Simeprevir plus sofosbuvir in patients with chronic hepatitis C virus genotype 1 infection and cirrhosis: A phase 3 study (OPTIMIST-2)

Pharmacophore-Assisted Covalent Docking Identifies a Potential Covalent Inhibitor for Drug-Resistant Genotype 3 Variants of Hepatitis C Viral NS3/4A Serine Protease

The emergence of drug-resistance-inducing mutations in Hepatitis C virus (HCV) coupled with genotypic heterogeneity has made targeting NS3/4A serine protease difficult. In this work, we investigated the mutagenic variations in the binding pocket of Genotype 3 (G3) HCV NS3/4A and evaluated ligands for efficacious inhibition. We report mutations at 14 positions within the ligand-binding residues of HCV NS3/4A, including H57R and S139P within the catalytic triad. We then modelled each mutational variant for pharmacophore-based virtual screening (PBVS) followed by covalent docking towards identifying a potential covalent inhibitor, i.e., cpd-217. The binding stability of cpd-217 was then supported by molecular dynamic simulation followed by MM/GBSA binding free energy calculation. The free energy decomposition analysis indicated that the resistant mutants alter the HCV NS3/4A-ligand interaction, resulting in unbalanced energy distribution within the binding site, leading to drug resistance. Cpd-217 was identified as interacting with all NS3/4A G3 variants with significant covalent docking scores. In conclusion, cpd-217 emerges as a potential inhibitor of HCV NS3/4A G3 variants that warrants further in vitro and in vivo studies. This study provides a theoretical foundation for drug design and development targeting HCV G3 NS3/4A.

Therapeutic Intervention of Serine Protease Inhibitors against Hepatitis C Virus

Hepatitis C virus (HCV) is a globally prevalent and hazardous disorder that is responsible for inducing several persistent and potentially fatal liver diseases. Current treatment strategies offer limited efficacy, often accompanied by severe and debilitating adverse effects. Consequently, there is an urgent and compelling need to develop novel therapeutic interventions that can provide maximum efficacy in combating HCV while minimizing the burden of adverse effects on patients. One promising target against HCV is the NS3-4A serine protease, a complex composed of two HCV-encoded proteins. This non-covalent heterodimer is crucial in the viral life cycle and has become a primary focus for therapeutic interventions. Although peginterferon, combined with ribavirin, is commonly employed for HCV treatment, its efficacy is hampered by significant adverse effects that can profoundly impact patients' quality of life. In recent years, the development of direct-acting antiviral agents (DAAs) has emerged as a breakthrough in HCV therapy. These agents exhibit remarkable potency against the virus and have demonstrated fewer adverse effects when combined with other DAAs. However, it is important to note that there is a potential for developing resistance to DAAs due to alterations in the amino acid position of the NS3-4A protease. This emphasizes the need for ongoing research to identify strategies that can minimize the emergence of resistance and ensure long-term effectiveness. While the combination of DAAs holds promise for HCV treatment, it is crucial to consider the possibility of drug-drug interactions. These interactions may occur when different DAAs are used concurrently, potentially compromising their therapeutic efficacy. Therefore, carefully evaluating and monitoring potential drug interactions are vital to optimize treatment outcomes. In the pursuit of novel therapeutic interventions for HCV, the field of computational biology and bioinformatics has emerged as a valuable tool. These advanced technologies and methodologies enable the development and design of new drugs and therapeutic agents that exhibit maximum efficacy, reduced risk of resistance, and minimal adverse effects. By leveraging computational approaches, researchers can efficiently screen and optimize potential candidates, accelerating the discovery and development of highly effective treatments for HCV, treatments.

Review of heart transplantation from hepatitis C-positive donors

Significant scarcity of a donor pool exists for heart transplantation (HT) as the prevalence of patients with end-stage refractory heart failure is increasing exceptionally. With the discovery of effective direct-acting antiviral and favorable short-term outcomes following HT, the hearts from hepatitis C virus (HCV) patient are being utilized to increase the donor pool. Short-term outcomes with regards to graft function, coronary artery vasculopathy, and kidney and liver disease is comparable in HCV-negative recipients undergoing HT from HCV-positive donors compared to HCV-negative donors. A significant high incidence of donor-derived HCV transmission was observed with great success of achieving sustained viral response with the use of direct-acting antivirals. By accepting HCV-positive organs, the donor pool has expanded with younger donors, a shorter waitlist time, and a reduction in waitlist mortality. However, the long-term outcomes and impact of specific HCV genotypes remains to be seen. We reviewed the current literature on HT from HCV-positive donors.

The art of managing hepatitis C virus in special population groups: a paradigm shift

The first direct-acting antiviral (DAA) medications were approved for the treatment of chronic hepatitis C virus (HCV) in 2011. Later, the appearance of novel DAAs had revolutionized the landscape of HCV treatment whose early treatment options were limited to interferon (IFN) either alone or in combinations. This review discusses the paradigm shift in legibility for treating different groups of patients with HCV after the introduction of DAAs, along with the consequent changes in treatment guidelines. IFN-based therapy was the firstly used for treating chronic HCV. Unfortunately, it exhibited many pitfalls, such as low efficacy in some patients and unsuitability for usage in lots of patients with some specific conditions, which could be comorbidities such as autoimmune thyroiditis, or liver related as in decompensated cirrhosis. Furthermore, IFN failed to treat all the extrahepatic manifestations of HCV. Nowadays, the breakthroughs brought by DAAs have benefited the patients and enabled the treatment of those who could not be treated or did not usually respond well to IFN. DAAs achieve a high success rate of HCV eradication in addition to avoiding unfavorable harms and, sometimes, adverse effects related to the previously used PEGylated IFN regimens.

Effectiveness of hepatitis C antiviral treatment and feasibility of hepatitis C elimination goal

OBJECTIVES

Second-generation direct-acting antivirals (DAAs) have shown high efficacy in the treatment of chronic hepatitis C virus (HCV) infections in clinical trials. This study aimed to estimate the effectiveness in real-life conditions and their capacity to eliminate HCV infection in the general population.

METHODS

In this observational cohort study, patients with active HCV infection who commenced DAA treatment between 2015 and 2020 in Navarre, Spain, were studied. Sustained virological response (SVR), defined as an undetectable viral load 12 weeks after the end of treatment, was evaluated until the end of 2021.

RESULTS

Of a total 1366 HCV-infected patients that commenced treatment, 19.3% (n = 263) were HIV-coinfected. After the first DAA treatment, SVR was achieved in 96.6% (n = 1320/1366) of patients and in 97.7% (95% confidence interval [CI] 96.6%-98.3%) of those who completed treatment (per-protocol analysis; n = 1320/1351). SVR was achieved in 97.9% (n = 1066/1089) and 96.9% (n = 254/262) of mono-infected and HIV-coinfected patients, respectively. Thirty-one patients had virological failure due to non-response (n = 19), poor compliance (n = 9), and with adverse events (n = 3). Of 27 patients that received a second treatment, 24 attained SVR (one after a third treatment), two died, and one that did not achieve SVR declined a third treatment. Three patients were re-infected, re-treated, and achieved SVR. At the end of the study, 1344 patients (98.4%, 95% CI 97.6%-98.9%) had achieved SVR, and only 1.8% needed more than one course of treatment. All patients who completed the treatment and were followed-up achieved SVR.

