Ledipasvir plus sofosbuvir for 12 weeks in patients with hepatitis C genotype 4 infection

'Unusual' HCV genotype subtypes: origin, distribution, sensitivity to direct-acting antiviral drugs and behaviour on antiviral treatment and retreatment

The high genetic diversity of hepatitis C virus (HCV) has led to the emergence of eight genotypes and a large number of subtypes in limited geographical areas. Currently approved pangenotypic DAA regimens have been designed and developed to be effective against the most common subtypes (1a, 1b, 2a, 2b, 2c, 3a, 4a, 5a and 6a). However, large populations living in Africa and Asia, or who have migrated from these regions to industrialised countries, are infected with 'unusual', non-epidemic HCV subtypes, including some that are inherently resistant to currently available direct-acting antiviral (DAA) drugs due to the presence of natural polymorphisms at resistance-associated substitution positions. In this review article, we describe the origin and subsequent global spread of HCV genotypes and subtypes, the current global distribution of common and unusual HCV subtypes, the polymorphisms naturally present in the genome sequences of unusual HCV subtypes that may confer inherently reduced susceptibility to DAA drugs and the available data on the response of unusual HCV subtypes to first-line HCV therapy and retreatment. We conclude that the problem of unusual HCV subtypes that are inherently resistant to DAAs and its threat to the global efforts to eliminate viral hepatitis are largely underestimated and warrant vigorous action.

Rare HCV subtypes and retreatment outcomes in a cohort of European DAA-experienced patients

Background and Aims

Data on the prevalence and characteristics of so-called rare HCV genotypes (GTs) in larger cohorts is limited. This study investigates the frequency of rare GT and resistance-associated substitutions and the efficacy of retreatment in a European cohort.

Methods

A total of 129 patients with rare GT1-6 were included from the European resistance database. NS3, NS5A, and NS5B were sequenced and clinical parameters and retreatment efficacies were collected retrospectively.

Results

Overall 1.5% (69/4,656) of direct-acting antiviral (DAA)-naive and 4.4% (60/1,376) of DAA-failure patients were infected with rare GT. Although rare GTs were almost equally distributed throughout GT1-6 in DAA-naive patients, we detected mainly rare GT4 (47%, 28/60 GT4; of these n = 17, subtype 4r) and GT3 (25%, 15/60 GT3, of these n = 8, subtype 3b) among DAA-failures. A total of 62% (37/60) of DAA failures had not responded to first-generation regimes and the majority was infected with rare GT4 (57%, 21/37). In contrast, among patients with failure to pangenotypic DAA regimens (38%, 23/60), infections with rare GT3 were overrepresented (57%, 13/23). Although NS5A RASs were uncommon in rare GT2, GT5a, and GT6, we observed combined RASs in rare GT1, GT3, and GT4 at positions 28, 30, 31, which can be considered as inherent. DAA failures with completed follow-up of retreatment, achieved a high SVR rate (94%, 45/48 modified intention-to-treat analysis; 92%, 45/49 intention-to-treat). Three patients with GT4f, 4r, or 3b, respectively, had virological treatment failure.

Conclusions

In this European cohort, rare HCV GT were uncommon. Accumulation of specific rare GT in DAA-failure patients suggests reduced antiviral activities of DAA regimens. The limited global availability of pangenotypic regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed.

Impact and implications

Data on the prevalence and characteristics of rare HCV genotypes (GT) in larger cohorts are still scarce. This study found low rates of rare HCV GTs among European HCV-infected patients. In direct-acting antiviral (DAA)-failure patients, rare GT3 subtypes accumulated after pangenotypic DAA treatment and rare GT4 after first generation DAA failure and viral resistance was detected at NS5A positions 28, 30, and 31. The limited global availability of pangenotypic DAA regimens for first line therapy as well as multiple targeted regimens for retreatment could result in HCV elimination targets being delayed.

Clinical Practice Guidelines of the Russian Society for the Study of the Liver, the Russian Gastroenterological Association, the National Scientific Society of Infectious Disease Specialists for the Diagnosis and Treatment of Chronic Hepatitis C

Аim:diagnosis and treatment algorithms in the clinical recommendations intended for general practitioners, gastroenterologists, infectious disease specialists, hepatologists on the of chronic hepatitis C are presented.

Summary.Chronic viral hepatitis C is a socially significant infection, the incidence of which in the Russian Federation remains significantly high. Over the past 10 years, great progress has been made in the treatment of hepatitis C — direct acting antiviral drugs have appeared. The spectrum of their effectiveness allows to achieve a sustained virological response in more than 90 % of cases, even in groups that were not previously considered even as candidates for therapy or were difficult to treat — patients receiving renal replacement therapy, after liver transplantation (or other organs), at the stage of decompensated liver cirrhosis, HIV co-infected, etc. Interferons are excluded from the recommendations due to their low effectiveness and a wide range of adverse events. The indications for the treatment have been expanded, namely, the fact of confirmation of viral replication. The terms of dispensary observation of patients without cirrhosis of the liver have been reduced (up to 12 weeks after the end of therapy). Also, these recommendations present approaches to active screening of hepatitis in risk groups, preventive and rehabilitation measures after the end of treatment.

Conclusion.Great success has been achieved in the treatment of chronic hepatitis C. In most cases, eradication of viral HCV infection is a real task even in patients at the stage of cirrhosis of the liver, with impaired renal function, HIV co-infection, after solid organs transplantation.

Evaluation of the Safety Profile of Direct-Acting Antivirals on Patients with Hepatitis C Virus: A Pharmacovigilance Study

BACKGROUND

Hepatitis C virus (HCV) is the primary contributor to chronic hepatic diseases. A rapid change in the situation took place with the advent of oral direct-acting antivirals (DAAs). However, a comprehensive review of the adverse event (AE) profile of the DAAs is lacking. This cross-sectional study aimed to analyze the reported Adverse Drug Reactions (ADRs) with DAA treatment using data from VigiBase, the WHO Individual Case Safety Report (ICSR) database.

METHODS

All ICSRs reported to VigiBase with sofosbuvir (SOF), daclatasvir (DCV), sofosbuvir /ledipasvir (SOF/LDV) and ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) in Egypt were extracted. Descriptive analysis was performed to summarize patients' and reactions' characteristics. Information components (ICs) and proportional reporting ratios (PRRs) for all reported ADRs were calculated to identify signals of disproportionate reporting. Logistic regression analysis was performed to identify the DAAs association with serious events of concern while adjusting for age, gender, pre-existing cirrhosis, and ribavirin use.

RESULTS

Out of 2925 reports, 1131 (38.6%) were serious. The most commonly reported reactions; anaemia (21.3%), HCV relapse (14.5%) and headache (14%). For the disproportionality signals; HCV relapse was reported with SOF/DCV (IC 3.65, 95% CrI 3.47-3.79) and SOF/RBV (IC 3.69, 95% CrI 3.37-3.92), while anaemia (IC 2.85, 95% CrI 2.26-3.27) and renal impairment (IC 2.12, 95% CrI 0.7-3.03) were reported with OBV/PTV/r.

CONCLUSION

The highest severity index and seriousness were reported with SOF/RBV regimen. A significant association was found for OBV/PTV/r with renal impairment and anaemia although being the superior regimen in terms of efficacy. The study findings call for further population-based studies for clinical validation.

Genotype 4 hepatitis C virus-a review of a diverse genotype

PURPOSE

Hepatitis C virus (HCV) infection remains a major health problem and one of the leading causes of chronic liver disease worldwide. The purpose of this paper was to summarize knowledge about the epidemiology of HCV genotype (GT) 4 infection, similarities and differences with other genotypes, specific problems associated with this genotype, and treatment regimens used to treat GT4-infected patients.

METHODS

We performed an accurate search for literature using the PubMed database to select high-quality reviews and original articles concerning this topic.

RESULTS

GT4 with a global prevalence of 8% takes third place, closing the global HCV podium in terms of frequency. However, there are regions where GT4 infections are dominant, such as sub-Saharan and North Africa, and the Middle East. The disease course and complications are generally similar to those of chronic hepatitis C caused by other genotypes, although the faster progression of fibrosis was demonstrated in patients with coexisting schistosomiasis. In the era of interferon-based therapy, GT4-infected patients were described as difficult to treat due to suboptimal response. A breakthrough in the treatment of HCV-infected patients, including those with GT4 infection, was the introduction of direct-acting antiviral drugs.

