Pharmacokinetics, safety and efficacy of a full dose sofosbuvir-based regimen given daily in hemodialysis patients with chronic hepatitis C

Successful Treatment of Chronic Hepatitis C Virus Infection With Sofosbuvir and Ledipasvir in Renal Transplant Recipients

BACKGROUND

Treatment of chronic hepatitis C virus (HCV) infection after renal allograft transplantation has been an obstacle because of contraindications associated with IFN-based therapies. Direct-acting antiviral agents are highly efficient treatment options that do not require IFN and may not require ribavirin. Therefore, we assessed the efficacy and safety of sofosbuvir and ledipasvir in renal transplant patients with chronic HCV infection.

METHODS

Fifteen renal allograft recipients with therapy-naive HCV genotype (GT) 1a, 1b, or 4 were treated with the combination of sofosbuvir and ledipasvir without ribavirin for 8 or 12 weeks. Clinical data were retrospectively analyzed for viral kinetics and for renal and liver function parameters. Patients were closely monitored for trough levels of immunosuppressive agents, laboratory values, and potential adverse effects.

RESULTS

Ten patients (66%) exhibited a rapid virologic response within 4 weeks (HCV GT1a, n = 4; HCV GT1b, n = 6). The other 5 patients exhibited a virologic response within 8 (HCV GT 1b, n = 4) or 12 weeks (HCV GT4, n = 1). One hundred percent of patients exhibited sustained virologic response at week 12 after the end of treatment. Clinical measures of liver function improved substantially for all patients. Adverse events were scarce; renal transplant function and proteinuria remained stable. Importantly, dose adjustments for tacrolimus were necessary for maintaining sufficient trough levels.

CONCLUSIONS

The described regimen appears to be safe and effective for patients after renal transplant and is a promising treatment regimen for eradicating HCV in this patient population.

Treatment of Extrahepatic Manifestations of Hepatitis C Virus

Chronic infection with hepatitis C virus (HCV) is a multifaceted disease characterized by many extrahepatic manifestations (EHMs) that affect outcome and quality of life. HCV eradication by antiviral treatment has been proved beneficial in preventing the development of EHMs and is also able to improve many HCV-related severe disorders and neurocognitive outcomes and quality of life. Until recently, antiviral therapy of EHMs was limited to the presence of interferon-based treatment, and was contraindicated in many patients because of hematologic toxicity or risk of exacerbating immune-mediated disorders. The availability of interferon-free regimens solves this issue allowing for enhanced safety and efficacy to provide universal treatment of HCV-related EHMs.

Direct-acting antivirals for hepatitis C virus in patients on maintenance dialysis

The frequency of hepatitis C virus (HCV) infection remains high in patients with chronic kidney disease (CKD) and plays a detrimental role in mortality in this population. According to the latest survey, the adjusted hazard ratio for HCV-positive versus HCV-negative patients on long-term dialysis was 1.12 (95% CI, 1.05 to 1.20) and 1.10 (95% CI, 0.98 to 1.22) for all-cause and cardiovascular mortality, respectively. An impairment on quality of life has also been documented in HCV-infected patients undergoing regular dialysis. Most clinicians have been so far reluctant to treat hepatitis C in patients with advanced CKD, due to concerns regarding low efficacy and safety of interferon-based regimens. The advent of all-oral, direct-acting antivirals (DAAs) has revolutionized treatment paradigms for HCV, including patients with other comorbidities such as CKD. Two combinations of DAAs have been recently approved for the treatment of HCV in advanced CKD: elbasvir/grazoprevir (evaluated in 1 randomized controlled trial) and ombitasvir/paritaprevir/ritonavir/dasabuvir with or without ribavirin (examined in some observational, single-arm studies). These antiviral combinations have provided high safety and efficacy (SVR12 rates >90%) in HCV-infected patients with stage 4-5 CKD. Sofosbuvir, a nucleotide analogue inhibitor of the HCV NS5B polymerase, is the cornerstone of most anti-HCV current regimens but is not currently recommended for patients with severe renal insufficiency (eGFR <30 mL/min per 1.73 m2). However, several small-sized studies have been published on the safety and efficacy of sofosbuvir-based regimens for patients with hepatitis C on maintenance dialysis; overall, the viral response was satisfactory (SVR12 rates ranging between 58% and 100%) with a few drug-related drop-outs. Studies are in progress to assess whether ribavirin-free antiviral combinations with novel DAAs are a viable option for patients with severe renal impairment and chronic HCV infection.

