Association Between Seroclearance of Hepatitis B Surface Antigen and Long-term Clinical Outcomes of Patients With Chronic Hepatitis B Virus Infection: Systematic Review and Meta-analysis

Predictive models for functional cure in patients with CHB receiving PEG-IFN therapy based on HBsAg quantification through meta-analysis

BACKGROUND AND AIMS

The efficacy of achieving HBsAg clearance through pegylated interferon (PEG-IFNα) therapy in patients with chronic hepatitis B (CHB) remains uncertain, especially regarding the probability of achieving functional cure among patients with varying baseline HBsAg levels. We aimed to investigate the predictive value of HBsAg quantification for HBsAg seroclearance in CHB patients undergoing PEG-IFNα treatment.

METHODS

A systematic search was conducted in PubMed, Embase, and the Cochrane Library up to January 11, 2022. Subgroup analyses were performed for HBeAg-positive and HBeAg-negative patients, PEG-IFNα monotherapy and PEG-IFNα combination therapy, treatment-naive and treatment-experienced patients, and patients with or without liver cirrhosis.

RESULTS

This predictive model incorporated 102 studies. The overall HBsAg clearance rates at the end of treatment (EOT) and the end of follow-up (EOF) were 10.6% (95% CI 7.8-13.7%) and 11.1% (95% CI 8.4-14.1%), respectively. Baseline HBsAg quantification was the most significant factor. According to the model, it is projected that when baseline HBsAg levels are 100, 500, 1500, and 10,000 IU/ml, the HBsAg clearance rates at EOF could reach 53.9% (95% CI 40.4-66.8%), 32.1% (95% CI 24.8-38.7%), 14.2% (95% CI 9.8-18.8%), and 7.9% (95% CI 4.2-11.8%), respectively. Additionally, treatment-experienced patients with HBeAg-negative status, and without liver cirrhosis exhibited higher HBsAg clearance rates after PEG-IFNα treatment.

CONCLUSION

A successful predictive model has been established to predict the achievement of functional cure in CHB patients receiving PEG-IFNα therapy.

Predictors of HBsAg seroclearance in patients with chronic HBV infection treated with pegylated interferon-α: a systematic review and meta-analysis

BACKGROUND AND AIMS

The identification of reliable predictors for hepatitis B surface antigen (HBsAg) seroclearance remains controversial. We aimed to summarize potential predictors for HBsAg seroclearance by pegylated interferon-α (PegIFNα) in patients with chronic HBV infection.

METHODS

A systematic search of the Cochrane Library, Embase, PubMed, and Web of Science databases was conducted from their inception to 28 September 2022. Meta-analyses were performed following the PRISMA statement. Predictors of HBsAg seroclearance were evaluated based on baseline characteristics and on-treatment indicators.

RESULTS

This meta-analysis encompasses 27 studies, including a total of 7913 patients. The findings reveal several factors independently associated with HBsAg seroclearance induced by PegIFNα-based regimens. These factors include age (OR = 0.961), gender (male vs. female, OR = 0.537), genotype (A vs. B/D; OR = 7.472, OR = 10.738), treatment strategy (combination vs. monotherapy, OR = 2.126), baseline HBV DNA (OR = 0.414), baseline HBsAg (OR = 0.373), HBsAg levels at week 12 and 24 (OR = 0.384, OR = 0.294), HBsAg decline from baseline to week 12 and 24 (OR = 6.689, OR = 6.513), HBsAg decline from baseline ≥ 1 log10 IU/ml and ≥ 0.5 log10 IU/ml at week 12 (OR = 18.277; OR = 4.530), and ALT elevation at week 12 (OR = 3.622). Notably, subgroup analysis suggests no statistical association between HBsAg levels at week 12 and HBsAg seroclearance for treatment duration exceeding 48 weeks. The remaining results were consistent with the overall analysis.

CONCLUSIONS

This is the first meta-analysis to identify predictors of HBsAg seroclearance with PegIFNα-based regimens, including baseline and on-treatment factors, which is valuable in developing a better integrated predictive model for HBsAg seroclearance to guide individualized treatment and achieve the highest cost-effectiveness of PegIFNα.

Interim analysis of the PARADISE study: Benefits of add-on peginterferon-α in NA-treated patients with CHB

This study aimed to investigate whether peginterferon-α (IFN) add-on nucleos(t)ide analogs(NAs) can further reduce hepatocellular carcinoma(HCC) risk compared with NAs monotherapy in NA-treated patients with chronic hepatitis B(CHB). In this multi-center randomized controlled trial "PARADISE study" (NCT05671315), CHB patients with intermediate to high risk of HCC after more than 24-week NAs pretreatment were recruited, randomized to two groups at a ratio of 1:2 and followed up for 240 weeks. NAs group maintained NAs monotherapy, while IFN + NAs group received IFN add-on NAs therapy for 48 weeks, then switched to NAs monotherapy. Totally, 196 patients were included in interim analysis (NAs group 68, IFN + NAs group 128). The 96-week cumulative HCC incidence was lower in IFN + NAs group than NAs group (0% vs. 4.5%, p < 0.05). Compared with NAs group, IFN + NAs group had significantly higher rates of HBsAg loss at week 48 and 96 (22.7% vs. 0%; 16.7% vs. 0%, both p < 0.05). A new scoring system was established to predict HBsAg decline >2log10 IU/ml, HBsAg <10 IU/ml or HBsAg loss at the end of 48-week IFN treatment. The area under ROC curve was 0.914, 0.922 or 0.905 in the original cohort (n = 128) and 0.896, 0.896 or 0.864 in the external validation cohort (n = 162) for the aforementioned three outcomes, respectively. IFN add-on NAs therapy may suggest the dual benefits of reducing HCC development and facilitating HBsAg loss among NA-treated CHB patients with intermediate to high risk of HCC. The new scoring system helps to make the most of IFN treatment for a higher cost-effectiveness in healthcare.

Optimal Treatment Based on Interferon No Longer Makes Clinical Cure of Chronic Hepatitis B Far Away: An Evidence-Based Review on Emerging Clinical Data

Chronic hepatitis B (CHB) remains a major global public health problem. The functional cure is the ideal therapeutic target recommended by the latest guidelines, and pursuing a functional cure has become the key treatment end point of current therapy and for upcoming clinical trials. In this review, based on the latest published clinical research evidence, we analyzed the concept and connotation of clinical cures and elaborated on the benefits of clinical cures in detail. Secondly, we have summarized various potential treatment methods for achieving clinical cures, especially elaborating on the latest research progress of interferon-based optimized treatment strategies in achieving clinical cures. We also analyzed which populations can achieve clinical cures and conducted a detailed analysis of relevant virological and serological markers in screening clinical cure advantage populations and predicting clinical cure achievement. In addition, we also introduced the difficulties that may be encountered in the current pursuit of achieving a clinical cure.

Quantitative hepatitis B core antibody and quantitative hepatitis B surface antigen: Novel viral biomarkers for chronic hepatitis B management

The management of hepatitis B virus (HBV) infection now involves regular and appropriate monitoring of viral activity, disease progression, and treatment response. Traditional HBV infection biomarkers are limited in their ability to predict clinical outcomes or therapeutic effectiveness. Quantitation of HBV core antibodies (qAnti-HBc) is a novel non-invasive biomarker that may help with a variety of diagnostic issues. It was shown to correlate strongly with infection stages, hepatic inflammation and fibrosis, chronic infection exacerbations, and the presence of occult infection. Furthermore, qAnti-HBc levels were shown to be predictive of spontaneous or treatment-induced HBeAg and HBsAg seroclearance, relapse after medication termination, re-infection following liver transplantation, and viral reactivation in the presence of immunosuppression. qAnti-HBc, on the other hand, cannot be relied on as a single diagnostic test to address all problems, and its diagnostic and prognostic potential may be greatly increased when paired with qHBsAg. Commercial qAnti-HBc diagnostic kits are currently not widely available. Because many methodologies are only semi-quantitative, comparing data from various studies and defining universal cut-off values remains difficult. This review focuses on the clinical utility of qAnti-HBc and qHBsAg in chronic hepatitis B management.

Efficacy, safety, and pharmacokinetics of capsid assembly modulator linvencorvir plus standard of care in chronic hepatitis B patients

BACKGROUND/AIMS

Four-week treatment of linvencorvir (RO7049389) was generally safe and well tolerated, and showed anti-viral activity in chronic hepatitis B (CHB) patients. This study evaluated the efficacy, safety, and pharmacokinetics of 48-week treatment with linvencorvir plus standard of care (SoC) in CHB patients.

METHODS

This was a multicentre, non-randomized, non-controlled, open-label phase 2 study enrolling three cohorts: nucleos(t)ide analogue (NUC)-suppressed patients received linvencorvir plus NUC (Cohort A, n=32); treatment-naïve patients received linvencorvir plus NUC without (Cohort B, n=10) or with (Cohort C, n=30) pegylated interferon-α (Peg-IFN-α). Treatment duration was 48 weeks, followed by NUC alone for 24 weeks.

RESULTS

68 patients completed the study. No patient achieved functional cure (sustained HBsAg loss and unquantifiable HBV DNA). By Week 48, 89% of treatment-naïve patients (10/10 Cohort B; 24/28 Cohort C) reached unquantifiable HBV DNA. Unquantifiable HBV RNA was achieved in 92% of patients with quantifiable baseline HBV RNA (14/15 Cohort A, 8/8 Cohort B, 22/25 Cohort C) at Week 48 along with partially sustained HBV RNA responses in treatment-naïve patients during follow-up period. Pronounced reductions in HBeAg and HBcrAg were observed in treatment-naïve patients, while HBsAg decline was only observed in Cohort C. Most adverse events were grade 1-2, and no linvencorvir-related serious adverse events were reported.

