Ribavirin revisited in the era of direct-acting antiviral therapy for hepatitis C virus infection

An Antiherpesviral Host-Directed Strategy Based on CDK7 Covalently Binding Drugs: Target-Selective, Picomolar-Dose, Cross-Virus Reactivity

The repertoire of currently available antiviral drugs spans therapeutic applications against a number of important human pathogens distributed worldwide. These include cases of the pandemic severe acute respiratory coronavirus type 2 (SARS-CoV-2 or COVID-19), human immunodeficiency virus type 1 (HIV-1 or AIDS), and the pregnancy- and posttransplant-relevant human cytomegalovirus (HCMV). In almost all cases, approved therapies are based on direct-acting antivirals (DAAs), but their benefit, particularly in long-term applications, is often limited by the induction of viral drug resistance or side effects. These issues might be addressed by the additional use of host-directed antivirals (HDAs). As a strong input from long-term experiences with cancer therapies, host protein kinases may serve as HDA targets of mechanistically new antiviral drugs. The study demonstrates such a novel antiviral strategy by targeting the major virus-supportive host kinase CDK7. Importantly, this strategy focuses on highly selective, 3D structure-derived CDK7 inhibitors carrying a warhead moiety that mediates covalent target binding. In summary, the main experimental findings of this study are as follows: (1) the in vitro verification of CDK7 inhibition and selectivity that confirms the warhead covalent-binding principle (by CDK-specific kinase assays), (2) the highly pronounced antiviral efficacies of the hit compounds (in cultured cell-based infection models) with half-maximal effective concentrations that reach down to picomolar levels, (3) a particularly strong potency of compounds against strains and reporter-expressing recombinants of HCMV (using infection assays in primary human fibroblasts), (4) additional activity against further herpesviruses such as animal CMVs and VZV, (5) unique mechanistic properties that include an immediate block of HCMV replication directed early (determined by Western blot detection of viral marker proteins), (6) a substantial drug synergism in combination with MBV (measured by a Loewe additivity fixed-dose assay), and (7) a strong sensitivity of clinically relevant HCMV mutants carrying MBV or ganciclovir resistance markers. Combined, the data highlight the huge developmental potential of this host-directed antiviral targeting concept utilizing covalently binding CDK7 inhibitors.

Beyond genotype-4: Direct-acting antiviral agents in patients with chronic hepatitis C infection from the Eastern Province of Saudi Arabia

Background and Aims

Direct-acting antiviral agents (DAAs) have revolutionized the treatment of patients with chronic hepatitis C virus (HCV) infection, resulting in a high sustained virologic response (SVR) rate. However, the published data from the Eastern Province of Saudi Arabia are limited to small patient groups and specific DAAs used for patients with genotype-4.(GT-4). This study aimed to investigate the effectiveness and safety of DAAs for treating HCV infection in Saudi Arabia in a real-life setting.

Methods

This retrospective study from January 2015 to December 2019 included all HCV-infected patients who received DAAs at a tertiary university hospital in Saudi Arabia. Baseline characteristics and laboratory data were collected from health records, including HCV RNA level, genotype, and presence of liver cirrhosis or steatosis. The primary outcome was undetectable HCV RNA at 12 weeks posttreatment (SVR12). Results were stratified based on different DAAs and HCV genotypes. Treatment-related adverse events were recorded. Statistical analyses were performed using SPSS version 25.0.

Results

Of the 117 patients included, 43.2% had advanced fibrosis or cirrhosis, and the majority (90.6%) were treatment-naïve. The mean age was 50.1 ± 15.5 years, with 57.3% females. The most common genotype was GT-4 (44.4%), followed by GT-1 (40.2%). Most patients (64.3%) received sofosbuvir and daclatasvir ± ribavirin, while the remaining patients received various DAAs. Overall, 98.3% of the patients achieved SVR12. The therapy was well tolerated, with fatigue and headache being the most common side effects.

Conclusions

Treatment with DAAs is highly effective across different genotypes and various DDA regimens in the real world for treating HCV infection in the Eastern Province of Saudi Arabia, contributing to improved patient outcomes and the overall goal of HCV elimination.

A randomized controlled trial of SOF/VEL/VOX with or without ribavirin for retreatment of chronic hepatitis C

BACKGROUND & AIMS

The combination of sofosbuvir, velpatasvir and voxilaprevir (SOF/VEL/VOX) is recommended retreatment for patients with hepatitis C virus (HCV) infection who failed previous direct-acting antiviral (DAA) treatment. However, whether ribavirin further increases the therapeutic efficacy of SOF/VEL/VOX retreatment remains unclear. We aimed to test this hypothesis by a randomized controlled trial.

METHODS

We randomly assigned 315 patients with DAA treatment failure from 5 Egyptian sites into two groups. Group A (n=158) received SOF/VEL/VOX for 12 weeks, and group B (n=157) received SOF/VEL/VOX + weight-based ribavirin for 12 weeks. Therapeutic efficacy was defined as SVR12 (undetectable HCV RNA 12 weeks after treatment completion). Safety and tolerability were evaluated by monitoring treatment-related adverse events (AEs) and laboratory abnormalities.

RESULTS

Seventeen patients in each group were lost to follow-up. SVR12 rates by intention-to-treat (ITT) were 87.3% (138/158), and by per-protocol analysis, 97.8% (138/141) in group A; and 87.9% (138/157) and 98.5% (138/140) in group B (p=NS for ITT and PP). Males comprised 53.9% of group A, and 57.1% in group B (p=0.58), with mean ages of 51.8 and 47.3 years in group A and B, respectively. Both regimens were well-tolerated, with no deaths and only one serious AE (anemia) in group B requiring ribavirin discontinuation. Fifty-five patients in group A vs. 77 in group B experienced any adverse events (p=0.002).

CONCLUSION

This randomized controlled trial showed equal, high efficacy of both regiments in retreating previous DAA failures, although ribavirin was associated with more adverse events. Therefore SOF/VEL/VOX monotherapy should be the preferred retreatment strategy.

IMPACT AND IMPLICATIONS

HCV treatment guidelines recommend retreating DAA treatment failures with the combination of sofosbuvir, velpatasvir and voxilaprevir (SOF/VEL/VOX) for 12 weeks. However, whether ribavirin exerts an additional/synergistic effect remains unclear. The present study confirmed that SOF/VEL/VOX without ribavirin is the best regimen for retreating DAA treatment failures, and thus will help clinicians caring for patients who are not cured with a first course of DAA therapy. CLINCIALTRIALS.

GOV NUMBER

NCT04695769.

Efficacy and safety of ombitasvir/paritaprevir/ritonavir-based therapy in HCV patients with chronic kidney disease

BACKGROUND AND STUDY AIMS

Hepatitis C virus (HCV) prevalence inchronic kidney disease (CKD) patients is significantly higher than in the general population. This study evaluated the efficacy and safety of combined ombitasvir/paritaprevir/ritonavir-based therapy in HCV patients with renal impairment.

PATIENTS AND METHODS

Our study included 829 patients with normal kidney functions (group 1) and 829 patients with CKD (group 2),which were subdivided into patients not requiring dialysis (group 2a) and those on hemodialysis (group2b). Patients received regimens of ombitasvir/paritaprevir/ritonavir with or without ribavirin or sofosbuvir/ombitasvir/paritaprevir/ritonavir with or without ribavirin for 12 weeks. Clinical and laboratory assessment was done before treatment, and patients were followed up for12 weeks after treatment.

RESULTS

The sustained virological response (SVR) at week 12 was significantly higher in group 1 than in the other three groups/subgroups, being 94.2% vs 90.2%, 90%, and 90.7%, respectively. The regimen with the highest SVR was ombitasvir/paritaprevir/ritonavir with ribavirin. The most common adverse event was anemia, which was more common in group 2.

CONCLUSION

Ombitasvir/paritaprevir/ritonavir-based therapy in chronic HCV patients with CKD is highly effective, with minimal side effects despite ribavirin-induced anemia.

Mechanisms and Consequences of Genetic Variation in Hepatitis C Virus (HCV)

Chronic infection with hepatitis C virus (HCV) is an important contributor to the global incidence of liver diseases, including liver cirrhosis and hepatocellular carcinoma. Although common for single-stranded RNA viruses, HCV displays a remarkable high level of genetic diversity, produced primarily by the error-prone viral polymerase and host immune pressure. The high genetic heterogeneity of HCV has led to the evolution of several distinct genotypes and subtypes, with important consequences for pathogenesis, and clinical outcomes. Genetic variability constitutes an evasion mechanism against immune suppression, allowing the virus to evolve epitope escape mutants that avoid immune recognition. Thus, heterogeneity and variability of the HCV genome represent a great hindrance for the development of vaccines against HCV. In addition, the high genetic plasticity of HCV allows the virus to rapidly develop antiviral resistance mutations, leading to treatment failure and potentially representing a major hindrance for the cure of chronic HCV patients. In this chapter, we will present the central role that genetic diversity has in the viral life cycle and epidemiology of HCV. Incorporation errors and recombination, both the result of HCV polymerase activity, represent the main mechanisms of HCV evolution. The molecular details of both mechanisms have been only partially clarified and will be presented in the following sections. Finally, we will discuss the major consequences of HCV genetic diversity, namely its capacity to rapidly evolve antiviral and immunological escape variants that represent an important limitation for clearance of acute HCV, for treatment of chronic hepatitis C and for broadly protective vaccines.

Efficacy and safety of sofosbuvir/velpatasvir with or without ribavirin in hepatitis C genotype 3 compensated cirrhosis: A meta-analysis

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of liver cirrhosis and hepatocellular carcinoma globally. Sofosbuvir/velpatasvir (SOF/VEL) is an effective pan-genotypic direct-acting antiviral combination for treatment of chronic HCV infection. While the addition of ribavirin (RBV) to SOF/VEL improved sustained virological response (SVR12) in genotype 3 (GT3) decompensated cirrhosis patients, the benefits of RBV in GT3 compensated cirrhosis patients receiving SOF/VEL remains unclear.

AIM

To evaluate the efficacy and safety of SOF/VEL, with or without RBV in GT3 compensated cirrhosis patients.

