Randomized controlled trial of twice-a-day administration of natural interferon beta for chronic hepatitis C

Efficacy of the regimen using twice-daily β-interferon followed by the standard of care for chronic hepatitis C genotype 1b with high viral load

AIM

  In patients with refractory genotype 1b chronic hepatitis C with high viral loads, we retrospectively compared the efficacy of standard of care treatment (SOC: combined PEG-IFN-α-2b/ribavirin for 48 weeks) and a regimen in which 2 weeks of SOC induction was replaced by twice-daily β-interferon alone (IFN-β induction therapy).

METHODS

  Seventeen patients received the IFN-β induction therapy plus SOC (IFN-β induction group) and 13 patients received SOC alone (SOC group).

RESULTS

  In the IFN-β induction group and SOC group, early virological response (EVR) rates were 88.2% and 53.8%, respectively. The end of treatment rates were 100.0% and 92.3%, and sustained virological response (SVR) rates were 70.6% and 53.8%, respectively. By induction with IFN-β, even in refractory cases, the high virus negative conversion rate in the early treatment phase and actions of pegylated IFN-α-2b and ribavirin in the maintenance treatment phase led to an additive effect. In the analysis of contributing factors, only the achievement of EVR was associated with a significant difference in SVR (P = 0.0011). The univariate logistic regression analysis showed that only IFN-β treatment was associated with a significant difference in EVR (P = 0.0492, odds ratio = 6.248, 95% confidence interval = 1.026-40.252), whereas no significant factors were found in the multivariate analysis due to small samples.

CONCLUSION

  IFN-β induction therapy with higher EVR might be beneficial for protease inhibitor-refractory chronic hepatitis C patients.

1990-2010: two decades of interferon-based therapy

Twenty-five years have passed since interferon-α was first used in the treatment of chronic hepatitis C infection, and even now it remains an essential part of the standard of care for this condition. At present, the recommended treatment is a combination of pegylated interferon and ribavirin A. There have been enormous advances in our understanding of the mechanisms through which interferon works and in identifying factors related to the response to this treatment. Even with the development of new protease inhibitors, it is likely that interferon will remain an essential component of hepatitis C treatment.

Twenty four-week peginterferon plus ribavirin after interferon-β induction for genotype 1b chronic hepatitis C

AIM

To investigate the possibility of shortening the duration of peginterferon (Peg-IFN) plus ribavirin (RBV) combination therapy by incorporating interferon-β (IFN-β) induction therapy.

METHODS

A one treatment arm, cohort prospective study was conducted on seventy one patients. The patients were Japanese adults with genotype 1b chronic hepatitis C, HCV-RNA levels of ≥ 5.0 Log IU/mL or 100 KIU/mL, and platelet counts of ≥ 90 000/μL. The treatment regimen consisted of a 2 wk course of twice-daily administration of IFN-β followed by 24 wk Peg-IFN plus RBV combination therapy. We prolonged the duration of the Peg-IFN plus RBV therapy to 48 wk if the patient requested it.

RESULTS

The patients, including 44% males, were characterized by an median age of 63 years (range: 32-78 years), an median platelet count of 13.9 (range: 9.1-30.6) × 10(4)/μL, 62% IFN-naïve, and median HCV-RNA of 6.1 (range: 5.1-7.2) Log IU/mL. The sustained virologic response (SVR) rates were 34% (Peg-IFN: 1-24 wk, n = 61, 95% confidence interval (CI): 24%-47%) and 55% (Peg-IFN: 20-24 wk, n = 31, 95% CI: 38%-71%, P < 0.001; vs Peg-IFN: 1-19 wk). The SVR rate when the administration was discontinued early was 13% (Peg-IFN: 1-19 wk, n = 30, 95% CI: 5%-30%), and that when the administration was prolonged was 50% (Peg-IFN: 25-48 wk, n = 10, 95% CI: 24%-76%, P < 0.05; vs Peg-IFN: 1-19 wk). In the patients who received 20-24 wk of Peg-IFN plus RBV, only the higher platelet count (≥ 130 000/μL) was significantly correlated with the SVR (odds ratio: 11.680, 95% CI: 2.3064-79.474, P = 0.0024). In 45% (14/31) of the patients with a higher platelet count (≥ 130 000/μL) before therapy, the HCV-RNA level decreased to below 3.3 Log IU/mL at the completion of IFN-β, and their SVR rate was 93% (13/14) after 20-24 wk administration of Peg-IFN plus RBV.

CONCLUSION

These results suggest the possibilities of shortening the duration of Peg-IFN plus RBV combination therapy by actively reducing HCV-RNA levels using the IFN-β induction regimen.

Is {beta}-interferon a promising therapeutic option for the management of hepatitis C?

Using interferon-alpha (IFN-alpha) as the conventional therapeutic antiviral drug, physicians generally achieve a treatment success of <50% in cases with chronic hepatitis C. Owing to the structural similarities between IFN-alpha and interferon-beta (IFN-beta), the latter is a candidate for obtaining sustained viral response. In this review, we have compiled the published information on the use of IFN-beta for the management of acute and chronic hepatitis C up to 2007. We have looked at the rates of success and side effects. IFN-beta might be helpful if IFN-alpha fails to achieve a favourable outcome. This antiviral drug may be helpful for the management of chronic hepatitis C in both age extremes, in case of a relapse after receiving IFN-alpha and for preventing the development of the carrier state after acute hepatitis C. Further studies are required on the efficacy of IFN-beta for the management of acute and chronic hepatitis C.