CONCLUSION

With DAAs, SVR was achieved in all patients with active HCV infection who completed follow-up, and a second course of treatment was only necessary in a small proportion of patients. Adherence to treatment is essential for HCV infection elimination.

National Brazilian survey on the outcomes of hepatitis c retreatment in patients non-responders to direct antiviral agents

BACKGROUND AND AIMS

Treatment of hepatitis C with direct antiviral agents (DAA) is associated with almost 95% of sustained virological response. However, some patients need retreatment. In Brazil, it should be done according to the Ministry of Health guidelines, frequently updated to include newly available drugs. This study aimed to conduct a national survey about the characteristics and outcomes of retreatment of hepatitis C in previously non-responders to DAAs.

PATIENTS AND METHODS

Institutions from all over the country were invited to participate in a national registry for retreatment, including information about clinical and epidemiological characteristics of the patients, type and outcomes of retreatment regimens. Only patients previously treated with interferon-free regimens were included.

RESULTS

As previous treatments the distribution was: SOF/DCV (56%), SOF/SIM (22%), 3D (11%), SOF/LED (6%) and SOF/RBV (5%). For retreatment the most frequently used drugs were SOF/GP (46%), SOF/DCV (23%) and SOF/VEL (11%). From 159 patients retreated, 132/159 (83%) had complete information in the registry and among them only seven patients were non-responders (SVR of 94.6%). All retreatments were well tolerated, without any serious adverse events or interruptions.

CONCLUSION

The retreatment of patients previously non-responders to DAAs was associated with high rate of SVR in this sample of Brazilian patients. This finding allows us to conclude that the retreatment options available in the public health system in Brazil are effective and safe and are an important component of the strategy of elimination of hepatitis C in our country.

Successful treatment of hepatitis C genotype 4 using sofosbuvir, daclatasvir, simeprevir and ribavirin in Egyptian patients with direct-acting antiviral agent treatment failure

Introduction

In chronic hepatitis C virus (HCV) patients in whom prior direct-acting antiviral agent (DAA) treatment had failed, outcomes after retreatment are optimal. Combination of sofosbuvir (SOF), daclatasvir (DCV), simeprevir (SIM), and ribavirin (RBV) in treatment experienced patients is recommended in current guidelines despite insufficient data. Our aim is to determine the efficacy and safety of SOF, DCV, SIM plus RBV in HCV infected patients who failed prior DAA treatment.

Material and methods

One hundred and seventeen patients who failed to respond to SOF containing regimens were randomized according to previous response to therapy to non-responders and relapsers. Duration of therapy depends on fibrosis stages. SOF, DCV, SIM and weight based RBV 12 weeks for F1 and F2 (group I) and 24 weeks for F3 and F4 (group II).

Results

In the non-responder group, a sustained virologic response (SVR) occurred in 100% in group I (F1 and F2) and 97% in group II (F3 and F4). Relapse was 3% in group II (F3 and F4). No patients from either group had breakthrough or non-response. In relapsers SVR was 100% in group I (F1 and F2) and 96% in group II (F3 and F4). Breakthrough, relapse and non-response were 2%, 4%, 2% respectively only in group II (F3 and F4).

Conclusions

Combining multiple DAAs with different viral targets may be effective treatment protocol in previous non-responders and relapsers with short durations of treatment.

Direct-acting antivirals for chronic hepatitis C treatment: The experience of two tertiary university centers in Brazil

BACKGROUND

Hepatitis C virus (HCV) treatment has undergone major changes in recent years. Previous interferon-based therapies have been replaced by oral direct-acting antivirals (DAA) regimens, with high sustained virologic response (SVR) rates, and a lower incidence of adverse events (AEs).

AIM

To evaluate the efficacy and safety of DAAs for HCV treatment in subjects from two tertiary university centers in Brazil.

METHODS

This is a multicenter retrospective cohort study of 532 patients with chronic hepatitis C (CHC), undergoing treatment with interferon-free regimens from November 2015 to November 2019. The therapeutic regimen was defined by the current Brazilian guidelines for HCV management at the time of treatment. Demographic, anthropometric, clinical, and laboratory variables were evaluated. SVRs were assessed at 12 to 24 wk after therapy by intention-to-treat (ITT), and modified ITT (m-ITT) analysis. AEs and serious adverse events (SAEs) were registered. In the statistical analysis, a P value of < 0.05 was considered significant.

RESULTS

The mean age was 56.88 years, with 415 (78.5%) being HCV genotype 1, followed by genotype 3 (20.1%). Moreover, 306 (57.5%) subjects had cirrhosis, and a third of them had decompensated cirrhosis. Sofosbuvir (SOF) plus daclatasvir ± ribavirin was the most frequently used treatment (66.9%), followed by SOF plus simeprevir (21.2%). The overall ITT SVR was 92.6% (493/532), while the m-ITT SVR was 96.8% (493/509). Variables associated with treatment failure via ITT evaluation were hepatic encephalopathy (OR: 4.320; 95%CI: 1.920-9.721, P = 0.0004), presence of esophageal varices (OR: 2.381; 95%CI: 1.137-4.988, P = 0.0215), previous portal hypertensive bleeding (OR: 2.756; 95%CI: 1.173-6.471, P = 0.02), higher model for end-stage liver disease scores (OR: 1.143, 95%CI: 1.060–1.233, P = 0.0005), lower serum albumin levels (OR: 0.528, 95%CI: 0.322-0.867, P = 0.0115), higher serum creatinine (OR: 1.117, 95%CI: 1.056-1.312, P = 0.0033), and international normalized ratio (INR) levels (OR: 5.542, 95%CI: 2.023-15.182, P = 0.0009). AEs were reported in 41.1% (211/514) of patients, and SAEs in 3.7%. The female gender, higher body mass index, esophageal varices, higher INR values, and longer treatment duration were independently associated with AE occurrence.

CONCLUSION

Treatment with oral DAAs attains a high SVR rate, with fewer SAEs in a real-life cohort of subjects with CHC, from two tertiary university centers in Brazil.

Breakthroughs in hepatitis C research: from discovery to cure

In the 1970s, an unknown virus was suspected for documented cases of transfusion-associated hepatitis, a phenomenon called non-A, non-B hepatitis. In 1989, the infectious transmissible agent was identified and named hepatitis C virus (HCV) and, soon enough, the first diagnostic HCV antibody test was developed, which led to a dramatic decrease in new infections. Today, HCV infection remains a global health burden and a major cause of liver cirrhosis, hepatocellular carcinoma and liver transplantation. However, tremendous advances have been made over the decades, and HCV became the first curable, chronic viral infection. The introduction of direct antiviral agents revolutionized antiviral treatment, leading to viral eradication in more than 98% of all patients infected with HCV. This Perspective discusses the history of HCV research, which reads like a role model for successful translational research: starting from a clinical observation, specific therapeutic agents were developed, which finally were implemented in national and global elimination programmes.

