Comparative study of three doses of interferon-alpha 2a in chronic active hepatitis B. The International Hepatitis Trial Group

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.

New insights into how HBV manipulates the innate immune response to establish acute and persistent infection

The mechanisms by which HBV establishes and maintains chronic infection are poorly understood. Although adult acquired HBV is generally cleared by a robust immune response, most individuals infected at childbirth or in very early childhood develop lifelong chronic infection. In addition, acute infections are unresolved in approximately 5% of individuals infected in adulthood. The host cell mechanisms that ensure establishment and resolution of acute infection and persistent infection remain unclear. Currently, two schools of thought suggest that either HBV is a 'stealth' virus, which initially establishes infection by avoiding host innate immune responses, or that HBV facilitates initial infection and progression to persistence by actively manipulating the host innate immune response to its advantage. There is increasing evidence that activation of innate host cell signalling pathways plays a major role in limiting adult acquired HBV infection and that, in turn, HBV has evolved numerous strategies to counteract these defence mechanisms. In this review, we summarize current knowledge regarding innate immune responses to HBV infection and discuss how HBV regulates cell signalling pathways to its advantage, particularly in the setting of chronic HBV infection. In turn, we show how an intimate knowledge of innate immune responses is driving development of novel therapeutic agents to treat chronic HBV infection.

Do we need to determine viral genotype in treating chronic hepatitis B?

Many studies have attested that not only does HBV genotype influence the outcome of the disease but it also influences the outcome of therapy with interferons and pegylated interferons, with genotype A doing better than genotype D in Caucasians and genotype B better than genotype C in Asians. However, the guidelines from three regional bodies - AASLD, APASL and EASL - all stop short of recommending genotyping as part of the management of chronic hepatitis B. The recommendations, however, from several national organizations as well as from individual reviewers suggest that genotyping is essential to detect patients in whom the use of pegylated interferon will give a high likelihood of response with a finite course of therapy and avoid the disadvantages of nucleoside analogues with their viral resistance. It is concluded that determination of HBV genotype should form part of the management in treating chronic hepatitis B.

Revisão sistemática da eficácia do interferon alfa (convencional, peguilado) e lamivudina para o tratamento da hepatite crônica B

A hepatite crônica B constitui um grave problema de saúde pública e vem demonstrando crescentes gastos com financiamento de medicamentos de dispensação em caráter excepcional e de alto custo no Sistema Único de Saúde (SUS). O objetivo do estudo foi comparar a eficácia do interferon (convencional; peguilado - PEG2a) e lamivudina (LAM) para o tratamento da hepatite crônica B, pelo método de revisão sistemática selecionando ensaios clínicos randomizados e controlados identificados nas bases PubMed e LILACS. As medidas de resultado consideradas foram resposta virológica, soroconversão, resposta bioquímica, resposta histológica e efeitos adversos. Foram selecionados 35 artigos. A presença ou ausência do HBeAg e os níveis de alanina amino transferase (ALT) no pré-tratamento demonstraram papel fundamental na indicação terapêutica inicial. O tratamento com interferons convencionais permite a inativação da doença por longos períodos de tempo, podendo resultar em soroconversão HBsAg. O PEG 2a demonstrou eficácia superior ao interferon e LAM e efeitos colaterais semelhantes ao interferon. A LAM apresenta vantagem de ser sensível para os pacientes HBeAg negativo e apresenta como maior desvantagem o desenvolvimento de resistência.

Sustained response to peginterferon alfa-2a (40 kD) with or without lamivudine in Asian patients with HBeAg-positive and HBeAg-negative chronic hepatitis B

PURPOSE

The 2 reported trials investigated the effectiveness of treatment with peginterferon alfa-2a in Asian patients with chronic hepatitis B (CHB).

