Transaminase Elevations during Treatment of Chronic Hepatitis B Infection: Safety Considerations and Role in Achieving Functional Cure

While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.

Nucleic acid polymer REP 2139 and nucleos(T)ide analogues act synergistically against chronic hepadnaviral infection in vivo in Pekin ducks

Nucleic acid polymer (NAP) REP 2139 treatment was shown to block the release of viral surface antigen in duck HBV (DHBV)-infected ducks and in patients with chronic HBV or HBV/hepatitis D virus infection. In this preclinical study, a combination therapy consisting of REP 2139 with tenofovir disoproxil fumarate (TDF) and entecavir (ETV) was evaluated in vivo in the chronic DHBV infection model. DHBV-infected duck groups were treated as follows: normal saline (control); REP 2139 TDF; REP 2139 + TDF; and REP 2139 + TDF + ETV. After 4 weeks of treatment, all animals were followed for 8 weeks. Serum DHBsAg and anti-DHBsAg antibodies were monitored by enzyme-linked immunosorbent assay and viremia by qPCR. Total viral DNA and covalently closed circular DNA (cccDNA) were quantified in autopsy liver samples by qPCR. Intrahepatic DHBsAg was assessed at the end of follow-up by immunohistochemistry. On-treatment reduction of serum DHBsAg and viremia was more rapid when REP 2139 was combined with TDF or TDF and ETV, and, in contrast to TDF monotherapy, no viral rebound was observed after treatment cessation. Importantly, combination therapy resulted in a significant decrease in intrahepatic viral DNA (>3 log) and cccDNA (>2 log), which were tightly correlated with the clearance of DHBsAg in the liver.

CONCLUSION

Synergistic antiviral effects were observed when REP 2139 was combined with TDF or TDF + ETV leading to control of infection in blood and liver, associated with intrahepatic viral surface antigen elimination that persisted after treatment withdrawal. Our findings suggest the potential of developing such combination therapy for treatment of chronically infected patients in the absence of pegylated interferon. (Hepatology 2018;67:2127-2140).

Dual-Labeled Time-Resolved Immunofluorometric Assay for the Simultaneous Quantitative Detection of Hepatitis B Virus Antigens in Human Serum

In this paper, a novel time-resolved fluorescence immunoassay (TRFIA) is described that allows the simultaneous quantitative detection of hepatitis B virus surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in human serum to aid the diagnosis and monitoring of hepatitis B virus infection. The proposed method was developed based on a two-step sandwich immunoassay protocol in which monoclonal antibodies against HBsAg and HBeAg were co-coated in 96 microtitration wells, then tracer polyclonal antibodies against HBsAg labeled with samarium and tracer monoclonal antibodies against HBeAg labeled with europium chelates were used for detection. The detection range was 0.1-150 IU/mL for HBsAg and 0.5-160 PEIU/mL for HBeAg, and the detection limits were 0.03 IU/L and 0.09 PEIU/ml, respectively. The intra- and inter-assay coefficients of variation were below 8 % for both virus antigens. The dilution linearity and accuracy of the assay were satisfactory. No statistically significant differences were observed in sensitivity or specificity for the serum samples between the dual-label TRFIA and a commercial single-label TRFIA. These results demonstrate that an effective, reliable and convenient HBsAg/HBeAg dual-label TRFIA was successfully developed that may be clinically applicable for blood screening to monitor the course of hepatitis B virus infection and predict treatment responses.

Nucleic acid polymers: Broad spectrum antiviral activity, antiviral mechanisms and optimization for the treatment of hepatitis B and hepatitis D infection

Antiviral polymers are a well-studied class of broad spectrum viral attachment/entry inhibitors whose activity increases with polymer length and with increased amphipathic (hydrophobic) character. The newest members of this class of compounds are nucleic acid polymers whose activity is derived from the sequence independent properties of phosphorothioated oligonucleotides as amphipathic polymers. Although the antiviral mechanisms and broad spectrum antiviral activity of nucleic acid polymers mirror the functionality of other members of this class, they exert in addition a unique post entry activity in hepatitis B infection which inhibits the release of HBsAg from infected hepatocytes. This review provides a general overview of the antiviral polymer class with a focus on nucleic acid polymers and their development as therapeutic agents for the treatment of hepatitis B/hepatitis D. This article forms part of a symposium in Antiviral Research on ''An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B.''.