[The role of antiviral therapy in the management of patients with liver cirrhosis associated with chronic HBV and HCV infection]

The formation of the liver cirrhosis (LC) is an unfavorable event of the natural history of chronic liver diseases being accompanied by complications that often cause a fatal outcome. The study of the effectiveness of drugs that affect various etiopathogenetic mechanisms of this condition is an urgent problem of modern hepatology.The aim of the review was to show the role of antiviral therapy (AVT) in the management of patients with LC associated with chronic HBV (hepatitis B virus) and HCV (hepatitis C virus) infection.PubMed database, Google Scholar search engine, Cochrane Systematic Reviews, eLIBRARY.RU electronic scientific library, as well as the reference lists of articles were used to search for scientific articles. The relevant objectives of the review of the publications were identified for the period since 2000 up to 2021 by the search queries as following: «liver cirrhosis», «liver fibrosis», «chronic HBV infection», «chronic HCV infection», «portal hypertension», «treatment». The inclusion criteria were restricted to the management of patients with LC associated with chronic HBV and HCV infection.Current guidelines recommend indefinite treatment of patients with HBV-associated LC with nucleos(t)ide analogues regardless of serum HBV DNA levels, while the modern concept of using direct-acting antiviral drug combinations has become the standard treatment for HCV-associated cirrhosis. Studies have shown the ability of AVT to inhibit and reverse fibrotic processes in LC associated with chronic HBV and HCV infection. It has also been reported that HBV/HCV eradication prior to orthotopic liver transplantation improves long-term overall survival.This, in turn, can reduce the severity of portal hypertension and decrease the risk of associated complications, as well as normalize liver function. Thus, ensuring the availability of drugs for those in need of AVT will not only help prevent the development of LC, but also improve the quality of life and increase its expectancy of patients suffering from this disease.

Direct acting anti-hepatitis C combinations as potential COVID-19 protease inhibitors

The coronavirus pandemic could be the most threatening outbreak in the twenty-first century. According to the latest records of world health organization, more than 130 millions have been infected by COVID-19, with more than 2.9 million reported deaths. Yet, there is no magic cure for treatment of COVID-19. The concept of drug repurposing has been introduced as a fast, life-saving approach for drug discovery. Drug repurposing infers investigating already approved drugs for new indications, using the available information about pathophysiology of diseases and pharmacodynamics of drugs. In a recent work, more than 3000 FDA approved drugs were tested using virtual screening as potential antiviral agents for COVID-19. In this work, the top ranked five hits from the previous docking results together with drugs of similar chemical feature and/or mechanistic destinations were further tested using AutoDock Vina. The results showed that anti-HCV combinations could be potential therapeutic regimens for COVID-19 infections.

Hepatitis C Virus: Efficacy of New DAAs Regimens

BACKGROUND

HCV treatment showed dramatical change due to the introduction of potent, strong, direct antiviral drugs. Before the appearance of Direct-acting antivirals, multiple therapeutic interventions were used for hepatitis C, but none of these interventions were effective on patient-centered outcomes. Direct-acting antivirals cause disruption of viral replication because they target specific nonstructural viral proteins.

AIM

To review the advantages of efficient HCV therapy and its long term drawbacks.

METHODS

A search of the literature published in indexed databases (PubMed, Medline In-Process, and Embase) within the last 5 years was conducted. Any duplicated citations were excluded before first-pass screening. Citations (titles and abstracts) were screened for eligibility by a single reviewer. Full texts (including congress abstracts, posters and other congress communications) of citations deemed relevant during title and abstract screening were retrieved for second-pass review.

RESULTS

Studies on the clinical effects of DAAs for hepatitis C show better tolerance, improved survival and fewer complications when compared to previous interferon therapy.

CONCLUSION

HCV treatment has improved dramatically. Since that time, there are multiple approved oral therapies all with high efficacy. The most important factor which should be considered during choosing appropriate therapy is to ensure that it covers the viral genotype of the infected patients.

Sofosbuvir: Really Meets the Unmet Needs for Hepatitis C Treatment?

Chronic hepatitis C remains a major public health concern with a prevalence of more than 1% worldwide. Of late, with the discovery of newer drugs, chronic HCV treatment has touched new dimensions. The treatment has progressed from Interferons to Pegylated interferon (Peg IFN) based therapy, with or without ribavirin to treatment with orally active Direct Acting Antivirals (DAA) with Peg IFN and ribavirin and eventually to various combinations of DAA, without IFN. Introduction of newer DAAs has transfigured the treatment of chronic HCV. Chronic HCV patients with advanced liver disease, psychiatric condition, anemia or autoimmune diseases, not eligible for Peg IFN based therapy have a ray of hope now. Amongst all DAAs, nucleoside inhibitors have been the most promising agent. Thus the present review focuses on Sofosbuvir, one of the most effective nucleoside inhibitors; in terms of potency, resistance profile, activity against all genotypes of HCV and adverse effects. FDA approved Sofobuvir for clinical use in 2013. Chemically, it is 2'-deoxy-2'-α-fluoro-β-Cmethyluridine- 5'-triphosphate; a phosphoramidate prodrug that is activated by enzyme present in human liver. It is a highly potent inhibitor of HCV NS5B polymerase. Efficacy of the Sofosbuvir has been established in various phase 2 and phase 3 clinical trials like PROTON, ELECTRON, FUSION, POSITRON etc. Sofosbuvir has a good safety profile with few mild to moderate adverse effects. Evidence reveals that sofosbuvir has substantial impact on the treatment of HCV.

Direct antiviral therapy for treatment of hepatitis C: A real-world study from Brazil

INTRODUCTION AND OBJECTIVES

Direct antiviral agents (DAAs) including sofosbuvir (SOF), daclatasvir (DCV), simeprevir (SIM) and ombitasvir, paritaprevir and dasabuvir were introduced 2015 in Brazil for treatment of hepatitis C virus (HCV) infection. The aims of this study were to assess effectiveness and safety of HCV treatment with DAA in real-life world in a highly admixed population from Brazil.

MATERIALS AND METHODS

All Brazilian reference centers for HCV treatment were invited to take part in a web-based registry, prospectively conducted by the Brazilian Society of Hepatology, to assess outcomes of HCV treatment in Brazil with DAAs. Data to be collected included demographics, disease severity and comorbidities, genotype (GT), viral load, DAA regimens, treatment side effects and sustained virological response (SVR).

RESULTS

3939 patients (60% males, mean age 58±10 years) throughout the country were evaluated. Most had advanced fibrosis or cirrhosis, GT1 and were treated with SOF/DCV or SOF/SIM. Overall SVR rates were higher than 95%. Subjects with decompensated cirrhosis, GT2 and GT3 have lower SVR rates of 85%, 90% and 91%, respectively. Cirrhosis and decompensated cirrhosis in GT1 and male sex and decompensated cirrhosis in GT3 were significantly associated with no SVR. Adverse events (AD) and serious AD occurred in 18% and 5% of those subjects, respectively, but less than 1% of patients required treatment discontinuation.

CONCLUSION

SOF-based DAA regimens are effective and safe in the heterogeneous highly admixed Brazilian population and could remain an option for HCV treatment at least in low-income countries.

Detection of low-level HCV variants in DAA treated patients: comparison amongst three different NGS data analysis protocols

BACKGROUND

Notwithstanding the efforts of direct-acting antivirals (DAAs) for the treatment of chronically infected hepatitis C virus (HCV) patients, concerns exist regarding the emergence of resistance-associated substitutions (RAS) related to therapy failure. Sanger sequencing is still the reference technique used for the detection of RAS and it detects viral variants present up to 15%, meaning that minority variants are undetectable, using this technique. To date, many studies are focused on the analysis of the impact of HCV low variants using next-generation sequencing (NGS) techniques, but the importance of these minority variants is still debated, and importantly, a common data analysis method is still not defined.