METHODS

Patients with HBeAg-positive (n = 708) or HBeAg-negative (n = 332) CHB were enrolled in 2 randomized, double blind, placebo-controlled studies. Patients received peginterferon alfa-2a 180 mug once weekly, peginterferon plus lamivudine 100 mg per day, or lamivudine alone for 48 weeks. Patients were followed up at 6 and 12 months posttreatment.

RESULTS

Peginterferon alfa-2a provided significantly higher rates of HBeAg seroconversion (31%) in HBeAg-positive patients than did lamivudine (19%, P = 0.005) 6 months posttreatment, irrespective of genotype. Of these, 83% achieving seroconversion during treatment or early posttreatment sustained their response at 12 months posttreatment. In patients who seroconverted, 69% maintained HBV DNA suppression at <10,000 copies/ml and alanine aminotrasferase (ALT) normalization. In HBeAg-negative patients, peginterferon produced a significantly higher combined response of HBV DNA at <20,000 copies/ml and ALT normalization (45%) than lamivudine (31%, P = 0.032), irrespective of genotype. Almost 80% of these patients sustained their response at 12 months posttreatment.

CONCLUSIONS

In conclusion, a finite course of peginterferon alfa-2a provides significant and sustained treatment benefit in Asian CHB patients, who have traditionally been regarded as difficult to treat.

Optimal duration of therapy in HBV-related cirrhosis

It is estimated that one-third of the world's population has been exposed to hepatitis B virus and that 300-400 million people have chronic hepatitis B. In areas of the world where hepatitis B infection is endemic, this chronic viral infection is a major cause of premature morbidity and mortality related to hepatocellular carcinoma (HCC) and complications of end-stage liver disease. Recent data from population-based studies suggest that the level of viral replication in chronic hepatitis B is an independent predictor of the future complications of the disease; patients with hepatitis B viral DNA titres >10(4) copies/mL (especially those with titres >10(5) copies) have a significantly greater risk of developing HCC and cirrhosis. There is also recent evidence that treatment with antiviral therapy in patients with chronic hepatitis B who have advanced hepatic fibrosis is associated with a reduction in the risk of decompensation of liver disease and HCC. Several new antiviral medications have been recently approved for the treatment of chronic hepatitis B. Several recent position statements and practice guidelines have recommended treatment of patients with chronic hepatitis B with oral antiviral medications. However, there remains some disagreement as to the threshold of viral load before treatment should be initiated and the optimal duration of therapy in patients with cirrhosis due to hepatitis B. This article describes the current recommendations regarding therapy in this group of patients and suggests some criteria for treatment of patients with chronic hepatitis B-related cirrhosis or advanced hepatic fibrosis.

Peginterferon-alpha 2a for the treatment of hepatitis B infection

Chronic hepatitis B is one of the world's most common serious diseases with > 300 million patients worldwide. Currently recommended treatments include conventional interferon (IFN), lamivudine and adefovir. Recently, peginterferon-alpha2a (PEG-IFN-alpha2a, Pegasys; Hoffmann-La Roche & Co.) has been approved for use in patients with chronic hepatitis B in the US, the EU, Switzerland, Turkey and in several countries in the Asia-Pacific region. Several trials have been carried out using PEG-IFN-alpha2a (40 kDa) compared with conventional IFN, lamivudine monotherapy and a combination of PEG-IFN-alpha2a and lamivudine in patients with hepatitis Be antigen- (HBeAg) positive chronic hepatitis B, and patients with HBeAg-negative chronic hepatitis B. PEG-IFN-alpha2a was shown to be superior to conventional IFN in HBeAg-positive disease and to lamivudine in both HBeAg-positive and HBeAg-negative chronic hepatitis B. Although there was greater suppression of virus while on therapy, the combination of lamivudine and PEG-IFN-alpha2a did not enhance sustained response at the end of the 24-week follow-up period, compared with PEG-IFN monotherapy. In addition, approximately 3% of patients underwent hepatitis B surface antigen (HBsAg) seroconversion - the ultimate marker of therapeutic response, which is rarely seen following treatment with antiviral agents. The side effect profile was reasonable. PEG-IFN-alpha2a could become the treatment of choice in many patients with both HBeAg-positive and HBeAg-negative disease and, in those who fail to respond, consideration could then be given to the use of antiviral agents.

