Pegylated alpha-interferon-2a plus ribavirin compared with pegylated alpha-interferon-2b plus ribavirin for initial treatment of chronic hepatitis C virus: prospective, non-randomized study

Randomized trial of combined triple therapy comprising two types of peginterferon with simeprevir in patients with hepatitis C virus genotype 1b

Simeprevir (SMV) is a potent, macrocyclic hepatitis C virus (HCV) non-structural 3/4 A protease inhibitor. This prospective study compared the efficacy and safety of SMV in combination with peginterferon α2a + ribavirin (P2aR) and with peginterferon α2b + ribavirin (P2bR) in Japanese patients with HCV genotype 1b infection.

METHODS

Hepatitis C virus genotype 1b patients were randomly assigned to receive SMV (100 mg QD) with P2aR for 12 weeks, then P2aR alone for 12 or 36 weeks; or SMV (100 mg QD) with P2bR for 12 weeks, then P2bR alone for 12 or 36 weeks. The primary endpoint was a sustained virologic response 24 weeks after completing treatment (SVR24).

RESULTS

In total, 151 patients were randomly assigned to the P2aR (n = 76) or P2bR group (n = 75). Six patients dropped out. Sustained virologic response 24 weeks after completing treatment was achieved in 55 (75.3%) of 73 P2aR patients and 55 (76.4%) of 72 P2bR patients. There was no difference in the rate of SVR24 between the two groups (P = 0.88). No differences in the proportion of patients who became HCV RNA-negative were detected between the P2aR and P2bR groups. The two groups had comparable numbers of adverse events, which led to the discontinuation of treatment in 9.6% and 8.3% of participants in the P2aR and P2bR groups, respectively.

CONCLUSION

Peginterferon α2a or α2b in combination with SMV + ribavirin therapy showed identical antiviral effects in patients with chronic hepatitis C. Also, the incidence of adverse events was identical for both regimens.

Analysis of mutations in the core and NS5A genes of hepatitis C virus in non-responder and relapser patients after treatment with Peg-IFN-α and ribavirin

Mutations in several regions of HCV genome are shown to correlate with response to interferon (IFN) treatment. Persistence of HCV infection and poor susceptibility to treatment might be contributed by mutations arising within HCV genome which enable the virus to escape from host immune response/IFN treatment. This study investigated mutations in core and NS5A genes of HCV from non-responder and relapser patients after treatment with Peg-IFN-α and ribavirin. Viral RNA was extracted from patient sera and core and NS5A genes were amplified by RT-PCR. Nucleotide sequences of the core and NS5A genes were determined by direct sequencing, and converted to amino acid sequences. Nucleotide and amino acid sequences in the core region, ISDR, PKRBD, and V3 regions within NS5A after treatment were highly conserved when comparing to their corresponding sequences obtained before treatment. Interestingly, when comparing the virus from relapsers to those from non-responders, the number of mutations after treatment in N-terminal region of NS5A of virus from relapsers was significantly higher than those from non-responders (P < 0.05). Amino acid mutations at the N-terminus of NS5A of the virus in relapsers might help the virus to survive and somehow relapse after the cessation of the treatment.

The Role of Polymorphisms Near the IL28B Gene on Response to Peg-Interferon and Ribavirin in Thalassemic Patients With Hepatitis C

BACKGROUND

Hepatitis C Virus (HCV) is the major cause of liver failure in thalassemic patients. In these patients, iron overload and their comorbidities make difficulties during Pegylated-Interferon (PEG-IFN) and Ribavirin (RBV) therapy.

OBJECTIVES

We aimed to assess the impact of polymorphisms near the IL28B gene on virological response in HCV - infected thalassemic patients, who were treated with PEG-IFN and RBV.

PATIENTS AND METHODS

This cross - sectional study was conducted on 143 thalassemic patients with chronic hepatitis C, who were treated with a combination of PEG-IFN and RBV regimen. The rs12979860 and rs8099917 polymorphisms were assessed as the most common polymorphisms near the IL28B gene by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The rate of sustained virological response (SVR) was significantly lower in thalassemic patients with HCV genotype-1 infection compared to patients with HCV genotype-3 infection. Among baseline predictors, rs12979860 and rs8099917 polymorphisms were found to be the only parameters associated with achievement of SVR in thalassemic patients with HCV genotype-1 infection however, there was no association between these polymorphisms and the rate of SVR in thalassemic patients with HCV genotype-3 infection.

