1
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Debing Y, Vanrusselt H, Degrauwe L, Silva de Oliveira DA, Kariuki CK, Ebwanga EJ, Bashir S, Merckx W, Thatikonda SK, Rajwanshi V, Gohil V, Hong J, Kum DB, Acosta Sanchez A, Chanda S, Blatt LM, Jekle A, Symons JA, Smith DB, Raboisson P, Lin TI, Beigelman L, Paeshuyse J. An in vivo duck hepatitis B virus model recapitulates key aspects of nucleic acid polymer treatment outcomes in chronic hepatitis B patients. Antiviral Res 2024; 224:105835. [PMID: 38401714 DOI: 10.1016/j.antiviral.2024.105835] [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: 12/11/2023] [Revised: 01/30/2024] [Accepted: 02/13/2024] [Indexed: 02/26/2024]
Abstract
Nucleic acid polymers (NAPs) are an attractive treatment modality for chronic hepatitis B (CHB), with REP2139 and REP2165 having shown efficacy in CHB patients. A subset of patients achieve functional cure, whereas the others exhibit a moderate response or are non-responders. NAP efficacy has been difficult to recapitulate in animal models, with the duck hepatitis B virus (DHBV) model showing some promise but remaining underexplored for NAP efficacy testing. Here we report on an optimized in vivo DHBV duck model and explore several characteristics of NAP treatment. REP2139 was efficacious in reducing DHBV DNA and DHBsAg levels in approximately half of the treated ducks, whether administered intraperitoneally or subcutaneously. Intrahepatic or serum NAP concentrations did not correlate with efficacy, nor did the appearance of anti-DHBsAg antibodies. Furthermore, NAP efficacy was only observed in experimentally infected ducks, not in endogenously infected ducks (vertical transmission). REP2139 add-on to entecavir treatment induced a deeper and more sustained virological response compared to entecavir monotherapy. Destabilized REP2165 showed a different activity profile with a more homogenous antiviral response followed by a faster rebound. In conclusion, subcutaneous administration of NAPs in the DHBV duck model provides a useful tool for in vivo evaluation of NAPs. It recapitulates many aspects of this class of compound's efficacy in CHB patients, most notably the clear division between responders and non-responders.
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Affiliation(s)
| | | | - Lars Degrauwe
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium
| | | | | | - Ebanja Joseph Ebwanga
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Shahbaz Bashir
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Wouter Merckx
- TRANSfarm, Science, Engineering & Technology Group, KU Leuven, Leuven, Belgium
| | | | | | - Vikrant Gohil
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | - Jin Hong
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | | | | | | | | | - Andreas Jekle
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | | | - David B Smith
- Aligos Therapeutics, Inc., South San Francisco, CA, USA
| | | | | | | | - Jan Paeshuyse
- Laboratory of Host Pathogen Interactions, Department of Biosystems, KU Leuven, Leuven, Belgium.
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2
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Lam R, Lim JK. Advances in discovery of novel investigational agents for functional cure of chronic hepatitis B: A comprehensive review of phases II and III therapeutic agents. World J Hepatol 2024; 16:331-343. [PMID: 38577537 PMCID: PMC10989302 DOI: 10.4254/wjh.v16.i3.331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/23/2024] [Accepted: 02/29/2024] [Indexed: 03/27/2024] Open
Abstract
Chronic hepatitis B virus (HBV) infection affects over 295 million people globally and an estimated 1.6 million people in the United States. It is associated with significant morbidity and mortality due to cirrhosis, liver failure, and liver cancer. Antiviral therapy with oral nucleos(t)ide analogues is associated with high rates of virologic suppression, which in turn has been associated with a decreased risk of liver complications. However, current antiviral regimens are limited by concerns with adverse effects, adherence, resistance, long-term treatment, and ongoing risk for liver events. Novel investigational agents are currently in development and are targeted at achieving functional cure with sustained hepatitis B surface antigen (HBsAg) loss and suppression of HBV DNA. Herein we review key evidence from phases II and III trials defining the efficacy and safety profiles for key investigational agents for functional cure of chronic hepatitis B, including core/capsid inhibitors, entry inhibitors, RNA interference (siRNA/ASO), HBsAg inhibitors, Toll-like receptor agonists, checkpoint inhibitors, and therapeutic vaccines.
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Affiliation(s)
- Robert Lam
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Joseph K Lim
- Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, United States.
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3
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Patra S, Pareek D, Gupta PS, Wasnik K, Singh G, Yadav DD, Mastai Y, Paik P. Progress in Treatment and Diagnostics of Infectious Disease with Polymers. ACS Infect Dis 2024; 10:287-316. [PMID: 38237146 DOI: 10.1021/acsinfecdis.3c00528] [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] [Indexed: 02/10/2024]
Abstract
In this era of advanced technology and innovation, infectious diseases still cause significant morbidity and mortality, which need to be addressed. Despite overwhelming success in the development of vaccines, transmittable diseases such as tuberculosis and AIDS remain unprotected, and the treatment is challenging due to frequent mutations of the pathogens. Formulations of new or existing drugs with polymeric materials have been explored as a promising new approach. Variations in shape, size, surface charge, internal morphology, and functionalization position polymer particles as a revolutionary material in healthcare. Here, an overview is provided of major diseases along with statistics on infection and death rates, focusing on polymer-based treatments and modes of action. Key issues are discussed in this review pertaining to current challenges and future perspectives.
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Affiliation(s)
- Sukanya Patra
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Divya Pareek
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Prem Shankar Gupta
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Kirti Wasnik
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Gurmeet Singh
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Desh Deepak Yadav
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Yitzhak Mastai
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Pradip Paik
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
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4
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Kasianchuk N, Dobrowolska K, Harkava S, Bretcan A, Zarębska-Michaluk D, Jaroszewicz J, Flisiak R, Rzymski P. Gene-Editing and RNA Interference in Treating Hepatitis B: A Review. Viruses 2023; 15:2395. [PMID: 38140636 PMCID: PMC10747710 DOI: 10.3390/v15122395] [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: 10/28/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
The hepatitis B virus (HBV) continues to cause substantial health and economic burdens, and its target of elimination may not be reached in 2030 without further efforts in diagnostics, non-pharmaceutical prevention measures, vaccination, and treatment. Current therapeutic options in chronic HBV, based on interferons and/or nucleos(t)ide analogs, suppress the virus replication but do not eliminate the pathogen and suffer from several constraints. This paper reviews the progress on biotechnological approaches in functional and definitive HBV treatments, including gene-editing tools, i.e., zinc-finger proteins, transcription activator-like effector nucleases, and CRISPR/Cas9, as well as therapeutics based on RNA interference. The advantages and challenges of these approaches are also discussed. Although the safety and efficacy of gene-editing tools in HBV therapies are yet to be demonstrated, they show promise for the revitalization of a much-needed advance in the field and offer viral eradication. Particular hopes are related to CRISPR/Cas9; however, therapeutics employing this system are yet to enter the clinical testing phases. In contrast, a number of candidates based on RNA interference, intending to confer a functional cure, have already been introduced to human studies. However, larger and longer trials are required to assess their efficacy and safety. Considering that prevention is always superior to treatment, it is essential to pursue global efforts in HBV vaccination.
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Affiliation(s)
- Nadiia Kasianchuk
- Faculty of Biology, Adam Mickiewicz University in Poznań, 61-614 Poznań, Poland
| | | | - Sofiia Harkava
- Junior Academy of Sciences of Ukraine, Regional Branch in Dnipro, 49000 Dnipro, Ukraine;
| | - Andreea Bretcan
- National College “Ienăchiță Văcărescu”, 130016 Târgoviște, Romania;
| | - Dorota Zarębska-Michaluk
- Department of Infectious Diseases and Allergology, Jan Kochanowski University, 25-317 Kielce, Poland;
| | - Jerzy Jaroszewicz
- Department of Infectious Diseases and Hepatology, Medical University of Silesia in Katowice, 41-902 Bytom, Poland;
| | - Robert Flisiak
- Department of Infectious Diseases and Hepatology, Medical University of Białystok, 15-540 Białystok, Poland;
| | - Piotr Rzymski
- Department of Environmental Medicine, Poznan University of Medical Sciences, 60-806 Poznań, Poland
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5
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Angelo L, Vaillant A, Blanchet M, Labonté P. Pangenomic antiviral effect of REP 2139 in CRISPR/Cas9 engineered cell lines expressing hepatitis B virus surface antigen. PLoS One 2023; 18:e0293167. [PMID: 37910550 PMCID: PMC10619774 DOI: 10.1371/journal.pone.0293167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 10/06/2023] [Indexed: 11/03/2023] Open
Abstract
Chronic hepatitis B remains a global health problem with 296 million people living with chronic HBV infection and being at risk of developing cirrhosis and hepatocellular carcinoma. Non-infectious subviral particles (SVP) are produced in large excess over infectious Dane particles in patients and are the major source of Hepatitis B surface antigen (HBsAg). They are thought to exhaust the immune system, and it is generally considered that functional cure requires the clearance of HBsAg from blood of patient. Nucleic acid polymers (NAPs) antiviral activity lead to the inhibition of HBsAg release, resulting in rapid clearance of HBsAg from circulation in vivo. However, their efficacy has only been demonstrated in limited genotypes in small scale clinical trials. HBV exists as nine main genotypes (A to I). In this study, the HBsAg ORFs from the most prevalent genotypes (A, B, C, D, E, G), which account for over 96% of human cases, were inserted into the AAVS1 safe-harbor of HepG2 cells using CRISPR/Cas9 knock-in. A cell line producing the D144A vaccine escape mutant was also engineered. The secretion of HBsAg was confirmed into these new genotype cell lines (GCLs) and the antiviral activity of the NAP REP 2139 was then assessed. The results demonstrate that REP 2139 exerts an antiviral effect in all genotypes and serotypes tested in this study, including the vaccine escape mutant, suggesting a pangenomic effect of the NAPs.
