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

Burden of disease in patients with chronic hepatitis C in the Austrian REAL study

BACKGROUND

The direct-acting antiviral regimen of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r) ± dasabuvir (DSV) ± ribavirin (RBV) is approved to treat patients with chronic hepatitis C (CHC) infection genotypes 1 or 4, including compensated cirrhosis. The aim of the prospective, multicenter, observational REAL study was to provide evidence of the effectiveness of this regimen in an Austrian real-world setting and to determine the impact on patient-reported outcomes (PROs).

METHODS

Effectiveness was defined as sustained virologic response 12 weeks after the end of treatment (SVR12). EuroQol 5 Dimension 5 Level (EQ-5D-5L) and Work Productivity and Activity Impairment HepC v2.0 (WPAI) questionnaires were used to assess PROs.

RESULTS

A total of 173 patients were enrolled. The SVR12 was 95.9% (140/146) in the core population with sufficient follow-up (i. e. patients without SVR12 data not due to efficacy/safety reasons, such as lost to follow-up, were excluded) and 84.8% (140/165) in the core population (CP). Data at all timepoints for the EQ-5D-5L index score and visual analog scale and the total activity impairment score of the WPAI were available for 88, 95 and 72 patients, respectively. All PROs remained generally unaltered during treatment with OBV/PTV/r ± DSV ± RBV but showed a statistically significant (p < 0.01) improvement 12 weeks after the end of treatment versus baseline.

CONCLUSIONS

These are the first data on PROs in a real-world setting with OBV/PTV/r ± DSV ± RBV treatment; this study demonstrated that treatment did not negatively impact quality of life. Results from the Austrian REAL study support the effectiveness of OBV/PTV/r ± DSV ± RBV in patients with CHC genotype 1 and 4 in everyday clinical practice.

Minor contribution of CYP3A5 to the metabolism of hepatitis C protease inhibitor paritaprevir in vitro

Paritaprevir (PTV) is a non-structural protein 3/4A protease inhibitor developed for the treatment of hepatitis C disease as a fixed dose combination of ombitasvir (OBV) and ritonavir (RTV) with or without dasabuvir. The aim of this study was to evaluate the effects of cytochrome P450 (CYP) 3A5 on in vitro PTV metabolism using human recombinant CYP3A4, CYP3A5 (rCYP3A4, rCYP3A5) and human liver microsomes (HLMs) genotyped as either CYP3A5*1/*1, CYP3A5*1/*3 or CYP3A5*3/*3. The intrinsic clearance (CL_int, V_max/K_m) for the production of a metabolite from PTV in rCYP3A4 was 1.5 times higher than that in rCYP3A5. The PTV metabolism in CYP3A5*1/*1 and CYP3A5*1/*3 HLMs expressing CYP3A5 was comparable to that in CYP3A5*3/*3 HLMs, which lack CYP3A5. CYP3A4 expression level was significantly correlated with PTV disappearance rate and metabolite formation. In contrast, there was no such correlation found for CYP3A5 expression level. This study represents that the major CYP isoform involved in PTV metabolism is CYP3A4, with CYP3A5 having a minor role in PTV metabolism. The findings of the present study may provide foundational information on PTV metabolism, and may further support dosing practices in HCV-infected patients prescribed PTV-based therapy.

Efficacy and Safety of Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir With or Without Ribavirin in Patients With Chronic Hepatitis C Virus Genotype 1 Infection Receiving Opioid Substitution Therapy: A Post Hoc Analysis of 12 Clinical Trials

BACKGROUND

We evaluated the impact of opioid substitution therapy (OST) on the completion, adherence, efficacy, and safety of the 3-direct-acting antiviral regimen of ombitasvir, paritaprevir (identified by AbbVie and Enanta) co-dosed with ritonavir, and dasabuvir ± ribavirin among patients infected with hepatitis C virus (HCV) genotype (GT) 1, with or without compensated cirrhosis.

METHODS

Data were pooled from GT1-infected patients enrolled in 12 phase II/III/IIIb clinical trials and categorized by use of OST. Patients with ongoing drug use were excluded. HCV treatment completion, treatment adherence (≥90%), sustained virologic response at post-treatment week 12 (SVR12), and adverse events were assessed.

RESULTS

Of 4747 patients, 3% (n = 149) received OST. Among patients receiving OST vs those not receiving OST, 82% (n = 122) vs 52% (n = 2409) had GT1a infection; 76% (n = 113) vs 61% (n = 2792) were treatment naïve; and 17% (n = 25) vs 18% (n = 830) had cirrhosis, respectively. The proportion of patients completing HCV treatment did not differ between those receiving and not receiving OST (97% [n = 144] vs 98% [n = 4510], respectively), whereas adherence to treatment was reduced in patients receiving vs those not receiving OST (88% [n = 105] vs 97% [n = 4057], respectively). SVR12 was similar between patients receiving and not receiving OST (94% [n = 140] vs 96% [n = 4405], respectively; P = .273). Treatment was well tolerated.

CONCLUSIONS

Although treatment adherence was lower in patients receiving OST vs those not receiving OST, treatment completion and SVR12 were similar between groups. These data support the use of direct-acting antiviral therapies in patients receiving OST.

