Re-treatment of chronic hepatitis C virus genotype 1 infection after relapse: an open-label pilot study

Direct-Acting Antiviral Therapy for Patients with Chronic Hepatitis C Infection and Decompensated Cirrhosis

Patients with chronic hepatitis C virus (HCV) infection and decompensated cirrhosis are an important population for antiviral therapy yet under-represented in clinical trials. HCV direct-acting antiviral (DAA) therapies, unlike interferon-containing regimens, can be safely utilized in decompensated patients. Per guidelines from the American Association for the Study of Liver Diseases (AASLD), therapy of choice in HCV and decompensated cirrhosis is sofosbuvir, an HCV polymerase inhibitor, combined with a replication complex inhibitor (NS5A inhibitor) with or without ribavirin. Combination therapy with a HCV protease inhibitor and an NS5A inhibitor is effective in this population but is specifically not recommended in AASLD guidelines due to safety concerns. Important risk factors for further decompensation during DAA therapy are serum albumin < 3.5 g/dL, MELD (Model for End-Stage Liver Disease) score > 14, or HCV genotype 3 infection. Although sustained virologic response (SVR) is achieved less often in patients with decompensated vs compensated cirrhosis, in clinical studies response rates are > 80%. Both Child-Turcotte-Pugh Class at baseline and viral genotype can affect these response rates. Achieving SVR lowers risk of mortality, but to a lesser extent than in individuals with compensated cirrhosis. Likewise, treating patients for HCV infection along with successful treatment for hepatocellular carcinoma improves risks of both liver-related and overall mortality. In fewer than one third of cases, treating transplant-eligible, HCV-infected patients pre-transplant enables their delisting from transplant wait lists.

Hepatitis C Guidance 2023 Update: AASLD-IDSA Recommendations for Testing, Managing, and Treating Hepatitis C Virus Infection

The Infectious Diseases Society of America and the American Association for the Study of Liver Diseases have collaboratively developed evidence-based guidance regarding the diagnosis, management, and treatment of hepatitis C virus (HCV) infection since 2013. A panel of clinicians and investigators with extensive infectious diseases or hepatology expertise specific to HCV infection periodically review evidence from the field and update existing recommendations or introduce new recommendations as evidence warrants. This update focuses on changes to the guidance since the previous 2020 published update, including ongoing emphasis on recommended universal screening; management recommendations for incomplete treatment adherence; expanded eligibility for simplified chronic HCV infection treatment in adults with minimal monitoring; updated treatment and retreatment recommendations for children as young as 3 years old; management and treatment recommendations in the transplantation setting; and screening, treatment, and management recommendations for unique and key populations.

DNA Methylation and Immune Cell Markers Demonstrate Evidence of Accelerated Aging in Patients with Chronic Hepatitis B Virus or Hepatitis C Virus, with or without Human Immunodeficienct Virus Co-infection

BACKGROUND

Several chronic diseases accelerate biological aging. We investigated age acceleration and the association between peripheral blood DNA methylation (DNAm) and immune cell markers in patients chronically infected with the hepatitis B virus (HBV) or the hepatitis C virus (HCV) with and without human immunodeficiency virus (HIV) co-infection.

METHODS

Age acceleration was measured as the difference between epigenetic age (Horvath clock) and chronological age. The immune marker model of age acceleration was developed using Elastic Net regression to select both the immune markers and their associated weights in the final linear model.

RESULTS

Patients with chronic HBV (n = 51) had a significantly higher median epigenetic age compared to chronological age (age accelerated) (P < .001). In patients with chronic HCV infection (n = 63), age acceleration was associated with liver fibrosis as assessed by histology (P < .05), or presence of HIV co-infection (P < .05), but not HCV mono-infection. Age acceleration defined by immune markers was concordant with age acceleration by DNA methylation (correlation coefficient = .59 in HBV; P = .0025). One-year treatment of HBV patients with nucleoside therapy was associated with a modest reduction in age acceleration, as measured using the immune marker model (-.65 years, P = .018).

CONCLUSION

Our findings suggest that patients with chronic viral hepatitis have accelerated epigenetic aging, that immune markers define biological age, and have the potential to assess the effects of therapeutic intervention on age acceleration.

Lymphocyte Landscape after Chronic Hepatitis C Virus (HCV) Cure: The New Normal

Chronic HCV (CHC) infection is the only chronic viral infection for which curative treatments have been discovered. These direct acting antiviral (DAA) agents target specific steps in the viral replication cycle with remarkable efficacy and result in sustained virologic response (SVR) or cure in high (>95%) proportions of patients. These treatments became available 6–7 years ago and it is estimated that their real impact on HCV related morbidity, including outcomes such as cirrhosis and hepatocellular carcinoma (HCC), will not be known for the next decade or so. The immune system of a chronically infected patient is severely dysregulated and questions remain regarding the immune system’s capacity in limiting liver pathology in a cured individual. Another important consequence of impaired immunity in patients cleared of HCV with DAA will be the inability to generate protective immunity against possible re-infection, necessitating retreatments or developing a prophylactic vaccine. Thus, the impact of viral clearance on restoring immune homeostasis is being investigated by many groups. Among the important questions that need to be answered are how much the immune system normalizes with cure, how long after viral clearance this recalibration occurs, what are the consequences of persisting immune defects for protection from re-infection in vulnerable populations, and does viral clearance reduce liver pathology and the risk of developing hepatocellular carcinoma in individuals cured with these agents. Here, we review the recent literature that describes the defects present in various lymphocyte populations in a CHC patient and their status after viral clearance using DAA treatments.

Metabolic Changes in Chronic Hepatitis C Patients Who Carry IFNL4-ΔG and Achieve Sustained Virologic Response With Direct-Acting Antiviral Therapy

BACKGROUND

Clearance of hepatitis C virus (HCV) results in rapid changes in metabolic parameters early in direct-acting antiviral (DAA) therapy. Long-term changes after sustained virologic response (SVR) remain unknown.

