and effectiveness data from the HCV-TARGET study, we found treatment with ledipasvir and sofosbuvir, with or without ribavirin, to be effective and well tolerated by treatment-experienced patients with genotype 1 HCV infection and compensated cirrhosis. There were no significant differences in rate of SVR12 among patients treated with ledipasvir and sofosbuvir for 12 or 24 weeks, with or without ribavirin. Patients with decompensated cirrhosis appear to benefit from the addition of ribavirin or extension of ledipasvir and sofosbuvir treatment to 24 weeks. ClinicalTrials.gov no: NCT10474811.

Simple In Vitro Assay To Evaluate the Incorporation Efficiency of Ribonucleotide Analog 5'-Triphosphates into RNA by Human Mitochondrial DNA-Dependent RNA Polymerase

There is a growing body of evidence suggesting that some ribonucleoside/ribonucleotide analogs may be incorporated into mitochondrial RNA by human mitochondrial DNA-dependent RNA polymerase (POLRMT) and disrupt mitochondrial RNA synthesis. An assessment of the incorporation efficiency of a ribonucleotide analog 5′-triphosphate by POLRMT may be used to evaluate the potential mitochondrial toxicity of the analog early in the development process. In this report, we provide a simple method to prepare active recombinant POLRMT. A robust in vitro nonradioactive primer extension assay was developed to assay the incorporation efficiency of ribonucleotide analog 5′-triphosphates. Our results show that many ribonucleotide analogs, including some antiviral compounds currently in various preclinical or clinical development stages, can be incorporated into newly synthesized RNA by POLRMT and that the incorporation of some of them can lead to chain termination. The discrimination (D) values of ribonucleotide analog 5′-triphosphates over those of natural ribonucleotide triphosphates (rNTPs) were measured to evaluate the incorporation efficiency of the ribonucleotide analog 5′-triphosphates by POLRMT. The discrimination values of natural rNTPs under the condition of misincorporation by POLRMT were used as a reference to evaluate the potential mitochondrial toxicity of ribonucleotide analogs. We propose the following criteria for the potential mitochondrial toxicity of ribonucleotide analogs based on D values: a safe compound has a D value of >10⁵; a potentially toxic compound has a D value of >10⁴ but <10⁵; and a toxic compound has a D value of <10⁴. This report provides a simple screening method that should assist investigators in designing ribonucleoside-based drugs having lower mitochondrial toxicity.

Effectiveness and safety of sofosbuvir plus ribavirin for the treatment of HCV genotype 2 infection: results of the real-world, clinical practice HCV-TARGET study

OBJECTIVE

Due to a high efficacy in clinical trials, sofosbuvir (SOF) and ribavirin (RBV) for 12 or 16 weeks is recommended for treatment of patients with HCV genotype (GT) 2 infection. We investigated safety and effectiveness of these regimens for GT2 in HCV-TARGET participants.

DESIGN

HCV-TARGET, an international, prospective observational study evaluates clinical practice data on novel antiviral therapies at 44 academic and 17 community medical centres in North America and Europe. Clinical data were centrally abstracted from medical records. Selection of treatment regimen and duration was the investigator's choice. The primary efficacy outcome was sustained virological response 12 weeks after therapy (SVR12).

RESULTS

Between December 2013 and April 2015, 321 patients completed 12 weeks (n=283) or 16 weeks (n=38) of treatment with SOF and RBV. Prior treatment experience and cirrhosis was more frequent among patients in the 16-week regimen compared with 12 weeks (52.6% vs 27.6% and 63.2% vs 21.9%, respectively). Overall, SVR12 was 88.2%. The SVR12 in patients without cirrhosis was 91.0% and 92.9% for 12 or 16 weeks of therapy, respectively. In patients with cirrhosis treated for 12 or 16 weeks, SVR12 was 79.0% and 83%. In the multivariate analysis, liver cirrhosis, lower serum albumin and RBV dose at baseline were significantly associated with SVR12. Common adverse events (AEs) included fatigue, anaemia, nausea, headache, insomnia, rash and flu-like symptoms. Discontinuation due to AEs occurred in 2.8%.

CONCLUSIONS

In this clinical practice setting, SOF and RBV was safe and effective for treatment of patients with HCV GT2 infection.

TRIAL REGISTRATION NUMBER

NCT01474811.

(-)-Epigallocatechin-3-gallate enhances poly I:C-induced interferon-λ1 production and inhibits hepatitis C virus replication in hepatocytes

AIM

To investigate the effect of (-)-epigallocatechin-3-gallate (EGCG) on polyinosinic-polycytidylic acid (poly I:C)-triggered intracellular innate immunity against hepatitis C virus (HCV) in hepatocytes.