Viral determinants predicting hepatitis B surface antigen (HBsAg) seroclearance in HIV-/HBV-coinfected patients

The aim of this retrospective study was the identification of clinically useful viral determinants for the prediction of hepatitis B surface antigen (HBsAg) seroclearance and sustained virological response in hepatitis B virus/human immunodeficiency virus (HBV-/HIV)-coinfected patients receiving HBV-active combined antiretroviral therapy (cART). Quantification of HBsAg, HBeAg and HBV DNA before and after initiation of HBV-active cART in a cohort of 59 HIV-/HBV-coinfected patients was performed. Calculations of receiver operating characteristics (ROC) and Kaplan-Meier analysis were used for the identification of predictors of HBsAg seroclearance for HBeAg-positive [HBeAg(+); n = 36] and HBeAg-negative [HBeAg(-);n = 23] patients. HBeAg(+) patients with an HBsAg on-treatment decline ≥ 1 log IU/mL per year achieved higher HBsAg loss rates (P = 0.0294), whereas the quantification of HBeAg had no predictive value for HBsAg seroclearance. Among HBeAg(-) patients, a pretreatment baseline cut-off level of HBsAg ≤ 100 IU/mL was highly predictive for HBsAg seroclearance. No significant influence of the HBV genotype on HBsAg seroclearance was observed among the entire cohort. Quantitative determination of HBsAg provides a clinically useful viral parameter for the prediction of HBsAg seroclearance both in HBeAg(+) and HBeAg(-) HIV-/HBV-coinfected patients receiving HBV-active cART.

Guidelines for avoiding risks resulting from discontinuation of nucleoside/nucleotide analogs in patients with chronic hepatitis B

Nucleoside/nucleotide analogs (NUC) can lead to rapid reduction in hepatitis B virus (HBV) DNA levels in blood and normalization of alanine aminotransferase levels in many patients. They also provide histological improvement which results in a reduction in liver carcinogenesis. However, it is difficult to completely remove viruses even by NUC and there are some problems such as emergence of resistant strains and hepatitis relapse resulting from discontinuation of treatment. One of the reasons for this is that NUC reduce the HBV DNA level in blood but have almost no effects on the HBV cccDNA level in hepatocyte nuclei, which are the origins of HBV replication, and HBV cccDNA remains for a long period. For treatment with NUC in patients with hepatitis B, it is considered that NUC should not be easily discontinued because discontinuation often results in hepatitis relapse. However, it has not been clearly revealed when and how hepatitis relapses after discontinuation. Although some patients do not experience hepatitis relapse after discontinuation of NUC, or experience only mild relapse and finally achieve a stable condition, it has not been established how to identify such patients efficiently. We performed research to investigate characteristics of the course after discontinuation of treatment and definition of hepatitis relapse and estimate the relapse rate. "Guidelines for avoiding risks resulting from discontinuation of NUCs 2012" is summarized based on the study results. Because the guidelines are written in Japanese, we explain them in English as a review article.

Hepatitis B viral factors and treatment responses in chronic hepatitis B

Baseline and on-treatment hepatitis B viral factors are reported to affect treatment responses. A lower baseline hepatitis B virus (HBV) DNA level is a strong predictor of the response to antiviral therapy. HBV genotype A/B patients have better responses to interferon-based therapy than those with genotypes C/D. Regarding the association of HBV mutants with responses to antiviral therapy, current evidence is limited. On-treatment viral suppression is the most important predictor of response to nucleoside analogs. On-treatment hepatitis B surface antigen decline is significantly associated with response to pegylated interferon. In the future, individualized therapy should be based on treatment efficacy, adverse effects, baseline and on-treatment predictors of antiviral therapy.

Combination of hepatitis B viral antigens and DNA for prediction of relapse after discontinuation of nucleos(t)ide analogs in patients with chronic hepatitis B

AIM

  The factors associated with hepatitis recurrence after discontinuation of nucleos(t)ide analogs (NAs) in patients with chronic hepatitis B were analyzed to predict the risk of relapse more accurately.

METHODS

  A total of 126 patients who discontinued NA therapy were recruited retrospectively. The clinical conditions of a successful discontinuation were set as alanine aminotransferase (ALT) below 30 IU/L and serum hepatitis B virus (HBV) DNA below 4.0 log copies/mL.