CONCLUSIONS

The availability of safe and effective therapy has created a real opportunity for HCV eradication in line with the goal set by the World Health Organization. An example of a country where this is happening is Egypt, where GT4 accounts for more than 90% of HCV infections. There, broad access to therapy has been effectively supported by population-based screening.

Real-World Outcomes of Direct-Acting Antiviral Treatment and Retreatment in United Kingdom-Based Patients Infected With Hepatitis C Virus Genotypes/Subtypes Endemic in Africa

BACKGROUND

Chronic hepatitis C virus (HCV) infection affects 71 million individuals, mostly residing in low- and middle-income countries (LMICs). Direct-acting antivirals (DAAs) give high rates of sustained virological response (SVR) in high-income countries where a restricted range of HCV genotypes/subtypes circulate.

METHODS

We studied United Kingdom-resident patients born in Africa to examine DAA effectiveness in LMICs where there is far greater breadth of HCV genotypes/subtypes. Viral genome sequences were determined from 233 patients.

RESULTS

Full-length viral genomic sequences for 26 known subtypes and 5 previously unidentified isolates covering 5 HCV genotypes were determined. From 149 patients who received DAA treatment/retreatment, the overall SVR was 93%. Treatment failure was associated primarily with 2 subtypes, gt1l and gt4r, using sofosbuvir/ledipasvir. These subtypes contain natural resistance-associated variants that likely contribute to poor efficacy with this drug combination. Treatment failure was also significantly associated with hepatocellular carcinoma.

CONCLUSIONS

DAA combinations give high SVR rates despite the high HCV diversity across the African continent except for subtypes gt1l and gt4r, which respond poorly to sofosbuvir/ledipasvir. These subtypes are widely distributed across Western, Central, and Eastern Africa. Thus, in circumstances where accurate genotyping is absent, ledipasvir and its generic compounds should not be considered as a recommended treatment option.

Hepatitis C virus genotype 4: A poorly characterized endemic genotype

Globally, 13% of all hepatitis C virus (HCV) infections are caused by genotype 4 (GT4), which consists of 17 subtypes with various levels of susceptibility to anti-HCV therapy. This genotype is endemic in the Middle East and Africa and has considerably spread to Europe lately. The molecular features of HCV-GT4 infection, as well as its appropriate therapeutics, are poorly characterized as it has not been the subject of widespread basic research. As such, in this review, we aim to gather the current state of knowledge of this genotype with a particular emphasis on its heterogeneity, sequence signatures, resistance-associated substitutions, and available in vivo and in vitro models used for its study. We urge developing more cell-culture models based on different GT4 subtypes to better understand the virology and therapeutic response of this particular genotype. This review may raise more awareness about this genotype and trigger more basic research work to develop its research tools. This will be critical to design better therapeutics and help to provide adequate guidelines for physicians working with HCV-GT4 patients.

The Role of RASs /RVs in the Current Management of HCV

The approval of combination therapies with direct-acting antiviral (DAA) regimens has led to significant progress in the field of hepatitis C virus (HCV) treatment. Although most patients treated with these agents achieve a virological cure, resistance to DAAs is a major issue. The rapid emergence of resistance-associated substitutions (RASs), in particular in the context of incomplete drug pressure, has an impact on sustained virological response (SVR) rates. Several RASs in NS3, NS5A and NS5B have been linked with reduced susceptibility to DAAs. RAS vary based on HCV characteristics and the different drug classes. DAA-resistant HCV variant haplotypes (RVs) are dominant in cases of virological failure. Viruses with resistance to NS3-4A protease inhibitors are only detected in the peripheral blood in a time frame ranging from weeks to months following completion of treatment, whereas NS5A inhibitor-resistant viruses may persist for years. Novel agents have been developed that demonstrate promising results in DAA-experienced patients. The recent approval of broad-spectrum drug combinations with a high genetic barrier to resistance and antiviral potency may overcome the problem of resistance.

Discovery and Optimization of a 4-Aminopiperidine Scaffold for Inhibition of Hepatitis C Virus Assembly

The majority of FDA-approved HCV therapeutics target the viral replicative machinery. An automated high-throughput phenotypic screen identified several small molecules as potent inhibitors of hepatitis C virus replication. Here, we disclose the discovery and optimization of a 4-aminopiperidine (4AP) scaffold targeting the assembly stages of the HCV life cycle. The original screening hit (1) demonstrates efficacy in the HCVcc assay but does not show potency prior to or during viral replication. Colocalization and infectivity studies indicate that the 4AP chemotype inhibits the assembly and release of infectious HCV. Compound 1 acts synergistically with FDA-approved direct-acting antiviral compounds Telaprevir and Daclatasvir, as well as broad spectrum antivirals Ribavirin and cyclosporin A. Following an SAR campaign, several derivatives of the 4AP series have been identified with increased potency against HCV, reduced in vitro toxicity, as well as improved in vitro and in vivo ADME properties.

Current treatment for hepatitis C virus/human immunodeficiency virus coinfection in adults

Hepatitis C virus (HCV)/human immunodeficiency virus (HIV) coinfection is a major problem among HIV-infected patients, resulting in increased morbidity and mortality rates due to the acceleration of liver fibrosis progression by HIV, leading to liver cirrhosis and hepatocellular carcinoma. Although the efficacy of direct-acting antiviral therapy in patients with HIV/HCV coinfection and HCV monoinfection are similar in terms of sustained virologic response rate, there are some additional complications that arise in the treatment of patients with HIV/HCV coinfection, including drug-drug interactions and HCV reinfection due to the high risk behavior of these patients. This review will summarize the current management of HIV/HCV coinfection.

Efficacy and Safety of Ombitasvir plus Paritaprevir, Ritonavir and Ribavirin in Non-cirrhotic Treatment-naïve and Treatment-experienced Egyptians with Chronic HCV Genotype-4 Infection

Hepatitis C virus genotype 4 (HCV-GT4) is a risk factor for cirrhosis, hepatocellular carcinoma and liver failure. A combination of three new direct-acting antivirals ombitasvir, paritaprevir, and ritonavir has been recommended for treatment of HCV-GT4 infection. The current study was aimed to assess the efficacy and safety of this combination plus ribavirin in non-cirrhotic, treatment-naïve and -experienced Egyptians with HCV-GT4 infection in a real-world setting. A total of 255 Egyptians with HCV-GT4 infection were enrolled, including 82 treatment-experienced and 173 treatment-naïve patients. All of them completed 12-week treatment protocol of ombitasvir, paritaprevir and ritonavir as an oral dose combination with ribavirin. Virological response (VR) was measured, as well as the biochemical parameters related to treatment efficacy and adverse events at baseline and after treatment, at 4 (VR4) and 12 (VR12) weeks post-treatment. The results showed that the VR4 rates were 98.8% in both groups, and VR12 rates were 97.7% and 96.3% in treatment-naïve and -experienced patients, respectively, with no significant differences found between the groups concerning VR4 (P=0.9) and VR12 (P=0.3). The most common adverse events were headache and fatigue, which were significantly more common (P=0.001 and 0.003, respectively) in treatment-experienced than in treatment-naïve group. The quadruple regimen was well-tolerated, and the reported adverse events were generally mild to moderate. This real-world setting study confirms that the combination of ombitasvir, paritaprevir, ritonavir, and ribavirin is highly effective in the treatment of HCV- GT4 infection with a good safety and tolerability profile.

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 12th 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 27th 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.

HCV Diagnosis and Sequencing Using Dried Blood Spots from Patients in Kinshasa (DRC): A Tool to Achieve WHO 2030 Targets

The World Health Organization has established an elimination plan for hepatitis C virus (HCV) by 2030. In Sub-Saharan Africa (SSA) access to diagnostic tools is limited, and a number of genotype 4 subtypes have been shown to be resistant to some direct-acting antivirals (DAAs). This study aims to analyze diagnostic assays for HCV based on dried blood spots (DBS) specimens collected in Kinshasa and to characterize genetic diversity of the virus within a group of mainly HIV positive patients. HCV antibody detection was performed on 107 DBS samples with Vidas® anti-HCV and Elecsys anti-HCV II, and on 31 samples with INNO-LIA HCV. Twenty-six samples were subjected to molecular detection. NS3, NS5A, and NS5B regions from 11 HCV viremic patients were sequenced. HCV seroprevalence was 12.2% (72% with detectable HCV RNA). Both Elecsys Anti-HCV and INNO-LIA HCV were highly sensitive and specific, whereas Vidas® anti-HCV lacked full sensitivity and specificity when DBS sample was used. NS5B/NS5A/NS3 sequencing revealed exclusively GT4 isolates (50% subtype 4r, 30% 4c and 20% 4k). All 4r strains harbored NS5A resistance-associated substitutions (RAS) at positions 28, 30, and 31, but no NS3 RAS was detected. Elecsys Anti-HCV and INNO-LIA HCV are reliable methods to detect HCV antibodies using DBS. HCV subtype 4r was the most prevalent among our patients. RASs found in subtype 4r in NS5A region confer unknown susceptibility to DAA.

