Combination of Tenofovir Disoproxil Fumarate and Peginterferon α-2a Increases Loss of Hepatitis B Surface Antigen in Patients With Chronic Hepatitis B

Long-term effects of peginterferon-based therapy versus nucleos(t)ide analogue monotherapy in non-cirrhotic HBeAg-positive chronic hepatitis B patients

BACKGROUND & AIMS

The long-term clinical benefits of interferon (IFN)-based therapy compared to nucleos(t)ide analogue (NA) monotherapy in HBeAg-positive chronic hepatitis B (CHB) have not been well defined. This study aimed to evaluate the cumulative incidence of new-onset cirrhosis, serological responses, and hepatocellular carcinoma (HCC) development between these treatment strategies.

METHODS

Two independent cohorts of non-cirrhotic, HBeAg-positive CHB patients were analyzed: a treatment-naïve cohort (n = 686) and an NA-experienced cohort (n = 531). Patients received either IFN-based therapy or NA monotherapy. Propensity score matching (PSM) was employed to minimize intergroup heterogeneity. The primary endpoint was the cumulative incidence of new-onset cirrhosis.

RESULTS

After PSM, the 10-year cumulative incidence of new-onset cirrhosis was significantly lower in the IFN-based therapy group compared to the NA monotherapy group in both the treatment-naïve (3.3 % vs 20.0 %, p = 0.005) and NA-experienced (4.9 % vs 20.9 %, p = 0.034) cohorts. IFN-based therapy also resulted in significantly higher serological response rates across both cohorts, including HBeAg loss (treatment-naïve: 84.7 % vs 55.6 %; NA-experienced: 60.4 % vs 43.6 %, both p < 0.001) and HBsAg loss (treatment-naïve: 14.3 % vs 5.7 %, p = 0.006; NA-experienced: 10.2 % vs 1.3 %, p < 0.001). Subgroup analysis showed that patients receiving IFN-based therapy who achieved HBeAg loss within 96 weeks had the greatest long-term benefits, with lower cirrhosis incidence and higher HBsAg loss rates. Although the incidence of HCC was lower in the IFN-based group, the difference did not reach statistical significance (both p > 0.05).

CONCLUSIONS

IFN-based therapy provides superior long-term benefits over NA monotherapy in reducing cirrhosis risk and enhancing serological responses in HBeAg-positive CHB patients.

EASL Clinical Practice Guidelines on the management of hepatitis B virus infection

The updated EASL Clinical Practice Guidelines on the management of hepatitis B virus (HBV) infection provide comprehensive, evidence-based recommendations for its management. Spanning ten thematic sections, the guidelines address diagnostics, treatment goals, treatment indications, therapeutic options, hepatocellular carcinoma surveillance, management of special populations, HBV reactivation prophylaxis, post-transplant care, HBV prevention strategies, and finally address open questions and future research directions. Chronic HBV remains a global health challenge, with over 250 million individuals affected and significant mortality due to cirrhosis and hepatocellular carcinoma. These guidelines emphasise the importance of early diagnosis, risk stratification based on viral and host factors, and tailored antiviral therapy. Attention is given to simplified algorithms, vaccination, and screening to support global HBV elimination targets. The guidelines also discuss emerging biomarkers and evolving definitions of functional and partial cure. Developed through literature review, expert consensus, and a Delphi process, the guidelines aim to equip healthcare providers across disciplines with practical tools to optimise HBV care and outcomes worldwide.

Impact of hepatitis B surface antigen quantification on achieving a functional cure in patients with chronic hepatitis B: A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Baseline hepatitis B surface antigen (HBsAg) levels are associated with the likelihood of achieving HBsAg loss which defines the functional cure. However, optimal HBsAg cut-offs for predicting HBsAg loss have not been systematically investigated." Therefore, in this systematic review and meta-analysis, we evaluated the impact of baseline levels of HBsAg on achieving a functional cure in patients with chronic hepatitis B (CHB).

MATERIALS AND METHODS

We searched PubMed, Embase, and Cochrane Library up to December 31, 2023, to identify studies comparing combination therapy with nucleos(t)ide analogues (NAs) and conventional/pegylated interferon (IFN) versus monotherapy. We pooled the proportion of HBsAg loss among studies stratified by different 75th percentile of baseline HBsAg levels and other clinical characteristics.

RESULTS

We included 24 studies with 3446 participants. At the end of treatment, studies recruiting patients with 75th percentile of baseline HBsAg below 500 and 1000 IU/mL had the highest proportions of HBsAg loss in the combination group, reaching 14 % (95 % CI: 9-21 %) and 17 % (95 % CI: 10-24 %), respectively. One-year IFN-NAs combination treatment achieved a higher proportion of HBsAg loss (9 %, 95 % CI: 6-12 %) than six-month IFN-NAs treatment (1 %, 95 % CI: 0-2 %). Patients with normal alanine transaminase (ALT) had higher HBsAg loss (11 %, 95 % CI: 6-17 %) than those with elevated ALT (4 %, 95 % CI: 2-7 %). Meta-regression indicated a positive association between male percentage in studies and HBsAg loss.

CONCLUSIONS

The optimal baseline HBsAg thresholds would be 500-1000 IU/mL, which represents high-response subpopulation for achieving functional cure with currently available therapy.

Functional Cure for Hepatitis B Virus: Challenges and Achievements

The Hepatitis B Virus (HBV) presents a formidable global health challenge, impacting hundreds of millions worldwide and imposing a considerable burden on healthcare systems. The elusive nature of the virus, with its ability to establish chronic infection and evade immune detection, and the absence of curative agents have prompted efforts to develop novel therapeutic approaches beyond current antiviral treatments. This review addresses the challenging concept of a functional cure for HBV, a state characterized by the suppression of HBV and HBsAg, mitigating disease progression and transmission without a complete cure. We provide an overview of HBV epidemiology and its clinical impact, followed by an exploration of the current treatment landscape and its limitations. The immunological basis of a functional cure is then discussed, exploring the intricate interplay between the virus and the host immune response. Emerging therapeutic approaches, such as RNA interference-based interventions, entry inhibitors, nucleic acid polymers, and therapeutic vaccines, are discussed with regard to their success in achieving a functional cure. Lastly, the review underscores the urgent need for innovative strategies to achieve a functional cure for HBV.

Peripheral Blood CD4+/CD8+ T Cell Ratio Predicts HBsAg Clearance in Inactive HBsAg Carriers Treated with Peginterferon Alpha

BACKGROUND AND AIMS

T lymphocytes play a pivotal role in resolving hepatitis B virus infection. This study aimed to investigate the dynamics of peripheral blood T lymphocyte subsets during peginterferon alpha (peg-IFN-α) therapy and their association with hepatitis B surface antigen (HBsAg) clearance in inactive HBsAg carriers (IHCs).

METHODS

This prospective observational study enrolled 197 IHCs treated with peg-IFNα-2a/2b for 48 weeks and followed for 24 weeks (treatment group), and 221 IHCs who were regularly monitored for 72 weeks without treatment (IHC control group). Peripheral blood T lymphocyte subsets were evaluated using flow cytometry at baseline, and at 12, 24, 48, and 72 weeks in both groups. At 72 weeks, IHCs in the treatment group were categorized into an HBsAg clearance group and an HBsAg persistence group. Differences in T lymphocyte subsets among these groups were compared, and correlations between T lymphocyte subsets and HBsAg clearance were analyzed.

RESULTS

At 72 weeks, intention-to-treat analysis showed significantly higher HBsAg clearance (46.7%) and seroconversion rates (34.5%) in the treatment group compared to the IHC control group (HBsAg clearance rate of 1.4%, seroconversion rate of 0.9%; both p < 0.001). The median absolute counts of CD3+, CD4+, and CD8+ cells significantly decreased at 12, 24, and 48 weeks in both the HBsAg clearance and persistence groups, returning to baseline at 72 weeks (all p < 0.001). IHCs with HBsAg clearance had higher median percentages of CD3+ CD8+ cells and lower median percentages of CD3+ CD4+ cells and CD4+/CD8+ ratios at 12, 24, and 48 weeks compared to the HBsAg persistence and IHC control groups (all p < 0.001). Baseline HBsAg levels (below 2.0 log10 IU/mL) and hepatitis B virus DNA levels (below 20 IU/mL), alanine aminotransferase elevation at 12 weeks (greater than 2×upper limit of normal), and CD4+/CD8+ ratios (less than 1.5 at 12 weeks and below 1.4 at 24 weeks) were predictive of HBsAg clearance.