METHODS

A cell culture model of HCV infection was generated by infecting a hepatoma cell line, Huh7, with HCV JFH-1 strain (JFH-1-Huh7). Poly I:C with a high molecular weight and EGCG were used to stimulate the JFH-1-Huh7 cells. Real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of intracellular mRNAs and of intracellular and extracellular HCV RNA. Enzyme-linked immunosorbent assay was used to evaluate the interferon (IFN)-λ1 protein level in the cell culture supernatant. Immunostaining was used to examine HCV core protein expression in Huh7 cells.

RESULTS

Our recent study showed that HCV replication could impair poly I:C-triggered intracellular innate immune responses in hepatocytes. In the current study, we showed that EGCG treatment significantly increased the poly I:C-induced expression of Toll-like receptor 3 (TLR3), retinoic acid-inducible gene I, and IFN-λ1 in JFH-1-Huh7 cells. In addition, supplementation with EGCG increased the poly I:C-mediated antiviral activity in JFH-1-Huh7 cells at the intracellular and extracellular HCV RNA and protein levels. Further investigation of the mechanisms showed that EGCG treatment significantly enhanced the poly I:C-induced expression of IFN-regulatory factor 9 and several antiviral IFN-stimulated genes, including ISG15, ISG56, myxovirus resistance A, and 2'-5'-oligoadenylate synthetase 1, which encode the key antiviral elements in the IFN signaling pathway.

CONCLUSION

Our observations provide experimental evidence that EGCG has the ability to enhance poly I:C-induced intracellular antiviral innate immunity against HCV replication in hepatocytes.

Are the testing needs of key European populations affected by hepatitis B and hepatitis C being addressed? A scoping review of testing studies in Europe

AIM

To investigate whether or not key populations affected by hepatitis B and hepatitis C are being tested sufficiently for these diseases throughout the European region.

METHODS

We searched MEDLINE and EMBASE for studies on HBV and HCV testing in the 53 Member States of the World Health Organization European Region following PRISMA criteria.

RESULTS

136 English-language studies from 24 countries published between January 2007 and June 2013 were found. Most studies took place in 6 countries: France, Germany, Italy, the Netherlands, Turkey, and the United Kingdom. 37 studies (27%) addressed HBV, 46 (34%) HCV, and 53 (39%) both diseases. The largest categories of study populations were people who use drugs (18%) and health care patient populations (17%). Far fewer studies focused on migrants, prison inmates, or men who have sex with men.

CONCLUSIONS

The overall evidence base on HBV and HCV testing has considerable gaps in terms of the countries and populations represented and validity of testing uptake data. More research is needed throughout Europe to guide efforts to provide testing to certain key populations.

Second generation direct-acting antivirals - Do we expect major improvements?

The rapid progress in the development of direct-acting antiviral agents for hepatitis C has allowed the vast majority of patients to receive all oral therapy that will eliminate their virus. The success of the new regimens has led many to question the need for further developments in this field. Major improvements in drugs for hepatitis C are unlikely but we predict incremental improvements in the next few years. We hope that the next generation of drugs will address the unresolved issues for patients with genotype 3 infection where current treatments are still not entirely satisfactory and we anticipate improvements in the management of patients with renal failure. Shorter duration treatments, perhaps with novel modes of action, may allow simplified 'one-dose' treatments that will greatly expand our ability to treat patients who have difficulty accessing current services and we anticipate that the clinical community will better define the patients with advanced disease who will benefit from therapy prior to liver transplantation.

Systematic review: current concepts and challenges for the direct-acting antiviral era in hepatitis C cirrhosis

BACKGROUND

The burden of HCV cirrhosis is high and projected to increase significantly over the next decade. While interferon therapy is problematic in HCV cirrhosis, the era of direct-acting anti-viral (DAA) therapy provides effective treatment for patients with cirrhosis.

AIM

To systematically review the results of DAA therapy to date in patients with HCV cirrhosis, and highlight the ongoing challenges for DAA therapy in this population.

METHODS

A structured Medline search was conducted to obtain phase II and III HCV trials in patients with cirrhosis. Citations from review articles were cross-referenced and conference abstracts from EASL and AASLD liver meetings for the preceding 3 years were reviewed manually. Keywords used included hepatitis C, cirrhosis and the DAA's: sofosbuvir, ledipasvir, velpatasvir, grazoprevir, elbasvir, daclatasvir, beclabuvir, asunaprevir, simeprevir, paritaprevir, ombitasvir and dasabuvir.

