Adefovir dipivoxil for the treatment of hepatitis B e antigen-negative chronic hepatitis B

Nephrotoxicity, including acquired Fanconi's syndrome, caused by adefovir dipivoxil - is there a safe dose?

WHAT IS KNOWN AND OBJECTIVE

Adefovir dipivoxil (ADV) is an oral bioavailable prodrug of adefovir that possesses potent in vitro activity against hepadnaviruses, retroviruses and herpes viruses. ADV is excreted unchanged in the urine through glomerular filtration and tubular secretion and is known to be nephrotoxic at doses of 60mg daily and above. Thus, the long-term safety of ADV, particularly nephrotoxicity, is a major concern. Our objective is to comment on the nephrotoxcicity of low-dose (10mg daily) ADV through a case report.

COMMENT

The clinical features of nephrotoxicity because of ADV are described. A case report of acquired Fanconi's syndrome in a chronic hepatitis B patient treated with ADV 10mg daily is used to illustrate several key aspects.

WHAT IS NEW AND CONCLUSION

Adefovir dipivoxil can be nephrotoxic at conventional dosage and therefore, patients treated with long-term ADV should have regular monitoring of renal function, and calcium and phosphate levels.

Recent advances in the treatment of chronic hepatitis B

INTRODUCTION

At present, two strategies exist for the treatment of chronic hepatitis B (CHB): i) standard or pegylated interferon alpha (IFN) with mainly immune modulatory effects; and ii) nucleos(t)ide analogues (NA) with direct antiviral effects. The optimal treatment for an individual patient remains controversial.

AREAS COVERED

The treatment efficacy and prediction of response to antiviral agents for chronic hepatitis B are reviewed and discussed.

EXPERT OPINION

The rates of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) loss or seroconversion are continuously increasing in CHB patients after stopping a finite course of IFN, whereas long-term NA therapy is usually required to improve the adverse outcomes of CHB. Lower baseline HBV DNA level is a strong predictor for both sustained viral suppression and HBeAg seroconversion in patients receiving IFN-based as well as NAs therapy. In addition, HBeAg-positive patients with genotype A or B infection have better responses to IFN-based therapy than those with genotypes C or D infection. Furthermore, on-treatment predictors such as declines of serum HBV DNA, HBsAg and HBeAg levels may be helpful in making decisions of subsequent therapy. Regarding the association of host genetic factors with responses to antiviral therapy, current evidence is limited.

Tenofovir disoproxil fumarate for the treatment of chronic hepatitis B monoinfection

INTRODUCTION

Resistance in nucleoside/nucleotide analog (NA) therapy has always been a challenge in the management of chronic hepatitis B (CHB).

CLINICAL STUDIES

Initially developed for the treatment of HIV infection, early in vitro and clinical observational studies had shown tenofovir disoproxil fumarate (TDF) to be also active against CHB. Recent data from various multicenter phase 3 and 4 clinical trials have confirmed TDF being able to achieve a high viral suppression in both NA-naive and -experienced CHB patients. There are also emerging data on the efficacy of TDF in decompensated CHB. Although there are in vitro studies identifying certain mutation loci associated with a reduced susceptibility to TDF, there have so far been no reports of virologic resistance to TDF in clinical studies. TDF has a favorable safety profile, although more long-term data would be needed.

CONCLUSIONS

TDF has the makings of an "ideal" first-line drug for the treatment of CHB.

Drug safety evaluation of adefovir in HBV infection

INTRODUCTION

Several nucleos(t)ide analogs (NUC) are available for the management of patients with chronic hepatitis B (CHB). In most patients, NUC need to be administered on a long-term basis, thus increasing the risk of adverse effects. Adefovir dipivoxil (ADV), the first nucloeotide analog developed to treat CHB, may indeed cause nephrotoxicity.

AREAS COVERED

The pharmacokinetic mechanism of action, potential mechanism of renal damage and long-term safety profile of ADV in CHB patients have been reported. The current monitoring modalities, together with dosage adjustments, treatment of patients with ADV-related kidney impairment and the therapeutic algorithm in place at the authors' Liver Center are also summarized. Although, in short-term clinical trials, a daily dose of 10 mg of ADV was safe owing to a low rate of negligible nephrotoxic effects, the same dose may be associated with a usually reversible, proximal renal tubular toxicity as reflected by hypophosphatemia and elevated creatinine levels. Occasionally, Fanconi syndrome occurred in ADV-treated patients.

EXPERT OPINION

Renal function at baseline and during treatment should be carefully assessed in all patients receiving ADV to adjust the dose according to creatinine clearance, aimed to prevent or minimize nephrotoxicity.

CuBr catalyzed C-N cross coupling reaction of purines and diaryliodonium salts to 9-arylpurines

CuBr was found to be an efficient catalyst for the C-N cross coupling reaction of purine and diaryliodonium salts. 9-Arylpurines were synthesized in excellent yields with short reaction times (2.5 h). The method represents an alternative to the synthesis of 9-arylpurines via Cu(II) catalyzed C-N coupling reaction with arylboronic acids as arylating agents.

Future aspects of therapy for hepatitis B virus infection: value of surrogate markers, innovative therapy, and global collaboration

Both optimism and frustration exist regarding therapy for patients with chronic hepatitis B virus infection. Due to the recent advent of several drugs with potent antiviral capacities and comparatively low rates of adverse effects, considerable optimism has developed regarding the treatment of these patients. Chronic hepatitis B is now a treatable disease, and suppression of hepatitis B virus replication, normalization of alanine aminotransferase levels, seronegativity/seroconversion of hepatitis B e antigen and hepatitis B surface antigen, and decreased hepatic inflammation and liver fibrosis have been documented in chronic hepatitis B virus-infected patients treated with antiviral therapy. In contrast, many frustrations regarding antiviral therapy for chronic hepatitis B have arisen, because the disease, although treatable, is not curable. The present regimens of antiviral therapy modulate some intermediate parameters or so-called surrogate markers in chronic hepatitis B virus-infected patients, but usually fail to improve all intermediate parameters or ultimate clinical outcomes. In addition, major concerns remain about the applicability and use of antiviral drugs in developing and resource-constrained countries in which healthcare delivery systems do not support the proper use of antiviral therapy. New and more effective therapeutic regimens for chronic hepatitis B patients are needed that take into account potential surrogate markers of treatment outcomes and allow for effective collaboration between resource-constrained and advanced countries.

Virological breakthrough and resistance in patients with chronic hepatitis B receiving nucleos(t)ide analogues in clinical practice

Virological breakthrough (VBT) is the first manifestation of antiviral drug resistance during nucleos(t)ide analogue (NUC) treatment of chronic hepatitis B (CHB), but not all VBTs are due to drug resistance. This study sought to determine the incidence of VBT and genotypic resistance (GR) in patients with CHB who were receiving NUCs in clinical practice. Records of patients with CHB who were receiving NUCs were reviewed. All patients with VBT were tested for drug resistance mutations. Of 148 patients included, 73% were men and mean age was 44.9 years. During a mean follow-up of 37.5 ± 20.1 months, 39 (26%) patients had at least 1 VBT. Of these 39 patients, 15 (38%) were not confirmed to have VBT on retesting, and 10 of these 15 had no evidence of GR. The cumulative probability of VBT, confirmed VBT, and GR at 5 years was 46.1%, 29.7%, and 33.9%, respectively. In multivariate analysis, failure to achieve undetectable hepatitis B virus (HBV) DNA was the only factor significantly associated with VBT. Among the 10 patients who had VBT but no confirmed VBT or GR and who were maintained on the same medications, serum HBV DNA decreased in all 10, and nine had undetectable HBV DNA at a mean of 6.8 months after the VBT. Four patients had persistently undetectable HBV DNA, six had transient increase in HBV DNA during follow-up, and none had GR.

