A randomized controlled trial of high-dose maintenance interferon therapy in chronic hepatitis C

A decade of trials of interferon-alpha for chronic hepatitis C. A meta-regression analysis

The most relevant randomized controlled trials of interferon-alpha (IFN) for naive patients with chronic hepatitis C (CHC) published in a decade, just before appearance of pegylated IFN trials in 2000, were included in this paper. Its purpose is to review the relationship between sustained biochemical response in active versus control group versus usual clinical variables as IFN regimens, cirrhosis, genotype and versus less frequently addressed variables as funding, methodological quality or location of principal author. Meta-analysis estimates of global treatment effect varied according to trial design: group 1=IFN versus placebo/no treatment, 32 RCTs, 2499 pts, OR 9.5 (6.3-14.2); group 2a=comparison of IFN schedules, 43 RCTs, 7454 pts, OR 1.6 (1.4-1.9); group 2b=IFN+other drugs versus standard IFN, 30 RCTs, 4737 pts, OR 2.0 (1.6-2.6). Fixed effects (arm-level) meta-regression on the complete data set (171 arms, 10,580 pts) revealed that sustained response was most likely in experimental arms of IFN+ribavirin or other drugs (OR 2.4), arms using yearly schedule (OR 2.0), trial principal author from Asia (OR 1.7), trial sample size >200 (OR 1.4) and arms enrolling less than 50% of cirrhotics (OR 1.3). Moreover, focus was on some significant interactions too, as the effect of trial's quality interacting to the recorded funding (more benefit if no-profit, less if for-profit) and the effect of trial funding interacting to the location of first author (more benefit if from Asia). Three main effects (experimental arm, cirrhosis, funding) and one interaction (funding*location of principal author) explained 31% of between study variability in a random-effect meta-regression. In a subgroup analysis on a data set including available information on HCV genotype (93 arms, around 7000 pts), meta-regression revealed that genotype 1 or 4 less than 50% per arm and specialistic journal were significant predictors of either biochemical (transaminases) or virological (HCV-RNA) sustained response, in a model including the same main effects identified in the complete data set analysis. Finally, although mostly captured by different IFN regimens along time, heterogeneity of effect in a large set of (not-pegylated) IFN trials was also explained by HCV genotype and variables of quality and reporting, such as trial's principal author from Asia.

First-line therapy with daily versus thrice-weekly interferon alfa-2b plus ribavirin for chronic hepatitis C

OBJECTIVES

Combination therapy with interferon and ribavirin is the most effective treatment for chronic hepatitis C today. Before pegylated interferons became available, higher and more frequent doses of interferon were expected to be more effective than the standard regimen of three million units thrice weekly. In fact, daily dosing is still proposed for non-pegylated interferon. The aim of this study was to compare the efficacy and safety of daily versus thrice-weekly interferon alfa-2b in combination with ribavirin as first-line treatment of chronic hepatitis C.

METHODS

A total of 116 treatment-naive patients were randomised to receive either interferon alfa-2b three million units daily or thrice-weekly in combination with ribavirin for 24 weeks. Patients with hepatitis C virus (HCV) genotype 1 who were HCV-RNA negative at 24 weeks continued treatment with thrice-weekly interferon plus ribavirin for another 24 weeks. Sustained virological response was defined as an undetectable HCV-RNA level 24 weeks after treatment was completed (end of follow-up).

RESULTS

In an intention-to-treat analysis, HCV-RNA was undetectable at the end of treatment in 71% and 74% of patients treated with daily and thrice-weekly interferon, respectively. At the end of follow-up, HCV-RNA was undetectable in 47% and 57% of patients treated with daily and thrice-weekly interferon, respectively. Sustained virological response rates were almost twice as high in patients with genotypes 2 and 3 as in patients with genotype 1 but were not different between treatment groups.

CONCLUSIONS

This study could not show any difference between daily and thrice-weekly standard interferon plus ribavirin in achieving end-of-treatment and sustained virological responses in chronic hepatitis C.

Weight-based dosing of pegylated interferon-alpha in chronic hepatitis C: just a marketing 'gag'?

Today medical-scientific data are diluted by the marketing strategies of the biomedical industry making it difficult for practising physicians to decide what is correct or wrong. One typical example is the use of pegylated interferons for treatment of chronic hepatititis C. In this report the arguments pro and contra weight-based dosing are critically discussed. The factors contributing to success or failure to eradicate the virus are manifold, and include the sensitivity of the virus to interferon, viral genotype, age, gender stage of fibrosis, presence or absense of steatosis. Weight by itself plays just a minor role. The impact of weight-based dosing in general is overestimated and certainly not needed when 40 kD branched PEG-IFNalpha2a with a restricted volume of distribution is used. Whether weight-based dosing of 12 kD linear PEG-IFNalpha2b provides any benefit over a flat dose of the drug remains to be studied.

