A randomized controlled trial of pegylated interferon alpha-2a (40 KD) or interferon alpha-2a plus ribavirin and amantadine vs interferon alpha-2a and ribavirin in treatment-naïve patients with chronic hepatitis C

Prevalence and Incidence of Depression during Interferon-Based Antiviral Therapy in Chronic Hepatitis C Patients in the Republic of Korea

Background/Aims

The association between depression and chronic hepatitis C virus (HCV) infection or pegylated interferon α and ribavirin therapy (PR therapy) has not been extensively studied in Korea. We aimed to clarify the prevalence of depression and its incidence during PR therapy in chronic hepatitis C (CHC) patients.

Methods

In this prospective, multicenter study, 114 CHC patients were screened for depression using two self-reported scales, the Beck Depression Inventory-I (BDI-I) and the Hospital Anxiety and Depression scale (HADS). The incidence of depression during PR therapy was evaluated in 62 patients who underwent PR therapy during the study period.

Results

The prevalence of baseline depression was 17.5% according to the BDI-I score ≥10 criterion and 4.4% according to the HADS-D score ≥8 criterion in the 114 CHC patients, and it was significantly associated with an unmarried state. During PR therapy, depression developed in 34.6% according to the BDI-I scale and 29.5% according to the HADS-D, which negatively affected sustained virologic response (SVR).

Conclusions

The prevalence of depression in Korean CHC patients appears to be low compared to that in Western patients; however, its incidence during PR therapy (approximately 30%) was similar to that of other populations, which led to a lower SVR rate. Active screening and multidisciplinary management of depression during PR therapy is warranted.

Peginterferon plus ribavirin versus interferon plus ribavirin for chronic hepatitis C

BACKGROUND

Pegylated interferon (peginterferon) plus ribavirin is the recommended treatment for patients with chronic hepatitis C, but systematic assessment of the effect of this treatment compared with interferon plus ribavirin is needed.

OBJECTIVES

To systematically evaluate the benefits and harms of peginterferon plus ribavirin versus interferon plus ribavirin for 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), MEDLINE, EMBASE, Science Citation Index-Expanded, and LILACS. We also searched conference abstracts, journals, and grey literature. The last searches were conducted in September 2013.

SELECTION CRITERIA

We included randomised clinical trials comparing peginterferon plus ribavirin versus interferon plus ribavirin with or without co-intervention(s) (e.g., other antiviral drugs) for chronic hepatitis C. Quasi-randomised and observational studies retrieved through the searches for randomised clinical trials were also considered for reports of harms. Our primary outcomes were liver-related morbidity, all-cause mortality, serious adverse events, adverse events leading to treatment discontinuation, other adverse events, and quality of life. Our secondary outcome was sustained virological response in serum, that is, undetectable hepatitis C virus RNA in serum by sensitive tests six months after the end of treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently used a standardised data collection form. We meta-analysed data with both fixed-effect and random-effects models. For each outcome, we calculated the odds ratio (OR) (for liver-related morbidity or all-cause mortality) or the risk ratio (RR) along 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 risk of random errors (play of chance).For each outcome, we calculated the RR with 95% CI based on intention-to-treat analysis. Effects of interventions on outcomes were assessed according to GRADE.

MAIN RESULTS

We included 27 randomised trials with 5938 participants. All trials had high risk of bias. We considered that the risk of bias did not impact on the quality of evidence for liver-related mortality and adverse event outcomes, but it did for virological response. All trials compared peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin versus interferon plus ribavirin for participants with chronic hepatitis C. Three trials administered co-interventions (amantadine hydrochloride 200 mg daily to both intervention groups), and 24 trials were conducted without co-interventions. The effect observed between the two intervention groups regarding liver-related morbidity plus all-cause mortality (5/907 (0.55%) versus 4/882 (0.45%) was imprecise: OR 1.14 ( 95% CI 0.38 to 3.42; five trials; low quality of evidence), as was the risk of adverse events leading to treatment discontinuation (332/2692 (12.3%) versus 409/2176 (18.8%); RR 0.86, 95% CI 0.68 to 1.09; 15 trials; low quality of evidence) or regarding adverse events leading to treatment discontinuation (332/2692 (12.3%) versus 409/2176 (18.8%); RR 0.86, 95% CI 0.66 to 1.12; 17 trials; low quality of evidence). However, peginterferon plus ribavirin versus interferon plus ribavirin significantly increased the risk of neutropenia (332/2202 (15.1%) versus 117/1653 (7.1%); RR 2.15, 95% CI 1.76 to 2.61; 13 trials), thrombocytopenia (65/1113 (5.8%) versus 23/1082 (2.1%); RR 2.63, 95% CI 1.68 to 4.11; 10 trials), arthralgia (517/1740 (29.7%) versus 282/1194 (23.6%); RR 1.19, 95% CI 1.05 to 1.35; four trials), injection site reaction (627/1168 (53.7%) versus 186/649 (28.7%); RR 1.71, 95% CI 1.50 to 1.93; four trials), and nausea (606/1784 (34.0%) versus 354/1239 (28.6%); RR 1.13, 95% CI 1.01 to 1.26; four trials). The most frequent adverse event was fatigue, which occurred in 57% of participants (2024/3608). No significant difference was noted between peginterferon plus ribavirin versus interferon plus ribavirin in terms of fatigue (1177/2062 (57.1%) versus 847/1546 (54.8%); RR 1.01, 95% CI 0.96 to 1.07; 12 trials). No significant differences were reported between the two treatment groups regarding anaemia, headache, rigours, myalgia, pyrexia, weight loss, asthenia, depression, insomnia, irritability, alopecia, pruritus, skin rash, thyroid malfunction, decreased appetite, or diarrhoea. We were unable to identify any data on quality of life. Peginterferon plus ribavirin versus interferon plus ribavirin seemed to significantly increase the number of participants achieving sustained virological response (1673/3300 participants (50.7%) versus 1081/2804 patients (36.7%); RR 1.39, 95% CI 1.25 to 1.56; I2 = 64%; 27 trials; very low quality of evidence). However, the risk of bias in the 13/27 (48.1%) trials reporting on this outcome was high and was considered only 'lower' in the remainder. Because the conventional meta-analysis did not reach its required information size (n = 14,486 participants), we used trial sequential analysis to control for risks of random errors. Again, in this analysis, the estimated effect was statistically significant in favour of peginterferon. Subgroup analyses according to risk of bias, viral genotype, baseline viral load, past treatment history, and type of intervention yielded similarly significant results favouring peginterferon over interferon on the outcome of sustained virological response.

