Hepatitis B virus (HBV) DNA integration into the host cell genome is reportedly a major cause of liver cancer, and a source of hepatitis B surface antigen (HBsAg). High HBsAg levels can alter immune responses which therefore contributes to the progression of HBV-related disease. However, to what extent integration leads to the persistent circulating HBsAg is unclear. Here, we aimed to determine if the extent of HBV DNA integration is associated with the persistence of circulating HBsAg in people exposed to HBV. We established a digital droplet quantitative inverse PCR (dd-qinvPCR) method to quantify integrated HBV DNA in patients who had been exposed to HBV (anti-HBc positive and HBeAg-negative). Total DNA extracts from both liver resections (n = 32; 14 HBsAg-negative and 18 HBsAg-positive) and fine-needle aspirates (FNA, n = 10; 2 HBsAg-negative and 8 HBsAg-positive) were analysed. Using defined in vitro samples for assay establishment, we showed that dd-qinvPCR could detect integrations within an input of <80 cells. The frequency of integrated HBV DNA in those who had undergone HBsAg loss (n = 14, mean ± SD of 1.514 × 10-3 ± 1.839 × 10-3 integrations per cell) was on average 9-fold lower than those with active HBV infection (n = 18, 1.16 × 10-2 ± 1.76 × 10-2 integrations per cell; p = 0.0179). In conclusion, we have developed and validated a highly precise, sensitive and quantitative PCR-based method for the quantification of HBV integrations in clinical samples. Natural clearance of HBV is associated with fewer viral integrations. Future studies are needed to determine if dynamics of integrated HBV DNA can inform the development of curative therapies.

Among the factors influencing relapse after clinical cure of chronic hepatitis B(CHB). There is no standardization of baseline HBsAg levels and end-of-treatment HBsAb levels. This multicenter, retrospective study enrolled 136 patients who achieved functional cure from June 2019 to December 2023, and a total of 48 weeks of follow-up was conducted after treatment cessation according to the CHB guidelines. Baseline characteristics of patients were analyzed using univariates. Multifactorial logistic regression was used to analyze the different levels of HBsAg at baseline and HBsAb at the end of treatment in CHB recurrence. The working characteristic curve of the subject was constructed and observed by the column line graphical prediction model. Our data showed the cumulative recurrence rate using Kaplan-Meier survival analysis. At baseline, the level of HBsAg was significantly greater in the group with recurrence than in the group without recurrence (P = 0.038). At EOT, HBsAb levels were lower in the relapsed group than in the nonrelapsed group (P = 0.014). Multivariate logistic regression analysis revealed that a baseline serum HBsAg concentration ≥ 100 IU/mL was a risk factor for recurrence, and an EOT serum HBsAb concentration ≥ 500 mIU/mL was a protective factor for recurrence. Kaplan-Meier survival analysis showed relapse rates of 3.8% and 12.2% for HBsAg ≤ 100 IU/mL at baseline and HBsAb ≥ 500 mIU/mL at the end of treatment, respectively. Functionally cured patients with CHB when baseline HBsAg ≤ 100 IU/mL and HBsAb ≥ 500 mIU/mL at the end of treatment have a low relapse rate.

Studies have shown that blocking the programmed cell death-1/programmed cell death ligand 1 pathway may lead to a potential cure for HBV infections. ASC22 (envafolimab) is a humanized, single-domain programmed cell death ligand 1 antibody administered subcutaneously. This study aimed to evaluate the efficacy and safety of ASC22 in virally suppressed patients with chronic hepatitis B on nucleos(t)ide analogs.

This randomized, single-blind, phase IIb trial enrolled patients with chronic hepatitis B in 2 cohorts for a 24-week treatment with ASC22 or placebo (PBO) once every 2 weeks and 24-week follow-up. In total, 60, 59, and 30 patients were treated with 1.0, 2.5 mg/kg ASC22, and PBO, respectively. The mean changes in HBsAg from baseline at weeks 24 and 48 were -0.309 ( p < 0.001) and -0.272 ( p < 0.023) log 10 IU/mL in the 1.0 mg/kg ASC22 group, -0.231 ( p = 0.007) and -0.205 ( p = 0.12) log 10 IU/mL in the 2.5 mg/kg ASC22 group, and -0.003 and -0.063 log 10 IU/mL in the PBO group, respectively (intent-to-treat population). Three out of 10 patients with baseline HBsAg levels ≤100 IU/mL in the 1.0 mg/kg group obtained on-treatment HBsAg loss. Most adverse events were mild (97.9%). There were no study drug-related serious adverse events in the 1.0 mg/kg ASC22 group.

Subcutaneous administration of 1.0 mg/kg ASC22 once every 2 weeks for 24 weeks was shown to be safe and well-tolerated in virally suppressed patients with chronic hepatitis B on nucleos(t)ide analogs and can induce HBsAg decline, especially in patients with HBsAg ≤100 IU/mL.

The hepatitis B virus (HBV) infection is a major global health problem, with chronic infection leading to liver complications and high death toll. Current treatments, such as nucleos(t)ide analogs and interferon-α, effectively suppress viral replication but rarely cure the infection. To address this, new antivirals targeting different components of the HBV molecular machinery are being developed. Here we investigated the hepatitis B core protein (HBc) that forms the viral capsids and plays a vital role in the HBV life cycle. We explored two distinct binding pockets on the HBV capsid: the central hydrophobic pocket of HBc-dimers and the pocket at the tips of capsid spikes. We synthesized a geranyl dimer that binds to the central pocket with micromolar affinity, and dimeric peptides that bind the spike-tip pocket with sub-micromolar affinity. Cryo-electron microscopy further confirmed the binding of peptide dimers to the capsid spike tips and their capsid-aggregating properties. Finally, we show that the peptide dimers induce HBc aggregation in vitro and in living cells. Our findings highlight two tractable sites within the HBV capsid and provide an alternative strategy to affect HBV capsids.

