Efficacy and tolerability of peginterferon alfa-2a or alfa-2b plus ribavirin in the daily routine treatment of patients with chronic hepatitis C in Germany: the PRACTICE study

A real-world intention-to-treat analysis of a decade's experience of treatment of hepatitis C with interferon-based therapies

Objectives: To assess the uptake of pegylated interferon (PegIFN) plus ribavirin (RBV)-based regimens in patients with hepatitis C virus (HCV) in a large, single-centre, real-world setting over 10 years.

Methods: This was a single centre, retrospective analysis of data from patients who attended their first appointment for treatment of HCV genotype 1–3 between 2003 and 2013. Patients were stratified by HCV genotype. The total number of patients who attended their first appointment, incidence of patients who did not proceed to treatment and associated reasons, and incidence of patients treated were analysed. Sustained virological response (SVR) rates were also reported for all patient populations.

Results: Overall, 1,132 patients attended their first appointment; 47.8% were included in the genotype 1 group (genotype 1a: 22.2%, genotype 1b: 13.3%, genotype 1 other: 12.3%), 7.7% in the genotype 2 group and 44.5% in the genotype 3 group. A greater proportion of patients received treatment versus those who did not receive treatment (84.4% vs 15.6%, respectively). Reasons for declining treatment included: patient declined treatment with PegIFN plus RBV: 35.0%, medical contraindications: 20.3% and mental health-related contraindications: 13.6%. An SVR was achieved in 52.6% of patients who attended their first appointment and 62.3% of patients who received treatment.

Conclusions: Approximately half of the patients included in this study achieved an SVR. A noteworthy proportion of patients did not receive treatment due to a reluctance to receive PegIFN plus RBV or contraindications to therapy. Results suggest an ongoing need for improvement in the treatment uptake and overall outcomes – particularly for genotype 2 and 3 patients for whom availability of interferon-free regimens is limited. The introduction of more tolerable direct-acting antiviral regimes may help overcome barriers to uptake demonstrated within this cohort.

Differential antiviral effects of pegylated interferon-α2a and pegylated interferon-α2b in chronic hepatitis C

BACKGROUND AND OBJECTIVES

Pegylated interferon (peg-IFN)-α2a and -α2b show different pharmacokinetic properties but are used interchangeably for hepatitis C treatment in traditional dual combinations and with newer agents. We assessed whether peg-IFN antiviral effects vary with peg-IFN subtype, affecting viral response in a differential manner.

METHODS

Chronic hepatitis C patients treated with ribavirin combined with peg-IFN-α2a (N = 109) or -α2b (N = 114) were studied. Hepatitis C virus RNA quantitation was performed by Cobas TaqMan 5 min before treatment start and subsequently after 48/72 h and 7, 14, 28 and 90 days. Antiviral effect was assessed in terms of viraemia changes over treatment. Histology grading and staging, interleukin-28B (IL28B) status and baseline viral genotype, alanine aminotransferase, gamma glutamyltransferase and glucose were analysed.

RESULTS

Viraemia decline after 48/72 h and 7 days was significantly greater with peg-IFN-α2b (1.96 and 2.12 vs 1.49 and 1.20 log10 IU/mL with peg-IFN-α2a; p < 0.001). Differences were of larger extent in patients with advanced fibrosis (p = 0.002), genotype 1 infection (p = 0.002) and CT/TT genotypes of IL28B (p = 0.001). A rebound in viral load was observed significantly more often after the first dose in patients treated with peg-IFN-α2b (78 vs 28 % in those with peg-IFN-α2a; p = 0.0001). Differences between peg-IFNs disappeared by day 28 of treatment.

CONCLUSION

There are significant pharmacodynamic differences between peg-IFN-α2a and -α2b in the early phase of chronic hepatitis C treatment. The greater early viral decline observed with peg-IFN-α2b was essentially confined to 'difficult to treat' patients. Whether this could affect response-guided treatment decision making, as well as triple drug regimens, needs to be assessed.