AUTHORS' CONCLUSIONS

Peginterferon plus ribavirin versus interferon plus ribavirin seems to significantly increase the proportion of patients with sustained virological response, as well as the risk of certain adverse events. However, we have insufficient evidence to recommend or reject peginterferon plus ribavirin for liver-related morbidity plus all-cause mortality compared with interferon plus ribavirin. The clinical consequences of achieved sustained virological response are unknown, as sustained virological response is still an unvalidated surrogate outcome. We found no evidence of the potential benefits on quality of life in patients with achieved sustained virological response. Further high-quality research is likely to have an important impact on our confidence in the estimate of patient-relevant outcomes and is likely to change our estimates.There is very low quality evidence that peginterferon plus ribavirin increases the proportion of patients with sustained virological response in comparison with interferon plus ribavirin. There is evidence that it also increases the risk of certain adverse events.

Differences in clinical outcomes among hepatitis C genotype 1-infected patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin: a meta-analysis

Background

With the development of new direct acting antiviral (DAA) therapy for hepatitis C, the backbone peginterferon alpha used may be of importance in maximizing treatment outcomes. To this end, the rates of sustained virologic response (SVR), relapse, and treatment discontinuation among hepatitis C genotype 1-infected patients given peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin were determined using a meta-analysis.

Methods

Randomized trials examining peginterferon alpha-2a or peginterferon alpha-2b co-administered with ribavirin for 48 weeks were included. Data were extracted on SVR, relapse, and treatment discontinuations for treatment-naïve and treatment-experienced patients. Pooled proportions using fixed and random effects meta-analysis were calculated.

Results

Twenty-six trials provided data on patients treated with peginterferon alpha-2a plus ribavirin, and 19 trials provided data on patients treated with peginterferon alpha-2b plus ribavirin. Five trials were direct head-to-head evaluations. In the subset of trials that included head-to-head evaluations, no significant differences were observed between the two treatments for treatment-naïve (relative risk [RR]: 1.07, 95% confidence intervals [CI]: 0.97–1.18) and treatment-experienced patients (RR: 1.27, 95% CI: 0.58–2.77). Using only active trial arms, a larger proportion of the treatment- naïve patients who were provided peginterferon alpha-2a plus ribavirin achieved a SVR (47%), which is greater than that of treatment-naïve patients who were provided peginterferon alpha- 2b plus ribavirin (40% SVR achievement); however, a larger proportion of treatment- experienced patients who were provided peginterferon alpha-2b plus ribavirin achieved a SVR (16%) when compared with treatment-experienced patients given peginterferon alpha-2a plus ribavirin (12% SVR achievement). A larger proportion of relapses occurred among both treatment-naïve and treatment-experienced patients given peginterferon alpha-2a plus ribavirin, when compared with treatment-naïve and treatment-experienced patients taking peginterferon alpha-2b plus ribavirin. The proportion of patients discontinuing treatment was greater among treatment-naïve patients taking peginterferon alpha-2a plus ribavirin, but smaller among treatment-experienced patients.

Conclusion

There are small differences in treatment outcomes for different types of peginterferon- alpha. Patient status and complexity of administration may differentiate clinical outcomes.

Response-guided and -unguided treatment of chronic hepatitis C

Over time, HCV therapy with pegylated interferon and ribavirin has evolved from a fixed duration strategy to one of response guided therapy and this has enabled us to optimize treatment duration. With the evolution of protease inhibitor based therapy, the paradigm of response guided therapy has further helped in decreasing treatment duration in greater number of patients and which then translates into shorter duration of adverse events. However, several population groups have done better with extended duration therapy as opposed to response guided therapy despite early viral clearance. These include the Black population, and those with cirrhosis, decreased interferon sensitivity, and unfavorable IL28B genotypes. The proper identification of those who might benefit from extended duration HCV therapy will undoubtedly lead to optimal care and outcomes.

Suppressor of cytokine signal 3 and IL28 genetic variation predict the viral response to peginterferon and ribavirin

AIM

  The aim of this study was to investigate the relationship among the expression of suppressor of cytokine signaling 3 (SOCS 3) in the liver, the SNPs in the IL28B locus, and the outcome of interferon therapy.

METHODS

  Prior to interferon treatment, we immunostained 67 liver specimens from chronic hepatitis C (CHC) patients who were receiving peginterferon alpha-2b/ribavirin therapy for suppressor of cytokine signaling 3 (SOCS3), and compared the expression of SOCS3, IL28 polymorphisms and other clinical factors between the patients and compared their eventual outcomes.

RESULTS

  Significant differences between the low SOCS3 group and high SOCS3 group were found in age, as well as in the platelet, transaminase, gamma-glutamyl transpeptidase levels. The incidence of high SOCS3 was not significantly different between subjects with the TT genotype and the TG genotype (TT : TG = 71%:29%, P = 0.250). In a multivariate analysis, age (≥65 years old) (odds ratio 0.221 [0.120-0.966], P = 0.045), IL28B gene (genotype TT) (odds ratio 5.422 [1.254-23.617], P = 0.024) and SOCS3 (high) (odds ratio 0.308 [0.104-0.948], P = 0.040) were significant predictors of the interferon response. In patients with the TT genotype, those with low SOCS3 immunostaining showed a high sustained virological response (69%), while the sustained virological rate was low (27%) in the patients with high SOCS3 immunostaining.

CONCLUSIONS

  Using a combination of the SOCS3 immunostained area in the liver and the expression of IL28B single nucleotide polymorphisms might be a useful predictor of hepatitis C virus clearance by interferon therapy.