CONCLUSION

48-week linvencorvir plus SoC was generally safe and well tolerated, and resulted in potent HBV DNA and RNA suppression. However, 48-week linvencorvir plus NUC with or without Peg-IFN did not result in the achievement of functional cure in any patient.

Addition of PEG-interferon to long-term nucleos(t)ide analogue therapy enhances HBsAg decline and clearance in HBeAg-negative chronic hepatitis B: Multicentre Randomized Trial (PAS Study)

We studied whether 48 weeks of PEG-IFN alfa-2a add-on increases HBsAg-decline and clearance in HBeAg-negative patients on long-term nucleo(s)tide analogue (NA) therapy. In this investigator-initiated, randomized, controlled trial conducted in Europe and Canada, HBeAg-negative patients treated with NA > 12 months, with HBVDNA < 200 IU/mL, were enrolled. Patients were randomized 2:1 to 48 weeks of PEG-IFN alfa-2a add-on (180 μg per week) or continued NA-monotherapy with subsequent follow-up to Week 72. Endpoints were HBsAg decline (≥1 log10 IU/mL) and HBsAg clearance at Week 48. Of the 86 patients in the modified-intention-to-treat analysis, 58 patients received PEG-IFN add-on, and 28 continued NA monotherapy. At Week 48, 16(28%) patients achieved HBsAg decline ≥1 log10 in the add-on arm versus none on NA-monotherapy (p < .001), and HBsAg clearance was observed in 6 (10%) PEG-IFN add-on patients versus 0% NA-monotherapy (p = .01). HBVRNA was only detected in 2% after PEG-IFN treatment versus 19% in NA-monotherapy (p = .002) at Week 48. PEG-IFN add-on therapy was well tolerated in majority of patients. Low baseline HBsAg levels (<10 IU/mL) identified patients most likely to achieve HBsAg loss with PEG-IFN add-on, whereas an HBsAg level > 200 IU/mL at on-treatment Week 12 was highly predictive of non-response (NPV = 100%). Addition of PEG-IFN to long-term NA enhanced HBsAg decline and increased the chance of HBsAg clearance in HBeAg-negative patients on long-term NA. On-treatment HBsAg levels >200 IU/mL identify patients unlikely to benefit from PEG-IFN add-on and could be used as a potential stopping-rule for PEG-IFN therapy. Our findings support further exploration of immune modulation add-on to antiviral therapy, preferably using response-guided strategies, to increase functional cure rates in patients with CHB.

Prediction model for hepatitis B e antigen seroconversion in chronic hepatitis B with peginterferon-alfa treated based on a response-guided therapy strategy

BACKGROUND

Models for predicting hepatitis B e antigen (HBeAg) seroconversion in patients with HBeAg-positive chronic hepatitis B (CHB) after nucleos(t)ide analog treatment are rare.

AIM

To establish a simple scoring model based on a response-guided therapy (RGT) strategy for predicting HBeAg seroconversion and hepatitis B surface antigen (HBsAg) clearance.

METHODS

In this study, 75 previously treated patients with HBeAg-positive CHB underwent a 52-week peginterferon-alfa (PEG-IFNα) treatment and a 24-wk follow-up. Logistic regression analysis was used to assess parameters at baseline, week 12, and week 24 to predict HBeAg seroconversion at 24 wk post-treatment. The two best predictors at each time point were used to establish a prediction model for PEG-IFNα therapy efficacy. Parameters at each time point that met the corresponding optimal cutoff thresholds were scored as 1 or 0.

RESULTS

The two most meaningful predictors were HBsAg ≤ 1000 IU/mL and HBeAg ≤ 3 S/CO at baseline, HBsAg ≤ 600 IU/mL and HBeAg ≤ 3 S/CO at week 12, and HBsAg ≤ 300 IU/mL and HBeAg ≤ 2 S/CO at week 24. With a total score of 0 vs 2 at baseline, week 12, and week 24, the response rates were 23.8%, 15.2%, and 11.1% vs 81.8%, 80.0%, and 82.4%, respectively, and the HBsAg clearance rates were 2.4%, 3.0%, and 0.0%, vs 54.5%, 40.0%, and 41.2%, respectively.

CONCLUSION

We successfully established a predictive model and diagnosis-treatment process using the RGT strategy to predict HBeAg and HBsAg seroconversion in patients with HBeAg-positive CHB undergoing PEG-IFNα therapy.

Construction and validation of a machine learning-based nomogram to predict the prognosis of HBV associated hepatocellular carcinoma patients with high levels of hepatitis B surface antigen in primary local treatment: a multicenter study

Background

Hepatitis B surface antigen (HBsAg) clearance is associated with improved long-term outcomes and reduced risk of complications. The aim of our study was to identify the effects of levels of HBsAg in HCC patients undergoing TACE and sequential ablation. In addition, we created a nomogram to predict the prognosis of HCC patients with high levels of HBsAg (≥1000U/L) after local treatment.

Method

This study retrospectively evaluated 1008 HBV-HCC patients who underwent TACE combined with ablation at Beijing Youan Hospital and Beijing Ditan Hospital from January 2014 to December 2021, including 334 patients with low HBsAg levels and 674 patients with high HBsAg levels. The high HBsAg group was divided into the training cohort (N=385), internal validation cohort (N=168), and external validation cohort (N=121). The clinical and pathological features of patients were collected, and independent risk factors were identified using Lasso-Cox regression analysis for developing a nomogram. The performance of the nomogram was evaluated by C-index, receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA) curves in the training and validation cohorts. Patients were classified into high-risk and low-risk groups based on the risk scores of the nomogram.

Result

After PSM, mRFS was 28.4 months (22.1-34.7 months) and 21.9 months (18.5-25.4 months) in the low HBsAg level and high HBsAg level groups (P<0.001). The content of the nomogram includes age, BCLC stage, tumor size, globulin, GGT, and bile acids. The C-index (0.682, 0.666, and 0.740) and 1-, 3-, and 5-year AUCs of the training, internal validation, and external validation cohorts proved good discrimination of the nomogram. Calibration curves and DCA curves suggested accuracy and net clinical benefit rates. The nomogram enabled to classification of patients with high HBsAg levels into low-risk and high-risk groups according to the risk of recurrence. There was a statistically significant difference in RFS between the two groups in the training, internal validation, and external validation cohorts (P<0.001).

Conclusion

High levels of HBsAg were associated with tumor progression. The nomogram developed and validated in the study had good predictive ability for patients with high HBsAg levels.

The Use of Tenofovir Disoproxil Fumarate in the Management of eAg-Negative Chronic Hepatitis B Infection

Background/Objectives: Currently, there are insufficient data to recommend the treatment of patients with hepatitis B e antigen (HBeAg)-negative chronic infection who have normal ALT and low HBV DNA, since the prognosis is generally regarded as favorable. The aim of this pilot study was to determine whether the use of tenofovir disoproxil fumarate (TDF) 300 mg/day for 3 years was able to achieve functional cure (HBsAg loss) and HBsAg seroconversion in HBeAb-positive individuals. Methods: Fifty patients not on antiviral therapy (40% men, mean age 48.9 ± 10.9 years, 84% Asians) with minimal fibrosis were enrolled. Results: TDF reduced HBV DNA significantly to undetectable levels after 6 months. Overall, 48.3% of inactive carriers (baseline HBV DNA < 2000 IU/mL) remained HBV DNA negative 6 months after treatment withdrawal, which was significantly higher than the 5.6% in those who were not inactive carriers (baseline HBV DNA ≥ 2000 IU/mL) (p = 0.003). The HBsAg levels did not drop throughout the study period with no difference between inactive carriers versus those who were not. Five inactive carriers achieved functional cure, but none of these were amongst those who were not inactive carriers. No renal dysfunction or ALT flare on treatment withdrawal was observed. Conclusions: TDF could potentially be used to induce functional cure in patients who are inactive carriers with normal ALT, low HBV DNA and without advanced fibrosis.

Hepatocellular carcinoma reduced, HBsAg loss increased, and survival improved after finite therapy in hepatitis B patients with cirrhosis

BACKGROUND AND AIMS

Long-term nucleos(t)ide analog (Nuc) treatment can reduce HCC in patients with HBV-related liver cirrhosis (HBV-LC). Earlier small cohort studies showed a comparable 5-year incidence of HCC in HBeAg-negative patients with HBV-LC who stopped and those continued Nuc therapy. This study aimed to validate these findings using a large cohort with 10-year follow-up.

APPROACH AND RESULTS

From 2 centers, 494 HBeAg-negative patients with HBV-LC who stopped (finite group) and 593 who continued (continuous group) Nuc therapy were recruited. HCC, HBsAg loss, liver-related mortality/transplantation, and overall survival rates were compared between 2 groups with 1:1 propensity score matching of sex, treatment history, types of Nuc, age, transaminases, platelet count, and HBsAg levels at end of therapy in finite group or 3-year on-therapy in continuous groups. During a median follow-up of 6.2 (3.4-8.9) years, the annual and 10-year HCC incidence were lower in finite group (1.6 vs. 3.3%/y and 10-y 15.7% vs. 26.8%, respectively; log-rank test, p <0.0001). The finite group showed greater HBsAg decline/year (-0.116 vs. -0.095 log 10 IU/mL, p =0.0026) and 7.6 times higher 10-year incidence of HBsAg loss (22.7% vs. 3%, p <0.0001). Multivariate Cox regression showed finite therapy an independent factor for HBsAg loss (adjusted HR: 11.79) but protective against HCC (adjusted HR: 0.593), liver-related mortality/transplantation (adjusted HR: 0.312), and overall mortality (adjusted HR: 0.382).

