Direct-acting antiviral agents for hepatitis C virus infection

Chronic Hepatitis C Virus Infection, Extrahepatic Disease and the Impact of New Direct-Acting Antivirals

Chronic hepatitis C virus infection is an important cause of liver cirrhosis, hepatocellular carcinoma and death. Furthermore, it is estimated that about 40-70% of patients develop non-hepatic alterations in the course of chronic infection. Such manifestations can be immune-related conditions, lymphoproliferative disorders and metabolic alterations with serious adverse events in the short and long term. The introduction of new Direct-Acting Antivirals has shown promising results, with current evidence indicating an improvement and remission of these conditions after a sustained virological response.

iAVPs-ResBi: Identifying antiviral peptides by using deep residual network and bidirectional gated recurrent unit

Human history is also the history of the fight against viral diseases. From the eradication of viruses to coexistence, advances in biomedicine have led to a more objective understanding of viruses and a corresponding increase in the tools and methods to combat them. More recently, antiviral peptides (AVPs) have been discovered, which due to their superior advantages, have achieved great impact as antiviral drugs. Therefore, it is very necessary to develop a prediction model to accurately identify AVPs. In this paper, we develop the iAVPs-ResBi model using k-spaced amino acid pairs (KSAAP), encoding based on grouped weight (EBGW), enhanced grouped amino acid composition (EGAAC) based on the N5C5 sequence, composition, transition and distribution (CTD) based on physicochemical properties for multi-feature extraction. Then we adopt bidirectional long short-term memory (BiLSTM) to fuse features for obtaining the most differentiated information from multiple original feature sets. Finally, the deep model is built by combining improved residual network and bidirectional gated recurrent unit (BiGRU) to perform classification. The results obtained are better than those of the existing methods, and the accuracies are 95.07, 98.07, 94.29 and 97.50% on the four datasets, which show that iAVPs-ResBi can be used as an effective tool for the identification of antiviral peptides. The datasets and codes are freely available at https://github.com/yunyunliang88/iAVPs-ResBi.

Old age as a risk factor for liver diseases: Modern therapeutic approaches

Recent scientific interest has been directed towards age-related diseases, driven by the significant increase in global life expectancy and the growing population of individuals aged 65 and above. The ageing process encompasses various biological, physiological, environmental, psychological, behavioural, and social changes, leading to an augmented susceptibility to chronic illnesses. Cardiovascular, neurological, musculoskeletal, liver and oncological diseases are prevalent in the elderly. Moreover, ageing individuals demonstrate reduced regenerative capacity and decreased tolerance towards therapeutic interventions, including organ transplantation. Liver diseases, such as non-alcoholic fatty liver disease, alcoholic liver disease, hepatitis, fibrosis, and cirrhosis, have emerged as significant public health concerns. Paradoxically, these conditions remain underestimated despite their substantial global impact. Age-related factors are closely associated with the severity and unfavorable prognosis of various liver diseases, warranting further investigation to enhance clinical management and develop novel therapeutic strategies. This comprehensive review focuses specifically on age-related liver diseases, their treatment strategies, and contemporary practices. It provides a detailed account of the global burden, types, molecular mechanisms, and epigenetic alterations underlying these liver pathologies.

Association between Direct-Acting Agents Adherence and Health-Related Quality of Life of Patients with Hepatitis C

This observational study included all patients undergoing HCV treatment with direct-acting antiviral (DAA)-based therapy between May 2020 and September 2023 at the Dolj County Hospital, Romania. The aim was to investigate adherence to DAAs among HCV patients and the effect of this treatment on their health-related quality of life (HRQoL). Chronic HCV-infected patients were prospectively evaluated at baseline (T0), before the beginning of treatment, and 12 weeks after completing DAAs treatment (T1). The HCV-AD10 questionnaire was used to measure DAAs adherence, and HRQoL was assessed with the 15D instrument. The 15D questionnaire was administered at two time points: T0 and T1, during which the Sustained Virologic Response (SVR) was also measured. The primary outcome was DAAs adherence, with secondary outcomes including quality of life (QoL), and sustained virologic response (SVR). DAAs based therapy was initiated for 368 patients, all of whom were health insured. HRQoL and psychological state of HCV patients clinically improved. The DAAs adherence was very good (mean±SD, 91.51±8.34), being influenced by age (younger patients were much adherent, rho=-0.112, p-value=0.031) and the severity of the disease (patients with more severe hepatitis were less adherent, rho=-0.167, p-value=0.001). DAAs had a significant effect on improving HRQoL of HCV patients, but did not influence medication adherence.

iACVP: markedly enhanced identification of anti-coronavirus peptides using a dataset-specific word2vec model

The COVID-19 pandemic caused several million deaths worldwide. Development of anti-coronavirus drugs is thus urgent. Unlike conventional non-peptide drugs, antiviral peptide drugs are highly specific, easy to synthesize and modify, and not highly susceptible to drug resistance. To reduce the time and expense involved in screening thousands of peptides and assaying their antiviral activity, computational predictors for identifying anti-coronavirus peptides (ACVPs) are needed. However, few experimentally verified ACVP samples are available, even though a relatively large number of antiviral peptides (AVPs) have been discovered. In this study, we attempted to predict ACVPs using an AVP dataset and a small collection of ACVPs. Using conventional features, a binary profile and a word-embedding word2vec (W2V), we systematically explored five different machine learning methods: Transformer, Convolutional Neural Network, bidirectional Long Short-Term Memory, Random Forest (RF) and Support Vector Machine. Via exhaustive searches, we found that the RF classifier with W2V consistently achieved better performance on different datasets. The two main controlling factors were: (i) the dataset-specific W2V dictionary was generated from the training and independent test datasets instead of the widely used general UniProt proteome and (ii) a systematic search was conducted and determined the optimal k-mer value in W2V, which provides greater discrimination between positive and negative samples. Therefore, our proposed method, named iACVP, consistently provides better prediction performance compared with existing state-of-the-art methods. To assist experimentalists in identifying putative ACVPs, we implemented our model as a web server accessible via the following link: http://kurata35.bio.kyutech.ac.jp/iACVP.

Flavivirus enzymes and their inhibitors

Flaviviruses such as dengue, Japanese encephalitis, West Nile, Yellow Fever and Zika virus, cause viral hemorrhagic fever and encephalitis in humans. However, antiviral therapeutics to treat or prevent flavivirus infections are not yet available. Thus, there is pressing need to develop therapeutics and vaccines that target flavivirus infections. All flaviviruses carry a positive-sense single-stranded RNA genome, which encodes ten proteins; three structural proteins form the virus shell, and seven nonstructural (NS) proteins are involved in replication of the viral genome. While all NS proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) are part of a functional membrane-bound replication complex, enzymatic activities required for flaviviral replication reside in only two NS proteins, NS3 and NS5. NS3 functions as a protease, helicase, and triphosphatase, and NS5 as a capping enzyme, methyltransferase, and RNA-dependent RNA polymerase. In this chapter, we provide an overview of viral replication focusing on the structure and function of NS3 and NS5 replicases. We further describe strategies and examples of current efforts to identify potential flavivirus inhibitors against NS3 and NS5 enzymatic activities that can be developed as therapeutic agents to combat flavivirus infections.

