Treatment of HCV with ABT-450/r-ombitasvir and dasabuvir with ribavirin

Grazoprevir/elbasvir for the treatment of adults with chronic hepatitis C: a short review on the clinical evidence and place in therapy

Chronic hepatitis C virus (HCV) infection impacts approximately 71 million people and approximately 400,000 deaths are attributed to HCV-related liver disease annually worldwide. Mainstay of treatment for over 25 years has been pegylated interferon until the advent of protease inhibitors, which has led to all-oral HCV treatment regimens that have changed the outlook of hepatitis C treatment. Grazoprevir/elbasvir provides high rates of efficacy and tolerability and is an all-oral once daily treatment option for HCV infection. Efficacy of grazoprevir/elbasvir has been proven in patients with cirrhosis, patients who have previously failed treatment with peginterferon and ribavirin (RBV), patients with end-stage renal disease and patients with HIV co-infection. Data have shown a high barrier to resistance despite the presence of resistance-associated substitutions. Grazoprevir/elbasvir represents a very promising regimen for treatment of HCV infection. This review provides a summary of pharmacology, efficacy, and safety of grazoprevir/elbasvir for the treatment of HCV infection.

Treatment of hepatitis C in special populations

Hepatitis C virus (HCV) infection is one of the primary causes of liver cirrhosis and hepatocellular carcinoma. In hemodialysis patients, the rate of HCV infection is high and is moreover associated with a poor prognosis. In liver transplantation patients with HCV infection, recurrent HCV infection is universal, and re-infected HCV causes rapid progression of liver fibrosis and graft loss. Additionally, in patients with HCV and human immunodeficiency virus (HIV) co-infection, liver fibrosis progresses rapidly. Thus, there is an acute need for prompt treatment of HCV infection in these special populations (i.e., hemodialysis, liver transplantation, HIV co-infection). However, until recently, the standard anti-HCV treatment involved the use of interferon-based therapy. In these special populations, interferon-based therapies could not achieve a high rate of sustained viral response and moreover were associated with a higher rate of adverse events. With the development of novel direct-acting antivirals (DAAs), the landscape of anti-HCV therapy for special populations has changed dramatically. Indeed, in special populations treated with interferon-free DAAs, the sustained viral response rate was above 90%, with a lower incidence and severity of adverse events.

Highlights of the Structure-Activity Relationships of Benzimidazole Linked Pyrrolidines Leading to the Discovery of the Hepatitis C Virus NS5A Inhibitor Pibrentasvir (ABT-530)

Curative interferon and ribavirin sparing treatments for hepatitis C virus (HCV)-infected patients require a combination of mechanistically orthogonal direct acting antivirals. A shared component of these treatments is usually an HCV NS5A inhibitor. First generation FDA approved treatments, including the component NS5A inhibitors, do not exhibit equivalent efficacy against HCV virus genotypes 1-6. In particular, these first generation NS5A inhibitors tend to select for viral drug resistance. Ombitasvir is a first generation HCV NS5A inhibitor included as a key component of Viekira Pak for the treatment of patients with HCV genotype 1 infection. Since the launch of next generation HCV treatments, functional cure for genotype 1-6 HCV infections has been achieved, as well as shortened treatment duration across a wider spectrum of genotypes. In this paper, we show how we have modified the anchor, linker, and end-cap architecture of our NS5A inhibitor design template to discover a next generation NS5A inhibitor pibrentasvir (ABT-530), which exhibits potent inhibition of the replication of wild-type genotype 1-6 HCV replicons, as well as improved activity against replicon variants demonstrating resistance against first generation NS5A inhibitors.

Paritaprevir/Ritonavir/Ombitasvir Plus Dasabuvir Regimen in the Treatment of Genotype 1 Chronic Hepatitis C Infection in Patients with Severe Renal Impairment and End-Stage Renal Disease: a Real-Life Cohort

BACKGROUND/AIMS

Chronic hepatitis C (HCV) virus infection reactivates under immunosuppressive drugs and therefore has a negative impact on long-term survival of kidney transplant recipients. Treatment-induced clearance of hepatitis C virus (HCV) in kidney transplant candidates prevents virus reactivation after transplantation. Paritaprevir/Ritonavir/Ombitasvir with Dasabuvir (PrOD) represents a highly effective treatment regimen for HCV genotype 1 (GT1), also suitable for patients with end-stage renal disease (ESRD). Serious drug-drug interactions may represent a limiting factor of this regimen. The aim of this retrospective study was to evaluate safety, efficacy and drug-drug interactions management associated with PrOD treatment in the Czech real-world cohort.

METHODS

Emphasizing concomitant medication adjustment, we described the treatment course with PrOD regimen in 23 patients (4 with CKD4 and 19 on maintenance haemodialysis) infected with HCV GT1 (21 GT1b, 2 GT1a), 18 males and 5 females with an average age of 53.7 years. Six patients had compensated liver cirrhosis and 3 of them were liver transplant recipients.

RESULTS

All 23 patients completed the 12-week treatment and achieved sustained virological response 12 weeks after the treatment (SVR12 rate 100%). None of the patients presented with a significant decrease in haemoglobin level, white blood cell and platelet count during the treatment period. The most frequent adverse events were nausea, hypotension, diarrhoea, and hyperkalemia. Four patients presented with a serious adverse event unrelated to the antiviral drugs (salmonellosis, non-functional kidney graft rejection, early gastric cancer, renal cyst infection, initiation of haemodialysis). Concomitant medication had to be modified with the treatment initiation in 10 out of 23 (43.5%) patients (calcium channel blockers, ACE inhibitors, statins, diuretics, tacrolimus); four patients required further adjustment of antihypertensive drugs or tacrolimus dosage on-treatment.

CONCLUSION

PrOD regimen demonstrated an excellent efficacy and good tolerability. Both prospective adjustment of concomitant medication and further on-treatment adjustment allowed for a safe treatment course.

Healing livers, saving lives: Hepatitis C screening in an era of cure

Chronic hepatitis C affects more than 3 million people in the United States. In the past, drug therapy with interferon and ribavirin resulted in low overall cure rates and early discontinuation due to adverse reactions. The new direct-acting antivirals offer not only a shorter duration of treatment with fewer adverse reactions, but greatly improved overall cure rates as high as 96%. Updated national screening recommendations (including a one-time screening for patients born between 1945 and 1965), combined with timely referral and treatment, offer a prime opportunity for healthcare providers to improve public health outcomes and reduce healthcare costs.

Interferon-free treatment choice according to baseline RASs leads to high SVR rates in HCV genotype 1 infected patients

AIM

Different combinations of direct antiviral agents (DAA) lead to high SVR rates in HCV genotype 1 infected patients. However, presence of baseline resistance-associated substitutions (RASs) represents a major risk factor for treatment failure. It is unknown whether choice of treatment based on RASs has the potential to decrease virologic failure rates.

METHODS

Population-based sequencing of NS3 and NS5A genes was performed in HCV genotype 1 infected patients at a German university hospital. Treatment was individually selected based on resistance analyses.

RESULTS

In total, 319 patients (50% treatment-experienced and 30% with cirrhosis) were included. With the treatment choice based on the baseline NS3 and NS5A resistance profile SVR rates between 96 and 100% were observed in all subgroups, including treatment-experienced patients with cirrhosis and HCV genotype 1a infected cirrhotic patients.

CONCLUSIONS

The choice of treatment based on the RASs status at baseline may be beneficial for optimizing treatment efficacy in patients with HCV genotype 1 infection and risk factors for treatment failure.

Management of Chronic Hepatitis C in End-stage Renal Disease

Treatment for chronic viral hepatitis C has advanced dramatically to current standard of care all-oral direct-acting antiviral regimens with relatively short treatment duration and high efficacy. Patients with comorbid end-stage renal disease have constituted a "special patient population" with data and treatment options lagging behind that of the broader population of patients with chronic hepatitis C until recently. Herein we review the current evidence base for direct-acting antiviral therapy in this population. We provide a suggested algorithm for the evaluation of such patients for therapy. We highlight special considerations in regards to the choice of regimen, duration, and timing in regards to potential kidney transplantation.