CONCLUSION

VBT was common in patients with CHB receiving NUCs in clinical practice, but nearly 40% of the VBTs were not related to antiviral drug resistance. Counseling of patients with CHB on medication adherence and confirmation of VBT and/or GR can avoid unnecessary changes in antiviral medications.

Antiviral therapy in patients with hepatitis B virus-related cirrhosis

Antiviral therapy can lead to biochemical remission, histological improvement, and even complete reversibility of liver cirrhosis in patients with hepatitis B virus-related cirrhosis, thereby significantly reducing the incidence of hepatic decompensation, hepatocellular carcinoma and liver disease-related death. Interferon alpha is not contraindicated in compensated cirrhosis and can be used in finite treatment for 6 or 12 months. Long-term treatment with nucleoside/nucleotide analogues is recommended for both compensated and decompensated cirrhosis. Biochemical and virological changes should be carefully monitored during antiviral treatment to promptly find viral breakthrough and prevent hepatitis B recurrence and liver failure. In addition, hepatocellular carcinoma is required to be screened in all cirrhotic patients.

Association of intrahepatic cccDNA reduction with the improvement of liver histology in chronic hepatitis B patients receiving oral antiviral agents

Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is difficult to eradicate using current antiviral therapy. This study compares cccDNA reduction with relation to liver histology in nucleoside/nucleotide-naïve chronic hepatitis B patients receiving oral antiviral monotherapy (n=35), including entecavir (ETV, n=13), adefovir dipivoxil (ADV, n=22) or placebo (n=14). Serum HBV DNA, intrahepatic total HBV DNA and cccDNA are quantified. Histological hepatic examination is performed at baseline and at 48 weeks of treatment. Treatment with ETV or ADV shows significant median reduction in serum HBV DNA (-6.21 and -4.27 log(10) copies/mL) and intrahepatic total HBV DNA (-1.69 and -1.23 log(10) copies/cell). Intrahepatic cccDNA levels are reduced slightly in the ETV and the ADV groups, but do not differ statistically from the placebo group (-0.17 vs. -0.01 vs. 0.02 copies/cell). Only the level of intrahepatic cccDNA correlates with Knodell necroinflammation activity (r=0.527, P<0.001) and Ishak fibrosis severity (r=0.348, P=0.015) before treatment. Multivariate logistic regression analysis indicates that treatment-induced cccDNA reduction is associated with improved necroinflammation (P=0.041) and fibrosis (P=0.026). In conclusion, baseline intrahepatic cccDNA loads correlate with histologic activity. Although one-year ETV or ADV treatment is insufficient for cccDNA eradication, oral antiviral therapies may improve liver histology, probably by suppressing intrahepatic cccDNA.

Parallel decline of CD8+CD38+ lymphocytes and viremia in treated hepatitis B patients

AIM: To assess the peripheral T lymphocyte subsets in chronic hepatitis B virus (HBV) infection, and their dynamics in response to adefovir dipivoxil monotherapy.

METHODS: Proportions and absolute counts of peripheral natural killer cells, B cells, CD8+, CD4+, CD8+CD38+, CD8+CD28+ and CD4+CD28+ T cells were determined using three-color flow cytometry in chronic hepatitis B patients (n = 35), HBV carriers (n = 25) and healthy controls (n = 35). Adefovir dipivoxil was initiated in 17 chronic hepatitis B patients who were regularly followed for 72 wk, during which period the T cell subsets and serum viral load were measured at each follow-up point.

RESULTS: The peripheral CD4+ T cell counts and CD8+ T cell counts decreased in chronic HBV infection. In chronic hepatitis B patients, proportions of CD8+CD38+ T cells were 62.0% ± 14.7%, much higher than those of HBV carriers and healthy controls. In the 13 hepatitis B patients who were treated and responded to adefovir dipivoxil, proportions of CD8+CD38+ T cells decreased from 53.9% ± 18.4% pre-therapy to 20.1% ± 11.3% by week 72 (P < 0.001), concomitant with viral load decline (HBV DNA fell from 7.31 to 3 log copies/mL). CD8+ T cell counts also underwent an average increase of 218 cells/μL by the end of 72-wk treatment. In those who failed the therapy, the CD8+CD38+ T cell population had more fluctuations.

CONCLUSION: CD8+ T cells abnormally activated in chronic HBV infection can be partially reversed by antiviral therapy. HBV-associated immune activation may be a crucial part of the pathogenesis and a promising target of treatment.

Hepatitis B therapy

The goal of hepatitis B treatment is to prevent cirrhosis, liver decompensation and hepatocellular carcinoma. In clinical practice, treatment response is determined by suppression of serum HBV DNA levels, hepatitis B e antigen seroconversion to hepatitis B e antibody, hepatitis B surface antigen loss, normalization of alanine aminotransferase levels and improvement in liver histology. Patients with life-threatening liver disease, and those with high levels of HBV replication and active or advanced liver disease, should be treated. Other patients should be monitored so that treatment can be initiated when indicated. Currently, seven medications are approved for the treatment of hepatitis B: two formulations of interferon and five nucleos(t)ide analogues. Interferon is administered for a finite duration while nucleos(t)ide analogues are usually administered for many years. Antiviral drug resistance is a major limiting factor to the success of nucleos(t)ide analogue treatment; therefore, treatment should be initiated with drugs that have a high genetic barrier to resistance (that is, a low potential for drug resistance). In addition, treatment response should be closely monitored to detect virologic breakthroughs, and the importance of medication adherence should be emphasized. Management of patients with treatment failure should be tailored according to the type of treatment failure (lack of initial response versus virologic breakthrough), the treatment that the patient is receiving, history of prior treatment, and the pretreatment characteristics of both the patient and the disease.

[The efficacy of adefovir dipivoxil, entecavir and telbivudine for chronic hepatitis B treatment: a systematic review]

INTRODUCTION

Chronic hepatitis B is one of the most frequent infectious disease in the world and represents a serious problem of public health

METHODS

A systematic review of randomized clinical trials was conducted to evaluate the efficacy of the nucleoside/nucleotide analogues (adefovir, entecavir and telbivudine) used for the treatment of chronic hepatitis B. The databases PubMed and LILACS were consulted, among others

RESULTS

Twenty nine articles published between January/1970 to December/2009 were selected

CONCLUSIONS

All nucleoside/nucleotide analogues demonstrate upper or similar efficacy to lamivudine. The entecavir can be appropriate for patients with chronic hepatitis B, HBeAg positive and negative treatment-naive as alternative to lamivudine, considering its low potential of viral resistance. The addition of adefovir to lamivudine presented good results in lamivudine resistant patients. The use of entecavir and telbivudine in those patients presents risk of crossed resistance. TBV is one of the most recent antivirals available, but antiviral resistance already documented represents limitation to its use as therapeutic option to LAM. Adverse events of nucleoside/nucleotide analogues were similar in characteristics, gravity and incidence when compared to the lamivudina and placebo.