CONCLUSIONS

In HCV genotype-1- infected thalassemic patients with rs12979860 CC genotype and without severe comorbidities, PEG-IFN and RBV combination therapy can be tried yet in those with rs12979860 CT/TT it may be reasonable to treat cases with new direct-acting antivirals.

The role of HCV proteins on treatment outcomes

For many years, the standard of treatment for hepatitis C virus (HCV) infection was a combination of pegylated interferon alpha (Peg-IFN-α) and ribavirin for 24–48 weeks. This treatment regimen results in a sustained virologic response (SVR) rate in about 50 % of cases. The failure of IFN-α-based therapy to eliminate HCV is a result of multiple factors including a suboptimal treatment regimen, severity of HCV-related diseases, host factors and viral factors. In recent years, advances in HCV cell culture have contributed to a better understanding of the viral life cycle, which has led to the development of a number of direct-acting antiviral agents (DAAs) that target specific key components of viral replication, such as HCV NS3/4A, HCV NS5A, and HCV NS5B proteins. To date, several new drugs have been approved for the treatment of HCV infection. Application of DAAs with IFN-based or IFN-free regimens has increased the SVR rate up to >90 % and has allowed treatment duration to be shortened to 12–24 weeks. The impact of HCV proteins in response to IFN-based and IFN-free therapies has been described in many reports. This review summarizes and updates knowledge on molecular mechanisms of HCV proteins involved in anti-IFN activity as well as examining amino acid variations and mutations in several regions of HCV proteins associated with the response to IFN-based therapy and pattern of resistance associated amino acid variants (RAV) to antiviral agents.

[Lead-in period and week 8 as predictive tools for response to boceprevir therapy: a retrospective study of Spanish real clinical practice]

INTRODUCTION

Most discontinuations due to lack of virological response occur during the first few weeks of hepatitis C virus (HCV) triple therapy. Improved knowledge of baseline factors and their correlation with boceprevir decision points may predict treatment success.

METHODS

An observational, retrospective study was conducted to describe the lead-in period as a clinical decision tool in HCV genotype 1 patients treated with boceprevir. Data were collected from the medical records of 186 consecutive patients distributed across 20 Spanish general hospitals.

RESULTS

This study included 171 patients. A total of 80% had fibrosis F3/F4, 74% were previously treated, and 26% were treatment-naïve. After the lead-in period, 54.5% of the patients had a reduction of ≥1 log10; this reduction occurred in 52.5% of those with advanced fibrosis. Boceprevir therapy was started in 94% of the patients. Discontinuations at week 4 were limited to null responders with cirrhosis. The baseline factors associated with virological response at week 4 were IL28B, previous response, and fibrosis score. At week 8, HCV-RNA was undetectable in 48.8% of the patients. The correlation between responses at weeks 8 and 12 was 88%.

CONCLUSION

In the Spanish clinical setting, lead-in was mainly used as a clinical decision point for non-responders with cirrhosis. The good correlation between stopping rules at weeks 8 and 12 could be used to anticipate discontinuation, thus saving adverse events and costs.

Hepatitis C virus genotypes circulating in patients with chronic hepatitis C in Thailand and their responses to combined PEG-IFN and RBV therapy

Different genotypes of hepatitis C virus (HCV) are circulating in different areas of the world. In Thailand, distribution of HCV genotypes has been investigated mostly in the central area while the information in other regions is limited. This study aimed to determine the HCV genotypes circulating in chronic hepatitis C patients in Chiang Mai, Thailand and to investigate the response of different HCV genotypes to pegylated interferon (PEG-IFN) and ribavirin (RBV) treatment. Patients infected chronically with HCV were treated with PEG-IFN/RBV based on the standard regimens for each HCV genotype and followed up the patients until the end of treatment and 6 months afterward. Out of 158 patients, three major HCV genotypes and eight subtypes were identified. Genotype 3 was the most predominant at 54.5%, followed by genotypes 1 (31%) and 6 (14.5%). Among subtypes, 3a was the most prevalent subtype (45%), followed by 1b (18.4%), 1a and 6f (each at 12.6%), 3b (9.5%), and 6a, 6i, 6n (each at 0.63%). Patients with genotype 3 showed higher rate of responding to the treatment at 80.2% compared to genotypes 1 (73.5%) and 6f (65%). Additionally, patients with genotype 6f showed higher rate of relapsing (25%) compared to genotypes 1 and 3 (14.3% and 16.3%, respectively). In conclusion, this study reported multiple HCV genotypes circulated in Thai patients and the response of different HCV genotypes to PEG-IFN/RBV treatment.

