Seven-Year Treatment Outcome of Entecavir in a Real-World Cohort: Effects on Clinical Parameters, HBsAg and HBcrAg Levels

Hepatitis B core-related antigen as a promising serological marker for monitoring hepatitis B virus cure

Hepatitis B virus (HBV) infection is a global health concern. The current sequential endpoints for the treatment of HBV infection include viral suppression, hepatitis B e antigen (HBeAg) seroconversion, functional cure, and covalently closed circular DNA (cccDNA) clearance. Serum hepatitis B core-related antigen (HBcrAg) is an emerging HBV marker comprising three components: HBeAg, hepatitis B core antigen, and p22cr. It responds well to the transcriptional activity of cccDNA in the patient's liver and is a promising alternative marker for serological testing. There is a strong correlation, and a decrease in its level corresponds to sustained viral suppression. In patients with chronic hepatitis B (CHB), serum HBcrAg levels are good predictors of HBeAg seroconversion (both spontaneous and after antiviral therapy), particularly in HBeAg-positive patients. Both low baseline HBcrAg levels and decreasing levels early in antiviral therapy favored HBsAg seroconversion, which may serve as a good surrogate option for treatment endpoints. In this review, we summarize the role of serum HBcrAg in the treatment of CHB. Therefore, long-term continuous monitoring of serum HBcrAg levels contributes to the clinical management of patients with CHB and optimizes the choice of treatment regimen, making it a promising marker for monitoring HBV cure.

VIR-2218 (elebsiran) plus pegylated interferon-alfa-2a in participants with chronic hepatitis B virus infection: a phase 2 study

BACKGROUND

Chronic hepatitis B virus (HBV) remains a global concern, with current treatments achieving low rates of HBsAg seroclearance. VIR-2218 (elebsiran), a small interfering RNA agent against HBV transcripts, reduces HBsAg concentrations. We aimed to evaluate the safety and antiviral activity of VIR-2218 with and without pegylated interferon-alpha-2a treatment in participants with chronic HBV.

METHODS

This open-label, phase 2 study was conducted at 23 sites in six countries (New Zealand, Australia, Hong Kong, Thailand, South Korea, and Malaysia). Adults (aged 18-65 years) with chronic HBV infection without cirrhosis and with HBsAg more than 50 IU/mL and HBV DNA less than 90 IU/mL who were on continued nucleoside or nucleotide reverse transcriptase inhibitor (NRTI) therapy for 2 months or longer were eligible. Participants were enrolled into one of six cohorts to receive VIR-2218 200 mg subcutaneously every 4 weeks, with or without 180 μg subcutaneous pegylated interferon-alfa-2a once per week. Cohort 1 received six doses of VIR-2218 (total 20 weeks); cohort 2 received six doses of VIR-2218 starting at day 1, plus 12 doses of pegylated interferon-alfa-2a starting at week 12 (total 24 weeks); cohort 3 received six doses of VIR-2218 and 24 doses of pegylated interferon-alfa-2a (total 24 weeks); cohort 4 received six doses of VIR-2218 and up to 48 doses of pegylated interferon-alfa-2a (total 48 weeks); cohort 5 received up to 13 doses of VIR-2218 and up to 44 doses of pegylated interferon-alfa-2a (total 48 weeks); and cohort 6 received three doses of VIR-2218 and 12 doses of pegylated interferon-alfa-2a (total 12 weeks). The primary endpoints were the incidence of adverse events and clinical assessments (including results of laboratory tests). Secondary endpoints were the mean maximum reduction of serum HBsAg at any timepoint; the proportion of participants with serum HBsAg seroclearance at any timepoint and for more than 6 months after the end of treatment; and the proportion of participants with anti-HBs seroconversion at any timepoint. For patients who were HBeAg-positive, we also assessed the proportion with HBeAg seroclearance or anti-HBe seroconversion at any timepoint. This study is registered with ClinicalTrials.gov, NCT03672188, and is ongoing.

FINDINGS

Between July 2, 2020, and Nov 2, 2021, 124 individuals were screened for eligibility, 84 of whom were enrolled (15 in cohort 1, 15 in cohort 2, 18 in cohort 3, 18 in cohort 4, 13 in cohort 5, and five in cohort 6). Participants were predominantly HBeAg-negative, Asian, and male (66 [79%] participants were male and 18 [21%] were female). Most treatment emergent adverse events were grades 1-2. Three (20%) participants in cohort 1, four (27%) in cohort 2, eight (44%) in cohort 3, seven (39%) in cohort 4, six (46%) in cohort 5, and two (40%) in cohort 6 reported treatment-emergent adverse events related to VIR-2218. 12 (80%) participants in cohort 2, 12 (67%) in cohort 3, 14 (78%) in cohort 4, 13 (100%) in cohort 5, and three (60%) in cohort 6 reported treatment-emergent adverse events related to pegylated interferon-alfa-2a. Two (13%) participants in cohort 1 had elevations in alanine aminotransferase, compared with 13 (87%) participants in cohort 2, 15 (83%) in cohort 3, 17 (94%) in cohort 4, 11 (85%) in cohort 5, and three (60%) in cohort 6. The mean maximum change from baseline at any timepoint in HBsAg concentration was -2·0 log10 IU/mL (95% CI -2·1 to -1·8) in cohort 1, -2·2 log10 IU/mL (-2·5 to -1·8) in cohort 2, -2·5 log10 IU/mL (-2·8 to -2·1) in cohort 3, -2·4 log10 IU/mL (-3·1 to -1·8) in cohort 4, -3·0 log10 IU/mL (-3·7 to -2·3) in cohort 5, and -1·7 log10 IU/mL (-2·1 to -1·4) in cohort 6. 11 participants (one in cohort 2, one in cohort 3, five in cohort 4, and four in cohort 5) receiving VIR-2218 plus pegylated interferon-alfa-2a had HBsAg seroclearance at any timepoint. Of these, ten (91%; one in cohort 2, five in cohort 4, and four in cohort 5) had anti-HBs seropositivity. Six participants (one in cohort 2, three in cohort 4, and two in cohort 5) had sustained HBsAg seroclearance through to 24 weeks after the end of treatment. No participants receiving VIR-2218 monotherapy (cohort 1) or VIR-2218 plus pegylated interferon-alfa-2a 12-week regimen (cohort 6) had HBsAg seroclearance. 12 (42%) of 26 participants (one of four in cohort 1, two of six in cohort 2, four of seven in cohort 3, four of six in cohort 4, and one of three in cohort 5) who were HBeAg positive at baseline had HBeAg seroclearance or anti-HBe seroconversion.

INTERPRETATION

The results of this phase 2 study support further development of VIR-2218 as a potential therapy for patients with chronic HBV infection. Additional clinical trials of VIR-2218 with and without pegylated interferon-alfa-2a in combination with an HBsAg-targeting monoclonal antibody are ongoing.

FUNDING

Vir Biotechnology.

Trajectories and Decline of Serum Hepatitis B Surface Antigen Predict Outcomes in Patients With Chronic Hepatitis B

Background

The kinetics of serum hepatitis B surface antigen (HBsAg) levels during long-term nucleos(t)ide analogue (NA) therapy remains unclear. We delineated the kinetics of HBsAg and analyzed its association with long-term treatment outcomes.

Methods

We enrolled 912 treatment-naïve patients with chronic hepatitis B (CHB) who had received NA therapy for >12 months and analyzed the kinetic patterns through group-based trajectory models (GBTMs).

Results

The median treatment duration for the entire cohort was 60.3 months. GBTMs revealed 4 patterns in patients achieving HBsAg loss (groups 1-4) in the study population and in patients achieving HBsAg <100 IU/mL among those with HBeAg-negative CHB with baseline HBsAg ≥100 IU/mL (groups A-D). Patients in groups 1 and A had the highest rates of HBsAg loss (22.2%, 6/27) and of achieving HBsAg <100 IU/mL (47.5%, 56/118), respectively. HBsAg <40 IU/mL and <400 IU/mL at 12 months of treatment predicted group 1 and group A membership among all patients and those with HBeAg-negative CHB, respectively. Multivariable Cox regression analysis identified HBsAg trajectory group (group 1 vs groups 3 and 4: hazard ratio [HR], 179.46; P < .001; group 2 vs groups 3 and 4: HR, 24.34; P < .001) and HBsAg decline (HR, 82.14; P < .001) as independent predictors of both HBsAg loss and achieving HBsAg <100 IU/mL.

Conclusions

Serum HBsAg trajectories and decline can predict HBsAg loss and the achievement of HBsAg <100 IU/mL in patients with CHB receiving long-term NA therapy.

HBV Biomarkers and Their Role in Guiding Treatment Decisions

Over 300 million individuals worldwide are chronically infected with hepatitis B virus and at risk for progressive liver disease. Due to the lack of a therapy that reliably achieves viral elimination and the variability of liver disease progression, treatment decisions are guided by the degree of liver disease and viral biomarkers as the viral life-cycle is well characterized and largely conserved between individuals. In contrast, the immunological landscape is much more heterogeneous and diverse and the measurement of its components is less well standardized. Due to the lack of a universal and easily measurable set of biomarkers, clinical practice guidelines remain controversial, aiming for a balance between simplifying treatment decisions by reducing biomarker requirements and using all available biomarkers to avoid overtreatment of patients with low risk for disease progression. While approved therapies such as nucleos(t)ide analogs improve patient outcomes, the inability to achieve a complete cure highlights the need for novel therapies. Since no treatment candidate has demonstrated universal efficacy, biomarkers will remain important for treatment stratification. Here, we summarize the current knowledge on virological and immunological biomarkers with a specific focus on how they might be beneficial in guiding treatment decisions in chronic hepatitis B.