As new evidence emerges, treatment strategies toward the functional cure of chronic hepatitis B are evolving. In 2019, a panel of national hepatologists published a Consensus Statement on the functional cure of chronic hepatitis B. Currently, an international group of hepatologists has been assembled to evaluate research since the publication of the original consensus, and to collaboratively develop the updated statements. The 2.0 Consensus was aimed to update the original consensus with the latest available studies, and provide a comprehensive overview of the current relevant scientific literatures regarding functional cure of hepatitis B, with a particular focus on issues that are not yet fully clarified. These cover the definition of functional cure of hepatitis B, its mechanisms and barriers, the effective strategies and treatment roadmap to achieve this endpoint, in particular new surrogate biomarkers used to measure efficacy or to predict response, and the appropriate approach to pursuing a functional cure in special populations, the development of emerging antivirals and immunomodulators with potential for curing hepatitis B. The statements are primarily intended to offer international guidance for clinicians in their practice to enhance the functional cure rate of chronic hepatitis B.

Current antiviral therapy for the chronic hepatitis B virus (HBV) has a low clinical cure rate, high administration frequency, and limited efficacy in reducing HBsAg levels, leading to poor patient compliance. Novel agents are required to achieve HBV functional cure, and reduction of HBV antigenemia may enhance the activation of effective and long-lasting host immune control. HT-101 is a siRNA currently in phase I clinical trials with promising prospects for future applications. By designing and synthesizing siRNA targeting the conserved HBV S region, we evaluated its inhibitory effect on HBV biomarkers across four different genotypes (A-D). Additionally, potential cytotoxic effects were investigated. The in vivo effects and duration of inhibition were assessed using a HBV/adeno-associated virus mouse model. The EC50 values for HBV DNA, HBsAg, HBeAg, and HBV RNA in the supernatant of HepG2.2.15 cells were determined to be 0.3348 0.1696, 4.329, and 2.831 nM, respectively, while the CC50 of HT-101 against the viability of Hep2, H1 HeLa, MRC-5, HEK293, and Huh7 cell lines all exceeded 1 μM significantly. Compared with the vehicle group from days 7 to 70 postdosing, especially in the high-dose group (9 mpk), plasma levels of HBsAg, HBeAg, and HBV DNA were significantly reduced with mean reduction values ranging from 1.72 to 3.38 log10 copy/mL due to long-lasting suppression of HBsAg below the lower limit of quantitation (LLOQ), ultimately leading to induction of anti-HBs. In summary, the preclinical data demonstrate that HT-101 represents a significant breakthrough in reducing antigens and provides a promising strategy for functional cure of HBV.

The diagnosis of occult hepatitis B virus (HBV) infection (OBI) is influenced by factors such as the lower limit of detection (LOD) of the HBV DNA test. However, in clinical practice and scientific research, the lower limit of quantification (LOQ) is often misused as the LOD. This study aims to investigate the impact of misuse of the LOD of the HBV DNA test on the detection rate of OBI, as well as the risk factors for OBI. Four hundred twelve patients who were HBsAg-negative and had undergone high-sensitivity HBV DNA testing were included in this study. HBV DNA was detected using the Cobas 6800 System with an LOD of 2.4 IU/mL and an LOQ of 10 IU/mL. The effect of using the LOQ as the LOD on the detection rate of OBI was compared, and univariate and multivariate logistic regression analyses were used to explore the risk factors for OBI. (1) Of the 412 patients, 63.3% (n = 261) were male, with a median age of 47 (range 34-55) years. A total of 473 HBV DNA test results were obtained, with 366 individuals undergoing only one HBV DNA test and the remaining 46 patients undergoing 2 to 5 HBV DNA tests (resulting in a total of 107 test results). (2) Considering only the first HBV DNA test result, the detection rate of OBI was 4.1% (17/412). However, when the LOQ (10 IU/mL) was used as the LOD, the detection rate of OBI was only 1.5% (6/412) (p < 0.001). (3) Univariate analysis showed that there were statistically significant differences in age, anti-HBe positivity rate and anti-HBc positivity rate between OBI and non-OBI individuals (p < 0.05). Multivariate regression analysis showed that anti-HBe positivity was an independent risk factor for OBI in this study (odds ratio [OR] = 3.807, 95% confidence interval [CI]: 1.065-13.617, p = 0.040), while anti-HBs positivity was a protective factor against OBI (OR = 0.271, 95% CI: 0.093-0.787, p = 0.016). (4) Among the 46 patients who underwent repeated testing, a total of seven individuals were found to be HBV DNA-positive in the first test, and six individuals tested positive for HBV DNA one or more times in subsequent tests. When OBI was confirmed by ≥ 1 out of 1-5 tests with detectable HBV DNA, the detection rate of OBI in this study could increase from 4.1% to 5.6%. The detection rate of OBI among HBsAg-negative adult patients attending hepatology departments in this region is 4.1%. Misusing the LOQ as LOD can significantly decrease the detection rate of OBI. The presence of anti-HBe positivity and undergoing multiple HBV DNA tests can lead to a significant increase in the detection rate of OBI.

Due to the lack of agents that directly target covalently closed circular DNA and integrated HBV DNA in hepatocytes, achieving a complete cure for chronic hepatitis B (CHB) remains challenging. The latest guidelines recommend (hepatitis B surface antigen) HBsAg loss as the ideal treatment target for improving liver function, histopathology, and long-term prognosis. However, even after HBsAg loss, hepatitis B virus can persist, with a risk of recurrence, reactivation, cirrhosis, and hepatocellular carcinoma. Therefore, follow-up and surveillance are still necessary. With increasing treatment options available for achieving HBsAg loss in patients with CHB, developing effective surveillance strategies has become crucial. Recent studies on outcomes following HBsAg loss provide new insights for refining current surveillance strategies, though further improvement is needed through long-term observation and follow-up.

