Boceprevir for previously treated chronic HCV genotype 1 infection

Boceprevir plus pegylated interferon/ribavirin to re-treat hepatitis C virus genotype 1 in HIV-HCV co-infected patients: final results of the Spanish BOC HIV-HCV Study

INTRODUCTION

Boceprevir (BOC) was one of the first oral inhibitors of hepatitis C virus (HCV) NS3 protease to be developed. This study assessed the safety and efficacy of BOC+pegylated interferon-α2a/ribavirin (PEG-IFN/RBV) in the retreatment of HIV-HCV co-infected patients with HCV genotype 1.

METHODS

This was a phase III prospective trial. HIV-HCV (genotype 1) co-infected patients from 16 hospitals in Spain were included. These patients received 4 weeks of PEG-IFN/RBV (lead-in), followed by response-guided therapy with PEG-IFN/RBV plus BOC (a fixed 44 weeks was indicated in the case of cirrhosis). The primary endpoint was the sustained virological response (SVR) rate at 24 weeks post-treatment. Efficacy and safety were evaluated in all patients who received at least one dose of the study drug.

RESULTS

From June 2013 to April 2014, 102 patients were enrolled, 98 of whom received at least one treatment dose. Seventy-three percent were male, 34% were cirrhotic, 23% had IL28b CC, 65% had genotype 1a, and 41% were previous null responders. The overall SVR rate was 67%. Previous null-responders and cirrhotic patients had lower SVR rates (57% and 51%, respectively). Seventy-six patients (78%) completed the therapy scheme; the most common reasons for discontinuation were lack of response at week 12 (12 patients) and adverse events (six patients).

CONCLUSIONS

Response-guided therapy with BOC in combination with PEG-IFN/RBV led to an overall SVR rate of 67%, but an SVR rate of only 51% in patients with cirrhosis. The therapy was generally well tolerated. Although the current standards of care do not include BOC+PEG-IFN/RBV, the authors believe that this combination can be beneficial in situations where new HCV direct antiviral agent interferon-free therapies are not available yet.

NS3 protease polymorphisms and genetic barrier to drug resistance of distinct hepatitis C virus genotypes from worldwide treatment-naïve subjects

Hepatitis C virus (HCV) NS3 protease inhibitors have been primarily designed against genotype 1, the one with the lowest response to dual therapy. However, less evidence of their efficacy on non-1 genotypes is available, and any such information is mostly concentrated on genotypes 2-4. This study evaluated HCV protease resistance profiles in the major six HCV genotypes and identified genetic barrier (GB) profiles to each available protease inhibitor across HCV strains from different locations worldwide. We obtained 15 099 HCV sequences from treatment-naïve subjects retrieved at the Los Alamos HCV Sequence Database. The wild-type codons of different HCV genotypes were used to analyse the smallest number of nucleotide substitution steps required for changing that codon to the closest one associated with drug resistance. The 36L and 175L RAVs were found as genetic signatures of genotypes 2-5, while the 80K RAV was found in all genotype 5 sequences. Genotypes 4 and 6 showed a higher GB to RAV mutations conferring resistance to telaprevir, while genotypes 2-5 presented baseline resistance to that drug, carrying the 36L mutation. Genotype 4 had a higher GB to simeprevir resistance, requiring three substitutions to acquire the 155K mutation. Subtype 1b showed a higher GB than subtype 1a to resistance for most PIs, with RAVs at codons 36 and 155. Geographic disparities were also found in frequencies of certain RAVs in genotypes 2 and 3. Under a scenario of unprecedented evolution of anti-HCV direct-acting agents, the genetic composition of the circulating HCV sequences should be evaluated worldwide to choose the most appropriate/feasible therapeutic schemes with the highest genetic barriers to resistance.

A phase 3, open-label study of daclatasvir plus asunaprevir in Asian patients with chronic hepatitis C virus genotype 1b infection who are ineligible for or intolerant to interferon alfa therapies with or without ribavirin

BACKGROUND AND AIM

Daclatasvir plus asunaprevir has demonstrated efficacy and safety in patients with chronic hepatitis C virus genotype 1b infection. This study focused on evaluating daclatasvir plus asunaprevir in interferon (±ribavirin)-ineligible or -intolerant Asian patients with genotype 1b infection from mainland China, Korea, and Taiwan.

METHODS

Interferon (±ribavirin)-ineligible and -intolerant patients with genotype 1b infection received daclatasvir 60 mg tablets once daily plus asunaprevir 100 mg soft capsules twice daily for 24 weeks. The primary endpoint was sustained virologic response at post-treatment week 24 (SVR24).

RESULTS

Of the 159 patients treated, 89.3% were Chinese, 65.4% were female, and 73.6% were interferon-intolerant. Cirrhosis was present in 32.7% of patients, and 40.3% had IL28B non-CC genotypes. SVR24 was achieved by 145/159 (91.2%) patients (100% concordance with SVR12) and was similarly high in cirrhotic patients (47/52, 90.4%). SVR24 was higher in patients without baseline NS5A (L31M or Y93H) resistance-associated variants (RAVs) (137/139, 98.6%), including those with cirrhosis (43/44, 97.7%). Prevalence of baseline NS5A RAVs was low (19/159, 11.9%), particularly in mainland China (10/127, 7.9%). One death (0.6%), five serious adverse events (3.1%), and three grade 4 laboratory abnormalities (1.9%) occurred on treatment; none were considered related to study drugs. Two patients (1.3%) discontinued because of adverse events. Treatment was generally well tolerated regardless of cirrhosis status.

CONCLUSIONS

Daclatasvir plus asunaprevir achieved a SVR24 rate of 91.2%, rising to 98.6% in patients without baseline NS5A RAVs, and was generally well tolerated in interferon (±ribavirin)-ineligible or -intolerant patients with genotype 1b infection from mainland China, Korea, and Taiwan.

Treatment of hepatitis C virus genotype 3 infection with direct-acting antiviral agents

Hepatitis C virus (HCV) genotype 3 is responsible for 30.1% of chronic hepatitis C infection cases worldwide. In the era of direct-acting antivirals, these patients have become one of the most challenging to treat, due to fewer effective drug options, higher risk of developing cirrhosis and hepatocellular carcinoma and lower sustained virological response (SVR) rates. Currently there are 4 recommended drugs for the treatment of HCV genotype 3: pegylated interferon (PegIFN), sofosbuvir (SOF), daclatasvir (DCV) and ribavirin (RBV). Treatment with PegIFN, SOF and RBV for 12 weeks has an overall SVR rate of 83–100%, without significant differences among cirrhotic and non-cirrhotic patients. However, this therapeutic regimen has several contraindications and can cause significant adverse events, which can reduce adherence and impair SVR rates. SOF plus RBV for 24 weeks is another treatment option, with SVR rates of 82–96% among patients without cirrhosis and 62–92% among those with cirrhosis. Finally, SOF plus DCV provides 94–97% SVR rates in non-cirrhotic patients, but 59–69% in those with cirrhosis. The addition of RBV to the regimen of SOF plus DCV increases the SVR rates in cirrhotic patients above 80%, and extending treatment to 24 weeks raises SVR to 90%. The ideal duration of therapy is still under investigation. For cirrhotic patients, the optimal duration, or even the best regimen, is still uncertain. Further studies are necessary to clarify the best regimen to treat HCV genotype 3 infection.

Network meta-analysis of first- and second-generation protease inhibitors for chronic hepatitis C genotype 1: efficacy based on RVR and SVR 24

PURPOSE

This study aimed to compare the efficacy among direct-acting antiviral agents (first and second-generation direct-acting antiviral agents (DAAs)) with placebo and with standard dual therapy (pegylated interferon + ribavirin (Peg-IFN + RBV)) in terms of rapid virologic response (RVR) and sustained virologic response (SVR) in chronic hepatitis C genotype 1 treatment.

METHODS

We performed a systematic review of randomized controlled trials (RCTs) in MEDLINE, International Pharmaceutical Abstracts, Cochrane Library, SCIELO, and Scopus and conducted a network meta-analysis to compare the efficacy of boceprevir (BOC), daclatasvir (DCV), grazoprevir, simeprevir (SMV) and telaprevir (TVR), in treatment-naive and treatment-experienced patients.