Ombitasvir/Paritaprevir/Ritonavir With or Without Dasabuvir and With or Without Ribavirin for Adolescents With HCV Genotype 1 or 4

In adults, treatment of hepatitis C virus (HCV) infection with ombitasvir (OBV)/paritaprevir (PTV)/ritonavir (r) with or without dasabuvir (DSV) and ±ribavirin (RBV) results in high rates of sustained virologic response (SVR). However, these regimens have not been investigated in adolescents. This ongoing, open-label, phase 2/3 study evaluated the pharmacokinetics, safety, and efficacy of OBV/PTV/r+DSV±RBV treatment for 12 weeks in adolescents infected with HCV genotype (GT) 1 without cirrhosis (part 1) and the safety and efficacy of OBV/PTV/r±DSV±RBV treatment for 12 or 24 weeks in adolescents infected with GT1 or GT4 without cirrhosis or with compensated cirrhosis (parts 1 and 2). Patients were 12-17 years of age and treatment naive or interferon experienced. Treatment regimens were based on HCV GT and cirrhosis status. Endpoints were SVR at posttreatment week 12 (SVR12), adverse events (AEs), and pharmacokinetic parameters. Thirty-eight adolescents were enrolled, 66% were female patients, and 76% were White; 42%, 40%, and 18% of patients had HCV GT1a, GT1b, and GT4 infections, respectively. Median age was 15 years (range, 12-17 years), and 1 patient had cirrhosis. The SVR12 rate was 100% (38/38; 95% confidence interval [CI], 90.8%-100%). No treatment-emergent grade 3 or 4 laboratory abnormalities were reported. No serious AEs occurred on treatment, and no AEs led to study drug discontinuation. The most common AEs were headache (21%), fatigue (18%), nasopharyngitis (13%), pruritus (13%), and upper respiratory tract infection (11%). Intensive pharmacokinetic results showed OBV, PTV, DSV, and ritonavir drug exposures were comparable to those seen in adults. Conclusion: Treatment with OBV/PTV/r±DSV±RBV was well tolerated and highly efficacious in adolescents with HCV GT1 or GT4 infection.

Efficacy and Safety of Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir ± Ribavirin for HCV in Brazilian Adults with Advanced Fibrosis

INTRODUCTION AND AIM

Approximately 650,000 people in Brazil have chronic hepatitis C virus (HCV) infection. We evaluated the safety and efficacy of ombitasvir (OBV)/paritaprevir (PTV)/ritonavir (r) plus dasabuvir (DSV) with/without ribavirin (RBV) in an openlabel multicenter phase 3b trial in treatment-naive or interferon (IFN) treatment-experienced Brazilian patients with advanced hepatic fibrosis (METAVIR F3/4) and HCV genotype (GT) 1 infection.

MATERIAL AND METHODS

All patients received coformulated OBV/PTV/r daily + DSV twice daily (3-DAA). GT1a-infected patients received 3-DAA plus RBV for 12 weeks, except for prior pegIFN/RBV nonresponders with cirrhosis who were treated for 24 weeks. GT1b-infected patients received 3-DAA alone (F3) or in combination with RBV (F4) for 12 weeks. The primary endpoint was sustained virologic response (HCV RNA &lt; 15 IU/mL) at post-treatment Week 12 (SVR12).

RESULTS

The study enrolled 222 patients, 214 achieved an SVR12 (96.4%; 95% CI, 93.1-98.2%), one GT1a-infected patient experienced virologic breakthrough, six (5 GT1a) relapsed, and one was lost to follow-up. SVR12 was achieved in 111/ 112 (99.1%) GT1b-infected patients, including 42/43 (97.7%) noncirrhotic, and 69/69 (100%) cirrhotic patients; and in 103/110 (93.6%) GT1a-infected patients, including 44/46 (95.7%) noncirrhotic and 59/64 (92.2%) cirrhotic patients. Overall there was a low rate of serious adverse events (n = 6, 2.7%). One patient experienced a treatment-related serious adverse event and one patient discontinued treatment because of an adverse event.

DISCUSSION

The results confirm that the 3-DAA regimen with/without RBV is well tolerated and had a favorable safety profile and is efficacious in GT1-infected patients with advanced fibrosis (METAVIR F3/4).

Epidemiology and Elimination of HCV-Related Liver Disease

Hepatitis C virus (HCV) infection, defined by active carriage of HCV RNA, affects nearly 1.0% of the worldwide population. The main risk factors include unsafe injection drug use and iatrogenic infections. Chronic HCV infection can promote liver damage, cirrhosis and hepatocellular carcinoma (HCC) in affected individuals. The advent of new second-generation, direct-acting antiviral (DAA) agents allow a virological cure in more than 90% of treated patients, and therefore prevent HCV-related complications. Recently, concerns have been raised regarding the safety of DAA-regimens in cirrhotic patients with respect to the occurrence and the recurrence of HCC. Here, we review the current available data on HCV epidemiology, the beneficial effects of therapy, and discuss the recent controversy with respect to the potential link with liver cancer. We also highlight the challenges that have to be overcome to achieve the ambitious World Health Organization objective of HCV eradication by 2030.