Comparison of peginterferon alfa-2a and alfa-2b for treatment of patients with chronic hepatitis C: a retrospective study using the Japanese Interferon Database

Purpose

We aimed to compare the rates of sustained virologic response (SVR) achieved with peginterferon (PEG-IFN) alfa-2a and alfa-2b in combination with ribavinin (RBV) for chronic hepatitis C, using a large database of hepatitis cases to improve the generalizability of these results.

Methods

We identified patients with chronic hepatitis C who were treated with PEG-IFN alfa-2a or alfa-2b and RBV, from the Japanese Interferon Database, between December 2009 and April 2013. This database contains the medical records of IFN treatment collected from 36 prefectures in Japan. Multivariable logistic regression analysis was used to compare SVR rates obtained with PEG-IFN alfa-2a and alfa-2b, in combination with RBV.

Results

A total of 16,349 patients were recorded in the Japanese Interferon Database. After application of the exclusion criteria, 12,706 patients (3,578 [1,710 males, 1,868 females] on PEG-IFN alfa-2a; and 9,128 [4,652 males, 4,476 females] on PEG-IFN alfa-2b) were included in this analysis. The SVR rate in the PEG-IFN alfa-2b group was 62.0%, as compared with a rate of 55.1% in the PEG-IFN alfa-2a group (crude odds ratio =1.31; 95% confidence interval [CI]: 1.23 to 1.44). There was no significant difference in the adjusted SVR rates between the two groups (adjusted odds ratio =0.96; 95% CI: 0.88 to 1.05). Similar proportions of adverse events were observed in the two groups, with the exception of thrombocytopenia, retinopathy, and anemia.

Conclusion

There was no significant difference in the SVR rates and safety profile between chronic hepatitis C patients treated with the PEG-IFN alfa-2a and alfa-2b.

Pegylated interferon-α2a and ribavirin versus pegylated interferon-α2b and ribavirin in chronic hepatitis C : a meta-analysis. Drugs. 2013;73:263-277. [PMID: 23436591 DOI: 10.1007/s40265-013-0027-1]

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.

The Effect of Peginterferon Alpha-2a vs. Peginterferon Alpha-2b in Treatment of Naive Chronic HCV Genotype-4 Patients: A Single Centre Egyptian Study

BACKGROUND

Egypt has one of the highest (16-8%) prevalence rates of HCV infection in the world. Approximately 90% of Egyptian HCV isolates belong to a single subtype (4a), which responds less successfully to interferon therapy than other subtypes. Studies comparing the efficacy and safety of PEGIFN alfa-2a and PEGIFN alfa-2b in treatment-naive HCV-infected patients have shown conflicting results.

OBJECTIVES

Assessing the effects of Peginterferon alpha-2a versus Peginterferon alpha-2b on the sustained virological response in naive chronic HCV genotype-4 Egyptian patients.

PATIENTS AND METHODS

This retrospective study cohort consists of 3718 chronic HCV patients admitted to a large, Egyptian medical center. 1985 patients had been treated with PEG-IFN alfa-2a plus RBV and 1733 patients with PEG-IFN alfa-2b plus RBV between years 2007-2011. Efficacy outcomes were sustained virologic response (SVR) and treatment discontinuation rates due to serious adverse effects.

RESULTS

The ETR & SVR in patients treated with PEGIFN alfa-2a was 64.1% and 59.6% as compared to treatment with PEGIFN alfa-2b where these parameters were 58.2% and 53.9% respectively (P < 0.05). Treatment discontinuation rates, were similar in the two types of PEGIFN [0.66 (0.37-1.16); P = 0.15]. Significant dose reduction was evident with peginterferon alfa-2b (35.3%) than peginterferon alpha-2a (27.3 %) (P < 0.01). Patients with lower base line AFP and ALT were most likely to achieve SVR using INF alpha 2-a.

CONCLUSIONS

Peginterferon alpha-2a has a higher efficacy regarding ETR and SVR as compared to Peginterferon alfa-2b in treatment of naive chronic HCV genotype-4 patients.