Peginterferon alpha-2a versus peginterferon alpha-2b for chronic hepatitis C

BACKGROUND

A combination of weekly pegylated interferon (peginterferon) alpha and daily ribavirin still represents standard treatment of chronic hepatitis C infection in the majority of patients. However, it is not established which of the two licensed peginterferon products, peginterferon alpha-2a or peginterferon alpha-2b, is the most effective and has a better safety profile.

OBJECTIVES

To systematically evaluate the benefits and harms of peginterferon alpha-2a versus peginterferon alpha-2b in head-to-head randomised clinical trials in patients with chronic hepatitis C.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and LILACS until October 2013. We also searched conference abstracts, journals, and grey literature.

SELECTION CRITERIA

We included randomised clinical trials comparing peginterferon alpha-2a versus peginterferon alpha-2b given with or without co-intervention(s) (for example, ribavirin) for chronic hepatitis C. Quasi-randomised studies and observational studies as identified by the searches were also considered for assessment of harms. Our primary outcomes were all-cause mortality, liver-related morbidity, serious adverse events, adverse events leading to treatment discontinuation, other adverse events, and quality of life. The secondary outcome was sustained virological response in the blood serum.

DATA COLLECTION AND ANALYSIS

Two authors independently used a standardised data collection form. We meta-analysed data with both the fixed-effect and the random-effects models. For each outcome we calculated the relative risk (RR) with 95% confidence interval (CI) based on intention-to-treat analysis. We used domains of the trials to assess the risk of systematic errors (bias) and trial sequential analyses to assess the risks of random errors (play of chance). Intervention effects on the outcomes were assessed according to GRADE.

MAIN RESULTS

We included 17 randomised clinical trials which compared peginterferon alpha-2a plus ribavirin versus peginterferon alpha-2b plus ribavirin in 5847 patients. All trials had a high risk of bias. Very few trials reported data on very few patients for the patient-relevant outcomes all-cause mortality, liver-related morbidity, serious adverse events, and quality of life. Accordingly, we were unable to conduct meta-analyses on all-cause mortality, liver-related morbidity, and quality of life. Twelve trials reported on adverse events leading to discontinuation of treatment without clear evidence of a difference between the two peginterferons (197/2171 (9.1%) versus 311/3169 (9.9%); RR 0.84, 95% CI 0.57 to 1.22; I2 = 44%; low quality evidence). A trial sequential analysis showed that we could exclude a relative risk reduction of 20% or more on this outcome. Peginterferon alpha-2a significantly increased the number of patients who achieved a sustained virological response in the blood serum compared with peginterferon alpha-2b (1069/2099 (51%) versus 1327/3075 (43%); RR 1.12, 95% CI 1.06 to 1.18; I2= 0%, 12 trials; moderate quality evidence). Trial sequential analyses supported this result. Subgroup analyses based on risk of bias, viral genotype, and treatment history yielded similar results. Trial sequential analyses supported the results in patients with genotypes 1 and 4, but not in patients with genotypes 2 and 3.

AUTHORS' CONCLUSIONS

There is lack of evidence on patient-important outcomes and paucity of evidence on adverse events. Moderate quality evidence suggests that peginterferon alpha-2a is associated with a higher sustained virological response in serum than with peginterferon alpha-2b. This finding may be affected by the high risk of bias of the included studies . The clinical consequences of peginterferon alpha-2a versus peginterferon alpha-2b are unknown, and we cannot translate an effect on sustained virological response into comparable clinical effects because sustained virological response is still an unvalidated surrogate outcome for patient-important outcomes. The lack of evidence on patient-important outcomes and the paucity of evidence on adverse events means that we are unable to draw any conclusions about the effects of one peginterferon over the other.

