Early viral clearance and sustained response in chronic hepatitis C: a controlled trial of interferon and ribavirin after high-dose interferon induction

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.

Impact of high-dose peginterferon alfa-2A on virological response rates in patients with hepatitis C genotype 1: a randomized controlled trial

This study tested the hypothesis that high-dose peginterferon alfa-2a (PEG-IFNalpha-2a) for the first 12 weeks would increase early and sustained virological response (SVR) rates in patients with chronic hepatitis C genotype 1. Eight hundred ninety-six patients were randomized 1:1 to 360 microg (n = 448) or 180 microg (n = 448) PEG-IFNalpha-2a weekly plus ribavirin at 1000-1200 mg/day for 12 weeks, followed by 36 weeks of 180 microg PEG-IFNalpha-2a weekly plus ribavirin at 1000-1200 mg/day with 871 patients evaluable for the intention-to-treat analysis. Virological responses were assessed by TaqMan (limit of detection 15 IU/mL) at week 4, 8, 12, 24, 48 (end of therapy), and 24 weeks following therapy (SVR). Undetectable hepatitis C virus RNA rates were significantly higher among patients receiving high-dose induction therapy at week 4 (36% versus 26%, P < 0.005), week 8 (61% versus 50%, P < 0.005), and week 12 (74% versus 62%, P < 0.005). However, SVR was not significantly different between patients receiving high-dose (53%) and standard (50%) therapy. Significant baseline prognostic factors for SVR included age, sex, race, histological stage, and viral load. SVR was considerably higher among patients with no or minimal fibrosis (64% and 60%, respectively) compared to those with severe fibrosis/cirrhosis (28% and 24%, respectively). The frequency of serious adverse events and drug discontinuations were similar in both groups, whereas PEG-IFN dose modification, weight and appetite reduction, and grade IV neutropenia were significantly higher in the induction arm.

CONCLUSION

Induction dosing with 360 microg/week PEG-IFNalpha-2a for 12 weeks was well tolerated and enhanced early virological response but not SVR rates. The high SVR rates in patients with minimal fibrosis highlight the benefit of early treatment in patients with hepatitis C virus genotype 1.

Randomized trial of high-dose interferon-alpha-2b combined with ribavirin in patients with chronic hepatitis C: Correlation between amino acid substitutions in the core/NS5A region and virological response to interferon therapy

The aim of this study was to compare the efficacy of high-dose interferon (IFN)-alpha-2b with standard dose of IFN-alpha-2b in combination with ribavirin (RBV) for patients with chronic hepatitis C virus (HCV) infection, and to investigate the predictive factors associated with virological response. Two hundred Japanese patients with high HCV viral load (>100 KIU/ml) were randomized to 6 or 10 mega units (MU) of 24-week IFN-alpha-2b with RBV. Predictive factors were investigated; including pretreatment amino acid (aa) sequences of the core region and the IFN-sensitive determining region (ISDR). The sustained virological response rate was not different in the two groups (24% vs. 30%) but the incidence of depression was significantly higher in the 10 MU group than 6 MU group (7% vs. 0%, P = 0.02). Younger age (<60) and HCV genotype (2a/b) were significant predictors of sustained virological response. In patients infected with genotype 1b, substitutions of core aa 70 and/or 91 were predictive for non-virological response (P < 0.001), and substitutions in the ISDR was observed frequently in virological responders. Early viral kinetics study showed that serum HCV core antigen decreased more slowly in both patients with aa 70 and/or 91 substitutions in the core and with absence of substitutions in the ISDR. In conclusion, the use of a higher dose of IFN-alpha-2b in combination with RBV did not improve virological response but resulted in higher incidence of depression. Amino acid substitutions in the core and ISDR are predictive of virological response to the therapy in patients with genotype 1b and high viral load.

Short-duration therapy for hepatitis C: suitable for all?