CONCLUSIONS

Finite Nuc therapy in HBeAg-negative HBV-LC may reduce HCC incidence, increase HBsAg loss, and improve survival. Greater HBsAg decline/loss may reflect enhanced immunity and contribute to the reduction of hepatic carcinogenesis.

Preclinical Antiviral and Safety Profiling of the HBV RNA Destabilizer AB-161

HBV RNA destabilizers are a class of small-molecule compounds that target the noncanonical poly(A) RNA polymerases PAPD5 and PAPD7, resulting in HBV RNA degradation and the suppression of viral proteins including the hepatitis B surface antigen (HBsAg). AB-161 is a next-generation HBV RNA destabilizer with potent antiviral activity, inhibiting HBsAg expressed from cccDNA and integrated HBV DNA in HBV cell-based models. AB-161 exhibits broad HBV genotype coverage, maintains activity against variants resistant to nucleoside analogs, and shows additive effects on HBV replication when combined with other classes of HBV inhibitors. In AAV-HBV-transduced mice, the dose-dependent reduction of HBsAg correlated with concentrations of AB-161 in the liver reaching above its effective concentration mediating 90% inhibition (EC90), compared to concentrations in plasma which were substantially below its EC90, indicating that high liver exposure drives antiviral activities. In preclinical 13-week safety studies, minor non-adverse delays in sensory nerve conductance velocity were noted in the high-dose groups in rats and dogs. However, all nerve conduction metrics remained within physiologically normal ranges, with no neurobehavioral or histopathological findings. Despite the improved neurotoxicity profile, microscopic findings associated with male reproductive toxicity were detected in dogs, which subsequently led to the discontinuation of AB-161's clinical development.

Mechanism of interferon alpha therapy for chronic hepatitis B and potential approaches to improve its therapeutic efficacy

Hepatitis B virus (HBV) chronically infects 296 million people worldwide and causes more than 820,000 deaths annually due to cirrhosis and hepatocellular carcinoma. Current standard-of-care medications for chronic hepatitis B (CHB) include nucleos(t)ide analogue (NA) viral DNA polymerase inhibitors and pegylated interferon alpha (PEG-IFN-α). NAs can efficiently suppress viral replication and improve liver pathology, but not eliminate or inactivate HBV covalently closed circular DNA (cccDNA). CCC DNA is the most stable HBV replication intermediate that exists as a minichromosome in the nucleus of infected hepatocyte to transcribe viral RNA and support viral protein translation and genome replication. Consequentially, a finite duration of NA therapy rarely achieves a sustained off-treatment suppression of viral replication and life-long NA treatment is most likely required. On the contrary, PEG-IFN-α has the benefit of finite treatment duration and achieves HBsAg seroclearance, the indication of durable immune control of HBV replication and functional cure of CHB, in approximately 5% of treated patients. However, the low antiviral efficacy and poor tolerability limit its use. Understanding how IFN-α suppresses HBV replication and regulates antiviral immune responses will help rational optimization of IFN therapy and development of novel immune modulators to improve the rate of functional cure. This review article highlights mechanistic insight on IFN control of HBV infection and recent progress in development of novel IFN regimens, small molecule IFN mimetics and combination therapy of PEG-IFN-α with new direct-acting antivirals and therapeutic vaccines to facilitate the functional cure of CHB.

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.

First-in-human randomized study of RNAi therapeutic RG6346 for chronic hepatitis B virus infection

BACKGROUND & AIMS

RG6346 is an N-acetyl-D-galactosamine (GalNAc)-conjugated, double-stranded RNA interference agent targeting the HBV genome S-region. We investigated the safety, tolerability, pharmacokinetics, and pharmacodynamics of RG6346 in healthy volunteers and patients with chronic HBV infection (CHB).

METHODS

This first-in-human, adaptive, randomized, double-blinded, phase I study recruited three groups of participants: Group A, 30 healthy volunteers received single-dose RG6346 at 0.1, 1.5, 3.0, 6.0, or 12.0 mg/kg, or placebo; Group B, nucleos(t)ide analogue-naïve participants with CHB received single-dose RG6346 at 3.0 mg/kg (n = 6) or placebo (n = 3); Group C, participants with nucleos(t)ide-suppressed CHB received four doses (every 28 days) of RG6346 at 1.5, 3.0, or 6.0 mg/kg (n = 4 in each cohort) or placebo (n = 6).

RESULTS

RG6346 treatment for up to 4 months was safe and well tolerated. The most common adverse event was a mild injection site reaction. Several nucleos(t)ide-naïve participants exhibited self-resolving transaminase elevations with preserved liver function. By the end of RG6346 treatment in Group C (Day 112), the mean reduction from baseline in hepatitis B surface antigen (HBsAg) was 1.39, 1.80, and 1.64 log10 IU/ml in the 1.5, 3.0, and 6.0 mg/kg cohorts, respectively. Of the 12 participants in Group C, 11 (91.7%) achieved a ≥1 log10 IU/ml reduction in HBsAg (3 of 11 [27.3%] had the response sustained at conditional follow-up Day 448). No dose-response relationship was apparent between RG6346 and serum HBsAg levels. The RG6346-induced HBsAg response was independent of hepatitis B e antigen status. Moderate-to-marked sustained reductions of hepatitis B core-related antigen, HBV RNA, HBV DNA (in nucleos[t]ide analogue-naïve participants), and hepatitis B e antigen levels were observed.

CONCLUSIONS

These favorable safety and pharmacodynamic data support the clinical development of RG6346 as the backbone of a finite antiviral treatment regimen, with the goal of sustained HBsAg loss (functional cure) in patients with CHB.

CLINICAL TRIAL NUMBER

ClinicalTrials.gov NCT03772249.

IMPACT AND IMPLICATIONS

Currently available therapies for chronic HBV infection are associated with low rates of functional cure and new, more efficacious treatments are needed. This first-in-human study of RG6346, an RNA interference therapy, showed a favorable safety profile as well as marked and durable reductions in hepatitis B surface antigen levels. These results support the continued development of RG6346 as the backbone of a finite treatment regimen targeting high functional cure rates and are important for HBV researchers and physicians.

Clinical impact of hepatic steatosis on chronic hepatitis B patients in Asia: A systematic review and meta-analysis

Chronic hepatitis B (CHB) and hepatic steatosis (HS) are two prevalent chronic liver diseases in Asia. The incidence of CHB combined with HS is increasing due to the rising obesity rates. However, the impact of HS on CHB remains a topic of debate. Hereby, this meta-analysis aims to examine the effect of HS on Asian patients with CHB. Searches were conducted on four databases to identify articles published from 2005 to 2023. The random-effects or fixed-effects model was used to calculate pooled odds ratios (ORs), weighted mean difference (WMD), and confidence intervals (CIs) for the included articles. Of the 15,959 records screened, 88 studies were included in the analysis of HS prevalence in Asian CHB patients with a prevalence of 36.5% (95% CI: 33.7%-39.3%). In addition, age, sex, body mass index (BMI), waist circumference (WC), alanine aminotransferase (ALT) and combined metabolic diseases have varying degrees of impact on HS in CHB patients. Furthermore, the coexistence of HS was negatively associated with the response to antiviral therapy, including hepatitis B surface antigen (HBeAg) seroconversion (OR = 0.69, 95% CI: 0.53-0.89) and ALT normalization (OR = 0.75, 95% CI: 0.61-0.92) in CHB patients after 48 weeks of treatment. Regarding disease prognosis, HS was not significantly associated with fibrosis or cirrhosis in CHB patients, while an inverse association was observed between HS and hepatocellular carcinoma (HCC) (OR = 2.93, 95% CI: 1.23-6.99). This implies that the coexistence of HS in CHB patients may exacerbate the progression of HCC, which needs to be verified by further studies.

The efficacy and safety of pegylated interferon α-2b-based immunotherapy for inactive hepatitis B surface antigen carriers

OBJECTIVES

Pegylated interferon α-2b (PegIFNα-2b) therapy can help inactive hepatitis B surface antigen (HBsAg) carriers (IHCs) achieve clinical cure. To explore and compare the efficacy, safety, and relevant influential factors of PegIFNα-2b monotherapy and PegIFNα-2b-based immunotherapy for IHCs.

METHODS

This exploratory, prospective, single-center, randomized controlled trial enrolled 40 IHCs who were randomized into group A (PegIFNα-2b treatment for 68 weeks) and group B (two cycles of PegIFNα-2b treatment with a lead-in period of GM-CSF and vaccine treatment before each cycle). The primary endpoint was 68-week HBsAg loss rate.

RESULTS

At week 68, the HBsAg loss rates were 45.45% [full analysis set (FAS)] and 46.67% [per-protocol set (PPS)]. There was no statistically significant difference in HBsAg loss rate between groups A and B ( P  > 0.05). Univariate analysis revealed that age ≤40 years old, baseline HBsAg <200 IU/ml, and 24-week HBsAg decline ≥2 log 10 IU/ml were significantly associated with HBsAg loss in FAS population ( P  < 0.05). Multivariate analysis showed that only 24-week HBsAg decline ≥2 log 10 IU/ml was the independent influencing factor in both FAS and PPS populations ( P  < 0.05). The adverse events were common and mild, and the therapies were well-tolerated.