METHODS

We investigated longitudinal changes in metabolic and inflammatory outcomes in chronic hepatitis C (CHC) patients: low-density lipoprotein (LDL), high-density lipoprotein, triglycerides, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) using a general linear model for repeated measurements at 5 clinical time points and by human immunodeficiency virus (HIV) coinfection and IFNL4 genotype.

RESULTS

The mean LDL increased markedly during DAA therapy (pre-DAA, 86.6 to DAA, 107.4 mg/dL; P < .0001), but then it decreased to 97.7 mg/dL by post-SVR year 1 (P < .001 compared with DAA; P = .0013 compared with SVR). In patients who carry the IFNL4-ΔG allele, mean LDL increased during treatment, then decreased at post-SVR year 1; however, in patients with TT/TT, genotype did not change during and after DAA treatment. The mean ALT and AST normalized rapidly between pre-DAA and DAA, whereas only mean ALT continued to decrease until post-SVR. Metabolic and inflammatory outcomes were similar by HIV-coinfection status.

CONCLUSIONS

Changes in LDL among CHC patients who achieved SVR differed by IFNL4 genotype, which implicates the interferon-λ4 protein in metabolic changes observed in HCV-infected patients.

Paediatric hepatitis C virus infection and its treatment: Present, past, and future

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease in the world. It is a challenging medico-social problem in the paediatric population. High HCV infection rates are reported in low and middle incomes countries. From the health economic point of view treatment of hepatitis C virus (HCV) with subsequent virus eradication is very effective as it eliminates the long-term sequelae of untreated or maltreated HCV. In this review we summarize the updates and highlight the historical approach of treatment of chronic HCV infection in children in the new era of directly acting antiviral (DAA) agents.

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

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

Immunological recovery in T-cell activation after sustained virologic response among HIV positive and HIV negative chronic Hepatitis C patients

BACKGROUND

Rapid decreases in activated CD4+ and CD8+ (HLA-DR + and CD38+ co-expressed) T-lymphocytes have been described within 1-2 weeks of initiating direct-acting antiviral (DAA) therapy among chronic Hepatitis C (CHC) patients. However, it is not known whether these changes are maintained past sustained virologic response (SVR), particularly in those who are HIV/HCV-coinfected.

METHODS

We investigated the changes in immune parameters of T-lymphocytes from pre-DAA therapy to post-SVR among HIV negative and HIV positive patients with CHC. Repeated measurements of activated CD4+ and CD8+ T cells were analyzed by flow cytometry at pre-DAA therapy, DAA therapy, end of treatment, SVR, and post-SVR. A general linear model for repeated measurements was used to estimate the mean outcome at each timepoint and change between timepoints.

RESULTS

HCV-monoinfected (n = 161) and HIV/HCV-coinfected (n = 59) patients who achieved SVR with DAA therapy were predominately middle aged, male, black, and non-cirrhotic. At pre-DAA therapy, HCV-monoinfected patients had significantly higher CD4+ T cells and CD4+:CD8+ T-cell ratio, while significantly lower CD8+ and activated CD4+ and CD8+ T cells compared to HIV/HCV-coinfected patients (p < 0.0001). HCV-monoinfected and HIV/HCV-coinfected patients had a significant mean decrease from pre-DAA therapy to post-SVR year 1 for activated CD4+ (HCV-monoinfected: 4.8-3.9%, p < 0.0001; HIV/HCV-coinfected: 6.6-4.5%, p < 0.0001) and activated CD8+ T cells (HCV-monoinfected V: 13.8-11.8%, p = 0.0002; HIV/HCV-coinfected: 18.0-12.4%, p < 0.0001).

CONCLUSION

This longitudinal study showed CHC patients treated with DAA therapy had continued decrease of T-lymphocytes from start of DAA therapy to after achievement of SVR suggesting improvement as HCV clearance normalizes activated T-cell phenotype.

Real World Experience of Chronic Hepatitis C Retreatment with Genotype Specific Regimens in Nonresponders to Previous Interferon-Free Therapy

BACKGROUND AND AIM

The development of interferon- (IFN-) free regimens substantially improved efficacy of treatment for HCV, but despite excellent effectiveness the failures still occur. The aim of our study was to evaluate the efficacy of retreatment with genotype specific direct acting antivirals- (DAA-) based regimens in nonresponders to previous IFN-free therapy.

MATERIALS AND METHODS

Analysed population consisted of 31 nonresponders to IFN-free regimen, which received second IFN-free rescue therapy, selected from 6228 patients included in a national database EpiTer-2.

RESULTS

Age and gender distribution were similar, whereas proportion of genotype 1b was slightly higher and genotype 4 lower in the whole population compared to studied one. Patients included in the study demonstrated much more advanced fibrosis. Primary therapy was discontinued in 12 patients, which were recognized as failures due to nonvirologic reason, whereas virologic reason of therapeutic failure was recognized in 19 patients which completed therapy. Overall sustained virologic response (SVR) rate was 81% and 86% in intent-to-treat (ITT) and modified ITT analysis, respectively (74% and 78% in virologic failures, 92% and 100% in nonvirologic failures). Resistance-associated substitutions (RAS) testing was carried out in 8 patients from the group of completed primary therapy and three of them had potential risk for failure of rescue therapy due to NS5A association, while two of them achieved SVR.

CONCLUSIONS

We demonstrated moderate effectiveness of genotype specific rescue therapy in failures due to virologic reason and high in those who discontinued primary therapy. Therefore rescue therapy with genotype specific regimens should be considered always if more potent regimens are not available.

The interplay between viruses and TRIM family proteins

Novel therapeutic options are urgently needed to improve the global treatment of viral infections. Tripartite motif (TRIM) family proteins are involved in various biological and cellular functions including differentiation, development, proliferation, oncogenesis, innate immunity, and viral autophagy. Various TRIM proteins show antiviral properties against different viral infections and are now transitioning from ubiquitin proteins to an efficient and emerging therapeutic class of proteins. TRIM proteins combat viruses by targeting them at pre/post transcription levels. This review summarizes the comprehensive roles of different TRIM proteins along with their expression systems and their applications towards antiviral therapeutics.