Long-term hepatitis B surface antigen response after finite treatment of ARC-520 or JNJ-3989

BACKGROUND AND AIMS

RNA interference has been extensively explored in patients with chronic hepatitis B (CHB) infection. We aimed to characterise the long-term efficacy of small interfering RNA (siRNA) on hepatitis B surface antigen (HBsAg) suppression.

METHODS

We prospectively followed up participants with CHB who received siRNA, either ARC-520 or JNJ-73763989 (JNJ-3989), in combination with nucleoside analogue (NUC) in our centre. Participants enrolled included 15 receiving 4 monthly injections of ARC-520, 38 receiving 3 injections of JNJ-3989 at 1, 2 or 4 weekly intervals and 5 receiving placebo in previous clinical trials. Serial blood sampling was performed according to the original protocols and on completion every 24 weeks until last follow-up (LFU) with mean duration of 52.5 months.

RESULTS

Among the 53 NUC+siRNA-treated participants (mean age 46.8, baseline HBsAg 3.08 log, 83% previously on NUC, 34% hepatitis B e antigen+), the proportion of patients achieving HBsAg seroclearance or <100 IU/mL at LFU was 1.9% and 32.1%, respectively, compared with 0% and 0% for placebo. Among siRNA-recipients, 48.5% and 5.0% of those with HBsAg <100 IU/mL and >100 IU/mL at nadir or ≤24 weeks from last dose could maintain or achieve HBsAg <100 IU/mL at LFU, respectively. Compared with placebo recipients, siRNA-recipients demonstrated faster overall annual decline of HBsAg (0.08 vs 0.21 log IU/mL/year) contributed predominantly by changes in the first year. Age was negatively correlated with HBsAg reduction at LFU (r=-0.427, p=0.001).

CONCLUSION

Short-duration siRNA treatment suppressed HBsAg expression with a prolonged effect for up to 6 years in some participants.

Disease modifiers and novel markers in hepatitis B virus-related hepatocellular carcinoma

Chronic hepatitis B (CHB) infection is responsible for 40% of the global burden of hepatocellular carcinoma (HCC) with a high case fatality rate. The risk of HCC differs among CHB subjects owing to differences in host and viral factors. Modifiable risk factors include viral load, use of antiviral therapy, co-infection with other hepatotropic viruses, concomitant metabolic dysfunctionassociated steatotic liver disease or diabetes mellitus, environmental exposure, and medication use. Detecting HCC at early stage improves survival, and current practice recommends HCC surveillance among individuals with cirrhosis, family history of HCC, or above an age cut-off. Ultrasonography with or without serum alpha feto-protein (AFP) every 6 months is widely accepted strategy for HCC surveillance. Novel tumor-specific markers, when combined with AFP, improve diagnostic accuracy than AFP alone to detect HCC at an early stage. To predict the risk of HCC, a number of clinical risk scores have been developed but none of them are clinically implemented nor endorsed by clinical practice guidelines. Biomarkers that reflect viral transcriptional activity and degree of liver fibrosis can potentially stratify the risk of HCC, especially among subjects who are already on antiviral therapy. Ongoing exploration of these novel biomarkers is required to confirm their performance characteristics, replicability and practicability.

Long-term entecavir therapy of chronic hepatitis B in real-life setting-Importance of quantitative HBsAg level

BACKGROUND

The global burden of chronic hepatitis B remains high and the best possible treatment remains long-term viral suppression expecting cure.

METHODS

Total 154 patients of chronic hepatitis B (48 HBeAg positive, e + ve) treated with oral entecavir (0.5 mg/1 mg per day) were recruited from June 2007 and followed prospectively until December 2022 for persistent HBV DNA negativity, HBeAg and HBsAg loss/seroconversion and other liver and drug-related events in real-life settings.

RESULTS

The mean duration of therapy was 6.78 (2-14) years with 1364 person-years of follow-up. All patients were HBV DNA negative by 15 months and remained so until the last follow-up. As many as 16.7% lost HBeAg after eight to 13 years of therapy, but not HBsAg. The mean fall in serum HBsAg level per year was 0.158 log IU/mL, being significantly higher in e + ve patients at baseline and until two years of therapy. The decline was significant until six years in e + ve patients compared to two years in e - ve ones. None had biochemical or virological breakthrough (except eight defaulters), flares or any untoward effects. The incidence of liver-related events, hepatocellular carcinoma and death was 10.4%, 1.9% and 14.3%, respectively, and 5.2% deaths were liver-related whose predictors were presence of cirrhosis (log rank 46.5, p > 0.001) and higher HBsAg level > 4 log IU/mL (log rank 18.15, p < 0.001) at baseline.

CONCLUSION

Long-term entecavir therapy provides additional benefits of continuous reduction of serum HBsAg levels beyond suppression of HBV DNA.

N-Heterocycles as Promising Antiviral Agents: A Comprehensive Overview

Viruses are a real threat to every organism at any stage of life leading to extensive infections and casualties. N-heterocycles can affect the viral life cycle at many points, including viral entrance into host cells, viral genome replication, and the production of novel viral species. Certain N-heterocycles can also stimulate the host's immune system, producing antiviral cytokines and chemokines that can stop the reproduction of viruses. This review focused on recent five- or six-membered synthetic N-heterocyclic molecules showing antiviral activity through SAR analyses. The review will assist in identifying robust scaffolds that might be utilized to create effective antiviral drugs with either no or few side effects.

Clinical Significance and Remaining Issues of Anti-HBc Antibody and HBV Core-Related Antigen

Currently, hepatitis B virus (HBV) core antibody (anti-HBc antibody) and HBV core-related antigen (HBcrAg) are widely used as serum markers for diagnosis based on the HBV core region. This review focused on anti-HBc antibodies and HBcrAg and aimed to summarize the clinical significance of currently used assay systems and the issues involved. While anti-HBc is very significant for clinical diagnosis, the clinical significance of quantitative assay of anti-HBc antibody has been reevaluated with improvements in diagnostic performance, including its association with clinical stage and prediction of carcinogenesis and reactivation. In addition, concerning the new HBcrAg, a high-sensitivity assay method has recently been established, and its diagnostic significance, including the prediction of reactivation, is being reevaluated. On the other hand, the quantitative level of anti-HBc antibody expressed in different units among assay systems complicates the interpretation of the results. However, it is difficult to standardize assay systems as they vary in advantages, and caution is needed in interpreting the assay results. In conclusion, with the development of highly sensitive HBcrAg and anti-HBc antibody, a rapid and sensitive detection assay system has been developed and used in clinical practice. In the future, it is hoped that a global standard will be created based on the many clinical findings.

Quantitative Measurement of Serum HBcrAg Can Be Used to Assess the Feasibility of Safe Discontinuation of Antiviral Therapy for Chronic Hepatitis B

Hepatitis B virus (HBV) infection is a serious global health problem, and chronic HBV infection significantly increases the risk of liver fibrosis, cirrhosis, and even hepatocellular carcinoma in patients. Current first-line therapeutics such as nucleos(t)ide analogues and interferons are unable to completely clear cccDNA, so the vast majority of patients need to take long-term or even lifelong medication. However, long-term virological and biochemical responses can be achieved in some patients after drug withdrawal. Successfully screening these patients with drug withdrawal advantages is difficult. Hepatitis-B-core-related antigen (HBcrAg) is a new HBV serological marker that which can reflect the level and transcription activity of cccDNA in hepatocytes. Therefore, HBcrAg has potential value in guiding patients in drug withdrawal. This review summarizes previous reports on HBcrAg and evaluates the application value of HBcrAg in safe drug discontinuation.

Novel Drug Development in Chronic Hepatitis B Infection: Capsid Assembly Modulators and Nucleic Acid Polymers

Currently approved treatment of patients with chronic hepatitis B infection is insufficient to achieve functional cure. Numerous new compounds are identified, and among many, capsid assembly modulators (CAMs) and nucleic acid polymers (NAPs) are 2 classes of virus-directing agents in clinical development. CAMs interfere with viral pregenomic RNA encapsidation and are effective in viral load reduction but have limited effects on hepatitis B surface antigen (HBsAg). NAPs prevent HBsAg release from hepatocytes and induce intracellular degradation, leading to potent suppression of serum HBsAg when combined with nucleoside analogues and pegylated interferon demonstrated by initial data, but awaiting further confirmation studies.