Virological Factors Associated with Failure to the Latest Generation of Direct Acting Agents (DAA) and Re-Treatment Strategy: A Narrative Review

The availability of all oral direct acting antiviral agents (DAAs) has revolutionized the management of HCV infections in recent years, allowing to achieve a sustained virological response (SVR) in more than 95% of cases, irrespective of hepatitis C Virus (HCV) genotype or staging of liver disease. Although rare, the failure to the latest-generation regimens (grazoprevir/elbasvir, sofosbuvir/velpatasvir, pibrentasvir/glecaprevir) represents a serious clinical problem, since the data available in the literature on the virological characteristics and management of these patients are few. The aim of the present narrative review was to provide an overview of the impact of baseline RASs in patients treated with the latest-generation DAAs and to analyze the efficacy of the available retreatment strategies in those who have failed these regimens.

Hepatitis C Virus Treatment: Simplifying the Simple and Optimizing the Difficult

The availability of safe, efficacious, oral direct-acting antivirals (DAAs) have ushered in a new era of hepatitis C treatment with potential to eliminate hepatitis C as a public health threat. To achieve population-level effectiveness of these oral DAAs, hepatitis C treatment by a wide range of providers in different settings will be essential to increase the number of persons treated. We provide a clinical review of hepatitis C treatment with a focus on practical tools for management of hepatitis C in majority of currently infected individuals who can be easily cured and optimization of treatment for those in whom treatment may not be as simple.

Real Life Egyptian Experience of Daclatasvir Plus Sofosbuvir with Ribavirin in Naïve Difficult to Treat HCV Patients

BACKGROUND

Chronic infection with Hepatitis C virus (HCV) is considered as a major cause for developing liver cirrhosis and hepatocellular carcinoma. A new era in HCV treatment is ongoing using Direct Acting Antiviral activity (DAA). The first approved DAA drug was Sofosbuvir which has a high tolerability and preferable pharmacokinetic profile. Another recently developed drug is Daclatasvir a first-in-class HCV NS5A replication complex inhibitor. Both drugs are administered orally once daily and have potent antiviral activity with wide genotypic coverage.

METHODS

In the outpatient clinic, one hundred and fifty naïve difficult to treat chronic HCV patients were recruited from Tropical Medicine Department at Fayoum public hospital. A combination of Daclatasvir (60 mg) and Sofosbuvir (400 mg) (DCV/SOF) has been administered for those patients once daily with Ribavirin (1200 mg or 1000 mg based on patients' weight on two divided doses) over a period of 12 weeks. All patients have been followed up for clinical, laboratory assessment and HCV PCR to detect the efficacy and safety of the therapy.

RESULTS

Sustained Virologic Response rate (SVR12) was achieved in the vast majority of patients (90.67%). Cirrhotic patients showed lower SVR compared to non-cirrhotic patients (88.89% vs 90.91%, respectively). Around half of the patients (49.33%) developed adverse events (AEs) during treatment. The most common AEs were headache, fatigue and abdominal pain.

CONCLUSION

The available evidence seems to suggest that combination therapy of (DCV/SOF with RBV) in the treatment of chronic HCV genotype IV naïve difficult to treat patients either cirrhotic or non-cirrhotic is safe and effective. Monitoring for clinical and laboratory hepatic parameters was the basis for these findings.

Resistance-associated substitutions in patients with chronic hepatitis C virus genotype 4 infection

Data on the prevalence of resistance-associated substitutions (RASs) and their implications for treatment with direct-acting antivirals (DAAs) are sparse in European patients with HCV genotype 4. This study investigated RASs before and after DAA failure in different genotype 4 subtypes and evaluated retreatment efficacies. Samples of 195 genotype 4-infected patients were collected in the European Resistance Database and investigated for NS3, NS5A and NS5B RASs. Retreatment efficacies in DAA failure patients were analysed retrospectively. After NS5A inhibitor (NS5Ai) failure, subtype 4r was frequent (30%) compared to DAA-naïve patients (5%) and the number of NS5A RASs was significantly higher in subtype 4r compared to 4a or 4d (median three RASs vs no or one RAS, respectively, P < .0001). RASsL28V, L30R and M31L pre-existed in subtype 4r and were maintained after NS5Ai failure. Typical subtype 4r RASs were located in subdomain 1a of NS5A, close to membrane interaction and protein-protein interaction sites that are responsible for multimerization and hence viral replication. Retreatment of 37 DAA failure patients was highly effective with 100% SVR in prior SOF/RBV, PI/SOF and PI/NS5Ai failures. Secondary virologic failures were rare (n = 2; subtype 4d and 4r) and only observed in prior NS5Ai/SOF failures (SVR 90%). In conclusion, subtype 4r harboured considerably more RASs compared to other subtypes. A resistance-tailored retreatment using first- and second-generation DAAs was highly effective with SVR rates ≥90% across all subtypes and first-line treatment regimens.

Efficacy of NS5A inhibitors against unusual and potentially difficult-to-treat HCV subtypes commonly found in sub-Saharan Africa and South East Asia

BACKGROUND & AIMS

The efficacy of NS5A inhibitors against several less common subtypes of hepatitis C virus (HCV) is poorly characterised. Some subtypes including 3b, 3g, 6u and 6v commonly harbour amino acid residues in NS5A that may confer resistance to direct-acting antivirals (DAAs) in other common subtypes. Data from patients also suggest that 1l and 4r with amino acid substitutions at positions 28-31 and 93 in NS5A are relatively resistant to DAA therapy.

METHODS

In this study, we tested the efficacy of daclatasvir, elbasvir, ledipasvir, pibrentasvir and velpatasvir against these subtypes using the SGR-JFH1 replicon backbone.

RESULTS

NS5A inhibitors showed different levels of efficacy with only pibrentasvir effective against all tested subtypes. Daclatasvir and ledipasvir were ineffective against 6u and 6v (half maximal effective concentration [EC₅₀] values of 239-321 nM) while 3b and 3g were only susceptible to pibrentasvir. Analysis of effects of individual mutations indicated that Q30R in 1l increased the EC₅₀ of ledipasvir by 18-fold, conferring intermediate resistance, while those of L31M and Y93H in 4r induced increases in EC₅₀ values of 2,100- and 3,575-fold (high-level resistance).

CONCLUSION

The high ledipasvir EC₅₀ values of 1l with the Q30R substitution, 4r L31M and 4r Y93H may explain the treatment failure in patients who were infected with these viruses and treated with ledipasvir + sofosbuvir. This study also shows the ineffectiveness of the first generation NS5A inhibitors against 6u and 6v, and confirms the inherent resistance of 3b and 3g to most NS5A inhibitors. Clinical studies to confirm in vivo sensitivity to NS5A inhibitors are urgently needed so that rational, effective treatment strategies may be developed for unusual subtypes.

LAY SUMMARY

Little is known about the efficacy of NS5A inhibitors against some "unusual" hepatitis C virus (HCV) subtypes including 1l, 3b, 3g, 4r, 6u and 6v. In this study, we manufactured HCV replicons which express the NS5A protein from the unusual HCV subtypes 1l, 3b, 3g, 4r, 6u, 6v. We then tested the effect of the NS5A inhibitors daclatasvir, elbasvir, ledipasvir, pibrentasvir and velpatasvir on blocking replication, using these replicons. We show that these replicons are resistant at some level to all NS5A inhibitors other than pibrentasvir.

Hepatitis C genotype 4: A report on resistance-associated substitutions in NS3, NS5A, and NS5B genes

AUTHOR CONTRIBUTION

FN performed the literature review and wrote the manuscript; STZ coauthored, edited, and reviewed the manuscript.

