Comparison of long-term effects of lymphoblastoid interferon alpha and recombinant interferon alpha-2a therapy in patients with chronic hepatitis B

Prevention of hepatitis B virus-associated liver diseases by antiviral therapy

Hepatitis B virus (HBV) is a major cause of acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma, particularly in Asia-Pacific countries. The major complications in HBV carriers are hepatocellular carcinoma (HCC), liver failure and esophageal varices following the progression to cirrhosis, while some develop HCC without cirrhosis. The progression to liver fibrosis and these other complications could be prevented by treatment with nucleos(t)ide analogues (NUCs); however, NUCs must be continuously administered for a long time. Peginterferon could lead to HBV surface antigen loss. It is difficult to use peginterferon in HBV-infected patients with decompensated cirrhosis. Acute liver failure due to HBV infection and acute exacerbation of chronic hepatitis B could be treated by NUCs. Universal vaccination programs against HBV could prevent new HBV infections globally. Here, we review the currently available treatments for HBV infection.

Antiviral therapy for chronic hepatitis B viral infection in adults: A systematic review and meta-analysis

Chronic hepatitis B viral (HBV) infection remains a significant global health problem. Evidence-based guidelines are needed to help providers determine when treatment should be initiated, which medication is most appropriate, and when treatment can safely be stopped. The American Association for the Study of Liver Diseases HBV guideline methodology and writing committees developed a protocol a priori for this systematic review. We searched multiple databases for randomized controlled trials and controlled observational studies that enrolled adults ≥18 years old diagnosed with chronic HBV infection who received antiviral therapy. Data extraction was done by pairs of independent reviewers. We included 73 studies, of which 59 (15 randomized controlled trials and 44 observational studies) reported clinical outcomes. Moderate-quality evidence supported the effectiveness of antiviral therapy in patients with immune active chronic HBV infection in reducing the risk of cirrhosis, decompensated liver disease, and hepatocellular carcinoma. In immune tolerant patients, moderate-quality evidence supports improved intermediate outcomes with antiviral therapy. Only very low-quality evidence informed the questions about discontinuing versus continuing antiviral therapy in hepatitis B e antigen-positive patients who seroconverted from hepatitis B e antigen to hepatitis B e antibody and about the safety of entecavir versus tenofovir. Noncomparative and indirect evidence was available for questions about stopping versus continuing antiviral therapy in hepatitis B e antigen-negative patients, monotherapy versus adding a second agent in patients with persistent viremia during treatment, and the effectiveness of antivirals in compensated cirrhosis with low-level viremia.

CONCLUSION

Most of the current literature focuses on the immune active phases of chronic HBV infection; decision-making in other commonly encountered and challenging clinical settings depends on indirect evidence.

Role of antiviral therapy in the natural history of hepatitis B virus-related chronic liver disease

Hepatitis B virus (HBV) infection is a dynamic state of interactions among HBV, hepatocytes, and the host immune system. Natural history studies of chronic hepatitis B (CHB) infection have shown an association between active viral replication and adverse clinical outcomes such as cirrhosis and hepatocellular carcinoma. The goal of therapy for CHB is to improve quality of life and survival by preventing progression of the disease to cirrhosis, decompensation, end-stage liver disease, hepatocellular carcinoma (HCC) and death. This goal can be achieved if HBV replication is suppressed in a sustained manner. The accompanying reduction in histological activity of CHB lessens the risk of cirrhosis and of HCC, particularly in non-cirrhotic patients. However, CHB infection cannot be completely eradicated, due to the persistence of covalently closed circular DNA in the nucleus of infected hepatocytes, which may explain HBV reactivation. Moreover, the integration of the HBV genome into the host genome may favour oncogenesis, development of HCC and may also contribute to HBV reactivation.