RESULTS

Sixteen studies encompassing 7171 patients were analysed. Associations between DAAs therapies (IFN-free regimens) could not be addressed since no common comparator was found in the RCTs among these associations and the other agents included in the present analysis. All agents were more efficacious than placebo or Peg-IFN + RBV in terms of RVR, while only BOC and SMV showed statistically significant superiority for the SVR outcome when compared to placebo or standard dual therapy. No significant differences between the DAAs were observed. The analysis prioritized treatment with DCV for both efficacy outcomes. Node-splitting analysis showed that our networks are robust (p > 0.05).

CONCLUSIONS

The superiority of DAAs over placebo or standard dual therapy with Peg-IFN + RBV was confirmed, indicating the greater efficacy of DCV. This study is the first network meta-analysis that included RVR as an outcome in the evaluation of these agents via indirect comparison. Further investigation should be carried out addressing safety and tolerability outcomes.

A Randomized Study of Peginterferon Lambda-1a Compared to Peginterferon Alfa-2a in Combination with Ribavirin and Telaprevir in Patients with Genotype-1 Chronic Hepatitis C

BACKGROUND

A randomized, double-blind, multinational, phase 3 study was conducted comparing the efficacy and safety of peginterferon lambda-1a (Lambda)/ribavirin (RBV)/telaprevir (TVR) vs. peginterferon alfa-2a (Alfa)/RBV/TVR in patients with chronic hepatitis C virus (HCV) genotype-1 (GT-1) infection.

METHODS

Patients (treatment-naïve or relapsers on prior Alfa/RBV treatment) were randomly assigned in a 2:1 ratio to receive Lambda/RBV/TVR or Alfa/RBV/TVR. Total duration of treatment was either 24 or 48 weeks (response-guided treatment), with TVR administered for the first 12 weeks. The primary endpoint was the proportion of patients who achieved a sustained virologic response at post treatment week 12 (SVR12), which was tested for noninferiority of Lambda/RBV/TVR.

RESULTS

A total of 838 patients were enrolled, and 617 were treated; 411 and 206 patients received Lambda/RBV/TVR and Alfa/RBV/TVR, respectively. The majority of patients were treatment-naïve, with HCV GT-1b and a high baseline viral load (≥800,000 IU/mL). Less than 10% of patients had cirrhosis (Lambda, 7.5%; Alfa, 6.8%). Lambda/RBV/TVR did not meet the criterion for noninferiority (lower bound of the treatment difference interval was -12.3%); the SVR12 in all patients (modified intent-to-treat) was 76.2% in the Lambda arm and 82.0% in the Alfa arm. Overall, the frequency of adverse events in each arm was comparable (Lambda, 91.7%; Alfa, 97.1%). As expected based on the safety profile of the 2 interferons, there were more hepatobiliary events observed in the Lambda arm and more hematologic events in the Alfa arm.

CONCLUSIONS

In this comparison of Lambda/RBV/TVR and Alfa/RBV/TVR in patients who were treatment-naïve or had relapsed on prior Alfa/RBV treatment, Lambda failed to demonstrate noninferiority based on SVR12 results. Treatment with Lambda/RBV/TVR was associated with a higher incidence of relapse. More patients discontinued Lambda/RBV/TVR treatment during the first 4 weeks of study treatment, mainly due to hepatobiliary-related events, and more Lambda patients were lost to follow-up.

Diagnostics in hepatitis C: The end of response-guided therapy?

On-treatment hepatitis C virus (HCV) RNA has been used to predict response to interferon (IFN)-based therapy. The concept of response-guided treatment (RGT) was established to determine optimal treatment duration and to early identify patients not responding to futile therapies. RGT helped to improve sustained virologic response (SVR) rates and lower the rates of adverse effects. RGT was of particular importance for telaprevir- and boceprevir-based triple therapies. RGT strategies are dependent on highly sensitive and reproducible HCV RNA quantification. However, different HCV RNA assays are used in routine clinical practice and these differ significantly in their performance characteristics. The development of IFN-free therapies has fundamentally changed the role of on-treatment HCV RNA for SVR prediction. Given the high efficacy and excellent tolerability of IFN-free regimens, the interest in treatment individualization has decreased. However, shorter treatment durations may still be desirable, particularly with respect to the high costs of current IFN-free direct-acting antiviral agents (DAAs). Moreover, some difficult-to-treat patients remain, e.g., those infected with HCV genotype 3 in whom the current standard of care may not always be sufficient to achieve SVR, especially in treatment-experienced patients with cirrhosis. Here, a RGT extension may be feasible. However, current data on the predictive value of on-treatment HCV RNA are limited and have shown conflicting results. As more potent DAAs become available, the role of response prediction may diminish further. Currently, shorter treatment duration is only based on baseline HCV RNA whereas no RGT strategy is recommended for any of the approved DAA regimens available.

HCV novel therapeutic regimens in Wonderland: A budget impact analysis in the Lombardy Region

BACKGROUND

The advent of new HCV drugs has generated widespread economic concerns, particularly within the Italian setting, characterized by continuous linear cuts and spending review actions. The overall trade-off between investments and savings needs an in depth analysis.

AIMS

The study aimed to estimate the budget impact of the introduction of the novel drugs approved during the year 2015, compared with the historical situation based on the different treatment options available prior to 2015.

METHODS

A three-year budget impact model was developed, taking into consideration the Lombardy Region (Northern Italy) Health Service perspective. The degree of liver fibrosis, genotypes, presence of only HCV or HIV/HCV co-infections, presence or absence of sustained virological response, and direct healthcare total costs were the variables of the model.

RESULTS

With the introduction of the novel regimens, a higher number of HCV patients achieved a sustained virological response (+20%). Further analysis showed that an investment in innovative technologies would have given the Regional System significant economic savings within the 36-month period (-6.64%/-7.15%).

CONCLUSIONS

Treating HCV-infected persons in the Lombardy Region with the new drugs would reduce healthcare expenditure on this specific disease, in each forecast implemented, thus reducing the economic burden of the pathology.

Supplementing Conventional Treatment with Pycnogenol® May Improve Hepatitis C Virus-Associated Type 2 Diabetes: A Mini Review

Hepatitis C virus (HCV) infection and type 2 diabetes mellitus (T2DM) present a significant health burden, with increasing complications and mortality rates worldwide. Pycnogenol® (PYC), a natural product, possesses antidiabetic and antiviral properties that may improve HCV-associated T2DM. In this review, we present previously published data on the effectiveness of PYC against HCV replication and T2DM. We believe that supplementing conventional treatment with PYC may improve the current HCV therapy, attenuate HCV-associated T2DM, and reduce the risk of complications such as cirrhosis or hepatocellular carcinoma and cardiovascular disease.

Second-generation direct-acting-antiviral hepatitis C virus treatment: Efficacy, safety, and predictors of SVR12

AIM

To gather data on the antiviral efficacy and safety of second generation direct acting antiviral (DAA) treatment with respect to sustained virological response (SVR) 12 wk after conclusion of treatment, and to determine predictors of SVR12 in this setting.

METHODS

Two hundred and sixty patients treated with SOF combination partners PR (n = 51), R (n = 10), SMV (n = 30), DCV (n = 81), LDV (n = 73), or 3D (n = 15). 144/260 were pre-treated, 89/260 had liver cirrhosis, 56/260 had portal hypertension with platelets < 100/nL, 25/260 had a MELD score ≥ 10 and 17/260 were post-liver transplantation patients. 194/260 had HCV GT1, 44/260 HCV GT3.

RESULTS

Two hundred and forty/256 (93.7%) patients achieved SVR12 (mITT); 4/260 were lost to follow-up. SVR12 rates for subgroups were: 92% for SOF/DCV, 93% for each SOF/SMV, SOF/PR, 94% for SOF/LDV, 100% for 3D, 94% for pretreated, 87% for liver cirrhosis, 82% for patients with platelets < 100/nL, 88% post-liver transplantation, 95% for GT1a, 93% for GT1b, 90% for GT3, 100% for GT2, 4, and 6. 12 patients suffered from relapse, 6 prematurely discontinued treatment, of which 4 died. Negative predictors of SVR12 were a platelet count < 100/nL, MELD score ≥ 10 (P < 0.0001), liver cirrhosis (P = 0.005) at baseline. In Interferon-free treatment GT3 had significantly lower SVR rates than GT1 (P = 0.016). Side effects were mild.

CONCLUSION

Excellent SVR12 rates and the favorable side-effect profile of DAA-combination therapy can be well translated into “real-world”. Patients with advanced liver disease, signs of portal hypertension, especially with platelets < 100/nL and patients with GT3 are in special need for further research efforts to overcome comparatively higher rates of virological failure.