ABSTRACT

Treatment response in Hepatitis C virus (HCV) has generated varied effects in patients. Recently, nonresponsive and relapse patients related to host and genotype variabilities have been reported in clinical trials. However, these trials included minimal sample sizes of patients with genotype 4, the most prevalent genotype in Egypt and the Middle East, compared with genotypes 1 and 2. The genetic variabilities that have been detected within the HCV genes, especially the ones associated with genotype 4, and are linked to treatment response, will be the focus of this review with emphasis on direct acting antiviral agents. In addition, the major studies and clinical trials performed globally and their inclusivity of genotype 4 are reported. This review also delineates future study areas and missing data that need further investigation when it comes to genotype 4.

2020 Taiwan consensus statement on the management of hepatitis C: part (I) general population

Hepatitis C virus (HCV) infection remains a major public health issue with high prevalence in Taiwan. Recently, the advent of direct-acting antiviral (DAA) agents, with higher efficacy, excellent safety profile, and truncated treatment duration, has revolutionized the paradigm of hepatitis C treatment and made HCV elimination possible. To provide timely guidance for optimal hepatitis C management, the Taiwan Association for the Study of the Liver (TASL) established an expert panel to publish a 2-part consensus statement on the management of hepatitis C in the DAA era. After comprehensive literature review and a consensus meeting, patient-oriented, genotype-guided recommendations on hepatitis C treatment for the general and special populations have been provided based on the latest indications and scientific evidence. In the first part of this consensus, we present the epidemiology and treatment situation of hepatitis C in Taiwan, the development of DAA, pre-treatment evaluation, post sustained virologic response (SVR) monitoring, and most importantly the treatment recommendations for the general population with compensated liver disease. The second part will focus on the treatment recommendations for the special populations.

An educate, test and treat model towards elimination of hepatitis C infection in Egypt: Feasibility and effectiveness in 73 villages

BACKGROUND & AIMS

Egypt has one of the highest burdens of HCV infection worldwide. It has a large treatment programme, but reaching rural communities represents a major challenge. We report on the feasibility and effectiveness of a comprehensive community-based HCV prevention, testing and treatment model whose goal was to eliminate infection from all adult villagers.

METHODS

An HCV "educate, test and treat" programme was implemented in 73 villages across 7 governorates in Egypt between 06/2015 and 06/2018. The programme model comprised community mobilisation facilitated by a network of village promoters to support the education, testing and treatment of patients, as well as fundraising in the local community. Comprehensive testing, linkage to care and treatment were provided for all eligible villagers aged 12 to 80 years.

RESULTS

Of 221,855 eligible villagers, 204,749 (92.3%, 95% CI 91.6-93.5) were screened for HCV antibody and HBsAg, of whom 33,839 (16.5%, 95% CI 12.2-16.1) and 763 (0.4%, 95% CI 0.3-0.5) were positive, respectively. Nearly all 33,839 HCV antibody positive individuals had a sample immediately collected for HCV RNA testing, and 15,892 were HCV RNA positive. The overall prevalence of HCV viraemia was 7.8%. A total of 14,495 (91.2%, 95% CI 89.9-96.4) patients received treatment within a median of 2.1 weeks from serological diagnosis (IQR 0.6-3.3 weeks) and a sustained virological response was achieved among 14,238 of the treated cases (98.3%, 95% CI 96.7-98.6). Cirrhosis was present in 3,192 patients (20.1%), of whom 166 (5.2%) were diagnosed with hepatocellular carcinoma. There was treatment coverage and cure of 84.6% of the estimated 17,137 infected persons aged 12-80 years across the 73 villages.

CONCLUSION

In this study of more than 200,000 villagers, we demonstrated the feasibility and effectiveness of a community-based "educate, test and treat" programme as a model for the elimination of HCV infection in rural communities.

LAY SUMMARY

A large community-based educate, test and treat hepatitis C programme was conducted in more than 200,000 villagers across 73 villages in Egypt. This study demonstrates that a simplified care model can achieve high uptake of testing, linkage to care and treatment, with high cure rates. We consider this a model for the elimination of hepatitis C virus infection in rural communities, which can be applied to other countries highly affected by hepatitis C.

Screening for Hepatitis C Virus Infection in Adolescents and Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

A 2013 review for the US Preventive Services Task Force (USPSTF) of hepatitis C virus (HCV) screening found interferon-based antiviral therapy associated with increased likelihood of sustained virologic response (SVR) and an association between achieving an SVR and improved clinical outcomes. New direct-acting antiviral (DAA) regimens are available.

OBJECTIVE

To update the 2013 review on HCV screening to inform the USPSTF.

DATA SOURCES

Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews through February 2019, with surveillance through September 2019.

STUDY SELECTION

Randomized clinical trials (RCTs) and nonrandomized treatment studies of HCV screening and DAA therapy; cohort studies on screening, antiviral therapy, and the association between an SVR after antiviral therapy and clinical outcomes.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data; a second checked accuracy. Two investigators independently rated study quality.

MAIN OUTCOMES AND MEASURES

Mortality, morbidity, quality of life, screening and treatment harms, and screening diagnostic yield.

RESULTS

Eight RCTs of DAA therapy vs placebo or an outdated antiviral regimen, 48 other treatment studies, and 33 cohort studies, with a total of 179 230 participants, were included. No study evaluated effects of HCV screening vs no screening. One new study since the 2013 review (n = 5917) found similar diagnostic yield of risk-based screening (sensitivity, 82%; number needed to screen to identify 1 HCV case, 15) and birth cohort screening (sensitivity, 76%; number needed to screen, 29), assuming perfect implementation. Ten open-label studies (n = 3292) reported small improvements in some quality-of-life and functional outcomes (eg, less than 3 points on the 0 to 100 36-Item Short Form Health Survey physical and mental component summary scales) after DAA treatment compared with before treatment. Two cohort studies (n = 24 686) found inconsistent associations of antiviral therapy vs no therapy with risk of hepatocellular carcinoma. Forty-nine treatment studies (n = 10 181) found DAA regimens associated with pooled SVR rates greater than 95% across genotypes, and low short-term rates of serious adverse events (1.9%) and withdrawal due to adverse events (0.4%). An SVR after antiviral therapy was associated with decreased adjusted risk of all-cause mortality (13 studies, n = 36 986; pooled hazard ratio [HR], 0.40 [95% CI, 0.28-0.56) and hepatocellular carcinoma (20 studies, n = 84 491; pooled HR, 0.29 [95% CI, 0.23 to 0.38]) vs no SVR.

CONCLUSIONS AND RELEVANCE

Direct evidence on the effects of HCV screening on clinical outcomes remains unavailable, but DAA regimens were associated with SVR rates greater than 5% and few short-term harms relative to older antiviral therapies. An SVR after antiviral therapy was associated with improved clinical outcomes compared with no SVR.

Sofosbuvir-based regimens in the treatment of patients with chronic hepatitis C virus infection: Real-world efficacy in Thailand

Aims

To analyze the efficacy and safety of sofosbuvir (SOF)-based regimens in Thai patients with chronic hepatitis C virus infection who had pre-existing significant liver fibrosis.

Patients and methods

This was a retrospective cohort study, conducted between 1 June 2018 and 31 May 2019 at Rajavithi Hospital, Bangkok, Thailand. All patients completed 12 weeks of SOF-based regimens and had follow-up for at least 12 weeks after therapy discontinuation. The primary outcome was sustained virological response (SVR) 12 weeks after the end of therapy.

Result

A total of 185 patients were included, with 52, 63 and 70 taking SOF+Ledipasvir (SOF+LDV), SOF+LDV+ribavirin (RBV) and SOF+Pegylated interferon (Peg-IFN)+RBV (SOF+Peg-IFN+RBV) respectively. Genotype (GT) 1 was predominant at 40.0%, followed by GT3 at 37.8%, and GT6 at 22.2%. Overall 95.1% of patients in this study achieved SVR (n = 176/185), and the only factor associated with SVR was HCV genotype (p = 0.001). GT6 patients had lower SVR rates compared to GT1 and GT3 patients (82.9%, 98.6%, and 98.6% respectively) while there was no association between SVR and other factors (p >0.05) such as gender, age, BMI, underlying cirrhosis, baseline HCV viral load, or prior treatment history. No serious adverse events were reported in the present study.

Conclusion

Sofosbuvir-based regimens in the treatment of patients with chronic HCV infection were highly efficacious with excellent safety and tolerability profiles in a real-world setting; however, further research is required to establish whether or not such a regimen is an adequate treatment for all genotype 6 patients.