METHODS

Serum samples from four patients failing DAAs therapy were collected at baseline and failure, and amplification of NS3, NS5A and NS5B genes was performed on each sample. The genes amplified were sequenced using Sanger and NGS Illumina sequencing and the data generated were analyzed with different approaches. Three different NGS data analysis methods, two homemade in silico pipeline and one commercially available certified user-friendly software, were used to detect low-level variants.

RESULTS

The NGS approach allowed to infer also very-low level virus variants. Moreover, data processing allowed to generate high accuracy data which results in reduction in the error rates for each single sequence polymorphism. The results improved the detection of low-level viral variants in the HCV quasispecies of the analyzed patients, and in one patient a low-level RAS related to treatment failure was identified. Importantly, the results obtained from only two out of the three data analysis strategies were in complete agreement in terms of both detection and frequency of RAS.

CONCLUSIONS

These results highlight the need to find a robust NGS data analysis method to standardize NGS results for a better comprehension of the clinical role of low-level HCV variants. Based on the extreme importance of data analysis approaches for wet-data interpretation, a detailed description of the used pipelines and further standardization of the in silico analysis could allow increasing diagnostic laboratory networking to unleash true potentials of NGS.

HCV genotype profile in Brazil of mono-infected and HIV co-infected individuals: A survey representative of an entire country

INTRODUCTION

To be eligible for government-provided treatment in Brazil, all HCV-infected individuals are required to be genotyped shortly after diagnosis. We describe the HCV genotype (G) profiles by geographic region, gender, age and HIV co-infection.

METHODS

We assessed 29,071 genotypes collected from HCV-infected individuals from March 2016 to March 2018 (Abbott Real-Time HCV Genotype). We randomly selected 12,336 samples for HIV co-infection testing using an EIA rapid test kit (TR DPP HIV 1/2 Bio-Manguinhos). Descriptive statistical analyses were performed using R.

RESULTS

Overall, HCV genotype distribution was 40.9% G1A, 30.2% G1B, 23.8% G3, 3.8% G2, 0.7% G4, 0.1% G5 and 0.6% with multiples genotypes. G1A prevalence was 44.4% among males and 35.8% among females. G1B and G2 were more prevalent in older individuals than G1A and G3. G3 was more prevalent in the South region. Of samples tested for HIV co-infection, 15% were HIV+. Median age among HCV/HIV co-infected individuals was 50 years old compared to 57 years old among mono-infected individuals. Distinct HCV genotype prevalence between HCV/HIV co-infected and HCV mono-infected individuals were respectively: G1A 60.6% versus 37.8%, G1B 15.2% versus 32.9%, and G3 18.9% versus 24.7%. G4 was detected among co-infected young men (3.5% versus 0.2% among mono-infected).

CONCLUSION

The increasing prevalence of G3, as inferred by the younger ages of the HCV-infected individuals, poses an extra challenge with regards to disease progression. Distinct genotypical profiles between HCV mono-infection and HCV/HIV co-infection warrant future research in order to better understand and help mitigate HCV chains of transmission.

Direct-acting Antiviral in the Treatment of Chronic Hepatitis C: Bonuses and Challenges

Owing to the rapid development and wide clinical application of direct acting antiviral (DAA) drugs in the treatment of hepatitis C virus (HCV) infection, the era of interferon-based therapy has almost come to an end. Cumulative studies show that DAA therapy renders high cure efficiency (>90%) and good safety profile, and may even bring some unexpected benefits to the patients. However, some issues of concern arise, one of which is the resistance mutation of HCV genome leading to failure of treatment. With the aim of providing some meaningful references for the treatment of chronic hepatitis C (CHC), this article summarizes the research progress on benefits of DAA accompanied by viral clearance in the treatment of chronic hepatitis and the drug resistance.

Liver stiffness measurements and FIB-4 are predictors of response to sofosbuvir-based treatment regimens in 7256 chronic HCV patients

Objectives: To assess the role of baseline liver stiffness (LS) by Transient elastography (TE) and FIB-4 in the prediction of virological response to sofosbuvir - based regimens in chronic HCV patients.Methods: A retrospective, multicenter study including 7256 chronic HCV patients who received different sofosbuvir-based regimens. Baseline demographic and laboratory data were recorded. TE was performed with FIB-4 calculation at baseline.Results: Sustained virological response at week 12 post-treatment (SVR12) was 91.4%. Pretreatment TE values and FIB-4 were significantly lower among sustained responders (17.8 ± 11.5 kPa, 2.66 ± 1.98, respectively) versus relapsers (24.5 ± 13.9 kPa, 4.02 ± 3.3, respectively). Best cutoff levels for LS by TE and FIB-4 score for prediction of failure to treatment response were 16.7 kPa and 2.4, respectively. Among different treatment protocol, patients with FIB-4 > 2.4, TE values >16.7 kPa are more prone to treatment failure except when using SOF/SIM treatment regimens.Conclusion: Baseline LS by TE and FIB-4 score may be useful for predicting treatment outcome in the new era of DAAs and could be integrated into pretreatment assessment of chronic HCV patients for better optimization of patient management.

Worldwide prevalence of baseline resistance-associated polymorphisms and resistance mutations in HCV against current direct-acting antivirals

BACKGROUND

HCV infections can now be completely cured, thanks to the currently marketed direct-acting antivirals (DAAs). It is known that HCV patients carry viral populations with baseline polymorphisms and/or mutations that make them resistant against some of these DAAs, which can negatively impact the patient's treatment outcome. Using complete HCV coding sequences isolated from 1,306 treatment-naive patients of genotypes (GTs) 1, 2, 3, 4 and 6 from around the globe, we studied the prevalence of baseline resistance-associated polymorphisms (RAPs) and resistance mutations (RMs) against DAAs that are currently on the market or in clinical trials.

METHODS

The HCV genome sequences used in this study were retrieved from the NCBI database. RAPs and RMs, with reference to HCV GT1a, were identified using the HCV Geno2pheno web server.

RESULTS

Nearly 50% of the total amino acid positions (including NS3 protease, NS5A and NS5B) studied are baseline polymorphisms that differentiated one GT from the rest. A proportion of these baseline polymorphisms and baseline non-polymorphic RMs could confer a significant increase in resistance against DAAs.

CONCLUSIONS

In this study, we show the presence and prevalence of RAPs and RMs in DAA treatment-naive patients against currently used DAAs or DAAs in clinical trials. Our study suggests that RAPs and RMs profiling of HCV patients should be performed before the start of the therapy. Our results should be relevant especially in low- and middle-income countries, where the patients have a large variation of GTs and subtypes, and where the generic HCV treatment is now increasingly available.

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.

Hepatitis C infection: Updates on treatment guidelines

Hepatitis C virus (HCV) is a major cause of chronic liver disease worldwide. Due to the asymptomatic nature of the infection, many acute cases of HCV infection are left undiagnosed, so screening individuals at risk is an important public health priority. New medications offer sustained virologic response rates of over 95%, fewer adverse reactions, and shorter durations of therapy. This article reviews the new treatment guidelines for the evaluation and management of patients with HCV infection.

