Sustained HBeAg and HBsAg loss after long-term follow-up of HBeAg-positive patients treated with peginterferon alpha-2b

Variations and mutations in the hepatitis B virus genome and their associations with clinical characteristics

Hepatitis B virus (HBV) infection is major global issue, because chronic HBV infection is strongly associated with liver cancer. HBV spread worldwide with various mutations and variations. This variability, called quasispecies, is derived from no proof-reading capacity of viral reverse transcriptase. So far, thousands of studies reported that the variety of genome is closely related to the geographic distribution and clinical characteristics. Recent technological advances including capillary sequencer and next generation sequencer have made in easier to analyze mutations. The variety of HBV genome is related to not only antigenicity of HBs-antigen but also resistance to antiviral therapies. Understanding of these variations is important for the development of diagnostic tools and the appropriate therapy for chronic hepatitis B. In this review, recent publications in relation to HBV mutations and variations are updated and summarized.

Gene therapeutic approaches to inhibit hepatitis B virus replication

Acute and chronic hepatitis B virus (HBV) infections remain to present a major global health problem. The infection can be associated with acute symptomatic or asymptomatic hepatitis which can cause chronic inflammation of the liver and over years this can lead to cirrhosis and the development of hepatocellular carcinomas. Currently available therapeutics for chronically infected individuals aim at reducing viral replication and to slow down or stop the progression of the disease. Therefore, novel treatment options are needed to efficiently combat and eradicate this disease. Here we provide a state of the art overview of gene therapeutic approaches to inhibit HBV replication. We discuss non-viral and viral approaches which were explored to deliver therapeutic nucleic acids aiming at reducing HBV replication. Types of delivered therapeutic nucleic acids which were studied since many years include antisense oligodeoxynucleotides and antisense RNA, ribozymes and DNAzymes, RNA interference, and external guide sequences. More recently designer nucleases gained increased attention and were exploited to destroy the HBV genome. In addition we mention other strategies to reduce HBV replication based on delivery of DNA encoding dominant negative mutants and DNA vaccination. In combination with available cell culture and animal models for HBV infection, in vitro and in vivo studies can be performed to test efficacy of gene therapeutic approaches. Recent progress but also challenges will be specified and future perspectives will be discussed. This is an exciting time to explore such approaches because recent successes of gene therapeutic strategies in the clinic to treat genetic diseases raise hope to find alternative treatment options for patients chronically infected with HBV.

Pharmacokinetic characteristics, pharmacodynamic effect and in vivo antiviral efficacy of liver-targeted interferon alpha

Interferon alpha (IFNα) is used for the treatment of hepatitis B virus infection, and whilst efficacious, it is associated with multiple adverse events caused by systemic exposure to interferon. We therefore hypothesise that targeting IFN directly to the intended site of action in the liver would reduce exposure in blood and peripheral tissue and hence improve the safety and tolerability of IFNα therapy. Furthermore we investigated whether directing IFN to the reservoir of infection in the liver may improve antiviral efficacy by increasing local concentration in target organs and tissues. Our previous results show that the mIFNα2 fused to an ASGPR specific liver targeting antibody, DOM26h-196-61, results in a fusion protein which retains the activity of both fusion partners when measured in vitro. In vivo targeting of the liver by mIFNα2-DOM26h-196-61, hereafter referred to as targeted mIFNα2, was observed in microSPECT imaging studies in mice. In this study we show by pharmacokinetic analysis that antibody mediated liver-targeting results in increased uptake and exposure of targeted mIFNα2 in target tissues, and correspondingly reduced uptake and exposure in systemic circulation, clearance organs and non-target tissues. We also show that cytokine activity and antiviral activity of liver-targeted IFN is observed in vivo, but that, contrary to expectations, liver-targeting of mIFNα2 using ASGPR specific dAbs actually leads to a reduced pharmacodynamic effect in target organs and lower antiviral activity in vivo when compared to non-targeted mIFNα2-dAb fusions.

Improving clinical outcomes of chronic hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a global health problem, leading to cirrhosis, hepatocellular carcinoma (HCC) and liver-related deaths. Universal hepatitis B vaccination is the most cost-effective way to eradicate HBV infection with the remarkable reduction of chronic carriage, neonatal fulminant hepatitis and childhood HCC. The introduction of highly effective antiviral agents, including lamivudine, adefovir dipivoxil, entecavir, telbivudine, tenofovir disoproxil fumarate and pegylated interferons further improve short-, medium- and long-term outcomes of chronic HBV infection, such as ALT normalization, HBV DNA suppression, HBeAg seroconversion, HBsAg seroclearance, fibrosis regression, reduction of cirrhosis, HCC, liver-related deaths and the need for liver transplantation. Above all, sustained and profound viral suppression is the key to improve the clinical outcomes of chronic hepatitis B.

Targeting the Achilles heel of the hepatitis B virus: a review of current treatments against covalently closed circular DNA

Chronic infection with hepatitis B virus (HBV) often leads to the development of liver cancer and cirrhosis, creating immense sociological, clinical and economic burdens worldwide. Although current anti-HBV medications manage to control the disease progression and help restore normal liver functions, they often fail to eliminate the virus completely. A major reason for this failure is the presence of a stable viral genome in the hepatocyte nucleus: the covalently closed circular DNA (cccDNA). Targeting HBV cccDNA is a promising approach that could lead to a complete cure. Here, we review various research approaches that are directed toward eliminating HBV cccDNA. This is a brief, yet comprehensive, summary of current state-of-the-art developments in this emerging area of interest.

Loss of hepatitis B surface antigen in a real-life clinical cohort of patients with chronic hepatitis B virus infection

BACKGROUND & AIMS

Hepatitis B surface antigen (HBsAg) clearance is the main indicator of viral cure in patients infected with the hepatitis B virus (HBV). We sought to identify the parameters associated with HBsAg loss in a well-characterized real-life clinical cohort of chronically HBV-infected patients.

METHODS

Patients with chronic HBV infection were prospectively included, classified according to the disease stage, and followed up to determine parameters associated with HBsAg clearance.

RESULTS

In total, 315 patients were followed up for a mean of almost 6 years. At study entry, 109 (34.6%) were inactive HBsAg carriers, 204 (64.8%) had chronic active hepatitis (CAH), and two (0.6%) were immune-tolerant carriers. During follow-up, 128 (62.7%) of the 204 patients with CAH received antiviral therapy. Sixty-nine had HBeAg-positive CAH: 55 (79.7%) were treated and 14 (20.3%) untreated. One hundred thirty-five had HBeAg-negative CAH: 73 (54.1%) were treated and 62 (45.9%) untreated. Inactive carriers showed an annual HBsAg clearance incidence rate of 23.4 cases per 1000 persons-years, which was higher than that of CAH groups. The clearance incidence rates (in cases per 1000 persons-years) of CAH groups were: treated HBeAg-positive (20.7), untreated HBeAg-positive (19.1), treated HBeAg-negative (10.1), and untreated HBeAg-negative (8.1). Older age (P = 0.001) and inactive carrier status (P = 0.019) were independent predictors of HBsAg clearance.

CONCLUSION

In a well-characterized real-life clinical cohort of chronically HBV-infected patients in various disease phases, older age, and inactive HBsAg carrier status were the only predictors of HBsAg clearance, whereas anti-HBV therapy only marginally increased annual incidence of HBsAg loss.

