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Gish RG, Asselah T, Squires K, Mayers D. Active site polymerase inhibitor nucleotides (ASPINs): Potential agents for chronic HBV cure regimens. Antivir Chem Chemother 2022; 30:20402066221138705. [PMID: 36423233 PMCID: PMC9703507 DOI: 10.1177/20402066221138705] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/06/2022] [Indexed: 10/03/2023] Open
Abstract
Chronic hepatitis B virus (HBV) infection affects 240 to 300 million people worldwide. In the nucleus of infected hepatocytes, the HBV genome is converted to covalently closed circular DNA (cccDNA), which persists and serves as a transcriptional template for viral progeny. Therefore, a long-term cure for chronic HBV infection will require elimination of cccDNA. Although currently available nucleos(t)ide analogues (eg, tenofovir disoproxil fumarate, tenofovir alafenamide, entecavir) effectively control HBV replication, they are seldom curative (functional cure rate ∼10%) and require lifelong treatment for most patients. As such, antiviral agents with novel mechanisms of action are needed. Active site polymerase inhibitor nucleotides (ASPINs) noncompetitively distort the HBV polymerase active site to completely inhibit all polymerase functions, unlike traditional chain-terminating nucleos(t)ide analogues, which only target select polymerase functions and are consumed in the process. Clevudine, a first-generation ASPIN, demonstrated potent and prolonged HBV suppression in phase 2 and 3 clinical studies, but long-term treatment was associated with reversible myopathy in a small number of patients. ATI-2173, a novel next-generation ASPIN, is structurally similar to clevudine but targets the liver and demonstrates potent anti-HBV activity on and off treatment, and may ultimately demonstrate an improved pharmacokinetic and safety profile by significantly reducing systemic clevudine exposure. Thus, ATI-2173 is currently in clinical development as an agent for HBV cure. Here, we review the mechanism of action and preclinical and clinical profiles of clevudine and ATI-2173 to support the role of ASPINs as part of curative regimens for chronic HBV infection.
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Affiliation(s)
- Robert G Gish
- Hepatitis B Foundation, Doylestown, PA, USA
- Robert G. Gish Consultants, LLC, La Jolla, CA, USA
| | - Tarik Asselah
- Université de Paris, Inserm U1149, Centre de Recherche sur l’inflammation, Paris, France
- Department of Hepatology, AP-HP, Hôpital Beaujon, Clichy, France
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Rajput MK. Mutations and methods of analysis of mutations in Hepatitis B virus. AIMS Microbiol 2020; 6:401-421. [PMID: 33364535 PMCID: PMC7755589 DOI: 10.3934/microbiol.2020024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/23/2020] [Indexed: 12/13/2022] Open
Abstract
Immunization programmes against hepatitis-B are being carried out since more than three decades but still HBV is a major public health problem. Hepatitis B virus (HBV) genome consists of circular and partial double stranded DNA. Due to partial double stranded DNA, it uses an RNA intermediate during replication. This replicative strategy of HBV and lack of polymerase proofreading activity give rise to error occurrences comparable to retroviruses. The low fidelity of polymerase, overlapping reading frames and high replication rate produces many non-identical variants at every cycle of replication. Therefore, HBV spreads with mutations and variations. The mutations have been reported both in non-structural as well as structural genes of HBV genome. Recent advances in molecular biology have made easier to analyse these mutations. Hepatitis B antiviral therapy and immunization are all influenced by genetic variability. The analysis and understanding of these mutations are important for therapy against hepatitis B and updating of diagnostic tools. The present review discusses about mutations occurring in whole HBV genome. The mutation occurring both in structural and non-structural genes and non-coding regions have been described in details. It is much more informative because most of literature available, covers only individual gene or DNA regions of HBV.
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HBV quasispecies composition in Lamivudine-failed chronic hepatitis B patients and its influence on virological response to Tenofovir-based rescue therapy. Sci Rep 2017; 7:44742. [PMID: 28303969 PMCID: PMC5356183 DOI: 10.1038/srep44742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/13/2017] [Indexed: 12/15/2022] Open
Abstract
The present study sought to evaluate the structure of HBV quasispecies in Lamivudine (LMV)-failed chronic hepatitis B (CHB) patients and its impact in defining the subsequent virological responses to Tenofovir (TDF)-based rescue-therapy. By analyzing HBV clones encompassing reverse transcriptase (RT) and surface (S) region from LMV-failed and treatment-naïve CHB patients, we identified 5 classical and 12 novel substitutions in HBV/RT and 9 substitutions in immune-epitopes of HBV/S that were significantly associated with LMV failure. In silico analysis showed spatial proximity of some of the newly-identified, mutated RT residues to the RT catalytic centre while most S-substitutions caused alteration in epitope hydrophobicity. TDF administration resulted in virological response in 60% of LMV-failed patients at 24-week but non-response in 40% of patients even after 48-weeks. Significantly high frequencies of 6 S-substitutions and one novel RT-substitution, rtH124N with 6.5-fold-reduced susceptibility to TDF in vitro, were noted at baseline in TDF non-responders than responders. Follow-up studies depicted greater evolutionary drift of HBV quasispecies and significant decline in frequencies of 3 RT and 6 S-substitutions in responder-subgroup after 24-week TDF-therapy while most variants persisted in non-responders. Thus, we identified the HBV-RT/S variants that could potentially predict unfavorable response to LMV/TDF-therapy and impede immune-mediated viral clearance.
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In Vitro Studies Show that Sequence Variability Contributes to Marked Variation in Hepatitis B Virus Replication, Protein Expression, and Function Observed across Genotypes. J Virol 2016; 90:10054-10064. [PMID: 27512071 DOI: 10.1128/jvi.01293-16] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/02/2016] [Indexed: 01/05/2023] Open
Abstract
The hepatitis B virus (HBV) exists as 9 major genotypes (A to I), one minor strain (designated J) and multiple subtypes. Marked differences in HBV natural history, disease progression and treatment response are exhibited by many of these genotypes and subtypes. For example, HBV genotype C is associated with later hepatitis B e antigen (HBeAg) seroconversion and high rates of liver cancer compared to other HBV genotypes, whereas genotype A2 is rarely associated with HBeAg-negative disease or liver cancer. The reasons for these and other differences in HBV natural history are yet to be determined but could in part be due to sequence differences in the HBV genome that alter replicative capacity and/or gene expression. Direct comparative studies on HBV replication and protein expression have been limited to date due largely to the absence of infectious HBV cDNA clones for each of the HBV genotypes present in the same genetic arrangement. We have produced replication-competent infectious cDNA clones of the most common subtypes of genotypes A to D, namely, A2, B2, C2, D3, and the minor strain J, and compared their HBV replication phenotype using transient-transfection models. We identified striking differences in HBV replicative capacity as well as HBeAg and surface (HBsAg) protein expression across genotypes, which may in part be due to sequence variability in regulatory regions of the HBV genome. Functional analysis showed that sequence differences in the major upstream regulatory region across genotypes impacted promoter activity. IMPORTANCE There have been very few studies directly comparing the replication phenotype of different HBV genotypes, for which there are marked differences in natural history and disease progression worldwide. We have generated replication-competent 1.3-mer cDNA clones of the major genotypes A2, B2, C2, and D3, as well as a recently identified strain J, and identified striking differences in replicative capacity and protein expression that may contribute to some of the observed differences in HBV natural history observed globally.
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Franchini S, Battisti UM, Sorbi C, Tait A, Cornia A, Jeong LS, Lee SK, Song J, Loddo R, Madeddu S, Sanna G, Brasili L. Synthesis, structural characterization and biological evaluation of 4'-C-methyl- and phenyl-dioxolane pyrimidine and purine nucleosides. Arch Pharm Res 2016; 40:537-549. [PMID: 27615010 DOI: 10.1007/s12272-016-0825-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 08/24/2016] [Indexed: 11/25/2022]
Abstract
Nucleoside analogues play an important role in antiviral, antibacterial and antineoplastic chemotherapy. Herein we report the synthesis, structural characterization and biological activity of some 4'-C -methyl- and -phenyl dioxolane-based nucleosides. In particular, α and β anomers of all natural nucleosides were obtained and characterized by NMR, HR-MS and X-ray crystallography. The compounds were tested for antimicrobial activity against some representative human pathogenic fungi, bacteria and viruses. Antitumor activity was evaluated in a large variety of human cancer cell-lines. Although most of the compounds showed non-significant activity, 23α weakly inhibited HIV-1 multiplication. Moreover, 22α and 32α demonstrated a residual antineoplastic activity, interestingly linked to the unnatural α configuration. These results may provide structural insights for the design of active antiviral and antitumor agents.
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Affiliation(s)
- Silvia Franchini
- Department of Life Sciences, University of Modena & Reggio Emilia, Via G. Campi 103, 41125, Modena, Italy
| | - Umberto M Battisti
- Department of Life Sciences, University of Modena & Reggio Emilia, Via G. Campi 103, 41125, Modena, Italy
| | - Claudia Sorbi
- Department of Life Sciences, University of Modena & Reggio Emilia, Via G. Campi 103, 41125, Modena, Italy
| | - Annalisa Tait
- Department of Life Sciences, University of Modena & Reggio Emilia, Via G. Campi 103, 41125, Modena, Italy
| | - Andrea Cornia
- Department of Chemical and Geological Sciences, University of Modena & Reggio Emilia, Via G. Campi 103, 41125, Modena, Italy
| | - Lak Shin Jeong
- College of Pharmacy, Seoul National University, Seoul, 151-742, Republic of Korea
| | - Sang Kook Lee
- College of Pharmacy, Seoul National University, Seoul, 151-742, Republic of Korea
| | - Jayoung Song
- College of Pharmacy, Seoul National University, Seoul, 151-742, Republic of Korea
| | - Roberta Loddo
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, CA, Italy
| | - Silvia Madeddu
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, CA, Italy
| | - Giuseppina Sanna
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, CA, Italy
| | - Livio Brasili
- Department of Life Sciences, University of Modena & Reggio Emilia, Via G. Campi 103, 41125, Modena, Italy.
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A novel method for nucleos(t)ide analogues susceptibility assay of hepatitis B virus by viral polymerase transcomplementation. Antiviral Res 2015; 126:99-107. [PMID: 26738784 DOI: 10.1016/j.antiviral.2015.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 12/18/2015] [Accepted: 12/22/2015] [Indexed: 02/06/2023]
Abstract
Nucleos(t)ide analogues (NUCs) susceptibility assay is important for the study of hepatitis B virus (HBV) drug resistance. The purpose of susceptibility assay is to test the sensitivity of a specific HBV variant to NUCs in vitro, by which assesses if and to what extent the mutant virus is resistant to a specific NUC. Among the existing susceptibility assay methods, stable cell line expressing the specific variant is one of the commonly used assessment systems based on its high repeatability. However, establishment of stable cell lines expressing individual variant is laborious and time-consuming. In the present study, we developed a novel strategy for rapidly establishing HBV replicating stable cell lines. We first established an acceptor cell line stably transfected with a polymerase-null HBV 1.1mer genome DNA, then lentiviruses expressing different mutant HBV polymerases were transduced into the acceptor cell line respectively. Stable cell lines replicating HBV DNA with the trans-complemented HBV polymerases were established by antibiotics selection. Lamivudine and entecavir susceptibility data from these polymerase-complementing cell lines were validated by comparing with other assays. Taken together, this transcomplementation strategy for establishment of stable cell lines replicating HBV DNA with clinically isolated HBV polymerase provides a new tool for NUC susceptibility assay of HBV.