Real-world experiences with direct-acting antiviral agents for chronic hepatitis C treatment

As direct-acting antiviral (DAA) agents become more readily available for the treatment of chronic hepatitis C, it is important to understand real-world treatment experiences. In order to assess the effectiveness of DAA regimens and factors that influence sustained virologic response (SVR) rates in the Veterans Affairs healthcare system, we retrospectively identified veterans with chronic hepatitis C who were treated with DAAs from January 2014 to June 2015. We determined SVR rates and collected data on demographics, genotype (GT), previous interferon-based treatment, antiviral regimens, and co-morbidities (HIV, prior solid organ transplant, haemodialysis) for analysis. Of 15 720 veterans, the majority were infected with genotype 1a (GT1a, 60.5%). Excluding the special populations, the overall cohort SVR rate was 92%. Compared to treatment-experienced patients, treatment-naïve patients had significantly higher SVR rates (90% vs 92%, P = .006). Subgroups associated with lower likelihood of achieving SVR-included African Americans (OR 0.79, 95% CI 0.69-0.91), GT3 (OR 0.65, CI 0.50-0.86), and cirrhosis (OR 0.91, CI 0.84-0.99) or decompensated cirrhosis (ascites: OR 0.78, CI 0.67-0.91, variceal bleed: OR 0.75, CI 0.57-0.99). The only treatment regimen independently associated with lower SVR rates was SOF+RBV+IFN (OR 0.65, CI 0.50-0.84). Special populations achieved high SVR rates: HIV 92%, haemodialysis 93%, liver transplant 96% and renal transplant 94%. In conclusion, overall SVR rates were comparable to those reported in clinical trials and carried over to historically more difficult-to-treat patients. Several patient- and treatment-related factors were identified as independent predictors of treatment failure and suggest subgroups to target for efforts to improve therapeutic strategies.

Pangenotypic direct acting antivirals for the treatment of chronic hepatitis C virus infection: A systematic literature review and meta-analysis

BACKGROUND

Recent approval and adoption of pangenotypic direct acting antivirals (DAAs) necessitated a revision of the 2015 World Health Organization guidelines for the management of persons with hepatitis C virus (HCV) infection.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and relevant conference proceedings to identify randomized and non-randomized trials, as well as prospective observational studies of DAAs. The proportions of persons with events were pooled for sustained virological response at 12 weeks post-treatment (SVR12), discontinuations due to adverse events (DAEs), serious adverse events (SAEs), and all-cause mortality. Analyses were stratified by HCV genotype and antiviral treatment experience, with subgroup analyses based on presence of cirrhosis and HIV-HCV coinfection.

FINDINGS

The evidence base consisted of 238 publications describing 142 studies. In the overall analysis, which included all persons irrespective of treatment experience or comorbidities, the pooled proportion achieving SVR12 exceeded 0.94 for all pangenotypic regimens across genotypes 1, 2, and 4. Some heterogeneity may have led to lower SVR rates in persons with genotype 3 infection. High SVR12 (>0.90) was observed in persons with genotype 1 infection with cirrhosis, though evidence varied and was limited for genotypes 2-4. Evidence was sparse for persons with HIV-HCV coinfection. All regimens were associated with small proportions of persons with DAEs, SAEs, or all-cause mortality.

INTERPRETATION

Based on this and other supporting evidence, the WHO issued updated guidelines with a conditional recommendation, based on moderate quality evidence, for the use of pangenotypic DAA regimens for persons with chronic HCV infection aged 18 years and older (July 2018).

FUNDING

This study was funded by the World Health Organization.

Schizosaccharomyces pombe can Reduce Acetic Acid Produced by Baijiu Spontaneous Fermentation Microbiota

The spontaneous fermentation of alcoholic beverage is a bioprocess donated by microbiota with complex stress environments. Among various microbes, non-Saccharomyces yeasts have high stress tolerance and significantly affect the taste and quality of products in process. Although many researchers have focused on the influence of acid stress, the mechanism of non-Saccharomyces yeasts to tolerant stress remains unclear in microbiota. To bridge the gap, we constructed in situ and in vitro studies to explore the reduction pathway of acetic acid in non-Saccharomyces yeasts. In this study, we found Schizosaccharomyces pombe has special capacities to resist 10 g/L acetic acid in laboratory cultures and decrease the average concentration of acetic acid from 9.62 to 6.55 g/kg fermented grains in Chinese Maotai-flavor liquor (Baijiu) production. Moreover, Schi. pombe promoted metabolic level of mevalonate pathway (high expressions of gene ACCAT1, HMGCS1, and HMGCR1) to degrade a high concentration of acetic acid. Meanwhile, Schi. pombe also improved the concentration of mevalonic acid that is the precursor of terpenes to enhance the taste and quality of Baijiu. Overall, the synchronicity of reduction and generation in Schi. pombe advances the current knowledge to guide more suitable strategies for mechanism studies of non-Saccharomyces yeasts in fermented industries of alcoholic beverages.

Consensus recommendations for resistance testing in the management of chronic hepatitis C virus infection: Public Health England HCV Resistance Group

The treatment of hepatitis C virus (HCV) infection has been revolutionised by the advent of oral, well-tolerated, direct acting antiviral therapies (DAA), with high cure rates. However, in some scenarios, HCV resistance to antiviral therapies may have an impact on treatment success. Public Health England's HCV Resistance Group was established to support clinicians treating people with HCV, where the issue of resistance may be a factor in clinical decision-making, and this review includes the Group's current recommendations on the use of HCV resistance testing. The authors describe the principles behind and approach to HCV resistance testing and consider evidence from in vitro studies, clinical trials and real world cohorts on the impact of HCV resistance on treatment outcomes for particular DAA regimens. Five scenarios are identified in the UK and similar settings, where, in the Group's opinion, resistance testing should be performed.

Viral Hepatitis C Therapy: Pharmacokinetic and Pharmacodynamic Considerations: A 2019 Update

It has been estimated by the World Health Organization (WHO) that over 71 million people were infected with the hepatitis C virus (HCV) in 2015. Since then, a number of highly effective direct-acting antiviral (DAA) regimens have been licensed for the treatment of chronic HCV infection: sofosbuvir/daclatasvir, sofosbuvir/ledipasvir, elbasvir/grazoprevir, sofosbuvir/velpatasvir, glecaprevir/pibrentasvir, and sofosbuvir/velpatasvir/voxilaprevir. With these treatment regimens, almost all chronic HCV-infected patients, even including prior DAA failures, can be treated effectively and safely. It is therefore likely that further development of DAAs will be limited. In this descriptive review we provide an overview of the clinical pharmacokinetic characteristics of currently available DAAs by describing their absorption, distribution, metabolism, and excretion. Potential drug-drug interactions with the DAAs are briefly discussed. Furthermore, we summarize what is known about the pharmacodynamics of the DAAs in terms of efficacy and safety. We briefly discuss the relationship between the pharmacokinetics of the DAAs and efficacy or toxicity in special populations, such as hard to cure patients and patients with liver cirrhosis, liver transplantation, renal impairment, hepatitis B virus or HIV co-infection, bleeding disorders, and children. The aim of this overview is to educate/update prescribers and pharmacists so that they are able to safely and effectively treat HCV-infected patients even in the presence of underlying co-infections or co-morbidities.

International Liver Transplantation Society Asian Consensus on the Management of Hepatitis C Virus Infection in Resource Limited Setting-From Noncirrhotic to Decompensated Disease and After Liver Transplantation

BACKGROUND

The population of Asia exceeds 4.4 billion people. Chronic hepatitis C virus (HCV) infection in Asia is characterized by specific distribution of genotypes, lack of access to specific therapeutic agents, relatively high cost of treatment, and lack of experienced healthcare providers. Clear consensus on the diagnosis, management, and monitoring of HCV infection specific to the Asian region is a major unmet need. The consensus guidelines documents that have been published to date by major medical societies presume access to an array of direct acting antiviral agents and diagnostic tests that are not broadly applicable to resource limited settings, including Asia.

METHODS

To address the lack of an Asia-specific set of HCV treatment guidelines, we assembled a panel of 15 HCV experts in the field of hepatology from India, Indonesia, Myanmar, Vietnam, Pakistan, Philippines, and Mongolia convened in April 2017 to review the updated literature and provide recommendations on the diagnosis and management of chronic HCV infection that reflects local conditions.

