1418 DACLATASVIR COMBINED WITH PEGINTERFERON ALFA-2A AND RIBAVIRIN FOR 12 OR 16 WEEKS IN PATIENTS WITH HCV GENOTYPE 2 OR 3 INFECTION: COMMAND GT2/3 STUDY

A Closing Chapter: Hepatitis C Genotype 3 Elimination in Liver Transplant; Sofosbuvir/Daclatasvir in a Hard-to-Treat Population

OBJECTIVES

Historically, hepatitis C virus genotype 3 infection has not been as hard to treat as genotype 1 using interferon-based therapy. Now, genotype 3 infection can be treated using interferon-free regimes such as the combination of sofosbuvir and daclatasvir, which is a highly successful and reliable therapeutic option before liver transplant. However, real world data are rather limited regarding the use of antivirals (sofosbuvir/daclatasvir) for hepatitis C virus genotype 3 recurrence after liver transplant. Here, we present the results of antiviral treatment with sofosbuvir and daclatasvir in patients with genotype 3 recurrence after liver transplant and also viewed published data, to finally close the chapter on genotype 3 elimination.

MATERIALS AND METHODS

We analyzed 11 patients who received liver transplants due to hepatitis C virus genotype 3-associated cirrhosis at our center. Two patients were nadve for any antiviral therapy. All patients received antiviral treatment with sofosbuvir/daclatasvir for 12 weeks after liver transplant, with 1 patient also having ribavirin. The endpoint was hepatitis C virus RNA-free survival after 12 weeks of therapy. Secondary endpoints were preservation of renal and liver function and incidence of adverse events.

RESULTS

All patients were free of hepatitis C virus RNA by at least 8 weeks after therapy initiation. Elevated transaminases and gamma-glutamyltransferase at the beginning of therapy normalized quickly during treatment. Synthesis and excretion were stable at all dates. Patients displayed no severe adverse effects, especially regarding renal function and blood counts. Sustained virologic response rates at week 12 were achieved in all 11 patients.

CONCLUSIONS

Hepatitis C virus could be eliminated in all patients after liver transplant with 12-week sofosbuvir/daclatasvir therapy. Sofosbuvir combined with daclatasvir is safe and reliable for recurrent hepatitis C virus genotype 3 infection. Our results have closed the chapter on genotype 3 recurrence after liver transplant in our outpatient clinic.

Chronic hepatitis C: This and the new era of treatment

Over the last years it has started a real revolution in the treatment of chronic hepatitis C. This occurred for the availability of direct-acting antiviral agents that allow to reach sustained virologic response in approximately 90% of cases. In the near future further progress will be achieved with the use of pan-genotypic drugs with high efficacy but without side effects.

Mechanisms of Hepatitis C Viral Resistance to Direct Acting Antivirals

There has been a remarkable transformation in the treatment of chronic hepatitis C in recent years with the development of direct acting antiviral agents targeting virus encoded proteins important for viral replication including NS3/4A, NS5A and NS5B. These agents have shown high sustained viral response (SVR) rates of more than 90% in phase 2 and phase 3 clinical trials; however, this is slightly lower in real-life cohorts. Hepatitis C virus resistant variants are seen in most patients who do not achieve SVR due to selection and outgrowth of resistant hepatitis C virus variants within a given host. These resistance associated mutations depend on the class of direct-acting antiviral drugs used and also vary between hepatitis C virus genotypes and subtypes. The understanding of these mutations has a clear clinical implication in terms of choice and combination of drugs used. In this review, we describe mechanism of action of currently available drugs and summarize clinically relevant resistance data.

New treatment strategies for hepatitis C infection

Hepatitis C infection can lead to cirrhosis and hepatocellular carcinoma and it is an important cause of mortality and morbidity. Achieving a sustained virological response has been the major aim for decades. Interferon treatment was the primarily developed therapy against the infection. Addition of the guanosine analog ribavirin to stop viral RNA synthesis increased the response rates as well as the adverse effects of the treatment. The increasing demands for alternative regimens led to the development of direct-acting antivirals (DAAs). The approval of sofosbuvir and simeprevir signaled a new era of antiviral treatment for hepatitis C infection. Although the majority of studies have been performed with DAAs in combination with interferon and resulted in a decrease in treatment duration and increase in response rates, the response rates achieved with interferon-free regimens provided hope for patients ineligible for therapy with interferon. Most DAA studies are in phase II leading to phase III. In the near future more DAAs are expected to be approved. The main disadvantage of the therapy remains the cost of the drugs. Here, we focus on new treatment strategies for hepatitis C infection as well as agents targeting hepatitis C virus replication that are in clinical development.