CONCLUSIONS

Peripheral blood CD4+/CD8+ ratios at 12 and 24 weeks may serve as predictive markers for HBsAg clearance in IHCs treated with peg-IFN-α.

Sequential Peg-IFN after bepirovirsen may reduce post-treatment relapse in chronic hepatitis B

BACKGROUND & AIMS

Bepirovirsen, an antisense oligonucleotide, induces sustained reductions in hepatitis B surface antigen (HBsAg) and HBV DNA to below the lower limit of quantification (

METHODS

In this phase IIb, multicentre, open-label trial, participants on stable nucleos(t)ide analogue (NA) therapy were randomised 1:1 to bepirovirsen 300 mg once weekly (plus loading dose on Days 4 and 11) for 24 (Arm 1) or 12 (Arm 2) weeks followed by Peg-IFN 180 μg once weekly for up to 24 weeks, with up to 36 weeks follow-up. Participants continued NA therapy throughout. The primary outcome was the proportion of participants with HBsAg <0.05 IU/ml and HBV DNA

RESULTS

The intent-to-treat population included 108 participants (Arm 1, n = 55; Arm 2, n = 53). The primary outcome was achieved by 5 (9%) participants in Arm 1 and 8 (15%) in Arm 2. All responders had baseline HBsAg ≤3,000 IU/ml. Indirect comparison with the phase IIb study B-Clear indicates that sequential addition of Peg-IFN may reduce the relapse rates previously observed with bepirovirsen alone. The proportions of participants with adverse events and treatment-related adverse events in both treatment windows were similar between treatment arms.

CONCLUSIONS

Sequential therapy with bepirovirsen followed by Peg-IFN is tolerable and effective in participants with chronic HBV infection on stable NA therapy. This proof-of-concept trial demonstrates a potential strategy to extend responses to bepirovirsen by reducing relapse.

IMPACT AND IMPLICATIONS

This phase IIb study investigated whether sequential therapy with bepirovirsen followed by Peg-IFN could improve off-treatment response rates to bepirovirsen alone by converting partial bepirovirsen responders to full responders and/or reducing relapse rates in participants with chronic HBV. These data show that sequential therapy with bepirovirsen followed by Peg-IFN is tolerable and effective; in patients with a bepirovirsen response, sequential treatment with Peg-IFN may help to reduce off-treatment relapses in participants on stable NA. Participants had a similar response during bepirovirsen treatment as seen in B-Clear, with increased response rates in participants with lower baseline HBsAg; all responders to the sequential regimen had baseline HBsAg <3000 IU/mL. As the first study of antisense oligonucleotide-mediated RNA silencing followed by interferon immunomodulation in patients with chronic HBV infection, this study is an important proof-of-concept for sequential therapy, shedding light on the therapeutic potential of utilising immunomodulators following suppression of HBV antigens.

CLINICAL TRIAL NUMBER

NCT04676724.

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Key Words

• Hepatitis B
• antisense oligonucleotide
• bepirovirsen
• pegylated interferon-α-2a
• sequential therapy

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MESH Headings

• Humans
• Hepatitis B, Chronic/drug therapy
• Hepatitis B, Chronic/blood
• Hepatitis B, Chronic/virology
• Polyethylene Glycols/administration & dosage
• Polyethylene Glycols/adverse effects
• Male
• Female
• Interferon-alpha/administration & dosage
• Interferon-alpha/adverse effects
• Middle Aged
• Adult
• Antiviral Agents/administration & dosage
• Antiviral Agents/adverse effects
• Recombinant Proteins/administration & dosage
• Recombinant Proteins/adverse effects
• Recombinant Proteins/therapeutic use
• DNA, Viral/blood
• Hepatitis B virus/genetics
• Recurrence
• Hepatitis B Surface Antigens/blood
• Drug Therapy, Combination
• Oligonucleotides, Antisense/administration & dosage
• Treatment Outcome
• Oligonucleotides/administration & dosage
• Drug Administration Schedule

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Affiliation(s)

Maria Buti Liver Unit, Hospital Vall d'Hebrón, Barcelona and CIBER-EHD del Instituto Carlos III, Barcelona, Spain.
Jeong Heo Department of Internal Medicine, College of Medicine, Pusan National University, Busan, Republic of Korea; Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea.
Yasuhito Tanaka Department of Gastroenterology and Hepatology, Kumamoto University Hospital, Kumamoto, Japan
Pietro Andreone Medicina Interna a indirizzo Metabolico-Nutrizionale, Ospedale Clinicizzato di Baggiovara, AOU di Modena, Modena, Italy; Dipartimento SMECHIMAI, Università di Modena e Reggio Emilia, Modena, Italy
Masanori Atsukawa Nippon Medical School Hospital, Tokyo, Japan
Joaquín Cabezas Gastroenterology and Hepatology Department, University Hospital Marques de Valdecilla, Santander, Spain; Clinical and Translational Research in Digestive Diseases, Valdecilla Research Institute (IDIVAL), Santander, Spain
Eric Chak UC Davis, Sacramento, California, USA
Carla S Coffin Department of Medicine, Cumming School of Medicine, University of Calgary, Alberta, Calgary, Canada
Kei Fujiwara Nagoya City University Hospital, Aichi, Japan
Natalya Gankina Krasnojarsk Regional Center of AIDS prevention, Krasnojarsk, Russian Federation
Stuart C Gordon Henry Ford Health and Wayne State University School of Medicine, Detroit, MI, USA
Ewa Janczewska Department of Basic Medical Sciences, Faculty of Public Health in Bytom, Medical University of Silesia, Myslowice, Poland
Atsumasa Komori National Hospital Organization, NHO Nagasaki Medical Center, Nagasaki, Japan
Pietro Lampertico Division of Gastroenterology and Hepatology, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; CRC "A. M. and A. Migliavacca" Center for Liver Disease, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
Stuart McPherson Hepatology and Newcastle NIHR Biomedical Research Centre, The Newcastle Upon Tyne Hospitals NHS Foundation Trust, Freeman Hospital, Newcastle-upon-Tyne, UK
Vyacheslav Morozov Hepatologist Medical Company, Samara, Russian Federation
Robert Plesniak University of Rzeszow Centrum Medyczne w Lancucie Sp. z o.o., Lancut, Poland
Sébastien Poulin Clinique Médecine Urbaine du Quartier Latin, Montréal, Québec, Canada
Pablo Ryan Hospital Infanta Leonor and CIBERINFEC, del Instituto Carlos III., Madrid, Spain
Olga Sagalova South Ural State Medical University, Chelyabinsk, Russian Federation
Guoping Sheng Department of Infectious Disease, Shulan (Hangzhou) Hospital Affiliated to Zhejiang Shuren University, Shulan International Medical College, Hangzhou, Zhejiang, China
Natalya Voloshina Medical Centre Healthy Family, Novosibirsk, Russian Federation
Qing Xie Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
Hyung Joon Yim Korea University Ansan Hospital, Ansan, Republic of Korea
Susan Dixon GSK, London, UK
Melanie Paff GSK, Collegeville, PA, USA
Leigh Felton GSK, London, UK
Maximilian Lee GSK, Collegeville, PA, USA
Thomas Greene GSK, Collegeville, PA, USA
Jessica Lim GSK, Collegeville, PA, USA
Divya Lakshminarayanan GSK, Collegeville, PA, USA
Grant McGonagle GSK, London, UK
Helene Plein GSK, London, UK
Amir S Youssef GSK, Collegeville, PA, USA
Rob Elston GSK, Stevenage, UK
Stuart Kendrick GSK, Stevenage, UK
Dickens Theodore GSK, Durham, NC, USA

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Update on the treatment navigation for functional cure of chronic hepatitis B: Expert consensus 2.0

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.