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Affiliation(s)
- Léna Angelo
- Institut National de la Recherche Scientifique–Centre Armand-Frappier Santé Biotechnologies, Laval, Canada
| | | | - Matthieu Blanchet
- Institut National de la Recherche Scientifique–Centre Armand-Frappier Santé Biotechnologies, Laval, Canada
- Replicor Inc, Montréal, Canada
| | - Patrick Labonté
- Institut National de la Recherche Scientifique–Centre Armand-Frappier Santé Biotechnologies, Laval, Canada
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6
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Roca Suarez AA, Batbold E, Bartosch B, Dashdorj N, Testoni B, Zoulim F. Emerging anti-HDV drugs and HBV cure strategies with anti-HDV activity. Liver Int 2023; 43 Suppl 1:87-95. [PMID: 37017060 DOI: 10.1111/liv.15417] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/25/2022] [Accepted: 09/05/2022] [Indexed: 04/06/2023]
Abstract
Hepatitis delta virus (HDV) is a satellite RNA virus that requires the presence of hepatitis B virus (HBV) for its replication. HDV/HBV co-infection is often associated with a faster disease progression of chronic hepatitis in comparison to HBV mono-infection. Therefore, the development of novel antiviral therapies targeting HDV represents a high priority and an urgent medical need. In this review, we summarize the ongoing efforts to evaluate promising HDV-specific drugs, such as lonafarnib (LNF), pegylated interferon lambda (PEG-IFN-λ) and their use as a combination therapy. Furthermore, we review the most recent developments in the area of anti-HBV drugs with potential effects against HDV, including therapeutic agents targeting hepatitis B surface antigen (HBsAg) expression, secretion and function. Finally, we consider the important insights that have emerged from the development of these potential antiviral strategies, as well as the intriguing questions that remain to be elucidated in this rapidly changing field.
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Affiliation(s)
- Armando A Roca Suarez
- INSERM U1052, CNRS UMR-5286, Cancer Research Center of Lyon (CRCL), Lyon, France
- University of Lyon, Université Claude-Bernard (UCBL), Lyon, France
| | | | - Birke Bartosch
- INSERM U1052, CNRS UMR-5286, Cancer Research Center of Lyon (CRCL), Lyon, France
- University of Lyon, Université Claude-Bernard (UCBL), Lyon, France
| | | | - Barbara Testoni
- INSERM U1052, CNRS UMR-5286, Cancer Research Center of Lyon (CRCL), Lyon, France
- University of Lyon, Université Claude-Bernard (UCBL), Lyon, France
| | - Fabien Zoulim
- INSERM U1052, CNRS UMR-5286, Cancer Research Center of Lyon (CRCL), Lyon, France
- University of Lyon, Université Claude-Bernard (UCBL), Lyon, France
- Hospices Civils de Lyon (HCL), Lyon, France
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7
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Metin O, Zeybel M, Yurdaydin C. Treatment endpoints for chronic hepatitis D. Liver Int 2023; 43 Suppl 1:60-68. [PMID: 36196680 DOI: 10.1111/liv.15447] [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: 07/12/2022] [Revised: 09/20/2022] [Accepted: 10/03/2022] [Indexed: 02/13/2023]
Abstract
Management of chronic hepatitis D (CHD) has entered a new era. In this new era, the virus entry inhibitor bulevirtide has received conditional approval as a treatment for compensated CHD. Three phase 3 studies with two new compounds are ongoing for the treatment of CHD. In this context, surrogate markers of treatment efficacy have been well defined for chronic hepatitis B (CHB) (7) and chronic hepatitis C (8) but not for CHD. The aim of this review is to give a perspective on treatment endpoints in CHD. For this, we took guidance from CHB studies and tried to make suggestions which differed according to finite versus prolonged treatment durations and also took into account the different characteristics of the new compounds.
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Affiliation(s)
- Olga Metin
- Department of Gastroenterology, Prof. Cemil Taşçioğlu City Hospital, Istanbul, Turkey
| | - Müjdat Zeybel
- Department of Gastroenterology and Hepatology, Koç University Medical School, Istanbul, Turkey
| | - Cihan Yurdaydin
- Department of Gastroenterology and Hepatology, Koç University Medical School, Istanbul, Turkey
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8
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DiNunno N, Bianchini EN, Liu H, Wang JCY. Protein Structure Predictions, Atomic Model Building, and Validation Using a Cryo-EM Density Map from Hepatitis B Virus Spherical Subviral Particle. Bio Protoc 2023; 13:e4751. [PMID: 37497443 PMCID: PMC10367000 DOI: 10.21769/bioprotoc.4751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 04/01/2023] [Accepted: 05/22/2023] [Indexed: 07/28/2023] Open
Abstract
Hepatitis B virus (HBV) infection is a global public health concern. During chronic infection, the HBV small-surface antigen is expressed in large excess as non-infectious spherical subviral particles (SVPs), which possess strong immunogenicity. To date, attempts at understanding the structure of HBV spherical SVP have been restricted to 12-30 Å with contradictory conclusions regarding its architecture. We have used cryo-electron microscopy (cryo-EM) and 3D image reconstruction to solve the HBV spherical SVP to 6.3 Å. Here, we present an extended protocol on combining AlphaFold2 prediction with a moderate-resolution cryo-EM density map to build a reliable 3D model. This protocol utilizes multiple software packages that are routinely used in the cryo-EM community. The workflow includes 3D model prediction, model evaluation, rigid-body fitting, flexible fitting, real-space refinement, model validation, and model adjustment. Finally, the described protocol can also be applied to high-resolution cryo-EM datasets (2-4 Å).
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Affiliation(s)
- Nadia DiNunno
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Emily N Bianchini
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Haitao Liu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Joseph Che-Yen Wang
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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9
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Olsen K, Mahgoub S, Al-Shakhshir S, Algieder A, Atabani S, Bannaga A, Elsharkawy AM. Recent treatment advances and practical management of hepatitis D virus. Clin Med (Lond) 2023; 23:403-408. [PMID: 38614656 PMCID: PMC10541033 DOI: 10.7861/clinmed.2022-0556] [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] [Indexed: 06/25/2023]
Abstract
Hepatitis D virus (HDV), also referred to as hepatitis delta virus, is the smallest virus capable of causing human disease. It is unable to replicate on its own and can only propagate in the presence of hepatitis B virus (HBV). Infection with both HBV and HDV frequently results in more severe disease than HBV alone, with higher instances of cirrhosis, liver failure and hepatocellular carcinoma (HCC). Thus, there is a need for effective treatment for HDV; however, currently approved treatment options are very limited both in terms of their efficacy and availability. This makes the management of HDV a challenge for physicians. In this review, we look at the background, diagnosis and treatment of HDV, informed by our hospital data, to set out the optimal management of HDV; we also explore novel treatment options for this disease.
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Affiliation(s)
- Kathryn Olsen
- Liver Unit, Queen Elizabeth Hospital Birmingham, Birmingham, UK
| | - Sara Mahgoub
- Liver Unit, Queen Elizabeth Hospital Birmingham, Birmingham, UK
| | | | - Akram Algieder
- Liver Unit, Queen Elizabeth Hospital Birmingham, Birmingham, UK
| | | | - Ayman Bannaga
- Queen Elizabeth Hospital Birmingham, Birmingham, UK.
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10
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Keskin O, Yurdaydin C. Emerging drugs for hepatitis D. Expert Opin Emerg Drugs 2023:1-12. [PMID: 37096555 DOI: 10.1080/14728214.2023.2205639] [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: 04/26/2023]
Abstract
INTRODUCTION Chronic hepatitis delta (CHD) is the most severe form of chronic viral hepatitis. Until recently, its treatment consisted of pegylated interferon alfa (pegIFN) use. AREAS COVERED Current and new drugs for treating CHD. Virus entry inhibitor bulevirtide has received conditional approval by the European Medicines Agency. Prenylation inhibitor lonafarnib and pegIFN lambda are in phase 3 and nucleic acid polymers in phase 2 of drug development. EXPERT OPINION Bulevirtide appears to be safe. Its antiviral efficacy increases with treatment duration. Combining bulevirtide with pegIFN has the highest antiviral efficacy short-term. The prenylation inhibitor lonafarnib prevents hepatitis D virus assembly. It is associated with dose dependent gastrointestinal toxicity and is better used with ritonavir which increases liver lonafarnib concentrations. Lonafarnib also possesses immune modulatory properties which explains some post-treatment beneficial flare cases. Combining lonafarnib/ritonavir with pegIFN has superior antiviral efficacy. Nucleic acid polymers are amphipathic oligonucleotides whose effect appears to be a consequence of phosphorothioate modification of internucleotide linkages. These compounds led to HBsAg clearance in a sizeable proportion of patients. PegIFN lambda is associated with less IFN typical side effects. In a phase 2 study it led to 6 months off treatment viral response in one third of patients.