Analysis of Clinical Trials of New Drugs for Liver Diseases in China

Background

Liver diseases are a major public health concern worldwide, and the development of novel therapeutic drugs is an important research focus. But no overview has been conducted so far on the current research and development for liver-specific drugs in China, and the actual situation regarding the development and evaluation of new drugs in clinical trials.

Methods

The information of all clinical trials on liver diseases were obtained through the "Pharmaceutical Clinical Trial Registration and Information Disclosure Platform" before December 31, 2020.

Results

A total of 751 clinical trials on liver disease-related drugs were published on the above platform, including 574 chemical drugs, 128 biological products, and 49 traditional Chinese medicine (TCM)/natural drugs. The number of annual registrations has increased on an annual basis. The main indications for these clinical trials are viral hepatitis, liver malignancies, liver abscess, liver transplantation, congenital liver metabolic disease, and other hepatitis-related diseases. Hepatitis B, hepatitis C and liver cancer accounted for 72.4% of the total clinical trials, and the majority are related to generic drug research. There are 103 innovative drugs currently in clinical testing, mainly for hepatitis B, hepatitis C and hepatocellular carcinoma.

Conclusion

The stronger macro-control is required for the clinical trials conducted in China, and it is necessary to identify new therapeutic targets and develop novel drugs for the key liver diseases, as well as preventive hepatitis C vaccines, and targeted therapy, TCM/natural drugs and immunotherapy for liver cancer.

Molecular Docking Study on Several Benzoic Acid Derivatives against SARS-CoV-2

Several derivatives of benzoic acid and semisynthetic alkyl gallates were investigated by an in silico approach to evaluate their potential antiviral activity against SARS-CoV-2 main protease. Molecular docking studies were used to predict their binding affinity and interactions with amino acids residues from the active binding site of SARS-CoV-2 main protease, compared to boceprevir. Deep structural insights and quantum chemical reactivity analysis according to Koopmans’ theorem, as a result of density functional theory (DFT) computations, are reported. Additionally, drug-likeness assessment in terms of Lipinski’s and Weber’s rules for pharmaceutical candidates, is provided. The outcomes of docking and key molecular descriptors and properties were forward analyzed by the statistical approach of principal component analysis (PCA) to identify the degree of their correlation. The obtained results suggest two promising candidates for future drug development to fight against the coronavirus infection.

Resistance-associated substitutions (RASs) to HCV direct-acting antivirals (DAAs) at baseline of treatment in thalassemia patients: a referral center study

Patients with thalassemia major are at high risk of hepatitis C through blood transfusion from donors infected by hepatitis C virus (HCV). The use of direct-acting antiviral (DAA) therapy against such HCV infections has increased in different populations. However, resistant viral variants can affect treatment outcomes, and therefore improved surveillance strategies are needed. Accordingly, we aimed to evaluate resistance-associated substitutions (RASs) to HCV DAAs at the baseline of treatment in thalassemia patients in a referral center. Out of 89 thalassemia patients who suffered from HCV infection and were referred to our center between 2016 and 2017, 43 underwent further analysis of the HCV nonstructural proteins NS5A and NS5B using polymerase chain reaction (PCR) sequencing methods. Unique primers were designed using bioinformatics software for separate detection of HCV subtypes 1a, 3a, and 1b. Detection of RASs was performed based on previously published literature. Statistical analysis was carried out using SPSS version 19. The participants, 60.4% (26/43) of whom were male, had a mean age ± standard deviation (SD) of 33.0 ± 5.0 years. HCV subtype 1a was found in 27 cases, 3a in 13, and 1b in three. In HCV subtype 1a there were 163 mutations in NS5A and 212 mutations in NS5B. The frequency of RASs was 20.9% (8 RASs in 9 patients), including M28V and H58P in subtype 1a, L28M, R30Q, C316N, and C316S in subtype 1b, and S24F in subtype 3a. Statistically, the subtype 1b and a higher mutation rate in NS5A were associated with RASs (p-value < 0.05). The emergence of natural RASs to HCV DAAs serves as a warning of the risk of drug resistance in response to the broad usage of antivirals. However, relapses in these DAA-treated HCV-infected thalassemia patients are rarely reported. Our findings indicate that the prevalence of RASs prevalence at baseline was 20.9% in these patients, and this calls for extrapolation to a larger population study, as highlighted in other studies, with larger sample sizes, high-throughput methods, and follow-up in order to fully evaluate treatment outcomes in RASs-detected individuals. Optimized therapeutic strategies, particularly in complex, difficult-to-cure patients, can effectively prevent DAA treatment failure as a result of selection for RASs.

Eradicating hepatitis C virus: The APRN's role

Chronic hepatitis C virus (HCV) infection is a leading cause of liver disease. The World Health Organization has called for the global elimination of HCV by 2030. NPs can significantly expand the availability of community-based providers and bridge gaps in HCV treatment to assist in eradicating this curable virus.

Efficacy and safety of a fixed dose combination tablet of asunaprevir + beclabuvir + daclatasvir for the treatment of Hepatitis C

Introduction: Hepatitis C virus (HCV) is estimated to infect approximately 70 million people worldwide. If left untreated, chronic infection can progress to cirrhosis, liver failure or hepatocellular carcinoma. The advent of new direct-acting antivirals (DAA) has revolutionized patients' chances of treatment and viral elimination. Currently, several DAA options are available on the market.Areas covered: This review focuses on the pharmacokinetics, efficacy, tolerability and safety profile of DCV-TRIO, a twice-daily fixed-dose combination of daclatasvir, asunaprevir and beclabuvir approved in Japan for the treatment of genotype 1 HCV infection.Expert opinion: The DCV-TRIO combination achieved good response rates in genotype 1 patients (SVR12 ≥ 95% in naïve subtype 1b), independently from IL28B genotype, cirrhotic status and prior interferon exposure. On the other hand, unsatisfying response rates were reported in DAA-experienced patients and the risk of RAS selection should not be underestimated. Moreover, DCV-TRIO lacks differentiation from its earlier-launched DAA rivals, presents an inconvenient twice-daily dosing schedule and is not recommended in patients with advanced liver and kidney disease. All these drawbacks considerably limit its effective commercial potential. However, it can be a therapeutic option against HCV in tailored approaches according to the needs of different markets across the world.Abbreviations AE: adverse event; ALT: alanine aminotransferase; AST: aspartate aminotransferase; ASV: asunaprevir; AUC: area under the curve; BCRP: Breast Cancer Resistance Protein; BCV: boceprevir; BID: bis in die; CI: confidence intervals; CLcr: creatinine clearance; DAA: direct acting antivirals; DCV: daclatasvir; EC50: Half maximal effective concentration; GT: genotype; HCV: Hepatitis C virus; IFN: Interferon; NHL: non-Hodgkin lymphoma; OATP: Organic anion transporting polypeptides; OR: odds ratio; P-gp: P-glycoprotein; PK: pharmacokinetics; QD: quo die; RAS: resistance-associated substitutions; SVR: sustained virological response; USD: Unites States dollar.