Little is known about the clinical significance of hepatic flare following effective antiretroviral therapy (ART) on HBsAg seroclearance and prognosis in HBV/HIV co-infection. This observational cohort study recruited HBV/HIV-1 co-infected patients from the China National Free Antiretroviral Treatment Program. We obtained longitudinal information on demographic characteristics, clinical indicators, and treatment outcomes. Hepatic flare was defined as an elevation of ALT of more than five times the upper limit of the normal range without an upsurge of HBV DNA or HBsAg at any time point between ART initiation and 12 months. Among the 1354 enrolled patients, 98.7% received two anti-HBV drugs containing ART and 95.1% achieved good viral control. Hepatic flare was observed in 88 (6.5%) patients and was more frequent in those with lower baseline immune function but subsequently enhanced immune reconstitution. Over a median follow-up of 4.7 years, we observed 99 HBsAg seroclearance, 9 hepatic events, 6 HIV-associated malignancy, 3 non-HIV-associated malignancy, and 3 all-cause mortality. The 3-, 5-, and 10-year cumulative incidence of HBsAg seroclearance was 6.4%, 8.9%, and 12.9%, respectively. Compared to patients without hepatic flare, patients with hepatic flare had significantly higher rates of HBsAg seroclearance (13.6% vs. 6.9%, p = 0.018) but had no recorded adverse outcome. Multivariate analysis with different models indicated that hepatic flare was independently associated with HBsAg seroclearance especially in patients with low immune function, normal ALT, and high levels of HBV DNA and HBsAg at baseline. In HBV/HIV-1 co-infection, hepatic flare following effective ART is associated with HBsAg seroclearance. HBV-specific T cells immune reconstitution may represent a potential mechanism which deserves further investigation.

The long-term stability of hepatitis B surface antigen (HBsAg) seroclearance following peginterferon alpha (peg-IFN-α)-based therapy has not been extensively studied, leaving the full potential and limitations of this strategy unclear.

To assess HBsAg recurrence after seroclearance achieved by peg-IFN-α regimens.

This prospective, multicenter, observational study was conducted from November 2015 to June 2021 at three Chinese hospitals: The Second Affiliated Hospital of Xi'an Jiaotong University, Ankang Central Hospital, and The Affiliated Hospital of Yan'an University. Participants who achieved HBsAg seroclearance following peg-IFN-α-based treatments were monitored every 4-12 weeks post-treatment for hepatitis B virus (HBV) markers, HBV DNA, and liver function. The primary outcome was HBV recurrence, defined as the reemergence of HBsAg, HBV DNA, or both, at least twice within 4-8 weeks of follow-up.

In total, 121 patients who achieved HBsAg seroclearance were enrolled. After a median follow-up of 84.0 (48.0, 132.0) weeks, four subjects were lost to follow-up. HBsAg recurrence was detected in 16 patients. The cumulative HBsAg recurrence rate in the intention-to-treat population was 15.2%. Multivariate logistic regression analysis demonstrated that consolidation time < 12 weeks [odds ratio (OR) = 28.044, 95%CI: 4.525-173.791] and hepatitis B surface antibody disappearance during follow-up (OR = 46.445, 95%CI: 2.571-838.957) were strong predictors of HBsAg recurrence. HBV DNA positivity and decompensation of liver cirrhosis and hepatocellular carcinoma were not observed.

HBsAg seroclearance following peg-IFN-α treatment was durable over 84 weeks of follow-up with a cumulative recurrence rate of 15.2%.

Hepatitis B virus (HBV) infection is associated with the progression of liver disease. Occult HBV infection (OBI) is defined as the existence of detectable HBV DNA in HBV surface antigen negative individuals. However, HBV DNA is negative in serum while HBV surface antigen remains positive in incompletely cured chronic HBV infection. Hence, combined detection of HBV surface antigen and HBV DNA is essential for the accurate detection and rehabilitation of HBV infection. Therefore, a multiplex detection strategy based on branched DNA nanostructures was developed. The single-stranded segment of a branched DNA nanostructure (segments of S4 and S2) assembled by four single-stranded DNA was hybridized with the aptamer of HBV surface antigen and DNA hairpin to construct a DNA nanosensor, which can achieve high specificity identification and highly sensitive fluorescence responses to the targets. The detection limits of the developed nanosensor for HBV and HBV DNA are 50 pM and 5 nM, respectively. The combined detection of HBV surface antigen and HBV DNA provides a new insight for more thorough diagnostic evaluation of HBV infection and rehabilitation.

The objective of antiviral therapy for chronic viral hepatitis B infection (CHB) is to achieve a functional cure. An important viral marker in the serum of patients with CHB is the serum hepatitis B core-related antigen (HBcrAg). However, there is limited research on HBcrAg in juvenile patients with CHB. In this study, we aimed to investigate the correlation between serum HBcrAg and other hepatitis B virus (HBV) markers in children with CHB and its predictive significance for prognosis during antiviral therapy.

A single-center retrospective study was conducted involving 79 children with CHB, aged between 0 and 16 years. All the children were treated with interferon [or combined nucleos(t)ide analogs] for 48 weeks. HBcrAg, hepatitis B surface antigen (HBsAg), and HBV DNA were measured before treatment, and at 12 and 48 weeks after treatment. The enrolled children were classified into the seroclearance group and the nonseroclearance group based on the therapeutic outcome.

HBsAg seroclearance was observed in 28 out of 79 patients and hepatitis B e antigen seroconversion without HBsAg seroclearance was observed in 14 out of 79 patients following the conclusion of the treatment, with baseline HBcrAg titer levels showing no statistical significance in both the seroclearance and nonseroclearance groups ( P  = 0.277). HBsAg and HBV DNA were positively correlated with HBcrAg in children with CHB ( R2  = 0.3289, 0.4388). The area under the receiver operating characteristic curve of the decrease in HBcrAg at 12 weeks of treatment as a predictor of seroclearance at 48 weeks of treatment, exhibited a value of 0.77.