Pegylated versus standard interferon plus ribavirin in chronic hepatitis C genotype 4: A systematic review and meta-analysis

AIM

Treatment of hepatitis C genotype 4 (HCV-G4) with pegylated interferon (PEG IFN) has not been adequately studied and is considered to be challenging. The aim of this meta-analysis is to systematically review and evaluate the effectiveness of 48 weeks of combined PEG IFN plus ribavirin (RBV) compared to standard interferon (IFN) plus RBV. The outcome of interest is sustained virological response (SVR).

METHODS

We searched for eligible randomized controlled trials (RCT) through May 2012. Random effects meta-analysis was used to pool the risk ratio (RR) of achieving SVR across trials.

RESULTS

Five RCT enrolling 386 patients were included. The PEG IFN/RBV group had increased likelihood of achieving SVR (RR = 1.51, 95% confidence interval [CI] = 1.08-2.10). SVR was significantly higher in PEG IFN-α-2a compared to the -α-2b group (P = 0.02). There was no statistically significant effect of ribavirin dosage on SVR (P = 0.55). The quality of evidence was moderate overall and limited by heterogeneity.

CONCLUSION

In treatment-naive patients with HCV-G4, treatment with PEG IFN plus RBV achieves higher SVR rate than treatment with IFN plus RBV.

[Efficacy of peginterferon and ribavirin combination therapy of chronic hepatitis C: a pooled analysis]

BACKGROUND/AIMS

A combination of peginterferon and ribavirin is the standard therapy for chronic hepatitis C (CHC). However, the respective study has not been carried out in a large scale in Korea. The purpose of this study was to collect the studies that have been reported in Korea in order to analyze the therapeutic effect of combination therapy and compare to find racial difference.

METHODS

Twenty-eight papers related to the therapeutic effect of combination therapy in CHC patients were analyzed based on pooled analysis.

RESULTS

Based on the analysis for genotype 1 in Korea, early virologic response (EVR), end of treatment response (ETR), and sustained virologic response (SVR) were 79.6% (125/157), 80.1% (166/207), and 62.7% (341/543). The EVR, ETR, and SVR for genotype 2 and 3 were 89.4% (119/133), 92.2% (203/220), and 84.1% (434/516). Data from other Asians showed that EVR and SVR for genotype 1 were 88.9% (290/326) and 64.4% (491/762) respectively and 88.8% (135/152), and 79.4% (151/190) for genotype 2 and 3 respectively. In Western, EVR and SVR for genotype 1 were 51.3% (1,981/3,860) and 42.4% (1,798/4,231) respectively, and for genotype 2 and 3 were 87.7% (350/399) and 77.8% (533/685) respectively. Based on the comparative analysis, no statistical difference in SVR between Koreans and other Asians (p=0.955) was observed; However, the SVR of Koreans was higher with significance than that of Westerns (p<0.001) On the other hand, there was no difference what so ever, in SVR for genotype 2 amongst the different races.

CONCLUSIONS

The SVR of combination therapy for the Korean chronic hepatitis C patients was similar to other Asians but higher than Westerns.

Pegylated interferon-α2a and ribavirin versus pegylated interferon-α2b and ribavirin in chronic hepatitis C : a meta-analysis

INTRODUCTION

Results of trials and meta-analyses comparing pegylated interferon (PEG-IFN)-α2a and PEG-IFN-α2b for the treatment of chronic hepatitis C are conflicting.

OBJECTIVE

Our objective was to determine which PEG-IFN (α2a or α2b), in association with ribavirin, is the most effective for the treatment of chronic hepatitis C by performing an updated meta-analysis.