Efficacy and safety of direct-acting antivirals-based antiviral therapies for hepatitis C virus patients with stage 4-5 chronic kidney disease: a meta-analysis

BACKGROUND & AIMS

The aim of this study was to assess the efficacy and safety of direct-acting antivirals (DAA)-based antiviral therapies for HCV patients with stage 4-5 chronic kidney disease.

METHODS

We conducted a systematic literature search in PubMed, EMBASE, Web of Science, and CENTRAL on the Cochrane Library without time and language limitations. The search strategy used was "(End stage renal disease OR chronic kidney failure OR severe renal impairment OR chronic kidney disease OR dialysis) AND (sofosbuvir OR simeprevir OR grazoprevir OR elbasvir OR ombitasvir OR paritaprevir OR ritonavir OR dasabuvir OR daclatasvir OR asuparevir OR direct-acting antiviral OR DAA)". Sustained virologic response at 12 weeks after the end of treatment (SVR12), adverse events (AEs) and/or serious adverse events (SAEs) with 95% confidence intervals (CI) were pooled.

RESULTS

Eleven studies, comprising a total of 264 patients were included for our meta-analysis. The pooled SVR12 rate were 93.2% (95% CI 89.9%-95.9%, I² =0.0%), 89.4% (95% CI 82.0%-95.0%, I² =0.0%) and 94.7% (95% CI 91.0%-97.5%, I² =0.0%) in total population, patients with sofosbuvir-based therapies and patients with non-sofosbuvir-based therapies respectively. For HCV genotype 1 patients, the pooled SVR12 rate was 93.1% (95% CI 88.3%-96.7%, I² =20.0%). The pooled incidence of SAEs was 12.1% (95% CI 6.2%-19.7%, I² =55.0%). The pooled discontinuation rate because of AEs or SAEs in our meta-analysis was 2.2% (95% CI 0.8%-4.4%, I² =0.0%).

CONCLUSIONS

DAA-based antiviral therapies are effective and well-tolerated for HCV patients with stage 4-5 chronic kidney disease.

Treatment of Hepatitis C virus infection in Italy: A consensus report from an expert panel

Hepatitis C virus (HCV) infection remains one of the main causes of chronic liver disease worldwide. The advent of direct-acting antivirals (DAAs) has significantly improved the course of patients with chronic HCV infection (CHC), due to the ability of these drugs to achieve high rates of sustained virological response (SVR). These exceedingly high rates of SVR and the excellent safety data have been confirmed in real life practice. Evolving guidelines have been issued by national and international scientific societies in accordance with the progression of clinical knowledge and the availability of new DAAs. These recommendations, however, may not be applied universally because of delays in drugs reimbursability in different countries and because some National Health Systems identify only patients with advanced disease as a treatment priority. Italy in this regard is a prototype about DAAs treatment of CHC patients. With the aim to assess the Italian treatment experience with DAAs and to respond to unmet needs in treatment optimization of antiviral therapy in specific settings of CHC patients, a group of Italian experts met in Stresa in February 2017. The summary of the considerations arising from this two-day meeting and some statements regarding a few open issues are reported in this position paper.

The frequency of acute kidney injury in patients with chronic hepatitis C virus infection treated with sofosbuvir-based regimens

BACKGROUND

Guidelines recommend withholding sofosbuvir (SOF) in patients with an estimated glomerular filtration rate (eGFR) of less than 30 mL/min.

AIM

To assess the risk of acute kidney injury (AKI) in patients with no renal contraindications for SOF-based treatment.

METHODS

This multicenter retrospective observational study included all consecutive patients that were treated with SOF-based or telaprevir/boceprevir (TVR/BOC)-based regimens at two tertiary university centers in North America. AKI was defined as an increase of ≥0.3 mg/dL (≥26.5 μmol/L) in serum creatinine level. Multivariable logistic regression analysis was used to identify risk factors for the occurrence of AKI.

RESULTS

In total, 426 patients were included and treated with a SOF-based regimen (n=233, 54.7%) or TVR/BOC-based regimen (n=193, 45.3%). Among patients treated with a TVR/BOC-based regimen 34 (18%) of 193 patients experienced AKI compared to 26 (11%) of 233 patients treated with SOF-based regimens (P=.056). Multivariable logistic regression analysis showed that the presence of ascites (OR: 4.44, 95%CI: 1.46-13.54, P=.009) and the use of NSAIDs (OR: 4.47, 95%CI: 1.32-15.19, P=.016) were associated with a risk of AKI during SOF-based antiviral therapy. Creatinine levels returned to normal at end of follow-up in 23 (88%) of the 26 patients who experienced AKI with a SOF-based regimen and had a creatinine level available during follow-up.