A decrease in serum HBcrAg levels in children with hepatitis B serves as a prognostic indicator.

Chronic hepatitis B (CHB) remains a global health challenge, necessitating innovative therapeutic strategies. Enhancing the body's immune response against the hepatitis B virus (HBV) emerges as a fundamental strategy for achieving a functional cure. While acupuncture has shown potential in immune modulation, its specific anti-HBV effects are not well understood. This study evaluates the potential of electroacupuncture (EA) in HBV infection and explores its underlying immunological mechanisms using a mouse model.

HBV-infected mice were established using the high-pressure hydrodynamic method and divided into four groups: normal saline (NS), EA, sham EA (SE), and tenofovir disoproxil fumarate (TF), with n = 6 per group. During treatment, blood was collected every Sunday via the orbital sinus to monitor HBV DNA, HBsAg, and HBeAg levels. Transcriptomics and metabolomics analyses were employed to unearth clues regarding EA's anti-HBV mechanism. Validation of these mechanisms included splenic T-cell flow analysis, Western blotting, RT-qPCR, immunofluorescence, and ELISA.

Serum HBV DNA levels decreased by 1.10, 0.19, and 1.98 log10 IU/mL in the EA, SE, and TF-treated mice, respectively, compared to the NS. Concurrently, the hepatic HBV DNA levels decreased by 1.09, 0.24, and 2.03 log10 IU/mL. EA also demonstrated superior inhibition of HBV antigens, with serum HBeAg levels decreasing by 43.86%, 8.74%, and 8.03%, and serum HBsAg levels decreasing by 28.01%, 0.26%, and 9.39% in the EA, SE, and TF groups, respectively. Further analysis through transcriptomics and metabolomics revealed that EA's anti-HBV effects primarily hinge on immune modulation, particularly the IFN-γ/JAK/STAT pathway and taurine metabolism. EA also increased the ratio of splenic CD8+ CD69+ and CD8+ IFN-γ+ T-cells while upregulating key proteins in the JAK/STAT pathway and cytokines associated with antiviral immunity.

EA manifests inhibitory effects on HBV, particularly in antigen suppression, with its mode of action intricately linked to the regulation of IFN-γ/JAK/STAT.

The worldwide impact of liver diseases is increasing steadily, with a consistent upswing evidenced in incidence and mortality rates. Chronic liver diseases (CLDs) refer to the liver function's progressive deterioration exceeding six months, which includes abnormal clotting factors, detoxification failure, and hepatic cholestasis. The most common etiologies of CLDs are mainly composed of chronic viral hepatitis, MAFLD/MASH, alcoholic liver disease, and genetic factors, which induce inflammation and harm to the liver, ultimately resulting in cirrhosis, the irreversible final stage of CLDs. The latest research has shown that tripartite motif family proteins (TRIMs) function as E3 ligases, which participate in the progression of CLDs by regulating gene and protein expression levels through post-translational modification. In this review, our objective is to clarify the molecular mechanisms and potential therapeutic targets of TRIMs in CLDs and provide insights for therapy guidelines and future research.

Chronic infection induced by immune tolerance to hepatitis B virus (HBV) is one of the most common causes of hepatic cirrhosis and hepatoma. Fortunately, the application of therapeutic vaccine can not only reverse HBV-tolerance, but also serve a potentially effective therapeutic strategy for treating chronic hepatitis B (CHB). However, the clinical effect of the currently developed CHB therapeutic vaccine is not optimistic due to the weak immunogenicity. Given that the human leukocyte antigen CTLA-4 owns strong binding ability to the surface B7 molecules (CD80 and CD86) of antigen presenting cell (APCs), the immunoglobulin variable region of CTLA-4 (IgV_CTLA-4) was fused with the L protein of HBV to contrive a novel therapeutic vaccine (V_C4HBL) for CHB in this study. We found that the addition of IgV_CTLA-4 did not interfere with the formation of L protein T cell and B cell epitopes after analysis by means of immunoinformatics approaches. Meanwhile, we also found that the IgV_CTLA-4 had strong binding force to B7 molecules through molecular docking and molecular dynamics (MD) simulation. Notably, our vaccine V_C4HBL showed good immunogenicity and antigenicity by in vitro and in vivo experiments. Therefore, the V_C4HBL is promising to again effectively activate the cellular and humoral immunity of CHB patients, and provides a potentially effective therapeutic strategy for the treatment of CHB in the future.Communicated by Ramaswamy H. Sarma.

This study aimed to develop a pan-genotypic and multifunctional small interfering RNA (siRNA) against hepatitis B virus (HBV) with an efficient delivery system for treating chronic hepatitis B (CHB), and explore combined RNA interference (RNAi) and immune modulatory modalities for better viral control. Twenty synthetic siRNAs targeting consensus motifs distributed across the whole HBV genome were designed and evaluated. The lipid nanoparticle (LNP) formulation was optimized by adopting HO-PEG2000-DMG lipid and modifying the molar ratio of traditional polyethylene glycol (PEG) lipid in LNP prescriptions. The efficacy and safety of this formulation in delivering siHBV (tLNP/siHBV) along with the mouse IL-2 (mIL-2) mRNA (tLNP/siHBVIL2) were evaluated in the rAAV-HBV1.3 mouse model. A siRNA combination (terms "siHBV") with a genotypic coverage of 98.55% was selected, chemically modified, and encapsulated within an optimized LNP (tLNP) of high efficacy and security to fabricate a therapeutic formulation for CHB. The results revealed that tLNP/siHBV significantly reduced the expression of viral antigens and DNA (up to 3log10 reduction; vs PBS) in dose- and time-dependent manners at single-dose or multi-dose frequencies, with satisfactory safety profiles. Further studies showed that tLNP/siHBVIL2 enables additive antigenic and immune control of the virus, via introducing potent HBsAg clearance through RNAi and triggering strong HBV-specific CD4+ and CD8+ T cell responses by expressed mIL-2 protein. By adopting tLNP as nucleic acid nanocarriers, the co-delivery of siHBV and mIL-2 mRNA enables synergistic antigenic and immune control of HBV, thus offering a promising translational therapeutic strategy for treating CHB.

