The relative efficacy of boceprevir and telaprevir in the treatment of hepatitis C virus genotype 1

Identification of levomenthol derivatives as potential dipeptidyl peptidase-4 inhibitors: a comparative study with gliptins

Dipeptidyl peptidase-4 (DPP4) inhibitors are a potent therapeutic treatment for type 2 diabetes mellitus (T2DM). There is a family of compounds used as DPP4 inhibitors (DPP4Is) called gliptins. They bind tightly to DPP4 to form an inactive protein-ligand complex. However, there remains a need to identify novel DPP4Is that are more efficacious and safer due to the increasing prevalence of T2DM and the undesirable side effects of gliptins. To identify potential DPP4Is, we screened over 1800 novel compounds in a comparative study with gliptins. We performed dual-factor molecular docking to assess the binding affinity of the compounds to DPP4 and found four compounds with a higher binding affinity to DPP4 than currently used gliptins. The newly identified compounds interacted with the dyad glutamate (GLU205 and GLU206) and tyrosine (TYR662 and TYR666) residues in DPP4's active site. We performed molecular dynamics simulations to determine the stability of the protein-ligand complexes formed by the compounds and DPP4. Furthermore, we examined the toxicity and pharmacological profile of the compounds. The compounds are drug-like, easy to synthesize, and relatively less toxic than gliptins. Collectively, our results suggest that the novel compounds are potential DPP4Is and should be considered for further studies to develop novel antidiabetics.Communicated by Ramaswamy H. Sarma.

Anti-spike IgG causes severe acute lung injury by skewing macrophage responses during acute SARS-CoV infection

Newly emerging viruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV), Middle Eastern respiratory syndrome CoVs (MERS-CoV), and H7N9, cause fatal acute lung injury (ALI) by driving hypercytokinemia and aggressive inflammation through mechanisms that remain elusive. In SARS-CoV/macaque models, we determined that anti-spike IgG (S-IgG), in productively infected lungs, causes severe ALI by skewing inflammation-resolving response. Alveolar macrophages underwent functional polarization in acutely infected macaques, demonstrating simultaneously both proinflammatory and wound-healing characteristics. The presence of S-IgG prior to viral clearance, however, abrogated wound-healing responses and promoted MCP1 and IL-8 production and proinflammatory monocyte/macrophage recruitment and accumulation. Critically, patients who eventually died of SARS (hereafter referred to as deceased patients) displayed similarly accumulated pulmonary proinflammatory, absence of wound-healing macrophages, and faster neutralizing antibody responses. Their sera enhanced SARS-CoV-induced MCP1 and IL-8 production by human monocyte-derived wound-healing macrophages, whereas blockade of FcγR reduced such effects. Our findings reveal a mechanism responsible for virus-mediated ALI, define a pathological consequence of viral specific antibody response, and provide a potential target for treatment of SARS-CoV or other virus-mediated lung injury.

Identification of the Best Direct-Acting Antiviral Regimen for Patients With Hepatitis C Virus Genotype 3 Infection: A Systematic Review and Network Meta-analysis

BACKGROUND & AIMS

Direct-acting antivirals (DAAs) are effective in the treatment of chronic hepatitis C virus (HCV) infection, although results for patients infected with genotype 3 are suboptimal. There are several regimens available, however, direct comparisons have not been made and are unlikely to occur. We aimed to identify the most effective DAA regimen for patients infected with HCV genotype 3 and to assess the role of ribavirin.

METHODS

We conducted a systematic search of PubMed, Embase, and Web of Science databases through March 2016. We performed a Bayesian network meta-analysis using a random-effects model to indirectly compare regimens in patients with and without cirrhosis. We calculated mean estimated sustained virologic response (SVR) with 95% credible intervals (95% CrI) per regimen and effect of ribavirin as odds ratio. We focused on current recommended regimens and regimens under evaluation by regulatory authorities.