Treatment strategies for patients with decompensated liver cirrhosis due to hepatitis C virus infection eligible for liver transplantation: real-life data from five German transplant centers

BACKGROUND

Even with highly effective direct-acting antivirals (DAAs) treatment of patients with decompensated hepatitis C (HCV) cirrhosis remains challenging. Clinical deterioration and the need for liver transplantation (LT) may arise despite previous antiviral treatment. It is unclear whether in patients with high Model for End-Stage Liver Disease (MELD) antiviral treatment is too risky and should thus be deferred until after LT. Treatment choices that are currently made in the real-world setting are unclear.

METHODS

We performed a retrospective multicenter data analysis of patients with decompensated HCV cirrhosis (MELD ≥15) that presented to liver transplant centers that are part of the German Center for Infection Research when highly active DAA therapy was available. Choice of treatment strategy (DAA first vs. transplantation first) was analyzed and correlated with baseline and outcome parameters.

RESULTS

Thirty-five patients fulfilled the inclusion criteria and their mean MELD score was 18.5±3.78 (median: 17, interquartile range=16-19). In the majority of patients (85.7%) DAA therapy was initiated before LT; survival rates and change in MELD were numerically better in this group compared with those where DAA therapy was withheld (82.1 vs. 40%, P=0.078; ΔMELD: -2.68±6.2 vs. 5.8±14.4, P=0.157). However, DAA treatment was more often initiated in patients with better liver function (MELD: 18±3.54 vs. 21.8±3.9, P=0.008). Three patients discontinued DAA treatment because of clinical deterioration; these patients all had a MELD score above 20 at the start of therapy.

CONCLUSION

At liver transplant centers in Germany DAA before LT is attempted in the majority of cases. It appears to be associated with an improved outcome and seems safe at least in individuals with MELD below or equal to 20.

Next-generation sequencing for the clinical management of hepatitis C virus infections: does one test fits all purposes?

While the prospect of viral cure is higher than ever for individuals infected with the hepatitis C virus (HCV) due to ground-breaking progress in antiviral treatment, success rates are still negatively influenced by HCV's high genetic variability. This genetic diversity is represented in the circulation of various genotypes and subtypes, mixed infections, recombinant forms and the presence of numerous drug resistant variants among infected individuals. Common misclassifications by commercial genotyping assays in combination with the limitations of currently used targeted population sequencing approaches have encouraged researchers to exploit alternative methods for the clinical management of HCV infections. Next-generation sequencing (NGS), a revolutionary and powerful tool with a variety of applications in clinical virology, can characterize viral diversity and depict viral dynamics in an ultra-wide and ultra-deep manner. The level of detail it provides makes it the method of choice for the diagnosis and clinical assessment of HCV infections. The sequence library provided by NGS is of a higher magnitude and sensitivity than data generated by conventional methods. Therefore, these technologies are helpful to guide clinical practice and at the same time highly valuable for epidemiological studies. The decreasing costs of NGS to determine genotypes, mixed infections, recombinant strains and drug resistant variants will soon make it feasible to employ NGS in clinical laboratories, to assist in the daily care of patients with HCV.

HCV Extrahepatic Manifestations

Hepatitis C virus (HCV) has been shown to affect many tissues other than liver. However, of the many extrahepatic manifestations (EMs) that have been associated with HCV, including cryoglobulinemia, lymphoma, insulin resistance, type 2 diabetes and neurological disorders, only a few have been shown to be directly related to HCV infection of extrahepatic tissues. HCV-triggered immune-mediated mechanisms account for most of the EMs. It is estimated that up to 74% of patients with chronic hepatitis C can develop at least one EM. All HCV patients with EMs should be considered for antiviral therapy, although not all will resolve with sustained virological response.

Interferon at the cellular, individual, and population level in hepatitis C virus infection: Its role in the interferon-free treatment era

The advent of powerful direct-acting antiviral agents (DAAs) has revolutionized the treatment of hepatitis C. DAAs cure nearly all patients with short duration, oral treatments. Significant efforts are now underway to optimize DAA-based treatments. We discuss the potential role of interferon in this optimization. Clinical studies present compelling evidence that DAAs perform better in treatment-naive individuals than in individuals who previously failed treatment with interferon, a surprising correlation because interferon and DAAs are thought to act independently. Recent mathematical models explore a mechanistic hypothesis underlying this correlation. The hypothesis invokes the action of interferon at the cellular, individual, and population levels. Strong interferon responses prevent the productive infection of cells, reduce viral replication, and impede the development of resistance to DAAs in infected individuals and improve cure rates elicited by DAAs in treated populations. The models develop descriptions of these processes, integrate them into a comprehensive framework, and capture clinical data quantitatively, providing a successful test of the hypothesis. Individuals with strong endogenous interferon responses thus present a promising subpopulation for reducing DAA treatment durations. This review discusses the conceptual advances made by the models, highlights the new insights they unravel, and examines their applicability to optimize DAA-based treatments.

The Observed Effect of Gastric Bypass Surgery on Direct-acting Antiviral Treatment: a Case Report

Chronic hepatitis C virus (HCV) infection can be cured with treatment using direct-acting antivirals (DAAs). Although these drugs have been widely studied, information about certain special populations is missing. In this case report we describe a treatment-experienced patient with chronic HCV infection genotype 1b, treated with 150 mg/day simeprevir, 400 mg/day sofosbuvir, and 1,000 mg/ day ribavirin for 24 weeks, after a Roux-and-Y gastric bypass. At steady-state a pharmacokinetic curve was recorded of sofosbuvir, GS-331007, and simeprevir. Ribavirin trough plasma concentration (Ctrough) was determined. The simeprevir area under the-concentration time curve (AUClast) and Ctrough were 9.42 h.mg/L and 0.046 mg/L, respectively. Compared to what was described in the literature, simeprevir exposure was low and therefore the simeprevir dose was increased to 300 mg/day. The increased dose of simeprevir was well tolerated and Ctrough was 0.532 mg/L. Sofosbuvir AUClast and Ctrough were 0.63 h.mg/L and 0.0013 mg/L. GS-331007 AUClast and Ctrough were 21.02 h.mg/L and 0.35 mg/L. Ribavirin Ctrough was 2.5 mg/L. Sofosbuvir, GS-331007, and ribavirin exposure were comparable with levels described in literature. The patient achieved a sustained virological response twelve weeks after the completion of treatment.

Personalized treatment of hepatitis C genotype 1a in Norway and Sweden 2014-2016: a study of treatment outcome in patients with or without resistance-based DAA-therapy

OBJECTIVES

Resistance-associated substitutions (RASs) may impair treatment response to direct-acting antivirals (DAA) in hepatitis C virus (HCV) treatment. We investigated the effects of baseline NS3-RASs (Q80K and R155K) and clinically relevant NS5A-RASs in patients with HCV genotype (GT) 1a infection on treatment outcome, with or without resistance-based DAA-treatment. This multi-center study was carried out between 2014 and 2016.

PATIENTS/METHODS

Treatment in the intervention group (n = 92) was tailored to baseline resistance. Detection of NS3-RAS led to an NS5A-inhibitor-based regimen and detection of NS5A-RAS to a protease-inhibitor regimen. Patients without baseline RAS in the intervention group and all patients in the control group (n = 101) received recommended standard DAA-treatment.