Fibrosis in chronic viral hepatitis

In the last years, several studies have been performed with the aim to evaluate the real impact of antiviral treatments on fibrosis progression in patients with chronic viral hepatitis. The main goal of therapy in patients with chronic hepatitis B is viral suppression. This outcome leads to an important improvement in both hepatic inflammation and fibrosis and reduces the HCC occurrence. An histological improvement has been largely demonstrated in patient treated with oral nucleoside and nucleotide analogs achieving the rate of 72% with entecavir and tenofovir. Similarly, in patients with chronic hepatitis C, sustained virologic response to interferon therapy is associated with regression of fibrosis and lower liver decompensation and HCC occurrence. In the next future further studies will assess the real impact of the new directly anti-viral agents on liver necroinflammation and fibrosis in chronic hepatitis C.

Initial virological response and viral mutation with adefovir dipivoxil added to ongoing Lamivudine therapy in Lamivudine-resistant chronic hepatitis B

BACKGROUND

Although adefovir dipivoxil (ADV) has been used for antiviral treatment of lamivudine (LAM)-resistant chronic hepatitis B (CHB) patients, the long-term efficacy of this treatment is not well understood. Initial virological response (IVR) has been reported to be an important factor in relation to the development of ADV-resistance.

AIMS

We therefore examined the factors associated with IVR and ADV mutation in these patients.

METHODS

Forty-nine LAM-resistant CHB patients with ADV add-on LAM therapy, 47% of whom were hepatitis B e-antigen (HBeAg)-positive with median treatment duration of 23 months, were enrolled in this study. Patients were classified into IVR and non-IVR groups on the basis of viral suppression status. Mutational analysis of the HBV polymerase/reverse transcriptase (rt) domain was performed by PCR-direct sequencing.

RESULTS

Serum HBV DNA was undetectable (<2.6 log10 copies/mL) in 67, 82, and 84% of patients at 24, 48, and 96 weeks, respectively, after ADV add-on LAM therapy. IVR was achieved in 82% of patients, and ALT normalized at week 24 in 90% of IVR and 78% of non-IVR patients. The lower pretreatment HBV DNA level and virus-containing mutations other than double mutation of rtL180M + rtM204V were significantly associated with IVR (P=0.002 and P=0.014, respectively). ADV-resistant mutations in the RT motif, reported previously, were not detected.

CONCLUSION

IVR is useful for predicting the antiviral efficacy of ADV and LAM combination therapy in LAM-resistant CHB.

The level of HBV DNA at month 12 is an important predictor of virological breakthrough during adefovir monotherapy in chronic hepatitis B patients with lamivudine resistance

BACKGROUND AND AIMS

The aim of this study was to determine the optimal time and HBV DNA levels during the treatment period for prediction of virological breakthrough (VBT) 3 years after adefovir monotherapy in chronic hepatitis B (CHB) patients with lamivudine resistance.

METHODS

We consecutively analyzed HBV DNA levels within 12 months in 210 lamivudine-resistant CHB patients treated with adefovir monotherapy for more than 36 months.

RESULTS

VBT, genotypic adefovir mutations, and virologic responses were observed in 52 (24.8%), 37 (17.6%), and 117 (55.7%) cases within 3 years of treatment, respectively. Using receiver-operating characteristic curve analysis, HBV DNA levels at month 12 had a greater power (AUROC, 0.839; 95% CI, 0.759-0.919; p<0.001) to predict VBT after 3 years of treatment. The best cut-off value of HBV DNA levels at month 12 for predicting VBT at 3 years of treatment was 200 IU/ml with a sensitivity and negative predictive value of 88.5 and 94.3%, respectively. Using this time and cut-off value, VBT had developed in six (5.7%) of the patients with HBV DNA levels<200 IU/ml (n=105) and 46 (43.8%) of the patients with HBV DNA levels≥200 IU/ml (n=105) at month 12 (p<0.001). Moreover, virological response or HBeAg seroconversion remained higher at 82.9 and 81.2%, respectively.

CONCLUSIONS

In patients who were switched to adefovir monotherapy as rescue therapy for lamivudine resistance before the introduction of current therapeutic guidelines, measurements of HBV DNA levels at month 12 should be performed to predict VBT. Early termination of adefovir monotherapy should be considered for patients who still have HBV DNA≥200 IU/ml (3 log10 copies/ml) at 12 months of treatment.

[Long-term therapy for chronic hepatitis B in HIV co-infected patients]

As human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are acquired through the same routes of contamination, the prevalence of HBV serological markers found in the HIV-infected population is approximately 7%. Liver-related mortality and morbidity is higher in HIV/HBV co-infected patients than in HBV mono-infected patients. Both viruses must be considered before a treatment decision is made. According to the European consensus conference on the treatment of chronic hepatitis B and C in HIV coinfected patients, treatment is based on whether there is an existing indication of anti- HIV therapy or not. In patients with no indication of anti-HIV therapy, drugs with dual anti-viral activity (lamivudine, entecavir, tenofovir disoproxil fumarate) should not be used due to the risk of developing HIV-resistance. Interferon or adefovir in combination with telbivudine are recommended. In patients with an indication of anti-HIV therapy, a backbone of highly active anti-retroviral therapy should include tenofovir in combination with lamivudine or emtricitabine. The same regimen is recommended in patients who develop lamivudine resistance.

A single-center, prospective and randomized controlled study: Can the prophylactic use of lamivudine prevent hepatitis B virus reactivation in hepatitis B s-antigen seropositive breast cancer patients during chemotherapy?

Over the past four decades, chemotherapy has played an important role in prolonging survival in breast cancer patients. However, it may also result in undesirable side effects such as hepatitis B virus (HBV) reactivation seen in this study. With the increasing use of chemotherapy paralleling the rise in breast cancer incidence, the occurrence of HBV reactivation is likely to further increase. Several strategies use lamivudine to deal with this problem. Initially, lamivudine had been used to treat patients who developed alanine transaminase elevation attributable to HBV reactivation during chemotherapy. However, using this strategy, fatal reactivation has also been reported. Later studies have suggested that prophylactic lamivudine significantly reduces HBV reactivation and its associated morbidity. However, these studies were based mainly on patients with lymphoma, whereas studies on breast cancer patients were few. Moreover, these studies were retrospective. Recently, a prospective study has recommended that deferred preemptive lamivudine could be a comparable alternative to the prophylactic strategy. However, it was not a randomized controlled study. In this study, it was examined the efficacy of the prophylactic strategy in hepatitis B s-antigen seropositive breast cancer patients during chemotherapy using a prospective, randomized controlled study. Two groups were studied. One group consisted of 21 patients who were treated with prophylactic lamivudine, the other group consisted of 21 patients who were not treated with prophylactic lamivudine. The results showed that the prophylactic lamivudine strategy significantly decreased the incidence of HBV reactivation (0 vs. 28.6%, P = 0.021). It was conclude that the prophylactic lamivudine strategy significantly reduces the incidence of HBV reactivation for hepatitis B s-antigen seropositive breast cancer undergoing chemotherapy.