High-dose interferon alpha-2a with ribavirin and amantadine in naïve chronic hepatitis C patients--results of a randomized, prospective, pilot study

BACKGROUND

Hepatitis C viral kinetic studies have demonstrated the increased anti-viral effect of higher than standard dosages of interferon and of daily treatment schedules.

AIM

To compare, in a prospective, randomized, controlled trial, the efficacy and safety of high-dose interferon-alpha therapy vs. standard-dosage interferon-alpha therapy, in a triple therapy combination with ribavirin and amantadine.

METHODS

Previously untreated patients with chronic hepatitis C were randomized to the standard interferon-alpha group (n = 15), receiving thrice weekly 6 MU interferon-alpha for 12 weeks, followed by 3 MU interferon-alpha for 36 weeks, or the high-dose interferon-alpha group (n = 15), receiving daily 9 MU interferon-alpha for 4 weeks, followed by 6 MU (weeks 5-8), 3 MU (weeks 9-12) and 1.5 MU (weeks 13-48) interferon-alpha. All patients were given ribavirin (1000-1200 mg) and amantadine (200 mg) daily for 48 weeks.

RESULTS

At the end of treatment and after the 24-week follow-up period, serum hepatitis C virus RNA was undetectable in eight (53%) and six (40%) patients treated with standard-dosage interferon-alpha, respectively, compared with 11 (73%) and 10 (67%) treated with high-dose interferon-alpha, respectively (not significant). The safety profile of both treatment regimens was similar. Severe adverse events leading to withdrawal from the study occurred in one patient (7%) in each group, and in both groups one patient (7%) was lost during therapy for unknown reasons.

CONCLUSIONS

The findings suggest that, although the difference between the response rates of standard and high-dose interferon-alpha regimens (within a triple anti-viral therapy combination) did not reach statistical significance, there was a clear trend towards a higher response with high-dose interferon-alpha therapy and an equal safety profile.

A randomized trial of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon

BACKGROUND

Conventional interferon monotherapy fails to achieve virological clearance in most hepatitis C-infected patients. The use of high-dose induction regimens may improve the initial clearance of virus, while the addition of ribavirin appears to improve the rates of sustained response once clearance is achieved.

AIM

To compare the efficacy and safety of re-treatment with an induction regimen of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon monotherapy.

METHODS

Previous virological non-responders to standard dose interferon (3-5 MU three times weekly for > or = 12 weeks) were randomized to receive, unblind, either 10 MU interferon alpha-2b daily for 10 days, then 5 MU daily for 74 days, then 5 MU three times weekly for 24 weeks (total 36 weeks) (group A), or the above regimen with the addition of ribavirin, 1000-1200 mg/day, at day 11 (group B). All patients were followed up for 24 weeks after completion of therapy.

RESULTS

End of treatment virological response was noted in one of 10 (10%) patients in group A and in eight of 15 (54%) patients in group B (P=0.04). The sole end treatment responder in group A and three in group B relapsed on follow-up. The apparent improvement in response in group B compared to group A nearly reached statistical significance (group B 5/15 vs. group A 0/10; P=0.06).

CONCLUSIONS

In this small pilot study, a 36-week high-dose induction interferon monotherapy protocol did not yield sustained responses in previous non-responders to standard dose interferon. However, the same regimen with ribavirin yielded a 33% sustained response rate, nearly reaching statistical significance. The therapy was well tolerated, despite the higher doses of interferon used and the addition of ribavirin. High-dose interferon with ribavirin appears to be a therapeutic option for non-responders to conventional interferon monotherapy.

Interferon for interferon naive patients with chronic hepatitis C

BACKGROUND

A previous meta-analysis of interferon therapy in naive patients with chronic hepatitis C has documented its efficacy in achieving virologic clearance, and improving liver biochemistry and histology; however, since its publication additional trials have been reported.

OBJECTIVES

To evaluate the response to interferon in interferon naive patients with chronic hepatitis C. The effect of treatment dose and duration, and the response in patients with cirrhosis and those with normal aminotransferases was also investigated.

SEARCH STRATEGY

The Cochrane Controlled Trials Register (Cochrane Library Issue 1, 1999), MEDLINE (January 1966 to December 1999), and reference lists were searched, and pharmaceutical companies were contacted for unpublished trials.