Synthetic bulky NS4A peptide variants bind to and inhibit HCV NS3 protease

NS4A is a non-structural multi-tasking small peptide that is essential for HCV maturation and replication. The central odd-numbered hydrophobic residues of NS4A (Val-23‘ to Leu-31‘)i are essential for activating NS3 upon NS3/4A protease complex formation. This study aims to design new specific allosteric NS3/4A protease inhibitors by mutating Val-23‘, Ile-25‘, and Ile-29‘ into bulkier amino acids. Pep-15, a synthetic peptide, showed higher binding affinity towards HCV-NS3 subtype-4 than native NS4A. The K_d of Pep-15 (80.0 ± 8.0 nM) was twice as high as that of native NS4A (169 ± 37 nM). The mutant Pep-15 inhibited the catalytic activity of HCV-NS3 by forming an inactive complex. Molecular dynamics simulations suggested that a cascade of conformational changes occurred, especially in the catalytic triad arrangements, thereby inactivating NS3. A large shift in the position of Ser-139 was observed, leading to loss of critical hydrogen bonding with His-57. Even though this study is not a classic drug discovery study—nor do we propose Pep-15 as a drug candidate—it serves as a stepping stone towards developing a potent inhibitor of hitherto untargeted HCV subtypes.

Antiviral peptides as promising therapeutic drugs

While scientific advances have led to large-scale production and widespread distribution of vaccines and antiviral drugs, viruses still remain a major cause of human diseases today. The ever-increasing reports of viral resistance and the emergence and re-emergence of viral epidemics pressure the health and scientific community to constantly find novel molecules with antiviral potential. This search involves numerous different approaches, and the use of antimicrobial peptides has presented itself as an interesting alternative. Even though the number of antimicrobial peptides with antiviral activity is still low, they already show immense potential to become pharmaceutically available antiviral drugs. Such peptides can originate from natural sources, such as those isolated from mammals and from animal venoms, or from artificial sources, when bioinformatics tools are used. This review aims to shed some light on antimicrobial peptides with antiviral activities against human viruses and update the data about the already well-known peptides that are still undergoing studies, emphasizing the most promising ones that may become medicines for clinical use.

Review on chemogenomic approaches towards hepatitis C viral targets

Hepatitis C virus (HCV) is the most prevalent viral pathogen that infects more than 185 million people worldwide. HCV infection leads to chronic liver diseases such as liver cirrhosis and hepatocellular carcinoma. Direct-acting antivirals (DAAs) are the recent combination therapy for HCV infection with reduced side effects than prior therapies. Sustained virological response (SVR) acts as a gold standard marker to monitor the success of antiviral treatment. Older treatment therapies attain 50-55% of SVR compared with DAAs which attain around 90-95%. The current review emphasizes the recent chemogenomic updates that have been unfolded through structure-based drug design of HCV drug target proteins (NS3/4A, NS5A, and NS5B) and ligand-based drug design of DAAs in achieving a stable HCV viral treatment strategies.

HCV-Associated Nephropathies in the Era of Direct Acting Antiviral Agents

Hepatitis C virus (HCV) infection is a systemic disorder that frequently associates with extrahepatic manifestations, including nephropathies. Cryoglobulinemia is a typical extrahepatic manifestation of HCV infection that often involves kidneys with a histological pattern of membranoproliferative glomerulonephritis. Other, less common renal diseases related to HCV infection include membranous nephropathy, focal segmental glomerulosclerosis, IgA nephropathy, fibrillary and immunotactoid glomerulopathy. Over the last decades, the advent of direct-acting antiviral therapies has revolutionized treatment of HCV infection, dramatically increasing the rates of viral clearance. In patients where antiviral therapy alone fails to induce renal disease remission add-on B-cell depleting agents represent an alternative to counteract the synthesis of pathogenic antibodies. Immunosuppressive therapies, such as steroids, alkylating agents, and plasma exchanges, may still represent an effective option to inhibit immune-complex driven inflammatory response, but the potentially associated increase of HCV replication and worsening of liver disease represent a serious limitation to their use.

G2 Dendrimer as a Carrier Can Enhance Immune Responses Against HCV-NS3 Protein in BALB/c Mice

BACKGROUND

Hepatitis C virus (HCV) infection is a major issue of public health. It seems of paramount importance to find an effective vaccine against HCV infection. The best vaccine candidate should induce robust cellular responses. The aim of the current study was to evaluate immunogenicity effects of novel conjugated dendrimer G2 with the recombinant NS3 antigen as a vaccine candidate for eliciting Th1-oriented cellular responses.

METHODS

Female BALB/c mice were immunized with different regimes especially with NS3 conjugated with G2 dendrimer. The humoral responses (Total IgG and IgG iso-typing) and cellular responses (Ex vivo IFN-γ and IL-4 ELISpot assays, in vitro CTL assay and proliferation) were evaluated and compared in immunized mice.

RESULTS

The results indicated that induced specific total IgG in all mice groups immunized with rNS3 formulated with different adjuvants and IgG2a subclass was the predominant isotype in rNS3-G2 (p≤0.05). For preliminary evaluation of cellular response, ex vivo ELISpot assay has shown that the higher frequency of IFN-γ producing cells was in groups immunized with rNS3+M720 and rNS3-G2 (p= 0.0012) than control groups. Finally, the rNS3-specific CTLs activity showed the highest percentage of specific lysis (LDH release) of the target cells in rNS3-G2 and rNS3+M720 groups.

CONCLUSION

In the present study, as our knowledge, this is first time that the immunogenicity of nanodendrimer G2 as a biocompatible adjuvant with the HCV-NS3 antigen was evaluated. The results showed high capability of the regimen to induce strong Th1-orinted cellular response in mice model, indicating the dendrimer G2 as a novel adjuvant candidate for HCV vaccine studies.

Sustained Virologic Response and Costs Associated with Direct-Acting Antivirals for Chronic Hepatitis C Infection in Oklahoma Medicaid

BACKGROUND

Outcomes involving newer direct-acting antiviral (DAA) hepatitis C virus (HCV) regimens have not been studied extensively among the Medicaid population.

OBJECTIVE

To assess clinical (treatment failure) and economic outcomes for chronic HCV-infected Oklahoma Medicaid members following treatment with DAAs and to measure associations with patient, treatment, and clinical characteristics.

METHODS

This cross-sectional study used Oklahoma Medicaid pharmacy and medical claims data for adult members who used a newer DAA agent and had reported a successful or failed sustained virological response rate 12 weeks after therapy completion (SVR12) from January 1, 2014, to June 30, 2016. Multivariable logistic and gamma regressions assessed predictors of SVR12 failure and costs controlling for member demographics (i.e., age, sex, race, rural residence); type of DAA and adherence; clinical characteristics (e.g., comorbid conditions, advanced liver disease); and the implementation of changes to a prior authorization program.