How to use virological tools for the optimal management of chronic hepatitis C

Approximately 180 million individuals are chronically infected with hepatitis C, which is strongly associated with the development of cirrhosis, end-stage liver disease and hepatocellular carcinoma. Several virological tools (anti-HCV antibody assays, measurement of HCV-RNA, HCV-genotyping) are useful in management of hepatitis C infected patients. The primary goal of antiviral therapy in chronic hepatitis C is a sustained virological response (SVR). The HCV genotype should be determined in every patient considered for antiviral therapy because the currently recommended treatment duration and ribavirin doses differ among HCV genotypes. Exact subtyping might gain increased importance for future therapies with direct-acting antiviral agents (DAA) because of differences of antiviral activities and barriers to resistance among HCV subtypes. Monitoring HCV RNA by a highly sensitive assay (LOD ≤ 15 IU/ml) is the basis for management of response guided therapy of chronic hepatitis C with pegylated IFN plus ribavirin. Rules for early discontinuation of antiviral therapy in non-responders and determination of optimal treatment durations in virologic responders have been developed for application of individualized treatment strategies.

Meta-analysis: re-treatment of genotype I hepatitis C nonresponders and relapsers after failing interferon and ribavirin combination therapy

BACKGROUND

The efficacy of re-treating genotype I hepatitis C virus (HCV) patients who failed combination therapy with interferon/pegylated interferon (PEG-IFN) and ribavirin remains unclear.

AIMS

To quantify sustained virological response (SVR) rates with different re-treatment regimens through meta-analysis of randomized controlled trials (RCTs).

METHODS

Randomized controlled trials of genotype I HCV treatment failure patients that compared currently available re-treatment regimens were selected. Two investigators independently extracted data on patient population, methods and results. The pooled relative risk of SVR for treatment regimens was computed using a random effects model.

RESULTS

Eighteen RCTs were included. In nonresponders to standard interferon/ribavirin, re-treatment with high-dose PEG-IFN combination therapy improved SVR compared with standard PEG-IFN combination therapy (RR=1.49; 95% CI: 1.09-2.04), but SVR rates did not exceed 18% in most studies. In relapsers to standard interferon/ribavirin, re-treatment with high-dose PEG-IFN or prolonged CIFN improved SVR (RR=1.57; 95% CI: 1.16-2.14) and achieved SVR rates of 43-69%.

CONCLUSIONS

In genotype I HCV treatment failure patients who received combination therapy, re-treatment with high-dose PEG-IFN combination therapy is superior to re-treatment with standard combination therapy, although SVR rates are variable for nonresponders (≤18%) and relapsers (43-69%). Re-treatment may be appropriate for select patients, especially relapsers and individuals with bridging fibrosis or compensated cirrhosis.

No beneficial effects of amantadine in treatment of chronic hepatitis C patients

BACKGROUND

Benefit of adding amantadine to antiviral therapy for hepatitis C is controversial.

AIMS

We aimed to examine whether such policy enhances sustained viral response in treatment-naïve patients.

METHODS

297 naïve hepatitis C patients were randomized for treatment with amantadine 200mg or placebo, combined with weight-based ribavirin and 12-day high-dose interferon alpha-2b induction therapy, followed by PEG-interferon alpha-2b (1.5 microg/kg/week up to 26 weeks and thereafter, 1.0 microg/kg/week until week 52). Treatment was discontinued if hepatitis C virus (HCV) RNA was positive at week 24.

RESULTS

49% of patients were (former) drug users. Genotype 1 occurred in 45%, high viral load in 70% and severe fibrosis/cirrhosis in 32%, without differences between amantadine or placebo groups. 90 patients prematurely discontinued treatment, mainly because of grade 3 or 4 toxicity. Intention-to-treat analysis revealed sustained viral response in 47% and 51% of amantadine and placebo groups (p=0.49). Amantadine did not enhance sustained viral response in patients with genotype 1 or high viral load nor did it improve primary non-response, breakthrough or relapse rates. Genotype non-1 and lower pre-treatment gamma GT levels were independent predictors for sustained viral response.

CONCLUSION

Adding amantadine to antiviral therapy of previously untreated chronic hepatitis C patients has no beneficial effects.

Predictive value of suppressor of cytokine signal 3 (SOCS3) in the outcome of interferon therapy in chronic hepatitis C

AIMS

Suppressor of cytokine signaling 3 (SOCS3) can suppress Janus kinase (JAK)-signal transducers and activators of transcription (STAT) signaling by blocking an IFN-induced protein. In this study, the relationship between SOCS3 and phosphorylation of STAT1 in the liver and outcome of interferon therapy were examined.

METHODS

Prior to interferon treatment, we immunostained for SOCS3 and phosphorylated-STAT1 (P-STAT1) in 59 liver specimens from chronic hepatitis C virus (CHC) patients and compared the expression of SOCS3 and clinicopathological factors. Fifty-one patients were receiving peg-interferon alpha-2b and ribavirin therapy and also compared interferon therapy effect and the expression of SOCS3.

RESULTS

Immunostaining for SOCS3 was mainly seen in the periportal area. The concentration of P-STAT1 nuclei was significantly larger in specimens with < 30% area immunostaining to SOCS3 than those in which this area was >/= 30% (10.6 +/- 8.8 vs. 4.6 +/- 6.1, P = 0.004). SOCS3 immunostaining score was significantly correlated with aspartate amino transferase (r = 0.373, P = 0.003), alanine amino transferase (r = 0.337, P = 0.008), platelets (r = -0.273, P = 0.037), and homeostatic model assessment (r = 0.339, P = 0.008). On univariate analysis and multivariate analysis, SOCS3 immunostaining score (0 or 1) and age (<60 years old) were significant predictors of interferon response (odds ratio 10.888; P = 0.010; odds ratio 3.817, P = 0.045 respectively).

CONCLUSION

SOCS3 expression in the liver prior to interferon therapy was correlated with increased insulin resistance and might be a useful predictor of HCV clearance by interferon therapy.

Another ten stories in antiviral drug discovery (part C): "Old" and "new" antivirals, strategies, and perspectives

The ten stories told here deal with (i) ribavirin as an inhibitor of IMP dehydrogenase and (ii) ribavirin, in combination with pegylated interferon, as the present "standard of care" for hepatitis C; (iii) S-adenosylhomocysteine hydrolase inhibitors as antiviral agents; (iv) new adamantadine derivatives for the treatment of influenza A virus infections; (v) 5-substituted 2'-deoxyuridines (i.e. IDU, TFT) for the treatment of herpes simplex virus (HSV) infections; (vi) acyclic guanosine analogues (e.g. acyclovir) for the treatment of HSV infections; (vii) OMP decarboxylase inhibitors (i.e. pyrazofurin) and CTP synthetase inhibitors (i.e. cyclopentenylcytosine) as possible antiviral agents; (viii) the future of cidofovir (and alkoxyalkyl esters thereof) and ST-246 as potential antipoxvirus agents; (ix) the two decade journey from tivirapine to rilpivirine in the ultimate therapy of HIV infections; and (x) the extension of the therapeutic application of tenofovir disoproxil fumarate (Viread) to the treatment of hepatitis B virus infection, in addition to HIV infection.

