Maintenance therapy for chronic hepatitis C

Non-invasive assessment of liver fibrosis progression in hepatitis C patients retreated for 96 weeks with antiviral therapy: a randomized study

BACKGROUND

The efficacy of a maintenance therapy in non-responder patients with chronic hepatitis C has been essentially evaluated by histological semiquantitative scores.

AIM

The aim was to evaluate the efficiency of 2 years of treatment with peginterferon alpha-2a vs alpha-tocopherol in these patients by histology, morphometry and blood markers of fibrosis.

METHOD

Hundred and five HCV patients with a Metavir fibrosis score > or = 2 were randomized to receive peginterferon alpha-2a 180 microg/week (PEG) (n=55) or alpha-tocopherol (TOCO) 1000 mg/day (n=50) for 96 weeks. The primary endpoint was improvement or stabilization of the Metavir fibrosis score by biopsy performed at week 96. Secondary endpoints included a quantitative assessment of fibrosis by morphometry and changes in blood markers of fibrosis.

RESULTS

There was no difference at baseline between PEG and TOCO according to the metavir (83.3 vs 86.8%, P=0.751) stage. The median fibrosis rate, measured with morphometry was 2.72 and 2.86% at day 0, and 3.66 and 2.82% at week 96, in the PEG and TOCO groups (P=0.90) respectively. However, the percentage of patients with metavir activity grade improvement was significantly higher in the PEG group vs the TOCO group (52.8 vs 23.7%, P=0.016). Non-invasive markers analysis did not show any significant change in both groups.

CONCLUSION

Long-term therapy with peginterferon alpha-2a did not reduce liver fibrosis degree assessed by morphometry and blood tests as compared with alpha-tocopherol. Blood tests could be useful to assess liver fibrosis changes in clinical trials.

Hepatitis C: current options for nonresponders to peginterferon and ribavirin

Hepatitis C virus infection remains a significant health problem worldwide. The development of interferon-based therapies has led to increased success in eradicating this viral infection; however, no recent additions to the current treatment care regimen (peginterferon and ribavirin) have been made. Nonresponders to peginterferon/ribavirin make up a diverse patient population that can be difficult to manage. Through a better understanding of treatment response and viral kinetics, clinicians are employing altered dosing schedules to minimize the burden of viral illness. Consequently, clinicians can now manage nonresponders by providing supportive care and reserving retreatment for those most likely to respond to additional antiviral therapy, particularly when correctable factors from a previous treatment course with the potential for positive intervention have been identified. The decision for further medical management is based on clinical and laboratory parameters that have been shown to predict which patients will benefit most from another attempt at therapy.

Sequence uniqueness and sequence variability as modulating factors of human anti-HCV humoral immune response

We recently compared the HCV polyprotein to the human proteome in order to test whether amino acid sequences unique to the virus could represent immunodominant epitopic determinants of the human humoral immune response against HCV. We identified a relatively limited number of HCV fragments with no/low similarity to the human host that represented exclusive HCV motifs. In this study, the peptides corresponding to low/zero similarity sequences were synthesized and assayed with HCV-infected sera. With different patterns, the synthetic HCV peptides corresponding to low/zero similarity sequences were found to be immunoreactive. In particular, the HCV E1 (315-323) HRMAWDMMM, HCV E2/NS1 (547-555) NWFGCTWMN, and HCV NS5 (2638-2646) YDTRCFDST sequences were immunodominant in the HCV-infected cohort under study. These three peptides correspond to sequences that are endowed with low-similarity to the human proteome, are highly conserved among various HCV strains, and have, potentially, a scarce susceptibility to proteolytic attacks. These data may be of help in defining the multiple factors which concur in the modulation of the human immune response against HCV, eventually providing information for the design of effective anti-HCV vaccines.

In the clinic. Hepatitis C

Chronic hepatitis C virus (HCV) infection is the most common blood-borne infection in the United States, with an estimated overall prevalence of 3.2 million persons (1.3%) and prevalence peaks between age 40 to 49 years (1). The worldwide prevalence of HCV infection is even higher at 2.0%, corresponding to 140 million persons (2). In terms of complications, cirrhosis due to HCV disease is the most frequent indication for liver transplantation in the United States (3), and the overall incidence of hepatocellular carcinoma, a complication of HCV cirrhosis, continues to increase at alarming rates. In an evaluation of population-based registries of the Surveillance, Epidemiology, and End Results (SEER) program in the United States, the overall age-adjusted incidence rates of hepatocellular carcinoma increased from 1.4 per 100 000 in 1975 to 1977 to 3.0 per 100 000 in 1996 to 1998 (4).

Personalized therapy for chronic viral hepatitis C in the naive patient: How can we optimize treatment duration as a function of viral genotype?