Systematic review: treatment of chronic hepatitis B virus infection by pegylated interferon

BACKGROUND

Pegylated interferon-alpha has been shown to be more efficacious than conventional interferon in treating chronic hepatitis C. The use of peginterferon in chronic hepatitis B virus infection with positive hepatitis B e antigen has also been tested in a number of trials since 2003.

AIM

To systematically summarize and compare the results of these studies.

METHODS

Four studies were identified from PubMed, Medline and reference lists. Data from the trials were extracted and analysed. Where appropriate, combined odds ratio of different trials was calculated. Safety data including serious adverse events and emergence of drug-resistant mutants were recorded.

RESULTS

Three of the four trials contained predominantly Asian patients. Peginterferon is found to be superior to lamivudine monotherapy and induced sustained biochemical and virological responses in about one-thirds of patients after 12 months of therapy. Coadministration of lamivudine did not result in improvement in viral suppression. Peginterferon appears to reduce the emergence of YMDD mutation in the combination treatment groups. It was well tolerated with serious adverse events reported in <10% of patients in most trials.

CONCLUSIONS

Peginterferon-alpha treatment of at least 6 months should be considered as one of the first-line therapeutic options for hepatitis B virus infection.

Treatment of hepatitis B with interferon and combination therapy

Pegylated interferon alpha-a (40 kDa) has recently been shown to be superior to conventional interferon. Furthermore, in a pilot study, pegylated interferon alpha-2b together with lamivudine was superior to lamivudine monotherapy. Therefore, the pegylated interferons alone or in combination with antiviral agents are likely to be the treatment of the future. Selecting patients for treatment and knowing when to treat them is as important as knowing which medicine to treat them with.

Hepatitis B virus epidemiology, disease burden, treatment, and current and emerging prevention and control measures

Hepatitis B virus (HBV) infection is a serious global health problem, with 2 billion people infected worldwide, and 350 million suffering from chronic HBV infection. The 10th leading cause of death worldwide, HBV infections result in 500 000 to 1.2 million deaths per year caused by chronic hepatitis, cirrhosis, and hepatocellular carcinoma; the last accounts for 320 000 deaths per year. In Western countries, the disease is relatively rare and acquired primarily in adulthood, whereas in Asia and most of Africa, chronic HBV infection is common and usually acquired perinatally or in childhood. More efficacious treatments, mass immunization programs, and safe injection techniques are essential for eliminating HBV infection and reducing global HBV-related morbidity and mortality. Safe and effective vaccines against HBV infection have been available since 1982. The implementation of mass immunization programs, which have been recommended by the World Health Organization since 1991, have dramatically decreased the incidence of HBV infection among infants, children, and adolescents in many countries. However, not all countries have adopted these recommendations and there remains a large number of persons that were infected with HBV prior to the implementation of immunization programs. Antiviral treatment is the only way to reduce morbidity and mortality from chronic HBV infection. Conventional interferon alfa and lamivudine have been the primary treatments to date. Conventional interferon alfa produces a durable response in a moderate proportion of patients but has undesirable side-effects and must be administered subcutaneously three times per week. Lamivudine also produces a response in a modest proportion of patients and causes few side-effects. However, prolonged treatment is often necessary to prevent relapse on cessation of therapy, and continuous treatment can lead to the development of lamivudine resistance. Promising emerging new treatments include adefovir, entecavir and peginterferon alfa-2a (40 kDa).