Study of liver-targeted regulatory T cells in hepatitis B and C virus in chronically infected patients

INTRODUCTION

Regulatory T cells (Tregs) play a critical role in chronic viral infections. The role of Tregs in chronic hepatitis B (CHB) and chronic hepatitis C (CHC) is unknown. This study examined the distribution and frequency of forkhead box p3(+) (Foxp3(+)) Tregs in the liver tissue and compared the clinicopathological characteristics of CHB and CHC patients.

METHODS

Liver needle biopsies were obtained from 26 patients who were hepatitis B surface antigen positive and 27 patients who were hepatitis C virus antibody positive.

RESULTS

The ratio of Foxp3(+) Tregs in CD3(+) T cells was similar in HBV and in HCV cases. In HBV cases, the variables that were positively associated with the ratio of Foxp3(+) Tregs in CD3(+) T cells included the serum alanine aminotransferase level (R=0.402, P=0.025) and the ratio of CD8(+) T cell plus CD56(+) NK cell against CD4(+) T cell (R=0.53, P=0.005). The ratio of Foxp3(+) Tregs in CD3(+) T cells increased more in the severe activity group than in the mild activity group (P=0.04). In HCV cases, the ratio of Foxp3(+) Tregs in CD3(+) T cells increased significantly in terms of the genotype2 (P=0.0002) and male gender (P=0.04). In addition, the ratio of Foxp3(+) Tregs in CD3(+) T cells showed a negative correlation with the ratio of CD8(+) T cell plus CD56(+) NK cell against CD4(+) T cell (R=-0.508, P=0.005) and HCV viral load (R=-0.482, P=0.001).

CONCLUSIONS

Liver-targeted regulatory T cells present similarly in CHB and CHC, but their relationship with the effector cell population, the inflammation grade or the viral load is different between CHB and CHC.

Interferon alpha delivery systems for the treatment of hepatitis C

Hepatitis C virus (HCV) infections are the most common chronic blood-borne viral infections in the world. The prevalence of HCV infections varies significantly by race or ethnicity, with a high prevalence of the disease displayed in the Hispanic population. Additionally, Hispanics with chronic HCV have also more advanced hepatic fibrosis and faster liver fibrosis progression rates than either African Americans or Caucasians. Furthermore, a higher prevalence of cirrhosis and extent of mortality from liver cirrhosis is also observed in the Hispanic population compared with other groups. Current recommendations for treatment of hepatitis C are interferon alpha (IFNalpha)-based monotherapy and combination of IFNalpha preparations with ribavirin. Future treatment regimens will still be based on IFNalpha therapy with or without other effective antiviral agents, currently under investigation. However, there are some inherent limitations, mainly their relative short systemic circulation lifespan, and their unwanted effects on some non-target tissues. New research focuses on the development of novel modified interferon molecules which demonstrate reduced side effects and extended systemic circulation time, which can ultimately provide greater efficacy. Alternative routes for IFNalpha delivery, such as oral delivery, demonstrate challenging but promising areas of research for improving future patient compliance.

Placebo-controlled trial of 400 mg amantadine combined with peginterferon alfa-2a and ribavirin for 48 weeks in chronic hepatitis C virus-1 infection

The impact of amantadine on virologic response rates of interferon-based treatment of chronic hepatitis C is controversial. The aim of this study was to compare virological response rates in patients with chronic hepatitis C virus (HCV)-1 infection treated with 400 mg amantadine or placebo in combination with peginterferon alfa-2a (40 kD) and ribavirin for 48 weeks. Seven hundred four previously untreated chronically HCV-1-infected patients (mean age, 46 +/- 12 years) were randomized to (A) amantadine-sulphate (400 mg/day) (n = 352) or (B) placebo (n = 352), both in combination with 180 microg peginterferon alfa-2a once weekly and ribavirin (1000-1200 mg/day) for 48 weeks. End of treatment and sustained virological response after a 24-week follow-up period were assessed by qualitative reverse transcription polymerase chain reaction (RT-PCR) (sensitivity, 50 IU/mL). Demographic and baseline virological parameters were similar in both treatment groups. In groups A and B, 231 of 352 patients (66%) and 256 of 352 patients (72%) achieved an end of treatment response, and 171 of 352 patients (49 %) and 186 of 352 patients (53 %) a sustained virological response, respectively. On-treatment dropout rate in the amantadine group was significantly higher than in the placebo group (32% versus 23%; P = 0.01). However, adverse events and laboratory abnormalities were similar between both groups. Per-protocol analysis revealed similar sustained virological response rates in both treatment groups (53% versus 55%).

CONCLUSION

In this large placebo-controlled multicenter study, amantadine even at a dose of 400 mg/day did not improve virological response rates of peginterferon alfa-2a and ribavirin in patients with chronic genotype HCV-1 infection.

Distribution and dynamics of adamantanes in a lipid bilayer

The adamantanes are a class of compounds that have found use in the treatment of influenza A and Parkinson's disease, among others. The mode of action for influenza A is based on the adamantanes' interaction with the transmembrane M2 channel, whereas the treatment of Parkinson's disease is thought to relate to a channel block of N-methyl-D-aspartate receptors. An understanding of how these compounds interact with the lipid bilayer is thus of great interest. We used molecular-dynamics simulations to calculate the potential of mean force of adamantanes in a lipid bilayer. Our results demonstrate a preference for the interfacial region of the lipid bilayer for both protonated and deprotonated species, with the protonated species proving significantly more favorable. However, the protonated species have a large free-energy barrier in the center of the membrane. In contrast, there is no barrier (compared with aqueous solution) at the center of the bilayer for deprotonated species, suggesting that the permeant species is indeed the neutral form, as commonly assumed. We discuss the results with respect to proposed mechanisms of action and implications for drug-delivery in general.

