48 weeks pegylated interferon alpha-2a is superior to 24 weeks of pegylated interferon alpha-2b in achieving hepatitis B e antigen seroconversion in chronic hepatitis B infection

Peginterferon-alpha-2a (40 kD): A review of its use in chronic hepatitis B

Peginterferon-alpha-2a (40 kD) [Pegasys] comprises an inert, branched, 40 kD polyethylene glycol (PEG) moiety attached to interferon-alpha-2a. Subcutaneous peginterferon-alpha-2a (40 kD) is indicated for the treatment of adults with hepatitis B e antigen (HBeAg)-positive or -negative chronic hepatitis B who have compensated liver disease with evidence of viral replication and hepatic inflammation. Subcutaneous peginterferon-alpha-2a (40 kD) has antiviral and immunomodulatory properties and a convenient once-weekly administration schedule. Forty-eight weeks of therapy with peginterferon-alpha-2a (40 kD) with or without lamivudine was more effective than lamivudine alone in achieving a sustained response in patients with HBeAg-positive or -negative chronic hepatitis B. A long-term follow-up study in patients with HBeAg-positive disease who received peginterferon-alpha-2a (40 kD) monotherapy revealed an HBeAg seroconversion rate of 42%, 1 year after the end of treatment. A long-term follow-up study in patients with HBeAg-negative disease who received peginterferon-alpha-2a (40 kD) with or without lamivudine revealed hepatitis B surface antigen (HBsAg) clearance in 12% of patients and inactive chronic hepatitis B in 17% of patients, 5 years after the end of treatment. Various predictors of response may be useful in terms of identifying patients who may be candidates for shorter or longer peginterferon-alpha-2a (40 kD) treatment durations. For example, quantifying serum HBeAg (in HBeAg-positive disease) and HBsAg levels during therapy may be useful. Adverse events typical of the influenza-like symptoms seen with alpha-interferons occurred more frequently in patients with chronic hepatitis B receiving peginterferon-alpha-2a (40 kD) with or without lamivudine than in those receiving lamivudine alone. In conclusion, peginterferon-alpha-2a (40 kD) is a valuable option for the first-line treatment of HBeAg-negative or -positive chronic hepatitis B.

Interferons and their use in persistent viral infections

In 2007, the world celebrated the 50th anniversary of the discovery of interferon (IFN) by Isaacs and Lindenmann. Subsequently, the IFN-alpha gene was cloned, fully sequenced and IFN-alpha was produced in recombinant form. Recombinant IFN-alpha is now used as the basis for treatment of chronic hepatitis C virus infection and can also be used to treat certain forms of chronic hepatitis B virus infections. IFNs have also been used in other viral infections, although with less success. The antiviral mechanisms of IFNs are reviewed in this chapter as well as the utility of IFNs in the treatment of persistent viral infections.

A treatment algorithm for the management of chronic hepatitis B virus infection in the United States: 2008 update

Chronic HBV infection is an important public health problem worldwide and in the United States. A treatment algorithm for the management of this disease, published previously by a panel of U.S. hepatologists, has been revised on the basis of new developments in the understanding of the disorder, the availability of more sensitive molecular diagnostic tests, and the licensure of new therapies. In addition, a better understanding of the advantages and disadvantages of new treatments has led to the development of strategies for reducing the rate of resistance associated with oral agents and optimizing treatment outcomes. This updated algorithm was based primarily on available evidence by using a systematic review of the literature. Where data were lacking, the panel relied on clinical experience and consensus expert opinion. The primary aim of antiviral therapy is durable suppression of serum HBV DNA to low or undetectable levels. Assays can now detect serum HBV DNA at levels as low as 10 IU/mL and should be used to establish a baseline level, monitor response to antiviral therapy, and survey for the development of drug resistance. Interferon alfa-2b, lamivudine, adefovir, entecavir, peginterferon alfa-2a, telbivudine, and tenofovir are approved as initial therapy for chronic hepatitis B and have certain advantages and disadvantages. Although all of these agents can be used in selected patients, the preferred first-line treatment choices are entecavir, peginterferon alfa-2a, and tenofovir. Issues for consideration for therapy include efficacy, safety, rate of resistance, method of administration, and cost.