METHOD

MEDLINE (1950-2012) and EMBASE (1974-2012) databases, as well as the Cochrane Central Register of controlled trials and the Cochrane Database of Systematic Reviews, were searched. Reference lists of retrieved articles were scanned, and proceedings of major international conferences were manually searched for abstracts. Randomized clinical trials and non-randomized clinical studies comparing PEG-IFN-α2a with PEG-IFN-α2b in association with ribavirin in adult patients with chronic hepatitis C were included. Studies including HIV-positive patients or liver transplant recipients were excluded. The data extraction from each study was conducted independently by two authors, with disagreements resolved by consensus or by a third reviewer. The trial quality of randomized clinical trials was assessed by taking into account generation of allocation sequence, allocation concealment, efficacy of randomization, investigator blindness, description of withdrawals and dropouts and adherence to the intention-to-treat principle. Two meta-analyses were performed, the first including randomized clinical trials only, and the second including both randomized and non-randomized clinical studies. The primary outcome measure was frequency of sustained virological response (SVR). Heterogeneity and publication bias were systematically taken into account.

RESULTS

This meta-analysis included 26 studies, 11 randomized and 15 non-randomized, with a total of 18,260 patients: 8,125 treated with PEG-IFN-α2a and 10,135 treated with PEG-IFN-α2b. In the meta-analysis that included randomized trials only, the SVR was significantly higher for patients treated with PEG-IFN-α2a than for those treated with PEG-IFN-α2b for genotypes 1 and 4 [odds ratio (OR) 1.45; 95 % CI 1.09-2.06; p = 0.013] and for all genotypes (OR 1.34; 95 % CI 1.05-1.72; p = 0.02). In the meta-analysis including both randomized and non-randomized studies, the SVR was significantly higher for PEG-IFN-α2a than for PEG-IFN-α2b for all genotypes (OR 1.24; 95 % CI 1.10-1.40; p < 0.001) and for genotypes 1 and 4 (OR 1.25; 95 % CI 1.14-1.36; p < 0.001); for genotypes 2 and 3, the SVR was greater for treatment with PEG-IFN-α2a than with PEG-IFN-α2b, with the difference tending towards significance (OR 1.15; 95 % CI 0.98-1.35; p = 0.08). A certain degree of heterogeneity was present amongst the various studies included in this meta-analysis. Publication bias was detected (particularly for analyses including only randomized controlled trials) and taken into account using appropriate statistical methods.

CONCLUSION

Current evidence suggests that PEG-IFN-α2a and ribavirin is associated with a higher SVR than PEG-IFN-α2b and ribavirin in patients mono-infected with hepatitis C, particularly for genotypes 1 and 4.

Estimates of HCV-1 patients attaining RVR following dual therapy with peg-interferon and ribavirin

BACKGROUND

Given the significant side-effects and healthcare costs associated with telaprevir- or boceprevir-combination therapy, identifying patients likely to respond to dual therapy peg-interferon (Peg-IFN)/ribavirin is highly desirable. Since the perception of how large the pool of patients who may achieve rapid virologic response (RVR) is vaguely ascertained, we searched the literature for this information.

METHODS

Studies on patients treated with Peg-IFN/ribavirin were identified by searching MEDLINE and analyzed by meta-analysis. The primary end point was weighted estimates of RVR. The influence on race/ethnicity, baseline viremia, type of Peg-IFN, ribavirin dosage, and significant hepatic fibrosis on the results was evaluated.

RESULTS

Across 38 studies on 13,219 patients, the fraction of RVR patients was 19.6 %. The only baseline factor influencing RVR was race/ethnicity, with higher rates in Asian (26.7 %) and Caucasian patients (22.5 %). Of the 1,735 RVR patients, 85.1 % attained sustained virologic response (SVR). In these, SVR was influenced by ribavirin dose (86.8 vs. 72.8 % for high or low), type of Peg-IFN (91.8 % for alpha-2b vs. 82.9 % for alpha-2a), and treatment duration (91.7 % for 48 weeks vs. 79.4 % for 24 weeks).

CONCLUSIONS

One fifth to one fourth of hepatitis C virus genotype 1 (HCV-1) patients can be safely treated with dual therapy of Peg-IFN/ribavirin, and may be spared from cost and inconvenience of regimens considering the addition of HCV protease inhibitors.

Efficacy of Pegylated interferon α-2a and α-2b in patients with genotype 1 chronic hepatitis C: a meta-analysis

Background

Two formulations of Pegylated interferon (Peg-IFN) are on the market for treatment of chronic hepatitis C virus (HCV) infection. The purpose of this meta-analysis was to assess the efficacy of Peg-IFN α-2a versus Peg-IFN α-2b in combination with ribavirin in anti-human immunodeficiency virus (HIV)-negative patients with genotype 1 chronic HCV infection.