Peginterferon alpha (PegIFN alpha) plus ribavirin achieves sustained virological response (SVR) in more than 50% of patients with chronic hepatitis C virus (HCV) infection. Although in the trials which led to the registration of this combination therapy, only a 48-week period of treatment had been evaluated, current international guidelines state that 48 or 24 weeks of treatment should be recommended in accordance with genotype; i.e. 48 weeks for genotypes 1 and 4, and 24 weeks for 2 and 3. However, side effects and the high cost of antiviral therapy forced investigators to evaluate further reductions in the treatment duration. Based on the new evidence that fast and persistent viral clearance is highly predictive of SVR, a week 4 negative HCV RNA by a sensitive molecular assay was recently utilized as a criterion for halving the duration of treatment to 12-16 weeks for genotypes 2 and 3, and 24 weeks for genotype 1 patients. However, some issues on this topic, are still open. In this review, existing evidence is discussed, and both the relevance and limitations of published studies are considered.

Prolonged Negative HCV-RNA Status Led to a Good Outcome in Chronic Hepatitis C Patients with Genotype 1b and Super-High Viral Load

OBJECTIVE

We examined whether a sustained negative HCV-RNA status for 48 weeks affects the outcome in patients with genotype 1b and super-high viral load, and also investigated whether the outcome is affected by the induction therapy of twice-daily pre-administrated interferon (IFN)-beta.

METHODS

78 eligible patients were divided into four groups. 40 were patients assigned to the short treatment protocol. 13 patients received 3 MU IFN-beta twice daily for 2 weeks followed by IFN-alpha2b+ribavirin for 22 weeks (beta-induction group: group 1). 27 patients received IFN-alpha2b+ribavirin for 24 weeks (standard combination group: group 2). 38 patients were assigned to the maintenance treatment protocol. All of the 13 in the beta-induction group (group 3) and 21 of 25 patients in the standard combination group (group 4) who were negative HCV-RNA PCR at week 24 had IFN monotherapy to maintain a negative HCV-RNA result for 48 weeks.

RESULTS

An HCV-RNA-negative status at week 24 was observed in 96% (25/26) of groups 1 and 3 versus in 79% (41/52) of groups 2 and 4 (p<0.01). The sustained virological response (SVR) was 38% (5/13) in group 1 and 11% (3/27) in group 2 (p<0.05). In the maintenance treatment, SVR was observed in 46% (6/13) of group 3 and 32% (8/25) of group 4 (NS).

CONCLUSIONS

A sustained negative HCV-RNA status for 48 weeks might be associated with viral elimination in patients with genotype 1 and super-high viral load.

High dose daily interferon-alpha induction and secondary adjunction of ribavirin in treatment-naive patients with chronic hepatitis C

OBJECTIVES

To evaluate in naive patients with chronic hepatitis C 1- the efficacy and safety of one month interferon alpha (IFN-alpha) induction regimen; 2- the potential virological benefit of a secondary adjunction of ribavirin among HCV RNA negative patients after 20 weeks of IFN therapy, with or without an initial 4-week IFN induction.

MATERIAL AND METHODS

151 naive HCV-RNA positive patients presenting with biopsy- proven chronic hepatitis C and elevated ALT were randomised in a 2: 1 ratio in two arms: IFN-alpha 3 MU thrice a week (tiw) for 24 weeks (non-induced patients); IFN-alpha 6 MU daily for two weeks, then 3 MU daily for two weeks then 3 MU tiw for 20 weeks (induced patients). At week 24, HCV-RNA negative patients were randomised to receive in addition or not ribavirin 1-1.2 g daily for 24 additional weeks. Induction efficacy was assessed on the early viral response (EVR) defined as undetectable HCV RNA at week 4 then week 20. Ribavirin efficacy was assessed on the proportion of maintained complete response until the end of follow-up, 24 weeks after discontinuation of treatment. Data were analysed on an intent-to-treat basis.