Optimal therapy of chronic hepatitis B: how do I treat HBeAg-positive patients?

Current agents for the treatment of chronic hepatitis B (CHB) can be classified into interferon-α (standard or pegylated) (IFN) and nucleos(t)ide analogues (NAs). IFN therapy has the advantage of a finite duration (48 weeks) with a chance for durable sustained off-treatment response in HBeAg positive CHB patients. However, these benefits are limited to approximately 30% of HBeAg positive patients, while parenteral administration and potential side effects are common patient concerns. Thus, patients who can benefit from IFN therapy must be carefully selected and monitored. Recently, stopping rules for IFN non-responders were developed based on 12-week HBsAg levels. NAs are currently used in most CHB patients. They are administered in one tablet daily and can be used in all patients with excellent tolerability and a good safety profile. The current first-line options, entecavir (ETV) and tenofovir (TDF), are highly potent with a minimal risk of resistance during long-term monotherapy. Prolongation of entecavir or tenofovir maintains the initially high virological remission rates in adherent HBeAg positive patients and modifies the long-term outcomes. The need for a long-term, perhaps indefinite, treatment duration is the main limitation of ETV or TDF, which may sometimes be safely discontinued in HBeAg positive patients who achieve stable HBeAg seroconversion. Since there will always be safety concerns and family planning issues with long-term therapy, NAs should be used carefully particularly in young HBeAg positive patients with minimal-mild liver disease.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Challenges in the management of chronic HBV infection in West Africa: The clinician's perspective

BACKGROUND

Hepatitis B infection has become a public health issue in recent years. Approximately 350 million of the world's population are chronically infected reaching endemic proportions in West Africa. Guidelines for treatment are continuously improving but are becoming more complex.

AIM

To determine the challenges hepatologists experience in the management of patients with chronic hepatitis B.

METHODS

This was a cross-sectional descriptive study conducted among hepatologists in West Africa during a regional hepatitis conference in 2013.

RESULTS

Forty-six hepatologists completed the questionnaire. When evaluating a patient for chronic hepatitis B, the preferred investigations were: LFT (100%); abdominal ultrasound (93.5%); HBeAg (93.5%); HBV DNA (78%); HBsAg measure (22%); HBV genotype (15.2%); and liver biopsy (34.8%). Most had their patients on nucleoside/nucleotide analogue but follow-up visits after 1 year were problematic.

CONCLUSION

The majority of hepatologists had good intentions regarding the evaluation of their patients, but only a small percentage of patients are properly investigated.

Hepatitis B virus infection

Hepatitis B virus infection is a major public health problem worldwide; roughly 30% of the world's population show serological evidence of current or past infection. Hepatitis B virus is a partly double-stranded DNA virus with several serological markers: HBsAg and anti-HBs, HBeAg and anti-HBe, and anti-HBc IgM and IgG. It is transmitted through contact with infected blood and semen. A safe and effective vaccine has been available since 1981, and, although variable, the implementation of universal vaccination in infants has resulted in a sharp decline in prevalence. Hepatitis B virus is not cytopathic; both liver damage and viral control--and therefore clinical outcome--depend on the complex interplay between virus replication and host immune response. Overall, as much as 40% of men and 15% of women with perinatally acquired hepatitis B virus infection will die of liver cirrhosis or hepatocellular carcinoma. In addition to decreasing hepatic inflammation, long-term antiviral treatment can reverse cirrhosis and reduce hepatocellular carcinoma. Development of new therapies that can improve HBsAg clearance and virological cure is warranted.

Viral Hepatitis B and C. Cure or Treatment?

HBV and HCV infections are among the most important global health problems; both represent also the leading cause of cirrhosis and HCC worldwide. HBV treatment cannot be considered cure but effective viral suppression can be achieved and remains the current principal goal of therapy. Talking about HCV treatment today equals to talking about total cure of the patient, with treatments of very high SVR rates, shorter if not shortest duration, minimal risk for resistance, pangenotypic and practically with no serious adverse events, no fibrosis or previous treatment status limitations, but also with a very high cost.

Kinetics of hepatitis B surface antigen loss in patients with HBeAg-positive chronic hepatitis B treated with tenofovir disoproxil fumarate

BACKGROUND & AIMS

In a study of 266 chronic hepatitis B e antigen (HBeAg)-positive patients, 23 experienced hepatitis B surface antigen (HBsAg) loss with up to 5 years of tenofovir disoproxil fumarate (TDF) treatment. HBsAg kinetics in patients with and without HBsAg loss and predictors of HBsAg loss were evaluated.

METHODS

HBsAg levels were quantified every 12 weeks. A multivariable regression analysis, involving prespecified baseline characteristics and on-treatment response parameters, was performed; a stepwise procedure identified independent predictors of HBsAg loss.

RESULTS

Among patients with HBsAg loss, 14 (61%), 1 (4%), 0 and 7 (30%) were genotypes A through D, respectively; 1 (4%) was genotype F. HBsAg loss was preceded by viral suppression (HBV DNA <29 IU/ml; n=23) and HBeAg loss (n=19). Among treated patients the strongest independent predictors of HBsAg loss were Caucasian race with genotype A/D and ⩽4 years of infection (HR=14.3, 95% confidence interval [CI] 4.7-43.4; p<0.0001) and an HBsAg decline of ⩾1 log10 IU/ml at week 24 (HR=13.7, 95% CI 5.6-33.7; p<0.0001). Among TDF-treated patients, a reduction in HBsAg level of ⩾1-log10 by week 12 or 24 had a positive predictive value of 35%-45%, respectively, and a negative predictive value of 94%-97%, respectively.

CONCLUSIONS

HBsAg loss in HBeAg-positive patients receiving TDF involves a chronology of virologic and serologic responses; patients with HBV genotypes A or D and a rapid early decline in HBsAg are more likely to lose HBsAg.

Switching from entecavir to PegIFN alfa-2a in patients with HBeAg-positive chronic hepatitis B: a randomised open-label trial (OSST trial)

BACKGROUND & AIMS

Durable post-treatment response is uncommon in chronic hepatitis B (CHB) patients on nucleos(t)ide analogue therapy. Response, response predictors and safety were assessed in patients who switched from long-term entecavir (ETV) to peginterferon alfa-2a.

METHODS

Hepatitis B e antigen (HBeAg)-positive CHB patients who had received ETV for 9-36 months, with HBeAg <100 PEIU/ml and HBV DNA ⩽1000 copies/ml, were randomised 1:1 to receive peginterferon alfa-2a 180 μg/week or ETV 0.5mg/day for 48 weeks. The primary endpoint was HBeAg seroconversion at week 48 (ClinicalTrials.gov: NCT00940485).

RESULTS

200 patients were randomised; 197 received ⩾1 study drug dose. Five patients who were anti-HBe-positive at baseline were excluded from the modified intention-to-treat population (peginterferon alfa-2a, n = 94; ETV, n = 98). Patients who switched to peginterferon alfa-2a achieved higher week 48 HBeAg seroconversion rates vs. those who continued ETV (14.9% vs. 6.1%; p = 0.0467). Only patients receiving peginterferon alfa-2a achieved HBsAg loss (8.5%). Among peginterferon alfa-2a-treated patients with HBeAg loss and HBsAg <1500 IU/ml at randomisation, 33.3% and 22.2% achieved HBeAg seroconversion and HBsAg loss, respectively. Early on-treatment HBsAg decline predicted response at week 48; highest rates were observed in patients with week 12 HBsAg <200 IU/ml (HBeAg seroconversion, 66.7%; HBsAg loss, 77.8%). Alanine aminotransferase elevations were not associated with viral rebound (n = 38). Peginterferon alfa-2a was well-tolerated.