RESULTS

The sustained virologic response rates (SVR) in the intervention and control groups were 97.8% (90/92) and 93.1% (94/101), respectively (p = .174). A trend toward higher SVR-rate in cirrhotic patients (p = .058) was noticed in the intervention group compared to the control group with SVR-rates 97.5% (39/40) and 83.3% (35/42), respectively. All patients with baseline NS3 (Q80K/R155K) or NS5A-RASs in the intervention group achieved SVR with personalized resistance-based treatment. In the control group, five patients with Q80K or R155K at baseline were treated with simeprevir + sofosbuvir and treatment failed in two of them. Furthermore, one of three patients who failed ledipasvir + sofosbuvir treatment had NS5A-RASs at baseline.

CONCLUSIONS

In line with the findings of the OPTIMIST-2 trial for Q80K and the EASL-guidelines 2016 for NS5A-RASs, baseline RASs appeared to have an impact on treatment outcome albeit a statistical significance was not observed in this low-prevalence population.

Safety and efficacy of the combination simeprevir-sofosbuvir in HCV genotype 1- and 4-mono-infected patients from the French ANRS CO22 hepather cohort

BACKGROUND

Although real-life results of sofosbuvir/simeprevir have been extensively reported from the United States, data from other geographical areas are limited. In the French observational cohort, ANRS CO22 HEPATHER, 9432 patients were given the new oral antivirals from December 2013 to June 30, 2018. We report the results of sofosbuvir/simeprevir in genotypes 1- and 4-infected patients.

METHODS

Demographics and history of liver disease were collected at entry in the cohort. Clinical, adverse events, and virological data were collected throughout treatment and post-treatment follow-up. The choice of treatment duration or addition of ribavirin was left up to the physician.

RESULTS

Five hundred ninety-nine HCV (467 genotype 1 and 132 genotype 4) mono-infected, naïve for all oral-DAAs regimen patients were given sofosbuvir/simeprevir with (n = 63) or without ribavirin (n = 536) for 12 or 24 weeks; 56% had cirrhosis (4% decompensated) and 71% had prior treatment failure to interferon-based regimen. 7 patients (1.16%) were lost to follow-up. The overall SVR12 rate was 92.6%. The SVR12 was 90% in GT1a, 94.2% in GT1b and 91.6% in GT4 with no significant difference for genotype, treatment duration or ribavirin addition. Severity of liver disease was not associated with a lower SVR12 rate on multivariate analysis but was associated with a higher rate of severe side effects. Early treatment discontinuations were rare; no new safety signals were reported.

CONCLUSION

In this real life, observational, prospective cohort study, the 12-week sofosbuvir/simeprevir+/-ribavirin combination appears to be efficient and safe.

TRIAL REGISTRATION

Trial registration with ClinicalTrials.gov NCT01953458 .

In Vitro Susceptibility of Hepatitis C Virus Genotype 1 through 6 Clinical Isolates to the Pangenotypic NS3/4A Inhibitor Voxilaprevir

Voxilaprevir is a direct-acting antiviral agent (DAA) that targets the NS3/4A protease of hepatitis C virus (HCV). High sequence diversity of HCV and inadequate drug exposure during unsuccessful treatment may lead to the accumulation of variants with reduced susceptibility to DAAs, including NS3/4A protease inhibitors such as voxilaprevir. The voxilaprevir susceptibility of clinical and laboratory strains of HCV was assessed. The NS3 protease regions of viruses belonging to 6 genotypes and 29 subtypes from 345 DAA-naive or -experienced (including protease inhibitor) patients and 344 genotype 1 to 6 replicons bearing engineered NS3 resistance-associated substitutions (RASs) were tested in transient-transfection assays. The median voxilaprevir 50% effective concentration against NS3 from protease inhibitor-naive patient samples ranged from 0.38 nM for genotype 1 to 5.8 nM for genotype 3. Voxilaprevir susceptibilities of HCV replicons with NS3 RASs were dependent on subtype background and the type and number of substitutions introduced. The majority of RASs known to confer resistance to other protease inhibitors had little to no impact on voxilaprevir susceptibility, except A156L, T, or V in genotype 1 to 4 which conferred >100-fold reductions but exhibited low replication capacity in most genotypes. These data support the use of voxilaprevir in combination with other DAAs in DAA-naive and DAA-experienced patients infected with any subtype of HCV.

Real-World Clinical Efficacy and Tolerability of Direct-Acting Antivirals in Hepatitis C Monoinfection Compared to Hepatitis C/Human Immunodeficiency Virus Coinfection in a Community Care Setting

Background/Aims

Limited data exist comparing the safety and efficacy of direct-acting antivirals (DAAs) in hepatitis C virus (HCV) monoinfected and HCV/human immunodeficiency virus (HIV) coinfected patients in the real-world clinic practice setting.

Methods

All HCV monoinfected and HCV/HIV coinfected patients treated with DAAs between January 2014 and October 2017 in community clinic settings were retrospectively analyzed. Pretreatment baseline patient characteristics, treatment efficacy, factors affecting sustained virologic response at 12 weeks (SVR12) after treatment, and adverse reactions were compared between the groups.

Results

A total of 327 patients were included in the study, of which 253 were HCV monoinfected, and 74 were HCV/HIV coinfected. There was a statistically significant difference observed in SVR12 when comparing HCV monoinfection and HCV/HIV coinfection (94% and 84%, respectively, p=0.005). However, there were no significant factors identified as a predictor of a reduced response. The most common adverse effect was fatigue (27%). No significant drug interaction was observed between DAA and antiretroviral therapy. None of the patients discontinued the treatment due to adverse events.

Conclusions

In a real-world setting, DAA regimens have lower SVR12 in HCV/HIV coinfection than in HCV monoinfection. Further studies involving a higher number of HCV/HIV coinfected patients are needed to identify real predictors of a reduced response.

Psychometric Validation of the Hepatitis C Symptom and Impact Questionnaire (HCV-SIQv4) in a Diverse Sample of Adults with Chronic Hepatitis C Virus Infection Treated with an Interferon-free Simeprevir-containing Regimen

BACKGROUND

Hepatitis C virus (HCV) infection and its treatments are associated with significant symptoms, side effects and impact on patients functioning. The Hepatitis C Symptom and Impact Questionnaire version 4 (HCV-SIQv4) was developed according to FDA Patient Reported Outcomes (PRO) Guidance, for evaluating chronic HCV infection and its treatment.

OBJECTIVES

This study evaluated the psychometric properties and clinically important change (CIC) thresholds of the measure.

METHODS

PRO data were pooled from three Phase IIb and III trials evaluating interferon-free simeprevir-containing regimens for treatment of chronic HCV infection. Scale range adequacy, reliability, validity, responsiveness and CIC thresholds were assessed incorporating knowledge of the appropriate measurement model.

RESULTS

Data from 437 patients were analyzed. Stage of liver disease was associated with symptom severity and functioning at baseline. Reliability was acceptable (test-retest ICC ≥0.7) for most scores except the Gastrointestinal and Integumentary domains. Convergent validity was observed between HCV-SIQv4 scores and concurrent measures of conceptual similarity. Greater symptom severity and worse impact scores were associated with liver cirrhosis, depression, severe fatigue and health limitations. Patients who achieved SVR12 had better outcomes than those failing to. HCV-SIQv4 symptom and domain scores were responsive to changes in health state (effect sizes ≥0.5). Exploratory thresholds for change in scores indicating a clinically important improvement and worsening were HCV-SIQv4 Overall Body System Score (BSS), 8 and 8; Constitutional BSS, 10 and 10; Gastrointestinal BSS, 5 and 5; Psychiatric BSS, 8 and 8; Neurocognitive BSS, 8 and 8; and Integumentary BSS, 5 and 5.