RESULTS

Efficacy of IFN-alpha induction: 104 patients were randomised to the non-induction group, 47 to the induction group. Gender, age, genotype distribution and HCV viral load at baseline did not differ significantly between the two groups. There was one treatment discontinuation because of adverse events in induced patients versus four in non-induced patients (P > 0.05). The 4 week EVR was significantly greater in induced patients in patients with HCV genotype 1, 4 or 5 (47% vs 12%, P=0.0002) only. There was no impact of induction in patients with HCV genotype 2 or 3. Efficacy of ribavirin: at week 24, 28 and 26 HCV-RNA negative patients were randomised to addition of ribavirin or not, respectively. Patients randomised to secondary additive ribavirin were more often HCV-RNA negative at the end of follow-up than patients treated with IFN-alpha alone: 18/28 (64%) vs 10/26 (39%); P=0.06. Among patients randomised to bitherapy, the relapse rate was significantly lower in patients with genotype 2 or 3 (0/12 vs 6/13, P=0.01) and not in those with genotype 1, 4 or 5 (5/11 vs 3/6, P=0.99).

CONCLUSION

A 4 week IFN-alpha induction significantly increases the EVR rate in patients with HCV genotype 1, 4 or 5. Late secondary adjunction of ribavirin to IFN-alpha for 6 months in HCV-RNA negative patients after 6 months of IFN-alpha significantly decreases the relapse rate in patients with HCV genotype 2 or 3, but not in patients with genotypes 1, 4 or 5.

Early viral kinetics and treatment outcome in combination of high-dose interferon induction vs. pegylated interferon plus ribavirin for naive patients infected with hepatitis C virus of genotype 1b and high viral load

An investigation was carried out to determine whether early viral monitoring could predict efficiently the virological response to combination therapy of two different regimens in treatment-naive chronic hepatitis C patients infected with genotype 1b with high baseline viral load. Patients were randomly assigned to receive interferon (IFN) alpha-2b induction (6 MU daily for 2 weeks) followed by 6 MU thrice weekly for 46 weeks (IFN/R group; n = 20), or pegylated IFN alpha-2b (1.5 microg/kg) weekly for 48 weeks (PEG/R group; n = 28), in combination with ribavirin (600-1,000 mg daily). Serum HCV RNA was quantitated at 0, 6, 12, 24, and 48 hr post-dose, weekly during the first 4 weeks, and thereafter viral kinetics were assessed every 4 weeks. The sustained virological response rates in the IFN/R and PEG/R groups were 40% (8/20) and 43% (12/28), respectively. The non-virological response rates were 40% (8/20) and 39% (11/28), respectively. The cumulative virological response rates were similar in both groups. Multivariate analyses identified no independent baseline variables linked to sustained virological or non-virological response. Early log viral load changes from baseline in both groups were significantly greater at all time-points after 24 hr in virological response patients than in non-virological response patients (P < 0.001 for all). On the receiver operating characteristics curves for prediction of non-virological response, the area under the curves (0.951-1.000), sensitivity (90%-100%), and negative predictive value (96%- 100%) were similar at any time-points after 24 hr. For prediction of sustained virological response, sensitivity of 80% with 86% negative predictive value was observed for negative HCV RNA at week 12, with the highest area under the curves value of 0.919. The results suggest that early monitoring of viral kinetics is a useful measure to predict virological response, and might facilitate development of rational and effective therapeutic strategies.

Combination therapy for the treatment of hepatitis C in the veteran population: higher than expected rates of therapy discontinuation

AIM

To compare the efficacy of high-dose induction with standard dose interferon therapy for the treatment of chronic hepatitis C virus at the Dallas Veterans Affairs Medical Center.

METHODS

Patients were randomized to receive 5 million units daily interferon-alpha2b for 4-weeks followed by 44-weeks for genotype 1 or 20 weeks for non-genotype 1 of standard dose therapy (3 million units three times a week) or standard dose therapy for total treatment duration. Daily weight-based ribavirin was used for entire therapy interval.