RESULTS

Successful direct-acting anti-viral treatment is now possible in patients with HCV-related cirrhosis including those with liver decompensation with several regimens now offering sustained virological response (SVR) of 90-95%. Overall success rates in GT1 cirrhosis are excellent while GT3-infected patients with cirrhosis remain hard to cure. The pangenotypic combination of sofosbuvir and velpatasvir holds promise for GT3 cirrhosis achieving SVR of ~90%.

CONCLUSIONS

Potent DAA therapies provide much needed, safe and highly effective treatment options for persons with HCV cirrhosis including those previously deemed unsuitable for treatment. Combination therapy with two or more classes of drug is essential to achieve high efficacy and minimise viral resistance, with the role of ribavirin still under evaluation. However, several challenges remain including the hard-to-cure groups of GT3 cirrhosis and direct-acting anti-viral failures, and managing drug-drug interactions.

Response to Pegylated Interferon Plus Ribavirin in Patients with Hepatitis C Virus Genotype 6a Infection from Guangdong and Guangxi Province of China

Aim. Our aim is to survey the treatment effect of PEG-IFN plus ribavirin in patients infected with HCV genotype 6a in Guangdong and Guangxi province of China and investigate best course of antiviral treatment for patients with HCV-6a infection. Methods. 515 eligible patients received subcutaneous 180 μg PEG-IFNα-2a or 1.5 μg/kg PEG-IFNα-2b once weekly plus oral ribavirin. Primary outcome was SVR by intention-to-treat analysis. Secondary outcome was RVR, cEVR, ETR, and relapse rate. Results. SVR in patients with HCV-6a infection treated for 48 weeks was comparable to that in patients with HCV-2/3 infection (80.9% versus 82.5%, p = 0.812) and higher than that in patients with HCV-1b infection (80.9% versus 67.2%, p = 0.014). ETR (98.9% versus 90.6%, p = 0.016), virological response at month 3 of end-of- treatment (88.8% versus 76.6%, p = 0.044), SVR (80.9% versus 65.6%, p = 0.032), and virological response at month 12 of end-of-treatment (76.4% versus 60.9%, p = 0.04) in patients with HCV-6a infection treated for 48 weeks were higher than those in patients with HCV-6a infection treated for 24 weeks. Conclusion. SVR in patients with HCV-6a treated for 48 weeks was comparable to that in patients with HCV-2/3 infection and higher than that in patients with HCV-1b infection; patients with HCV-6a infection treated for 48 weeks had a superior treatment response than patients treated for 24 weeks.

(-)-Epigallocatechin-3-Gallate Enhances Hepatitis C Virus Double-Stranded RNA Intermediates-Triggered Innate Immune Responses in Hepatocytes

(-)-Epigallocatechin-3-gallate (EGCG), a major polyphenol component of green tea, has recently been identified as an inhibitor of hepatitis C virus (HCV) entry. Here, we examined whether EGCG can enhance hepatocyte-mediated intracellular innate immunity against HCV. HCV dsRNAs (Core, E1-P7, NS-3'NTR and NS5A) induced interferon-λ1 (IFN-λ1) expression in human hepatocytes. These HCV dsRNAs also induced the expression of Toll-like receptor 3 (TLR3), retinoic acid-inducible gene I (RIG-I) and several antiviral IFN-stimulated genes (ISGs) expression. Although EGCG treatment of hepatocytes alone had little effect on TLR3 and RIG-I signaling pathways, EGCG significantly enhanced HCV dsRNAs-induced the expression of IFN-λ1, TLR3, RIG-I and antiviral ISGs in hepatocytes. Furthermore, treatment of HCV-infected hepatocytes with EGCG and HCV dsRNAs inhibited viral replication. Given that EGCG has the ability to enhance HCV dsRNAs-induced intracellular antiviral innate immunity against HCV, suggesting the potential application of EGCG as a new anti-HCV agent for HCV therapy.

Treatment of hepatitis C in patients with cirrhosis: remaining challenges for direct-acting antiviral therapy

Chronic hepatitis C virus (HCV) infection is a major global health concern, resulting in significant morbidity and mortality. Treatment using interferon-based therapy in patients with HCV-related cirrhosis has been problematic due to toxicity and poor tolerability. Furthermore, interferon therapy is contraindicated in those with advanced cirrhosis or clinical decompensation, who are arguably the group most in need of viral eradication. The arrival of the direct-acting antiviral (DAA) era has resulted in the development of well-tolerated and highly effective interferon-free drug regimens that promise to dramatically change the therapeutic landscape for those with advanced HCV-related liver disease, including patients with clinical decompensation or pre-liver transplantation. Many successful DAA combinations have emerged; however, a number of challenges remain including the establishment of the optimal treatment duration, the ideal combination of drug classes and determining the role of ribavirin. Moreover, the identification of treatment-experienced patients with genotype 3 HCV cirrhosis as a difficult-to-treat subgroup is a significant impediment to overcome, as are those who have failed prior DAA therapy. Despite these barriers, the ongoing prolific development of safe and effective DAA combinations indicates the future is optimistic for the ultimate goal of HCV eradication.