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Affiliation(s)
- Onur Keskin
- Department of Gastroenterology, Hacettepe University Medical School, Ankara, Turkey
| | - Cihan Yurdaydin
- Department of Gastroenterology & Hepatology, Koc University Medical School, Istanbul, Turkey
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11
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Pan Y, Xia H, He Y, Zeng S, Shen Z, Huang W. The progress of molecules and strategies for the treatment of HBV infection. Front Cell Infect Microbiol 2023; 13:1128807. [PMID: 37009498 PMCID: PMC10053227 DOI: 10.3389/fcimb.2023.1128807] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/03/2023] [Indexed: 03/17/2023] Open
Abstract
Hepatitis B virus infections have always been associated with high levels of mortality. In 2019, hepatitis B virus (HBV)-related diseases resulted in approximately 555,000 deaths globally. In view of its high lethality, the treatment of HBV infections has always presented a huge challenge. The World Health Organization (WHO) came up with ambitious targets for the elimination of hepatitis B as a major public health threat by 2030. To accomplish this goal, one of the WHO’s strategies is to develop curative treatments for HBV infections. Current treatments in a clinical setting included 1 year of pegylated interferon alpha (PEG-IFNα) and long-term nucleoside analogues (NAs). Although both treatments have demonstrated outstanding antiviral effects, it has been difficult to develop a cure for HBV. The reason for this is that covalently closed circular DNA (cccDNA), integrated HBV DNA, the high viral burden, and the impaired host immune responses all hinder the development of a cure for HBV. To overcome these problems, there are clinical trials on a number of antiviral molecules being carried out, all -showing promising results so far. In this review, we summarize the functions and mechanisms of action of various synthetic molecules, natural products, traditional Chinese herbal medicines, as clustered regularly interspaced short palindromic repeats and their associated proteins (CRISPR/Cas)-based systems, zinc finger nucleases (ZFNs), and transcription activator-like effector nucleases (TALENs), all of which could destroy the stability of the HBV life cycle. In addition, we discuss the functions of immune modulators, which can enhance or activate the host immune system, as well some representative natural products with anti-HBV effects.
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12
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New hepatitis B drug development disillusions: time to reset? Lancet Gastroenterol Hepatol 2023; 8:192-197. [PMID: 36343654 DOI: 10.1016/s2468-1253(22)00341-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/03/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022]
Abstract
After more than 5 years of intense preclinical and clinical research, the development of new hepatitis B virus (HBV) drugs appears to be stalling. The main reasons for this are the major limitations of the developmental path, including the use of inappropriate endpoints for clinical development, the standards for efficacy and approval being too strict (functional cure after short finite treatment duration), expecting compounds to do what they cannot do because of their known targets and mechanisms of action, and hoping that one size will fit all, despite the fact that HBV infection is heterogeneous. A functional HBV cure cannot be easily attained with only a few weeks or months of treatment with the classes of compounds that are currently in development. Therefore, researchers, drug developers, and regulators need to establish a new consensus about endpoints that are both clinically relevant and achievable, and redefine the objectives, timelines, and pathways of new HBV drug development.
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13
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Khalfi P, Kennedy PT, Majzoub K, Asselah T. Hepatitis D virus: Improving virological knowledge to develop new treatments. Antiviral Res 2023; 209:105461. [PMID: 36396025 DOI: 10.1016/j.antiviral.2022.105461] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/21/2022] [Accepted: 11/05/2022] [Indexed: 11/16/2022]
Abstract
Hepatitis delta virus (HDV), a satellite of hepatitis B virus (HBV), possesses the smallest viral genome known to infect animals. HDV needs HBV surface protein for secretion and entry into target liver cells. However, HBV is dispensable for HDV genome amplification, as it relies almost exclusively on cellular host factors for replication. HBV/HDV co-infections affect over 12 million people worldwide and constitute the most severe form of viral hepatitis. Co-infected individuals are at higher risk of developing liver cirrhosis and hepatocellular carcinoma compared to HBV mono-infected patients. Bulevirtide, an entry inhibitor, was conditionally approved in July 2020 in the European Union for adult patients with chronic hepatitis delta (CHD) and compensated liver disease. There are several drugs in development, including lonafarnib and interferon lambda, with different modes of action. In this review, we detail our current fundamental knowledge of HDV lifecycle and review antiviral treatments under development against this virus, outlining their respective mechanisms-of-action. Finally, we describe the antiviral effect these compounds are showing in ongoing clinical trials, discussing their promise and potential pitfalls for managing HDV infected patients.
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Affiliation(s)
- Pierre Khalfi
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, Montpellier 34293 cedex 5, France
| | - Patrick T Kennedy
- The Blizard Institute, Queen Mary University of London, The Royal London Hospital, Barts Health NHS Trust, London, UK
| | - Karim Majzoub
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS-UMR 5535, Montpellier 34293 cedex 5, France.
| | - Tarik Asselah
- Université de Paris, Cité CRI, INSERM UMR 1149, Department of Hepatology, AP-HP Hôpital Beaujon, Clichy, France.
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14
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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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15
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Vaillant A. Oligonucleotide-Based Therapies for Chronic HBV Infection: A Primer on Biochemistry, Mechanisms and Antiviral Effects. Viruses 2022; 14:v14092052. [PMID: 36146858 PMCID: PMC9502277 DOI: 10.3390/v14092052] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 11/21/2022] Open
Abstract
Three types of oligonucleotide-based medicines are under clinical development for the treatment of chronic HBV infection. Antisense oligonucleotides (ASOs) and synthetic interfering RNA (siRNA) are designed to degrade HBV mRNA, and nucleic acid polymers (NAPs) stop the assembly and secretion of HBV subviral particles. Extensive clinical development of ASOs and siRNA for a variety of liver diseases has established a solid understanding of their pharmacodynamics, accumulation in different tissue types in the liver, pharmacological effects, off-target effects and how chemical modifications and delivery approaches affect these parameters. These effects are highly conserved for all ASO and siRNA used in human studies to date. The clinical assessment of several ASO and siRNA compounds in chronic HBV infection in recent years is complicated by the different delivery approaches used. Moreover, these assessments have not considered the large clinical database of ASO/siRNA function in other liver diseases and known off target effects in other viral infections. The goal of this review is to summarize the current understanding of ASO/siRNA/NAP pharmacology and integrate these concepts into current clinical results for these compounds in the treatment of chronic HBV infection.
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Affiliation(s)
- Andrew Vaillant
- Replicor Inc., 6100 Royalmount Avenue, Montreal, QC H4P 2R2, Canada
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16
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Medical Advances in Hepatitis D Therapy: Molecular Targets. Int J Mol Sci 2022; 23:ijms231810817. [PMID: 36142728 PMCID: PMC9506394 DOI: 10.3390/ijms231810817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/25/2022] Open
Abstract
An approximate number of 250 million people worldwide are chronically infected with hepatitis B virus, making them susceptible to a coinfection with hepatitis D virus. The superinfection causes the most severe form of a viral hepatitis and thus drastically worsens the course of the disease. Until recently, the only available therapy consisted of interferon-α, only eligible for a minority of patients. In July 2020, the EMA granted Hepcludex conditional marketing authorization throughout the European Union. This first-in-class entry inhibitor offers the promise to prevent the spread in order to gain control and eventually participate in curing hepatitis B and D. Hepcludex is an example of how understanding the viral lifecycle can give rise to new therapy options. Sodium taurocholate co-transporting polypeptide, the virus receptor and the target of Hepcludex, and other targets of hepatitis D therapy currently researched are reviewed in this work. Farnesyltransferase inhibitors such as Lonafarnib, targeting another essential molecule in the HDV life cycle, represent a promising target for hepatitis D therapy. Farnesyltransferase attaches a farnesyl (isoprenyl) group to proteins carrying a C-terminal Ca1a2X (C: cysteine, a: aliphatic amino acid, X: C-terminal amino acid) motif like the large hepatitis D virus antigen. This modification enables the interaction of the HBV/HDV particle and the virus envelope proteins. Lonafarnib, which prevents this envelopment, has been tested in clinical trials. Targeting the lifecycle of the hepatitis B virus needs to be considered in hepatitis D therapy in order to cure a patient from both coexisting infections. Nucleic acid polymers target the hepatitis B lifecycle in a manner that is not yet understood. Understanding the possible targets of the hepatitis D virus therapy is inevitable for the improvement and development of a sufficient therapy that HDV patients are desperately in need of.
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17
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Tan YC, Lee GH, Huang DQ, Lim SG. Future anti-HDV treatment strategies, including those aimed at HBV functional cure. Liver Int 2022; 43:1157-1169. [PMID: 35946084 DOI: 10.1111/liv.15387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/11/2022] [Accepted: 08/08/2022] [Indexed: 02/13/2023]
Abstract
HDV is a defective virus that uses the HBV surface antigen to enter hepatocytes. It is associated with an accelerated course of liver fibrosis progression and an increased risk of hepatocellular carcinoma. Negative HDV RNA 24 weeks after the end of therapy has been proposed as an endpoint but late relapses make this endpoint suboptimal, hence HBsAg loss appears to be more appropriate. Current HBV antiviral agents have poor activity against HDV hence the search for improved therapy. Drugs only active against HDV, such as lonafarnib, have shown efficacy in combination with nucleoside analogues and peginterferon, but do not lead to HBsAg loss. HBsAg loss sustained 24 weeks after the end of therapy with negative HBV DNA is termed functional cure. Agents that are being investigated for functional cure include those that inhibit replication such as entry inhibitors, polymerase inhibitors and capsid assembly modulators but seldom lead to functional cure. Agents that reduce HBV antigen load such as RNA interference and inhibitors of HBsAg secretion are promising. Immunomodulators on their own seldom achieve functional cure, hence these agents in combination to assess the optimal combination are being investigated. Consequently, agents leading to functional cure of HBV are ideal for both HBV and HDV.