CONCLUSIONS

For patients who achieve virological suppression with ETV, switching to a finite course of peginterferon alfa-2a significantly increases rates of HBeAg seroconversion and HBsAg loss. A response-guided approach may identify patients with the greatest chance of success.

HBsAg loss in patients treated with peginterferon alfa-2a and adefovir is associated with SLC16A9 gene variation and lower plasma carnitine levels

BACKGROUND & AIMS

Achievement of HBsAg loss remains the hallmark of chronic hepatitis B treatment. In order to identify host factors contributing to treatment-induced HBsAg loss, we performed a genome-wide screen of single nucleotide polymorphisms (SNPs) and studied its immunological consequence.

METHODS

Chronic hepatitis B patients (40 HBeAg-positive and 44 HBeAg-negative) treated with peginterferon alfa-2a and adefovir were genotyped for 999,091 SNPs, which were associated with HBsAg loss at week 96 (n = 9). Plasma carnitine levels were measured by tandem-mass spectrometry, and the effect of carnitine on the proliferative capacity of hepatitis B virus (HBV)-specific and non-specific CD8 T cells was studied in vitro.

RESULTS

One polymorphism, rs12356193 located in the SLC16A9 gene, was genome-wide significantly associated with HBsAg loss at week 96 (p = 1.84 × 10(-8)). The previously reported association of rs12356193 with lower carnitine levels was confirmed in our cohort, and baseline carnitine levels were lower in patients with HBsAg loss compared to patients with HBsAg persistence (p = 0.02). Furthermore, we demonstrated that carnitine suppressed HBV-specific CD8 T cell proliferation.

CONCLUSIONS

In chronic hepatitis B patients treated with peginterferon and adefovir, we identified strong associations of SLC16A9 gene variation and carnitine levels with HBsAg loss. Our results further suggest that a lower baseline plasma carnitine level increases the proliferative capacity of CD8 T cells, making patients more susceptible to the immunological effect of this treatment. These novel findings may provide new insight into factors involved in treatment-induced HBsAg loss, and play a role in the prediction of treatment outcome.

Polymorphisms of HLA-DP are associated with response to peginterferon in Caucasian patients with chronic hepatitis B

BACKGROUND

Polymorphisms of the HLA-DP gene are associated with the natural clearance of the hepatitis B virus in Asian patients.

AIM

To investigate the association of HLA-DP polymorphisms with response to peginterferon (PEG-IFN) in Caucasian chronic hepatitis B (CHB) patients.

METHODS

We studied 262 Caucasian chronic hepatitis B patients infected with HBV genotype A or D, treated with PEG-IFN for 1 year in two randomised controlled trials (HBV 99-01 and PARC study). Response was defined as an HBV DNA <2000 IU/mL at 6 months post-treatment. Variations at HLA-DPA1 and HLA-DPB1 were genotyped.

RESULTS

Of the 262 patients, 58% was HBeAg-positive and HBV genotype A and D was observed in 32% and 68%, respectively. At 6 months post-treatment, 57 (22%) patients had achieved an HBV DNA <2000 IU/mL. HLA-DPB1 was independently associated with virological response [adjusted odds ratio (OR) 1.8, 95% confidence interval (CI):1.1-3.0, P = 0.025], and with an undetectable HBV DNA (adjusted OR 2.4 95% CI: 1.2-4.7, P = 0.015) when adjusted for HBeAg status and other known response modifiers. In HBeAg-positive patients, combined HBeAg seroconversion with HBV DNA <2000 IU/mL was increasingly observed with each addition of an HLA-DPB1 G-allele (adjusted OR 2.7, 95% CI: 1.2-5.9, P = 0.012). Furthermore, HLA-DPA1 and HLA-DPB1 haplotype block GG showed comparable results for virological and combined response.

CONCLUSION

In this large cohort of Caucasian chronic hepatitis B patients infected with HBV genotypes A or D, polymorphisms of HLA-DP are independently associated with both virological and serological response to PEG-IFN therapy at 6 months post-treatment.

Baseline hepatitis B surface antigen (HBsAg) as predictor of sustained HBsAg loss in chronic hepatitis B patients treated with pegylated interferon-α2a and adefovir

BACKGROUND

In this study, we aimed to identify baseline predictors of response in chronic hepatitis B patients treated with a combination of pegylated interferon (PEG-IFN)-α2a and adefovir.

METHODS

We treated 92 chronic hepatitis B patients (44 hepatitis B e antigen [HBeAg]-positive and 48 HBeAg-negative) with HBV DNA > 100,000 copies/ml (> 17,182 IU/ml) with PEG-IFN and adefovir for 48 weeks and followed them up for 2 years. Baseline markers for HBeAg loss, combined response (HBeAg negativity, HBV DNA levels ≤ 2,000 IU/ml and alanine aminotransferase [ALT] normalization) and hepatitis B surface antigen (HBsAg) loss were evaluated.

RESULTS

Two years after the end of treatment, rates of HBeAg loss and HBsAg loss in HBeAg-positive patients were 18/44 (41%) and 5/44 (11%), respectively. In HBeAg-negative patients, rates of combined response and HBsAg loss were 12/48 (25%) and 8/48 (17%), respectively. HBeAg-negative patients with HBsAg loss had lower baseline HBsAg levels than those without HBsAg loss (mean HBsAg 2.35 versus 3.55 log10 IU/ml; P < 0.001). They also had lower HBV DNA levels and were more often (PEG-)IFN experienced. Baseline HBsAg was the only independent predictor of HBsAg loss (OR 0.02; P = 0.01).

CONCLUSIONS

With combination therapy of PEG-IFN and adefovir for 48 weeks, a high rate of HBsAg loss was observed in both HBeAg-positive (11%) and HBeAg-negative (17%) patients 2 years after treatment ended. In HBeAg-negative patients, a low baseline HBsAg level was a strong predictor for HBsAg loss.

Chronic hepatitis B in 2014: great therapeutic progress, large diagnostic deficit

This review analyzes progress and limitations of diagnosis, screening, and therapy of patients with chronic hepatitis B infection. A literature review was carried out by framing the study questions. Vaccination in early childhood has been introduced in most countries and reduces the infection rate. Treatment of chronic hepatitis B can control viral replication in most patients today. It reduces risks for progression and may reverse liver fibrosis. The treatment effect on development of hepatocellular carcinoma is less pronounced when cirrhosis is already present. Despite the success of vaccination and therapy chronic hepatitis B remains a problem since many infected patients do not know of their disease. Although all guidelines recommend screening in high risk groups such as migrants, these suggestions have not been implemented. In addition, the performance of hepatocellular cancer surveillance under real-life conditions is poor. The majority of people with chronic hepatitis B live in resource-constrained settings where effective drugs are not available. Despite the success of vaccination and therapy chronic hepatitis B infection remains a major problem since many patients do not know of their disease. The problems in diagnosis and screening may be overcome by raising awareness, promoting partnerships, and mobilizing resources.