Methods

The following criteria were to be met for inclusion in the meta-analysis: (a) original data from randomized and non-randomized clinical trials; (b) study on the efficacy of conventional doses of Peg-IFN α-2a (180 μg/week) versus Peg-IFN α-2b (1.5 μg/kg of body weight/week), both in combination with ribavirin, in antiviral therapy-naïve HCV-genotype 1 subjects; (c) at least one of these primary outcomes: Rapid Virological Response (RVR); Early Complete Virological Response (EVR); End of Treatment Response (ETR); Sustained Virological Response (SVR); (d) odds ratio estimates of relative risk (RR) and associated 95% confidence intervals (CIs) or at least data enabling them to be computed; (e) English language; and (f) published as a full paper up to December 2011.

Results

Seven published studies met the inclusion criteria, allowing a meta-analysis on 3,026 patients. Peg-IFN α-2a and Peg-IFN α-2b showed similar rate of RVR (RR = 1.05; 95% CI = 0.87-1.27, p = 0.62) and SVR (RR = 1.08; 95% CI = 0.99-1.18, p = 0.098). Peg-IFN α-2a more frequently than Peg-IFN α-2b achieved EVR (RR = 1.11; 95% CI = 1.02-1.21, p = 0.013) and ETR (RR = 1.22; 95% CI = 1.14-1.31, p < 0.0001).

Conclusion

The standard schedules of Peg-IFN α-2a and Peg-IFN α-2b, both in combination with ribavirin, can be used indifferently for patients with chronic HCV genotype 1 who are anti- to eliminate HIV-negative and antiviral treatment-naïve.

A lower serum gamma-glutamyltransferase level does not predict a sustained virological response in patients with chronic hepatitis C genotype 1

Background/Aims

Low gamma-glutamyltransferase (GGT) level was shown to be an independent predictor of a sustained virological response (SVR) in chronic hepatitis C. We aimed to determine factors associated with high GGT level, and to evaluate whether low GGT level is an independent predictor of a SVR in chronic hepatitis C genotype 1.

Methods

We retrospectively reviewed our data of patients with chronic hepatitis C genotype 1 treated with pegylated interferon-α and ribavirin. Baseline features were compared between patients with normal and high GGT levels. Factors associated with high GGT level and those associated with a SVR were determined by univariate and multivariate analysis.

Results

This study included 57 patients. Mean age was 52.28±9.35 years. GGT levels was elevated in 27 patients (47.4%). GGT levels were normal in 63.3% of the patients who achieved a SVR and in 40.7% of those who did not achieve a SVR (p>0.05). By multivariate logistic regression analysis, the presence of cirrhosis (odds ratio [OR], 9.41; 95% confidence interval [CI], 1.08 to 102.61) and female gender (OR, 6.77; 95% CI, 1.23 to 37.20) were significantly associated with high GGT level, and only rapid virological response was associated with a SVR (OR, 8.369; 95% CI, 1.82 to 38.48).

Conclusions

Low GGT level does not predict a SVR; however, it may be a predictor of high fibrosis scores.

Antiviral therapy: why does it fail in HCV-related chronic hepatitis?

HCV infection is a very common cause of chronic viral hepatitis. It is a worldwide health problem with approximately 170 million persons infected and areas of high endemicity in which the percentage of the population infected reaches 30%. It is a progressive disease that can lead to complications such as severe liver fibrosis and cirrhosis, ascites, esophageal varices, gastrointestinal bleeding and, in 30-50% of patients with cirrhosis, hepatocellular carcinoma. Extrahepatic pathologies such as mixed cryoglobulinemia, non-Hodgkin lymphoma and membrano-proliferative glomerulonephritis have been associated with HCV infection. Effective treatment exists, and is based on IFN-α. Sustained disappearance of the virus (sustained virological response) radically changes the natural history of chronic hepatitis C, with reduced or no disease progression and complications. Interferon-based treatment has improved over the years owing to the association with ribavirin and subsequently with 'pegylation' of interferon molecules. The present standard of care results in a response rate of up to 80% in some subpopulations. Nevertheless, some patients do not respond to this therapy. Several factors predicting nonresponse to interferon therapy have been investigated since it became available. These factors include the characteristics of the virus and of the subject infected, and the therapy used. The aim of this article is to provide an overview of these factors, and insights into the newly recognized causes of nonresponse to help clinicians select the most appropriate therapy for HCV viral hepatitis.