SELECTION CRITERIA

Randomised clinical trials comparing interferon with placebo, no treatment, or different regimens of interferon were selected. Abstracts were excluded.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was sustained disappearance of serum HCV RNA (virologic sustained response (SR)). Biochemical and end of treatment responses, liver histology, and adverse events were also recorded. Assessment of drug efficacy used the methods of Peto and Der Simonian and Laird.

MAIN RESULTS

Fifty-four trials enrolling 6545 patients were included. Compared with no treatment, interferon 3 MU thrice weekly for 12 months increased the probability of a virologic SR (Peto odds ratio (OR) 4.60; 95% confidence interval (CI) 1.53 to 13.85). At this dosage and duration of therapy, the rate of virologic SR was 17% (95% CI 10 to 28%) in interferon-treated patients versus 3% (95% CI 1 to 10%) in controls. A dose of 6 MU was more effective than 3 MU thrice weekly (OR for 12 months treatment, 2.21; 95% CI 1.10 to 4.45), as were durations of 12 months or greater versus six months (OR 1.87; 95% CI 1.30 to 2.67). Adverse events were more common with higher doses and prolonged durations of treatment. Compared with no therapy, interferon increased the probability of histologic improvement (OR 9.22; 95% CI 5.69 to 14.94). The response to interferon in cirrhotic patients (virologic SR, 17%; 95% CI 11 to 26%) was similar to that in non-cirrhotic patients. However, interferon was no more effective than control in patients with normal aminotransferases.

REVIEWER'S CONCLUSIONS

Interferon is effective in achieving viral clearance and improving liver biochemistry and histology in interferon naive patients with chronic hepatitis C. Higher doses and prolonged durations are more effective, but associated with more frequent adverse events. Interferon is associated with similar benefits in patients with cirrhosis, but the efficacy in patients with normal aminotransferases is unproven.

Meta-analysis of interferon randomized trials in the treatment of viral hepatitis C in naive patients: 1999 update

The aim of this study was to update our previous meta-analysis of interferon (IFN) in the treatment of hepatitis C and to analyse new factors, namely, HCV RNA end-point, patients with cirrhosis and patients with normal ALT. We use the Der Simonian and Laird method, with heterogeneity and sensitivity analyses. Seventy-six randomized control trials (RCTs) in naive patients were found but we focused our analysis on 59 RCTs with chronic hepatitis C (26 vs. controls and 33 comparing different regimens) and on seven RCTs in acute hepatitis. Interferon-alpha (IFN-alpha) at 3 MU thrice weekly (TIW) for 12 months exhibited 39% of virological end-of-treatment response (ETR) and 17% of virological sustained response (SR), respectively, vs. 1% and 3% in untreated controls (all P < 0.001). There was a significant dose effect (in favour of 6 vs. 3 MU TIW): the virological SR at 6 months were 35% in the 6 MU group (95% CI: 24-47) and 16% in the 3 MU group (95% CI: 8-27) and were at 12 months 43% in the 6 MU group (95%CI: 31-56) and 25% in the 3 MU group (95% CI: 16-37). There was a significant duration effect (12 vs. 6 months) upon the virological SR rate both at 3 and 6 MU: 3 MU provided 14% of virological SR (95% CI: 11-19) in the 12 months group vs. 7% (95% CI: 5-11) in the 6 months group and 6 MU provided 22% (95% CI: 17-29) and 16% (95% CI: 11-22) virological SR in the 12 and 6 months groups, respectively. Cirrhotic treated patients had 17% of virological SR (95 CI: 9-24%; P < 0.001) vs. 0% in controls and provided a 20% reduction rate (95 CI: -2% to -37%, P=0.03) in hepatocellular carcinoma incidence. In acute hepatitis C, a 3-month treatment with IFN-alpha showed significant efficacy vs. controls upon the virological SR rate (32% vs. 4%, P < 0.001). In conclusion, we confirm the dose and duration effect of IFN in chronic hepatitis C, and the efficacy of IFN-alpha in the treatment of acute hepatitis and in cirrhotic patients.