Localization of unlabeled bepirovirsen antisense oligonucleotide in murine tissues using in situ hybridization and CARS imaging

Current methods for detecting unlabeled antisense oligonucleotide (ASO) drugs rely on immunohistochemistry (IHC) and/or conjugated molecules, which lack sufficient sensitivity, specificity, and resolution to fully investigate their biodistribution. Our aim was to demonstrate the qualitative and quantitative distribution of unlabeled bepirovirsen, a clinical stage ASO, in livers and kidneys of dosed mice using novel staining and imaging technologies at subcellular resolution. ASOs were detected in formalin-fixed paraffin-embedded (FFPE) and frozen tissues using an automated chromogenic in situ hybridization (ISH) assay: miRNAscope. This was then combined with immunohistochemical detection of cell lineage markers. ASO distribution in hepatocytes versus nonparenchymal cell lineages was quantified using HALO AI image analysis. To complement this, hyperspectral coherent anti-Stokes Raman scattering (HS-CARS) imaging microscopy was used to specifically detect the unique cellular Raman spectral signatures following ASO treatment. Bepirovirsen was localized primarily in nonparenchymal liver cells and proximal renal tubules. Codetection of ASO with distinct cell lineage markers of liver and kidney populations aided target cell identity facilitating quantification. Positive liver signal was quantified using HALO AI, with 12.9% of the ASO localized to the hepatocytes and 87.1% in nonparenchymal cells. HS-CARS imaging specifically detected ASO fingerprints based on the unique vibrational signatures following unlabeled ASO treatment in a totally nonperturbative manner at subcellular resolution. Together, these novel detection and imaging modalities represent a significant increase in our ability to detect unlabeled ASOs in tissues, demonstrating improved levels of specificity and resolution. These methods help us understand their underlying mechanisms of action and ultimately improve the therapeutic potential of these important drugs for treating globally significant human diseases.

Vector-Transmitted Flaviviruses: An Antiviral Molecules Overview

Flaviviruses cause numerous pathologies in humans across a broad clinical spectrum with potentially severe clinical manifestations, including hemorrhagic and neurological disorders. Among human flaviviruses, some viral proteins show high conservation and are good candidates as targets for drug design. From an epidemiological point of view, flaviviruses cause more than 400 million cases of infection worldwide each year. In particular, the Yellow Fever, dengue, West Nile, and Zika viruses have high morbidity and mortality-about an estimated 20,000 deaths per year. As they depend on human vectors, they have expanded their geographical range in recent years due to altered climatic and social conditions. Despite these epidemiological and clinical premises, there are limited antiviral treatments for these infections. In this review, we describe the major compounds that are currently under evaluation for the treatment of flavivirus infections and the challenges faced during clinical trials, outlining their mechanisms of action in order to present an overview of ongoing studies. According to our review, the absence of approved antivirals for flaviviruses led to in vitro and in vivo experiments aimed at identifying compounds that can interfere with one or more viral cycle steps. Still, the currently unavailability of approved antivirals poses a significant public health issue.

Past, present, and future of long-term treatment for hepatitis B virus

The estimated world prevalence of hepatitis B virus (HBV) infection is 316 million. HBV infection was identified in 1963 and nowadays is a major cause of cirrhosis and hepatocellular carcinoma (HCC) despite universal vaccination programs, and effective antiviral therapy. Long-term administration of nucleos(t)ide analogues (NA) has been the treatment of choice for chronic hepatitis B during the last decades. The NA has shown a good safety profile and high efficacy in controlling viral replication, improving histology, and decreasing the HCC incidence, decompensation, and mortality. However, the low probability of HBV surface antigen seroclearance made necessary an indefinite treatment. The knowledge, in recent years, about the different phases of the viral cycle, and the new insights into the role of the immune system have yielded an increase in new therapeutic approaches. Consequently, several clinical trials evaluating combinations of new drugs with different mechanisms of action are ongoing with promising results. This integrative literature review aims to assess the knowledge and major advances from the past of hepatitis B, the present of NA treatment and withdrawal, and the future perspectives with combined molecules to achieve a functional cure.

Bepirovirsen (GSK3228836) in chronic hepatitis B infection: an evaluation of phase II progress

INTRODUCTION

Chronic hepatitis B infection is a major global health issue associated with significant liver-related morbidity and mortality. While existing treatments can suppress the virus effectively, they are incapable of inducing functional cure, as defined by hepatitis B surface antigen (HBsAg) seroclearance. Currently, numerous novel compounds are being developed, including bepirovirsen, an antisense oligonucleotide (ASO).

AREAS COVERED

This review summarizes the mechanism of action, pharmacokinetics, clinical efficacy and safety data collected from phase I and II studies of bepirovirsen. The data were extracted from publications relevant to the pivotal trials of bepirovirsen, in either full manuscript or conference abstracts.

EXPERTOPINION

Bepirovirsen, a 20-mer ASO, has already entered phase III clinical evaluation using the optimal dosing regimen of 300 mg subcutaneous injection weekly for 24 weeks in nucleoside analogue-treated HBeAg-negative non-cirrhotic patients with low (<3000 IU/mL) baseline HBsAg. The durability and long-term clinical outcomes among Bepirovirsen responders will need to be evaluated. The stop-to-cure approach in those reaching HBsAg < 100 IU/mL should also be explored. In the long run, Bepirovirsen has the potential to facilitate viral hepatitis elimination.

Utility of novel viral and immune markers in predicting HBV treatment endpoints: A systematic review of treatment discontinuation studies

Background & Aims

Antivirals represent the mainstay of chronic hepatitis B treatment given their efficacy and tolerability, but rates of functional cure remain low during long-term therapy. Treatment discontinuation has emerged as a strategy to maintain partial cure and achieve functional cure in select patient groups. We aimed to evaluate how data from treatment discontinuation studies exploring novel viral and/or immune markers could be applied to the functional cure program.

Methods

Treatment discontinuation studies evaluating novel viral and/or immune markers were identified by a systematic search of the PubMed database through to October 30, 2022. Data extraction focused on information regarding novel markers, including identified cut-off levels, timing of measurement, and associated effect on study outcomes of virological relapse, clinical relapse, and HBsAg seroclearance.

Results

From a search of 4,492 citations, 33 studies comprising a minimum of 2,986 unique patients met the inclusion criteria. Novel viral markers, HBcrAg and HBV RNA, were demonstrated across most studies to be helpful in predicting off-therapy partial cure, with emerging evidence to support a link with functional cure. From novel immune marker studies, we observed that treatment discontinuation has the potential to trigger immune restoration, which may be associated with a transient virological relapse. To this end, these studies support the combination of virus-directing agents with immunomodulator therapies to induce two key steps underlying functional cure: viral antigen load reduction and restoration of the host immune response.

Conclusions

Patients with a favourable profile of novel viral and immune markers stand to benefit from a trial of antiviral treatment discontinuation alongside novel virus-directing agents with the aim of achieving functional cure without excessive risk of severe clinical relapse.

Impact and implications

Select patients with chronic hepatitis B undergoing nucleoside analogue therapy may benefit from a trial of treatment discontinuation, aiming to maintain partial cure and/or achieve functional cure. We propose a profile of novel viral and immune markers to identify patients who are likely to achieve these goals without excessive risk of hepatic decompensation. Furthermore, treatment discontinuation may also be considered as a therapeutic strategy to trigger immune restoration, which may increase the chance of functional cure when used in conjunction with novel virus-directing agents.

Advances in determining new treatments for hepatitis B infection by utilizing existing and novel biomarkers

INTRODUCTION

Chronic hepatitis B (CHB) infection is a major global health threat and accounts for significant liver-related morbidity and mortality. An improved understanding of how hepatitis B virus (HBV) interacts with the host immune system allows the discovery of novel biomarkers and new treatment options. Viral biomarkers including hepatitis B surface antigen (HBsAg) and newer ones like HBV RNA and hepatitis B core-related antigen appear to be useful to select patients who are likely to benefit from cessation of long-term antiviral therapy. These markers can also help to confirm target engagement for novel compounds, and efficacy in HBsAg reduction and seroclearance is deemed essential as this is how the current treatment endpoint of functional cure is defined.

AREAS COVERED

In this review, the authors discuss the current standard of care and the gaps between such standard and the ideal goals for treatment in CHB. The authors highlight novel viral and immunological biomarkers that are potentially useful to evaluate treatment response. Novel treatment approaches in relation to these novel biomarkers are also evaluated.

EXPERT OPINION

Novel serum viral biomarkers and immunological markers are indispensable in the HBV functional cure program. These will likely become part of standard monitoring soon.

Trend patterns of HBsAg kinetics in chronic hepatitis B patients during nucleos(t)ide analogue therapy based on ARMA models

BACKGROUND

Trend pattern analysis are lacking for hepatitis B surface antigen (HBsAg) kinetics in chronic hepatitis B (CHB) patients during nucleos(t)ide analogue (Nuc) therapy. We evaluated the trend patterns of HBsAg kinetics by time series analysis and forecasting times to HBsAg seroclearance accordingly.

METHODS

A total of 116 CHB patients with documented three-month HBsAg levels during the previous more than five years of Nuc therapy were included. The piecewise linear trends of the autoregressive-moving average (ARMA) model were used for time series analysis of HBsAg kinetics trends. Best fitted models were created for each patient using HBsAg datasets with backtracking capability. Predicted time to HBsAg seroclearance was calculated accordingly.