RESULTS

Our search identified 2167 articles; 27 studies (comprising 3415 patients) were included. Among patients without cirrhosis, the greatest rates of SVR were estimated for those receiving sofosbuvir + velpatasvir with ribavirin (99%; 95% CrI, 98%-100%) and without ribavirin (97%; 95% CrI, 95%-99%), sofosbuvir + daclatasvir + ribavirin (96%; 95% CrI, 92%-98%), and sofosbuvir + peginterferon + ribavirin (95%; 95% CrI, 91%-98%), all for 12 weeks. Among patients with cirrhosis, the highest rates of SVR were estimated for those receiving sofosbuvir + velpatasvir for 24 weeks (96%; 95% CrI, 92%-99%), sofosbuvir + daclatasvir + ribavirin for 24 weeks (94%; 95% CrI, 87%-98%), and sofosbuvir + velpatasvir + ribavirin for 12 weeks (94%; 95% CrI, 86%-98%). Ribavirin increases efficacy in patients with and without cirrhosis (odds ratio, 2.6-4.5).

CONCLUSIONS

An indirect comparison of DAA-based treatments, using Bayesian network meta-analysis, found regimens containing sofosbuvir and velpatasvir to be the best option for patients with HCV genotype 3 infection. Our analyses indicated that ribavirin significantly increases SVR rates and should be considered if tolerated.

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.

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.

A meta-analysis platform methodology for determining the comparative effectiveness of antihepatitis C virus regimens

AIM

Many hepatitis C virus regimens are unlikely to be compared head to head. In more difficult to treat populations where there is no standard of care, trials are single arm. We describe a flexible meta-analysis platform in this setting.

METHODS

Our meta-analysis is literature based. We illustrate our methodology and show how inference can be extended to single-arm trials.

RESULTS

As an example, in the single arm setting, a regimen with response rates of 84, 72 and 54% in genotype 1a across treatment naive, previous partial responders and previous null responders, respectively, would have 95% probability of superiority to IFN-α + RBV + TPV.

CONCLUSION

This is a rigorous approach to comparative effectiveness that accounts for varying patient populations and plans for the incorporation of emerging treatments.

Hepatitis C in the era of direct-acting antivirals: real-world costs of untreated chronic hepatitis C; a cross-sectional study

BACKGROUND

Recent advances in Hepatitis C therapeutics offer the possibility of cure but will be expensive. The cost of treatment may be partially offset by the avoidance of advanced liver disease. We performed a micro-costing study of the ambulatory healthcare utilisation of patients with Hepatitis C supplemented with inpatient diagnosis related group costs.

METHODS

The staff utilisation costs associated with a Hepatitis C ambulatory visit were measured and combined with the costs of investigations to establish a mean cost per consultation. An annualised estimate of cost was produced by multiplying this by the number of consultations accessed, stratified by degree of liver impairment. Inpatient costs were established by identifying the number of inpatient episodes and multiplying by Irish diagnosis related group costs. Non-parametric bootstrapping was performed to derive mean and 95%CI values.

RESULTS

Two hundred and twenty-five patients were identified. The cost of an outpatient medical review was €136 (€3.60 SD). The cost of a Hepatitis C nursing review was €128 (€7.30 SD). The annual mean costs of care were as follows (95%CI): Mild €398 (€336, €482), Moderate €417(€335, €503), Compensated cirrhosis €1790 (€990, €3164), Decompensated cirrhosis €8302 (€3945, €14,637), Transplantation Year 1 €137,176 (€136,024, €138,306), Transplantation after Year 1 €5337 (€4942, €5799), Hepatocellular carcinoma €21,992 (€15,222, €29,467), Sustained virological response €44 (€16, €73).

CONCLUSIONS

The direct medical cost associated with Hepatitis C care in Ireland is substantial and increases exponentially with progression of liver disease. The follow-up costs of patients with a sustained virological response in this cohort were low in comparison to patients with chronic infection.

A network meta-analysis to compare simeprevir with boceprevir and telaprevir in combination with peginterferon-α and ribavirin in patients infected with genotype 1 Hepatitis C virus

OBJECTIVE

To conduct a network meta-analysis (NMA) to assess the relative efficacy and safety of simeprevir, a second generation oral protease inhibitor (PI), compared to telaprevir and boceprevir in combination with pegylated interferon-α and ribavirin (PR) in patients with chronic hepatitis C.

