Treatment of chronic hepatitis C in patients who failed interferon monotherapy: effects of higher doses of interferon and ribavirin combination therapy. The Virginia Cooperative Hepatitis Treatment Group

A statistical method for removing unbalanced trials with multiple covariates in meta-analysis

In meta-analysis literature, there are several checklists describing the procedures necessary to evaluate studies from a qualitative point of view, whereas preliminary quantitative and statistical investigations on the "combinability" of trials have been neglected. Covariate balance is an important prerequisite to conduct meta-analysis. We propose a method to identify unbalanced trials with respect to a set of covariates, in presence of covariate imbalance, namely when the randomized controlled trials generate a meta-sample that cannot satisfy the requisite of randomization/combinability in meta-analysis. The method is able to identify the unbalanced trials, through four stages aimed at achieving combinability. The studies responsible for the imbalance are identified, and then they can be eliminated. The proposed procedure is simple and relies on the combined Anderson-Darling test applied to the Empirical Cumulative Distribution Functions of both experimental and control meta-arms. To illustrate the method in practice, two datasets from well-known meta-analyses in the literature are used.

Pharmacokinetics, Food Effect, Ketoconazole Interaction, and Safety of JTK-853, a Novel Nonnucleoside HCV Polymerase Inhibitor, After Ascending Single and Multiple Doses in Healthy Subjects

Pharmacokinetics, safety, and tolerability of JTK-853, a novel HCV polymerase inhibitor, were evaluated in single and multiple ascending dose (SAD, MAD) studies, with food- and ketoconazole-related effects on exposure to JTK-853 and its active (CYP3A4 mediated) metabolite M2. JTK-853 was safe and well tolerated in both studies. In the SAD study, at doses >1600 mg (with standard breakfast [SBF]), JTK-853 exposure did not increase further, was substantially higher (AUC_inf increase: 3- to 8-fold) with SBF (vs fasted), with a moderate increase in AUC_inf (approximately 1.5-fold [1600 mg]) with a high-fat breakfast (vs SBF). In the SAD study (400-1600 mg, SBF), mean effective half-life (t_1/2(eff) ) of JTK-853 was 8.3 to 10.9 hours, and 20.3 to 27.3 hours in the MAD study (twice daily dosing, fed condition), with 2- to 3-fold accumulation in exposure (AUC_tau ). At steady-state, AUC_tau increased dose proportionally, and was approximately 2-fold higher with ketoconazole coadministration. Metabolite M2 (equipotent to JTK-853 in vitro) did not contribute significantly to parent drug exposure and decreased with increase in dose, repeated dosing, and ketoconazole coadministration. Trial simulation-based ratios (n = 1000/dose level) of trough JTK-853 plasma concentrations to the in vitro EC₉₀ for HCV genotype 1b were assessed for dose selection in a separate proof-of-concept study in patients. The studies enabled delineation of key drug attributes for further assessments in the target population.

Interferon for interferon nonresponding and relapsing patients with chronic hepatitis C

BACKGROUND

The widely-accepted treatment outcome for chronic hepatitis C is the sustained viral response (that is, no measurable viral RNA in blood six months after treatment). However, this surrogate outcome (as well as the previously employed biochemical and histologic ones) has never been validated. This situation exists because there are very few randomized clinical trials that have used clinical events (mortality or manifestations of decompensated cirrhosis) as outcomes, because those clinical events only occur after many years of infection. Patients in whom initial therapy fails to produce sustained viral responses do become potential candidates for retreatment; some of these individuals are not candidates for ribavirin or protease inhibitors and consideration could be given to retreatment with interferon alone.

OBJECTIVES

To assess the benefits and harms of interferon monotherapy retreatment in chronic hepatitis C patients and to validate the currently employed surrogate outcomes in this group of patients.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until 16 August 2012.

SELECTION CRITERIA

Randomized trials comparing interferon versus placebo or no treatment in chronic hepatitis C nonresponders and relapsers to previous interferon.

DATA COLLECTION AND ANALYSIS

The primary outcomes were mortality (all-cause and hepatic), quality of life, and adverse events. Secondary outcomes were liver-related morbidity, sustained viral responses, biochemical responses, histologic improvements, and costs. We used both fixed-effect and random-effects model meta-analyses, reporting only the former if no difference existed.

MAIN RESULTS

Seven trials were identified. Two of them were at low risk of bias (the HALT-C and EPIC3 trials) and included 1676 patients. Both of these trials addressed the role of long-term low-dose pegylated interferon therapy in patients with severe fibrosis (demonstrated on liver biopsy) and were designed to assess the clinical outcomes. The remaining five trials included 300 patients and were at high risk of bias. Based on all trials reporting the outcomes, no significant difference was observed in either all-cause mortality (78/843 (9.3%) versus 62/867 (7.2%); risk ratio (RR) 1.30, 95% confidence interval (CI) 0.95 to 1.79; 3 trials) or hepatic mortality (41/532 (7.7%) versus 40/552 (7.2%); RR 1.07, 95% CI 0.70 to 1.63; 2 trials); however, when only the two trials at low risk of bias were combined, all-cause mortality was significantly higher in the recipients of the pegylated interferon (78/828 (9.4%) versus 57/848 (6.7%); RR 1.41, 95% CI 1.02 to 1.96) although trial sequential analysis could not exclude the possibility of random error. There was less variceal bleeding in the recipients of the interferon (4/843 (0.5%) versus 18/867 (2.1%); RR 0.24, 95% CI 0.09 to 0.67; 3 trials), although again trial sequential analysis could not exclude the presence of a type I error and the effect could not be confirmed in a random-effects model meta-analysis. No significant differences were seen with regard to the development of ascites, encephalopathy, hepatocellular carcinoma, or the need for liver transplantation. One trial reported quality of life data; the pain score was significantly worse in the recipients of the pegylated interferon. Adverse effects tended to be more common in the interferon recipients; the ones that were significantly more common included hematologic complications, infections, flu-like symptoms, and rash. The recipients of interferon had significantly more sustained viral responses (20/557 (3.6%) versus 1/579 (0.2%); RR 15.38, 95% CI 2.93 to 80.71; 4 trials) and a type I error was excluded by trial sequential analysis. The METAVIR activity score also improved (36/55 (65%) versus 20/46 (43.5%); RR 1.49, 95% CI 1.02 to 2.18; 2 trials). No significant differences were seen with regard to histologic fibrosis assessments.