Sofosbuvir plus ledipasvir in combination for the treatment of hepatitis C infection

Sofsobuvir is the first-in-class NS5B nucleotide inhibitor to be launched as a treatment for the hepatitis C virus (HCV). Its viral potency, pan genotypic activity and high barrier to resistance make it the ideal candidate to become a backbone for several IFN-free regimens. Ledipasvir is a NS5A inhibitor with multi genotypic activity but modest barrier to resistance. The once-daily fixed-dose combination of sofosbuvir plus ledipasvir is the first-in-market single-tablet regimen for the treatment of hepatitis C infection. Recent data demonstrated that this FDC alone, or in combination with ribavirin, is able to achieve HCV cure of at least 90% or more among genotype 1,4, 5 and 6 patients. This combination appears to be suboptimal in genotype 3 patients and other direct acting antiviral combinations with sofosbuvir will help to fulfill this gap in the near future. The safety profile of the fixed dose combination is good. Resistance is not an issue with sofosbuvir but may be a significant issue with regards to ledipasvir for those rare individuals who harbor baseline HCV NS5A resistance-associated variants that conferred a high resistance level. The rational for using FDCs and the available clinical data are reviewed.

Limited Generalizability of Registration Trials in Hepatitis C: A Nationwide Cohort Study

Background

Approval of drugs in chronic hepatitis C is supported by registration trials. These trials might have limited generalizability through use of strict eligibility criteria. We compared effectiveness and safety of real world hepatitis C patients eligible and ineligible for registration trials.

Methods

We performed a nationwide, multicenter, retrospective cohort study of chronic hepatitis C patients treated in the real world. We applied a combined set of inclusion and exclusion criteria of registration trials to our cohort to determine eligibility. We compared effectiveness and safety in eligible vs. ineligible patients, and performed sensitivity analyses with strict criteria. Further, we used log binomial regression to assess relative risks of criteria on outcomes.

Results

In this cohort (n = 467) 47% of patients would have been ineligible for registration trials. Main exclusion criteria were related to hepatic decompensation and co-morbidity (cardiac disease, anemia, malignancy and neutropenia), and were associated with an increased risk for serious adverse events (RR 1.45–2.31). Ineligible patients developed significantly more serious adverse events than eligible patients (27% vs. 11%, p< 0.001). Effectiveness was decreased if strict criteria were used.

Conclusions

Nearly half of real world hepatitis C patients would have been excluded from registration trials, and these patients are at increased risk to develop serious adverse events. Hepatic decompensation and co-morbidity were important exclusion criteria, and were related to toxicity. Therefore, new drugs should also be studied in these patients, to genuinely assess benefits and risk of therapy in the real world population.

Protease Inhibitors Drug Resistance Mutations in Turkish Patients with Chronic Hepatitis C

BACKGROUND

Drug resistance development is an expected problem during treatment with protease inhibitors (PIs), this is largely due to the fact that Pls are low-genetic barrier drugs. Resistance-associated variants (RAVs) however may also occur naturally, and prior to treatment with Pls, the clinical impact of this basal resistance remains unknown. In Turkey, there is yet to be an investigation into the hepatitis C (HCV) drug associated resistance to oral antivirals.

MATERIALS AND METHODS

178 antiviral-naïve patients infected with HCV genotype 1 were selected from 27 clinical centers of various geographical regions in Turkey and included in the current study. The basal NS3 Pls resistance mutations of these patients were analyzed.

RESULTS

In 33 (18.5%) of the patients included in the study, at least one mutation pattern that can cause drug resistance was identified. The most frequently detected mutation pattern was T54S while R109K was the second most frequently detected. Following a more general examination of the patients studied, telaprevir (TVR) resistance in 27 patients (15.2%), boceprevir (BOC) resistance in 26 (14.6%) patients, simeprevir (SMV) resistance in 11 (6.2%) patients and faldaprevir resistance in 13 (7.3%) patients were detected. Our investigation also revealed that rebound developed in the presence of a Q80K mutation and amongst two V55A mutations following treatment with TVR, while no response to treatment was detected in a patient with a R55K mutation.

CONCLUSION

We are of the opinion that drug resistance analyses can be beneficial and necessary in revealing which variants are responsible for pre-treatment natural resistance and which mutations are responsible for the viral breakthrough that may develop during the treatment.

ITPA deficiency and ribavirin level are still predictive of anaemia in HCV-HIV-coinfected patients receiving ribavirin combined with a first-generation DAA (ANRS HC27 study)

BACKGROUND

We aimed to determine the impact of inosine triphosphatase (ITPA) deficiency on ribavirin (RBV)-induced anaemia in HIV-HCV-coinfected patients receiving a triple therapy including the haematotoxic direct-acting antiviral agent boceprevir (BOC).

METHODS

Patients of the ANRS HC27 BocepreVIH study were genotyped for two ITPA single nucleotide polymorphisms involved in ITPA deficiency. RBV trough concentration (Ctrough) was determined at week (W)4 and W8. Impact of ITPA deficiency on anaemia, RBV Ctrough, response and haematotoxicity (grade 3/4 anaemia, erythropoietin [EPO] use, RBV dose reduction or transfusion between day [D]0 and W8) was evaluated. Impact of RBV Ctrough on anaemia was also studied.

RESULTS

Among the 63 genotyped patients, 33% had a predicted ITPA deficiency. ITPA deficiency was associated with a lower haemoglobin (Hb) decline both at W4 (-1.0 g/dl versus -2.1 g/dl; P=0.02) and W8 (-2.7 g/dl versus -4.1 g/dl; P=0.05). None of the patients with ITPA deficiency received EPO between D0-W8 versus 26% of patients without ITPA deficiency (P=0.01). RBV Ctrough was associated with Hb decrease both at W4 and W8 and an RBV Ctrough cutoff value of 2 µg/ml was significantly associated with a W4 Hb decline >2 g/dl. Haematotoxicity was significantly associated with a lower W4 Hb level (P=0.017), absence of ITPA deficiency (P=0.018) and higher RBV Ctrough (P=0.012). ITPA deficiency, W4 RBV Ctrough and gender were independent predictors of anaemia at W4. ITPA deficiency was not associated with virological response.

CONCLUSIONS

ITPA deficiency and RBV Ctrough are still predictive of RBV-induced anaemia in HIV-HCV-coinfected patients treated with RBV combined with a first-generation direct antiviral agent.

Human Transbodies to HCV NS3/4A Protease Inhibit Viral Replication and Restore Host Innate Immunity

A safe and effective direct acting anti-hepatitis C virus (HCV) agent is still needed. In this study, human single chain variable fragments of antibody (scFvs) that bound to HCV NS3/4A protein were produced by phage display technology. The engineered scFvs were linked to nonaarginines (R9) for making them cell penetrable. HCV-RNA-transfected Huh7 cells treated with the transbodies produced from four different transformed E. coli clones had reduced HCV-RNA inside the cells and in the cell spent media, as well as fewer HCV foci in the cell monolayer compared to the transfected cells in culture medium alone. The transbodies-treated transfected cells also had up-expression of the genes coding for the host innate immune response, including TRIF, TRAF3, IRF3, IL-28B, and IFN-β. Computerized homology modeling and intermolecular docking predicted that the effective transbodies interacted with several critical residues of the NS3/4A protease, including those that form catalytic triads, oxyanion loop, and S1 and S6 pockets, as well as a zinc-binding site. Although insight into molecular mechanisms of the transbodies need further laboratory investigation, it can be deduced from the current data that the transbodies blocked the HCV NS3/4A protease activities, leading to the HCV replication inhibition and restoration of the virally suppressed host innate immunity. The engineered antibodies should be tested further for treatment of HCV infection either alone, in combination with current therapeutics, or in a mixture with their cognates specific to other HCV proteins.