Baseline dasabuvir resistance in Hepatitis C virus from the genotypes 1, 2 and 3 and modeling of the NS5B-dasabuvir complex by the in silico approach

Background: Current combination treatments with direct-acting antiviral agents (DAAs) can cure more than 95% of hepatitis C virus (HCV) infections. However, resistance-associated substitutions (RASs) may emerge and can also be present in treatment-naïve patients. Methods, results and discussion: In this study, a semi-pan-genotypic population sequencing method was developed and used to assess all NS5B amino acid variants between residue positions 310 and 564. Our method successfully sequenced more than 90% of genotype (GT) 1a, 1b, 2b and 3a samples. By using the population sequencing method with a cut-off of 20%, we found the dasabuvir RASs A553V and C445F to be a baseline polymorphism of GT 2b (8 out of 8) and GT 3a (18 out of 18) sequences, respectively. In GT 1a and 1b treatment-naïve subjects (n=25), no high-fold resistance polymorphism/RASs were identified. We further predicted dasabuvir’s binding pose with the NS5B polymerase using the in silico methods to elucidate the reasons associated with the resistance of clinically relevant RASs. Dasabuvir was docked at the palm-I site and was found to form hydrogen bonds with the residues S288, I447, Y448, N291 and D318. The RAS positions 316, 414, 448, 553 and 556 were found to constitute the dasabuvir binding pocket.

Hepatitis C virus genetic diversity by geographic region within genotype 1-6 subtypes among patients treated with glecaprevir and pibrentasvir

Hepatitis C virus (HCV) is genetically diverse and includes 7 genotypes and 67 confirmed subtypes, and the global distribution of each HCV genotype (GT) varies by geographic region. In this report, we utilized a large dataset of NS3/4A and NS5A sequences isolated from 2348 HCV GT1-6-infected patients treated with the regimen containing glecaprevir/pibrentasvir (GLE/PIB) to assess genetic diversity within HCV subtypes by geographic region using phylogenetic analyses, and evaluated the prevalence of baseline amino acid polymorphisms in NS3 and NS5A by region/country and phylogenetic cluster. Among 2348 NS3/4A and NS5A sequences, phylogenetic analysis identified 6 genotypes and 44 subtypes, including 3 GT1, 8 GT2, 3 GT3, 13 GT4, 1 GT5, and 16 GT6 subtypes. Phylogenetic analysis of HCV subtype 1a confirmed the presence of two clades, which differed by geographic region distribution and NS3 Q80K prevalence. We detected phylogenetic clustering by country in HCV subtypes 1a, 1b, 2a, 2b, and 5a, suggesting that genetically distinct virus lineages are circulating in different countries. In addition, two clades were detected in HCV GT4a and GT6e, and NS5A amino acid polymorphisms were differentially distributed between the 2 clades in each subtype. The prevalence of NS3 and NS5A baseline polymorphisms varied substantially by genotype and subtype; therefore, we also determined the activity of GLE or PIB against replicons containing NS3/4A or NS5A from HCV GT1-6 clinical samples representing 6 genotypes and 21 subtypes overall. GLE and PIB retained activity against the majority of HCV replicons containing NS3/4A or NS5A from HCV GT1-6 clinical samples, with a median EC50 of 0.29 nM for GLE and 1.1 pM for PIB in a transient replicon assay. The data presented in this report expands the available data on HCV epidemiology, subtype diversity by geographic region, and NS3 and NS5A baseline polymorphism prevalence.

Effectiveness and cost-effectiveness of interventions targeting harm reduction and chronic hepatitis C cascade of care in people who inject drugs: The case of France

Direct-acting antivirals (DAAs) represent an opportunity to improve hepatitis C virus (HCV) care cascade. This combined with improved harm reduction interventions may lead to HCV elimination especially in people who inject drugs (PWID). We assessed the effectiveness/cost-effectiveness of improvements in harm reduction and chronic hepatitis C (CHC) care cascade in PWID in France. We used a dynamic model of HCV transmission and CHC natural history and evaluated the following: improved needle/syringe programmes-opioid substitution therapies, faster diagnosis/linkage to care, earlier treatment initiation, alone and in combination among active PWID (mean age = 36). Outcomes were as follows: life expectancy in discounted quality-adjusted life years (QALYs); direct lifetime discounted costs; incremental cost-effectiveness ratio (ICER); number of infections/reinfections. Under the current practice, life expectancy was 15.846 QALYs, for a mean lifetime cost of €20 762. Treatment initiation at F0 fibrosis stage alone was less effective and more costly than faster diagnosis/linkage to care combined with treatment initiation at F0, which increased life expectancy to 16.694 QALYs, decreased new infections by 37%, with a ICER = €5300/QALY. Combining these interventions with harm reduction improvements was the most effective scenario (life expectancy = 16.701 QALYs, 41% decrease in new infections) but was not cost-effective (ICER = €105 600/QALY); it became cost-effective with higher initial HCV incidence rates and lower harm reduction coverage than in our base-case scenario. This study illustrated the high effectiveness, and cost-effectiveness, of a faster diagnosis/linkage to care together with treatment from F0 with DAAs. This "Test and treat" strategy should play a central role both in improving the life expectancies of HCV-infected patients, and in reducing HCV transmission.