AUTHORS' CONCLUSIONS

The clinical data were limited to patients with histologic evidence of severe fibrosis who were retreated with pegylated interferon. In this scenario, retreatment with interferon did not appear to provide significant clinical benefit and, when only the trials at low risk of bias were considered, retreatment for several years may even have increased all-cause mortality. Such treatment also produced adverse events. On the other hand, the treatment did result in improvement in some surrogate outcomes, namely sustained viral responses and histologic evidence of inflammation. Interferon monotherapy retreatment cannot be recommended for these patients. No clinical data are available for patients with less severe fibrosis. The sustained viral response cannot be used as a surrogate marker for hepatitis C treatment in this clinical setting with low sustained viral response rates and needs to be validated in others in which higher sustained viral response rates are reported.

Ribavirin plus interferon versus interferon for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. Standard therapy is ribavirin plus pegylated interferon to achieve undetectable level of virus in the blood, but the effect on clinical outcomes is controversial.

OBJECTIVES

To assess the beneficial and harmful effects of ribavirin and interferon combination therapy versus interferon monotherapy for chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, approaching authors of trials, and pharmaceutical companies until March 2009.

SELECTION CRITERIA

We included randomised trials, irrespective of blinding, language, or publication status, comparing ribavirin plus interferon versus interferon for treatment of chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were serum sustained loss of hepatitis C virus, liver-related morbidity plus all-cause mortality, and adverse events. We performed subgroup analyses of patients who were naive, relapsers, or non-responders to previous antiviral treatment. All outcomes were analysed with the random-effects model. We used Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of morbidity plus mortality. The remaining outcomes were presented as relative risks (RR). We used trial sequential analyses to examine the robustness of our findings.

MAIN RESULTS

We included 83 randomised trials with 12,707 patients. Most trials had unclear or high risk of bias. We did not find any significant influence of bias on our results but cannot exclude outcome measure reporting bias as many trials did not report on the primary outcomes of this review. Compared with interferon, ribavirin plus interferon had a significant beneficial effect on sustained virological response in subgroups of naive patients (RR 0.72, 95% confidence interval (CI) 0.68 to 0.75), relapsers (RR 0.62, 95% CI 0.54 to 0.70), non-responders (RR 0.89, 95% CI 0.84 to 0.93), and in all patients (RR 0.75, 95% CI 0.71 to 0.79). Combination therapy significantly reduced morbidity plus mortality in all patients (Peto OR, 0.43, 95% CI 0.23 to 0.79), but not in naive, relapsers, or non-responders individually. Combination therapy significantly increased the risk of haematological, dermatological, gastrointestinal, infectious, and miscellaneous (cough, dyspnoea, fatigue) adverse reactions. Accordingly, combination therapy significantly increased the risk of treatment discontinuation and dose reductions. Trial sequential analyses confirmed our findings regarding virological effects, but not regarding liver-related morbidity and all-cause mortality.

AUTHORS' CONCLUSIONS

Compared with interferon alone, ribavirin plus interferon is more effective in clearing hepatitis C virus from the blood. Combination therapy may reduce liver-related morbidity and all-cause mortality, but we need more evidence. The number needed to treat to obtain a beneficial effect is considerable considering the increased risk of several severe adverse reactions and costs.

Ribavirin monotherapy for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. A high proportion of patients never experience symptoms. Peginterferon plus ribavirin is the recommended treatment for chronic hepatitis C. However, ribavirin monotherapy may be considered for some patients.

OBJECTIVES

To assess the beneficial and harmful effects of ribavirin monotherapy for patients with chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies until March 2009.

SELECTION CRITERIA

We included all randomised trials irrespective of blinding, language, or publication status comparing ribavirin versus no intervention, placebo, or interferon for chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were serum sustained virological response (loss of hepatitis C virus RNA at least six months after treatment), liver-related morbidity plus all-cause mortality, and adverse events. Secondary outcome measures were end of treatment virological response, biochemical response (transaminase activity), and histological response. Randomisation methods, blinding, data handling, and funding were extracted as measures of bias control. Random-effects and fixed-effect meta-analyses were performed for all outcomes. We only present the results of the fixed-effect model if both models provide the same result regarding statistical significance. We present data as risk difference (RD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 14 randomised trials with 657 patients. The majority of trials had unclear control of bias. Compared with placebo or no intervention, ribavirin had no significant effect on the sustained virological response (RD 0%, 95% CI -2% to 3%, five trials) or end of treatment virological response (RD 0% 95% CI -3% to 3%, ten trials). Ribavirin had no significant effect on liver-related morbidity plus mortality (RD 0%, 95% CI -2% to 3%, 11 trials). Ribavirin significantly increased the risk of adverse reactions, including anaemia. Ribavirin significantly improved end of treatment biochemical and histological response but not the sustained biochemical response. Ribavirin was significantly inferior to interferon regarding virological and biochemical responses (five trials).

AUTHORS' CONCLUSIONS

Ribavirin seems without beneficial effects on serum virological response and liver-related morbidity or mortality, and significantly increased the risk of adverse reactions. Ribavirin monotherapy seems significantly inferior to interferon monotherapy. The total number of included patients is small, and more trials are perhaps needed. The use of ribavirin monotherapy for chronic hepatitis C cannot be recommended outside randomised trials.

Optimizing the current therapy for chronic hepatitis C virus: peginterferon and ribavirin dosing and the utility of growth factors

Achieving a sustained virologic response depends on the patient achieving three sequential independent milestones: virologic response, maintaining this response throughout treatment, and not relapsing after treatment has been completed. The ability to achieve these milestones depends on the doses of interferon/peginterferon and ribavirin used and on whether treatment with these medications is adjusted, interrupted, or prematurely discontinued in response to adverse events. This review discusses strategies to optimize peginterferon and ribavirin dosing and the impact that growth factors may have on the ability to achieve a sustained virologic response.