METHODS

We searched four electronic databases (PubMed/Medline, Embase, Cochrane Library and Web of Science) from inception up to June 2021 using both free text and MeSH terms. There was no restriction on language, geography, publication dates and publication status (full text or abstracts). All GT3 compensated cirrhosis patients treated with 12 wk of SOF/VEL, with or without RBV, were included, regardless of age, gender or prior treatment experience. The primary outcome was sustained virological response 12-wk post-treatment (SVR12). The secondary outcome was treatment-related adverse events, as defined by symptomatic anemia requiring transfusion or a drop in hemoglobin beyond 2 g/dL. The pooled relative risk (RR), 95%CI and heterogeneity (I²) were estimated using Review Manager version 5.3.

RESULTS

From 1752 citations, a total of seven studies (2 randomized controlled trials, 5 cohort studies) with 1088 subjects were identified. The SVR12 was similar in GT3 compensated cirrhosis patients, regardless of the use of RBV, for both the intention-to-treat RR 1.03, 95%CI: 0.99-1.07; I² = 0%) and the per-protocol analysis (RR: 1.03, 95%CI: 0.99-1.07; I² = 48%). The overall pooled rate of treatment-related adverse events was 7.2%. Addition of RBV increased the pooled risk of treatment-related adverse events in GT3 compensated cirrhosis patients receiving SOF/VEL (RR: 4.20, 95%CI: 1.29-13.68; I² = 0%). Subgroup analysis showed that RBV was associated with a higher SVR12 in GT3 compensated cirrhosis patients with baseline resistance-associated substitutions. However, addition of RBV did not significantly increase the SVR12 among treatment-experienced GT3 compensated cirrhosis patients.

CONCLUSION

Ribavirin was not associated with higher SVR12 in GT3 compensated cirrhosis patients receiving SOF/VEL. Our findings suggest a limited role for RBV as routine add-on therapy to SOF/VEL in GT3 compensated cirrhosis patients.

Four Weeks Treatment with Glecaprevir/Pibrentasvir + Ribavirin-A Randomized Controlled Clinical Trial

Enhancing treatment uptake for hepatitis C to achieve the elimination goals set by the World Health Organization could be achieved by reducing the treatment duration. The aim of this study was to compare the sustained virological response at week 12 (SVR12) after four weeks of glecaprevir/pibrentasvir (GLE/PIB) + ribavirin compared to eight weeks of GLE/PIB and to estimate predictors for SVR12 with four weeks of treatment through a multicenter open label randomized controlled trial. Patients were randomized 2:1 (4 weeks:8 weeks) and stratified by genotype 3 and were treatment naïve of all genotypes and without significant liver fibrosis. A total of 27 patients were analyzed for predictors for SVR12, including 15 from the first pilot phase of the study. In the ‘modified intention to treat’ group, 100% (7/7) achieved cure after eight weeks and for patients treated for four weeks the SVR12 was 58.3% (7/12). However, patients with a baseline viral load <2 mill IU/mL had 93% SVR12. The study closed prematurely due to the low number of included patients due to the COVID-19 pandemic. Our results suggest that viral load should be taken into account when considering trials of short course treatment.

Characterization of the NiRAN domain from RNA-dependent RNA polymerase provides insights into a potential therapeutic target against SARS-CoV-2

Apart from the canonical fingers, palm and thumb domains, the RNA dependent RNA polymerases (RdRp) from the viral order Nidovirales possess two additional domains. Of these, the function of the Nidovirus RdRp associated nucleotidyl transferase domain (NiRAN) remains unanswered. The elucidation of the 3D structure of RdRp from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), provided the first ever insights into the domain organisation and possible functional characteristics of the NiRAN domain. Using in silico tools, we predict that the NiRAN domain assumes a kinase or phosphotransferase like fold and binds nucleoside triphosphates at its proposed active site. Additionally, using molecular docking we have predicted the binding of three widely used kinase inhibitors and five well characterized anti-microbial compounds at the NiRAN domain active site along with their drug-likeliness. For the first time ever, using basic biochemical tools, this study shows the presence of a kinase like activity exhibited by the SARS-CoV-2 RdRp. Interestingly, a well-known kinase inhibitor- Sorafenib showed a significant inhibition and dampened viral load in SARS-CoV-2 infected cells. In line with the current global COVID-19 pandemic urgency and the emergence of newer strains with significantly higher infectivity, this study provides a new anti-SARS-CoV-2 drug target and potential lead compounds for drug repurposing against SARS-CoV-2.

The on-going coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is significantly affecting the world health. Unfortunately, over 180 million cases of COVID-19 resulting in nearly 4 million deaths have been reported till June, 2021. In this study, using a combination of bioinformatics, biochemical and mass spectrometry methods, we show that the Nidovirus RdRp associated Nucleotidyl transferase (NiRAN) domain of the RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 exhibits a kinase like activity. Additionally, we also show that few broad spectrum anti-cancer and anti-microbial drugs dampen this kinase like activity. Of note, Sorafenib, an FDA approved anti-cancer kinase inhibiting drug significantly reduces the SARS-CoV-2 load in cell lines. Our study suggests that NiRAN domain of the SARS-CoV-2 RdRp is indispensible for the successful viral life cycle and shows that abolishing this enzymatic function of RdRp by small molecule inhibitors may open novel avenues for COVID-19 therapeutics.

Characterization of the NiRAN domain from RNA-dependent RNA polymerase provides insights into a potential therapeutic target against SARS-CoV-2

Apart from the canonical fingers, palm and thumb domains, the RNA dependent RNA polymerases (RdRp) from the viral order Nidovirales possess two additional domains. Of these, the function of the Nidovirus RdRp associated nucleotidyl transferase domain (NiRAN) remains unanswered. The elucidation of the 3D structure of RdRp from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), provided the first ever insights into the domain organisation and possible functional characteristics of the NiRAN domain. Using in silico tools, we predict that the NiRAN domain assumes a kinase or phosphotransferase like fold and binds nucleoside triphosphates at its proposed active site. Additionally, using molecular docking we have predicted the binding of three widely used kinase inhibitors and five well characterized anti-microbial compounds at the NiRAN domain active site along with their drug-likeliness. For the first time ever, using basic biochemical tools, this study shows the presence of a kinase like activity exhibited by the SARS-CoV-2 RdRp. Interestingly, a well-known kinase inhibitor- Sorafenib showed a significant inhibition and dampened viral load in SARS-CoV-2 infected cells. In line with the current global COVID-19 pandemic urgency and the emergence of newer strains with significantly higher infectivity, this study provides a new anti-SARS-CoV-2 drug target and potential lead compounds for drug repurposing against SARS-CoV-2.

Strategic treatment optimization for HCV (STOPHCV1): a randomised controlled trial of ultrashort duration therapy for chronic hepatitis C

Background: The World Health Organization (WHO) has identified the need for a better understanding of which patients with hepatitis C virus (HCV) can be cured with ultrashort course HCV therapy. Methods: A total of 202 individuals with chronic HCV were randomised to fixed-duration shortened therapy (8 weeks) vs variable-duration ultrashort strategies (VUS1/2). Participants not cured following first-line treatment were retreated with 12 weeks' sofosbuvir/ledipasvir/ribavirin. The primary outcome was sustained virological response 12 weeks (SVR12) after first-line treatment and retreatment. Participants were factorially randomised to receive ribavirin with first-line treatment. Results: All evaluable participants achieved SVR12 overall (197/197, 100% [95% CI 98-100]) demonstrating non-inferiority between fixed-duration and variable-duration strategies (difference 0% [95% CI -3.8%, +3.7%], 4% pre-specified non-inferiority margin). First-line SVR12 was 91% [86%-97%] (92/101) for fixed-duration vs 48% [39%-57%] (47/98) for variable-duration, but was significantly higher for VUS2 (72% [56%-87%] (23/32)) than VUS1 (36% [25%-48%] (24/66)). Overall, first-line SVR12 was 72% [65%-78%] (70/101) without ribavirin and 68% [61%-76%] (69/98) with ribavirin (p=0.48). At treatment failure, the emergence of viral resistance was lower with ribavirin (12% [2%-30%] (3/26)) than without (38% [21%-58%] (11/29), p=0.01). Conclusions: Unsuccessful first-line short-course therapy did not compromise retreatment with sofosbuvir/ledipasvir/ribavirin (100% SVR12). SVR12 rates were significantly increased when ultrashort treatment varied between 4-7 weeks rather than 4-6 weeks. Ribavirin significantly reduced resistance emergence in those failing first-line therapy. ISRCTN Registration: 37915093 (11/04/2016).

Strategic treatment optimization for HCV (STOPHCV1): a randomised controlled trial of ultrashort duration therapy for chronic hepatitis C

Background: The world health organization (WHO) has identified the need for a better understanding of which patients with hepatitis C virus (HCV) can be cured with ultrashort course HCV therapy. Methods: A total of 202 individuals with chronic HCV were randomised to fixed-duration shortened therapy (8 weeks) vs variable-duration ultrashort strategies (VUS1/2). Participants not cured following first-line treatment were retreated with 12 weeks' sofosbuvir/ledipasvir/ribavirin. The primary outcome was sustained virological response 12 weeks (SVR12) after first-line treatment and retreatment. Participants were factorially randomised to receive ribavirin with first-line treatment. Results: All evaluable participants achieved SVR12 overall (197/197, 100% [95% CI 98-100]) demonstrating non-inferiority between fixed-duration and variable-duration strategies (difference 0% [95% CI -3.8%, +3.7%], 4% pre-specified non-inferiority margin). First-line SVR12 was 91% [86%-97%] (92/101) for fixed-duration vs 48% [39%-57%] (47/98) for variable-duration, but was significantly higher for VUS2 (72% [56%-87%] (23/32)) than VUS1 (36% [25%-48%] (24/66)). Overall, first-line SVR12 was 72% [65%-78%] (70/101) without ribavirin and 68% [61%-76%] (69/98) with ribavirin (p=0.48). At treatment failure, the emergence of viral resistance was lower with ribavirin (12% [2%-30%] (3/26)) than without (38% [21%-58%] (11/29), p=0.01). Conclusions: Unsuccessful first-line short-course therapy did not compromise retreatment with sofosbuvir/ledipasvir/ribavirin (100% SVR12). SVR12 rates were significantly increased when ultrashort treatment varied between 4-7 weeks rather than 4-6 weeks. Ribavirin significantly reduced resistance emergence in those failing first-line therapy. ISRCTN Registration: 37915093 (11/04/2016).