Prevention of hepatocellular carcinoma: beyond hepatitis B vaccination

Chronic hepatitis B (CHB) infection is the major cause of hepatocellular carcinoma (HCC), accounting for approximately 50% of the underlying etiologies. We reviewed the primary, secondary, and tertiary measures for the prevention of hepatitis B virus (HBV)-related HCC. The most effective method for preventing HBV-related HCC is vaccination. Universal hepatitis B vaccination has been shown to reduce the rates of HBV infection and HCC significantly. Once chronic HBV infection is established, antiviral treatment using interferon or nucleos(t)ide analogs is used to prevent disease progression to cirrhosis, HCC, or both. Studies have found viral replication indicated by HBV DNA level to be a strong risk factor for development of HCC. Additionally, periodic surveillance using ultrasonography and serum α-fetoprotein for earlier detection of HCC is also important so that curative treatments with survival benefit can be possible. Finally, adjuvant antiviral treatment using interferon or nucleos(t)ide analogs is used to prevent tumor recurrence after curative resection. Adjuvant interferon treatment prevented early recurrence, not late recurrence, probably due to its antiangiogenetic and antiproliferative effects. Adjuvant nucleos(t)ide analogs demonstrated promising results for preventing late recurrence, probably due to effective suppression of viral replication. Further investigations are required to establish the optimal preventive plans for HBV-related HCC.

The kinetics of the hepatitis B surface antigen level after the initiation of antiretroviral therapy for hepatitis B virus and human immunodeficiency virus coinfected patients

BACKGROUND

Hepatic flares (HF), which reflect hepatitis B virus (HBV)-related immune reconstitution inflammatory syndrome (IRIS), frequently occur in patients with HBV and human immunodeficiency virus (HIV) coinfection after the start of antiretoroviral therapy (ART). The rate of hepatitis B envelope antigen (HBeAg) and hepatitis B surface antigen (HBsAg) loss is higher for patients with HF after the initiation of ART.

METHODS

We retrospectively examined the kinetics of the HBsAg and HBeAg levels of six HBV/HIV coinfected patients after the commencement of ART that included tenofovir. All were male and HBeAg positive.

RESULTS

Three patients developed HF after the initiation of ART. All subsequently lost HBeAg and one of them lost HBsAg after HF. None who did not experience HF lost HBeAg. The HBsAg and HBeAg levels remarkably decreased when HF occurred, but the decline of HBsAg was very slow in the periods before and after HF. The median decline of the HBsAg level at 48 weeks was 2.20 Log IU/mL for patients with HF, but only 1.00 Log IU/ml for patients without HF. Little decline was seen for either group in the median decline of the HBsAg level from 48 weeks to 96 weeks, 0.28 Log IU/mL in the HF group and 0.06 Log IU/mL in the non-HF group.

CONCLUSION

The immune reconstitution of a HBV/HIV coinfected patient plays an important role in the clearance of HBV. If HBsAg and HBeAg levels decrease rapidly when HF occurs, the hepatic flare would be due to HBV-related IRIS.

Treatment options for chronic hepatitis B and C infection in children

There has been a dramatic increase in treatment options for both chronic hepatitis B (CHB) and chronic hepatitis C (CHC) infection in adults over the past 5-10 years, resulting in standardized regimes for initial treatment, relapsers and even infection in the setting of recurrence post-liver transplantation. These regimes have resulted in the halting of the disease progression, reduction in the risk of hepatocellular carcinoma and removal of these infections as a contraindication for liver transplantation. However, treatment in children must be considered carefully in the context of the natural history of these infections and host factors, particularly the immunological mileu, which may affect response to therapy. The as yet unknown long-term effects of medications must also be balanced with the probability of significant life-long morbidity or mortality from chronic hepatitis and its complications. Furthermore, the development of drug resistance, particularly in the case of CHB, has significant implications for the pediatric patient who may exhaust effective therapeutic options at a relatively young age. For these reasons, initiation of therapy must be based on sound criteria. Based on the current data, we recommend that therapy should be offered to children with CHB who have an elevation in alanine aminotransferase (>2-3 x upper limit of normal) for more than 6 months. Therapy with interferon-alpha should be offered in the majority of cases with the aim of immune clearance as measured by early antigen seroconversion. By contrast, treatment indication for CHC in children remains controversial. If used, combination therapy with pegylated interferon and ribavirin is likely to produce the highest rates of sustained viral response.