How to achieve immune control in chronic hepatitis B?

Chronic hepatitis B infection remains a major global health problem despite the existence of an effective vaccine. The current treatment options are either nucleos(t)ide analog therapy, which inhibits viral replication, or peginterferon-α, which has mainly immunomodulatory effects. However, treatment-induced HBeAg seroconversion with suppressed viral replication is mostly not sustainable, and loss of HBsAg is a rarely achieved endpoint. In addition, the hepatitis B virus persists in hepatocytes even after HBsAg clearance as covalently closed circular DNA is not eliminated from the hepatocytes. Because the course of chronic hepatitis B is determined by an ongoing interaction between the virus and the host immune system, immunomodulation may be the most logical approach in attempting to accomplish control or even cure of chronic hepatitis B. In the last years, methods for measuring the degree of immune control have been a major area of interest, with an important role for monitoring of HBsAg levels. In addition, new immunomodulatory agents are being developed and tested, providing promising options for future treatment.

Effect of hepatitis B virus genotypes on the efficacy of adefovir dipivoxil antiviral therapy

BACKGROUND

Hepatitis B is a common infectious disease in China. Many studies have shown that the genotype of hepatitis B virus (HBV) is probably associated with the efficacy of some antiviral drugs such as interferon α (IFN-α) and Lamivudine (LAM). However, the association between HBV genotype and adefovir dipivoxil (ADV) is controversial. ADV is the most popular antiviral drug in China due to its low price, good antiviral efficacy, few side effects, and convenient of administration.

OBJECTIVES

This study focused on the effect of HBV genotypes on antiviral efficacy of ADV in patients with chronic hepatitis B infection (CHB).

PATIENTS AND METHODS

A total of 526 HBeAg-positive patients with CHB were randomly allocated into two groups. One group took ADV and another group took placebo. Nested Polymerase Chain Reaction (PCR) with multiple pairs of genotype-specific primers (nPCR-MPP) was used to analyze genotypes of HBV in these patients. Antiviral efficacy after treatment for three, six, 12 months was compared among the patients with different HBV genotypes.

RESULTS

Genotype B (73.6%) and genotype C (26.4%) were detected in these patients. After treatment for 12 months, the rate of HBV DNA seroclearance, ALT normalization, and HBeAg seroconversion were significantly higher in ADV group than in placebo group (P < 0.05). However, there were no significant differences in these three rates between patients infected with genotype B and C (P > 0.05).

CONCLUSIONS

HBV genotypes B and C have no significant difference in virologic, biochemical, and immunologic response to ADV.

Off-treatment virologic relapse and outcomes of re-treatment in chronic hepatitis B patients who achieved complete viral suppression with oral nucleos(t)ide analogs

Background

The durability of off-treatment virologic responses has not been fully elucidated in chronic hepatitis B (CHB) patients who have previously achieved complete virologic suppression with nucleos(t)ide analog (NA) therapy. This study aimed to assess off-treatment virologic relapse rates and to characterize the outcomes of subsequent re-treatment in CHB patients who have discontinued oral NA following complete virologic suppression.

Methods

Ninety-five CHB patients who showed complete virologic suppression were withdrawn from NAs: entecavir, lamivudine, and clevudine in 67, 15, and 13 patients, respectively. Consolidation therapy was given for 6 and 12 months for HBeAg-positive and -negative CHB, respectively, before cessation. Virologic relapse was managed with the same NA that had induced complete virologic response before discontinuation.

Results

The cumulative rates of virologic relapse at 12 and 24 months were 73.8% and 87.1%, respectively. The relapse rates were independent of HBeAg positivity, HBeAg seroconversion, and type of oral NA. In a multivariate analysis, duration of oral NA therapy was the only significant predicting factor associated with off-treatment virologic relapse. Although the majority of patients regained complete virologic suppression, some patients did not respond to re-treatment with the initial NA and developed genotypic resistance.

Conclusions

NA consolidation therapy for 6 and 12 months is associated with high off-treatment virologic relapse in HBeAg-positive and -negative CHB patients, respectively. Drugs with high genetic barriers to resistance should be considered as a rescue therapy for off-treatment relapse in CHB.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-439) contains supplementary material, which is available to authorized users.

HBV clinical isolates expressing adefovir resistance mutations show similar tenofovir susceptibilities across genotypes B, C and D

BACKGROUND & AIMS

Hepatitis B virus (HBV) genotypes can influence clinical outcomes as well as response to antiviral therapy. This study evaluated the tenofovir (TFV) susceptibility of HBV genotype B, C and D clinical isolates with adefovir resistance-associated mutations (ADV-R).

METHODS

Full-length HBV isolates from patients infected with genotype B, C and D virus had rtA181T, rtA181V, rtN236T, rtA181T+rtN236T and rtA181V+rtN236T mutations introduced by site-directed mutagenesis. Phenotypic analyses were performed in HepG2 cells and susceptibility to TFV and ADV were assessed.

RESULTS

Clinical HBV isolates containing rtA181T, rtA181V or rtN236T as single mutants remained sensitive to TFV across genotypes B, C and D. Clinical isolates containing the rtA181T+rtN236T double mutant remained sensitive to TFV in genotype D but exhibited reduced susceptibility to TFV in genotypes B and C. Viruses containing the double mutant rtA181V+rtN236T in genotypes B and D exhibited reduced susceptibility to TFV with EC50 fold changes (FC) of 3.8 and 2.5, respectively, while genotype C viruses containing rtA181V+rtN236T either remained sensitive (FC=1.3) or exhibited reduced susceptibility to TFV (FC=2.9) depending on the isolate. All rtA181V+rtN236T isolates conferred reduced susceptibility to ADV (FC values 2.3-4.2).

CONCLUSIONS

Genotype B, C and D isolates with single ADV resistance mutations remained fully sensitive to TFV, while the double mutants rtA181T+rtN236T and rtA181V+rtN236T exhibited either no change or low-level reduced susceptibility to TFV across genotypes. These results are consistent with the clinical efficacy observed with tenofovir disoproxil fumarate (TDF) treatment across all genotypes in vivo and the limited impact of ADV-R mutations on TDF therapy.

HBsAg seroclearance after nucleoside analogue therapy in patients with chronic hepatitis B: clinical outcomes and durability

OBJECTIVE

Little is known about the long-term clinical outcome and durability of HBsAg seroclearance following nucleos(t)ide analogue (NUC) therapy in patients with chronic hepatitis B (CHB).

DESIGN

During a median follow-up period of 6 years (33 567 patient-years) of 5409 CHB patients who were initially treated with lamivudine or entecavir, a total of 110 achieved HBsAg seroclearance (0.33% annual seroclearance rate) and were included in this study.