RESULTS

Four trend patterns of HBsAg kinetics were found: no trend (n = 22, 19.0%), single trend (n = 16, 13.8%), biphasic trend with rapid-slow decline (n = 56, 48.2%) and biphasic trend with rise-decline (n = 22, 19.0%). Except for no-trend patients, the trend became slow reduction as HBsAg declined. Only 6.1% of patients continued rapid decline when the initial HBsAg of the last trend reached <100 IU/mL. Last trend slopes < -10 and rise-decline patterns indicate greater chances of achieving HBsAg seroclearance within two years.

CONCLUSIONS

Best fitted ARMA models of HBsAg kinetics can be created individually for patients during Nuc therapy. About 67.2% patients have biphasic trend patterns, suggesting the dynamic nature of HBsAg kinetics over time. Trend patterns and last trend slopes predict individual times to HBsAg seroclearance.

Current Challenges and Future Perspectives of Diagnosis of Hepatitis B Virus

It is estimated that approximately 260 million people worldwide are infected with the hepatitis B virus (HBV), which is one of the leading causes of liver disease and liver cancer throughout the world. Compared with developed countries, low-income and middle-income countries have limited access to resources and advanced technologies that require highly specialized staff for HBV diagnosis. In spite of the heavy burden caused by hepatitis B virus, 90% of people are still undiagnosed. The World Health Organization (WHO) goal of eliminating hepatitis B by 2030 seems very difficult to achieve due to the existing diagnostic infrastructure in low-resource regions. The majority of diagnostic laboratories still use hepatitis B surface antigen (HBsAg)-based tests. WHO's elimination plan is at risk of derailment due to phases like the window period, immune control, and occult HBV infection (OBI) not being detected by standard tests. Here, in this article, we are focusing on various diagnostic platforms for the better diagnosis of HBV. The aim of the elimination of HBV can only be achieved by detecting all phases of HBV infection, which can be executed by a combined approach of using new marker assays along with advanced pretesting and testing methods.

A phase 2, open-label, randomized, multiple-dose study evaluating Inarigivir in treatment-naïve patients with chronic hepatitis B

BACKGROUND/AIMS

Novel agents acting against hepatitis B virus (HBV) are needed to improve HBsAg seroclearance or termed as 'functional cure'. Inarigivir (retinoic acid-inducible gene I agonist) has immunomodulatory and direct antiviral actions against HBV. We aimed to determine the safety and efficacy of Inarigivir for the treatment of HBV infection.

PATIENTS/METHODS

80 treatment-naïve patients were randomized in 4 ascending dose cohorts to receive 12 weeks of Inarigivir 25, 50, 100, 200 mg or placebo in a ratio of 4:1. All patients were then given tenofovir for another 12 weeks.

RESULTS

Least squares (LS) mean reductions in HBV DNA from baseline increased with higher doses of Inarigivir (0.6116 in 25 mg and 1.5774 in 200 mg groups vs. 0.0352 in placebo group) (95% CI 0.9518-0.2011 and 1.921-1.1634 respectively). LS mean changes in HBV RNA and HBsAg from baseline ranged from -0.3856 to -0.5794 versus -0.1474 and -0.0956 to -0.1818 versus +0.0026 in Inarigivir-treated versus placebo groups respectively. During the tenofovir-treated period, LS mean reductions in HBsAg in the Inarigivir-treated groups ranged from 0.1709 to 0.3529 versus 0.1984 in the placebo group. Inarigivir-treated groups showed mean reductions in ALT from baseline between 23.3 and 33.8 versus 0.7 U/L in the placebo group. Treatment-emergent adverse events related to Inarigivir and placebo occurred in 4.7% and 6.3% patients respectively.

CONCLUSIONS

Twelve-week Inarigivir up to 200 mg dose was associated with a reduction of HBV DNA, HBV RNA and antigen levels. A trend for greater HBsAg reduction was observed in Inarigivir pre-treated patients after switching to tenofovir.

Hepatitis B virus pre-genomic RNA and hepatitis B core-related antigen reductions at week 4 predict favourable hepatitis B surface antigen response upon long-term nucleos(t)ide analogue in chronic hepatitis B

BACKGROUND/AIMS

We investigated the dynamics of serum HBV pre-genomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) in patients receiving nucleos(t)ide analogues (NAs) and their predictability for favourable suppression of serum hepatitis B surface antigen (HBsAg).

METHODS

Serum viral biomarkers were measured at baseline, weeks 4, 12, 24, 36, and 48 of treatment. Patients were followed up thereafter and serum HBsAg level was measured at end of follow-up (EOFU). Favourable HBsAg response (FHR) was defined as ≤100 IU/mL or HBsAg seroclearance upon EOFU.

RESULTS

Twenty-eight hepatitis B e antigen (HBeAg)-positive and 36 HBeAg-negative patients (median, 38.2 years old; 71.9% male) were recruited with median follow-up duration of 17.1 years (interquartile range, 12.8-18.2). For the entire cohort, 22/64 (34.4%) achieved FHR. For HBeAg-positive patients, serum HBV pgRNA decline at week 4 was significantly greater for patients with FHR compared to non-FHR (5.49 vs. 4.32 log copies/mL, respectively; P=0.016). The area under the receiver-operating-characteristic curve (AUROC) for week 4 HBV pgRNA reduction to predict FHR in HBeAg-positive patients was 0.825 (95% confidence interval [CI], 0.661-0.989). For HBeAg-negative patients, instead of increase in serum HBcrAg in non-FHR patients, FHR patients had median reduction in HBcrAg at week 4 (increment of 1.75 vs. reduction of 2.98 log U/mL; P=0.023). The AUROC for week 4 change of HBcrAg to predict FHR in HBeAg-negative patients was 0.789 (95% CI, 0.596-0.982).

CONCLUSION

Early on-treatment changes of serum HBV pgRNA and HBcrAg at 4 weeks predict HBsAg seroclearance or ≤100 IU/mL in NA-treated CHB patients upon long-term FU.

HBcrAg Predicts Hepatocellular Carcinoma Development in Chronic B Hepatitis Related Liver Cirrhosis Patients Undergoing Long-Term Effective Anti-Viral

Hepatitis B core-related antigen (HBcrAg) is a predictor of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients. Studies on anti-viral therapy have shown that the use of NUC therapy in HBV patients could reduce the incidence of HCC. However, the incidence of HCC continues to increase after long-term anti-viral therapy. The relationship between HBcrAg and HCC development in CHB-related liver cirrhosis (LC) patients undergoing long-term anti-viral therapy is still unclear. This study enrolled 1108 treatment-naïve CHB patients diagnosed with HBV-related LC receiving NUC therapy from April 1999 to February 2015. The baseline biomarkers, disease history, and following results were collected by the hospital. Among the 1108 patients, 219 developed HCC within a median follow-up period of 6.85 years. A multivariable Cox regression model was used, with adjustment for age, gender, FIB-4, DM, and HBsAg-HQ. The adjusted hazard ratios for the HBcrAg tertile levels were 1.70 (95%CI: 1.21, 2.39) and 2.14 (95%CI: 1.50, 3.05) for levels 3.4-4.9 and >4.9 logU/mL, respectively, compared with levels ≤3.4. The effect of the HBcrAg level on HCC incidence was found to be significantly modified by HBsAg-HQ, where lower HBsAg-HQ (≤ 3) values were associated with a significantly higher risk, but HBsAg-HQ levels >3 were not. Our results highlight that, after adjustment for potential confounding factors, patients with CHB-related LC and higher HBcrAg levels are at significant risk for HCC development, even while undergoing long-term effective anti-viral therapy. The HBcrAg level is therefore an independent risk factor for HCC development, especially for patients with HBsAg-HQ levels <3.

Chronic Viral Hepatitis in Elite Athletes: Approaches to Risk Assessment, Prevention and Management

Elite athletes who participate in contact sports are at risk of bleeding injuries, leading to transmission of blood-borne viruses including hepatitis type B, C and D (HBV, HCV and HDV) capable of causing chronic liver disease, liver failure and liver cancer. In view of the significant advances in the viral hepatitis field over the past decade, more structured approaches should be in place to screen for and manage viral hepatitis in elite athletes. HBV status should be assessed in all elite athletes, and those infected should receive nucleos(t)ide analogues for viral suppression, while uninfected individuals should receive HBV vaccination. The all-oral direct acting antivirals for HCV are highly effective and safe, thus the remaining challenge with hepatitis C is case identification and linkage to care. HDV is only found in HBV-infected individuals, which is characterized by rapid disease progression and higher rates of cirrhosis and liver cancer in infected subjects. Pegylated interferon was the mainstay of treatment for HDV infection until bulevirtide, a viral entry inhibitor, was recently approved by the European Union (EMA) and FDA in America, while multiple novel therapies are already in clinical trials as part of the HBV cure program. Overall, awareness of chronic viral hepatitis in athletes should be improved. Prevention remains the cornerstone of the management of viral hepatitis in sport coupled with rigorous disease assessment in infected individuals, and antiviral therapy where indicated.

Review article: novel biomarkers in hepatitis B infection

BACKGROUND

Chronic hepatitis B remains a global health problem with an estimated 296 million people affected worldwide. Individuals are at risk of serious complications such as cirrhosis and hepatocellular carcinoma and accurately predicting these clinical endpoints has proven difficult. However, several viral biomarkers have recently been developed, including quantitative HBV surface antigen (qHBsAg), hepatitis B RNA (HBV RNA) and core-related antigen (HBcrAg), and shown promise in a range of clinical settings.