RESULTS

Of 934 Medicaid members eligible for treatment with DAAs between January 1, 2014, and June 30, 2016, 906 received DAA treatment, 40.6% (368/906) had reported SVR12 outcomes, and 59.4% (n = 538) did not have a reported SVR recorded. Of those with reported SVR12 outcomes, patients were 53.1 ± 9.7 years of age, 51.1% were male, 8.4% had SVR12 failure, and each member had mean costs of $140,283 ± $52,779. Multivariable analyses indicated higher odds of SVR12 failure was independently associated with cirrhosis (OR [decompensated] = 6.69 and OR [compensated] = 3.52, P < 0.001), while males had higher odds of failure than females (OR = 3.34, P < 0.010). No significant difference in SVR12 failure was noted, according to DAA type or a medication adherence threshold of > 95%. Ledipasvir/sofosbuvir was independently associated with lower costs (exp[b] = 0.81; P < 0.001) compared with sofosbuvir, while higher costs were associated with decompensated cirrhosis (exp[b] = 1.22; P < 0.001) and treatment failure (exp[b] = 1.18, P < 0.010). In an analysis including members without reported SVR12 outcomes, decompensated and compensated cirrhosis had lower odds (P < 0.001) of no reported SVR12 from ambulatory clinic settings.

CONCLUSIONS

Almost 60% of Medicaid members receiving DAA treatment did not have a final reported SVR12 outcome. Among those with viral load measurements, treatment success was high and both decompensated and compensated cirrhosis were independently associated with significantly higher odds of treatment failure. Addressing a loss to follow-up among HCV patients and curtailing the development of cirrhosis to improve treatment success may warrant interventions that improve access to care and remove barriers that impede treatment initiation and completion.

DISCLOSURES

No outside funding supported this study. Pham, Keast, Holderread, Nesser, and Skrepnek disclose either employment by the Oklahoma Health Care Authority or contractual work for this employer. Pham discloses fellowship funding from Purdue Pharma unrelated to this study. Keast and Skrepnek disclose research grant funding from Gilead Sciences and Abbvie. Holderread also reports grant funding from Gilead Sciences and fees from PRIME Education. Thompson, Farmer, and Rathbun have nothing to disclose.

Sulfur(vi) fluoride exchange as a key reaction for synthesizing biaryl sulfate core derivatives as potent hepatitis C virus NS5A inhibitors and their structure-activity relationship studies

Extremely potent, new hepatitis C virus (HCV) nonstructural 5A (NS5A) featuring substituted biaryl sulfate core structures was designed and synthesized. Based on the previously reported novel HCV NS5A inhibitors featuring biaryl sulfate core structures which exhibit two-digit picomolar half-maximal effective concentration (EC50) values against HCV genotype 1b and 2a, the new inhibitors equipped with the sulfate core structures containing diversely substituted aryl groups were explored. In this study, highly efficient, chemoselective coupling reactions between an arylsulfonyl fluoride and an aryl silyl ether, known as the sulfur(vi) fluoride exchange (SuFEx) reaction, were utilized. Among the inhibitors prepared based on the SuFEx chemistry, compounds 14, 15 and 29 exhibited two-digit picomolar EC50 values against GT-1b and single digit or sub nanomolar activities against the HCV GT-2a strain. Nonsymmetrical inhibitors containing an imidazole and amide moieties on each side of the sulfate core structures were also synthesized. In addition, a biotinylated probe targeting NS5A protein was prepared for labeling using the same synthetic methodology.

Grazoprevir/elbasvir for the treatment of adults with chronic hepatitis C: a short review on the clinical evidence and place in therapy

Chronic hepatitis C virus (HCV) infection impacts approximately 71 million people and approximately 400,000 deaths are attributed to HCV-related liver disease annually worldwide. Mainstay of treatment for over 25 years has been pegylated interferon until the advent of protease inhibitors, which has led to all-oral HCV treatment regimens that have changed the outlook of hepatitis C treatment. Grazoprevir/elbasvir provides high rates of efficacy and tolerability and is an all-oral once daily treatment option for HCV infection. Efficacy of grazoprevir/elbasvir has been proven in patients with cirrhosis, patients who have previously failed treatment with peginterferon and ribavirin (RBV), patients with end-stage renal disease and patients with HIV co-infection. Data have shown a high barrier to resistance despite the presence of resistance-associated substitutions. Grazoprevir/elbasvir represents a very promising regimen for treatment of HCV infection. This review provides a summary of pharmacology, efficacy, and safety of grazoprevir/elbasvir for the treatment of HCV infection.

Human single chain-transbodies that bound to domain-I of non-structural protein 5A (NS5A) of hepatitis C virus

A safe and broadly effective direct acting anti-hepatitis C virus (HCV) agent that can withstand the viral mutation is needed. In this study, human single chain antibody variable fragments (HuscFvs) to conserved non-structural protein-5A (NS5A) of HCV were produced by phage display technology. Recombinant NS5A was used as bait for fishing-out the protein bound-phages from the HuscFv-phage display library. NS5A-bound HuscFvs produced by five phage transfected-E. coli clones were linked molecularly to nonaarginine (R9) for making them cell penetrable (become transbodies). The human monoclonal transbodies inhibited HCV replication in the HCVcc infected human hepatic cells and also rescued the cellular antiviral immune response from the viral suppression. Computerized simulation verified by immunoassays indicated that the transbodies used several residues in their multiple complementarity determining regions (CDRs) to form contact interface with many residues of the NS5A domain-I which is important for HCV replication complex formation and RNA binding as well as for interacting with several host proteins for viral immune evasion and regulation of cellular physiology. The human monoclonal transbodies have high potential for testing further as a new ramification of direct acting anti-HCV agent, either alone or in combination with their cognates that target other HCV proteins.

Patterns in Liver-Related Health Outcomes with Hepatitis C Virus Treatments and Health Equity Implications for Decision Makers: A Cohort Analysis of Medicaid Patients

Introduction: Hepatitis C virus (HCV) infection is a blood-borne communicable disease that, in perhaps 20% of cases, results in a chronic disease. However, traditional peginterferon/ribavirin therapies pose many adverse side effects that are difficult to tolerate, and many patients do not complete the therapy. However, healthcare access to these newer, efficacious treatments are reduced, due to inadequate or lack of coverage of direct acting antiviral (DAA) medication. The objective of this study was to evaluate the impact of HCV treatment regimens on outcomes of care for HCV-infected Medicaid beneficiaries without cirrhosis/liver disease scarring. Methods: A cohort analysis was performed to evaluate the changes in cirrhosis, hepatocellular carcinoma (liver cancer), and liver transplantation with use of HCV treatments in Medicaid beneficiaries with HCV, and was followed over a period of 10 years. The cohort of Medicaid beneficiaries and relevant variables were generated from published literature. Results: Finally, considering the impact on health expenditures due to improved access to new treatments in Medicaid beneficiaries, DAAs resulted in the lowest decompensated cirrhosis and hepatocellular carcinoma-related healthcare cost per person over the 10-year time frame the cohort was followed. Conclusions: The risk of liver-related disease is higher in patients with cirrhosis, as reaching treatment success results in continued disease progression, not normal health status; thus, liver cancer healthcare costs are higher in patients with cirrhosis, compared to those without cirrhosis.