As a hepatotropic virus, hepatitis B virus (HBV) can establish a persistent chronic infection in the liver, termed, chronic hepatitis B (CHB), which causes a series of liver-related complications, including fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). HCC with HBV infection has a significantly increased morbidity and mortality, whereas it could be preventable. The current goal of antiviral therapy for HBV infection is to decrease CHB-related morbidity and mortality, and achieve sustained suppression of virus replication, which is known as a functional or immunological cure. The natural history of chronic HBV infection includes four immune phases: the immune-tolerant phase, immune-active phase, inactive phase, and reactivation phase. However, many CHB patients do not fit into any of these defined phases and are regarded as indeterminate. A large proportion of indeterminate patients are only treated with dynamic monitoring rather than recommended antiviral therapy, mainly due to the lack of definite guidelines. However, many of these patients may gradually have significant liver histopathological changes during disease progression. Recent studies have focused on the prevalence, progression, and carcinogenicity of indeterminate CHB, and more attention has been given to the prevention, detection, and treatment for these patients. Herein, we discuss the latest understanding of the epidemiology, clinical characteristics, and therapeutic strategies of indeterminate CHB, to provide avenues for the management of these patients.

Advancements in our understanding of the hepatitis B viral (HBV) life cycle have paved the way for novel approaches to treat HBV infection. This review summarizes the various strategies being pursued to achieve a functional cure, defined as loss of hepatitis B surface antigen (HBsAg) and absence of viral replication 6 months off-therapy.

Direct acting antiviral, host targeting antiviral, and immunological approaches are in various stages of development as treatment for chronic HBV infection.

Novel treatments are being developed in pursuit of a cure for HBV. Current evidence suggests a single therapeutic agent alone may be insufficient, necessitating the need for combination therapy targeting HBV and the host immune response. Ongoing research focused on identifying the best therapeutic combination holds promise in achieving functional cure for HBV.

Functional cure of hepatitis B virus (HBV) is an optimal treatment goal for chronic hepatitis B, with the loss of hepatitis B surface antigen (HBsAg) being a crucial indicator. However, the adequacy of HBsAg loss for evaluating functional cure of HBV in patients co-infected with HBV/human immunodeficiency virus (HIV) remains controversial. In this study, we measured HBV pregenomic RNA (pgRNA), a potential biomarker that correlates with covalently closed circular DNA, in the frozen plasma of 98 patients with HBsAg loss from a large HIV/HBV co-infection cohort in Guangzhou, China. HBV pgRNA was still detected in 43.9% (44/98) of the patients, suggesting active HBV replication in individuals with HBsAg loss. Our observations imply that HBsAg loss may not be a reliable predictor of HBV functional cure in cases of HIV/HBV co-infection.

The investigational first-generation core inhibitor vebicorvir (VBR) demonstrated safety and antiviral activity over 24 weeks in two phase IIa studies in patients with chronic HBV infection. In this long-term extension study, patients received open-label VBR with nucleos(t)ide reverse transcriptase inhibitors (NrtIs).

Patients in this study (NCT03780543) previously received VBR + NrtI or placebo + NrtI in parent studies 201 (NCT03576066) or 202 (NCT03577171). After receiving VBR + NrtI for ≥52 weeks, stopping criteria (based on the treatment history and hepatitis B e antigen status in the parent studies) were applied, and patients either discontinued both VBR + NrtI, discontinued VBR only, or continued both VBR + NrtI. The primary efficacy endpoint was the proportion of patients with HBV DNA <20 IU/ml at 24 weeks off treatment.

Ninety-two patients entered the extension study and received VBR + NrtI. Long-term VBR + NrtI treatment led to continued suppression of HBV nucleic acids and, to a lesser extent, HBV antigens. Forty-three patients met criteria to discontinue VBR + NrtI, with no patients achieving the primary endpoint; the majority of virologic rebound occurred ≥4 weeks off treatment. Treatment was generally well tolerated, with few discontinuations due to adverse events (AEs). There were no deaths. Most AEs and laboratory abnormalities were related to elevations in alanine aminotransferase and occurred during the off-treatment or NrtI-restart phases. No drug-drug interactions between VBR + NrtI and no cases of treatment-emergent resistance among patients who adhered to treatment were observed.

Long-term VBR + NrtI was safe and resulted in continued reductions in HBV nucleic acids following completion of the 24-week parent studies. Following treatment discontinuation, virologic relapse was observed in all patients. This first-generation core inhibitor administered with NrtI for at least 52 weeks was not sufficient for HBV cure.

NCT03780543.

Approved treatments for chronic hepatitis B virus infection (cHBV) suppress viral replication, but viral rebound is almost always observed after treatment discontinuation, highlighting an unmet need for improved therapies with finite treatment duration producing greater therapeutic responses that can be sustained off treatment. First-generation core inhibitors, such as vebicorvir, have mechanisms of action orthogonal to standard-of-care therapies that deeply suppress HBV viral replication during treatment; however, to date, durable virologic responses have not been observed after treatment discontinuation. The results reported here will help researchers with the design and interpretation of future studies investigating core inhibitors as possible components of finite treatment regimens for patients with cHBV. It is possible that next-generation core inhibitors with enhanced potency may produce deeper and more durable antiviral activity than first-generation agents, including vebicorvir.