RESULTS

Forty-five patients were enrolled in the trial with genotype 1 comprising 75.6% of the sample. Cirrhosis or bridging-fibrosis was present in 69% of the patients. Of the 29 liver biopsies available for Knodell scoring, 41% and 51% had scores of 6-10 and 11-15, respectively. Rates of sustained virological response did not differ significantly between the two treatment groups. Therapy type and/or early intervention for depression did not affect the rate of therapy discontinuation, which was 26.6%.

CONCLUSION

The rate of sustained virological response was similar between the two treatment groups and higher than anticipated among patients with cirrhosis or bridging-fibrosis. The rate of therapy discontinuation was also higher than anticipated but was not attributable to therapy type or untreated depression.

A randomized controlled trial of amantadine plus interferon-alpha2a vs. interferon-alpha2a alone in naive patients with chronic hepatitis C randomized according to the early virological response to interferon-alpha2a monotherapy

BACKGROUND

An early virological response to interferon-alpha treatment is a strong predictor of sustained response, but it has never been exploited to stratify patients in clinical trials.

AIM

To evaluate the efficacy of amantadine plus interferon-alpha compared with interferon-alpha alone in naive patients with chronic hepatitis C who were randomized on the basis of the early virological response to interferon-alpha.

METHODS

One hundred and eighty-one patients received recombinant interferon-alpha2a (3 MU three times weekly) for 2 months and 164 were evaluated for early (i.e. month 2) virological response. Hepatitis C virus (HCV) RNA-negative patients (n = 66) were randomized to receive 3 MU of interferon-alpha three times weekly, with or without amantadine (200 mg/day); HCV RNA-positive patients (n = 98) were randomized to receive 6 MU of interferon-alpha three times weekly, with or without amantadine (200 mg/day). HCV RNA-positive patients at 6 months discontinued treatment, and all others completed 12 months.

RESULTS

At month 6, HCV RNA-negative patients made up 54.2% of the interferon + amantadine group and 42.0% of the monotherapy group (P = 0.07). At month 12, HCV RNA-negative patients made up 38.5% of the interferon + amantadine group and 28.4% of the monotherapy group (N.S.). The sustained virological response rates were 21.6% and 20.9%, respectively (N.S.).

CONCLUSION

The addition of amantadine does not enhance the sustained virological response to interferon-alpha in naive patients with chronic hepatitis C; however, an additive effect of amantadine occurs in the first 6 months, mainly in patients without an early response to monotherapy. Early response to interferon-alpha is a strong predictor of sustained virological response.

Interferon alfa2a induction therapy in combination with ribavirin and amantadine for the treatment of naive patients with chronic HCV infection

Pilot studies have suggested that the addition of amantadine to interferon (IFN) is effective against hepatitis C virus (HCV). Furthermore, IFN induction therapy seems to improve virological response rates. In this open, randomized, multicentre trial we compared safety and efficacy of a triple therapy comprising IFN alpha 2a, ribavirin and amantadine using high induction doses (6 MU IFN alpha daily for the first 6 weeks) against a therapy with standard IFN alpha dosages over the entire treatment period plus amantadine and ribavirin. A total of 158 naive patients with chronic HCV infection were randomized 1:1. Group A (n = 81): induction therapy with 6 MU IFN alpha daily for 6 weeks, followed by 6 MU three times a week (tiw) for 18 weeks and then 3 MU tiw until week 48. Group B (n = 77): standard therapy with 6 MU IFN alpha tiw for 24 weeks, followed by 3 MU until week 48. All patients received oral ribavirin (10 mg/kg/day) and amantadine (200 mg/day). The triple therapy was safe and well tolerated. There were no significant differences between the groups with respect to biochemical response rates. Groups A and B did not differ in virological response rates at the end of treatment (33%vs 35%) or at the end of the 6 month follow up period (37%vs 39%). We could not detect favourable effects on sustained virological response rates using induction therapy, in either genotype 1 or non-1 infected patients. In summary, induction therapy with 6 MU IFN alpha daily did not result in increased overall response rates compared with standard IFN alpha dosages of 6 MU tiw.