Retreatment of chronic hepatitis C in previous non-responders and relapsers

Therapy for chronic hepatitis C has improved dramatically over the past 20 years. Unfortunately, approximately 50% of those treated do not have a durable response to therapy. Non-responders and relapsers after previous interferon-based therapy are particularly challenging with regard to clinical management. This article provides a general overview of the treatment of hepatitis C and reviews present data regarding management of patients with chronic hepatitis C who are non-responders or relapsers after previous treatment. The review ends with the authors' opinion regarding present management of non-responders and relapsers and future emerging therapies.

Combination Therapy of Interferon and Ribavirin Versus Interferon Monotherapy in Treatment of Chronic Hepatitis C: A Meta-analysis of Clinical Trials

This meta-analysis was conducted to assess the efficacy and safety of interferon and ribavirin combination therapy (CT) versus interferon monotherapy (IMT) in inducing sustained response in interferon-naïve, relapser, and nonresponder chronic hepatitis C patients. A literature search was performed using the MEDLINE database for clinical trials published in the period between 1995 and 2003. A total of 31 randomized trials and 7 nonrandomized trials comparing CT with interferon alone or comparing different dose regimens of CT were included in this meta-analysis. The primary outcome measure was sustained virological response. The summary estimate of the odds ratio was obtained using the random effect model. The study showed that sustained virological response rate was significantly higher in interferon-naïve, relapser, and nonrespondent chronic hepatitis C patients who were on CT compared to IMT (odds ratio = 3.23, 17.65, and 4.71, respectively). There was no statistically significant difference in virological and biochemical responses between different dose regimens of CT. Side effects, dose reduction, and treatment discontinuation rates were significantly higher in patients receiving CT compared with IMT. Treatment with interferon plus ribavirin has a significant benefit on the virological and biochemical response in patients with chronic hepatitis C irrespective to the previous treatment, and it should be considered the treatment of choice in naïve, relapser, and nonrespondent chronic hepatitis C patients.

Chronic hepatitis C: treatment of pegylated interferon/ribavirin nonresponders

Patients with chronic hepatitis C virus (HCV) who were nonresponders to previous treatment with pegylated interferon and ribavirin are a growing population. The vast majority have genotype 1, a high viral load, advanced fibrosis or cirrhosis, and are of African-American race. The evaluation of these patients should include a thorough review of the previous treatment record and characterization of the previous nonresponse. Patients with prior null response are likely resistant to the effects of interferon. In contrast, patients with partial virologic response, breakthrough, and relapse could potentially achieve sustained virologic response if one or more correctable factors that contributed to the prior nonresponse are identified and addressed before and during retreatment. Many HCV nonresponders, especially those with no fibrosis or mild fibrosis, have an excellent prognosis, are at low risk to develop cirrhosis, and should simply be monitored at periodic intervals until more effective therapy has been developed.

A randomized trial of pegylated interferon alpha-2b plus ribavirin in the retreatment of chronic hepatitis C

OBJECTIVES

The efficacy of combination therapy with pegylated interferon (PEG IFN) alpha plus ribavirin (RBV) in the retreatment of chronic hepatitis C (CHC) in patients who previously failed combination standard IFN plus RBV or IFN monotherapy has not been well established.

METHODS

Three hundred and twenty-one CHC patients including virologic nonresponders to combination IFN plus RBV (n = 219) or IFN monotherapy (n = 47), and relapsers to combination therapy (n = 55) were randomized to receive PEG IFN alpha-2b 1.5 microg/kg per wk plus RBV 800 mg per day (Regimen A, n = 160) or PEG IFN alpha-2b 1.0 microg/kg per wk plus RBV 1,000-1,200 mg per day (Regimen B, n = 161) for 48 wks.

RESULTS

Sustained virologic response (SVR) occurred in 16% of the overall study population (Regimen A vs B, 18%vs 13%, p= 0.21), in 8% of the combination therapy nonresponders (10%vs 6%, p= 0.35), in 21% of the IFN monotherapy nonresponders (16%vs 27%, p= 0.35), and in 42% of the combination therapy relapsers (50%vs 32%, p= 0.18). In nonresponders to prior combination therapy, HCV ribonucleic acid levels <100,000 copies/mL at the end of the prior treatment course were associated with an increased SVR compared with levels >or=100,000 copies/mL (21%vs 5%, p= 0.002). In the overall study population, genotype 1 patients had lower SVR rates than others (14%vs 33%, p= 0.01), and African Americans had lower SVR than Caucasians (4%vs 18%, p= 0.01).

CONCLUSION

Combination therapy with PEG IFN alpha-2b plus RBV is more effective in patients who relapsed after combination standard IFN plus RBV than in nonresponders to either combination therapy or IFN monotherapy. There was no significant effect of dosing regimen.

Ribavirin monotherapy for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades. Ribavirin monotherapy may represent a treatment for some patients.

OBJECTIVES

To assess the beneficial and harmful effect of ribavirin monotherapy for patients with chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies until May 2005.

SELECTION CRITERIA

We included all randomised trials irrespective of blinding, language, or publication status comparing ribavirin versus no intervention, placebo, or interferon for chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the six months sustained loss of hepatitis C virus RNA in blood after end of treatment and liver-related morbidity plus all-cause mortality. Secondary outcome measures were end of treatment virological response, biochemical response, histological response, and adverse events. Random- and fixed-effects meta-analyses with 95% confidence intervals (CI) were performed for all outcomes. We used Peto odds ratios (OR) for analysis of morbidity plus mortality and relative risks (RR) for the remaining outcomes.

MAIN RESULTS

We identified 13 randomised trials including 594 patients with chronic hepatitis C. Most trials had low methodological quality. Compared with placebo/no intervention, ribavirin had no significant effect on sustained (RR 1.01, 95% CI 0.96 to 1.07, five trials) or end of treatment virological response (RR 1.00, 95% CI 0.94 to 1.07, ten trials). Ribavirin had no significant effect on liver-related morbidity plus mortality (Peto OR 1.96, 95% CI 0.20 to 19.0, eleven trials). Ribavirin significantly improved end of treatment biochemical and histological response but not sustained biochemical response. Further, ribavirin significantly increased the risk of anaemia. Ribavirin was significantly inferior to interferon regarding virological and biochemical response (four trials).