Pegylated interferons for chronic hepatitis C virus infection: an indirect analysis of randomized trials

Dual therapy with pegylated interferon and ribavirin is recommended for patients with chronic hepatitis C virus infection who meet criteria for treatment, but it is unclear whether pegylated interferon alfa-2a or pegylated interferon alfa-2b is more effective or associated with fewer adverse events. Because data from head-to-head trials of pegylated interferon regimens are sparse, we performed adjusted indirect analysis using trials comparing dual therapy with pegylated interferon alfa-2a or pegylated interferon alfa-2b vs dual therapy with non-pegylated interferon. We searched for potentially relevant randomized controlled trials using electronic databases and reference lists. A total of 16 trials met inclusion criteria. Adjusted indirect comparisons found no statistically significant differences between dual therapy with pegylated interferon alfa-2a and dual therapy with pegylated interferon alfa-2b on the outcomes sustained virologic response [relative risk (RR) = 1.59, 95% CI: 0.56-4.46], withdrawal due to adverse events (RR = 0.86, 95% CI: 0.29-2.55), anaemia (RR = 1.67, 95% CI: 0.32-8.84), depression (RR = 1.09, 95% CI: 0.41-2.90) or flu-like symptoms (RR = 1.10, 95% CI: 0.53-2.29). Adjusting for potential publication bias and stratifying analyses by indicators of methodological quality, human immunodeficiency virus infection status, hepatitis C virus genotype, dose of ribavirin or dose of pegylated interferon did not change conclusions. There is insufficient evidence to support conclusions that dual therapy with one pegylated interferon is superior to the other. However, because estimates are imprecise, our results also do not rule out a clinically significant difference. Head-to-head trials are needed to verify the results of indirect analyses and provide additional guidance on optimal treatment choices.

Peginterferon alpha-2a and ribavirin versus peginterferon alpha-2a monotherapy in early virological responders and peginterferon alpha-2a and ribavirin versus peginterferon alpha-2a, ribavirin and amantadine triple therapy in early virological nonresponders: the SMIEC II trial in naïve patients with chronic hepatitis C

OBJECTIVE

The objective of this study was to compare the efficacy of anti-hepatitis C virus (anti-HCV) treatment schedules on the basis of an early virological response (EVR), defined as undetectable serum HCV-RNA (<50 IU/ml) after a 12-week induction course of peginterferon alpha-2a (PEG-IFN) 180 mcg/week.

METHODS

A total of 210 interferon-naïve patients (69% male; median age, 42 years) with histologically proven chronic hepatitis C infection (genotype 1: 62%) received PEG-IFN 180 mcg/week for 12 weeks. Patients with EVR (58%) were randomized to continue PEG-IFN monotherapy (n=64) or to add ribavirin (RBV), 800 mg/day (n=57), for 36 additional weeks. Patients without EVR (42%) were randomized to add RBV (n=42), or RBV plus amantadine, 200 mg/day (n=47), for 36 additional weeks. Sustained virological response (SVR, undetectable HCV-RNA 24 weeks after treatment completion) was compared among treatment groups.

RESULTS

Patients with EVR: SVR rate was 60.3% in the PEG-IFN group versus 67.2% in the PEG-IFN+RBV group (NS). In genotypes 2/3, SVR rates were 66.7 versus 73.1% (NS); in genotypes 1/4, SVR rates were 51.6 versus 61.3%, respectively (NS). Patients without EVR: SVR was 16.7% in the PEG-IFN+RBV group versus 31.9% in the triple therapy group (P=0.07). In patients with genotypes 1/4, SVR rates were 9.4 versus 29.7% (P=0.041).

CONCLUSION

In genotypes 1/4 patients without EVR, triple therapy results in higher SVR rates than standard dual therapy. This study confirms that addition of amantadine is beneficial in early-recognized 'difficult-to-treat' patients.

Effect of lactoferrin in patients with chronic hepatitis C: combination therapy with interferon and ribavirin

OBJECTIVES

Lactoferrin has been reported to inhibit hepatitis C virus (HCV) infection in cultured human hepatocytes and HCV viremia in patients with chronic hepatitis C (CHC). The aim of this study was to evaluate the effect of combined triple therapy of lactoferrin, interferon and ribavirin in patients with CHC.

METHODS

A total of 111 Japanese patients with CHC were randomly assigned to a lactoferrin group (n = 50) and a control group (n = 61). The lactoferrin group was treated with lactoferrin for 8 weeks and then with lactoferrin, interferon and ribavirin for 24 weeks; the control group was treated with interferon and ribavirin for 24 weeks. Serum anti-lactoferrin antibody, clinical and laboratory measurement were determined.

RESULTS

The mean HCV RNA titer significantly decreased at the end of lactoferrin monotherapy. Sustained virological response to therapy was significantly higher (P < 0.05) in the lactoferrin responder group (55%) than in the control group (18%).

CONCLUSIONS

The results show that the decrease in HCV RNA titer by lactoferrin monotherapy contributes to the effectiveness of the combined therapy of interferon and ribavirin in patients with CHC. Lactoferrin is a potential useful adjunct treatment for patients with CHC.

Efficacy of amantadine on quality of life in patients with chronic hepatitis C treated with interferon-alpha and ribavirin: results from a randomized, placebo-controlled, double-blind trial

AIM

The aim of this study was to investigate whether amantadine reduces deterioration of quality of life in patients with chronic hepatitis C during and after treatment with interferon-alpha (IFN-alpha) and ribavirin.

PATIENTS AND METHODS

In this randomized, prospective, placebo-controlled, multicenter trial, previously untreated patients with chronic hepatitis C were treated with IFN-alpha plus ribavirin [17] and randomized for treatment with amantadine (200 mg/day, orally, n=136) or placebo (n=131). Quality of life was assessed with the 'Profile of Mood States' scale and the 'Everyday Life' questionnaire at baseline, treatment week (TW) 8, TW24, TW48, and at follow-up.

RESULTS

Early during treatment at TW8, quality of life was not different between patients in the control and the amantadine group. At TW24, the control group but not the amantadine group, however, showed significant deterioration of the modalities depression, fatigue, and vigor compared with baseline. Especially, nonresponders in the amantadine group showed significantly lower deterioration of depression, anger, mind function, everyday life, and zest for life than those in the placebo group. After treatment, the beneficial effects of amantadine disappeared.