CONCLUSIONS

The HCV-SIQv4 offers reliable, responsive assessments within HCV clinical development. CIC thresholds are now available to aid score interpretation.

Estimation of liver fibrosis by noncommercial serum markers in comparison with transient elastography in patients with chronic hepatitis C virus infection receiving direct-acting antiviral treatment

Treatment decisions are based on extent of fibrosis in patients with chronic hepatitis C (HCV) infection. Noninvasive diagnostic tools may help to avoid liver biopsy. We investigated the diagnostic accuracy of noncommercial serum scores in comparison with transient elastography (TE). Data analysis was undertaken based on 2458 patients enrolled in the German Hepatitis C Registry, in a prospective, observational study. Aspartate aminotransferase-to-platelet ratio index (APRI), FORNS index and FIB-4 score were calculated and the diagnostic accuracy was compared to TE. As estimated by TE, 955 (38.9%) patients had absence of significant fibrosis (SF), 736 (29.9%) patients had SF, and 767 (31.2%) patients were shown to have cirrhosis. Patients with absence of SF had a sustained virological response (SVR) rate of 97.9%, whereas SVR was attained in 96.2% and 92.2% in those with SF and cirrhosis, respectively (P < 0.0001). The area under the receiver operator characteristic curve (AUROC), sensitivity and specificity in discriminating of SF were 0.789, 0.596 and 0.939 by APRI; 0.838, 0.852 and 0.748 by FORNS index; and 0.828, 0.658 and 0.946 by FIB-4 score. AUROCs for the prediction of cirrhosis, sensitivity and specificity were 0.881, 0.851 and 0.854 by APRI; 0.846, 0.948 and 0.628 by FORNS index; and 0.907, 0.907 and 0.848 by FIB-4 score. In conclusion, in the present multicentre real-world cohort, SF and cirrhosis were predicted with high accuracy with noncommercial serum markers using TE as reference. Further prospective long-term follow-up is necessary to compare biomarkers with TE concerning liver-related outcome and overall mortality.

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.

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.

Should we cure hepatitis C virus in patients with hepatocellular carcinoma while treating cancer?

Direct acting antivirals stabilize or improve liver function in the majority of patients with hepatitis C virus cirrhosis. Hepatic decompensation is the main driver of death of patients with early, successfully treated hepatocellular carcinoma superimposed to cirrhosis. Treatment with direct acting antivirals could improve the prognosis of these subjects, independently from the subsequent course of hepatocellular carcinoma, if the efficacy in obtaining viral clearance is as high as in patients without a history of hepatocellular carcinoma, and if the risk of hepatocellular carcinoma recurrence is unaffected. When dealing with hepatocellular carcinoma patients, direct acting antivirals can be indicated in two different settings: (a) subjects in which hepatocellular carcinoma has been already successfully treated ("cured" hepatocellular carcinoma), or (b) subjects whose hepatocellular carcinoma is still untreated or untreatable ("active" hepatocellular carcinoma). Although there are abundant data on "cured" hepatocellular carcinoma, evidence supporting treatment decisions in patients with "active" hepatocellular carcinoma is at best scarce and controversial, since these patients as well as patients with hepatocellular carcinoma listed for liver transplantation are usually excluded from treatment.

Hepatitis C virus early kinetics and resistance-associated substitution dynamics during antiviral therapy with direct-acting antivirals

The emergence of resistance-associated substitutions (RASs) can compromise the high efficacy of direct-acting antivirals (DAAs). Little is known about RASs selection at very early time points during DAA treatment. Therefore, we analyzed the potential emergence of RASs immediately after therapy initiation. Samples of 71 patients treated with different DAAs were collected at baseline, during therapy (hours 4 and 8; days 1-7; weeks 2-4) or until target not detected. HCV-RNA levels were determined by qPCR, and RASs were detected by deep sequencing. Sixty-three (89%) patients achieved a sustained virological response (SVR), 7 (10%) relapsed, and 1 (1%) experienced a breakthrough. Almost all non-SVR (7/8, 88%) showed RASs either at baseline or relapse. High-frequency RASs detected at baseline (Y93H and L159F+C316N) remained detectable at early time points during therapy and reappeared as most prevalent substitutions at relapse. Conversely, emergent RASs at relapse (Q80R, D168E/V, R155K and L31V) were not observed during the first hours-days, before HCV-RNA became undetectable. HCV-RNA decay and genetic evolution of the quasispecies followed a similar pattern during the first hours of therapy in SVR and non-SVR patients. In conclusion, the absence of early RASs selection and the similar dynamics of HCV kinetics and quasispecies in SVR and non-SVR patients after therapy initiation suggest that RASs selection may occur at later stages in the remaining reservoir, where viral populations persist hidden at very low replication levels. Nevertheless, we cannot completely exclude very early selection, when RASs are present below the sensitivity limit of deep sequencing.

Viral resistance in HCV infection

The introduction of new multi-genotypic direct acting antivirals (DAA) in clinical practice has revolutionized HCV treatment, permitting the achievement of >95% rates of sustained virological response in many patients. However, virological failures can occur particularly if the treatments are sub optimal and/or with too short duration. Failure is often associated with development of resistance. The wide genetic variability in terms of different genotypes and subtypes, together with the natural presence and/or easy development of resistance during treatment, are intrinsic characteristics of HCV that may affect the treatment outcome and the chances of achieving a virological cure. This review explores in detail the aspects of HCV innate and treatment-induced resistance to new interferon-free DAA regimens.

In Vitro Antiviral Profile of Ruzasvir, a Potent and Pangenotype Inhibitor of Hepatitis C Virus NS5A

Inhibition of NS5A has emerged as an attractive strategy to intervene in hepatitis C virus (HCV) replication. Ruzasvir (formerly MK-8408) was developed as a novel NS5A inhibitor to improve upon the potency and barrier to resistance of early compounds. Ruzasvir inhibited HCV RNA replication with 50% effective concentrations (EC50s) of 1 to 4 pM in Huh7 or Huh7.5 cells bearing replicons for HCV genotype 1 (GT1) to GT7. The antiviral activity was modestly (10-fold) reduced in the presence of 40% normal human serum. The picomolar potency in replicon cells extended to sequences of clinical isolates available in public databases that were synthesized and tested as replicons. In GT1a, ruzasvir inhibited common NS5A resistance-associated substitutions (RASs), with the exception of M28G. De novo resistance selection studies identified pathways with certain amino acid substitutions at residues 28, 30, 31, and 93 across genotypes. Substitutions at position 93 were more common in GT1 to -4, while changes at position 31 emerged frequently in GT5 and -6. With the exception of GT4, the reintroduction of selected RASs conferred a ≥100-fold potency reduction in the antiviral activity of ruzasvir. Common RASs from other classes of direct-acting antiviral agents (DAAs) did not confer cross-resistance to ruzasvir. The interaction of ruzasvir with an NS3/4A protease inhibitor (grazoprevir) and an NS5B polymerase prodrug (uprifosbuvir) was additive to synergistic, with no evidence of antagonism or cytotoxicity. The antiviral profile of ruzasvir supported its further evaluation in human trials in combination with grazoprevir and uprifosbuvir.

