Improved outcomes in patients with hepatitis C with difficult-to-treat characteristics: randomized study of higher doses of peginterferon alpha-2a and ribavirin

Effect of HCV treatment response on insulin resistance: A systematic review and meta-analysis

Sustained virological response (SVR) in hepatitis C virus (HCV) patients treated with pegylated interferon α-2a and ribavirin is associated with reduced insulin resistance (IR), measured as a reduction of homeostasis model assessment (HOMA) scores after 24 weeks of therapy, and reduced fasting serum insulin and serum glucose levels. The present meta-analysis aimed to evaluate the effect of HCV treatment response on IR in HCV patients who achieved SVR and those who did not (non-SVR) after receiving interferon (IFN)-based therapy. The PubMed, Cochrane and Embase databases were searched using combinations of the following search terms: ‘HCV’, ‘hepatitis C’, ‘interferon’, ‘antiviral’, ‘treatment response’ and ‘insulin resistance’. The incidence of IR, HOMA-IR and HOMA-β, as well as fasting glucose and fasting insulin levels, were summarized in terms of basal values and values after the end of treatment for each study. A total of 8 studies were included in the final analysis. There was no significant difference in the reduction in IR between the SVR and non-SVR groups (odds ratio, 0.995; 95% CI=0.613–1.616; P=0.984). However, the SVR group had a significantly higher mean reduction in HOMA-IR (difference in means=−0.485; 95%CI=−0.713 to −0.256; P<0.001) and HOMA-β (difference in means=−15.448; 95%CI=−23.326 to −7.570; P<0.001) compared to the non-SVR group. In conclusion, HCV patients who achieved SVR after IFN-based therapy exhibited improvement in HOMA-IR and HOMA-β. The present results suggest that clinical management of IR and serum glucose levels may be an important way to impact the therapeutic response in HCV patients.

Dose-escalation study evaluating pegylated interferon alpha-2a in patients with cutaneous T-cell lymphoma

BACKGROUND

This open-label, multicenter, dose-escalation study evaluated the safety, tolerability, and efficacy of subcutaneous pegylated (40 kD) interferon α-2a (PEG-IFN α-2a) in patients with cutaneous T-cell lymphoma (CTCL).

PATIENTS AND METHODS

PEG-IFN α-2a was administered subcutaneously at 180 (n = 4), 270 (n = 6), or 360 μg (n = 3) once weekly for 12 weeks. Efficacy was assessed by the proportion of patients with complete response (CR) or partial response (PR).

RESULTS

PEG-IFN α-2a was generally well tolerated, with a moderate number of reductions or withholding of doses because of adverse events (AEs) (25% (n = 1), 66% (n = 4), and 0% (n = 0) in the 180-, 270-, and 360-μg/week groups, respectively). The only dose-limiting toxicity was a grade 3 elevation of liver enzymes in the 270-μg dose group. The most common AEs were fatigue, acute flu-like symptoms, and hepatic toxicity. The major response rate (CR or PR) was 50% in the 180-μg group (CR, 50%; PR, 0%), 83% in the 270-μg group (CR, 67%; PR, 17%), and 66% in the 360-μg group (CR, 33%; PR, 33%).

CONCLUSION

PEG-IFN α-2a at doses up to 360 μg once weekly was well tolerated in patients with CTCL up to the highest dose group and showed good response rates. Due to their good tolerance even in high doses, they might be an option for patients not tolerating standard IFN-α preparations. However, for this purpose and to evaluate comparability between standard and PEG-IFN larger clinical trials are needed, alone and in combination with oral photochemotherapy (PUVA).

Improved pharmacodynamics and pharmacokinetics after i.v. application of peginterferon alfa-2a in hepatitis C null responders

BACKGROUND & AIM

Mechanisms of non-responsiveness to peginterferon alfa-2a are not completely understood. Inadequate plasma levels may contribute to reduced response. The aim of this prospective, multicentre, crossover, Phase 1 study was to evaluate the pharmacokinetics and viral kinetics of intravenous vs. subcutaneous peginterferon alfa-2a in patients with genotype 1 chronic hepatitis C infection who showed null response to previous peginterferon/ribavirin.

METHODS

Patients were randomized in four treatment arms to subcutaneous or intravenous peginterferon alfa-2a 180 μg, once or twice weekly for 2 weeks. After a washout phase of 6 weeks, patients first receiving intravenous administration switched to subcutaneous or vice versa for additional 2 weeks.

RESULTS

Intravenous administration of pegylated interferon resulted in a stronger and faster decline in HCV RNA than subcutaneous administration with a maximum decline of 1.17 log10 vs. 0.41 log10 or 1.32 log10 vs. 0.54 log10 after a once or twice weekly application, respectively. Pharmacokinetic studies revealed significantly higher maximum concentration (C(max))(0-12) h and C(max 0-7) d following intravenous administration, irrespective of dosing frequency A rapid rebound in HCV RNA was observed in all treatment arms. Adverse events occurred more frequently following intravenous administration.

CONCLUSION

Intravenous administration of peginterferon alfa-2a results in considerably higher plasma concentration and a stronger decline in HCV RNA and offers an interesting approach in order to overcome interferon non-responsive state in patients with full null response to previous peginterferon/ribavirin combination therapy.

Identification of naïve HVC-4 patients who may be treated with pegylated-interferon and ribavirin according to IL28B polymorphisms

BACKGROUND

The current treatment of HCV-4 patients is dual therapy with PEG-IFN and ribavirin; however, new drugs against this genotype will be available within few months. Despite the evidenced good virological response in IFN-free regimens, the high cost of these new therapies will require patient selection. In our paper we propose the use of both rs8099917 and rs12979860 IL28-B polymorphisms, in order to identify potentially categories of SVR, null-responder and relapse and consequently to choose the dual therapy or novel approach.

METHODS

One hundred and sixty-nine patients with chronic hepatitis C and genotype 4 treated with pegylated interferon and ribavirin for 48weeks were retrospectively studied. All patients were genotyped for rs8099917 and rs12979860 interleukin-28B polymorphisms.

RESULTS

80 patients with SVR (88.8%) had the TT/CC or TT/TC (rs8099917/rs12979860) (p<0.001) genotypes; the null-responders (n=13), 9 (69.2%) showed the GG/TT allelic distribution (p<0.001); relapsers showed a prevalent distribution of the TG/TC genotype (83.3%) (p<0.001). The 6 (100%) breakthrough patients showed TT/TC genotype, while the partial responders patients did not show any particular IL-28B genetic profile. Genetic profiles different from TT/CC showed 94.9% negative predictive value for SVR, with 92.6% of sensitivity and 65.2% of specificity. Insulin-resistance, diabetes and liver fibrosis were not relevant in our multivariate analysis.

CONCLUSIONS

The combination of both rs8099917/rs12979860 polymorphisms is useful for early identification of SVR, null-responders and relapsers. This could be used to chose between standard dual therapy or novel approach with IFN-free regimens.