Novel combined single dose anti-hepatitis C therapy: a pilot study

The new anti-hepatitis C virus (HCV) molecules improve treatment regimens and outcomes, but there are drawbacks. New combinations should target the HCV infectious cycle and be effective against all HCV genotypes. We developed the novel formulation Catvira, composed of epigallocatechingallate (EGCG) + sofosbuvir + ribavirin. Here, we compared Catvira to sofosbuvir + ribavirin tablets in patients with CHC genotype 4 in a randomized open-label efficacy and safety study. Treatment-naïve and treatment-experienced patients (n = 80) were randomly assigned to receive a single daily fixed dose of Catvira or sofosbuvir + ribavirin for 12 or 24 weeks. Both Catvira and sofosbuvir + ribavirin yielded similar outcomes of viral load (p < 0.001). Patients receiving Catvira had a significantly more rapid rate of viral load decline with sustained virologic response (SVR12) achieved by 90% of patients receiving 12 weeks of treatment. Catvira did not impact hemoglobin levels while sofosbuvir + ribavirin showed significant decline in hemoglobin levels after 24 weeks (p < 0.05). In this clinical trial (ClinicalTrials.gov Identifier NCT02483156), we found that Catvira administered daily for 12 or 24 weeks is safe, effective, and well-tolerated in both naïve and treatment-experienced patients with HCV genotype 4.

Treatment of hepatitis C virus infection with direct-acting antivirals plus ribavirin eliminates viral RNA from peripheral blood mononuclear cells and reduces virologic relapse in diverse hepatic parenchymal changes

Elimination of hepatitis C virus (HCV) may fail, leading to a non-response outcome because of inappropriate testing for viral RNA in peripheral blood mononuclear cells (PBMCs). Sequelae of HCV genotype 4 therapy with sofosbuvir and daclatasvir ± ribavirin were assessed in our study at the 12^th week after end of treatment (EOT) by screening for viral genomic RNA in serum and PBMCs with correlation to hepatic parenchymal changes. We recruited 102 out of 2165 patients who had received sofosbuvir/daclatasvir, either alone (n = 1573) or together with ribavirin (n = 592). Subjects were classified into three groups based on testing by single-step reverse transcription PCR: group I, HCV negative in both serum and PBMCs (n = 25); group II, HCV positive in PBMCs only (n = 52); and group III, HCV positive in both serum and PBMCs (n = 25). Groups I and II (n = 77) were selected out of 2102 (every 27^th subject), while group III (n = 25) were selected from every second or third serologic relapse (n = 63). The pre-sampling population (n = 2165) showed sustained virologic response (SVR) in 33.21%; serologic relapse in 2.91%; HCV RNA only in PBMCs (66.79%) compared to serologic relapses and potential cure (P < 0.0001); higher serologic (38 out of 63, P = 0.03210) and cellular (36 out of 52, P = 0.0002) relapses in dual therapy than in triple therapy. The post-sampling population (n = 102) showed more HCV relapses in dual (50 out of 60) than in triple (27 out of 42) therapy (P = 0.0351); increased HCV antisense RNA strand in relapses compared to positive-sense strands alone (P < 0.001); and significant SVR events in undetectable (15 out of 31) compared to early (10 out of 55, P = 0.0058) and cirrhotic liver tissue changes (0 out of 16, P = 0.0006). In summary, HCV treatment with sofosbuvir/daclatasvir is followed by higher rates of serologic and intracellular viral RNA relapse than treatment with sofosbuvir/daclatasvir plus ribavirin. Cellular and serum viral RNA relapses are accompanied by HCV-induced hepatic pathology. An increased SVR with no detectable liver tissue changes was observed after triple therapy due to elimination of HCV RNA from PBMCs.

Mutations Identified in the Hepatitis C Virus (HCV) Polymerase of Patients with Chronic HCV Treated with Ribavirin Cause Resistance and Affect Viral Replication Fidelity

Ribavirin has been used for 25 years to treat patients with chronic hepatitis C virus (HCV) infection; however, its antiviral mechanism of action remains unclear. Here, we studied virus evolution in a subset of samples from a randomized 24-week trial of ribavirin monotherapy versus placebo in chronic HCV patients, as well as the viral resistance mechanisms of the observed ribavirin-associated mutations in cell culture. Thus, we performed next-generation sequencing of the full-length coding sequences of HCV recovered from patients at weeks 0, 12, 20, 32 and 40 and analyzed novel single nucleotide polymorphisms (SNPs), diversity, and mutation-linkage. At week 20, increased genetic diversity was observed in 5 ribavirin-treated compared to 4 placebo-treated HCV patients due to new synonymous SNPs, particularly G-to-A and C-to-U ribavirin-associated transitions. Moreover, emergence of 14 nonsynonymous SNPs in HCV nonstructural 5B (NS5B) occurred in treated patients, but not in placebo controls. Most substitutions located close to the NS5B polymerase nucleotide entry site. Linkage analysis showed that putative resistance mutations were found in the majority of genomes in ribavirin-treated patients. Identified NS5B mutations from genotype 3a patients were further introduced into the genotype 3a cell-culture-adapted DBN strain for studies in Huh7.5 cells. Specific NS5B substitutions, including DBN-D148N+I363V, DBN-A150V+I363V, and DBN-T227S+S183P, conferred resistance to ribavirin in long-term cell culture treatment, possibly by reducing the HCV polymerase error rate. In conclusion, prolonged exposure of HCV to ribavirin in chronic hepatitis C patients induces NS5B resistance mutations leading to increased polymerase fidelity, which could be one mechanism for ribavirin resistance.

Potential treatment methods targeting 2019-nCoV infection

The novel coronavirus, 2019-nCoV, has quickly spread across the world and pose serious threat to public health because it can infect people very easily. The major clinical symptoms of 2019-nCoV infection include fever, dry cough, myalgia, fatigue, and diarrhea. The 2019-nCoV belongs to the betacoronavirus family, and gene sequencing results demonstrate that it is a single-stranded RNA virus, closely related to Severe Acute Respiratory Syndrome CoV (SARS-CoV) and Middle East Respiratory Syndrome CoV (MERS-CoV). It has been observed that the virus invades human body mainly through binding to angiotensin-converting enzyme 2 (ACE2) receptors similar to SARS-CoV and the main protease (Mpro) acts as a critical protease for digesting the polyprotein into functional polypeptides during the replication and transcription process of 2019-nCoV. In this review, we summarized the real-time information of 2019-nCoV treatment methods and mainly focused on the chemical drugs including lopinavir/ritonavir, chloroquine, hydroxychloroquine, arbidol, remdesivir, favipiravir and other potential innovative active molecules. Their potential targets, activity, clinical status and side effects are described. In addition, Traditional Chinese Medicine (TCM), Convalescent plasma therapy (CPT) and biological reagents available, as well as the promising vaccine candidates against 2019-nCoV are also discussed.

Anti-rods/rings autoantibody and IMPDH filaments: an update after fifteen years of discovery

Autoantibodies to unknown subcellular rod and ring-shaped structures were first discovered in sera from hepatitis C patients in 2005. Early studies showed a strong association between these anti-rods/rings antibodies (anti-RR) and the standard of care interferon-α plus ribavirin combination therapy (IFN/RBV), suggesting that anti-RR are drug-induced autoantibodies. In the context of hepatitis C, anti-RR have been linked with relapse from or lack of response to IFN/RBV in some patient cohorts. However, examples of anti-RR in other diseases and healthy individuals have also been reported over the years, although anti-RR remains a rare autoantibody response in general. The advent of new direct-acting antiviral drugs for chronic hepatitis C and studies of anti-RR from different parts of the world are also beginning to change the perception of anti-RR. The nucleotide biosynthetic enzyme inosine monophosphate dehydrogenase (IMPDH) has been identified as the major autoantigen recognized by anti-RR. Coincidentally, the assembly of IMPDH into micron-scale rod and ring-shaped structures was discovered around the same time as anti-RR. Knowledge of the fundamental biological properties and cellular functions of these structures, referred to as "IMPDH filaments" by cell biologists, has advanced in parallel to anti-RR antibodies. Recent studies have revealed that IMPDH filament assembly is a mechanism to prevent feedback inhibition of IMPDH and is therefore important for the increased nucleotide production required in hyperproliferating cells, like activated T cells. Fifteen years later, we review the history and current knowledge in both the anti-RR autoantibody and IMPDH filament fields. TAKE-HOME MESSAGE: Anti-rods/rings are recognized as an example of a drug-induced autoantibody in hepatitis C patients treated with interferon and ribavirin, although new studies suggest anti-rods/rings may be detected in other contexts and may depend on unknown environmental or genetic factors in different populations. Recent data suggest that the assembly of IMPDH into rod and ring structures, the targets of anti-rods/rings autoantibody, is a mechanism for hyperproliferating cells, like activated T cells, to maintain increased guanine nucleotide levels to support rapid cell division.

Enhanced Efficacy of Direct-Acting Antivirals in Hepatitis C Patients by Coadministration of Black Cumin and Ascorbate as Antioxidant Adjuvants

The widespread adaptation of a new generation of direct-acting antiviral agents (DAAs) unveils a superlative effect in the eradication of the hepatitis C virus (HCV). However, this therapy has been reported to exhibit vigorous side effects that pose a risk in fleet recovery. This study was conducted to investigate the efficacy of DAAs: sofosbuvir (SOF) and ribavirin (RBV), along with black cumin (BLC) and ascorbate (ASC), as adjuvants on hematological parameters; oxidative stress markers such as total antioxidant status (TAS), superoxide dismutase (SOD), reduced (GSH) and oxidized (GSSG) glutathione (GSH), gamma-glutamyl transferase (GGT), and malondialdehyde (MDA); liver function markers such as aspartate transaminase (AST), alanine aminotransferase (ALT), bilirubin, and alkaline phosphatase (ALP); and viral load with determined genotypes. HCV-infected patients (n = 30) were randomly divided into two equal groups: control group (n = 15) and treatment group (n = 15). The control group was subjected only to SOF and RBV (400 mg each/day). Synergistically, the treatment group was administered with adjuvant therapy of BLC (250 mg/day) and ASC (1000 mg/day) along with DAAs (400 mg each/day) for 8 weeks. All selected patients were subjected to sampling at pre- and posttreatment stages for the assessment of defined parameters. The data revealed that the BLC/ASC adjuvant therapy boosted the efficacy of DAAs by reducing the elevated levels of liver markers such as AST, ALT, ALP, and bilirubin in the treatment group compared with those in the control group (P > 0.05). The adjuvant therapy synchronously showed an ameliorating effect on hematological parameters. The SOF/RBV with adjuvant therapy also demonstrated an increasing effect in the activity of SOD, TAS, and GSH and a decreasing effect for GSSG, GGT, and malondialdehyde (MDA; P > 0.05) followed by curtailing a RT-PCR-quantified viral load. Our findings provide evidence that systemic administration of BLC/ASC efficiently alleviates hematological, serological, and antioxidant markers as well as the viral load in hepatitis C patients. This highlights a potentially novel role of BLC and ASC in palliating hepatitis C.