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Affiliation(s)
- Yong Chuan Tan
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Division of Gastroenterology and Hepatology, National University Health System, Singapore
| | - Guan Huei Lee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Division of Gastroenterology and Hepatology, National University Health System, Singapore
| | - Daniel Q Huang
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Division of Gastroenterology and Hepatology, National University Health System, Singapore
| | - Seng Gee Lim
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Division of Gastroenterology and Hepatology, National University Health System, Singapore
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18
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Suresh M, Menne S. Recent Drug Development in the Woodchuck Model of Chronic Hepatitis B. Viruses 2022; 14:v14081711. [PMID: 36016334 PMCID: PMC9416195 DOI: 10.3390/v14081711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/22/2022] [Accepted: 07/31/2022] [Indexed: 11/24/2022] Open
Abstract
Infection with hepatitis B virus (HBV) is responsible for the increasing global hepatitis burden, with an estimated 296 million people being carriers and living with the risk of developing chronic liver disease and cancer. While the current treatment options for chronic hepatitis B (CHB), including oral nucleos(t)ide analogs and systemic interferon-alpha, are deemed suboptimal, the path to finding an ultimate cure for this viral disease is rather challenging. The lack of suitable laboratory animal models that support HBV infection and associated liver disease progression is one of the major hurdles in antiviral drug development. For more than four decades, experimental infection of the Eastern woodchuck with woodchuck hepatitis virus has been applied for studying the immunopathogenesis of HBV and developing new antiviral therapeutics against CHB. There are several advantages to this animal model that are beneficial for performing both basic and translational HBV research. Previous review articles have focused on the value of this animal model in regard to HBV replication, pathogenesis, and immune response. In this article, we review studies of drug development and preclinical evaluation of direct-acting antivirals, immunomodulators, therapeutic vaccines, and inhibitors of viral entry, gene expression, and antigen release in the woodchuck model of CHB since 2014 until today and discuss their significance for clinical trials in patients.
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19
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Mak LY, Cheung KS, Fung J, Seto WK, Yuen MF. New strategies for the treatment of chronic hepatitis B. Trends Mol Med 2022; 28:742-757. [PMID: 35780008 DOI: 10.1016/j.molmed.2022.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 10/17/2022]
Abstract
Functional cure, as defined by seroclearance of hepatitis B surface antigen (HBsAg), is the desired treatment endpoint for chronic hepatitis B (CHB) infection, yet is rarely achieved with the currently approved therapy. Novel treatments currently in the clinical phase of development act by inhibiting viral replication/antigen reduction and/or by restoring host immune control. Although some agents are effective in reducing the viral antigen load, a greater magnitude of suppression is required to achieve functional cure. Compounds that target the covalently closed circular DNA (cccDNA) pool, hepatitis B X (HBx) protein inhibition, and mRNA destabilization are also in the preclinical phase of development. Challenges which remain include the clinical implications, immunological perturbations, and safety of these novel compounds to be used in the real-life setting.
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Affiliation(s)
- Lung-Yi Mak
- Department of Medicine, School of Clinical Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Ka-Shing Cheung
- Department of Medicine, School of Clinical Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong; Department of Medicine, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - James Fung
- Department of Medicine, School of Clinical Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Wai-Kay Seto
- Department of Medicine, School of Clinical Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong; Department of Medicine, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Man-Fung Yuen
- Department of Medicine, School of Clinical Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong; State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong.
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20
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Abstract
The last few years have seen a resurgence of activity in the hepatitis B drug pipeline, with many compounds in various stages of development. This review aims to provide a comprehensive overview of the latest advances in therapeutics for chronic hepatitis B (CHB). We will discuss the broad spectrum of direct-acting antivirals in clinical development, including capsids inhibitors, siRNA, HBsAg and polymerase inhibitors. In addition, host-targeted therapies (HTT) will be extensively reviewed, focusing on the latest progress in immunotherapeutics such as toll-like receptors and RIG-1 agonists, therapeutic vaccines and immune checkpoints modulators. A growing number of HTT in pre-clinical development directly target the key to HBV persistence, namely the covalently closed circular DNA (cccDNA) and hold great promise for HBV cure. This exciting area of HBV research will be highlighted, and molecules such as cyclophilins inhibitors, APOBEC3 deaminases and epigenetic modifiers will be discussed.
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Affiliation(s)
- Sandra Phillips
- Institute of Hepatology Foundation for Liver Research London UK, School of Immunology and Microbial Sciences King's College London, UK
| | - Ravi Jagatia
- Institute of Hepatology Foundation for Liver Research London UK, School of Immunology and Microbial Sciences King's College London, UK
| | - Shilpa Chokshi
- Institute of Hepatology Foundation for Liver Research London UK, School of Immunology and Microbial Sciences King's College London, UK
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21
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Editorial: In vitro mechanistic evaluation of nucleic acid polymers: A cautionary tale. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 28:168-174. [PMID: 35402067 PMCID: PMC8956958 DOI: 10.1016/j.omtn.2022.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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22
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Targeting Subviral Particles: A Critical Step in Achieving HBV Functional Cure but Where Are We with Current Agents in Clinical Development? Viruses 2022; 14:v14061193. [PMID: 35746664 PMCID: PMC9227515 DOI: 10.3390/v14061193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 02/04/2023] Open
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23
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Zi J, Gao X, Du J, Xu H, Niu J, Chi X. Multiple Regions Drive Hepatitis Delta Virus Proliferation and Are Therapeutic Targets. Front Microbiol 2022; 13:838382. [PMID: 35464929 PMCID: PMC9022428 DOI: 10.3389/fmicb.2022.838382] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 03/11/2022] [Indexed: 12/02/2022] Open
Abstract
Hepatitis Delta Virus (HDV) is the smallest mammalian single-stranded RNA virus. It requires host cells and hepatitis B virus (HBV) to complete its unique life cycle. The present review summarizes the specific regions on hepatitis D antigen (HDAg) and hepatitis B surface antigen (HBsAg) that drive HDV to utilize host cell machinery system to produce three types of RNA and two forms of HDAg, and hijack HBsAg for its secretion and de novo entry. Previously, interferon-α was the only recommended therapy for HDV infection. In recent years, some new therapies targeting these regions, such as Bulevirtide, Lonafarnib, Nucleic acid polymers have appeared, with better curative effects and fewer adverse reactions.
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Affiliation(s)
- Jun Zi
- Gene Therapy Laboratory, Center for Pathogen Biology and Infectious Diseases, First Hospital of Jilin University, Changchun, China
| | - Xiuzhu Gao
- Department of Hepatology, Center for Pathogen Biology and Infectious Diseases, First Hospital of Jilin University, Changchun, China
| | - Juan Du
- Institute of Virology and AIDS Research, First Hospital of Jilin University, Changchun, China
| | - Hongqin Xu
- Department of Hepatology, Center for Pathogen Biology and Infectious Diseases, First Hospital of Jilin University, Changchun, China
| | - Junqi Niu
- Department of Hepatology, Center for Pathogen Biology and Infectious Diseases, First Hospital of Jilin University, Changchun, China
| | - Xiumei Chi
- Gene Therapy Laboratory, Center for Pathogen Biology and Infectious Diseases, First Hospital of Jilin University, Changchun, China
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24
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Nagra N, Kozarek RA, Burman BE. Therapeutic Advances in Viral Hepatitis A-E. Adv Ther 2022; 39:1524-1552. [PMID: 35220557 DOI: 10.1007/s12325-022-02070-z] [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: 12/16/2021] [Accepted: 01/31/2022] [Indexed: 11/25/2022]
Abstract
Viral hepatitis remains a significant global health problem. All forms of viral hepatitis A through E (A-E) can lead to acute symptomatic infection, while hepatitis B and C can lead to chronic infection associated with significant morbidity and mortality related to progression to cirrhosis, end-stage-liver disease, and liver cancer. Viral hepatitis occurs worldwide, though certain regions are disproportionately affected. We now, remarkably, have highly effective curative regimens for hepatitis C, and safe and tolerable medications to suppress hepatitis B activity, and to prevent liver damage and slow disease progression. We have effective vaccines for hepatitis A and B which provide long-lasting immunity, while improved sanitation and awareness can curb outbreaks of hepatitis A and E. However, more effective and available preventive and curative strategies are needed to achieve global eradication of viral hepatitis. This review provides an overview of the epidemiology, transmission, diagnosis, and clinical features of each viral hepatitis with a primary focus on current and future therapeutic and curative options.
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Affiliation(s)
- Navroop Nagra
- Department of Gastroenterology, University of Louisville, Louisville, KY, 40202, USA
| | - Richard A Kozarek
- Center for Digestive Health, Virginia Mason Franciscan Health, 1100 9th Ave., Seattle, WA, 98101, USA
| | - Blaire E Burman
- Center for Digestive Health, Virginia Mason Franciscan Health, 1100 9th Ave., Seattle, WA, 98101, USA.
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25
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Usai C, Gill US, Riddell AC, Asselah T, Kennedy P. Review article: emerging insights into the immunopathology, clinical and therapeutic aspects of hepatitis delta virus. Aliment Pharmacol Ther 2022; 55:978-993. [PMID: 35292991 PMCID: PMC9314912 DOI: 10.1111/apt.16807] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/06/2021] [Accepted: 01/25/2022] [Indexed: 12/16/2022]
Abstract
BACKGROUND Hepatitis delta virus (HDV), which causes the most severe form of viral hepatitis, is an obligated hepatitis B (HBV) satellite virus that can either infect naïve subjects simultaneously with HBV (co-infection), or chronically infect HBV carriers (super-infection). An estimated 12 million people are infected by HDV worldwide. AIMS To summarise the most relevant aspects of the molecular biology of HDV, and to discuss the latest understanding of the induced pathology, interactions with the immune system, as well as both approved and investigational treatment options. METHODS References for this review were identified through searches of PubMed with the terms "HDV" "viral hepatitis" "co-infection" and "super-infection," published between 1980 and October 2021 RESULTS: The limited access to the HDV-infected liver has hampered the investigation of the intrahepatic compartment and our understanding of the mechanisms of HDV pathogenesis. In the absence of standardised and sensitive diagnostic tools, HDV is often underdiagnosed and owing to its strong dependence on host cellular factors, the development of direct antiviral agents has been challenging. New therapeutic agents targeting different steps of the viral cycle have recently been investigated, among which bulevirtide (which was conditionally approved by EMA in July 2020) and lonafarnib; both drugs having received orphan drug designation from both the EMA and FDA. CONCLUSIONS The HBV cure programme potentially offers a unique opportunity to enhance HDV treatment strategies. In addition, a more comprehensive analysis of the intrahepatic compartment is mandated to better understand any liver-confined interaction of HDV with the host immune system.