Current therapies for chronic hepatitis C

Hepatitis C virus affects more than 180 million people worldwide and as many as 4 million people in the United States. Given that most patients are asymptomatic until late in the disease progression, diagnostic screening and evaluation should be performed in patients who display high-risk behaviors associated with acquisition of hepatitis C. Chronic hepatitis C is associated with cirrhosis, hepatic failure, and death; therefore, treatment is aimed at reducing these complications, as well as improving quality of life and minimizing adverse effects. The American Association for the Study of Liver Diseases Practice Guidelines on the Diagnosis, Management, and Treatment of Hepatitis C represent the gold standard for guidance on the management of hepatitis C. Standard treatment for hepatitis C is peginterferon alpha in combination with ribavirin. Currently, two pegylated interferon products are approved by the U.S. Food and Drug Administration for the treatment of hepatitis C. The duration of therapy with peginterferon and ribavirin is dictated by viral genotype and virologic response. Additional therapies are under investigation for treatment of chronic hepatitis C and show early promise of comparative efficacy and fewer adverse effects. Special considerations in certain populations, including patients coinfected with human immunodeficiency virus, those with end-stage renal disease, injection drug users, pregnant women, and pediatric patients, should guide treatment decisions.

A meta-analysis that compares the use of either peginterferon-α2a or peginterferon-α2b plus ribavirin for HCV infection

Background

Two kinds of peginterferons, peginterferon-α2a (PEG-IFN-α2a) and peginterferon-α2b (PEG-IFN-α2b), are used in the treatment of chronic hepatitis C virus (HCV) infection. However, it is unclear which is better in terms of virological responses and patient compliance. We conducted a meta-analysis to assess which peginterferon was better when used with ribavirin.

Methods

Relevant clinical trials were identified through the PubMed and EMBASE databases. Primary outcomes included early virological response (EVR), end of treatment response (ETR) and sustained virological response (SVR). Secondary outcomes included biochemical and histological responses and the discontinuation of treatment after adverse events. Meta-analysis was performed using fixed-effect or random-effect methods, depending on absence or presence of significant heterogeneity. Analyses were performed with Review Manager Version 4.2.2.

Results

Seven clinical trials were included that involved 3,526 patients in total; six were randomized clinical trials (RCTs) and one was nonrandomized. PEG-IFN-α2a plus ribavirin was better than PEG-IFN-α2b plus ribavirin with regards to ETR (relative risk [RR] = 1.21, 95% confidence interval [CI]: 1.14–1.28). This advantage was less obvious for EVR (RR = 1.12, 95% CI: 1.06–1.19) and SVR (RR = 1.10, 95% CI: 1.02–1.18). Patients who received PEG-IFN-α2a were less likely to discontinue treatment for safety reasons (RR = 0.85, 95% CI: 0.52–1.38).

Conclusion

We demonstrated that PEG-IFN-α2a was a better choice than PEG-IFN-α2b in terms of virological responses.

Pegylated interferons for the treatment of chronic hepatitis C: pharmacological and clinical differences between peginterferon-alpha-2a and peginterferon-alpha-2b