Role of Ribavirin in the Era of Direct-Acting Antiviral Therapies of Chronic Hepatitis C

BACKGROUND

The efficacy of adding ribavirin (RBV) to direct antivirals (DAAs) in HCV treatment is still debatable, with allegations of insecure profiles.

OBJECTIVES

To evaluate safety and efficacy of RBV in the era of DAAs in chronic HCV Egyptian patients.

METHODS

In this cohort retrospective study, data of 847 HCV patients treated with different regimens of DAAs with or without RBV were recruited between June 2017 and September 2018. Cases were categorized into five groups: non-cirrhotic (318), compensated (196), decompensated liver cirrhosis (53), post liver transplantation (30), and 250 treatment experienced patients. All patients' demographics and laboratory characteristics were evaluated at baseline, week_{4, 12, 24} of treatment. Ribavirin was prescribed or banned outside international guideline recommendations of HCV treatment in cases assembled from the private sector.Results: No statistically significant difference between RBV and non-RBV treated patients was documented regarding SVR₁₂ (97.2%, 97.8%) respectively in the whole cohort (p 0.509). On grouping, adding RBV was only significant in the treatment experienced patients (96.8%, 85% in RBV and non-RBV regimens respectively) (p 0.001). Adding RBV to DAA regimens was generally associated with modest adverse events particularly anemia (8.5%), and hepatic decompensation (jaundice and ascites) (0.3%). Bilirubin, INR, and platelet counts all were found to be the most independent predictors of SVR achievement by multivariate analysis (p ≤ 0.05).Conclusion: RBV may still have an augmenting role in treatment experienced patients; permitting effectual shortening of therapy particularly in patients with cirrhosis, with modest side and adverse consequences.

Antiviral Effects of Novel 2-Benzoxyl-Phenylpyridine Derivatives

Coxsackievirus B3 (CVB3) is the most common cause of acute and chronic viral myocarditis, primarily in children, while human adenovirus infections represent a significant cause of morbidity and mortality worldwide, in people of all ages. A series of novel 2-benzoxyl-phenylpyridine derivatives were evaluated for their potential antiviral activities against CVB3 and adenovirus type 7 (ADV7). Preliminary assays indicated that some of these compounds exhibited excellent antiviral effects on both CVB3 and ADV7 viruses; they could effectively inhibit virus-induced cytopathic effects, reduce viral progeny yields, and had similar or superior antiviral activities compared with the control drug, ribavirin. Further, these compounds targeted the early stages of CVB3 replication in cells, including viral RNA replication and protein synthesis, rather than inactivating the virus directly, inhibiting virus adsorption/entry, or affecting viral release from cells. Our data demonstrate that the tested 2-benzoxyl-phenylpyridine derivatives are effective inhibitors of CVB3 and ADV7, raising the possibility that these compounds might be feasible candidates for anti-viral agents.

Medicinal chemistry strategies toward host targeting antiviral agents

Direct‐acting antiviral agents (DAAs) represent a class of drugs targeting viral proteins and have been demonstrated to be very successful in combating viral infections in clinic. However, DAAs suffer from several inherent limitations, including narrow‐spectrum antiviral profiles and liability to drug resistance, and hence there are still unmet needs in the treatment of viral infections. In comparison, host targeting antivirals (HTAs) target host factors for antiviral treatment. Since host proteins are probably broadly required for various viral infections, HTAs are not only perceived, but also demonstrated to exhibit broad‐spectrum antiviral activities. In addition, host proteins are not under the genetic control of viral genome, and hence HTAs possess much higher genetic barrier to drug resistance as compared with DAAs. In recent years, much progress has been made to the development of HTAs with the approval of chemokine receptor type 5 antagonist maraviroc for human immunodeficiency virus treatment and more in the pipeline for other viral infections. In this review, we summarize various host proteins as antiviral targets from a medicinal chemistry prospective. Challenges and issues associated with HTAs are also discussed.

Preclinical evaluation of AT-527, a novel guanosine nucleotide prodrug with potent, pan-genotypic activity against hepatitis C virus

Despite the availability of highly effective direct-acting antiviral (DAA) regimens for the treatment of hepatitis C virus (HCV) infections, sustained viral response (SVR) rates remain suboptimal for difficult-to-treat patient populations such as those with HCV genotype 3, cirrhosis or prior treatment experience, warranting development of more potent HCV replication antivirals. AT-527 is the hemi-sulfate salt of AT-511, a novel phosphoramidate prodrug of 2’-fluoro-2’-C-methylguanosine-5'-monophosphate that has potent in vitro activity against HCV. The EC₅₀ of AT-511, determined using HCV laboratory strains and clinical isolates with genotypes 1–5, ranged from 5–28 nM. The active 5'-triphosphate metabolite, AT-9010, specifically inhibited the HCV RNA-dependent RNA polymerase. AT-511 did not inhibit the replication of other selected RNA or DNA viruses in vitro. AT-511 was approximately 10-fold more active than sofosbuvir (SOF) against a panel of laboratory strains and clinical isolates of HCV genotypes 1–5 and remained fully active against S282T resistance-associated variants, with up to 58-fold more potency than SOF. In vitro, AT-511 did not inhibit human DNA polymerases or elicit cytotoxicity or mitochondrial toxicity at concentrations up to 100 μM. Unlike the other potent guanosine analogs PSI-938 and PSI-661, no mutagenic O⁶-alkylguanine bases were formed when incubated with cytochrome P450 (CYP) 3A4, and AT-511 had IC₅₀ values ≥25 μM against a panel of CYP enzymes. In hepatocytes from multiple species, the active triphosphate was the predominant metabolite produced from the prodrug, with a half-life of 10 h in human hepatocytes. When given orally to rats and monkeys, AT-527 preferentially delivered high levels of AT-9010 in the liver in vivo. These favorable preclinical attributes support the ongoing clinical development of AT-527 and suggest that, when used in combination with an HCV DAA from a different class, AT-527 may increase SVR rates, especially for difficult-to-treat patient populations, and could potentially shorten treatment duration for all patients.

Ribavirin facilitates early viral kinetics in chronic hepatitis C patients receiving daclatasvir/asunaprevir

BACKGROUND AND AIM

Ribavirin (RBV) remains crucial in difficult-to-cure chronic hepatitis C patients receiving directly acting antivirals (DAAs). The current study aimed to address whether RBV enhanced early viral kinetics in patients with DAAs.

METHODS

Hepatitis C virus (HCV) genotype-1b patients were allocated to daclatasvir/asunaprevir +weight-based RBV (1000-1200 mg/day) for 12-24 weeks. HCV RNA levels were compared at day 1, week 1, week 2, and week 4 of treatment.

RESULTS

The sustained virological response rate was 100% (67/67) and 96.7% (59/61) in the RBV and non-RBV group, respectively. The HCV RNA levels at treatment week 2 (W2) were significantly lower in the RBV group than in the non-RBV group (0.42 ± 0.81 log IU/mL vs 0.79 ± 1.03 log IU/mL, P = 0.04). Among the intermediate responders who remained to have detectable RNA after W1 of treatment, patients with RBV had a significantly higher rate of undetectable HCV RNA (71.4% vs 36.0%, P = 0.003) and lower HCV RNA level at W2 (0.55 ± 0.89 log IU/mL vs 1.32 ± 1.04 log IU/mL, P = 0.001). A more significant magnitude of HCV RNA reduction was also noted from baseline to day 1 (3.15 ± 0.38 log IU/mL vs 2.80 ± 0.70 log IU/mL, P = 0.009) and W1 to W2 (1.40 ± 0.65 log IU/mL vs 0.88 ± 0.78 log IU/mL, P = 0.007) in the RBV group compared to the non-RBV group among the intermediate responders. Logistic regression analysis revealed that adding RBV independently predicted undetectable HCV RNA at W2 (odds ratio/confidence interval: 4.74/1.54-14.57, P = 0.007) in the intermediate responders.

CONCLUSIONS

Adding RBV to DAAs improved early viral kinetic, in particular, for intermediate responders.

Adjuvant ribavirin and longer direct-acting antiviral treatment duration improve sustained virological response among hepatitis C patients at risk of treatment failure

The role of ribavirin (RBV) in the era of direct-acting antivirals (DAA) is not clear, and DAA studies have been largely genotype- and regimen-specific. Using data from the Chronic Hepatitis Cohort Study, we evaluated the role of RBV and increased DAA treatment duration among patients with chronic hepatitis C (HCV) in routine clinical care. We performed multivariable analysis of data from 4133 patients receiving any of the following: sofosbuvir (SOF); daclatasvir + SOF; grazoprevir + elbasvir; paritaprevir/ritonavir + ombitasvir; simeprevir + SOF; and SOF + ledipasvir; SOF + velpatasvir ± voxilaprevir; and glecaprevir + pibrentasvir-all with/ without RBV. Inverse probability treatment weighting was used to adjust for treatment selection bias. Sustained virological response (SVR) was defined by undetectable HCV RNA 12 weeks after end of therapy. The overall SVR rate was 95%. Mean treatment duration was 12 ± 4.5 weeks. The final model included treatment duration and diabetes, as well as the interaction of RBV with previous treatment status (treatment naïve, interferon treatment failure [TF] or previous DAA TF), cirrhosis status, and HCV genotype (GT). Each one-month increment of treatment duration increased odds of SVR by 99% (aOR = 1.99). Diabetes, previous DAA TF, and decompensated cirrhosis significantly reduced odds of SVR. RBV significantly increased the likelihood of SVR among patients with decompensated cirrhosis (aOR = 5.05), previous DAA treatment failure (aOR = 5.43), and GT3 (aOR = 13.28). Among RBV-free regimens, patients with GT3 were less likely to achieve SVR than those with GT1 or 2 (aOR 0.07). Diabetes, decompensated cirrhosis, and prior DAA TF independently reduced the likelihood of SVR. Longer treatment duration increased likelihood of SVR. Conclusion: RBV increased likelihood of SVR among patients with GT3, previous DAA TF, or decompensated cirrhosis.