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Affiliation(s)
- Carla Usai
- Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine and DentistryQueen Mary University of LondonLondonUK,Present address:
Unitat mixta d’Investigació IRTA‐UAB en Sanitat AnimalCentre de Recerca en Sanitat Animal (CReSA)Campus de la Universitat Autònoma de Barcelona (UAB)Bellaterra08193Spain
| | - Upkar S. Gill
- Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine and DentistryQueen Mary University of LondonLondonUK,The Royal London HospitalBarts Health NHS TrustLondonUK
| | - Anna C. Riddell
- Division of Infection, Virology DepartmentBarts Health NHS TrustLondonUK
| | - Tarik Asselah
- Centre de recherche sur l'inflammation, Inserm U1149Université́ de ParisParisFrance,Department of Hepatology, AP‐HPHôpital BeaujonClichyFrance
| | - Patrick T. Kennedy
- Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine and DentistryQueen Mary University of LondonLondonUK,The Royal London HospitalBarts Health NHS TrustLondonUK
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26
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Michelet M, Alfaiate D, Chardès B, Pons C, Faure-Dupuy S, Engleitner T, Farhat R, Riedl T, Legrand AF, Rad R, Rivoire M, Zoulim F, Heikenwälder M, Salvetti A, Durantel D, Lucifora J. Inducers of the NF-κB pathways impair hepatitis delta virus replication and strongly decrease progeny infectivity in vitro. JHEP Rep 2022; 4:100415. [PMID: 35141510 PMCID: PMC8792426 DOI: 10.1016/j.jhepr.2021.100415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 11/03/2021] [Accepted: 12/02/2021] [Indexed: 10/26/2022] Open
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27
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Roy S, Sarkhel S, Bisht D, Hanumantharao SN, Rao S, Jaiswal A. Antimicrobial Mechanisms of Biomaterials: From Macro to Nano. Biomater Sci 2022; 10:4392-4423. [DOI: 10.1039/d2bm00472k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Overcoming the global concern of antibiotic resistance is one of the biggest challenge faced by scientists today and the key to tackle this issue of emerging infectious diseases is the...
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28
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Kuroki A, Tay J, Lee GH, Yang YY. Broad-Spectrum Antiviral Peptides and Polymers. Adv Healthc Mater 2021; 10:e2101113. [PMID: 34599850 DOI: 10.1002/adhm.202101113] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/13/2021] [Indexed: 12/18/2022]
Abstract
As the human cost of the pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still being witnessed worldwide, the development of broad-spectrum antiviral agents against emerging and re-emerging viruses is seen as a necessity to hamper the spread of infections. Various targets during the viral life-cycle can be considered to inhibit viral infection, from viral attachment to viral fusion or replication. Macromolecules represent a particularly attractive class of therapeutics due to their multivalency and versatility. Although several antiviral macromolecules hold great promise in clinical applications, the emergence of resistance after prolonged exposure urges the need for improved solutions. In the present article, the recent advancement in the discovery of antiviral peptides and polymers with diverse structural features and antiviral mechanisms is reviewed. Future perspectives, such as, the development of virucidal peptides/polymers and their coatings against SARS-CoV-2 infection, standardization of antiviral testing protocols, and use of artificial intelligence or machine learning as a tool to accelerate the discovery of antiviral macromolecules, are discussed.
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Affiliation(s)
- Agnès Kuroki
- Yong Loo Lin School of Medicine National University of Singapore Singapore 117597 Singapore
- Institute of Bioengineering and Bioimaging 31 Biopolis Ways, The Nanos Singapore 138669 Singapore
| | - Joyce Tay
- Institute of Bioengineering and Bioimaging 31 Biopolis Ways, The Nanos Singapore 138669 Singapore
| | - Guan Huei Lee
- Yong Loo Lin School of Medicine National University of Singapore Singapore 117597 Singapore
| | - Yi Yan Yang
- Institute of Bioengineering and Bioimaging 31 Biopolis Ways, The Nanos Singapore 138669 Singapore
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29
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Abstract
The hepatitis B virus (HBV) is a member of the Hepadnaviridae family, which includes small DNA enveloped viruses that infect primates, rodents, and birds and is the causative factor of chronic hepatitis B. A common feature of all these viruses is their great specificity by species and cell type, as well as a peculiar genomic and replication organization similar to that of retroviruses. The HBV virion consists of an external lipid envelope and an internal icosahedral protein capsid containing the viral genome and a DNA polymerase, which also functions as a reverse transcriptase.
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Affiliation(s)
- Alessandro Loglio
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122 Milan, Italy
| | - Mauro Viganò
- Hepatology Division, San Giuseppe Hospital Multimedica Spa, Via San Vittore 12, 20123 Milan, Italy
| | - Pietro Lampertico
- Division of Gastroenterology and Hepatology, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122 Milan, Italy; Department of Pathophysiology and Transplantation, CRC "A. M. and A. Migliavacca" Center for Liver Disease, University of Milan, Via F. Sforza 35, Milan 20122, Italy.
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30
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Urban S, Neumann-Haefelin C, Lampertico P. Hepatitis D virus in 2021: virology, immunology and new treatment approaches for a difficult-to-treat disease. Gut 2021; 70:1782-1794. [PMID: 34103404 PMCID: PMC8355886 DOI: 10.1136/gutjnl-2020-323888] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/26/2021] [Indexed: 02/06/2023]
Abstract
Approximately 5% of individuals infected with hepatitis B virus (HBV) are coinfected with hepatitis D virus (HDV). Chronic HBV/HDV coinfection is associated with an unfavourable outcome, with many patients developing liver cirrhosis, liver failure and eventually hepatocellular carcinoma within 5-10 years. The identification of the HBV/HDV receptor and the development of novel in vitro and animal infection models allowed a more detailed study of the HDV life cycle in recent years, facilitating the development of specific antiviral drugs. The characterisation of HDV-specific CD4+ and CD8+T cell epitopes in untreated and treated patients also permitted a more precise understanding of HDV immunobiology and possibly paves the way for immunotherapeutic strategies to support upcoming specific therapies targeting viral or host factors. Pegylated interferon-α has been used for treating HDV patients for the last 30 years with only limited sustained responses. Here we describe novel treatment options with regard to their mode of action and their clinical effectiveness. Of those, the entry-inhibitor bulevirtide (formerly known as myrcludex B) received conditional marketing authorisation in the European Union (EU) in 2020 (Hepcludex). One additional drug, the prenylation inhibitor lonafarnib, is currently under investigation in phase III clinical trials. Other treatment strategies aim at targeting hepatitis B surface antigen, including the nucleic acid polymer REP2139Ca. These recent advances in HDV virology, immunology and treatment are important steps to make HDV a less difficult-to-treat virus and will be discussed.
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Affiliation(s)
- Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany,German Center for Infection Research (DZIF) - Heidelberg Partner Site, Heidelberg, Germany
| | - Christoph Neumann-Haefelin
- Department of Medicine II, Freiburg University Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Pietro Lampertico
- Division of Gastroenterology and Hepatology, Fondazione 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
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31
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Novel Antivirals in Clinical Development for Chronic Hepatitis B Infection. Viruses 2021; 13:v13061169. [PMID: 34207458 PMCID: PMC8235765 DOI: 10.3390/v13061169] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/06/2021] [Accepted: 06/15/2021] [Indexed: 02/07/2023] Open
Abstract
Globally, chronic hepatitis B (CHB) infection is one of the leading causes of liver failure, decompensated cirrhosis, and hepatocellular carcinoma. Existing antiviral therapy can suppress viral replication but not fully eradicate the virus nor the risk of liver-related complications. Novel treatments targeting alternative steps of the viral cycle or to intensify/restore the host’s immunity are being developed. We discuss novel drugs that have already entered clinical phases of development. Agents that interfere with specific steps of HBV replication include RNA interference, core protein allosteric modulation, and inhibition of viral entry or viral protein excretion (NAPs and STOPS). Agents that target the host’s immunity include toll-like receptor agonists, therapeutic vaccines, immune checkpoint modulators, soluble T-cell receptors, and monoclonal antibodies. Most have demonstrated favorable results in suppression of viral proteins and genomic materials (i.e., HBV DNA and/or pre-genomic RNA), and/or evidence on host-immunity restoration including cytokine responses and T-cell activation. Given the abundant clinical experience and real-world safety data with the currently existing therapy, any novel agent for CHB should be accompanied by convincing safety data. Combination therapy of nucleos(t)ide analogue, a novel virus-directing agent, and/or an immunomodulatory agent will be the likely approach to optimize the chance of a functional cure in CHB.
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Vaillant A. HBsAg, Subviral Particles, and Their Clearance in Establishing a Functional Cure of Chronic Hepatitis B Virus Infection. ACS Infect Dis 2021; 7:1351-1368. [PMID: 33302622 DOI: 10.1021/acsinfecdis.0c00638] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In diverse viral infections, the production of excess viral particles containing only viral glycoproteins (subviral particles or SVP) is commonly observed and is a commonly evolved mechanism for immune evasion. In hepatitis B virus (HBV) infection, spherical particles contain the hepatitis B surface antigen, outnumber infectious virus 10 000-100 000 to 1, and have diverse inhibitory effects on the innate and adaptive immune response, playing a major role in the chronic nature of HBV infection. The current goal of therapies in development for HBV infection is a clinical outcome called functional cure, which signals a persistent and effective immune control of the infection. Although removal of spherical SVP (and the HBsAg they carry) is an important milestone in achieving functional cure, this outcome is rarely achieved with current therapies due to distinct mechanisms for assembly, secretion, and persistence of SVP, which are poorly targeted by direct acting antivirals or immunotherapies. In this Review, the current understanding of the distinct mechanisms involved in the production and persistence of spherical SVP in chronic HBV infection and their immunoinhibitory activity will be reviewed as well as current therapies in development with the goal of clearing spherical SVP and achieving functional cure.