RESULTS

Baseline alanine aminotransferase (ALT) level >5 times of upper limit of normal was associated with higher probability of HBsAg seroclearance (HR 1.80, p<0.01), while HBeAg positivity (HR 0.46, p<0.01), high HBV DNA level (log(10) IU/mL; HR 0.61, p<0.01), and cirrhosis (HR 0.48, p<0.01) were inversely associated with the probability of HBsAg seroclearance by multivariable analysis. During follow-up for 287 patient-years after HBsAg seroclearance, only two patients with baseline cirrhosis developed hepatocellular carcinoma (HCC) or died (0.7% annual risk), which was of a significantly lower rate compared with propensity score-matched patients without HBsAg seroclearance (HR 0.09, p<0.01). HBsAg reversion and/or HBV DNA reversion occurred in 18 patients, most of which were transient with extremely low serum levels of HBsAg (0.05-1.00 IU/mL) and HBV DNA (17-1818 IU/mL). None required retreatment. The cumulative probability of anti-HBs seroconversion (detection of anti-HBs) at 4 years was 67.4% by Kaplan-Meier analysis. Selection for lamivudine-resistance HBV mutants during treatment was not associated with composite reversion (p=0.66).

CONCLUSIONS

HBsAg seroclearance achieved after NUC treatment was associated with favourable clinical outcomes and was durable in most cases during long-term follow-up.

IFNL3 (IL28B) polymorphism does not predict long-term response to interferon therapy in HBeAg-positive chronic hepatitis B patients

The impact of IFNL3 (IL28B) polymorphism on response to interferon (IFN) treatment in patients infected with hepatitis B virus (HBV) is controversial. We aimed to investigate whether IFNL3 polymorphism (rs12979860) influences the long-term response of chronic hepatitis B (CHB) treatment to conventional IFN.

DESIGN

Ninety-seven HBeAg-positive patients treated with IFN were evaluated in this study. Associations were investigated between IFNL3 genotypes and (i) HBeAg seroconversion at the end of treatment (EOT), (ii) sustained virological response (SVR) and (iii) HBsAg seroconversion through long-term follow-up (LTFU). Patients were followed for a median of 14 years. The majority of patients were infected with HBV genotype A (69.6%) and were Caucasian (77.9%). Ninety-five patients were genotyped at rs12979860. Similar IFNL3 distribution was observed among the different ethnicities (P = 0.62) or across HBV genotypes A through G (P = 0.70). Thirty-six patients experienced HBeAg seroconversion at EOT; HBeAg seroconversion rates were 37.0 and 35.5% in patients with CC and CT/TT genotypes, respectively (P = 0.82). Among the 44 patients (45%) who achieved a SVR, SVR rates were 48.9 and 39.6% in patients with CC and CT/TT IL28B genotypes, respectively (P = 0.80). HBsAg seroconversion occurred through LTFU in 28 patients. HBsAg seroconversion rates were 25.5 and 31.2% in patients with CC and CT/TT genotypes, respectively (P = 0.51). No significant relationship between IFNL3 rs12979860 and fibrosis stage was observed (P = 0.85). IFNL3 genotype was neither associated with SVR, nor with HBeAg seroconversion and long-term HBsAg seroconversion in HBeAg-positive CHB patients responding to IFN therapy.

Peginterferon α in the treatment of chronic hepatitis B

INTRODUCTION

Hepatitis B virus (HBV) infection is a global health problem. Peginterferon α (PEG-IFN), which includes PEG-IFN α-2a (Pegasys) and PEG-IFN α-2b (Peg-Intron), can be used to treat patients with chronic hepatitis B (CHB) infection. A finite duration of PEG-IFN therapy may lead to long-term viral suppression. Clinically, it is important to identify super-responders and null-responders to PEG-IFN due to its substantial side effects.

AREAS COVERED

From the literature review, it is known that PEG-IFN is more effective for hepatitis B e antigen (HBeAg)-positive patients who have high pre-treatment alanine aminotransferase level, lower HBV DNA level and genotype A (vs genotype D), as well as those with more favourable viral predictors, such as precore stop codon or basal core promoter mutants infections in Asian patients and wild-type virus in Caucasian patients. For HBeAg-positive patients and HBeAg-negative patients with genotype D infection, PEG-IFN therapy could be terminated early at week 12 or 24 in primary non-responders defined by the Hepatitis B surface antigen stopping rules. With regard to host factors, single nucleotide polymorphisms of IL28B do not seem to affect the treatment outcomes in Asian patients, but its role in Caucasian patients remains disputed.

EXPERT OPINION

Most of the known predictors need validation by large prospective trials. In addition, we need to identify more baseline predictors for super-responders in order to achieve personalised PEG-IFN treatment for CHB.

The natural course of chronic hepatitis B virus infection and its management

Chronic infection with the hepatitis B virus (HBV) runs a long natural course during which underlying changes in liver histology can progress to cirrhosis and hepatic decompensation, as well as to hepatocellular carcinoma. Therapeutic intervention is currently aiming at suppression of HBV replication by applying a number of pharmacological agents. For an optimum use of available therapies, good knowledge of the natural course of chronic infection, as well as of the role played by several viral, host, and environmental factors, is mandatory. The larger part of this chapter deals with how to treat the various subsets of patients with chronic hepatitis B (CHB), using mainly three first-line drugs: pegylated interferon-α2a, entecavir, and tenofovir, administered either in finite courses or indefinitely. The frequency of virological, serological, biochemical, and histological responses in the various subsets of patients, both during and after stopping treatment, is reviewed. It is stressed that the application of the highly potent antivirals entecavir and tenofovir, with acceptable safety records and with a high barrier to HBV resistance, represents major progress in the treatment of CHB. Despite the hitherto important developments in the treatment of viral hepatitis B, clinical cure of chronic HBV infection with HBsAg loss is achievable only in a few treated patients while eradication of HBV infection appears unrealistic. Development of new pharmacological agents acting at multiple targets of the replicative cycle of HBV may achieve higher efficacy and even cure of CHB.

Molecular identification of hepatitis B virus genotypes/subgenotypes: revised classification hurdles and updated resolutions

The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the high genetic variability of HBV, the virus can be categorized into different HBV genotypes and subgenotypes, which considerably differ with respect to geographical distribution, transmission routes, disease progression, responses to antiviral therapy or vaccination, and clinical outcome measures such as cirrhosis or hepatocellular carcinoma. However, HBV (sub)genotyping has caused some controversies in the past due to misclassifications and incorrect interpretations of different genotyping methods. Thus, an accurate, holistic and dynamic classification system is essential. In this review article, we aimed at highlighting potential pitfalls in genetic and phylogenetic analyses of HBV and suggest novel terms for HBV classification. Analyzing full-length genome sequences when classifying genotypes and subgenotypes is the foremost prerequisite of this classification system. Careful attention must be paid to all aspects of phylogenetic analysis, such as bootstrapping values and meeting the necessary thresholds for (sub)genotyping. Quasi-subgenotype refers to subgenotypes that were incorrectly suggested to be novel. As many of these strains were misclassified due to genetic differences resulting from recombination, we propose the term "recombino-subgenotype". Moreover, immigration is an important confounding facet of global HBV distribution and substantially changes the geographic pattern of HBV (sub)genotypes. We therefore suggest the term "immigro-subgenotype" to distinguish exotic (sub)genotypes from native ones. We are strongly convinced that applying these two proposed terms in HBV classification will help harmonize this rapidly progressing field and allow for improved prophylaxis, diagnosis and treatment.

Patients with interferon-induced HBeAg seroconversion have a higher risk of HBV reactivation and HBeAg seroreversion

PURPOSE

It remains unclear whether chronic hepatitis B patients who undergo interferon (IFN)-induced hepatitis B e antigen (HBeAg) seroconversion have a higher risk of hepatitis B virus (HBV) reactivation and HBeAg seroreversion than those with spontaneous HBeAg seroconversion.