METHODS

A systematic literature review and NMA of randomized controlled trials involving anti-virals added to PR were conducted. Electronic database searches and hand searches were conducted to identify relevant publications. Outcomes of interest included sustained virologic response (SVR), incidence of adverse events (AEs), and discontinuation due to AEs. Networks were based on treatment-, dose-, and duration-specific nodes. Sub-group analyses were conducted to investigate heterogeneity, based on Metavir scores, sub-genotypes 1a/1b, and prior response.

RESULTS

A total of 15 publications were considered for the base case of the meta-analysis. Simeprevir was associated with higher SVR rates than PR alone. Compared to telaprevir and boceprevir, SVR rates tended to be higher for simeprevir, with odds ratios ranging from 1.27 [0.81-2.00] to 2.61 [1.44-4.74] in treatment-naïve and from 1.04 [0.78-1.38] to 1.74 [0.84-3.61] in treatment-experienced patients, respectively. In terms of safety, the risks of anemia and discontinuations due to AEs were lower for simeprevir compared to PR alone, telaprevir, and boceprevir. The risk of rash was lower for simeprevir compared to telaprevir, and similar compared to PR alone and boceprevir.

CONCLUSION

This NMA in genotype 1 HCV patients suggests a similar or better efficacy and tolerability profile for simeprevir compared to telaprevir and boceprevir.

Aspartic acid based nucleoside phosphoramidate prodrugs as potent inhibitors of hepatitis C virus replication

A series of novel nucleoside phosphoramidate protides has been synthesized and shown as potent inhibitors of hepatitis C virus replication. The conjugates are having a diverse structural variation in the promoiety part and can be catalytically processed to deliver active nucleotides.

Cost utility of telaprevir-PR (peginterferon-ribavirin) versus boceprevir-PR and versus PR alone in chronic hepatitis C in The Netherlands

BACKGROUND

The hepatitis C virus may lead to cirrhosis, liver cancer, liver transplant, and increased mortality. With standard treatment peginterferon-alpha and ribavirin (PR), sustained viral response (SVR) was less than 50 %. SVR rates improve greatly when PR is combined with telaprevir or boceprevir.

OBJECTIVES

The aim of this study was to assess the cost utility of telaprevir-peginterferon-ribavirin (TPR) versus PR and boceprevir-peginterferon-ribavirin (BPR) in treatment-naïve (TN) and treatment-experienced (TE) adults with chronic hepatitis C in the Netherlands.

METHODS

A Markov model with a lifelong time horizon and annual cycles was developed. Clinical data stemmed from phase III trials (TPR vs PR, BPR vs PR). A mixed treatment comparison (MTC) was developed to compare TPR and BPR indirectly. Unit costs and utilities based on EQ-5D were established in a Dutch cross-sectional study. Cost per quality-adjusted life-years (QALYs) was calculated according to the societal perspective.

RESULTS

Treating TN patients with TPR generates 1.12 additional QALYs with €333 additional cost compared with PR, resulting in an incremental cost-utility ratio of €299/QALY. In TE patients, TPR dominates PR with cost savings (-€7,819) and 1.63 additional QALYs. TPR dominates BPR yielding additional QALYs (0.26 in TN; 0.71 in TE) and cost savings (-€7,296, -€18,144, respectively).

CONCLUSIONS

TPR seems a cost-effective alternative to PR in TN patients and dominant in TE patients. TPR was a dominant, more effective and less costly alternative to BPR in both patient types. The cost effectiveness of both TPR and BPR is well below generally accepted willingness-to-pay thresholds and may be considered cost effective.