Achieving chronic hepatitis B functional cure: Factors and potential mechanisms

Chronic hepatitis B (CHB) is a significant global health issue affecting approximately 254 million individuals worldwide. Achieving the loss of hepatitis B surface antigen (HBsAg), either with or without seroconversion to hepatitis B surface antibody (HBsAb), is regarded as a functional cure and the optimal goal for addressing CHB, and can be achieved through various approaches, including induction with nucleos(t)ide analogues (NAs), induction with pegylated interferon alpha (PegIFNα), and spontaneous clearance of HBsAg. Spontaneous clearance of HBsAg is rare, while NAs can directly inhibit HBV DNA, they are unable to act on covalently closed circular DNA (cccDNA), hence inhibiting HBsAg production or clearing HBsAg is extremely challenging. On the other hand, functional cure based on PegIFNα shows good long-term durability, but over 10 % of patients still experience relapse, mostly within 48 weeks after functional cure. Factors related to CHB functional cure with antiviral therapy are complex, including host factors, viral factors, environmental factors, etc. The integration of HBV DNA into liver cells, persistence of HBV cccDNA, insufficient B cell responses and compromised T cell function pose significant barriers to HBV clearance. Therefore, this study systematically reviewed the relevant factors and potential mechanisms influencing functional cure CHB, which can provide a basis for personalized treatment, help predict treatment outcomes and assess prognosis, and provide theoretical support for the advancement of novel treatment strategies and medications.

Mechanisms underlying the compromised clinical efficacy of interferon in clearing HBV

Hepatitis B virus (HBV) is a hepatotropic DNA virus that can cause acute or chronic hepatitis, representing a significant global health concern. By 2019, approximately 296 million individuals were chronically infected with HBV, with 1.5 million new cases annually and 820,000 deaths due to HBV-related cirrhosis and liver cancer. Current treatments for chronic hepatitis B include nucleotide analogs (NAs) and interferons (IFNs), particularly IFN-α. NAs, such as entecavir and tenofovir, inhibit viral reverse transcription, while IFN-α exerts antiviral effects by directly suppressing viral replication, modulating viral genome epigenetics, degrading cccDNA, and activating immune responses. Despite its potential, IFN-α shows limited clinical efficacy, partly due to HBV's interference with the IFN signaling pathway. HBV encodes proteins like HBc, Pol, HBsAg, and HBx that disrupt IFN-α function. For example, HBV Pol inhibits STAT1 phosphorylation, HBsAg suppresses STAT3 phosphorylation, and HBx interferes with IFN-α efficacy through multiple mechanisms. Additionally, HBV downregulates key genes in the IFN signaling pathway, further diminishing IFN-α's antiviral effects. Understanding these interactions is crucial for improving IFN-α-based therapies. Future research may focus on overcoming HBV resistance by targeting viral proteins or optimizing IFN-α delivery. In summary, HBV's ability to resist IFN-α limits its therapeutic effectiveness, highlighting the need for new strategies to enhance treatment outcomes.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

Vir Biotechnology.

TCR-like bispecific antibodies toward eliminating infected hepatocytes in HBV mouse models

Therapeutics for eradicating hepatitis B virus (HBV) infection are still limited and current nucleos(t)ide analogs (NAs) and interferon are effective in controlling viral replication and improving liver health, but they cannot completely eradicate the hepatitis B virus and only a very small number of patients are cured of it. The TCR-like antibodies recognizing viral peptides presented on human leukocyte antigens (HLA) provide possible tools for targeting and eliminating HBV-infected hepatocytes. Here, we generated three TCR-like antibodies targeting three different HLA-A2.1-presented peptides derived from HBV core and surface proteins. Bispecific antibodies (BsAbs) were developed by fuzing variable fragments of these TCR-like mAbs with an anti-CD3ϵ antibody. Our data demonstrate that the BsAbs could act as T cell engagers, effectively redirecting and activating T cells to target HBV-infected hepatocytes in vitro and in vivo. In HBV-persistent mice expressing human HLA-A2.1, two infusions of BsAbs induced marked and sustained suppression in serum HBsAg levels and also reduced the numbers of HBV-positive hepatocytes. These findings highlighted the therapeutic potential of TCR-like BsAbs as a new strategy to cure hepatitis B.

Recurrence and influencing factors of hepatitis B surface antigen seroclearance induced by peginterferon alpha-based regimens

BACKGROUND

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.

AIM

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

METHODS

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.

RESULTS

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.

CONCLUSION

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

Systematic review with network meta-analysis: sustained hepatitis B surface antigen clearance after pegylated interferon cessation

The efficacy of different pegylated interferon (PEG-IFN) treatment strategies for achieving sustained hepatitis B surface antigen (HBsAg) clearance in chronic hepatitis B (CHB) remains controversial. This study assesses the efficacy of different PEG-IFN treatment regimens and factors influencing sustained HBsAg clearance after PEG-IFN discontinuation. PubMed , Embase , Web of Science , and the Cochrane Library databases were searched from inception to June 2023, regarding PEG-IFN therapy in CHB. Methodological quality was assessed using the Cochrane risk of bias tool. We explored sources of heterogeneity through univariate meta-regression. Frequentist network meta-analyses were used to compare the efficacy of different PEG-IFN treatment strategies. We analyzed 53 studies (including 9338 CHB patients). After PEG-IFN withdrawal, the annual rates of HBsAg clearance and seroconversion were 6.9% [95% confidence interval (CI), 5.10-9.31] and 4.7% (95% CI, 2.94-7.42). The pooled 1-, 3-, and 5-year sustained HBsAg clearance rates were 7.4%, 9.9%, and 13.0%, and the sustained HBsAg seroconversion rates were 6.6%, 4.7%, and 7.8%, respectively. HBsAg quantification, hepatitis B e antigen status, and PEG-IFN treatment protocols were major sources of heterogeneity. Baseline HBsAg quantification was significantly lower in patients with sustained HBsAg clearance versus those without ( P  < 0.046). PEG-IFN combined with tenofovir has the highest probability of achieving HBsAg seroconversion (surface under the cumulative ranking of 81.9%). Sustained HBsAg clearance increased approximately linearly from years 1 to 5 after PEG-IFN discontinuation. Low baseline HBsAg quantification has a significant impact on sustained HBsAg clearance. PEG-IFN combined with tenofovir may be optimal in achieving sustained HBsAg seroconversion.

Hepatitis B Management in the Middle East: A Narrative Review of Current Antiviral Treatments

Introduction: Chronic hepatitis B (CHB) is a significant public health issue worldwide, especially in the Middle East region. Around 8% to 20% of patients with CHB develop cirrhosis, which may progress to hepatocellular carcinoma. The significant morbidity and mortality associated with CHB denote the importance of high-quality treatment. Methods: We searched the PubMed, Medline, and Cochrane databases from inception to January 2024 to identify relevant studies. Search terms were generated using established treatment guidelines for CHB. We also manually searched the bibliographies of relevant literature to obtain additional papers. Results: In this narrative review, we evaluated the seven currently licensed antiviral therapies for chronic Hepatitis B treatment, including nucleos(t)ide analogs (NAs) and pegylated interferon-alpha (PEG-IFNα). NAs can be divided into two categories: high barrier to resistance and low barrier to resistance. Tenofovir disoproxil fumarate, tenofovir alafenamide, and entecavir are NAs with a high barrier to resistance. Telbivudine has shown promise in providing high efficacy with low viral resistance rates; however, it is not recommended because of insufficient evidence and lack of cost-effectiveness. Lamivudine and adefovir dipivoxil, despite being efficacious, have a low barrier to resistance, the primary reason they are no longer recommended. PEG-IFNα has high efficacy and can be completed in 48 weeks. It is not associated with resistance; however, it has been reported to have several systemic adverse effects. Conclusions: Current first-line NA treatments in the Middle East include entecavir, tenofovir disoproxil fumarate, and tenofovir alafenamide. These drugs are favored over other NAs because of their low rates of resistance. PEG-IFNα has superiority over NAs in inducing a more durable antiviral response and having a finite treatment duration. The main drawback of PEG-IFNα is an unfavorable safety profile.

Hepatitis B virus enhancer 1 activates preS1 and preS2 promoters of integrated HBV DNA impairing HBsAg secretion

Background & Aims

The expression of HBsAg from integrated HBV DNA limits the achievement of functional cure for chronic hepatitis B. Thus, characterising the unique expression and secretion of HBsAg derived from integrated HBV DNA is of clinical significance.

Methods

A total of 563 treatment-naive patients and 62 functionally cured patients were enrolled, and HBsAg and HBcAg immunohistochemistry of their liver biopsy tissues was conducted followed by semi-quantitative analysis. Then, based on stratified analysis of HBeAg-positive and -negative patients, long-read RNA sequencing analysis, as well as an in vitro HBV integration model, we explored the HBsAg secretion characteristics of integrated HBV DNA and underlying mechanisms.