Infection of Common Marmosets with GB Virus B Chimeric Virus Encoding the Major Nonstructural Proteins NS2 to NS4A of Hepatitis C Virus

A lack of immunocompetent-small-primate models has been an obstacle for developing hepatitis C virus (HCV) vaccines and affordable antiviral drugs. In this study, HCV/GB virus B (GBV-B) chimeric virus carrying the major nonstructural proteins NS2 to NS4A (HCV NS2 to -4A chimera) was produced and used to infect common marmosets, since HCV NS2 to NS4A proteins are critical proteases and major antigens. Seven marmosets were inoculated intrahepatically with HCV NS2 to -4A chimera RNA for primary infection or intravenously injected with chimera-containing serum for passage infection. Three animals used as controls were injected with phosphate-buffered saline (PBS) or GBV-B, respectively. Six of seven HCV NS2 to -4A chimera-infected marmosets exhibited consistent viremia and one showed transient viremia during the course of follow-up detection. All six infected animals with persistent circulating viremia presented characteristics typical of viral hepatitis, including viral RNA and proteins in hepatocytes and histopathological changes in liver tissue. Viremia was consistently detected for 5 to 54 weeks of follow-up. FK506 immunosuppression facilitated the establishment of persistent chimera infection in marmosets. An animal with chimera infection spontaneously cleared the virus in blood 7 weeks following the first inoculation, but viral-RNA persistence, low-level viral protein, and mild necroinflammation remained in liver tissue. The specific antibody and T-cell response to HCV NS3 in this viremia-resolved marmoset was boosted by rechallenging, but no viremia was detected during 57 weeks of follow-up. The chimera-infected marmosets described can be used as a suitable small-primate animal model for studying novel antiviral drugs and T-cell-based vaccines against HCV infection.

IMPORTANCE

HCV infection causes approximately 70% of chronic hepatitis and is frequently associated with primary liver cancer globally. Chimpanzees have been used as a reliable primate model for HCV infection, but ethical considerations have restricted their utility in biomedical research. GB virus B (GBV-B) is a flavivirus related to HCV. It can infect common marmosets, a New World small primate, and induces viral hepatitis similar to HCV infection in humans. To minimize differences between GBV-B and HCV, we generated HCV NS2 to -4A/GBV-B chimeric viruses and established a chimera-infected marmoset model. HCV NS2 to -4A chimera-infected marmosets provide a small-animal model for evaluating novel antiviral drugs targeting HCV NS3-NS4A protease and T-cell-based HCV vaccines.

Pharmacogenetics of ribavirin-induced anemia in hepatitis C

Pharmacogenetics assesses inherited genetic differences in drug metabolic pathways and its role in medicine is growing. Ribavirin (RBV) and peginterferon were the standard of care therapy in hepatitis C virus infection during 15 years, with the addition of first-generation protease inhibitors at the beginning of 2010s. New direct-acting agents are the new standard of care, but RBV remains important in some scenarios. The main adverse effect of RBV is anemia, which requires dose reduction and even stopping treatment in some patients. Pharmacogenetics has identified ITPA and SLC28/29 genes to be closely related to RBV-induced anemia. The routine evaluation of these genes could help to identify those patients at risk of developing anemia during the hepatitis C virus treatment.

Copy number variation of genes involved in the hepatitis C virus-human interactome

Copy number variation (CNV) is a newly discovered form of intra-species genetic polymorphism that is defined as deletions or duplications of genome segments ranging from 1 kbp to several Mbp. CNV accounts for the majority of the genetic variation observed in humans (CNV regions cover more than 10% of the human genome); therefore, it may significantly influence both the phenotype and susceptibility to various diseases. Unfortunately, the impact of CNV on a number of diseases, including hepatitis C virus (HCV) infection, remains largely unexplored. Here, we analyzed 421 human genes encoding proteins that have been shown to interact with HCV proteins or genomic RNA (proteins from the HCV-human interactome). We found that 19 of the 421 candidate genes are located in putative CNV regions. For all of these genes, copy numbers were determined for European, Asiatic and African populations using the multiplex ligation-dependent amplification (MLPA) method. As a result, we identified 4 genes, IGLL1, MLLT4, PDPK1, PPP1R13L, for which the CN-genotype ranged from 1 to 6. All of these genes are involved in host-virus interaction; thus, their polymorphism has a potential impact on the development of HCV infection and/or therapy outcome.

Boceprevir or telaprevir in hepatitis C virus chronic infection: The Italian real life experience

AIM

To check the safety and efficacy of boceprevir/telaprevir with peginterferon/ribavirin for hepatitis C virus (HCV) genotype 1 in the real-world settings.

METHODS

This study was a non-randomized, observational, prospective, multicenter. This study involved 47 centers in Italy. A database was prepared for the homogenous collection of the data, was used by all of the centers for data collection, and was updated continuously. All of the patients enrolled in this study were older than 18 years of age and were diagnosed with chronic infection due to HCV genotype 1. The HCV RNA testing was performed using COBAS-TaqMan2.0 (Roche, LLQ 25 IU/mL).

RESULTS

All consecutively treated patients were included. Forty-seven centers enrolled 834 patients as follows: Male 64%; median age 57 (range 18-78), of whom 18.3% were over 65; mean body mass index 25.6 (range 16-39); genotype 1b (79.4%); diagnosis of cirrhosis (38.2%); and fibrosis F3/4 (71.2%). The following drugs were used: Telaprevir (66.2%) and PEG-IFN-alpha2a (67.6%). Patients were naïve (24.4%), relapsers (30.5%), partial responders (14.8%) and null responders (30.3%). Overall, adverse events (AEs) occurred in 617 patients (73.9%) during the treatment. Anemia was the most frequent AE (52.9% of cases), especially in cirrhotic. The therapy was stopped for 14.6% of the patients because of adverse events or virological failure (15%). Sustained virological response was achieved in 62.7% of the cases, but was 43.8% in cirrhotic patients over 65 years of age.

CONCLUSION

In everyday practice, triple therapy is safe but has moderate efficacy, especially for patients over 65 years of age, with advanced fibrosis, non-responders to peginterferon + ribavirin.

Optimisation of triple therapy for patients with chronic hepatitis C: a systematic review

BACKGROUND

Triple therapy with Pegylated-Interferon α (PEG-IFNα)/Ribavirin (RBV) and Boceprevir (Boc) or Telaprevir (Tel) significantly improved sustained virological response (SVR) rates for patients with genotype 1 HCV infection compared to PEG-IFNα/RBV alone (dual therapy). However, less is known about factors associated with rates of SVR and of adverse events (AEs).

MATERIAL AND METHODS

The aim of this systematic review was to evaluate the evidence regarding the factors affecting response and rate of AEs associated with triple therapy. We performed systematic electronic searches in Medline, Embase, Scopus and Central as well as a list of reference literature. We included randomised controlled trials examining triple therapy compared with dual therapy and reporting data according to patients features and about AEs. Odds ratios (OR) were pooled using either fixed or random effect model, as appropriate.

RESULTS

We included data from 14 studies. Treatment with triple therapy increased SVR rate compared to dual therapy especially in patients previously treated with PEG-IFNα/RBV and with increased pretreatment alanine aminotransferase (ALT) levels. Higher rate of serious AEs and treatment discontinuation due to AEs was also observed particularly in treatment-experienced patients.

CONCLUSIONS

The present study shows how improved results of triple therapy are mainly observed in some patients' subsets and are accompanied by increased risk of AEs compared to dual therapy. These results might be useful for optimising treatment of chronic hepatitis C when IFN-free regimens are unavailable.

A Primary Care-based Collaborative Hepatitis C Clinic: Clinical Structure and Virologic Outcomes with Direct Acting Antiviral Therapy

Background:

Currently 4 million persons in the US have active hepatitis C virus (HCV) infection and most have never successfully completed antiviral treatment. Newer therapies herald potential for wider uptake and acceptance of treatment, but the number of hepatology specialists is limited and newer models are needed to increase access to care. The aim of this study is to describe a collaborative primary care-based clinic for HCV treatment.

Methods:

Retrospective analysis of a collaborative primary care clinic developed for the evaluation and treatment of patients with chronic hepatitis C at one VA medical center. A half-day clinic was organized with 4 primary care MDs, 2 hepatologists, 2 nurse practitioners, and a co-located psychiatrist, pharmacist and nurse case manager. Clinic productivity and outcomes related to the number of patients who initiated and completed treatment with direct acting antivirals (DAA) and pegylated interferon and ribavirin were evaluated.

Results:

In this 18 month period, the clinic had 1890 confirmed HCV registry patients and 1690 clinic visits. 74 HCV genotype 1 patients initiated DAA therapy. Primary care providers treated 47 patients (32% cirrhotic) and hepatologists treated 27 patients (48% cirrhotic). Final SVR rate was 54.6% (39.2% cirrhotics vs. 65.2% noncirrhotics). SVR rates were higher in patients with primary care providers (61.7%) vs. hepatologists (44.4%). Despite numerous adverse events, early treatment termination for adverse events occurred in 5.3% vs. 21.3% for virologic non-response. Multivariate analysis revealed no significant differences between primary care and hepatology for SVR and treatment discontinuations.