Ribavirin inhibition of cell-culture infectious hepatitis C genotype 1-3 viruses is strain-dependent

Ribavirin remains relevant for successful treatment of chronic hepatitis C virus (HCV) infections in low-income settings, as well as for therapy of difficult-to-treat HCV patients. We studied the effect of ribavirin against cell-culture adapted HCV of genotypes 1, 2 and 3, representing ~80% of global infections. TNcc(1a) was the most sensitive to ribavirin, while J6/JFH1(2a) was the most resistant. EC₅₀s ranged from 21 μM (95%CI: 20-22 μM) to 189 μM (95%CI: 173-207 μM). Substitutions at position 415 of NS5B resulted in little or no change to ribavirin sensitivity (0.7-0.9 fold) but conferred moderate drug resistance during extended treatment of genotype 1 (1.8-fold). NS5A and NS5B sequences could alter ribavirin sensitivity 2-4-fold, although their contribution was not simply additive. Finally, we detected limited accumulation of mutations associated with ribavirin treatment. Our findings show that the antiviral effect of ribavirin on HCV is strain-dependent and is influenced by the specific sequence of multiple HCV nonstructural proteins.

Bauhinia holophylla (Bong.) Steud. leaves-derived extracts as potent anti-dengue serotype 2

Dengue virus (DENV) is the most prevalent mosquito-borne viral pathogen and made the disease a major health concern worldwide. However, specific antiviral drugs against this arbovirose or vaccines are not yet available for treatment or prevention. Thus, here we aimed to study the antiviral activity of hydroethanolic extract, fraction ethyl acetate and subfractions of the leaves of Bauhinia holophylla (Fabaceae:Cercideae), a native plant of the Brazilian Cerrado, against DENV-2 by methylthiazolyldiphenyl-tetrazolium bromide (MTT) method in mammalian cells culture. As results, the hydroethanolic extract showed the most potent effect, with an inhibitory concentration (IC₅₀) of 3.2 μg mL^-1 and selectivity index (SI) of 27.6, approximately 16-times higher anti-DENV-2 activity than of the ribavirin (IC₅₀ 52.8 μg mL^-1). Our results showed in this study appointed that B. holophylla has a promising anti-dengue activity, which was associated mainly with the presence of flavonoids.

Efficacy and safety of ombitasvir/paritaprevir/ritonavir and dasabuvir with low-dose ribavirin in patients with chronic hepatitis C virus genotype 1a infection without cirrhosis

Patients infected with hepatitis C virus (HCV) treated with interferon-free direct-acting antivirals may still require ribavirin. However, ribavirin is associated with adverse events that can limit its use. This open-label, multicentre, Phase 3 study evaluated the safety and efficacy of ombitasvir/paritaprevir/ritonavir + dasabuvir (OBV/PTV/r + DSV) with low-dose ribavirin for 12 weeks in genotype 1a-infected patients without cirrhosis. The primary efficacy endpoint was sustained virologic response at post-treatment Week 12 (SVR12). The primary safety endpoint was haemoglobin <10 g/dL during treatment and decreased from baseline. Overall, 105 patients enrolled. The SVR12 rate was 89.5% (n/N = 94/105; 95% CI, 83.7-95.4). The study did not achieve noninferiority versus the historic SVR12 rate for OBV/PTV/r + DSV plus weight-based ribavirin. Five patients experienced virologic failure, four discontinued, and two had missing SVR12 data. Excluding nonvirologic failures, the SVR12 rate was 94.9% (n/N = 94/99). One patient met the primary safety endpoint. OBV/PTV/r + DSV plus low-dose ribavirin offers an alternative option for patients in whom full-dose ribavirin may compromise tolerability, although noninferiority to the weight-based ribavirin regimen was not met.

Reference standards for the detection of anti-mitochondrial and anti-rods/rings autoantibodies

Background:

Anti-mitochondrial antibodies (AMA) are found in >90% of primary biliary cholangitis patients. Anti-rods/rings antibodies (anti-RR) are most commonly associated with interferon-α and ribavirin treatment in hepatitis C patients. Clinical laboratories routinely screen for AMA and anti-RR using indirect immunofluorescence on HEp-2 cells (HEp-2-IFA). Therefore, we sought to establish reference materials for use in AMA and anti-RR testing.

Methods:

AMA-positive and anti-RR-positive human plasma samples (AMA-REF and RR-REF), identified as potential reference materials based on preliminary data, were further validated by multiple laboratories using HEp-2-IFA, immunoprecipitation (IP), western blotting, IP-western, line immunoassay (LIA), addressable laser bead immunoassay (ALBIA) and enzyme-linked immunosorbent assay (ELISA).

Results:

AMA-REF showed a strong positive cytoplasmic reticular/AMA staining pattern by HEp-2-IFA to ≥1:1280 dilution and positive signal on rodent kidney/stomach/liver tissue. AMA-REF reacted with E2/E3, E3BP, E1α and E1β subunits of the pyruvate dehydrogenase complex by IP and western blotting and was positive for AMA antigens by LIA, ALBIA and ELISA. RR-REF showed a strong positive rods and rings staining pattern by HEp-2-IFA to ≥1:1280 dilution. RR-REF reacted with inosine monophosphate dehydrogenase by IP, IP-western and ALBIA. RR-REF also produced a nuclear homogenous staining pattern by HEp-2-IFA, immunoprecipitated proteins associated with anti-U1RNP antibody and reacted weakly with histones, nucleosomes, Sm and nRNP/Sm by LIA.

Conclusions:

AMA-REF and RR-REF are useful reference materials for academic or commercial clinical laboratories to calibrate and establish internal reference standards for immunodiagnostic assays. AMA-REF and RR-REF are now available for free distribution to qualified laboratories through Plasma Services Group.

Timing of hepatitis C virus infection treatment in kidney transplant candidates

Hepatitis C virus (HCV) infection is prevalent in patients with kidney disease including transplant candidates and recipients. It is associated with increased morbidity and mortality in end-stage renal disease patients and also increases the risk of allograft rejection and decreases allograft and patient survival post-transplant. Newly developed direct acting antivirals have revolutionized the way HCV is treated. Whether patients are treated before or after kidney transplantation, the cure rates with direct acting antivirals are >90%. Great debate has formed revolving the optimal timing to treat kidney transplant candidates. On the one hand, treatment before transplantation decreases early post-transplant complications related to HCV. On the other, postponing treatment until after transplantation opens the possibility of transplanting a kidney from a HCV positive donor, which is associated with shorter waiting time and improved organ utilization by expanding the organ donor pool. Most patients living in an area where waiting time is reduced by accepting an HCV positive kidney would benefit by the strategy of treatment post-transplantation, but this decision needs to be individualized in a patient-by-patient basis given that there are special circumstances (i.e., severe HCV-related extrahepatic manifestations, availability of live donors, etc.) in which treatment before transplant might be preferred.

Mechanism of Inhibition of Ebola Virus RNA-Dependent RNA Polymerase by Remdesivir

Remdesivir (GS-5734) is a 1'-cyano-substituted adenosine nucleotide analogue prodrug that shows broad-spectrum antiviral activity against several RNA viruses. This compound is currently under clinical development for the treatment of Ebola virus disease (EVD). While antiviral effects have been demonstrated in cell culture and in non-human primates, the mechanism of action of Ebola virus (EBOV) inhibition for remdesivir remains to be fully elucidated. The EBOV RNA-dependent RNA polymerase (RdRp) complex was recently expressed and purified, enabling biochemical studies with the relevant triphosphate (TP) form of remdesivir and its presumptive target. In this study, we confirmed that remdesivir-TP is able to compete for incorporation with adenosine triphosphate (ATP). Enzyme kinetics revealed that EBOV RdRp and respiratory syncytial virus (RSV) RdRp incorporate ATP and remdesivir-TP with similar efficiencies. The selectivity of ATP against remdesivir-TP is ~4 for EBOV RdRp and ~3 for RSV RdRp. In contrast, purified human mitochondrial RNA polymerase (h-mtRNAP) effectively discriminates against remdesivir-TP with a selectivity value of ~500-fold. For EBOV RdRp, the incorporated inhibitor at position i does not affect the ensuing nucleotide incorporation event at position i+1. For RSV RdRp, we measured a ~6-fold inhibition at position i+1 although RNA synthesis was not terminated. Chain termination was in both cases delayed and was seen predominantly at position i+5. This pattern is specific to remdesivir-TP and its 1'-cyano modification. Compounds with modifications at the 2'-position show different patterns of inhibition. While 2'-C-methyl-ATP is not incorporated, ara-ATP acts as a non-obligate chain terminator and prevents nucleotide incorporation at position i+1. Taken together, our biochemical data indicate that the major contribution to EBOV RNA synthesis inhibition by remdesivir can be ascribed to delayed chain termination. The long distance of five residues between the incorporated nucleotide analogue and its inhibitory effect warrant further investigation.

Is the conquest of Hepatitis C imminent?

Hepatitis C virus represents a global pathogen of human health significance. In the space of less than three decades, we have witnessed the discovery of the virus, a growing understanding of the structure and biology of the viral-encoded proteins and their interaction with the host cell and the sequencing of the viral genome. Most importantly, we have moved from early therapeutic strategies aimed at crude boosting of host anti-viral immunity, limited by side effects and with poor response rates, to therapies that directly exploit our understanding of viral biology. In this review, we discuss the significance of the virus, its' discovery and outline the advances in the molecular characterisation of the virus, before setting these within the context of contemporary and emerging therapeutic strategies as well as viral resistance mechanisms.