Daily induction combination treatment with alpha 2b interferon and ribavirin or standard combination treatment in naive chronic hepatitis C patients. A multicentre randomized controlled trial

The standard treatment for patients with chronic hepatitis C is a 6-12-month combination therapy with interferon alpha and ribavirin. Induction treatment could result in a faster early decline of the hepatitis C virus (HCV) load and a better response rate. Naive chronically infected HCV patients (n = 454) were randomized into two arms to receive either induction treatment with interferon alpha 2b 5 million units (MU) subcutaneously (s.c.) daily during a period of 8 weeks (arm A); or treatment with interferon alpha 2b 5 MU s.c. three times a week (TIW) for a period of 8 weeks (arm B). After week 8, interferon treatment in both arms was 3 MU s.c. TIW for a total period of 12 months. In both arms, ribavirin (1000-1200 mg orally per day) was added at week 4. Induction treatment resulted in a higher virological response at week 8 of treatment (66%vs 47%; P < 0.01). However, response at the end of treatment and at 6 months follow-up was not different (53%vs 50%, 41%vs 33%). The occurrence of adverse events and the drop-out rate were similar in both arms. Although an early virological response is observed more frequently in the induction treatment, end of treatment response and sustained responses did not differ.

A randomized trial to assess the efficacy of interferon-alpha daily in combination with ribavirin in the treatment of naïve patients with chronic hepatitis C

A randomized trial was conducted to assess the efficacy of interferon-alpha (IFN) daily in combination with ribavirin in 301 naïve patients with chronic hepatitis C (CHC). Patients were randomized to receive ribavirin 1.2 g daily (QD) for 48 weeks with either IFN 5 MU (thrice weekly) TIW for 8 weeks followed by IFN 3 MU TIW for 40 weeks (IFN TIW, n = 154) or IFN 5 MU QD for 8 weeks followed by IFN 3 MU QD for 16 weeks followed by IFN 3 MU TIW for 24 weeks (IFN QD, n = 147). Treatment discontinuation rates, because of adverse events, were similar in the two arms (14.9% in IFN TIW and 14.3% in IFN QD, P = 0.87). The proportion of patients with sustained virological response (SVR) was 27.9% for patients treated TIW and 38.8% for those treated QD (P = 0.046). According to logistic regression analysis, patients in the IFN QD arm had 1.7 times higher probability of achieving SVR, than those receiving IFN TIW (P = 0.038). Low baseline viral load (P = 0.017) and genotype non-1 (P = 0.036) were associated with higher SVR rates. Combination of IFN/ribavirin for 48 weeks is more effective when IFN is administered daily for the first 24 weeks in naïve patients with CHC.

Hepatitis C virus RNA levels during initial induction or standard interferon therapy: influence of continued treatment on sustained response

Hepatitis C virus (HCV) RNA kinetics were studied at baseline weeks 4, 8 and 12 during interferon-alpha (IFN) monotherapy in 65 patients (mean age 39 y, range 19-66 y) with chronic HCV infection. IFN treatment was given either as initial induction (n = 34) or as standard dosing 3 times a week (n = 31). Patients with genotypes 2 and 3 had a significantly steeper decline in HCV RNA levels than patients with genotype 1 at weeks 4, 8 and 12 (p < 0.001 at all points measured). The decline in viral load was more pronounced in patients with induction therapy than with standard therapy at weeks 4, 8 and 12 (p < 0.02, 0.054 and 0.01, respectively). Patients with a sustained viral response had a 3-log decline in viral levels at week 4, with few exceptions. Two patients with non-response at week 12 (1 each with genotype 1 and non-1) responded after supplementation with ribavirin.