Conclusion:

This clinic demonstrated effectiveness and safety with DAA therapy. This illustrates potential for a primary care based collaborative clinic, which will be crucial for expanding access to effective HCV care.

Anti-hepatitis C virus potency of a new autophagy inhibitor using human liver slices model

AIM

To evaluate the antiviral potency of a new anti-hepatitis C virus (HCV) antiviral agent targeting the cellular autophagy machinery.

METHODS

Non-infected liver slices, obtained from human liver resection and cut in 350 μm-thick slices (2.7 × 10(6) cells per slice) were infected with cell culture-grown HCV Con1b/C3 supernatant (multiplicity of infection = 0.1) cultivated for up to ten days. HCV infected slices were treated at day 4 post-infection with GNS-396 for 6 d at different concentrations. HCV replication was evaluated by strand-specific real-time quantitative reverse transcription - polymerase chain reaction. The infectivity titers of supernatants were evaluated by foci formation upon inoculation into naive Huh-7.5.1 cells. The cytotoxic effect of the drugs was evaluated by lactate dehydrogenase leakage assays.

RESULTS

The antiviral efficacy of a new antiviral drug, GNS-396, an autophagy inhibitor, on HCV infection of adult human liver slices was evidenced in a dose-dependent manner. At day 6 post-treatment, GNS-396 EC50 was 158 nmol/L without cytotoxic effect (compared to hydroxychloroquine EC50 = 1.17 μmol/L).

CONCLUSION

Our results demonstrated that our ex vivo model is efficient for evaluation the potency of autophagy inhibitors, in particular a new quinoline derivative GNS-396 as antiviral could inhibit HCV infection in a dose-dependent manner without cytotoxic effect.

Outcomes and Costs of Treating Hepatitis C Patients in the Era of First Generation Protease Inhibitors - Results from the PAN Study

1 OBJECTIVE

Chronic hepatitis C virus infections (HCV) cause a significant public health burden. Introduction of telaprevir (TVR) and boceprevir (BOC) has increased sustained virologic response rates (SVR) in genotype 1 patients but were accompanied by higher treatment costs and more side effects. Aim of the study was to assess outcomes and costs of treating HCV with TVR or BOC in routine care.

2 MATERIAL AND METHODS

Data was obtained from a non-interventional study. This analysis relates on a subset of 1,786 patients for whom resource utilisation was documented. Sociodemografic and clinical parameters as well as resource utilisation were collected using a web-based data recording system. Costs were calculated using official remuneration schemes.

3 RESULTS

Mean age of patients was 49.2 years, 58.6% were male. In treatment-naive patients SVR-rates of 62.2% and 55.7% for TVR and BOC were observed (prior relapser: 68.5% for TVR and 63.5% for BOC; prior non-responder: 45.6% for TVR and 39.1% for BOC). Treatment costs are dominated by costs for pharmaceuticals and range between €39,081 and €53,491. We calculated average costs per SVR of €81,347 (TVR) and €70,163 (BOC) in treatment-naive patients (prior relapser: 78,089 €/SVR for TVR and 82,077 €/SVR for BOC; prior non-responder: 116,509 €/SVR for TVR and 110,156 €/SVR for BOC). Quality of life data showed a considerable decrease during treatment.

4 CONCLUSION

Our study is one of few investigating both, outcomes and costs, of treating HCV in a real-life setting. Data can serve as a reference in the discussion of increasing costs in recently introduced agents.

Hepatitis C virus: Promising discoveries and new treatments

Despite advances in therapy, hepatitis C virus (HCV) infection remains an important global health issue. It is estimated that a significant part of the world population is chronically infected with the virus, and many of those affected may develop cirrhosis or liver cancer. The virus shows considerable variability, a characteristic that directly interferes with disease treatment. The response to treatment varies according to HCV genotype and subtype. The continuous generation of variants (quasispecies) allows the virus to escape control by antivirals. Historically, the combination of ribavirin and interferon therapy has represented the only treatment option for the disease. Currently, several new treatment options are emerging and are available to a large part of the affected population. In addition, the search for new substances with antiviral activity against HCV continues, promising future improvements in treatment. Researchers should consider the mutation capacity of the virus and the other variables that affect treatment success.

Daclatasvir plus asunaprevir for HCV genotype 1b infection in patients with or without compensated cirrhosis: a pooled analysis

BACKGROUND & AIMS

We compared outcomes by cirrhosis status across studies of the all-oral combination of daclatasvir (DCV) plus asunaprevir (ASV).

METHODS

Outcomes from global and Japanese phase 2 and 3 clinical studies of DCV+ASV in patients with genotype (GT) 1b infection were assessed by cirrhosis status. Sustained virological response (SVR) was assessed in individual phase 3 studies; a pooled analysis was carried out for safety outcomes.

RESULTS

In the Japanese phase 3 study, SVR12 was achieved by 91% of patients with cirrhosis (n = 22) and 84% of patients without cirrhosis (n = 200); in the global phase 3 study, SVR12 was achieved by 84% of patients with cirrhosis (n = 206) and by 85% of patients without cirrhosis (n = 437). The frequency of serious adverse events, adverse events leading to treatment discontinuation and treatment-emergent grade 3/4 laboratory abnormalities was low (<10%) and similar among patients with (n = 229) or without (n = 689) compensated cirrhosis receiving DCV+ASV. Grade 3/4 reductions in platelets and neutrophils were more common among patients with cirrhosis (1.3 and 2.2%, respectively) compared with those without cirrhosis (both 0.6%). Grade 3/4 liver function test abnormalities were less common among patients with cirrhosis (1.8%) compared with those without cirrhosis (3.5-4.7%). Alanine aminotransferase elevations were not associated with hepatic decompensation.

CONCLUSIONS

The safety and efficacy of DCV+ASV were similar in patients with or without compensated cirrhosis. This all-oral, interferon- and ribavirin-free combination is an effective and well-tolerated treatment option for patients with HCV GT1b infection and cirrhosis. Trial registrations numbers: Clinicaltrials.gov identifiers: NCT01012895; NCT01051414; NCT01581203; NCT01497834.

Does Hepatitis C Treatment Adherence Affect Risk of Liver Transplantation? A Historical Cohort Study

BACKGROUND

Chronic hepatitis C virus (HCV) is the primary cause of liver failure leading to transplantation, and medication adherence is essential to the therapeutic efficacy of HCV treatments. While there is evidence linking poor adherence with increased utilization and cost, published literature lacks examination of the association between medication adherence and risk of liver transplant. In addition, the impact of HCV treatment on total costs of liver transplantation is not well documented.

OBJECTIVES

To compare (a) the relative risk of liver transplant by adherence in patients treated for HCV and (b) the total health care costs in treated and untreated patients who require liver transplant.

METHODS

This observational, historical cohort study was conducted using administrative data from the Humana Research Database. To be included, patients were required to have a documented HCV diagnosis or treatment between January 1, 2008, and June 30, 2013. Patients were excluded if they had a hepatitis B diagnosis, were not fully insured by a commercial or Medicare Advantage Prescription Drug plan, or were outside the age range of 19-89 years. No minimum pre- or post-index enrollment period was required, and patients were followed for their entire post-index enrollment through December 31, 2013. The study population was divided into treated and untreated groups and then subdivided by presence or absence of a liver transplant. Date of liver transplant was defined as the index date for untreated liver transplant patients; otherwise, the index date was defined as either the date of first observed HCV treatment or diagnosis date (if no treatment or liver transplant). Cox proportional hazards models were used to estimate the relative risk of liver transplant by level of treatment adherence (> 80%, 50%-79%, and < 50%) based on proportion of days covered. General linearized models with log link and gamma distribution were used to compare median total health care costs from index date until end of study period (or death/disenrollment, whichever came first) between treated and untreated liver transplant patients. All costs were converted to 2013 U.S. dollars and reported as total costs per patient and per patient per month (PPPM) to account for varying follow-up periods.