AUTHORS' CONCLUSIONS

We found that ribavirin versus placebo/no intervention had no significant beneficial effect on virological response and liver morbidity, but may improve biochemical and histological response transiently. Ribavirin increased the risk of anaemia. Therefore, we cannot recommend ribavirin monotherapy for patients with chronic hepatitis C outside randomised trials.

Ribavirin plus interferon versus interferon for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. The disease progresses without symptoms for several decades and most patients are diagnosed based on the presence of hepatitis C virus ribonucleic acid and elevated transaminases.

OBJECTIVES

To assess the beneficial and harmful effects of ribavirin and interferon combination therapy versus interferon monotherapy for chronic hepatitis C.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, approaching authors of trials and pharmaceutical companies, until May 2004.

SELECTION CRITERIA

We included randomised trials, irrespective of blinding, language, or publication status, comparing ribavirin plus interferon versus interferon alone for treatment of chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the sustained loss of hepatitis C virus and liver-related morbidity plus all-cause mortality. We separately analysed patients who were naive, relapsers, or non-responders to previous antiviral treatment. Random-effects and fixed-effect model meta-analyses were performed for all outcomes. We used Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of morbidity plus mortality. The remaining outcomes were presented as relative risks (RR).

MAIN RESULTS

We included 72 randomised trials with 9991 patients. Most trials had low methodological quality but we did not find any significant influence of quality on our results. Compared with interferon, combination therapy had a significant beneficial effect on sustained virological response (RR 0.73, 95% CI 0.71 to 0.75) and in subgroups of naive patients (RR 0.72, 95% CI 0.68 to 0.76), relapsers (RR 0.63, 95% CI 0.54 to 0.73), and non-responders (RR 0.89, 95% CI 0.84 to 0.94) individually. Combination therapy significantly reduced morbidity plus mortality (Peto OR 0.46, 95% CI 0.22 to 0.96), but not in naive, relapsers, or non-responders individually. Combination therapy also had a significant beneficial effect on the histological response. Combination therapy significantly increased the risk of anaemia (RR 10.48, 95% CI 5.34 to 20.55), which occurred in 22% of patients on combination therapy. Combination therapy also significantly increased the risk of dermatological, gastrointestinal, infectious, and miscellaneous (cough, dyspnea, fatigue) adverse events. Accordingly, combination therapy significantly increased the risk of treatment discontinuation (RR 1.19, 95% CI 1.01 to 1.39).

AUTHORS' CONCLUSIONS

Compared with interferon alone, ribavirin plus interferon is more effective in clearing hepatitis C virus and improving liver histology. This may lead to reduced morbidity and mortality. However, combination therapy significantly increased the risk of several adverse events.

Pegylated interferon alpha-2b, ribavirin and amantadine for chronic hepatitis C

In an attempt to improve the efficacy of antiviral therapy for chronic hepatitis C, a three-drug combination of pegylated interferon alpha-2b, ribavirin, and amantadine has been suggested. Despite the initial enthusiasm, the role of amantadine in the treatment of chronic hepatitis C remains controversial. In a multi-center, open-label clinical trial, the potential efficacy and safety of this triple combination regimen were assessed. In this open-label pilot study, two separate patient populations with chronic hepatitis C and viremia were enrolled: treatment-naive and those who had failed a previous course of treatment. Patients were started on pegylated interferon alpha-2b at a dose of 1.5 microg/kg weekly with ribavirin, 1000-1200 mg/day, and amantadine, 200 mg/day, for 4 weeks, followed by pegylated interferon alpha-2b, 0.5 microg/kg weekly, ribavirin, 1000-1200 mg/day, and amantadine, 200 mg/day, for another 20 weeks. Patients with undetectable HCV RNA at week 24 continued this regimen for a total of 48 weeks and were followed for another 24 weeks. Patients with undetectable virus (<50 IU/mL) after 24 weeks of follow-up were considered to have SVR. Health-related quality of life and safety data were also collected. Sixty-nine treatment-naive and 99 nonresponder patients with chronic hepatitis C were enrolled in the study. Of all patients enrolled, 74% were male, aged 47.27+/-5.76 years; their body mass index (BMI) was 28.87+/-5.05 kg/m2, 79.4% were white, 85% had HCV genotypes 1 and 4, and 36% had cirrhosis. Their baseline HCV RNA was 689,242+/-698,030 IU/mL, with a baseline ALT of 107.25+/-79.08. Of the entire cohort, 35 (21%) discontinued early due to side effects or loss to follow-up. Significant anemia (hemoglobin, < 10 g/dL) occurred in 11% (19/168), while severe anemia (hemoglobin, <8.5 g/dL) occurred in 0.6% (1/168). In the treatment-naive group, sustained virologic response (SVR) was 34.3%, versus 19.4% for the group who had previously failed to respond to a course of treatment (P = 0.01). For both groups combined, virologic response after 24 weeks of therapy was 40.5%, with an end-of-treatment virologic response of 35.7% and a SVR of 26.2%. Patients with genotypes 1 and 4 had lower response rates than those with genotypes 2 and 3 (SVR, 21 vs. 46%; P = 0.001). Patients with advanced fibrosis (Metavir stages 3 and 4) tended to have lower response rates than those with minimal or mild fibrosis (Metavir stages 0-2) (SVR, 10 vs. 30%; P = 0.08). African-American patients with HCV had lower response rates than Caucasians or other ethnic groups (SVR, 4 vs. 29 vs. 20%; P = 0.04). Age, gender, and BMI did not affect SVR. The addition of amantadine to pegylated interferon alpha-2b and ribavirin does not seem to increase the efficicacy of this regimen.

Randomized trial of three different regimens for 24 weeks for re-treatment of chronic hepatitis C patients who failed to respond to interferon-alpha monotherapy in Taiwan

With the favorable result of interferon (IFN)-ribavirin combination therapy for 24 weeks among naive Taiwanese chronic hepatitis C (CHC) patients, the optimal regimens of re-treatment for CHC patients who failed initial IFN monotherapy is not well-established. The study evaluated the effectiveness of re-treatment for 24 weeks with 3 different regimens and predictors for sustained virological response (SVR).