CONCLUSION

The addition of amantadine to IFN-alpha plus ribavirin combination therapy may reduce deterioration of depression, fatigue, and vigor during treatment but does not affect quality of life after treatment.

Cochrane systematic review: pegylated interferon plus ribavirin vs. interferon plus ribavirin for chronic hepatitis C

BACKGROUND

About 170 million patients worldwide have chronic hepatitis C. Pegylated interferon plus ribavirin is currently the recommended therapy.

AIM

To evaluate the beneficial and harmful effects of pegylated interferon plus ribavirin vs. interferon plus ribavirin for chronic hepatitis C infection.

METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, Science Citation Index Expanded and contacted pharmaceutical companies and authors of trials (to March 2005).

RESULTS

We included 18 randomized clinical trials with 4811 patients. Eleven trials (61%) had allocation bias risks and all had assessment bias risk because of lack of blinding. Compared with interferon plus ribavirin, pegylated interferon plus ribavirin had significant beneficial effects on sustained virological response [risk ratio (RR): 0.80; 95% CI: 0.74-0.88]. Data were insufficient to determine impact on long-term outcomes. Pegylated interferon plus ribavirin significantly increased dose reductions (RR: 1.44; 95% CI: 1.14-1.82) and adverse events including neutropenia (RR: 2.25; 95% CI: 1.58-3.21), thrombocytopenia (RR: 2.28; 95% CI: 1.14-4.54), arthralgia (RR: 1.19; 95% CI: 1.05-1.35), and injection-site reaction (RR: 2.56; 95% CI: 1.06-6.22).

CONCLUSIONS

Pegylated interferon plus ribavirin compared with interferon plus ribavirin increased the proportion of patients with sustained virological response, but at the cost of more adverse events.

Triple therapy of initial high-dose interferon with ribavirin and amantadine for patients with chronic hepatitis C

AIMS

We previously reported the potential effect of combination therapy of an initial high-dose interferon (IFN) and amantadine on the eradication of HCV-RNA in patients with chronic hepatitis C. The additive effects of amantadine on interferon and ribavirin combination therapy remain controversial. In this study we investigated the efficacy of initial high-dose IFN with ribavirin and amantadine on the virological response in patients with chronic hepatitis C with a high viral load of genotype 1b.

METHODS

Twenty-two patients with high viral loads of genotype 1b hepatitis C virus were enrolled in this pilot study. Patients were administered IFN-beta for four weeks and then IFN-alpha2b for 22 weeks with daily oral administration of ribavirin and amantadine.

RESULTS

A sustained virological response (SVR) was shown in 31.8% (seven of 22 patients). With the naïve patients, the SVR rate was 21.4% (three of 14 patients). In patients who could not eradicate HCV-RNA by previous IFN monotherapy, the SVR rate was 50% (four of eight patients).

CONCLUSION

Triple therapy with an initial high dose of IFN with ribavirin and amantadine may be effective, especially for chronic hepatitis C IFN-retreatment patients with a high viral load of genotype 1b.

Viral determinants of resistance to treatment in patients with hepatitis C

Chronic hepatitis C virus (HCV) infection affects more than 170 million persons worldwide and is responsible for the development of liver cirrhosis in many cases. Standard treatment with pegylated alpha interferon (IFN-alpha) in combination with the nucleoside analogue ribavirin leads to a sustained virologic response in approximately half of the patients. IFN-alpha is classified as an indirect treatment, as it interacts with the host's immune response. The mechanism of action of ribavirin is still unknown. The benefit of triple therapy by adding other antiviral agents, e.g., amantadine, is controversial. Currently, new direct antiviral drugs (HCV protease/polymerase inhibitors) are being evaluated in phase 1/phase 2 trials. Phenotypic resistance to antiviral therapy has been attributed to amino acid variations within distinct regions of the HCV polyprotein. While sensitivity to IFN-alpha-based antiviral therapy in vivo is clearly correlated with the number of mutations within the HCV NS5A protein, the underlying functional mechanisms for this association are unknown. In turn, in vitro, several mechanisms to circumvent the host immune defense or to block treatment-induced antiviral activities have been described for different HCV proteins. By the introduction of direct antiviral drugs, hepatitis C therapy now is entering a new era in which the development of resistance may become the most important parameter for treatment success or failure.

Peginterferon-α2a in the treatment of chronic hepatitis C

Chronic hepatitis C virus infection occurs worldwide and affects over 2.7 million adults in North America. Current standard of care is the combination of pegylated (peg) interferon and ribavirin for 24 weeks in hepatitis C virus genotypes 2 or 3 and at least 48 weeks in chronic hepatitis C virus infection genotypes 1 or 4. Peginterferon-α2a is a 40-kDa linear pegylated molecule that alters the pharmacokinetic properties of unmodified interferon-α. In clinical trials evaluating the combination of peginterferon-α2a and ribavirin in chronic chronic hepatitis C virus infection, sustained virologic response rates have been achieved in 46–52% of patients with genotype 1 and 76–80% of patients with genotypes 2 or 3. Studies on the role of longer treatment duration and retreatment in prior nonresponders are in progress. The main toxicities of peginterferon-α2a are flu-like symptoms and neuropsychiatric disorders, especially depression and cytopenias, and are found in similar rates to those observed with regular inteferon. Future areas of study include the role of peginterferon-α2a in combination with the newer oral chronic hepatitis C virus infection active agents in development.

Optimizing Treatment Outcomes in Chronic Hepatitis C: Management of Non-Response

The overarching goal in treating chronic hepatitis C (CHC) is the prevention of serious hepatic complications such as cirrhosis, end-stage liver disease and hepatocellular carcinoma. Successful eradication of the hepatitis C virus has been shown to prevent liver disease progression and even promote regression of fibrosis. The treatment of CHC has improved significantly over the past decade with the introduction of interferons (IFNs), and more recently, pegylated IFNs. Up to two-thirds of all patients treated with a pegylated IFN combined with ribavirin can now achieve viral eradication if treated according to current guidelines. Despite this success rate, limited treatment options currently exist for the growing number of patients who do not respond to this combination, and those who have previously failed treatment with conventional IFN-based regimens. There are numerous host-and viral-related factors that can contribute to these outcomes. In addition, treatment insufficiency, whether due to treatment type, side effects or non-compliance, can result in inadequate antiviral pressure and a reduced likelihood of response. This review explores putative management strategies for patients who have previously failed to achieve a response to IFN-based therapy, and summarises retreatment options that have been, and are currently being evaluated.