CONCLUSION

Treatment of IHCs with PegIFNα-2b-based therapy could result in a high HBsAg loss rate. The HBsAg loss rate of combined immunotherapy was similar to that of PegIFNα-2b monotherapy, and the safety was good.

CLINICALTRIALSGOV ID

NCT05451420.

The incidence of hepatocellular carcinoma and clearance of hepatitis B surface for CHB patients in the indeterminate phase: a systematic review and meta-analysis

Background

Nearly 30%-40% of patients with chronic hepatitis B do not fall into any of the traditional natural history classification and thus are classified as indeterminate. However, it is unclear whether patients in the indeterminate phase (IP) are at a higher risk for hepatocellular carcinoma (HCC) than those in the defined phases (DP) and would benefit from antiviral therapy. We performed a systematic review and meta-analysis of HCC incidence and HBsAg clearance among patients in the IP versus DP.

Methods

We defined the clinical phases as per the AASLD 2018 hepatitis B guidance. We searched PubMed, Embase, Medline, and Web of Science for relevant studies that reported HCC incidence or HBsAg clearance in IP versus DP patients published between January 2007 and March 2023. Annual HCC incidence and HBsAg clearance rates were pooled using a random/common-effects model.

Results

We analyzed data from 14 studies, comprising 7798 IP patients (222 patients developed HCC and 239 achieved HBsAg clearance) and 10,725 DP patients. The pooled annual HCC incidence was 2.54 cases per 1,000 person-years (95% CI, 1.14-4.39) and HBsAg clearance rate was 12.36 cases per 1,000 person-years (95% CI, 10.70-14.13) for the IP patients. IP patients were associated with significantly higher HCC incidence risk (RR = 1.64, 95% CI, 1.34-2.00) and slightly lower annual HBsAg clearance rate (RR = 0.83, 95% CI, 0.70-0.99) than the DP patients. In addition, HBeAg-negative IP patients (2.31%; 95% CI, 0.87-4.45) showed a significantly higher HCC incidence than those who were HBeAg positive (0.00%; 95% CI, 0.00-0.99) (p< 0.001). The Asia-Pacific region IP patients (4.30%; 95% CI, 2.07-7.27) were also associated with a higher HCC incidence versus Europe (0.05%; 95% CI, 0.00-1.39) (p< 0.001). However, there were no significant differences between different strategies (treated vs. untreated: 2.56%; 95% CI, 1.01-4.63 vs. 1.61%; 95% CI, 0.00-5.81, p = 0.09), and heterogeneity was substantial across the studies (I2 = 89%).

Conclusion

The systematic review and meta-analysis showed a high HCC incidence and low HBsAg clearance among patients in the IP, especially for HBeAg-negative patients and the Asian population. We emphasize that future multicenter prospective cohort studies or randomized trials are needed to verify if expanding antiviral therapy for patients in the IP is associated with reduced HCC risk or good treatment outcomes.

Awareness of HBV Functional Cure and Attitude Toward Related Clinical Trials Among Patients with Chronic Hepatitis B in China

Purpose

HBV functional cure is an optimal treatment goal for chronic hepatitis B (CHB) at present and numerous new drugs aiming for HBV functional cure are in development. We carried out an internet-based survey to understand the treatment status, unmet needs, awareness of HBV functional cure and attitude toward related clinical trials among CHB patients in China.

Patients and Methods

An internet-based anonymous survey was conducted on CHB patients who reside in mainland China. Determinants of awareness and attitude were identified by logistic regression models.

Results

Of the 1220 CHB patients who completed the survey questionnaire, 11.1% (135/1220) were aware of HBV functional cure and 50.2% (612/1220) answered "definitely will" to participate in related clinical trials. Participants who knew their HBsAg level (HBsAg<1500 IU/mL: OR=3.03, 95% CI: 1.87-4.92; HBsAg≥1500 IU/mL: OR=2.57, 95% CI: 1.35-4.88), who expected to achieve HBsAg loss with treatment (OR=1.63, 95% CI: 1.07-2.50) and who were dissatisfied with current treatment due to the failure of achieving HBsAg loss (OR=1.67, 95% CI: 1.10-2.53) had better awareness of HBV functional cure. Participants who had HBsAg level less than 1500 IU/mL (OR=1.45, 95% CI: 1.05-1.99), treatment with pegylated interferon alpha with or without nucleos(t)ide (OR=1.68, 95% CI: 1.11-2.53) and better awareness of HBV functional cure (OR=1.62, 95% CI: 1.01-2.61) were more likely to say "definitely will" to participate in related clinical trials.

Conclusion

Chinese CHB patients reported a low awareness of HBV functional cure. Although CHB patients in China reported a low rate of HBV functional cure awareness, they had a high acceptance of related clinical trials.

Rapid monophasic HBsAg decline during nucleic-acid polymer-based therapy predicts functional cure

BACKGROUND AND AIMS

Analyzing the interplay among serum HBV DNA, HBsAg, anti-HBs, and alanine aminotransferase (ALT) during nucleic-acid polymer (NAP)-based therapy for chronic hepatitis B provides a unique opportunity to identify kinetic patterns associated with functional cure.

METHODS

All participants with HBeAg-negative chronic HBV infection in the REP 401 study (NCT02565719) first received 24 weeks of tenofovir-disoproxil-fumarate (TDF) monotherapy. The early triple therapy group (n = 20) next received 48 weeks of TDF+pegylated interferon-α2a (pegIFN)+NAPs. In contrast, the delayed triple therapy group (n = 20) next received 24 weeks of TDF+pegIFN before 48 weeks of triple therapy. Three participants discontinued treatment and were excluded. Functional cure (HBsAg and HBV DNA not detectable with normal ALT) was assessed at 48 weeks post-treatment. Different kinetic phases were defined by at least a 2-fold change in slope. A single-phase decline was categorized as monophasic, and 2-phase declines were categorized as biphasic.

RESULTS

Fourteen (35%) participants achieved a functional cure. HBV DNA remained below or near undetectable for all participants by the end of TDF monotherapy and during subsequent combination therapies. Three HBsAg kinetic patterns were found in both the early and delayed groups, nonresponders (n = 4 and n = 4), monophasic (n = 11 and n = 11), and biphasic (n = 4 and n = 3), respectively. All participants who achieved a functional cure had a monophasic HBsAg kinetic pattern during triple therapy. Among participants with a monophasic HBsAg decline, those who had a functional cure had a shorter median time to HBsAg loss of 21 (interquartile range=11) weeks compared with those who did not achieve functional cure [median: 27 (7) weeks] (p = 0.012).

CONCLUSIONS

Functional cure was associated with a rapid monophasic HBsAg decline during NAP-based therapy. A nonmonophasic HBsAg kinetic pattern had a 100% negative predictive value (NPV) for a functional cure.

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.

TLR7 agonist RO7020531 versus placebo in healthy volunteers and patients with chronic hepatitis B virus infection: a randomised, observer-blind, placebo-controlled, phase 1 trial

BACKGROUND

Toll-like receptor 7 (TLR7) agonists augment immune activity and have potential for the treatment of chronic hepatitis B virus (HBV) infection. We aimed to assess the safety and tolerability of RO7020531 (also called RG7854), a prodrug of the TLR7 agonist RO7011785, in healthy volunteers and patients with chronic HBV infection.

METHODS

This randomised, observer-blind, placebo-controlled, phase 1 study was done in two parts. Part 1 was done at one site in New Zealand and part 2 was done at 12 sites in Bulgaria, Hong Kong, Italy, New Zealand, the Netherlands, Taiwan, Thailand, and the UK. In part 1, healthy volunteers were randomly assigned (4:1) within one of eight dose cohorts (3 mg, 10 mg, 20 mg, 40 mg, 60 mg, 100 mg, 140 mg, or 170 mg) to receive a single RO7020531 dose or placebo or randomly assigned (4:1) within one of three dose cohorts (100 mg, 140 mg, or 170 mg) to receive either RO7020531 or placebo every other day for 13 days. In part 2, nucleoside or nucleotide analogue-suppressed patients with chronic HBV infection were randomly assigned (4:1) within cohorts 1-3 (150 mg, 150 mg, or 170 mg) to receive either RO7020531 or placebo and treatment-naive patients with chronic HBV infection were randomly assigned (3:1) in cohort 4 to receive either 150 mg of RO7020531 or placebo. Patients were treated every other day for 6 weeks. Study medication was administered orally to participants after they had fasted. Study participants and investigational staff were masked to treatment allocation. The primary outcome was the safety and tolerability of RO7020531, as measured by the incidence and severity of adverse events and the incidence of laboratory, vital sign, and electrocardiogram abnormalities, and was analysed in all participants who received at least one dose of the study medication. This trial is registered with ClinicalTrials.gov, NCT02956850, and the study is complete.

FINDINGS

Between Dec 12, 2016, and March 21, 2021, 340 healthy volunteers were screened in part 1, of whom 80 were randomly assigned in the single ascending dose study (eight assigned RO7020531 in each cohort and 16 assigned placebo) and 30 were randomly assigned in the multiple ascending dose study (eight assigned RO7020531 in each cohort and six assigned placebo), and 110 patients were screened in part 2, of whom 30 were randomly assigned in cohorts 1-3 (16 assigned RO7020531 150 mg, eight assigned RO7020531 170 mg, and six assigned placebo) and 20 were randomly assigned in cohort 4 (15 assigned RO7020531 and five assigned placebo). All randomly assigned participants received at least one dose of a study drug and were included in the safety analysis. All tested doses of RO7020531 were safe and had acceptable tolerability in healthy volunteers and patients. The most frequent treatment-related adverse events among the total study population were headache (15 [9%] of 160 participants), influenza-like illness (seven [4%] of 160 participants), and pyrexia (ten [6%] of 160 participants). Most adverse events were mild and transient. There were no severe or serious adverse events in healthy volunteers. In the patient cohorts, there was one severe adverse event (influenza-like illness with 170 mg of RO7020531) and one serious adverse event (moderate influenza-like illness with a 3-day hospitalisation in a treatment-naive patient receiving RO7020531). There were no treatment-related deaths.