Ginsenoside Rg3 restores hepatitis C virus-induced aberrant mitochondrial dynamics and inhibits virus propagation

Hepatitis C virus (HCV) alters mitochondrial dynamics associated with persistent viral infection and suppression of innate immunity. Mitochondrial dysfunction is also a pathologic feature of direct-acting antiviral (DAA) treatment. Despite the high efficacy of DAAs, their use in treating patients with chronic hepatitis C in interferon-sparing regimens occasionally produces undesirable side effects such as fatigue, migraine, and other conditions, which may be linked to mitochondrial dysfunction. Here, we show that clinically prescribed DAAs, including sofosbuvir, affect mitochondrial dynamics. To counter these adverse effects, we examined HCV-induced and DAA-induced aberrant mitochondrial dynamics modulated by ginsenoside, which is known to support healthy mitochondrial physiology and the innate immune system. We screened several ginsenoside compounds showing antiviral activity using a robust HCV cell culture system. We investigated the role of ginsenosides in antiviral efficacy, alteration of mitochondrial transmembrane potential, abnormal mitochondrial fission, its upstream signaling, and mitophagic process caused by HCV infection or DAA treatment. Only one of the compounds, ginsenoside Rg3 (G-Rg3), exhibited notable and promising anti-HCV potential. Treatment of HCV-infected cells with G-Rg3 increased HCV core protein-mediated reduction in the expression level of cytosolic p21, required for increasing cyclin-dependent kinase 1 activity, which catalyzes Ser616 phosphorylation of dynamin-related protein 1. The HCV-induced mitophagy, which follows mitochondrial fission, was also rescued by G-Rg3 treatment.

CONCLUSION

G-Rg3 inhibits HCV propagation. Its antiviral mechanism involves restoring the HCV-induced dynamin-related protein 1-mediated aberrant mitochondrial fission process, thereby resulting in suppression of persistent HCV infection. (Hepatology 2017;66:758-771).

Structure-Activity Relationship Study of QL47: A Broad-Spectrum Antiviral Agent

Here we report the structure-activity relationship (SAR) investigations of QL-XII-47 (QL47), a compound that possesses broad-spectrum antiviral activity against dengue virus and other RNA viruses. A medicinal chemistry campaign initiated from QL47, a previously reported covalent BTK inhibitor, to derive YKL-04-085, which is devoid of any kinase activity when screened against a panel of 468 kinases and with improved pharmacokinetic properties. Both QL47 and YKL-04-085 are potent inhibitors of viral translation and exhibit cellular antiviral activity at 35-fold lower concentrations relative to inhibition of host-cell proliferation.

New direct-acting antivirals for patients with chronic HCV infection: can we monitor treatment using an HCV core antigen assay?

We evaluated the diagnostic usefulness of an HCV core antigen (HCV-Ag) assay in HCV-infected patients undergoing treatment with direct-acting antivirals. We analyzed 103 samples from 28 patients. Compared with RT-PCR, sensitivity was 96.2% and specificity was 100%. The correlation between techniques was excellent (Pearson coefficient: 0.871). HCV-Ag proved to be useful in patients with sustained viral response and in patients who experienced treatment failures.

Pharmacodynamics and pharmacokinetics of elbasvir and grazoprevir in the treatment of hepatitis C

INTRODUCTION

Approximately 130 - 150 million people have chronic hepatitis C virus (HCV) infection and upwards of 500,000 deaths annually are attributed to HCV related liver disease worldwide. Pegylated interferon and ribavirin have been the mainstay of treatment for greater than 25 years until recent advent of protease inhibitors which has led to all oral HCV treatment regimens that have changed the outlook of hepatitis C treatment.

AREAS COVERED

This review provides summary of pharmacokinetics, pharmacodynamics, efficacy and safety of grazoprevir/elbasvir therapy for treatment of HCV infection.

EXPERT OPINION

Grazoprevir/elbasvir provides an all-oral once daily treatment option for HCV infection with high rates of efficacy and tolerability in a pangenotypic fashion. It highly efficacious in treating patients with cirrhosis, patients who have previously failed treatment with pegylated interferon and ribavirin, and patients with HIV co-infection. Grazoprevir/elbasvir has demonstrated higher barrier to resistance even in the presence of variants associated with resistance such as Q41R, F43S, R155K, V36M, T54S, and D168. It is one of only few HCV treatment regimens evaluated for use in patients with advanced chronic kidney disease and dialysis. It is a very promising regimen for treatment of HCV infection.

Human Transbodies to HCV NS3/4A Protease Inhibit Viral Replication and Restore Host Innate Immunity

A safe and effective direct acting anti-hepatitis C virus (HCV) agent is still needed. In this study, human single chain variable fragments of antibody (scFvs) that bound to HCV NS3/4A protein were produced by phage display technology. The engineered scFvs were linked to nonaarginines (R9) for making them cell penetrable. HCV-RNA-transfected Huh7 cells treated with the transbodies produced from four different transformed E. coli clones had reduced HCV-RNA inside the cells and in the cell spent media, as well as fewer HCV foci in the cell monolayer compared to the transfected cells in culture medium alone. The transbodies-treated transfected cells also had up-expression of the genes coding for the host innate immune response, including TRIF, TRAF3, IRF3, IL-28B, and IFN-β. Computerized homology modeling and intermolecular docking predicted that the effective transbodies interacted with several critical residues of the NS3/4A protease, including those that form catalytic triads, oxyanion loop, and S1 and S6 pockets, as well as a zinc-binding site. Although insight into molecular mechanisms of the transbodies need further laboratory investigation, it can be deduced from the current data that the transbodies blocked the HCV NS3/4A protease activities, leading to the HCV replication inhibition and restoration of the virally suppressed host innate immunity. The engineered antibodies should be tested further for treatment of HCV infection either alone, in combination with current therapeutics, or in a mixture with their cognates specific to other HCV proteins.

Promising Anti-Hepatitis C Virus Compounds from Natural Resources

Hepatitis C virus (HCV) infection is a major worldwide problem, which involves approximately 170 million people. High morbidity of patients is caused by chronic infection, which leads to liver cirrhosis, hepatocellular carcinoma and other HCV-related diseases. The sustained virological response (SVR) has been markedly improved to be >90% by the current standard interferon (IFN)-free treatment regimens with a combination of direct-acting antiviral agents (DAAs) targeting the viral NS3 protease, NS5A multi-function protein and NS5B RNA-dependent RNA polymerase, compared with 50–70% of SVR rates achieved by the previous standard IFN-based treatment regimens with or without an NS3 protease inhibitor. However, the emergence of DAA-resistant HCV strains and the limited access to the DAAs due to their high cost could be major concerns. Also, the long-term prognosis of patients treated with DAAs, such as the possible development of hepatocellular carcinoma, still needs to be further evaluated. Natural resources are considered to be good candidates to develop anti-HCV agents. Here, we summarize anti-HCV compounds obtained from natural resources, including medicinal plant extracts, their isolated compounds and some of their derivatives that possess high antiviral potency against HCV.