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Nucleoside/nucleotide analog inhibitors of hepatitis B virus polymerase: mechanism of action and resistance. Curr Opin Virol 2014; 8:1-9. [PMID: 24814823 DOI: 10.1016/j.coviro.2014.04.005] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 04/14/2014] [Accepted: 04/16/2014] [Indexed: 02/07/2023]
Abstract
Hepatitis B virus (HBV) polymerase and human immunodeficiency virus (HIV) reverse transcriptase are structurally related. However, the HBV enzyme has a protein priming activity absent in the HIV enzyme. Approved nucleoside/nucleotide inhibitors of the HBV polymerase include lamivudine, adefovir, telbivudine, entecavir and tenofovir. Although most of them target DNA elongation, guanosine and adenosine analogs (e.g. entecavir and tenofovir, respectively) also impair protein priming. Major mutational patterns conferring nucleoside/nucleotide analog resistance include the combinations rtL180M/rtM204(I/V) (for lamivudine, entecavir, telbivudine and clevudine) and rtA181V/rtN236T (for adefovir and tenofovir). However, development of drug resistance is very slow for entecavir and tenofovir. Novel nucleoside/nucleotide analogs in advanced clinical trials include phosphonates similar to adefovir or tenofovir, and new tenofovir derivatives with improved pharmacological properties.
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De Clercq E. Potential of acyclic nucleoside phosphonates in the treatment of DNA virus and retrovirus infections. Expert Rev Anti Infect Ther 2014; 1:21-43. [PMID: 15482100 DOI: 10.1586/14787210.1.1.21] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The acyclic nucleoside phosphonates [HPMPC: cidofovir, Vistide; PMEA: adefovir dipivoxil, Hepsera; and PMPA: tenofovir, Viread] have proven to be effective in vitro (cell culture systems) and in vivo (animal models and clinical studies) against a wide variety of DNA virus and retrovirus infections, for example, cidofovir against herpesvirus [herpes simplex virus type 1 and 2, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, human herpesvirus type 6, 7 and 8), polyoma-, papilloma-, adeno- and poxvirus (variola virus, cowpox virus, vaccinia virus, molluscum contagiosum virus and orf) infections; adefovir against herpesvirus, hepadnavirus [human hepatitis B virus] and retrovirus [HIV type-1 and 2, simian immunodeficiency virus and feline immunodeficiency virus] infections; and tenofovir against both hepadna- and retrovirus infections. Cidofovir has been officially approved for the treatment of cytomegalovirus retinitis in AIDS patients, tenofovir disoproxil fumarate (Viread) for the treatment of HIV infections (i.e., AIDS) and adefovir dipivoxil for the treatment of chronic hepatitis B.
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Affiliation(s)
- Eric De Clercq
- Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
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Cavallone D, Moriconi F, Colombatto P, Oliveri F, Bonino F, Brunetto MR. Optimization of in vitro HBV replication and HBsAg production in HuH7 cell line. J Virol Methods 2013; 189:110-7. [DOI: 10.1016/j.jviromet.2013.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 01/04/2013] [Accepted: 01/28/2013] [Indexed: 12/12/2022]
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Cabuang LM, Shaw T, Littlejohn M, Colledge D, Sozzi V, Soppe S, Warner N, Thompson A, Preiss S, Lam N, Walsh R, Lewin SR, Thio CL, Matthews G, Locarnini SA, Revill PA. In vitro replication phenotype of a novel (-1G) hepatitis B virus variant associated with HIV co-infection. J Med Virol 2012; 84:1166-76. [PMID: 22711344 DOI: 10.1002/jmv.23328] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The -1G mutant HBV is more prevalent in individuals co-infected with HIV/HBV than in individuals infected with HBV alone and in some cases is the dominant virus in circulation. This mutant is created by the deletion of a dGMP (-1G) from the guanine rich homopolymer sequence located at nts 2,085-2,090 (numbering from EcoRI site as position 1) in the HBV core gene. This deletion causes a frameshift generating a premature stop codon at (64) Asn in the HBV core gene (codon 93 in the precore gene), that truncates the precore protein, precursor of the secreted hepatitis B "e" antigen (HBeAg), and the core protein which forms the viral nucleocapsid. However, the replication phenotype of the -1G mutant HBV is unknown. An in vitro cell culture model in which hepatoma cells were transiently transfected with infectious cDNAs was used to show that the -1G mutant HBV is incapable of autonomous replication and, as expected, replication was restored to wild-type (wt) levels by supplying HBV core protein in trans. Although the -1G mutation had no deleterious effect on intracellular HBV-DNA levels, high levels of -1G mutant HBV relative to wt HBV reduced virus secretion and HBeAg secretion relative to empty vector controls. Importantly, the -1G mutant HBV also caused intracellular retention of truncated precore protein in the endoplasmic reticulum (ER) and Golgi apparatus. Together, these effects may be contributing to the increased pathology observed in the setting of HIV/HBV co-infection.
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Affiliation(s)
- Liza M Cabuang
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Victoria, Australia
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Zhou Y, Zhang Y, Yang X, Zhao J, Zheng L, Sun C, Jiang J, Yang Q, Wang Q, Chang J. Novel nucleoside analogue FNC is effective against both wild-type and lamivudine-resistant hepatitis B virus clinical isolates. Antivir Ther 2012; 17:1593-9. [DOI: 10.3851/imp2292] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2012] [Indexed: 10/28/2022]
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Deng L, Tang H. Hepatitis B virus drug resistance to current nucleos(t)ide analogs: Mechanisms and mutation sites. Hepatol Res 2011; 41:1017-24. [PMID: 21917087 DOI: 10.1111/j.1872-034x.2011.00873.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Nucleos(t)ide analogs (NAs) have become the mainstream drugs for the treatment of chronic hepatitis B virus infection. Drug resistance to NAs, however, has posed a major obstacle in obtaining sustained viral suppression. Standardized definitions of terms and nomenclature in discussing NAs resistance have been proposed. Drug resistance to NAs is produced by a combination of viral, host and antiviral drug factors. A detailed understanding of the mechanisms and effects of mutation sites that cause resistance to NAs is important for the design of rational treatment and management of patients with existing drug resistance.
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Affiliation(s)
- Lihui Deng
- Center of Infectious Diseases, West China Hospital of Sichuan University Division of Infectious Diseases, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, Sichuan Province, China
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Wilson R, Warner N, Ryan K, Selleck L, Colledge D, Rodgers S, Li K, Revill P, Locarnini S. The hepatitis B e antigen suppresses IL-1β-mediated NF-κB activation in hepatocytes. J Viral Hepat 2011; 18:e499-507. [PMID: 21914069 DOI: 10.1111/j.1365-2893.2011.01484.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Previous clinical studies have demonstrated an association between the hepatitis B e antigen and Toll-like receptor (TLR) expression and signalling. Therefore, the aim of this study was to develop an in vitro assay to measure the effect of hepatitis B virus proteins, including the precore protein, on signalling mediated by members of the Toll-like/interleukin 1 (TIR) superfamily, by measuring NF-κB promoter activity. The basal level of NF-κB reporter activity was measured in three hepatocyte cell lines (Huh7, HepG2 and PH5CH8) and one kidney cell line (HEK293) using a luciferase assay. All cell lines were virtually refractory to stimulation with lipopolysaccharide; however, PH5CH8 cells had a robust activation of NF-κB in response to IL-1β stimulation, with ∼ 40-fold higher activation than the unstimulated control, a higher degree of activation than that observed in either Huh7 and HepG2, or HEK293 and HEK293-TLR2 cells. In PH5CH8 cells transfected with pCI expression constructs and stimulated with IL-1β, we showed that the precursor form of the precore protein, p25, inhibits NF-κB activation by up to 30% and the cytosolic form, p22, inhibits NF-κB activation by 70%. The core protein, p21, which shares significant homology with the precore protein except for a 10-amino acid extension at the N-terminus, had no effect on NF-κB activation. We hypothesize that the inhibition of IL-1β-mediated NF-κB activation by the precore protein may be a mechanism that allows the virus to persist, suggesting a role for the pool of precore protein that remains intracellular.
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Affiliation(s)
- R Wilson
- Research & Molecular Development, Victorian Infectious Diseases Reference Laboratory, North Melbourne, Victoria, Australia
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Kim JH, Yim HJ, Jung ES, Jung YK, Kim JH, Seo YS, Yeon JE, Lee HS, Um SH, Byun KS. Virologic and biochemical responses to clevudine in patients with chronic HBV infection-associated cirrhosis: data at week 48. J Viral Hepat 2011; 18:287-93. [PMID: 20367793 DOI: 10.1111/j.1365-2893.2010.01304.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Clevudine shows high rates of virologic and biochemical responses in patients with chronic hepatitis B. However, the efficacy and safety of clevudine in patients with cirrhosis are unknown. The aims of this study were to evaluate the safety and to assess the virologic and the biochemical responses to clevudine in patients with cirrhosis with chronic hepatitis B virus (HBV) infection. We reviewed data from treatment-naïve patients with chronic hepatitis B with and without cirrhosis who started clevudine between April 2007 and March 2008 (n = 52, hepatitis B without cirrhosis n = 21 and chronic hepatitis B with cirrhosis n = 31) at Korea University Ansan/Guro Hospital. All of the patients were treated for more than 48 weeks. The mean age was older in the patients with cirrhosis. Baseline HBV DNA levels were 6.9 and 7.78 log copies/mL (P = 0.042), and alanine aminotransferase (ALT) levels were 104.9 and 147.4 IU/L (P = 0.204), for those with and without cirrhosis, respectively. Virologic response (HBV DNA <1000 copies/mL) (87.1%vs 71.4%, P = 0.24) and biochemical response (83.9%vs 80.9%, P = 0.99) at week 48 were not significantly different between the two groups. Early virologic response at week 12 was even higher in the patients with cirrhosis (61.3%vs 28.6%, P = 0.026). Neither ALT flare nor newly onset hepatic decompensation was found in the patients with cirrhosis, whereas ALT flare was transiently observed in 14.3% of the chronic hepatitis group. In conclusion, although clevudine may produce a transient elevation of ALT during the early treatment period, such findings were not observed in patients with cirrhosis and the virologic and biochemical responses of the groups were comparable.