INTERPRETATION

Due to acceptable safety and tolerability, RO7020531 should continue to be developed for the treatment of patients with chronic HBV infection.

FUNDING

F Hoffmann-La Roche.

Discovery of a first-in-class orally available HBV cccDNA inhibitor

BACKGROUND & AIMS

The persistence of covalently closed circular DNA (cccDNA) in infected hepatocytes is the major barrier preventing viral eradication with existing therapies in patients with chronic hepatitis B. Therapeutic agents that can eliminate cccDNA are urgently needed to achieve viral eradication and thus HBV cure.

METHODS

A phenotypic assay with HBV-infected primary human hepatocytes (PHHs) was employed to screen for novel cccDNA inhibitors. A HBVcircle mouse model and a uPA-SCID (urokinase-type plasminogen activator-severe combined immunodeficiency) humanized liver mouse model were used to evaluate the anti-HBV efficacy of the discovered cccDNA inhibitors.

RESULTS

Potent and dose-dependent reductions in extracellular HBV DNA, HBsAg, and HBeAg levels were achieved upon the initiation of ccc_R08 treatment two days after the HBV infection of PHHs. More importantly, the level of cccDNA was specifically reduced by ccc_R08, while it did not obviously affect mitochondrial DNA. Additionally, ccc_R08 showed no significant cytotoxicity in PHHs or in multiple proliferating cell lines. The twice daily oral administration of ccc_R08 to HBVcircle model mice, which contained surrogate cccDNA molecules, significantly decreased the serum levels of HBV DNA and antigens, and these effects were sustained during the off-treatment follow-up period. Moreover, at the end of follow-up, the levels of surrogate cccDNA molecules in the livers of ccc_R08-treated HBVcircle mice were reduced to below the lower limit of quantification.

CONCLUSIONS

We have discovered a small-molecule cccDNA inhibitor that reduces HBV cccDNA levels. cccDNA inhibitors potentially represent a new approach to completely cure patients chronically infected with HBV.

IMPACT AND IMPLICATIONS

Covalently closed circular DNA (cccDNA) persistence in HBV-infected hepatocytes is the root cause of chronic hepatitis B. We discovered a novel small-molecule cccDNA inhibitor that can specifically reduce cccDNA levels in HBV-infected hepatocytes. This type of molecule could offer a new approach to completely cure patients chronically infected with HBV.

Hepatitis B

Hepatitis B virus (HBV) infection is a major public health problem, with an estimated 296 million people chronically infected and 820 000 deaths worldwide in 2019. Diagnosis of HBV infection requires serological testing for HBsAg and for acute infection additional testing for IgM hepatitis B core antibody (IgM anti-HBc, for the window period when neither HBsAg nor anti-HBs is detected). Assessment of HBV replication status to guide treatment decisions involves testing for HBV DNA, whereas assessment of liver disease activity and staging is mainly based on aminotransferases, platelet count, and elastography. Universal infant immunisation, including birth dose vaccination is the most effective means to prevent chronic HBV infection. Two vaccines with improved immunogenicity have recently been approved for adults in the USA and EU, with availability expected to expand. Current therapies, pegylated interferon, and nucleos(t)ide analogues can prevent development of cirrhosis and hepatocellular carcinoma, but do not eradicate the virus and rarely clear HBsAg. Treatment is recommended for patients with cirrhosis or with high HBV DNA levels and active or advanced liver disease. New antiviral and immunomodulatory therapies aiming to achieve functional cure (ie, clearance of HBsAg) are in clinical development. Improved vaccination coverage, increased screening, diagnosis and linkage to care, development of curative therapies, and removal of stigma are important in achieving WHO's goal of eliminating HBV infection by 2030.

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.

Risk of hepatic decompensation but not hepatocellular carcinoma decreases over time in patients with hepatitis B surface antigen loss

BACKGROUND & AIMS

We examined the long-term incidence of hepatocellular carcinoma (HCC) and hepatic decompensation among chronic hepatitis B (CHB) patients who have achieved hepatitis B surface antigen (HBsAg) seroclearance.

METHODS

All adult CHB-monoinfected patients who cleared HBsAg between January 2000 and December 2020 were identified using a territory-wide database in Hong Kong. Patients who underwent liver transplantation and/or developed HCC before HBsAg seroclearance or less than 6 months follow-up were excluded. The primary and secondary endpoints were HCC and hepatic decompensation respectively.

RESULTS

We identified 9,769 patients with CHB who achieved HBsAg seroclearance (mean age 57 years, 60.0% male, 13.2% cirrhosis); most had compensated liver function at HBsAg loss. At a median (25th-75th percentile) follow-up of 4.6 (2.2-8.4) years, 106 (1.1%) patients developed HCC. Patients who developed HCC were older, more likely to be male and have cirrhosis, and had higher alanine aminotransferase and lower platelets at the time of HBsAg loss than patients without HCC. The cumulative incidence of HCC remained steady 0-7 and 8-12 years after HBsAg loss (p = 0.898) (crude annual incidence drop: -0.04%, 95% CI -0.13% to 0.04%, p = 0.265). Moreover, 124/9,640 (1.3%) patients developed hepatic decompensation. The growth in cumulative incidence of hepatic decompensation decelerated 8-12 years after HBsAg loss (p = 0.009) (crude annual incidence drop: -0.23%, 95% CI -0.40% to -0.06%, p = 0.012). In multivariable analysis, HBsAg loss for over 7 years was associated with a reduced risk of hepatic decompensation (adjusted subdistribution hazard ratio [aSHR] 0.55, 95% CI 0.31-0.97, p = 0.039) but not HCC (aSHR 1.35, 95% CI 0.83-2.19, p = 0.230).

CONCLUSION

HCC risk persists in patients after HBsAg loss, whereas the risk of hepatic decompensation decreases over time.

IMPACT AND IMPLICATIONS

Patients with chronic hepatitis B (CHB) still have a non-negligible risk of hepatocellular carcinoma (HCC) after 12 years of HBsAg seroclearance, especially among those with cirrhosis. The risk of developing hepatic decompensation decreases over time after HBsAg seroclearance. In clinical practice, although patients with CHB who cleared HBsAg have a more favourable clinical outcome than those who remain chronically infected, long-term HCC surveillance would still be necessary for patients with cirrhosis and other high-risk subgroups after HBsAg seroclearance.

An Ideal Hallmark Closest to Complete Cure of Chronic Hepatitis B Patients: High-sensitivity Quantitative HBsAg Loss

In the era of antiviral therapy, the main goal of treatment has shifted from the persistent inhibition of hepatitis B virus (HBV) replication to the pursuit of serological clearance of HBs surface antigen (HBsAg). Based on the life cycle of HBV, HBsAg originates from covalently closed circular DNA (cccDNA) and integrated HBV DNA, thus reflecting their transcriptional activity. Complete HBsAg loss may mean elimination or persistent inactivity of the HBV genome including cccDNA and integrated HBV DNA. HBsAg loss improves the recovery of abnormal immune function, which in turn, may further promote the clearance of residual viruses. Combined with functional cure and the great improvement of clinical outcomes, the continuous seroclearance of high-sensitivity quantitative HBsAg may represent the complete cure of chronic hepatitis B (CHB). For many other risk factors besides HBV itself, patients with HBsAg loss still need regular monitoring. In this review, we summarized the evolution of CHB treatment, the origin of serum HBsAg, the pattern of HBsAg seroclearance, and the effect of HBsAg loss on immune function and disease outcomes. In addition, we discuss the significance of high-sensitivity HBsAg detection and its possibility as a surrogate of complete cure.

Prognostic Relevance of Metabolic Dysfunction-associated Steatohepatitis for Patients with Chronic Hepatitis B

BACKGROUND AND AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) is prevalent in patients with chronic hepatitis B (CHB). The effect of the histologic MAFLD phenotype on long-term CHB outcomes is unknown. We performed a longitudinal study to determine the prognostic relevance of biopsy-proven hepatic steatosis and steatohepatitis for CHB patients.

METHODS

Clinical and laboratory data were obtained from CHB patients who underwent liver biopsy during 2002-2008 and were treated with antiviral drugs. A hepatopathologist reviewed the biopsy specimens. Cox proportional hazards regression was used to estimate the adjusted hazard ratio (aHR) of outcomes, including all-cause mortality, liver transplantation, and liver-related events.

RESULTS

In accordance with Brunt's classification, 408 patients had steatohepatitis (n=34), "steatosis but not steatohepatitis" (n=118), or "non-steatosis" (n=256). All steatohepatitis patients had features of metabolic dysfunction. Over a mean follow-up of 13.8±3.1 years, 18 patients died or underwent liver transplantation. In multivariate-adjusted analysis, steatohepatitis (aHR, 6.37; 95% confidence interval [CI]: 1.59-25.5) compared with non-steatosis and advanced fibrosis (aHR, 11.3; 95% CI: 1.32-96.3) compared with no fibrosis were associated with overall mortality/liver transplantation. Thirty-five patients developed 43 liver-related events, among which 32 were hepatocellular carcinoma. These events were associated with steatohepatitis (aHR, 5.55; 95% CI: 2.01-15.3) compared with non-steatosis and advanced fibrosis (aHR, 6.23; 95% CI: 1.75-22.2) compared with no fibrosis. The steatosis but not steatohepatitis group had a non-significantly higher risk of overall mortality and liver-related events.