A randomized, placebo-controlled study of the NS5B inhibitor beclabuvir with peginterferon/ribavirin for HCV genotype 1

Beclabuvir is a potent, non-nucleoside inhibitor of the HCV NS5B RNA polymerase, with nanomolar activity against HCV genotypes 1, 3, 4, 5 and 6 in vitro. This study evaluated the efficacy and safety of beclabuvir, in combination with peginterferon alfa-2a (pegIFN) and ribavirin (RBV), in HCV genotype 1. In this randomized (1:1:1), double-blinded, placebo-controlled, dose-ranging phase 2a study, 39 treatment-naive patients chronically infected with HCV genotype 1 were treated for 48 weeks with beclabuvir (75 mg or 150 mg) plus pegIFN (180 μg) and RBV (1000 mg/day [<75 kg] or 1200 mg/day [≥ 75 kg]) vs pegIFN/RBV alone. The primary efficacy endpoint of extended rapid virologic response (undetectable HCV RNA at treatment weeks 4 and 12) was achieved by 76.9% (10/13) of patients receiving beclabuvir 75 mg and 38.5% (5/13) receiving beclabuvir 150 mg vs 0% receiving pegIFN/RBV alone. Higher response rates were observed among patients receiving beclabuvir 75 mg for all secondary efficacy endpoints, including sustained virologic response at follow-up weeks 12 or 24. Three patients experienced virologic breakthrough on treatment, all in the beclabuvir 150-mg treatment group. Beclabuvir was well tolerated at both doses, with the most commonly observed adverse events (headache, fatigue, nausea, decreased appetite, irritability, depression and insomnia) consistent with those observed with pegIFN/RBV. In conclusion, beclabuvir was both effective and well tolerated when administered in combination with pegIFN/RBV for the treatment of chronic HCV GT 1, supporting the study of beclabuvir as part of an all-oral regimen for HCV GT1.

The pharmacokinetics of daclatasvir and asunaprevir administered in combination in studies in healthy subjects and patients infected with hepatitis C virus

BACKGROUND AND OBJECTIVES

The combination of direct-acting antiviral agents in patients with chronic hepatitis C virus (HCV) infection has demonstrated clinical benefit; however, evaluation of potential drug-drug interactions is required prior to therapy.

METHODS

An open-label study assessed the pharmacokinetics and tolerability of the HCV NS5A replication complex inhibitor daclatasvir and the HCV NS3 protease inhibitor asunaprevir when co-administered in healthy subjects. Daclatasvir 60 mg once daily and asunaprevir 600 mg twice daily were dosed for 7 days alone followed by combination dosing for 14 days at 30 mg once daily and 200 mg twice daily, respectively. Further assessments were provided comparing exposures from the current study with those from studies in HCV-infected patients receiving either the same or higher doses of daclatasvir or asunaprevir administered alone or together.

RESULTS

Dose-normalized daclatasvir and asunaprevir morning exposures were comparable with control in healthy subjects, with geometric mean area under the concentration-time curve ratios of 1.202 (90 % CI 1.113-1.298) and 0.868 (90 % CI 0.726-1.038), respectively. In HCV patients daclatasvir and asunaprevir exposures were largely comparable, when administered together or alone.

CONCLUSIONS

Additional data support the conclusion that there is no clinically meaningful interaction between daclatasvir and asunaprevir in either healthy subjects or HCV-infected patients, including those also receiving peginterferon-α/ribavirin, and that the combination of daclatasvir 60 mg once daily and asunaprevir 200 mg twice daily is generally well-tolerated.

Interferon-λ3 polymorphisms in pegylated-interferon-α plus ribavirin therapy for genotype-2 chronic hepatitis C

AIM

To evaluate interferon-λ3 (IFNL3) polymorphisms in response-guided pegylated interferon-α plus ribavirin (Peg-IFNα/RBV) therapy for genotype 2 (G2) chronic hepatitis C.