Short-term treatment duration for HCV-2 and HCV-3 infected patients

BACKGROUND

We have shown that 12-14 weeks treatment is effective in HCV-2 or -3 patients with undetectable HCV-RNA after 4 weeks of therapy (rapid virologic response).

PATIENTS

To identify predictors of sustained virologic response, rapid virologic response and relapse following short treatment, we pooled data from the original Italian and Norwegian studies. Four hundreds and three patients were treated with PegIFN alpha-2b (1.0, n=281 or 1.5 microg/kg, n=122) and ribavirin (800-1200 mg) for 12-14 or 24 weeks, depending on negative or positive HCV-RNA at week 4.

RESULTS

Sustained virologic response differed between cases with and without rapid virologic response (85% versus 62%, P<0.0001), mild and severe fibrosis (83% versus 67%, P=0.004), and HCV-2 and -3 (81% versus 73%, P=0.05). In a regression model, RVR (odds ratio 3.49, confidence interval 1.73-5.36) and mild fibrosis (odds ratio 2.91, confidence interval 1.57-5.38) independently predicted sustained virologic response. Rapid virologic response was obtained in 274 (68%) patients, 163/242 (67%) HCV-2, and 111/161 (69%) HCV-3. Patients with RVR had more frequently mild fibrosis (70% versus 54%, P=0.03), and high PegIFN dose (78% versus 64%, P=0.005). In a regression model, mild fibrosis independently predicted rapid virologic response (odds ratio 1.87, confidence interval 1.10-3.16). In rapid virologic response patients, sustained virologic response was achieved in 85% of both HCV-2 and -3. Virologic relapse was observed in 10.6% rapid virologic response patients and was more frequent among those with low ALT (14% versus 2%, P=0.04).

CONCLUSION

In HCV-2 or -3, the HCV-RNA status after 4 weeks of therapy may guide treatment duration. HCV-2 and HCV-3 patients with severe fibrosis are less likely to experience both rapid virologic response and sustained virologic response, and more frequently relapse after a 12 or 14 weeks duration of antiviral therapy.

A randomized trial of pegylated-interferon-alpha2a plus ribavirin with or without amantadine in the re-treatment of patients with chronic hepatitis C not responding to standard interferon and ribavirin

BACKGROUND

There is yet no established treatment for chronic hepatitis C patients non-responder to standard interferon and ribavirin.

AIM

To evaluate efficacy and safety of pegylated-interferon-alpha2a plus ribavirin with or without amantadine in such patients.

METHODS

161 non-responders to standard interferon and ribavirin were randomized into two groups: 81 patients (Group 1) were given weekly Peg-IFN-alpha2a 180 microg plus ribavirin 1,000-1,200 mg/daily for 12 months, 80 patients (Group 2) received weekly Peg-IFN-alpha2a 180 microg plus ribavirin 1,000-1,200 mg/daily and amantadine 200 mg/daily for 12 months.

RESULTS

At the end of follow-up, HCV-RNA was negative in 29.6% of Group 1 and in 21.2% of Group 2 patients (P = 0.22). Patients with genotypes 1 and 4 responded better to bi-therapy (21.7%) than to triple therapy (17.3%, P = 0.5) while among patients with genotypes 2 and 3 there was a trend towards a higher sustained virological response rate when retreated with triple treatment (80% vs. 75%, P = 0.82). On multivariate analysis, genotype 1 or 4, high body mass index and >20% reduction of Peg-interferon were associated with the treatment failure.

CONCLUSIONS

The addition of amantadine does not improve the overall SVR rate in non-responder patients retreated with Peg-IFN and ribavirin; however, about 30% of non-responders may achieve a sustained response, in particular patients with genotypes 2 and 3 show a high SVR (75%).

Cost-effectiveness of Chronic Hepatitis C Treatment with Thymosin Alpha-1

BACKGROUND

More than one million individuals in Mexico are infected with hepatitis C virus (HCV), and 80% are at risk for developing a chronic infection that could lead to hepatic cirrhosis and other complications that impact quality of life and institutional costs. The objective of the study was to determine the most cost-effective treatment against HCV among the following: peginterferon, peginterferon plus ribavirin, peginterferon plus ribavirin plus thymosin, and no treatment.

METHODS

We carried out cost-effectiveness analysis using the institutional perspective, including a 45-year time frame and a 3% discount rate for costs and effectiveness. We employed a Bayesian-focused decision tree and a Markov model. One- and two-way sensitivity analyses were performed, as well as threshold-oriented and probabilistic analyses, and we obtained acceptability curves and net health benefits.

RESULTS

Triple therapy (peginterferon plus ribavirin plus thymosin alpha-1) was dominant with lower cost and higher utility in relationship with peginterferon + ribavirin option, peginterferon alone and no-treatment option. In triple therapy the cost per unit of success was of 1,908 [USD/quality-adjusted life years (QALY)] compared with peginterferon plus ribavirin 2,277/QALY, peginterferon alone 2,929/QALY, and no treatment 4,204/QALY. Sensitivity analyses confirmed the robustness of the base case.

CONCLUSIONS

Peginterferon plus ribavirin plus thymosin alpha-1 option was dominant (lowest cost and highest effectiveness). Using no drug was the most expensive and least effective option.

Amino Acid Variations in Hepatitis C Virus P7 and Sensitivity to Antiviral Combination Therapy with Amantadine in Chronic Hepatitis C

Background

Formation of transmembrane ion channels by hepatitis C virus (HCV) p7 and abrogation of channel function by amantadine was demonstrated in vitro. The relevance of HCV p7 amino acid (aa) variations for response to antiviral therapy with amantadine is unknown.

Methods

HCV p7 was sequenced in 86 individuals who were infected with HCV genotype 1. Thirty-six of 86 patients received amantadine within an interferon-α (IFN-α)-based antiviral therapy. Helical wheel modelling for HCV p7 was performed.

