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Gopalakrishna H, Ghany MG. Perspective on Emerging Therapies to Achieve Functional Cure of Chronic Hepatitis B. CURRENT HEPATOLOGY REPORTS 2024; 23:241-252. [PMID: 38699562 PMCID: PMC11062629 DOI: 10.1007/s11901-024-00652-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/24/2024] [Indexed: 05/05/2024]
Abstract
Purpose of Review Advancements in our understanding of the hepatitis B viral (HBV) life cycle have paved the way for novel approaches to treat HBV infection. This review summarizes the various strategies being pursued to achieve a functional cure, defined as loss of hepatitis B surface antigen (HBsAg) and absence of viral replication 6 months off-therapy. Recent Findings Direct acting antiviral, host targeting antiviral, and immunological approaches are in various stages of development as treatment for chronic HBV infection. Summary Novel treatments are being developed in pursuit of a cure for HBV. Current evidence suggests a single therapeutic agent alone may be insufficient, necessitating the need for combination therapy targeting HBV and the host immune response. Ongoing research focused on identifying the best therapeutic combination holds promise in achieving functional cure for HBV.
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Affiliation(s)
- Harish Gopalakrishna
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 10 Center Drive, Building 10, Room 9B-16, Bethesda, MD 20892‐1800, USA
| | - Marc G. Ghany
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 10 Center Drive, Building 10, Room 9B-16, Bethesda, MD 20892‐1800, USA
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Kato D, Choy RWY, Canales E, Dick RA, Lake AD, Shapiro ND, Chin E, Li J, Zhang JR, Wu Q, Saito RD, Metobo S, Aktoudianakis E, Schroeder SD, Yang ZY, Glatt DM, Balsitis S, Gamelin L, Yu M, Cheng G, Delaney WE, Link JO. Discovery of Hepatitis B Virus Surface Antigen Suppressor GS-8873. ACS Med Chem Lett 2024; 15:546-554. [PMID: 38628802 PMCID: PMC11017420 DOI: 10.1021/acsmedchemlett.4c00037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
Chronic hepatitis B (CHB) virus infection afflicts hundreds of millions of people and causes nearly one million deaths annually. The high levels of circulating viral surface antigen (HBsAg) that characterize CHB may lead to T-cell exhaustion, resulting in an impaired antiviral immune response in the host. Agents that suppress HBsAg could help invigorate immunity toward infected hepatocytes and facilitate a functional cure. A series of dihydropyridoisoquinolizinone (DHQ) inhibitors of human poly(A) polymerases PAPD5/7 were reported to suppress HBsAg in vitro. An example from this class, RG7834, briefly entered the clinic. We set out to identify a potent, orally bioavailable, and safe PAPD5/7 inhibitor as a potential component of a functional cure regimen. Our efforts led to the identification of a dihydropyridophthalazinone (DPP) core with improved pharmacokinetic properties. A conformational restriction strategy and optimization of core substitution led to GS-8873, which was projected to provide deep HBsAg suppression with once-daily dosing.
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Affiliation(s)
- Darryl Kato
- Gilead
Sciences, Foster City, California 94404, United States
| | | | - Eda Canales
- Gilead
Sciences, Foster City, California 94404, United States
| | - Ryan A. Dick
- Maze
Therapeutics, South
San Francisco, California 94080, United States
| | - April D. Lake
- Gilead
Sciences, Foster City, California 94404, United States
| | | | - Elbert Chin
- Gilead
Sciences, Foster City, California 94404, United States
| | - Jiayao Li
- Gilead
Sciences, Foster City, California 94404, United States
| | | | - Qiaoyin Wu
- Gilead
Sciences, Foster City, California 94404, United States
| | - Roland D. Saito
- Gilead
Sciences, Foster City, California 94404, United States
| | - Sammy Metobo
- Circle
Pharma, South San Francisco, California 94080, United States
| | | | | | - Zheng-Yu Yang
- Gilead
Sciences, Foster City, California 94404, United States
| | - Dylan M. Glatt
- 23andMe
Therapeutics, South
San Francisco, California 94080, United States
| | - Scott Balsitis
- Gilead
Sciences, Foster City, California 94404, United States
| | - Lindsay Gamelin
- Gilead
Sciences, Foster City, California 94404, United States
| | - Mei Yu
- Gilead
Sciences, Foster City, California 94404, United States
| | - Guofeng Cheng
- AusperBio
Therapeutics Inc., San Mateo, California 94401, United States
| | | | - John O. Link
- Gilead
Sciences, Foster City, California 94404, United States
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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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