Peginterferon alpha-2a (40 kDa): an advance in the treatment of hepatitis B e antigen-positive chronic hepatitis B

Current therapies for chronic hepatitis B (CHB) have a number of limitations, and better treatment options are needed. Peginterferon alpha-2a (40 kDa) is superior to conventional interferon alpha-2a in the treatment of chronic hepatitis C. This is the first report on peginterferon alpha-2a (40 kDa) in the treatment of CHB. In this phase II study, 194 patients with CHB not previously treated with conventional interferon-alpha were randomized to receive weekly subcutaneous doses of peginterferon alpha-2a (40 kDa) 90, 180 or 270 microg, or conventional interferon alpha-2a 4.5 MIU three times weekly. Twenty-four weeks of therapy were followed by 24 weeks of treatment-free follow-up. All subjects were assessed for loss of hepatitis B e antigen (HBeAg), presence of hepatitis B antibody (anti-HBe), suppression of hepatitis B virus (HBV) DNA, and normalization of serum alanine transaminase (ALT) after follow-up. At the end of follow-up, HBeAg was cleared in 37, 35 and 29% of patients receiving peginterferon alpha-2a (40 kDa) 90, 180 and 270 microg, respectively, compared with 25% of patients on conventional interferon alpha-2a. The combined response (HBeAg loss, HBV DNA suppression, and ALT normalization) of all peginterferon alpha-2a (40 kDa) doses combined was twice that achieved with conventional interferon alpha-2a (24%vs 12%; P = 0.036). All treatment groups were similar with respect to frequency and severity of adverse events. These results indicate that peginterferon alpha-2a (40 kDa) is superior in efficacy to conventional interferon alpha-2a in chronic hepatitis B based on clearance of HBeAg, suppression of HBV DNA, and normalization of ALT.

A systematic approach to hepatic complications in hematopoietic stem cell transplantation

Hepatic injury is a common complication of hematopoietic stem cell transplantation (HSCT) and carries a high risk of early morbidity and mortality. Evaluation of the patient for hepatic complications should begin in the pretransplant period with the identification of pretransplant risk factors, such as hepatitis status, that may predict severe liver complications and continue through the early and late transplant periods. Early hepatic complications include drug toxicity, hepatic veno-occlusive disease (VOD), acute graft-versus-host disease (GVHD), infection, and cholestatic disorders. With increased survival of HSCT recipients, long-term liver complications from chronic viral hepatitis, chronic GVHD, and iron overload are being reported. The diagnosis and management of hepatic disorders in transplant can be complex, because one must decide whether a given symptom is due to one or a combination of diverse causes. Making the diagnosis can be crucial, because specific therapies can improve one condition but worsen another. This review describes a systematic approach to the evaluation of HSCT patients with hepatic complications with an emphasis on the need to intervene early with radiologic imaging and liver biopsy. Updated treatment options are also discussed. It is hoped that a standard approach will help to streamline clinical management of these very complex patients.

Oropharyngeal pemphigus in a patient with chronic hepatitis C during interferon alpha-2a therapy

There are a few reports in the literature concerning pemphigus induced by interferon given for hepatitis C. We present the case of a 28-year-old woman with post-transfusional chronic hepatitis C who developed ulcers and vesicles on her tongue, cheeks, posterior oropharynx and vocal cords 5 months after beginning treatment with recombinant interferon alpha-2a. The direct and indirect immunofluorescence was diagnostic of pemphigus vulgaris. The drug was promptly withdrawn; the patient was medicated with prednisolone and azathioprine and recovered only 3 months later. Although there are several publications describing the occurrence of other autoimmune diseases in patients receiving interferon alpha therapy, this is the first report of a pemphigus induced by interferon in hepatitis C patients involving oropharyngeal and laryngeal mucosae without cutaneous involvement.