Results

No significant correlation of overall aa variations within HCV p7 was observed with response to IFN-α-based therapy with amantadine in HCV genotype 1a/b infected patients. When analysis was restricted to non-conservative aa variations, a higher number of aa substitutions within complete HCV p7 and transmem-brane helix 2 was associated with non-response in HCV-1b-infected patients receiving therapy with amantadine ( P=0.015 and P=0.037, respectively), without amantadine ( P=0.106 and P=0.118, respectively), and in the total cohort of HCV-1b-infected patients ( P=0.00007 and P=0.011, respectively). Furthermore, substitution L20F was observed more often in non-responders than responders with HCV-1b infection and therapy with amantadine ( P=0.099). By in silico modelling, aa 20 was located toward the p7 channel lumen. Substitution L20F may impair amantadine action by altering the shape of the ion channel pore.

Conclusion

Substitution L20F within HCV p7 may be associated with non-response to combination therapy specifically with amantadine in HCV-1b-infected patients. Non-responders with HCV-1b infection showed higher numbers of non-conservative aa variations within HCV p7 than responders, irrespective of the application of amantadine.

Bile acids alter the subcellular localization of CNT2 (concentrative nucleoside cotransporter) and increase CNT2-related transport activity in liver parenchymal cells

CNT2 (concentrative nucleoside cotransporter) is a plasma membrane high-affinity Na+-coupled adenosine transporter, also localized in intracellular structures. This transporter protein may play additional roles other than nucleoside salvage, since it has recently been shown to be under purinergic control via K(ATP) channels, by a mechanism that does not seem to involve changes in its subcellular localization. In an attempt to identify the agents that promote CNT2 trafficking, bile acids were found to increase CNT2-related transport activity in a K(ATP) channel-independent manner in both Fao hepatoma and rat liver parenchymal cells. A maximum effect was recorded after treatment with hydrophilic anions such as TCA (taurocholate). However, this effect did not involve changes in the amount of CNT2 protein, it was instead associated with a subcellular redistribution of CNT2, resulting in an accumulation of the transporter at the plasma membrane. This was deduced from subcellular fractionation studies, biotinylation of plasma membrane proteins and subsequent CNT2 detection in streptavidin precipitates and in vivo confocal microscopic analysis of the distribution of a YFP (yellow fluorescent protein)-CNT2 construct. The induction of CNT2 translocation, triggered by TCA, was inhibited by wortmannin, dibutyryl-AMPc, PD98059 and colchicine, thus suggesting the involvement of the PI3K/ERK (phosphoinositide 3-kinase/extracellular-signal related kinase) pathway in microtubule-dependent activation of recombinant CNT2. These are novel effects of bile-acid physiology and provide the first evidence for short-term regulation of CNT2 translocation into and from the plasma membrane.

Hepatitis C: a review for primary care physicians

Primary care physicians see many of the estimated 250 000 Canadians chronically infected with the hepatitis C virus (HCV). Of this number, about one-third are unaware they are infected, which constitutes a large hidden epidemic. They continue to spread HCV unknowingly and cannot benefit from advances in antiviral therapy that may clear them of the virus. Many HCV-infected people remain asymptomatic, which means it is important to assess for risk factors and test patients accordingly. The third-generation enzyme immunoassay for HCV antibodies is a sensitive and specific test, although the presence of the virus can be confirmed by polymerase chain reaction testing for HCV RNA in some circumstances. Pegylated interferon-alpha and ribavirin combination therapy clears the virus in about 45%-80% of patients, depending on viral genotype. Preventive strategies and counselling recommendations are also reviewed.

Synthesis and Biological Evaluation of Novel 9-Substituted-8-Hydroxyadenine Derivatives as Potent Interferon Inducers

Recently we reported the adenine derivatives 3a-d as novel interferon (IFN) inducers. In the present study, we conducted a detailed structure-activity relationship study of analogues of 3a-d with respect to their IFN-inducing activity, mainly focusing on the N(9)-position of the adenine. From this study, we found that introduction of the 3-pyridylmethyl moiety was effective to increase in vitro activity, and compound 9ae was identified as being the most potent IFN inducer. This compound gave a minimum effective concentration (MEC) of 3 nM, which is comparable with that of R-848, a second generation IFN inducer. Compound 9ae also demonstrated potent IFN-inducing activity at a dose of 0.1 mg/kg by oral administration in mice. Furthermore, compound 9ae induced IFN in monkeys in a dose dependent manner, with a potency superior to that of R-848. In addition, 9ae did not cause emesis in ferrets even at a dose of 30 mg/kg. In this study the maximum plasma concentration of 9ae was 1019 ng/mL (ca. 3.1 microM), which was approximately 1000-fold higher than the MEC value. Therefore, with respect to both the efficacy and the safety margin, compound 9ae (SM-276001) is considered to be a promising compound as an orally active IFN inducer.

Update on Liver Disease in Hemophilia Patients

Prior to the introduction of viral inactivation techniques in the mid-1980s, the vast majority of patients with hemophilia who received plasma-derived clotting factor concentrates were exposed to and infected with the hepatitis C virus (HCV), a lipid-enveloped bloodborne pathogen. Hemophilia patients may also have been co-infected with the human immunodeficiency virus (HIV) after receiving contaminated blood products. HCV mono-infection has a very slow progression, but patients with hemophilia who are co-infected with HCV and HIV can exhibit a comparatively rapid progression of liver disease. Potential complications of chronic HCV infection are subsequent cirrhosis with hepatic failure and the ultimate onset of hepatocellular carcinoma. The treatment of either of these may involve orthotopic liver transplantation. Liver biopsy and morphologic evaluation of tissue remain the current "gold standard" by which the severity of HCV-induced liver disease can be reliably assessed. Although there has been a reluctance to perform invasive percutaneous liver biopsies in patients with hemophilia, available evidence suggests that they appear to be safe and they certainly provide greater specificity and sensitivity than radiographic techniques such as computerized tomography or magnetic resonance imaging. Treatment of HCV-infected patients is targeted towards preventing the progression of early cirrhosis and end-stage liver disease. The current standard of care for individuals with hemophilia has generally been considered to be the combination of standard interferon-alpha (IFN-alpha) with ribavirin for at least 6 months. Data concerning the use of PEGylated IFN, substituting for standard IFN-alpha, are now emerging, although relatively little of this information relates specifically to hemophilia patients with liver disease. Nevertheless, the favorable data from large non-hemophilia-related HCV disease with early cirrhosis have been extrapolated to the hemophilia scenario, and there has been no evidence in the limited number of hemophiliacs treated in this way to refute this conclusion.