Expert opinion on the management of hepatitis C infection in Kuwait

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

Ribavirin dose management in HCV patients receiving ombitasvir/paritaprevir/ritonavir and dasabuvir with ribavirin

BACKGROUND & AIMS

Some individuals with hepatitis C virus infection treated with direct-acting antivirals require ribavirin to maximize sustained virological response rates. We describe the clinical management of ribavirin dosing in hepatitis C virus-infected patients receiving ombitasvir/paritaprevir/ritonavir and dasabuvir with ribavirin.

METHODS

We performed a post hoc analysis of patients receiving ombitasvir/paritaprevir/ritonavir and dasabuvir with ribavirin for 12 or 24 weeks in six phase 3 trials. Multivariate stepwise logistic regression models assessed predictors associated with ribavirin dose adjustments and with developing anaemia.

RESULTS

Of 1548 patients, 100 (6.5%) modified ribavirin dose due to haemoglobin declines, of which 99% achieved sustained virological response at 12 weeks post-treatment. Median time to first ribavirin dose reduction was 37 days. Low baseline haemoglobin was significantly associated with an increased risk of requiring ribavirin dose modification (odds ratio: 0.618 [0.518, 0.738]; P < .001) and developing anaemia (odds ratio: 0.379 [0.243, 0.593]; P < .001).

CONCLUSIONS

Ribavirin dose reductions were infrequent, occurred early in treatment, and did not impact sustained virological response at 12 weeks post-treatment. Patients with low baseline haemoglobin should be monitored for on-treatment anaemia.

Molecular Mechanism of Resistance in a Clinically Significant Double-Mutant Variant of HCV NS3/4A Protease

Despite significant progress in hepatitis C virus (HCV) protease inhibitor (PI) drug design, resistance remains a problem causing treatment failure. Double-substitution variants, notably Y56H/D168A, have emerged in patients who fail therapy with a PI-containing regimen. The resistance conferred by Asp168 substitutions has been well characterized and avoided in newer inhibitors. However, an additional mutation at Tyr56 confers resistance to even the most robust inhibitors. Here, we elucidate the molecular mechanisms of resistance for the Y56H/D168A variant against grazoprevir (and four analogs), paritaprevir, and danoprevir through inhibition assays, co-crystal structures, and molecular dynamics simulations. The PIs' susceptibility to Y56H/D168A varies, with those stacking on the catalytic His57 losing the most potency. For such inhibitors, the Y56H substitution disrupts favorable stacking interactions with the neighboring catalytic His57. This indirect mechanism of resistance threatens to cause multi-PI failure as all HCV PIs in clinical development rely on interactions with the catalytic triad.

Pretreatment Hepatitis C Virus NS5A/NS5B Resistance-Associated Substitutions in Genotype 1 Uruguayan Infected Patients

Hepatitis C Virus (HCV) infection treatment has dramatically changed with the advent of direct-acting antiviral agents (DAAs). However, the efficacy of DAAs can be attenuated by the presence of resistance-associated substitutions (RASs) before and after treatment. Indeed, RASs detected in DAA treatment-naïve HCV-infected patients could be useful for clinical management and outcome prediction. Although the frequency of naturally occurring HCV NS5A and NS5B RASs has been addressed in many countries, there are only a few reports on their prevalence in the South American region. The aim of this study was to investigate the presence of RASs to NS5A and NS5B inhibitors in a DAA treatment naïve cohort of Uruguayan patients infected with chronic hepatitis C and compare them with reports from other South American countries. Here, we found that naturally occurring substitutions conferring resistance to NS5A and NS5B inhibitors were present in 8% and 19.2%, respectively, of treatment-naïve HCV genotype 1 infected patients. Importantly, the baseline substitutions in NS5A and NS5B herein identified differ from the studies previously reported in Brazil. Furthermore, Uruguayan strains subtype 1a clustered within all major world clades, showing that HCV variants currently circulating in this country are characterized by a remarkable genetic diversity.

Direct-acting antiviral drugs for chronic hepatitis C and risk of major vascular events: a systematic review

Direct-acting antiviral drugs (DAAs) were recently approved for treating hepatitis C virus-related chronic hepatitis. As advanced chronic liver disease may predispose patients to thrombotic events, it is still uncertain whether DAAs may influence the actual risk of major arterial and venous thrombotic events. We performed a systematic review to assess the incidence of major vascular events in patients receiving DAAs for HCV chronic hepatitis during phase-III randomized controlled trials (RCTs). Two reviewers identified studies through Pubmed database until October 2015. Reporting and incidence of any vascular events were compared with reporting and incidence of major bleeding, anemia (a prespecified safety outcome) and headache (a common non-prespecified safety outcome). 33 RCTs, encompassing 14,764 patients, were included. Only 13 (39%) and 4 (12%) RCTs provide data on any arterial or venous events, respectively. Occurrence of anemia and headache is reported in all studies. Crude unweighted rate of major arterial events is 0.16% (95% CI 0.10-0.24) of the total included population and 0.47% in those 13 RCTs reporting data. Crude unweighted rate of major venous events is 0.03% of the total included population (95% CI 0.01-0.08) and 0.22% in those four RCTs reporting data. Crude unweighted rate of major bleeding is 0.07% (95% CI 0.03-0.1). Incidence of thrombotic events in HCV patients receiving DAAs may be low, but an incorrect estimation cannot be excluded.