Impact of the peginterferon-α 2a and ribavirin plasma levels on viral kinetics and sustained virological response in genotype 1 HCV/HIV-co-infected patients with the unfavourable non-CC IL28B genotypes

Studies on the association between the peginterferon-α and ribavirin levels and sustained virological response (SVR) have shown yielded conflicting results, but most of them were performed before the influence of IL28B polymorphisms was known. Our aim was to assess the effects of peginterferon-α 2a and ribavirin plasma levels on viral kinetics and SVR in hepatitis C virus genotype 1 HCV-1/HIV-co-infected patients according to IL28B genotype. This was a cohort study of HCV-1/HIV-co-infected patients who were HCV-treatment naïve and for whom the efficacy of peginterferon-α 2a plus ribavirin was evaluated by per-protocol analysis. The peginterferon-α 2a and ribavirin levels were measured by ELISA and HPLC-UV, respectively. The relationships among host and viral factors, the trough drugs levels and virological responses were analysed by multivariate regression analyses. A total of 131 Caucasian patients were included (cirrhosis:38.9%). Overall, SVR rate was 39.6%. In patients with CC IL28B genotype, SVR was related neither to peginterferon-α 2a nor to ribavirin plasma levels, while higher levels of both drugs were the only variables independently associated with SVR in individuals with CT/TT IL28B genotypes (OR, 5.02; CI95 , 1.45-17.1; P = 0.001 and 4.0; CI95 , 1.08-14.7; P = 0.038, respectively). Moreover, faster viral declines were observed in CT/TT patients when pegIFN-α 2a and ribavirin plasma levels were greater than 3400 pg/mL and 1.6 μg/mL, respectively. In contrast to the results for CC patients, the results in patients carrying the unfavourable CT/TT IL28B genotypes showed that plasma levels of both drugs have significant effects on viral kinetics and SVR.

Kinetics of relapse after pegylated interferon and ribavirin therapy for chronic hepatitis C

To optimize standard treatment of chronic hepatitis C in responder patients who have achieved undetectable viral load, a prospective study was conducted to determine the factors and kinetics of virologic relapse. Responder patients were monitored 2, 4, 8, 12, 16, and 24 weeks after the end of treatment with pegylated interferon and ribavirin. Forty-seven of the 154 patients (30.5%) relapsed. Relapse was significantly associated with absence of rapid virologic response (RVR), retreatment, higher baseline viral load, older age, and lower weight-based dose of pegylated interferon. Relapse was more frequent in patients failing to achieve a RVR after receiving pegylated interferon alpha 2a < 2.5 µg/week or alpha 2b < 1.5 µg/week (P = 0.002). Among patients infected with hepatitis C virus (HCV) genotype 1 with non-CC IL-28B polymorphism (rs12979860), viral decay during treatment was lower in relapsers (P = 0.003 at week 4). Relapse was detected at weeks 2, 4, 8, and 12 after the end of treatment for 5, 8, 10, and 6 patients infected with HCV genotype 1, respectively. Positive predictive values for sustained virologic response were 70.9%, 80.2%, 91.9%, and 98.8% at weeks 2, 4, 8, and 12, respectively. Only one patient relapsed beyond 24 weeks. Closer follow-up and treatment adaptation in patients failing to achieve RVR may decrease the relapse rate in slower responders and heavier patients. Monitoring viral load as early as 1 month after the end of treatment could be useful to assess virologic response.

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.

Meta-analysis: mortality and serious adverse events of peginterferon plus ribavirin therapy for chronic hepatitis C

BACKGROUND

Pegylated interferon (PEG-IFN) plus ribavirin (RBV) therapy is the current standard of care for patients with chronic hepatitis C. Determining precisely the risk of serious adverse events (SAEs) and mortality from a single study is rather difficult because of the infrequency of such events. The aim of this systematic review was to assess the rates of SAEs and the mortality of PEG-IFN/RBV therapy in a pooled large sample, and to assess the relationship between SAEs and mortality rates and therapeutic characteristics.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and the Cochrane Library to identify randomized controlled trials evaluating the efficacy and safety of PEG-IFN/RBV therapy. We calculated the crude mortality and SAE rates with 95% confidence intervals (CIs).

RESULTS

Eighty studies with 153 treatment arms that included 27569 patients were enrolled (14401 patients treated with Peg-IFN alpha-2a/RBV and 13168 with Peg-IFN alpha-2b/RBV). All-cause and treatment-related deaths were observed in 50 (0.18%; 95% confidence interval [CI] 0.13-0.24%) and sixteen (0.058%; 95% CI 0.033-0.094%) patients, respectively. The crude SAE rate was 7.08% (95% CI 6.75-7.41%). Subgroup analysis revealed higher SAE rates in patients receiving PEG-IFN alpha-2a than in those with PEG-IFN alpha-2b (7.45 vs. 6.74%), and higher SAE rates with higher doses than with the lower doses in PEG-IFN-2a and 2b (11.94 vs. 6.99%, 7.10 vs. 5.05%, respectively), and with extended duration (> 48 weeks) than with standard duration (48 weeks) (15.5 vs. 6.67%) in PEG-IFN alpha-2a.

CONCLUSION

The mortality rate during PEG-IFN/RBV therapy was acceptably low, but the rate of SAEs was not negligible in a treatment for a benign disease, and the rate was affected by treatment regimens.

Safety profile of standard- vs. high-dose peginterferon alfa-2a plus standard-dose ribavirin in HCV genotype 1/4 patients: pooled analysis from 5 randomized studies

OBJECTIVE

This analysis examines the safety profile of standard- versus high-dose peginterferon alfa-2a.

METHODS

Data were pooled from five trials including HCV genotype 1- or 4-infected naive and treatment-experienced patients (n = 2,940). Patients were randomized to receive peginterferon alfa-2a at 180 μg/week (standard-dose; n = 1,672) or 360 μg/week (high-dose; n = 1,268) plus ribavirin 1,000/1,200 mg/day for 12 weeks; after 12 weeks, all received standard dose. This safety analysis was restricted to the first 12 weeks.

RESULTS

In standard and high-dose groups, similar frequencies of serious adverse events (SAEs, 3.2 and 4.2%, respectively) and treatment discontinuations for safety reasons (2.8 and 2.9%) were reported. More patients reported weight decrease as an adverse event (AE) in the 360 μg/week group (7.7 vs. 3.3%). Significant (p < 0.05) independent predictors for discontinuation due to safety were older age, male gender, lower albumin and low neutrophil count, but not the starting dose of peginterferon alfa-2a. Although more laboratory abnormalities were reported in patients receiving high-dose peginterferon alfa-2a, this was not reflected in AEs or discontinuations, suggesting these are adequately managed by dose modification.

CONCLUSIONS

High-dose peginterferon alfa-2a for 12 weeks does not significantly increase the incidence of SAEs or discontinuations for safety reasons, beyond that of a standard dose regimen.

Treatment indication and response to standard of care with peginterferon and ribavirin in acute and chronic HCV infection

Great strides have been made in the treatment of hepatitis C virus (HCV) infection in the past decade. Although there is much focus on the development of new direct-acting antivirals (DAA), interferon and ribavirin remain the backbone of therapy for both acute and chronic HCV infections. While DAA therapy will likely eventually largely replace interferon, in much of the world and for genotype non-1 patients, peginterferon and ribavirin remain first-line therapy. Interferon-based therapy is highly effective in acute HCV with high response rates with short courses of therapy. Unfortunately once infection progresses to chronicity, treatment success rates drop off considerably. The indications, pre-treatment evaluation and efficacy of peginterferon and ribavirin therapy in the treatment of acute and chronic HCV infection are discussed with strategies to improve outcomes and manage adverse events.