CONCLUSIONS

Although the risk for AKI was lower than for patients treated with TVR/BOC-based regimens, AKI was seen during 11% of SOF-based regimens and was mostly reversible. Patients with ascites and patients using NSAIDs have an increased risk for AKI during SOF-based antiviral therapy.

Combination of sofosbuvir and daclatasvir in the treatment of genotype 3 chronic hepatitis C virus infection in patients on maintenance hemodialysis

Chronic hepatitis C virus infection (HCV) has a negative impact on the long-term survival of recipients of kidney transplants. HCV should be treated in hemodialyzed patients before their enlistment for kidney transplantation in order to avoid the reactivation of virus after transplantation. Direct-acting antivirals represent the current standard of care in hemodialyzed patients with HCV genotypes 1 and 4; in patients with genotypes 2 or 3, the optimal regimen is yet to be established. Sofosbuvir (SOF) and daclatasvir (DCV) represent an antiviral pangenotypic regimen with favorable pharmacokinetics in hemodialyzed patients. We retrospectively evaluated safety and efficacy of the combination of SOF and DCV in the treatment of genotype 3a chronic HCV in six male patients (mean age of 39 years, range 25-53 years) with end-stage renal disease on maintenance hemodialysis; these patients were treated with a reduced dose of SOF (one half of a 400 mg tablet) and 60 mg of DCV once daily. The anticipated treatment duration was 12 weeks. Initial HCV RNA ranged from 120,000 to 11,000,000 IU/mL. Two of the six patients had compensated liver cirrhosis based on shear-wave elastography result. All of the patients completed a 12-week treatment. Viremia became negative on treatment and remained negative 12 weeks after the end of therapy in all the patients. All of them (6/6, 100%) achieved sustained virological response, including two with cirrhosis and two with HCV RNA >6,000,000 IU/mL. The treatment was well tolerated: none of the patients presented with a serious adverse event requiring hospital admission and none had anemia or any significant changes in blood count. One patient had a short period of diarrhea, which was resolved with antibiotic treatment. The combination of reduced-dose SOF and full-dose DCV, daily, was a safe and effective treatment in our group of hemodialyzed patients infected with HCV genotype 3.

Chronic hepatitis C and chronic kidney disease: Advances, limitations and unchartered territories

Over the past few years, treatment options for chronic hepatitis C virus (HCV) infection have evolved dramatically. The current approved interferon-free direct-acting antiviral (DAA) regimens have been shown to be safe and effective with sustained virologic response (SVR) rates of >90% in most patients. Unique issues yet remain such as the challenges in patients with impaired renal function or decompensated cirrhosis. Patients with stages 4-5 chronic kidney disease (CKD) have a higher prevalence of HCV infection compared with the general population. Chronic HCV in those on dialysis and in kidney transplant recipients is associated with higher morbidity and mortality than uninfected patients. The HCV-infected population is also at risk of developing extrahepatic manifestations associated with altered immune system function and chronic inflammation with cryoglobulinaemic vasculitis being the most common of these manifestations. Therefore, patients with CKD stages 4-5 have to be considered priority patients for HCV therapy. New antiviral therapies have the potential to improve outcomes in this vulnerable patient population, including those on haemodialysis. Recently published studies conducted in kidney transplant recipients have demonstrated successful outcomes. It is thus essential that we carefully select the most appropriate DAA regimen and the best time for treatment in the context of kidney transplantation or cryoglobulinaemic vasculitis. While sofosbuvir, the only approved nucleotide NS5B inhibitor, has been the backbone of most pangenotypic therapeutic regimens, it has a limitation in those with advanced kidney disease. The currently approved regimens for those with stage 4/5 CKD, while effective, have challenges in that they apply to genotype 1/4 and may require RBV for genotype 1a. Globally, genotype 3 is a common infection, and thus, this group with CKD presents a huge unmet need for effective therapies. As therapy of HCV in renal transplant recipients has been highly successful, it provides an opportunity to expand the use of HCV-infected organs in solid organ transplantation.

Elbasvir plus grazoprevir in patients with hepatitis C virus infection and stage 4-5 chronic kidney disease: clinical, virological, and health-related quality-of-life outcomes from a phase 3, multicentre, randomised, double-blind, placebo-controlled trial

BACKGROUND

In the C-SURFER study, therapy with the all-oral elbasvir plus grazoprevir regimen for 12 weeks in patients with chronic hepatitis C virus (HCV) infection and stage 4-5 chronic kidney disease resulted in a high rate of virological cure compared with placebo. Here, we report sustained virological response (SVR), safety data, health-related quality-of-life (HRQOL), and virological resistance analyses in patients in C-SURFER who received immediate antiviral therapy or who received placebo before therapy.