Case selection for interferon treatment of hepatitis C

To establish a case selection algorithm for the treatment of hepatitis C, predictive factors were studied and reported articles were reviewed and analysed. Because of the relatively poor efficacy of interferon (IFN) monotherapy, which is ineffective in 60-70% of patients, case selection at present is determined by the likelihood of attaining a sustained response (SR; defined by normalizing serum ALT and eliminating serum HCV RNA after treatment) to therapy. According to the present study, viral load and genotype, and IL-10 and IL-1ra serum levels, are the most predictive of achieving SR after IFN monotherapy given in a comparatively high dose regimen for 6 months. In addition, reported studies with logistic analyses were carefully reviewed and analysed for the most effective predictive factors of case selection. The results again indicated that viral load and HCV-genotype (serotype). were closely related to SR. Age, gender, and histological changes at treatment were also considered for case selection. These results, however, relate solely to IFN-monotherapy. Future development of more effective strategies for treating hepatitis C could alter the exclusion criteria for IFN treatment and will negate the need for the case selection algorithm discussed here.

Methodological issues in papers on IFN therapy: time for reappraisal

We conducted an analytical review of 194 full papers on interferon (IFN) therapy for chronic hepatitis C to evaluate current methodology (i.e. study design, criteria for evaluating the efficacy of therapy and predictors of response). Of the papers evaluated, 64 were randomized controlled trials (RCT), 40 were non-randomized controlled trials (NRCT) and 90 were observational studies (OS). The methodological analysis was focused mainly on clinical trials. The number of patients enrolled in RCT was higher compared with the number enrolled in NRCT. Uniform enrolment criteria were used in less than 50% of the trials. Only 20% of RCT and 2.5% of NRCT used criteria for defining sample size. The response rate was calculated on an intention-to-treat basis in 36 of the RCT and in 14 of the NRCT. The outcome of treatment and the criteria employed to define the response to treatment were found to be far from standardized. In 51.5% of the RCT and 42.5% of the NRCT, normalization of alanine aminotransferase (ALT) level at the end of follow-up was the only marker of response studied. Only 57.6% of the trials considered histological evidence as an important outcome. Among the clinical trials, 71.1% evaluated predictors of good response to IFN therapy. In 51% of the OS, ALT normalization by the end of follow-up was the only criterion for defining response. In conclusion, to ensure a high level of reliability in comparing or combining the results of different studies, some basic general requirements must be followed when planning trials on antiviral therapy.

New schedules of interferon for chronic hepatitis C

Current treatment regimens with either long-term interferon monotherapy or interferon-ribavirin combination achieve sustained response rates of 40-50%. Options to improve the sustained response to interferon include longer treatment duration, higher fixed doses throughout the course of therapy, de-escalating strategies in which more intensive treatment is given during the initial weeks of treatment (so-called induction dosing) or escalation strategies in which the dose is progressively increased until a response occurs. Published literature supports the use of a treatment period of at least 12 months. Although higher doses which are fixed throughout the treatment course result in a moderate increase in sustained response rate, this may not be justified by the cost and added side effects. Although high dose induction strategies may result in a more rapid decline in serum HCV RNA levels, it is not yet known whether this will result in better longterm outcome. Preliminary evidence suggests that the benefit may be confined to subgroups of patients who might be predicted to have a poor response to standard therapy, such as those with high pre-treatment viral levels.

Predictors of sustained response to alpha interferon therapy in chronic hepatitis C

OBJECTIVES

To utilize cytokine levels to predict sustained response (SR) to alpha interferon (IFN alpha) therapy in chronic hepatitis C patients, and to determine the relationship between serum tumor necrosis factor alpha (TNF alpha), interleukin (IL) IL 6, IL 8, IL 12, transforming growth factor beta (TGF beta 1) and the degree of liver damage as reflected by traditional markers.

DESIGN AND METHODS

Serum cytokine levels were assessed using ELISA in 18 patients included in a controlled clinical trial of IFN alpha.

RESULTS

Of the 18 patients, 27% were sustained responders (SR), 27% were response and relapse responders (RR), and 46% were non-responders (NR). Multivariate analysis showed that a low serum TNF alpha level and high serum IL 8 levels were independent factors associated with SR to IFN alpha therapy. Serum TNF alpha level highly correlated with viral load and genotype predictive values (p < 0.001). Therapy lowered the IL 6 and IL 12 profile. TGF beta 1 levels in serum are positively correlated with fibrinogenesis.

CONCLUSIONS

IFN alpha therapy modulates immune response to hepatitis C virus, contributing to sustained response.

Chronic hepatitis C and interferon alpha: conventional and cumulative meta-analyses of randomized controlled trials

OBJECTIVE

The purpose of this study was to evaluate the clinical usefulness of surrogate markers of the interferon effect (i.e., alanine aminotransferase levels and serum HCV-RNA status) as predictors of long term response, and to identify the optimal schedule of treatment for patients with chronic hepatitis C by means of meta-analysis.