Results

In contrast to the significantly lower serum HBsAg levels, no significant decrease of intrahepatic HBsAg protein was observed in HBeAg-negative patients, as compared with HBeAg-positive patients. The results of long-read RNA sequencing of liver tissues from patients with chronic HBV infection and in vitro studies using integrated HBV DNA mimicking dslDNA plasmid revealed that, the lower HBsAg secretion efficiency seen in HBeAg-negative patients might be attributed to an increased proportion of preS1 mRNA derived from integrated HBV DNA instead of covalently closed circular DNA. The latter resulted in an increased L-HBsAg proportion and impaired HBsAg secretion. Enhancer 1 (EnhI) in integrated HBV DNA could retarget preS1 (SP1) and preS2 (SP2) promoters to disrupt their transcriptional activity balance.

Conclusions

The secretion of HBsAg originating from integrated HBV DNA was impaired. Mechanistically, functional deficiency of core promoter leads to retargeting of EnhI and thus uneven activation of the SP1 over the SP2 promoter, resulting in an increase in the proportion of L-HBsAg.

Impact and implications

Integrated hepatitis B virus (HBV) DNA can serve as an important reservoir for HBV surface antigen (HBsAg) expression, and this limits the achievement of a functional cure. This study revealed that secretion efficiency is lower for HBsAg derived from integrated HBV DNA than HBsAg derived from covalently closed circular DNA, as determined by the unique sequence features of integrated HBV DNA. This study can broaden our understanding of the role of HBV integration and shed new light on antiviral strategies to facilitate a functional cure. We believe our results are of great general interest to a broad audience, including patients and patient organisations, the medical community, academia, the life science industry and the public.

A high functional cure rate was induced by pegylated interferon alpha-2b treatment in postpartum hepatitis B e antigen-negative women with chronic hepatitis B virus infection: an exploratory study

Background and aims

Limited data have been reported on achieving functional cure using pegylated interferon (Peg-IFN) alpha-2b treatment for postpartum hepatitis B e antigen (HBeAg)-negative women with chronic hepatitis B virus (HBV) infection. This study was to assess the effectiveness and safety of Peg-IFN alpha-2b in HBV postpartum women without HBeAg and identify factors linked to the functional cure.

Methods

A total of 150 HBeAg-negative postpartum women were retrospectively recruited.47 patients received Peg-IFN alpha-2b [Peg-IFN(+) group] and 103 patients did not [Peg-IFN(-) group]. Propensity score matching (PSM) was used to adjust the baseline imbalance between the two groups. The patients were followed for at least 48 weeks. The primary endpoints were hepatitis B surface antigen(HBsAg) loss and HBsAg seroconversion at 48 weeks. Logistic regression analysis was used to assess factors associated with HBsAg loss at 48 weeks.

Results

At week 48,the HBsAg loss and seroconversion rate in Peg-IFN(+) group were 51.06%(24/47) and 40.43%(19/47), respectively. Even after PSM, Peg-IFN(+) group still showed higher HBsAg loss rate (50.00% vs 7.14%,p<0.001) and higher HBsAg seroconversion rate (38.10% vs 2.38%,p<0.001). Baseline HBsAg levels (Odds Ratio [OR]: 0.051, 95% Confidence Interval [CI]: 0.003-0.273, P=0.010), HBsAg at week 24 (OR:0.214, 95%CI:0.033-0.616, P=0.022), HBsAg decline at week 24 (OR:4.682, 95%CI: 1.624-30.198, P=0.022) and postpartum flare (OR:21.181, 95%CI:1.872-633.801, P=0.030) were significantly associated with HBsAg loss at week 48 after Peg-IFN alpha-2b therapy. Furthermore, the receiver operating characteristic curve (ROC) showed that the use of baseline HBsAg<182 IU/mL, HBsAg at week24 < 4 IU/mL and HBsAg decline at week24>12IU/mL were good predictors of HBsAg loss. No serious adverse events were reported.

Conclusion

Peg-IFN alpha-2b treatment could achieve a high rate of HBsAg loss and seroconversion in HBeAg-negative postpartum women with reliable safety, particularly for patients experience postpartum flare and have low baseline HBsAg levels.

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.

Systematic review and meta-analysis: de novo combination of nucleos(t)ide analogs and pegylated interferon alpha versus pegylated interferon alpha monotherapy for the functional cure of chronic hepatitis B

Introduction: Chronic hepatitis B (CHB) is a worldwide infectious disease caused by hepatitis B virus (HBV). Optimizing antiviral treatment strategies could improve the functional cure (FC) rate of patients with CHB. This study aims to systematically review the FC rate of the de novo combination of nucleos(t)ide analogs (NAs) and pegylated interferon α (PEG-IFNα) versus that of PEG-IFNα monotherapy for CHB. Methods: Databases were searched until 31 December 2023. Selected studies included randomized controlled trials on the de novo combination of NAs and PEG-IFNα versus PEG-IFNα monotherapy for 48 weeks in patients with CHB to achieve FC, which was defined as hepatitis B surface antigen (HBsAg) loss and/or HBsAg seroconversion. Meta-analysis was conducted in accordance with the efficacy at the end of treatment and different time points during follow-up. Results: A total of 10 studies, encompassing 2,339 patients in total, were included. Subgroup analysis was conducted in accordance with whether first-line NAs were used. It found no statistically significant difference between HBsAg loss and HBsAg seroconversion at the end of treatment. Serum HBV DNA <500 copies/mL significantly differed between the two groups at the end of treatment and did not significantly differ during follow-up. Meanwhile, HBsAg loss and HBsAg seroconversion showed statistically significant differences at 24 weeks of follow-up. By contrast, no statistically significant difference was found in HBsAg loss at 48 weeks of follow-up. Discussion: Without distinguishing the eligible preponderant population, the efficacy of the de novo combination of NAs and PEG-IFNα in treating patients with CHB was not superior to that of PEG-IFNα monotherapy. Systematic Review Registration: PROSPERO, identifier CRD42022325239.

Hepatitis B cure: Current situation and prospects

Achievement of a 'clinical cure' in chronic hepatitis B (CHB) implies sustained virological suppression and immunological control over the infection, which is the ideal treatment goal according to domestic and international CHB management guidelines. Clinical practice has shown encouraging results for specific patient cohorts using tailored treatment regimens. These regimens incorporate either nucleos(t)ide analogs, immunomodulatory agents such as pegylated interferon α, or a strategic combination of both, sequentially or concurrently administered. Despite these advancements in the clinical handling of hepatitis B, achieving a clinical cure remains elusive for a considerable subset of patients due to the number of challenges that preclude the realization of optimal treatment outcomes. These include, but are not limited to, the emergence of antiviral resistance, incomplete immune recovery, and the persistence of covalently closed circular DNA. Moreover, the variance in response to interferon therapy and the lack of definitive biomarkers for treatment cessation also contribute to the complexity of achieving a clinical cure. This article briefly overviews the current research progress and existing issues in pursuing a clinical cure for hepatitis B.

Long-term open-label vebicorvir for chronic HBV infection: Safety and off-treatment responses

BACKGROUND & AIMS

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

CLINICAL TRIAL NUMBER

NCT03780543.

IMPACT AND IMPLICATIONS

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.

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.

Safety, pharmacodynamics, and antiviral activity of selgantolimod in viremic patients with chronic hepatitis B virus infection

BACKGROUND & AIMS

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

IMPACT AND IMPLICATIONS

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.

CLINICAL TRIAL NUMBER

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

Effect of interferon therapy on quality of life in patients with chronic hepatitis B

Interferon therapy is the most effective treatment for achieving clinical cure in chronic hepatitis B (CHB) patients. However, the treatment outcomes of interferon therapy are uncertain, multiple side effects can occur during treatment, and the treatment is expensive. Although these characteristics may affect patients' quality of life, research examining this topic is limited. We used a cross-sectional design to examine 100 CHB patients receiving interferon, 100 receiving nucleoside/nucleotide analogues, and 87 receiving non-antiviral treatment. Characteristic information, the Hepatitis B Quality of Life Instrument, Connor Davidson Resilience Scale, and Work Productivity and Activity Impairment Questionnaire were used to collect information. We found that quality of life in the interferon treatment group was higher than that in the non-antiviral treatment and nucleoside/nucleotide analogue treatment groups (p < 0.05). The factors influencing quality of life were resilience, presenteeism, hair loss, and antiviral treatment (p < 0.05). Although interferon therapy has some potential side effects, the results suggested that it did not negatively affect quality of life. Overall, interferon therapy did not have a major impact on CHB patients' daily lives and work.

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.