METHODS

In this phase 3, multicentre, randomised, placebo-controlled study, we randomly assigned adults with HCV genotype 1 infection and stage 4-5 chronic kidney disease enrolled at 68 centres worldwide to either elbasvir 50 mg plus grazoprevir 100 mg once per day for 12 weeks (immediate treatment group) or placebo for 12 weeks followed by elbasvir 50 mg plus grazoprevir 100 mg once per day for 12 weeks beginning at week 16 (deferred treatment group). The primary safety and efficacy endpoints for the immediate treatment group and placebo phase of the deferred treatment group have been reported previously. Here, we report safety and efficacy data for the treatment phase of the deferred treatment group, as well as HRQOL assessed using the 36-Item Short Form Health Survey for all groups, and baseline and treatment-emergent resistance-associated substitutions (RASs). SVR at 12 weeks (SVR12) was assessed in the modified full analysis set (FAS), defined as all patients excluding those who did not receive at least one dose of study drug, who died, or who discontinued the study before the end of treatment for reasons determined to be unrelated to HCV treatment. This trial is registered with ClinicalTrials.gov, Number NCT02092350.

FINDINGS

Between March 30 and Nov 28, 2014, 235 patients were enrolled and received at least one dose of study drug. The modified FAS included 116 patients assigned to immediate treatment and 99 assigned to deferred treatment. 115 (99·1%; 95% CI 95·3-100·0) of 116 assigned to immediate treatment achieved SVR12 compared with 97 (98·0%; 92·9-99·7) of 99 assigned to deferred treatment. In patients with genotype 1a infections, SVR12 was achieved by 11 (84·6%) of 13 patients with detectable baseline NS5A RASs and in 98 (100%) of 98 without. HRQOL did not differ at week 12 between immediate treatment and the placebo phase of deferred treatment. Safety was generally similar between patients receiving immediate treatment and those receiving placebo in the deferred treatment group. One serious adverse event during deferred treatment (interstitial nephritis) and one during the placebo phase of deferred treatment (raised lipase concentration) were deemed related to study drug. Four patients died, one who received immediate treatment (cardiac arrest) and three who received deferred treatment (aortic aneurysm, pneumonia, and unknown cause); all four deaths were considered unrelated to study drugs. Of the three deaths in the deferred treatment group, one occurred during placebo treatment and two occurred before starting active treatment. There were no notable differences in aminotransferase elevations in the deferred treatment group compared with the immediate treatment group, and no patients in the deferred treatment group had total bilirubin elevations.

INTERPRETATION

These data add to the growing body of clinical evidence for the fixed-dose combination regimen of elbasvir plus grazoprevir for 12 weeks and support use of this therapy in patients with HCV genotype 1 infection and stage 4-5 chronic kidney disease.

FUNDING

Merck Sharp & Dohme.

The New Era of Hepatitis C: Therapy in Liver Transplant Recipients

Hepatitis C virus (HCV) is the leading cause of end-stage liver disease in both Europe and the United States and is the most common reason for liver transplant. In the absence of antiviral therapy, recurrent infection is the norm with subsequent graft hepatitis and impaired survival. Whether it may be better to postpone therapy in patients in whom higher risk of failure and toxicity is coupled with lower chance of liver function improvement likely depends on several factors, including waiting time, center allocation policy, presence of hepatocellular carcinoma and local prevalence of anti-HCV-positive donors.

Hemodialysis Patients Treated for Hepatitis C Using a Sofosbuvir-based Regimen

Introduction

There is paucity of data on sofosubvir (SOF)−based therapy in patients on maintenance hemodialysis (MHD). The objective of this report is to describe our experience using SOF-based direct antiviral agent (DAA) therapy in MHD patients in India.

Methods

All patients on MHD and treated with SOF-based therapy were included in this study. Before starting treatment, viral load, genotype, liver fibroscan, and upper gastrointestinal endoscopy were performed in all patients. SOF 400 mg/d or on an alternate day, ribavirin 200 mg/d and daclatasvir 60 mg/d were used in different regimens. Hepatitis C virus RNA was assessed at day 10 and at 4 weeks, at end of therapy, and at 12 weeks after stopping therapy.