Closed tube method for rapid screening of IL28B polymorphisms involved in response to hepatitis C treatment

BACKGROUND & AIM

Hepatitis C is a liver disease caused by the hepatitis C virus. Interferon and ribavirin combination therapy has been a standard treatment of chronic hepatitis C. But only about 50% of patients have positive response to treatment and achieve so called sustained virological response. Recent studies indicate association of several single nucleotide polymorphisms near IL28B gene and response of hepatitis C patients to combined interferon/ribavirin treatment. In this study, rapid, specific and cost-effective small amplicon genotyping method for the two clinically important polymorphisms, rs12979860 C > T and rs8099917 T > G, near the IL28B gene is described.

METHODS

The distribution of genotypes of 181 HCV-uninfected Slovak Caucasians was analyzed using this novel method, based on a real-time melting analysis of the small amplicon.

RESULTS AND CONCLUSIONS

The frequency of wild-type (TT) homozygotes for rs8099917 was 66.30%, frequency of heterozygotes (TG) was 30.94% and we found only 2.76% subjects homozygous for risk G allele (allelic frequencies: T = 81.77%, G = 18.23%) were found. The frequency of wild-type genotype (CC) for rs12979860 was 49.72%, frequencies of heterozygous (CT) and risk-allele homozygous genotypes (TT) were 39.78% and 10.50%, respectively (allele frequencies: C = 69.61%, T = 30.39%). Statistically significant differences in the distribution of the alleles between the men and the women were not found. The novel method developed in our laboratory proved to be simple and highly customizable.

Impact of ribavirin dose on retreatment of chronic hepatitis C patients

AIM: To study the efficacy and factors associated with a sustained virological response (SVR) in chronic hepatitis C (CHC) relapsing patients.

METHODS: Out of 1228 CHC patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV), 165 (13%) had a relapse. Among these, 62 patients were retreated with PEG-IFN-α2a or -α2b and RBV. Clinical, biological, virological and histological data were collected. Initial doses and treatment modifications were recorded. The efficacy of retreatment and predictive factors for SVR were analyzed.

RESULTS: An SVR was achieved in 42% of patients. SVR was higher in young (< 50 years) (61%) than old patients (27%) (P = 0.007), and in genotype 2 or 3 (57%) than in genotype 1 or 4 (28%) patients (P = 0.023). Prolonging therapy for at least 24 wk more than the previous course was associated with higher SVR rates (53% vs 28%, P = 0.04). Also, a better SVR rate was observed with RBV dose/body weight > 15.2 mg/kg per day (70% vs 35%, P = 0.04). In logistic regression, predictors of a response were age (P = 0.018), genotype (P = 0.048) and initial RBV dose/body weight (P = 0.022). None of the patients without a complete early virological response achieved an SVR (negative predictive value = 100%).

CONCLUSION: Retreatment with PEG-IFN/RBV is eff-ective in genotype 2 or 3 relapsers, especially in young patients. A high dose of RBV seems to be important for the retreatment response.

Impact of obesity on the bioavailability of peginterferon-α2a and ribavirin and treatment outcome for chronic hepatitis C genotype 2 or 3

Background and Aims

Having a body mass index above or equal to 30 kg/m² in conjunction with chronic hepatitis C virus infection is associated with non-responsiveness to treatment with interferon and ribavirin, but details regarding the mechanisms whereby obesity reduces the efficacy of therapy remain unclear.

Methods

This study evaluated impact of obesity on outcome as well as interferon and ribavirin concentrations following standard-of-care fixed dosing with peginterferon-α2a 180 µg once weekly and ribavirin 800 mg daily among 303 HCV genotype 2/3-infected patients enrolled in the per-protocol analysis of a recently completed phase III trial (NORDynamIC).

Results

Patients with BMI ≥30 kg/m² showed poorer outcome following 24 weeks of therapy (SVR 62% vs. 89% for BMI ≥30 vs. <30; P = 0.006) along with significantly higher steatosis grade (P = 0.002), HOMA-IR (P<0.0001), triglyceride levels (P = 0.0002), and baseline viral load (P = 0.028). Obesity was also significantly associated with lower plasma interferon concentrations on days 3, 7, and 29 (P = 0.02, P = 0.0017, and P<0.0001, respectively) and lower plasma ribavirin concentrations day 29 (P = 0.025), and lower concentration of interferon in turn was associated with a poorer first phase reduction in HCV RNA (P<0.0001). In multivariate analysis, ribavirin concentrations week 12, interferon concentrations day 29, and baseline HCV RNA levels were independent predictors of achieving SVR among patients treated for 24 weeks (n = 140).

Conclusions

Reduced bioavailability of interferon and ribavirin along with higher baseline viral load are dominant risk factors for treatment failure in obese patients with chronic hepatitis C.

Polyfunctional CD8(+) T cells are associated with the vaccination-induced control of a novel recombinant influenza virus expressing an HCV epitope

In hepatitis C virus (HCV) infection, CD8(+) T cell responses have been shown to be important in viral clearance. Examining the efficacy of CD8(+) T cell vaccines against HCV has been limited by the lack of an HCV infectious model in mice and the differences between MHC restriction in humans and mice. Using HLA-A2 transgenic HHD mice, we demonstrate that intranasally delivered Pam2Cys-based lipopeptides containing HLA-A2-restricted HCV epitopes can induce polyfunctional CD8(+) T cell responses in several organs including the liver. To examine the activity of these responses in an infectious context, we developed a recombinant influenza virus that expresses the NS5B(2594-2602) epitope from non-structural protein 5B of hepatitis C virus (PR8-HCV(NS5B)). We showed that mice inoculated with a lipopeptide containing the NS5B epitope had reduced viral loads following challenge with the PR8-HCV(NS5B) virus. This reduction was associated with the induction of NS5B(2594-2602)-specific IFN-γ and TNF-α co-producing CD8(+) T cells. The T cell receptor usage in the NS5B(2594-2602) response was found to exhibit a Vβ8.1/8.2 bias that was characterized by a narrow repertoire and a common CDR3β motif. This work has identified CD8(+) T cell functions induced by lipopeptides that are associated with viral control and demonstrate the potential of lipopeptide-based vaccines as candidates for treatment of HCV infection.

Relative impact of ribavirin monitoring and HIV coinfection on sustained virological response in patients with chronic hepatitis C

BACKGROUND

In chronic hepatitis C, higher ribavirin (RBV) concentrations are associated with sustained virological response (SVR); target concentration cutoffs have been proposed. As RBV displays interindividual variability, monitoring of RBV plasma levels appears relevant. The impact of RBV therapeutic drug monitoring (TDM(RBV)) on SVR has not been explored in current practice. Our study aimed to assess this impact.

METHODS

Three patient groups were defined as RBV cutoffs achieved at week 12 (group A1), not achieved (group A2), and one without RBV concentration assessment (group B). A predictive model assessed the group impact on SVR in multivariate analysis, while adjusting for additional predictive factors. A specific evaluation of HIV-HCV-coinfected patients was performed.

RESULTS

A total of 122 patients were included. In group A1 (n=30, HIV-positive =18), SVR, relapse and non-response rates were 60%, 17% and 23%, respectively; in group A2 (n=32, HIV-positive =18), 25%, 19% and 56%, respectively; and in group B (n=60, HIV-positive =3), 52%, 33% and 15%, respectively (P=0.0004). The patient group was an independent predictor of SVR (P=0.01), along with baseline viral load and HCV genotype. HIV coinfection did not impede the SVR rate. The cutoffs were achieved in 62% and 28% (P=0.008) of patients, when TDM(RBV) was performed or not, respectively.