Comparison of the efficacy of tenofovir and adefovir in the treatment of chronic hepatitis B: a systematic review

Chronic viral hepatitis B remains a global public health concern. Currently, several drugs, such as tenofovir and adefovir, are recommended for treatment of patients with chronic hepatitis B. tenofovir is a nucleoside analog with selective activity against hepatitis b virus and has been shown to be more potent in vitro than adefovir. But the results of trials comparing tenofovir and adefovir in the treatment of chronic hepatitis B were inconsistent. However, there was no systematic review on the comparison of the efficacy of tenofovir and adefovir in the treatment of chronic hepatitis B. To evaluate the comparison of the efficacy of tenofovir and adefovir in the treatment of chronic hepatitis B we conducted a systematic review and meta-analysis of clinical trials. We searched PUBMED, Web of Science, EMBASE, CNKI, VIP database, WANFANG database, the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Review. Finally six studies were left for analysis which involved 910 patients in total, of whom 576 were included in tenofovir groups and 334 were included in adefovir groups. At the end of 48-week treatment, tenofovir was superior to adefovir at the HBV-DNA suppression in patients[RR = 2.59; 95%CI(1.01-6.67), P = 0.05]. While there was no significant difference in the ALT normalization[RR = 1.15; 95%CI(0.96-1.37), P = 0.14], HBeAg seroconversion[RR = 1.32; 95%CI(1.00-1.75), P = 0.05] and HBsAg loss rate[RR = 1.19; 95%CI(0.74-1.91), P = 0.48]. More high-quality, well-designed, randomized controlled, multi-center trails are clearly needed to guide evolving standards of care for chronic hepatitis B.

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.

Review article: chronic hepatitis B - anti-viral or immunomodulatory therapy?

BACKGROUND

First-line treatment options for chronic hepatitis B (CHB) consist of nucleos(t)ide analogues with a high barrier to resistance (entecavir and tenofovir) or the immunomodulatory agent peginterferon (PEG-IFN). The optimal choice for individual patients remains controversial.

AIM

To review treatment options for CHB, with a focus on deciding between prolonged nucleos(t)ide analogue therapy or a finite course of PEG-IFN.

METHODS

A comprehensive literature search was undertaken.

RESULTS

Long-lasting, treatment-maintained suppression of hepatitis B virus (HBV) DNA without resistance is achievable in most patients by entecavir or tenofovir. A sustained off-treatment response is, however, unlikely and long-term therapy must be anticipated. PEG-IFN offers a higher rate of sustained response in a subgroup of patients, but is frequently complicated by side effects. Pre-treatment predictors of response, including HBV genotype, alanine aminotransferase and HBV DNA levels, aid in selecting patients for PEG-IFN therapy. Furthermore, on-treatment markers such as quantitative hepatitis B surface antigen may be applied to identify nonresponders early during the PEG-IFN treatment course, thereby preventing unnecessary treatment.

CONCLUSIONS

Both nucleos(t)ide analogues and PEG-IFN can be prescribed as first-line treatment options for CHB. However, PEG-IFN should only be considered for patients with a high chance of response based on pre-treatment and on-treatment factors.

A personalized approach to optimize hepatitis B treatment in treatment-naive patients

In a treatment-naive patient with chronic hepatitis B, a personalized approach allows treatment efficacy to be optimized. Firstly, the selection of good candidates for therapy is crucial. Patients with chronic active hepatitis B--with relatively low levels of HBV DNA replication (<10(9) copies/ml) and relatively high alanine aminotransferase (ALT) levels--are good candidates for therapy. By contrast, patients with chronic hepatitis B in the immunotolerance phase, who have high levels of HBV DNA and persistently normal ALT levels, as well as inactive hepatitis B surface antigen (HBsAg) carriers with low HBV DNA and normal ALT levels do not have an indication for therapy as they are poor responders. Secondly, the characteristics of the patient (for example, gender, age, immune status, general health status and comorbidities), the characteristics of the liver disease (for example, presence of cirrhosis and liver function) and the characteristics of the virus (for example, genotype) are important when assessing the chance of success and when choosing the best therapeutic strategy (nucleoside/nucleotide analogue or interferon). Thirdly, during therapy, the antiviral effect--assessed by decrease in HBV DNA level--allows an individualized response-guided approach. In addition, quantification of HBsAg after 3-6 months of interferon therapy appears to be a good predictor of sustained virological response after treatment and HBsAg clearance. Continuing interferon therapy until week 48 is justified in patients with a significant decrease in HBsAg. Ongoing and future studies will provide useful information regarding prolonging interferon therapy beyond 48 weeks in some patients in order to increase efficacy, and also regarding the role of combination therapy with interferon and potent nucleoside/nucleotide analogues, such as entecavir or tenofovir disoproxil fumarate.

Long-term nucleos(t)ide analogues therapy for adults with chronic hepatitis B reduces the risk of long-term complications: a meta-analysis

Background

The effect of antiviral therapy in chronic hepatitis B (CHB) on reducing the risk of long-term complications (LTCs) remains unclear so far. To study whether long-term nucleos(t)ide analogues therapy can reduce the risk of long-term complications.

Methods

We searched MEDLINE, EMBASE, OVID, the Cochrane Central Register of Controlled Trials. Relative risks (RRs) of long-term complications with or without treatment were studied. Also subgroup analyses including the status of drug-resistance, HBeAg and pre-existing compensated cirrhosis were done using relative risks of long-term complications either with or without treatment or among nucleos(t)ide analogues treatment groups.

Results

Six eligible studies (3644 patients in all) were included. Data showed the incidence of long-term complications in treatment groups was induced by 74%(RR:0.26, 95% CI: 0.15-0.47) compared with no treatment. Whether drug-resistant happened or not during the long-term therapy, the incidence of long-term complications was still significantly induced respectively by 45%(RR: 0.55,95%CI:0.40-0.76) and 78% (RR:0.22, 95%CI: 0.13-0.36). For both different status of HBeAg and pre-existing compensated cirrhosis, there was significant lower incidence of long-term complications in treatment groups compared with no treatment, too. Moreover, among the NA treatment groups, patients with drug-resistance had 2.64 times (RR:2.64, 95%CI: 1.58-4.41) higher chance of developing to long-term complications, and patients with pre-existing compensated cirrhosis also had 3.07 times (RR:3.07, 95%CI: 1.04-9.11) higher chance of developing to long-term complications.

Conclusions

Long-term nucleos(t)ide analogue therapy for adults with CHB prevents or delays the development of long-term complications including decompensated cirrhosis, CHB-related death or CHB-related HCC in patients with CHB. The patients who need take antiviral drugs should receive the antiviral therapy as soon as possible.

Safety and efficacy of entecavir for the treatment of chronic hepatitis B

Entecavir is a cyclopentyl deoxyguanosine analog that was approved for the treatment of the hepatitis B virus (HBV) in 2005. In Phase III trials, it showed potent HBV suppression with drops of 6- to 7-log copies/mL in HBV DNA at 1 year. In addition, rates of genotypic resistance in nucleos(t)ide-naïve patients are low, reaching only 1.2% after 6 years. Safety and efficacy have been established in compensated cirrhosis and HIV-coinfected patients. Studies in decompensated cirrhosis also show efficacy. Because of potent viral suppression and a large genetic barrier to resistance, entecavir is now a first-line choice in most HBV treatment guidelines and has become an integral part of the HBV treatment armamentarium.