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Affiliation(s)
- J H Kim
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
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Vivekanandan P, Singh OV. Molecular methods in the diagnosis and management of chronic hepatitis B. Expert Rev Mol Diagn 2011; 10:921-35. [PMID: 20964611 DOI: 10.1586/erm.10.75] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Chronic hepatitis B (CHB) infection remains a major global problem but the recent advances in molecular methods have revolutionized the diagnosis and management of CHB. Hepatitis B virus (HBV) DNA quantitation is the most useful molecular marker for the diagnosis and management of CHB. There is increasing evidence that the clinical outcome and efficacy of antiviral therapy for CHB could vary with the infecting HBV genotype, core promoter and precore mutations. Early identification of drug resistance is imperative in the management of CHB. The molecular methods for HBV DNA quantitation, HBV genotyping, the identification of mutants, genotypic and phenotypic methods for monitoring drug resistance and their utility and limitations for use in the diagnosis and monitoring of CHB are discussed in this article.
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Affiliation(s)
- Perumal Vivekanandan
- School of Biological Sciences, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India.
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Niu C, Bao H, Tolstykh T, Micolochick Steuer HM, Murakami E, Korba B, Furman PA. Evaluation of the in vitro anti-HBV activity of clevudine in combination with other nucleoside/nucleotide inhibitors. Antivir Ther 2010; 15:401-12. [PMID: 20516559 DOI: 10.3851/imp1541] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND To reduce the incidence of drug resistance and to maintain viral suppression, patients chronically infected with HBV might require combination therapy using two or more drugs with different resistance profiles. We investigated the activity of clevudine (CLV) in combination with other nucleoside/nucleotide analogues to determine if these combinations were compatible in vitro. METHODS Using the HepAD38 cell line, which expresses wild-type HBV, and a real-time PCR assay, we tested the anti-HBV activity of CLV in combination with entecavir, lamivudine, adefovir, tenofovir and telbivudine (TBV). We evaluated the uptake and phosphorylation of CLV in the presence of TBV, using HepAD38 cells and primary hepatocytes to determine the effect of TBV on the phosphorylation of CLV and vice versa. Phosphorylation of TBV and CLV to their corresponding monophosphate by deoxycytidine kinase, thymidine kinase-1 and thymidine kinase-2, and the phosphorylation of TBV monophosphate and CLV monophosphate by thymidylate kinase was evaluated and compared. RESULTS When CLV was combined with entecavir, lamivudine, adefovir or tenofovir, a synergistic antiviral effect was observed; however, the combination of CLV and TBV gave an antagonistic antiviral response. The results of in vitro metabolism and enzyme studies suggest that the antagonism observed with the CLV/TBV combination involves competition for uptake and phosphorylation. CONCLUSIONS The results of our studies demonstrate that combination treatments can provide enhanced antiviral activity and, when used in conjunction with appropriate metabolic investigations, provide a rational basis for the design and development of combination regimens for treating chronic HBV infection.
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Kim KH, Kim ND, Seong BL. Discovery and development of anti-HBV agents and their resistance. Molecules 2010; 15:5878-908. [PMID: 20802402 PMCID: PMC6257723 DOI: 10.3390/molecules15095878] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 08/24/2010] [Accepted: 08/26/2010] [Indexed: 02/07/2023] Open
Abstract
Hepatitis B virus (HBV) infection is a prime cause of liver diseases such as hepatitis, cirrhosis and hepatocellular carcinoma. The current drugs clinically available are nucleot(s)ide analogues that inhibit viral reverse transcriptase activity. Most drugs of this class are reported to have viral resistance with breakthrough. Recent advances in methods for in silico virtual screening of chemical libraries, together with a better understanding of the resistance mechanisms of existing drugs have expedited the discovery and development of novel anti-viral drugs. This review summarizes the current status of knowledge about and viral resistance of HBV drugs, approaches for the development of novel drugs as well as new viral and host targets for future drugs.
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Affiliation(s)
- Kyun-Hwan Kim
- Department of Pharmacology, School of Medicine, and Center for Cancer Research and Diagnostic Medicine, IBST, Konkuk University, Seoul 143-701, Korea
- Research Institute of Medical Sciences, Konkuk University, Seoul 143-701, Korea
- Author to whom correspondence should be addressed; E-Mail: (K.H.K.); Tel.: +82 2 2030 7833; Fax: +82 2 2049 6192; E-Mail: (B.L.S.); Tel.: +82 2 2123 2885; Fax: +82 2 392 3582
| | - Nam Doo Kim
- R&D Center, Equispharm Inc., 11F Gyeonggi Bio-Center, 864-1 Iui-Dong, Yeongtong-gu, Suwon-Shi, Gyeonggi-Do 443-766, Korea
| | - Baik-Lin Seong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
- Translational Research Center for Protein Function Control, Yonsei University, Seoul 120-749, Korea
- Author to whom correspondence should be addressed; E-Mail: (K.H.K.); Tel.: +82 2 2030 7833; Fax: +82 2 2049 6192; E-Mail: (B.L.S.); Tel.: +82 2 2123 2885; Fax: +82 2 392 3582
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Tak WY, Park SY, Cho CM, Jung MK, Jeon SW, Kweon YO, Park JY, Sohn YK. Clinical, biochemical, and pathological characteristics of clevudine-associated myopathy. J Hepatol 2010; 53:261-6. [PMID: 20466447 DOI: 10.1016/j.jhep.2010.03.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 03/04/2010] [Accepted: 03/09/2010] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS The aim of this study was to define the clinical, biochemical, and pathological characteristics of myopathy developed during clevudine therapy. METHODS We prospectively enrolled 36 consecutive myopathy patients who were receiving clevudine therapy for the treatment of chronic hepatitis B (CHB). We evaluated patients with a complete medical history, neurologic examination with a questionnaire on neuromuscular diseases, laboratory tests, electrophysiology studies, and muscle biopsies. RESULTS The median duration of clevudine therapy was 18.0 months (ranging from 9 to 24 months). The chief complaint was weakness of the lower extremities in 30 patients (83.3%) and asthenia in five patients (13.9%). One patient (2.8%) had only persistently elevated serum muscle enzyme without any symptoms. Weakness of the lower extremity mainly involved proximal muscle group of the lower extremity, characterized by difficulty in climbing stairs (83.3%), a decrease in exercise capacity (75.0%) and difficulty in walking (55.6%). All patients showed an elevation of more than two of serum creatine kinase, lactate dehydrogenase, and lactate levels. Muscle biopsies performed in 23 patients revealed myopathic features with abnormal mitochondria in 21 patients, and nonspecific myositis in two patients. Motor weakness gradually improved after discontinuation of clevudine. CONCLUSIONS Myopathy associated with clevudine is characterized by a weakness in proximal muscles of the lower extremities with elevated muscle enzymes and presumably caused by mitochondrial toxicities. Careful medical and serologic examinations are essential for the early detection and management of this potential adverse reaction in CHB patients under clevudine therapy.
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Affiliation(s)
- Won Young Tak
- Department of Internal Medicine, Liver Research Institute, Graduate School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
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Kim HJ, Park DI, Park JH, Cho YK, Sohn CI, Jeon WK, Kim BI. Comparison between clevudine and entecavir treatment for antiviral-naïve patients with chronic hepatitis B. Liver Int 2010; 30:834-40. [PMID: 20408946 DOI: 10.1111/j.1478-3231.2010.02245.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND AIMS There has been no study comparing the clinical efficacy of clevudine and entecavir in antiviral-naïve patients with chronic hepatitis B (CHB). METHODS A total of 128 antiviral-naïve CHB patients were included to receive clevudine 30 mg (n=55) or entecavir 0.5 mg (n=73) once daily for a mean follow-up period of 18.4 months. RESULTS Thirty-three (60.0%) in the clevudine group and 40 (54.8%) in the entecavir group were HBeAg positive (P>0.05). At 6 months from the baseline, the mean decreases in HBV-DNA were 4.86 and 4.72 log(10) copies/ml in the clevudine and entecavir groups respectively (P>0.05). The proportion of patients with undetectable serum HBV-DNA (<300 copies/ml) at 6 months was 65.5 and 74.0% in the clevudine and entecavir groups respectively (P>0.05). The proportion of patients with normal alanine aminotransferase levels at 6 months was 74.5 and 84.9% in the clevudine and entecavir groups respectively. During the mean follow-up of 18.4 months, genotypic resistance was noted in three patients (5.5%) in the clevudine group and no cases in the entecavir group. Eight patients (14.6%) in the clevudine group experienced symptoms, signs and laboratory abnormalities relevant to clevudine-induced myopathy. CONCLUSIONS Clevudine and entecavir treatment effectively suppresses HBV replication in most antiviral-naïve patients with CHB. During a mean follow-up of 18.9 months, a small proportion (5.5%) of patients in the clevudine group developed genotypic resistance. However, a substantial proportion (14.6%) of patients in the clevudine group had an adverse effect of clevudine-induced myopathy.
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Affiliation(s)
- Hong Joo Kim
- Department of Internal Medicine, Division of Gastroenterology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
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20
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Kim IH, Lee S, Kim SH, Kim SW, Lee SO, Lee ST, Kim DG, Choi CS, Kim HC. Treatment outcomes of clevudine versus lamivudine at week 48 in naïve patients with HBeAg positive chronic hepatitis B. J Korean Med Sci 2010; 25:738-45. [PMID: 20436711 PMCID: PMC2858834 DOI: 10.3346/jkms.2010.25.5.738] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Accepted: 09/28/2009] [Indexed: 12/21/2022] Open
Abstract
The authors assessed the efficacy and antiviral resistance of 48-week clevudine therapy versus lamivudine in treatment of naïve patients with HBeAg positive chronic hepatitis B. In this retrospective study, a total of 116 HBeAg positive patients, who received 30 mg of clevudine once daily (n=53) or 100 mg of lamivudine once daily (n=63) for 48 weeks, were included. At week 48, clevudine therapy produced a significantly greater mean reductions in serum HBV DNA levels from baseline than lamivudine therapy (-5.2 vs. -4.2 log(10)IU/mL; P=0.005). Furthermore, a significantly higher proportion of patients on clevudine achieved negative serum HBV DNA by PCR (<13 IU/mL) at week 48 (60.4% vs. 38.1%; P=0.025). The incidence of virologic breakthrough in the clevudine group was significantly lower than in the lamivudine group (9.4% vs. 25.4%; P=0.031). However, rates of alanine aminotransferase normalization and HBeAg loss or seroconversion were similar in the two groups (83.0% vs. 81.0%, 11.3% vs. 11.1%; P=0.813, 1.000, respectively). In conclusion, clevudine is more potent for viral suppression and lower for antiviral resistance at week 48 than lamivudine in treatment of naïve patients with HBeAg positive chronic hepatitis B.