CONCLUSIONS

The achievement of RBV cutoffs is a predictive factor of SVR independent of HIV coinfection. It makes it possible to reach high SVR rates, avoid relapse and obtain the same SVR rates in HIV-HCV-coinfected as in HCV-monoinfected patients. TDM(RBV) enables RBV concentration cutoffs to be reached more frequently and could thus be a useful tool to optimize hepatitis C treatment.

Reducing Peg-IFN doses causes later virologic response or no response in HCV genotype 1 patients treated with Peg-IFN alfa-2b plus ribavirin

BACKGROUND

The timing to the first undetectable hepatitis C virus (HCV) RNA level is strongly associated with sustained virologic response in pegylated interferon (Peg-IFN) plus ribavirin combination therapy for patients with chronic hepatitis C (CH-C) with genotype 1. This study was conducted to clarify the impact of drug exposure to Peg-IFN on the timing of HCV RNA negativity in Peg-IFN plus ribavirin combination therapy for CH-C patients with genotype 1.

METHODS

A total of 1409 patients treated with Peg-IFN alfa-2b plus ribavirin were enrolled and classified into four categories according to the Peg-IFN dosage. Furthermore, 100 patients were extracted from each Peg-IFN dosage category to adjust for characteristic factors, using the propensity score method.

RESULTS

Peg-IFN exposure was dose-dependently associated with the timing of HCV RNA negativity (p ≤ 0.001). The HCV RNA negative rate at week 4 decreased from 12% with a Peg-IFN dose of >1.5 μg/kg/week to 1-3% with a dose of <1.5 μg/kg/week (p ≤ 0.001), and at week 12 the rate had decreased from 44% with a dose of ≥1.2 μg/kg/week to 18% with a dose of <1.2 μg/kg/week (p = 0.001). Treatment failure (patients without a 1-log decrease of HCV RNA at week 4 or a 2-log decrease of HCV RNA at week 12, or positive at week 24) was found in 54-66% of patients given <1.2 μg/kg/week (p ≤ 0.001), and these patients accounted for 64% of the non-responders.

CONCLUSIONS

The timing of HCV RNA negativity depends significantly on the Peg-IFN dose. Reducing the Peg-IFN dose can induce a later virologic response or non-response in HCV genotype 1 patients treated with Peg-IFN plus ribavirin.

Insulin resistance impairs viral dynamics independently of ethnicity or genotypes

BACKGROUND AND AIM

Data concerning the influence of insulin resistance (IR) and ethnicity on early phases of viral kinetics after initiation of peginterferon plus ribavirin in treatment-naive, chronic hepatitis C (CHC) patients are limited.

METHODS

A total of 263 nondiabetic CHC patients treated with peginterferon plus ribavirin were enrolled for analysis from an Egyptian and Spanish center. IR was evaluated by homeostasis model assessment (HOMA)-IR. Hepatitis C virus (HCV) RNA levels were measured at baseline, 48 hours, 2, 4, and 12 weeks after treatment initiation. Sustained virological response (SVR) was examined 24 weeks after therapy discontinuation.

RESULTS

Baseline HOMA-IR strongly influenced 48 hours viral dynamics. HCV-RNA decay observed at 48 hours after the first injection of peginterferon was significantly lower (0.91±0.51 log) in patients with HOMA ≥2 compared with those with HOMA <2 (1.8±0.95 log, P=0.005) this effect was independent of stage of liver fibrosis, HCV genotype, and ethnicity. These differences remained with several cutoffs such as HOMA >3 or HOMA >4. Multivariate analysis identified baseline insulin levels as the main independent variable affecting the 48-hour response in addition to baseline HCV-RNA. The difference in early viral kinetics between patients with HOMA ≥2 or <2 is associated with a significant difference in the percentage of patients achieving both rapid virological response and SVR.

CONCLUSIONS

IR is a major determinant of the early viral kinetic response to peginterferon plus ribavirin, which has a great impact on subsequent rapid virological response and SVR in CHC patients. This suggests that strategies to improve IR may have a positive effect on SVR and may be early monitored.

A randomized, multicenter study comparing steroid-free immunosuppression and standard immunosuppression for liver transplant recipients with chronic hepatitis C

This randomized, prospective, multicenter trial compared the safety and efficacy of steroid-free immunosuppression (IS) to the safety and efficacy of 2 standard IS regimens in patients undergoing transplantation for hepatitis C virus (HCV) infection. The outcome measures were acute cellular rejection (ACR), severe HCV recurrence, and survival. The patients were randomized (1:1:2) to tacrolimus (TAC) and corticosteroids (arm 1; n = 77), mycophenolate mofetil (MMF), TAC, and corticosteroids (arm 2; n = 72), or MMF, TAC, and daclizumab induction with no corticosteroids (arm 3; n = 146). In all, 295 HCV RNA-positive subjects were enrolled. At 2 years, there were no differences in ACR, HCV recurrence (biochemical evidence), patient survival, or graft survival rates. The side effects of IS did not differ, although there was a trend toward less diabetes in the steroid-free group. Liver biopsy samples revealed no significant differences in the proportions of patients in arms 1, 2, and 3 with advanced HCV recurrence (ie, an inflammation grade ≥ 3 and/or a fibrosis stage ≥ 2) in years 1 (48.2%, 50.4%, and 43.0%, respectively) and 2 (69.5%, 75.9%, and 68.1%, respectively). Although we have found that steroid-free IS is safe and effective for liver transplant recipients with chronic HCV, steroid sparing has no clear advantage in comparison with traditional IS.

Viral kinetics during the first weeks of pegylated interferon and ribavirin treatment can identify patients at risk of relapse after its discontinuation: new strategies for such patients?

BACKGROUND

Pegylated interferon (PEG-IFN) and ribavirin is the most effective treatment for chronic hepatitis C virus (HCV) hepatitis, but the rate of sustained virological response (SVR) remains approximately 50%, and 15-20% of all treated patients have a virological relapse after completing the treatment. Studies on the SVR have failed to discriminate between non-responders and relapsers.

AIMS

To identify the risk factors for relapse among patients with an end-of-treatment response (ETR).

METHODS

We retrospectively analyzed 281 patients consecutively treated with PEG-IFN and ribavirin with a follow-up period of at least 24 weeks. The baseline details collected on each patient included demographic data, histological features, and biochemical profiles.

RESULTS

Forty-six patients (16.4%) relapsed during the first 6 months of follow-up after discontinuing the therapy. Relapser patients were significantly older, had more steatosis, fibrosis, and showed significantly lower rapid virological response (RVR) rates compared with SVR patients. By logistic regression analysis, only the absence of RVR was found to be significantly associated with relapses in both subgroups of patients with genotypes 1 and 4 (p < 0.004) and those with genotypes 2 and 3 (p < 0.006). Severe fibrosis was also predictive of relapsing disease, but only for genotypes 2 and 3 patients (p < 0.003). During the treatment, serum HCV-RNA decreased more rapidly in patients with SVR compared to non-responder and relapser patients (p < 0.001). Interestingly, relapser patients exhibited an intermediate serum HCV-RNA decay during the first 4 weeks of therapy.

CONCLUSION

Among HCV patients treated with PEG-IFN and ribavirin, the absence of RVR was the most important independent predictor of relapse, independent of the HCV genotype. In the subgroup of genotypes 2 and 3 patients, the severity of fibrosis was also an important factor associated with the relapse rate.