Community-based provision of direct-acting antiviral therapy for hepatitis C: study protocol and challenges of a randomized controlled trial

BACKGROUND

To achieve the World Health Organization hepatitis C virus (HCV) elimination targets, it is essential to increase access to treatment. Direct-acting antiviral (DAA) treatment can be provided in primary healthcare services (PHCS), improving accessibility, and, potentially, retention in care. Here, we describe our protocol for assessing the effectiveness of providing DAAs in PHCS, and the impact on the HCV care cascade. In addition, we reflect on the challenges of conducting a model of care study during a period of unprecedented change in HCV care and treatment.

METHODS

Consenting patients with HCV infection attending 13 PHCS in Australia or New Zealand are randomized to receive DAA treatment at the local tertiary institution (standard care arm), or their PHCS (intervention arm). The primary endpoint is the proportion commenced on DAAs and cured. Treatment providers at the PHCS include: hepatology nurses, primary care practitioners, or, in two sites, a specialist physician. All PHCS offer opioid substitution therapy.

DISCUSSION

The Prime Study is the first real-world, randomized, model of care study exploring the impact of community provision of DAA therapy on HCV-treatment uptake and cure. Although the study has faced challenges unique to this period of time characterized by changing treatment and service delivery, the data gained will be of critical importance in shaping health service policy that enables the elimination of HCV.

TRIAL REGISTRATION

ClinicalTrials.gov , ID: NCT02555475 . Registered on 15 September 2015.

Clinical Pharmacokinetics of Paritaprevir

Paritaprevir is a potent hepatitis C virus (HCV) nonstructural (NS) protein 3/4A protease inhibitor that is used in combination with other direct-acting antivirals (DAAs) for the treatment of chronic HCV infection. Paritaprevir is primarily metabolized by cytochrome P450 (CYP) 3A4 and is administered with a low dose of ritonavir to achieve drug concentrations suitable for once-daily dosing. Coadministration of paritaprevir with ritonavir increases the half-life of single-dose paritaprevir from approximately 3 h to 5-8 h, doubles the time to maximum plasma concentration (T _max) from 2.3 to 4.7 h, and increases exposures 30-fold for maximum observed plasma concentration (C _max), 50-fold for area under the plasma concentration-time curve (AUC), and >300-fold for trough concentration (C ₂₄). Paritaprevir displays highly variable, nonlinear pharmacokinetics, with C _max and AUC increasing in a greater than dose proportional manner when administered with or without ritonavir. In the presence of ritonavir, paritaprevir is excreted mostly unchanged in feces via biliary excretion. Paritaprevir exposures are higher in Japanese subjects compared with Caucasian subjects; however, no dose adjustment is needed for Japanese patients as the higher exposures are safe and well tolerated. The pharmacokinetic characteristics of paritaprevir are similar between healthy subjects and HCV-infected patients, and are not appreciably altered by mild or moderate hepatic impairment or mild, moderate, or severe renal impairment, including those on dialysis. Paritaprevir exposures are increased in patients with severe hepatic impairment. Although the presence of a low dose of ritonavir in paritaprevir-containing regimens increases the likelihood of drug-drug interactions, results from several drug interaction studies demonstrated that paritaprevir-containing regimens can be coadministered with many comedications that are commonly prescribed in HCV-infected patients.

Clinical Pharmacokinetics of Dasabuvir

Dasabuvir is a nonstructural (NS) 5B non-nucleoside inhibitor of the hepatitis C virus (HCV) used in combination with ombitasvir/paritaprevir/ritonavir for the treatment of chronic HCV infection. It is primarily metabolized by cytochrome P450 (CYP) 2C8, with a minor contribution from CYP3A. Biotransformation of dasabuvir forms the M1 metabolite, which retains antiviral activity. Dasabuvir exhibits linear pharmacokinetics with a terminal half-life of approximately 5-8 h, allowing for twice-daily dosing. The M1 metabolite of dasabuvir is the major metabolite in plasma and has a half-life similar to that of dasabuvir. Dasabuvir exposures in Asian subjects are comparable with Caucasian subjects. The pharmacokinetic characteristics of dasabuvir are similar between healthy subjects and HCV-infected patients, and are not appreciably altered by mild, moderate, or severe renal impairment or dialysis. Dasabuvir pharmacokinetic parameters were not significantly altered in subjects with mild or moderate hepatic impairment; however, exposures were significantly increased in subjects with severe hepatic impairment. Dasabuvir should be administered with food to maximize absorption. Coadministration of dasabuvir with a strong CYP2C8 inhibitor increased dasabuvir exposures by greater than tenfold, whereas coadministration with strong CYP3A inhibitors increased dasabuvir exposures by less than 50%. Furthermore, coadministration of dasabuvir with a CYP3A inducer decreased dasabuvir exposures by 55-70%. Coadministration of dasabuvir with strong CYP2C8 inhibitors or strong CYP3A/CYP2C8 inducers is contraindicated. Results from several drug interaction studies demonstrated that dasabuvir in combination with ombitasvir/paritaprevir/ritonavir can be coadministered with most comedications that are commonly prescribed in HCV-infected patients.