Challenges and perspectives of direct antivirals for the treatment of hepatitis C virus infection

Treatment of chronic hepatitis C virus infection has been revolutionised by the development of direct-acting antivirals (DAAs). All-oral, once-daily, 8- to 12-week treatment regimens are now standard of care, with viral eradication possible in >95% of patients across different populations. Despite these advances, several unresolved issues remain, including treatment of patients with hepatitis C virus genotype 3, chronic kidney disease, and those in whom DAA therapy has previously failed. Glecaprevir/pibrentasvir and sofosbuvir/velpatasvir/voxilaprevir are the most recently approved DAA regimens. Given the overwhelming success of modern DAA-based therapies, glecaprevir/pibrentasvir and sofosbuvir/velpatasvir/voxilaprevir are also likely to represent the last DAAs to be approved. Both are pangenotypic, once-daily, all-oral DAA combinations that have the potential to close the gaps in the current DAA treatment portfolio. Herein, we review the challenges associated with current DAAs and how these two regimens may be implemented in existing treatment algorithms.

Recent update of the 2017 Korean Association for the Study of the Liver (KASL) treatment guidelines of chronic hepatitis C: Comparison of guidelines from other continents, 2017 AASLD/IDSA and 2016 EASL

The paradigm for the treatment of chronic hepatitis C (CHC) has been changed due to the development of direct acting antivirals (DAAs) of hepatitis C virus (HCV). The high sustained virologic response rate and ease of administration makes the DAAs approach ideal to contribute to the complete eradication of HCV. Currently, treatment options for individual patients vary depending on the genotype or subtype of HCV, presence or absence of liver cirrhosis, previous experience of antiviral treatment or resistance associated substitutions. Because of drug avalilability, cost-effectiveness, preference, compliance and greater possibility of desirable effects and presumed patient-important outcomes may vary between countries, treatment options for individual patients are different. The review focuses on the comparing the current treatment options for CHC in other continents with the 2017 Korea Association for the Study of the Liver guidelines.

Ledipasvir/sofosbuvir for treatment of hepatitis C virus in sofosbuvir-experienced, NS5A treatment-naïve patients: Findings from two randomized trials

BACKGROUND & AIMS

We report data from two similarly designed studies that evaluated the efficacy, safety, and optimal duration of ledipasvir/sofosbuvir (LDV/SOF) ± ribavirin (RBV) for retreatment of chronic hepatitis C virus (HCV) in individuals who failed to achieve sustained virological response (SVR) with prior SOF-based, non-NS5A inhibitor-containing regimens.

METHODS

The RESCUE study enrolled HCV mono-infected adults with genotype (GT) 1 or 4. Non-cirrhotic participants were randomized to 12 weeks of LDV/SOF or LDV/SOF + RBV. Compensated cirrhotic participants were randomized to LDV/SOF + RBV (12 weeks) or LDV/SOF (24 weeks). The AIDS Clinical Trials Group A5348 study randomized genotype 1 adults with HCV/HIV co-infection to LDV/SOF + RBV (12 weeks) or LDV/SOF (24 weeks). Both studies used SVR at 12 weeks post-treatment (SVR12) as the primary endpoint.

RESULTS

In the RESCUE study, 82 participants were randomized and treated, and all completed treatment. Overall, SVR12 was 88% (72/82); 81-100% in non-cirrhotic participants treated with LDV/SOF or LDV/SOF + RBV for 12 weeks and 80-92% in cirrhotic participants treated with LDV/SOF + RBV for 12 weeks or LDV/SOF for 24 weeks. Adverse events (AEs), mostly mild-to-moderate in severity, were experienced by 78% of participants, with headache and fatigue most frequently reported. One serious AE, not related to treatment, was observed. No premature discontinuations of study drug, or deaths occurred. In the A5348 study, seven participants were randomized (cirrhotic n = 1; GT1a n = 5) and all attained SVR12, with no serious AEs or premature discontinuations.

CONCLUSIONS

In this SOF-experienced, NS5A inhibitor-naïve population, which included participants with cirrhosis or HCV/HIV co-infection, high SVR12 rates were achieved.

Benefit-risk assessment for sofosbuvir/velpatasvir/voxilaprevir based on patient population and hepatitis C virus genotype: U. S. Food and Drug Administration's evaluation

On July 18, 2017, the U.S. Food and Drug Administration (FDA) approved sofosbuvir/velpatasvir/voxilaprevir (SOF/VEL/VOX) (Vosevi) fixed-dose combination (FDC), an interferon-free, complete regimen for adult patients with chronic hepatitis C virus (HCV) infection without cirrhosis or with compensated cirrhosis (Child-Pugh A) who have: • genotype 1, 2, 3, 4, 5, or 6 infection and have previously been treated with an HCV regimen containing a nonstructural protein 5A (NS5A) inhibitor; and • genotype 1a or 3 infection and have previously been treated with an HCV regimen containing sofosbuvir without an NS5A inhibitor. Approval was based on an acceptable safety profile and high sustained virological response rates 12 weeks after the end of treatment (SVR12) in two phase 3 clinical trials in subjects previously treated with a direct-acting antiviral (DAA) regimen. In POLARIS-1, 96% of SOF/VEL/VOX-treated subjects achieved SVR12. In POLARIS-4, 98% of SOF/VEL/VOX-treated subjects achieved SVR12. A key and challenging question in evaluating the data was determining the contribution of VOX to SOF/VEL and how this differed depending on the genotype and patient population. In this article, we provide our perspective on the issues considered in making these determinations, especially regarding the POLARIS-4 data in subjects who have previously been treated with a chronic HCV regimen containing sofosbuvir without an NS5A inhibitor. Conclusion: We seek to provide context as to why a broad indication was given for NS5A inhibitor-experienced patients (HCV genotypes 1-6) while the indication for NS5A inhibitor- naïve patients was limited to HCV genotypes 1a and 3 only. (Hepatology 2018;67:482-491).