Potent induction therapy with interferon and ribavirin combination therapy does not achieve a higher sustained virological response rate in chronic hepatitis C with genotype 1b and high hepatitis C virus RNA level

AIMS

To compare twice-daily interferon (IFN)-beta administration and once-daily IFN-alpha-2b administration as induction therapy in ribavirin combination therapy in chronic hepatitis C with a high viral load of genotype-1b hepatitis C virus (HCV).

METHODS

Sixty-one chronic hepatitis patients with a high viral load of genotype-1b HCV were randomly divided into three groups: group A was given IFN-beta 6 MU induction therapy twice daily for 2 weeks; group B was given IFN-alpha-2b 6 MU induction therapy once daily for 2 weeks; and group C was given no induction therapy. All three groups were then given IFN-alpha-2b 6 MU 3 days/week for the rest of the 24-week study period. Ribavirin was given for the entire 24-week study period.

RESULTS

Although the cumulative HCV-RNA negative rates tended to be higher in group A than in group B, the differencewas not significant. The HCV-RNA negative rate at week 2 was significantly higher in groups A and B than in group C (P < 0.05). The sustained virological response (SVR) rate was 16% overall, 21% for groups A and B, and 5% for group C; the SVR rate of groups A plus B tended to be higher than that of group C (P = 0.093).

CONCLUSIONS

There was no difference between the effects of the two induction therapies; potent induction therapy does achieve higher early viral clearance but not a higher SVR rate.

Is interferon-beta an alternative treatment for chronic hepatitis C

The treatment of chronic hepatitis C (CHC) is still far from optimal, particularly for those subpopulations that do not respond to the standard combination therapy with Interferon-α (IFNα) plus ribavirin. Although in some cases the use of higher doses or longer treatment periods may be effective, these approaches are generally associated with a higher incidence of adverse events, which may either lead to a reduction in patient compliance or require drug withdrawal. IFNβ could represent an interesting alternative for treating CHC patients. Controversial data about IFNβ efficacy in CHC exist, the main reason being that many results stem from pilot studies with small cohorts of patients. However, promising results have been obtained in some subgroups of patients that fail to respond to IFNα. Additionally, the good tolerability of IFNβ represents an important advantage of the drug. The rates of dropouts in controlled clinical trials, as well as the need for dose reductions or treatment discontinuation are very low. It might be worth assessing the value of IFNβ plus ribavirin in randomized studies with a larger cohort of patients, not eligible or not tolerating standard therapy, and for non-responders.

Induction therapy with twice-daily interferon-beta does not improve the therapeutic efficacy of consensus interferon monotherapy for chronic hepatitis C

We examined therapeutic superiority of induction therapy with twice-daily IFN-beta (3X2=6 million units/day) onto 6-months consensus interferon monotherapy for chronic hepatitis C. Patients were randomly assigned to monotherapy without (group I, n=16) and with induction therapy (group II, n=12). The mean age of group II was older than that of group I, and other baseline condition was not statistically significant. Sustained virological response (SVR) rates of group I and II were 81.3% (13/16) and 58.3% (7/12), respectively (p=0.365). SVR rates in patients with genotype 1b were 66.7% (4/6) and 0% (0/2, because of drop-out), and those with high viral load were 70% (7/10) and 75% (6/8) in group I and II, respectively (p=1.000). Drop-out rates during therapy were 6.3% (1/16) and 33.3% (4/12) in group I and II, respectively (p=0.176). Age less than 50 years was the only independent factor that was shown by multivariate logistic model analysis to be associated with a sustained virological response. Although randomization failed to produce and equal age distribution in the two groups in this study, our results suggest that induction therapy with twice-daily IFN-beta has no beneficial effect on the efficacy of monotherapy with consensus interferon, probably because of the higher drop-out rates and incidence of adverse reactions with induction therapy.

Biochemical response to interferon therapy correlates with interferon sensitivity-determining region in hepatitis C virus genotype 1b infection

Biochemical responders maintain normal alanine aminotransferase levels after interferon (IFN) therapy despite persistent presence of hepatitis C virus (HCV) RNA in their sera. There have been few reports on predictive factors for biochemical response. A region associated with sensitivity to IFN was identified in the nonstructural protein 5 A of genotype 1b [aa 2209-2248; IFN sensitivity-determining region (ISDR)]. The substitutions in ISDR correlate with sustained response to IFN. In this report, we assessed the association of ISDR with biochemical response. The sequences of ISDR were determined in 62 patients with HCV genotype 1b treated by IFN in two randomized controlled trials. 30 patients had wild ISDR (identical to HCV-J), 20 intermediate ISDR (1-3 amino acid substitutions compared with HCV-J), and 12 mutant ISDR (four or more amino acid substitutions). All 12 patients with mutant ISDR had a sustained response, while only one of those with wild or intermediate ISDR had a sustained response (P < 0.0001). In the 49 patients other than sustained responders, the patients with intermediate ISDR obtained biochemical response significantly more frequently (52.6%, 10/19) than those with wild-type ISDR (20.0%, 6/30) (P < 0.05). Multivariate analysis indicated the number of substitutions in ISDR as the most important predictor for biochemical response (discriminant coefficient=1.08, P < 0.05) and sustained response (discriminant coefficient=6.13, P < 0.0001). In phylogenetic analysis, clustering of sustained responders and biochemical responders was observed. These results demonstrate that the substitutions in ISDR are the most important predictor for biochemical response to IFN in patients infected with genotype 1b as well as for sustained response.