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Affiliation(s)
- Andrew Vaillant
- Replicor Inc., 6100 Royalmount Avenue, Montreal, Quebec H8Y 3E6, Canada
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Bazinet M, Pântea V, Placinta G, Moscalu I, Cebotarescu V, Cojuhari L, Jimbei P, Iarovoi L, Smesnoi V, Musteata T, Jucov A, Dittmer U, Krawczyk A, Vaillant A. Benefit of transaminase elevations in establishing functional cure of HBV infection during nap-based combination therapy. J Viral Hepat 2021; 28:817-825. [PMID: 33556206 DOI: 10.1111/jvh.13483] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 01/18/2021] [Indexed: 12/12/2022]
Abstract
Treatment of HBV infection with nucleic acid polymers and pegIFN is accompanied by transaminase elevations in 95% of participants. HBV viral rebound, partial cure (HBV DNA < 2000 IU/mL, normal ALT) or functional cure (HBV DNA target not detected, HBsAg <LLOQ, normal ALT) occurred in 27%, 38% and 35% of participants. Correlations between ALT, AST and GGT elevations, virologic baseline, response during therapy and HBV therapeutic outcome were investigated. A retrospective analysis of all 40 participants in the REP 401 study (NCT02565719) included maxima and area under the curve for ALT, AST and GGT, baseline virology, HBsAg and anti-HBs response and HBV therapeutic outcomes. ALT, AST and GGT elevations were asymptomatic, independent of baseline virologic status and anti-HBs response but correlated with HBsAg reduction ≥3 log10 from baseline. Functional cure was associated with significantly lower HBsAg during the nadir of ALT flares versus viral rebound or partial cure. ALT elevations >3X ULN while HBsAg was <1 IU/mL occurred in 3/11 (27%), 11/15 (74%) and 14/14 (100%) of participants experiencing viral rebound, partial or functional cure. ALT elevation >3X ULN during HBsAg <1 IU/mL and <10 IU/mL were the best predictors of partial and functional cure. In conclusion, elevations in ALT, AST or GGT while HBsAg <10 IU/ml during therapy with REP 2139 + pegIFN are associated with partial and functional cure. More potent HBsAg reduction during flare nadir is associated with the establishment of functional cure, suggesting a critical role for HBsAg-specific immunity to achieve this outcome. These on-therapy milestones may have similar positive prognostic value with other combination therapies.
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Affiliation(s)
| | - Victor Pântea
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Gheorghe Placinta
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Iurie Moscalu
- ARENSIA Exploratory Medicine, Republican Clinical Hospital Chișinău, Moldova
| | - Valentin Cebotarescu
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Lilia Cojuhari
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Pavlina Jimbei
- Toma Ciorbă Infectious Clinical Hospital, Chișinău, Republic of Moldova
| | - Liviu Iarovoi
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Valentina Smesnoi
- Toma Ciorbă Infectious Clinical Hospital, Chișinău, Republic of Moldova
| | - Tatiana Musteata
- Toma Ciorbă Infectious Clinical Hospital, Chișinău, Republic of Moldova
| | - Alina Jucov
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova.,ARENSIA Exploratory Medicine, Republican Clinical Hospital Chișinău, Moldova
| | - Ulf Dittmer
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Adalbert Krawczyk
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.,Department of Infectious Diseases, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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Transaminase Elevations during Treatment of Chronic Hepatitis B Infection: Safety Considerations and Role in Achieving Functional Cure. Viruses 2021; 13:v13050745. [PMID: 33922828 PMCID: PMC8146791 DOI: 10.3390/v13050745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 11/17/2022] Open
Abstract
While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.
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Gençdal G, Yurdaydin C. Developing New Therapies for Delta Hepatitis: The Race Is On. Hepatol Commun 2021; 5:556-558. [PMID: 33860114 PMCID: PMC8034575 DOI: 10.1002/hep4.1685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 11/25/2022] Open
Affiliation(s)
- Genco Gençdal
- Department of Gastroenterology and HepatologyKoç University Medical SchoolIstanbulTurkey
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Zhang Z, Urban S. New insights into HDV persistence: The role of interferon response and implications for upcoming novel therapies. J Hepatol 2021; 74:686-699. [PMID: 33276031 DOI: 10.1016/j.jhep.2020.11.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/12/2020] [Accepted: 11/22/2020] [Indexed: 02/06/2023]
Abstract
Chronic hepatitis D (CHD), a global health problem, manifests as the most severe form of viral hepatitis. The causative agent, HDV, is the smallest known human virus; it replicates its circular single-stranded RNA genome in the nucleus of hepatocytes. HDV requires HBV-encoded envelope proteins for dissemination and de novo cell entry. However, HDV can also spread through cell division. Following entry into hepatocytes, replicative intermediates of HDV RNA are sensed by the pattern recognition receptor MDA5 (melanoma differentiation antigen 5) resulting in interferon (IFN)-β/λ induction. This IFN response strongly suppresses cell division-mediated spread of HDV genomes, however, it only marginally affects HDV RNA replication in already infected, resting hepatocytes. Monotherapy with IFN-α/λ shows efficacy but rarely results in HDV clearance. Recent molecular insights into key determinants of HDV persistence and the accelerated development of specifically acting antivirals that interfere with the replication cycle have revealed promising new therapeutic perspectives. In this review, we briefly summarise our knowledge on replication/persistence of HDV, the newly discovered HDV-like agents, and the interplay of HDV with the IFN response and its consequences for persistence. Finally, we discuss the possible role of IFNs in combination with upcoming therapies aimed at HDV cure.
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Affiliation(s)
- Zhenfeng Zhang
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Infection Research (DZIF) - Heidelberg Partner Site, Heidelberg, Germany.
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Vaillant A. Clarifying the Chemistry, Activity, and Safety of Nucleic Acid Polymers. Gastroenterology 2021; 160:1427. [PMID: 32931787 DOI: 10.1053/j.gastro.2020.07.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/31/2020] [Indexed: 12/02/2022]
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Affiliation(s)
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- Replicor Inc, Montreal, Quebec, Canada
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39
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Bazinet M, Pântea V, Cebotarescu V, Cojuhari L, Jimbei P, Anderson M, Gersch J, Holzmayer V, Elsner C, Krawczyk A, Kuhns MC, Cloherty G, Dittmer U, Vaillant A. Persistent Control of Hepatitis B Virus and Hepatitis Delta Virus Infection Following REP 2139-Ca and Pegylated Interferon Therapy in Chronic Hepatitis B Virus/Hepatitis Delta Virus Coinfection. Hepatol Commun 2021; 5:189-202. [PMID: 33553968 PMCID: PMC7850315 DOI: 10.1002/hep4.1633] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 02/04/2023] Open
Abstract
The nucleic acid polymer REP 2139 inhibits assembly/secretion of hepatitis B virus (HBV) subviral particles. Previously, REP 2139-Ca and pegylated interferon (pegIFN) in HBV/hepatitis delta virus (HDV) coinfection achieved high rates of HDV RNA and hepatitis B surface antigen (HBsAg) loss/seroconversion in the REP 301 study (NCT02233075). The REP 301-LTF study (NCT02876419) examined safety and efficacy during 3.5 years of follow-up. In the current study, participants completing therapy in the REP 301 study were followed for 3.5 years. Primary outcomes were safety and tolerability, and secondary outcomes were HDV functional cure (HDV RNA target not detected [TND], normal alanine aminotransferase [ALT]), HBV virologic control (HBV DNA ≤2,000 IU/mL, normal ALT), HBV functional cure (HBV DNA TND; HBsAg <0.05 IU/mL, normal ALT), and HBsAg seroconversion. Supplemental analysis included high-sensitivity HBsAg (Abbott ARCHITECT HBsAg NEXT), HBV pregenomic RNA (pgRNA), HBsAg/hepatitis B surface antibody (anti-HBs) immune complexes (HBsAg ICs), and hepatitis B core-related antigen (HBcrAg). Asymptomatic grade 1-2 ALT elevations occurred in 2 participants accompanying viral rebound; no other safety or tolerability issues were observed. During therapy and follow-up, HBsAg reductions to <0.05 IU/mL were also <0.005 IU/mL. HBsAg ICs declined in 7 of 11 participants during REP 2139-Ca monotherapy and in 10 of 11 participants during follow-up. HDV functional cure persisted in 7 of 11 participants; HBV virologic control persisted in 3 and functional cure (with HBsAg seroconversion) persisted in 4 of these participants. Functional cure of HBV was accompanied by HBV pgRNA TND and HBcrAg <lower limit of quantitation. Conclusion: REP 2139-Ca + pegIFN is not associated with long-term safety or tolerability issues. The establishment of HDV functional cure and HBV virologic control/functional cure and HBsAg seroconversion are durable over 3.5 years and may reflect removal of integrated HBV DNA from the liver. Further investigation is warranted in larger studies.