Real-world efficacy and safety of ombitasvir, paritaprevir/r+dasabuvir+ribavirin in genotype 1b patients with hepatitis C virus cirrhosis

BACKGROUND

Direct antiviral agents (DAA) showed very good results in terms of efficacy and safety in clinical trials, but real-life data are still needed in order to confirm this profile.

MATERIAL AND METHODS

In Romania, through a nationwide government-funded programme in 2015-2016, approx.5800 patients with virus C cirrhosis received fully reimbursed DAA therapy with OBV/PTV/r+DSV+RBV for 12 weeks. We analysed a national prospective cohort enrolling the first 2070 patients, all with genotype 1b. The only key inclusion criteria was advanced fibrosis (Metavir stage F4) confirmed by Fibromax testing (or liver biopsy/Fibroscan). Efficacy was assessed by the percentage of patients achieving SVR 12 weeks post-treatment (SVR12).

RESULTS

Forty patients stopped the treatment because of hepatic decompensation (1.9%), 21 stopped because of other adverse events and one was lost to follow-up. This cohort was 51% females, mean age 60 years (25÷82), 67% pretreated, 70% associated NASH, 67% with severe necro-inflammation (severity score 3-Fibromax), 37% with comorbidities, 10.4% with Child Pugh A6, 0.5% B7. The median MELD score was 8.09 (6 ÷ 22). SVR by intention-to-treat was reported in 1999/2070(96.6%), 55/2070 failed to respond. Liver decompensation was statistically associated in multivariate analysis with platelets< 105 /mm3 (P = .03), increased total bilirubin (P < .001), prolonged INR (P = .02), and albumin<3.5 g/dL (P = .03).

CONCLUSIONS

OBV/PTV/r+DSV+RBV proved to be highly efficient in our population of cirrhotics with a 96.6% SVR. Serious adverse events related to therapy were reported in 61/2070(2.9%), most of them liver decompensation (1.9%), related to hepatic dysfunction, and lower platelet count.

Diagnosis and Management of Hepatitis C Infection in Primary Care Settings

Hepatitis C virus (HCV) infection is a significant health problem worldwide, and is the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplantation in the United States. The management of HCV has changed significantly over the last 5 years, as treatments have become simpler and more efficacious. Medication efficacy is now greater than 90%, with a high barrier to resistance and few side effects. This review is a collaboration between primary care and hepatology providers to explore all aspects of HCV management: acute versus chronic HCV infection, transmission and testing, and diagnosis and treatment. Specific medications for the treatment of HCV infection are considered, and patient and medication factors including genotype, liver disease status, and comorbidities affecting medication choice are discussed. This is a new era for the management of HCV infection, and interested primary care physicians, family doctors, and general internists can be at the forefront of diagnosis, management, and treatment of HCV.

Protease inhibitor therapy for hepatitis C virus-infection

INTRODUCTION

The hepatitis C virus (HCV) has affected an estimated of 80 million individuals worldwide and is a strain on public health. Around 25-30% of patients in Europe and the US who are infected with HIV are coinfected with HCV. Prior to 2013, treatment modalities containing an NS3/4A protease inhibitor in combination with pegylated interferon and ribavirin improved sustained virological response (SVR) rates. However, rates of severe side effects were high. Nowadays, oral direct-acting antiviral (DAA) combination therapy offers excellent treatment efficacy, safety and tolerability.

AREAS COVERED

This review focuses on the current literature and clinical evidence and their impact regarding NS3/4A protease inhibitors. The pitfalls encountered in treating HIV- and HBV-coinfected patients are also discussed.

EXPERT OPINION

In the era of DAA treatment, third-generation pan-genotypic NS3/4A protease inhibitors (mainly glecaprevir and voxilaprevir) show high antiviral activity and a genetic resistance barrier with cure rates of over 95% when combined with an NS5A inhibitor, irrespective of baseline resistance associated variants (RASs) being present. These new key components of DAA combination therapy are impressive options to eradicate HCV in the so-called difficult-to-treat population (e.g. compensated cirrhosis, end-stage renal disease and patients who failed previous DAA treatment).

Transmission genetics of drug-resistant hepatitis C virus

Antiviral development is plagued by drug resistance and genetic barriers to resistance are needed. For HIV and hepatitis C virus (HCV), combination therapy has proved life-saving. The targets of direct-acting antivirals for HCV infection are NS3/4A protease, NS5A phosphoprotein and NS5B polymerase. Differential visualization of drug-resistant and -susceptible RNA genomes within cells revealed that resistant variants of NS3/4A protease and NS5A phosphoprotein are cis-dominant, ensuring their direct selection from complex environments. Confocal microscopy revealed that RNA replication complexes are genome-specific, rationalizing the non-interaction of wild-type and variant products. No HCV antivirals yet display the dominance of drug susceptibility shown for capsid proteins of other viruses. However, effective inhibitors of HCV polymerase exact such high fitness costs for drug resistance that stable genome selection is not observed. Barriers to drug resistance vary with target biochemistry and detailed analysis of these barriers should lead to the use of fewer drugs.

Viruses are simple organisms that consist of genetic information and a few types of proteins. They cannot replicate on their own, and instead hijack the molecular machinery of a host cell to produce more of themselves.

Inside an infected cell, the genetic information of the virus is replicated and ‘read’ to create viral proteins. These components are then assembled to form a new generation of viruses. During this process, genetic errors may occur that lead to modifications in the viral proteins, and help the virus become resistant to treatment. For instance, a viral protein that used to be targeted by a drug can change slightly and not be recognized anymore.

Currently, the most efficient way to fight drug resistance is to use combination therapy, where several drugs are given at the same time. This strategy is successful, for example to treat infections with the hepatitis C virus, but it is also expensive, especially for developing countries.

An alternative approach is dominant-drug targeting, which exploits the fact that both drug-resistant and drug-susceptible viruses are ‘born’ in the same cell. There, the susceptible viruses can overwhelm and ‘mask’ the benefits of the resistant ones. For example, proteins from resistant strains, which are no longer detected by a treatment, can bind to proteins from susceptible viruses; drugs will still be able to recognize these resulting viral structures. The proteins that operate in such ways are potential dominant-drug targets. However, resistant and susceptible strains can also cohabit without any contacts if their proteins do not interact with each other.

Now, van Buuren et al. screen several viral proteins, including one called NS5A, to test whether a dominant drug target exists for the hepatitis C virus. Only a few molecules of a drug that targets NS5A can stop the virus from growing. In theory, drug-bound NS5A proteins could block their non-drug-bound neighbors, but when these drugs have been used on their own, resistance quickly emerged.

Experiments showed that NS5A is not a dominant drug target because the drug-resistant and drug-susceptible proteins do not mix. Unless ‘forced’ in the laboratory, NS5A proteins only bind to the ones produced by the same strain of virus. This explains why resistant viruses quickly take over when NS5A drugs are the sole treatment. However, other hepatitis C proteins, such as the HCV core protein, are known to mix during the assembly of the virus, and thus are likely be dominant drug targets.

Host-targeting therapies for hepatitis C virus infection: current developments and future applications

Chronic hepatitis C virus (HCV) infection is a leading cause of chronic liver diseases and hepatocellular carcinoma (HCC) worldwide. In the past few years, anti-HCV therapies have undergone a revolution with the approval of multiple direct-acting antivirals (DAAs), which enable interferon-free treatments with considerable improvement of sustained virologic response in patients. Today, DAAs have become the standard of care for HCV therapy. However, several limitations remain, which include access to therapy, treatment failure in a subset of patients and persistent risk of HCC development following cure in patients with advanced fibrosis. By targeting conserved host proteins involved in the HCV life cycle, host-targeting agents (HTAs) offer opportunities for pan-genotypic antiviral approaches with a high barrier to drug resistance. Moreover, when applied in combination with DAAs, HTAs could improve the management of difficult-to-treat patients by acting through a complementary mechanism of action. In this review, we summarize the different HTAs evaluated in preclinical and clinical development and discuss their potential role for anti-HCV therapies.

Direct acting antivirals for the treatment of hepatitis C in ethnic minority populations

INTRODUCTION

Direct acting antivirals (DAA's) have revolutionized the treatment of hepatitis C (HCV). However, questions persist concerning their efficacy in minority populations.