RESULTS

Of the 53,423 patients identified with HCV, 10,377 met exclusion criteria, leaving 43,046 patients (primarily Caucasian, males, mean age of 58 years) in the initial cohort. Only 6.29% (n = 2,708) of the total HCV cohort received HCV treatment, and less than 1% (n = 366, 0.8%) received a liver transplant. Although there were no significant differences in the risk of liver transplant by adherence level, there was an upwards trend in the rate of liver transplant as adherence worsened (> 80%: 1.25%; 50%-79%: 1.30%; and < 50%: 1.99%), and the average days to liver transplant was longer with higher adherence (> 80%: 683; 50%-79%: 623; < 50%: 454). Only 48 (13.11%) patients who received a liver transplant were treated for HCV. Adjusted median total and PPPM health care costs measured from index date until end of the study period were significantly higher for patients who received HCV treatment compared with those who did not (total=$231,139 vs. $86,167, adjusted P < 0.001; PPPM=$20,583 vs. $5,778, adjusted P = 0.008), driven by HCV-related medical costs and total pharmacy costs.

CONCLUSIONS

Adherence with HCV regimens did not affect risk of liver transplant, underscoring the need for further evidence linking treatment adherence to future liver transplant risk. HCV-treated patients who required liver transplant incurred significantly higher health care costs than those without HCV treatment before liver transplant. Introduction of newer all-oral direct-acting antiviral regimens, with higher acquisition costs, will require further research to more accurately assess medication adherence and its relationship with transplantation, as well as with total health care costs.

DISCLOSURES

No outside funding supported this research. Ems, Worley, Racsa, Gregory, Anderson, and Holt are employees of Humana. Brill has participated in a physician advisory board at Humana. The authors have no other financial disclosures to report. Study concept and design were contributed by Ems, Racsa, Worley, and Anderson, along with Gregory, Brill, and Holt. Racsa took the lead in data collection, along with Ems and Worley. All authors participated in data interpretation. Anderson, along with the other authors, wrote the manuscript, which was revised by Brill and Holt, with assistance from the other authors.

Achieving sustained virologic response after interferon-free hepatitis C virus treatment correlates with hepatic interferon gene expression changes independent of cirrhosis

Chronic hepatitis C virus (HCV) infection can now be treated with oral directly acting antiviral agents, either with or without ribavirin (RBV). Virologic relapse after treatment can occur, and in some studies was more common in cirrhotic subjects. We previously observed changes in hepatic immunity during interferon (IFN)-free therapy that correlated with favourable outcome in subjects with early liver disease. Here, we compared changes in endogenous IFN pathways during IFN-free, RBV-free therapy between cirrhotic and noncirrhotic subjects. mRNA and microRNA (miRNA) expression analyses were performed on paired pre- and post-treatment liver biopsies from genotype-1 HCV subjects treated with sofosbuvir/ledipasvir (SOF/LDV) for 12 weeks (n = 4, 3 cirrhotics) or SOF/LDV combined with GS-9669 or GS-9451 for 6 weeks (n = 6, 0 cirrhotics). Nine of ten subjects achieved a sustained virologic response (SVR), while one noncirrhotic subject relapsed. Hepatic IFN-stimulated gene expression decreased with treatment in the liver of all subjects, with no observable impact of cirrhosis. Hepatic gene expression of type III IFNs (IFNL1, IFNL3, IFNL4-ΔG) similarly decreased with treatment, while IFNA2 expression, undetectable in all subjects pretreatment, was detected post-treatment in three subjects who achieved a SVR. Only the subject who relapsed had detectable IFNL4-ΔG expression in post-treatment liver. Other IFNs had no change in gene expression (IFNG, IFNB1, IFNA5) or could not be detected. Although expression of multiple hepatic miRNAs changed with treatment, many miRNAs previously implicated in HCV replication and IFN signalling had unchanged expression. In conclusion, favourable treatment outcome during IFN-free HCV therapy is associated with changes in the host IFN response regardless of cirrhosis.

Predictors of early treatment discontinuation and severe anemia in a Brazilian cohort of hepatitis C patients treated with first-generation protease inhibitors

The aim of this study was to determine risk factors for adverse events (AE)-related treatment discontinuation and severe anemia among patients with chronic hepatitis C virus (HCV) genotype 1 infection, treated with first-generation protease inhibitor (PI)-based therapy. We included all patients who initiated treatment with PI-based therapy at a Brazilian university hospital between November 2013 and December 2014. We prospectively collected data from medical records using standardized questionnaires and used Epi Info 6.0 for analysis. Severe anemia was defined as hemoglobin ≤8.5 mg/dL. We included 203 patients: 132 treated with telaprevir (TVR) and 71 treated with boceprevir (BOC). AE-related treatment discontinuation rate was 19.2% and anemia was the main reason (38.5%). Risk factors for treatment discontinuation were higher comorbidity index (OR=1.85, CI=1.05-3.25) for BOC, and higher bilirubin count (OR=1.02, CI=1.01-1.04) and lower BMI (OR=0.98, CI=0.96-0.99) for TVR. Severe anemia occurred in 35 (17.2%) patients. Risk factors for this outcome were lower estimated glomerular filtration rate (eGFR; OR=0.95, CI=0.91-0.98) for patients treated with TVR, and higher comorbidity index (OR=2.21, CI=1.04-4.67) and ribavirin dosage (OR=0.84, CI=0.72-0.99) for those treated with BOC. Fifty-five (57.3%) patients treated with TVR and 15 (27.3%) patients treated with BOC achieved sustained virological response (SVR). Among patients who received TVR and interrupted treatment due to AE (n=19), only 26.3% (n=5) achieved SVR (P=0.003). Higher number of comorbidities, lower eGFR and advanced liver disease are associated with severe anemia and early treatment cessation, which may compromise SVR achievement.

Efficacy and safety of daclatasvir and asunaprevir for hepatitis C virus genotype 1b infection

BACKGROUND/AIMS

The treatment strategy for hepatitis C virus (HCV) has been changing rapidly since the introduction of direct-acting antivirals such as daclatasvir (DCV) and asunaprevir (ASV). We evaluated the efficacy and safety of DCV and ASV for HCV in real-life practice.

METHODS

Patients were treated with 60 mg of DCV once daily plus 200 mg of ASV twice daily for 24 weeks, and followed for 12 weeks. The primary endpoint was a sustained virological response at 12 weeks after treatment (SVR12) and safety.

RESULTS

This retrospective study included eight patients with chronic HCV genotype 1b infection. All of the enrolled patients were diagnosed with liver cirrhosis, and their mean age was 65.75 years. One patient was a nonresponder and two patients relapsed with previous pegylated interferon (PegIFN) and ribavirin (RBV) treatment. None of the patient showed NS5A mutation. An SVR12 was achieved in 88% of cases by the DCV and ASV combination therapy. The serum transaminase level and the aspartate-aminotransferase-to-platelet ratio were improved after the treatment. DCV and ASV were well tolerated in most of the patients, with treatment discontinuation due to adverse events (elevated liver enzyme and decompensation) occurring in two patients.

CONCLUSION

In this study, combination of DCV and ASV treatment achieved a high sustained virological response with few adverse events even in those with cirrhosis, advanced age, and nonresponse/relapse to previous interferon-based therapy. Close monitoring of safety issues may be necessary when treating chronic HCV patients receiving DCV and ASV, especially in older patient and those with cirrhosis.

Systematic review: current concepts and challenges for the direct-acting antiviral era in hepatitis C cirrhosis

BACKGROUND

The burden of HCV cirrhosis is high and projected to increase significantly over the next decade. While interferon therapy is problematic in HCV cirrhosis, the era of direct-acting anti-viral (DAA) therapy provides effective treatment for patients with cirrhosis.

AIM

To systematically review the results of DAA therapy to date in patients with HCV cirrhosis, and highlight the ongoing challenges for DAA therapy in this population.

METHODS

A structured Medline search was conducted to obtain phase II and III HCV trials in patients with cirrhosis. Citations from review articles were cross-referenced and conference abstracts from EASL and AASLD liver meetings for the preceding 3 years were reviewed manually. Keywords used included hepatitis C, cirrhosis and the DAA's: sofosbuvir, ledipasvir, velpatasvir, grazoprevir, elbasvir, daclatasvir, beclabuvir, asunaprevir, simeprevir, paritaprevir, ombitasvir and dasabuvir.

RESULTS

Successful direct-acting anti-viral treatment is now possible in patients with HCV-related cirrhosis including those with liver decompensation with several regimens now offering sustained virological response (SVR) of 90-95%. Overall success rates in GT1 cirrhosis are excellent while GT3-infected patients with cirrhosis remain hard to cure. The pangenotypic combination of sofosbuvir and velpatasvir holds promise for GT3 cirrhosis achieving SVR of ~90%.