Pegylated interferon plus ribavirin is the standard treatment for chronic hepatitis C (CHC). It yields sustained virological response (SVR) rates of 42-52% for genotype 1, 66-72% for genotype 4, and 76-80% for genotypes 2 and 3. Hence, the patient's genotype appears to be a determining predictive factor for the SVR. We have reviewed the literature in order to determine whether a genotype-specific treatment duration should be envisaged. The largest study to date of patients infected with HCV genotype 2 or 3 confirmed the value of the standard treatment duration of 24 weeks. Shorter treatments exposed the patients to a greater risk of relapse. For genotype 1, it was possible to offer a shorter, 24-week course of treatment to the 35% of patients with an initial viral load below 600,000 IU/mL and an early virological response (EVR) at week 4 (negative PCR), resulting in an SVR of 89%. For the remaining two-thirds of genotype 1 patients with a high viral load, the treatment duration should remain at 48 weeks. A subgroup of patients - the "slow virological responders" (positive PCR at week 12 but with less than 6000 IU/mL; negative PCR at week 24) - benefited from the extension of the treatment to 72 weeks, with an SVR of 88%. For patients infected with genotype 4 virus, combination therapy should feature a ribavirin dose of more than 1000 mg/day for an optimal duration of 48 weeks.

Interferon-based treatment of chronic hepatitis C

The treatment of patients with chronic hepatitis C has rapidly evolved in the past 10 years centered on the use of interferon alpha 2 as an antiviral and immunomodulatory agent against hepatitis C virus. Firstly used as a monotherapy associated with a deceiving long-term efficacy, interferon alpha was then combined with ribavirin, a nucleoside analog with large antiviral properties. Combination of both drugs dramatically improved the efficacy of treatment with 50% of patients reaching a sustained viral response, characterized by the final eradication of the virus from the infected individual. Surprisingly, this synergistic effect remains greatly unexplained. The third step consisted in the use of pegylated interferon in order to adapt its pharmacokinetics and to allow a better efficacy with a more tolerable dosing schedule: once weekly subcutaneous injection instead of thrice weekly. Pegylated interferon combined with ribavirin during 24-48 weeks of treatment is the current standard of care with nearly 60% of sustained virologic response, overall. Development of new forms of interferon alpha are on the way with promising preliminary results.

Sustained virological response to interferon reduces cirrhosis in chronic hepatitis C: a 1,386-patient study from Taiwan

BACKGROUND

The long-term benefits of interferon-based therapy on preventing cirrhosis at non-cirrhotic stage in chronic hepatitis C patients are not fully clarified.

AIM

To evaluate the effectiveness of interferon-based therapy regarding to cirrhosis prevention in non-cirrhotic chronic hepatitis C patients.

METHODS

A total of 1386 biopsy-proven, non-cirrhotic chronic hepatitis C patients (892 received interferon-based therapy and 494 untreated) were enrolled.

RESULTS

Fifty-six untreated and 51 treated (24 sustained virologic responders and 27 non-responders) patients developed cirrhosis during a mean follow-up period of 5.0 (1-16) and 5.1 (1-15.3) years, respectively. The annual incidences of cirrhosis in untreated and treated groups were 2.26 and 1.11% (non-responders: 1.99%, sustained responders: 0.74%), respectively. The 15-year cumulative incidence of cirrhosis was significantly lower in treated (9.9%) than untreated patients (39.8%, P = 0.0008, log-rank test). The 14.5-year cumulative incidence of cirrhosis was significantly lower in sustained responders (4.8%) compared with non-responders (21.6%, P = 0.0007) and untreated patients (36.6%, P < 0.0001). The difference was not significant between non-responders and untreated controls. Cox proportional hazards regression showed sustained virologic responders and younger age were independent negative factors for cirrhosis development.

CONCLUSION

A sustained virologic response secondary to IFN-based therapy could reduce cirrhosis development in chronic hepatitis C patients.

A Sustained Virological Response to Interferon or Interferon/Ribavirin Reduces Hepatocellular Carcinoma and Improves Survival in Chronic Hepatitis C: A Nationwide, Multicentre Study in Taiwan

Background

The long-term benefit for chronic hepatitis C (CHC) patients treated with interferon (IFN)/ribavirin (RBV) combination therapy remains unclear. We aimed to evaluate the long-term effects of IFN monotherapy and IFN/RBV combination therapy on reducing hepatocellular carcinoma (HCC) and mortality in patients with chronic hepatitis C virus (HCV) infection, adjusting for risk factors.

Methods

A total of 1,619 patients with biopsy-proven CHC, including 1,057 receiving IFN-based therapy (760 on IFN/RBV combination therapy) and 562 untreated controls from three medical centres and one regional core hospital in Taiwan were enrolled in this retrospective-prospective cohort study.

Results

The incidence of HCC and survival during a follow-up period of 1.0–15.3 (mean 5.18) and 1–16 (mean 5.15) years in treated and untreated patients, respectively, was analysed using Cox proportional hazards regression. The cumulative incidence of HCC was 35.2% and 12.2% for untreated and treated groups, respectively ( P=0.0013). The cumulative survival rate was 93.1% and 96.2% for untreated and treated groups, respectively ( P=0.3928). Significantly lower incidences of HCC and mortality were observed in sustained virological responders (both for IFN monotherapy and IFN/RBV combination) but not in non-responders when compared with untreated patients. HCV genotype 1 patients had significantly higher incidences of HCC than genotype non-1 patients. In multivariate analysis, pre-existing cirrhosis, non-response, HCV geno-type-1 and age were associated with HCC; pre-existing cirrhosis and non-response correlated to mortality.

Conclusion

A sustained virological response secondary to IFN monotherapy or IFN/RBV combination therapy could reduce the risk for HCC and improve survival of CHC patients.