AREAS COVERED

In this review, the authors review outcomes for treatment of HCV by race and ethnicity among the clinical trials that have led to the current recommended treatments for HCV. The authors highlight the efficacy and safety differences by race and ethnicity. They also highlight deficiencies within the literature including small populations of racial/ethnic minorities within HCV clinical trials. DAA's can achieve cure rates for HCV over 95% with the use of once daily medications that have minimal side effects and few significant drug-drug interactions. Regimens with high pan-genotypic efficacy have further simplified treatment paradigms. The purpose of this review is to describe the data on DAA's in treating HCV in racial/ethnic populations.

EXPERT OPINION

While the overall data in racial/ethnic minority populations is sparse, DAA's appear to have high efficacy in curing HCV in diverse racial/ethnic populations. Although achieving high sustained virologic response (SVR) rates, there are also data that suggests that some disparities in SVR persist, especially when considering shorter regimens for HCV treatment in racial/ethnic populations.

Patterns of Resistance-Associated Substitutions in Patients With Chronic HCV Infection Following Treatment With Direct-Acting Antivirals

BACKGROUND & AIMS

Little is known about substitutions that mediate resistance of hepatitis C virus (HCV) to direct-acting antivirals (DAAs), due to the small number of patients with treatment failure in approval studies. It is important to identify resistance patterns to select effective salvage treatments.

METHODS

We performed a comprehensive analysis for resistance-associated substitutions (RASs) in HCV genes (nonstructural protein [NS]3, NS5A, NS5B) targeted by DAAs. We compared NS3, NS5A, and NS5B sequences from 626 patients in Europe with DAA failure with sequences from 2322 DAA-naïve patients, infected with HCV genotypes 1 to 4. We considered RASs to be relevant if they were associated with DAA failure in patients or conferred a greater than twofold change in susceptibility compared with a reference strain in in vitro replicon assays. Data were collected on pretreatment status, DAA regimen, the treatment initiation date and duration, and virologic response. Patients who received at least 4 weeks of antiviral treatment were included in the analysis.

RESULTS

RASs in NS3 associated with simeprevir or paritaprevir failure include R155K and D168E/V. In addition, several RASs were specifically associated with failure of simeprevir (Q80K/R in patients with genotype 1a or 4) or paritaprevir (Y56H in combination with D168V in patients with genotype 1b). Y93H in NS5A was the RAS most frequently associated with failure of daclatasvir, ledipasvir, or ombitasvir in patients with genotype 1b infection, and L31M was associated with failure of daclatasvir or ledipasvir, but not ombitasvir. RASs in NS5A were heterogeneous among patients with HCV genotype 1a or genotype 4 infections. In patients with HCV genotype 3, Y93H was associated with resistance to daclatasvir, but no RASs were associated with ledipasvir failure, pointing to a limited efficacy of ledipasvir in patients with genotype 3. Among patients failed by sofosbuvir-containing regimens, L159F was enriched in patients with genotype 1b (together with C316N) or genotype 3 infection, whereas the RAS S282T was rarely observed.

CONCLUSIONS

We compared RASs in NS3, NS5A, and NS5B among patients failed by DAA therapy. Theses varied with the HCV genotype and subtype, and the different drug classes. These findings might be used to select salvage therapies.

Hepatitis C and human immunodeficiency virus coinfection in the era of direct-acting antiviral agents: No longer a difficult-to-treat population

The treatment of chronic hepatitis C (HCV) in human immunodeficiency virus 1 (HIV)-infected individuals has been historically marked by low sustained virologic response (SVR) rates in comparison to those without HIV infection, resulting in the Food and Drug Administration labeling those coinfected as a "special population with an unmet medical need." We systematically reviewed the treatment of chronic HCV infection in those infected with HIV. We propose that with the advent of direct-acting antiviral (DAA) agents, patients coinfected with HCV and HIV have similar SVR rates as HCV-monoinfected persons and that DAAs address an unmet medical need in this population. A review was performed using Medical Subject Heading terms within the PubMed, EMBASE, and Cochrane Library databases to search for studies dated between January 2004 and July 2017. Keywords used in the study included "hepatitis C," "HIV," "coinfection," and "direct-acting antiviral." SVR rates for those with HCV and HIV coinfection treated with interferon-based therapies were substantially lower that SVR rates of HCV-monoinfected individuals. The advent of DAA agents has resulted in similar SVR rates between monoinfected and coinfected individuals, with SVR >93%. These medications have been demonstrated to have improved safety, efficacy, and tolerability in comparison to interferon-based regimens.

CONCLUSION

The designation of a "special population" for those with coinfection requires reconsideration; DAA therapies have resulted in similarly high rates of SVR for HCV infection in those with and without HIV infection; despite these improvements, however, clinicians must be cognizant of negative predictors of SVR and barriers to treatment that may be more common in the coinfected population. (Hepatology 2018;67:847-857).

Early Successes in an Open Access, Provincially Funded Hepatitis C Treatment Program in Prince Edward Island

INTRODUCTION

The availability of curative hepatitis C therapies has created an opportunity to improve treatment delivery and access. Local providers, government, industry, and community groups in Prince Edward Island developed an innovative province-wide care model. Our goal was to describe the first year of program implementation.

MATERIAL AND METHODS

Using a communitybased prospective observational study design, all chronic hepatitis C referrals received from April 2015 to April 2016 were recorded in a database. Primary analysis assessed the time from referral to assessment/treatment, as well as the number of referrals, assessments, and treatment initiations. Secondary objectives included: (1) treatment effectiveness using intention-to-treat analysis; and (2) patient treatment experience assessed using demographics, adverse events, and medication adherence.

RESULTS

During the study period 242 referrals were received, 123 patients were seen for intake assessments, and 93 initiated direct-acting antiviral therapy based on medical need. This is compared to 4 treatment initiations in the previous 2 years. The median time from assessment to treatment initiation was 3 weeks. Eighty-two of 84 (97.6%, 95% CI 91.7 - 99.7%) patients for whom outcome data were available achieved sustained virologic response at 12 weeks post-treatment; 1 was lost to follow-up and 1 died from an unrelated event. In the voluntary registry, 39.7% of patients reported missed treatment doses.

CONCLUSION

In conclusion, results from the first 12 months of this multi-phase hepatitis C elimination strategy demonstrate improved access to treatment, and high rates of safe engagement and cure for patients living with chronic hepatitis C genotype 1 infections.

Treatment of hepatitis C virus infection for adults and children: updated Swedish consensus guidelines 2017

AIM

Following the approval of two new therapeutic combinations within the European Union in 2017, the former Swedish recommendations for the treatment of hepatitis C virus (HCV) infection from 2016 were deemed in need of updating.

MATERIALS AND METHODS

An expert meeting to this end was held in Stockholm, Sweden in October 2017.

RESULTS AND CONCLUSIONS

An interferon-free combination of direct-acting antiviral agents is now recommended for all patients with chronic HCV infection, regardless of liver fibrosis stage, in order to limit morbidity and spread of the disease. An extended discussion of treatment for people who inject drugs in order to diminish transmission is included.

Epidemiologic features of 348 children with hepatitis C virus infection over a 30-year period: a nationwide survey in Japan

BACKGROUND

Although the epidemiology of hepatitis C virus (HCV) infection among children may be rapidly changing, few reports have characterized large nationwide cohorts of children with HCV infection. We, therefore, sought to clarify the epidemiology and natural history of HCV infection in Japanese children born over the last three decades.

METHODS

Sixty-five pediatric centers retrospectively and prospectively recruited consecutive, otherwise-healthy HCV-infected children born during 1986 to 2015.

RESULTS

Entry criteria were met by 348 children. Age at initial diagnosis of infection has decreased significantly in recent years. Cirrhosis and hepatocellular carcinoma were not identified. Prevalence of spontaneous clearance and of interferon treatment with/without ribavirin were 9 and 54%, respectively. Maternal transmission has increased significantly, representing over 99% of cases in the last decade. No transfusion-related cases have been seen after 1994. HCV genotype 2 has increased to become the most prevalent in Japanese children. Histopathology examination of liver specimens showed no or mild fibrosis in most children with chronic hepatitis C; none showed cirrhosis.

CONCLUSIONS

This largest nationwide cohort study of Asian children with HCV infection spanned the last three decades. None of these Japanese children developed cirrhosis or hepatocellular carcinoma. Maternal transmission increased to account for 99% of cases during the last decade. Genotype 2 now is most prevalent in these children. Histopathologically, most children with chronic hepatitis C showed mild fibrosis or none.