CONCLUSIONS

Potent DAA therapies provide much needed, safe and highly effective treatment options for persons with HCV cirrhosis including those previously deemed unsuitable for treatment. Combination therapy with two or more classes of drug is essential to achieve high efficacy and minimise viral resistance, with the role of ribavirin still under evaluation. However, several challenges remain including the hard-to-cure groups of GT3 cirrhosis and direct-acting anti-viral failures, and managing drug-drug interactions.

Inhibition of HCV replication by humanized-single domain transbodies to NS4B

NS4B of hepatitis C virus (HCV) initiates membrane web formation, binds RNA and other HCV proteins for viral replication complex (RC) formation, hydrolyses NTP, and inhibits innate anti-viral immunity. Thus, NS4B is an attractive target of a novel anti-HCV agent. In this study, humanized-nanobodies (VHs/VHHs) that bound to recombinant NS4B were produced by means of phage display technology. The nanobodies were linked molecularly to a cell penetrating peptide, penetratin (PEN), for making them cell penetrable (become transbodies). Human hepatic (Huh7) cells transfected with HCV JFH1-RNA that were treated with transbodies from four Escherichia coli clones (PEN-VHH7, PEN-VHH9, PEN-VH33, and PEN-VH43) had significant reduction of HCV RNA amounts in their culture fluids and intracellularly when compared to the transfected cells treated with control transbody and medium alone. The results were supported by the HCV foci assay. The transbody treated-transfected cells also had upregulation of the studied innate cytokine genes, IRF3, IFNβ and IL-28b. The transbodies have high potential for testing further as a novel anti-HCV agent, either alone, adjunct of existing anti-HCV agents/remedies, or in combination with their cognates specific to other HCV enzymes/proteins.

Conceptual framework for outcomes research studies of hepatitis C: an analytical review

Hepatitis C virus infection is one of the main causes of chronic liver disease worldwide. Until recently, the standard antiviral regimen for hepatitis C was a combination of an interferon derivative and ribavirin, but a plethora of new antiviral drugs is becoming available. While these new drugs have shown great efficacy in clinical trials, observational studies are needed to determine their effectiveness in clinical practice. Previous observational studies have shown that multiple factors, besides the drug regimen, affect patient outcomes in clinical practice. Here, we provide an analytical review of published outcomes studies of the management of hepatitis C virus infection. A conceptual framework defines the relationships between four categories of variables: health care system structure, patient characteristics, process-of-care, and patient outcomes. This framework can provide a starting point for outcomes studies addressing the use and effectiveness of new antiviral drug treatments.

IMPACT OF THE PEGYLATED-INTERFERON AND RIBAVIRIN THERAPY ON THE TREATMENT-RELATED MORTALITY OF PATIENTS WITH CIRRHOSIS DUE TO HEPATITIS C VIRUS

Although the protease inhibitors have revolutionized the therapy of chronic hepatitis C (CHC), the concomitant use of pegylated-interferon (PEG-IFN) and ribavirin (RBV) is associated to a high rate of adverse effects. In this study, we evaluated the consequences of PEG-IFN and RBV and their relationship with mortality in patients with cirrhosis.

METHODS

Medical records of CHC who underwent treatment with PEG-IFN and RBV in a public hospital in Brazil were evaluated. All the patients with cirrhosis were selected, and their clinical and laboratory characteristics, response to treatment, side effects and mortality were evaluated.

RESULTS

From the 1,059 patients with CHC, 257 cirrhotic patients were evaluated. Of these, 45 (17.5%) achieved sustained viral response (SVR). Early discontinuation of therapy occurred in 105 (40.8%) patients, of which 39 (15.2%) were due to serious adverse effects. The mortality rate among the 257 cirrhotic patients was 4.3%, occurring in 06/242 (2.4%) of the Child-A, and in 05/15 (33.3%) of the Child-B patients. In conclusion, the treatment of patients with cirrhosis due to HCV with PEG-IFN and RBV shows a low SVR rate and a high mortality, especially in patients with liver dysfunction.

New combination antiviral for the treatment of hepatitis C

PURPOSE

The pharmacology, pharmacokinetics, clinical efficacy, and safety of Viekira, as well as its place in hepatitis C virus (HCV) therapy, are reviewed.

SUMMARY

Ombitasvir 25 mg-paritaprevir 150 mg-ritonavir 100 mg plus dasabuvir 250 mg (Viekira) is approved in the United States as a combination direct-acting antiviral agent for treatment-naive or treatment-experienced patients with HCV genotype 1 infection, including those with compensated cirrhosis. It is the first coformulated direct-acting antiviral that targets different stages of the virus's life cycle. Viekira is administered as an oral, interferon-free regimen. Phase III clinical trials demonstrated that Viekira administered with or without ribavirin can achieve sustained virological response rates of ≥90%. These results are notable because they show that high virological cure rates can be achieved without peginterferon and ribavirin. Viekira is also effective for special patient populations, such as individuals coinfected with HIV, liver transplant recipients, and those with advanced renal disease. The most frequently reported adverse effects among patients associated with Viekira without ribavirin were nausea, pruritus, and insomnia. During clinical trials, the most common adverse effects among patients receiving Viekira with ribavirin were fatigue, nausea, pruritus, insomnia, and weakness.

CONCLUSION

Viekira, the first coformulated direct-acting antiviral that targets different stages of the HCV life cycle, is an interferon-free treatment for HCV genotype 1 infection. It is associated with a virological cure rate of ≥90% and treatment durations of 12 and 24 weeks. Viekira is also effective and safe for patients who have undergone liver transplantation, are coinfected with HIV, or have advanced kidney disease.

Two-Year Follow-Up Analysis of Telaprevir-Based Antiviral Triple Therapy for HCV Recurrence in Genotype 1 Infected Liver Graft Recipients as a First Step towards Modern HCV Therapy

Objective. The introduction of protease inhibitors telaprevir and boceprevir in 2011 had extended the antiviral treatment options especially in genotype 1 infected hepatitis C relapsers and nonresponders to interferon/ribavirin therapy. The aim of this study was to analyze the long-term treatment efficiency of telaprevir-based triple therapy for patients with hepatitis C reinfection after orthotopic liver transplantation. Patients and Methods. We included 12 patients with histologically confirmed graft fibrosis due to hepatitis C reinfection. The treatment duration was scheduled as 12 weeks of telaprevir-based antiviral triple therapy followed by 36 weeks of dual therapy with pegylated interferon/ribavirin. The patients were followed up for two years after the end of triple therapy. Results. Of the 12 patients, 6 (50%) completed the full 48 weeks of antiviral treatment. An end of treatment response and a sustained virological response 52 weeks after the end of the antiviral treatment course were achieved in 8/12 (67%) and 7/12 (58%) patients, respectively. Conclusion. Telaprevir-based triple therapy was shown to be a long-term effective but complex treatment option for individual patients with hepatitis C graft. With the recent improvements in hepatitis C therapy options telaprevir may not be recommended as a standard therapy for this indication anymore.

History and future of antiviral therapy of chronic hepatitis C

Hepatitis C virus (HCV) infection often leads to chronic diseases, and antiviral therapy is an important way to prevent chronic hepatitis C from progressing to end-stage liver disease. Up to now, hepatitis C antiviral therapy has successively experienced eras of interferon monotherapy, interferon and ribavirin combination therapy, and combination therapy of pegylated-interferon (PEG-IFN) and ribavirin. Now we are entering into a new era of direct-acting antiviral agents (DAAs). Just like acquired immune deficiency syndrome (AIDS) cocktails, combination therapy consists of two or more antiviral agents. DAAs will be the primary antiviral therapy for hepatitis C in the future for their better tolerance, lower drug resistance, higher sustained virological response and shorter treatment course. In this article, we review the history and future of antiviral therapy of HCV infection.

