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Gopalakrishna H, Ghany MG. Perspective on Emerging Therapies to Achieve Functional Cure of Chronic Hepatitis B. CURRENT HEPATOLOGY REPORTS 2024; 23:241-252. [PMID: 38699562 PMCID: PMC11062629 DOI: 10.1007/s11901-024-00652-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/24/2024] [Indexed: 05/05/2024]
Abstract
Purpose of Review Advancements in our understanding of the hepatitis B viral (HBV) life cycle have paved the way for novel approaches to treat HBV infection. This review summarizes the various strategies being pursued to achieve a functional cure, defined as loss of hepatitis B surface antigen (HBsAg) and absence of viral replication 6 months off-therapy. Recent Findings Direct acting antiviral, host targeting antiviral, and immunological approaches are in various stages of development as treatment for chronic HBV infection. Summary Novel treatments are being developed in pursuit of a cure for HBV. Current evidence suggests a single therapeutic agent alone may be insufficient, necessitating the need for combination therapy targeting HBV and the host immune response. Ongoing research focused on identifying the best therapeutic combination holds promise in achieving functional cure for HBV.
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Affiliation(s)
- Harish Gopalakrishna
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 10 Center Drive, Building 10, Room 9B-16, Bethesda, MD 20892‐1800, USA
| | - Marc G. Ghany
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 10 Center Drive, Building 10, Room 9B-16, Bethesda, MD 20892‐1800, USA
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Smekalova EM, Martinez MG, Combe E, Kumar A, Dejene S, Leboeuf D, Chen CY, Dorkin JR, Shuang LS, Kieft S, Young L, Barrera LA, Packer MS, Ciaramella G, Testoni B, Gregoire F, Zoulim F. Cytosine base editing inhibits hepatitis B virus replication and reduces HBsAg expression in vitro and in vivo. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102112. [PMID: 38292874 PMCID: PMC10825689 DOI: 10.1016/j.omtn.2023.102112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/21/2023] [Indexed: 02/01/2024]
Abstract
Chronic hepatitis B virus (HBV) infection remains a global health problem due to the lack of treatments that prevent viral rebound from HBV covalently closed circular (ccc)DNA. In addition, HBV DNA integrates in the human genome, serving as a source of hepatitis B surface antigen (HBsAg) expression, which impairs anti-HBV immune responses. Cytosine base editors (CBEs) enable precise conversion of a cytosine into a thymine within DNA. In this study, CBEs were used to introduce stop codons in HBV genes, HBs and Precore. Transfection with mRNA encoding a CBE and a combination of two guide RNAs led to robust cccDNA editing and sustained reduction of the viral markers in HBV-infected HepG2-NTCP cells and primary human hepatocytes. Furthermore, base editing efficiently reduced HBsAg expression from HBV sequences integrated within the genome of the PLC/PRF/5 and HepG2.2.15 cell lines. Finally, in the HBV minicircle mouse model, using lipid nanoparticulate delivery, we demonstrated antiviral efficacy of the base editing approach with a >3log10 reduction in serum HBV DNA and >2log10 reduction in HBsAg, and 4/5 mice showing HBsAg loss. Combined, these data indicate that base editing can introduce mutations in both cccDNA and integrated HBV DNA, abrogating HBV replication and silencing viral protein expression.