Results

A total of 62 treatment-naïve patients were included. Mean age was 33.3 ± 10.2 years; 66% were men. Median number of copies were 10⁶/dl. None had clinical evidence of cirrhosis. The most common genotype was genotype 1 in 64.5% of cases, followed by genotype 3 in 29% of cases. Thirty-nine patients were treated with SOF every other day/ribavirin, 2 patients with SOF daily/ribavirin, 6 with SOF every other day/daclatasvir, and 15 patients with SOF daily/daclatasvir. All patients were treated for 12 weeks. Fifty-nine (95.2%) patients had a sustained viral response (SVR). There was no impact of genotype on SVR. Twenty-three patients (37%) had complications while on therapy; 13 (20.3%) had dyspepsia, 4 had tuberculosis, and 3 had bacterial pneumonia. Most of the patients (n = 23; 56%) in the ribavirin group required an increase in the erythropoietin dose. No patient discontinued therapy due to complications.

Discussion

SOF-based DAAs were well tolerated and efficacious in this cohort of patients on MHD.

Sofosbuvir-based regimens for the treatment of chronic hepatitis C in severe renal dysfunction

Sofosbuvir (SOF) is a nonstructural 5B polymerase inhibitor with activity in all hepatitis C virus (HCV) genotypes and is the backbone of many anti-HCV drug regimens. SOF is converted into inactive metabolites that undergo renal excretion. Patients with an estimated glomerular filtration rate (eGFR) < 30 mL/minute/1.73 m² may experience increased drug exposure and thus potential toxicities along with decreased efficacy due to dose reduction or drug discontinuation. This is a single-center study evaluating safety and effectiveness of SOF-based regimens in patients with severe renal dysfunction, defined as eGFR <30 mL/minute/1.73 m², including those receiving concurrent hemodialysis. Data were collected from patients with HCV and severe renal dysfunction who started full-dose (400 mg) SOF-based antiviral therapy ± ribavirin between April 2014 and February 2016. Medical records were reviewed for demographics, medical history, laboratory, radiologic imaging, echocardiography, transplant status, and liver pathologic findings. Twenty-nine patients were identified; 12 had cirrhosis and 4 of those had decompensated cirrhosis. Fourteen patients had undergone transplantation of liver and/or kidney and were on calcineurin inhibitors, with 42% requiring dose increases or decreases while on therapy. All patients attained viral suppression on treatment, and 97% had a sustained viral response at 12 weeks posttreatment. There were no early treatment discontinuations. One death occurred posttreatment from a non-ST elevation myocardial infarction in a patient with a history of coronary artery disease and ischemic cardiomyopathy. Conclusion: SOF-based regimens appear safe in a broad range of patients with severe renal dysfunction, including those with decompensated cirrhosis and liver transplant. To confirm these retrospective findings, prospective studies that include SOF and SOF metabolite measurements coupled with prospective serial monitoring of electrocardiograms and echocardiograms are needed. (Hepatology Communications 2017;1:248-255).

Direct-acting antivirals: the endgame for hepatitis C?

Directly-acting antivirals (DAA) have finally allowed all patients to be potentially cured from chronic hepatitis C (HCV) infection. All-oral, Interferon (IFN)-free regimens are based upon the combination of molecules targeting different sites of the HCV replication process. Three classes of DAA exist: protease inhibitors (anti-NS3/4A), RNA-dependent polymerase inhibitors (anti-NS5B) and anti-NS5A inhibitors, which are characterized by different antiviral potency and barrier to resistance and therefore are usually combined in different treatment schedules. Treatment regimens are still largely dependent on HCV genotype and stage of liver disease, with duration ranging between 12 weeks and 24 weeks, while overall treatment efficacy has climbed to nearly 95% in most patient groups, including historically difficult-to-treat categories (HCV genotype 1, advanced liver disease). The elimination of IFN has allowed safe and efficacious treatment of patients formerly contraindicated to antiviral therapy, such as decompensated cirrhosis and solid organ transplant recipients. Availability of potent and safe antiviral drugs combined with improvement of worldwide access to treatment could finally lead to HCV elimination in the next decades.

Efficacy and safety of sofosbuvir-based regimens in chronic hepatitis C patients on dialysis

INTRODUCTION

Patients with end-stage renal disease (ESRD) have poor treatment tolerance and outcome to interferon-based regimens. Sofosbuvir-based regimens have improved treatment success in chronic hepatitis C. There is limited data in ESRD patients as sofosbuvir is excreted by the kidney. Several small studies have shown good results.

METHODS

Sixteen consecutive patients of ESRD (on dialysis) and chronic hepatitis C were treated with sofosbuvir-based regimens as they were prospective kidney transplantation recipients, at a tertiary care center in north India. Sofosbuvir was given 400 mg on alternate days. Data is shown as number, mean (SD), and median (range).