Adverse effects of direct acting antiviral-based regimens in chronic hepatitis C patients: a Brazilian experience

Background Direct-acting antivirals (DAA) are currently used for the treatment of chronic hepatitis C (HCV). However, few studies describe the adverse effects (AE) associated with DAA therapy in "real-word" cohorts. Aim To evaluate AE in Brazilian chronic HCV patients after DAA-therapy. Setting A reference center for hepatitis treatment in Rio de Janeiro, Brazil. Methods An observational "real-world" study was conducted with 102 chronic HCV patients undergoing DAA therapy for 12 or 24 weeks. The self-reported AE were correlated with cirrhosis status, genotype, age, current therapeutic schemes and comorbidities. Serious AE were also investigated. Main outcome measure Frequency of AE during DAA therapy. Results Overall, mean ± SD age was 60.9 ± 9.4 years, 67% were females, HCV-genotype 1 was the most prevalent (81%) and 74% were cirrhotic. Moreover, all patients reached sustained virological response. About 90% of patients reported at least one AE associated with current treatment, with a mean of 2.7 symptoms per patient. The most frequently reported AE were fatigue (43%), headache (42%), neuropsychiatric symptoms (30%) and nausea (26%). Furthermore, hemoglobin < 12 mg/dL was the most frequent (38%) laboratory abnormality observed. Neuropsychiatric symptoms were the only AE significantly different in treatment-experienced group when compared to naïve patients (41.7 vs. 12.5, P = 0.002). The higher frequency of AE did not correlate with the presence of previous treatment, cirrhosis, genotype, age, current therapeutic schemes with DAA or comorbidities. Conclusion DAA-based therapeutic regimens demonstrated safety in a Brazilian "real-world" cohort of chronic hepatitis C patients.

Augmentation of hepatitis C virus-specific immunity and sustained virologic response

Treatment for chronic hepatitis C virus (HCV) infection has rapidly evolved into interferon-free directly acting antiviral regimens (DAA) that result in high sustained virologic response. DAAs primarily work by suppressing HCV replication and rely less on the immune system than interferon-based therapies. However, it is unclear whether the immune system recovers with suppression of HCV replication and contributes to HCV clearance with DAA therapy. We previously demonstrated HCV clearance is associated with increased HCV-specific immunity in CHCV-GT-1-infected patients during treatment with sofosbuvir (SOF)+ribavirin (RBV). Here, we aimed to analyse changes in HCV-specific immunological responses associated with viral clearance with combination DAA therapy of SOF+ledipasvir (LDV) for 12 weeks in CHCV-GT1 (N=14) patients who relapsed without augmentation of HCV-specific immunity during treatment with SOF+RBV. Phenotypic and functional changes within the T-cell compartment of PBMCs pre- and post-treatment were analysed. Retreatment of relapsers with LDV/SOF resulted in all patients attaining SVR12 . Suppression of HCV was associated with a decline in T-cell exhaustion markers (CD57; Tim3; PD1) along with augmented of HCV-specific T-cell IFN-gamma responses post-treatment. Addition of LDV to SOF was associated with augmentation of HCV-specific immunity and SVR in patients who previously failed SOF+RBV therapy without increased immunity. These findings demonstrate a novel effect of DAA in inducing host immune responses to aid HCV clearance and achieve SVR.

Resistance to hepatitis C virus. Implications and therapeutic options

We are currently living in an unprecedented era of hepatitis C treatment with the availability of highly effective drugs yielding minimal side effects. The problem we currently face is the retreatment of patients refractory to these drugs. Although several factors can influence treatment failure, this review focuses on antiviral resistance. Resistance-associated substitutions may be identified at baseline or be treatment-emergent. The latter seem to be more clinically relevant and must be studied in the event of treatment failure (no virological response). In this article, we present the latest data from clinical trials and studies in real-life clinical practice. Finally, based on this current evidence, we propose some recommendations for the management and retreatment of these patients.

The emergence of NS5B resistance associated substitution S282T after sofosbuvir-based treatment

S282T in NS5B is the primary amino acid substitution associated with resistance to sofosbuvir (SOF) but has rarely been detected in patients treated with a SOF‐based regimen. Here, the emergence and fitness of the S282T substitution in virologic failure patients administered SOF‐based regimens across the SOF and ledipasvir (LDV)/SOF phase 2 and 3 programs was evaluated. Plasma samples collected at baseline and at virologic failure were amplified and deep sequenced (1% cutoff). To date, over 12,000 patients have been treated in SOF or LDV/SOF phase 2 and 3 studies. Of these, deep sequencing was available at baseline in 8598 patients (62.4% genotype [GT] 1, 10.7% GT2, 20.9% GT3, and 6.0% GT4‐6) and at virologic failure in 901 patients. In the 8598 patients, no S282T substitution was detected at baseline; at virologic failure, 10 of the 901 (1%) patients had S282T detected. The SOF‐based regimen associated with treatment‐emergent S282T was SOF monotherapy in two patients, retreatment with LDV/SOF in prior LDV/SOF failures in three patients, LDV/SOF for 8 weeks in 1 GT1 patient, LDV/SOF for 12 weeks in 1 patient each with GT3, GT4, and GT5, and LDV/SOF + ribavirin for 12 weeks in 1 GT6 patient. Nine of 10 patients with emergent S282T received an SOF‐based retreatment regimen, eight of whom achieved sustained virologic response 12 weeks after treatment and one of whom failed retreatment. Conclusion: The emergence of S282T substitution was rare in patients who fail SOF‐based regimens. Successful retreatment of prior SOF failure patients is possible in the presence of S282T substitution with SOF in combination with various direct‐acting antiviral agents. (Hepatology Communications 2017;1:538–549)

Direct Acting Anti-hepatitis C Virus Drugs: Clinical Pharmacology and Future Direction