Comparative effectiveness and safety study of triple therapy with simeprevir or telaprevir for non-cirrhotic patients with chronic hepatitis C virus genotype 1b infection

BACKGROUND AND AIM

The addition of hepatitis C virus (HCV) NS3/4A protease inhibitors to pegylated-interferon alpha (PEG-IFNα) and ribavirin (triple therapy) has greatly improved treatment outcome. The aim of this study was to compare the effectiveness and safety of simeprevir-based or telaprevir-based triple therapy for non-cirrhotic patients in real-world clinical practice.

METHODS

This multicenter study consisted of 835 consecutive Japanese HCV genotype 1b patients treated in a clinical setting, 716 of whom were enrolled (simeprevir = 256 and telaprevir = 460). Logistic regression was carried out after propensity score matching to assess the sustained virological response at week 12 after the end of treatment (SVR12).

RESULTS

In the propensity-matched cohort (253 matched pairs), the SVR12 rates of the patients who underwent simeprevir-based or telaprevir-based triple therapy were 85.0% and 84.2%, respectively, by intention-to-treat analysis. Prior treatment response to PEG-IFNα/ribavirin and IL28B genotype was independently associated with SVR12 in both groups. No significant differences in the SVR12 rates stratified by prior treatment response to PEG-IFNα/ribavirin were found between the simeprevir (treatment-naïve 89.1%, prior relapse 94.3%, prior partial response 65.0%, and prior null response 33.3%) and telaprevir (treatment-naïve 87.8%, prior relapse 90.1%, prior partial response 68.4%, and prior null response 50.0%) groups. The incidence of adverse effects, such as anemia, severe rash, and the elevation of serum creatinine, was markedly higher in the telaprevir group.

CONCLUSIONS

Considering the effectiveness and safety, simeprevir-based triple therapy will continue to be a useful treatment option in Japan for treatment-naïve or prior relapse patients with a favorable IL28B genotype.

Inflammation-adapted liver stiffness values for improved fibrosis staging in patients with hepatitis C virus and alcoholic liver disease

BACKGROUND & AIMS

It is well known that inflammation increases liver stiffness (LS) in patients with chronic hepatitis C (HCV) and alcoholic liver disease (ALD) independent of fibrosis stage, but no inflammation-adapted cut-off values have been settled so far. An early identification of rapid fibrosers, however, is essential to decide whom to treat first with the novel but expensive antiviral drugs.

METHODS

Liver stiffness, biopsy-proven fibrosis stages F0-F4 (METAVIR or Kleiner score) and routine laboratory parameters were studied in 2068 patients with HCV (n = 1391) and ALD (n = 677).

RESULTS

Among the routine parameters for liver damage, AST correlated best with LS (HCV: r = 0.54, P < 0.0001 and ALD: r = 0.34, P < 0.0001). In the absence of elevated transaminases, cut-off values were almost identical between HCV and ALD for F1-2, F3 and F4 (HCV: 5.1, 9.0 and 11.9 kPa vs ALD: 4.9, 8.1 and 10.5 kPa). These cut-off values increased exponentially as a function of median AST level. The impact of AST on LS was higher in lobular-pronounced ALD as compared to portal tract-localized HCV. Most notably, Cohen's weighted Kappa displayed an improved agreement of the novel AST-dependent cut-off values with histological fibrosis stage both for HCV (0.68 vs 0.65) and ALD (0.80 vs 0.76).

CONCLUSIONS

The novel AST-adapted cut-off values improve non-invasive fibrosis staging in HCV and ALD and may be also applied to other liver diseases. Especially in HCV, they could help to decide whom to treat first with the novel but expensive antiviral drugs.

Capitalizing on knowledge of hepatitis C virus neutralizing epitopes for rational vaccine design

Hepatitis C virus infects nearly 3% of the world's population and is often referred as a silent epidemic. It is a leading cause of liver cirrhosis and hepatocellular carcinoma in endemic countries. Although antiviral drugs are now available, they are not readily accessible to marginalized social groups and developing nations that are disproportionally impacted by HCV. To stop the HCV pandemic, a vaccine is needed. Recent advances in HCV research have provided new opportunities for studying HCV neutralizing antibodies and their subsequent use for rational vaccine design. It is now recognized that neutralizing antibodies to conserved antigenic sites of the virus can cross-neutralize diverse HCV genotypes and protect against infection in vivo. Structural characterization of the neutralizing epitopes has provided valuable information for design of candidate immunogens.