Inhibition of HCV replication by humanized-single domain transbodies to NS4B

NS4B of hepatitis C virus (HCV) initiates membrane web formation, binds RNA and other HCV proteins for viral replication complex (RC) formation, hydrolyses NTP, and inhibits innate anti-viral immunity. Thus, NS4B is an attractive target of a novel anti-HCV agent. In this study, humanized-nanobodies (VHs/VHHs) that bound to recombinant NS4B were produced by means of phage display technology. The nanobodies were linked molecularly to a cell penetrating peptide, penetratin (PEN), for making them cell penetrable (become transbodies). Human hepatic (Huh7) cells transfected with HCV JFH1-RNA that were treated with transbodies from four Escherichia coli clones (PEN-VHH7, PEN-VHH9, PEN-VH33, and PEN-VH43) had significant reduction of HCV RNA amounts in their culture fluids and intracellularly when compared to the transfected cells treated with control transbody and medium alone. The results were supported by the HCV foci assay. The transbody treated-transfected cells also had upregulation of the studied innate cytokine genes, IRF3, IFNβ and IL-28b. The transbodies have high potential for testing further as a novel anti-HCV agent, either alone, adjunct of existing anti-HCV agents/remedies, or in combination with their cognates specific to other HCV enzymes/proteins.

Simeprevir plus peginterferon/ribavirin for HCV genotype 1-infected treatment-naïve patients in China and South Korea

BACKGROUND AND AIM

Approximately one-third of patients with hepatitis C virus (HCV) genotype (GT) 1 infection live in East Asia. This study evaluated the efficacy, pharmacokinetics, safety, and tolerability of simeprevir plus peginterferon alpha-2a and ribavirin (PR) in HCV GT1-infected, treatment-naïve, Asian patients with compensated liver disease.

METHODS

This phase III, randomized study (NCT01725529) was conducted in China and South Korea. Patients received simeprevir 150 mg once daily (QD), simeprevir 100 mg QD, or placebo, in combination with PR for 12 weeks. Patients in the simeprevir groups received PR alone for a further 12 or 36 weeks based on response-guided treatment criteria. Patients in the placebo group received a further 36 weeks of PR alone. The primary efficacy endpoint was sustained virologic response 12 weeks after planned end of treatment (SVR12). Secondary endpoints were safety, pharmacokinetics, tolerability, and patient-reported outcomes.

RESULTS

Overall, 457 patients were treated; the majority had GT1b infection (452/457 [99%]) and IL28B CC GT (364/457 [80%]). Of the 454 patients who had liver biopsy, 26 had cirrhosis (6%). SVR12 rates were superior for both the simeprevir 100 mg (89%; P = 0.003) and 150 mg (91%; P < 0.001) groups versus placebo (76%). Adverse events were mainly grade 1/2 and occurred at a similar incidence across all treatment groups. Overall, eight patients (2%) discontinued simeprevir or placebo treatment because of adverse events.

CONCLUSIONS

Both simeprevir (100 mg and 150 mg QD) plus PR achieved superiority in SVR12 versus placebo plus PR in treatment-naïve, HCV GT1-infected, Asian patients and were well tolerated.

HCV Council--critical appraisal of data: recommendations for clinical practice in a rapidly evolving therapeutic landscape

BACKGROUND & AIMS

HCV Council 2014, like its predecessor HCV Council 2011, assembled leading clinicians and researchers in the field of hepatitis C to critically evaluate current data regarding best practices for managing patients with chronic hepatitis C virus (HCV).

METHODS

Clinical practice statements were developed that reflect the areas of potential controversy with high clinical impact. Faculty members were responsible for reviewing the literature to support or reject these statements. After a review and comprehensive discussion of the data, the HCV Council faculty voted on the nature of the evidence and the level of support for each statement.

RESULTS

The results of the detailed analysis with expert opinion are summarized in this article.

CONCLUSION

Numerous questions regarding optimal management of certain populations and clinical scenarios remain unanswered. The discussion in the article provides a summary of evidenced-based expert opinion that may help guide clinicians as additional information is developed.

Dasabuvir (ABT333) for the treatment of chronic HCV genotype I: a new face of cure, an expert review

Hepatitis C virus (HCV) affects nearly 1.3% of US population and around 2% of people worldwide. It is associated with serious complication of Cirrhosis and Hepatocellular carcinoma leading to significant morbidity and mortality. Until now the only treatment option for this serious disease was interferon based therapy which had poor tolerance and at best SVR (Sustained virological response) in only 50% of cases. With the introduction of other direct - acting antiviral agents the treatment of HCV has been revolutionized with significantly high rates of cure. Among novel Direct acting antivirals are non-nucleoside inhibitor NS5B which is highly effective in treatment of HCV genotype 1 a and 1b including those with compensated cirrhosis achieving high cure rates with SVR more than 97 % in pooled analysis from six different phase 3 trials. This review will discuss the DAA - Dasabuvir, a non - nucleoside NS5B inhibitor, its mechanism of action, efficacy, safety & tolerance, and drug resistance. Dasabuvir is approved by FDA in combination with other DAA agents called as the 3D(Viekira Pak) in various interferon free regimens achieving high cure rates (SVR >95%) with low adverse effects. In Europe, it is approved by European medicines agency for use in combination with Ombitasvir, Paritaprevir, and ritonavir with or without ribavirin. The drug is used in treatment naive as well as previously treated patient with high success rates. It is also approved in patients with compensated cirrhosis, patients with HIV co-infection and liver transplant recipients which were in the past were excluded from treatment with interferon based therapy. Dasabuvir is extensively evaluated in large clinical trials and shown excellent SVR among HCV genotype1 patient population in combination with other oral DAAs, with good safety profile and tolerance. Its drawback is its genotype restriction, need for ribavirin (RBV) for 1a genotype, low resistance barrier and high cost. It is well tolerated with less than 1 % of patients permanently discontinuing treatment and 2% of patient experiencing a serious adverse reaction. It is contraindicated in patients with known hypersensitivity to ritonavir (e.g. Steven - Johnson syndrome) and strong inducers of CYP3A and CYP2CB.

Hepatitis C Virus NS4B Can Suppress STING Accumulation To Evade Innate Immune Responses

The cyclic dinucleotide 2',3'-cGAMP can bind the adaptor protein STING (stimulator of interferon [IFN] genes) to activate the production of type I IFNs and proinflammatory cytokines. We found that cGAMP added to the culture medium could suppress the replication of the hepatitis C virus (HCV) genotype 1b strain Con1 subgenomic replicon in human hepatoma cells. Knockdown of STING expression diminished the inhibitory effect on replicon replication, while overexpression of STING enhanced the inhibitory effects of cGAMP. The addition of cGAMP into 1b/Con1 replicon cells significantly increased the expression of type I IFNs and antiviral interferon-stimulated genes. Unexpectedly, replication of the genotype 2a JFH1 replicon and infectious JFH1 virus was less sensitive to the inhibitory effect of cGAMP than was that of 1b/Con1 replicon. Using chimeric replicons, 2a NS4B was identified to confer resistance to cGAMP. Transient expression of 2a NS4B resulted in a pronounced inhibitory effect on STING-mediated beta IFN (IFN-β) reporter activation compared to that of 1b NS4B. 2a NS4B was found to suppress STING accumulation in a dose-dependent manner. The predicted transmembrane domain of 2a NS4B was required to inhibit STING accumulation. These results demonstrate a novel genotype-specific inhibition of the STING-mediated host antiviral immune response.