Chronic viral hepatitis in kidney transplantation

Chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection in potential kidney transplant candidates-once considered absolute contraindications to kidney transplantation-no longer creates overt barriers to transplantation. Advances in the medical management of HBV and HCV infection have created opportunities for a substantial number of patients to be effectively treated with antiviral therapy before transplantation. For HBV infection, a number of new drugs enable clearance of the virus with minimal adverse effects and drug resistance. Pretransplantation antiviral therapy is advisable for patients with HCV infection, but adverse effects are common and viral eradication remains challenging. Regardless of viral clearance, pretransplant patients without bridging fibrosis (as confirmed by liver biopsy) or clinical stigmata of cirrhosis should be considered for kidney transplantation as survival is superior when compared to treatment with dialysis, and progression of liver disease is unlikely. For patients with advanced liver disease, simultaneous liver-kidney transplantation is an important consideration. These treatment advances further increase the burden of organ donor shortage; however, organs from deceased donors with chronic HBV or HCV infection could be efficiently allocated to certain individuals with a viral infection of the same type to increase the pool of available transplant organs.

Antiviral drugs for HBV liver disease

INTRODUCTION

Chronic hepatitis B (CHB) virus infection affects about 400 million people around the globe and is among the world's leading causes of death. The management of CHB has evolved rapidly, several therapeutic options are now available to prevent both progression of liver disease and anticipated liver morbidity and mortality.

AREAS COVERED

Current treatment modalities for CHB patients, together with suggestions from our own experience are summarized. The most relevant works published in recent years on pegylated interferon, nucleos(t)ides analogues (NUC) and the 2009 update of the American Association for the Study of Liver Diseases Practice Guidelines and the 2009 European Association for the Study of the Liver (EASL) Clinical Practice Guidelines on the management of chronic hepatitis B are discussed.

EXPERT OPINION

Pegylated interferon and NUC have advantages and limitations, as short-term interferon treatment induces a sustained virological response in a third of patients, whereas long-term suppressive therapy by NUC rapidly inhibits HBV replication in most patients but drug resistance and safety in the long-term will remain the most important unresolved questions. Careful evaluation of patient history, staging of liver disease and virological factors should guide the start of treatment and the choice to the most appropriate individualized treatment strategy in all CHB patients.

Persistence and adherence to nucleos(t)ide analogue treatment for chronic hepatitis B

BACKGROUND & AIMS

Long-term treatment with nucleos(t)ide analogues (NUCs) is associated with increasing rates of antiviral drug resistance. Medication adherence is important in preventing drug resistance. This study aimed to determine, first, the persistence rates and the adherence rates to NUCs in patients with chronic hepatitis B (CHB), and second, the factors associated with adherence.

METHODS

Pharmacy claims of three cohorts of patients with CHB who were receiving lamivudine, adefovir, or entecavir in January 2007, January 2008, and January 2009, and data of patients receiving tenofovir in January 2009, were analyzed. Persistence was defined as continuing acquisition of pharmacy claims during a 12-month period and adherence as the percent of days in which patients had medication during the period in which the medication was prescribed.

RESULTS

A total of 11,100 patients were included, 4.7% were patients newly started on a NUC and 95.3% were existing patients already on a NUC at the start of each year. The mean ± SD persistence rate was 81 ± 3.8%, and was higher among existing patients than among new patients, 81.4% vs. 73.4% (p < 0.001). The mean ± SD adherence rate was 87.8 ± 19.1% and was higher among existing patients than among new patients, 88% vs. 84.6% (p = 0.001). Multivariate analysis showed that new patients (OR = 0.68, 95% CI 0.53-0.86), those receiving lamivudine (OR = 0.66, 95% CI 0.58-0.76), and young adult patients (OR=0.82, 95% CI 0.74-0.91) were less likely to have adherence rate > 90%.

CONCLUSIONS

Persistence and adherence to NUCs were high among CHB patients. Counseling of young and/or new patients on medication adherence may decrease the rate of antiviral drug resistance.

The Role of Antiviral Therapy for HBV-Related Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a highly prevalent and lethal cancer worldwide; despite the curative treatment for HCC, the rate of tumor recurrence after hepatectomy remains high. Tumor recurrence can occur early (<2 years) or late (>2 years) as metastases or de novo tumors. Several tumor factors were associated with HCC recurrence; high hepatitis B virus (HBV) load is the major risk factor for late recurrence of HCC after resection. Preoperative antiviral therapy improves liver function, and postoperative reduce HCC recurrence. In this paper, we focus on antiviral treatment to improve the liver function, prevent recurrence, and lengthen the overall survival for HBV-related HCC.

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.

Treatment of HBeAg-negative chronic hepatitis B patients with nucleos(t)ide analogues

Current agents used in the treatment of chronic hepatitis B (CHB) can be classified into interferons-α (IFN-α: standard or pegylated) and nucleos(t)ide analogues (NUCs). NUCs are now used in most CHB patients for several reasons. They can be given to all CHB patients, even those with contraindications to IFN-α. NUCs are more convenient to use (one oral tablet daily) than IFN-α (subcutaneous injections) and are well tolerated with a good safety profile, while IFN-α has frequent and potentially severe side effects and worsens the patient's quality of life. All NUCs are potent anti-hepatitis B virus agents (all but adefovir are more potent than IFN-α) with entecavir(ETV) and tenofovir offering the highest potency and most importantly minimal to negligible risk of resistance during long-term monotherapy [corrected]. Prolongation of entecavir or tenofovir monotherapy maintains and slightly increases the initially high virological remission rates (67-76% of HBeAg-positive and 90-93% of HBeAg-negative patients) and this is expected to result in improved long-term outcomes. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs and the finite duration (48 weeks) the main advantage of IFN-α. However, only a minority of IFN-α-treated patients achieve durable sustained off-treatment responses (HBeAg-positive: 30-35%, HBeAg-negative: 20-25%), while NUCs may be safely discontinued in HBeAg-positive patients with stable HBeAg seroconversion. Because there will always be concerns for safety and family planning issues with long-term therapy, NUCs should be used judiciously and should not be prescribed in young CHB patients with mild liver disease.

Immunohistochemical localization of transforming growth factor β-1 and its relationship with collagen expression in advanced liver fibrosis due to biliary atresia

PURPOSE

Biliary atresia (BA) is the most common indication of liver transplantation in children. Pathogenesis of hepatic fibrosis, which is a prominent feature of BA, remains obscure. The purpose of this work was to determine the cellular sources of transforming growth factor beta-1 (TGFβ1) and establish the relationship between TGFβ1-producing cells and extracellular matrix producing myofibroblasts (MFBs) in advanced BA.

METHODS

Trichrome staining and immunohistochemistry were carried out to determine the expression pattern of collagen and TGFβ1 protein in explant liver specimens from patients with BA. The intensities of portal and lobular TGFβ1 expressions were compared. Immunofluorescence technique was carried out to determine the relationship between α-smooth muscle actin (α-SMA)-positive-MFB and TGFβ1-positve cells.

RESULTS

Lobular TGFβ1 protein expression was significantly higher than portal (89 ± 6 versus 10 ± 1 arbitrary units, P ≤ 0.05), whereas no difference was noted in livers used as control (10 ± 1.6 versus 19 ± 5 arbitrary units, P = 0.11). TGFβ1 expression was more in the center of nodules versus MFB in surrounding fibrous septa. Contrary to TGFβ1 expression, α1-SMA was mostly expressed in the portal structures and the adjacent fibrous septa enacting lobulation of the parenchyma. The results obtained by coimmunofluorescence staining showed no colocalization of α-SMA and TGFβ1.