AIMS

To critically appraise these novel biomarkers, exploring their potential uses, availability of assays and areas for future development.

METHODS

We performed a literature search of PubMed, identifying articles published in the field of hepatitis B biomarkers between 2010 and 2022.

RESULTS

Novel biomarkers such as HBcrAg, HBV RNA and qHBsAg may be useful in predicting treatment outcomes, stratifying the risk of future complications and estimating off-treatment viral reactivation. Furthermore, HBV RNA and HBcrAg titres may accurately reflect cccDNA transcriptional activity, and this is particularly informative in the context of nucleoside analogue therapy. On a cautionary note, most studies have been performed in Caucasian or Asian populations, and methods for detecting HBV RNA lack standardisation.

CONCLUSION

Novel viral biomarkers have the potential to provide additional insights into the natural history of infection and allow a more bespoke, cost-effective framework of care. However, access remains limited, and further efforts are needed to validate their use in ethnically diverse populations, confirm predictive cut-off values, and establish their role in the era of novel antiviral therapies.

Effectiveness of antiviral treatment in HBeAg-negative chronic hepatitis B patients with normal or mildly elevated alanine aminotransferase: a retrospective study

Background

There are inadequate data and no histological evidence regarding the effects of antiviral treatment for hepatitis B e-antigen (HBeAg)-negative chronic hepatitis B (CHB) patients with normal or mildly elevated alanine aminotransferase (ALT). This study investigated the effects of antiviral treatment on these patients.

Methods

We retrospectively analysed the outcomes of antiviral treatment for HBeAg-negative CHB patients with normal or mildly elevated ALT who were treated with nucleoside/nucleotide analogues (NAs) for up to 96 weeks.

Results

A total of 128 patients were enrolled; 74 patients had normal ALT and 54 patients had mildly elevated ALT. The total cumulative rates of viral suppression were 64.06%, 81.97%, and 96.39%, at weeks 24, 48, and 96, respectively. The cumulative rates of viral suppression for the normal and mildly elevated ALT groups were 67.85% and 58.97%, 86.39% and 76.31%, and 93.13% and 97.04% at weeks 24, 48, and 96, respectively. The serum HBV DNA levels at week 12 and hepatitis B surface antigen (HBsAg) levels at week 24 were significant predictors of the 96-week virological response. Of the 128 patients, 54 with normal ALT and 33 with mildly elevated ALT underwent FibroScan at baseline. Significant fibrosis (F ≥ 2) was found in 44.4% (n = 24) and 51.5% (n = 17) of the patients in the normal ALT group and mildly elevated ALT group, respectively. Compared with the values at baseline, liver stiffness values significantly decreased at week 48 (8.12 kPa vs. 6.57 kPa; p < 0.001) and week 96 (8.87 kPa vs. 6.43 kPa; p < 0.001), respectively.

Conclusions

HBeAg-negative CHB patients with normal ALT could benefit from antiviral therapy with NAs, similar to patients with mildly elevated ALT. Antiviral treatment is strongly recommended for HBeAg-negative CHB patients with normal ALT. Additionally, significant liver fibrosis is not rare in HBeAg-negative CHB patients with ALT less than two-times the upper limit of normal, and FibroScan should be performed regularly for these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02471-y.

First-line therapies for hepatitis B in the United States: A 3-year prospective and multicenter real-world study after approval of tenofovir alefenamide

Real-world data are limited on tenofovir alafenamide (TAF). We aimed to study TAF real-world outcomes with other first-line regimens for chronic hepatitis B (CHB). We enrolled patients with CHB from 10 centers retrospectively and followed them for 36 months prospectively. We analyzed switching patterns of antiviral therapy and treatment outcomes of TAF, tenofovir disoproxil fumarate (TDF), and entecavir therapy. For efficacy and safety, we analyzed a subset of patients with complete data at 24 months after switching to TAF or remaining on TDF or entecavir. Among 1037 enrollees, 889 patients were analyzed. The mean age was 52%, and 72% were hepatitis B e antigen-negative. After enrollment, shifts in therapies were mostly in reduced use of TDF from 63% to 30% due to switching to TAF. Clinical parameters were compared at enrollment or initiation to measures at 24 months for patients remaining on TAF (187), TDF (229), or entecavir (181). At 24 months, a significantly higher portion of patients on TAF achieved hepatitis B virus (HBV) DNA ≤ 20 IU/ml (93% vs. 86%; p = 0.012) and normalized alanine aminotransferase (ALT) (66% vs. 56%; p = 0.031) with stable estimated glomerular filtration rates (eGFRs). However, a higher percentage of the patient with eGFR < 60 ml/mi/1.7 m² was observed in the TDF-treated group (9% vs. 4%; p = 0.010). In patients who remained on entecavir or TDF for 24 months, ALT and HBV-DNA results did not differ significantly from baseline. Treatment of CHB in the United States has significantly shifted from TDF to TAF. Our data suggest that switching from TDF or entecavir to TAF may result in increased frequency of ALT normalization and potential clearance of viremia at the 24-month time point.

New strategies for the treatment of chronic hepatitis B

Functional cure, as defined by seroclearance of hepatitis B surface antigen (HBsAg), is the desired treatment endpoint for chronic hepatitis B (CHB) infection, yet is rarely achieved with the currently approved therapy. Novel treatments currently in the clinical phase of development act by inhibiting viral replication/antigen reduction and/or by restoring host immune control. Although some agents are effective in reducing the viral antigen load, a greater magnitude of suppression is required to achieve functional cure. Compounds that target the covalently closed circular DNA (cccDNA) pool, hepatitis B X (HBx) protein inhibition, and mRNA destabilization are also in the preclinical phase of development. Challenges which remain include the clinical implications, immunological perturbations, and safety of these novel compounds to be used in the real-life setting.

Virological Treatment Monitoring for Chronic Hepatitis B

More than 250 million people worldwide are currently infected with hepatitis B, despite the effectiveness of vaccination and other preventive measures. In terms of treatment, new therapeutic approaches are rapidly developing, promising to achieve the elimination of infected cells and the complete cure of infection. The on-treatment monitoring of these innovative antiviral treatments will require the implementation of new virological tools. Therefore, new biomarkers are being evaluated besides the traditional virological and serological assays in order to obtain information on different steps of the viral replication cycle and to monitor response to therapy more accurately. The purpose of this work is to describe both standard and innovative tools for chronic hepatitis B treatment monitoring, and to analyse their potential and feasibility.

Finding a chink in the armor: Update, limitations, and challenges toward successful antivirals against flaviviruses

Flaviviruses have caused large epidemics and ongoing outbreaks for centuries. They are now distributed in every continent infecting up to millions of people annually and may emerge to cause future epidemics. Some of the viruses from this group cause severe illnesses ranging from hemorrhagic to neurological manifestations. Despite decades of research, there are currently no approved antiviral drugs against flaviviruses, urging for new strategies and antiviral targets. In recent years, integrated omics data-based drug repurposing paired with novel drug validation methodologies and appropriate animal models has substantially aided in the discovery of new antiviral medicines. Here, we aim to review the latest progress in the development of both new and repurposed (i) direct-acting antivirals; (ii) host-targeting antivirals; and (iii) multitarget antivirals against flaviviruses, which have been evaluated both in vitro and in vivo, with an emphasis on their targets and mechanisms. The search yielded 37 compounds that have been evaluated for their efficacy against flaviviruses in animal models; 20 of them are repurposed drugs, and the majority of them exhibit broad-spectrum antiviral activity. The review also highlighted the major limitations and challenges faced in the current in vitro and in vivo evaluations that hamper the development of successful antiviral drugs for flaviviruses. We provided an analysis of what can be learned from some of the approved antiviral drugs as well as drugs that failed clinical trials. Potent in vitro and in vivo antiviral efficacy alone does not warrant successful antiviral drugs; current gaps in studies need to be addressed to improve efficacy and safety in clinical trials.

Long-term serological, virological and histological responses to RNA inhibition by ARC-520 in Chinese chronic hepatitis B patients on entecavir treatment

OBJECTIVE

We examined the serological, virological (in serum and liver) and histological profiles in chronic hepatitis B virus (HBV) patients during and after completion of multiple dose (MD) ARC-520.

DESIGN

The present phase 1b study was a multidose, open-label extension cohort of patients that had received single dose ARC-520 in our previous study. Eight patients received 4-9 4 weekly doses of MD ARC-520 and entecavir. Liver biopsies were performed in six patients. Intrahepatic and serum HBV DNA, HBV RNA and viral antigens were measured.

RESULTS

All patients had 28.9-30.4 months of follow-up after the last MD. All three hepatitis B e antigen (HBeAg)-positive patients had profound reductions in hepatitis B surface antigen (HBsAg), HBeAg, hepatitis B core-related antigen and HBV RNA with two undergoing HBeAg seroconversion. One further achieved HBsAg seroconversion (anti-HBs level of 25.1 IU/L) and the remaining two had HBsAg reductions of -1.7 and -3.5 log IU/mL >30 months after MD. Among the five HBeAg-negative patients, four had modest HBsAg reduction >29 months after completion of MD and one achieved HBsAg seroconversion (anti-HBs level of 152.5 IU/L) and was negative for liver HBsAg staining. Entecavir was successfully stopped in this patient 12 months after HBsAg seroconversion. Temporally related alanine aminotransferase elevations preceded by HBsAg reductions were observed in three patients suggesting immune activation. HBcAg staining was negative in all six biopsied patients. Two patients with <10% HBsAg positive staining of hepatocytes had correspondingly low serum HBsAg levels of 1.5 and 11.5 IU/mL.