IMPORTANCE

The cyclic dinucleotide cGAMP was found to potently inhibit the replication of HCV genotype 1b Con1 replicon but was less effective for the 2a/JFH1 replicon and infectious JFH1 virus. The predicted transmembrane domain in 2a NS4B was shown to be responsible for the decreased sensitivity to cGAMP. The N terminus of NS4B has been reported to suppress STING-mediated signaling by disrupting the interaction of STING and TBK1 and/or MAVS. We show that 2a/JFH1 NS4B has an additional mechanism to evade STING signaling through suppressing STING accumulation.

Novel benzidine and diaminofluorene prolinamide derivatives as potent hepatitis C virus NS5A inhibitors

Our study describes the discovery of a series of highly potent hepatitis C virus (HCV) NS5A inhibitors based on symmetrical prolinamide derivatives of benzidine and diaminofluorene. Through modification of benzidine, l-proline, and diaminofluorene derivatives, we developed novel inhibitor structures, which allowed us to establish a library of potent HCV NS5A inhibitors. After optimizing the benzidine prolinamide backbone, we identified inhibitors embedding meta-substituted benzidine core structures that exhibited the most potent anti-HCV activities. Furthermore, through a battery of studies including hERG ligand binding assay, CYP450 binding assay, rat plasma stability test, human liver microsomal stability test, and pharmacokinetic studies, the identified compounds 24, 26, 27, 42, and 43 are found to be nontoxic, and are expected to be effective therapeutic anti-HCV agents.

Combination of pharmacophore hypothesis and molecular docking to identify novel inhibitors of HCV NS5B polymerase

Hepatitis C virus (HCV) infection or HCV-related liver diseases are now shown to cause more than 350,000 deaths every year. Adaptability of HCV genome to vary its composition and the existence of multiple strains makes it more difficult to combat the emergence of drug-resistant HCV infections. Among the HCV polyprotein which has both the structural and non-structural regions, the non-structural protein NS5B RNA-dependent RNA polymerase (RdRP) mainly mediates the catalytic role of RNA replication in conjunction with its viral protein machinery as well as host chaperone proteins. Lack of such RNA-dependent RNA polymerase enzyme in host had made it an attractive and hotly pursued target for drug discovery efforts. Recent drug discovery efforts targeting HCV RdRP have seen success with FDA approval for sofosbuvir as a direct-acting antiviral against HCV infection. However, variations in drug-binding sites induce drug resistance, and therefore targeting allosteric sites could delay the emergence of drug resistance. In this study, we focussed on allosteric thumb site II of the non-structural protein NS5B RNA-dependent RNA polymerase and developed a five-feature pharmacophore hypothesis/model which estimated the experimental activity with a strong correlation of 0.971 & 0.944 for training and test sets, respectively. Further, the Güner-Henry score of 0.6 suggests that the model was able to discern the active and inactive compounds and enrich the true positives during a database search. In this study, database search and molecular docking results supported by experimental HCV viral replication inhibition assays suggested ligands with best fitness to the pharmacophore model dock to the key residues involved in thumbs site II, which inhibited the HCV 1b viral replication in sub-micro-molar range.

Dasabuvir : a new direct antiviral agent for the treatment of hepatitis C

INTRODUCTION

Treatment of hepatitis C virus (HCV) infection with direct-acting antivirals (DAAs) has revolutionized the care of infected patients. Among these novel compounds are non-nucleoside analogs, which bind viral RNA-dependent RNA polymerase resulting in a conformational change inhibiting RNA synthesis.

AREAS COVERED

Efficacy and tolerability of treatment regimens containing the non-nucleoside analog polymerase inhibitor dasabuvir (ABT-333).

EXPERT OPINION

Dasabuvir-containing regimens achieve high rates of sustained virologic response in HCV genotype 1a and 1b-infected patients when combined with other DAAs, namely paritaprevir (ABT-450), ritonavir and ombitasvir (ABT-267). In the populations studied, dasabuvir seems to be well tolerated and safe. The major limitations of this novel drug are its genotype-restricted activity, the necessity to include ribavirin for HCV genotype 1a and the emergence of resistance if not combined with other DDAs.

Characterization of the activity of 2'-C-methylcytidine against dengue virus replication

Dengue virus (DENV) is a severe mosquito-borne viral pathogen. Neither vaccines nor antiviral therapy is currently available to treat DENV infection. Nucleoside inhibitors targeting viral polymerase have proved promising for the development of drugs against viruses. In this study, we report a nucleoside analog, 2'-C-methylcytidine (2CMC), which exerts potent anti-DENV activity in DENV subgenomic RNA replicon and infectious systems, with an IC50 value of 11.2±0.3μM. This study utilized both cell-based and cell-free reporter assay systems to reveal the specific anti-DENV RNA polymerase activity of 2CMC. In addition, both xenograft bioluminescence-based DENV replicon and DENV-infected Institute of Cancer Research (ICR) suckling mice models evaluated the anti-DENV replication activity of 2CMC in vivo. Collectively, these findings provide a promising compound for the development of direct-acting antivirals against DENV infection.

Three- and four-class classification models for P-glycoprotein inhibitors using counter-propagation neural networks

P-glycoprotein (P-gp) is an ATP binding cassette (ABC) transporter that helps to protect several certain human organs from xenobiotic exposure. This efflux pump is also responsible for multi-drug resistance (MDR), an issue of the chemotherapy approach in the fight against cancer. Therefore, the discovery of P-gp inhibitors is considered one of the most popular strategies to reverse MDR in tumour cells and to improve therapeutic efficacy of commonly used cytotoxic drugs. Until now, several generations of P-gp inhibitors have been developed but they have largely failed in preclinical and clinical studies due to lack of selectivity, poor solubility and severe pharmacokinetic interactions. In this study, three models (SION, SIO, SIN) to classify specific 'true' P-gp inhibitors as well as three other models (CPBN, CPB1, CPN) to distinguish between P-gp inhibitors, CYP 3A inhibitors and co-inhibitors of these proteins with rather high accuracy values for the test set and the external set were generated based on counter-propagation neural networks (CPG-NN). Such three and four-class classification models helped provide more information about the bioactivities of compounds not only on one target (P-gp), but also on a combination of multiple targets (P-gp, CYP 3A).