RESULTS

  Relapse of hepatitis B were judged to occur when maximal serum ALT became higher than 79 IU/L or when maximal serum HBV DNA surpassed 5.7 log copies/mL following NA discontinuation since these values corresponded with mean values of ALT (30 IU/L) and HBV DNA (4.0 log copies/mL), respectively. At least 90% of patients with either detectable hepatitis B e antigen or serum HBV DNA higher than 3.0 log copies/mL at the time of NA discontinuation relapsed within one year. In the remaining patients, higher levels of both hepatitis B surface and core-related antigens at the time of discontinuation, as well as a shorter course of NA treatment, were significantly associated with relapse by multivariate analysis.

CONCLUSIONS

  It appears that negative results for hepatitis B e antigen and serum HBV DNA lower than 3.0 log copies/mL are essential for successful NA discontinuation, which may be attained by a longer treatment period. Levels of hepatitis B surface and core-related antigens are also significant factors independently associated with relapse of hepatitis.

Serum hepatitis B surface antigen monitoring in long-term lamivudine-treated hepatitis B virus patients

Serum hepatitis B virus surface antigen (HBsAg) levels have been suggested to predict interferon response in chronic hepatitis B. A few data are available on the role of HBsAg measurement in nucleos(t)ide analogues (NA) treatment. We retrospectively investigated the relation between HBsAg changes and main treatment outcomes during long-term lamivudine treatment in hepatitis e antigen (HBeAg)-negative chronic hepatitis B. A total of 42 HBeAg-negative patients were consecutively enrolled in an open-label study on long-term lamivudine monotherapy (150 mg/die). Serum HBsAg levels were quantified every 6 months by Architect assay (Abbott Diagnostics). HBV-DNA was quantified quarterly by real-time PCR (Roche Diagnostics). The median duration of lamivudine treatment was 66 months (20-153). One patient (2%) was a primary nonresponder, 35 (83%) developed virological breakthrough (VB) and the remaining six patients (14%) were classified as long-term on-treatment responders. During treatment, HBsAg levels decreased only in long-term on-treatment responders, while no changes were observed in resistant patients. Failure to achieve a decrease of 0.7 log(10) IU/mL in serum HBsAg at month six of lamivudine had a positive predictive value of developing VB of 90% and a negative predictive value of 100%. These high predictive values were also maintained in the subgroup of patients negative for HBV-DNA at month six. The results of this study with a small sample size suggest a role of on-treatment HBsAg quantification in the management of lamivudine-treated patients. If validated prospectively in a larger patient cohort, HBsAg measurements would be a useful adjunct to optimize antiviral therapy.

Sequential therapy with adefovir dipivoxil and pegylated interferon alfa-2a for HBeAg-negative patients

To assess the impact of sequential therapy with adefovir dipivoxil (ADV) and pegylated interferon alfa-2a (PEG-IFN) on virological (serum HBV-DNA) and serological (serum HBsAg) response in 20 consecutive HBeAg-negative patients. Patients received ADV for 20 weeks, then ADV and PEG-IFN for 4 weeks and lastly PEG-IFN for 44 weeks. Serum HBV-DNA and HBsAg were assessed at baseline, during therapy (weeks 20, 44 and 68) and follow-up (weeks 92 and 116). Sustained virological response (SVR) was defined as serum HBV-DNA <10 000 copies/mL (partial) or <70 copies/mL (complete) 24 weeks after stopping treatment. A serological response was defined as a serum HBsAg decrease ≥1 log(10) IU/mL at the end of treatment. Baseline median serum HBV-DNA and HBsAg levels were 7.6 log(10) copies/mL and 3.8 log(10) IU/mL, respectively. Ten patients (50%) achieved SVR, six of them had partial response and four complete response. Four patients (20%) achieved serological response. Complete SVRs showed a major and steep decline in HBsAg level with a median decrease of 0.5, 1.6 and 2.0 log(10) IU/mL at treatment week 20, 44 and 68, respectively. Partial SVRs showed a slight and slow decline in serum HBsAg level (0.1, 0.4, and 0.6 log IU/mL at weeks 20, 44 and 68, respectively). On-treatment serum HBsAg decrease had a high accuracy to predict SVR (AUROC = 0.88). Our results suggest that sequential therapy might be an interesting strategy for HBeAg-negative patients. Serum HBsAg kinetics seem to be an accurate tool to predict SVR. Large clinical trials are needed to explore this strategy with more potent analogues.

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.