CONCLUSIONS

MD ARC-520 therapy achieved sustained and profound reductions of viral antigens and HBV RNA. HBsAg seroclearance was achievable.

TRIAL REGISTRATION NUMBER

NCT02065336.

Methodological challenges of performing meta-analyses to compare the risk of hepatocellular carcinoma between chronic hepatitis B treatments

Despite several recent meta-analyses on the topic, the comparative risk of hepatocellular carcinoma in patients with chronic hepatitis B (CHB) receiving entecavir (ETV) or tenofovir disoproxil fumarate (TDF) remains controversial. The controversy partly results from the arbitrary nature of significance levels leading to contradictory conclusions from very similar datasets. However, the use of observational data, which is prone to both within- and between-study heterogeneity of patient characteristics, also lends additional uncertainty. The asynchronous introduction of ETV and TDF in East Asia, where the majority of these studies have been conducted, further complicates analyses, as does the ensuing difference in follow-up time between ETV and TDF cohorts. Researchers conducting meta-analyses in this area must make many methodological decisions to mitigate bias but are ultimately limited to the methodologies of the included studies. It is therefore important for researchers, as well as the audience of published meta-analyses, to be aware of the quality of observational studies and meta-analyses in terms of patient characteristics, study design and statistical methodologies. In this review, we aim to help clinicians navigate the published meta-analyses on this topic and to provide researchers with recommendations for future work.

How to interpret viral markers in the management of chronic hepatitis B infection

BACKGROUND

Hepatitis B virus (HBV) infection is a global public health issue with several unsolved clinical challenges. As multiple new drugs are under development, HBV markers are gaining importance for both diagnostic and prognostic purposes.

OBJECTIVES

This review summarizes the most important data on the usefulness of HBV markers in the natural history of this infection, and in predicting clinical and treatment outcomes.

SOURCES

Selected peer-reviewed publications on HBV markers published between January 2009 and July 2021.

CONTENT

In addition to the classical markers (e.g. HBV-DNA), newer ones, such as quantitative HBsAg, HBcrAg, HBV-RNA and quantitative anti-HBc, have proven useful for predicting events within the natural history of HBV infection, the development of complications (e.g. hepatocellular carcinoma) and the response to antiviral therapy. Most data regarding the response to treatment have been related to nucleos(t)ide analogues, whereas evidence on new therapeutic agents, such as capsid assembly modulators or small interference RNAs, is promising, but still scarce.

IMPLICATIONS

Knowledge on the use of viral markers is a key factor for optimizing the clinical appraisal of HBV infection. The new markers have an enhanced ability to predict clinical outcomes. Further studies should expand the current evidence on the use of markers in relation to antiviral agents currently under evaluation. Wide availability of these markers in regions with a high incidence of HBV infection is of paramount importance.

Seroreversion of hepatitis B surface antigen among subjects with resolved hepatitis B virus infection: A community-based cohort study

BACKGROUND AND AIM

Hepatitis B virus (HBV) surface antigen (HBsAg) seroreversion usually occurs during immunosuppressive therapy. The risk and factors of HBsAg seroreversion from resolved HBV infection in the general population remained unclear.

METHODS

This retrospective study enrolled subjects with resolved HBV infection and who had received at least two times of screening in a longitudinal community screening program. HBsAg, hepatitis B surface antibody (anti-HBs), and hepatitis C virus antibody (anti-HCV) were tested every time in all subjects. The primary endpoint was HBsAg seroreversion.

RESULTS

Of the 7630 subjects enrolled, 5158 (67.6%) subjects had positive anti-HBs at baseline. HBsAg seroreversion occurred in 84 subjects during 42 815-person-year follow-up with an annual incidence of 0.2% and a 10-year cumulative risk of 1.9%. Anti-HBV treatment-experienced subjects had a significantly higher risk of HBsAg seroreversion than anti-HBV treatment-naive subjects (83/310 [26.8%] vs 1/7320 [0.01%], P < 0.001). Lower rates of positive anti-HBs and anti-HCV were observed in anti-HBV treatment-experienced subjects who developed HBsAg seroreversion. Both positive anti-HBs (hazard ratio/95% confidence interval: 0.56/0.348-0.903, P = 0.017) and positive anti-HCV (hazard ratio/95% confidence interval: 0.08/0.030-0.234, P < 0.001) were independent factors of HBsAg seroreversion in anti-HBV treatment-experienced subjects. Less than 5% of the HBsAg seroreverters had clinical hepatitis flare at HBsAg seroreversion. The HBsAg titer was low, and only transient reappeared in most of the HBsAg seroreverters.

CONCLUSIONS

Subjects with resolved HBV infection were at a minimal risk of HBsAg seroreversion, unless with prior anti-HBV treatment experience. Fortunately, even with a reappearance of HBsAg, it was transient and clinically non-relevant.

Analysis of HBsAg Immunocomplexes and cccDNA Activity During and Persisting After NAP-Based Therapy

Therapy with nucleic acid polymers (NAPs), tenofovir disoproxil fumarate (TDF), and pegylated interferon (pegIFN) achieve high rates of HBsAg loss/seroconversion and functional cure in chronic hepatitis B virus (HBV) infection. The role of hepatitis B surface antigen (HBsAg) seroconversion and inactivation of covalently closed circular DNA (cccDNA) in establishing functional cure were examined. Archived serum from the REP 401 study was analyzed using the Abbott ARCHITECT HBsAg NEXT assay (Chicago, IL), Abbott research use-only assays for HBsAg immune complexes (HBsAg ICs), circulating HBV RNA, and the Fujirebio assay for hepatitis B core-related antigen (HBcrAg; Malvern, PA). HBsAg became < 0.005 IU/mL in 23 participants during NAP exposure, which persisted in all participants with functional cure. HBsAg IC declined during lead-in TDF monotherapy and correlated with minor declines in HBsAg. Following the addition of NAPs and pegIFN, minor HBsAg IC increases (n = 13) or flares (n = 2) during therapy were not correlated with HBsAg decline, hepatitis B surface antibody (anti-HBs) titers, or alanine aminotransferase. HBsAg IC universally declined during follow-up in participants with virologic control or functional cure. Universal declines in HBV RNA and HBcrAg during TDF monotherapy continued with NAP + pegIFN regardless of therapeutic outcome. At the end of therapy, HBV RNA was undetectable in only 5 of 14 participants with functional cure but became undetectable after removal of therapy in all participants with functional cure. Undetectable HBV RNA at the end of therapy in 5 participants was followed by relapse to virologic control or viral rebound. Conclusion: Anti-HBs-independent mechanisms contribute to HBsAg clearance during NAP therapy. Inactivation of cccDNA does not predict functional cure following NAP-based therapy; however, functional cure is accompanied by persistent inactivation of cccDNA. Persistent HBsAg loss with functional cure may also reflect reduction/clearance of integrated HBV DNA. Clinicaltrials.org number NCT02565719.

Antiviral Therapy Reduces Mortality in Hepatocellular Carcinoma Patients with Low-Level Hepatitis B Viremia

Background and Aims

Although antiviral treatment has been shown to reduce mortality in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) patients with high HBV-DNA levels, it is still unclear whether it is useful in reducing mortality in patients with low HBV-DNA levels.

Methods

A retrospective analysis of 756 HBV-associated HCC patients at the Beijing Ditan Hospital with HBV-DNA levels < 500 IU/mL was conducted between January 2008 and June 2017. Patients were divided into antiviral and non-antiviral groups based on whether they received nucleos(t)ide analogue (NA) treatment when they were diagnosed with HCC in our hospital for the first time. We used 1:4 frequency matching by age, gender, tumor size, Barcelona Clinic Liver Cancer (BCLC) staging, anti-tumor therapy, cirrhosis, diabetes, and hyperlipoidemia to compare the antiviral (n = 366) and non-antiviral (n = 100) groups. A Cox multivariate regression analysis was employed to evaluate the effects of NA therapy on the hazard ratio (HR), and the Kaplan–Meier survival curve was used to determine the mortality risk in patients with HCC. A Log rank test was performed to analyze the effects of NA therapy on the survival rate of patients with HCC.

Results

After propensity score matching, the 1-, 3-, and 5-year overall survival (OS) rates for the antiviral and non-antiviral groups were 82.5%, 68.6%, and 52.2%, and 61.0%, 51.0%, and 38.0%, respectively. The l-year progression-free survival (PFS) rates for the two groups were 68.0% and 47.0%, respectively. The OS of the antiviral group was significantly higher than that of the control group (P < 0.001, P = 0.001, and P = 0.013, respectively). The 1-year PFS for the antiviral group was also significantly better than that for the non-antiviral groups (P = 0.005). After adjusting for confounding prognostic factors in the Cox model, the HR of 5-year death after antiviral treatment was 0.721 (95% confidence interval [CI], 0.530–0.980, P = 0.037). Antiviral therapy is an independent protective factor for 5-year mortality in patients with HCC and low-level viremia.