RESULTS

Sixteen patients (12 males) aged 45±12 years received sofosbuvir-based treatment. These patients were on hemodialysis from 10 (2-48) months. Eleven of these patients had genotype 1, four had genotype 3, and one had genotype 4 infection; baseline RNA was 7 (5-8) log. The following treatment regimens were used: sofosbuvir, ribavirin, and low dose peginterferon (n = 8; 6 genotype 1 and one each had genotype 3 and 4); sofosbuvir and daclatasvir (n = 7); sofosbuvir, ribavirin, and daclatasvir (n = 1). Ten patients achieved end of treatment response and 8 (80%) of these achieved sustained virological response at 12 weeks (SVR12); six are on treatment. Two patients with genotype one (including one with cirrhosis) had relapse. Seven patients needed blood transfusion; interferon was stopped in one due to thrombocytopenia. Fatigue was present in 4 patients.

CONCLUSION

Sofosbuvir-based regimens can be used in ESRD patients on dialysis with good efficacy.

Interferon-free regimens in patients with hepatitis C infection and renal dysfunction or kidney transplantation

Treatment of patients with chronic kidney disease (CKD) and chronic hepatitis C (CHC) differs from that used in the general CHC population mostly when glomerular filtration rate (GFR) is below 30 mL/min, as sofosbuvir, the backbone of several current regimens, is officially contraindicated. Given that ribavirin free regimens are preferable in CKD, elbasvir/grazoprevir is offered in CHC patients with genotype 1 or 4 and ombitasvir/paritaprevir and dasabuvir in genotype 1b for 12 wk. Although regimens containing peginterferon with or without ribavirin are officially recommended for patients with CKD and genotype 2, 3, 5, 6, such regimens are rarely used because of their low efficacy and the poor safety and tolerance profile. In this setting, especially in the presence of advanced liver disease, sofosbuvir-based regimens are often used, despite sofosbuvir contraindication. It seems to have good overall safety with only 6% or 3.4% of CKD patients to discontinue therapy or develop serious adverse events without drug discontinuation. In addition, sustained virological response (SVR) rates with sofosbuvir based regimens in CKD patients appear to be comparable with SVR rates in patients with normal renal function. Treatment recommendations for kidney transplant recipients are the same with those for patients with CHC, taking into consideration potential drug-drug interactions and baseline GFR before treatment initiation. This review summarizes recent data on the current management of CHC in CKD patients highlighting their strengths and weaknesses and determining their usefulness in clinical practice.

Treatment Options in Hepatitis C

BACKGROUND

Among patients with chronic hepatitis C, 20-30% develop hepatic cirrhosis and its complications within 30 years. The antiviral treatment of hepatitis C, previously interferon-based, has recently become inter - feron-free, with resulting improvements in sustained virological response rates, safety, and tolerability and a shorter duration of treatment.

METHODS

This review is based on relevant publications retrieved by a selective literature search, and particularly on studies and reviews concerning the course and treatment of hepatitis C.

RESULTS

The available drugs for interferon-free antiviral treatment of hepatitis C include inhibitors of the RNAdependent RNA polymerase, NS3/4A protease, and NS5A protein of the hepatitis C virus (HCV), and ribavirin. Typically, two specific inhibitors are given in combination; the usual duration of treatment is 12 weeks.The antiviral drugs differ in their genotypic antiviral effectiveness and resistance barriers. The appropriate drug(s) should be chosen in consideration of the patient's hepatic and renal function and potential drug interactions. These drugs are safe and well-tolerated and result in sustained virological response rates between 90% and 100%.

CONCLUSION

All patients with hepatitis C, whatever their disease stage, can derive a sustained eradication of HCV from a combination of drugs with direct antiviral activity. Viral eradication is associated with a better quality of life and with lower morbidity and mortality.

Special populations: treating hepatitis C in patients with decompensated cirrhosis and/or advanced renal impairment

Direct-acting antivirals have revolutionized the treatment of hepatitis C. Sustained virological response rates of at least 95% have become common in the general population. However, along with the ageing of the HCV population, physicians face a growing group of HCV-infected patients with advanced liver and/or renal impairment. The safety and efficacy of treatment remains a clinical challenge in these patients. This review focuses on the current state of knowledge and treatment regimens in patients with decompensated cirrhosis and severe renal impairment. It shows that distinct interferon-free treatments can achieve favourable sustained virological response rates in these difficult-to-treat patients. Moreover, pitfalls and special considerations as well as new emerging challenges in an era of interferon-free regimens will be presented in this article.