The Mexican consensus on the treatment of hepatitis C

The aim of the Mexican Consensus on the Treatment of HepatitisC was to develop clinical practice guidelines applicable to Mexico. The expert opinion of specialists in the following areas was taken into account: gastroenterology, infectious diseases, and hepatology. A search of the medical literature was carried out on the MEDLINE, EMBASE, and CENTRAL databases through keywords related to hepatitisC treatment. The quality of evidence was subsequently evaluated using the GRADE system and the consensus statements were formulated. The statements were then voted upon, using the modified Delphi system, and reviewed and corrected by a panel of 34 voting participants. Finally, the level of agreement was classified for each statement. The present guidelines provide recommendations with an emphasis on the new direct-acting antivirals, to facilitate their use in clinical practice. Each case must be individualized according to the comorbidities involved and patient management must always be multidisciplinary.

Pharmacokinetic and pharmacodynamic evaluation of daclatasvir, asunaprevir plus beclabuvir as a fixed-dose co-formulation for the treatment of hepatitis C

INTRODUCTION

Many reports have evaluated the clinical efficacy and safety of the fixed-dose all-oral combination of daclatasvir, asunaprevir, and beclabuvir (DCV-TRIO), which was approved in Japan in December 2016 for the treatment of hepatitis C genotype (GT)-1 infection. Areas covered: This article reviews the pharmacodynamic and pharmacokinetic properties of the DCV-TRIO combination. The topics covered include data regarding the drug's absorption, distribution, metabolism, excretion, and antiviral activity strategies. Its therapeutic efficacy and safety in GT-1 infection from phase 2/3 clinical trials are also discussed. Expert opinion: The ideal regimen for the treatment of Hepatitis C virus infection should be potent, pangenotypic, Ribavirin-free, safe, co-formulated, and affordable. Considering these characteristics, DCV-TRIO is neither pangenotypic nor potent enough against GT-1a, regardless of the presence or absence of cirrhosis. Other potential limitations of this regimen are its dosification (twice-daily), and the fact that since it includes a protease inhibitor, it is contraindicated in decompensated cirrhosis. For these reasons, it has only been approved in Japan, where more than 70% of the patients are infected with GT-1b. However, this co-formulation might still have a place in the treatment of non-cirrhotic patients infected with GT-1b provided that massive access to treatment is facilitated.

Efficacy and safety of ombitasvir/paritaprevir/ritonavir combination therapy for genotype 1b chronic hepatitis C patients complicated with chronic kidney disease

AIM

The aim of this study was to clarify the effects and safety of ombitasvir/paritaprevir/ritonavir (OBT/PTV/r) therapy in genotype 1b chronic hepatitis C patients with non-dialysis chronic kidney disease (CKD).

METHODS

This retrospective, multicenter study of 12-week OBT/PTV/r therapy included genotype 1b patients with non-dialysis CKD. Chronic kidney disease was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 . Virologic responses and treatment-emergent adverse events (TEAEs) in patients with CKD were compared with those in patients without CKD.

RESULTS

Two hundred and thirty-five patients with a median age of 67 years (range, 27-89 years) were enrolled, consisting of 181 patients without CKD and 54 patients with CKD. Overall, the rates of rapid virologic response (RVR), end of treatment response (ETR), and sustained virologic response (SVR) were 78.7%, 98.7%, and 98.7%, respectively. Among the 181 non-CKD patients, the rates were 77.3% (140/181), 98.9% (179/181), and 98.9% (179/181), respectively. Among the 54 CKD patients, the rates were 83.3% (45/54), 98.1% (53/54), and 98.1% (53/54), respectively. There were no significant differences in the virologic response rates between the two groups (P = 0.449 for RVR, 0.545 for ETR, and 0.545 for SVR). In the CKD group, the eGFR level did not significantly change throughout the treatment period. There was no significant difference in the incidence of TEAEs or treatment discontinuation due to TEAEs between the two groups.

CONCLUSION

The present study showed that the effects and safety of OBV/PTV/r therapy in genotype 1b chronic hepatitis C patients with non-dialysis CKD were not inferior to those in patients without CKD.

Impact of hepatitis C virus polymorphisms on direct-acting antiviral treatment efficacy: Regulatory analyses and perspectives

Several highly effective, interferon-free, direct-acting antiviral (DAA)-based regimens are available for the treatment of chronic hepatitis C virus (HCV) infection. Despite impressive efficacy overall, a small proportion of patients in registrational trials experienced treatment failure, which in some cases was associated with the detection of HCV resistance-associated substitutions (RASs) at baseline. In this article, we describe methods and key findings from independent regulatory analyses investigating the impact of baseline nonstructural (NS) 3 Q80K and NS5A RASs on the efficacy of current United States Food and Drug Administration (FDA)-approved regimens for patients with HCV genotype (GT) 1 or GT3 infection. These analyses focused on clinical trials that included patients who were previously naïve to the DAA class(es) in their investigational regimen and characterized the impact of baseline RASs that were enriched in the viral population as natural or transmitted polymorphisms (i.e., not drug-selected RASs). We used a consistent approach to optimize comparability of results across different DAA regimens and patient populations, including the use of a 15% sensitivity cutoff for next-generation sequencing results and standardized lists of NS5A RASs. These analyses confirmed that detection of NS3 Q80K or NS5A baseline RASs was associated with reduced treatment efficacy for multiple DAA regimens, but their impact was often minimized with the use of an intensified treatment regimen, such as a longer treatment duration and/or addition of ribavirin. We discuss the drug resistance-related considerations that contributed to pretreatment resistance testing and treatment recommendations in drug labeling for FDA-approved DAA regimens.