CONCLUSIONS

Metabolic dysfunction-associated steatohepatitis increased the risk of long-term mortality/transplantation and liver-related events in CHB patients.

The scientific basis of combination therapy for chronic hepatitis B functional cure

Functional cure of chronic hepatitis B (CHB) - or hepatitis B surface antigen (HBsAg) loss after 24 weeks off therapy - is now the goal of treatment, but is rarely achieved with current therapy. Understanding the hepatitis B virus (HBV) life cycle and immunological defects that lead to persistence can identify targets for novel therapy. Broadly, treatments fall into three categories: those that reduce viral replication, those that reduce antigen load and immunotherapies. Profound viral suppression alone does not achieve quantitative (q)HBsAg reduction or HBsAg loss. Combining nucleos(t)ide analogues and immunotherapy reduces qHBsAg levels and induces HBsAg loss in some patients, particularly those with low baseline qHBsAg levels. Even agents that are specifically designed to reduce viral antigen load might not be able to achieve sustained HBsAg loss when used alone. Thus, rationale exists for the use of combinations of all three therapy types. Monitoring during therapy is important not just to predict HBsAg loss but also to understand mechanisms of HBsAg loss using viral and immunological biomarkers, and in selected cases intrahepatic sampling. We consider various paths to functional cure of CHB and the need to individualize treatment of this heterogeneous infection until a therapeutic avenue for all patients with CHB is available.

Study on pathological and clinical characteristics of chronic HBV infected patients with HBsAg positive, HBV DNA negative, HBeAg negative

Aims

Study of clinical characteristics of hepatitis B virus deoxyribonucleic acid (HBV DNA)-negative, hepatitis B surface antigen (HBsAg)-positive, hepatitis B e antigen (HBeAg)-negative patients based on liver histopathology.

Methods

We retrospectively enrolled patients with chronic HBV infection diagnosis at Beijing Ditan Hospital from May 2008 to November 2020. To study the differences between patients with significant hepatic histopathology and those without significant hepatic histopathology. And to study the independent factors of significant hepatic histopathology.

Results

85 HBV DNA-negative and HBeAg-negative patients were 37.90 ± 10.30 years old, 23.50% of patients with grade of inflammation (G) >1, 35.30% of patients with liver fibrosis stage (S) >1, 44.70% patients were diagnosed with significant hepatic histopathology. Compared to the no significant hepatic histopathology group, another group had older age (41.70 ± 10.70 vs 34.80 ± 8.87 years, t=-3.28, P=0.002), higher total bilirubin (TBIL) [14.9(10.3, 22.4) vs 11(8.9, 14.4) μmol/L, z=-2.26, P=0.024], lower cholinesterase (CHE) (t=-2.86, P=0.005, 7388.00 ± 2156.00 vs 8988.00 ± 2823.00 U/L) and lower platelet (PLT) (t=2.75, P=0.007, 157.00 ± 61.40 vs 194.00 ± 61.00 10^9/L). Abnormal ALT patients are more likely to have significant hepatic histopathology (z=5.44, P=0.020, 66.70% vs 337.50%). G had significant correlation with CHE (P=0.008, r=-0.23), alanine aminotransferase (ALT) (P=0.041, r=0.18), aspartate aminotransferase (AST) (P=0.001, r=0.29). S had significant correlation with TBIL (P = 0.008, r = 0.23), age (P < 0.001, r = 0.32), international normalized ratio (INR) (P = 0.04, r = 0.23), CHE (P < 0.001, r = -0.30), PLT (P < 0.001, r = -0.40) and prothrombin time activity (PTA) (P = 0.046, r = -0.22). Multivariate logistic analysis indicated only age (95%CI=1.014~1.130, OR=1.069, P=0.013) was an impact factor for significant hepatic histopathology. The cutoff point of age was 34.30 years.

Conclusions

A large proportion of chronic HBV infection patients with HBeAg-negative and HBV DNA-negative still have chronic hepatitis. Age is an independent factor for significant hepatic histopathology.

Early clinical efficacy of pegylated interferon treatment in patients with different phases of chronic HBV infection: A real-world analysis

Although there are therapeutic advantages for hepatitis B virus (HBV) withpegylated interferon alpha (peg-IFNα) treatment compared with nucleos(t)ide analog (NAs) therapy, the effect difference in infected population at different phases has not been well established. We studied the clinical efficacy of peg-IFNα in two populations with HBV infection, including inactive HBsAg carrier (IHC) and chronic hepatitis B (CHB). A total of 328 HBV-infected patients were included in this real-world analysis. Patients were divided into two groups according to the infected stages. Peg-IFNα monotherapy or combination therapy with NAs were used in IHCs, and peg-IFNα added-on NAs therapy was applied to patients with CHB. The primary efficacy endpoint was HBsAg loss at Week 24. Results: The Kaplan-Meier cumulative rates of HBsAg loss were 39.50% (n = 47/119) in IHC group and 28.71% (n = 60/209) in CHB group at Week 24 (p < .05). After Propensity Score Matching (PSM), the HBsAg loss rates were 36.84% (n = 35/95) and 32.63% (n = 31/95), respectively (p > .05). Patients with baseline HBsAg level < 100 IU/ml achieved higher rates of HBsAg clearance in IHC and CHB group (before PSM: 47.44% vs. 42.86%, after PSM: 49.12% vs. 45.83%, all p values > .05). Baseline HBsAg level and its level decline from baseline to Week 12 can be as the predictors for HBsAg loss at Week 24 in both groups. Hence, the efficacy of HBsAg clearance was broadly similar between IHCs and NA-treated CHB patients during the early peg-IFNα therapy. A significant downward trend of HBsAg level was observed in both groups during peg-IFNα therapy.

Metabolic-Associated Fatty Liver Disease, Hepatitis B Surface Antigen Seroclearance, and Long-Term Risk of Hepatocellular Carcinoma in Chronic Hepatitis B

The value of metabolic-associated fatty liver disease (MAFLD) and its ability to assess hepatocellular carcinoma (HCC) risk remains uncertain for chronic hepatitis B (CHB). We evaluated the impacts of MAFLD and its coincidental metabolic abnormalities and related genetic predisposition on HCC incidence and mortality outcomes in CHB. We analyzed data from 1453 HBsAg-positive men (median age = 49.2 years at baseline) from a cohort of civil servants recruited from 1989−1992. MAFLD was defined as hepatic steatosis on ultrasound with obesity, diabetes, or metabolic dysfunction at baseline. During follow-up (median = 19.3 years), 105 HCC events occurred. MAFLD was not associated with HCC (adjusted hazard ratio (aHR) = 1.02) but was associated with a higher HBsAg seroclearance rate (aHR = 1.43). In mediation analysis, HBsAg seroclearance driven by hepatic steatosis explained 31.6% of the association between MAFLD and HCC. Antiviral treatment or fatty liver disease-associated genetic variants did not influence the MAFLD−HCC association. In contrast, even after adjustment for MAFLD and the other metabolic abnormalities, diabetes (aHR = 2.28), obesity (aHR = 1.72), and metabolic dysfunction (aHR = 3.30) increased the risk of HCC (all p < 0.030). The risk of HCC increased with the number of metabolic abnormalities (vs 0: aHR = 2.05 and 5.72 for 2 and ≥ 3 metabolic abnormalities, respectively), and the cumulative effect of metabolic abnormalities was found across subgroups categorized by hepatic steatosis as well as in participants both with and without HBsAg seroclearance. In conclusion, MAFLD was not associated with increased HCC incidence in CHB. A more informative assessment of HCC risk can be obtained by taking into account the number of metabolic abnormalities.

Systematic review: Clinical outcomes of discontinuation of oral antivirals in hepatitis B-related liver cirrhosis

Background

Discontinuation of Nucleos(t)ide analogs (NAs) remains one of the most controversial topics in the management of hepatitis B-related liver cirrhosis. However, clinical outcomes after NAs discontinuation have not been studied.

Aim

The aim of this systematic review is to evaluate existing data on clinical outcomes of NAs withdrawal in chronic hepatitis B (CHB) patients with cirrhosis.

Methods

A literature search (until May 2022) was performed in order to identify all published studies including hepatitis B-related cirrhotic patients who discontinued NAs in virological remission with off-therapy follow-up >12 months.

Results

Nineteen studies with 1,287 hepatitis B-related cirrhotic patients were included. Most cirrhotic patients were compensated and achieved complete virological suppression when they stopped the antiviral therapy. The pooled proportions of virological relapse and clinical relapse after NAs discontinuation in cirrhotic patients were 55.23 (95% CI: 40.33-69.67) and 43.56% (95% CI: 26.13-61.85), respectively. HBsAg loss was observed in 56 of 500 (pooled proportion = 13.68%, 95% CI: 5.82-24.18) cirrhotic patients. And the pooled proportions of HCC development, hepatic decompensation and overall mortality were 8.76 (95% CI: 2.25-18.95), 3.63 (95% CI: 1.31-7.03), and 0.85% (95% CI: 0.35-1.57), respectively, after NAs discontinuation in cirrhotic patients.