CONCLUSIONS

TGFβ1 protein expression is mostly localized to hepatocytes in advanced BA. These findings suggest a paracrine mechanisms of TGFβ1-driven fibrogenesis in advanced BA.

Mixed treatment comparison meta-analysis evaluating the relative efficacy of nucleos(t)ides for treatment of nucleos(t)ide-naive patients with chronic hepatitis B

BACKGROUND/AIMS

Five nucleoside/nucleotide treatments are now available for chronic hepatitis B (CHB). This meta-analysis aimed to assess the relative efficacy of adefovir, entecavir, lamivudine, telbivudine, tenofovir disoproxil fumarate (TDF), and nucleos(t)ide combinations in the treatment of CHB.

METHODS

A systematic review of MEDLINE and the Cochrane library was conducted to identify all studies evaluating these nucleos(t)ides in adults with CHB. Randomized controlled trials were included in the meta-analysis if they reported the proportion of patients with undetectable hepatitis B virus (HBV) DNA or hepatitis B e antigen (HBeAg) loss/seroconversion at 1 year. Bayesian mixed treatment comparison meta-analyses were conducted in WinBUGS to assess relative efficacy.

RESULTS

A random-effects meta-analysis of trials on treatment-naive patients with HBeAg-positive CHB demonstrated that 94% of patients will achieve HBV DNA < 300 copies/ml after 1 year with TDF, compared with 73% for entecavir, 50% for adefovir, and 38% for lamivudine. There was a 97.7% probability that TDF enabled a greater proportion of patients to achieve HBV DNA < 300 copies/ml at 1 year than all other treatments considered in the analysis. TDF was significantly superior to all nucleos(t)ides for this outcome at the 0.05 level. There were no statistically significant differences between nucleos(t)ides in HBeAg seroconversion at 1 year, based on a fixed-effects meta-analysis in the same population. More trials on HBeAg-negative and drug-resistant patients are required to facilitate meta-analyses for these subgroups.

CONCLUSIONS

In nucleos(t)ide-naive patients with HBeAg-positive CHB, TDF is associated with the highest probability of achieving undetectable HBV DNA at 1 year of all nucleos(t)ides considered.

Th1 and Th2 immune response in chronic hepatitis B patients during a long-term treatment with adefovir dipivoxil

Adefovir dipivoxil treatment has significantly improved the outcome of chronic hepatitis B virus (HBV) infection. However, it remains largely unknown how immune system responds to the treatment. Chronic HBV patients were treated with adefovir dipivoxil and examined for serum HBV DNA loads, cytokines, and T helper (Th1) and 2 (Th2) cytokine producing T cells during 104 weeks of the treatment. Th1/Th2 cytokines producing T cells were significantly lower in chronic HBV patients as compared to normal individuals. Adefovir dipivoxil treatment led to the increase of Th1/Th2 cytokines producing T cells and serum cytokine levels in association with the decline of HVB DNA load. In contrast, Th1/Th2 cytokines producing T cells remained lower in one patient detected with adefovir dipivoxil resistant HBV A181T/V mutation. This study has established inverse correlation of the increase of Th1/Th2 immunity and the decline of HBV DNA load in chronic HBV patients during adefovir dipivoxil treatment.

High rate of adefovir-lamivudine combination therapy in nucleoside-naïve patients with chronic hepatitis B in France: results of a national survey in 1730 patients

BACKGROUND/AIMS

This study describes the types of therapy used in chronic hepatitis B (CHB) in France and patient characteristics according to therapy.

METHODS

This was a descriptive, multicenter, retrospective study in 1730 patients (54 centers). We collected information about demographics, epidemiology, severity of hepatitis B virus-related liver disease, antiviral therapy, response (hepatitis B viral DNA and alanine aminotransferase normalization changes), dose modification, or treatment interruption.

RESULTS

Approximately, 60% of patients enrolled had never been treated for CHB and 33.1% were currently receiving treatment (47% first line). Of those receiving treatment, 30% were receiving adefovir-lamivudine combination. Of those receiving first-line therapy, 40, 30, and 15% were receiving lamivudine, adefovir, or adefovir-lamivudine combination, respectively. Complete and partial virological responses were seen in 59 and 13% of patients, respectively. In patients having been treated at least once, biochemical response was seen in 45%. Lamivudine or adefovir-resistant mutants were detected in 32.6 and 22.1% of patients treated by these antiviral agents, respectively.

CONCLUSION

In France, among patients with CHB, we observed that one-third were receiving therapy, and, of these, 30% were receiving first-line (15%) or second-line (15%) adefovir-lamivudine combination therapy. This observation highlights that clinical practice is influenced by available scientific data on resistance induced by monotherapy.

HBcrAg is a predictor of post-treatment recurrence of hepatocellular carcinoma during antiviral therapy

BACKGROUND/AIMS

The recurrence rate of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is high even in patients receiving curative therapy. In this study, we analysed the risk factors for tumour recurrence after curative therapy for HBV-related HCC while under treatment with nucleot(s)ide analogues (NAs) by measuring serum HBcrAg and intrahepatic covalently closed circular DNA (cccDNA) levels to elucidate the viral status associated with HCC recurrence.

METHODS

We enrolled 55 patients who developed HCC during NA therapy and underwent either curative resection or percutaneous ablation for HCC.

RESULTS

Hepatocellular carcinoma recurred in 21 (38%) of the patients over a period of 2.2 (range, 0.2-7.4) years. In multivariate analysis, serum HBcrAg levels ≥4.8 log U/ml at the time of HCC diagnosis (hazard ratio, 8.96; 95% confidential interval, 1.94-41.4) and portal vein invasion (3.94, 1.25-12.4) were independent factors for HCC recurrence. The recurrence-free survival rates of the high cccDNA group were significantly lower than those of the low cccDNA group only in patients who underwent resection (P=0.0438). A positive correlation (P=0.028; r=0.479) was observed between the intrahepatic cccDNA and the serum HBcrAg levels at the incidence of HCC.

CONCLUSION

HBcrAg is a predictor of the post-treatment recurrence of HCC during antiviral therapy. Serum HBcrAg and intrahepatic cccDNA suppression by NAs may be important to prevent HCC recurrence.

Treatment of chronic hepatitis B in Asia-Pacific countries: is the Asia-Pacific consensus statement being followed?

BACKGROUND

The Asia-Pacific consensus guidelines for the management of chronic hepatitis B state that the principal indicators for starting therapy are increased HBV DNA levels (> or =20,000 IU/ml for hepatitis B e antigen [HBeAg]-positive status and >2,000 IU/ml for HBeAg-negative status) and alanine aminotransferase (ALT) levels >2x the upper limit of normal. We aimed to determine whether clinicians in the Asia-Pacific region are treating patients with chronic hepatitis B according to the Asia-Pacific consensus statement on the management of chronic hepatitis B.

METHODS

An online survey of chronic hepatitis B treatment practices was prepared, consisting of 14 questions grouped into seven categories: patient statistics, treatment statistics, treatment decision, first-choice treatment, treatment duration, future directions and patient preference.