METHODS

Between January 2006 and June 2012, a total of 180 patients with chronic infections of G2 hepatitis C virus (HCV) were treated with response-guided Peg-IFNα/RBV therapy. The treatment duration was 24 wk for patients who achieved rapid virologic response (RVR), and 36 or 48 wk for patients who did not. Then, the impact of the IFNL3 single nucleotide polymorphism genotype (TT/non-TT at rs8099917) on treatment outcomes was evaluated in the 180 patients, and between patients infected with either HCV sub-genotype 2a or 2b.

RESULTS

Of the 180 patients evaluated, 111 achieved RVR, while the remaining 69 patients did not. In RVR patients, the sustained virologic response (SVR) rate was 96.4%, and the IFNL3 genotype did not influence the SVR rate (96.6% vs 95.8% in IFNL3 genotype TT vs non-TT). However, in non-RVR patients, the SVR rate decreased to 72.5% (P < 0.0001), and this rate was significantly different between the IFNL3 genotype TT and non-TT groups (80.0% vs 42.9%, P = 0.0146). Multivariate regression analysis in non-RVR patients identified the IFNL3 genotype TT as the only baseline-significant factor associated with SVR (OR = 5.39, 95%CI: 1.29-22.62; P = 0.0189). In analysis according to HCV sub-genotype, no significant difference in the SVR rate was found between HCV sub-genotypes 2a and 2b.

CONCLUSION

In response-guided Peg-IFNα/RBV combination therapy for chronically HCV G2-infected patients, the impact of the IFNL3 genotype on SVR was limited to non-RVR patients.

Hepatitis C

Hepatitis C virus (HCV) infection is a major health problem worldwide. The effects of chronic infection include cirrhosis, end-stage liver disease, and hepatocellular carcinoma. As a result of shared routes of transmission, co-infection with HIV is a substantial problem, and individuals infected with both viruses have poorer outcomes than do peers infected with one virus. No effective vaccine exists, although persistent HCV infection is potentially curable. The standard of care has been subcutaneous interferon alfa and oral ribavirin for 24-72 weeks. This treatment results in a sustained virological response in around 50% of individuals, and is complicated by clinically significant adverse events. In the past 10 years, advances in HCV cell culture have enabled an improved understanding of HCV virology, which has led to development of many new direct-acting antiviral drugs that target key components of virus replication. These direct-acting drugs allow for simplified and shortened treatments for HCV that can be given as oral regimens with increased tolerability and efficacy than interferon and ribavirin. Remaining obstacles include access to appropriate care and treatment, and development of a vaccine.

Hepatitis C virus genotype 3: a genotype that is not 'easy-to-treat'

The efficacy of antiviral treatment depends on which of the seven genotypes (G1-G7) of hepatitis C virus (HCV) has infected the patient. Conventionally, clinicians regarded G2 and G3 infections as 'easy-to-treat': dual therapy with pegylated interferon and ribavirin produces a sustained virologic response in approximately 40-50% of patients with G1 infection, compared with 80% when analyses report combined data for G2 and G3 patients, which is standard practice in many clinical studies. However, sustained virologic response rates appear to be lower in certain subgroups of people infected with G3 compared with those with G2 or the general HCV-infected population. This review examines the growing evidence that factors related to the virus (e.g., baseline viral load and a rapid virologic response) and host characteristics (e.g., steatosis and fibrosis, metabolic syndrome, host polymorphisms and ethnicity) contribute to variations in therapeutic success in G3 HCV.