The potential effect of HBV vaccination on off-treatment HBsAg reversion after interferon-induced HBsAg clearance

Off-treatment HBsAg reversion occurs in a considerable number of chronic hepatitis B(CHB) patients after IFN(interferon)-induced HBsAg clearance. HBV vaccination protects the general population against HBV infection. However, it remains unclear whether HBV vaccination could prevent off-treatment HBsAg reversion in CHB patients with HBsAg clearance. CHB patients (n = 199) with HBsAg clearance were included in the current study, comprising spontaneous HBsAg clearance group (n = 51), NA (nucleoside/nucleotide analogues)-induced group (n = 36) and IFN-induced group (n = 112). Log-rank test was performed to compare the cumulative incidences of HBsAg reversion between groups. Cox regression model was used to identify the factors associated with off-treatment HBsAg reversion. The 5-year cumulative incidence of HBsAg reversion in IFN-induced group was significantly higher than that in NA-induced group or spontaneous group (27.6% vs. 3.3% vs. 8.1%, both p < .05). In IFN-induced group, 66.7% of CHB patients received HBV vaccination. The cumulative incidence of HBsAg reversion in individuals with strong responses to HBV vaccination (HBsAb level >100mIU/ml) was significantly lower than that in those with weak responses to HBV vaccination (HBsAb level ≤100mIU/ml) or without HBV vaccination in IFN-induced group (7.7% vs. 58.5% vs. 31.9%, both p < .05). Multivariate Cox regression analysis confirmed strong responses to HBV vaccination were independently associated with a lower cumulative incidence of HBsAg reversion after IFN-induced HBsAg clearance (HR = 0.246, 95%CI: 0.066-0.907, p = .035). HBV vaccination has potential to prevent off-treatment HBsAg reversion in CHB patients after IFN-induced HBsAg clearance via a sufficiently high level of HBsAb, helping clinicians optimize the clinical management of such patients.

Guidance on treatment endpoints and study design for clinical trials aiming to achieve cure in chronic hepatitis B and D: Report from the 2022 AASLD-EASL HBV-HDV Treatment Endpoints Conference

Representatives from academia, industry, regulatory agencies, and patient advocacy groups convened under the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) in June 2022 with the primary goal of achieving consensus on chronic HBV and HDV treatment endpoints to guide clinical trials aiming to "cure" HBV and HDV. Conference participants reached an agreement on some key points. The preferred primary endpoint for phase II/III trials evaluating finite treatments for chronic hepatitis B (CHB) is a "functional" cure, defined as sustained HBsAg loss and HBV DNA less than the lower limit of quantitation (LLOQ) 24 weeks off-treatment. An alternate endpoint would be "partial cure" defined as sustained HBsAg level <100 IU/mL and HBV DNA Collapse

Key Words

• HBV
• HDV
• diagnosis

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MESH Headings

• Humans
• Hepatitis B, Chronic/drug therapy
• Hepatitis B, Chronic/virology
• Hepatitis B, Chronic/therapy
• Antiviral Agents/therapeutic use
• Hepatitis D, Chronic/drug therapy
• Hepatitis Delta Virus/genetics
• Research Design
• Clinical Trials as Topic/methods
• DNA, Viral/blood
• DNA, Viral/analysis
• Hepatitis B virus/genetics
• Hepatitis B Surface Antigens/blood
• Endpoint Determination/methods
• Treatment Outcome
• Clinical Trials, Phase II as Topic/methods

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Grants

• 001 World Health Organization

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Affiliation(s)

Marc G Ghany Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
Maria Buti Liver Unit, Vall d'Hebron University Hospital and CIBEREHD del Instituto Carlos III, Barcelona, Spain
Pietro Lampertico Division of Gastroenterology and Hepatology, Milan, Italy; CRC "A. M. and A. Migliavacca" Center for Liver Disease, Milan, Italy
Hannah M Lee Department of Gastroenterology, Hepatology and Nutrition, Stravitz Sanyal Institute for Liver Disease and Metabolic Health, Virginia Commonwealth University, Richmond, Virginia, USA

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Collaborators Collapse

Immunomodulatory and Antiviral Therapy Improved Functional Cure Rate in CHB Patients with High HBsAg Level Experienced NA

BACKGROUND AND AIMS

A functional cure, or hepatitis B virus (HBV) surface antigen (HBsAg) loss, is difficult to achieve in patients with hepatitis B virus e antigen (HBeAg)-positive chronic hepatitis B. The HBV vaccine and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been reported to help reduce HBsAg levels and promote HBsAg loss. In this prospective randomized trial, we evaluated HBsAg loss in patients receiving pegylated interferon-α2b (PEGIFN-α2b) and tenofovir disoproxil fumarate (TDF), with and without GM-CSF and HBV vaccination.

METHODS

A total of 287 patients with HBeAg positive chronic hepatitis B and seroconversion after nucleot(s)ide analog treatment were assigned randomly to three treatment groups for 48 weeks, TDF alone (control), PEGIFN-α2b + TDF, and PEGIFN-α2b + TDF + GM-CSF + HBV vaccine. The primary endpoints were the proportions of patients with HBsAg loss and seroconversion at 48 and 72 weeks.

RESULTS

The cumulative HBsAg loss rates in the control, PEGIFN-α2b + TDF, and PEGIFN-α2b + TDF + GM-CSF + HBV vaccine groups at week 48 were 0.0%, 28.3%, and 41.1%, respectively. The cumulative HBsAg seroconversion rates in these groups at week 48 were 0.0%, 21.7%, and 33.9%, respectively. Multivariate regression analysis showed that GM-CSF use plus HBV vaccination was significantly associated with HBsAg loss (p=0.017) and seroconversion (p=0.030).

CONCLUSIONS

In patients with HBeAg-positive chronic hepatitis B and seroconversion after nucleot(s)ide analog treatment, immunomodulatory/antiviral treatment regimens effectively improved HBsAg loss, and the regimen including GM-CSF and HBV vaccination was most effective.

A real-world retrospective single-centre study of the cost-effectiveness and long-term outcomes of pegylated interferon for chronic hepatitis B

Background

Pegylated interferon (Peg-IFN) is recommended as first-line therapy for chronic hepatitis B (CHB) but has significant side effects and is rarely used compared to oral nucleos(t)ide analogues (NA). There are limited recent clinical efficacy or economic analysis data comparing approved CHB therapy in North America.

Methods

This retrospective study examined clinical outcomes, off-treatment durability, and cost-effectiveness of Peg-IFN versus NA for CHB. Demographic (age, sex, ethnicity), clinical data (i.e., liver tests, hepatitis B virus DNA, serology, transient elastography) and documented side effects were collected by retrospective chart review of patients followed in the University of Calgary Liver Unit who received Peg-IFN therapy from January 2007 to December 2020. The cost-effectiveness of Peg-IFN versus NA therapy was modelled over a 10-year time horizon.

Results

Sixty-eight CHB patients were treated with Peg-IFN (median age 45.65, 74% male, 84% Asian); 50/68 (74%) completed 48 weeks of treatment with a median follow-up of 6.54 years (interquartile range 5.07). At the last known follow-up, 23/68 (34%) have not required NA treatment and one had HBsAg loss; 27 have been started on NA. Predictors of obtaining a sustained virological response included being hepatitis B e antigen-negative at treatment end and a quantitative hepatitis B surface antigen <1000 IU/mL. Economic modelling showed that finite Peg-IFN was not cost-effective versus NA at a 10-year time horizon.

Conclusions

PEG-IFN remains a potential treatment for CHB although there is a significant intolerance/failure rate. Using PEG-IFN based on patient preference is reasonable and optimal patient selection may improve treatment cost-effectiveness.

Interferon-based treatment of chronic hepatitis D

Treatment of hepatitis D virus (HDV) infection has been based on the administration of interferon-alfa for more than three decades. First studies to treat HDV-infected patients with type 1 interferons were already performed in the 1980s. Several smaller trials and case series were reported thereafter. During the mid 2000s the use of pegylated interferons for hepatitis D was established. Since then, additional trials were performed in different countries exploring strategies to personalize treatment including extended treatment durations. The overall findings were that about one-quarter to one-third of patients benefit from interferon treatment with persistent suppression of HDV replication. However, only few patients achieve also functional cure of hepatitis B with HBsAg loss. Importantly, several studies indicate that successful interferon treatment is associated with improved clinical long-term outcomes. Still, only a proportion of patients with hepatitis D can be treated with interferons. Even though alternative treatments are currently developed, it is likely that pegylated interferon-alfa will still have an important role in the management of hepatitis D - either alone or in combination. Therefore, better biomarkers are needed to select patients with a high likelihood to benefit from interferon-based treatments. In this review we are discussing basic principles of mode of action of interferon alpha against HDV, summarize previous data on interferon treatment of hepatitis D and give an outlook on potential combinations with novel drugs currently in development.