Real-world effectiveness and safety of paritaprevir/ritonavir, ombitasvir, and dasabuvir with or without ribavirin for patients with chronic hepatitis C virus genotype 1b infection in Taiwan

BACKGROUND AND AIM

The real-world effectiveness and safety of paritaprevir/ritonavir, ombitasvir, and dasabuvir (PrOD) remain limited for East Asian hepatitis C virus genotype 1b (HCV-1b) patients. The study aimed to evaluate the antiviral responses of PrOD-based regimens for HCV-1b patients in Taiwan.

METHODS

The study performed a retrospective analysis of 103 HCV-1b patients receiving PrOD with or without ribavirin (RBV) for 12 weeks. Data were analyzed to assess the on-treatment and off-therapy HCV viral load and on-treatment adverse events. The pre-specified characteristics related to sustained virologic response 12 weeks off therapy (SVR12 ) were compared.

RESULTS

At treatment week 4, 100 of 102 patients (98.0%) had serum HCV RNA level < 25 IU/mL. The SVR12 was achieved in 101 of 103 patients (98.1%, [95% confidence interval: 93.2-99.5%]). All except one (99.0%) patients tolerated treatment well without treatment interruption. One cirrhotic patient discontinued treatment at week 1 due to hepatic decompensation. Twenty-four patients (23.3%) had ≥ grade 2 elevation in total bilirubin levels, and 21 of them (87.5%) had indirect type hyperbilirubinemia. The stratified SVR12 rates were comparable in terms of sex, age, body mass index, prior treatment experience, hepatitis B virus surface antigen status, RBV usage, baseline and week 2 viral load, renal function, and hepatic fibrosis stage.

CONCLUSIONS

Paritaprevir/ritonavir, ombitasvir, and dasabuvir with or without RBV are efficacious and generally well tolerated for treatment of HCV-1b patients in Taiwan.

Developing a community HCV service: project ITTREAT (integrated community-based test - stage - TREAT) service for people who inject drugs

Background and aims Majority of the individuals with hepatitis C virus (HCV) infection in England are people who inject drugs, a vulnerable and disenfranchised cohort with poor engagement with secondary care. Our aim is to describe our experiences in setting up a successful nurse led HCV service at a substance misuse service (SMS).

METHODS

We justify the need for a community HCV service and review the different community based models. Our experiences in engaging with stakeholders, obtaining funding, service set up, challenges faced and key recommendations are discussed. Finally, a summary of interim clinical outcomes is presented.

RESULTS

A successful community based "one-stop" nurse led HCV service was set up in Dec 2013 at a large SMS. It provides all aspects of care (blood borne virus screening, non-invasive assessment of hepatic fibrosis, Hepatology input, HCV treatment, peer mentor, social and psychiatrist support, and opiod substitution) at one site. Interim clinical data indicate high service uptake with HCV treatment outcomes comparable to secondary care.

CONCLUSIONS

The advent of direct acting antivirals provides a unique opportunity for HCV elimination in England by 2030. Our "one-stop" integrated and multidisciplinary community HCV model suggests that HCV care can be successfully delivered outside of a hospital setting and warrants national adoption.

Hepatitis C virus drug resistance associated substitutions and their clinical relevance: Update 2018

Nowadays, due to the development of potent Direct-Acting Antiviral Agents (DAAs) that specifically target NS3, NS5A and NS5B viral proteins, several new and highly efficacious options to treat chronic Hepatitis C virus (HCV) infection are available. The natural presence of resistance associated substitutions (RASs), as well as their rapid emergence during incomplete drug-pressure, are intrinsic characteristics of HCV that greatly affect treatment outcome and the chances to achieve a virolgical cure. To date, a high number of RASs in NS3, NS5A, and NS5B have been associated in vivo and/or in vitro with reduced susceptibility to DAAs, but no comprehensive RASs list is available. This review thus provides an updated, systematic overview of the role of RASs to currently approved DAAs or in phase II/III of clinical development against HCV-infection, discriminating their impact in different HCV-genotypes and DAAs, providing assistance for a fruitful use of HCV resistance testing in clinical practice.

Design, synthesis and identification of silicon-containing HCV NS5A inhibitors with pan-genotype activity

Modification of a HCV NS5A inhibitor, ombitasvir, led to the identification of 10d with improved pan-genotype NS5A inhibition and better pharmacokinetic properties. The key structural changes to ombitasvir include bioisosteric replacement of carbon with silicon atom. Compared with ombitasvir, the activity of anti-HCV genotypes (GT 1 to 6) of 10d is increased to some extent, especially the inhibitory activity against genotype 3a and 6a is increased by more than seven times, and the dog's in vivo pharmacokinetics properties were also superior to ombitasvir. Further drug evaluation showed that 10d was similar to ombitasvir on plasma protein binding and liver distribution profiles, with no cytotoxicity and no inhibitory effect on both CYP 450 and hERG ligand binding. However, permeability assay results indicated that 10d was not the substrate of P-gp or BCRP transporter, which is different from that of ombitasvir. The results of a 14-day repeat-dose toxicity study identified no toxicity with 10d. Our findings in preclinical tests suggest that the silicon-containing compound 10d could be worthy of continued study as a potential drug candidate.

Beclabuvir in combination with asunaprevir and daclatasvir for hepatitis C virus genotype 1 infection: A systematic review and meta-analysis

Daclatasvir, asunaprevir (ASV), and beclabuvir (BCV) are direct-acting antivirals (DAAs) for patients with hepatitis C virus genotype 1 infection. This systematic review and meta-analysis investigating the efficacy and safety of this three-drug combination in HCV genotype 1 infection. Eleven electronic search engines were searched for relevant publications. Studies were screened for eligibility and data was extracted. The outcomes were pooled as event rate and risk ratio (RR). The protocol was registered in PROSPERO (CRD42017054391). Among the included six studies, five studies were included for the meta-analysis (n = 1261). The three-drug combination showed a high response rate in naïve patients with sustained virologic response at week-12 posttreatment (SVR₁₂ ) rate = 95.7% (95%CI [93.8-97.1]) and no difference detected by adding ribavirin (RBV) (the pooled RR = 0.98, 95%CI [0.90-1.08], P = 0.70) or comparing with interferon-experienced patients (RR = 1.02, 95%CI [0.98-1.07], P = 0.31) regardless the genotype 1 subtypes or IL28B genotype. Treatment failure was minimal and showed no difference regarding the previous comparisons. Increasing the dose or the duration did not show a significant increase in the efficacy. In conclusion, this analysis showed high response rates in HCV genotype 1-infected patients treated with daclatasvir, ASV, and BCV irrespective of RBV use, prior interferon-based therapy, or restriction on non-cirrhotic patients, IL28B genotype, or baseline resistance-associated variants.

Restrictions for reimbursement of interferon-free direct-acting antiviral drugs for HCV infection in Europe

All-oral direct-acting antiviral drugs (DAAs) for hepatitis C virus, which have response rates of 95% or more, represent a major clinical advance. However, the high list price of DAAs has led many governments to restrict their reimbursement. We reviewed the availability of, and national criteria for, interferon-free DAA reimbursement among countries in the European Union and European Economic Area, and Switzerland. Reimbursement documentation was reviewed between Nov 18, 2016, and Aug 1, 2017. Primary outcomes were fibrosis stage, drug or alcohol use, prescriber type, and HIV co-infection restrictions. Among the 35 European countries and jurisdictions included, the most commonly reimbursed DAA was ombitasvir, paritaprevir, and ritonavir, with dasabuvir, and with or without ribavirin (33 [94%] countries and jurisdictions). 16 (46%) countries and jurisdictions required patients to have fibrosis at stage F2 or higher, 29 (83%) had no listed restrictions based on drug or alcohol use, 33 (94%) required a specialist prescriber, and 34 (97%) had no additional restrictions for people co-infected with HIV and hepatitis C virus. These findings have implications for meeting WHO targets, with evidence of some countries not following the 2016 hepatitis C virus treatment guidelines by the European Association for the Study of Liver.