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Affiliation(s)
| | - Victor Pântea
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | - Valentin Cebotarescu
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | - Lilia Cojuhari
- Department of Infectious DiseasesNicolae Testemiţanu State University of Medicine and PharmacyChișinăuRepublic of Moldova
| | - Pavlina Jimbei
- Toma Ciorbă Infectious Clinical HospitalChișinăuRepublic of Moldova
| | | | | | | | - Carina Elsner
- Institute for VirologyUniversity Hospital EssenUniversity of Duisburg-EssenEssenGermany
| | - Adalbert Krawczyk
- Institute for VirologyUniversity Hospital EssenUniversity of Duisburg-EssenEssenGermany.,Department of Infectious DiseasesUniversity Hospital EssenUniversity of Duisburg-EssenEssenGermany
| | | | | | - Ulf Dittmer
- Institute for VirologyUniversity Hospital EssenUniversity of Duisburg-EssenEssenGermany
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Kadelka S, Dahari H, Ciupe SM. Understanding the antiviral effects of RNAi-based therapy in HBeAg-positive chronic hepatitis B infection. Sci Rep 2021; 11:200. [PMID: 33420293 PMCID: PMC7794570 DOI: 10.1038/s41598-020-80594-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 12/21/2020] [Indexed: 01/29/2023] Open
Abstract
The RNA interference (RNAi) drug ARC-520 was shown to be effective in reducing serum hepatitis B virus (HBV) DNA, hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) in HBeAg-positive patients treated with a single dose of ARC-520 and daily nucleosidic analogue (entecavir). To provide insights into HBV dynamics under ARC-520 treatment and its efficacy in blocking HBV DNA, HBsAg, and HBeAg production we developed a multi-compartmental pharmacokinetic-pharamacodynamic model and calibrated it with frequent measured HBV kinetic data. We showed that the time-dependent single dose ARC-520 efficacies in blocking HBsAg and HBeAg are more than 96% effective around day 1, and slowly wane to 50% in 1-4 months. The combined single dose ARC-520 and entecavir effect on HBV DNA was constant over time, with efficacy of more than 99.8%. The observed continuous HBV DNA decline is entecavir mediated, the strong but transient HBsAg and HBeAg decays are ARC-520 mediated. The modeling framework may help assess ongoing RNAi drug development for hepatitis B virus infection.
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Affiliation(s)
- Sarah Kadelka
- Department of Mathematics, Virginia Tech, Blacksburg, VA, 24060, USA
| | - Harel Dahari
- Program for Experimental and Theoretical Modeling, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, 60153, USA
| | - Stanca M Ciupe
- Department of Mathematics, Virginia Tech, Blacksburg, VA, 24060, USA.
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Bassit L, Ono SK, Schinazi RF. Moving Fast Toward Hepatitis B Virus Elimination. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1322:115-138. [PMID: 34258739 DOI: 10.1007/978-981-16-0267-2_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Currently, there are two safe and effective therapeutic strategies for chronic hepatitis B treatment, namely, nucleoside analogs and interferon alpha (pegylated or non-pegylated). These treatments can control viral replication and improve survival; however, they do not eliminate the virus and therefore require long-term continued therapy. In addition, there are significant concerns about virus rebound on discontinuation of therapy and the development of fibrosis and hepatocellular carcinoma despite therapy. Therefore, the search for new, more effective, and safer antiviral agents that can cure hepatitis B virus (HBV) continues. Anti-HBV drug discovery and development is fundamentally impacted by our current understanding of HBV replication, disease physiopathology, and persistence of HBV covalently closed circular DNA (cccDNA). Several HBV replication targets are the basis for novel anti-HBV drug development strategies. Many of them are already in clinical trial phase 1 or 2, while others with promising results are still in preclinical stages. As research intensifies, potential HBV curative therapies and modalities in the pipeline are now on the horizon.
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Affiliation(s)
- Leda Bassit
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Suzane Kioko Ono
- Department of Gastroenterology, University of Sao Paulo School of Medicine, Sao Paulo, SP, Brazil
| | - Raymond F Schinazi
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, Atlanta, GA, USA.
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42
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Alexopoulou A, Vasilieva L, Karayiannis P. New Approaches to the Treatment of Chronic Hepatitis B. J Clin Med 2020; 9:jcm9103187. [PMID: 33019573 PMCID: PMC7601587 DOI: 10.3390/jcm9103187] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 02/07/2023] Open
Abstract
The currently recommended treatment for chronic hepatitis B virus (HBV) infection achieves only viral suppression whilst on therapy, but rarely hepatitis B surface antigen (HBsAg) loss. The ultimate therapeutic endpoint is the combination of HBsAg loss, inhibition of new hepatocyte infection, elimination of the covalently closed circular DNA (cccDNA) pool, and restoration of immune function in order to achieve virus control. This review concentrates on new antiviral drugs that target different stages of the HBV life cycle (direct acting antivirals) and others that enhance both innate and adaptive immunity against HBV (immunotherapy). Drugs that block HBV hepatocyte entry, compounds that silence or deplete the cccDNA pool, others that affect core assembly, agents that degrade RNase-H, interfering RNA molecules, and nucleic acid polymers are likely interventions in the viral life cycle. In the immunotherapy category, molecules that activate the innate immune response such as Toll-like-receptors, Retinoic acid Inducible Gene-1 (RIG-1) and stimulator of interferon genes (STING) agonists or checkpoint inhibitors, and modulation of the adaptive immunity by therapeutic vaccines, vector-based vaccines, or adoptive transfer of genetically-engineered T cells aim towards the restoration of T cell function. Future therapeutic trends would likely be a combination of one or more of the aforementioned drugs that target the viral life cycle and at least one immunomodulator.
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Affiliation(s)
- Alexandra Alexopoulou
- Department of Medicine, Medical School, National & Kapodistrian University of Athens, Hippokration General Hospital, 11527 Athens, Greece;
- Correspondence: ; Tel.: +30-2132-088-178; Fax: +30-2107-706-871
| | - Larisa Vasilieva
- Department of Medicine, Medical School, National & Kapodistrian University of Athens, Hippokration General Hospital, 11527 Athens, Greece;
| | - Peter Karayiannis
- Department of Basic and Clinical Sciences, Medical School, University of Nicosia, Engomi, CY-1700 Nicosia, Cyprus;
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Zhang BY, Chai DP, Wu YH, Qiu LP, Zhang YY, Ye ZH, Yu XP. Potential Drug Targets Against Hepatitis B Virus Based on Both Virus and Host Factors. Curr Drug Targets 2020; 20:1636-1651. [PMID: 31362671 DOI: 10.2174/1389450120666190729115646] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/24/2019] [Accepted: 06/28/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND Hepatitis B is a very harmful and epidemic disease caused by hepatitis B virus (HBV). Although an effective anti-HBV vaccine is available, chronic infection poses still a huge health burden in the whole world. The present anti-HBV drugs including nucleoside analogues and interferonalpha have their limitations without exception. There is no effective drug and therapeutic method that can really and truly cure hepatitis B so far. The variability of HBV genome results in that a significant number of patients develop drug resistance during the long-term use of anti-HBV drugs. Hence, it is urgently needed to discover novel targets and develop new drugs against hepatitis B. OBJECTIVE The review aims to provide the theory support for designing of the anti-HBV innovative drugs by offering a summary of the current situation of antiviral potential targets. RESULTS AND CONCLUSION Since HBV is obligate intracellular parasite, and as such it depends on host cellular components and functions to replicate itself. The targeting both virus and host might be a novel therapeutic option for hepatitis B. Accordingly, we analyse the advances in the study of the potential drug targets for anti-HBV infection, focusing on targeting virus genome, on targeting host cellular functions and on targeting virus-host proteins interactions, respectively. Meanwhile, the immune targets against chronic hepatitis B are also emphasized. In short, the review provides a summary of antiviral therapeutic strategies to target virus factors, host factors and immune factors for future designing of the innovative drug against HBV infection.
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Affiliation(s)
- Bing-Yi Zhang
- Department of Pharmacy, Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Dan-Ping Chai
- Department of Pharmacy, Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Yi-Hang Wu
- Department of Pharmacy, Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Li-Peng Qiu
- Institute of Life Sciences, Jiangsu University, Zhenjiang 212013, China
| | - Yong-Yong Zhang
- Department of Pharmacy, Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Zi-Hong Ye
- Department of Pharmacy, Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
| | - Xiao-Ping Yu
- Department of Pharmacy, Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
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Hepatitis B surface antigen seroclearance: Immune mechanisms, clinical impact, importance for drug development. J Hepatol 2020; 73:409-422. [PMID: 32333923 DOI: 10.1016/j.jhep.2020.04.013] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/03/2020] [Accepted: 04/07/2020] [Indexed: 12/16/2022]
Abstract
HBsAg seroclearance occurs rarely in the natural history of chronic hepatitis B (CHB) infection and is associated with improved clinical outcomes. Many factors are associated with HBsAg seroconversion, including immune and viral factors. However, the immune mechanisms associated with HBsAg seroclearance are still difficult to elucidate. HBsAg seroclearance is the ideal aim of HBV treatment. Unfortunately, this goal is rarely achieved with current treatments. Understanding the mechanisms of HBsAg loss appears to be important for the development of curative HBV treatments. While studies from animal models give insights into the potential immune mechanisms and interactions occurring between the immune system and HBsAg, they do not recapitulate all features of CHB in humans and are subject to variability due to their complexity. In this article, we review recent studies on these immune factors, focusing on their influence on CHB progression and HBsAg seroconversion. These data provide new insights for the development of therapeutic approaches to partially restore the anti-HBV immune response. Targeting HBsAg will ideally relieve the immunosuppressive effects on the immune system and help to restore anti-HBV immune responses.
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45
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Boulon R, Blanchet M, Lemasson M, Vaillant A, Labonté P. Characterization of the antiviral effects of REP 2139 on the HBV lifecycle in vitro. Antiviral Res 2020; 183:104853. [PMID: 32585322 DOI: 10.1016/j.antiviral.2020.104853] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/22/2020] [Accepted: 06/11/2020] [Indexed: 12/18/2022]
Abstract
During hepatitis B virus (HBV) infection, HBV subviral particles (SVP) are produced in large excess in comparison to infectious virions and account for the major source of HBV surface antigen (HBsAg) in the blood. This abundant circulating HBsAg has been postulated to promote HBV chronicity by inducing immune exhaustion against HBsAg. Nucleic acid polymers (NAPs) such as REP 2139 display promising antiviral activity against both HBV and hepatitis Delta virus (HDV) in clinical trials. REP 2139 is accompanied by clearance of HBsAg from blood with concomitant reappearance of anti-HBsAg antibodies. To decipher the mechanism-of-action of NAPs, a recently developed cell-based assay in human HepG2.2.15 cells was used (Blanchet et al., 2019). This assay recapitulates the HBsAg secretion inhibition observed in treated patients. In the present study, we analysed the antiviral effect of REP 2139 on the HBV lifecycle. Importantly, we confirm here the potent inhibitory activity of the compound on HBsAg secretion, and report minor or no effect on other viral markers such as intracellular DNA and RNA, and HBeAg or Dane particle secretion. Notably, intracellular HBsAg accumulation is prevented by proteasomal and lysosomal degradation.
