Efficacy of prolonged interferon-alpha treatment in chronic hepatitis B patients with HBeAb: comparison between 6 and 12 months of therapy

Systematic review of the literature on comparative effectiveness of antiviral treatments for chronic hepatitis B infection

OBJECTIVES

To evaluate the comparative effectiveness of antiviral drugs in adults with chronic hepatitis B monoinfection for evidence-based decision-making.

METHODS

A systematic review of randomized controlled clinical trials (RCTs) published in English. Results after interferon and nucleos(t)ides analog therapies were synthesized with random-effects meta-analyses and number needed to treat (NNT).

RESULTS

Despite sustained improvements in selected biomarkers, no one drug regimen improved all intermediate outcomes. In 16 underpowered RCTs, drug treatments did not reduce mortality, liver cancer, or cirrhosis. Sustained HBV DNA clearance was achieved in one patient when two were treated with adefovir (NNT from 1 RCT=2 95%CI 1;2) or interferon alpha-2b (NNT from 2 RCTs=2 95%CI 2;4), 13 with lamivudine (NNT from 1 RCT=13 95%CI 7;1000), and 11 with peginterferon alpha-2a vs. lamivudine (NNT from 1 RCT=11 95%CI 7;25). Sustained HBeAg seroconversion was achieved in one patient when eight were treated with interferon alpha-2b (NNT from 2 RCTs=8 95%CI 5;33) or 10--with peginterferon alpha-2b vs. interferon alpha-2b (NNT from 1 RCT=10 95%CI 5;1000). Greater benefits and safety after entecavir vs. lamivudine or pegylated interferon alpha-2b vs. interferon alpha-2b require future investigation of clinical outcomes. Adverse events were common and more frequent after interferon. Treatment utilization for adverse effects is unknown.

CONCLUSIONS

Individual clinical decisions should rely on comparative effectiveness and absolute rates of intermediate outcomes and adverse events. Future research should clarify the relationship of intermediate and clinical outcomes and cost-effectiveness of drugs for evidence-based policy and clinical decisions.

Occult hepatitis B virus and hepatitis C virus infections

Occult HBV infection is a well-recognised clinical entity characterised by the detection of HBV-DNA in serum and/or in liver in the absence of detectable hepatitis B surface antigen (HBsAg). Occult HBV infection has been described not only in patients who have resolved an acute or chronic HBV infection but also in patients without any serological markers of a past HBV infection. Occult HBV infection in patients with chronic HCV infection may induce more severe liver disease and lower response rate to interferon treatment. The existence of occult HCV infections has been also reported more recently. Occult HCV infection is characterised by the presence of HCV-RNA in liver and peripheral blood mononuclear cells in the absence of detectable serum HCV-RNA. Occult HCV infection may occur under two different clinical situations: in hepatitis C antibody-(anti-HCV) negative and serum HCV-RNA-negative patients with abnormal liver function tests and in anti-HCV-positive patients who have no detectable serum HCV-RNA and who have normal liver enzymes. The clinical relevance of occult HCV infections is still under investigation.

Treatment options in HBV

The available evidence on interferon-alpha (IFN) treatment for chronic hepatitis B is sufficient to conclude that in patients with HBeAg positive chronic hepatitis, standard IFN therapy significantly improves clearance of HBeAg (number needed to treat [NNT] = 4), loss of HBV-DNA (NNT = 4) and clearance of HBsAg (NNT = 18). HBeAg positive patients with normal or slightly raised ALT should be treated only if there is histological evidence of progressive disease. In patients with HBeAg negative chronic hepatitis, less than 20% of subjects who have achieved an end-of-treatment virological response after a course of standard IFN maintain a sustained virological response in the long-term. IFN treatment could help to delay or prevent disease decompensation and liver-related deaths but further large studies are needed. Lamivudine is effective at reducing, and sometimes clearing, HBV replication in heavily immunosuppressed patients and can be safely administered to patients with advanced liver disease. Lamivudine should be continued over an undefined extended period of time, with a switch from lamivudine to adefovir if there is an HBV-DNA breakthrough under therapy. Adefovir, excluding cost, is preferable to lamivudine as a first-choice because there is less chance of inducing resistance. The long-term benefit of lamivudine and adefovir and the role of combinations is under investigation.