Using pharmacokinetic and viral kinetic modeling to estimate the antiviral effectiveness of telaprevir, boceprevir, and pegylated interferon during triple therapy in treatment-experienced hepatitis C virus-infected cirrhotic patients

Triple therapy combining a protease inhibitor (PI) (telaprevir or boceprevir), pegylated interferon (PEG-IFN), and ribavirin (RBV) has dramatically increased the chance of eradicating hepatitis C virus (HCV). However, the efficacy of this treatment remains suboptimal in cirrhotic treatment-experienced patients. Here, we aimed to better understand the origin of this impaired response by estimating the antiviral effectiveness of each drug. Fifteen HCV genotype 1-infected patients with compensated cirrhosis, who were nonresponders to prior PEG-IFN/RBV therapy, were enrolled in a nonrandomized study. HCV RNA and concentrations of PIs, PEG-IFN, and RBV were frequently assessed in the first 12 weeks of treatment and were analyzed using a pharmacokinetic/viral kinetic model. The two PIs achieved similar levels of molar concentrations (P=0.5), but there was a significant difference in the 50% effective concentrations (EC50) (P=0.008), leading to greater effectiveness for telaprevir than for boceprevir in blocking viral production (99.8% versus 99.0%, respectively, P=0.002). In all patients, the antiviral effectiveness of PEG-IFN was modest (43.4%), and there was no significant contribution of RBV exposure to the total antiviral effectiveness. The second phase of viral decline, which is attributed to the loss rate of infected cells, was slow (0.19 day(-1)) and was higher in patients who subsequently eradicated HCV (P=0.03). The two PIs achieved high levels of antiviral effectiveness. However, the suboptimal antiviral effectiveness of PEG-IFN/RBV and the low loss of infected cells suggest that a longer treatment duration might be needed in cirrhotic treatment-experienced patients and that a future IFN-free regimen may be particularly beneficial in these patients.

Overview and recent trends of systematic reviews and meta-analyses in hepatology

A systematic review (SR) is a research methodology that involves a comprehensive search for and analysis of relevant studies on a specific topic. A strict and objective research process is conducted that comprises a systematic and comprehensive literature search in accordance with predetermined inclusion/exclusion criteria, and an assessment of the risk of bias of the selected literature. SRs require a multidisciplinary approach that necessitates cooperation with clinical experts, methodologists, other experts, and statisticians. A meta-analysis (MA) is a statistical method of quantitatively synthesizing data, where possible, from the primary literature selected for the SR. Review articles differ from SRs in that they lack a systematic methodology such as a literature search, selection of studies according to strict criteria, assessment of risk bias, and synthesis of the study results. The importance of evidence-based medicine (EBM) in the decision-making for public policy has recently been increasing thanks to the realization that it should be based on scientific research data. SRs and MAs are essential for EBM strategy and evidence-based clinical practice guidelines. This review addresses the current trends in SRs and MAs in the field of hepatology via a search of recently published articles in the Cochrane Library and Ovid-MEDLINE.

Peg-interferon plus ribavirin with or without boceprevir or telaprevir for HCV genotype 1: a meta-analysis on the role of response predictors

Background & aim

To compare the efficacy of pegylated-interferon (Peg-IFN) α-2a or α-2b and ribavirin given as dual therapy versus triple therapy (Peg-IFN and ribavirin plus boceprevir or telaprevir) in patients with HCV-1 chronic hepatitis naïve for anti-HCV therapy or relapsers to dual therapy in relation to the presence of constitutional, clinical and virological predictors of treatment response.

Methods

Included in the meta-analysis were studies meeting these criteria: original data from randomized trials on the efficacy of dual versus triple therapy in therapy-naïve patients or relapsers; at least one primary outcome clearly defined: sustained virological response in patients with or without rapid virological response (RVR), with genotype 1a or 1b, low or high HCV load, IL28-B CC or non-CC genotype, mild or severe fibrosis; odds ratio estimates of relative risk (RR) and 95% confidence intervals; English language; and published up to the end of June 2013.

Results

Seven original studies met the inclusion criteria, allowing a meta-analysis on 3,652 patients. Triple therapy was more effective than dual, regardless of IL-28B genotype, HCV sub-genotype, liver fibrosis, and baseline HCV load. In 1,045 patients who achieved RVR, SVR was more frequently achieved with dual therapy (RR = 1.11; p = 0.002) than triple. The same results were achieved when only the therapy-naïve patients were considered.