Chronic hepatitis C virus (HCV) infection is a leading cause of chronic liver disease. The introduction of direct acting antiviral agents (DAAs) for its treatment represents a major advance in terms of sustained virologic response (SVR) rates and adverse effect profiles. Mechanistically, DAAs inhibit specific HCV non-structural proteins (NS) that are vital for its replication. Boceprevir, telaprevir, simeprevir, asunaprevir, grazoprevir and paritaprevir are NS3/4A inhibitors. Ombitasvir, ledipasvir, daclatasvir, elbasvir and velpatasvir are NS5A inhibitors. Sofosbuvir and dasabuvir are NS5B inhibitors. Currently, a combination of two or more DAAs is the corner stone for the treatment of HCV infection. However, the success of DAA therapy is facing several challenges, including the potential of drug-drug interactions and resistant variance. Moreover, the shortage of relevant clinical pharmacological data and drug interaction regarding DAA is a clinical concern. The present review discusses the clinical pharmacology of DAAs with special emphasis on drug-drug interaction.

Common issues in the management of patients in the waiting list and after liver transplantation

The present document contains the recommendations of an expert panel of transplant hepatologists, appointed by the Italian Association for the Study of the Liver (AISF), on how to manage the most common aspects of liver transplantation: the topics covered include: new treatments for HCV in patients on the waiting list for liver transplantation; antiviral treatments in patients with HCV recurrence after liver transplantation; prophylaxis for HBV recurrence after liver transplantation; indications for liver transplantation in alcoholic liver disease; and Immunosuppressive therapy. The statements on each topic were approved by participants at the AISF Transplant Hepatologist Expert Meeting (organized by the Permanent Committee on Liver Transplantation in Mondello on 4-5 October 2015), and are graded according to the Oxford classification of levels of evidence.

Hepatitis C Virus Therapy for Decompensated and Posttransplant Patients

Treatment of hepatitis C (HCV) has been revolutionized with the introduction of the direct-acting antivirals (DAA). The DAAs allowed patients to better tolerate HCV therapy with much lower side effects and better efficacy. The DAA also offered hope for a cure in HCV patients who cannot tolerate interferon-based therapy. Such populations include patients with decompensated cirrhosis and postliver transplantation. Despite DAA therapy showing cure rate of over 95% in the absence of cirrhosis, cure rate in the decompensated liver disease setting remains lower. In this paper, we aim to review the current recommendations for the treatment of HCV in patients with decompensated cirrhosis and postliver transplantation.

Current therapy for chronic hepatitis C: The role of direct-acting antivirals

One of the most exciting developments in antiviral research has been the discovery of the direct-acting antivirals (DAAs) that effectively cure chronic hepatitis C virus (HCV) infections. Based on more than 100 clinical trials and real-world studies, we provide a comprehensive overview of FDA-approved therapies and newly discovered anti-HCV agents with a special focus on drug efficacy, mechanisms of action, and safety. We show that HCV drug development has advanced in multiple aspects: (i) interferon-based regimens were replaced by interferon-free regimens; (ii) genotype-specific drugs evolved to drugs for all HCV genotypes; (iii) therapies based upon multiple pills per day were simplified to a single pill per day; (iv) drug potency increased from moderate (∼60%) to high (>90%) levels of sustained virologic responses; (v) treatment durations were shortened from 48 to 12 or 8 weeks; and (vi) therapies could be administered orally regardless of prior treatment history and cirrhotic status. However, despite these remarkable achievements made in HCV drug discovery, challenges remain in the management of difficult-to-treat patients.

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HCV genotype-specific drugs evolve to pan-genotypic drugs.

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Drug potency increases from moderate (∼60%) to high (>90%) levels of sustained virologic response.

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Treatment durations are shortened from a 48-week to 12-week or 8-week period.

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HCV therapies based upon multiple pills per day are simplified to a single pill per day.

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HCV therapies are administered orally regardless of prior treatment history and cirrhotic status.

Sofosbuvir/velpatasvir regimen promises an effective pan-genotypic hepatitis C virus cure

Hepatitis C virus (HCV) is a global pandemic, with nearly 200 million infected patients worldwide. HCV is the most common blood-borne infection in the US with numerous health implications including liver fibrosis, cirrhosis, and hepatocellular cancer. Traditional genotype-based HCV therapies with interferon resulted in moderate success in the sustained elimination of viral genome. Recent clinical trials of the once-daily combination tablet of sofosbuvir, a nonstructural (NS) 5B polymerase inhibitor, and velpatasvir, an NS5A inhibitor, demonstrate sustained virologic response rates of about 95%, regardless of prior treatment experience or presence of cirrhosis across all HCV genotypes. Patients reported improvements in general health, fatigue, and emotional and mental well-being after completing combination therapy. The combination treatment is effective, but does need to be administered with caution in patients receiving certain medications or with certain diseases. Herein, we review the safety and efficacy of sofosbuvir/velpatasvir combination regimen for all HCV genotypes.

Clinical Laboratory Testing in the Era of Directly Acting Antiviral Therapies for Hepatitis C

Directly acting antiviral (DAA) combination therapies for chronic hepatitis C virus (HCV) infection are highly effective, but treatment decisions remain complex. Laboratory testing is important to evaluate a range of viral, host, and pharmacological factors when considering HCV treatment, and patients must be monitored during and after therapy for safety and to assess the viral response. In this review, we discuss the laboratory tests relevant for the treatment of HCV infection in the era of DAA therapy, grouped according to viral and host factors.

Efficacy and Safety of Ledipasvir/Sofosbuvir with and without Ribavirin in Patients with Chronic Hepatitis C Virus Genotype 1 Infection: a meta-analysis

BACKGROUND

The addition of ribavirin (RBV) to the combination treatment of Ledipasvir (LDV) and Sofosbuvir (SOF) remains controversial in the treatment of hepatitis C virus (HCV) infection. We performed a meta-analysis to assess the efficacy and safety of the LDV-SOF with and without RBV in treating HCV genotype 1 patients.