Non-immunological complications following kidney transplantation

Kidney transplantation (KT) is the most effective way to decrease the high morbidity and mortality of patients with end-stage renal disease. However, KT does not completely reverse the damage done by years of decreased kidney function and dialysis. Furthermore, new offending agents (in particular, immunosuppression) added in the post-transplant period increase the risk of complications. Cardiovascular (CV) disease, the leading cause of death in KT recipients, warrants pre-transplant screening based on risk factors. Nevertheless, the screening methods currently used have many shortcomings and a perfect screening modality does not exist. Risk factor modification in the pre- and post-transplant periods is of paramount importance to decrease the rate of CV complications post-transplant, either by lifestyle modification (for example, diet, exercise, and smoking cessation) or by pharmacological means (for example, statins, anti-hyperglycemics, and so on). Post-transplantation diabetes mellitus (PTDM) is a major contributor to mortality in this patient population. Although tacrolimus is a major contributor to PTDM development, changes in immunosuppression are limited by the higher risk of rejection with other agents. Immunosuppression has also been implicated in higher risk of malignancy; therefore, proper cancer screening is needed. Cancer immunotherapy is drastically changing the way certain types of cancer are treated in the general population; however, its use post-transplant is limited by the risk of allograft rejection. As expected, higher risk of infections is also encountered in transplant recipients. When caring for KT recipients, special attention is needed in screening methods, preventive measures, and treatment of infection with BK virus and cytomegalovirus. Hepatitis C virus infection is common in transplant candidates and in the deceased donor pool; however, newly developed direct-acting antivirals have been proven safe and effective in the pre- and post-transplant periods. The most important and recent developments on complications following KT are reviewed in this article.

Efficacy and safety of 12 weeks of daclatasvir, asunaprevir plus ribavirin for HCV genotype-1b infection without NS5A resistance-associated substitutions

BACKGROUND/PURPOSE

Treatment with daclatasvir plus asunaprevir (DCV + ASV) for 24 weeks provided a sustained virologic response (SVR) rate of over 90% in hepatitis C virus genotype 1b (HCV-1b) infected patients without non-structural 5A (NS5A) resistance-associated substitutions (RASs) at the L31 and Y93 sites. In this study, we investigated whether adding ribavirin to the DCV + ASV combination could shorten the original treatment regimen to 12 weeks without compromising the treatment efficacy for HCV-1b patients without NS5A RASs.

METHODS

In the prospective, open-label, single-arm, nationwide multi-center phase III study, a total of 70 interferon-naïve or interferon-experienced HCV-1b patients without baseline L31/Y93 RASs received daclatasvir (60 mg/day) and asunaprevir (100 mg twice daily) plus weight-based ribavirin (1000-1200 mg/day) for 12 weeks, with a 12-week post-treatment follow-up. The primary end-point was the rate of undetectable HCV RNA 12 weeks post-treatment (SVR12).

RESULTS

The SVR12 rate was 97.1% (68/70) and 100% (68/68) in the full-analysis-set and the per-protocol population, respectively. None of the 68 patients who completed the 12-week treatment experienced relapse during post-treatment follow-up. Two patients withdrew from the study at treatment days 21 and 34 due to anorexia and fatigue, which were considered ribavirin-related and resolved post medication cessation. A total of 4 serious adverse events were reported and considered treatment-unrelated. No deaths or grade 4 adverse events requiring hospitalization was observed throughout the study.

CONCLUSION

Truncated regimen of DCV + ASV plus ribavirin for 12 weeks was highly effective and safe in HCV-1b patients without NS5A L31/Y93 RAS.

Ribavirin-induced down-regulation of CCAAT/enhancer-binding protein α leads to suppression of lipogenesis

Recently, we demonstrated that the anti-viral drug ribavirin (RBV) had the ability to suppress lipogenesis through down-regulation of retinoid X receptor α (RXRα) under the control of the intracellular GTP-level and AMP-activated protein kinase-related kinases, especially microtubule affinity regulating kinase 4 (MARK4). RXRα-overexpression attenuated but did not abolish lipogenesis suppression by RBV, implying that additional factor(s) were involved in this suppressive effect. In the present study, we found that the protein level, but not the mRNA level, of CCAAT/enhancer-binding protein α (C/EBPα) was down-regulated by RBV in hepatic cells. Treatment with proteasome inhibitor attenuated RBV-induced down-regulation of C/EBPα, suggesting that RBV promoted degradation of C/EBPα protein via the ubiquitin-proteasome pathway. Depletion of intracellular GTP through inosine monophosphate dehydrogenase inhibition by RBV led to down-regulation of C/EBPα. In contrast, down-regulation of C/EBPα by RBV was independent of RXRα and MARK4. Knockdown of C/EBPα reduced the intracellular neutral lipid levels and the expression of genes related to the triglyceride (TG) synthesis pathway, especially glycerol-3-phosphate acyltransferase, mitochondrial (GPAM), which encodes the first rate-limiting TG enzyme. Overexpression of C/EBPα yielded the opposite results. We also observed that RBV decreased GPAM expression. Moreover, overexpression of GPAM attenuated RBV-induced reduction in the intracellular neutral lipid levels. These data suggest that down-regulation of C/EBPα by RBV leads to the reduction in GPAM expression, which contributes to the suppression of lipogenesis. Our findings about the mechanism of RBV action in lipogenesis suppression will provide new insights for therapy against the active lipogenesis involved in hepatic steatosis and hepatocellular carcinomas.

Sofosbuvir in combination with ribavirin or simeprevir: real-life study of patients with hepatitis C genotype 4

BACKGROUND

The discovery of direct-acting antiviral agents (DAA) is an outstanding achievement of modern medicine in the current century. The current study aimed to explore the effectiveness and safety of two regimens sofosbuvir (SOF) in combination with either ribavirin (RBV) or simeprevir (SMV) in chronic hepatitis C (CHC) genotype (GT) 4 patients in Egypt.

METHODS

A total of 201 patients, treatment-naïve and experienced, with CHC GT4 infection were allocated into two groups based on the type of the regimen used. All eligible patients were treated orally with SOF plus daily oral weight-based RBV (24 weeks; group 1), or SOF plus daily oral SMV (12 weeks; group 2).

RESULTS

In the patients who received SOF/RBV therapy for 24 weeks, a sustained virological response (SVR12) was achieved by 89% (90/101) of all patients, 92% (49/53) of naïve patients and 85% (41/48) of experienced patients. In the SOF/SMV group, the SVR12 rate was 92% (92/100) for overall patients, 93% (70/75) of naïve patients and 88% (22/25) of experienced patients. Adverse events (AEs) were reported in 70% of patients in the SOF/RBV group and 42% patients in the SOF/SMV group. The most common AEs in both groups were fatigue, headache, nausea, and dyspnea.

CONCLUSIONS

The present comparative study suggests that both SOF/RBV and SOF/SMV combination regimens are highly effective in CHC GT4 treatment. However, the two-DAA regimen (SOF/SMV) may offer well-tolerated treatment, with a shorter duration and better safety compared to SOF/RBV.

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

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

Impact of treatment with direct-acting antivirals on anxiety and depression in chronic hepatitis C

BACKGROUND AND AIM

Treatment of hepatitis C with direct-acting antiviral agents (DAA) has few side effects. Although pivotal studies suggested that DAA were safe in patients with psychiatric diseases who could not be treated with previous antiviral therapies, their effects on anxiety and depression have not yet been analysed in clinical practice. The aim of our study was to analyse anxiety and depression in the setting of DAA treatment in a clinical practice series.

METHODS

All patients starting DAA treatment between November 1, 2014 and October 31, 2015 were eligible. Patients completed the Hospital Anxiety and Depression scale at different times during treatment. The results were plotted on line graphs and evaluated using a linear regression model with repeated measures.

RESULTS

One hundred and forty-five patients were included (11% with major psychiatric disorders; 32% on psychiatric treatment). Sustained virologic response (SVR) was achieved in 97.3% of cases. Anxiety and depression measures did not differ between time points. No differences between patients on psychiatric treatment or with advanced fibrosis or cirrhosis were found at any time point analysed.

CONCLUSION

DAA treatment had no impact on anxiety or depression during or after chronic hepatitis C infection treatment, even in high-risk patients with major psychiatric disorders.

Meta-Analysis of Grazoprevir plus Elbasvir for Treatment of Hepatitis C Virus Genotype 1 Infection

BACKGROUND AND AIM

Grazoprevir is an NS3/4A protease inhibitor (PI), while elbasvir is an NS5A inhibitor. We performed this meta-analysis to directly compare grazoprevir plus elbasvir and ribavirin regimen vs. grazoprevir and elbasvir without ribavirin in the treatment of hepatitis C virus genotype 1 infection and to precisely evaluate the efficacy of the latter regimen in cirrhotic, IL28 CC genotype patients and those coinfected with human immunodeficiency virus.

MATERIAL AND METHODS

A computer literature search of PubMed, Scopus, EBSCO, Embase, and Cochrane central was conducted. Studies were screened for eligibility. Sustained virologic response (SVR) rates were pooled using OpenMeta[Analyst] software for windows. A subgroup analysis was performed to stratify the treatment efficacy according to the different baseline characteristics of HCV patients.

RESULTS

Eight randomized controlled trials (n = 1,297 patients) were pooled in the final analysis. The overall SVR rate was 96.6% with 95% CI [95.5% to 98%]. For cirrhotic patients, the SVR rate was 95.7% with 95% CI [93.9% to 97.5%] and for non-cirrhotic patients, the SVR rate was 97% with 95% CI [95.9% to 98.4%]. Furthermore, the addition of ribavirin (RBV) to the treatment regimen did not significantly improve the SVR (RR 1.003, 95% CI [0.944 to 1.065]). The dual regimen was effective in patient populations with NS3 resistance-associated (RAS). However, this regimen achieved lower SVR rates (&lt; 90%) in patients with NS5A RAS.

CONCLUSIONS

We conclude that the 12-week treatment regimen of the fixed dose combination of grazoprevir plus elbasvir achieved high SVR rates in patients with HCV genotype 1 infection. The addition of ribavirin to this regimen did not add a significant benefit.