METHODS

Total 120 Taiwanese CHC patients (81 males, 70 relapsers, mean age: 48.6 years) who failed initial IFN monotherapy were enrolled. They were assigned randomly (with a ratio of 1:1:2) to receive one of the three regimens for re-treatment for 24 weeks; group A: IFN 6 million units (MU) monotherapy (N=30), group B: combination therapy with ribavirin and IFN 3 MU (N=30) or group C: combination therapy with ribavirin and IFN 6 MU (N=60). The intention-to-treat rate of sustained virological response (SVR) was 38.3%. The SVR rate in group C (53.3%) was significantly higher than group A (16.7%, P<0.005) and group B (30%, P<0.05). Drop-out rates were similar between the three groups. Patients achieving SVR had significant improvement histologically. Hepatitis C virus (HCV) genotype non-1b infection, lower pretreatment HCV RNA levels, combined with ribavirin and with higher IFN dose, and relapsers were independent predictors for SVR.

CONCLUSION

We concluded that more than one-third Taiwanese CHC patients achieved SVR after 24 weeks re-treatment and combination therapy, especially with higher dose of IFN, yielded higher efficacy.

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Treatment of chronic hepatitis C virus in the virginia department of corrections: can compliance overcome racial differences to response?

OBJECTIVE

Chronic hepatitis C virus (HCV) is common in the correctional setting and there are few data on the use of interferon (IFN)/ribavirin(RVN) combination therapy in this population. Given the high proportion of African Americans (AA) in correctional facilities, which may be associated with reduced response rates, the correctional setting allows a unique opportunity to compare the response rates of AA to Caucasians (CA). The present study describes our experience of treating HCV in the inmate population of the Virginia Department of Corrections.

METHODS

Of the 119 inmates evaluated between 1998 and 2000, a retrospective analysis of 59 consecutive inmates (mean age 41, 83% male, 55% CA, 73% genotype (GT)1, and 41% with advanced fibrosis) who underwent HCV therapy with IFN a-2b (3 MU TIW) and RVN (1,000-1,200 mg/d) under direct observation was performed. Patients were followed by telemedicine and the primary endpoint was sustained virologic response (SVR) defined as an undetectable HCV RNA at least 24 wk after completion of therapy.

RESULTS

All but one patient completed at least 12 wk of therapy and no patient required dose reduction. By wk 24, 34 inmates (58%) responded (negative HCV RNA) which was higher in CA compared to AA (70%vs 40%; p= 0.037). Although overall SVR was higher in CA compared to AA (41%vs 28%; p= ns), we observed no difference in SVR when comparing only GT 1 CA to AA (33%vs 29%).

CONCLUSIONS

HCV can be effectively treated in the correctional setting with response rates similar to, if not better than the published literature. In this controlled setting of direct observational therapy, we observed similar SVR in CA and AA.

Early virologic response to treatment with peginterferon alfa-2b plus ribavirin in patients with chronic hepatitis C

Interferon-based regimens for the treatment of chronic hepatitis C have become increasingly effective and are able to eradicate virus in more than one half of cases. Early identification of patients who will not respond is desirable because treatment might be stopped, thereby avoiding the expense and inconvenience of unnecessary therapy. We examined the accuracy of different degrees of viral inhibition during the early weeks of treatment (early virologic response [EVR]) with pegylated interferon alfa-2b and ribavirin (PEG/R) in identifying patients who would not respond to therapy. The best definition of EVR was a reduction in hepatitis C virus (HCV) RNA by at least 2 logs after the first 12 weeks of treatment compared with baseline. Between 69% and 76% of patients achieved this threshold, depending on the treatment regimen, and sustained virologic response (SVR) occurred in 67% to 80% of these patients. Patients who did not reach EVR did not respond to further therapy. If treatment had been stopped in patients without EVR, drug costs would have been reduced by more than 20%. In conclusion, early confirmation of viral reduction following initiation of antiviral therapy for chronic hepatitis C is worthwhile. It provides a goal to motivate adherence during the first months of therapy and a milepost at which to reassess the need for continued treatment. Most patients who are able to complete the first 12 weeks of therapy achieve EVR and have a high probability of SVR. Patients who fail to achieve EVR will not clear virus even if an additional 9 months of therapy is received. Therapy can be confidently discontinued in those cases.

Treatment of chronic hepatitis C in nonresponders to previous therapy

About 55% to 60% of treatment-naïve patients fail to achieve a sustained virologic response after therapy with standard interferon and ribavirin. The use of polyethylene glycol-enhanced interferon (PEG-IFN) plus ribavirin for retreatment of this challenging group is currently being evaluated by several investigators. Although no sustained virologic response rates have been reported yet from these trials, reported on-treatment response rates for previous nonresponders range from 25% to 30%, and an early estimate of the sustained virologic response rate is about 11%. Outcomes for treatment of relapsers and interferon monotherapy nonresponders have been significantly better than those for combination nonresponders. On-treatment responses of 40% to 43% in previous combination therapy nonresponders are now being seen with the addition of amantadine (triple therapy), and sustained response rates with this regimen are awaited. Large trials are underway to evaluate the role of maintenance therapy for virologic nonresponders with advanced liver disease.

Treatment of chronic hepatitis C: a systematic review

This systematic review addressed 3 issues regarding current treatments for chronic hepatitis C: (1) efficacy and safety in treatment-naive patients; (2) efficacy and safety in selected subgroups of patients; and (3) effects on long-term clinical outcomes. Electronic databases were searched for articles from January 1996 to March 2002. Additional articles were identified by searching references in pertinent articles and recent journals and by questioning experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, or clinical outcome measures. For data collection, paired reviewers assessed the quality of each study and abstracted data. This systematic review found that the combination of high-dose peginterferon and ribavirin was more efficacious than standard interferon and ribavirin in persons infected with hepatitis C virus (HCV) genotype 1 (sustained virologic response [SVR] rate: 42% vs. 33%) and that ranges of SVR rates were higher with peginterferon than standard interferon monotherapy in naïve patients (10% to 39% vs. 3% to 19%). Reports were consistent in showing treatment with interferon and ribavirin was more efficacious than interferon monotherapy in treatment-naive persons and previous nonresponders and relapsers. Studies were moderately consistent in showing that treatment decreases the risk for hepatocellular carcinoma (HCC). The evidence on treatment in important subgroups was limited by a lack of randomized controlled trials. Thus, the combination of peginterferon and ribavirin was the most efficacious treatment in patients with HCV genotype 1. Long-term outcomes were improved in patients with hepatitis C who achieved an SVR with treatment.