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Affiliation(s)
| | - Matthieu Blanchet
- INRS-Institut Armand Frappier, Laval, H7V 1B7, Canada; Replicor Inc. Montréal, H4P 2R2, Canada
| | - Matthieu Lemasson
- Institut National de La Transfusion Sanguine, CNRS-INSERM U1134, Paris, 75739, France
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Taylor JM. Infection by Hepatitis Delta Virus. Viruses 2020; 12:v12060648. [PMID: 32560053 PMCID: PMC7354607 DOI: 10.3390/v12060648] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 02/06/2023] Open
Abstract
Hepatitis delta virus (HDV) and hepatitis B virus (HBV) are blood-borne viruses that infect human hepatocytes and cause significant liver disease. Infections with HBV are more damaging when there is a coinfection with HDV. The genomes and modes of replication of these two viruses are fundamentally different, except for the fact that, in nature, HDV replication is dependent upon the envelope proteins of HBV to achieve assembly and release of infectious virus particles, ones that use the same host cell receptor. This review focuses on what has been found of the various ways, natural and experimental, by which HDV particles can be assembled and released. This knowledge has implications for the prevention and treatment of HDV infections, and maybe for an understanding of the origin of HDV.
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Affiliation(s)
- John M Taylor
- Fox Chase Cancer Center, Philadelphia, PA 19111, USA
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Durantel D, Asselah T. Nucleic Acid Polymers are Effective in Targeting Hepatitis B Surface Antigen, but More Trials Are Needed. Gastroenterology 2020; 158:2051-2054. [PMID: 32311360 DOI: 10.1053/j.gastro.2020.04.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 04/10/2020] [Indexed: 12/18/2022]
Affiliation(s)
- David Durantel
- INSERM, U1052, Cancer Research Center of Lyon, Université de Lyon, Lyon, France.
| | - Tarik Asselah
- Paris University, INSERM UMR 1149, Department of Hepatology, AP-HP Hôpital Beaujon, Clichy, France
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Bazinet M, Pântea V, Placinta G, Moscalu I, Cebotarescu V, Cojuhari L, Jimbei P, Iarovoi L, Smesnoi V, Musteata T, Jucov A, Dittmer U, Krawczyk A, Vaillant A. Safety and Efficacy of 48 Weeks REP 2139 or REP 2165, Tenofovir Disoproxil, and Pegylated Interferon Alfa-2a in Patients With Chronic HBV Infection Naïve to Nucleos(t)ide Therapy. Gastroenterology 2020; 158:2180-2194. [PMID: 32147484 DOI: 10.1053/j.gastro.2020.02.058] [Citation(s) in RCA: 131] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 02/27/2020] [Accepted: 02/27/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Nucleic acid polymers (NAPs) inhibit assembly and secretion of hepatitis B virus (HBV) subviral particles. We performed an open-label, phase 2 study of the safety and efficacy of the NAPs REP 2139 or REP 2165 combined with tenofovir disoproxil fumarate (TDF) and pegylated interferon alfa-2a (pegIFN) in patients with chronic HBV infection who were negative for hepatitis B e antigen. METHODS Following 24 weeks TDF therapy, 40 patients were randomly assigned to groups that received 48 weeks of experimental therapy (TDF + pegIFN + REP 2139-Mg or REP 2165-Mg) or 24 weeks of control therapy (TDF + pegIFN) followed by 48 weeks of experimental therapy. Patients were then followed for a treatment-free period of 48 weeks. Primary outcomes were the safety and tolerability of REP 2139-Mg or REP 2165-Mg in combination with TDF + pegIFN compared with TDF + pegIFN alone through the first 48 weeks of therapy and subsequently throughout 48 weeks of NAP-based combination therapy (treatment weeks 24-72 in the experimental group and weeks 48-96 in the control group). Secondary outcomes were reductions in hepatitis B surface antigen (HBsAg) in control and experimental groups over the first 48 weeks of the study and throughout 48 weeks of combination therapy and virologic control (HBsAg positive, HBV DNA below 2000 IU/mL, normal level of alanine aminotransferase) or functional cure (HBsAg below 0.05 IU/mL, HBV DNA target not detected, normal level of alanine aminotransferase) after removal of all therapy. RESULTS Levels of HBsAg, anti-HBs, and HBV DNA did not differ significantly between the groups given REP 2139 vs REP 2165. PegIFN-induced thrombocytopenia (P = .299 vs controls) and neutropenia (P = .112 vs controls) were unaffected by NAPs (REP 2139 vs REP 2165). Increases in levels of transaminases were significantly more frequent (P < .001 vs controls) and greater (P = .002 vs controls) in the NAP groups (but did not produce symptoms), correlated with initial decrease in HBsAg, and normalized during therapy and follow-up. During the first 24 weeks of TDF and pegIFN administration, significantly higher proportions of patients in NAP groups had decreases in HBsAg to below 1 IU/mL (P < .001 vs control) and HBsAg seroconversion (P = .046 vs control). At the time patients completed the TDF + pegIFN + NAP regimen, HBsAg levels were 0.05 IU/mL or lower in 24/40 participants (all with seroconversion up to 233,055 mIU/mL). During 48 weeks of treatment-free follow-up, virologic control persisted in 13 of 40 participants (2 lost to follow-up after 24 weeks), whereas functional cure persisted in 14 of 40 participants (all completing 48 weeks of follow-up) with persistent HBsAg seroconversion. One participant had a viral rebound during follow-up with hepatic decompensation and was placed on TDF therapy. CONCLUSIONS In a phase 2 randomized trial, we found that addition of NAPs to TDF + pegIFN did not alter tolerability and significantly increased rates of HBsAg loss and HBsAg seroconversion during therapy and functional cure after therapy. Clinicaltrials.gov no: NCT02565719.
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Affiliation(s)
| | - Victor Pântea
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Gheorghe Placinta
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Iurie Moscalu
- ARENSIA Exploratory Medicine, Republican Clinical Hospital Chișinău, Moldova
| | - Valentin Cebotarescu
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Lilia Cojuhari
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Pavlina Jimbei
- Toma Ciorbă Infectious Clinical Hospital, Chișinău, Republic of Moldova
| | - Liviu Iarovoi
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova
| | - Valentina Smesnoi
- Toma Ciorbă Infectious Clinical Hospital, Chișinău, Republic of Moldova
| | - Tatiana Musteata
- Toma Ciorbă Infectious Clinical Hospital, Chișinău, Republic of Moldova
| | - Alina Jucov
- Department of Infectious Diseases, Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Republic of Moldova; ARENSIA Exploratory Medicine, Republican Clinical Hospital Chișinău, Moldova
| | - Ulf Dittmer
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Adalbert Krawczyk
- Institute for Virology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany; Department of Infectious Diseases, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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Modelling hepatitis D virus RNA and HBsAg dynamics during nucleic acid polymer monotherapy suggest rapid turnover of HBsAg. Sci Rep 2020; 10:7837. [PMID: 32398799 PMCID: PMC7217939 DOI: 10.1038/s41598-020-64122-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/06/2020] [Indexed: 12/18/2022] Open
Abstract
Hepatitis D virus (HDV) requires hepatitis B surface antigen (HBsAg) for its assembly and release. Current HBV treatments are only marginally effective against HDV because they fail to inhibit HBsAg production/secretion. However, monotherapy with the nucleic acid polymer REP 2139-Ca is accompanied by rapid declines in both HBsAg and HDV RNA. We used mathematical modeling to estimate HDV-HBsAg-host parameters and to elucidate the mode of action and efficacy of REP 2139-Ca against HDV in 12 treatment-naive HBV/HDV co-infected patients. The model accurately reproduced the observed decline of HBsAg and HDV, which was simultaneous. Median serum HBsAg half-life (t1/2) was estimated as 1.3 [0.9–1.8] days corresponding to a pretreatment production and clearance of ~108 [107.7–108.3] IU/day. The HDV-infected cell loss was estimated to be 0.052 [0.035–0.074] days−1 corresponding to an infected cell t1/2 = 13.3 days. The efficacy of blocking HBsAg and HDV production were 98.2 [94.5–99.9]% and 99.7 [96.0–99.8]%, respectively. In conclusion, both HBsAg production and HDV replication are effectively inhibited by REP 2139-Ca. Modeling HBsAg kinetics during REP 2139-Ca monotherapy indicates a short HBsAg half-life (1.3 days) suggesting a rapid turnover of HBsAg in HBV/HDV co-infection.
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Targeting the Host for New Therapeutic Perspectives in Hepatitis D. J Clin Med 2020; 9:jcm9010222. [PMID: 31947588 PMCID: PMC7019876 DOI: 10.3390/jcm9010222] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 02/07/2023] Open
Abstract
Hepatitis D virus (HDV) is a small satellite virus of hepatitis B virus (HBV) requiring HBV infection to complete its life cycle. It has been recently estimated that 13% of chronic HBV infected patients (60 million) are co-infected with HDV. Chronic hepatitis D is the most severe form of viral hepatitis with the highest risk to develop cirrhosis and liver cancer. Current treatment is based on pegylated-interferon-alpha which rarely controls HDV infection and is complicated by serious side effects. The development of novel antiviral strategies based on host targeting agents has shown promising results in phase I/II clinical trials. This review summarizes HDV molecular virology and physiopathology as well as new therapeutic approaches targeting HDV host factors.
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