Chronic hepatitis B virus (HBV) infection affects over 295 million people globally and an estimated 1.6 million people in the United States. It is associated with significant morbidity and mortality due to cirrhosis, liver failure, and liver cancer. Antiviral therapy with oral nucleos(t)ide analogues is associated with high rates of virologic suppression, which in turn has been associated with a decreased risk of liver complications. However, current antiviral regimens are limited by concerns with adverse effects, adherence, resistance, long-term treatment, and ongoing risk for liver events. Novel investigational agents are currently in development and are targeted at achieving functional cure with sustained hepatitis B surface antigen (HBsAg) loss and suppression of HBV DNA. Herein we review key evidence from phases II and III trials defining the efficacy and safety profiles for key investigational agents for functional cure of chronic hepatitis B, including core/capsid inhibitors, entry inhibitors, RNA interference (siRNA/ASO), HBsAg inhibitors, Toll-like receptor agonists, checkpoint inhibitors, and therapeutic vaccines.

Annually, more than 1.5 million preventable new hepatitis B (HBV) infections continue to occur, with an estimated global burden of 296 million individuals living with chronic hepatitis B infection. This substantial health challenge results in over 820,000 annual deaths being attributed to complications such as liver cirrhosis and hepatocellular carcinoma (HCC). The HBV vaccination remains the cornerstone of public health policy to prevent chronic hepatitis B and its related complications. It serves as a crucial element in the global effort to eliminate HBV, as established by the World Health Organization (WHO), with an ambitious 90% vaccination target by 2030. However, reports on global birth dose coverage reveal substantial variability, with an overall coverage rate of only 46%. This comprehensive review thoroughly examines global trends in HBV vaccination coverage, investigating the profound impact of vaccination on HBV prevalence and its consequences across diverse populations, including both high-risk and general demographics. Additionally, the review addresses the essential formidable challenges and facilitating factors for achieving WHO's HBV vaccination coverage objectives and elimination strategies in the coming decade and beyond.

As new therapeutic options become available, better understanding the potential impact of emerging therapies on clinical outcomes of hepatits D virus (HDV) is critical.

The aim of this study was to develop a natural history model for patients with hepatitis D virus.

We developed a model (decision tree followed by a Markov cohort model) in adults with chronic HDV infection to assess the natural history and impact of novel treatments on disease progression versus best supportive care (BSC). The model time horizon was over a lifetime (up to 100 years of age); state transitions and health states were defined by responder status. Patients in fibrosis stages 0 through 4 received treatment; decompensated patients were not treated. Response was defined as the combined response endpoint of achievement of HDV-RNA undetectability/≥2-log10 decline and alanine aminotransferase normalization; response rates of 50% and 75% were explored. Health events associated with advanced liver disease were modeled as the number of events per 10,000 patients. Scenario analyses of early treatment, alternate treatment response, and no fibrosis regression for treatment responders were also explored.

The model was able to reflect disease progression similarly to published natural history studies for patients with HBV/HDV infection. In a hypothetical cohort of patients reflecting a population enrolled in a recent clinical trial, fewer advanced liver disease events were observed with a novel HDV treatment versus BSC. Fewer liver-related deaths were observed under 50% and 75% response (900 and 1,358 fewer deaths, respectively, per 10,000 patients). Scenario analyses showed consistently fewer advanced liver disease events with HDV treatment compared with BSC, with greater reductions observed with earlier treatment.

This HDV disease progression model replicated findings from natural history studies. Furthermore, it found that a hypothetical HDV treatment results in better clinical outcomes for patients versus BSC, with greater benefit observed when starting treatment early. This validated natural history model for HBV/HDV infection can serve as a foundation for future clinical and economic analyses of novel HDV treatments that can support healthcare stakeholders in the management of patients with chronic HDV.

Novel finite therapies for chronic hepatitis B (CHB) are needed, since lifelong treatment is usually required with current available oral antivirals. This phase II study (NCT03615066) evaluated the safety, pharmacodynamics, and antiviral activity of selgantolimod (a Toll-like receptor 8 agonist [TLR8]) with tenofovir alafenamide (TAF).

Viremic patients with CHB not receiving treatment were stratified by HBeAg status and randomized 2:2:1 to TAF 25 mg/day with selgantolimod 3 mg orally once weekly (QW), selgantolimod 1.5 mg QW, or placebo. Combination therapy continued until week (W)24, followed by TAF monotherapy until W48; patients then discontinued TAF and were followed until W96 (treatment-free follow-up [TFFU] period). The primary efficacy endpoint was the proportion with ≥1 log10 IU/ml HBsAg decline at W24.

Sixty-seven patients received study drug; 27 were followed during TFFU. Nausea, headache, vomiting, fatigue, and dizziness were the most common adverse events. Most adverse events were grade 1. Alanine aminotransferase flares were not observed up to W48. Four patients experienced alanine aminotransferase and hepatitis flares during TFFU; all had HBV DNA increases. Selgantolimod increased serum cytokines and chemokines and redistributed several circulating immune cell subsets. No patients achieved the primary efficacy endpoint. Mean HBsAg changes were -0.12, -0.16, and -0.12 log10 IU/ml in the selgantolimod 3 mg, selgantolimod 1.5 mg, and placebo groups, respectively, at W48; HBV DNA declined in all groups by ≥2 log10 IU/ml as early as W2, with all groups rebounding to baseline during TFFU. No HBsAg or HBeAg loss or seroconversion was observed throughout TFFU.

Selgantolimod up to 3 mg was safe and well tolerated. Pharmacodynamics and antiviral activity in viremic patients support continued study of selgantolimod in combination CHB therapies.