A case-controlled study on the use of HBsAg-positive donors for allogeneic hematopoietic cell transplantation

To compare the clinical and serological outcomes of patients receiving donors' marrow positive or negative for hepatitis B surface antigen (HBsAg), we studied 18 patients of allogeneic hematopoietic cell transplantation receiving HBsAg-positive marrow (group 1) and 18 receiving HBsAg-negative marrow (group 2). The recipients of the 2 groups were matched for hepatitis B virus (HBV) serology, sex, age, underlying hematological diseases, conditioning regimen, and prophylaxis against graft-versus-host diseases. Eight (44.4%) recipients in group 1 and 2 (11.1%) in group 2 suffered from HBV-related hepatitis posttransplant (P = .03). Furthermore, HBV-related hepatic failure was seen in 6 group 1 patients, but in none of the group 2 patients (P = .007). Five of the 9 (55.5%) HBsAg-negative recipients in group 1 became positive after receiving HBsAg-positive marrow. Serum HBV DNA was positive in all 5 donors of these patients, but in none of the donors of recipients who remained HBsAg negative (P = .008). Group 1 patients developing HBV-related hepatitis posttransplant were more likely to have a donor carrying a precore A1896 and/or core promoter T1762/A1764 HBV variant (62.5% versus 0%, P = .007). This study has demonstrated that a high incidence of HBV-related hepatitis was associated with the use of HBsAg-positive marrow for transplant, and a high viral load in the donor appeared to predispose recipients to the development of HBV-related hepatitis posttransplant. Further clinical trials will be necessary to determine the optimal management approach to this problem, including the use of the antiviral agents in the donors and the recipients.

A case-controlled study on the use of HBsAg-positive donors for allogeneic hematopoietic cell transplantation

To compare the clinical and serological outcomes of patients receiving donors' marrow positive or negative for hepatitis B surface antigen (HBsAg), we studied 18 patients of allogeneic hematopoietic cell transplantation receiving HBsAg-positive marrow (group 1) and 18 receiving HBsAg-negative marrow (group 2). The recipients of the 2 groups were matched for hepatitis B virus (HBV) serology, sex, age, underlying hematological diseases, conditioning regimen, and prophylaxis against graft-versus-host diseases. Eight (44.4%) recipients in group 1 and 2 (11.1%) in group 2 suffered from HBV-related hepatitis posttransplant (P = .03). Furthermore, HBV-related hepatic failure was seen in 6 group 1 patients, but in none of the group 2 patients (P = .007). Five of the 9 (55.5%) HBsAg-negative recipients in group 1 became positive after receiving HBsAg-positive marrow. Serum HBV DNA was positive in all 5 donors of these patients, but in none of the donors of recipients who remained HBsAg negative (P = .008). Group 1 patients developing HBV-related hepatitis posttransplant were more likely to have a donor carrying a precore A1896 and/or core promoter T1762/A1764 HBV variant (62.5% versus 0%, P = .007). This study has demonstrated that a high incidence of HBV-related hepatitis was associated with the use of HBsAg-positive marrow for transplant, and a high viral load in the donor appeared to predispose recipients to the development of HBV-related hepatitis posttransplant. Further clinical trials will be necessary to determine the optimal management approach to this problem, including the use of the antiviral agents in the donors and the recipients.

A phase I/II study of recombinant human interleukin-12 in patients with chronic hepatitis B

BACKGROUND/AIMS

Interleukin-12 (IL-12) may be active against hepatitis B virus (HBV). The objective of the study was to assess the tolerability, activity, pharmacokinetics, and pharmacodynamics of three dose levels (0.03 microg/kg b.w., n=15; 0.25 microg/kg b.w., n=15; 0.50 microg/kg b.w., n=16) of recombinant human (rHu) IL-12 given s.c. once a week for 12 consecutive weeks.

METHODS

Forty-six patients with chronic hepatitis B, HBV DNA positivity and aminotransferase elevation were included in a multicenter prospective randomized phase I/II study.