Hepatitis B virus-related immune reconstitution inflammatory syndrome in two patients coinfected with human immunodeficiency virus diagnosed with a liver biopsy

Hepatic flares occurred in two patients with HBV/HIV coinfection following the commencement of antiretroviral therapy (ART). At that time, the HIV RNA and HBV DNA levels had decreased. The results of liver biopsies showed lymphocytic infiltration that was diffusely positive for CD8(+) T cells in the portal areas and lobules. These findings suggested HBV-related immune reconstitution inflammatory syndrome (IRIS). The alanine aminotransferase levels of both patients gradually decreased with the continuation of ART. Because there are few reports of the liver histology of HBV-related IRIS, these cases provide a better understanding of the pathogenesis of HBV-related IRIS.

Effects of hepatitis B virus infection on the interferon response in immunodeficient human hepatocyte chimeric mice

Complementary DNA microarray analysis of human livers cannot exclude the influence of the immunological response. In this study, complementary DNA microarray analysis was performed under immunodeficient conditions with human hepatocyte chimeric mice, and gene expression profiles were analyzed by hepatitis B virus (HBV) infection and/or interferon treatment. The expression levels of 183 of 525 genes upregulated by interferon treatment were significantly suppressed in response to HBV infection. Suppressed genes were statistically significantly associated with the interferon signaling pathway and pattern recognition receptors in the bacteria/virus recognition pathway (P = 1.0 × 10(-8) and P = 1.2 × 10(-8), respectively). HBV infection attenuated virus recognition and interferon response in hepatocytes, which facilitated HBV escape from innate immunity.

Long-term effect of interferon treatment on the progression of chronic hepatitis B: Bayesian meta-analysis and meta-regression

AIM

  The long-term effects of interferon treatment on the progression of chronic hepatitis B (CHB) have been studied extensively, but its true clinical benefits and the predictors of its efficacy remain unclear.

METHODS

  A systematic published work search was undertaken. Eligible studies included those with interferon treatment and control groups, and with liver cirrhosis (LC), hepatocellular carcinoma (HCC) or death as main outcomes. Bayesian meta-analysis and meta-regression were performed to assess associations between interferon treatment and disease progression, and the impacts of potential covariates.

RESULTS

  Eleven articles met the inclusion criteria. LC, HCC and death were end-points in four, nine and six studies, respectively. In all studies, interferon was associated with significant preventive effects on HCC according to the DerSimonian-Laird method (relative risk [RR] = 0.470, 95% confidence interval [CI] = 0.260-0.850) and Bayesian method adjusting underlying risk (RR = 0.249, 95% Bayesian credible intervals [BCI] = 0.049-0.961), but not according to Bayesian meta-analysis (RR = 0.274, 95% BCI = 0.059-1.031); and it showed similar effects in death but not in LC. However, most of the high-quality studies never revealed protective benefits in these end-points. Bayesian meta-regression identified Asian ethnicity in death, higher hepatitis B e-antigen (HBeAg) seroconversion rate or positivity rate, and length of follow up (≤5 years) in HCC as potentially protective against disease progression. Subgroup analysis confirmed similar effects from these factors in HCC and death.

CONCLUSION

  Additional evidence is needed to support the role of interferon in delaying CHB progression.

Management of hepatitis B: Consensus of the Japan Society of Hepatology 2009

Recently, much progress has been made in the field of hepatitis B, such as natural history of the disease in relation to the amount of hepatitis B virus (HBV) DNA, genotypes of HBV influencing the natural course and treatment effects, mutations of HBV influencing the severity of the disease and development of hepatocellular carcinoma, and antiviral treatment such as nucleos(t)ide analogues and pegylated interferon. To make the consensus for the diagnosis, management and treatment of hepatitis B, a meeting was held during 45th annual meeting of Japan Society of Hepatology (JSH) in June 2009. In the meeting, recommendations and informative statements were discussed on the following subjects: (i) natural history of HBV infection; (ii) clinical implication of HBV genotypes; (iii) HBV mutations and their potential impact on pathogenesis of HBV infection; (iv) indications for antiviral treatment of chronic hepatitis B; (v) nucleos(t)ide analogues for chronic hepatitis B; and (vi) interferon therapy for chronic hepatitis B. The presenters reviewed the data on these subjects and proposed the consensus statements and recommendations. These statements were discussed among the organizers and presenters, and were approved by the participants of the meeting. In the current report, the relevant data were reviewed and the 12 consensus statements and nine recommendations on chronic hepatitis B were described.