METHOD

The electronical databases of PubMed Medline, EMBASE database, Cochrane Central Register of Controlled Trials (CENTRAL) and ClinicalTrials.gov website with registered trials were searched. Eligible studies were randomized controlled trials (RCTs) and prospective cohort studies that assessed the efficacy and safety of LDV-SOF with or without RBV in patients with HCV genotype 1 (GT 1). Two reviewers independently screened studies, extracted data and assessed methodology quality. Review Manager 5.3 software was used to analyze the data.

RESULTS

Seven studies involving 2,626 patients with HCV GT 1 - some of whom had cirrhosis - were included in this meta-analysis. The addition of RBV to LDV- SOF regimen neither significantly improved sustained viral response at 12 weeks (SVR12) after the last dose of treatment (RR=1.00, 95%CI 0.99-1.01, p=0.99) nor decreased virologic breakthrough (RR=1.01, 95%CI 0.14-7.19, p=0.99) and relapse (RR=1.36, 95% CI 0.81-2.29, p=0.24). There was no significant difference in the incidence of discontinuation (RR=0.61, 95%CI 0.25-1.53, p=0.30) between LDV- SOF therapy and LDV- SOF plus RBV. LDV- SOF plus RBV therapy had significantly higher rate of the overall adverse events (RR=0.88, 95%CI=0.84- 0.92, p<0.00001). LDV - SOF therapy had higher incidence of serious adverse events (RR=1.60, 95%CI=1.00-2.56, p=0.05) than LDV-SOF plus RBV.

CONCLUSION

This meta-analysis suggests that LDV-SOF based therapy is a safe and effective treatment for patients with GT 1 HCV. The addition of RBV to LDV-SOF may increase toxicity without achieving improved efficacy. However, due to the relatively small sample sizes and moderate risk of bias of included studies, large-scale and high-quality clinical research is still needed to confirm the results.

Late Relapse Versus Hepatitis C Virus Reinfection in Patients With Sustained Virologic Response After Sofosbuvir-Based Therapies

BACKGROUND

 The development of direct-acting antivirals in recent years has dramatically enhanced rates of viral eradication to >90% in patients with chronic hepatitis C virus (HCV) infection. To determine true treatment efficacy and define the most appropriate retreatment, it is important to distinguish virologic relapse from reinfection when patients in whom HCV is eradicated during treatment become infected with a new HCV strain after treatment.

METHODS

 We investigated the prevalence of late recurrent viremia (patients with sustained virologic response 12 weeks after the end of treatment but detectable HCV RNA at follow-up week 24) and used refined phylogenetic analysis of multiple HCV genes to distinguish virologic relapse from reinfection.

RESULTS

 Across 11 phase 3 clinical trials of ledipasvir-sofosbuvir (SOF) and SOF, only 12 of 3004 patients had detectable HCV RNA following sustained virologic response 12 weeks after the end of treatment. Of these 12 patients with late recurrent viremia, 11 had the same HCV genotype/subtype at baseline and at recurrence. Phylogenetic analysis demonstrated that 58% (7 of 12) of these patients were successfully treated with the SOF-based regimen, with HCV eradication achieved, but became reinfected with a different HCV strain after treatment. The remaining 5 patients with late recurrent viremia had virologic relapse in which the HCV present at baseline persisted in the liver or another compartment and reemerged in the blood 24 weeks after treatment.

CONCLUSIONS

 The incidence of late recurrent viremia was low. Distinguishing reinfection from virologic relapse has implications for determining true treatment efficiency and selecting optimal retreatment strategies.

Management of hepatitis C patients with decompensated liver disease

Little is known about the tolerance and effectiveness of novel oral direct acting antivirals (DAA) in hepatitis C patients with decompensated cirrhosis. To examine the studies relevant to the treatment of hepatitis C virus(HCV)-related decompensated liver disease, we performed computer-based searches for English articles between 1947 and August 2015. Fourteen articles including HCV patients with decompensated cirrhosis were reviewed. The combinations of ledipasvir(LDV)/sofosbuvir(SOF)/ribavirin(RBV) for 12 weeks, or daclatasvir/SOF/RBV for 12 weeks are safe and effective for HCV genotype 1 or 4 infection, and daclatasvir/SOF/RBV for 12 weeks or SOF/RBV for 24 weeks might be effective and safe for HCV genotype 2 or 3 infection. In conclusion, current evidence supports the use of all oral DAA regimens in HCV patients with decompensated cirrhosis.

Possible Simeprevir/Sofosbuvir-Induced Hepatic Decompensation With Acute Kidney Failure

A patient with hepatitis C infection and hepatocellular carcinoma developed significant hyperbilirubinemia and acute kidney injury after initiation of a simeprevir and sofosbuvir regimen.

Ledipasvir/Sofosbuvir: a review of its use in chronic hepatitis C

The single-tablet regimen of the hepatitis C virus (HCV) NS5A inhibitor ledipasvir and the HCV NS5B polymerase inhibitor sofosbuvir (ledipasvir/sofosbuvir; Harvoni(®)) was recently approved in the US and the EU. The phase III ION trials included treatment-naive (ION-1 and -3) or treatment-experienced (ION-2) patients with chronic HCV genotype 1 infection (≈20 % of patients in ION-1 and -2 had cirrhosis, whereas no patient in ION-3 had cirrhosis). A sustained virological response 12 weeks' post-treatment (SVR12) was seen in 99 % of treatment-naive patients receiving ledipasvir/sofosbuvir for 12 weeks in ION-1, with no additional benefit conferred by the addition of ribavirin or extending the treatment duration to 24 weeks. Moreover, in ION-3, an 8-week regimen achieved an SVR12 rate of 94 % overall and 97 % in the subgroup of patients with a baseline HCV RNA level of <6 million IU/mL. SVR12 rates of 94 and 99 % were seen in treatment-experienced patients who received ledipasvir/sofosbuvir for 12 and 24 weeks in ION-2. Data also support the use of ledipasvir/sofosbuvir in chronic HCV genotype 4 infection, in HCV and HIV co-infection and, in combination with ribavirin, in patients with chronic HCV genotype 1 or 4 infection who have decompensated cirrhosis or are liver transplant recipients and in chronic HCV genotype 3 infection. Oral ledipasvir/sofosbuvir was generally well tolerated. In conclusion, ledipasvir/sofosbuvir is an important new single-tablet regimen that represents a significant advance in the treatment of chronic hepatitis C.