Personal view: the management of chronic hepatitis B infection

There are two new nucleoside analogues available for the management of chronic hepatitis B, adefovir and entecavir, and several more in development. In addition, pegylated interferon has become available. Large-scale population studies have re-emphasized the significance of viral load in predicting a poor outcome over the longer term. These new developments have prompted a reassessment of the indications and objectives of therapy for chronic hepatitis B. Hepatitis B virus deoxyribonucleic acid, rather than alanine aminotransferase should be the prime indication for therapy. Hepatitis B e antigen seroconversion can be achieved in 30-40% of treated patients whatever agent is used. However, it takes longer for nucleoside analogues to achieve the same seroconversion rates as interferon. In anti-HBe-positive disease long-term therapy is required for most patients because the relapse rate after withdrawal of therapy is very high, irrespective of the agent used. Viral resistance limits the use of lamivudine, and to a lesser extent adefovir. Resistance to entecavir has so far only been described in pre-existing lamivudine resistance. Although therapy with combinations of nucleoside analogues has not been investigated to any extent, this is the only way to reduce the emergence or resistance, and studies are urgently needed.

Chinese herbal medicine and interferon in the treatment of chronic hepatitis B: a meta-analysis of randomized, controlled trials

OBJECTIVES

This meta-analysis was conducted to examine the effectiveness of Chinese herbal medicine (either alone or with interferon alfa) in treating chronic hepatitis B.

METHODS

We searched the TCMLARS, AMED, CISCOM, EMBASE, MEDLINE, and Cochrane Collaboration databases and then hand-searched the articles' bibliographies.

RESULTS

Chinese herbal medicine significantly increased seroreversion of HBsAg and was equivalent to interferon alfa in seroreversion of HBeAg and hepatitis B virus (HBV) DNA; Chinese herbal medicine combined with interferon alfa significantly increased seroreversion of HBsAg, HBeAg, and HBV DNA. The Chinese herbal medicine active component bufotoxin combined with interferon alfa significantly increased HBeAg and HBV DNA seroreversion. The Chinese herbal medicine active component kurorinone was equivalent to interferon alfa in seroreversion of HBeAg and HBV DNA.

CONCLUSIONS

Although the quality of existing studies was poor, these data suggest that further trials of Chinese Herbal Medicine and interferon in chronic hepatitis B infection are justified.

Efficacy of lamivudine in HBeAg-negative chronic hepatitis B

Hepatitis B e antigen (HBeAg)-negative chronic hepatitis B results from infection with hepatitis B virus mutants unable to produce HBeAg. It accounts for 7-30% of patients with chronic hepatitis B virus (HBV) worldwide, with the highest rates reported for Mediterranean Europe and Asia. Interferon (IFN) is currently the only approved therapy for these patients, but it has an unfavorable tolerance profile and limited efficacy. Studies show that responses to IFN are lower in HBeAg-negative than in HBeAg-positive patients; joint HBV DNA loss/ALT normalization is obtained in 38-59% of HBeAg-negative patients treated for 4-24 months with a high rate of virological relapse (54-87%), at 6-24 months posttreatment. Lamivudine is a nucleoside analogue with potent antiviral properties against HBV. Studies show that response rates in HBeAg-negative and HBeAg-positive patients are equivalent. After 12 months of treatment, 65-96% of HBeAg-negative patients have joint HBV DNA loss/ALT normalization, although 48-74% of patients relapse within 1 year posttreatment. 60% of patients have histological improvement after 12 months of treatment. Lamivudine is well tolerated with a safety profile equivalent to that of placebo. The incidence of YMDD variants increases with extended lamivudine treatment, present in up to 57-64% of patients after 2 years. Their clinical impact is unclear; some studies show breakthrough infection associated with their emergence, whereas other studies show maintained response to lamivudine. Lamivudine has benefits over IFN in its safety and efficacy profile in this patient group. Extended lamivudine treatment beyond 2 years is an option, but further investigation is required to define stopping criteria and the impact of YMDD variants.

Molecular analysis of hepatitis B virus DNA in serum and peripheral blood mononuclear cells from hepatitis B surface antigen-negative cases