Conclusions

Triple therapy provides a significantly higher SVR rate than dual therapy, but dual therapy obtains a significantly higher SVR rate in patients with RVR. The data stress the clinical importance of a 4-week lead-in phase in direct-acting antiviral-based treatment.

Incident severe thrombocytopenia in veterans treated with pegylated interferon plus ribavirin for chronic hepatitis C infection

PURPOSE

We sought to determine the incidence and risks for severe thrombocytopenia (platelets < 50,000/μL) in United States Veteran patients treated with pegylated interferon (PEG-IFN) plus ribavirin for hepatitis C virus-positive (HCV) chronic liver disease (CLD).

METHODS

Using a retrospective, observational cohort study design to analyze databases from the New England Veterans Healthcare System, we identified 979 patients diagnosed with HCV-positive CLD treated solely with PEG-IFN plus ribavirin. The cohort was stratified by pre-treatment platelet counts of 50,000-100,000/μL (N = 90), >100,000-150,000/μL (N = 162), and >150,000μL (N = 727). The cumulative incidence of severe thrombocytopenia and major bleeding events were determined for each baseline platelet group for 48 weeks following treatment initiation. Multivariable Cox regression was used to identify risk factors for incident severe thrombocytopenia.

RESULTS

Overall, severe thrombocytopenia occurred in 6.1% (N = 60), but in 41.1% of patients with pre-treatment platelet counts 50, 000-100,000/μL compared with 11.7% (p < 0.001) and 0.55% (p < 0.001) in the two higher pre-treatment platelet groups. Most episodes occurred within the first 12 weeks of treatment. Median nadir count for these 60 patients was 35,000/μL (inter-quartile range 28,000, 44,000). Baseline platelet counts of 50,000-100,000/μL [adjusted hazard ratio (HR) = 3.81; 95%CI = 2.07-7.00] and hemoglobin <10 g/dL (adjusted HR = 3.39; 95%CI = 1.45-7.960) associated with severe thrombocytopenia. Major bleeding events during the 48-week observation period were rare (N = 5, 0.51%).

CONCLUSIONS

The incidence of severe thrombocytopenia in a large, observational cohort of veteran patients with HCV CLD treated with PEG-IFN plus ribavirin was 6.1%. Low pre-treatment platelet counts and hemoglobin levels associated with early, incident severe thrombocytopenia.

Treatment of chronic HCV genotype 1 infection with telaprevir: a Bayesian mixed treatment comparison of fixed-length and response-guided treatment regimens in treatment-naïve and -experienced patients

Background

Telaprevir (TVR) has been approved for response-guided-therapy (RGT) of chronic hepatitis C (HCV) genotype-1-infection in treatment-naïve and –experienced patients. In RGT-regimens patients that did not achieve extended rapid-virological-response (eRVR) within the first 4–12 weeks undergo treatment for 48-weeks, whereas in fixed-length-treatment (FLT) patients are treated for a fixed-duration regardless of their RVR.

Methods

This systematic review and Bayesian mixed-treatment-comparison (MTC) aimed to compare the efficacy and safety of standard-therapy with pegylated-interferon-α/ribavirin (Peg-IFN-α/RBV (48 weeks), group A), FLT with TVR, Peg-IFN-α/RBV for 12 weeks with a long (+36 weeks, group B) or short (+12 weeks, group C) tail of Peg-IFN-α/RBV treatment, and RGT with 12 weeks of TVR, Peg-IFN-α/RBV followed by 12 weeks of Peg-IFN-α/RBV (group D) or no therapy (group E).