METHODS

A total of 80 and 251 non-cirrhotic patients with interferon-induced and spontaneous HBeAg seroconversion, respectively, were analyzed.

RESULTS

Compared to spontaneous HBeAg seroconverters, more IFN-induced HBeAg seroconverters were males (p = 0.004). For all patients, the IFN-induced HBeAg seroconverters faced a higher risk of HBV reactivation and HBeAg seroreversion than spontaneous HBeAg seroconverters (p < 0.001). For spontaneous HBeAg seroconverters, age at HBeAg seroconversion, male sex, HBV genotype C, and pre-S deletions were independent predictors of HBV reactivation. For IFN-induced HBeAg seroconverters, older age at baseline and HBV genotype C were independent predictors of HBV reactivation. To determine whether the difference in the rates of HBV reactivation or HBeAg seroreversion between two groups was age-dependent, patients were grouped and analyzed according to their age at HBeAg seroconversion (20-30, 31-39, ≥40 years). IFNs treatment was an independent factor in HBV reactivation and HBeAg seroreversion only in the groups of patients 31-39 and ≥40 years of age, but not in the group of patients 20-30 years of age.

CONCLUSIONS

IFN-induced rather than spontaneous HBeAg seroconversion was associated with higher risk of HBV reactivation and HBeAg seroreversion, especially in patients who were older than 30 years at HBeAg seroconversion.

Management of chronic hepatitis B infection: current treatment guidelines, challenges, and new developments

Chronic hepatitis B (CHB) virus infection is a global public health problem, affecting more than 400 million people worldwide. The clinical spectrum is wide, ranging from a subclinical inactive carrier state, to progressive chronic hepatitis, cirrhosis, decompensation, and hepatocellular carcinoma. However, complications of hepatitis B virus (HBV)-related chronic liver disease may be reduced by viral suppression. Current international guidelines recommend first-line treatment of CHB infection with pegylated interferon, entecavir, or tenofovir, but the optimal treatment for an individual patient is controversial. The indications for treatment are contentious, and increasing evidence suggests that HBV genotyping, as well as serial on-treatment measurements of hepatitis B surface antigen and HBV DNA kinetics should be used to predict antiviral treatment response. The likelihood of achieving a sustained virological response is also increased by extending treatment duration, and using combination therapy. Hence the paradigm for treatment of CHB is constantly evolving. This article summarizes the different indications for treatment, and systematically reviews the evidence for the efficacy of various antiviral agents. It further discusses the shortcomings of current guidelines, use of rescue therapy in drug-resistant strains of HBV, and highlights the promising clinical trials for emerging therapies in the pipeline. This concise overview presents an updated practical approach to guide the clinical management of CHB.

Chronic hepatitis B: Advances in treatment

Treatment of chronic hepatitis B (CHB) has markedly improved in the last 15 years due to the availability of direct antivirals which greatly increase therapeutic options. Currently, there are two classes of agents licensed for CHB treatment: standard or pegylated interferon alpha (IFN or Peg-IFN) and five nucleoside/nucleotide analogues (NAs). Long-term treatment with NAs is the treatment option most often used in the majority of CHB patients. Entecavir and tenofovir, the most potent NAs with high barrier to resistance, are recommended as first-line monotherapy by all major treatment guidelines and can lead to long-lasting virological suppression, resulting in histological improvement or reversal of advanced fibrosis and reduction in disease progression and liver-related complications. In this review, we focus on current treatment strategies of chronic hepatitis B and discuss the most recent efficacy and safety data from clinical trials and real life clinical practice. Recent findings of response-guided approaches are also discussed.

Telbivudine versus entecavir for nucleos(t)ide-naive HBeAg-positive chronic hepatitis B: a meta-analysis

BACKGROUND

We performed a meta-analysis to compare the efficacies of entecavir and telbivudine in treatment-naive hepatitis B e-antigen (HBeAg)-positive Asian patients with chronic hepatitis B (CHB).

METHODS

Randomized controlled trials (January 1, 2000 to March 30, 2012) directly comparing entecavir 0.5 mg/d and telbivudine 600 mg/d, used for a minimum of 12 weeks in nucleos(t)ide-naive Asian patients with HBeAg-positive CHB, were searched in the PubMed, Embase, OVID, Cochrane Library, CNKI, VIP and WanFang databases. Publication quality was assessed using the Jadad quality scale. The rates of viral response, biochemical response, HBeAg loss and HBeAg seroconversion were analyzed using forest plots.

RESULTS

Seven eligible articles (867 patients in total) were included in this meta-analysis. With regard to the rates of hepatitis B virus DNA suppression, there were no significant differences between patients treated with entecavir or telbivudine at 12 and 48 weeks, but telbivudine was superior at 24 weeks. Twelve, 24 and 48 weeks after the start of therapy, the rates of alanine aminotransferase normalization were similar between the 2 drugs, and patients treated with telbivudine had higher HBeAg loss and seroconversion rates than patients treated with entecavir.

CONCLUSIONS

In nucleos(t)ide-naive Asian patients with HBeAg-positive CHB, assessed 12, 24, and 48 weeks after beginning treatment, telbivudine was as potent as entecavir in viral suppression, but superior with regard to HBeAg loss and seroconversion. Telbivudine seems to be more effective and suitable for these patients.

HBeAg-positive chronic hepatitis B: why do i treat my patients with Nucleos(t)ide analogs?

The ultimate goal of therapy for hepatitis B virus (HBV) infection is to obtain a clinical benefit for the patient by reducing infection-related complications, including hepatocellular carcinoma (HCC). Two main types of antiviral agents have been approved to treat patients in the immune clearance phase: interferon (IFN) and nucleos(t)ide analogues (NAs). NAs are used in most HBeAg-positive chronic hepatitis B patients for several reasons. They are oral drugs that are taken once a day and can be prescribed to all chronic hepatitis B patients, even those with contraindications for IFN. The current first-line NA options, entecavir (ETV) and tenofovir (TDF), have minimal or no risk of long-term resistance, and the sustained virological response is achieved in almost 100% of adherent HBeAg-positive patients. Tolerance is excellent and the safety profile is good, whereas IFN can be associated with adverse events that affect the patients' quality of life. There is considerable evidence to show that NAs modify the natural history of chronic hepatitis B, and increasing evidence that they reduce the risk of developing HCC. The need for long-term, perhaps indefinite treatment in patients who do not achieve anti-HBe seroconversion is the main limitation of NAs, but this is offset by their excellent tolerance and safety profile.

HBeAg-positive chronic hepatitis B: why do I treat my patients with pegylated interferon?