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Affiliation(s)
- In Hee Kim
- Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea
- The Research Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Seok Lee
- Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea
- The Research Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Seong Hun Kim
- Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea
- The Research Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Sang Wook Kim
- Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea
- The Research Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Seung Ok Lee
- Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea
- The Research Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Soo Teik Lee
- Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea
- The Research Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Dae Ghon Kim
- Department of Internal Medicine, Chonbuk National University Medical School and Hospital, Jeonju, Korea
- The Research Institute for Medical Science, Chonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Chang Soo Choi
- Department of Internal Medicine, Wonkwang University College of Medicine and Hospital, Iksan, Korea
| | - Haak Cheoul Kim
- Department of Internal Medicine, Wonkwang University College of Medicine and Hospital, Iksan, Korea
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Romeo G, Chiacchio U, Corsaro A, Merino P. Chemical Synthesis of Heterocyclic−Sugar Nucleoside Analogues. Chem Rev 2010; 110:3337-70. [PMID: 20232792 DOI: 10.1021/cr800464r] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Giovanni Romeo
- Dipartimento Farmaco-Chimico, Università di Messina, Via SS Annunziata, 98168 Messina, Italy, Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy, and Laboratorio de Sintesis Asimetrica, Departamento de Quimica Organica, Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza, CSIC, E-50009 Zaragoza, Aragon, Spain, Pedro Merino:
| | - Ugo Chiacchio
- Dipartimento Farmaco-Chimico, Università di Messina, Via SS Annunziata, 98168 Messina, Italy, Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy, and Laboratorio de Sintesis Asimetrica, Departamento de Quimica Organica, Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza, CSIC, E-50009 Zaragoza, Aragon, Spain, Pedro Merino:
| | - Antonino Corsaro
- Dipartimento Farmaco-Chimico, Università di Messina, Via SS Annunziata, 98168 Messina, Italy, Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy, and Laboratorio de Sintesis Asimetrica, Departamento de Quimica Organica, Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza, CSIC, E-50009 Zaragoza, Aragon, Spain, Pedro Merino:
| | - Pedro Merino
- Dipartimento Farmaco-Chimico, Università di Messina, Via SS Annunziata, 98168 Messina, Italy, Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy, and Laboratorio de Sintesis Asimetrica, Departamento de Quimica Organica, Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza, CSIC, E-50009 Zaragoza, Aragon, Spain, Pedro Merino:
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Liu LJ, Wang JH, Du SC, Tian JH, Yang RF, Wei L. rtE218G, a novel hepatitis B virus mutation with resistance to adefovir dipivoxil in patients with chronic hepatitis B. J Viral Hepat 2010; 17 Suppl 1:66-72. [PMID: 20586936 DOI: 10.1111/j.1365-2893.2010.01273.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Antiviral therapy is a potentially successful approach for the treatment of patients with Hepatitis B virus (HBV) infection. One antiviral agent is the nucleoside analogue adefovir dipivoxil (ADV). Its efficiency is compromised by the emergence of drug-resistant HBV mutants. Although three major ADV-resistant mutations of HBV are known, rtA181T/V and rtN236T, HBV mutations associated with ADV resistance have not been fully identified. We analyzed DNA sequences that covered a 244 base pair region of the HBV polymerase gene from patients with clinical manifestations of ADV resistance. A novel pattern of amino acid substitutions in HBV polymerase was detected in 26 out of 86 patients. This mutant exhibited a substitution of glycine for glutamic acid at residue 218 (rtE218G). Transient transfection of the HBV replication-competent construct including the rtE218G mutation was performed in HepG2 cells in order to determine the relevance of this mutation to ADV resistance. Phenotypic analyses demonstrated that the rtE218G mutation could independently confer resistance to ADV in vitro, with a 50% inhibitory concentration (IC(50)) 5.5-fold higher than wild-type HBV. RtE218G-mutated HBV also showed a decreased replication capacity in vitro, equal to 87% of wild-type HBV. The present study showed that the rtE218G mutation may be a novel ADV-resistant mutation. Further work will focus on resistance surveillance and cross-resistance analyses, and the molecular mechanisms involved.
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Affiliation(s)
- L J Liu
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing, China
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23
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Identification and characterization of clevudine-resistant mutants of hepatitis B virus isolated from chronic hepatitis B patients. J Virol 2010; 84:4494-503. [PMID: 20164224 DOI: 10.1128/jvi.02066-09] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Clevudine (CLV) is a nucleoside analog with potent antiviral activity against chronic hepatitis B virus (HBV) infection. Viral resistance to CLV in patients receiving CLV therapy has not been reported. The aim of this study was to characterize CLV-resistant HBV in patients with viral breakthrough (BT) during long-term CLV therapy. The gene encoding HBV reverse transcriptase (RT) was analyzed from chronic hepatitis B patients with viral BT during CLV therapy. Sera collected from the patients at baseline and at the time of viral BT were studied. To characterize the mutations of HBV isolated from the patients, we subjected the HBV mutants to in vitro drug susceptibility assays. Several conserved mutations were identified in the RT domain during viral BT, with M204I being the most common. In vitro phenotypic analysis showed that the mutation M204I was predominantly associated with CLV resistance, whereas L229V was a compensatory mutation for the impaired replication of the M204I mutant. A quadruple mutant (L129M, V173L, M204I, and H337N) was identified that conferred greater replicative ability and strong resistance to both CLV and lamivudine. All of the CLV-resistant clones were lamivudine resistant. They were susceptible to adefovir, entecavir, and tenofovir, except for one mutant clone. In conclusion, the mutation M204I in HBV RT plays a major role in CLV resistance and leads to viral BT during long-term CLV treatment. Several conserved mutations may have a compensatory role in replication. Drug susceptibility assays reveal that adefovir and tenofovir are the most effective compounds against CLV-resistant mutants. These data may provide additional therapeutic options for CLV-resistant patients.
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Walsh AW, Langley DR, Colonno RJ, Tenney DJ. Mechanistic characterization and molecular modeling of hepatitis B virus polymerase resistance to entecavir. PLoS One 2010; 5:e9195. [PMID: 20169198 PMCID: PMC2820545 DOI: 10.1371/journal.pone.0009195] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Accepted: 01/06/2010] [Indexed: 01/25/2023] Open
Abstract
Background Entecavir (ETV) is a deoxyguanosine analog competitive inhibitor of hepatitis B virus (HBV) polymerase that exhibits delayed chain termination of HBV DNA. A high barrier to entecavir-resistance (ETVr) is observed clinically, likely due to its potency and a requirement for multiple resistance changes to overcome suppression. Changes in the HBV polymerase reverse-transcriptase (RT) domain involve lamivudine-resistance (LVDr) substitutions in the conserved YMDD motif (M204V/I ± L180M), plus an additional ETV-specific change at residues T184, S202 or M250. These substitutions surround the putative dNTP binding site or primer grip regions of the HBV RT. Methods/Principal Findings To determine the mechanistic basis for ETVr, wildtype, lamivudine-resistant (M204V, L180M) and ETVr HBVs were studied using in vitro RT enzyme and cell culture assays, as well as molecular modeling. Resistance substitutions significantly reduced ETV incorporation and chain termination in HBV DNA and increased the ETV-TP inhibition constant (Ki) for HBV RT. Resistant HBVs exhibited impaired replication in culture and reduced enzyme activity (kcat) in vitro. Molecular modeling of the HBV RT suggested that ETVr residue T184 was adjacent to and stabilized S202 within the LVDr YMDD loop. ETVr arose through steric changes at T184 or S202 or by disruption of hydrogen-bonding between the two, both of which repositioned the loop and reduced the ETV-triphosphate (ETV-TP) binding pocket. In contrast to T184 and S202 changes, ETVr at primer grip residue M250 was observed during RNA-directed DNA synthesis only. Experimentally, M250 changes also impacted the dNTP-binding site. Modeling suggested a novel mechanism for M250 resistance, whereby repositioning of the primer-template component of the dNTP-binding site shifted the ETV-TP binding pocket. No structural data are available to confirm the HBV RT modeling, however, results were consistent with phenotypic analysis of comprehensive substitutions of each ETVr position. Conclusions Altogether, ETVr occurred through exclusion of ETV-TP from the dNTP-binding site, through different, novel mechanisms that involved lamivudine-resistance, ETV-specific substitutions, and the primer-template.
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Affiliation(s)
- Ann W. Walsh
- Research and Development, Bristol-Myers Squibb Inc., Wallingford, Connecticut, United States of America
| | - David R. Langley
- Research and Development, Bristol-Myers Squibb Inc., Wallingford, Connecticut, United States of America
- * E-mail: (DRL); (DJT)
| | - Richard J. Colonno
- Research and Development, Bristol-Myers Squibb Inc., Wallingford, Connecticut, United States of America
| | - Daniel J. Tenney
- Research and Development, Bristol-Myers Squibb Inc., Wallingford, Connecticut, United States of America
- * E-mail: (DRL); (DJT)
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Lack of pharmacokinetic interaction between amdoxovir and reduced- and standard-dose zidovudine in HIV-1-infected individuals. Antimicrob Agents Chemother 2009; 54:1248-55. [PMID: 20038617 DOI: 10.1128/aac.01209-09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Amdoxovir (AMDX) inhibits HIV-1 containing the M184V/I mutation and is rapidly absorbed and deaminated to its active metabolite, beta-D-dioxolane guanosine (DXG). DXG is synergistic with zidovudine (ZDV) in HIV-1-infected primary human lymphocytes. A recent in silico pharmacokinetic (PK)/enzyme kinetic study suggested that ZDV at 200 mg twice a day (b.i.d.) may reduce toxicity without compromising efficacy relative to the standard 300-mg b.i.d. dose. Therefore, an intense PK clinical study was conducted using AMDX/placebo, with or without ZDV, in 24 subjects randomized to receive oral AMDX at 500 mg b.i.d., AMDX at 500 mg plus ZDV at 200 or 300 mg b.i.d., or ZDV at 200 or 300 mg b.i.d. for 10 days. Full plasma PK profiles were collected on days 1 and 10, and complete urine sampling was performed on day 9. Plasma and urine concentrations of AMDX, DXG, ZDV, and ZDV-5'-O-glucuronide (GZDV) were measured using a validated liquid chromatography-tandem mass spectrometry method. Data were analyzed using noncompartmental methods, and multiple comparisons were performed on the log-transformed parameters, at steady state. Coadministration of AMDX with ZDV did not significantly change either of the plasma PK parameters or percent recovery in the urine of AMDX, DXG, or ZDV/GZDV. Larger studies with AMDX/ZDV, with a longer duration, are warranted.
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Thompson AJ, Colledge D, Rodgers S, Wilson R, Revill P, Desmond P, Mansell A, Visvanathan K, Locarnini S. Stimulation of the interleukin-1 receptor and Toll-like receptor 2 inhibits hepatitis B virus replication in hepatoma cell lines in vitro. Antivir Ther 2009; 14:797-808. [PMID: 19812442 DOI: 10.3851/imp1294] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Toll-like receptors (TLRs) are a key component of the innate immune system and TLR2 has been shown to be involved in the immunopathogenesis of hepatitis B virus (HBV) infection in vivo. We investigated the role of TLR2 stimulation of virus-infected hepatocyte cell lines as a potential antiviral mechanism in vitro. METHODS The hepatoblastoma cell line HepG2 was transduced with recombinant HBV baculoviruses and the hepatoma cell line Huh-7 was transiently transfected with complimentary DNA clones of HBV. HBV viral replication was quantified after stimulation with interleukin (IL)-1beta and Pam-2-Cys, a synthetic TLR2 ligand, by measuring intracellular core-associated single-stranded HBV DNA using Southern blot hybridization, as well as viral nucleocapsid formation using a non-denaturing immunoblot method. RESULTS Stimulation of both cell lines in vitro with IL-1beta and Pam-2-Cys, both known to induce expression of the pro inflammatory cytokines tumour necrosis factor-alpha and IL-8 via a nuclear factor-kappaB dependent pathway, resulted in the inhibition of HBV DNA replication in the transduced HepG2 cells by up to 90% and nucleocapsid formation in the transiently transfected Huh-7 cells by up to 30%, when compared with mock-treated cells. CONCLUSIONS Hepatoma cell lines expressed functional IL-1 receptor and TLR2 receptors, which when stimulated led to a signalling cascade that inhibited HBV replication. These data support an active role for hepatocytes in inhibiting HBV replication and provide a rationale for the development of TLR agonists as potentially novel antiviral agents.