Ledipasvir-Sofosbuvir: A Once-Daily Oral Treatment Option for Chronic Hepatitis C Virus Genotype 1 Infection

Chronic hepatitis C virus (HCV) genotype 1 historically has been the most difficult to treat HCV genotype, and patients infected with this genotype had been previously treated with interferon-based therapy. In recent years, however, treatment options for chronic HCV infection have rapidly changed to an all-oral regimen. Ledipasvir-sofosbuvir is an oral fixed-dose (ledipasvir 90 mg-sofosbuvir 400 mg) combination of two direct-acting antiviral drugs. Four phase 3 clinical trials (ION-1-4) evaluated ledipasvir-sofosbuvir with and without ribavirin in patients with HCV genotype 1. High rates of sustained virologic response (SVR) occurred with ledipasvir-sofosbuvir alone in treatment-naïve and treatment-experienced patients without cirrhosis as well as in treatment-naïve patients with cirrhosis when administered for 12 weeks. In treatment-experienced patients with cirrhosis, 24 weeks of ledipasvir-sofosbuvir was also highly effective. Furthermore, treatment-naïve patients without cirrhosis (particularly those with HCV RNA serum concentrations < 6 million IU/ml) can achieve a similar SVR with only 8 weeks of therapy. Similarly, in patients coinfected with human immunodeficiency virus and HCV genotype 1 who were treated with ledipasvir-sofosbuvir for 12 weeks, a high SVR was observed in those with and without cirrhosis as well as treatment-naïve and treatment-experienced patients. Ledipasvir-sofosbuvir is well tolerated, with fatigue, headache, nausea, diarrhea, and insomnia being the most common adverse effects, which are typically mild to moderate in nature. This combination antiviral can be taken with or without food. Key factors to consider when prescribing ledipasvir-sofosbuvir are drug interactions including those mediated by the P-glycoprotein transporter and increased pH, cost of the drug or insurance coverage, comorbid conditions, and patient and provider preferences. Postmarketing experience and ongoing clinical trials will further define the safety and role of ledipasvir-sofosbuvir in the treatment of HCV genotype 1.

Treatment of HCV in Patients who Failed First-Generation PI Therapy: a Review of Current Literature

The addition of the first direct-acting antiviral agents, the NS3 protease inhibitors boceprevir or telaprevir, to peg interferon and ribavirin was a major advance in the treatment of genotype 1 hepatitis C individuals with sustained virological response (SVR) rates of 63-75 %. Those who did not achieve SVR had high rates of resistance-associated variants against NS3 protease domain. Retreatment options for those who have failed first-generation protease inhibitors generally are guided by retreatment with direct-acting antiviral agents from other classes. Phase 2 and phase 3 data have demonstrated that retreatment with 12-24 weeks of a NS5B inhibitor (sofosbuvir) in combination with a NS5a inhibitor (daclatasvir or ledipasvir) with or without ribavirin can achieve SVR at high rates comparable to treatment-naive individuals.

Effect of Gender on the Response to Hepatitis C Treatment in an Inner-City Population

INTRODUCTION

Hepatitis C virus (HCV) is the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplantation in the United States. Response to treatment has improved with the addition of direct acting protease inhibitors. However, there are limited real-world data on the role of gender in achieving a sustained virologic response (SVR).

METHODS

We conducted a cross-sectional study in 70 patients treated for HCV, genotype 1 infection with pegylated alpha interferon, ribavirin, and either telaprevir or boceprevir at our inner-city liver clinic.

RESULTS

The SVR was significantly lower in women than in men (24% vs. 59%; p < .01). Statistical significance persisted after adjusting for age, race, genotype, prior treatment status, duration of therapy, and stage of fibrosis. The adjusted odds ratio for achieving SVR was significantly lower in women than in men (odds ratio [OR], 0.13; 95% CI, 0.03-0.58; p = .01). Relapse after completing treatment was more likely to occur in women (p = .02). Thirty-four patients (48%) did not complete therapy. Discontinuation because of loss to follow-up was more likely in women, whereas discontinuation owing to therapy limiting adverse drug events were more common in men. Discontinuation rates owing to failure of therapy were similar in men and women.

CONCLUSIONS

There was a significant difference in SVR between men and women. Both biological and nonbiological factors, the latter including access to care, adherence to therapy, and attitudes of and toward health care providers all could play a role in contributing to the observed disparity between sexes in treatment response.

Simeprevir with peginterferon/ribavirin for patients with hepatitis C virus genotype 1: high frequency of viral relapse in elderly patients

Purpose

The tolerability and efficacy of simeprevir in combination with peginterferon and ribavirin in patients infected with hepatitis C virus (HCV) genotype 1 under actual clinical conditions were investigated.

Methods

A total of 176 patients with chronic HCV genotype 1 infection were treated with simeprevir for 12 weeks plus Peg-IFN/RBV for 24 weeks. Overall, 107 (60.7 %) patients were aged 60 years or more, and 16 (9 %) patients were aged 70 years or more. Treatment discontinuation, sustained virological response 12 (SVR12), and viral relapse were evaluated and compared between younger patients and elderly patients.

Results

The rates of undetectable HCV RNA at the end of treatment were 95.8, 100 and 93.1 % in treatment-naïve, prior relapse, and prior non-responders, respectively. However, the rates of SVR12 were 82.4, 88.2 and 69.2 %, respectively. Especially in prior non-responders, viral relapse was relatively frequent. Treatment discontinuation and SVR12 were not different between patients aged <70 and ≥70 years, but viral relapse after completing treatment was significantly more frequent in patients aged ≥70 years (p = 0.012).

Conclusions

In simeprevir with peginterferon and ribavirin therapy, viral relapse was relatively frequent. Especially in elderly patients, the relapse rate was high after completing treatment, instead of low frequency of discontinuation by the adverse events.

Resistance to direct-acting antiviral agents: clinical utility and significance

PURPOSE OF REVIEW

This article examines the dynamics and factors underlying hepatitis C virus (HCV) resistance, along with their impact on daily clinical management of HCV-infected patients.

RECENT FINDINGS

Across available treatment-regimens, GT-3 is the most difficult-to-cure genotype, but also genotype-1a may show lower success-rates compared with genotype-1b. Natural resistance to NS3, NS5A and NS5B inhibitors may contribute to treatment failures. The Q80K NS3-protease mutation affects sensibility to simeprevir + peg-interferon/ribavirin combinations. It reaches up to 48% prevalence in genotype-1a in some studies (but it is lower in other). Resistant variants (particularly in NS5A) developed at failure can persist, in a substantial proportion of patients, even 3 years after treatment-discontinuation, potentially affecting readministration of the same direct-acting antiviral agent (DAA)-class. This will become an issue for those patients failing all-oral regimens with multiple-resistant viruses.

SUMMARY

Recent data support the importance of an accurate genotype and genotype-1 subtype (1a/1b) assignment prior therapy. Resistance testing at baseline has no clear indication so far in clinical practice for all-DAA regimens selection, while it remains a valuable option at the retreatment of patients who failed DAA-containing regimens, provided that data are generated to inform treatment decisions based on the results of resistance testing. In this context, long-term RAVs persistence after failure should be taken into account.

A new paradigm evaluating cost per cure of HCV infection in the UK

Background

New interferon (IFN)-free treatments for hepatitis C are more effective, safer but more expensive than current IFN-based therapies. Comparative data of these, versus current first generation protease inhibitors (PI) with regard to costs and treatment outcomes are needed. We investigated the real-world effectiveness, safety and cost per cure of 1st generation PI-based therapies in the UK.

Methods

Medical records review of patients within the HCV Research UK database. Patients had received treatment with telaprevir or boceprevir and pegylated interferon and ribavirin (PR). Data on treatment outcome, healthcare utilisation and adverse events (AEs) requiring intervention were collected and analysed overall and by subgroups. Costs of visits, tests, therapies, adverse events and hospitalisations were estimated at the patient level. Total cost per cure was calculated as total median cost divided by SVR rate.

Results

154 patients from 35 centres were analysed. Overall median total cost per cure was £44,852 (subgroup range,: £35,492 to £107,288). Total treatment costs were accounted for by PI: 68.3 %, PR: 26.3 %, AE management: 5.4 %. Overall SVR was 62.3 % (range 25 % to 86.2 %). 36 % of patients experienced treatment-related AEs requiring intervention, 10 % required treatment-related hospitalisation.

Conclusions

This is the first UK multicentre study of outcomes and costs of PI-based HCV treatments in clinical practice. There was substantial variation in total cost per cure among patient subgroups and high rates of treatment-related discontinuations, AEs and hospitalisations. Real world safety, effectiveness and total cost per cure for the new IFN free combinations should be compared against this baseline.

Electronic supplementary material

The online version of this article (doi:10.1186/s41124-016-0002-z) contains supplementary material, which is available to authorized users.