Chronic infection with hepatitis C virus (HCV) is a major healthcare problem, affecting an estimated 170 million people worldwide. Interferon-alpha has formed the basis of treatment regimens since the identification of HCV, either alone or in conjunction with the nucleoside analogue ribavirin. The relatively recent introduction of pegylated forms of interferon-alpha, with greater stability and in vivo activity, has substantially improved sustained virological response (SVR) rates compared with unmodified interferon-alpha, with SVR rates of 35-66% when used in conjunction with ribavirin in randomized controlled trials. Two pegylated interferon (peginterferon)-alpha molecules are commercially available for the treatment of chronic hepatitis C, and these differ in the size and nature of the covalently attached polyethylene glycol (PEG) moiety, with resulting differences in pharmacokinetics and in dosing regimens. Peginterferon-alpha-2b has a linear 12 kDa PEG chain covalently attached primarily to histidine-34 of interferon-alpha-2b via an unstable urethane bond that is subject to hydrolysis once injected, releasing native interferon-alpha-2b. The branched, 40 kDa PEG chain of peginterferon-alpha-2a is covalently attached via stable amide bonds to lysine residues of interferon-alpha-2a, and circulates as an intact molecule. Consequently, peginterferon-alpha-2a has a very restricted volume of distribution, longer half-life and reduced clearance compared with native interferon-alpha-2a, and can be given once weekly independently of bodyweight. Peginterferon-alpha-2b has a shorter half-life in serum than peginterferon-alpha-2a and requires bodyweight-based dosing. The majority of head-to-head randomized controlled trials, including the large, randomized IDEAL (Individualized Dosing Efficacy versus Flat Dosing to Assess Optimal Pegylated Interferon Therapy) trial (n = 3070), demonstrated similar SVR rates for peginterferon-alpha-2a and peginterferon-alpha-2b (41% vs 39% in IDEAL), in combination with ribavirin; however, two randomized controlled trials (n = 431 and 320) demonstrated a statistically significant benefit for peginterferon-alpha-2a (66% vs 54%, and 69% vs 54%). Furthermore, two large retrospective studies and one prospective observational study in real-life settings have shown a significant benefit for peginterferon-alpha-2a versus peginterferon-alpha-2b, although SVR rates were generally lower than those seen in controlled trials. The use of interferon-alpha with or without ribavirin is frequently associated with a range of adverse effects, including influenza-like symptoms, haematological changes and neuropsychiatric disturbances, and this is true also of the peginterferons, with similar levels of adverse events, dose reduction and discontinuation from treatment. Peginterferon-alpha-2a and peginterferon-alpha-2b appear from comparative studies to be similarly tolerated, with few differences of clinical significance noted. Peginterferon plus ribavirin, as the standard of care for patients with chronic hepatitis C, may in the future form the basis of improved treatment regimens that include new, targeted anti-HCV agents to increase SVR rates even further.

Treatment persistence in and cost of therapy for patients with chronic hepatitis C: Peginterferon alfa-2a plus ribavirin versus peginterferon alfa-2b plus ribavirin

PURPOSE

Treatment persistence and cost of therapy for patients with chronic hepatitis C (CHC) treated with peginterferon alfa-2a plus ribavirin and peginterferon alfa-2b plus ribavirin were evaluated.

METHODS

This retrospective database analysis used eligibility, pharmacy, and medical claims data from a large U.S. health plan for patients with CHC treated with peginterferon alfa-2a plus ribavirin and peginterferon alfa-2b plus ribavirin from January 2002 through June 2006. For the purposes of this analysis, the study population included all hepatitis C virus (HCV) genotypes. Comparable groups for assessment of outcomes were constructed using propensity score matching to reduce the effect of known sources of bias. Outcome variables included treatment persistence and annualized overall and HCV-attributable health care costs.

RESULTS

A total of 1783 matched pairs were analyzed. Compared with patients receiving peginterferon alfa-2a plus ribavirin, patients receiving peginterferon alfa-2b plus ribavirin were 18% less likely to be persistent with therapy at week 48 (p = 0.013). During the first six months of follow-up, mean all-cause costs (p = 0.0368) and HCV-attributable costs (p < 0.0001) were significantly lower for peginterferon alfa-2a plus ribavirin than for peginterferon alfa-2b plus ribavirin. Mean annualized all-cause costs (p = 0.0060) and HCV-attributable costs (p = 0.0167) over the entire follow-up period were significantly lower for patients treated with peginterferon alfa-2a plus ribavirin versus peginterferon alfa-2b plus ribavirin.

CONCLUSION

Analysis of information from a health care claims database suggests that treating CHC with peginterferon alfa-2a plus ribavirin may improve treatment persistence and help reduce the health care costs imposed by CHC compared with treatment with peginterferon alfa-2b plus ribavirin.