Provider verification of electronic health record receipt and nonreceipt of direct-acting antivirals for the treatment of hepatitis C virus infection

PURPOSE

Pharmacoepidemiologic studies using electronic health record data could serve an important role in assessing safety and effectiveness of direct-acting antiviral therapy for chronic hepatitis C virus (HCV) infection, but the validity of these data needs to be determined. We evaluated the accuracy of pharmacy fill records in the national Veterans Health Administration (VA) Corporate Data Warehouse (CDW) as compared to facility-level electronic health record.

METHODS

Patients prescribed a direct-acting antiviral regimen at five VA sites between 2014 and 2016 were randomly selected and reviewed. A random sample of patients with chronic HCV infection without evidence of HCV treatment during the study period also underwent chart review. We calculated positive predictive value and negative predictive value overall and by site.

RESULTS

Of the 501 patients who received a total of 2416 prescriptions, 494 were validated using data extracted from CDW 6 months after the study period, yielding a positive predictive value of 98.6% (95% confidence interval, 97.6%-99.6%). Of the 100 patients with chronic HCV infection without prescriptions for HCV treatment, 99 were confirmed not to have received antiviral treatment (negative predictive value, 99.0%; 95% confidence interval, 97.1%-100%).

CONCLUSIONS

These findings provide assurance to researchers who use national VA CDW data for retrospective cohort studies that the CDW contains accurate information on HCV therapies in the modern treatment era.

Era of direct acting anti-viral agents for the treatment of hepatitis C

Hepatitis C infection is universal and the most common indication of liver transplantation in the United States. The period of less effective interferon therapy with intolerable side effects has gone. Now we have stepped into the era of direct acting anti-viral agents (DAAs) against hepatitis C virus. Treatment of hepatitis C is now extremely effective, tolerable and requires a short duration of intake of oral agents. Less monitoring is required with the current therapy and drug-drug interactions are less than the previous regimen. The current treatment options of chronic hepatitis C with various DAAs are discussed in this article.

Population Pharmacokinetics of AL-335 and Its Two Main Metabolites (ALS-022399, ALS-022227) in Monotherapy and in Combination with Odalasvir and/or Simeprevir

The aim of the current study was to characterize the time course of plasma concentrations of AL-335 and its main metabolites (ALS-022399 and ALS-022227) after oral administration in healthy and hepatitis C virus (HCV)-infected subjects, in monotherapy as well as in combination with simeprevir and/or odalasvir. AL-335, ALS-022399, and ALS-022227 plasma concentrations from subjects receiving 800 mg of AL-335 orally once daily (qd) as monotherapy or in combination were pooled and analyzed using a nonlinear mixed effect modeling approach. The typical values (between subject variability) of AL-335 and ALS-022399 apparent linear clearances were 3300 L/h (33.9%) and 1910 L/h (30.0%), respectively. ALS-022227 elimination was characterized as a nonlinear process, with typical values of V_{max,ALS-022227} and K_m,ALS-022227 estimated to be 84,799 ng/h (14.9%) and 450.2 ng/mL, respectively. AL-335 and ALS-022399 plasma concentrations were increased more than 2-fold in presence of simeprevir and/or odalasvir, while the effect on ALS-022227 plasma concentrations was limited. The effect of simeprevir and/or odalasvir might be explained by their capacity to inhibit P-glycoprotein. Internal evaluation confirmed that the population pharmacokinetic model developed was deemed appropriate to describe the time course of AL-335, ALS-022399, and ALS-022227 plasma concentrations and their associated variability in both healthy and HCV-infected subjects, as well as the interaction effect of simeprevir and/or odalasvir over AL-335 and its metabolites in healthy subjects. This model can be used as a starting point to evaluate drug-drug interaction processes in HCV-infected patients and support the development of a direct-acting antiviral (DAA) combination.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

DISCLOSURES

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

Baseline resistance-guided therapy does not enhance the response to interferon-free treatment of HCV infection in real life

Hepatitis C virus (HCV) response to direct-acting antivirals (DAAs) may be influenced by the presence of resistance-associated substitutions (RASs). This study aimed to assess if NS5A baseline RAS-guided treatment enhances the rate of sustained viral response (SVR) in naïve HCV-infected patients in clinical practice. All HCV-infected patients who initiated treatment with interferon (IFN)-free DAA-based regimens between March 2016 and May 2017 in 17 Spanish hospitals and who had evaluable SVR 12 weeks (SVR12) after the end of therapy were included. Patients had to be DAA naïve, with the exception of sofosbuvir with/without IFN. In one hospital, participants received therapy guided by the presence of NS5A-RASs (RGT population). Patients enrolled in the remaining hospitals, without baseline RASs testing, constituted the control population. A total of 120 and 512 patients were included in the RGT and control populations, respectively. Nine (7.5%) individuals in the RGT population showed baseline NS5A-RASs. All of them achieved SVR12. The SVR12 rate in the RGT population was 97.2% (three relapses) whereas it was 98.8% (six relapses) in the control population (p = 0.382). Our findings suggest that testing for baseline NS5A-RASs in naïve HCV-infected patients does not enhance the rate of SVR to DAA-based IFN-free therapy in clinical practice.

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.

Optimal cure rate by personalized HCV regimens in real-life: a proof-of-concept study

Background

Pretreatment evaluation of HCV-infected patients is a complex interplay between multiple clinical and viral parameters, leading to a tailored approach that may bring real-life sustained virological response (SVR) rates close to 98%-99%.

Objectives

As proof-of-concept, we evaluated the efficacy of all-oral direct-acting antiviral (DAA) regimens in patients whose personalization included pre-therapy evaluation of natural resistance-associated substitutions (RASs), in addition to international guideline recommendations.

Methods

One hundred and thirty-one patients who started a first-line all-oral DAA regimen between April 2015 and December 2016 were tested for baseline NS3 and NS5A RASs by Sanger sequencing. SVR12 was defined as HCV-RNA undetectability 12 weeks after treatment discontinuation.

Results

Compatibly with a real-life context, 74.0% (97 of 131) of patients presented ≥2 pretreatment risk factors for failure to achieve SVR12 (infection by GT-1a/GT-3a; cirrhosis; previous treatment experience; HCV-RNA ≥800 000 IU/mL) and 33.6% had ≥3 risk factors. Natural RASs were frequently detected (32.1% prevalence), with substantial prevalence of NS5A RASs (15.3%), mostly represented by Y93H in GT-1b (3 of 36, 8.3%) and GT-3a (3 of 25, 12.0%) and F28C in GT-2c (2 of 11, 18.2%). Overall, personalized treatment led to 100% SVR12, even in those patients for whom treatment strategy was either strengthened (by ribavirin inclusion and/or duration increase) or simplified (by ribavirin exclusion and/or duration reduction), thanks to baseline RAS evaluation.

Conclusions

Even with newer DAA regimens, an integrated interpretation of clinical and virological pretreatment parameters, including natural RASs, may play a relevant role in bringing SVR rates close to the highest achievable. Treatment tailoring can be foreseen in 'hard-to-treat' patients, but also in 'easy' patients with favourable indicators, whereby a simplification/shortening of recommended regimens can be indicated.