Implications of the changes in the levels of HBV DNA and HBsAg during the treatment of chronic hepatitis B

With the development of new drugs, there has been a significant progression in the treatment of viral hepatitis B over the past five years. Based on their effect mechanisms, the currently available seven different drugs can be classified either as those of the interferon group or those of the nucleoside analogue group. Despite the pharmacological advances, it is still rare to achieve sustained response. The chances of a long-term inactive hepatitis stage, however, have greatly increased with the growing opportunities for personalized pharmacological treatment based on the selection of the correct type of drug, the timely modification of therapy in case of ineffectiveness and the determination of the optimal time and length of the therapy. For this, it is necessary to monitor several predictive, non-invasive biomarkers. For the initiation of the therapy, the most important markers are HBeAg, alanine-aminotranferase and HBV DNA serum levels and the viral genotype. During therapy, quantitative monitoring of the HBV DNA and HbsAg levels helps most to differentiate between those who will respond fast, those who will need longer treatment and those who are unlikely to respond and therefore need alternative drug therapy. A rapid decrease in or disappearance of HBsAg is predictive of successful response during interferon therapy, while changes in the HBV DNA level are more informative during treatment with nucleoside analogues. It is expected that information on the effects of combination therapy will become available soon and this may alter both the currently recommended treatment and monitoring strategy. Orv. Hetil., 2011, 152, 866–868.

[HBsAg seroclearance: prognostic value for the response to treatment and the long-term outcome]

Chronic hepatitis B is a major cause of liver disease worldwide, ranking as the first cause of cirrhosis and hepatocellular carcinoma. Hepatitis B surface antigen (HBsAg) is usually used as a qualitative marker for the diagnosis of hepatitis B virus (HBV) infection. HBsAg clearance is the closest to cure outcome as one can expect to achieve in hepatitis B. Support for this comes from natural history studies demonstrating increased length of survival, lower rates of hepatic decompensation, reduction in the frequency of hepatocellular carcinoma, and regression of liver fibrosis in patients who clear HBsAg. HBsAg seroclearance may occur spontaneously at a yearly incidence of 1-2%, preceded usually by a long period of inactive disease. Interferon treatment enhanced HBsAg seroclearance by approximately three-fold in western studies and sixfold in Asian studies compared with non-treated patients. Pegylated interferon induced a 10-15% yearly rate of HBsAg seroclearance in patients who developed sustained virological response in clinical trials. By contrast, treatment with nucleos (t) ides analogues did not significantly affect the rate of HBsAg seroclearance, especially in patients with hepatitis B e antigen (HBeAg) - negative disease. Recently, serum HBsAg has been shown to be a surrogate marker of covalently closed circular DNA (cccDNA) concentration in the liver. Quantification of serum HBsAg has also been recently shown to be a promising tool for monitoring virologic response in HBeAg-negative patients treated with pegylated interferon.

Serum HBeAg sero-conversion correlated with decrease of HBsAg and HBV DNA in chronic hepatitis B patients treated with a therapeutic vaccine

Currently, there are various approaches for developing therapeutic vaccines for chronic hepatitis B patients. Previously, an antigen-antibody-based therapeutic vaccine (YIC) has been conducted in a double-blind placebo controlled phase IIb clinical trial in 242 chronic hepatitis B patients. At the end of follow-up for 24 weeks, HBeAg sero-conversion rate was 21.6% in the 60 μg immunized group, compared to 9% in the alum immunized control group (p=0.03). To analyze the correlation between HBeAg-seroconversion, and decrease of serum HBsAg and HBV DNA, serum samples were back quantified for serum HBsAg and HBV DNA collected at baseline, end of treatment, and end of follow-up from patients who were treated either with 60 μg of YIC, or with placebo. Patients were dichotomized to HBeAg sero-converted and non-converted groups in comparison with patients in the placebo group. The correlations between HBeAg seroconversion and the decrease of HBsAg, HBV DNA and ALT levels during study period were analyzed using a logistic regression model. Results showed marked and sustained reduction of HBsAg, HBV DNA and ALT level in HBeAg sero-converted patients compared to those in patients of HBeAg non-converted and placebo groups. Reduction of HBV DNA and elevation of ALT was markedly associated with HBeAg seroconversion with an adjusted OR of 0.09 (95%CI: 0.01-0.62) and 0.08 (95%CI: 0.02-0.37) respectively after adjusted by age and sex, while reduction of HBsAg level was close to of significance (p=0.054). Analysis indicated that HBeAg sero-conversion was a reasonable endpoint for therapeutic vaccination.