Conclusion

Antiviral therapy significantly reduced mortality in HCC patients with low HBV-DNA levels.

Safety, tolerability and antiviral activity of the antisense oligonucleotide bepirovirsen in patients with chronic hepatitis B: a phase 2 randomized controlled trial

Chronic infection with hepatitis B virus (HBV) leads to an increased risk of death from cirrhosis and hepatocellular carcinoma. Functional cure rates are low with current treatment options (nucleos(t)ide analogs (NAs) and pegylated interferons). Bepirovirsen is an antisense oligonucleotide targeting all HBV messenger RNAs; in cell culture and animal models, bepirovirsen leads to reductions in HBV-derived RNAs, HBV DNA and viral proteins. This phase 2 double-blinded, randomized, placebo-controlled trial is the first evaluation of the safety and activity of an antisense oligonucleotide targeting HBV RNA in both treatment-naïve and virally suppressed individuals with chronic HBV infection. The primary objective was to assess the safety and tolerability of bepirovirsen in individuals with chronic hepatitis B (CHB) (NCT02981602). The secondary objective was to assess antiviral activity, including the change from baseline to day 29 in serum hepatitis B surface antigen (HBsAg) concentration. Participants with CHB infection ≥6 months and serum HBsAg ≥50 IU ml^-1 were enrolled from seven centers across Hong Kong and the Republic of Korea and randomized (3:1 within each dose cohort) to receive bepirovirsen or placebo via subcutaneous injection twice weekly during weeks 1 and 2 (days 1, 4, 8 and 11) and once weekly during weeks 3 and 4 (days 15 and 22). Participants were then followed for 26 weeks. Twenty-four participants were treatment-naïve and seven were receiving stable NA therapy. Treatment-emergent adverse events were mostly mild/moderate (most commonly injection site reactions). Eleven (61.1%) and three (50.0%) treatment-naïve participants experienced one or more treatment-emergent adverse event in the bepirovirsen and placebo groups, respectively. In participants receiving NA therapy, the corresponding numbers were three (60.0%) and one (50.0%). Transient, self-resolving alanine aminotransferase flares (≥2× upper limit of normal) were observed in eight treatment-naïve participants and three participants on stable NA regimens in the bepirovirsen treatment arms. HBsAg reductions were observed and were significant versus placebo for treatment-naïve participants receiving bepirovirsen 300 mg (P = 0.001), but not for the bepirovirsen 150 mg group (P = 0.245) or participants receiving stable NA therapy (P = 0.762). Two participants in each of the 300 mg dose groups achieved HBsAg levels below the lower limit of quantitation by day 29 (n = 3) or day 36 (n = 1). Bepirovirsen had a favorable safety profile. These preliminary observations warrant further investigation of the safety and activity of bepirovirsen in a larger CHB patient population.

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Should Treatment Indications for Chronic Hepatitis B Be Expanded?

BACKGROUND & AIM

Antiviral therapy has greatly improved the outcomes of patients with chronic hepatitis B virus (HBV) infection and active liver disease or advanced fibrosis/cirrhosis. However, current treatment does not eradicate HBV and long-term treatment is needed in most patients to maintain clinical benefit. Thus, professional society guidelines do not recommend treatment of all patients with chronic HBV infection. This review article will examine evidence for and against expansion of treatment to patients in whom treatment is not recommended based on current guidelines.

RESULTS

Available data support expanding treatment to immune tolerant patients and patients in the grey zones who have evidence of active/advanced liver disease based on liver biopsy or non-invasive tests and those who remain in the immune tolerant phase after age 40. Evidence supporting treatment expansion to confirmed inactive carriers and other immune tolerant patients is lacking.

CONCLUSIONS

HBV treatment indications can be more liberal when new therapies that can achieve HBsAg loss safely in a high percentage of patients after a finite course of treatment are available.

Current Trends and Limitations in Dengue Antiviral Research

Dengue is the most prevalent arthropod-borne viral disease worldwide and affects approximately 2.5 billion people living in over 100 countries. Increasing geographic expansion of Aedes aegypti mosquitoes (which transmit the virus) has made dengue a global health concern. There are currently no approved antivirals available to treat dengue, and the only approved vaccine used in some countries is limited to seropositive patients. Treatment of dengue, therefore, remains largely supportive to date; hence, research efforts are being intensified for the development of antivirals. The nonstructural proteins, 3 and 5 (NS3 and NS5), have been the major targets for dengue antiviral development due to their indispensable enzymatic and biological functions in the viral replication process. NS5 is the largest and most conserved nonstructural protein encoded by flaviviruses. Its multifunctionality makes it an attractive target for antiviral development, but research efforts have, this far, not resulted in the successful development of an antiviral targeting NS5. Increase in structural insights into the dengue NS5 protein will accelerate drug discovery efforts focused on NS5 as an antiviral target. In this review, we will give an overview of the current state of therapeutic development, with a focus on NS5 as a therapeutic target against dengue.

Entecavir Reduced Serum Hepatitis B Core-Related Antigen in Chronic Hepatitis B Patients with Hepatocellular Carcinoma

Serum hepatitis B core-related antigen (HBcrAg) was shown to predict the risk of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients undergoing treatment. We investigated the longitudinal profile of HBcrAg in entecavir (ETV)-treated CHB patients with subsequent HCC development. We identified HCC cases diagnosed at ≥1 year after ETV initiation. CHB patients without HCC (matched for age, sex, cirrhosis status, baseline hepatitis B virus [HBV] DNA level, and ETV treatment duration) were identified as controls at an HCC:non-HCC ratio of 1:2. Serum samples were retrieved at baseline (ETV initiation) and at 3 and 5 years of ETV therapy for HBcrAg measurement (log IU/mL). In total, 180 patients (60 HCC patients matched with 120 CHB patients without HCC; median age, 56.5 years; 80.6% male; baseline HBV DNA, 5.9 log IU/mL; median follow-up, 6.8 years) were recruited. The median time from ETV initiation to HCC development was 3.2 years. HBcrAg levels were higher in HCC cases than in controls at all three time points: 5.69 log IU/mL versus 5.02 log IU/mL (p=0.025), 4.23 log IU/mL versus 3.36 log IU/mL (p=0.007), and 3.86 log IU/mL versus 3.36 log IU/mL (p=0.009), respectively. ETV led to similar rates of decline in HBcrAg from baseline to 3 years in both groups (0.34 log IU/mL/year vs 0.39 log IU/mL/year, p=0.774), although the decline from 3 to 5 years was slower in the non-HCC group (0.05 log IU/mL/year) than in the HCC group (0.09 log IU/mL/year, p=0.055). ETV time-dependently reduced HBcrAg in HCC and non-HCC patients. HBcrAg interpretation should consider the antiviral treatment duration.

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

APASL guidance on stopping nucleos(t)ide analogues in chronic hepatitis B patients

Chronic hepatitis B virus (HBV) infection is currently incurable. Long-term treatment with potent and safe nucleos(t)ide analogs (NAs) can reduce hepatocellular carcinoma (HCC) and cirrhosis-related complications through profound viral suppression. However, indefinite therapy raises several crucial issues with pros and cons. Because seroclearance of hepatitis B surface (HBsAg) as functional cure is not easily achievable, a finite therapy including sequential 48-week pegylated interferon therapy may provide an opportunity to facilitate HBsAg seroclearance by the rejuvenation of exhausted immune cells. However, the cost of stopping NA is the high incidence of virological relapse and surge of alanine aminotransferase (ALT) levels, which may increase the risk of adverse outcomes (e.g., decompensation, fibrosis progression, HCC, or liver-related mortality). So far, the APASL criteria to stop NA treatment is undetectable HBV DNA levels with normalization of ALT; however, this criterion for cessation of treatment is associated with various incidence rates of virological/clinical relapse and more than 40% of NA-stoppers eventually receive retreatment. A very intensive follow-up strategy and identification of low-risk patients for virological/clinical relapse by different biomarkers are the keys to stop the NA treatment safely. Recent studies suggested that decreasing HBsAg level at the end-of-treatment to < 100-200 IU/mL seems to be a useful marker for deciding when to discontinue NAs therapy. In addition, several viral and host factors have been reviewed for their potential roles in predicting clinical relapse. Finally, the APASL guidance has proposed rules to stop NA and the subsequent follow-up strategy to achieve a better prognosis after stopping NA. In general, for both HBeAg-positive and HBeAg-negative patients who have stopped treatment, these measurements should be done every 1-3 months at the minimum until 12 months.