New paradigms for the treatment of chronic hepatitis B

The main goals of chronic hepatitis B treatment should be the long-term suppression of viral replication to minimize disease progression and the risk for the development of hepatocellular carcinoma. Treatment end-points, depending on surrogate markers alone, in particular hepatitis B e-antigen seroconversion, may not be ideal for patients who acquire the disease early in life. Currently-available drugs include interferons and oral nucleoside/nucleotide analogs. Although interferon therapy provides a finite treatment period, a significant proportion of patients may not respond, and long-term outcome is inconclusive. Long-term efficacy has been demonstrated for both lamivudine and adefovir. However, prolonged nucleoside/nucleotide analog therapy is associated with the emergence of drug-resistant mutations. Therefore, nucleoside/nucleotide analogs with a high genetic barrier and potent antiviral activity, such as entecavir, should be used to reduce the chance of developing drug-resistant mutations. Drugs with a low genetic barrier, including lamivudine and telbivudine, should be used in conjunction with early testing for antiviral response. This can predict favorable outcomes in the long term. The early detection of drug-resistant mutations should prompt clinicians to either add or switch to another agent with a different drug-resistance profile. There are currently no treatment models in the use of combination or sequential therapy in treatment-naïve patients. To date, long-term treatment appears to be the most effective option. Despite recent advances made with better understanding on the natural history of chronic hepatitis B infection and with newer antiviral drugs available, challenges remain with respect to treatment criteria, treatment end-points, and duration of treatment.

Serum adiponectin is increased in advancing liver fibrosis and declines with reduction in fibrosis in chronic hepatitis B

BACKGROUND/AIMS

Despite the possible role of adiponectin in the pathogenesis of liver cirrhosis, few data have been collected from patients in different stages of liver fibrosis. We studied the role of adiponectin in 2 chronic hepatitis B (CHB)-patient cohorts.

METHODS

Serum adiponectin was quantified by enzyme-linked immunosorbent assay. One-hundred liver biopsy specimens from CHB patients with different stages of fibrosis and 38 paired liver biopsies from hepatitis B e antigen-positive patients randomized to lamivudine (n=15), pegylated interferon alfa-2a (n=15) or pegylated interferon alfa-2a plus lamivudine (n=8) therapy for 48 weeks were assessed.

RESULTS

Serum adiponectin was detected at levels ranging over fourfold magnitude with advancing fibrosis stage and correlated positively with fibrosis stage [r=0.45, p<0.001]. CHB patients with stage 0-1 fibrosis had higher composition of high molecular weight (HMW) form of adiponectin when compared with CHB patients with liver cirrhosis [mean+/-SEM 51.2+/-2.1% vs. 40.9+/-1.7%, respectively, p=0.001]. After antiviral therapy, patients with fibrosis reduction had marked decline in serum adiponectin level and increase in HMW form of adiponectin [mean+/-SEM 43.5+/-1.2% vs. 37.0+/-3.0%, respectively, p=0.04].

CONCLUSIONS

Serum adiponectin may have a role in fibrosis progression in CHB infection. A marked decline in serum adiponectin after antiviral therapy is associated with fibrosis reduction.

Future prospectives for the management of chronic hepatitis B

Chronic hepatitis B virus infection affects about 400 million people around the globe and causes approximately one million deaths a year. Since the discovery of interferon-α as a therapeutic option the treatment of hepatitis B has evolved fast and management has become increasingly complicated. The amount of viral replication reflected in the viral load (HBV-DNA) plays an important role in the development of cirrhosis and hepatocellular carcinoma. The current treatment modalities for chronic hepatitis B are immunomodulatory (interferons) and antiviral suppressants (nucleoside and nucleotide analogues) all with their own advantages and limitations. An overview of the treatment efficacy for both immunomodulatory as antiviral compounds is provided in order to provide the clinician insight into the factors influencing treatment outcome. With nucleoside or nucleotide analogues suppression of viral replication by 5-7 log₁₀ is feasible, but not all patients respond to therapy. Known factors influencing treatment outcome are viral load, ALT levels and compliance. Many other factors which might influence treatment are scarcely investigated. Identifying the factors associated with response might result in stopping rules, so treatment could be adapted in an early stage to provide adequate treatment and avoid the development of resistance. The efficacy of compounds for the treatment of mutant virus and the cross-resistance is largely unknown. However, genotypic and phenotypic testing as well as small clinical trials provided some data on efficacy in this population. Discontinuation of nucleoside or nucleotide analogues frequently results in viral relapse; however, some patients have a sustained response. Data on the risk factors for relapse are necessary in order to determine when treatment can be discontinued safely. In conclusion: chronic hepatitis B has become a treatable disease; however, much research is needed to tailor therapy to an individual patient, to predict the sustainability of response and determine the best treatment for those failing treatment.