RESULTS

Compared with the baseline, HBV DNA levels had decreased significantly at the end of rHuIL-12 treatment and after the 12-week follow-up period (p<0.001). The response to rHuIL-12 treatment was dose-dependent: at the end of the study HBV DNA clearance was greater in patients treated with 0.50 microg/kg b.w. (25%) or with 0.25 microg/kg b.w. (13%) compared with those given 0.03 microg/kg b.w. (7%). Moreover, HBeAg became undetectable at the end of follow-up in five of the patients given the 0.25microg/kg (2/15) or the 0.50 microg/kg (3/16) dose. The drug pharmacology showed that IL-12 had an estimated half-life of 30 h with levels remaining detectable for more than 48 h after rHuIL-12 administration. The serum levels of IL-12, interferon-gamma, IL-10, neopterin and beta2-microglobulin as well as the area under the curve (AUC) were rHuIL-12 dose-related. Side effects were observed more frequently with higher doses, including moderate decreases in lymphocyte and neutrophil counts; three patients withdrew prematurely from treatment. The local reaction observed at the injection site was unrelated to the drug dose. Only one patient showed detectable antibody levels to rHuIL-12 without clinical impact.

CONCLUSIONS

Treatment with rHuIL-12 at the doses investigated is safe and tolerable, and appears to be active against HBV in patients with chronic hepatitis B.

Retreatment of chronic hepatitis B e antigen-positive patients with recombinant interferon alfa-2a. The European Concerted Action on Viral Hepatitis (EUROHEP)

Fifty-seven patients with chronic hepatitis B, hepatitis B virus (HBV) e antigen (HBeAg) and HBV DNA positivity, and aminotransferase elevation despite a previous course of any type of adequate interferon alfa (IFN-alpha) therapy were included in a multicenter prospective randomized controlled trial. The objective of the study was to compare a second course of IFN-alpha therapy (9 million units [MU] of IFN-alpha-2a, Roferon-A, thrice weekly for 6 months) versus no therapy in terms of loss of HBV DNA and HBeAg. At the end of the study, a sustained clearance of HBV DNA and HBeAg was observed in 9 of the 27 (33.3%) patients who had received retreatment with IFN-alpha compared with 3/30 (10%) patients who spontaneously cleared these markers in the untreated control group (chi2 = 4.66, P =.031; odds ratio: 4.5, 95%; confidence interval: 1.1-18.9). None of the responders lost HBsAg. Patients retreated with IFN-alpha were more likely to have biochemical remission in association with HBV clearance (5/27, 18.5%) compared with untreated patients (1/30, 3. 3%; Fisher's exact test P =.09 ). Histological improvement in the liver necroinflammatory activity was observed among sustained responders to IFN-alpha retreatment, consisting of regression of the portal and periportal inflammation and of the piecemeal necrosis; there was no change in the degree of liver fibrosis. Side effects were similar to those previously reported during IFN-alpha treatment; these were mild and reversible on IFN-alpha discontinuation. None of the baseline features were associated with response by Cox's regression analysis. In summary, viremic patients with chronic HBeAg-positive hepatitis may experience disease remission following retreatment with IFN-alpha. Thus, retreatment with IFN-alpha may be considered a therapeutic option.

The long-term effect of treatment with interferon-alpha 2a in chronic hepatitis B. The Long-Term Follow-up Investigator Group. The European Study Group on Viral Hepatitis (EUROHEP). Executive Team on Anti-Viral Treatment