Meta-analysis: reduction in hepatic events following interferon-alfa therapy of chronic hepatitis B

BACKGROUND

The long-term benefit of interferon-alfa (IFN-α) treatment in preventing various hepatic complications is not certain.

AIM

To study the effects of IFN-α on reducing the risk of developing overall hepatic events (hepatocellular carcinoma, cirrhotic complications and liver-related mortality) in chronic hepatitis B patients.

METHODS

Randomized controlled trials, case-control studies and cohort studies were retrieved from electronic databases and conference abstracts. Relative risks (RRs) of different hepatic complications among patients treated by IFN-α vs. no treatment or placebo were studied.

RESULTS

Eleven studies were identified totalling 975 patients treated by IFN-α vs. 1147 untreated controls for analysis. Patients were treated by IFN-α for 1-24 months with a post-treatment follow-up of 1-13 years. Treatment by IFN-α reduced the risk of overall hepatic events (RR 0.55, 95% confident interval or CI 0.43-0.70, P < 0.001) and cirrhotic complications (RR 0.46, 95% CI 0.32-0.67, P < 0.001) by 45% and 54% respectively. Patients who responded to IFN-α had more profound reduction in overall hepatic events (RR 0.20, 95% CI 0.05-0.87, P = 0.03) and cirrhotic complications (RR 0.19, 95% CI 0.09-0.38, P < 0.001) vs. the untreated controls.

CONCLUSION

Interferon-alfa treatment reduces the risk of hepatic events particularly among responders to treatment.

Does chemotherapy prevent HBV-related hepatocellular carcinoma? Cons

The retrospective scrutiny of studies that were originally designed to assess the antiviral activity of interferon (IFN) and nucleos(t)ide analogues (NUC) suggested reduced incidence of hepatocellular carcinoma (HCC) in responders. The interpretation of these studies, however, is questioned by the heterogeneity of patient referral, adoption of surrogate end-points, lack of control arms and, overall, by the lack of power to capture enough hard end-points of the natural history of hepatitis B, including HCC. Another point of criticism is that above all, IFN studies could have been affected by study enrolment skewed towards patients with less advanced liver disease, who had a better predicted compliance to therapy but a lower risk of developing HCC in the short-term. In my opinion, these constraints coupled with the lack of patient stratification by HCC predictors, make the evaluation of the prophylactic activity of IFN and NUC even more difficult. Overall, while single studies provide some evidence for a reduced HCC incidence in virological responders, particularly in those with moderate liver fibrosis, we still lack confirmation that anti-HBV therapy prevents HCC in patients with an established cirrhosis, too. Finally, tertiary prevention with anti-HBV treatments is controversial, due to the existence of a few, methodologically flawed studies.

Prevention of hepatocellular carcinoma in hepatitis B virus infection

Chronic hepatitis B is the main risk factor for hepatocellular carcinoma (HCC) in Asia. The most important preventive strategy's adoption of the universal hepatitis B vaccination program is now in its third decade. There is a clear reduction in both chronic hepatitis B virus (HBV) infection (hepatitis B surface antigen "carriage") but also in childhood HCC in Taiwan. An outstanding concern is variability in vaccine coverage between countries. For patients with chronic hepatitis B, serum HBV DNA levels have emerged as the key risk factor for development of HCC. The initial treatment for chronic hepatitis B was interferon. One randomized control trial, and several case-control or cohort studies have shown benefits for preventing HCC, particularly in cirrhotic patients who responded to therapy. With nucleos(t)ide analogs, the most important study has been the Asian Cirrhosis Lamivudine multicenter randomized controlled trial. This showed that lamivudine can reduce disease progression in HBV-related cirrhosis, including an approximately 50% decrease in HCC incidence. Such efficacy was achieved despite emergence of drug resistance in approximately 50% of cases. Case-control studies have suggested that hepatitis B cases without cirrhosis may also benefit. In conclusion, it is now possible to prevent HBV-related HCC. The most effective method is hepatitis B vaccination, which prevents chronic HBV infection and chronic liver disease resulting therefrom. Interferon therapy appears to confer benefit but the evidence is weaker. First-generation oral antiviral (lamivudine) reduces HCC risk, particularly in cirrhotics. Long-term outcome data with newer, more potent HBV antivirals that have a higher genetic barrier to drug resistance are eagerly awaited.