Conclusion

In hepatitis B-related compensated cirrhosis, who have achieved complete virological suppression, discontinuation of oral antivirals still carries a high relapse rate, but the incidence of adverse events is generally low and controlled during follow-up of at least 12 months. Of attention is that discontinuation of NAs can achieve a high rate of HBsAg seroclearance. This study may be helpful in the management of NAs in cirrhotic patients.

Systematic review registration

http://www.crd.york.ac.uk/PROSPERO, identifier: CRD42020170103.

Pegylated interferon-α-2b combined with tenofovir disoproxil fumarate, granulocyte-macrophage colony-stimulating factor, and hepatitis B vaccine treatment for naïve HBeAg-positive chronic hepatitis B patients: A prospective, multicenter, randomized controlled study

Hepatitis B surface antigen (HBsAg) loss or seroconversion is an ideal treatment endpoint for patients with chronic hepatitis B but is rarely achievable in  hepatitis B e-antigen (HBeAg)-positive patients using existing treatment strategies. In this study, the effect of pegylated interferon (peg-IFN) alfa-2b plus tenofovir disoproxil fumarate (TDF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and hepatitis B vaccine was evaluated. This randomized controlled trial was conducted at nine liver centers in Chinese university hospitals from May 2018 to July 2020. Patients (n = 303) enrolled were randomly administered peg-IFN-α-2b combined with TDF, GM-CSF, and hepatitis B vaccine (experimental group); peg-IFN-α-2b plus TDF (control group 2); or interferon-α-2b alone (control group 1). The primary efficacy endpoint was HBsAg seroconversion at 48 weeks and the secondary endpoint included safety. No differences in baseline HBsAg levels were observed among the groups. The primary endpoint was achieved in three (3.0%), one (1.03%), and one (1.19%) patient in the experimental group, control group 2, and control group 1, respectively. The incidence of HBsAg seroconversion at week 48 was not significantly different among the three groups (p = 0.629). However, the decrease in serum levels of HBsAg at week 48 was significantly higher in the experimental and control group 2 compared with that in control group 1 (p = 0.008 and 0.006, respectively). No significant difference between the experimental and control group 2 was observed (p = 0.619). Adverse events were not significantly different among the groups except for the lower incidence of neutropenia in the experimental group. Peg-IFN-α-2b combined with TDF, GM-CSF, and hepatitis B vaccine is not superior to peg-IFN-α-2b combined with TDF in HBeAg-positive naïve patients. Clinical Trials Registration: ChiCTR1800016173.

Perspectives on current controversial issues in the management of chronic HBV infection

Clinical and basic research in the past decades has achieved consensus in the understanding of chronic hepatitis B virus (HBV) infection and the management of chronic hepatitis B and HBV-cirrhosis. However, debatable challenges to the existing consensus in the concept and/or definitions have emerged. These include (1). alanine aminotransferase upper limit of normal: traditional laboratory-defined vs fixed; (2). nomenclature for phases of chronic HBV infection: classical vs EASL proposal; (3). indication of antiviral therapy: to treat patients vs to treat HBV; (4). finite vs indefinite long-term antiviral therapy: A. finite therapy in HBV-cirrhosis; B. retreatment decision: biochemical markers vs HBsAg/ALT kinetics. The pros and cons of these controversial issues were reviewed, assessed, and discussed in depth based on relevant lines of scientific evidence, intended to clarify or solve these controversial issues.

Describing immune factors associated with Hepatitis B surface antigen loss: A nested case-control study of a Chinese sample from Wuwei City

Background

Hepatitis B surface antigen (HBsAg) loss is considered a functional cure for chronic hepatitis B (CHB), however, several factors influence HBsAg loss.

Methods

29 CHB patients who had achieved HBsAg loss, were selected and 58 CHB patients with persistent HBsAg were matched, according to gender and age (+/- 3 years). Logistic regression and restricted cubic spline (RCS) modelling were performed.

Results

Multivariate-adjusted logistic regression, based on stepwise selection, showed that baseline HBsAg levels negatively correlated with HBsAg loss (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.98-0.99). Interferon treatment positively related with HBsAg loss (OR = 7.99, 95%CI = 1.62-44.88). After adjusting for age, HBsAg level, ALT level, HBeAg status and interferon treatment, MMP-1 (OR = 0.66, 95%CI = 0.44-0.97), CXCL9 (OR = 0.96, 95%CI = 0.93-0.99) and TNF-R1 (OR = 0.97, 95%CI = 0.94-0.99) baseline levels all negatively correlated with HBsAg loss. Our multivariate-adjusted RCS model showed that baseline CXCL10 was associated with HBsAg loss although the relationship was “U-shaped”.

Conclusions

Cytokines such as MMP-1, CXCL9, CXCL10 and TNF-R1 are important factors which influence HBsAg loss. It may be possible to develop a nomogram which intercalates these factors; however, further research should consider immune processes involved in HBsAg loss.

A risk prediction model for hepatocellular carcinoma after hepatitis B surface antigen seroclearance

BACKGROUND & AIMS

After hepatitis B surface antigen (HBsAg) seroclearance, the risk of hepatocellular carcinoma (HCC) remains, and the optimal surveillance strategy has yet to be determined. Herein, we aimed to evaluate incidence and risk factors for HCC and establish a novel prediction model for HCC development after HBsAg seroclearance.

METHODS

A total of 1,443 patients with chronic hepatitis B who achieved HBsAg seroclearance between 1991 and 2020 were retrospectively screened for study eligibility. The data from 831 of these patients were included in the final analysis. A prediction model was developed based on multivariable Cox models. Harrell's C-index and a time-dependent AUROC were used for discrimination. Bootstrap analysis was performed for internal validation.

RESULTS

Overall, 40 patients (4.8%) developed HCC after HBsAg seroclearance during a follow-up of 4,644 person-years (0.86%/year). Age at HBsAg seroclearance, presence of cirrhosis, family history of HCC, and more-than-moderate alcohol consumption were independently predictive of HCC, and these 4 independent variables were used to develop the prediction model. The C-index of the model was 0.804. The time-dependent AUROCs of the score for HCC prediction at 5, 10, and 15 years were 0.799, 0.835, and 0.817, respectively. The score also showed good discrimination in the internal validation and sensitivity analysis.

CONCLUSIONS

The novel prediction model based on age, cirrhosis, family history of HCC, and alcohol consumption enables reliable risk estimation of HCC after HBsAg seroclearance and may serve as a useful reference for decision-making in HCC surveillance for HBsAg-cleared patients.

LAY SUMMARY

After spontaneous hepatitis B surface antigen (HBsAg) seroclearance, the risk of hepatocellular carcinoma (HCC) remains. Age at HBsAg seroclearance, presence of cirrhosis, family history of HCC, and more-than-moderate alcohol consumption were independently associated with HCC development after HBsAg seroclearance. The novel prediction model using these 4 variables enables reliable risk estimation of HCC and serves as a useful reference for decision-making in HCC surveillance and management for HBsAg-cleared patients.

HBsAg isoform dynamics during NAP-based therapy of HBeAg-negative chronic HBV and HBV/HDV infection

Nucleic acid polymers block the assembly of hepatitis B virus (HBV) subviral particles, effectively preventing hepatitis B surface antigen (HBsAg) replenishment in the circulation. Nucleic acid polymer (NAP)-based combination therapy of HBV infection or HBV/hepatitis D virus (HDV) co-infection is accompanied by HBsAg clearance and seroconversion, HDV-RNA clearance in co-infection, and persistent functional cure of HBV (HBsAg < 0.05 IU/ml, HBV-DNA target not dected, normal alanine aminotransferase) and persistent clearance of HDV RNA. An analysis of HBsAg isoform changes during quantitative HBsAg declines (qHBsAg), and subsequent treatment-free follow-up in the REP 301/REP 301-LTF (HBV/HDV) and REP 401 (HBV) studies was conducted. HBsAg isoforms were analyzed from frozen serum samples using Abbott Research Use Only assays for HBsAg isoforms (large [L], medium [M], and total [T]). The relative change over time in small HBsAg relative to the other isoforms was inferred by the change in the ratio over time of T-HBsAg to M-HBsAg. HBsAg isoform declines followed qHBsAg declines in all participants. No HBsAg isoforms were detectable in any participants with functional cure. HBsAg declines > 2 log₁₀ IU/ml from baseline were correlated with selective clearance of S-HBsAg in 39 of 42 participants. Selective S-HBsAg decline was absent in 9 of 10 participants with HBsAg decline < 2 log₁₀ IU/ml from baseline. Mild qHBsAg rebound during follow-up <10 IU/ml consisted mostly of S-HBsAg and M-HBsAg and not accompanied by significant covalently closed circular DNA activity. Conclusion: The faster observed declines in S-HBsAg indicate the selective clearance of subviral particles from the circulation, consistent with previous mechanistic studies on NAPs. Trace HBsAg rebound in the absence of HBV DNA may reflect HBsAg derived from integrated HBV DNA and not rebound of viral infection.

Surrogate Markers for Hepatitis B Virus Covalently Closed Circular DNA

Chronic infection with the hepatitis B virus (HBV) is one of the most common causes of liver disease worldwide. Chronic HBV infection is currently incurable because of the persistence of the viral template for the viral transcripts, covalently closed circular deoxyribonucleic acid (cccDNA). Detecting changes in cccDNA transcriptional activity is key to understanding fundamental virology, determining the efficacy of new therapies, and deciding the optimal clinical management of HBV patients. In this review, we summarize surrogate circulating biomarkers that have been used to infer cccDNA levels and activity in people with chronic hepatitis B. Moreover, we outline the current shortcomings of the current biomarkers and highlight the clinical importance in improving them and expanding their use.