RESULTS

An evidence-based comprehensive compilation of the literature supported by the graded recommendations from the expert panel for the optimization of the diagnosis, pretreatment, on treatment, and posttreatment assessments, and management of chronic HCV infection has been presented in this article.

CONCLUSIONS

With the evolving treatment landscape and addition of several new direct-acting antiviral agents and combination regimens into the therapeutic armamentarium, the current article may serve as a guide to the clinicians in optimizing the diagnosis and treatment selection for the management of chronic HCV infection in resource-limited settings.

Consensus on management of hepatitis C virus infection in resource-limited Ukraine and Commonwealth of Independent States regions

Globally, 69.6 million individuals were infected with hepatitis C virus (HCV) infection in 2016. Of the six major HCV genotypes (GT), the most predominant one is GT1, worldwide. The prevalence of HCV in Central Asia, which includes most of the Commonwealth of Independent States (CIS), has been estimated to be 5.8% of the total global burden. The predominant genotype in the CIS and Ukraine regions has been reported to be GT1, followed by GT3. Inadequate HCV epidemiological data, multiple socio-economic barriers, and the lack of region-specific guidelines have impeded the optimal management of HCV infection in this region. In this regard, a panel of regional experts in the field of hepatology convened to discuss and provide recommendations on the diagnosis, treatment, and pre-, on-, and posttreatment assessment of chronic HCV infection and to ensure the optimal use of cost-effective antiviral regimens in the region. A comprehensive evaluation of the literature along with expert recommendations for the management of GT1-GT6 HCV infection with the antiviral agents available in the region has been provided in this review. This consensus document will help guide clinical decision-making during the management of HCV infection, further optimizing treatment outcomes in these regions.

Clinical, Virological Characteristics, and Outcomes of Treatment with Sofosbuvir/Ledipasvir in Two Pediatric Patients Infected by HCV Genotype 4

Direct-acting antiviral drugs to cure infections with Hepatitis C virus (HCV) achieve a sustained virological response (SVR) in more than 90% of adult patients. At present, clinical trials are ongoing and real-life data are still limited in children. Herein, we report two cases of pediatric patients treated with fixed-dose combination of sofosbuvir/ledipasvir, already approved to treat HCV4 genotype. Both young girls achieved SVR even though HCV4 isolates carried L28M and M31L NS5A resistance-associated substitutions (RASs). Therefore, possible effects of these RASs merit further study, especially in children.

Tolerability and effectiveness of generic direct-acting antiviral drugs in eradication of hepatitis C genotype 4 among Egyptian patients

BACKGROUND

We investigated tolerability and effectiveness of generic, less expensive direct antiviral drugs in the treatment of hepatitis C virus genotype 4 (HCV GT-4) in an Egyptian cohort.

PATIENTS AND METHODS

Retrospectively, we analysed data from 648 patients with HCV GT4 attending Alexandria Main University Hospital from January 2016 to May 2017 [488 treatment naïve/160 treatment-experienced/288 with chronic hepatitis/360 with cirrhosis]. Patients received generic sofosbuvir/ledipasvir (n = 168, treatment naïve = 136, treatment-experienced = 32) or sofosbuvir/daclatasvir (n = 480, treatment naïve = 352, treatment-experienced = 128) ± ribavirin. We assessed sustained virologic response 12 weeks after treatment, non-response, relapse, treatment discontinuation and drug adverse reactions.

RESULTS

An overall sustained virologic response 12 weeks after treatment was achieved in 97.8%, non-response in 0.6%, relapse in 0.3% and discontinuation of treatment in 1.3% of patients. Sofosbuvir/ledipasvir ± ribavirin regimen attained an overall sustained virologic response 12 weeks after treatment in 96.4% of patients (100% of treatment-experienced vs 95.6% of treatment naïve, P = 0.28), vs 98.3% for sofosbuvir/daclatasvir ± ribavirin regimen (100% of treatment-experienced vs 97.7% of treatment naïve, P = 0.08). No severe drug adverse events or deaths were reported except anaemia due to ribavirin.

CONCLUSION

Generic direct antiviral drugs used in treating Egyptian patients with HCV GT-4 demonstrated equal potency, safety and tolerability compared to original brands, with low cost which would help to provide treatment to a larger scale of patients.

Ledipasvir/sofosbuvir with or without ribavirin for 8 or 12 weeks for the treatment of HCV genotype 4 infection: results from a randomised phase III study in Egypt

OBJECTIVE

We evaluated the efficacy and safety of ledipasvir/sofosbuvir alone and with ribavirin for 8 and 12 weeks in Egyptian patients with and without cirrhosis, who were infected with hepatitis C virus (HCV) genotype 4, including those who had failed previous treatment with sofosbuvir regimens.

DESIGN

In this open-label, multicentre, phase III study, treatment-naive patients were randomised to receive 8 or 12 weeks of ledipasvir/sofosbuvir±ribavirin. Interferon treatment-experienced patients were randomised to receive 12 weeks of ledipasvir/sofosbuvir±ribavirin, while sofosbuvir-experienced or ledipasvir/sofosbuvir-experienced patients received 12 weeks of ledipasvir/sofosbuvir+ribavirin. Randomisation was stratified by cirrhosis status. The primary endpoint was sustained virological response 12 weeks post-treatment (SVR12).

RESULTS

We enrolled 255 patients from four centres in Egypt. Among treatment-naive patients, SVR12 rates were 95% and 90% for those receiving 8 weeks of ledipasvir/sofosbuvir alone and with ribavirin, respectively, and 98% for those receiving 12 weeks of ledipasvir/sofosbuvir both alone and with ribavirin. Among interferon-experienced patients, SVR rates were 94% for those receiving 12 weeks of ledipasvir/sofosbuvir and 100% for those receiving 12 weeks of ledipasvir/sofosbuvir plus ribavirin. All patients previously treated with sofosbuvir regimens who received ledipasvir/sofosbuvir plus ribavirin achieved SVR12. The most common adverse events, headache and fatigue, were more common among patients receiving ribavirin.

CONCLUSION

Among non-cirrhotic treatment-naive patients with HCV genotype 4, 8 weeks of ledipasvir/sofosbuvir±ribavirin was highly effective. Twelve weeks of ledipasvir/sofosbuvir±ribavirin was highly effective regardless of presence of cirrhosis or prior treatment experience, including previous treatment with sofosbuvir or ledipasvir/sofosbuvir.

TRIAL REGISTRATION NUMBER

NCT02487030.

Highly Diverse Hepatitis C Strains Detected in Sub-Saharan Africa Have Unknown Susceptibility to Direct-Acting Antiviral Treatments

The global plan to eradicate hepatitis C virus (HCV) led by the World Health Organization outlines the use of highly effective direct-acting antiviral drugs (DAAs) to achieve elimination by 2030. Identifying individuals with active disease and investigation of the breadth of diversity of the virus in sub-Saharan Africa (SSA) is essential as genotypes in this region (where very few clinical trials have been carried out) are distinct from those found in other parts of the world. We undertook a population-based, nested case-control study in Uganda and obtained additional samples from the Democratic Republic of Congo (DRC) to estimate the prevalence of HCV, assess strategies for disease detection using serological and molecular techniques, and characterize genetic diversity of the virus. Using next-generation and Sanger sequencing, we aimed to identify strains circulating in East and Central Africa. A total of 7,751 Ugandan patients were initially screened for HCV, and 20 PCR-positive samples were obtained for sequencing. Serological assays were found to vary significantly in specificity for HCV. HCV strains detected in Uganda included genotype (g) 4k, g4p, g4q, and g4s and a newly identified unassigned g7 HCV strain. Two additional unassigned g7 strains were identified in patients originating from DRC (one partial and one full open reading frame sequence). These g4 and g7 strains contain nonstructural (ns) protein 3 and 5A polymorphisms associated with resistance to DAAs in other genotypes. Clinical studies are therefore indicated to investigate treatment response in infected patients. Conclusion: Although HCV prevalence and genotypes have been well characterized in patients in well-resourced countries, clinical trials are urgently required in SSA, where highly diverse g4 and g7 strains circulate.