Treatment of Recurrent Hepatitis C Genotype-4 Post-Liver Transplantation with Sofosbuvir plus Simeprevir

Hepatitis C virus (HCV) infection remains a leading indication for orthotopic liver transplantation (OLT) worldwide. Recurrence of HCV following OLT is universal. There is scarcity of data on the post-OLT treatment of HCV genotype-4-the predominant genotype in North Africa and the Middle East. Herein, we present three patients who have experienced HCV genotype-4 recurrence post-OLT. All three patients were interferon-naive and were treated with simeprivir (SIM) and sofosbuvir (SOF) combination therapy for 12-24 weeks. The data from this case series show that SIM+SOF are well-tolerated and effective for achieving viral clearance in HCV genotype-4 post-OLT patients. Given the limited nature of a case series, further research must be pursued regarding post-OLT HCV genotype-4 responses to direct-acting anti-viral therapy.

Hepatitis C surveillance in Canada

Background

Hepatitis C is a highly transmissible virus that can lead to chronic liver disease. It continues to be a major public health concern in Canada.

Objective

To describe surveillance trends of reported cases of Hepatitis C virus (HCV) in Canada by age and sex from 1991-2012.

Methods

Cases of HCV reported to the Canadian Notifiable Disease Surveillance System were compiled at the national level. As most reported cases are not differentiated by acute or chronic HCV infection status, presented results are based on total HCV cases. Time trends are provided from 1991-2012, with a more detailed examination of age and sex patterns from 2005-2012.

Results

The rate of reported HCV infection increased sharply from 1991 (the year it was first notifiable) until 1998, when the highest overall rate of 66.9 per 100,000 was observed. From that time until 2012, rates of reported cases decreased in both sexes, but remained consistently higher among males than females. In 2012, the overall rate of reported HCV infection was 29.3 per 100,000. In younger age groups, rates among females were marginally higher, while males in older age groups (30 and above) exhibited substantially higher rates.

Conclusion

This surveillance summary presents the longer-term trends in reported cases and corresponding rates of HCV in Canada using national surveillance data. Canada continues to experience a downward trend in HCV rates; however, the burden of infection will continue to increase as chronically infected individuals develop severe illness.

microRNAs: novel players in hepatitis C virus infection

Hepatitis C virus (HCV) is a single-stranded, positive-sense RNA virus. About 70% of patients exposed to HCV develop a chronic infection, which can lead to scarring of the liver and ultimately to cirrhosis, liver failure, and hepatocellular carcinoma. For the past decade, the standard therapy for HCV infection has been a combination of interferon-α and ribavirin. In recent years, direct-acting antiviral agents, boceprevir and telaprevir, have been added to the therapeutic regimen and considerably improve the cure rates for HCV infection. However, the treatment continues to cause substantial side effects and is associated with drug resistance due to frequent mutations in the HCV RNA genome resulting from the low fidelity of its RNA polymerase. MicroRNAs (miRNAs) are a class of small, non-coding RNAs approximately 22 nucleotides in length. They are derived from cellular or viral transcripts and bind to their target mRNAs in a sequence-specific manner, resulting in either mRNA cleavage or translational repression and subsequent modulation of the expression of the majority of the protein-coding genes. miRNAs have been implicated in regulating multiple aspects of HCV life cycles and certain miRNAs serve as essential mediators for the interferon-based antiviral therapy. Furthermore, recent studies have documented the potential values of miRNAs as novel therapeutic targets against hepatitis C infectivity.

Approach and management of patients with chronic hepatitis B and C during the course of inflammatory bowel disease

Inflammatory bowel disease and chronic viral hepatitis are 2 distinct but common conditions throughout the world. Mostly, both need life-long follow-up. Since immunosuppressive drugs remain corner stones of inflammatory bowel disease management, one should be aware of the concomitant presence of chronic viral hepatitis in such patients to prevent serious (even fatal) outcomes. Recently, new treatment options have become available in the treatment of both inflammatory bowel disease and chronic viral hepatitis. In this review, we have discussed and summarized current treatment and follow-up strategies for those 2 important public health issues in light of available literature.

Medication use and medical comorbidity in patients with chronic hepatitis C from a US commercial claims database: high utilization of drugs with interaction potential

BACKGROUND

With the advent of the direct-acting antiviral agents, significant drug-drug interaction (DDI) potential now exists for patients treated for chronic hepatitis C virus (HCV) infection. However, little is known about how often patients with HCV infection use medications that may interact with newer HCV treatments, especially those with cytochrome P450 3A (CYP3A) DDI potential.

METHODS

Using a large US commercial insurance database, medication use and comorbidity burden were examined among adult patients with a chronic HCV diagnosis from 2006 to 2010. Medications were examined in terms of total number of prescription claims, proportion of patients exposed, and DDI potential with the prototypical CYP3A direct-acting antiviral agents boceprevir and telaprevir, for which data were available.

RESULTS

Patient comorbidity burden was high and increased over the study period. Medication use was investigated in 53 461 patients with chronic HCV. Twenty-one (53%) of the top 40 most utilized medications were classified as having interaction potential, with 62% of patients receiving at least one of the top 22 interacting medications by exposure. Of these, 59 and 41% were listed in a common DDI resource but not in medication-prescribing information, 77 and 77% had not been investigated in DDI studies, 41 and 36% did not have clear recommendations for DDI management, and only 14 and 23% carried a recommendation to avoid coadministration for boceprevir and telaprevir, respectively.

CONCLUSION

Practitioners may expect a medication with CYP3A DDI potential in two-thirds of patients with HCV and may expect almost one-half of the most frequently used medications to have CYP3A DDI potential. However, DDI potential may not be reflected in prescribing information.

Medication use and medical comorbidity in patients with chronic hepatitis C from a US commercial claims database: high utilization of drugs with interaction potential

BACKGROUND

With the advent of the direct-acting antiviral agents, significant drug-drug interaction (DDI) potential now exists for patients treated for chronic hepatitis C virus (HCV) infection. However, little is known about how often patients with HCV infection use medications that may interact with newer HCV treatments, especially those with cytochrome P450 3A (CYP3A) DDI potential.

METHODS

Using a large US commercial insurance database, medication use and comorbidity burden were examined among adult patients with a chronic HCV diagnosis from 2006 to 2010. Medications were examined in terms of total number of prescription claims, proportion of patients exposed, and DDI potential with the prototypical CYP3A direct-acting antiviral agents boceprevir and telaprevir, for which data were available.

RESULTS

Patient comorbidity burden was high and increased over the study period. Medication use was investigated in 53 461 patients with chronic HCV. Twenty-one (53%) of the top 40 most utilized medications were classified as having interaction potential, with 62% of patients receiving at least one of the top 22 interacting medications by exposure. Of these, 59 and 41% were listed in a common DDI resource but not in medication-prescribing information, 77 and 77% had not been investigated in DDI studies, 41 and 36% did not have clear recommendations for DDI management, and only 14 and 23% carried a recommendation to avoid coadministration for boceprevir and telaprevir, respectively.

CONCLUSION

Practitioners may expect a medication with CYP3A DDI potential in two-thirds of patients with HCV and may expect almost one-half of the most frequently used medications to have CYP3A DDI potential. However, DDI potential may not be reflected in prescribing information.