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Affiliation(s)
- Alex J Thompson
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, VIC, Australia
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Zoulim F, Locarnini S. Hepatitis B virus resistance to nucleos(t)ide analogues. Gastroenterology 2009; 137:1593-608.e1-2. [PMID: 19737565 DOI: 10.1053/j.gastro.2009.08.063] [Citation(s) in RCA: 515] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 08/28/2009] [Accepted: 08/28/2009] [Indexed: 02/07/2023]
Abstract
Patients with chronic hepatitis B (CHB) can be successfully treated using nucleos(t)ide analogs (NA), but drug-resistant hepatitis B virus (HBV) mutants frequently arise, leading to treatment failure and progression to liver disease. There has been much research into the mechanisms of resistance to NA and selection of these mutants. Five NA have been approved by the US Food and Drug Administration for treatment of CHB; it is unlikely that any more NA will be developed in the near future, so it is important to better understand mechanisms of cross-resistance (when a mutation that mediates resistance to one NA also confers resistance to another) and design more effective therapeutic strategies for these 5 agents. The genes that encode the polymerase and envelope proteins of HBV overlap, so resistance mutations in polymerase usually affect the hepatitis B surface antigen; these alterations affect infectivity, vaccine efficacy, pathogenesis of liver disease, and transmission throughout the population. Associations between HBV genotype and resistance phenotype have allowed cross-resistance profiles to be determined for many commonly detected mutants, so genotyping assays can be used to adapt therapy. Patients that experience virologic breakthrough or partial response to their primary therapy can often be successfully treated with a second NA, if this drug is given at early stages of these events. However, best strategies for preventing NA resistance include first-line use of the most potent antivirals with a high barrier to resistance. It is important to continue basic research into HBV replication and pathogenic mechanisms to identify new therapeutic targets, develop novel antiviral agents, design combination therapies that prevent drug resistance, and decrease the incidence of complications of CHB.
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Hu JL, Cui J, Deng XY, Zhang WL, Li QL, Guo JJ, Zeng AZ, Huang AL. A new strategy for constructing in vitro replication-competent 1.3 copies of hepatitis B virus genome. J Virol Methods 2009; 161:63-9. [PMID: 19481116 DOI: 10.1016/j.jviromet.2009.05.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 05/19/2009] [Accepted: 05/20/2009] [Indexed: 12/13/2022]
Abstract
In the absence of a robust infectable cell culture system, assays related to replication of clinical HBV isolates are based on the transfection of replication-competent HBV DNA into hepatoma cell lines that are able to replicate and secrete HBV virions. Current methods for constructing HBV 1.1 genomes work well for drug susceptibility assays, but are not very suitable for research on HBV replication capacity or regulation since a heterogeneous promoter is required to drive pgRNA transcription. A new strategy for constructing HBV 1.3 genomes that contain HBV intrinsic promoter necessary for pgRNA transcription is reported in this paper. Using this strategy, three HBV 1.3 genomes from isolates of three patients were constructed. When the three HBV 1.3 genomes were transfected into the HepG2 cell line, replicative intermediates were detectable by Southern blotting with digoxigenin-labeled DNA probe in two of the three constructs. Using overlap extension PCR and avoiding as much as possible the digestion-and-ligation process, this strategy could be applied to constructing longer-than-genome units for most genotypes of HBV strains.
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Affiliation(s)
- Jie-li Hu
- Institute for Viral Hepatitis, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing University of Medical Sciences, Chongqing, China
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29
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Ultrasensitive genotypic detection of antiviral resistance in hepatitis B virus clinical isolates. Antimicrob Agents Chemother 2009; 53:2762-72. [PMID: 19433559 DOI: 10.1128/aac.00130-09] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Amino acid substitutions that confer reduced susceptibility to antivirals arise spontaneously through error-prone viral polymerases and are selected as a result of antiviral therapy. Resistance substitutions first emerge in a fraction of the circulating virus population, below the limit of detection by nucleotide sequencing of either the population or limited sets of cloned isolates. These variants can expand under drug pressure to dominate the circulating virus population. To enhance detection of these viruses in clinical samples, we established a highly sensitive quantitative, real-time allele-specific PCR assay for hepatitis B virus (HBV) DNA. Sensitivity was accomplished using a high-fidelity DNA polymerase and oligonucleotide primers containing locked nucleic acid bases. Quantitative measurement of resistant and wild-type variants was accomplished using sequence-matched standards. Detection methodology that was not reliant on hybridization probes, and assay modifications, minimized the effect of patient-specific sequence polymorphisms. The method was validated using samples from patients chronically infected with HBV through parallel sequencing of large numbers of cloned isolates. Viruses with resistance to lamivudine and other l-nucleoside analogs and entecavir, involving 17 different nucleotide substitutions, were reliably detected at levels at or below 0.1% of the total population. The method worked across HBV genotypes. Longitudinal analysis of patient samples showed earlier emergence of resistance on therapy than was seen with sequencing methodologies, including some cases of resistance that existed prior to treatment. In summary, we established and validated an ultrasensitive method for measuring resistant HBV variants in clinical specimens, which enabled earlier, quantitative measurement of resistance to therapy.
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30
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Tenney DJ, Rose RE, Baldick CJ, Pokornowski KA, Eggers BJ, Fang J, Wichroski MJ, Xu D, Yang J, Wilber RB, Colonno RJ. Long-term monitoring shows hepatitis B virus resistance to entecavir in nucleoside-naïve patients is rare through 5 years of therapy. Hepatology 2009; 49:1503-14. [PMID: 19280622 DOI: 10.1002/hep.22841] [Citation(s) in RCA: 653] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED Patients with chronic hepatitis B virus (HBV) infection who develop antiviral resistance lose benefits of therapy and may be predisposed to further resistance. Entecavir (ETV) resistance (ETVr) results from HBV reverse transcriptase substitutions at positions T184, S202, or M250, which emerge in the presence of lamivudine (LVD) resistance substitutions M204I/V +/- L180M. Here, we summarize results from comprehensive resistance monitoring of patients with HBV who were continuously treated with ETV for up to 5 years. Monitoring included genotypic analysis of isolates from all patients at baseline and when HBV DNA was detectable by polymerase chain reaction (> or = 300 copies/mL) from Years 1 through 5. In addition, genotyping was performed on isolates from patients experiencing virologic breakthrough (> or = 1 log(10) rise in HBV DNA). In vitro phenotypic ETV susceptibility was determined for virologic breakthrough isolates, and for HBV containing novel substitutions emerging during treatment. The results over 5 years of therapy showed that in nucleoside-naïve patients, the cumulative probability of genotypic ETVr and genotypic ETVr associated with virologic breakthrough was 1.2% and 0.8%, respectively. In contrast, a reduced barrier to resistance was observed in LVD-refractory patients, as the LVD resistance substitutions, a partial requirement for ETVr, preexist, resulting in a 5-year cumulative probability of genotypic ETVr and genotypic ETVr associated with breakthrough of 51% and 43%, respectively. Importantly, only four patients who achieved < 300 copies/mL HBV DNA subsequently developed ETVr. CONCLUSION Long-term monitoring showed low rates of resistance in nucleoside-naïve patients during 5 years of ETV therapy, corresponding with potent viral suppression and a high genetic barrier to resistance. These findings support ETV as a primary therapy that enables prolonged treatment with potent viral suppression and minimal resistance.
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Affiliation(s)
- Daniel J Tenney
- Bristol-Myers Squibb Company Research and Development, Wallingford, CT 06492, USA.
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Amini-Bavil-Olyaee S, Herbers U, Sheldon J, Luedde T, Trautwein C, Tacke F. The rtA194T polymerase mutation impacts viral replication and susceptibility to tenofovir in hepatitis B e antigen-positive and hepatitis B e antigen-negative hepatitis B virus strains. Hepatology 2009; 49:1158-65. [PMID: 19263474 DOI: 10.1002/hep.22790] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
UNLABELLED Tenofovir is a new effective treatment option for patients with chronic hepatitis B, but could be potentially hampered by mutations in the hepatitis B virus (HBV) polymerase conferring drug resistance. Drug resistance may occur preferentially if long-term administration is required, for example, in patients with hepatitis B e antigen (HBeAg)-negative HBV infection bearing precore (PC) and basal core promoter (BCP) mutations. The rtA194T polymerase mutation has been found in HBV/HIV coinfected patients during tenofovir treatment and may be associated with tenofovir resistance. We generated replication-competent HBV constructs harboring rtA194T alone or in addition to lamivudine (LAM) resistance (rt180M + rtM204V), PC mutations, and BCP mutations and assessed their replicative capacity after transient transfection in human hepatoma cells. The rtA194T polymerase mutation alone or in conjunction with LAM resistance reduced the replication efficiency as compared with wild-type (WT) HBV. In contrast, combination of rtA194T (+/- LAM resistance) with HBeAg-negative PC or BCP mutants increased the replication capacity of the drug-resistant polymerase mutants, thereby restoring the viral replication to similar levels as WT clones. Clones harboring rtA194T showed partial resistance to tenofovir in vitro and also to LAM but remained susceptible to telbivudine and entecavir. CONCLUSION The rtA194T polymerase mutation is associated with partial tenofovir drug resistance and negatively impacts replication competence of HBV constructs. Viral replication, however, can be restored to WT levels, if these polymerase mutations occur together with precore or basic core promoter substitutions as found in HBeAg-negative hepatitis B. Patients with HBeAg-negative chronic HBV infection may therefore be at particular risk when developing drug resistance to tenofovir. Telbivudine or entecavir should be considered as effective alternative treatment options for these patients.