Novel Treatment of Hepatitis C Virus Infection for Patients with Renal Impairment

Prevalence of hepatitis C virus (HCV) infection is high in patients with end-stage renal dysfunction, including patients undergoing hemodialysis (HD). The HCV infection itself can cause glomerulonephritis and puts individuals at increased risk of developing end-stage renal disease; fortunately, successful HCV eradication sometimes restore HCV-related renal dysfunction. Moreover, the prognosis of dialysis patients infected with HCV is significantly worse and the renal allograft survival in HCV-infected patients is also worse than in dialysis patients without HCV infection. If life prognosis is favorable, therefore, anti-HCV therapy is strongly recommended for HCV-infected patients with severe renal dysfunction. The standard therapy for HCV-infected patients with severe renal dysfunction has historically been interferon-based therapy. However, this therapy remains ineffective in achieving high, sustained viral response rates and the rate of adverse events and treatment discontinuation due to treatment-induced adverse events continues to be high in patients with severe renal dysfunction. Safe and effective anti-HCV therapies are urgently needed, and crucial, for patients with severe renal dysfunction. Recently, direct-acting antivirals (DAAs) that specifically target viral proteins have been developed, and these targets include the NS3, NS5A, and NS5B of HCV. Clinical trials have revealed high efficacy and safety of the DAA-based therapies, but patients with severe renal dysfunction were not included in the majority of these trials. However, several recent reports have shown high efficacy and safety for some regimens of DAA combination therapy for HCV-infected patients with severe renal dysfunction. In this review, we discuss novel treatments for HCV-infected patients with severe renal dysfunction and the pharmacokinetics of these drugs.

Effectiveness of direct-acting antivirals in Hepatitis C virus infection in haemodialysis patients

Hepatitis C virus (HCV) infection is highly prevalent among patients on haemodialysis and leads to a poorer prognosis compared to patients who do not have said infection. Treatment with interferon and ribavirin is poorly tolerated and there are limited data on the experience with new direct-acting antivirals (DAAs). The aim of this study is to retrospectively analyse the current prevalence of HCV infection and efficacy and safety results with different DAA regimens in the haemodialysis population of 2hospital areas. This is a multicentre, retrospective and observational study in which HCV antibodies were analysed in 465 patients, with positive antibody findings in 54 of them (11.6%). Among these, 29 cases (53.7%) with genotypes 1 and 4 were treated with different DAA regimens, including combinations of paritaprevir/ritonavir, ombitasvir, dasabuvir, sofosbuvir, simeprevir, daclatasvir and ledipasvir, with/without ribavirin. Mean age was 53.3±7.9 years, 72.4% of patients were male and the most important aetiology of chronic kidney disease involved glomerular abnormalities. In 100% of cases, a sustained viral response was achieved after 24 weeks, regardless of DAA regimen received. Adverse effects were not relevant and no case required stopping treatment. In 15 cases, ribavirin was combined with the DAA. In these cases, the most significant adverse effect was anaemic tendency, which was reflected in the increase of the dose of erythropoietin stimulating agents, although none required transfusions. In summary, we conclude that new DAAs for the treatment of HCV in haemodialysis patients are highly effective with minimal adverse effects; it is a very important advance in HCV management. These patients are therefore expected to have a much better prognosis than they have had until very recently.

Anti-hepatitis C virus drugs and kidney

Hepatitis C virus (HCV) mainly targets the liver but can also induce extrahepatic manifestations. The kidney may be impacted via an immune mediated mechanism or a cytopathic effect. HCV patients are clearly at a greater risk of chronic kidney disease (CKD) than uninfected patients are, and the presence of CKD increases mortality. Interferon-based therapies and ribavirin are difficult to manage and are poorly effective in end-stage renal disease and hemodialysis. These patients should be given priority treatment with new direct anti-viral agents (DAAs) while avoiding peginterferon and ribavirin. The first results were convincing. To aid in the correct use of these drugs in patients with renal insufficiency, their pharmacokinetic properties and potential renal toxicity must be known. The renal toxicity of these new drugs was not a safety signal in clinical trials, and the drugs are generally efficient in these frail populations. These drugs are usually well tolerated, but recent cohort studies have demonstrated that these new regimens may be associated with renal side effects, especially when using sofosbuvir combinations. HCV, renal diseases and comorbidities are intimately linked. The close monitoring of renal function is required, particularly for at-risk patients (transplanted, HIV-coinfected, CKD, hypertensive or diabetic patients). New DAA regimens, which will soon be approved, will probably change the landscape.