Therapeutic implications of hepatitis C virus resistance to antiviral drugs

Treatment of chronic hepatitis C is currently based on a combination of pegylated interferon-o! and ribavirin. Neither drug exerts direct selective pressure on viral functions, meaning that interferon-a/ribavirin treatment failure is not due to selection of interferon-a- or ribavirin-resistant viral variants. Several novel antiviral approaches are currently in preclinical or clinical development, and most target viral enzymes and functions, such as hepatitis C virus protease and polymerase. These new drugs all potentially select resistant viral variants both in vitro and in vivo, and resistance is therefore likely to become an important issue in clinical practice.

Meta-analysis: insulin resistance and sustained virological response in hepatitis C

BACKGROUND

A higher baseline homeostasis model assessment of insulin resistance (HOMA-IR) score has sometimes predicted a poorer sustained virological response (SVR) rate to peginterferon/ribavirin therapy in treatment-naïve chronic hepatitis C patients.

AIM

To perform a meta-analysis to evaluate the impact of HOMA-IR on SVR in hepatitis C.

METHODS

Relevant studies were identified by searching Medline and EMBASE. We identified 17 publications that addressed the influence of insulin resistance on SVR. The random effect model of Der Simonian and Laird method were used for heterogeneous studies using the Meta-Disc software 1.4, Madrid, Spain.

RESULTS

Normal insulin sensitivity was associated with a higher rate of SVR [odds ratio (OR) 2.86 (95%CI: 1.97-4.16)] in comparison with insulin resistance. Moreover, in separate analysis by genotype selecting studies that used HOMA-IR > 2 as cut-off defining insulin resistance, SVR was higher in patients with HOMA-IR < 2 in all genotypes: HCV-1 [OR: 2.16 (95%CI: 1.51-3.08)], HCV-2&3 [OR: 3.06 (95%CI: 1.06-8.82)] and HCV-4 [OR: 6.65(95%CI: 2.51-17.61)]. Studies reporting no association between HOMA and SVR included easy-to-cure cohorts, analysed variables strongly related with insulin resistance like body mass index, steatosis, hyper γGT, age and fibrosis and reported differences in handling and interpretation of HOMA-IR.

CONCLUSION

Elevated HOMA-IR was associated with a lower cure rate of patients with hepatitis C treated with Peg-IFN-α/ribavirin irrespective of genotype, and the more difficult-to-treat cohort, the better the HOMA-IR prediction. HOMA-IR is, as a surrogate marker of insulin resistance, susceptible to some biases derived from both handling and interpretation.

Rapid virological response is the most important predictor of sustained virological response across genotypes in patients with chronic hepatitis C virus infection

BACKGROUND & AIMS

The probability of response to peginterferon and ribavirin is associated with numerous host and virological factors. Attainment of a rapid virological response (RVR), defined as undetectable HCV RNA at week 4 during treatment with peginterferon and ribavirin, is highly predictive of sustained virological response (SVR). The aim of the present study was to determine the relative importance of the kinetics of antiviral response compared to baseline host and virological factors for predicting SVR.

METHODS

A retrospective analysis of 1383 patients, encompassing genotypes 1-4, treated with peginterferon alfa-2a and ribavirin, was performed. Baseline characteristics were compared across HCV genotypes and pretreatment factors associated with RVR were identified. The relative significance of RVR compared to other baseline factors for predicting SVR was analyzed by multiple logistic regression analysis.

RESULTS

RVR was achieved by 16% of patients with genotype 1 and 71% and 60% of those with genotype 2 and 3, respectively. Among patients who achieved RVR, the rate of SVR was high across all genotypes and ranged from 88% to 100% (genotypes 1-4). Baseline factors predictive of RVR included genotype, younger age, lower initial viral load, higher ALT ratio, absence of advanced fibrosis, and younger age. Notably, the presence of RVR generated the highest odds ratio (5.47, 95% confidence interval 3.97-7.52) for predicting SVR in multiple logistic regression analysis of these factors.

CONCLUSIONS

Attainment of RVR varies by genotype and is associated with several baseline factors. Patients who achieve RVR have the highest rates of SVR, regardless of genotype. These findings have important implications for predicting and managing response-guided combination antiviral therapies.

Should ribavirin be used to treat hepatitis C in dialysis patients?

Hepatitis C virus infection adversely affects outcomes in patients with chronic kidney disease undergoing maintenance dialysis. Pegylated interferon and ribavirin, the standard-of-care treatment in patients with intact renal function, is associated with severe side effects, toxicity, and high dropout rates in this population. Ribavirin has an important role in maintaining antiviral response following completion of therapy and increases sustained viral response (SVR) rates. However, the use of ribavirin in dialysis patients has been limited by the high frequency of severe hemolytic anemia and is currently reserved for study protocols and highly selected candidates treated at experienced centers. Encouraging data from small trials have shown a significant increase in SVR rates with the use of different dosing regimens of ribavirin in addition to interferon-based therapy and aggressive erythroid-stimulating agent support in dialysis patients. Use of ribavirin in selected dialysis patients, particularly renal transplant candidates, by experienced clinicians is appropriate.

Peginterferon and ribavirin treatment for hepatitis C virus infection

Pegylated interferon α (IFNα) in combination with ribavirin is currently recommended as a standard-of-care treatment for chronic hepatitis C virus (HCV) infection. This combination therapy has drastically improved the rate of sustained virological response, specifically in difficult-to-treat patients. Recently, individualized treatment, such as response-guided therapy, is being developed based on host-, HCV- and treatment-related factors. Furthermore, modified regimens with currently available medications, novel modified IFNα and ribavirin or combinations with specifically targeted antiviral therapy for HCV agents, are currently being investigated. The purpose of this review is to address some issues and epoch-making topics in the treatment of chronic HCV infection, and to discuss more optimal and highly individualized therapeutic strategies for HCV-infected patients.

Ribavirin potentiates interferon action by augmenting interferon-stimulated gene induction in hepatitis C virus cell culture models

The combination of pegylated interferon (PEG-IFN) and ribavirin is the standard treatment for chronic hepatitis C. Our recent clinical study suggests that ribavirin augments the induction of interferon-stimulated genes (ISGs) in patients treated for hepatitis C virus (HCV) infection. In order to further characterize the mechanisms of action of ribavirin, we examined the effect of ribavirin treatment on ISG induction in cell culture. In addition, the effect of ribavirin on infectious HCV cell culture systems was studied. Similar to interferon (IFN)-α, ribavirin potently inhibits JFH-1 infection of Huh7.5.1 cells in a dose-dependent manner, which spans the physiological concentration of ribavirin in vivo. Microarray analysis and subsequent quantitative polymerase chain reaction assays demonstrated that ribavirin treatment resulted in the induction of a distinct set of ISGs. These ISGs, including IFN regulatory factors 7 and 9, are known to play an important role in anti-HCV responses. When ribavirin is used in conjunction with IFN-α, induction of specific ISGs is synergistic when compared with either drug applied separately. Direct up-regulation of these antiviral genes by ribavirin is mediated by a novel mechanism different from those associated with IFN signaling and intracellular double-stranded RNA sensing pathways such as RIG-I and MDA5. RNA interference studies excluded the activation of the Toll-like receptor and nuclear factor κB pathways in the action of ribavirin.