Development of Therapy Based on the Exploration of Biological Events Underlying the Pathogenetic Mechanisms of Chronic Hepatitis B Infection

According to the World Health Organization (WHO), an estimated 296 million people are chronically infected with hepatitis B virus (HBV). Approximately 15-25% of these people develop complications such as advanced chronic liver diseases (ACLDs). Mortality due to HBV-related complications accounted for an estimated 882,000 deaths in 2019. Potent preventive vaccines have already restricted new HBV infections, and several drugs are available to treat chronic HBV infections. However, the positive impacts of these drugs have been recorded in only a few patients with chronic HBV infection. These drugs do not show long-term efficacy and cannot halt the progression to complications. Thus, more effective and evidence-based therapeutic strategies need to be urgently developed for patients with chronic HBV infection. CHB is a pathological entity induced by HBV that progresses due to impaired host immunity. This indicates the inherent limitations of antiviral-drug-based monotherapy for treating patients with chronic HBV infection. Additionally, commercially available antiviral drugs are not available to patients in developing and resource-constrained countries, posing a challenge to achieving the following WHO goal: "Elimination of Hepatitis by 2030". As such, this review aimed to provide insights regarding evidence-based and effective management strategies for chronic HBV infection.

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.

Randomized Trial of Tenofovir With or Without Peginterferon Alfa Followed by Protocolized Treatment Withdrawal in Adults With Chronic Hepatitis B

INTRODUCTION

Hepatitis B surface antigen (HBsAg) loss is associated with improved long-term outcomes of patients with chronic hepatitis B but is infrequently achieved with current monotherapies. We assessed whether combination strategies that included treatment withdrawal enhanced HBsAg loss.

METHODS

A randomized (1:1) trial of tenofovir disoproxil fumarate (TDF) for 192 weeks with or without peginterferon (PegIFN) alfa-2a for the first 24 weeks, followed by withdrawal of TDF at week 192 with 48 weeks of off-treatment follow-up to week 240. The primary end point was HBsAg loss at week 240.

RESULTS

Of 201 participants (52% HBeAg positive, 12%/6% genotype A/A2, 7% cirrhosis) randomized to TDF + PegIFN (n = 102) or TDF alone (n = 99), 6 participants had lost HBsAg at the end of the treatment phase (week 192), 5 (5.3%) in the combination group, and 1 (1.0%) in the TDF alone group ( P = 0.09). By week 240, 9 participants had cleared HBsAg, 5.3% in combination, and 4.1% in monotherapy arms ( P = 0.73). HBsAg decline and loss occurred earlier with TDF + PegIFN than TDF, with a ≥1-logIU/mL qHBsAg decline by week 24 in 28% in TDF + PegIFN compared with 6% in TDF ( P = 0.04). HBsAg loss occurred in 7 of 12 (58%) with hepatitis B virus subgenotype A2 (all HBeAg positive) compared with only 2 of 189 (1%) with other hepatitis B virus genotypes and in 8 of 93 (8.6%) HBeAg positive vs 1 of 87 (1.1%) HBeAg negative.

DISCUSSION

PegIFN combined TDF followed by protocolized TDF withdrawal led to earlier but not higher percentages of HBsAg clearance. Pretreatment HBeAg positivity and subgenotype A2 were strongly associated with HBsAg clearance.

CXCL13 variant predicts pegylated-interferon α treatment response in HBeAg-positive chronic hepatitis B patients

As a key immune cytokine, C-X-C motif chemokine ligand 13 (CXCL13) has been reported to play critical roles in immune control of hepatitis B virus (HBV) infection. We aimed to screen single-nucleotide polymorphisms (SNPs) of CXCL13 for predicting response to pegylated interferon-alpha (PegIFNα) therapy of chronic hepatitis B (CHB) patients. Two independent cohorts with a total of 945 (Cohort 1, n = 238; Cohort 2, n = 707) hepatitis B e antigen (HBeAg)-positive CHB patients treated with PegIFNα were enrolled in this retrospective cohort study. Eight candidate SNPs were selected through gene-wide SNP mining within or flanking CXCL13. A polygenic score (PGS) was utilized to assess the cumulative effects of multiple SNPs. The associations of candidate SNPs and PGS with combined response (CR, defined as the combination of HBeAg seroconversion and HBV DNA level <3.3log10 IU/mL) and hepatitis B surface antigen (HBsAg) level were evaluated. Among the eight candidate SNPs, rs76084459 which is located at upstream of CXCL13 was significantly associated with both CR (p = 0.002) and HBsAg level (p = 0.015). A PGS integrating CXCL13_rs76084459 and five other SNPs, which were previously identified as predictors of PegIFNα treatment response, was further strongly correlated with CR (p = 1.759 × 10-10 ) and HBsAg level (p = 0.004). This study demonstrated that CXCL13_rs76084459 can predict response to PegIFNα treatment of HBeAg-positive CHB patients. A PGS composed of six SNPs including CXCL13_rs76084459 predicts PegIFNα treatment response better.

Comparison of Pegylated Interferon Alfa Therapy in Combination with Tenofovir Alafenamide Fumarate or Tenofovir Disoproxil Fumarate for Treatment of Chronic Hepatitis B Patients

Purpose

The study aims to evaluate the effectiveness of a tenofovir alafenamide fumarate (TAF) and pegylated interferon alfa (PegIFN-α) regimen compared to a tenofovir disoproxil fumarate (TDF) and PegIFN-α therapy in patients with chronic hepatitis B (CHB).

Patients and Methods

Patients who were treated with PegIFN-α in combination with TAF or TDF were retrospectively enrolled. The primary outcome measured was the HBsAg loss rate. The rates of virological response, serological response for HBeAg, and normalization of alanine aminotransferase (ALT) were also calculated. The cumulative incidences of response rates were compared between the two groups using Kaplan-Meier analysis.

Results

A total of 114 patients were retrospectively enrolled in the study, with 33 receiving TAF plus PegIFN-α treatment and 81 receiving TDF plus PegIFN-α treatment. The HBsAg loss rate for the TAF plus PegIFN-α group was 15.2% at 24 weeks and 21.2% at 48 weeks, while the TDF plus PegIFN-α group had rates of 7.4% at 24 weeks and 12.3% at 48 weeks (P=0.204 at 24 weeks, P=0.228 at 48 weeks). In subgroup analysis of HBeAg positive patients, the TAF group had a higher HBsAg loss rate of 25% at week 48, compared to 3.8% in the TDF group (P=0.033). According to Kaplan-Meier analysis, the TAF plus PegIFN-α group achieved virological response more quickly than the TDF plus PegIFN-α group (p=0.013). There was no statistical difference in HBeAg serological rate or ALT normalization rate.

Conclusion

There was no significant difference in the HBsAg loss between the two groups. However, subgroup analysis revealed that TAF plus PegIFN-α treatment had a higher HBsAg loss rate than TDF plus PegIFN-α treatment in HBeAg-positive patients. Additionally, TAF plus PegIFN-α treatment demonstrated better virological suppression for CHB patients. Therefore, TAF plus PegIFN-α treatment regimen is recommended for CHB patients who aim to achieve functional cure.

Chronic hepatitis B: a scoping review on the guidelines for stopping nucleos(t)ide analogue therapy

INTRODUCTION

Nucleos(t)ide analogues (NAs) are effective in suppressing the replication of the hepatitis B virus. However, NAs cannot effectively induce hepatitis B surface antigen (HBsAg) seroclearance, which represents the optimal treatment endpoint in chronic hepatitis B (CHB). Hence, most CHB patients are advised for indefinite NA therapy, but recent data has supported the concept of finite NA therapy before HBsAg seroclearance.

AREAS COVERED

This article covered the latest evidence on stopping NAs in CHB, with a focused analysis on international guidelines. Articles were retrieved by a literature search on PubMed with the keywords 'chronic hepatitis B,' 'antiviral therapy,' 'nucleos(t)ide analogue,' 'cessation,' 'stopping', and 'finite.' Studies up till 1 December 2022 were included.