Exposure-Safety Response Relationship for Ombitasvir, Paritaprevir/Ritonavir, Dasabuvir, and Ribavirin in Patients with Chronic Hepatitis C Virus Genotype 1 Infection: Analysis of Data from Five Phase II and Six Phase III Studies

BACKGROUND AND OBJECTIVES

All-oral direct-acting antiviral regimens that include combinations of ombitasvir, paritaprevir, ritonavir, and dasabuvir with or without ribavirin were evaluated in hepatitis C virus-infected patients in phase II/III clinical studies. The objective of these analyses was to quantify the relationship between exposures of the components of the regimen and laboratory values and to determine covariates that could influence the relationship.

METHODS

Exposure-safety response relationships between individual components of the direct-acting antiviral regimens and clinically important laboratory values were explored using data from 2998 patients from 11 phase II/III clinical studies. Multivariate logistic regression analyses were used to identify significant relationships between predictor variables and response variables.

RESULTS

No statistically significant associations were observed between ombitasvir, dasabuvir, or ritonavir exposures and maximum post-baseline alanine aminotransferase (ALT) or total bilirubin grade or minimum hemoglobin grade. A two-fold increase in paritaprevir exposure from therapeutic exposure was predicted to increase the probability of experiencing a grade 3 or higher increase in ALT by 0.5% and bilirubin by 1.1%. In the phase II/III clinical studies, ALT and bilirubin increases were reversible with continued dosing or after treatment cessation. Other correlates with adverse events of clinical importance included concomitant ribavirin treatment, sex, race, and presence of cirrhosis, consistent with previous observations.

CONCLUSIONS

Exposure-response analyses from phase II/III studies with the combination direct-acting antiviral regimen indicated no statistically significant relationships with ombitasvir, dasabuvir, or ritonavir exposure, but a statistically significant association was observed between paritaprevir exposure and the probability of experiencing a grade 3 or higher increase in ALT or bilirubin.

Efficacy of Interferon-Free Therapies for Chronic Hepatitis C: A Systematic Review of All Randomized Clinical Trials

BACKGROUND AND OBJECTIVES

Second-generation direct-acting antivirals (DAAs) have recently arisen as more effective and safer treatments for chronic hepatitis C. These drugs can be combined into treatments without interferon (IFN), and are therefore called IFN-free therapies.

OBJECTIVE

The objective of this study systematic review was to evaluate the efficacy of IFN-free therapies for the treatment of chronic hepatitis C, and thus increase the clinical evidence for these therapies.

METHODS

A systematic review was conducted in accordance with Cochrane Collaboration recommendations. A search was performed in six different electronic databases using 'clinical trials', 'hepatitis C' and 'interferon-free' as the main descriptors, and studies that conformed to the inclusion criteria had their data extracted, including study information, baseline characteristics, and efficacy outcomes (sustained virologic response, rapid virologic response, and virologic failure).

RESULTS

Sixty-four randomized clinical trials including 15 different therapies were included in a total of 15,731 patients infected with the hepatitis C virus, mostly with genotype 1, and mainly treated for 12 or 24 weeks. The sustained virologic response rate after 12 weeks of treatment was approximately 89%, while the virologic failure rate was below 5%.

CONCLUSIONS

Second-generation DAAs presented several advantages: virologic response values higher than the average achieved by previous IFN-based therapies, reduced treatment duration, and the possibility of different combinations of therapies to meet patient needs. Thus, IFN-free therapies appear to be valuable alternatives for the treatment of chronic hepatitis C.

Hepatic Pharmacokinetics and Pharmacodynamics With Ombitasvir/Paritaprevir/Ritonavir Plus Dasabuvir Treatment and Variable Ribavirin Dosage

Background

It is unknown whether ribavirin (RBV) coadministration modifies the early rate of decline of hepatitis C virus (HCV) RNA in the liver versus plasma compartments, specifically.

Methods

This partially randomized, open-label, phase 2 study enrolled treatment-naive, noncirrhotic patients with HCV genotype 1a. Patients were randomized 1:1 into Arms A and B, and then enrolled in Arm C. Patients received ombitasvir/paritaprevir/ritonavir plus dasabuvir for 12 weeks with either: no RBV for the first 2 weeks followed by weight-based dosing thereafter (Arm A), weight-based RBV for all 12 weeks (Arm B), or low-dose RBV (600 mg) once daily for all 12 weeks. Fine needle aspiration (FNA) was used to determine HCV RNA decline within liver.

Results

Baseline HCV RNA was higher and declined more rapidly in plasma than liver; however, RBV dosing did not impact either median plasma or liver HCV RNA decline during the first 2 weeks of treatment. Liver-to-plasma drug concentrations were variable over time. The most common adverse event was pain associated with FNA.

Conclusions

Coadministration of RBV had minimal visible impact on the plasma or liver kinetics of HCV RNA decline during the first 2 weeks of treatment, regardless of RBV dosing.

Real-world treatment of hepatitis C with second-generation direct-acting antivirals: initial results from a multicentre Canadian retrospective cohort of diverse patients

BACKGROUND

High hepatitis C cure rates have been observed in registration trials with second-generation direct-acting antivirals. Real-world data also indicate high sustained viral response (SVR) rates. Our objective was to determine real-world SVR rates for patients infected with hepatitis C virus (HCV) who were treated with second-generation direct-acting antivirals in the first 18 months of their availability in Canada.

METHODS

Four centres in Calgary contributed their treatment data for a diverse patient population including those who had or had not undergone liver transplantation, those coinfected with HIV and vulnerable populations. We included all patients documented to have started hepatitis C treatment with direct-acting antivirals between October 2014 and April 2016, with follow-up through October 2016. We used multivariate analysis to determine independent predictors of treatment failure.

RESULTS

Outcome data were available for 351 patients, of whom 326 (92.9%) achieved an SVR (193/206 [93.7%], 57/59 [96.6%] and 44/51 [86.3%] for genotypes 1a, 1b and 3, respectively, p = 0.2). Independent predictors of not achieving SVR were older age (adjusted odds ratio [OR] 0.95 [95% confidence interval (CI) 0.90-1.00]), male sex (adjusted OR 0.30 [95% CI 0.10-0.89]) and, in patients with genotype 1a infection, history of hepatocellular carcinoma (adjusted OR 0.13 [95% CI 0.03-0.53]). In the entire cohort, the presence of cirrhosis, genotype and hepatocellular carcinoma were not associated with a lower SVR rate. There were no differences in SVR rate according to treatment centre, HIV coinfection or liver transplantation. Among patients with genotype 3 infection, a significantly lower SVR rate was observed for those treated outside of standard of care than for those treated within standard of care (33.3% v. 89.6%, p = 0.04). De novo hepatocellular carcinoma developed in 12 patients (3.4%) despite successful direct-acting antiviral therapy.

INTERPRETATION

We report high SVR rates in a real-world diverse cohort of HCV-infected patients treated with second-generation direct-acting antivirals. The results highlight the importance of conducting real-world analyses to elucidate clinical factors associated with poorer outcomes that may not be identified in registration trials.

Increasing Prevalence of Hepatitis C among Hospitalized Children Is Associated with an Increase in Substance Abuse

OBJECTIVE

To evaluate the impact of substance abuse on pediatric hepatitis C virus (HCV) prevalence, we examined geographic and demographic data on inpatient hospitalizations in children with HCV.

STUDY DESIGN

We examined hospitalizations in children using the Kids' Inpatient Database, a part of the Healthcare Cost and Utilization Project. We identified cases using the International Classification of Diseases, 9th edition, codes for HCV infection during 2006, 2009, and 2012. Nonparametric tests for trend were used to calculate trend statistics.

RESULTS

From 2006 to 2012 nationally, the number of hospitalizations of children with HCV increased 37% (2.69 to 3.69 per 10 000 admissions; P < .001). The mean age of children hospitalized was 17.6 years (95% CI, 17.4-17.8). HCV cases among those 19-20 years of age represented 68% of the total HCV diagnoses, with a 54% increase over the years sampled (P < .001 for trend). The burden of HCV in children was highest in whites, those in the lowest income quartile, and in the Northeast and Southern regions of the US (all P < .0001). The prevalence of substance use among children with HCV increased from 25% in 2006 to 41% in 2012 (P < .001).

CONCLUSION

The increases of HCV in hospitalized children are largely in teenagers, highly associated with substance abuse, and concentrated in Northeast and Southern states. These results strongly suggest that public health efforts to prevent and treat HCV will also need to include adolescents.