CONCLUSION

Independent regulatory analyses confirmed that baseline HCV RASs can reduce the efficacy of certain DAA-based regimens in selected patient groups. However, highly effective treatment options are available for patients with or without baseline RASs. (Hepatology 2018;67:2430-2448).

Paritaprevir/ritonavir/ombitasvir plus dasabuvir with ribavirin for treatment of recurrent chronic hepatitis C genotype 1 infection after liver transplantation: Real-world experience

BACKGROUND/AIMS

The registered trial has demonstrated that paritaprevir/ritonavir/ombitasvir plus dasabuvir (PrOD) with ribavirin was effective for recurrent hepatitis C virus genotype 1 (HCV-1) infection after liver transplantation in patients with mild fibrosis; however, the real-world efficacy and safety of this regimen have not been determined.

METHODS

The efficacy (sustained virological response, SVR12, undetectable HCV RNA 12 weeks post-treatment) and safety were evaluated in 12 patients with recurrent HCV-1 infection after liver transplantation.

RESULTS

Nine patients were treated for 24 weeks, and three patients (two treatment-naïve patients and one interferon-intolerant patient) were treated for 12 weeks. HCV RNA was undetectable at treatment day 1, week 1, week 4, week 12, and at the end of treatment in 8.3% (n = 1), 25% (n = 3), 83.3% (n = 10), 100% (n = 12), and 100% (n = 12) of patients, respectively. All twelve patients achieved SVR12. Treatment was temporarily stopped in one patient because of leucopenia. The other patient with minimal fibrosis experienced an elevation in alanine aminotransferase concentration, which returned to normal levels after dose reduction. Seven (58.3%) patients required RBV dose reduction and two (16.7%) required transient RBV discontinuation during treatment. There were no serious adverse events, and most adverse events were related to ribavirin. No patient developed graft rejection or deterioration in hepatic or renal function during treatment. Treatment efficacy and safety were comparable between patients with and without advanced liver fibrosis.

CONCLUSION

PrOD plus ribavirin had a highly satisfactory real-world efficacy and safety profile in the treatment of recurrent HCV-1 infection after liver transplantation in Asian patients.

Reduced ITPase activity and favorable IL28B genetic variant protect against ribavirin-induced anemia in interferon-free regimens

BACKGROUND

Genetic variants of inosine triphosphatase (ITPA) that confer reduced ITPase activity are associated with protection against ribavirin(RBV)-induced hemolytic anemia in peginterferon(IFN)/RBV-based treatment of hepatitis C virus (HCV). Patients with reduced ITPase activity showed improved treatment efficacy when treated with IFN/RBV. In addition, a genetic polymorphism near the IL28B gene is associated with an improved response to IFN/RBV treatment. RBV has been an important component of IFN-containing regimens, and is currently recommended in combination with several IFN-free regimens for treatment of harder to cure HCV infections.

AIM

To evaluate whether genetic variations that reduce ITPase activity impact RBV-induced anemia in IFN-free/RBV regimens.

METHODS

In this study, genetic analyses were conducted in the PEARL-IV trial to investigate the effect of activity-reducing ITPA variants as well as IL28B polymorphism on anemia, platelet (PLT) counts, and virologic response in HCV genotype1a-infected patients treated with the direct-acting antiviral (DAA) regimen of ombitasvir/paritaprevir/ritonavir and dasabuvir±RBV.

RESULTS

Reduction in ITPase activity and homozygosity for the IL28Brs12979860 CC genotype protected against RBV-induced anemia. In patients receiving RBV, reduced ITPase activity was associated with reduced plasma RBV concentration and higher PLT counts. ITPase activity had no impact on response to DAA treatment, viral kinetics, or baseline IP-10 levels.

CONCLUSIONS

Our study demonstrates that genetics of ITPA and IL28B may help identify patients protected from RBV-induced anemia when treated with IFN-free regimens. Our work demonstrates for the first time that IL28B genetics may also have an impact on RBV-induced anemia. This may be of particular significance in patients with difficult-to-cure HCV infections, such as patients with decompensated cirrhosis where RBV-containing regimens likely will continue to be recommended.

Utilizing Clinical Pharmacist Specialist to Manage Hepatitis C Virus Patients on Direct-Acting Antiviral Therapy

OBJECTIVES

To evaluate outcomes of a clinical pharmacist specialist (CPS)-managed hepatitis C virus (HCV) treatment clinic (HCVTC) in treating HCV-infected veterans with direct-acting antivirals (DAAs).