EXPERT OPINION

Finite NA therapy in CHB has the potential in enhancing HBsAg seroclearance, however it also carries rare but potentially severe risks. NA cessation before HBsAg seroclearance is only suitable for a highly selected group of patients, whereas the majority of CHB patients should be treated indefinitely or until HBsAg seroclearance. Current guidelines have provided recommendations on stopping NAs, but further research is required to optimize the monitoring and retreatment protocol after stopping NAs.

What will it take to cure hepatitis B?

The current treatment of chronic HBV infection, pegylated interferon-α (pegIFNα) and nucleos(t)ide analog (NA), can suppress HBV replication, reverse liver inflammation and fibrosis and reduce the risks of cirrhosis, HCC, and HBV-related deaths, but relapse is common when the treatment is stopped before HBsAg loss. There have been major efforts to develop a cure for HBV, defined as sustained HBsAg loss after a finite course of therapy. This requires the suppression of HBV replication and viral protein production and the restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. Immune modulatory therapies to stimulate adaptive or innate immunity and/or to remove immune blockade are being tested. NAs are included in most and pegIFNα in some regimens. Despite the combination of 2 or more therapies, HBsAg loss remains rare in part because HbsAg can be derived not only from the covalently closed circular DNA but also from the integrated HBV DNA. Achievement of a functional HBV cure will require therapies to eliminate or silence covalently closed circular DNA and integrated HBV DNA. In addition, assays to differentiate the source of circulating HBsAg and to determine HBV immune recovery, as well as standardization and improvement of assays for HBV RNA and hepatitis B core-related antigen, surrogate markers for covalently closed circular DNA transcription, are needed to accurately assess response and to target treatments according to patient/disease characteristics. Platform trials will allow the comparison of multiple combinations and channel patients with different characteristics to the treatment that is most likely to succeed. Safety is paramount, given the excellent safety profile of NA therapy.

Possible biological mechanisms of entecavir versus tenofovir disoproxil fumarate on reducing the risk of hepatocellular carcinoma

Hepatitis B virus (HBV) is a life-threatening infectious virus associated with the risk of liver failure and hepatocellular carcinoma (HCC). Regarding HBV treatment, the recent development of nucleoside/nucleotide analogs (NUC), HBV reverse transcriptase inhibitors, enabled favorable viral control as well as improved prognosis in patients with chronic hepatitis B. However, NUC fails to clear HBV because the formation of covalently closed circular DNA or HBV surface antigen occurs upstream of the point of action of NUC. Recently, we found that acyclic nucleoside phosphonates (ANP) such as adefovir or tenofovir, but not lamivudine or entecavir, induced IFN-λ3 productions in the gastrointestinal tract and modulated lipopolysaccharide (LPS)-mediated cytokine profiles in peripheral blood mononuclear cells, such as interleukin (IL)-12p70 induction and IL-10 inhibition, which are immunologically favorable cytokine profiles for HBV elimination. Furthermore, IFN-α, in combination with ANP, showed additional and synergistic effects on IFN-λ3 and IL-12p70 production, respectively, while not affecting IL-10 levels. Mechanistic analyses of the cytokine modulation by ANP revealed that ANP blocked the mammalian target of the rapamycin (mTOR) pathway by inhibiting Akt translocation to the plasma membrane, thereby inhibiting Akt phosphorylation. As it has been reported that IFN-λ inhibits tumor growth directly or indirectly and the mTOR pathway is generally activated in most cancer cells, ANP might have potential anti-HCC effects. Our in vitro and ex vivo findings might stir the debate on whether types of NUC affect the risk of HBV-related HCC incidence.

Predicting the loss of hepatitis B surface antigen following haematopoietic stem cell transplantation in patients with chronic HBV infection

Clearance of hepatitis B surface antigen (HBsAg) is an ideal therapeutic goal for patients with chronic hepatitis B virus (HBV) infection. Haematopoietic stem cell transplantation (HSCT) is the most effective therapy for a variety of haematological diseases. For patients with chronic HBV infection who received allo-HSCT, recipient hepatitis B serological status might change after allo-HSCT; however, data on the loss of HBsAg following allo-HSCT are relatively rare. We first reviewed patients with chronic HBV infection who received allo-HSCT in our centre from 2010 to 2020, and 125 patients were included in our study. A total of 62 patients (49.6%) with chronic HBV infection achieved HBsAg loss after allo-HSCT. Positivity for HBeAb and HBsAb in donors as well as no cytomegalovirus (CMV) infection were identified as independent risk factors for HBsAg loss after allo-HSCT. A predictive model including positivity for HBeAb and HBsAb in donors and no CMV infection was subsequently developed and performed well with effective discrimination and calibration. In addition, patients could benefit when this model is used in the clinic, as revealed via decision-curve analysis (DCA). However, multicentre prospective studies are required for validation.

Therapies against chronic hepatitis B infections: The times they are a-changin', but the changing is slow!

PREAMBULAR NOTA BENE

As a tribute to Dr Mike Bray, the following review of literature willbe mainly based on published data andconcepts, but will also contain my personal views, and in this respect could be more considered as a bioassay. Even though a cost-effective and excellent prophylactic vaccine exists since many years to protect against hepatitis B virus (HBV) infection, academic-researcher/drug-developers/stakeholders are still busy with the R&D of novel therapies that could eventually have an impact on its worldwide incidence. The Taiwanese experience have univocally demonstrated the effectiveness of constrained national HBV prophylactic vaccination programs to prevent the most dramatic HBV-induced end-stage liver disease, which is hepatocellular carcinoma; but yet the number of individuals chronically infected with the virus, for whom the existing prophylactic vaccine is no longer useful, remains high, with around 300 million individuals around the globe. In this review/bioassay, recent findings and novel concepts on prospective therapies against HBV infections will be discussed; yet it does not have the pretention to be exhaustive, as "pure immunotherapeutic concepts" will be mainly let aside (or referred to other reviews) due to a lack of expertise of this writer, but also due to the lack of, or incremental, positive results in clinical trials as-off today with these approaches.

Serum IL-5 levels predict HBsAg seroclearance in patients treated with Nucleos(t)ide analogues combined with pegylated interferon

Background

Knowing about cytokine profile contributes to clarify the underling immune mechanism of HBsAg seroclearance rate increase. This study aims to investigate cytokine changes during nucleos(t)ide analogues (NAs) and peginterferon-α (Peg-IFNα) therapy and their impact on the HBsAg serologic response.

Methods

A total of 78 HBV DNA-negative chronic Hepatitis B (CHB) patients were studied after a lead-in phase of NAs with complete serum cytokines. Serum cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-17 and TNF-α) were quantified by flow cytometry (FCM) every 24 weeks, before, during and at the end of NAs and Peg-IFNα treatment. Clinical and laboratory data were also taken at the same time. Analysis was performed between cured and uncured groups characterized by HBsAg seroclearance. PBMCs samples from five patients (two in cured group and three in uncured group) were analyzed by FCM.

Results

HBsAg seroclearance was achieved in 30 (38,5%) patients defined as the cured group. In comparison to uncured individuals, cured patients showed similar expressions of serum IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17 and TNF-α during the treatment of NAs and Peg-IFNα. Compared with the uncured groups, IL-5 was remarkably increased in cured patients. IL-5 at weeks 24 and 48 were associated with HBsAg seroconversion (p=0.033 and 0.027, respectively). PBMCs sample analysis confirmed the predicted value of IL-5 in response to NAs and Peg-IFNα treatment.

Conclusions

IL-5 at weeks 24 and 48 might be used as a biomarker for HBsAg seroclearance in NAs-experienced CHB patients treated with NAs combined with Peg-IFNα. More importantly, exploiting the expression of this cytokine may help to develop a better understanding of the immune pathogenesis of chronic HBV infection.