Meta-analysis: the effect of interferon on development of hepatocellular carcinoma in patients with chronic hepatitis B virus infection

PURPOSE

In patients chronically infected with hepatitis B virus, interferon has been used for the purpose of viral suppression by loss of hepatitis B e antigen (HBeAg) with or without seroconversion to antibody to HBeAg (anti-HBe). However, discussion about the effect of interferon on the development of hepatocellular carcinoma (HCC) has been controversial.

METHODS

We conducted a meta-analysis of published studies. Eight studies were retrieved (1,303 patients), including two randomized controlled trials (RCTs) and six non-RCTs (553 patients received interferon treatment).

RESULTS

The pooled estimate of the preventive effect of treatment was significantly in favor of interferon (risk difference -5.0%; 95% CI -9.4 to -0.5, P = 0.028). By subgroup analyses, the preventive effect of interferon treatment was shown in the Asian population (risk difference -8.5%; 95%CI -13.6 to -3.6, P = 0.0012), the population with the incidental rate of HCC >or=10% if untreated with interferon (risk difference -9.4%; 95%CI -14.2 to -4.6, P = 0.0001), and the population with the proportion of HBeAg-positive patients to the study population >or=70% (RD -6.0%; 95%CI -11.8 to -0.2, P = 0.043). However, the preventive effect of interferon was not shown in the European population, the population with a lower incidental rate of HCC if untreated with interferon, and the population with the lower proportion of HBeAg-positive patients to the study population. An evaluation using the Begg method indicated no evidence of publication bias.

CONCLUSIONS

Interferon treatment is considered to restrain HCC development in patients with chronic hepatitis B virus infection, especially in HBeAg-positive Asians.

Efficacy of consensus interferon in treatment of HbeAg-positive chronic hepatitis B: a multicentre, randomized controlled trial

Background

Consensus interferon (CIFN) is a newly developed type I interferon.

Aims

This multicentre, controlled trial was conducted to determine the efficacy of CIFN and to compare it with alpha-1b-interferon (IFN-α1b) in the treatment of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B.

Methods

144 Patients were randomly assigned to receive 9 μg CIFN (CIFN group) or 50 μg INF-α1b (IFN-alpha group) subcutaneously 3 times weekly for 24 weeks, followed by 24 weeks of observation. Efficacy was assessed by normalization of serum alanine transaminase (ALT) levels and the non-detectability of serum hepatitis B virus DNA or HBeAg at the end of treatment and 24 weeks after stopping treatment.

Results

There was no statistically significant difference in the serological, virological and biochemical parameters between CIFN and IFN-α1b groups at the end of the therapy and follow-up period (p > 0.05). Overall, at the end of treatment, 7.0% (5/71) and 35.2% (25/71) of patients in the CIFN group showed a complete or partial response compared with 7.4% (5/68) and 33.8% (23/68) of the IFN-alpha group (p = 0.10). At 24 weeks after stopping treatment, 6.9% (5/72) and 37.5% (27/72) of patients in the CIFN group showed complete response or partial response compared with 7.1% (5/70) and 34.3% (24/70) of the IFN-alpha group (p = 0.10).

Conclusion

These findings suggest that 9 μg CIFN is effective in the treatment of patients with HBeAg-positive chronic hepatitis B. It can gradually induce ALT normalization and HBV DNA clearance and HBeAg loss or HBeAg/HBeAb seroconversion.

Interferon therapy in chronic hepatitis B reduces progression to cirrhosis and hepatocellular carcinoma: a meta-analysis