METHODS

Pertinent randomized clinical trials and prospective studies were selected using MEDLINE (1986-1996), a reference list from published articles or reviews. Twenty-six prospective studies reporting data on surrogate markers of interferon response were selected. Thirty-nine trials comparing interferon alpha to no treatment and 25 trials comparing different schedules of interferon were reviewed. Conventional meta-analysis according to the DerSimonian and Laird method was used for the pooling of results.

RESULTS

The pooled probability of late relapse among sustained responders with negative serum HCV-RNA 6 months after treatment was very low (8.7%; 95% confidence interval 5.8-11.6%). The overall risk difference between treated and control groups was 16.63% (95% confidence interval 11.95-21.31%) for sustained aminotransferase normalization. Therapy with higher interferon dose compared with standard dose significantly improves the rate of sustained response (pooled risk difference 10.56%, 95% CI 5.47-15.65%). Cumulative meta-analyses suggest that a clear dose-response relationship exists across a wide range of interferon dosages. The multivariate meta-regression model confirms that the total interferon dose is an independent predictor of sustained response and that it seems more important than the length of treatment.

CONCLUSIONS

Testing for serum HCV-RNA, 6 months after interferon therapy in sustained biochemical responders, is useful for predicting long term response. The current standard total interferon dose of 234 mega-units is suboptimal. Further trials that directly compare different schedules of treatment are needed.

Leucocyte interferon-alpha retreatment for chronic hepatitis C patients previously intolerant to other interferons

The activity and tolerability of a retreatment cycle with leucocyte interferon-alpha (IFN-alpha) (6 million units (MU) three times weekly for 12 months) was evaluated in a group of 22 hepatitis C patients who had been intolerant to a previous course of lymphoblastoid IFN-alpha. Seven patients (31%) discontinued the new therapy owing to either a lack of response (six patients) or to severe leucopenia (one patient). Fifteen patients (68%) completed the 12-month treatment: all had a biochemical response and 10 (45%) also had disappearance of serum HCV RNA (complete response). Mild adverse reactions (fever, headaches and diarrhoea) were seen in these patients during retreatment. After 12 months of follow-up, 11 patients (50%) still maintained the biochemical response (long-term response); seven of these patients (32%) were also negative for serum HCV RNA. Biochemical and complete responses, at the end of both treatment and follow-up, were similar to those seen with lymphoblastoid IFN-alpha. The full dose of leucocyte IFN-alpha, when used in patients previously intolerant to the same dosage of lymphoblastoid IFN-alpha, was better tolerated: only one of the 15 patients who completed the 12-month treatment had a severe adverse event leading to withdrawal vs 22 of 68 patients treated with lymphoblastoid IFN-alpha. Furthermore, there were no manifestations of serological or clinical autoimmunity caused by leucocyte IFN-alpha, even in patients with autoantibodies associated with previous IFN therapy.

Long-term course of interferon-treated chronic hepatitis C

BACKGROUND/AIMS

To evaluate whether sustained response to a-interferon improves clinical outcome in patients with chronic hepatitis C.

METHODS

A cohort of 410 consecutive patients (65% with chronic hepatitis, 35% with cirrhosis) were treated with a-interferon in two trials (mean follow-up 62.1 months, range 7-109 months). All were serum HCV RNA positive before therapy and received first 10 then 5 million units of a-2b or a-nl interferon three times weekly for 6 to 12 months. Sustained response was defined as normal aminotransferases 12 months after stopping interferon.

RESULTS

Sixty-two patients (15.1%: 54 with chronic hepatitis, eight with cirrhosis) were sustained responders. At the end of follow-up, 56 out of 62 sustained responders (90.3%) were serum HCV RNA negative. No biochemical relapse after 12 months was seen in sustained responders, regardless of initial histology, HCV genotype or persistence of HCV RNA. Although three died of non-hepatic causes, no liver-related events were observed among sustained responders. Complications of liver disease occurred in 34 relapsers/non-responders: nine hepatocellular carcinomas, 21 ascites and four portal hypertensive bleedings. Eleven relapsers/nonresponders died: eight of hepatic and three of non-hepatic causes. Event-free survival was significantly longer in sustained responders than in all the remaining patients. In a regression analysis, sustained response to interferon, low age and absence of cirrhosis were independent predictors of event-free survival.

CONCLUSIONS

Hepatitis C virus is probably eradicated and progression of liver disease is prevented in most patients who remain HCV RNA negative with normal transaminases for more than 1 year after stopping treatment.