Screening for Hepatocellular Carcinoma in Chronic Hepatitis B: An Update

(1) Background: Hepatocellular carcinoma (HCC) is an important cause of mortality in individuals with chronic hepatitis B infection, with screening of high-risk groups recommended in all major international guidelines. Our understanding of the risk factors involved has improved over time, encouraging researchers to develop models that predict future risk of HCC development. (2) Methods: A literature search of the PubMed database was carried out to identify studies that derive or validate models predicting HCC development in patients with chronic hepatitis B. Subsequently, a second literature search was carried out to explore the potential role of novel viral biomarkers in this field. (3) Results: To date, a total of 23 models have been developed predicting future HCC risk, of which 12 have been derived from cohorts of treatment-naïve individuals. Most models have been developed in Asian populations (n = 20), with a smaller number in Caucasian cohorts (n = 3). All of the models demonstrate satisfactory performance in their original derivation cohorts, but many lack external validation. In recent studies, novel viral biomarkers have demonstrated utility in predicting HCC risk in patients with chronic hepatitis B, amongst both treated and treatment-naïve patients. (4) Conclusion: Several models have been developed to predict the risk of HCC development in individuals with chronic hepatitis B infection, but many have not been externally validated outside of the Asian population. Further research is needed to refine these models and facilitate a more tailored HCC surveillance programme in the future.

Growing Preferences towards Analog-based Drug Discovery

BACKGROUND

The major concern of today's time is the developing resistance in most of the clinically derived pathogenic micro-organisms for available drugs through several mechanisms. Therefore, there is a dire need to develop novel molecules with drug-like properties that can be effective against the otherwise resistant micro-organisms.

METHODS

New drugs can be developed using several methods like structure-based drug design, ligandbased drug design, or by developing analogs of the available drugs to further improve their effects. However, the smartness is to opt for the techniques that have comparatively less expenditure, lower failure rates, and faster discovery rates.

RESULTS

Analog-Based Drug Design (ABDD) is one such technique that researchers worldwide are opting to develop new drug-like molecules with comparatively lower market values. They start by first designing the analogs sharing structural and pharmacological similarities to the existing drugs. This method embarks on scaffold structures of available drugs already approved by the clinical trials, but are left ineffective because of resistance developed by the pathogens.

CONCLUSION

In this review, we have discussed some recent examples of anti-fungal and anti-bacterial (antimicrobial) drugs that were designed based on the ABDD technique. Also, we have tried to focus on the in silico tools and techniques that can contribute to the designing and computational screening of the analogs, so that these can be further considered for in vitro screening to validate their better biological activities against the pathogens with comparatively reduced rates of failure.

Reduced hepatic steatosis is associated with higher risk of hepatocellular carcinoma in chronic hepatitis B infection

BACKGROUND

Concomitant chronic hepatitis B infection (CHB) and non-alcoholic fatty liver disease (NAFLD) is common, but the implications of NAFLD on clinical outcomes of CHB, including hepatocellular carcinoma (HCC), are not well-investigated.

METHODS

CHB patients were recruited for transient elastography assessment for liver stiffness (LS), and controlled attenuation parameter (CAP), a non-invasive quantification of hepatic steatosis, and were prospectively followed up for development of HCC. Steatosis and severe steatosis were diagnosed by CAP ≥ 248 dB/m and ≥ 280 dB/m respectively, and advanced fibrosis/cirrhosis was diagnosed by LS ≥ 9 kPa. The independent effect of hepatic steatosis on HCC was examined via propensity score matching (PSM) of LS and other significant clinical variables.

RESULTS

Forty-eight patients developed HCC among 2403 CHB patients (55.6% male, median age 55.6 years, 57.1% antiviral-treated, median ALT 26 U/L) during a median follow-up of 46.4 months. Multivariate Cox regression analysis showed age (HR 1.063), male (HR 2.032), Albumin-Bilirubin score (HR 2.393) and CAP (HR 0.993) were associated with HCC development. The cumulative probability of HCC was 2.88%, 1.56% and 0.71%, respectively for patients with no steatosis, mild-to-moderate steatosis, and severe steatosis, respectively (p = 0.01). The risk of HCC increased from 1.56 to 8.89% in patients without severe steatosis if advanced fibrosis/cirrhosis was present (p < 0.001). PSM yielded 957 pairs of CHB patients and hepatic steatosis was independently associated with HCC (HR 0.41).

CONCLUSION

Reduced hepatic steatosis was significantly associated with a higher risk of incident HCC in CHB infection. Routine CAP and LS measurements are important for risk stratification.

HBV RNA Profiles in Patients With Chronic Hepatitis B Under Different Disease Phases and Antiviral Therapy

BACKGROUND AND AIMS

Large-scale comprehensive studies on HBV RNA in chronic hepatitis B are lacking. We aimed to study the HBV RNA profile and its correlation with other viral markers in patients with chronic hepatitis B who are treatment-naïve and patients receiving nucleos(t)ide analogues (NA).

APPROACH AND RESULTS

Biomarkers, including HBV RNA and hepatitis B core-related antigen (HBcrAg), were measured in 388 patients. Of these, 246 were treatment-naïve and were categorized into HBeAg-positive chronic infection (n = 41), HBeAg-positive chronic hepatitis (n = 81), HBeAg-negative chronic infection (n = 39), HBeAg-negative chronic hepatitis (n = 66), and HBsAg seroclearance (n = 19). These biomarkers were also measured in 142 patients who were NA-treated receiving tenofovir or entecavir at baseline, week 48, and week 96. The pattern of serum HBV RNA levels mirrored HBV DNA (1-2 logs higher than HBV RNA) and HBcrAg in patients who were treatment-naïve. HBV RNA correlated best with HBcrAg (r = 0.84) and to a lesser extent with HBV DNA (r = 0.737) (both P < 0.001). In patients with HBsAg seroclearance, 15.8% and 15.8% had detectable serum HBV RNA and HBcrAg, respectively. NA treatment reduced serum HBV RNA by 1.46 logs and 1.77 logs at weeks 48 and 96, respectively. At week 96 of NA therapy, only 19.1% patients who were tenofovir-treated and 25.7% patients who were entecavir-treated had unquantifiable HBV RNA (P > 0.05). In patients who were treated and had undetectable HBV DNA, 77.5% and 30% had quantifiable HBV RNA and HBcrAg, respectively.

CONCLUSIONS

HBV RNA showed distinct and corresponding profiles in patients with HBV in different disease phases. HBV RNA and HBcrAg could be used to monitor residual transcriptional activities in patients with HBsAg seroclearance. NA led to reduction of serum HBV RNA. Monitoring of viral activities can still be achieved in patients with undetectable HBV DNA by serum HBV RNA.

Entecavir Monotherapy Prevents Hepatitis B Virus Recurrence After Liver Transplant for Chronic Hepatitis B Patients: A Long-Term Retrospective Study

BACKGROUND

Limited data are available on the use of oral antiviral therapy, particularly the long-term use of entecavir monotherapy in patients with hepatitis B virus (HBV)-related diseases after liver transplant (LT).

METHODS

The clinical data on consecutive patients who underwent LT for HBV-related diseases from 2011 to 2019 were prospectively collected and retrospectively analyzed. All patients received entecavir monotherapy alone during the follow-up period; viral serology/load and liver biochemical tests were performed regularly.

RESULTS

Among the total of 89 patients were patients with decompensated cirrhosis (n = 27 [30%]), acute-on-chronic HBV (n = 21 [24%]), and hepatocellular carcinoma (HCC) (n = 41 [46%]). The median age of the patients was 50 years (range, 42-58 years), and the median follow-up was 37 months (range, 1-96 months). Before LT, 45 (51%) patients did not receive, whereas 44 (49%) were currently receiving, oral antiviral therapy. At the time of LT, serum level of HBV DNA of 34 (38%) patients was >20 IU/mL, with the median level being 270,000 IU/mL (range, 4270-2,020,000), and 53 patients (59%) had undetectable levels of HBV DNA (≤20 IU/mL). The cumulative rate of hepatitis B surface antigen loss was 79.8%, 100%, and 100% after 1 month, 1 year, and 5 years, respectively. Hepatitis B surface antigen positivity returned after seroclearance in 1 patient, who died of HCC recurrence with an undetectable level of HBV DNA. The overall survival rates at 1, 3, and 5 years after LT were 94.51%, 86.84%, and 85.27%, respectively. During the follow-up period, no entecavir adverse reactions or dose reductions were observed.

CONCLUSIONS

Long-term entecavir monotherapy was highly effective in preventing HBV reactivation and HBV-related diseases.

Novel Biomarkers of Hepatitis B Virus and Their Use in Chronic Hepatitis B Patient Management

Even though an approved vaccine for hepatitis B virus (HBV) is available and widely used, over 257 million individuals worldwide are living with chronic hepatitis B (CHB) who require monitoring of treatment response, viral activity, and disease progression to reduce their risk of HBV-related liver disease. There is currently a lack of predictive markers to guide clinical management and to allow treatment cessation with reduced risk of viral reactivation. Novel HBV biomarkers are in development in an effort to improve the management of people living with CHB, to predict disease outcomes of CHB, and further understand the natural history of HBV. This review focuses on novel HBV biomarkers and their use in the clinical setting, including the description of and methodology for quantification of serum HBV RNA, hepatitis B core-related antigen (HBcrAg), quantitative hepatitis B surface antigen (qHBsAg), including ultrasensitive HBsAg detection, quantitative anti-hepatitis B core antigen (qAHBc), and detection of HBV nucleic acid-related antigen (HBV-NRAg). The utility of these biomarkers in treatment-naïve and treated CHB patients in several clinical situations is further discussed. Novel HBV biomarkers have been observed to provide critical clinical information and show promise for improving patient management and our understanding of the natural history of HBV.