Direct-acting antivirals for the treatment of chronic hepatitis C in patients with chronic kidney disease

All-oral, direct-acting antivirals (DAAs) have significantly improved the efficacy and safety of chronic hepatitis C (CHC) treatment but their effectiveness and safety among patients with chronic kidney disease (CKD) remains poorly understood. Our aim was to assess the efficacy and safety of DAAs for treatment of CKD patients. The National Library of Medicine through PubMed was searched for studies evaluating the efficacy of DAAs for the treatment of patients with CKD stages 4 or 5, as defined by the Kidney Disease Outcomes Quality Initiative guidelines [i.e. glomerular filtration rate (GFR) 15-29 ml/min per 1.73 m² and GFR <15 ml/min per 1.73 m², respectively, or hemodialysis or peritoneal dialysis]. Randomized clinical trials (RCTs) and relevant cohort studies were included if they were published in English and included sustained viral response after 12 weeks (SVR12) as a primary or secondary endpoint. After applying inclusion and exclusion criteria, eight studies (one RCT and seven cohort studies) following 350 patients were selected. For patients with CKD stage 4 or 5, ± hemodialysis, the overwhelming majority of DAA regimens were well-tolerated and resulted in SVR12 rates of 90-100%. Most studies were small, with the exception of one RCT evaluating elbasvir and grazoprevir. Overall, treatment of CHC in patients with CKD is highly effective with SVR12 rates similar to those seen in patients without CKD and with acceptable adverse event profiles. In patients with hepatitis C virus (HCV) genotype (GT) 1a, 1b or 4 and Stage 4 or 5 CKD, the best evidence available is for the use of elbasvir and grazoprevir. This combination as well as the combination of paritaprevir/ritonavir/ombitasvir/dasabuvir for HCV GT-1b are recommended. More studies are needed to assess efficacy and adverse effects of DAAs and their impact on CKD patients and to fully elucidate the effect of curing CHC on the natural history and sequelae of renal disease in CHC patients with CKD.

Second generation direct-acting antivirals - Do we expect major improvements?

The rapid progress in the development of direct-acting antiviral agents for hepatitis C has allowed the vast majority of patients to receive all oral therapy that will eliminate their virus. The success of the new regimens has led many to question the need for further developments in this field. Major improvements in drugs for hepatitis C are unlikely but we predict incremental improvements in the next few years. We hope that the next generation of drugs will address the unresolved issues for patients with genotype 3 infection where current treatments are still not entirely satisfactory and we anticipate improvements in the management of patients with renal failure. Shorter duration treatments, perhaps with novel modes of action, may allow simplified 'one-dose' treatments that will greatly expand our ability to treat patients who have difficulty accessing current services and we anticipate that the clinical community will better define the patients with advanced disease who will benefit from therapy prior to liver transplantation.

Hepatitis C virus infection and chronic kidney disease: Time for reappraisal

Hepatitis C virus (HCV) infection is associated with tremendous morbidity and mortality due to liver complications. HCV infection is also associated with many extrahepatic manifestations including cardiovascular diseases, glucose metabolism impairment, cryoglobulinemia vasculitis, B cell non-Hodgkin lymphoma and chronic kidney disease (CKD). Many studies have shown a strong association between HCV and CKD, by reporting (i) an increased prevalence of HCV infection in patients on haemodialysis, (ii) an increased incidence of CKD and proteinuria in HCV-infected patients, and (iii) the development of membranoproliferative glomerulonephritis secondary to HCV-induced cryoglobulinemia vasculitis. HCV seropositivity is found to be associated with an increased relative risk for all-cause and cardiovascular mortality in the dialysis population. HCV seropositivity is linked to lower patient and graft survival after kidney transplantation. Such poor HCV-associated prognosis should have encouraged clinicians to treat HCV in CKD patients. However, due to frequent side effects and the poor efficacy of interferon-based treatments, very few HCV dialysis patients have received HCV medications until now. The emergence of new direct acting, interferon-free antiviral treatment, leading to HCV cure in most cases with a satisfactory safety profile, will shortly modify the management of HCV infection in CKD patients. In patients with a glomerular filtration rate (GFR) >30ml/min, the choice of DAA is not restricted. In those with a GFR <30 and >15ml/min, only paritaprevir/ritonavir/ombitasvir/dasabuvir or a grazoprevir plus elbasvir regimen are approved. In patients with end stage renal disease (GFR <15ml/min or dialysis), current data only allows for the use of a grazoprevir plus elbasvir combination. No doubt these data will be modified in the future with the advent of new studies including larger cohorts of HCV patients with renal impairment.