Psychosocial and Neurocognitive Factors Associated With Hepatitis C - Implications for Future Health and Wellbeing

Background: Hepatitis C virus (HCV) infection involves changes not only from the point of view of physical health, but also emotional, and social that have a significant impact on the quality of life of these patients. According to the literature review, it seems that there is an important association between psychosocial factors, in particular on a cognitive level and disease progression. The aim of this mini-review is to summarize recent literature looking at the associations between psychosocial and neurocognitive factors and HCV. Methods: PubMed/Medline was systematically searched for psychosocial and neurocognitive factors associated with hepatitis C, treatment adherence, and patient wellbeing. Results: Patients present with a range of extrahepatic symptoms including fatigue, anxiety, depression, and neurocognitive dysfunction. HCV's impact on quality of life and wellbeing has serious clinical and social implications. Conclusion: Hepatitis C and its management continue to have a profound impact on health and psychologic wellbeing. Considering the serious extrahepatic implications for individuals, it is imperative that healthcare professionals pay close attention to psychosocial and neurocognitive factors. The focus on combined clinical approaches could enhance understanding about the health and social impacts of hepatitis C along the life course.

Management of Hepatitis C/HIV Coinfection in the Era of Highly Effective Hepatitis C Virus Direct-Acting Antiviral Therapy

The increased life expectancy of persons infected with human immunodeficiency virus (HIV) treated with antiretroviral therapy (ART) has resulted in renewed attention to non-HIV-related diseases exacerbated by HIV infection. Coinfection with hepatitis C virus (HCV) is a particular area of concern, as the global prevalence has been estimated at 2.5-5 million people. In this article, we discuss the epidemiology of HCV infection and reinfection, HCV-related liver disease progression in the era of effective ART, and the efficacy of emerging HCV treatment strategies in persons with HIV/HCV coinfection. New data regarding treatment of persons with HIV/HCV coinfection suggest that HCV treatment should be a priority in those with HIV. Results from recent studies using all-oral HCV regimens have shown high rates of sustained virologic response in both clinical trials and real-world settings. A multidisciplinary approach to HCV treatment in those with HIV is recommended for optimal patient management. Following HCV cure, practitioners also need to be mindful of the risks for HCV reinfection and educate patients on protective measures.

Efficacy and safety of paritaprevir/ritonavir, ombitasvir, and dasabuvir with ribavirin for the treatment of HCV genotype 1b compensated cirrhosis in patients aged 70 years or older

Advanced age has been a major limitation of interferon-based treatment for chronic hepatitis C virus (HCV) infection because of its poor response and tolerability. Direct-acting antiviral (DAA) drug regimens are safe and highly effective, allowing administration of treatment also in elderly. This study aims to assess the efficacy and safety of paritaprevir/ritonavir, ombitasvir, and dasabuvir (PrOD) with ribavirin for the treatment of patients aged ≥70 years with HCV genotype 1b compensated cirrhosis.A total of 1008 patients with HCV genotype 1b compensated cirrhosis were prospectively treated with PrOD + ribavirin for 12 weeks, between December 2015 and July 2016. Sustained virologic response 12 weeks after the end of treatment (SVR12), adverse effects (AEs), comorbidities, discontinuation, and death rates were recorded. Efficacy and safety of therapy were assessed in patients aged ≥70 years and compared with data from patients <70 years.There were 117 patients aged ≥70 years, preponderantly females (58.9%), mean age 73.3 ± 2.8 years (range 70-82), and 37 (31.6%) were treatment-experienced. Comorbidities were reported in 60.6% of patients ≥70 years and in 39.8% of those <70 years (P < .001). SVR12 rates based on intention-to-treat and per-protocol analyses were 97.4% and 100%, respectively, in patients ≥70 years, compared to 97.8% and 99.6%, respectively, in patients <70 years (P = ns and P = ns). Severe AEs were reported in 4 (3.4%) patients ≥70 years, compared to 23 (2.6%) in those <70 years (P = ns). One death was recorded in a patient aged 79 years (0.9%) and 6 deaths (0.8%) in those <70 years (P = ns).Treatment with PrOD + ribavirin in patients 70 years of age or older with HCV genotype 1b compensated cirrhosis proved as effective, safe, and well tolerated, as it did in younger patients.

Daclatasvir/asunaprevir/beclabuvir, all-oral, fixed-dose combination for patients with chronic hepatitis C virus genotype 1

BACKGROUND AND AIM

This multinational (Taiwan, South Korea, Russia) phase 3 study evaluated the all-oral, ribavirin-free, fixed-dose combination (DCV-TRIO) of daclatasvir (NS5A inhibitor) 30 mg, asunaprevir (NS3 inhibitor) 200 mg, and beclabuvir (NS5B inhibitor) 75 mg, in patients with chronic hepatitis C virus genotype-1 infection, with or without compensated cirrhosis.

METHODS

UNITY-4 (NCT02170727) was an open-label, two-cohort study in which 169 patients, treatment-naive (n = 138) or treatment-experienced (n = 31), received twice-daily DCV-TRIO for 12 weeks with 24 weeks of post-treatment follow-up. The primary efficacy end point was sustained virologic response at post-treatment week 12 (SVR12) in treatment-naive patients.

RESULTS

Eighty-eight (52%) patients were men, 81 (48%) Taiwanese, 78 (46%) Korean, and 10 (6%) Russian; 23 (14%) had compensated cirrhosis, and 52 (31%) were IL28B (rs1297860) non-CC genotype. Baseline resistance-associated NS5A polymorphisms (L31 and/or Y93) were detected in 25/165 (15%) patients with available genotype-1 sequencing data. SVR12 was achieved by 98.6% (136/138; 95% confidence interval: 94.9-99.8%) of treatment-naive and 100% (31/31; 95% confidence interval: 88.8-100%) of treatment-experienced patients. Both virologic failures were found to be infected with hepatitis C virus genotype-6g; 100% SVR12 was observed for genotype-1a (n = 8) and genotype-1b (n = 157). Two patients experienced serious adverse events. Eight (5%) patients experienced reversible grade 3/4 alanine aminotransferase or aspartate aminotransferase elevations, leading to discontinuation in four (2%); all achieved SVR12. There were no grade 3/4 total bilirubin increases and no deaths.

CONCLUSIONS

Twelve weeks of DCV-TRIO was well tolerated and provided 100% SVR12 in treatment-naive and treatment-experienced patients with genotype-1 infection, with or without cirrhosis, including those with baseline NS5A-L31 or NS5A-Y93 resistance-associated substitutions.

Effect of Hepatitis C Treatment with Ombitasvir/Paritaprevir/R + Dasabuvir on Renal, Cardiovascular and Metabolic Extrahepatic Manifestations: A Post-Hoc Analysis of Phase 3 Clinical Trials

INTRODUCTION

We analyzed phase 3 trial data of ombitasvir/paritaprevir/ritonavir and dasabuvir (3D) ± ribavirin (RBV) in genotype 1 chronic hepatitis C patients to investigate the impact of 3D ± RBV on renal, cardiovascular and metabolic extrahepatic manifestations (EHMs), including persistency 52 weeks post treatment and differential impact by EHM disease severity.

METHODS

Estimated glomerular filtration rate (eGFR), fasting triglyceride and fasting glucose values from clinical trials were used to assess renal, cardiovascular and metabolic EHMs, respectively. Two placebo-controlled trials were used to study the effect of treatment, while the pooled sample of treated patients was used to study the persistency and differential effect of treatment by baseline EHM disease severity, as defined by baseline values of respective EHM biomarkers. Changes in EHM outcomes from baseline were assessed with mixed models adjusting for patient baseline demographic and clinical characteristics.

RESULTS

Treatment with 3D ± RBV resulted in statistically significant declines from baseline of triglycerides and glucose and no statistical change in eGFR. By 52 weeks post treatment patients with elevated triglycerides (-35.3 mg/dl), pre-diabetes (-4.4 mg/dl), diabetes (-34.2 mg/dl) and CKD stage 3 (+1.6 ml/min/1.73 m2) at baseline experienced a statistically significant improvement in their respective EHM values. Patients with CKD stages 2, 4 and 5 experienced no statistically significant change in eGFR from baseline.