We have analyzed the molecular bases of the persistence of hepatitis B virus (HBV) DNA in serum and peripheral blood mononuclear cells (PBMC) in the absence of detectable hepatitis B surface antigen (HBsAg) in hemodialysis patients and dialysis-unit staff members who had suffered acute hepatitis B that resolved previously. HBV DNA was found in both compartments by polymerase chain reaction (PCR) using primers of the pre-S/S region. Viral DNA was transcriptionally active in PBMC, because the covalently closed circular (ccc) HBV DNA, the template for the viral RNA transcription, was detected in 47% of the samples. Furthermore, all PBMC had HBV RNA. HBsAg-negative cases had statistically lower levels of HBV DNA in serum and PBMC than a control group of chronic HBsAg carriers. We have also studied the presence of immune complexes and the existence of mutations in the pre-S/S gene to explain the lack of detection of HBsAg in these cases. No serum HBsAg/hepatitis B surface antigen antibody (anti-HBs) immune complexes or mutations in the "a determinant of the S gene were found. However, we have observed that all HBsAg-negative cases were infected by a mixture of the wild-type virus and a deletion mutant in the pre-S1 region. This deletion (amino acids 58-118) affects the S gene promoter, and previous in vitro studies have shown that it produces a reduction of the HBsAg synthesis. In conclusion, this work shows that the lack of detection of HBsAg in the presence of low viral levels of replication may be caused by the existence of viral genomes harboring deletions in the pre-S1 region that affect the S promoter.

Mutations of the core promoter and response to interferon treatment in chronic replicative hepatitis B

In chronic replicative hepatitis B the significance of mutations in the basic core promoter (BCP), core upstream regulatory sequences (CURS) and negative regulatory element (NRE) for response to interferon (IFN) is unknown. A sequence analysis of the NRE, CURS, BCP, and precore region was performed from sera of 96 patients with chronic replicative hepatitis B (64 hepatitis B e antigen [HBeAg]-positive patients and 32 HBeAg-negative patients) treated with alfa-IFN (IFN-alpha). The overall sustained response (SR) rate to IFN was 30% with no significant difference between HBeAg-positive and HBeAg-negative patients. IFN responsiveness correlated to hepatitis B virus (HBV)-DNA levels, hepatitis B surface antigen (HBsAg) levels, the number of mutations in the complete BCP, especially nucleotide (nt) region 1753 to 1766 and mutations at nt 1762 and 1764. In HBeAg-positive hepatitis, SR to IFN was associated with a high number of mutations in the BCP (P <.04) and nucleotide region 1753 to 1766 (P <.015) as well as mutations at nucleotide 1764 (P <.007). In HBeAg-negative hepatitis, SR to IFN correlated with a low number of mutations in the BCP (P <.04) and nucleotide region 1753 to 1766 (P <.02) and a wild-type sequence at nt 1764 (P <.003). Prediction of IFN response was possible on the basis of nt 1764 in 77% of HBeAg-positive patients and 78% of HBeAg-negative patients. IFN response did not correlate with the occurrence of the 1896 mutation, mutations in the CURS or NRE, disease duration, ethnic origin of the patient, alanine transaminase (ALT) levels and HBV genotype. Our data suggest that HBV genome mutations located within the BCP are determinants of a response to IFN therapy.

Pilot study of combination therapy with ribavirin and interferon alfa for the retreatment of chronic hepatitis B e antibody-positive patients

Twenty-four patients with chronic hepatitis B virus (HBV), antibody to hepatitis B e antigen (anti-HBe), HBV DNA positivity, and alanine transaminase (ALT) elevation who failed previous interferon alfa (IFN-alpha) therapy were included in a pilot study of combination therapy with ribavirin and IFN-alpha. The patients received daily oral ribavirin (1,000-1,200 mg according to body weight) plus 5 million units (MU) IFN-alpha2b three times a week for 12 months and were followed-up for 12 months. The median viremia level decreased significantly at the end of treatment (1.2 x 10(3) copies/mL) and follow-up (4.0 x 10(2) copies/mL) compared with the baseline (3.0 x 10(6) copies/mL; P <.05). After 12 months, 8 of 24 (33%) patients had cleared HBV DNA and 12 (50%) had normal ALT levels. At the end of the study virological and biochemical response was 50% and 21%, respectively. Thus, virological and biochemical response sustained in 5 of 24 (21%) patients retreated with ribavirin and IFN-alpha; none of them lost hepatitis B surface antigen (HBsAg). Liver histology improved in 2 of 4 sustained responders but in none of the 12 nonresponders with paired biopsies (P =.05). The response was independent of dose and duration of previous treatment, viral load, or the distribution of HBV precore wild-type/mutant variants. However, sustained responders had significantly higher necroinflammation (P =.036) and fibrosis (P =.007) scores. IFN-alpha-related side effects were mild and reversible on discontinuation. In 4 (17%) patients who suffered nausea and diarrhea the ribavirin dosage was reduced by 50% after 1 month of therapy and finally discontinued in all of them. No patient had liver disease decompensation. In summary, combination therapy with ribavirin and IFN-alpha may be efficacious to treat viremic anti-HBe-positive patients with chronic hepatitis B who have failed previous IFN therapy.

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.