Results

We identified seven randomized controlled trials including 3505 patients. Compared to standard-treatment (group A), treatment-naïve patients allocated to groups B, C, and D were significantly more likely to achieve sustained-virological-response (SVR, odds ratios (OR): B vs. A 3.5 (credibility interval [CrI] 2.2-5.4), C vs. A 3.0 (CrI 1.8-4.9), D vs. A 3.4 (CrI 2.5-4.6)). Treatment-experienced patients achieved increased SVR rates when they were treated in group B (OR: 8.2 (CrI 5.0-13.5)), C (OR 7.0 (CrI 3.9-12.8)), or simulated group D (OR 8.2 (CrI 4.3-15.3)). Patients treated with short RGT (simulated group E) did also have a significant improvement when they were treatment-experienced (simulated OR 3.6 (CrI 1.6-8.2)), whereas the effect was not significant in treatment-naïve patients (OR E vs. A 1.6 (CrI 0.9-2.7)).

Conclusion

Long FLT and RGT regimens are useful treatment options for HCV-genotype-1 in both treatment-naïve and -experienced patients. A short 24-weeks FLT regimen does not seem to be inferior and should further be evaluated in clinical trials to reduce side effects and costs of treatment.

The discovery and development of boceprevir

INTRODUCTION

Boceprevir was the first direct acting agent developed for the treatment of hepatitis C virus infection. Boceprevir functions by targeting NS3 protease, a viral enzyme essential for replication. This peptidomimetic molecule was optimized from a peptide lead to provide a potent, selective and orally bioavailable drug that can be combined with ribavirin and peg interferon to achieve sustained viral response (undetectable HCV RNA levels for 24 weeks after completion of therapy) in patients infected with Genotype 1 of the virus.

AREAS COVERED

This article provides a review of the pre-clinical and clinical discovery of boceprevir. This review includes the role and function of its molecular target, NS3 protease, as well as the assays used to measure in vitro efficacy, compound optimization and clinical studies to demonstrate safety and efficacy.

EXPERT OPINION

As the first direct acting anti-HCV agent, boceprevir represents an important advance in therapy of this widespread chronic disease. Yet, while this therapy is a valuable approach, it does have limitations. Studies have suggested that 30% of patients do not achieve sustained viral response and 11% of patients have developed anemia and/or neutropenia. Current drug discovery and development efforts are underway to develop novel therapeutic options that address these issues.

Interpreting discordant indirect and multiple treatment comparison meta-analyses: an evaluation of direct acting antivirals for chronic hepatitis C infection

Indirect treatment comparison (ITC) and multiple treatment comparison (MTC) meta-analyses are increasingly being used to estimate the comparative effectiveness of interventions when head-to-head data do not exist. ITC meta-analyses can be conducted using simple methodology to compare two interventions. MTC meta-analyses can be conducted using more complex methodology, often employing Bayesian approaches, to compare multiple interventions. As the number of ITC and MTC meta-analyses increase, it is common to find multiple analyses evaluating the same interventions in similar therapeutic areas. Depending on the choice of the methodological approach, the conclusions about relative treatment efficacy may differ. Such situations create uncertainty for decision makers. An illustration of this is provided by four ITC and MTC meta-analyses assessing the efficacy of boceprevir and telaprevir for chronic hepatitis C virus infection. This paper examines why these evaluations provide discordant results by examining specific methodological issues that can strengthen or weaken inferences.

Treatment of chronic hepatitis C virus infection in Japan: update on therapy and guidelines

Hepatitis C virus (HCV) infection is a serious health problem leading to cirrhosis, liver failure and hepatocellular carcinoma. The recent introduction of telaprevir, which was approved in November 2011, in combination with peg-interferon and ribavirin is expected to markedly improve the eradication rate of the virus. However, side effects of triple therapy may be severe. In a phase three III clinical trial, 2250 mg of telaprevir, which is the same dosage used in clinical trials in Western countries, was given to Japanese patients. As this dosage is considered to be relatively high for Japanese patients, who typically have lower weight than patients in Western countries, reduction of telaprevir is recommended in the 2012 revision of the guidelines established by the Study Group for the Standardization of Treatment of Viral Hepatitis Including Cirrhosis published by the Ministry of Health, Labour and Welfare of Japan. Other protease inhibitors with fewer side effects are now in clinical trials in Japan. Alternatively, treatment of patients with combination of direct acting antivirals without interferon has been reported. In this review we summarize current treatment options in Japan and discuss how we treat patients with chronic HCV infection.