Host-based processes as therapeutic targets for Rift Valley fever virus

Rift Valley fever virus (RVFV) is an enveloped, segmented, negative sense RNA virus that replicates within the host's cytoplasm. To facilitate its replication, RVFV must utilize host cell processes and as such, these processes may serve as potential therapeutic targets. This review summarizes key host cell processes impacted by RVFV infection. Specifically the influence of RVFV on host transcriptional regulation, post-transcriptional regulation, protein half-life and availability, host signal transduction, trafficking and secretory pathways, cytoskeletal modulation, and mitochondrial processes and oxidative stress are discussed. Therapeutics targeted towards host processes that are essential for RVFV to thrive as well as their efficacy and importance to viral pathogenesis are highlighted.

Inosine Triphosphate Pyrophosphatase Dephosphorylates Ribavirin Triphosphate and Reduced Enzymatic Activity Potentiates Mutagenesis in Hepatitis C Virus

A third of humans carry genetic variants of the ITP pyrophosphatase (ITPase) gene (ITPA) that lead to reduced enzyme activity. Reduced ITPase activity was earlier reported to protect against ribavirin-induced hemolytic anemia and to diminish relapse following ribavirin and interferon therapy for hepatitis C virus (HCV) genotype 2 or 3 infections. While several hypotheses have been put forward to explain the antiviral actions of ribavirin, details regarding the mechanisms of interaction between reduced ITPase activity and ribavirin remain unclear. The in vitro effect of reduced ITPase activity was assessed by means of transfection of hepatocytes (Huh7.5 cells) with a small interfering RNA (siRNA) directed against ITPA or a negative-control siRNA in the presence or absence of ribavirin in an HCV culture system. Low ribavirin concentrations strikingly depleted intracellular GTP levels in HCV-infected hepatocytes whereas higher ribavirin concentrations induced G-to-A and C-to-U single nucleotide substitutions in the HCV genome, with an ensuing reduction of HCV RNA expression and HCV core antigen production. Ribavirin triphosphate (RTP) was dephosphorylated in vitro by recombinant ITPase to a similar extent as ITP, a naturally occurring substrate of ITPase, and reducing ITPA expression in Huh 7.5 cells by siRNA increased intracellular levels of RTP in addition to increasing HCV mutagenesis and reducing progeny virus production. Our results extend the understanding of the biological impact of reduced ITPase activity, demonstrate that RTP is a substrate of ITPase, and may point to personalized ribavirin dosage according to ITPA genotype in addition to novel antiviral strategies.IMPORTANCE This study highlights the multiple modes of action of ribavirin, including depletion of intracellular GTP and increased hepatitis C virus mutagenesis. In cell culture, reduced ITP pyrophosphatase (ITPase) enzyme activity affected the intracellular concentrations of ribavirin triphosphate (RTP) and augmented the impact of ribavirin on the mutation rate and virus production. Additionally, our results imply that RTP, similar to ITP, a naturally occurring substrate of ITPase, is dephosphorylated in vitro by ITPase.

Efficacy of Sofosbuvir and Velpatasvir, With and Without Ribavirin, in Patients With Hepatitis C Virus Genotype 3 Infection and Cirrhosis

BACKGROUND & AIMS

In phase 3 trials and real-world settings, smaller proportions of patients with genotype 3 hepatitis C virus (HCV) infection and cirrhosis have a sustained virologic response 12 weeks after treatment (SVR12) with the combination of sofosbuvir and velpatasvir than in patients without cirrhosis. It is unclear whether adding ribavirin to this treatment regimen increases SVRs in patients with genotype 3 HCV infection and cirrhosis.

METHODS

We performed a phase 2 trial of 204 patients with genotype 3 HCV infection and compensated cirrhosis (mean age 51 ± 7.4 years) at 29 sites in Spain from August 19, 2016 through April 18, 2017. Patients were assigned to groups given sofosbuvir and velpatasvir for 12 weeks (n = 101) or sofosbuvir and velpatasvir plus ribavirin for 12 weeks (n = 103). The primary efficacy end point was SVR12.

RESULTS

The overall rates of SVR12 were 91% (92 of 101; 95% CI 84-96) for the sofosbuvir-velpatasvir group and 96% (99 of 103; 95% CI 90-99) for the sofosbuvir-velpatasvir plus ribavirin group. In the sofosbuvir-velpatasvir group, a smaller proportion of patients with baseline resistance-associated substitutions (RASs) in nonstructural protein 5A (NS5A) achieved an SVR12 (84%) than did patients without (96%). In the sofosbuvir-velpatasvir plus ribavirin group, baseline RASs had less effect on the proportion of patients with an SVR12 (96% for patients with baseline RASs; 99% for patients without). The most common adverse events (which occurred in ≥10% of patients) were asthenia (12%) in the sofosbuvir-velpatasvir group and asthenia (27%), headache (24%), and insomnia (12%) in the sofosbuvir-velpatasvir plus ribavirin group.

CONCLUSIONS

Consistent with findings from previous studies, a high rate of patients (91% and 96%) with genotype 3 HCV infection and compensated cirrhosis achieved an SVR12 with sofosbuvir and velpatasvir, with or without ribavirin. Of patients treated with sofosbuvir and velpatasvir without ribavirin, fewer patients with baseline NS5A RASs achieved an SVR12 compared with patients without baseline NS5A. ClinicalTrials.govNCT02781558.

Effect of ombitasvir/paritaprevir/ritonavir + dasabuvir regimen on health-related quality of life for patients with hepatitis C

BACKGROUND & AIMS

This study analyses health-related quality of life data from 8 randomized clinical trials using ombitasvir/paritaprevir/ritonavir and dasabuvir ± ribavirin to investigate: (i) the impact of the treatment vs placebo during treatment on health-related quality of life; (ii) the sustainability of such treatment effect after 12-week treatment period; and (iii) if results from (i) and (ii) differ in subgenotypes 1a vs 1b.

METHODS

Six registration trials and 2 post-approval trials were pooled and analysed using longitudinal mixed models to estimate the effect of ombitasvir/paritaprevir/ritonavir and dasabuvir ± ribavirin on health-related quality of life outcomes adjusting for baseline scores, as well as patient demographics and clinical characteristics.

RESULTS

Patients treated with ribavirin-free ombitasvir/paritaprevir/ritonavir and dasabuvir regimen reported statistically significant increase in health-related quality of life outcomes as compared to placebo patients. While ombitasvir/paritaprevir/ritonavir and dasabuvir + ribavirin treatment saw statistically significant decline in health-related quality of life outcomes during treatment vs baseline and placebo, effect on health-related quality of life outcomes associated with ribavirin did not persist in the post-treatment period for ombitasvir/paritaprevir/ritonavir and dasabuvir patients followed for up to 52 weeks. The analysis also found Genotype 1b patients reported greater improvements in health-related quality of life as compared to genotype 1a patients.

CONCLUSIONS

During the active treatment period, small but statistically significant decrements in health-related quality of life outcomes were observed potentially driven by ribavirin, which were not sustained during the post-treatment follow-up period. Differences were observed by patient subgenotype, where health-related quality of life improvements were consistently higher for genotype 1b patients as compared to genotype 1a patients.

Hepatitis C seropositivity among newly incarcerated prisoners in Estonia: data analysis of electronic health records from 2014 to 2015

Background

Hepatitis C virus (HCV) infection is a widespread problem in prisons. The present study aimed to assess the prevalence of HCV seropositivity, HCV genotypes, factors associated with HCV seropositivity in newly incarcerated prisoners and to report experiences of treatment with pegylated interferon/ribavirin for HCV-positive inmates.

Methods

Patient data were extracted from the Estonian prison medical information system (Vanglate meditsiiniline infosüsteem) databases.

Results

Among 1845 prisoners newly incarcerated from January 2014 to January 2015, the overall prevalence of HCV was 56.3% (95% CI: 54 to 59), and 25.5% (95% CI: 23.5 to 27.6%) had HIV (39.0% had neither). The all-inclusive HCV testing strategy identified 37.7% more HCV infected prisoners than the risk-based (drug use history, HIV status) case finding. Factors associated with HCV seropositivity included history of drug use (aOR 6.51 95%CI 5.12–8.28), HIV co-infection (aOR 2.56 95%CI 1.92–3.43), previous incarceration (aOR 3.61 95%CI 2.48–4.04), and increasing age. The main HCV genotypes were 3a (n = 172, 44.4%) and 1b (n = 135, 35.2%). Twenty-five prisoners received HCV treatment: 60% (n = 15) were cured, 16% (n = 4) relapsed (3 with genotype 3a, one with 1b), and 12% (n = 3) were unresponsive (all with genotype 3a).

Conclusions

HCV seropositivity rate is high and HCV tretment rate is very low in Estonian prisons. Optimizing case finding and scaling up treatment is critical to addressing the health needs of prisoners and meeting public health goals.

Induction of inosine triphosphatase activity during ribavirin treatment for chronic hepatitis C

BACKGROUND

Ribavirin (RBV) is an antiviral agent and the primary component for chronic hepatitis C (CHC) therapy. Hemolytic anemia is limitation for RBV treatment. Inosine triphosphatase (ITPA) activity has been associated with severity of RBV-induced anemia. However, changes in ITPA activity during CHC therapy are unknown. The aim of this study was to measure the time-dependent change in ITPA activity over the RBV treatment.

METHODS

Forty-two patients with CHC were evaluated for ITPA activity over the course of RBV treatment.

RESULTS

The median value of ITPA activity at start of RBV treatment was 134.2 μmol/h/g hemoglobin (Hb; range, 26.3-251.0 μmol/h/g Hb). The ITPA activity values at 4, 8, and 12 weeks during RBV treatment were 143.2, 202.2, and 225.7 μmol/h/g Hb, respectively, and these ITPA values were significantly elevated compared with the start of treatment (p < 0.001). In patients with ITPA variants, patients with anemia (Hb < 10 g/dL) had greater elevated ITPA activities compared with patients without anemia at 12 weeks.

CONCLUSION

Our findings indicate that ITPA activities are elevated with RBV therapy, and this elevation may be a risk of anemia in late therapeutic phase in patients that began with low ITPA activity.