Successful Retreatment of Chronic HCV Genotype-1 Infection With Ledipasvir and Sofosbuvir After Initial Short Course Therapy With Direct-Acting Antiviral Regimens

BACKGROUND

The optimal retreatment strategy for chronic hepatitis C virus (HCV) patients who fail directly-acting antiviral agent (DAA)-based treatment is unknown. In this study, we assessed the efficacy and safety of ledipasvir (LDV) and sofosbuvir (SOF) for 12 weeks in HCV genotype-1 (GT-1) patients who failed LDV/SOF-containing therapy.

METHODS

In this single-center, open-label, phase 2a trial, 34 participants with HCV (GT-1) and early-stage liver fibrosis who previously failed 4-6 weeks of LDV/SOF with GS-9669 and/or GS-9451 received LDV/SOF for 12 weeks. The primary endpoint was HCV viral load below the lower limit of quantification 12 weeks after completion of therapy (sustained virological response [SVR]12). Deep sequencing of the NS3, NS5A, and NS5B regions were performed at baseline, at initial relapse, prior to retreatment, and at second relapse with Illumina next-generation sequencing technology.

RESULTS

Thirty-two of 34 enrolled participants completed therapy. Two patients withdrew after day 0. Participants were predominantly male and black, with median baseline HCV viral load of 1.3 × 10(6) IU/mL and Metavir fibrosis stage 1 and genotype-1a. Median time from relapse to retreatment was 22 weeks. Prior to retreatment, 29 patients (85%) had NS5A-resistant variants. The SVR12 rate was 91% (31/34; intention to treat, ITT) after retreatment. One patient relapsed.

CONCLUSIONS

In patients who previously failed short-course combination DAA therapy, we demonstrate a high SVR rate in response to 12 weeks of LDV/SOF, even for patients with NS5A resistance-associated variants.

CLINICAL TRIALS REGISTRATION

NCT01805882.

The importance of resistance to direct antiviral drugs in HCV infection in clinical practice

Treatment of chronic hepatitis C virus (HCV) infection with direct-acting antiviral agents (DAA) is associated with high rates of sustained virologic response. Remaining factors associated with treatment failure include advanced stages of liver fibrosis, response to previous antiviral therapy and viral factors such as baseline viral load and suboptimal interaction of the DAA with the target based on viral variants. Heterogeneity within NS3, NS5A, and NS5B areas interacting with DAAs exist between HCV geno- and subtypes as well as HCV isolates of the same geno- and subtype and amino acid polymorphisms associated with suboptimal efficacy of DAAs are termed resistance-associated variants (RAVs). RAVs may be associated with virologic treatment failure. However, virologic treatment failure typically occurs only if other negative predictive host or viral factors are present at the same time, susceptibility to additional antiviral agents is reduced or duration of treatment is suboptimal. In this review geno- and phenotypic resistance testing as well as clinical data on the importance of RAVs for conventional triple therapies with sofosbuvir, simeprevir, and daclatasvir and available interferon-free DAA combinations are discussed.

Recent Advances in Antiviral Therapy for Chronic Hepatitis C

Hepatitis C virus (HCV) infection is a major worldwide health problem. Chronic infection induces continuous inflammation in the liver, progression of hepatic fibrosis, eventual cirrhosis, and possible hepatocellular carcinoma. Eradication of the virus is one of the most important treatment aims. A number of promising new direct-acting antivirals (DAAs) have been developed over the past 10 years. Due to their increased efficacy, safety, and tolerability, interferon-free oral therapies with DAAs have been approved for patients with HCV, including those with cirrhosis. This review introduces the characteristics and results of recent clinical trials of several DAAs: NS3/4A protease inhibitors, NS5A inhibitors, and NS5B inhibitors. DAA treatment failure and prognosis after DAA therapy are also discussed.

A model-based meta-analysis of sofosbuvir-based treatments in chronic hepatitis C patients

The objective of this study was to compare the efficacy of sofosbuvir-based treatments in patients with chronic hepatitis C virus (HCV) infection using a model-based meta-analysis (MBMA). A bibliographic search was performed to identify clinical trials involving sofosbuvir as a unique direct-acting antiviral (DAA) agent or together with daclatasvir, ledipasvir or simeprevir for the treatment of diagnosed HCV infection. The time course of the virological response (VR) was modelled to estimate the effect of treatment and the influence of population characteristics on the longitudinal efficacy profile. The model was validated and simulations of 10 different treatment schedules were performed. Data from 19 clinical trials were included in the analysis. According to the developed model, therapy with sofosbuvir+ledipasvir is the most effective therapy in all scenarios, but it does not differ greatly in terms of sustained VR with respect to other combinations of DAA treatments. In conclusion, this MBMA generates knowledge regarding hypothetical head-to-head trials that have not been conducted previously. Therapies with sofosbuvir+ledipasvir are probably the most effective sofosbuvir-based treatments.

The impact of ledipasvir/sofosbuvir on patient-reported outcomes in cirrhotic patients with chronic hepatitis C: the SIRIUS study

BACKGROUND

Interferon- and ribavirin (RBV)-free regimens can improve patient-reported outcomes (PROs) during treatment.

AIM

To compare PROs during treatment with ledipasvir and sofosbuvir (LDV/SOF) to placebo and to LDV/SOF + RBV.