Although chronic hepatitis B (CHB) is a global health threat, it is now a preventable and treatable disease. Seven agents have been approved for the treatment of CHB. Although many patients prefer potent long-term nucleos(t)ide analogues (NAs) as the first-line therapy because they are convenient to use and well-tolerated, a finite duration of pegylated interferon (PEG-IFN) is still an attractive strategy because it provides higher rates of off-therapy host immune control over hepatitis B virus (HBV) compared with NAs. In addition, the rates of HBeAg/HBsAg loss or seroconversion increase over time in patients who respond to PEG-IFN therapy. Nevertheless, these benefits are limited to 30% of all patients, and significant adverse effects are still a concern. Therefore, patients who can benefit most from PEG-IFN therapy should be more carefully selected according to baseline host and viral predictors, such as age, ALT level, viral load, HBV genotype and HBV mutants. In addition, on-treatment predictors including HBV DNA, HBeAg and HBsAg kinetics, can help decide who should continue or discontinue PEG-IFN and shift to NA. Understanding these factors can help determine personalized PEG-IFN therapy for CHB patients. In the near future, the treatment paradigm of CHB should be tailored on the basis of viral (HBV DNA level, HBV genotype and HBV mutants) and host (age, gender, ALT level and host genetic polymorphisms) factors, disease status (stage of fibrosis and comorbidities) and the selection of antiviral agents (immunomodulatory effect, antiviral potency, adverse effects and rate of drug resistance).

Loss of HBsAg and antiviral treatment: from basics to clinical significance

Accurate prediction of the sustained virological response (SVR) to antiviral therapy against chronic hepatitis B (CHB) is still a crucial problem needing profound investigation. In recent years, quantification of hepatitis B surface antigen (HBsAg), a reliable predictor of SVR and an ideal endpoint of treatment, has attracted increasing attention. Serum HBsAg titer may reflect the level of intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in most patients, and vary with natural phases of chronic HBV infection, genotypes and variants, antiviral therapy, and other related factors. Serum HBsAg <200 IU/mL or yearly reduction ≥0.5 log10IU/mL may be the optimum cut-off values for prediction of the chance of spontaneous seroclearance of HBsAg. Serum HBsAg <1,000 IU/mL with HBV DNA <2,000 IU/mL may identify most of the inactive HBV carriers from active HBeAg(-) hepatitis. Interferon-based therapy can lead to more significant HBsAg decline than therapy based on nucleoside and/or nucleotide analogues. Different patterns or kinetics of HBsAg decline during therapy are related to different probabilities of SVR. A low HBsAg level, <3,000 IU/mL at baseline, or HBsAg level, <1,500 IU/mL at week 12, or a rapid on-treatment HBsAg decline of ≥0.5 log10IU/mL at week 12, may predict higher probability of SVR. However these cut-off values must be further validated for larger cohort of patients across genotypes worldwide. Incorporation of serum HBsAg level, HBeAg status, HBV DNA load, HBV genotypes, and other related factors might help establish new concept of more practical "response-guided treatment (RGT)" rules for antiviral therapy.

Management of hepatitis B: our practice and how it relates to the guidelines

Seven drugs have been approved for the treatment of chronic hepatitis B. Antiviral treatment has been shown to be effective in suppressing hepatitis B virus replication, decreasing inflammation and fibrosis in the liver, and preventing progression of liver disease. However, current medications do not eradicate hepatitis B virus; therefore, a key question is which patients need to start treatment and which patients can be monitored. Professional societies have developed guidelines to assist physicians in recognition, diagnosis, and optimal management of patients with chronic hepatitis B. These guidelines suggest preferred approaches, and physicians are expected to exercise clinical judgment to determine the most appropriate management based on the circumstances of the individual patient. This article reviews recommendations in hepatitis B guidelines and the basis for those recommendations, and we discuss what we do in our practice to illustrate factors that may influence decisions regarding hepatitis B management.

Strategies to eliminate HBV infection

Chronic HBV infection is a major public health concern affecting over 240 million people worldwide. Although suppression of HBV replication is achieved in the majority of patients with currently available newer antivirals, discontinuation of therapy prior to hepatitis B surface antigen loss or seroconversion is associated with relapse of HBV in the majority of cases. Thus, new therapeutic modalities are needed to achieve eradication of the virus from chronically infected patients in the absence of therapy. The basis of HBV persistence includes viral and host factors. Here, we review novel strategies to achieve sustained cure or elimination of HBV. The novel approaches include targeting the viral and or host factors required for viral persistence, and novel immune-based therapies, including therapeutic vaccines.

Anti-viral treatment and cancer control

Hepatitis B virus (HBV), hepatitis C virus (HCV), human papillomavirus (HPV), and Epstein-Barr virus (EBV) contribute to about 10-15 % global burden of human cancers. Conventional chemotherapy or molecular target therapies have been used to treat virus-associated cancers. However, a more proactive approach would be the use of antiviral treatment to suppress or eliminate viral infections to prevent the occurrence of cancer in the first place. Antiviral treatments against chronic HBV and HCV infections have achieved this goal, with significant reduction in the incidence of hepatocellular carcinoma in treated patients. Antiviral treatments for EBV, Kaposi's sarcoma-associated herpesvirus (KSHV), and human T-cell lymphotropic virus type 1 (HTLV-1) had limited success in treating refractory EBV-associated lymphoma and post-transplant lymphoproliferative disorder, KSHV-associated Kaposi's sarcoma in AIDS patients, and HTLV-1-associated acute, chronic, and smoldering subtypes of adult T-cell lymphoma, respectively. Therapeutic HPV vaccine and RNA-interference-based therapies for treating HPV-associated cervical cancers also showed some encouraging results. Taken together, antiviral therapies have yielded promising results in cancer prevention and treatment. More large-scale studies are necessary to confirm the efficacy of antiviral therapy. Further investigation for more effective and convenient antiviral regimens warrants more attention.

Cost-effectiveness of viral hepatitis B & C treatment

With the availability of effective antiviral therapies for chronic viral hepatitis B and C, cost-effectiveness studies have been performed to assess the outcomes and costs of these therapies to support health policy. It is now accepted that treatment of active CHB is cost-effective versus no treatment, although there are a variety of options. And with the new developments around CHC treatment and diagnostic tools it is of interest to both the clinician and policy makers to know both the costs and effects of these choices. The purpose of this article is to provide the reader with an insight into the recent treatment developments and cost-effectiveness issues related to chronic hepatitis B and C treatment, and an overview of recent cost-effectiveness studies evolving around HBV and HCV therapy.

Response-guided peginterferon therapy in hepatitis B e antigen-positive chronic hepatitis B using serum hepatitis B surface antigen levels

On-treatment levels of hepatitis B surface antigen (HBsAg) may predict response to peginterferon (PEG-IFN) therapy in chronic hepatitis B (CHB), but previously proposed prediction rules have shown limited external validity. We analyzed 803 HBeAg-positive patients treated with PEG-IFN in three global studies with available HBsAg measurements. A stopping-rule based on absence of a decline from baseline was compared to a prediction-rule that uses HBsAg levels of <1,500 IU/mL and >20,000 IU/mL to identify patients with high and low probabilities of response. Patients with an HBsAg level <1,500 IU/mL at week 12 achieved response (HBeAg loss with HBV DNA <2,000 IU/mL at 6 months posttreatment) in 45%. At week 12, patients without a decline in HBsAg achieved a response in 14%, compared to only 6% of patients with HBsAg >20,000 IU/mL, but performance varied across HBV genotype. In patients treated with PEG-IFN monotherapy (n = 465), response rates were low in patients with genotypes A or D if there was no decline of HBsAg by week 12 (negative predictive value [NPV]: 97%-100%), and in patients with genotypes B or C if HBsAg at week 12 was >20,000 IU/mL (NPV: 92%-98%). At week 24, nearly all patients with HBsAg >20,000 IU/mL failed to achieve a response, irrespective of HBV genotype (NPV for response and HBsAg loss 99% and 100%).