Ribavirin-induced mutagenesis across the complete open reading frame of hepatitis C virus genotypes 1a and 3a

Ribavirin (RBV) has been used for the last 20 years to treat patients with chronic hepatitis C virus (HCV) infection. This pluripotent drug is believed to induce mutagenesis in HCV RNA. However, for cell-cultured HCV (HCVcc) this phenomenon has only been investigated in genotype 2a recombinants. Here we studied the mutations that developed in HCVcc of genotypes 1a and 3a treated with RBV or ribavirin triphosphate (RBV-TP) compared to non-treated controls. Analysis was performed on the amplified full-length open reading frame (ORF) of recovered viruses following next-generation sequencing and clonal analyses. Compared to non-treated controls, the spread of TNcc(1a) and DBN3acc(3a) HCVcc was delayed by RBV and RBV-TP at concentrations of 40 µM or higher. The delay in HCVcc spread was associated with increased new single-nucleotide polymorphisms (SNP). Significantly higher numbers of new SNP were observed in TNcc(1a) viruses treated with RBV or RBV-TP compared to matched non-treated controls. RBV or RBV-TP treatment led to significantly increased proportions of new G-to-A and C-to-U SNP compared to non-treated TNcc(1a). Clonal analyses confirmed a significantly increased mutation rate in RBV-treated TNcc(1a). Synonymous pairwise distances increased in both viruses across the complete ORF under RBV and RBV-TP treatment compared to controls. Consensus-shifts in single samples of RBV- or RBV-TP-treated TNcc(1a) viruses occurred in proteins E1, p7, NS3 and NS4B. No non-synonymous consensus changes were observed in DBN3acc(3a). This study supports a biased G-to-A and C-to-U mutagenic effect of RBV and RBV-TP throughout the entire ORF of HCV genotypes 1a and 3a.

Efficacy and safety of sofosbuvir plus daclatasvir with or without ribavirin: large real-life results of patients with chronic hepatitis C genotype 4

BACKGROUND AND AIM

Clinical studies evaluating the efficacy of daclatasvir (DCV) for treatment of chronic hepatitis C virus (HCV) genotype 4 (GT4) infection are scarce. This study aims to evaluate the efficacy and safety of DCV plus sofosbuvir (SOF) with or without ribavirin (RBV) for treatment of Egyptian patients infected with HCV GT4.

METHODS

Between April 2016 and March of 2017, a large cohort of 946 patients with chronic HCV GT4 was enrolled for completing the treatment. Patients were classified into two groups: group 1 (easy to treat) was treated with a dual therapy of SOF/DCV daily for 12 weeks and group 2 (difficult to treat) was treated with a triple therapy of SOF/DCV/RBV daily for 12 weeks. Efficacy and safety of the treatments were estimated, and baseline characters associated with sustained virological response at 12 weeks post-treatment (SVR12) were investigated.

RESULTS

Among the patient's cohort, SVR12 was achieved by 94% (891/946) in the overall patients, by 95% (718/758) in the easy-to-treat group, and by 92% (173/188) in the difficult-to-treat group. The most common adverse events recorded were fatigue, headache, nausea, asthenia, and gastrointestinal troubles. No patient discontinued treatment due to severe adverse events.

CONCLUSION

The findings from the present study suggested that SOF/DCV (with or without RBV) regimen exhibited high effectiveness, was well tolerated in the treatment of chronic HCV GT 4, and revealed itself as a better option for patients with advanced liver disease, making the eradication of HCV a more realistic target to achieve.

Real-world effect of ribavirin on quality of life in HCV-infected patients receiving interferon-free treatment

BACKGROUND & AIMS

Ribavirin (RBV) is commonly used for the treatment of hepatitis C virus (HCV) infection. However, RBV is associated with a reduced quality of life (QOL). We aim to assess the impact of RBV on QOL in a real-world setting.

METHODS

In a prospective study, QOL was measured by a SF-36 questionnaire in 174 patients. In all, 85 patients were treated with RBV and 89 patients without RBV. QOL was assessed at baseline, week 12 of treatment and 24 weeks after treatment.

RESULTS

Patients treated with RBV were more likely to have HCV genotype 2 and 3 infection and cirrhosis (all P < .05). RBV-treated patients reported lower scores for several domains of QOL already at baseline. During HCV treatment, RBV-free treatment led to an increase in all measured dimensions of quality of life, whereas RBV treatment led to a decrease in the emotional and physical functioning. After treatment, all dimensions for QOL showed improvement across the study cohort, regardless whether RBV was part of the treatment regimen. However, 28.8%-45.2% of treated patients perceive a sustained reduction in their physical or mental capacity after treatment, not related to RBV usage or SVR, but related to older age (P = .03) and cirrhosis (P = .02).

CONCLUSIONS

During treatment, RBV leads to a reduced QOL, whereas RBV-free treatment leads to an increased QOL. After treatment, QOL strongly increases in both, RBV and RBV-free treated patients. Some patients perceive a sustained reduction in QOL, which seems unrelated to treatment.

Daclatasvir plus asunaprevir in treatment-naïve patients with hepatitis C virus genotype 1b infection

AIM

To assess daclatasvir plus asunaprevir (DUAL) in treatment-naïve patients from mainland China, Russia and South Korea with hepatitis C virus (HCV) genotype 1b infection.

METHODS

Patients were randomly assigned (3:1) to receive 24 wk of treatment with DUAL (daclatasvir 60 mg once daily and asunaprevir 100 mg twice daily) beginning on day 1 of the treatment period (immediate treatment arm) or following 12 wk of matching placebo (placebo-deferred treatment arm). The primary endpoint was a comparison of sustained virologic response at posttreatment week 12 (SVR12) compared with the historical SVR rate for peg-interferon plus ribavirin (70%) among patients in the immediate treatment arm. The first 12 wk of the study were blinded. Safety was assessed in DUAL-treated patients compared with placebo patients during the first 12 wk (double-blind phase), and during 24 wk of DUAL in both arms combined.

RESULTS

In total, 207 patients were randomly assigned to immediate (n = 155) or placebo-deferred (n = 52) treatment. Most patients were Asian (86%), female (59%) and aged < 65 years (90%). Among them, 13% had cirrhosis, 32% had IL28B non-CC genotypes and 53% had baseline HCV RNA levels of ≥ 6 million IU/mL. Among patients in the immediate treatment arm, SVR12 was achieved by 92% (95% confidence interval: 87.2-96.0), which was significantly higher than the historical comparator rate (70%). SVR12 was largely unaffected by cirrhosis (89%), age ≥ 65 years (92%), male sex (90%), baseline HCV RNA ≥ 6 million (89%) or IL28B non-CC genotypes (96%), although SVR12 was higher among patients without (96%) than among those with (53%) baseline NS5A resistance-associated polymorphisms (at L31 or Y93H). During the double-blind phase, aminotransferase elevations were more common among placebo recipients than among patients receiving DUAL. During 24 wk of DUAL therapy (combined arms), the most common adverse events (≥ 10%) were elevated alanine aminotransferase and upper respiratory tract infection; emergent grade 3-4 laboratory abnormalities were infrequently observed, and all grade 3-4 aminotransferase abnormalities (alanine aminotransferase, n = 9; aspartate transaminase, n = 6) reversed within 8-11 d. Two patients discontinued DUAL treatment; one due to aminotransferase elevations, nausea, and jaundice and the other due to a fatal adverse event unrelated to treatment. There were no treatment-related deaths.

CONCLUSION

DUAL was well-tolerated during this phase 3 study, and SVR12 with DUAL treatment (92%) exceeded the historical SVR rate for peg-interferon plus ribavirin of 70%.

Interferon-free direct-acting antiviral therapy for acute hepatitis C virus infection in HIV-infected individuals: A literature review

Dramatic rises in hepatitis C virus (HCV) coinfection rates in human immunodeficiency virus (HIV)-infected individuals have been observed recently, largely attributable to increasing recreational drug use combined with increased testing for HCV. In the era of direct-acting antiviral (DAA) therapy, treatment of acute HCV infection in HIV-infected individuals with short durations of these drugs may potentially reduce the disease and economic burden associated with HCV infection as well as reducing the likelihood of onward HCV transmission. We performed an extensive literature search of PubMed, Embase and Google Scholar up to 05 September 2017 for clinical trials of acute HCV infection in HIV-infected individuals. In the studies identified, rates of sustained virologic response at 12 weeks post-treatment (SVR12) ranged from 21% with 6 weeks of therapy up to 92% with 12 weeks of therapy with sofosbuvir and ribavirin. Ledipasvir/sofosbuvir for 6 weeks achieved an SVR of 77%. No HIV-related events occurred regardless of whether patients were receiving antiretroviral therapy (ART) and DAAs were well tolerated. Data is currently limited with regards to optimal regimens and durations of therapy, which need to be tailored based on potential interactions with concurrent ART and consideration for the fact that patients with higher baseline HCV RNA levels may require an extended duration of treatment.

Direct-acting antiviral therapy for hepatitis C virus infection in the kidney transplant recipient

Hepatitis C virus infection (HCV) is a common comorbidity in patients who have undergone kidney transplantation and is associated with increased morbidity and mortality compared with recipients who do not have chronic HCV infection. Because interferon-α-based therapies can precipitate acute rejection, they are relatively contraindicated after kidney transplantation. Thus, the majority of kidney transplant recipients with HCV remain untreated. There are now all-oral, interferon-free direct-acting antiviral therapies for HCV infection that are extremely effective and well tolerated in the general population. Recent reports in the literature demonstrate that direct-acting antiviral therapies effectively cured HCV in 406 of 418 kidney transplant recipients (97%); the majority were treated with sofosbuvir-based regimens. Smaller numbers of kidney transplant recipients have been treated with paritaprevir-ritonavir, ombitasvir and dasabuvir, elbasvir-grazoprevir, or glecaprevir-pibrentasvir with excellent success. Direct-acting antiviral therapies were well tolerated and did not increase the rate of acute rejection. The latest advances include approval of regimens that can treat patients with advanced allograft dysfunction (eGFR < 30 ml/min per 1.73 m²) and "pan-genotypic" regimens that have activity against all 6 major genotypes of HCV. This review summarizes what is known about the epidemiology of HCV infection in kidney transplant recipients, and presents the landscape of direct-acting antiviral therapies and areas in need of further investigation.