This study was performed to evaluate the long-term effects of interferon-alpha 2a (IFN-alpha 2a) vs no treatment in patients with chronic hepatitis B and to determine whether viral clearance, following therapy or occurring spontaneously, was sustained. Patients originating from three previously published multicentre, randomized, controlled trials were analysed. Information about survival and response during long-term follow-up was available in 340 (73%) and 308 (66%) of 469 randomized patients respectively. Response to therapy (viral clearance) was defined as: loss of hepatitis B virus (HBV) DNA and loss of hepatitis B e antigen (HBeAg) and improvement in alanine aminotransferase level. Scheduled treatment-free follow-up was 12 months in all studies. Median long-term follow-up time after inclusion in the individual studies was 4.7 years (range: 0.2-7.5 years). Viral clearance after IFN-alpha 2a, or occurring spontaneously, was sustained in 70 out of 80 evaluable patients (88%) who were responders at the end of the original trials and 21 (30%) lost hepatitis B surface antigen (HBsAg). A total of 80 patients received (re)treatment during the long-term follow-up period and 33% of them responded, irrespective of previous treatment category. Overall response rate was not significantly affected by gender, sexual inclination or ethnic origin. Durability of response did not depend upon ethnic origin or presence of cirrhosis. At the end of the original trial periods, 253 patients were histologically evaluated and 22 (9%) had histologically confirmed progression to cirrhosis. During long-term follow-up an additional five patients developed cirrhosis. Hepatocellular carcinoma developed in three patients (1%): in one patient during the follow-up period of the original trial and in two patients (one untreated) during the long-term follow-up period. Ten of 25 deaths were liver-related (hepatocellular carcinoma in three, gastrointestinal bleeding in two and liver failure in five). The distribution of clinical events (progression to cirrhosis, hepatocellular carcinoma and liver-related deaths) was unrelated to original treatment category and response to treatment. Hence, 90% of responding patients will, irrespective of treatment category, have a sustained response. At least 30% of responding patients will eventually lose HBsAg. For a number of reasons, the present patient population and observation period are insufficient to establish a presumed beneficial effect of IFN-alpha 2a on disease progression and survival.

Relation between treatment efficacy and cumulative dose of alpha interferon in chronic hepatitis B. European Concerted Action on Viral Hepatitis (Eurohep)

BACKGROUND/AIMS

Alpha interferon (IFN) is an established treatment of chronic hepatitis B. The effect has been shown to be dose related, recommended dose regimens being associated with a doubling of the spontaneous, baseline HBeAg to anti-HBe seroconversion rate. However, the efficacy of IFN treatment in relation to the dose of IFN actually received remains to be established. The aim of this study was to estimate the relative efficacy of IFN as a function of the cumulative IFN dose. In addition we determined if and when a patient returns to his baseline chance of seroconversion after stopping IFN therapy.

MATERIALS AND METHODS

Individual patient data from 10 clinical controlled trials were available for the present analysis, in all, 746 patients, of whom 491 received IFN and 255 were untreated controls. The data were analyzed performing a time-dependent Cox regression analysis of the relative efficacy of IFN using the cumulative IFN dose administered up to any given time during the observation period and the time after termination of therapy as explanatory variables.

RESULTS

In the proposed model, the chance of HBeAg disappearance for a treated patient relative to no therapy was estimated to 2.1 at a cumulative dose of 100 MU and leveled out at about 2.8 at a cumulative dose of 500 MU. The effect of IFN was shown to decay rapidly after discontinuation and after 3 months a patient could be considered to be back to his baseline chance of HBeAg disappearance. These findings show that IFN administered at a dose of 15-30 MU/week should be considered effective (relative efficacy approximately 2) already after 1-2 months of treatment.

CONCLUSIONS

The present findings do not lend any support to the concept that IFN treatment becomes less effective when a certain total dose of IFN has been administered or that the treatment effect reaches beyond 3 months after stopping IFN.

Combination low-dose lymphoblastoid interferon and thymosin alpha 1 therapy in the treatment of chronic hepatitis B

This open label study was initiated to assess the safety and efficacy of lymphoblastoid interferon-alpha (IFN-alpha) and thymosin alpha 1 (T alpha 1) in the treatment of 11 patients with chronic hepatitis B, who had failed to respond to standard IFN-alpha 2b therapy, and in four interferon naive patients. These fifteen hepatitis B surface antigen (HBsAg) positive and serum hepatitis B virus (HBV) DNA positive patients were given T alpha 1 (1 mg) subcutaneously (s.c.) on 4 consecutive days. Low-dose lymphoblastoid IFN-alpha (3 MU) was administered intramuscularly (i.m.) on the fourth day. Beginning with the second and for the subsequent 25 weeks, patients self-administered T alpha 1 twice weekly in the morning followed, 12 h later, by 3 million units (MU) lymphoblastoid IFN-alpha. Patients were followed-up for 12 months. Nine (60%) of the 15 patients, including six (55%) of the 11 patients previously treated with IFN-alpha 2b, responded by losing serum HBV DNA and normalizing alanine aminotransferase (ALT) values. Six of the nine responders seroconverted to HBsAg negativity. Significant improvements in the Knodell histological activity index were observed in the responders and no significant adverse effects were observed. Combination low-dose lymphoblastoid IFN-alpha and T alpha 1 treatment may provide a safe and potentially effective therapeutic approach in chronic hepatitis B. These results require confirmation in future randomized controlled studies.