Alanine aminotransferase elevation during peginterferon alpha-2a or alpha-2b plus ribavirin treatment

Alanine aminotransferase (ALT) elevation was occassionally observed during the treatment with combination peginterferon alpha plus ribavirin. Two forms of peginterferon are currently available as a standard of care with or without direct-acting antivirals against hepatitis C virus (HCV). Until the appearance of interferon-sparing regimen, peginterferon alpha plus ribavirin will play a central role in the eradication of HCV. In the present study, we compared ALT elevations in response to peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin in HCV genotype-1-infected patients. There were no significant differences in ALT elevations between treatments with the two peginterferons, but in a comparison of the proportions of patients with transient ALT elevation from baseline between the two groups, transient ALT elevation was observed more in sustained virological response (SVR) patients treated with peginterferon alpha-2a than with peginterferon alpha-2b. However, no patients discontinued treatment due to ALT elevation. Patients with transient ALT elevation from baseline during the treatment had less favorable IL28B rs8099917 genotype in the peginterferon alpha-2b group. Patients achieving SVR tended to have lower ALT levels, although some had persistent ALT elevation during treatment. In conclusion, clinicians should pay attention to possible ALT elevation during the treatment of chronic hepatitis C patients.

APASL consensus statements and management algorithms for hepatitis C virus infection

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on the "APASL Consensus Statements and Management Algorithms for Hepatitis C Virus Infection" in December, 2010, in order to revise "Asian Pacific Association for the Study of the Liver consensus statements on the diagnosis, management and treatment of hepatitis C virus infection (J Gastroenterol Hepatol 22:615-633, 2007)". The working party consisted of expert hepatologists from the Asian-Pacific region gathered at Makuhari, Chiba, Japan on 19 December 2010. New data were presented, discussed and debated to draft a revision. Participants of the consensus meeting assessed the quality of cited studies. Finalized recommendations are presented in this review.

New hepatitis C therapies in clinical development

With the current standard of care for the treatment of chronic hepatitis C, a combination of pegylated interferon alfa and ribavirin, sustained virologic response rates can be achieved in approximately 50% of patients only. - Improved understanding of the viral life cycle has led to the identification of numerous potential targets for novel, direct-acting antiviral compounds. Inhibitors of the NS3/4A protease are currently the most advanced in clinical development. Recently completed phase 3 studies of the two protease inhibitors telaprevir and boceprevir, each given in combination with standard of care, yielded sustained virologic response rates in the range of 66-75% in treatment-naive patients and 59-66% in treatment-experienced patients with HCV genotype 1 infection. Studies of second-generation protease inhibitors, with the potential advantage of improved potency, drug metabolism and pharmacokinetics profile, are already underway. - Inhibitors of the HCV NS5A protein and NS5B polymerase are potentially active across different HCV genotypes and have shown promising antiviral efficacy in early clinical studies. Other emerging mechanisms include silymarin components and inhibitors of cell proteins required for HCV replication. - While improved formulations of current HCV therapies are also being developed, future hopes lie on the combination of direct-acting antivirals with the eventual possibility of interferon-free treatment regimens.

Pharmacokinetics and pharmacodynamics of peginterferon and ribavirin: implications for clinical efficacy in the treatment of chronic hepatitis C

The pharmacokinetics and pharmacodynamics of standard interferon alfa-2a and interferon alfa-2b are substantially altered by pegylation. The size, geometry, and site of attachment of the PEG moiety affect the pharmacokinetics and pharmacodynamics as evidenced by the different absorption, volume of distribution, and clearance of the linear 12-kDa peginterferon alfa-2b and the branched 40-kDa peginterferon alfa-2a. Despite these differences, the clinical efficacy, safety, and tolerability of the 2 peginterferons are similar. However, evidence exists that peginterferon alfa-2 plus ribavirin is associated with small but significantly higher sustained virological response rates compared with peginterferon alfa-2b. This article discusses the pharmacokinetics and pharmacodynamics of the 2 peginterferons and their combination with ribavirin.