METHODS

Treatment-experienced CH-C genotype 1 patients with compensated cirrhosis (N = 154) were randomized to receive 24 weeks of LDV/SOF or 12 weeks of placebo followed by 12 weeks of LDV/SOF + RBV (the SIRIUS clinical trial). While blinded to their HCV RNA level and study treatment, patients completed PRO questionnaires (SF-36, FACIT-F, CLDQ-HCV, WPAI:SHP) at baseline, during and post-treatment.

RESULTS

Baseline PRO scores were similar between the two study arms. Patients receiving LDV/SOF showed improvement in a number of PROs (predominantly related to mental health) starting as early as 4 weeks after treatment initiation; no PRO decrement from baseline were noted, and no PRO scores were inferior to placebo (all P > 0.05). In the second 12 weeks, patients who were receiving LDV/SOF continued to improve PROs (up to +9.2% from a 100% maximum possible score, P < 0.05), while patients receiving LDV/SOF + RBV had less gains or no improvement in their PRO scores. However, regardless of the regimen, patients who successfully cleared the virus (N = 149) had significant improvement in all aspects of PROs (up to +12.2% by post-treatment week 12, up to +16.9% by week 24).

CONCLUSIONS

Treatment-experienced cirrhotic patients experience a notable improvement of their PROs during treatment with LDV/SOF. Furthermore, achieving SVR-12 is associated with significant PRO improvement, which further improves at post-treatment week 24 in this difficult to treat group of patients with chronic hepatitis C.

New hepatitis C therapies for special patient populations

INTRODUCTION

Chronic hepatitis C virus (HCV) infection has become a curable disease. More than 90% sustained virologic response rates have been obtained with 8-24 weeks of treatment with distinct combinations of direct-acting antivirals (DAA) in most registration trials. However, outcomes in real-world patients tend to be lower and treatment of special patient populations is often challenging.

AREAS COVERED

We address the treatment of chronic hepatitis C with DAA in major special patient populations, such as HIV-positive persons, transplant recipients, patients with advanced cirrhosis, renal insufficiency, hepatitis B or D coinfection, injection drug users (IDUs) and prior DAA failures.

EXPERT OPINION

Drug interactions between DAA and medications given to persons with HIV infection or transplant recipients can result in treatment failure and adverse events. Severe organ dysfunction as in kidney insufficiency or decompensated cirrhosis may lead to DAA overexposure and toxicities. Dysfunctional social circumstances and behavior are associated to poor drug adherence and increased risk for HCV re-infection in active IDUs. Finally, DAA response might be impaired by viral interference in patients with hepatitis B or D coinfection or drug resistance in HCV either at baseline or after prior DAA failures.

Mechanisms of Virologic Failure with Direct-Acting Antivirals in Hepatitis C and Strategies for Retreatment

The current standard of care for hepatitis C therapy is the combination of direct-acting antiviral (DAA) agents. These orally administered medications target the viral proteins and halt the hepatitis C virus lifecycle. Despite high cure rates with these novel drugs, virologic failure with DAAs are of mounting concern as real-world sustained virologic response 12 rates seem lower than expected. The mechanisms of virologic failure to DAAs are likely multifactorial, including baseline resistance variants, the efficacy of the agents used, and host factors. Salvage therapy for DAA virologic failures is an area of emerging research.

Impact of new treatment options for hepatitis C virus infection in liver transplantation

Liver transplant candidates and recipients with hepatitis C virus (HCV)-related liver disease greatly benefit from an effective antiviral therapy. The achievement of a sustained virological response before transplantation can prevent the recurrence of post-transplant HCV disease that occurs universally and correlates with enhanced progression to graft cirrhosis. Previous standard-of-care regimens (e.g., pegylated-interferon plus ribavirin with or without first generation protease inhibitors, boceprevir and telaprevir) displayed suboptimal results and poor tolerance in liver transplant recipients. A new class of potent direct-acting antiviral agents (DAA) characterized by all-oral regimens with minimal side effects has been approved and included in the recent guidelines for the treatment of liver transplant recipients with recurrent HCV disease. Association of sofosbuvir with ribavirin and/or ledipasvir is recommended in liver transplant recipients and patients with decompensated cirrhosis. Other regimens include simeprevir, daclatasvir, and combination of other DAA. Possible interactions should be monitored, especially in coinfected human immunodeficiency virus/HCV patients receiving antiretrovirals.

Improvement of liver function parameters in advanced HCV-associated liver cirrhosis by IFN-free antiviral therapies

BACKGROUND

Successful antiviral treatment of decompensated hepatitis B with HBV polymerase inhibitors is associated with improvement of liver function. To what extent liver function also improves in cirrhotic patients with chronic hepatitis C receiving novel interferon-free (IFN-free) therapies is unknown.

AIM

To study liver function in cirrhotic HCV patients receiving IFN-free therapies.

METHODS

We here studied 80 consecutive patients with advanced HCV associated liver cirrhosis including 34 patients (43%) with Child B/C cirrhosis and 42 patients (53%) with platelet counts of <90.000/μL receiving different combinations of direct acting antivirals without interferon [sofosbuvir/ribavirin (n = 56), sofosbuvir/simeprevir ± ribavirin (n = 15) and sofosbuvir/daclatasvir ± ribavirin (n = 9)]. The majority of patients was infected with HCV genotype 1 (n = 50); HCV genotypes 2, 3 and 4 were present in 4, 24 and 2 patients, respectively.

RESULTS

Liver function parameters including albumin, bilirubin, cholinesterase and prothrombin time all improved in the majority of patients during antiviral therapy irrespectively of the underlying HCV genotype, however, with different kinetics. MELD scores improved until post-treatment week 12 in 44% of the patients but worsened in 15%. A sustained virological response was achieved in 63% of the patients. HCV RNA relapse led to moderate ALT increases in 15/23 patients but was not associated with hepatic decompensations.

CONCLUSION

This real-world single centre study showed that interferon-free treatment of hepatitis C patients with advanced liver cirrhosis restores liver function, and may thereby reduce the need for liver transplantations.