RESULTS

In total, 124 respondents from 12 countries completed the survey. Most respondents indicated that detectable HBV DNA was either the first or second most important factor when deciding whether to initiate therapy. Many physicians were unsure about initiation of treatment in patients >40 years of age when ALT levels were within the normal range. Oral antiviral drugs were the most frequently used medication because of their effectiveness, safety and ability to provide sustained viral suppression. Conversely, the most important reasons for selecting interferon therapy were effectiveness, fixed duration of treatment and lack of drug resistance. Criteria for stopping treatment generally followed the recommendations included in the guidelines.

CONCLUSIONS

These data suggest that clinicians from the Asia-Pacific region use criteria beyond those advocated in treatment guidelines when deciding whether to initiate treatment in HBV-infected patients.

Tenofovir and entecavir are the most effective antiviral agents for chronic hepatitis B: a systematic review and Bayesian meta-analyses

BACKGROUND & AIMS

The relative efficacies of licensed antiviral therapies for treatment-naive chronic hepatitis B (CHB) infection in randomized controlled trials have not been determined. We evaluated the relative efficacies of the first 12 months of CHB treatments.

METHODS

Drugs evaluated were lamivudine, pegylated interferon, adefovir, entecavir, telbivudine, and tenofovir, as monotherapies and combination therapies, in treatment-naive individuals. Databases were searched for randomized controlled trials of the first 12 months of therapy in hepatitis B e antigen (HBeAg)-positive and/or HBeAg-negative patients with CHB published in English before October 31, 2009. Bayesian mixed treatment comparisons were used to calculate the odds ratios, including 95% credible intervals and predicted probabilities of surrogate outcomes to determine the relative effects of each treatment.

RESULTS

In HBeAg-positive patients, tenofovir was most effective in inducing undetectable levels of HBV DNA (predicted probability, 88%), normalization of alanine aminotransferase (ALT) levels (66%), HBeAg seroconversion (20%), and hepatitis B surface antigen loss (5%); it ranked third in histologic improvement of the liver (53%). Entecavir was most effective in improving liver histology (56%), second for inducing undetectable levels of HBV DNA (61%) and normalization of ALT levels (70%), and third in loss of hepatitis B surface antigen (1%). In HBeAg-negative patients, tenofovir was the most effective in inducing undetectable levels of HBV DNA (94%) and improving liver histology (65%); it ranked second for normalization of ALT levels (73%).

CONCLUSIONS

In the first year of treatment for CHB, tenofovir and entecavir are the most potent oral antiviral agents for HBeAg-positive patients; tenofovir is most effective for HBeAg-negative patients.

Endpoints of hepatitis B treatment

The goal of hepatitis B treatment is to prevent the development of cirrhosis, liver failure, and hepatocellular carcinoma. Ideally, clinical studies should demonstrate that hepatitis B therapies can prevent liver-related complications; however, these clinical endpoints evolve over years or decades. Therefore, clinical trials have relied on intermediate endpoints to evaluate the efficacy of treatment and to determine when treatment can be stopped. Intermediate endpoints that have been used include biochemical, histological, virological, and serological endpoints. This review will discuss the validity of these intermediate endpoints as surrogates of clinical endpoints, and the rates at which these intermediate endpoints can be achieved with currently available therapies.

Fanconi's Syndrome Associated with Prolonged Adefovir Dipivoxil Therapy in a Hepatitis B Virus Patient

Adefovir dipivoxil (ADV) is commonly used as an antiviral agent in the treatment of chronic hepatitis B or human immunodeficiency virus infection. Nephrotoxicity has been shown to occur at daily dosages of 60-120 mg. Fanconi's syndrome is a generalized dysfunction of the renal proximal tubular cells, which is usually accompanied by complications. Here we report a case of Fanconi's syndrome in a chronic hepatitis B patient who had been treated with a prolonged regimen of ADV at 10 mg/day. A 47-year-old man complained of severe back and chest-wall pain. He had chronic hepatitis B and had been treated with ADV at a daily dose of 10 mg for 38 months. He was hospitalized because of severe bone pain, and laboratory and radiologic findings suggested a diagnosis of Fanconi's syndrome with osteomalacia. After discontinuation of the ADV, he recovered and was discharged from hospital. His laboratory findings had normalized within 2 weeks. This case indicates that Fanconi's syndrome can be acquired by a chronic hepatitis B patient taking ADV at a conventional dosage of 10 mg/day. Therefore, patients treated with long-term ADV should be checked regularly for the occurrence of ADV-induced Fanconi's syndrome.

New pharmacologic therapies in chronic hepatitis B

Approximately 350 million persons worldwide are chronically infected with hepatitis B, which can result in cirrhosis, liver failure, and hepatocellular carcinoma. Currently, 2 interferons and 5 nucleos(t)ide analogues have been approved for the treatment of chronic hepatitis B (CHB). This article discusses the mechanisms of action, pharmacokinetics, optimal dose, clinical efficacy, and side effects of medications used for the treatment of CHB.

Histologic evidence of active liver injury in chronic hepatitis B patients with normal range or minimally elevated alanine aminotransferase levels

GOALS

To evaluate the proportion of patients with histologic evidence of active liver disease (HEALD) who have chronic hepatitis B (CHB) and normal/minimally elevated serum alanine aminotransferase (ALT). Sub-analysis was performed to determine whether HEALD based upon liver biopsy better correlates with ALT using modified ALT (30 men/19 women) upper limit of normal (ULN) criteria compared with local conventional laboratory.

BACKGROUND

There are limited data on CHB with normal range ALT (NRALT). We designed a study to evaluate histologic damage in this cohort of patients.

STUDY

A retrospective, multicenter study evaluated CHB patients with normal/minimally elevated ALT [< or = 1.2 x ULN (hepatitis B e antigen positive) or < or = 1.5 x ULN (hepatitis B e antigen negative)]. Liver biopsy specimens were reviewed by an independent histopathologist. HEALD was defined as Knodell necroinflammatory score greater than 5 and Ishak fibrosis stage greater than 1.

RESULTS

Forty-five patients met criteria: median age of 40 years; 51% males; 73% Asian; and 67% hepatitis B e antigen negative. Median hepatitis B virus DNA was 6.04 log10 copies/mL, aspartate aminotransferase (AST) 30 IU/L, and ALT 42 IU/L; and 40% of the patients had ALT greater than ULN. Overall, 20% had HEALD and among patients with NRALT, 4 of 27 (15%) and 0 of 5 (0%) had HEALD through conventional or modified ALT ULN, respectively.

CONCLUSIONS

One fifth of patients with CHB and normal/minimally elevated ALT had HEALD. Among the subset of patients with NRALT, 15% (4 of 27) had HEALD when using conventional laboratory compared with 0% (0 of 5) patients by modified ALT ULN criteria. Use of the modified ALT ULN will likely improve accuracy in identifying patients who may have HEALD compared with conventional laboratory ULN.

A randomized trial of peginterferon alpha-2a with or without ribavirin for HBeAg-negative chronic hepatitis B

OBJECTIVES

Hepatitis B e antigen (HBeAg)-negative chronic hepatitis B patients are at high risk of treatment relapse after any antiviral therapy. Combining peginterferon alpha-2a with ribavirin might improve sustained response rates.

METHODS

Overall, 138 HBeAg-negative chronic hepatitis B patients were randomized to receive monotherapy (peginterferon alpha-2a 180 microg weekly plus placebo) or combination therapy (peginterferon alpha-2a weekly plus ribavirin 1,000 or 1,200 mg daily, depending on body weight) for 48 weeks. Post-treatment follow-up lasted 24 weeks. Analyses were based on the modified intention-to-treat population after exclusion of five patients.