Novel therapeutics for chronic HBV infection are needed to achieve a functional cure. In this study, we confirmed the safety and tolerability of selgantolimod (formerly GS-9688, a TLR8) when administered with tenofovir alafenamide over 24 weeks in viremic patients with chronic HBV infection. Overall, declines in HBsAg levels with selgantolimod treatment were modest; subgroup analysis indicated that patients with alanine aminotransferase levels greater than the upper limit of normal had significantly greater declines compared to those with normal alanine aminotransferase levels (-0.20 vs. -0.03 log10 IU/ml; p <0.001). These findings suggest a potential differential response to selgantolimod based on patients' baseline HBV-specific immune response, which should be considered in future investigations characterizing the underlying mechanisms of selgantolimod treatment and in HBV cure studies using similar immunomodulatory pathways.

NCT03615066 be found at https://www.gileadclinicaltrials.com/transparency-policy/.

Hepatitis D virus (HDV) infection causes the most severe form of chronic viral hepatitis. However, it is still unclear to what extent the underlying cirrhosis may contribute to disease progression. The aim of this study was to compare the long-term outcome of HDV infection with HBV monoinfection in a single-center cohort of both non-cirrhotic and cirrhotic patients.

We retrospectively studied 175 patients with chronic hepatitis D (CHD) who were followed for at least 6 months (median of 6.3 (0.6-23.6) years). In addition, we selected 175 patients with HBV monoinfection (CHB) who were matched for gender, age, region of origin, HBeAg status, and bilirubin. Liver-related clinical end points were defined as hepatic decompensation (ascites, encephalopathy, variceal bleeding), liver transplantation, HCC, or liver-related death.

Clinical complications developed earlier (4.6 vs. 6.2 years) and more frequently (35.4% vs. 12.6%, p < 0.01) in CHD patients. In a multivariate Cox regression, HDV infection was independently associated with the development of end points (p < 0.01; HR: 3.0; 95% CI 1.4-6.4). However, in cirrhotic patients there were no significant differences between HBV and HDV in the development of end points. Besides, CHB patients with cirrhosis developed more frequently HCC (35.5%) than CHD patients with cirrhosis (18.5%).

Our results confirmed that HDV leads to a faster progression to cirrhosis compared to HBV. However, once cirrhosis is present, not HDV but the underlying cirrhosis is the dominate intrinsic risk factor for the development of liver-related end points and for the progression to HCC.

Chronic infection with hepatitis delta virus (HDV) affects between 12-20 million people worldwide and represents the most severe form of viral hepatitis, leading to accelerated liver disease progression, cirrhosis and its complications, such as end-stage-liver disease and hepatocellular carcinoma. From the discovery of HDV in 1977 by Prof. Mario Rizzetto, knowledge on the HDV life cycle and mechanisms of viral spread has expanded. However, little is still known about the natural history of the disease, host-viral interactions, and the role of the immune system in HDV persistence. Diagnosis of HDV is still challenging due to a lack of standardised assays, while accurate viral load quantification is needed to assess response and endpoints of antiviral treatment. Until recently, interferon has represented the only treatment option in patients with chronic hepatitis delta; however, it is associated with low efficacy and a high burden of side effects. The discovery of the entry inhibitor bulevirtide has represented a breakthrough in HDV treatment, by demonstrating high rates of viral suppression in phase II and III trials, results which have been confirmed in real-world settings and in patients with compensated advanced liver disease. In the meantime, other compounds (i.e. lonafarnib, new anti-hepatitis B virus drugs) are under development to provide alternative or combined strategies for HDV cure. The first international Delta Cure meeting was organised in Milan in October 2022 with the aim of sharing and disseminating the latest data; this review summarises key takeaway messages from state-of-the-art lectures and research data on HDV.

With growing interest and efforts to achieve a hepatitis B (HBV) cure, HBV therapeutics have increasingly entered the clinical testing phase. In designing an early phase clinical trial aimed at HBV cure, the heterogeneity in participants and the choice of a biomarker endpoint that signals a cure requires careful consideration. We describe the key elements to consider during the development of HBV clinical trials aimed at a functional cure, and how we have addressed them in the design of a phase II AIDS Clinical Trials Group (ACTG) study, A5394 (NCT05551273). The trial we present is for persons with both HIV and HBV, a unique population that has much to gain from an HBV cure. Our decisions on the design elements are specific to the study agent and the targeted population, but our deliberations may be informative in the emerging field of early phase HBV trials aimed at cure.

Chronic hepatitis B virus (HBV) infection leads to the development of cirrhosis and hepatocellular carcinoma. Lifelong treatment with nucleotides/nucleoside antiviral agents is effective at suppressing HBV replication, however, adherence to daily therapy can be challenging. This review discusses recent advances in the development of long-acting formulations for HBV treatment and prevention, which could potentially improve adherence. Promising new compounds that target distinct steps of the virus life cycle are summarized. In addition to treatments that suppress viral replication, curative strategies are focused on the elimination of covalently closed circular DNA and the inactivation of the integrated viral DNA from infected hepatocytes. We highlight promising long-acting antivirals and genome editing strategies for the elimination or deactivation of persistent viral DNA products in development.