CONCLUSION

Treatment with 3D ± RBV resulted in improvement or no worsening of cardiovascular, metabolic and renal EHM markers, especially in patients with severe EHMs at baseline, which persisted until 52 weeks post treatment.

FUNDING

Abbvie Inc.

Efficacy and safety of ombitasvir/paritaprevir/ritonavir in dialysis patients with genotype 1b chronic hepatitis C

AIM

From a pharmacokinetic viewpoint, the use of ombitasvir/paritaprevir/ritonavir, one of the standards of care for genotype 1b chronic hepatitis C in Japan, could be possible in patients with impaired renal function. The aim of this study was to assess the efficacy and safety of this combination that have not yet been addressed in patients undergoing dialysis.

METHODS

A retrospective, multicenter study evaluated the outcome of 12-week ombitasvir (non-structural protein [NS]5A inhibitor)/paritaprevir (NS3/4A protease inhibitor)/ritonavir combination therapy for dialysis patients. The primary end-point was sustained virologic response 12 weeks after therapy (SVR12).

RESULTS

The subjects were 31 patients with a median age of 64 years (range, 49-85 years), including 10 cirrhotic patients. All of the 31 patients had an estimated glomerular filtration rate level <15 mL/min/1.73 m² , defined as end-stage renal disease (ESRD). Pre-existing resistance-associated substitutions at position L31 and Y93 of the NS5A region were detected in 0% and 3.6% (1/28), respectively. The rates of rapid virologic response, end-of-treatment response, and SVR12 were 93.5% (29/31), 100% (31/31), and 96.8% (30/31), respectively. The incidence of adverse events was 35.5% (11/31). Of the 11 patients, one discontinued the treatment due to erythema multiforme and thereafter relapsed. The most frequent adverse event was pruritus (6.5%; 2/31).

CONCLUSIONS

The present study suggests that ombitasvir/paritaprevir/ritonavir combination therapy is effective and safe for genotype 1b chronic hepatitis C patients undergoing dialysis due to ESRD.

Protease inhibitors for the treatment of hepatitis C virus infection

The hepatitis C virus (HCV) has affected an estimate of 80 million individuals worldwide and is a strain of public health. Around 25-30% of patients in Europe and the US infected with HIV are coinfected with HCV. Despite treatment modalities containing a NS3/4A protease inhibitor in combination with pegylated interferon and ribavirin prior to 2013 improved SVR rates, the amount of severe side effects was high. Nowadays, oral direct-acting antivirals (DAAs) combination therapy offers excellent treatment efficacy, safety and tolerability. This review focuses on current literature and clinical evidence and their impact regarding NS3/4A protease inhibitors. In addition, pitfalls in treatment from HIV- and HBV-coinfected patients will also be discussed. In the era of DAA treatment, the third-generation pan-genotypic NS3/4A protease inhibitors (mainly grazoprevir, glecaprevir and voxilaprevir) show a high antiviral activity and genetic resistance barrier with cure rates of over 95% when combined with an NS5A inhibitor, irrespectively of baseline resistance associated variants (RASs) being present. These new key components of DAA combination therapy are impressive options to eradicate HCV in the so called difficult-to-treat population (e.g. compensated cirrhosis, end-stage renal disease and patients who failed previous DAA treatment).

Pharmacokinetics of Tacrolimus and Cyclosporine in Liver Transplant Recipients Receiving 3 Direct-Acting Antivirals as Treatment for Hepatitis C Infection

BACKGROUND

Interactions between tacrolimus and cyclosporine (CSA) and the 3 direct-acting antiviral regimen (3D) of ombitasvir, paritaprevir/ritonavir, and dasabuvir necessitate a priori dose adjustments for the immunosuppressants to achieve desired levels. Modeling and simulations based on data in healthy subjects predicted that tacrolimus 0.5 mg every 7 days or 0.2 mg every 3 days, and CSA at one-fifth the total daily dose administered once daily, would achieve desired trough concentrations (Ctrough) during 3D treatment. The success of these dosing recommendations was evaluated by analyzing pharmacokinetic data from liver transplant recipients in the CORAL-I study.

METHODS

A population pharmacokinetic model was developed using tacrolimus dosing and Ctrough data before and during 3D treatment (n = 29). The model was used to simulate various tacrolimus dosing regimens and predict tacrolimus concentration-time profiles during 3D treatment. CSA Ctrough data before and during 3D treatment (n = 5) were also summarized.

RESULTS

A one-compartment model with first-order absorption adequately described tacrolimus pharmacokinetic profiles during the first 4 weeks of 3D treatment. Estimated tacrolimus Ctrough values (median; interquartile range) before and during 3D treatment were comparable (5.7 ng/mL; 4.9-6.5 ng/mL versus 5.2 ng/mL; 4.2-6.3 ng/mL, respectively). Based on simulations, in a patient with a starting Ctrough of 6 ng/mL, 0.5 mg tacrolimus every 7 or 14 days or 0.2 mg tacrolimus every 3 days will result in Ctrough levels of 6-9 ng/mL, 4-6 ng/mL, and 6-10 ng/mL, respectively, during 3D treatment. For CSA, Ctrough values (median; interquartile range) before and during 3D treatment were comparable (126 ng/mL; 94-140 ng/mL versus 104 ng/mL; 82-140 ng/mL).

CONCLUSIONS

Observed data for tacrolimus and CSA in liver transplant recipients confirm that the recommended dosing strategies are valid and therapeutic levels of immunosuppression can be maintained during 3D treatment.

Pharmacokinetics and Tolerability of Anti-Hepatitis C Virus Treatment with Ombitasvir, Paritaprevir, Ritonavir, with or Without Dasabuvir, in Subjects with Renal Impairment

BACKGROUND

The direct-acting antiviral agent (DAA) combination of ombitasvir and paritaprevir (administered with ritonavir) with (3D regimen) or without (2D regimen) dasabuvir has shown very high efficacy rates in the treatment of chronic hepatitis C virus (HCV) infection. Renal impairment, a common comorbidity in patients with chronic HCV infection, can influence the pharmacokinetics of antiviral agents and hence their efficacy and safety profiles.

OBJECTIVE

The aim of this study was to evaluate the influence of renal impairment on the pharmacokinetics and tolerability of the 3D and 2D regimens.

METHODS

Overall, 24 subjects, six in each of four renal function groups (normal, mild, moderate, and severe), received a single dose of the 3D and 2D regimens in separate dosing periods. Plasma and urine were analyzed to assess the effect of renal impairment on drug exposure.

RESULTS

DAA exposures changed by up to 21, 37, and 50 % in subjects with mild, moderate, and severe renal impairment, respectively, versus subjects with normal renal function. Ritonavir exposure increased with the degree of renal impairment (maximum 114 %). The half-lives of DAAs and ritonavir in subjects with renal impairment were generally comparable with those in healthy subjects. No safety or tolerability concerns arose in this study.

CONCLUSION

The 3D and 2D regimens do not require dose adjustment for patients with HCV infection and concomitant renal impairment.

Real-world effectiveness of ombitasvir/paritaprevir/ritonavir±dasabuvir±ribavirin in patients with hepatitis C virus genotype 1 or 4 infection: A meta-analysis

The direct-acting antiviral regimen of ombitasvir (OBV)/paritaprevir (PTV)/ritonavir (r)±dasabuvir (DSV)±ribavirin (RBV) demonstrated high rates of sustained viral response at post-treatment week 12 (SVR12) in clinical trials for treatment of hepatitis C virus (HCV) genotypes (GT) 1 and 4. To confirm the effectiveness of this regimen in the real world, we conducted meta-analyses of published literature on 30 April 2016. Freeman-Tukey transformation determined the SVR rate within GTs 1a, 1b and 4, as well as specific SVR rates by cirrhosis or prior treatment experience status. Rates of virologic relapse, hepatic decompensation, drug discontinuation and serious adverse events were also analysed. In total, 20 cohorts across 12 countries were identified, totalling 5158 patients. The overall SVR12 rates were 96.8% (95% CI 95.8-97.7) for GT1 and 98.9% (95% CI 94.2-100) for GT4. For GT1a patients, the SVR rates were 94% and 97% for those with or without cirrhosis, and 94% overall. For GT1b patients, the SVR rates were 98% and 99% for those with or without cirrhosis, and 98% overall. The virologic relapse rate of GT1 patients was 1.3%, across 3524 patients in nine studies that reported this parameter. The rate of hepatic decompensation was less than 1% across five studies, including 3440 patients, 70% of which had cirrhosis.