CONCLUSION

Our study suggests that ribavirin, acting by way of a novel innate mechanism, potentiates the anti-HCV effect of IFN. Understanding the mechanism of action of ribavirin would be valuable in identifying novel antivirals.

Pegylated interferon plus optimized weight-based ribavirin dosing negate the influence of weight and body mass index on early viral kinetics and sustained virological response in chronic hepatitis C

AIM

Elevated body mass index (BMI) in chronic hepatitis C (CHC) has been associated with reduced rates of sustained virological response (SVR). The aims of this study were to determine whether early viral kinetics (and subsequently SVR) are influenced by weight or BMI by measuring HCV RNA at week 4 using two PCR assays with differing sensitivities.

METHODS

Patients with CHC treated with peginterferon plus weight-based ribavirin were included in this retrospective study. Body mass index, pretreatment viral load, genotype and liver histology were abstracted from the clinical database. HCV RNA PCR (lower limit of detection (LLD) <50 IU/mL) at treatment week 4 and 6 months after completion of therapy were recorded to determine the presence of rapid virological response (RVR-50) and SVR, respectively. In those who achieved RVR-50, stored week 4 serum was retested using Taqman (LLD < 15 IU/mL, RVR-15).

RESULTS

Of 134 patients included (genotype 1 57%, BMI 26.7 ± 4.5 kg/m², ribavirin dose 13.9 ± 2.6 mg/kg/day), 59% achieved SVR. RVR-50 was observed in 39.6% and RVR-15 in 27.6%. Neither body weight nor BMI influenced RVR-50, RVR-15 or SVR. The positive predictive values (PPVs) of RVR-50 and RVR-15 for SVR were 88.7% and 97.3% (P = 0.23). RVR-50 and RVR-15 superceded genotype and viral load as the strongest independent predictors of SVR (OR 9.25 (1.9-45.11) and OR 30.74 (3.08-317.96), respectively).

CONCLUSIONS

RVR is the strongest predictor of SVR. Early viral kinetics is not influenced by body weight or BMI when weight-based ribavirin is prescribed.

Induction pegylated interferon alfa-2a and high dose ribavirin do not increase SVR in heavy patients with HCV genotype 1 and high viral loads

BACKGROUND & AIMS

Patients infected with hepatitis C virus (HCV) genotype 1, body weight ≥85 kg, and high baseline viral load respond poorly to standard doses of pegylated interferon (peginterferon) and ribavirin. We evaluated intensified therapy with peginterferon alfa-2a plus ribavirin.

METHODS

This double-blind randomized trial included HCV genotype 1-infected outpatients from hepatology clinics with body weight ≥85 kg and HCV RNA titer ≥400,000 IU/mL. Patients were randomized to 180 μg/wk peginterferon alfa-2a for 48 weeks plus 1200 mg/day ribavirin (standard of care) (group A, n = 191) or 1400/1600 mg/day ribavirin (group B, n = 189). Additional groups included 360 μg/wk peginterferon alfa-2a for 12 weeks then 180 μg/wk peginterferon alfa-2a for 36 weeks plus 1200 mg/day ribavirin (group C, n = 382) or 1400/1600 mg/day ribavirin (group D, n = 383). Follow-up lasted 24 weeks after treatment.

RESULTS

Sustained virologic response rates (HCV RNA level <15 IU/mL at end of follow-up) in groups A, B, C, and D were 38%, 43%, 44%, and 41%, respectively. There were no significant differences among the 4 groups or between pooled peginterferon alfa-2a regimens (A + B vs C + D: odds ratio [OR], 1.08; 95% confidence interval [CI], 0.83-1.39; P = .584) or pooled ribavirin regimens (A + C vs B + D: OR, 1.00; 95% CI, 0.79-1.28; P = .974).

CONCLUSIONS

In patients infected with HCV genotype 1 who are difficult to treat (high viral load, body weight ≥85 kg), a 12-week induction regimen of peginterferon alfa-2a and/or higher-dose ribavirin is not more effective than the standard regimen.

Clinical characteristics of null responders to Peg-IFNα2b/ribavirin therapy for chronic hepatitis C

AIM

To predict which chronic hepatitis C patients are likely to be late-responders, we herein investigated the clinical characteristics of null-responders at 36 wk with hepatitis C virus (HCV) genotype Ib and a high viral load during the course of pegylated interferon (Peg-IFN)/ribavirin therapy.

METHODS

One hundred forty-two patients with genotype Ib HCV and a high viral load were included in this study. Peg-IFNα2b (1.5 μg/kg once a week) and ribavirin (600-1000 mg per day according to body weight) were administered for 48 wk. We defined null-responders as the cases that never cleared serum HCV RNA as determined using RT-PCR until 36 wk. Other patients were defined as responders. We compared the clinical characteristics (age, gender, body mass index, previous treatment) and HCV RNA titer during the therapy between null-responders and responders.

RESULTS

The HCV RNA clearance rate was 17.9% (24/134), 46.3% (62/134), 60.6% (86/142), 86.6% (123/142), and 88.0% (125/142) at 4, 8, 12, 24, and 36 wk, respectively. There were 17 patients (12.0%) who were still null-responders at 36 wk. There were no differences in the clinical characteristics between the responders and null-responders except for the titer and decline rates of HCV RNA at 1 wk and 4 wk. The HCV RNA titers at 1 wk and after 4 wk of treatment were significantly higher in the null-responders in comparison to the responders (P <0.01). The serum HCV RNA titers of the responders decreased by 1.3 log after 1 wk of treatment, and 1.6 log after 4 wk of treatment, respectively. On the other hand, the titers of the null responders decreased by only 0.5 log after 1 wk, and 0.7 log after 4 wk of treatment, respectively. The decrease rates of HCV RNA after 1 and 4 wk of treatment were significantly worse for null responders than for the responders (P <0.01).

CONCLUSION

The HCV RNA titer at 1 wk and 4 wk after initiating treatment may be useful for predicting null-responders to Peg-IFNα2b/ribavirin therapy. However, further investigation is needed to determine the optimal time at which the decision to discontinue the Peg-IFNα2b/ribavirin therapy for null-responders can be made.

A sustained virologic response is durable in patients with chronic hepatitis C treated with peginterferon alfa-2a and ribavirin

BACKGROUND & AIMS

A sustained virologic response (SVR) to therapy for hepatitis C virus (HCV) infection is defined as the inability to detect HCV RNA 24 weeks after completion of treatment. Although small studies have reported that the SVR is durable and lasts for long periods, it has not been conclusively shown.

METHODS

The durability of treatment responses was examined in patients originally enrolled in one of 9 randomized multicenter trials (n = 1343). The study included patients who received pegylated interferon (peginterferon) alfa-2a alone (n = 166) or in combination with ribavirin (n = 1077, including 79 patients with normal alanine aminotransferase levels and 100 patients who were coinfected with human immunodeficiency virus and HCV) and whose serum samples were negative for HCV RNA (<50 IU/mL) at their final assessment. Patients were assessed annually, from the date of last treatment, for a mean of 3.9 years (range, 0.8-7.1 years).

RESULTS

Most patients (99.1%) who achieved an SVR had undetectable levels of HCV RNA in serum samples throughout the follow-up period. Serum samples from 0.9% of the patients contained HCV RNA a mean of 1.8 years (range, 1.1-2.9 years) after treatment ended. It is not clear if these patients were reinfected or experienced a relapse.