Preclinical characterization of ABI-H2158, an HBV core inhibitor with dual mechanisms of action

The HBV core protein plays an integral role in multiple steps of the HBV lifecycle. Consequently, HBV core inhibitors interrupt multiple steps of the replication cycle, including blocking pgRNA encapsidation and prematurely disassembling existing nucleocapsids, thereby preventing them from transporting relaxed circular (rcDNA) to the nucleus for conversion to covalently closed circular DNA (cccDNA). ABI-H2158 is an HBV core inhibitor that advanced into Phase 2 clinical trials for the treatment of chronic hepatitis B virus infection (cHBV) but was discontinued due to hepatotoxicity. Here, the potency, selectivity, and mechanisms of action of ABI-H2158 were evaluated using a variety of cell-based assays. Antiviral activity was measured by quantifying intracellular or secreted HBV DNA, RNA, and antigens. ABI-H2158 inhibited HBV replication by blocking pgRNA encapsidation in induced HepAD38 cells (EC₅₀ = 22 nM) and had similar potency in HBV-infected HepG2-NTCP cells (EC₅₀ = 27 nM) and primary human hepatocytes (PHH) (EC₅₀ = 41 nM). ABI-H2158 is a pan-genotypic HBV inhibitor, with EC₅₀s ranging from 7.1 to 22 nM across HBV genotypes A-E. ABI-H2158 also potently blocked the formation of cccDNA in de novo HBV infections with EC₅₀s of ∼200 nM in HepG2-NTCP and PHH assays. These results indicate ABI-H2158 has dual mechanisms of action, inhibiting both early and late steps of the HBV replication cycle.

End-of-treatment anti-HBs levels and HBeAg status identify durability of HBsAg loss after PEG-IFN discontinuation

Background

Hepatitis B surface antigen (HBsAg) loss, namely, the functional cure, can be achieved through the pegylated interferon (PEG-IFN)-based therapy. However, it is an unignorable fact that a small proportion of patients who achieved functional cure develop HBsAg reversion (HRV) and the related factors are not well described.

Methods

A total of 112 patients who achieved PEG-IFN-induced HBsAg loss were recruited. HBV biomarkers and biochemical parameters were examined dynamically. HBV RNA levels were assessed in the cross-sectional analysis. The primary endpoint was HRV, defined as the reappearance of HBsAg after PEG-IFN discontinuation.

Results

HRV occurred in 17 patients during the follow-up period. Univariable analysis indicated that hepatitis B e antigen (HBeAg) status, different levels of hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) at the end of PEG-IFN treatment (EOT) were significantly associated with the incidence of HRV through using the log-rank test. Additionally, time-dependent receiver operating characteristic (ROC) analysis showed that the anti-HBs was superior to anti-HBc in predictive power for the incidence of HRV during the follow-up period. Multivariable Cox proportional hazard analysis found that anti-HBs ≥1.3 log₁₀IU/L (hazard ratio (HR), 0.148; 95% confidence interval (CI), 0.044-0.502) and HBeAg negativity (HR, 0.183; 95% CI, 0.052-0.639) at EOT were independently associated with lower incidence of HRV. Cross-sectional analysis indicated that the HBV RNA levels were significantly correlated with the HBsAg levels in patients with HRV (r=0.86, p=0.003).

Conclusions

EOT HBeAg negativity and anti-HBs ≥1.3 log₁₀IU/L identify the low risk of HRV after PEG-IFN discontinuation.

Sequence characterization of extracellular HBV RNA in patient plasma

Antiviral nucleos(t)ide analogue therapies inhibit HBV replication and suppress the HBV DNA levels in patients with chronic HBV infection. Since HBV RNAs are expressed from cccDNA or HBV integrated sequences, independently of viral genome replication, levels of HBV RNAs in plasma may remain high following treatment with nucleos(t)ide analogue. Thus, HBV RNAs have been proposed to be used as a viral biomarker for treatment outcome and disease progression. Recent investigations of plasma HBV RNAs described the presence of full length as well as subgenomic forms of RNA. To support the usage of plasma HBV RNAs as a viral biomarker, further understanding of HBV RNA composition in clinical samples is needed. Here, sequence of extracellular HBV RNAs was characterized in plasma samples of patients with chronic HBV infection using two independent RNA amplification methods that do not use HBV-specific primers for amplification: total RNA (NuGEN RNAseq) and mRNA (TruSeq RNAseq). Sequencing coverage was obtained across the full length of HBV genome for both methods, confirming the presence of full-length HBV RNA in plasma. The sequence of HBV RNA was nearly identical to plasma HBV DNA sequence in each sample with only 0-14 (median 4) mismatches over 3 kb. Thus, sequence of HBV RNA plasma reflects the intrahepatic viral reservoir and can be used for monitoring of sequence variants such as resistance in clinical trials. Additionally, RNA splice forms, different polyA tails start positions and presence of HBV-human chimeric transcript were identified.

Reduction of Hepatitis B Surface Antigen May Be More Significant in PEGylated Interferon-Alpha Therapy Combined with Nucleotide Analogues than Combined with Nucleoside Analogues in Chronic Hepatitis B Patients: A Propensity Score Matching Study

Background

Nucleotide analogues (NTs) monotherapy may have a more significant effect on reducing hepatitis B surface antigen (HBsAg) than nucleoside analogues (NSs) due to their immunomodulatory function. However, this superiority remains unknown when combined with PEGylated interferon α (PegIFNα). Therefore, this study aimed to explore whether NTs have more significant antiviral effects than NSs in combination therapy with PegIFNα.

Methods

Chronic hepatitis B (CHB) patients treated with PegIFNα plus nucleos(t)ide analogues (NAs) were retrospectively recruited. Efficacy and the predictors of hepatitis B surface antigen (HBsAg) reduction >1 log10 IU/mL after 48 weeks were analyzed.

Results

A total of 95 patients were included and divided into the PegIFNα + NTs group and the PegIFNα + NSs group. Propensity score matching (PSM) was performed. The PegIFNα + NTs group had a greater reduction of HBsAg (-3.52 vs. -2.33 log10 IU/mL, P=0.032) and a higher proportion of patients with HBsAg reduction >1 log10 IU/mL (100.0% vs. 72.2%, P=0.003) even after PSM. However, HBsAg and hepatitis B e-antigen (HBeAg) loss rates, HBeAg seroconversion rates, degree of HBeAg and hepatitis B virus (HBV) DNA decline, HBV DNA undetectable rates, and alanine aminotransferase (ALT) normalization rates showed no significant differences. Subgroup analyses showed the difference in the reduction of HBsAg was particularly evident in HBeAg-positive and the "add-on" subgroups. PegIFNα plus NTs (OR = 36.667, 95% CI = 3.837-350.384) was an independent predictor for HBsAg reduction >1 log10 IU/mL after 48 weeks.

Conclusion

This study suggests that PegIFNα plus NTs may lead to more HBsAg reduction, especially in HBeAg-positive and "add-on" patients.

Functional molecular expression of nature killer cells correlated to HBsAg clearance in HBeAg-positive chronic hepatitis B patients during PEG-IFN α-2a therapy

OBJECTIVE

To explore whether the frequencies and functional molecules expression of Natural Killer cells (NK cells) are related to hepatitis B surface antigen (HBsAg) disappearance in hepatitis B e envelope antigen (HBeAg)-positive patients with chronic hepatitis B (CHB) throughout peginterferon alpha-2a (PEG-IFN α-2a) treatment.

METHODS

In this prospective research, HBeAg-positive patients with CHB received PEG-IFN α-2a treatment, completing 4-year follow-up. After PEG-IFN α-2a treatment, undetectable HBV DNA, HBsAg loss, and HBeAg disappearance were defined as functional cure. Proportions of NK, CD56dim, CD56bright, NKp46+, NKp46dim, NKp46high, and interferon alpha receptor 2 (IFNAR2)+ NK cells, and the mean fluorescence intensity (MFI) of NK cell surface receptors IFNAR2 and NKp46 were detected.

RESULTS

66 patients were enrolled into the study in which 17 patients obtained functional cure. At baseline, hepatitis B virus desoxyribose nucleic acid (HBV DNA) titer in patients with functional cure was remarkably lower than that in Non-functional cure group. Compared with baseline, HBV DNA levels, HBsAg levels, and HBeAg levels significantly declined at week 12 and 24 of therapy in patients with functional cure. At baseline, the negative correlation between CD56bright NK% and HBV DNA and the negative correlation between CD56dim NK% and HBV DNA was showed; CD56bright NK% and IFNAR2 MFI in patients with functional cure were remarkably higher than those in patients without functional cure. After therapy, CD56bright NK% and NKp46high NK% in patients with functional cure were higher than those in patients without functional cure. In Functional cure group, after 24 weeks of treatment NK%, CD56bright NK%, IFNAR2 MFI weakly increased, and NKp46high NK% and NKp46 MFI significantly increased, meanwhile, CD56dim NK% and NKp46dim NK% decreased. Only NKp46 MFI increased after therapy in patients without functional cure.

CONCLUSION

The lower HBV DNA load and the higher CD56bright NK% before therapy, and the higher the post-treatment CD56bright NK%, IFNAR2 MFI, NKp46high NK%, the easier to achieve functional cure.