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Affiliation(s)
| | - Maria G. Martinez
- INSERM U1052, Cancer Research Center of Lyon, CNRS UMR 5286, 69008 Lyon, France
- University of Lyon, UMR_S1052, UCBL, 69008 Lyon, France
- Hepatology Institute of Lyon, 69008 Lyon, France
| | - Emmanuel Combe
- INSERM U1052, Cancer Research Center of Lyon, CNRS UMR 5286, 69008 Lyon, France
- University of Lyon, UMR_S1052, UCBL, 69008 Lyon, France
- Hepatology Institute of Lyon, 69008 Lyon, France
| | - Anuj Kumar
- INSERM U1052, Cancer Research Center of Lyon, CNRS UMR 5286, 69008 Lyon, France
- University of Lyon, UMR_S1052, UCBL, 69008 Lyon, France
- Hepatology Institute of Lyon, 69008 Lyon, France
| | | | | | | | | | | | | | | | | | | | | | - Barbara Testoni
- INSERM U1052, Cancer Research Center of Lyon, CNRS UMR 5286, 69008 Lyon, France
- University of Lyon, UMR_S1052, UCBL, 69008 Lyon, France
- Hepatology Institute of Lyon, 69008 Lyon, France
| | | | - Fabien Zoulim
- INSERM U1052, Cancer Research Center of Lyon, CNRS UMR 5286, 69008 Lyon, France
- University of Lyon, UMR_S1052, UCBL, 69008 Lyon, France
- Hepatology Institute of Lyon, 69008 Lyon, France
- Hepatology Department, Hospices Civils de Lyon (HCL), 69004 Lyon, France
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Hu JL, Huang AL. Classifying hepatitis B therapies with insights from covalently closed circular DNA dynamics. Virol Sin 2024; 39:9-23. [PMID: 38110037 PMCID: PMC10877440 DOI: 10.1016/j.virs.2023.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 12/13/2023] [Indexed: 12/20/2023] Open
Abstract
The achievement of a functional cure for chronic hepatitis B (CHB) remains limited to a minority of patients treated with currently approved drugs. The primary objective in developing new anti-HBV drugs is to enhance the functional cure rates for CHB. A critical prerequisite for the functional cure of CHB is a substantial reduction, or even eradication of covalently closed circular DNA (cccDNA). Within this context, the changes in cccDNA levels during treatment become as a pivotal concern. We have previously analyzed the factors influencing cccDNA dynamics and introduced a preliminary classification of hepatitis B treatment strategies based on these dynamics. In this review, we employ a systems thinking perspective to elucidate the fundamental aspects of the HBV replication cycle and to rationalize the classification of treatment strategies according to their impact on the dynamic equilibrium of cccDNA. Building upon this foundation, we categorize current anti-HBV strategies into two distinct groups and advocate for their combined use to significantly reduce cccDNA levels within a well-defined timeframe.
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Affiliation(s)
- Jie-Li Hu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China.
| | - Ai-Long Huang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China.
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Hillaire MLB, Lawrence P, Lagrange B. IFN-γ: A Crucial Player in the Fight Against HBV Infection? Immune Netw 2023; 23:e30. [PMID: 37670813 PMCID: PMC10475827 DOI: 10.4110/in.2023.23.e30] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/04/2023] [Accepted: 05/21/2023] [Indexed: 09/07/2023] Open
Abstract
About 0.8 million people die because of hepatitis B virus (HBV) infection each year. In around 5% of infected adults, the immune system is ineffective in countering HBV infection, leading to chronic hepatitis B (CHB). CHB is associated with hepatocellular carcinoma, which can lead to patient death. Unfortunately, although current treatments against CHB allow control of HBV infection, they are unable to achieve complete eradication of the virus. Cytokines of the IFN family represent part of the innate immune system and are key players in virus elimination. IFN secretion induces the expression of interferon stimulated genes, producing proteins that have antiviral properties and that are essential to cell-autonomous immunity. IFN-α is commonly used as a therapeutic approach for CHB. In addition, IFN-γ has been identified as the main IFN family member responsible for HBV eradication during acute infection. In this review, we summarize the key evidence gained from cellular or animal models of HBV replication or infection concerning the potential anti-HBV roles of IFN-γ with a particular focus on some IFN-γ-inducible genes.
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Affiliation(s)
| | - Philip Lawrence
- Confluence: Sciences et Humanités (EA 1598), Université Catholique de Lyon, Lyon, France
| | - Brice Lagrange
- Confluence: Sciences et Humanités (EA 1598), Université Catholique de Lyon, Lyon, France
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Laupèze B, Vassilev V, Badur S. A role for immune modulation in achieving functional cure for chronic hepatitis B among current changes in the landscape of new treatments. Expert Rev Gastroenterol Hepatol 2023; 17:1135-1147. [PMID: 37847193 DOI: 10.1080/17474124.2023.2268503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023]
Abstract
INTRODUCTION Chronic hepatitis B (CHB) is rarely cured using available treatments. Barriers to cure are: 1) persistence of reservoirs of hepatitis B virus (HBV) replication and antigen production (HBV DNA); 2) high burden of viral antigens that promote T cell exhaustion with T cell dysfunction; 3) CHB-induced impairment of immune responses. AREAS COVERED We discuss options for new therapies that could address one or more of the barriers to functional cure, with particular emphasis on the potential role of immunotherapy. EXPERT OPINION/COMMENTARY Ideally, a sterilizing cure for CHB would translate into finite therapies that result in loss of HBV surface antigen and eradication of HBV DNA. Restoration of a functional adaptive immune response, a key facet of successful CHB treatment, remains elusive. Numerous strategies targeting the high viral DNA and antigen burden and aiming to restore the host immune responses will enter clinical development in coming years. Most patients are likely to require combinations of several drugs, personalized according to virologic and disease characteristics, patient preference, accessibility, and affordability. The management of CHB is a global health priority. Expedited drug development requires collaborations between regulatory agencies, scientists, clinicians, and within the industry to facilitate testing of the best drug combinations.