CONCLUSIONS

In a large cohort of patients monitored for the durability of an SVR, the SVR was maintained for almost 4 years after treatment with peginterferon alfa-2a alone or in combination with ribavirin. In patients with chronic hepatitis C infection, the SVR is durable and these patients should be considered as cured.

Evolution of interferon-based therapy for chronic hepatitis C

Since 1986, interferon-alfa (IFN-α) monotherapy has been administered for patients with chronic hepatitis C (CHC). However, sustained response rate is only about 8% to 9%. Subsequent introduction of ribavirin in combination with IFN-α was a major breakthrough in the treatment of CHC. Sustained virological responses (SVRs) rate is about 30% in hepatitis C virus genotype 1 (HCV-1) patients, and is about 65% in HCV-2 or -3 patients. After 2000, pegylated interferon (PegIFN) much improved the rates of SVR. Presently, PegIFN-α-ribavirin combination therapy has been current standard of care for patients infected with HCV. In patients with HCV-1, treatment for 48 weeks is optimal, but 24 weeks of treatment is sufficient in HCV-2 or -3 infected patients. Clinical factors have been identified as predictors for the efficacy of the IFN-based therapy. The baseline factor most strongly predictive of an SVR is the presence of HCV-2 or -3 infections. Rapid virological response (RVR) is the single best predictor of an SVR to PegIFN-ribavirin therapy. If patients can't achieve a RVR but achieve a complete early virological response (cEVR), treatment with current standard of care can provide more than 90% SVR rate. HCV-1 patients who do not achieve an EVR should discontinue the therapy. Recent advances of protease inhibitor may contribute the development of a novel triple combination therapy.

Individualisation of antiviral therapy for chronic hepatitis C

The combination of pegylated-interferon (PEG-IFN)/ribavirin is currently the standard of care antiviral treatment for chronic hepatitis C (CHC), but optimal results require an individual approach. Key issues are to deliver doses that confer optimal antiviral efficacy against hepatitis C virus (HCV) for a time sufficient to minimise relapse. Viral monitoring during therapy guides the subsequent treatment course, particularly HCV RNA results at 4 weeks (rapid viral response [RVR]) and 12 weeks (complete early viral response [cEVR]). There is strong evidence that for most patients with genotypes 2 or 3 HCV infection, RVR allows truncation of treatment to 16 weeks, provided ribavirin dose is weight-based. However, those patients with cirrhosis, insulin resistance/diabetes or older than 50 years need 6-12 months treatment. For "difficult-to-treat" CHC (genotypes 1 and 4), RVR is infrequent (approximately 15% in European studies), but allows treatment to be truncated from 48 to 24 weeks. Without RVR, there is some evidence that longer treatment (72 weeks) improves sustained viral response (SVR). However, "induction dosing" first 12 weeks of PEG-IFN clearly does not improve SVR. To prevent dose reductions and complete therapy, it is critical to detect and treat depression and other disabling side-effects, including judicious use of growth factors for severe anemia or neutropenia and possibly, thrombocytopenia. Another potentially important aspect may be attempts to counter central obesity and insulin resistance, which confer suboptimal antiviral response with any HCV genotype. Treatment partnerships with specialist nurses, psychological therapists and other healthcare workers are also essential for optimal individual management of patients with CHC.

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.

Early identification of achieving a sustained virological response in chronic hepatitis C patients without a rapid virological response

BACKGROUND AND AIM

A number of hepatitis C virus (HCV) patients without a rapid virological response (RVR) achieved a sustained virological response (SVR) with peginterferon-alpha-2a/ribavirin. The aim of this study was to identify factors associated with SVR in non-RVR patients.

METHODS

Baseline and on-treatment factors were used to explore the prognostic factors for SVR in 113 HCV genotype-1 (HCV-1) and 20 HCV-2 non-RVR patients in two randomized trials.

RESULTS

The SVR rate in HCV-1 patients with a complete early virological response (cEVR) and partial early virological response was 91.9% versus 45% (P < 0.001) and 21.4% versus 10% (P = 0.62), respectively, after 48 and 24 weeks of treatment. The SVR rate in HCV-2 patients with a cEVR was 90.9% versus 57.1% (P = 0.25), respectively, after 24 and 16 weeks of treatment. Multivariate analysis showed that cEVR and standard regimen were independently associated with SVR. Viral kinetic study revealed that HCV viral loads < 10,000 IU/mL at week 4 were the best predictor of cEVR for both HCV-1 and HCV-2 non-RVR patients with the accuracy of 81% and 95%, respectively, and also of SVR with the accuracy of 78% and 92%, respectively, in patients receiving standard of care. The most important independent predictors for cEVR were HCV viral loads < 10(4) IU/mL at week 4, followed by increased ribavirin dose within 12 weeks of treatment.

CONCLUSIONS

Achieving a cEVR with standard of care is the most important predictor of SVR in non-RVR patients. Week 4 viral loads < 10,000 IU/mL could accurately predict cEVR early and following SVR in non-SVR patients.

Preemptive erythropoietin plus high ribavirin doses to increase rapid virological responses in HIV patients treated for chronic hepatitis C

Chronic hepatitis C affects one-third of HIV(+) patients worldwide. High ribavirin (RBV) exposure is crucial to maximize the response to hepatitis C therapy in this population, although it may increase the risk for hemolytic anemia. PERICO is a prospective multicenter trial in which HIV/HCV-coinfected patients are randomized to receive peginterferon (pegIFN) alfa-2a 180 microg/week plus either weight-based RBV (1000-1200 mg/day) or RBV 2000 mg/day, the latest along with erythropoietin alfa (EPO) 30,000 IU/week from the first day until week 4. A total of 149 patients were assessed in a planned interim analysis at week 4. In both arms, 22% of patients achieved negative HCV-RNA (rapid virological response, RVR). Multivariate analysis [OR (IC 95%), p] showed that factors associated with RVR were HCV genotypes 2/3 vs. 1/4 [20 (5-100), <0.01] and baseline HCV-RNA [0.16 (0.07-0.37) per log IU/ml, <0.01]. The occurrence of severe anemia (hemoglobin <10 g/dl) did not differ when comparing RBV vs. high RBV + EPO (7% vs. 3%; p = 0.4). Moreover, RBV plasma trough levels were comparable at week 4 (1.9 vs. 2.4 microg/ml; p = 0.2). Use of high RBV doses with preemptive EPO during the first 4 weeks of hepatitis C therapy is safe, but fails to enhance significantly RBV plasma exposure and RVR rates. Extensive intraerythrocyte accumulation of RBV following boosted production of red blood cells by EPO could explain these findings.