Getting to HBV cure: The promising paths forward

Chronic HBV infection is a global public health burden estimated to impact nearly 300 million persons worldwide. Despite the advent of potent antiviral agents that effectively suppress viral replication, HBV cure remains difficult to achieve because of the persistence of covalently closed circular DNA (cccDNA), HBV-DNA integration into the host genome, and impaired immune response. Indefinite treatment is necessary for most patients to maintain level of viral suppression. The success of direct-acting antivirals (DAAs) for hepatitis C treatment has rejuvenated the search for a cure for chronic hepatitis B (CHB), though an HBV cure likely requires an additional layer: immunomodulators for restoration of robust immune responses. DAAs such as entry inhibitors, capsid assembly modulators, inhibitors of subviral particle release, cccDNA silencers, and RNA interference molecules have reached clinical development. Immunomodulators, namely innate immunomodulators (Toll-like receptor agonists), therapeutic vaccines, checkpoint inhibitors, and monoclonal antibodies, are also progressing toward clinical development. The future of the HBV cure possibly lies in triple combination therapies with concerted action on replication inhibition, antigen reduction, and immune stimulation. Many obstacles remain, such as overcoming translational failures, choosing the right endpoint using the right biomarkers, and leveraging current treatments in combination regimens to enhance response rates. This review gives an overview of the current therapies for CHB, HBV biomarkers used to evaluate treatment response, and development of DAAs and immune-targeting drugs and discusses the limitations and unanswered questions on the journey to an HBV cure.

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.

JNJ-73763989 pharmacokinetics and safety: Liver-targeted siRNAs against hepatitis B virus, in Japanese and non-Japanese healthy adults, and combined with JNJ-56136379 and a nucleos(t)ide analogue in patients with chronic hepatitis B

BACKGROUND

JNJ-73763989 comprises two hepatitis B virus (HBV)-specific, liver-targeted N-galactosamine-conjugated short interfering RNA triggers, JNJ-73763976 and JNJ-73763924. JNJ-73763989 pharmacokinetics, safety and tolerability were assessed in two phase 1 studies: Japanese (NCT04002752), and non-Japanese healthy participants and chronic hepatitis B (CHB) patients also receiving the HBV capsid assembly modulator JNJ-56136379 and a nucleos(t)ide analogue (NA) (NCT03365947).

METHODS

Healthy participant cohorts were double-blind and randomized to receive a single subcutaneous JNJ-73763989 dose (non-Japanese participants, 35, 100, 200, 300 or 400 mg; Japanese participants, 25, 100 or 200 mg) or placebo. JNJ-73763976 and JNJ-73763924 plasma concentrations were assessed over 48 h. CHB patients received JNJ-73763989 200 mg every 4 weeks plus daily oral JNJ-56136379 250 mg and NA in an open-label fashion. Safety and tolerability were assessed through Day 28 (healthy participants) or Day 112 (patients).

RESULTS

Thirty non-Japanese (n = 4/dose; placebo, n = 10) and 24 Japanese healthy participants (n = 6/dose; placebo, n = 6) were randomized. JNJ-73763976 and JNJ-73763924 exposure generally increased in a dose-proportional manner. Mean plasma half-life was 4-9 h. No differences between pharmacokinetic parameters were apparent between non-Japanese and Japanese healthy participants. In the 12 CHB patients, mean JNJ-73763976, JNJ-73763924 and JNJ-56136379 plasma concentrations 2 h post-dose on Day 29 were 663, 269 and 14,718 ng/mL, respectively. In both studies, all adverse events were mild/moderate.

CONCLUSION

JNJ-73763976 and JNJ-73763924 had short plasma half-lives and exposure generally increased in a dose-proportional manner; there were no pharmacokinetic differences between Japanese and non-Japanese healthy adults. JNJ-73763989 with or without JNJ-56136379 and NA was generally safe and well tolerated.

Assessing the developing pharmacotherapeutic landscape in hepatitis B treatment: A spotlight on drugs at phase II clinical trials

INTRODUCTION

Functional cure, defined as sustained HBsAg seroclearance, is associated with favorable outcomes in chronic hepatitis B (CHB). While nucleos(t)ide analogues (NAs) are effective in suppressing HBV replication, NAs are unable to induce functional cure at high rates. A range of novel HBV antivirals, aiming to induce functional cure, are currently under development.

AREAS COVERED

This article covered novel hepatitis B virus (HBV) antivirals that have entered phase II trials. Virus-directing agents covered include entry inhibitors, transcription inhibitors, RNA silencers, core protein allosteric modulators, non-competitive polymerase inhibitors, and viral protein export inhibitors. Immunomodulators covered include innate immune stimulators, T-cell modulators, therapeutic vaccines, and monoclonal antibodies. Upcoming developmental directions would also be discussed.

EXPERT OPINION

Among novel HBV antivirals, RNA silencers, viral protein export inhibitors (with pegylated interferon) and entry inhibitors (with pegylated interferon) appear to be effective in suppressing HBsAg and may even induce functional cure. The other virus-targeting agents have variable effects on HBV DNA, HBsAg, HBeAg and HBcrAg. Immunomodulators have modest effects on HBsAg, but may have important roles in combination therapy. Upcoming trials will answer important questions on ideal dosing, long-term drug effects, and efficacy of combination regimens.

Aiming for Functional Cure With Established and Novel Therapies for Chronic Hepatitis B

Chronic hepatitis B virus (HBV) infection remains difficult to cure due to the persistent, self-replenishing nature of the viral genome and impaired host immune responses. Current treatment goals for chronic hepatitis B (CHB) are to prevent or significantly delay liver-related adverse outcomes and death, and two types of treatments are available: nucleos(t)ide analogues (NAs) and interferons (IFNs). NAs effectively suppress HBV replication, and IFNs improve serological response rates, thereby decreasing the risk of adverse outcomes. However, their efficacy in attaining serological responses, especially functional cure (i.e., loss of serum hepatitis B surface antigen), is very limited. Various strategies such as stopping antiviral therapy or combining therapies have been investigated to enhance response, but efficacy is only modestly improved. Importantly, the development of novel direct-acting antivirals and immunomodulators is underway to improve treatment efficacy and enhance rates of functional cure. The present review provides an overview of the treatment goals and indications, the possibility of expanding indications, and the safety and efficacy of different treatment strategies involving established and/or novel therapies as we continue our search for a cure.

HBsAg Loss as a Treatment Endpoint for Chronic HBV Infection: HBV Cure

Despite the availability of effective vaccines and antiviral therapy over the past two to three decades, chronic hepatitis B virus (HBV) infection remains a major global health threat as a leading cause of cirrhosis and liver cancer. Functional HBV cure defined as hepatitis B surface antigen (HBsAg) loss and undetectable serum HBV DNA is associated with improved clinical outcomes in patients with chronic HBV infection. However, spontaneous loss of HBsAg is rare and occurs in only 1% of all HBsAg-positive individuals annually. Furthermore, the rate of functional cure with currently available antiviral therapy is even lower, <1% patients on treatment per year. Nonetheless, HBsAg loss has become the new target or therapeutic endpoint for antiviral treatment. Recently, there has been much excitement surrounding the development of novel antiviral agents such as small interfering RNA (siRNA), core assembly modulators (CAMs), nucleic acid polymers (NAPs) among others, which may be used in combination with nucleos(t)ide analogs and possibly immunomodulatory therapies to achieve functional cure in a significant proportion of patients with chronic hepatitis B. Novel assays with improved sensitivity for detection of very low levels of HBsAg and to determine the source of HBsAg production will also be required to measure efficacy of newer antiviral treatments for HBV cure. In this narrative review, we will define HBV cure, discuss various sources of HBsAg production, evaluate rates of HBsAg loss with current and future antiviral agents, review clinical factors associated with spontaneous HBsAg loss, and explore clinical implications of functional cure.

Finite nucleos(t)ide analogue therapy in hepatitis B e antigen-negative chronic hepatitis B: From an "option" to an "active recommendation"

Nucleos(t)ide analogue (Nuc) including entecavir, tenofovir disoproxil fumarate, and tenofovir alafenamide may suppress hepatitis B virus (HBV) DNA profoundly but have no direct action on covalently closed circular DNA, which is a very stable template for HBV production. Therefore, decades of long-term Nuc therapy are required to maintain HBV suppression and to achieve hepatitis B surface antigen (HBsAg) loss in hepatitis B e antigen (HBeAg)-negative patients. However, there are concerns including financial burden, adherence, and willingness for indefinite long-term Nuc therapy. Patients lost to follow-up and hence not monitored may risk severe relapse that may deteriorate to hepatic decompensation or even hepatic failure. Cessation of Nuc therapy in HBeAg-negative patients was initially considered in early 2000s. Earlier findings in Asian patients that finite Nuc therapy over 2-3 years is feasible and safe have founded Asian-Pacific Association for the Study of Liver stopping rule since 2008. Subsequent studies have confirmed the feasibility and safety of the strategy of finite Nuc therapy, which has finally been accepted as "an option" by American and European liver associations since 2016. More recent large studies since 2018 have further confirmed the pivotal finding of greatly increased HBsAg loss rate (~5-year 39%) after stopping Nuc therapy. With the high HBsAg loss rate as the main justification, the paradigm shift from indefinite long-term therapy to finite Nuc therapy in HBeAg-negative patients has been changing from an "option" to an "active recommendation" aiming to achieve HBsAg loss. More studies are needed to fine-tuning the strategy, including research for the optimal duration of consolidation therapy, timing to stop, and to start retreatment.