Interferon (IFN) has been used in the treatment of chronic hepatitis B for decades. Beneficial effects including hepatitis B e antigen/HBV DNA seroclearance have been documented. However, the effect of treatment on the prevention of cirrhosis and hepatocellular carcinoma (HCC) development remains controversial. We conducted a meta-analysis of available literature to evaluate whether IFN reduces the incidence of liver cirrhosis and HCC in patients with chronic hepatitis B. Twelve clinical controlled trials, including 2082 patients and comparing IFN with no treatment, were selected. Data on the incidence of liver cirrhosis and HCC in IFN treated and untreated patients were extracted from each study. The evaluation of preventive effectiveness was performed with an intention-to-treat method. The relative risk (RR) and 95% confidence interval (CI) of the main outcomes as a measure of efficacy were used. Meta-analysis was performed using fixed-effect or random-effect methods, depending on absence or presence of significant heterogeneity. Analyses were performed with STATA version 9.0 and Review Manager Version 4.2. Five studies including the data on development of liver cirrhosis, and eleven studies including the data on development of HCC were analyzed. There was no evidence for publication bias on the funnel plot or by Egger's test, and the heterogeneity test indicated that the variation of trial-specific RR was not statistically significant. A different incidence of liver cirrhosis and HCC was observed between treated and untreated patients. The RR of liver cirrhosis and HCC was 0.65 (95% CI: 0.47, 0.91) and 0.59 (95% CI: 0.43, 0.81), respectively. In conclusion, the results of this meta-analysis indicate that IFN prevents or delays the development of liver cirrhosis and HCC in patients with chronic hepatitis B.

Peginterferon for the treatment of chronic hepatitis B in the era of nucleos(t)ide analogues

The practising clinician is currently faced with a number of effective treatment options for chronic hepatitis B, including two formulations of interferon (standard IFN and pegylated IFN) and five nucleos(t)ide analogues (lamivudine, adefovir, entecavir, telbivudine and tenofovir). Treatment strategies can be divided into those aiming for sustained response after discontinuation of therapy and those that need to be maintained by prolonged antiviral therapy. Sustained response is particularly achieved with interferon-based therapy, while treatment-maintained response can be achieved with long-term nucleos(t)ide analogue therapy in the majority of patients. Of currently available drugs for the treatment of chronic hepatitis B, PEG-IFN seems to result in the highest rate of off-treatment sustained response after a 1-year course of therapy. Sustained transition to the immune-control phase (inactive HBsAg carrier state) can be achieved in 30-35% of HBeAg-positive patients and 20-25% of HBeAg-negative patients. Loss of HBsAg has been observed in 11% of both HBeAg-positive and HBeAg-negative patients after 3-4 years. Since hepatitis B virus (HBV) genotype is an important predictor of response to PEG-IFN, determination of HBV genotype is essential in patients in whom sustained off-treatment response is pursued. Aiming for sustained response is of particular interest because many HBV-infected patients are in need of antiviral therapy at a young age and may otherwise require indefinite antiviral therapy.

Meta-analysis: Treatment of hepatitis B infection reduces risk of hepatocellular carcinoma

BACKGROUND

Chronic hepatitis B (CHB) infection leads to development of hepatocellular carcinoma (HCC), but the effects of treatment in preventing HCC are not clear.

AIM

To study the effects of interferon (IFN) or nucleoside/tide analogue (NA) on the risk of developing HCC in CHB patients.

METHODS

Randomized trials, case-control and cohort studies were retrieved from five electronic databases and international conferences over the past 10 years. Relative risks (RRs) of HCC with or without treatment were studied.

RESULTS

Twelve studies (n = 2742) enrolling patients treated by IFN vs. control showed that the risk of HCC after treatment was reduced by 34% (RR: 0.66, 95% CI: 0.48-0.89). Benefit is more significant among patients with early cirrhosis than among those without cirrhosis. Five studies (n = 2289) compared patients treated by NA with control. The risk of HCC after treatment was reduced by 78% (RR: 0.22, 95% CI: 0.10-0.50). HBeAg-positive patients showed more significantly reduced HCC risk with treatment. Patients without cirrhosis benefited more from NA than those with cirrhosis. Resistance to NA has obviated the benefit of the treatment.

CONCLUSIONS

IFN or NA treatment significantly reduces risk of HCC. While IFN benefited patients with cirrhosis, NA benefited patients with no cirrhosis and HBeAg-positive CHB infection.