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Kim MH, Kim KA, Lee JS, Lee HW, Kim HJ, Yun SG, Kim NH, Bae WK, Moon YS. Efficacy of 48-week clevudine therapy for chronic hepatitis B. THE KOREAN JOURNAL OF HEPATOLOGY 2009; 15:331-7. [PMID: 19783882 DOI: 10.3350/kjhep.2009.15.3.331] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Min Hwan Kim
- Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - Kyung-Ah Kim
- Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - June Sung Lee
- Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - Hyun Woong Lee
- Department of Internal Medicine, Chung Ang University College of Medicine, Seoul, Korea
| | - Hyung Joon Kim
- Department of Internal Medicine, Chung Ang University College of Medicine, Seoul, Korea
| | - Sang Gu Yun
- Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - Nam-Hoon Kim
- Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - Won Ki Bae
- Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - Young Soo Moon
- Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
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Suzuki F, Miyakoshi H, Kobayashi M, Kumada H. Correlation between serum hepatitis B virus core-related antigen and intrahepatic covalently closed circular DNA in chronic hepatitis B patients. J Med Virol 2008; 81:27-33. [PMID: 19031469 DOI: 10.1002/jmv.21339] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nucleos(t)ide analogues are utilized for the treatment of chronic HBV infection, and HBe seroconversion and HBV DNA levels are commonly used as markers of viral status and as primary treatment endpoints. Recently, a new assay was prepared for the detection of serum HBV core-related antigen (HBcrAg), consisting of HBcAg, HBeAg, and p22cr, which is a precore protein from amino acid -28 to at least amino acid 150, by coding the precore/core region. In this study, we examined the correlation between serum HBcrAg concentration and viral status by the analysis of serum HBeAg, HBsAg, peripheral HBV DNA, and intrahepatic covalently closed circular DNA (cccDNA) in 57 chronic hepatitis B patients. Intrahepatic cccDNA was detected in all 57 patients, 42 patients were HBcrAg-positive, and serum HBcrAg concentration level was closely correlated with cccDNA. Additionally, positive HBcrAg concentration level results were observed in 6 out of 13 HBsAg seroclearance patients and 20 out of 31 HBV DNA-negative patients. Moreover, the correlation between HBcrAg and cccDNA in these 31 HBV DNA-negative patients was statistically significant (r = 0.482, P = 0.006). These data suggest that serum HBcrAg concentration is well correlated with intrahepatic cccDNA level, and that the measurement of serum HBcrAg may be clinically useful for monitoring intrahepatic HBV viral status, especially in patients under treatment with nucleos(t)ide analogues.
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Seifer M, Patty A, Serra I, Li B, Standring DN. Telbivudine, a nucleoside analog inhibitor of HBV polymerase, has a different in vitro cross-resistance profile than the nucleotide analog inhibitors adefovir and tenofovir. Antiviral Res 2008; 81:147-55. [PMID: 19028525 DOI: 10.1016/j.antiviral.2008.10.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 10/16/2008] [Accepted: 10/24/2008] [Indexed: 12/24/2022]
Abstract
Telbivudine, a nucleoside analog inhibitor of the viral polymerase of hepatitis B virus (HBV), has been approved for the treatment of chronic HBV infection, along with the nucleoside inhibitors lamivudine and entecavir, and the nucleotide inhibitors adefovir and tenofovir. The resistance profiles of these agents were investigated via drug treatment of HepG2 cells stably transfected with wild-type or mutant HBV genomes bearing known resistance mutations. Telbivudine was not active against HBV strains bearing lamivudine mutations L180M/M204V/I but remained active against the M204V single mutant in vitro, potentially explaining the difference in resistance profiles between telbivudine and lamivudine. Against HBV genomes with known telbivudine-resistance mutations, M204I and L80I/M204I, telbivudine, lamivudine and entecavir lost 353- to >1000-fold activity whereas adefovir and tenofovir exhibited no more than 3-5-fold change. Conversely, against HBV cell lines expressing adefovir resistance mutations N236T and A181V, or the A194T mutant associated with resistance to tenofovir, telbivudine remained active as shown by respective fold-changes of 0.5 (N236T) and 1.0 (A181V and A194T). These in vitro results indicate that nucleoside and nucleotide drugs have different cross-resistance profiles. The addition of telbivudine to ongoing adefovir therapy could provide effective antiviral therapy to patients who develop adefovir resistance.
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Affiliation(s)
- Maria Seifer
- Idenix Pharmaceuticals Inc., 60 Hampshire Street, Cambridge, MA 02139, USA
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Preiss S, Littlejohn M, Angus P, Thompson A, Desmond P, Lewin SR, Sasadeusz J, Matthews G, Dore GJ, Shaw T, Sozzi V, Yuen L, Lau G, Ayres A, Thio C, Avihingsanon A, Ruxrungtham K, Locarnini S, Revill PA. Defective hepatitis B virus DNA is not associated with disease status but is reduced by polymerase mutations associated with drug resistance. Hepatology 2008; 48:741-9. [PMID: 18571815 PMCID: PMC2669111 DOI: 10.1002/hep.22386] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
UNLABELLED Defective hepatitis B virus DNA (dDNA) is reverse-transcribed from spliced hepatitis B virus (HBV) pregenomic messenger RNA (pgRNA) and has been identified in patients with chronic HBV (CH-B). The major 2.2-kb spliced pgRNA encodes a novel HBV gene product, the hepatitis B splice protein (HBSP) via a deletion and frame shift within the polymerase. Although spliced RNA and HBSP expression have been associated with increased HBV DNA levels and liver fibrosis, the role of dDNA in HBV-associated disease is largely undefined. Our aims were to (1) compare the relative proportions of dDNA (% dDNA) in a range of HBV-infected serum samples, including patients with human immunodeficiency virus (HIV)/HBV coinfection and HBV-monoinfected persons with differing severities of liver disease, and (2) determine the effect of mutations associated with drug resistance on defective DNA production. Defective DNA was detected in 90% of persons with CH-B. There was no significant difference in the relative abundance of dDNA between the monoinfected and HIV/HBV-coinfected groups. We also found no association between the % dDNA and alanine aminotransferase, hepatitis B e antigen status, HBV DNA levels, fibrosis levels, compensated or decompensated liver cirrhosis, genotype, or drug treatment. However, the % dDNA was significantly lower in individuals infected with lamivudine-resistant (LMV-R) HBV compared with wild-type HBV (P < 0.0001), indicating that antiviral drug resistance alters the balance between defective and genomic length DNA in circulation. Experiments in vitro using HBV encoding LMV-R mutations confirmed these results. CONCLUSION Our results identified no association between dDNA and parameters associated with disease status and suggested that the relative abundance of dDNA is largely dependent on the integrity of the HBV polymerase and is unrelated to the severity of liver disease.
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Affiliation(s)
- Scott Preiss
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
| | - Margaret Littlejohn
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
| | - Peter Angus
- Victorian Liver Transplant Unit, Austin & Repatriation Medical Centre, Melbourne, Australia
| | - Alex Thompson
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia,St. Vincents Hospital, Melbourne, Australia
| | | | | | - Joe Sasadeusz
- Royal Melbourne Hospital, VIDS, Melbourne, Australia
| | - Gail Matthews
- National Centre in HIV Epidemiology & Clinical Research, University of New South Wales, Sydney, Australia
| | - Gregory J. Dore
- National Centre in HIV Epidemiology & Clinical Research, University of New South Wales, Sydney, Australia
| | - Tim Shaw
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
| | - Vitini Sozzi
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
| | - Lilly Yuen
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
| | - George Lau
- Department of Medicine, University of Hong Kong, Hong Kong
| | - Anna Ayres
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
| | - Chloe Thio
- Division of Infectious Diseases, Johns Hopkins University, Baltimore, MD, USA
| | | | - Kiat Ruxrungtham
- HIV Netherlands Australia Thailand Research Collaboration, Bangkok, Thailand
| | - Stephen Locarnini
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
| | - Peter A. Revill
- Victorian Infectious Diseases Reference Laboratories, Research and Molecular Development, North Melbourne, Victoria, Australia
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Sharon A, Chu CK. Understanding the molecular basis of HBV drug resistance by molecular modeling. Antiviral Res 2008; 80:339-53. [PMID: 18765256 DOI: 10.1016/j.antiviral.2008.07.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 07/25/2008] [Accepted: 07/29/2008] [Indexed: 12/30/2022]
Abstract
Despite the significant successes in the area of anti-HBV agents, resistance and cross-resistance against available therapeutics are the major hurdles in drug discovery. The present investigation is to understand the molecular basis of drug resistance conferred by the B and C domain mutations of HBV-polymerase on the binding affinity of five anti-HBV agents [lamivudine (3TC, 1), adefovir (ADV, 2), entecavir (ETV, 3), telbivudine (LdT, 4) and clevudine (l-FMAU, 5)]. In this regard, homology modeled structure of HBV-polymerase was used for minimization, conformational search and induced fit docking followed by binding energy calculation on wild-type as well as on mutant HBV-polymerases (L180M, M204V, M204I, L180M+M204V, L180M-M204I). Our studies suggest a significant correlation between the fold resistances and the binding affinity of anti-HBV nucleosides. The binding mode studies reveals that the domain C residue M204 is closely associated with sugar/pseudosugar ring positioning in the active site. The positioning of oxathiolane ring of 3TC (1) is plausible due the induced fit orientation of the M204 residue in wild-type, and further mutation of M204 to V204 or I204 reduces the final binding affinity which leads to the drug resistance. The domain B residue L180 is not directly close ( approximately 6A) to the nucleoside/nucleoside analogs, but indirectly associated with other active-site hydrophobic residues such as A87, F88, P177 and M204. These five hydrophobic residues can directly affect on the incoming nucleoside analogs in terms of its association and interaction that can alter the final binding affinity. There was no sugar ring shifting observed in the case of adefovir (2) and entecavir (3), and the position of sugar ring of 2 and 3 is found similar to the sugar position of natural substrate dATP and dGTP, respectively. The exocyclic double bond of entecavir (3) occupied in the backside hydrophobic pocket (made by residues A87, F88, P177, L180 and M204), which enhances the overall binding affinity. The active site binding of LdT (4) and l-FMAU (5) showed backward shifting along with upward movement without enforcing M204 residue and this significant different binding mode makes these molecules as polymerase inhibitors, without being incorporated into the growing HBV-DNA chain. Structural results conferred by these l- and d-nucleosides, explored the molecular basis of drug resistance which can be utilized for future anti-HBV drug discovery.
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Affiliation(s)
- Ashoke Sharon
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA
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Selection of an entecavir-resistant mutant despite prolonged hepatitis B virus DNA suppression, in a chronic hepatitis B patient with preexistent lamivudine resistance: successful rescue therapy with tenofovir. Eur J Gastroenterol Hepatol 2008; 20:773-7. [PMID: 18617782 DOI: 10.1097/meg.0b013e3282f793d6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND OBJECTIVE Entecavir has potent activity against hepatitis B virus. Drug resistance has not been reported in nucleoside-naïve patients and is low in lamivudine-refractory patients. METHODS AND RESULTS A 43-year-old man was treated with lamivudine for hepatitis B e antigen-positive chronic hepatitis B. A viral breakthrough owing to a drug-resistant mutant was observed and entecavir 1 mg daily was added. After the viral load had been near the lower detection range of the PCR assay for 30 weeks, lamivudine was discontinued. The serum hepatitis B virus DNA remained low until a second viral breakthrough was observed after 45 weeks of entecavir monotherapy. Treatment was switched from entecavir to tenofovir disoproxil 245 mg daily, which resulted in a decline below 1000 copies/ml. Sequence analysis revealed the presence of rtL180M and rtM204V lamivudine-resistant-associated mutations at the start of entecavir treatment. During entecavir treatment, the rtS202G mutation was selected. Retrospective analysis revealed that during lamivudine treatment three other mutations had been selected as well, namely rtE1D, rtV207L, and rtI220L. CONCLUSION We describe the first case of entecavir resistance in a lamivudine-resistant patient with good initial suppression of viral replication for 70 weeks. On the basis of the data from cross-resistance and sensitivity testing in vitro and treatment outcomes, tenofovir proves to be a good treatment option for entecavir-resistant patients.