Role of liver biopsy in management of chronic hepatitis C: a systematic review

This systematic review addresses 2 questions pertinent to the need for pretreatment liver biopsy in patients with chronic hepatitis C: how well do liver biopsy results predict treatment outcomes for chronic hepatitis C? How well do biochemical blood tests and serologic measures of fibrosis predict the biopsy findings in chronic hepatitis C? Medline and other electronic databases were searched from January 1985 to March 2002. Additional articles were sought in references of pertinent articles and recent journals and by querying experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, pathologic, or clinical outcome measures. Paired reviewers assessed the quality of each eligible study and abstracted data. Studies suggested that advanced fibrosis or cirrhosis on initial liver biopsy is associated with a modestly decreased likelihood of a sustained virological response (SVR) to treatment. Also, studies relatively consistently showed that serum aminotransferases have modest value in predicting fibrosis on biopsy; that extracellular matrix tests hyaluronic acid and laminin may have value in predicting fibrosis, and that panels of tests may have the greatest value in predicting fibrosis or cirrhosis. Biochemical and serologic tests were best at predicting no or minimal fibrosis, or at predicting advanced fibrosis/cirrhosis, and were poor at predicting intermediate levels of fibrosis. Thus, evidence suggests that liver biopsy may have some usefulness in predicting efficacy of treatment in patients with chronic hepatitis C, and biochemical blood tests and serologic tests currently have only modest value in predicting fibrosis on liver biopsy.

Role of liver biopsy in management of chronic hepatitis C: a systematic review

This systematic review addresses 2 questions pertinent to the need for pretreatment liver biopsy in patients with chronic hepatitis C: how well do liver biopsy results predict treatment outcomes for chronic hepatitis C? How well do biochemical blood tests and serologic measures of fibrosis predict the biopsy findings in chronic hepatitis C? Medline and other electronic databases were searched from January 1985 to March 2002. Additional articles were sought in references of pertinent articles and recent journals and by querying experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, pathologic, or clinical outcome measures. Paired reviewers assessed the quality of each eligible study and abstracted data. Studies suggested that advanced fibrosis or cirrhosis on initial liver biopsy is associated with a modestly decreased likelihood of a sustained virological response (SVR) to treatment. Also, studies relatively consistently showed that serum aminotransferases have modest value in predicting fibrosis on biopsy; that extracellular matrix tests hyaluronic acid and laminin may have value in predicting fibrosis, and that panels of tests may have the greatest value in predicting fibrosis or cirrhosis. Biochemical and serologic tests were best at predicting no or minimal fibrosis, or at predicting advanced fibrosis/cirrhosis, and were poor at predicting intermediate levels of fibrosis. Thus, evidence suggests that liver biopsy may have some usefulness in predicting efficacy of treatment in patients with chronic hepatitis C, and biochemical blood tests and serologic tests currently have only modest value in predicting fibrosis on liver biopsy.

Retreatment of patients with chronic hepatitis C

Significant advances have been made in the treatment of chronic hepatitis C virus (HCV) infection during the past 5 years. As a consequence, there is continuing enthusiasm for retreating patients who did not achieve sustained virological response (SVR) with previous therapy. Retreatment of non-responders to standard interferon monotherapy using interferon and ribavirin has yielded SVR rates of 12% to 15%. Retreatment with peginterferon and ribavirin has been more effective; achieving SVR rates of 34% to 40%. Retreatment of patients who relapsed after interferon monotherapy using standard interferon and ribavirin yielded SVR rates of 47%, whereas retreatment with peginterferon and ribavirin resulted in an SVR rate of about 60%. The major factors associated with a higher likelihood of an SVR after retreatment include previous relapse, previous treatment with interferon monotherapy, HCV genotypes 2 or 3, lower serum levels of HCV RNA, and having a significant decrease in HCV RNA levels during the initial course of therapy. These results help to focus retreatment with peginterferon and ribavirin on subsets of patients who are most likely to benefit.

Treatment of chronic hepatitis C: a systematic review

This systematic review addressed 3 issues regarding current treatments for chronic hepatitis C: (1) efficacy and safety in treatment-naive patients; (2) efficacy and safety in selected subgroups of patients; and (3) effects on long-term clinical outcomes. Electronic databases were searched for articles from January 1996 to March 2002. Additional articles were identified by searching references in pertinent articles and recent journals and by questioning experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, or clinical outcome measures. For data collection, paired reviewers assessed the quality of each study and abstracted data. This systematic review found that the combination of high-dose peginterferon and ribavirin was more efficacious than standard interferon and ribavirin in persons infected with hepatitis C virus (HCV) genotype 1 (sustained virologic response [SVR] rate: 42% vs. 33%) and that ranges of SVR rates were higher with peginterferon than standard interferon monotherapy in naïve patients (10% to 39% vs. 3% to 19%). Reports were consistent in showing treatment with interferon and ribavirin was more efficacious than interferon monotherapy in treatment-naive persons and previous nonresponders and relapsers. Studies were moderately consistent in showing that treatment decreases the risk for hepatocellular carcinoma (HCC). The evidence on treatment in important subgroups was limited by a lack of randomized controlled trials. Thus, the combination of peginterferon and ribavirin was the most efficacious treatment in patients with HCV genotype 1. Long-term outcomes were improved in patients with hepatitis C who achieved an SVR with treatment.

Meta-analysis: combination therapy with interferon-alpha 2a/2b and ribavirin for patients with chronic hepatitis C previously non-responsive to interferon

BACKGROUND

The efficacy of interferon-alpha plus ribavirin treatment for patients not responding to interferon monotherapy is not well established.

AIM

To assess the efficacy and safety of combination therapy with interferon-alpha 2a/2b plus ribavirin by performing a meta-analysis of randomized clinical trials.

METHODS

A systematic search of electronic databases for randomized clinical trials of interferon-alpha 2a/2b plus ribavirin was conducted independently by two investigators. Data abstraction was performed. The primary end-point was a sustained virological response. Estimates of the common odds ratio were calculated using a random effects model.