Reviews for APASL guidelines: immunomodulator therapy of chronic hepatitis B

The primary aim of immunomodulator therapy is to help the natural human immune system to mount a defense against hepatitis B virus. IFN-alpha has been used for the treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B for over two decades and has been shown to be effective in suppressing HBV replication and in inducing serological response leading to long-term clinical benefits. IFN-alpha has been used in patients with well-compensated cirrhosis with comparable or better response to that in non-cirrhotic patients. IFN-alpha therapy in patients with cirrhosis has a similar side effect profile as in those without cirrhosis. However, IFN-alpha is contraindicated in patients with overt or decompensated cirrhosis. Pegylated IFN-alpha has been shown to be effective in treatment of chronic hepatitis B with sustained response rate in about one-third of the treated patients. Peg IFN-alpha treatment in non-responders to lamivudine or adefovir dipivoxil showed similar response rate to that seen in naïve patients. Thymosin alpha(1) is effective in treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B with a significantly increasing virological response over time after therapy.

New and emerging treatment of chronic hepatitis B

Conventional treatment of chronic hepatitis B with interferon alfa-2b, lamivudine, and adefovir is limited by low rates of sustained hepatitis B virus DNA suppression and hepatitis B e antigen (HBeAg) seroconversion, increasing rates of drug resistance to the oral agents, and poor tolerability of interferon. Recently several promising new antiviral agents have emerged that possess potent antiviral effects, less toxicity, and have little or no risk of drug resistance. Two new agents, entecavir and peginterferon alfa-2a, have received recent approval by regulatory authorities in the United States and several other countries for the treatment of adults with chronic hepatitis B. In large phase III clinical trials, these agents have demonstrated superior efficacy over lamivudine in both HBeAg-positive and HBeAg-negative patients. Drug resistance occurs at a low rate in lamivudine-refractory patients treated with entecavir or is, to date, nonexistent in nucleoside-naïve patients treated with entecavir and all patients receiving peginterferon. In addition, several novel agents in clinical development, such as emtricitabine, clevudine, telbivudine, valtorcitabine, and tenofovir, have shown promising clinical profiles in patients with chronic hepatitis B. This review summarizes the recent clinical studies of these new agents and discusses the implications of these data for the management of chronic hepatitis B.

Interferon therapy in HBeAg positive chronic hepatitis reduces progression to cirrhosis and hepatocellular carcinoma

BACKGROUND/AIMS

The long-term outcomes of interferon-alpha (IFN-alpha) therapy in hepatitis B e antigen (HBeAg) seropositive patients remain controversial. This study was conducted to address this issue.

METHODS

The long-term outcomes were compared in 233 IFN-treated patients and 233 well-matched untreated controls.

RESULTS

The cumulative incidence at the end of 15 years of follow-up (median 6.8 years, range 1.1-16.5 years) in the IFN-treated patients and controls was: HBeAg seroconversion 74.6% vs. 51.7% (P=0.031); hepatitis B surface antigen (HBsAg) seroclearance 3% vs. 0.4% (P=0.03); cirrhosis 17.8% vs. 33.7% (P=0.041); and hepatocellular carcinoma (HCC) 2.7% vs. 12.5% (P=0.011). Significant reduction of HCC was only observed in patients with pre-existing cirrhosis (P<0.01). Compared with untreated controls with persistent HBeAg, HBeAg seroconverters in untreated and IFN-treated group showed significantly lower incidence of cirrhosis and HCC (P=0.003-0.031), while non-seroconverters of IFN-treated group had marginally significant lower incidence of cirrhosis (P=0.065). Multivariate analysis showed that IFN therapy, HBeAg seroconversion and genotype B HBV infection are independent factors for better long-term outcomes.

CONCLUSIONS

IFN therapy reduces cirrhosis and HCC development.

Hepatitis B Virus Replication and Liver Disease Progression: The Impact of Antiviral Therapy

Chronic hepatitis B virus (HBV) infection is a serious health issue worldwide. The presence of HBV replication markers — hepatitis B e antigen (HBeAg) or HBV DNA — is associated with continuing hepatitis activity or intermittent hepatitis flares and subsequent disease progression, including hepatic decompensation and development of liver cirrhosis or hepatocellular carcinoma (HCC). Long-term (>10 years) prospective studies in patients ≥30 years of age have shown that HBeAg seropositivity is associated with increased risk of disease progression, and the risk of cirrhosis and HCC begins to increase at an HBV DNA level of 104 copies/ml. Therefore, elimination of HBV, or at least sustained or maintained suppression of HBV, is the key to reducing hepatitis and thereby halting or preventing disease progression. Therapy with interferon-α or a direct antiviral agent has been shown to reduce the risk of cirrhosis and prevent further disease worsening. In both the woodchuck hepatitis model and in HBV patients, maintained suppression of HBV replication by a direct antiviral agent may reduce the progression to HCC. However, the efficacy of current antiviral therapy is still far from satisfactory. The ability to achieve a high rate of sustained or maintained HBV suppression with a low risk of drug resistance would be the ultimate goal in the treatment of chronic HBV infection.