Comparison of four methods for quantitative measurement of hepatitis B viral DNA

AIMS/METHODS

Four assays for measuring HBV-DNA quantitatively have been compared with regard to sensitivity, precision and linearity. The methods were 125I-labelled solution hybridisation assay (liquid hybridisation, Abbott), an ELISA-based chemiluminescent RNA-DNA hybrid assay (RNA-DNA, Digene), a chemiluminescent branching oligonucleotide assay (bDNA, Chiron) and a membrane hybridisation assay using slot-blot equipment (slot blot).

RESULTS

The bDNA assay was linear over three orders of magnitude and was the most sensitive assay, being approximately ten times more sensitive than the other assays, so that samples negative on RNA-DNA, liquid hybridisation and slot blot gave quantifiable results on bDNA. Furthermore, intra- and inter-assay variability showed that the bDNA and liquid hybridisation assays had the greatest precision, with coefficients of variation of 6.6% to 11.5% and 2.3% to 10.5%, respectively. However, the nominated amounts of HBV DNA in the standards (from all assays) were not reproducible in the other assays, such that amounts measured with bDNA would give values approximately twice that of RNA-DNA and 60 times that of liquid hybridisation.

CONCLUSIONS

The recently developed bDNA assay has advantages compared with the other assays in quantitating samples with low levels of virus present. In addition, since the assays vary considerably by a number of criteria, the method of measurement should always be reported.

Interferon-alpha-2a. A review of its pharmacological properties and therapeutic use in the management of viral hepatitis

Interferon-alpha-2a is a recombinant interferon with antiviral, antitumour and immunomodulatory properties. Clinical studies have demonstrated that the drug offers therapeutic benefit in patients with some forms of chronic viral hepatitis. Remission, as measured by clearance of viral DNA and hepatitis B 'e' antigen (HBeAg), and normalisation of serum alanine aminotransferase levels, is observed in approximately 30 to 45% of patients with chronic hepatitis B receiving interferon-alpha-2a (2.5 to 18MU administered 3 times/week); about 5 to 15% of untreated controls remit spontaneously every year. Complete recovery [with loss of hepatitis B surface antigen (HBsAg)] is usually noted in < 20% of treated individuals. Similar response rates have been reported in the relatively small number of children evaluated to date. Although numerous studies have shown that interferon-alpha-2a (at various dosages) induces biochemical amelioration of chronic hepatitis C in approximately 50 to 75% of patients, relapse is common. Thus, long term remission may only be observed in about 15 to 30% of treated patients. On the other hand, this disorder remits spontaneously in only a few patients. The role of interferon-alpha-2a in the treatment of chronic hepatitis D remains unclear. Although preliminary data suggest it may be beneficial, cessation of therapy is generally followed by relapse. As with other types of interferons, most patients receiving interferon-alpha-2a experience an 'influenza-like' syndrome, which tends to diminish with continuing therapy. Other effects such as fatigue, lethargy, anorexia and weight loss are usually dose-limiting. Serum neutralising antibodies develop in approximately 10 to 20% of treated patients. Thus, although response rates are less than optimal, interferon-alpha-2a is a drug of first choice amongst the limited therapeutic options available for the management of well-compensated chronic viral hepatitis B or C.