Efficacy of new direct acting antivirals in transplant recipients and patients with advanced disease

The development of new direct acting antivirals constitutes a clinical revolution in the field of hepatitis C therapy and, most probably, in the history of Hepatology. Difficult-to-treat patients, such as cirrhotics or patients in the peri-transplant setting, will clearly benefit from these therapies, particularly from interferon-free all-oral combinations. However, despite the substantial improvement of the hepatitis C drug market, access to these therapies will likely be different around the world due to economic restrictions. This review aims to clarify the current stage of different antiviral strategies (with or without interferon) in these difficult populations by analysing specific efficacy and safety results in patients with cirrhosis, patients on the waiting list for liver transplantation and recipients with hepatitis C recurrence after liver transplantation. Hitherto, some important challenges still remain unanswered in these patients and will need to be assessed in clinical practice, such as the evaluation of safety and efficacy in advanced cirrhotic patients with portal hypertension, the impact (if any) of viral clearance on clinical outcomes in patients with decompensated liver disease, the role of ribavirin in all-oral combinations, the relevance of the development of multi-drug viral resistant strains and the drug-drug interaction profiles of these drugs, especially after liver transplantation.

[New direct-acting antiviral agents for the treatment of chronic hepatitis C in 2014]

BACKGROUND

The development of direct-acting antiviral agents (DAA) against the hepatitis C virus (HCV) has seen enormous progress in recent years. In 2011, the first protease inhibitors boceprevir (BOC) and telaprevir (TLV) were approved, which still need to be combined with pegylated interferon α (PEG-IFN α) and ribavirin (RBV) and are used only in patients with genotype 1. With sofosbuvir (SOF) and simeprevir (SMV), two new DAA are available. More DAA are in clinical development.

OBJECTIVES

Which changes in the treatment of chronic hepatitis C infection can be expected with the approval of the new DAA in 2014? Relevant phase IIb and phase III studies for the approval in 2014 were considered for drugs approved by the FDA or EMA at the editorial deadline.

CURRENT DATA

For patients with genotype 1, the combination of SOF, SMV or faldaprevir with PEG-IFN α and RBV was successfully evaluated in phase III studies. In contrast to previous treatment with PEG-IFN α, RBV and telaprevir (TLV) or boceprevir (BOC), therapy can be shortened in most cases with a significantly improved side-effect profile. Cure rates above 80 % are possible. Data are also available for an interferon-free therapy with either SOF and RBV or SOF and SMV in GT-1 patients. SVR rates exceeding 60 % and up to 90 % are possible. However, treatment experience with these combinations is low and an unrestricted interferon-free therapy for genotype 1 should not be expected before 2015. For patients with genotypes 2 and 3, valid data for interferon-free therapies are available. The combination of SOF and RBV for 12 weeks in genotype 2 and 24 weeks for genotype 3 is effective and shows equal or superior cure rates with fewer side effects than the PEG-IFN α/RBV therapy.

CONCLUSION

For patients with genotype 1, the duration of therapy can be further reduced with better side effect profile. In certain situations, therapy without PEG-IFN α is possible and should be considered. For patients with genotypes 2 and 3, an interferon-free therapy will be standard of care in 2014.

Update on hepatitis C virus resistance to direct-acting antiviral agents

Resistance to direct-acting antiviral (DAA) agents against hepatitis C virus (HCV) infection is driven by the selection of mutations at different positions in the NS3 protease, NS5B polymerase and NS5A proteins. With the exception of NS5B nucleos(t)ide inhibitors, most DAAs possess a low genetic barrier to resistance, with significant cross-resistance between compounds belonging to the same family. However, a specific mutation profile is associated with each agent or drug class and varies depending on the genotype/subtype (e.g., genotype 1b showed higher rates of sustained virological response (SVR) and a higher genetic barrier for resistance than genotype 1a). Moreover, some resistance mutations exist as natural polymorphisms in certain genotypes/subtypes at frequencies that require baseline drug resistance testing before recommending certain antivirals. For example, the polymorphism Q80K is frequently found among genotype 1a (19-48%) and is associated with resistance to simeprevir. Similarly, L31M and Y93H, key resistance mutations to NS5A inhibitors, are frequently found (6-12%) among NS5A genotype 1 sequences. In particular, the presence of these polymorphisms may be of relevance in poorly interferon-responsive patients (i.e., null responders and non-CC IL28B) under DAA-based therapies in combination with pegylated interferon-α plus ribavirin. The relevance of pre-existing resistance mutations for responses to interferon-free DAA therapies is unclear for most regimens and requires further study.

Is genotype 3 of the hepatitis C virus the new villain?