Ombitasvir/paritaprevir/ritonavir plus ribavirin for 24 weeks in patients with HCV GT4 and compensated cirrhosis (AGATE-I Part II)

BACKGROUND AND AIMS

AGATE-I Part I previously reported high sustained virologic response rates in hepatitis C genotype 4 patients with cirrhosis, with 12 and 16 weeks' treatment with a combination of two direct-acting antivirals, ombitasvir and paritaprevir (codosed with ritonavir), plus ribavirin. Part II, reported here, extended the trial to include a 24-week treatment arm to fully assess treatment duration in patients with chronic hepatitis C genotype 4 infection and compensated cirrhosis.

METHODS

Enrollment took place between June and November of 2015. Treatment-naive and interferon-experienced patients with chronic hepatitis C genotype 4 infection and compensated cirrhosis were enrolled into Arm C; patients previously treated with a sofosbuvir-based regimen were enrolled into Arm D. All patients received a 24-week treatment with ombitasvir, paritaprevir, and ritonavir plus ribavirin. The primary outcome was the proportion of patients with a sustained virologic response (hepatitis C virus RNA < 25 IU/mL) at posttreatment week 12 in the intention-to-treat population. The safety population included all patients who received at least one dose of study drug.

RESULTS

In total, 64 patients were enrolled into AGATE-I Part II. Sustained virologic response at posttreatment week 12 was achieved in 57 of 61 patients (93.4%; 97.5% confidence interval, 92.6-97.7) in Arm C and 3 of 3 patients (100%) in Arm D. Two patients were missing SVR12 data, and two prematurely discontinued treatment. The most common adverse events for Arm C were fatigue (16 [26%]) and asthenia (15 [25%]). Results were comparable with those reported in Part I.

CONCLUSIONS

AGATE-I Part II indicates that extending treatment beyond 12 weeks in genotype 4-infected patients with compensated cirrhosis does not offer additional benefit.

Identification of 19 Novel Hepatitis C Virus Subtypes-Further Expanding HCV Classification

Background

Hepatitis C virus (HCV) is currently classified into 8 genotypes and 86 subtypes. The objective of this study was to characterize novel HCV subtypes and to investigate the impact of subtypes on treatment outcome.

Methods

Full-genome sequencing was performed on HCV plasma samples with <85% sequence homology of NS3, NS5A, and/or NS5B to HCV genotype (GT) 1–8 reference strains.

Results

A total of 14 653 patients with GT1–6 HCV infection were enrolled in clinical studies of sofosbuvir-based regimens. For the majority of the patients, a specific subtype could be assigned based on a close genetic relationship to previously described subtypes. However, for 19 patients, novel subtypes were identified with <85% homology compared with previously described subtypes. These novel subtypes had the following genotypes: 9 in GT2, 5 in GT4, 2 in GT6, and 1 each in GT1, GT3, and GT5. Despite the presence of polymorphisms at resistance-associated substitution positions, 18 of the 19 patients treated with sofosbuvir-containing therapy achieved SVR12.

Conclusions

Nineteen novel HCV subtypes were identified, suggesting an even greater genetic diversity of HCV subtypes than previously recognized.

Frequent Antiviral Treatment Failures in Patients Infected With Hepatitis C Virus Genotype 4, Subtype 4r

Hepatitis C virus (HCV) genotype 4 is highly heterogeneous. HCV subtype 4r has been suggested to be less responsive to direct-acting antiviral (DAA) drug treatment than other genotype 4 subtypes. Among 537 DAA-treated patients who experienced a virological failure (VF) in France between 2015 and 2018, 121 (22.5%) were infected with genotype 4 and 27 of them (22.3%) with subtype 4r; subtype 4r was thus over-represented as compared to its prevalence in the French general population. Population sequencing of the nonstructural protein (NS) 3, NS5A, and NS5B genes was performed in all subtype 4r patients at treatment failure and in 6 at baseline, whereas full-length HCV genome sequencing was performed in two baseline and three treatment failure samples by means of an original shotgun metagenomics method based on deep sequencing. At treatment failure, all subtype 4r patients harbored two to three dominant NS5A resistance-associated substitutions (RASs), including at least L28A/C/I/M/V and L30R. Among 13 patients exposed to sofosbuvir and an NS5A inhibitor (daclatasvir, ledipasvir, or velpatasvir), 5 (38.5%) also harbored NS5B S282C/T RASs at treatment failure. An additional patient harbored S282C/T RASs at treatment failure by deep sequencing. Prevalence of S282C/T RASs at treatment failure was significantly higher in patients infected with genotype 4r than with other genotypes, including other subtypes of genotype 4. Conclusion: The lower rates of sustained virological response in patients infected with subtype 4r are related to the frequent preexistence at treatment baseline and subsequent selection by DAA treatment of both NS5A and NS5B S282 RASs. Our study suggests that these patients should be identified and receive a triple DAA combination regimen as first-line treatment.

Status of Direct-Acting Antiviral Therapy for Hepatitis C Virus Infection and Remaining Challenges

Chronic infection with hepatitis C virus is a major cause of liver disease and hepatocellular carcinoma worldwide. After the discovery of hepatitis C virus 3 decades ago, the identification of the structure of the viral proteins, combined with high-throughput replicon models, enabled the discovery and development of direct-acting antivirals. These agents have revolutionized patient care, with cure rates of more than 90%. We review the status of direct-acting antiviral therapies for hepatitis C virus infection and discuss remaining challenges. We highlight licensed compounds, discuss the potential to shorten therapy even further, and review different options for treatment failure and resistance. We also provide an overview of clinical experience with generic agents and evidence for their efficacy. Finally, we discuss the need for new drugs and outline promising targets for future therapies.

Treatment efficacy of ledipasvir/sofosbuvir for 8 weeks in non-cirrhotic chronic hepatitis C genotype 4 patients

BACKGROUND/AIMS

Ledipasvir/sofosbuvir (LDV/SOF) combination is administered for 12 to 24 weeks to treat hepatitis C virus (HCV); guidelines recommend 8 weeks treatment duration for HCV genotype (GT) 1 infection based on the patient's baseline characteristics. Data on treating HCV GT4 with LDV/SOF are limited. In this prospective cohort study, the efficacy and safety of 8 weeks treatment duration with LDV/SOF was evaluated in HCV GT4 patients in Saudi Arabia.

PATIENTS AND METHODS

Treatment-naïve, non-cirrhotic HCV GT4 patients received LDV/SOF for 8 weeks. HCV RNA levels and laboratory evaluations were recorded at baseline and at Weeks 4, 8, and 20. The primary endpoint was sustained virologic response 12 weeks after the end of the treatment (SVR12). Safety data were also recorded.

RESULTS

Forty-five patients with a mean age of 43.9 ± 17.2 years participated, of whom 57.8% were male. Mean log₁₀HCV RNA was 6.26 ± 6.32 IU/mL and most (91.1%) had baseline HCV RNA levels <6 million IU/mL. The most frequent comorbidities were hypertension and diabetes mellitus (20.0% each). Concomitant medication was taken by 18 patients (40.0%), of whom two took proton pump inhibitors. Overall, SVR12 was 97.8% (95% confidence interval [CI]: 88.2%-99.9%); one patient (2.2%) relapsed post treatment. No serious adverse events or discontinuations were reported. Eighteen patients (44.4%) had 38 adverse events related to LDV/SOF; the most frequent was headache.

CONCLUSIONS

An 8-week regimen of LDV/SOF was well tolerated and efficacious in this treatment-naïve, non-cirrhotic HCV GT4-infected population. This study provides valuable information on a short treatment regimen for HCV GT4 infection in a real-world setting.

Overview of Direct-Acting Antiviral Drugs and Drug Resistance of Hepatitis C Virus

The advent of direct-acting antivirals (DAAs) has brought about a sudden renaissance in the treatment of chronic hepatitis C virus (HCV) infection with SVR rates now routinely >90%. However, due to the error-prone nature of the HCV RNA polymerase, resistance-associated substitutions (RASs) to DAAs may be present at baseline and can result in a significant effect on treatment outcomes and hamper the achievement of sustained virologic response. By further understanding the patterns and nature of these RASs, it is anticipated that the incidence of treatment failure will continue to decrease in frequency with the development of drug regimens with increasing potency, barrier to resistance, and genotypic efficacy. This review summarizes our current knowledge of RASs associated with HCV infection as well as the clinical effect of RASs on treatment with currently available DAA regimens.