CONCLUSION

HBsAg is a strong predictor of response to PEG-IFN in HBeAg-positive CHB. HBV genotype-specific stopping-rules may be considered at week 12, but treatment discontinuation is indicated in all patients with HBsAg >20,000 IU/mL at week 24, irrespective of HBV genotype.

Extended treatment with peginterferon α-2a in combination with lamivudine or adefovir for 96 weeks yields high rates of HBeAg and HBsAg seroconversion

OBJECTIVE

The study aimed to investigate the efficacy and safety of peginterferon α-2a (PEG IFNα-2a) in combination with lamivudine or adefovir in the treatment of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB).

METHODS

In total, 47 patients with HBeAg-positive CHB received either PEG IFNα-2a (135 μg once weekly) plus lamivudine (100 mg daily) or adefovir (10 mg daily). All patients completed 96 weeks of therapy and were followed up for a further 24 weeks.

RESULTS

Baseline characteristics and treatment efficacy of the two groups were similar. All patients achieved hepatitis B virus (HBV) DNA <500 copies/mL at 96 weeks, and none had a virological rebound after stopping the therapy. The rate of HBeAg seroconversion was 46.8% at 48 weeks, increased to 74.5% at 96 weeks, and kept at 72.3% at 120 weeks. Hepatitis B surface antigen (HBsAg) seroconversion rate was 6.4% at 48 weeks, increased to 21.3% at 96 weeks, and kept at 27.7% at 120 weeks.

CONCLUSIONS

Extended treatment with PEG IFNα-2a with lamivudine or adefovir for 96 weeks is a promising strategy to achieve high rates of sustainable HBeAg and HBsAg seroconversion and HBV DNA suppression in patients with HBeAg-positive CHB.

Impact of therapy on the long-term outcome of chronic hepatitis B

Chronic hepatitis B virus (HBV) infection is a dynamic state of interactions between HBV, the hepatocytes, and the patient's immune system. HBV replication is the key driving force for the HBV-related immune clearance events that determine the outcomes. The extended immune clearance phase is associated with liver disease progression, including development of cirrhosis and hepatocellular carcinoma (HCC). Thus, the primary aim of therapy is to eliminate or permanently suppress HBV to reduce hepatitis activity and thereby reduce the risk or slow the progression of liver disease.

Clearance of hepatitis B surface antigen during long-term nucleot(s)ide analog treatment in chronic hepatitis B: results from a nine-year longitudinal study

BACKGROUND

Clearance of hepatitis B surface antigen (HBsAg) is considered the ultimate goal in chronic hepatitis B treatment. One treatment option is long-term nucleot(s)ide analog (NA) therapy. We followed a group of long-term NA therapy patients to evaluate the efficacy of this treatment in promoting clearance and longitudinal declines of HBsAg.

METHOD

The study included 791 NA therapy patients who received lamivudine as their first drug. At the baseline, 442 patients were hepatitis B e antigen (HBeAg)+ and 349 were HBeAg-. All analyses were performed after separating the HBeAg+ and HBeAg- cohorts. Cox proportional hazards models were used to determine which factors were associated with HBsAg clearance.

RESULTS

HBsAg clearance was observed in 18 (4.1 %) of the HBeAg+ patients and 20 (5.7 %) of the HBeAg- patients at baseline, giving seroclearance rates of 6.4 and 6.9 %, respectively, over the nine-year study period. HBsAg clearance was influenced by several independent factors that varied according to HBeAg cohort. For HBeAg+ patients, these included previous interferon therapy, infection with hepatitis B virus (HBV) genotype A, a ≥0.5 log IU/mL decline in HBsAg level within six months, and clearance of HBeAg at six months. For HBeAg- patients, these included infection with HBV genotype A, decline in HBsAg at six months, and a baseline HBsAg level of <730 IU/mL.

CONCLUSION

This study suggests that both direct antiviral potential and host immune response are needed to achieve HBsAg clearance by NA therapy. Viral genotype strongly influenced HBsAg clearance during NA therapy.

Results of treatment of chronic hepatitis B with pegylated interferon

Persistent viral eradication or suppression through a defined course of Pegylated-interferon (PegIFN) or the administration of a long-term potent nucleot(s)ide analogues (NUCs) can impact positively the natural course of HBV infection by preventing disease progression. Despite the higher rates of off-therapy response achieved with PegIFN compared with NUC, its benefits are restricted to a subgroup of patients only. To increase the rates of patients who may benefit from PegIFN treatment, minimizing the adverse events, careful patient selections based on baseline features and on treatment HBsAg kinetics for individual treatment optimization are required.

Serum levels of interferon-gamma-inducible protein 10 and response to peginterferon therapy in HBeAg-positive chronic hepatitis B

BACKGROUND & AIMS

Serum levels of interferon-gamma inducible protein 10 (IP-10) are a marker for immune activity, and may predict response to peginterferon (PegIFN) therapy in chronic hepatitis B.

METHODS

IP-10 was measured at baseline and on-treatment week 12 in 210 HBeAg-positive patients treated with PegIFN for 52 weeks. Response to treatment was assessed at 6 months post-treatment and defined as HBeAg loss, combined response (HBeAg loss with HBV DNA <10,000 c/ml) or HBsAg loss.

RESULTS

Median baseline IP-10 levels were 158 pg/ml. Higher baseline IP-10 was associated with more HBV DNA, HBeAg and HBsAg decline from week 4 onwards, and IP-10 was higher in patients who achieved HBeAg loss (p=0.001) and combined response (p=0.052). A combination of high IP-10 (>150 pg/ml) with absence of precore (PC) and core promoter (BCP) mutants strongly predicted combined response and HBsAg loss: 48% of patients with high IP-10 and no detectable mutants achieved a combined response (p<0.001). A minimal non-significant decline from baseline was observed to week 12 (0.015 log pg/ml, p=0.52 compared to baseline), but decline was somewhat more pronounced in patients who achieved HBeAg loss (0.05 logpg/ml, versus an increase of 0.05 in patients without HBeAg loss, p=0.04).

CONCLUSIONS

Higher pre-treatment IP-10 levels are associated with an increased probability of HBeAg loss after PegIFN therapy. A combination of high baseline IP-10 and absence of PC and BCP mutants identified patients with the highest probability of combined response and HBsAg loss. There appears little use for on-treatment quantification of IP-10 for prediction of response to PegIFN.

Precore and core promoter mutants are associated with higher HBeAg seroconversion but low disease remission rates in HBV patients treated with nucleos(t)ide analogues

HBeAg seroconversion in HBV patients is considered an important event. We determined precore (PC) and base core promoter (BCP) mutations in 137 HBeAg-positive nucleos(t)ide analogues (NA) treated patients by INNO-LiPA HBV PreCore assay (Innogenetics). The majority of patients with nongenotype A had PC/BCP mutants present at baseline (P = 0.02). During 29 months of therapy, 45 patients achieved HBeAg seroconversion. Probability of HBeAg seroconversion was higher in patients with PC and/or BCP mutants (P = 0.01). After HBeAg seroconversion, patients with BCP mutants had more HBeAg relapse (P = 0.07), and PC mutants less often achieved HBV DNA < 2000 IU/mL (P = 0.07).