METHODS

We established a CPS-managed HCVTC under a collaborative practice agreement with our infectious disease physician (IDP). A total of 132 veterans were treated between November 1, 2014, and November 30, 2015. The CPS engaged in pretreatment screening, drug selection, patient education, medication counseling, drug therapy monitoring, drug utilization review, addressing issues on drug adherence, and routine and posttreatment follow-up of patients to assess sustained virologic response (SVR) after 12 weeks of treatment.

RESULTS

Of 132 patients managed by the CPS, 87 (66%) were treated with ledipasvir/sofosbuvir (LDV/SOF), 29 (22%) with paritaprevir/ritonavir/ombitasvir + dasabuvir (PrOD), and 16 (12%) with sofosbuvir (SOF)-based regimen. The corresponding regimens demonstrated a SVR rate of 92% (n = 80), 100% (n = 29), and 93.8% (n = 15), respectively. We achieved an SVR rate of 94% against HCV genotype 1 (GT-1) and 100% against GT-2 to GT-4. The overall SVR rate was 94% across regimens, showing 93% in treatment-naive patients and 96% in treatment-experienced patients, and 93% in noncirrhotic and 94% in compensated cirrhotic patients. The results were comparable to SVR data reported in pivotal trials for DAAs.

CONCLUSION

The results suggest that CPS could be effectively utilized in drug therapy management of HCV-infected patients treated with DAAs.

Potential drug-drug interactions of OMBITASVIR, PARITAPREVIR/ritonavir ± DASABUVIR ± ribavirin in clinical practice

BACKGROUND & AIMS

Drug-drug interactions (DDIs) with ombitasvir/paritaprevir/ritonavir with or without dasabuvir and with or without ribavirin (OBV/PTV/r ± DSV ± RBV) are common in clinical trials. Our aim was to analyze the prevalence and management of potential DDIs and adverse events (AEs) related to DDIs in patients with chronic hepatitis C (CHC) receiving OBV/PTV/r ± DSV ± RBV in clinical practice.

METHODS

177 CHC patients started OBV/PTV/r ± DSV ± RBV in 4 Spanish hospitals and were screened for potential DDIs using the University of Liverpool database. Patients were classified according to the most serious potential DDIs at baseline and AEs during therapy.

RESULTS

At least one potential DDI was found in 110 (62.1%) patients: 100 (56.5%) had at least one manageable potential DDI and 10 (5.6%) at least one contraindicated. Patients with potential DDIs were receiving a higher number of concomitant drugs (4 vs. 2, P < 0.001). Routine medication was modified at baseline due to potential DDIs in 49 (27.7%) patients. During antiviral treatment, 67 (37.9%) patients presented at least one AE. In 9 (4.5%) patients, a DDI was suspected between OBV/PTV/r ± DSV ± RBV and the concomitant drug, requiring antiviral discontinuation in 4 patients.

CONCLUSIONS

Potential DDIs are frequent with OBV/PTV/r ± DSV ± RBV, although a change in baseline medication is made in only one-quarter of patients. More than half of potential DDIs were only followed, and only 5% of patients developed AEs in which the implication of DDIs could not be excluded.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Sofosbuvir and velpatasvir with or without voxilaprevir in direct-acting antiviral-naïve chronic hepatitis C: patient-reported outcomes from POLARIS 2 and 3

BACKGROUND

Chronic hepatitis C infection leads to impairment of patient-reported outcomes (PROs). Treatment with direct-acting antiviral regimens results in short- and long-term improvement of these outcomes.

AIM

To assess PROs in patients treated with a newly developed direct-acting antiviral, a fixed-dose combination of sofosbuvir/velpatasvir (SOF/VEL) with/without voxilaprevir (VOX).

METHODS

The PRO data were collected from participants of POLARIS-2 and POLARIS-3 clinical trials (DAA-naïve, all HCV genotypes). Participants self-administered SF-36v2, FACIT-F, CLDQ-HCV and WPAI:SHP instruments at baseline, during treatment, and in follow-up.

RESULTS

Of 1160 patients, 611 received SOF/VEL/VOX and 549 received SOF/VEL (52.8 ± 11.0 years, 55.9% male, 75.4% treatment-naïve, 33.9% cirrhotic). The sustained viral response at 12 weeks (SVR12) rates were 95%-98%. During treatment, improvements in most PRO scores were significant (all but one P < .01) and ranged from, on average, +2.3 to +15.0 points (on a 0-100 scale) by the end of treatment. These improvements were similar between SOF/VEL/VOX and SOF/VEL arms (all P > .05). After treatment discontinuation, patients treated with both regimens achieved significant and clinically meaningful PRO gains (+2.7 to +16.7 by post-treatment week 12, +3.9 to +20.1 by post-treatment week 24; all but one P < .001). Multivariate analysis showed that depression, anxiety and cirrhosis were the most consistent independent predictors of PRO impairment while no association of PROs with the treatment regimen choice was found (all P > .05).

CONCLUSIONS

The pan-genotypic regimens with SOF/VEL with or without VOX not only have excellent efficacy and safety, but also significantly positively impact patients' experience both during treatment and after achieving sustained virologic response in DAA-naïve patients with HCV.

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.