Genotype 3 of the hepatitis C virus (HCV) has been long considered an easy-to-treat infection, with higher cure rates (∼70%) than other viral genotypes with the standard combination of pegylated interferon-α and ribavirin. However, the relative insensitivity of this genotype to most protease inhibitors and the recent unexpected data on decreased effectiveness of sofosbuvir have raised questions on how to achieve universal cure, a goal that seems reasonable for other genotypes. In addition, increasing clinical and experimental data show that HCV genotype 3 may be associated not only with severe steatosis, but also with accelerated fibrosis progression rate and increased oncogenesis.

CONCLUSION

Currently available data suggest that we should increase our efforts to understand the virology and pathogenesis of HCV genotype 3, aiming at better and more potent, genotype-targeted treatments.

New hepatitis C therapies: the toolbox, strategies, and challenges

Therapy for hepatitis C is undergoing a revolution. Several new drugs against the hepatitis C virus (HCV) have reached the market and many others, including direct-acting antivirals and host-targeted agents, are in phase II or III clinical development. All-oral, interferon-free combinations of drugs are expected to cure more than 90% of infections. A vast amount of data from clinical trials are presented regularly at international conferences or released to the press before peer-review, creating confusion in the viral hepatitis field. The goal of this review is to clarify the current stage of HCV therapy and drug development. This review describes the different classes of drugs and their mechanisms and properties, as well as treatment strategies in development, including those that are interferon-based and interferon-free. HCV treatment options that will be available in 2014-2015 are presented for each genotype. A number of unanswered questions and challenges remain, such as how to treat special populations, the role of ribavirin in interferon-free regimens, the role of HCV resistance in treatment failures, and how to best re-treat patients who failed on treatment. Strategic choices, cost issues, HCV screening, and improving access to care in resource-constrained areas also are discussed.

Review article: HCV genotype 3 – the new treatment challenge

BACKGROUND

Over the past several years, hepatitis C therapy has been pegylated interferon and ribavirin based. Although protease inhibitor-based therapy has enhanced response rates in genotype 1, the recent advances in therapy have demonstrated a challenge in genotype 3, a highly prevalent infection globally.

AIM

To provide a comprehensive summary of the literature evaluating the unique characteristics and evolving therapies in genotype 3.

METHODS

A structured search in PubMed, the Cochrane Library and EMBASE was performed using defined key words, including only full text papers and abstracts in English.

RESULTS

HCV genotype 3 is more prevalent in Asia and among intra-venous drug users. Furthermore, it interferes with lipid and glucose metabolism, and the natural history involves a more rapid progression of liver disease and a higher incidence of hepatocellular carcinoma (HCC). New therapies with protease inhibitors have focused on genotype 1 largely and have demonstrated enhanced responses, but have limited activity against genotype 3. Thus far, in clinical trials, NS5B and NS5A inhibitors have performed more poorly in genotype 3, while a cyclophilin inhibitor, alisporivir, has shown promise.

CONCLUSIONS

As treatments for HCV have evolved, genotype 3 has become the most difficult to treat. Furthermore, genotype 3 has special characteristics, such as insulin resistance and alterations in lipid metabolism, which may partly explain the lower treatment responses. A great deal of emphasis on advancing therapy is needed in this population that appears to have a more rapid progression of liver disease and a higher incidence of HCC.

Randomized trial of daclatasvir and asunaprevir with or without PegIFN/RBV for hepatitis C virus genotype 1 null responders

BACKGROUND & AIMS

Patients with chronic hepatitis C virus (HCV) infection and prior null response (<2 log HCV RNA decline after ⩾ 12 weeks of PegIFN/RBV) have limited options. We evaluated daclatasvir plus once- or twice-daily asunaprevir in non-cirrhotic genotype 1 null responders.

METHODS

In this randomized, phase 2a, open-label, 24-week treatment study, 101 patients received daclatasvir (60 mg) once-daily. In addition, 38 genotype 1b patients received asunaprevir (200mg) twice- (DUAL A1) or once-daily (DUAL A2); 36 genotype 1a and 5 genotype 1b patients received asunaprevir twice- (QUAD B1) or once-daily (QUAD B2) plus PegIFN/RBV; and 18 genotype 1a and 4 genotype 1b patients received asunaprevir twice-daily plus ribavirin (TRIPLE B3). The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (sustained virologic response, SVR12).