Optimizing management strategies in special patient populations

Chronic hepatitis B infection presents a number of challenges to clinicians. There are additional considerations when defining management strategies for individuals with advanced liver disease, or coinfection, or those at high risk of developing hepatocellular carcinoma (HCC). Treatment of decompensated cirrhosis is particularly important. Evidence suggests that suppression of viral replication through nucleos(t)ide analog therapy leads to longer time to transplantation, improved liver function, and improved survival times. The use of interferon in patients with decompensated hepatitis B is associated with serious complications and is currently contraindicated for these patients by the AASLD Practice Guidelines. Hepatitis B coinfection is often associated with more extensive disease. In patients with HBV/HCV coinfection, one disease is usually dominant and consequently should be the focus of therapy. HIV/HBV coinfection increases the risk of progressive liver disease. Therapeutic agents active against both viruses should be utilized at the correct dose to limit the development of resistance. Agents specific for HBV, e.g., entecavir, enable hepatitis to be treated while avoiding the risk of HIV resistance developing. Dual infection with HBV and HDV is particularly challenging. Nucleos(t)ide analogs are ineffective in treating HDV infection, and there is limited data concerning the efficacy of interferon in this setting. The association between chronic hepatitis B infection and hepatocellular carcinoma (HCC) is well established. In patients at high risk of HCC, screening regimes may be effective. Furthermore, there is an increasing body of evidence indicating that effective suppression of viral replication may be associated with a reduced risk of HCC.

Established and emerging therapies for the treatment of viral hepatitis

Patients who are chronically infected with either hepatitis B or C viruses run the risk of developing cirrhosis and hepatocellular carcinoma in later life. Antiviral treatment offers the only means of interrupting this progression. To date, recombinant interferon alpha and the nucleos(t)ide analogues lamivudine and adefovir dipivoxil are the only licensed drugs for the treatment of chronic hepatitis B, whilst recombinant or pegylated interferons in combination with ribavirin are the ones used for chronic hepatitis C virus infections. The efficacy of these treatments, reasons for treatment failure, drug resistance and future options are discussed in the present review.

Changing disease burden of hepatocellular carcinoma in the Far East and Southeast Asia

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world, and has a marked difference in geographic distribution. More than 80% of HCC cases occur in developing countries, especially the Far East and Southeast Asia. Although immunization has been successful against hepatitis B virus (HBV), a changing disease burden of HCC has been observed in many parts of the world because of the increasing prevalence and duration of hepatitis C virus (HCV) infection in these countries. In addition, the age-specific incidence of HCC has progressively shifted toward younger people. Hepatitis B genotypes B and C are prevalent in the Far East and Southeast Asia, and the clinical relevance of HBV genotypes has become increasingly recognized. Compared with genotype C, genotype B is associated with earlier hepatitis B e antigen seroconversion, slower progression to cirrhosis and less frequent development of HCC. By using periodic examinations of serum alfa-fetoprotein levels and abdominal ultrasonography, small HCC can be detected and treated earlier. However, prevention of HBV and HCV infections as well as effective treatment of the chronic viral infections with timely interventions are still needed for the global control of HCC, particularly in the Far East and Southeast Asia.

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2005 update

BACKGROUND/AIMS

A large amount of new data on the treatment of chronic hepatitis B has become available such that the 2003 consensus statement requires revision and update.

METHODS

New data were presented, discussed and debated in an expert pre-meeting to draft a revision. The revised contents were finalized after discussion in a general meeting of APASL.

RESULTS

Conceptual background, including the efficacy and safety profile of currently available and emerging drugs, was reviewed. Nineteen recommendations were formed and unresolved issues and areas for further study were suggested.

CONCLUSION

The current therapy of chronic hepatitis B is modestly effective but not satisfactory. The development of new drugs and new strategies is required to further improve the outcomes of treatment.