Factors associated with rapid and early virologic response to peginterferon alfa-2a/ribavirin treatment in HCV genotype 1 patients representative of the general chronic hepatitis C population

Rapid virologic response (RVR) and complete early virologic response (cEVR) are associated with sustained virologic response to hepatitis C virus (HCV) therapy. We retrospectively examined baseline and on-treatment factors associated with RVR (HCV RNA undetectable at week 4) and cEVR (HCV RNA undetectable at week 12, regardless of week 4 response). The analysis comprised 1550 HCV genotype-1 patients from five clinical trials, including three enriched with difficult-to-treat populations, randomized to peginterferon alfa-2a 180 microg/week plus ribavirin 1000-1200 mg/day. Overall, 15.6% achieved RVR and 54.0% achieved cEVR. Baseline factors predictive of RVR were serum HCV RNA <or= 400,000 IU/mL (OR: 7.34; P < 0.0001), alanine aminotransferase >3 x ULN (OR: 2.01; P < 0.0001), non-cirrhotic status (OR: 1.92; P = 0.0087), age <or= 40 years (OR: 1.56; P = 0.0085), white non-Latino ethnicity (OR: 1.41; P = 0.0666) and individual study (P < 0.0001). These factors plus body mass index <or= 27 kg/m(2) were predictive of cEVR. After adjusting for these factors, mean on-treatment ribavirin dose >13 mg/kg/day was predictive of RVR (OR: 1.69; P = 0.005) and cEVR (OR: 1.24; P = 0.09), whereas peginterferon alfa-2a dose reduction was not. Greater decreases in haematologic parameters were observed in patients who achieved cEVR compared with patients who did not. In conclusion, several baseline and on-treatment factors were associated with RVR and cEVR to peginterferon alfa-2a plus ribavirin in difficult-to-treat HCV genotype-1 patients, providing important prognostic information on the antiviral response in a patient cohort that is reflective of the general chronic hepatitis C population.

On-treatment predictions of success in peg-interferon/ribavirin treatment using a novel formula

AIM: To predict treatment success using only simple clinical data from peg-interferon plus ribavirin therapy for chronic hepatitis C.

METHODS: We analyzed the clinical data of 176 patients with chronic hepatitis and hepatitis C virus genotype 1 who received 48 wk standard therapy, derived a predictive formula to assess a sustained virological response of the individual patient using a logistic regression model and confirmed the validity of this formula. The formula was constructed using data from the first 100 patients enrolled and validated using data from the remaining 76 patients.

RESULTS: Sustained virological response was obtained in 83 (47.2%) of the patients and we derived formulae to predict sustained virological response at pretreatment and weeks 4, 12 and 24. The likelihood of sustained virological response could be predicted effectively by the formulae at weeks 4, 12 and 24 (the area under the curve of the receiver operating characteristic: 0.821, 0.802, and 0.891, respectively), but not at baseline (0.570). The formula at week 48 was also constructed and validation by test data achieved good prediction with 0.871 of the area under the curve of the receiver operating characteristic. Prediction by this formula was always superior to that by viral kinetics.

CONCLUSION: These results suggested that our formula combined with viral kinetics provides a clear direction of therapy for each patient and enables the best tailored treatment.

Induction pegylated interferon alfa-2b in combination with ribavirin in patients with genotypes 1 and 4 chronic hepatitis C: a prospective, randomized, multicenter, open-label study

BACKGROUND & AIMS

Standard of care (SOC) treatment for chronic hepatitis C (CHC) involves weekly pegylated (PEG) interferon plus weight-based ribavirin with resultant sustained virologic response (SVR) rates at or near 50% for genotypes 1 and 4 virus. Induction therapy with higher doses of PEG interferon may improve first-phase viral kinetics and thus improve the overall SVR in genotypes 1 and 4 patients.

METHODS

This multicenter, randomized, open-label trial enrolled treatment-naive genotypes 1- and 4-infected CHC patients to either initial induction therapy versus SOC. The induction group received PEG interferon alfa-2b 3.0 mcg/kg/wk for 12 weeks followed by PEG interferon alfa-2b 1.5 mcg/kg/wk for 36 weeks and 13 +/- 2 mg/kg ribavirin daily for 48 weeks. SOC patients received PEG interferon alfa-2b 1.5 mcg/kg weekly for 48 weeks and 13 +/- 2 mg/kg ribavirin daily for 48 weeks. The primary end point was SVR.

RESULTS

There were 610 patients enrolled throughout the United States. Complete early virologic response was 62.6% versus 57.7% in induction versus SOC (NS). Overall SVR was 32% in induction versus 29% in SOC group (NS). Dose reduction of either PEG interferon (24.1% vs 23.8%) or ribavirin (26.8% vs 25.1%) was similar between the 2 groups. There was a trend toward a significant difference when comparing the SVR in induction therapy in patients weighing more than 85 kg versus those receiving SOC (38% vs 28%; P = .08).

CONCLUSIONS

Induction therapy does not enhance complete early virologic response or SVR rates in a predominantly genotype 1 CHC population compared with SOC therapy.

Factors associated with rapid and early virologic response to peginterferon alfa-2a/ribavirin treatment in HCV genotype 1 patients representative of the general chronic hepatitis C population

Rapid virologic response (RVR) and complete early virologic response (cEVR) are associated with sustained virologic response to hepatitis C virus (HCV) therapy. We retrospectively examined baseline and on-treatment factors associated with RVR (HCV RNA undetectable at week 4) and cEVR (HCV RNA undetectable at week 12, regardless of week 4 response). The analysis comprised 1550 HCV genotype-1 patients from five clinical trials, including three enriched with difficult-to-treat populations, randomized to peginterferon alfa-2a 180 microg/week plus ribavirin 1000-1200 mg/day. Overall, 15.6% achieved RVR and 54.0% achieved cEVR. Baseline factors predictive of RVR were serum HCV RNA <or= 400,000 IU/mL (OR: 7.34; P < 0.0001), alanine aminotransferase >3 x ULN (OR: 2.01; P < 0.0001), non-cirrhotic status (OR: 1.92; P = 0.0087), age <or= 40 years (OR: 1.56; P = 0.0085), white non-Latino ethnicity (OR: 1.41; P = 0.0666) and individual study (P < 0.0001). These factors plus body mass index <or= 27 kg/m(2) were predictive of cEVR. After adjusting for these factors, mean on-treatment ribavirin dose >13 mg/kg/day was predictive of RVR (OR: 1.69; P = 0.005) and cEVR (OR: 1.24; P = 0.09), whereas peginterferon alfa-2a dose reduction was not. Greater decreases in haematologic parameters were observed in patients who achieved cEVR compared with patients who did not. In conclusion, several baseline and on-treatment factors were associated with RVR and cEVR to peginterferon alfa-2a plus ribavirin in difficult-to-treat HCV genotype-1 patients, providing important prognostic information on the antiviral response in a patient cohort that is reflective of the general chronic hepatitis C population.

Update on viral hepatitis: 2008

PURPOSE OF REVIEW

The present review is a concise review of recent developments in the field of viral hepatitis, based on publications between December 2007 and November 2008.

RECENT FINDINGS

The incidence of acute hepatitis A and B infection has declined significantly, especially among children less than 15 years of age. Five oral antiviral agents have been approved for the treatment of chronic hepatitis B. Telbivudine is more potent than lamivudine but is associated with a high rate of antiviral resistance compared with entecavir or tenofovir. De-novo combination of lamivudine and adefovir reduces the rate of antiviral resistance compared with lamivudine monotherapy. Individualizing dose and duration of pegylated interferon and ribavirin according to on-treatment virologic response may improve sustained virologic response rates. Several specifically targeted antiviral therapies notably protease and polymerase inhibitors are promising but must be used in combination with pegylated interferon and ribavirin. Hepatitis E virus has been reported to result in chronic hepatitis in transplant patients.

SUMMARY

Multiple treatment options are available for hepatitis B but long-term treatment is required. Several specifically targeted antiviral therapies have shown promise. In the meantime, individualizing dose and duration of pegylated interferon and ribavirin might improve sustained virologic response rates in patients with hepatitis C.