RESULTS

At the end of follow-up, 14 (20%) of 69 patients assigned to monotherapy and 10 (16%) of 64 assigned to combination therapy had a combined response (hepatitis B virus (HBV) DNA <10,000 copies/ml (<1,714 IU/ml) and a normal alanine aminotransferase level, P=0.49). At the end of treatment, more patients had a combined response (25 (36%) vs. 26 (41%) in the monotherapy and combination therapy group, respectively, P=0.60), but subsequently relapsed during follow-up. Serum HBV DNA and hepatitis B surface antigen (HBsAg) levels decreased during treatment (mean change at week 48 compared with baseline -3.9 vs. -2.6 log copies/ml, P<0.001 and -0.56 vs. -0.34 log IU/ml, P=0.23, respectively). HBV DNA levels relapsed after treatment discontinuation; HBsAg remained at end-of-treatment levels. In general, combination therapy was well tolerated, although it was associated with a higher risk of anemia and neutropenia.

CONCLUSIONS

Treatment with peginterferon alpha-2a resulted in a limited sustained response rate in HBeAg-negative chronic hepatitis B patients. Addition of ribavirin did not improve response to therapy.

Management of end-stage liver disease in chronic hepatitis B

The consequences of chronic hepatitis B virus infection include hepatocellular carcinoma and liver cirrhosis. Effective antiviral therapy in patients with hepatitis B with advanced liver disease with viral suppression and sustained HBeAg seroconversion (where applicable) may abort hepatic decompensation, diminish hepatocellular risk, and reduce the risk of viral recurrence after transplantation. Overt hepatic decompensation is an indication for referral to a transplant center.

Long-term adefovir dipivoxil monotherapy for up to 5 years in lamivudine-resistant chronic hepatitis B

BACKGROUND

Large clinical studies assessing long-term adefovir dipivoxil salvage monotherapy in patients with lamivudine-resistant chronic hepatitis B (CHB) are lacking, particularly in patients positive for hepatitis B e antigen (HBeAg). We assessed the efficacy and resistance profile of adefovir dipivoxil monotherapy for up to 5 years in a large cohort of Korean patients with lamivudine-resistant CHB.

METHODS

A total of 320 patients (81.3% HBeAg-positive; 100% genotype C) with confirmed genotypic lamivudine-resistant CHB were switched to adefovir dipivoxil 10 mg once daily. Liver function tests and HBV DNA were monitored every 3 months. Genotypic resistance to adefovir dipivoxil was performed in patients with detectable HBV DNA.

RESULTS

The overall cumulative virological response rate at 5 years of adefovir dipivoxil therapy was 48.8%. The virological response rate was significantly higher in HBeAg-negative patients (62.0% versus 45.9%; P=0.010). Most cases of virological response (131/134, 97.8%) occurred within the first 36 months of therapy. The 5-year cumulative probability of genotypic resistance and virological breakthrough was 65.6% and 61.8%, respectively. Predictive factors for a virological response included baseline HBeAg seronegativity, HBV DNA< or =8 log(10) copies/ml and achievement of an on-treatment initial virological response.

CONCLUSIONS

Adefovir dipivoxil salvage monotherapy for lamivudine-resistant CHB resulted in a modest cumulative virological response rate at 5 years, which was associated with progressive antiviral resistance. Consequently, adefovir monotherapy is not preferable as a first-line strategy for lamivudine resistance where combination lamivudine plus adefovir dipivoxil therapy is available.

Lamivudine or adefovir dipivoxil alone or combined with immunoglobulin for preventing hepatitis B recurrence after liver transplantation

BACKGROUND

Recurrence of hepatitis B virus (HBV) infection in the liver graft is a grave complication following liver transplantation for HBV cirrhosis. Hepatitis B immunoglobulin (HBIg) seems effective in increasing survival after liver transplantation. HBIg and anti-viral drugs are given alone or in combination for its prevention.

OBJECTIVES

To assess the benefits and harms of different regimens for preventing HBV reactivation following liver transplantation.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until February 2010. We attempted to identify further trials by reviewing the reference lists and contacting the principal authors of identified trials.

SELECTION CRITERIA

Randomised clinical trials addressing benefits and harms of lamivudine or adefovir dipivoxil alone or in combination with hepatitis B immunoglobulins (HBIg) for preventing recurrent HBV infection in patients who are liver transplanted due to HBV infection with or without hepatocellular carcinoma.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trials for risk of bias and extracted data. We contacted study authors whenever information was lacking. We collected information on adverse events. The primary outcomes were all-cause mortality and reappearance of hepatitis B surface antigen in serum after liver transplantation. Relative risks were calculated from individual trials.

MAIN RESULTS

Four trials, recruiting 136 participants, were included. Two trials compared lamivudine alone versus HBIg alone. Randomisation was performed one week after transplantation in one of the trials and after six months after transplantation in another; from transplantation until randomisation, HBIg alone was given to all patients in the two trials. A third trial compared combination treatment with lamivudine and HBIg versus lamivudine alone after one month of combination treatment, and a fourth trial compared the combination of lamivudine and HBIg versus a combination of lamivudine and adefovir dipivoxil after at least 12-month of lamivudine and HBIg combination treatment. Statistically significant differences were not detected in any of the comparisons and outcomes. All trials were open-labelled, and none of the trials were adequately powered to show a difference in HBV recurrence. No meta-analyses were performed since the identified trials assessed different comparisons.

AUTHORS' CONCLUSIONS

This review could not derive clear evidence from randomised clinical trials for the treatment of patients with chronic HBV following liver transplantation for preventing recurrence of HBV infection. Large randomised clinical trials comparing long-term combination treatment to each of the monotherapy alone, including the newer antiviral drugs, are needed.

A Review of Oral Antiretroviral Therapy for the Treatment of Chronic Hepatitis B

Objective:

To describe the current evidence for the use of oral antiretroviral (ARV) agents in the treatment of chronic hepatitis B (CHB).

Data Sources:

A search from 1950 to April 2010 was conducted using the databases PubMed and MEDLINE with the search terms chronic hepatitis B, lamivudine, entecavir, adefovir, telbivudine, tenofovir, emtricitabine, clevudine, and pradefovir. The search was limited to trials conducted in humans that were published in the English language.

Study Selection and Data Extraction:

Studies were included if they evaluated the use of oral ARVs in patients with CHB infection who were not coinfected with hepatitis C, hepatitis D, or HIV.

Data Synthesis:

Oral ARVs have revolutionized the treatment of CHB. Studies conducted comparing ARVs have favored entecavir and tenofovir with respect to their ability to decrease hepatitis B virus DNA viral load while minimizing the development of resistance. However, low seroconversion rates, recurrent viremia when ARV therapy is discontinued, and increased resistance rates with longer treatment durations limit the benefit of oral ARVs in the treatment of CHB. Combination therapy has been a suggested solution; however, studies have yet to prove additional benefit over currently recommended monotherapy.

Conclusions:

Oral ARVs should continue to be used in the treatment of CHB; however, research is needed to define the optimal duration of therapy, evaluate the utility of combination therapy, and explore novel targets within the hepatitis B life cycle.