RESULTS

Of the 127 identified studies, 46 were considered for evaluation and 10 were included (1728 patients). The pooled sustained virological response was 12.6% (95% CI, 9.5-16.3%) for combination therapy vs. 2% (95% CI, 0.9-4.0%) for interferon monotherapy, with a common odds ratio of 5.49. Higher doses of interferon, a longer duration of therapy (48 weeks) and genotypes other than 1 and 4 were associated with an improvement in response. More side-effects and discontinuations were observed with combination therapy than with interferon monotherapy.

CONCLUSIONS

Non-responders to interferon may benefit from re-treatment with combination therapy, especially from a 48-week regimen.

Interferon-alpha-2b plus ribavirin: a review of its use in the management of chronic hepatitis C

Relatively few patients (< or =20%) with chronic hepatitis C achieve a sustained virological response after interferon-alpha monotherapy. Hence, alternative treatment strategies such as the addition of the broad spectrum antiviral agent ribavirin to interferon-alpha-2b have been investigated. Combination therapy with subcutaneous interferon-alpha-2b [3 million units (MU) three times per week] plus oral ribavirin (1000 to 1200 mg/day) has proven effective in several well designed trials of 24 to 48 weeks' duration in adult patients with compensated chronic hepatitis C. Compared with interferon-alpha-2b (3 or 6 MU three times per week) with or without placebo, combination treatment with interferon-alpha-2b plus ribavirin significantly enhanced end-of-treatment and sustained virological and biochemical response rates in treatment-naive and treatment-experienced patients [sustained virological response rates in treatment-naive recipients (6 to 19% vs 31 to 43% of patients); sustained overall (virological plus biochemical) response rates in nonresponders to (1 vs 14%) or relapsers (4 to 5% vs 30 to 44%) after previous interferon-alpha monotherapy]. Forty-eight weeks of combination therapy was superior to 24 weeks in treatment-naive patients infected with hepatitis virus C (HCV) genotype 1, whereas response rates were similar at 24 and 48 weeks in those infected with other HCV genotypes. Furthermore, there were marked improvements in histological inflammatory scores in patients who responded to treatment with either interferon-alpha-2b plus ribavirin or interferon-alpha-2b alone. Although adverse events associated with either drug during combination therapy occurred frequently, these were generally mild to moderate in intensity and were consistent with those reported for each individual agent. Twenty-six percent of patients required dosage modifications of one or both drugs during combination therapy.

CONCLUSIONS

Interferon-alpha-2b plus ribavirin is an efficacious first- and second-line therapy in adult patients with compensated chronic hepatitis C, significantly improving sustained virological and biochemical responses versus interferon-alpha-2b monotherapy. The tolerability profile of interferon-alpha-2b plus ribavirin therapy is consistent with the individual profiles of these agents with no evidence of additive effects. The place of interferon-alpha-2b plus ribavirin combination therapy in relation to newer agents, including pegylated interferons-alpha and other multidrug regimens, remains to be determined in this rapidly evolving area of therapeutic management. Currently, combination therapy with interferon-alpha-2b plus ribavirin is recommended as first-line therapy for patients with chronic hepatitis C and compensated liver disease, and is an option for use as second-line therapy in those who have relapsed after, or failed to respond to, previous treatment with interferon-alpha.

Interferon for interferon nonresponding and relapsing patients with chronic hepatitis C

BACKGROUND

Interferon monotherapy leads to sustained virologic clearance in a minority of patients with chronic hepatitis C. Studies have yielded conflicting results regarding retreatment with interferon in nonresponders and relapsers.

OBJECTIVES

To assess the beneficial and harmful effects of retreatment with interferon in chronic hepatitis C nonresponders and relapsers to previous interferon treatment.

SEARCH STRATEGY

Trials were identified through electronic databases, manual searches, authors, and pharmaceutical companies (August 2001).

SELECTION CRITERIA

Randomised trials comparing interferon versus control or different interferon regimens in chronic hepatitis C patients being nonresponders and relapsers to previous interferon were included.

DATA COLLECTION AND ANALYSIS

The primary outcome was failure to achieve a sustained virologic response defined as positive serum hepatitis C virus RNA at least six months following treatment. Secondary outcomes included liver-related morbidity, mortality, biochemical responses, adverse events, and histology.

MAIN RESULTS

Ten randomised trials involving 686 nonresponders and eight trials involving 484 relapsers were included; their methodological quality was poor. In nonresponders, interferon reduced the risk of not achieving an end of treatment biochemical response compared with no treatment (relative risk [RR] 0.77, 95% confidence interval [CI] 0.66 to 0.91); however, virologic responses were not reported. In a post hoc subgroup analysis, doses greater than 3 million units (MU) three times weekly offered no advantage compared with 3 MU three times weekly for biochemical sustained response. Failure to obtain a virologic sustained response was less likely with 48 than 24 weeks of therapy (RR 0.87, 95% CI 0.79 to 0.96). Adverse events did not differ significantly regardless of treatment dose or duration. In relapsers, none of the trials compared interferon with no treatment. In a post hoc analysis, doses greater than 3 MU three times weekly were no more effective in achieving a virologic sustained response than 3 MU three times weekly. Compared with 24 weeks, treatment durations of 48 weeks were less likely to fail to achieve a virologic sustained response (RR 0.69, 95% CI Random 0.51 to 0.95), but associated with more frequent dosage reduction (RR 9.07, 95% CI 1.20 to 68.63). No data regarding clinical outcomes or histology was available in either patient group.

REVIEWER'S CONCLUSIONS

Retreatment with interferon leads to sustained virologic clearance in a minority of chronic hepatitis C patients with nonresponse or relapse following interferon monotherapy. Treatment durations of 48 weeks are superior to 24 weeks, but doses greater than 3 MU three times weekly are no more effective. No data exists regarding the effect on clinical outcomes.