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Kumar M, Sarin SK. Pharmacology, clinical efficacy and safety of lamivudine in hepatitis B virus infection. Expert Rev Gastroenterol Hepatol 2008; 2:465-95. [PMID: 19072396 DOI: 10.1586/17474124.2.4.465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Lamivudine was the first nucleoside analog for the treatment of chronic hepatitis B (CHB). It is well-tolerated and induces a decrease in serum HBV DNA levels associated with normalization of serum alanine aminotransferase levels. However, a sustained response with hepatitis B 'e' antigen to anti-hepatitis B e seroconversion is obtained in a smaller proportion of patients and hepatitis B surface antigen loss is exceptional. The response is maintained during therapy, and needs to be continued indefinitely in the majority of patients since withdrawal of treatment is generally followed by a rapid reappearance of the virus. However, mutations can be induced in long-term treatment.
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Affiliation(s)
- Manoj Kumar
- Department of Gastroenterology, Academic Block, GB Pant Hospital, New Delhi-110002, India.
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Lim SG, Leung N, Hann HWL, Lau GKK, Trepo C, Mommeja-Marin H, Moxham C, Sorbel J, Snow A, Blum MR, Rousseau F, Marcellin P. Clinical trial: a phase II, randomized study evaluating the safety, pharmacokinetics and anti-viral activity of clevudine for 12 weeks in patients with chronic hepatitis B. Aliment Pharmacol Ther 2008; 27:1282-92. [PMID: 18363895 DOI: 10.1111/j.1365-2036.2008.03686.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Clevudine is a polymerase inhibitor that has the unusual feature of delayed viral rebound after therapy in some patients which may be related to its pharmacokinetics. AIM To characterize pharmacokinetic and pharmacodynamic profile of clevudine, a potent hepatitis B polymerase inhibitor. METHODS A multicenter, randomized study comparing 10, 30 and 50 mg clevudine once daily for 12 weeks with 24 weeks off-treatment follow-up. Patients had chronic HBV infection, were nucleoside-naïve without co-infection. HBV viral load (VL) was assayed using Digene Hybrid Capture II with a lower limit of detection of 4700 copies/mL (940 IU/mL). Clevudine levels were measured using a liquid chromatography/mass spectrometery method. RESULTS A total of 31 patients were enrolled into the 10 mg (n = 10), 30 mg (n = 11) and 50 mg (n = 10) groups, respectively. At week 12, the median VL change was -3.2, -3.7 and -4.2 log(10) copies/mL (-0.64, -0.74 and -0.84 log(10) IU/mL) in the 10, 30 and 50 mg groups, respectively (P = 0.012). At week 12, one of 10, five of 11 and two of 10 patients had VL below the assay lower limit of detection. Clevudine was well tolerated with no severe/serious adverse events. The mean plasma half-life of clevudine was 70 h and consequently is not the cause of the delayed viral rebound seen in some patients. Through modelling, 97% of the maximal treatment effect was reached with a 30 mg daily dose. Six patients had genomic changes without viral rebound. CONCLUSION Clevudine appears to be a potent and tolerable (over 12 weeks) anti-viral and the optimal dosage appears to be 30 mg once daily.
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Affiliation(s)
- S G Lim
- Department of Gastroenterology and Hepatology, National University Hospital, Yong Yoo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Rd, Singapore 119074.
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Hernandez-Santiago BI, Obikhod A, Fromentin E, Hurwitz SJ, Schinazi RF. Short communication cellular pharmacology of 9-(beta-D-1,3-dioxolan-4-yl) guanine and its lack of drug interactions with zidovudine in primary human lymphocytes. Antivir Chem Chemother 2008; 18:343-6. [PMID: 18320938 DOI: 10.1177/095632020701800606] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Amdoxovir, currently in Phase II clinical trials, is rapidly converted to 9-(beta-D-1,3-dioxolan-4-yl)guanine (DXG) by adenosine deaminase in vitro and in humans. The cellular pharmacology of DXG in primary human lymphocytes, including dose-response relationships, intracellular half-life of DXG triphosphate (DXG-TP), and combination studies were determined. DXG produced high levels of DXG-TP with a long half-life (16 h) in activated human peripheral blood mononuclear cells. Since zidovudine (ZDV) and DXG select for different resistance mutations, co-formulation of the these two drugs is an attractive proposition. A combination study between DXG and ZDV showed no reduction of DXG-TP or ZDV-TP. Taken together, these results suggest that an appropriately designed DXG prodrug could be given once a day and that co-formulation with ZDV might be a possibility.
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Affiliation(s)
- Brenda I Hernandez-Santiago
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Veterans Affairs Medical Center, Decatur, GA 30033, USA
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Pawlotsky JM, Dusheiko G, Hatzakis A, Lau D, Lau G, Liang TJ, Locarnini S, Martin P, Richman DD, Zoulim F. Virologic monitoring of hepatitis B virus therapy in clinical trials and practice: recommendations for a standardized approach. Gastroenterology 2008; 134:405-15. [PMID: 18242209 PMCID: PMC2676233 DOI: 10.1053/j.gastro.2007.11.036] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 11/01/2007] [Indexed: 02/07/2023]
Abstract
Treatment of chronic hepatitis B virus (HBV) infection is aimed at suppressing viral replication to the lowest possible level, and thereby to halt the progression of liver disease and prevent the onset of complications. Two categories of drugs are used in HBV therapy: the interferons, including standard interferon alfa or pegylated interferon alfa, and specific nucleoside or nucleotide HBV inhibitors that target the reverse-transcriptase function of HBV-DNA polymerase. The reported results of clinical trials have used varying definitions of efficacy, failure, and resistance based on different measures of virologic responses. This article discusses HBV virologic markers and tests, and their optimal use both for planning and reporting clinical trials and in clinical practice.
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Affiliation(s)
- Jean-Michel Pawlotsky
- French National Reference Center for Viral Hepatitis B, C and delta, Department of Virology, Henri Mondor Hospital, University of Paris XII, Créteil, France.
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Clevudine is Efficiently Phosphorylated to the Active Triphosphate form in Primary Human Hepatocytes. Antivir Ther 2008. [DOI: 10.1177/135965350801300206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Clevudine (CLV) is a nucleoside analogue of the unnatural l-configuration that has demonstrated potent activity against hepatitis B virus (HBV) in vitro and in Phase III clinical studies. Human hepatoma cell lines are the only liver-derived cells in which CLV metabolism has been investigated. Here, we examine CLV metabolism in primary human hepatocytes, which better represent CLV metabolism in the liver. Methods HPLC analysis of primary human hepatocyte extracts incubated with radiolabelled CLV was used to determine the time course of CLV phosphorylation. Effects of the exogenous cell concentration of CLV on phosphorylation were assessed and the half-life of the CLV phosphorylated forms was determined. Results The major CLV metabolite formed in human primary hepatocytes was 5‘-monophosphate, whereas in the hepatoma cell lines the major metabolite was 5’-triphosphate. The level of CLV 5’-triphosphate was similar in both cell types. In primary hepatocytes the conversion of CLV 5’-monophosphate to the corresponding 5’-diphosphate was the rate-limiting step in CLV phosphorylation; the level of CLV phosphorylation was dependent upon exogenous drug concentration and exposure time. CLV 5’-triphosphate accumulated rapidly with peak levels observed after ∼8 h. When cells were incubated with 1 μM CLV, the approximate maximal plasma concentration achieved in individuals receiving the 30 mg dose, the average intracellular concentration of CLV 5’-triphosphate was 41.3 ±8.4 pmols/106 cells (∼10 μM). The initial half-life of CLV triphosphate was ∼11 h. Conclusions These results are consistent with once daily CLV dosing currently being used in Phase III clinical studies.
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Abstract
The global prevalence of chronic hepatitis B and its associated serious sequelae demand technologically advanced techniques of management. Nucleic acid testing (NAT) plays a key role in the diagnosis, surveillance, and treatment of chronic hepatitis B. NAT includes quantitative PCR-based HBV DNA assays, HBV genotyping, tests for mutations associated with resistance to antiviral medications, and assays to detect precore and core promoter mutations. This article reviews the uses of NAT in the diagnosis and management of chronic hepatitis B.
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Affiliation(s)
- Robert G Gish
- California Pacific Medical Center, 2340 Clay St., Room 223, San Francisco, CA 94115, USA.
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Yoo BC, Kim JH, Kim TH, Koh KC, Um SH, Kim YS, Lee KS, Han BH, Chon CY, Han JY, Ryu SH, Kim HC, Byun KS, Hwang SG, Kim BI, Cho M, Yoo K, Lee HJ, Hwang JS, Kim YS, Lee YS, Choi SK, Lee YJ, Yang JM, Park JW, Lee MS, Kim DG, Chung YH, Cho SH, Choi JY, Kweon YO, Lee HY, Jeong SH, Yoo HW, Lee HS. Clevudine is highly efficacious in hepatitis B e antigen-negative chronic hepatitis B with durable off-therapy viral suppression. Hepatology 2007; 46:1041-8. [PMID: 17647293 DOI: 10.1002/hep.21800] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
UNLABELLED Clevudine is a pyrimidine analog with potent and sustained antiviral activity against HBV. In the present study, we evaluated the safety and efficacy of clevudine 30 mg daily for 24 weeks and assessed the durability of antiviral response for 24 weeks after cessation of dosing in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (e-CHB). We randomized a total of 86 patients (3:1) to receive clevudine 30 mg (n = 63) or placebo (n = 23) daily for 24 weeks. We followed patients for an additional 24 weeks after withdrawal of treatment. The median changes in HBV DNA from baseline were -4.25 and -0.48 log(10) copies/mL at week 24 in the clevudine and placebo groups, respectively (P < 0.0001). Viral suppression in the clevudine group was sustained after withdrawal of therapy, with 3.11 log(10) reduction at week 48. At week 24 and week 48, 92.1% and 16.4% of patients in the clevudine group had undetectable serum HBV DNA levels by Amplicor PCR assay (<300 copies/mL). The proportion of patients who achieved ALT normalization was 74.6% and 33.3% in the clevudine and placebo groups at week 24, respectively (P = 0.0006). ALT normalization in the clevudine group was well-maintained during the post-treatment follow-up period. The incidence of adverse events was similar in the 2 groups. No resistance to clevudine was detected during treatment. CONCLUSION A 24-week clevudine therapy was well-tolerated and showed potent and sustained antiviral effect without evidence of viral resistance in e-CHB patients. However, treatment for longer than 24 weeks would be needed to achieve durable remission.