CONCLUSIONS

Real-world SVR12 rates for OBV/PTV/r±DSV±RBV were consistently high across HCV GT1 and four irrespective of cirrhosis status or prior HCV treatment experience, confirming effectiveness within a diverse patient population across multiple cohorts and countries.

Hepatitis C Virus-Associated Extrahepatic Manifestations in Lung and Heart and Antiviral Therapy-Related Cardiopulmonary Toxicity

Besides liver cirrhosis and hepatocellular carcinoma, chronic hepatitis C virus (HCV) infection is associated with many extrahepatic manifestations (EHMs). HCV exhibits lymphotropism that is responsible for various EHM. An important characteristic of HCV is escape from the immune system, which enables it to produce chronic infections and autoimmune disorders along with accumulation of circulating immune complexes. These EHMs have large spectrum, because they affect many organs such as heart, lungs, kidney, brain, thyroid, and skin. HCV-related cardiac and pulmonary manifestations include myocarditis, cardiomyopathies, cardiovascular diseases (i.e., Stroke, ischemic heart disease), chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, asthma, and interstitial lung diseases. This review discusses etiology and pathogenesis of HCV-associated cardiac and pulmonary manifestations and how different genes, immune system, indirectly linked factors (mixed cryoglobulinemia), liver cirrhosis, and antiviral treatment are involved in HCV-related heart and lung diseases, however, their exact mechanism is not clear.

Primer on Hepatitis C Virus Resistance to Direct-Acting Antiviral Treatment: A Practical Approach for the Treating Physician

Treatment of hepatitis C virus has been vastly transformed by the arrival of all-oral, interferon-free, direct-acting antiviral regimens. Despite the high rate of success with these agents, a small portion of treated patients fail therapy and the emergence of viral resistance is the most common cause of treatment failure. Given the error-prone hepatitis C virus polymerase, baseline resistance-associated substitutions (RASs) may be present before direct-acting antiviral exposure. Clinicians need to understand the role of baseline RAS testing and the settings and manner in which the treatment regimens need to be customized based on the presence of RASs.

Safety and Efficacy of Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir with or without Ribavirin for Treatment of Hepatitis C Virus Genotype 1: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Interferon-free regimens are rapidly evolving for patients with chronic hepatitis C virus (HCV) infection. We performed this meta-analysis to investigate the safety and efficacy of a combination regimen (ombitasvir [OBV]/paritaprevir [PTV]/ritonavir [r] ± dasabuvir [DSV]) for the treatment of patients with HCV genotype 1 infection.

METHODS

A computerized literature search for relevant clinical trials was conducted during May 2017. Data on sustained virological response (SVR), virological relapse, and safety outcomes were extracted and calculated as pooled proportion (PP) or risk ratio (RR) with their 95% confidence interval (CI), using StatsDirect and RevMan software.

RESULTS

The final analysis included 13 studies for HCV genotype 1 (3115 patients). The pooled effect estimate showed that 12-week treatment of genotype 1 patients with the OBV/PTV/r regimen achieved a high SVR rate (PP = 94%, 95% CI 92-96) that increased to (PP = 97%, 95% CI 96-98) upon the addition of DSV. These results were consistent when independent subgroup analyses were conducted based on viral subgenotypes, the presence of cirrhosis, or former treatment failure. Adding ribavirin (RBV) to this regimen was not associated with increased SVR rates (risk ratio = 1, 95% CI 0.98-1.02), while it increased the risk of serious adverse events (p = 0.02), insomnia (p = 0.001), and pruritus (p < 0.001).

CONCLUSION

The current meta-analysis showed a high efficacy for the OBV/PTV/r regimen in the treatment of HCV genotype 1 (with DSV) infection, regardless of the presence of cirrhosis or former treatment failure. Adding RBV to this regimen slightly decreased the relapse rate. Future studies with larger sample sizes are required to investigate the efficacy of this regimen in other HCV genotypes and to establish the evidence about the effect of adding RBV to OBV/PTV/r + DSV.

Direct-acting antiviral agents for HCV infection affecting people who inject drugs

Globally, 12 million people are estimated to have injected drugs in the past year, 50% of whom have chronic HCV infection, with people who have previously injected drugs presenting an additional large reservoir of infection. The availability of simple and tolerable interferon-free direct-acting antiviral agents (DAAs) for HCV infection, which have a cure rate of >95% represents one of the most exciting advances in clinical medicine in the past few decades. Adherence and response to DAA therapy among people who inject drugs (PWID) receiving opioid substitution therapy (OST) in clinical trials are comparable to populations without a history of injecting drugs. Further data are required among current PWID not receiving OST. Given the potential prevention benefits of treatment, DAAs have enhanced cost-effectiveness among PWID. As HCV therapy is expanded to populations of PWID with high-risk behaviours for re-exposure, acknowledgement that HCV reinfection will occur is crucial, and appropriate strategies must be in place to maximize prevention of reinfection and offer retreatment for reinfection. This Review will also discuss essential components for broadening access to HCV care for PWID as we strive for the global elimination of HCV infection.

The risk of early occurrence and recurrence of hepatocellular carcinoma in hepatitis C-infected patients treated with direct-acting antivirals with and without pegylated interferon: A Belgian experience

Recently, concerns were raised of high rates of HCC recurrence in patients treated with direct-acting antivirals (DAA) for hepatitis C infection. We investigated the HCC occurrence and recurrence rates within 6 months after treatment with DAA with or without pegylated interferon (PEG-IFN) in real life. This is a retrospective, multicenter cohort trial, executed in 15 hospitals distributed across Belgium. Populations were matched based on fibrosis score (Metavir F3-F4). Patients with a Child-Pugh score ≥ B were excluded. In total, 567 patients were included, of whom 77 were treated with PEG-IFN+DAA between 2008 and 2013 and 490 with DAA without PEG-IFN between 2013 and 2015. Patients treated with PEG-IFN+DAA (53±9y) were younger than patients treated with DAA without PEG-IFN (59±12y) (P=.001). 47% of patients treated with PEG-IFN+DAA were in the F4 stage vs 67% of patients treated with DAA without PEG-IFN (P=.001). Screening was inadequate in 20% of both patient groups (P=.664). The early occurrence rate of HCC was 1.7% and 1.1% in patients treated with DAA with and without PEG-IFN, respectively (P=.540). The early recurrence rate was 0% in patients treated with PEG-IFN+DAA and 15.0% in patients treated with DAA without PEG-IFN (P=.857). There is no difference in early occurrence of new HCC between patients treated with DAA with and without PEG-IFN. We did observe a high early recurrence rate of HCC in patients treated with DAA without PEG-IFN. However, these patients were at baseline more at risk for HCC. Finally, in 20%, screening for HCC was inadequate.

Hepatitis C virus genotypes and subtypes circulating in Mainland China

The hepatitis C virus (HCV) exhibits global genotypic diversity. HCV genotyping plays an important role in epidemiological studies and clinical management. Herein, we report the results of HCV genotype and subtype detection in a large number of clinical samples, as performed by an independent laboratory in China. In total, four HCV genotypes and 18 subtypes were identified among 32 030 patients from 29 provinces and municipalities in China. Five dominant subtypes were detected from 98.84% of the samples: 1b (n=16 713, 52.18%), 2a (n=9188, 28.69%), 3b (n=2261, 7.06%), 6a (n=2052, 6.41%) and 3a (n=1479, 4.62%). Twelve rare subtypes were detected, of which four (that is, 6b, 6j, 6q and 6r) are reported for the first time in the Chinese population. Genotypes 4, 5 and 7 were not detected. Mixed infections of the dominant subtypes were found in a small portion of samples (n=65, 0.203%), in the following combinations: 1b–2a, 1b–3b, 1b–6a, 3a–3b, 1b–3a and 2a–6a. No mixed infections with rare subtypes were found. Males, compared with females, showed higher HCV subtype diversity, a lower percentage of HCV1b and 2a and a higher percentage of rare subtypes and mixed infections. Our analyses revealed the comprehensive distribution patterns of HCV genotypes in the general population of mainland China. HCV genotypic patterns were differentially distributed on the basis of geography, sex and age.