Influence of three successive antiviral treatments on viral heterogeneity in nonresponder chronic hepatitis C patients

The purpose of the present study was to assess the viral diversity of hepatitis C virus (HCV) in six nonresponder patients during three unsuccessful treatments. These patients were treated successively with IFN-alpha2a (IFN-alpha) at a posology of 3.10(6) units (MIU) three times a week, 10 MIU three times a week, and a combination of IFN-alpha (3 MIU) plus ribavirin (1,000 mg/day). However, only two chronically infected patients could be included in the study due to the persistence of HCV RNA during the three successive treatments. The viral diversity was analysed by cloning and sequencing the HVR-1 region. The treatment of the two nonresponder patients was associated with the persistence of a wide diversity in the viral population and with the emergence of new or minor variants. Under the influence of standard doses of IFN-alpha, a rearrangement of the quasispecies present was observed at this time point. No significant change in viral load or in the complexity of the quasispecies was observed. A second treatment with a high dose of IFN-alpha induced a significant decrease in the associated viral load and, in one case, resulted in a radical change of the viral diversity. Administration of a combination of IFN-alpha and ribavirin did not affect the evolution of the variants but was followed by the emergence of various multiple variants. These results reinforce the hypothesis of the presence of preexisting quasispecies best adapted to the host environment, and therefore resistant to any current therapy.

Management of interferon therapy nonresponders

Despite improvements in the therapies for chronic hepatitis C virus (HCV) over the past several years, many patients still fail to become hepatitis C virus ribonucleic acid (HCV-RNA) undetectable during treatment and are classified as nonresponders. Providing treatment recommendations for these patients requires that the likelihood of achieving any benefit from another course of therapy be balanced with the natural history of chronic HCV. The management of nonresponders represents the most challenging of all aspects in the care of patients with chronic HCV. Retreatment of interferon non-responders with interferon and ribavirin has yielded a long-term virologic benefit in only 10% to 25% of patients. The efficacy of peginterferon and peginterferon with ribavirin for nonresponders has yet to be defined.

African Americans with genotype 1 treated with interferon for chronic hepatitis C have a lower end of treatment response than Caucasians

African Americans as a group have a higher incidence of chronic hepatitis C (CHC) than Caucasians but are often under-represented in clinical trials used to define response rates to interferon therapy. The aim of this study was to compare African Americans with Caucasians with respect to end-of-treatment response to interferon. This retrospective study had 61 African Americans and 49 Caucasians with CHC. All patients were treated for at least 12 weeks with interferon-alpha2b (Intron A) thrice weekly. End-of-treatment response was defined as three consecutive nondetectable HCV RNA measurements at least 1 month apart. Sustained response was defined as a negative serum HCV RNA 6 months after end of treatment. Of the 110 patients, 19 achieved an end-of-treatment response (17%) but only four achieved a sustained response (4/110=4%). Of the patients achieving a sustained response, one was genotype 1 (male Caucasian), three were genotype 2/3 with four patients having no follow-up information. The end-of-treatment response was 7% for patients with genotype 1 and 71% for genotype non-1 (P < 0.005 for genotype non-1). The end-of-treatment response was significantly higher in Caucasians (14/49=31%) compared with African Americans (5/61=8%; P < 0.05). A lower response rate in African Americans with genotype 1 in contrast to Caucasians was the primary reason for the difference in end-of-treatment response (1/45=2% vs. 5/33=15%, P < 0.05). Hence, interferon treatment resulted in a poor sustained response rate in the group of patients representative of the urban populations with the highest prevalence of hepatitis C. A genotype other than type 1 was the strongest predictor of end-of-treatment response in patients treated but over 86% of patients in this urban clinic were genotype 1. Caucasians were more likely to respond than African Americans, especially in patients with genotype 1.

What is (cost) effective in patients with chronic hepatitis C virus infection?

Hepatitis C virus (HCV) infection often progresses to chronic hepatitis, cirrhosis, and possibly hepatocellular carcinoma. Chronic hepatitis C infection is a leading cause of chronic liver disease and the most common indication for liver transplantation. Combination therapy of interferon alpha and ribavirin is currently the standard regimen for chronic hepatitis C. This combination can achieve viral clearance in approximately 40% of patients, and improve histology and prognosis. The most cost-effective approach to guide duration of combination therapy is HCV genotyping. Cost effectiveness cannot be improved further by taking other well-defined predictive factors for sustained virological response into account. Recent insights into HCV kinetics and the correlation between initial viral decline and sustained virological response will allow us to optimize and individually tailor antiviral treatment Individualized treatment according to the initial viral decline, together with further improvements in drugs (e.g. by long-acting pegylated interferons), will have new impact on antiviral efficacy and cost effectiveness.

Viral hepatitis

Viral hepatitis constitutes the most common entity seen in hepatology practice. Hepatitis A vaccination is recommended for patients with chronic hepatitis. Both lamivudine and interferon are established therapies against chronic hepatitis B, with other treatments not equally effective. Adefovir dipivoxil is a promising new treatment for lamivudine-resistant hepatitis B mutants. Lamivudine and hepatitis B immunoglobulin are effective in preventing recurrence of hepatitis B after transplantation. The combination of interferon and ribavirin has been shown to be effective for treatment of hepatitis C. Studies support the antiviral, antifibrotic, and antineoplastic effect of interferon therapy. Recurrence of hepatitis C after transplantation has been associated with more rapid progression to cirrhosis. Other major advances in the field of viral hepatitis during the past year are highlighted.

Pegylated interferons: what role will they play in the treatment of chronic hepatitis C?

The primary therapy for patients with chronic hepatitis C virus (HCV) infection is interferon alfa. However, use of interferon for treatment of chronic HCV has several shortcomings that limit its effectiveness. Interferon has a very short half-life, must be administered multiple times weekly, and is associated with significant side effects. "PEGylation" is a process whereby the inert polymer, polyethylene glycol (PEG), is attached to a protein pharmaceutical. This process has been shown to alter the properties of PEGylated proteins in a manner that significantly extends half-life, reduces immunogenicity, and enhances biologic activity when compared with the native protein. In recent years, several PEGylated forms of interferon alfa have been developed. Recent studies have demonstrated that PEG-interferons have a significantly prolonged half-life and sustained virologic response when compared with standard interferon. Studies to evaluate the effects of combining PEG-interferons with ribavirin are currently underway. The role PEG-interferons will play in patients who have either relapsed or failed to respond to previous interferon or interferon/ribavirin therapy remains to be defined.