Treatment of chronic hepatitis C virus infection in Rwanda with ledipasvir-sofosbuvir (SHARED): a single-arm trial

BACKGROUND

Limited treatment data are available for hepatitis C virus (HCV) in sub-Saharan Africa, especially for genotype 4. Our objective was to establish the safety and efficacy of ledipasvir-sofosbuvir for chronic HCV genotype 1 or 4 infection in adults in Rwanda.

METHODS

We did a single-arm trial to evaluate the safety and efficacy of ledipasvir-sofosbuvir in Rwandan adults with chronic HCV infection at a single study site (Rwanda Military Hospital, Kigali, Rwanda). We enrolled individuals aged 18 years or older with HCV genotype 1 or 4 infection and a plasma HCV RNA concentration of more than 1000 IU/mL at screening. All participants were given ledipasvir (90 mg) and sofosbuvir (400 mg) in a single combination tablet once daily for 12 weeks. We established HCV genotype using an Abbott platform, and HCV subtype with PCR amplification. The primary endpoint was the proportion of participants with a sustained virological response 12 weeks after therapy (SVR12). All patients enrolled in the study were included in the primary endpoint analyses. This study is registered with ClinicalTrials.gov, number NCT02964091.

FINDINGS

300 participants were enrolled between Feb 6, 2017, and Sept 18, 2017, and the follow-up period was completed on March 1, 2018. On genotyping, 248 (83%) participants were reported as having genotype 4, four (1%) genotype 1, and 48 (16%) both genotype 1 and genotype 4. Subsequent viral sequencing showed all participants actually had genotype 4 infection with subtype 4k (134 [45%]), subtype 4r (48 [16%]), subtype 4q (42 [14%]), and subtype 4v (24 [8%]) predominating. Overall, 261 (87%, 95% CI 83-91) participants achieved SVR12. In participants with genotype 4r, SVR12 was observed in 27 (56%, 95% CI 41-71) participants versus 234 (93%, 90-96) individuals with other subtypes. There were no drug-related treatment discontinuations due to ledipasvir-sofosbuvir. The most common adverse events were hypertension (97 [32%]), headache (78 [26%]), dizziness (61 [20%]), and fatigue (56 [19%]). There were six serious adverse events; none were assessed to be due to the study drug. 296 participants had data for pill counts at week 4 and 8; 271 (92%) had 100% adherence and only one (<1%) had an adherence of less than 90%.

INTERPRETATION

This is the first large-scale prospective study reporting direct-acting antiviral outcomes in sub-Saharan Africa. The high adherence and treatment success without intensive support measures or highly specialised clinical providers, and lack of treatment discontinuations due to adverse events support the feasibility of HCV treatment decentralisation and scale-up in sub-Saharan Africa. Genotype 4r is uniquely expressed in this region and associated with high rates of treatment failure, suggesting a need for rigorous test-of-cure in clinical practice and consideration of the use of newer pangenotypic direct-acting antiviral regimens in this region.

FUNDING

Gilead Sciences.

Sofosbuvir, velpatasvir and voxilaprevir: a new triple combination for hepatitis C virus treatment. One pill fits all? Is it the end of the road?

The advent of oral direct-acting antiviral agents (DAAs) has dramatically improved the hepatitis C virus (HCV) treatment landscape in the last 4 years, providing cure rates over 95% with a shorter duration of treatment and a very good safety profile. This has enabled access to treatment in nearly all HCV infected patients. The launch of two pangenotypic fixed dose combinations (FDCs) in 2017 made a new step forward in HCV treatment by slightly increasing efficacy and more importantly allowing the treatment of patients without HCV genotyping, and in some cases without fibrosis assessment. However, retreatment of the few DAA failure patients was still an issue for some HCV genotypes. The launch of the triple regimen FDC, sofosbuvir/velpatasvir/voxilaprevir, solves this issue by providing a cure rate over 96% regardless of HCV genotype. In this review, we describe the current HCV treatment landscape and focus on the development of this triple FDC either in treatment-naïve or treatment-experienced patients with previous failure on a DAA regimen.

Resistance detection and re-treatment options in hepatitis C virus-related chronic liver diseases after DAA-treatment failure

BACKGROUND

Introduced in 2013-2014, the second- and third-wave directly acting antivirals (DAAs) have strongly enhanced the efficacy and tolerability of anti-HCV treatment, with a sustained virological response (SVR) in 90-95% of cases treated. The aim of this paper was to focus on the type and prevalence of viral strains with a reduced sensitivity to DAAs and on treatment choices for DAA-experienced patients.

METHODS

The Medline was searched for "HCV infection", "HCV treatment", "Directly acting antivirals","HCV resistance".

RESULTS

Most patients who did not achieve an SVR have been found to be infected with HCV mutant strains with a reduced susceptibility to these drugs. These mutants occur frequently in the NS5A region, with a moderate frequency in the NS3/4A regions and rarely in the NS5B region. Treatment-induced mutants resistant to NS5A DAAs persist for years after treatment discontinuation, whereas those resistant to the NS3 DAAs have a shorter duration.

CONCLUSIONS

Patients who have failed HCV treatment with DAA agents have several re-treatment options, but re-treatment selection may be intricate and resistance testing is recommended to optimize this choice. It is, therefore, important to bear in mind that the correct determination of HCV genotype and subtype and the identification of RASs are essential elements for choosing the optimal re-treatment. It is supposed that it is useful to give readers some other suggestions regarding therapeutic reprocessing.

Safety and Efficacy of Ledipasvir-Sofosbuvir With or Without Ribavirin for Chronic Hepatitis C in Children Ages 6-11

Currently, there are no interferon-free treatments available for hepatitis C virus (HCV)-infected patients younger than 12 years. We evaluated the safety and effectiveness of the all-oral regimen ledipasvir-sofosbuvir ± ribavirin in HCV-infected children aged 6 to <12 years. In an open-label study, patients aged 6 to <12 years received ledipasvir 45 mg-sofosbuvir 200 mg as two fixed-dose combination tablets 22.5/100 mg once daily, with or without ribavirin, for 12 or 24 weeks, depending on HCV genotype and cirrhosis status. The primary efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Twelve patients underwent intensive pharmacokinetic sampling to confirm the appropriateness of the ledipasvir and sofosbuvir dosages. Ninety-two patients were enrolled (88 genotype 1, 2 genotype 3, and 2 genotype 4), with a median age of 9 years (range, 6-11). Most were perinatally infected (97%) and treatment-naive (78%). Two were confirmed to have cirrhosis, while the degree of fibrosis was unknown in 55 patients. The overall SVR12 rate was 99% (91/92; 95% confidence interval, 94%-100%). The single patient not reaching SVR relapsed 4 weeks after completing 12 weeks of treatment. The most common adverse events were headache and pyrexia. One patient had three serious adverse events, which were considered to be not related to study treatment: tooth abscess, abdominal pain, and gastroenteritis. The area under the concentration-time curve and maximum concentration values for sofosbuvir, its primary metabolite GS-331007, and ledipasvir were within predefined pharmacokinetic equivalence boundaries (50%-200%) compared to values in adults in phase 2/3 of the ledipasvir and sofosbuvir studies. Conclusion: Ledipasvir-sofosbuvir was well tolerated and highly effective in children 6 to <12 years old with chronic HCV.

Expert opinion on the management of hepatitis C infection in Kuwait

Chronic hepatitis C virus (HCV) infection is a leading cause of death, especially in immunocompromised patients. The lack of clear prevalence data in the Middle East makes it difficult to estimate the true morbidity and mortality burden of HCV. In Kuwait, estimating the burden of disease is complicated by the constant flow of expatriates, many of whom are from HCV-endemic areas. The development of new and revolutionary treatments for HCV necessitates the standardization of clinical practice across all healthcare institutions. While international guidelines from the American Association for the Study of Liver Diseases (AASLD) and European Association for the Study of the Liver (EASL) do address this evolving treatment landscape, the cost-driven treatment prioritization of patients by these guidelines and unique HCV genotype presentation in the Kuwaiti population prompted the development of a more tailored approach. The predominant HCV genotypes prevalent in Kuwait are genotypes 4 and 1. The Kuwait Hepatology Club (KHC), comprising hepatologists across all major institutions in Kuwait, conducted several consensus meetings to develop the scoring criteria, evaluate all current evidence, and propose screening, diagnosis, and treatment suggestions for the management of HCV in this population. While these treatment suggestions were largely consistent with the 2016 AASLD and 2015 EASL guidelines, they also addressed gaps in the unmet needs of the Kuwaiti population with HCV.