HeberNasvac is a recently developed therapeutic vaccine for chronic hepatitis B (CHB) administered by intranasal (IN) and subcutaneous (SC) routes in a 14 days/10 doses schedule. To compare different schedules and routes of immunizations, a group of patients received four different vaccination regimens in a placebo-controlled factorial study. Subsequently, patients were followed for a minimum time of 48 weeks. Samples collected at the end of the follow-up were compared with initial samples. Groups I and II received the product by IN/SC routes, every 14 and 7 days, respectively. Groups III and IV were treated by SC route alone following a 14 and 7 days schedule. A group of 21 CHB patients received the vaccine in four different schedules and eight patients received placebo for a total of 29 patients enrolled. The 61.9% of vaccinees reduced their VL ≥2Log compared with baseline levels and 25% in placebo group. The 47.6% of vaccines reduced HBV levels to undetectable, 25% in placebo. HBeAg loss and seroconversion to anti-HBeAg was only achieved in vaccinees, 4 out of 9 (44.4%), and 40% (8 out of 20) developed anti-HBs response, none in placebo group. Reduction of HBsAg level in ≥1Log was achieved in the 35.0% of vaccinees and in none of the placebo-treated patients. Considering the individual and factorial analysis, significant HBV DNA reduction was detected in groups I and II, immunized by IN/SC routes. A significantly higher proportion of patients reducing VL to ≥2Log was also detected grouping the patients treated by IN/SC routes (G I + II) and grouping those inoculated every 14 days (G I + III), with 72.7% and 63.6%, respectively, compared with the placebo group (25.0%). The patients immunized every 14 days (G I + G III) also reduced the HBsAg levels compared with baseline. In conclusion, after more than 48 weeks of treatment-free follow-up, HeberNasvac-treated patients demonstrated superior responses compared with the placebo group in terms of antiviral and serological responses. The factorial analysis evidenced that the schedule combining the IN route of immunization and the frequency of 14 days resulted in the stronger antiviral and serological responses. Present results support the study of IN-only immunization schedules in future and was consistent with previous results. Long-lasting follow-ups were done to explore histological variables and the progression of serological variables in order to detect late responders.

Freyre FM, Aguiar JA, Cinza Z, et al. Impact of the Route and Schedule of Immunization on the Serological and Virological Response of Chronic Hepatitis B Patients Treated with HeberNasvac. Euroasian J Hepato-Gastroenterol 2023;13(2):73-78.

Over 296 million people are estimated to have chronic hepatitis B viral infection (CHB), and it poses unique challenges for elimination. CHB is the result of hepatitis B virus (HBV)-specific immune tolerance and the presence of covalently closed circular DNA as mini chromosome inside the nucleus and the integrated HBV. Serum hepatitis B core-related antigen is the best surrogate marker for intrahepatic covalently closed circular DNA. Functional HBV "cure" is the durable loss of hepatitis B surface antigen (HBsAg), with or without HBsAg seroconversion and undetectable serum HBV DNA after completing a course of treatment. The currently approved therapies are nucleos(t)ide analogues, interferon-alpha, and pegylated-interferon. With these therapies, functional cure can be achieved in < 10% of CHB patients. Any variation to HBV or the host immune system that disrupts the interaction between them can lead to reactivation of HBV. Novel therapies may allow efficient control of CHB. They include direct acting antivirals and immunomodulators. Reduction of the viral antigen load is a crucial factor for success of immune-based therapies. Immunomodulatory therapy may lead to modulation of the host immune system. It may enhance/restore innate immunity against HBV (as toll-like-receptors and cytosolic retinoic acid inducible gene I agonist). Others may induce adaptive immunity as checkpoint inhibitors, therapeutic HBV vaccines including protein (HBsAg/preS and hepatitis B core antigen), monoclonal or bispecific antibodies and genetically engineered T cells to generate chimeric antigen receptor-T or T-cell receptor-T cells and HBV-specific T cells to restore T cell function to efficiently clear HBV. Combined therapy may successfully overcome immune tolerance and lead to HBV control and cure. Immunotherapeutic approaches carry the risk of overshooting immune responses causing uncontrolled liver damage. The safety of any new curative therapies should be measured in relation to the excellent safety of currently approved nucleos(t)ide analogues. Development of novel antiviral and immune modulatory therapies should be associated with new diagnostic assays used to evaluate the effectiveness or to predict response.

CAMs were disclosed to alter cccDNA levels with sustained hepatitis B surface antigen (HBsAg) loss or seroconversion in preclinical investigation. Here, we report the discovery of a prodrug Yhhu6669 as CAMs based on the intestinal peptide transporter. This compound exhibited the promising anti-HBV activity with sustained suppression of HBV DNA, as well as HBsAg and HBeAg in the AAV HBV mouse model by oral treatment for 7 weeks and maintained for a further 8 weeks following drug withdraw. Our results show an alternative possibility for a functional cure by specific CAMs and provide the basis for the further mechanism study.

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.

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.

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

Treatment for chronic hepatitis B virus infection (cHBV) is mostly indefinite, with new finite-duration therapies needed. We report safety, pharmacokinetics and antiviral activity of the investigational HBV core inhibitor ABI-H2158. This Phase 1a/b study (NCT03714152) had three parts: Part A, participants received a single ascending oral dose of ABI-H2158 (5-500 mg) or placebo; Part B, participants received multiple doses of ABI-H2158 300 mg once (QD) or twice (BID) daily or placebo, for 10 days; Part C, cHBV patients received ABI-H2158 (100, 300, or 500 mg QD or 300 mg BID) or placebo, for 14 days. Ninety-three participants enrolled. In Parts A/B, there were no serious adverse events (SAEs) or deaths, and all treatment-emergent AEs (TEAEs) were Grade 1. In Part C, two patients had Grade 3 TEAEs unrelated to ABI-H2158; there were no deaths, SAEs or Grade 4 TEAEs. In Part A, median time to maximum ABI-H2158 plasma concentration (T_max ) and mean terminal elimination half-life (t_½ ) were 1-4 and 9.8-20.7 h, and area under the plasma concentration-time curve increased dose proportionally. In Part B, Day 10 T_max was 2 h, mean t_½ was 15.5-18.4 h, and exposure accumulated 1.7- to 3.1-fold. In Part C, Day 14 T_max was 1 h, exposure accumulated 1.4- to 1.8-fold, and ABI-H2158 was associated with >2 log₁₀ declines in HBV nucleic acids. In conclusion, ABI-H2158 in cHBV patients following 14 days of dosing was well tolerated and demonstrated potent antiviral activity. Safety and pharmacokinetics supported future QD dosing.