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Affiliation(s)
- Byung Chul Yoo
- Sungkyunkwan University Samsung Medical Center, Seoul, South Korea
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45
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Kim IH, Kim SH, Kim HC, Shin KD, Kim SW, Lee SO, Lee ST, Kim DG. [Effect of initial virologic response to adefovir on the development of resistance to adefovir in lamivudine-resistant chronic hepatitis B]. THE KOREAN JOURNAL OF HEPATOLOGY 2007; 13:349-62. [PMID: 17898551 DOI: 10.3350/kjhep.2007.13.3.349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND/AIMS Adefovir dipivoxil (ADV) resistance in patients with lamivudine-resistant chronic hepatitis B is not well understood. This study examined the initial virologic response (IVR) to ADV, the rate of ADV resistance and the factors associated with ADV resistance. METHODS Eighty one lamivudine-resistant HBeAg-positive patients were enrolled in this study. IVR was defined as HBV DNA < 4 log10 copies/mL after 6 months of therapy. RESULTS IVR was observed in 37/81(45.7%) patients and it was associated with higher pretreatment ALT (P=0.002), and low pretreatment HBV DNA level (P=0.015). The HBV DNA levels were significantly higher in the non-IVR patients than the IVR patients at 12, 18 and 24 months (4.73 vs 2.59, 4.53 vs 2.31, 4.39 vs 2.40 log10 copies/mL, respectively; P<0.01). During the follow-up period, 17(21.0%) patients showed phenotypic resistance to ADV and 9 (11.1%) patients had ADV-resistant mutations. The cumulative probabilities of the phenotypic resistance to ADV at 12 and 24 months were 8.7% and 32.5%, respectively. The cumulative probabilities of the genotypic resistance to ADV at 12 and 24 months were 0% and 14.6%, respectively. Resistance to ADV was associated with a higher pretreatment HBV DNA (P=0.019), and non-IVR (P<0.001). CONCLUSIONS The cumulative probabilities of the phenotypic and genotypic resistance to ADV at 24 months were 32.5% and 14.6%. The high pretreatment HBV DNA and non-IVR (HBV DNA >/= 4 log10 copies/mL after 6 months of therapy) were associated with ADV resistance.
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Affiliation(s)
- In Hee Kim
- Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Korea
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46
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Revill PA, Littlejohn M, Ayres A, Yuen L, Colledge D, Bartholomeusz A, Sasaduesz J, Lewin SR, Dore GJ, Matthews GV, Thio CL, Locarnini SA. Identification of a novel hepatitis B virus precore/core deletion mutant in HIV/hepatitis B virus co-infected individuals. AIDS 2007; 21:1701-10. [PMID: 17690567 DOI: 10.1097/qad.0b013e32826fb305] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Although HAART has resulted in improved health outcomes for most HIV-infected individuals, liver failure has emerged as a major cause of morbidity and mortality in people co-infected with hepatitis B virus (HBV). In HBV mono-infected individuals, core deletion mutants are associated with more aggressive liver disease. As HIV accelerates HBV liver disease progression, we hypothesized that HIV-HBV co-infected individuals have increased frequency of core mutations including deletions. To test this hypothesis, we have analysed genome-length sequences of HBV DNA from patients both prior to and during antiviral therapy. SETTING Prospective HIV/HBV co-infected cohort study. METHODS Genomic length HBV DNA was amplified by PCR from the serum samples of ten HIV/HBV co-infected individuals and five HBV mono-infected individuals prior to the commencement of lamivudine therapy and again after nine to 74 months of treatment. The complete genomes were sequenced and in order to further analyse some mutations, their frequency was determined in additional HIV/HBV co-infected and HBV mono-infected individuals. RESULTS A novel -1G mutation was identified in the HBV precore and overlapping core genes that truncated the deduced precore/core proteins. The mutant genome was the dominant species in some HIV/HBV co-infected individuals and was more prevalent in HIV/HBV co-infected individuals than HBV mono-infected individuals. The mutation was also associated with high HBV DNA concentrations in HIV/HBV co-infected individuals. Additional mutations were identified in the core/precore and polymerase genes and regulatory regions. CONCLUSION Mutations in the HBV core and precore genes may be contributing to disease pathogenesis in HIV/HBV co-infected individuals.
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Affiliation(s)
- Peter A Revill
- Victorian Infectious Diseases Reference Laboratory, 10 Wreckyn Street, North Melbourne, Victoria 3051, Australia.
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47
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Feld JJ, Colledge D, Sozzi V, Edwards R, Littlejohn M, Locarnini SA. The phenylpropenamide derivative AT-130 blocks HBV replication at the level of viral RNA packaging. Antiviral Res 2007; 76:168-77. [PMID: 17709147 DOI: 10.1016/j.antiviral.2007.06.014] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2007] [Revised: 05/25/2007] [Accepted: 06/27/2007] [Indexed: 12/20/2022]
Abstract
Nucleos(t)ide analogue antiviral therapy for chronic hepatitis B has proven to be effective in the short term but the frequent development of resistance limits its clinical utility. Agents targeting other stages of viral replication are needed in order to develop improved combination therapies. The phenylpropenamide derivatives AT-61 and AT-130 have been shown to inhibit HBV replication in vitro, but the mechanism of action of these compounds remains undefined. The aim of this study was to determine the mechanism of action of AT-130, a non-nucleoside inhibitor of HBV in several in vitro models of replication. These studies found that AT-130 inhibited HBV DNA replication in hepatoma cells but had no effect on viral DNA polymerase activity or core protein translation. Total HBV RNA production was also unaffected in the presence of the drug whilst the amount of encapsidated RNA was significantly reduced, thereby inhibiting subsequent viral reverse transcription. These studies have established that the inhibition of HBV genome replication by a non-nucleoside analogue acting at the level of viral encapsidation and packaging is a potentially useful strategy for future therapeutic drug development in the management of chronic hepatitis B.
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Affiliation(s)
- J J Feld
- Victorian Infectious Diseases Reference Laboratory, Melbourne, Australia
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48
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Lee KS, Byun KS, Chung YH, Paik SW, Han JY, Yoo K, Yoo HW, Yoo BC, Lee HS. Clevudine Therapy for 24 Weeks Further Reduced Serum Hepatitis B Virus DNA Levels and Increased ALT Normalization Rates without Emergence of Viral Breakthrough than 12 Weeks of Clevudine Therapy. Intervirology 2007; 50:296-302. [PMID: 17622789 DOI: 10.1159/000105442] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Accepted: 03/30/2007] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVES The objectives of the study were to evaluate the safety and antiviral activity of 24-week treatment with clevudine 30 mg in HBeAg(+) chronic hepatitis B patients. Biochemical and serological responses were also assessed. METHOD Twenty-one patients received clevudine 30 mg for 24 weeks and were followed up for another 24 weeks off therapy. RESULTS Median decreases from baseline in HBV DNA were 4.65 and 1.96 log(10) copies/ml at week 24 (end of treatment) and week 48 (24 weeks off therapy), respectively. Analysis of individual data showed that HBV DNA levels were below the lower limit of detection (300 copies/ml) by Amplicor PCR assay in 19, 57, 19 and 0% at week 12, 24, 34 and 48, respectively. The proportion of patients with normal ALT were 67, 81 and 75% at week 24 (end of treatment), 34 and 48 (24 weeks off therapy), respectively. The rates of HBeAg loss were 24 and 20% at week 24 and 48, respectively. No viral breakthrough during treatment was observed. CONCLUSION Clevudine 30 mg treatment for 24 weeks was well tolerated and exhibited more potent antiviral activity and a higher ALT normalization rate than 12-week treatment with durable efficacy at week 24 off therapy.
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49
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Lok AS, Zoulim F, Locarnini S, Bartholomeusz A, Ghany MG, Pawlotsky JM, Liaw YF, Mizokami M, Kuiken C. Antiviral drug-resistant HBV: standardization of nomenclature and assays and recommendations for management. Hepatology 2007; 46:254-65. [PMID: 17596850 DOI: 10.1002/hep.21698] [Citation(s) in RCA: 385] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Substantial advances have been made in the treatment of chronic hepatitis B in the past decade. Approved treatments for chronic hepatitis B include 2 formulations of interferon and 4 nucleos(t)ide analogues (NAs). Sustained viral suppression is rarely achieved after withdrawal of a 48-week course of NA therapy, necessitating long, and in many cases, indefinite treatment with increasing risk of development of drug resistance. Antiviral resistance and poor adherence are the most important factors in treatment failure of hepatitis B. Thus, there is a need to standardize nomenclature relating to hepatitis B antiviral resistance, and to define genotypic, phenotypic, and clinical resistance to NA therapy.
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Affiliation(s)
- Anna S Lok
- Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109-0362, USA.
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50
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Karatayli E, Karayalçin S, Karaaslan H, Kayhan H, Türkyilmaz AR, Sahin F, Yurdaydin C, Bozdayi AM. A Novel Mutation Pattern Emerging during Lamivudine Treatment Shows Cross-Resistance to Adefovir Dipivoxil Treatment. Antivir Ther 2007. [DOI: 10.1177/135965350701200509] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Aims This study was conducted to clarify the resistance profile of a novel mutation pattern emerging during lamivudine (3TC) therapy and showing cross-resistance to adefovir dipivoxil (ADV) in a patient with chronic hepatitis B. Methods and results Successful suppression of hepatitis B virus (HBV) replication by sequential therapy of 9 MU thrice weekly interferon (IFN) and 3TC was followed by genotypical resistance detected at month 28 of therapy (month 19 of lamivudine treatment). ADV was added to 3TC therapy on month 44 of antiviral treatment. Neither alanine aminotransferase normalization nor a stable decrease in HBV viral load was observed, although ADV was used for more than 40 months. The HBV pol region was amplified from serum samples obtained before and after ADV treatment. The complete genome was cloned into a TA vector. PCR products and 7–10 clones from each cloned vector were sequenced. A novel mutation, A181S, in the reverse transcriptase gene leading to a conversion of W172C in the overlapping surface antigen gene was detected along with a M204I mutation. The complete genome comprising the A181S+M204I pattern was cloned into an expression vector and its in vitro susceptibility to 3TC, ADV, tenofovir (PMPA), clevudine (l-FMAU) and emtricitabine (FTC) were determined in transiently transfected Huh7 cells. This mutation pattern displayed more than 1,000-fold resistance to the nucleoside analogues 3TC and FTC and approximately sixfold resistance to l-FMAU, while it confers 28.23- and 5.57-fold resistance for the nucleotide analogues ADV and PMPA, respectively. Conclusion A new mutation pattern, A181S+M204I, arising under lamivudine treatment confers cross-resistance to ADV both in vivo and in vitro.
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Affiliation(s)
| | - Selim Karayalçin
- Department of Gastroenterology, School of Medicine, Ankara University, Ankara, Turkey
| | - Hayri Karaaslan
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Selcuk University, School of Medicine, Konya, Turkey
| | - Handan Kayhan
- Institute of Hepatology, Ankara University, Ankara, Turkey
| | | | - Fikret Sahin
- Department of Microbiology, School of Medicine, Ankara University, Ankara, Turkey
| | - Cihan Yurdaydin
- Institute of Hepatology, Ankara University, Ankara, Turkey
- Department of Gastroenterology, School of Medicine, Ankara University, Ankara, Turkey
| | - A Mithat Bozdayi
- Institute of Hepatology, Ankara University, Ankara, Turkey
- Department of Gastroenterology, School of Medicine, Ankara University, Ankara, Turkey
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