RESULTS

Across all groups, mean HCV RNA was ⩾ 6 log IU/ml, and 99% of patients had a non-CC IL28B genotype. SVR12 rates were 78% (A1), 65% (A2), 95% (B1), and 95% (B2). In B3, most genotype 1a patients experienced virologic breakthrough. The most common adverse events were headache, diarrhea, and asthenia. Grade 3-4 aminotransferase elevations were infrequent and not treatment-limiting.

CONCLUSIONS

In genotype 1 null responders, daclatasvir plus twice-daily asunaprevir DUAL therapy is effective for most genotype 1b patients, and daclatasvir, asunaprevir, and PegIFN/RBV QUAD therapy is effective for nearly all genotype 1a and 1b patients; but neither DUAL nor TRIPLE therapy is effective for genotype 1a patients. Interferon-free regimens including daclatasvir and twice-daily asunaprevir for genotype 1 null responders should be tailored to subtype.

How to optimize current treatment of genotype 2 hepatitis C virus infection

The standard of care (SOC) for hepatitis C virus (HCV) genotype 2 is pegylated interferon (PEG-IFN) plus ribavirin (RBV). Even though most patients can be cured with this therapy after 24 weeks, tailoring treatment can improve its safety and efficacy in special populations. Thus, shortening treatment together with a weight-based RBV dosing approach has been considered satisfactory in patients with positive predictors of response. With the development of the direct antiviral agents (DAAs), shorter, better tolerated and more efficient treatments for HCV genotype 2 will become available, including interferon-free regimens. Until these new treatments are released, the decision to treat patients with HCV genotype 2 with currently approved drugs or to wait for future options must be made, taking into account the stage of fibrosis.

Treatment decisions and contemporary versus pending treatments for hepatitis C

The primary aim of antiviral therapy for chronic hepatitis C (CHC) is the prevention of progressive disease. A response to interferon (IFN) treatment is associated with an improvement in all-cause mortality and liver-related mortality from hepatitis C. Unless contraindicated, patients with CHC are thus potential candidates for treatment. Improved response rates are observed in patients with HCV genotype 1 infection treated with first-generation protease inhibitors. However, treatment with current first-generation protease inhibitors and IFN is complex and can result in appreciable adverse effects. The advent of potent, pan-genotypic all-oral direct-acting antiviral (DAA) regimens necessitates a critical examination of the immediate application of PEG-IFN, ribavirin and DAA regimens in patients with CHC. Current guidelines and position statements do not make clear recommendations, and are behind the emerging data. Some aspects of the conundrums facing physicians and patients are summarized in this Review. Cirrhosis presents an immediate threat of disease, and ideally treatment should be targeted at those patients who have advancing or advanced disease; unfortunately, a disparity exists, as response rates are reduced in patients with cirrhosis and the risks of adverse events are increased. On balance, patients with mild disease could consider deferring treatment.

NS5A inhibitor, daclatasvir, for the treatment of chronic hepatitis C virus infection

INTRODUCTION

Chronic Hepatitis C virus (HCV) infection is a major pandemic. The current standard of care includes peginterferon and ribavirin plus one of two protease inhibitors, boceprevir and telaprevir, for Genotype 1 patients and peginterferon and ribavirin for all other genotypes. The treatment landscape is rapidly evolving as a number of direct-acting antivirals (DAA) are being developed in clinical trials.

AREAS COVERED

Daclatasvir, formerly labeled BMS-790052, is a first-in-class HCV NS5A inhibitor that has been demonstrated in Phase I and II trials to have a very potent antiviral effect across all genotypes and to have a potent clinical efficacy in both treatment naive and experienced cohorts. This review covers the whole spectrum of development of daclatasvir from Phase I to III programs.

EXPERT OPINION

While daclatasvir has pangenotypic activity, it has a lower barrier to resistance in Genotype 1a but has been found to be very effective in Genotype 1b patients. However, Genotype 1a patients can be successfully treated with the addition of one or more DAAs alone or in combination with peginterferon and ribavirin. The future for daclatasvir and other DAAs is very encouraging in that all-oral therapies are likely to be effective and well-tolerated.