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Khan N, Almajed MR, Fitzmaurice MG, Jafri SM. Developments in pharmacotherapeutic agents for hepatitis B - how close are we to a functional cure? Expert Opin Pharmacother 2023; 24:1001-1011. [PMID: 37163255 DOI: 10.1080/14656566.2023.2211259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
INTRODUCTION Hepatitis B virus (HBV) remains a public health concern given its global prevalence and potential complications including hepatocellular carcinoma (HCC). Current therapies, including nucleos(t)ide analogs (NA) and interferons (IFN), are effective in chronic treatment of HBV but rarely provide a functional cure due to inadequate host response and the presence of viral DNA. Therefore, novel therapies that enhance the innate immune response while suppressing DNA transcription may provide definitive treatment of HBV. AREAS COVERED In this review, the authors provide a brief overview of commonly used agents and their efficacy in treatment of HBV. Newer therapies with direct antiviral agents such as bepirovirsen (antisense oligonucleotide (ASO)) and entry inhibitors such as bulevirtide have shown efficacy in reducing viral load but demonstrate further reductions in conjunction with immune modulators such as therapeutic vaccines. EXPERT OPINION Combination therapy is far superior to monotherapy alone, necessitating the need for both immunomodulators and direct antiviral agents in chronic treatment of HBV. Therapies that target covalently closed circular (cccDNA) with immunomodulators like therapeutic vaccines have shown promising results and may ultimately achieve functional cure. However, therapies need to be evaluated in the context of the patient, considering both financial and socioeconomic factors.
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Affiliation(s)
- Naoshin Khan
- Department of Internal Medicine, Henry Ford Hospital, 2799 West Grand Blvd, Detroit, MI 48202, USA
| | - Mohamed Ramzi Almajed
- Department of Internal Medicine, Henry Ford Hospital, 2799 West Grand Blvd, Detroit, MI 48202, USA
| | - Mary Grace Fitzmaurice
- Pharmacy Department and Transplant Institute, Henry Ford Hospital, 2799 West Grand Blvd, Detroit, MI 48202, USA
| | - Syed-Mohammed Jafri
- Division of Gastroenterology and Hepatology, Henry Ford Hospital, 2799 West Grand Blvd, Detroit, MI 48202, USA
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Durantel D. Therapies against chronic hepatitis B infections: The times they are a-changin', but the changing is slow! Antiviral Res 2023; 210:105515. [PMID: 36603773 DOI: 10.1016/j.antiviral.2022.105515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 01/04/2023]
Abstract
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.
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Affiliation(s)
- David Durantel
- Centre International de Recherche en Infectiologie (CIRI), INSERM U1111, UMR_5308 CNRS-Université de Lyon (UCBL1), ENS de Lyon, Lyon, 69007, France.
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Dondalska A, Axberg Pålsson S, Spetz AL. Is There a Role for Immunoregulatory and Antiviral Oligonucleotides Acting in the Extracellular Space? A Review and Hypothesis. Int J Mol Sci 2022; 23:ijms232314593. [PMID: 36498932 PMCID: PMC9735517 DOI: 10.3390/ijms232314593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022] Open
Abstract
Here, we link approved and emerging nucleic acid-based therapies with the expanding universe of small non-coding RNAs (sncRNAs) and the innate immune responses that sense oligonucleotides taken up into endosomes. The Toll-like receptors (TLRs) 3, 7, 8, and 9 are located in endosomes and can detect nucleic acids taken up through endocytic routes. These receptors are key triggers in the defense against viruses and/or bacterial infections, yet they also constitute an Achilles heel towards the discrimination between self- and pathogenic nucleic acids. The compartmentalization of nucleic acids and the activity of nucleases are key components in avoiding autoimmune reactions against nucleic acids, but we still lack knowledge on the plethora of nucleic acids that might be released into the extracellular space upon infections, inflammation, and other stress responses involving increased cell death. We review recent findings that a set of single-stranded oligonucleotides (length of 25-40 nucleotides (nt)) can temporarily block ligands destined for endosomes expressing TLRs in human monocyte-derived dendritic cells. We discuss knowledge gaps and highlight the existence of a pool of RNA with an approximate length of 30-40 nt that may still have unappreciated regulatory functions in physiology and in the defense against viruses as gatekeepers of endosomal uptake through certain routes.
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