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Szotowska I, Ledwoń A. Antiviral Chemotherapy in Avian Medicine-A Review. Viruses 2024; 16:593. [PMID: 38675934 PMCID: PMC11054683 DOI: 10.3390/v16040593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/06/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
This review article describes the current knowledge about the use of antiviral chemotherapeutics in avian species, such as farm poultry and companion birds. Specific therapeutics are described in alphabetical order including classic antiviral drugs, such as acyclovir, abacavir, adefovir, amantadine, didanosine, entecavir, ganciclovir, interferon, lamivudine, penciclovir, famciclovir, oseltamivir, ribavirin, and zidovudine, repurposed drugs, such as ivermectin and nitazoxanide, which were originally used as antiparasitic drugs, and some others substances showing antiviral activity, such as ampligen, azo derivates, docosanol, fluoroarabinosylpyrimidine nucleosides, and novel peptides. Most of them have only been used for research purposes and are not widely used in clinical practice because of a lack of essential pharmacokinetic and safety data. Suggested future research directions are also highlighted.
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Affiliation(s)
- Ines Szotowska
- Department of Pathology and Veterinary Diagnostics, Warsaw University of Life Sciences, 02-776 Warsaw, Poland;
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2
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Abd Ali AAkool W, Kashanian S, Hadidi S. Molecular interaction of antiviral drug penciclovir with DNA and HSA insights from experimental and docking studies. J Biomol Struct Dyn 2024:1-11. [PMID: 38263739 DOI: 10.1080/07391102.2024.2303382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/11/2023] [Indexed: 01/25/2024]
Abstract
One approach to accelerate the availability of new cancer drugs is to test drugs approved for other conditions as anticancer agents. During recent decades, penciclovir (PNV) has been frequently utilized as a potent antiviral drug, in particular against infections caused by herpes viruses. Many antivirals interact with DNA and change their expression level, so determining the binding mode is of great importance. In our laboratory, we have focused our attention to design improved drugs that target cellular DNA, to understand the mechanism of action at the molecular level, and also to investigate the effect of antiviral drugs as anticancer agents. The results of ct-DNA-PNV interactions at physiological pH using fluorescence spectroscopy, UV-visible absorption spectroscopy, and molecular modeling reveal this drug binds well to ct-DNA through groove binding. The circular dichroism measurements displayed that PNV caused a slight change in the DNA structure which affirmed that the binding of PNV with the DNA occurs through the groove mode. Besides, multi-spectroscopic and molecular docking were used to evaluate how PNV interacts with human serum albumin under physiological conditions. The findings of fluorescence quenching suggested that static quenching was involved in the spontaneous development of HSA-PNV complex through hydrophobic force. The docking simulation results validated the findings of spectroscopic techniques.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | | | - Saba Hadidi
- Inorganic Chemistry Department, Faculty of Chemistry, Razi University, Kermanshah, Iran
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3
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Al-nami SY, Alessa H, Alorabi AQ, Alaysuy O, Hameed A, Alamrani NA, Al-Qahtani SD, El-Metwaly NM. Novel deliberately sensitive and selective penciclovir voltammetric sensors depending on iron oxide nanoparticles carbon paste electrodes. Microchem J 2023. [DOI: 10.1016/j.microc.2023.108723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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4
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Affiliation(s)
- Yashpal Singh Malik
- ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Izatnagar, Uttar Pradesh India
| | - Raj Kumar Singh
- ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Izatnagar, Uttar Pradesh India
| | - Mahendra Pal Yadav
- ICAR-Indian Veterinary Research Institute (ICAR-IVRI), Izatnagar, Uttar Pradesh, India, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, India
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5
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Biophysical and In Silico Studies of the Interaction between the Anti-Viral Agents Acyclovir and Penciclovir, and Human Serum Albumin. Molecules 2017; 22:molecules22111906. [PMID: 29113080 PMCID: PMC6150291 DOI: 10.3390/molecules22111906] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 12/19/2022] Open
Abstract
Acyclovir (ACV) and penciclovir (PNV) have been commonly used during the last few decades as potent antiviral agents, especially for the treatment of herpes virus infections. In the present research their binding properties with human serum albumin (HSA) were studied using different advanced spectroscopic and in-silico methods. The interactions between ACV/PNV and HSA at the three investigated temperatures revealed a static type of binding. Extraction of the thermodynamic parameters of the ACV-HSA and PNV-HSA systems from the measured spectrofluorimetric data demonstrated spontaneous interactions with an enthalpy change (∆H0) of −1.79 ± 0.29 and −4.47 ± 0.51 kJ·mol−1 for ACV and PNV, respectively. The entropy change (∆S0) of 79.40 ± 0.95 and 69.95 ± 1.69 J·mol−1·K−1 for ACV and PNV, respectively, hence supported a potential contribution of electrostatic binding forces to the ACV-HSA and PNV-HSA systems. Putative binding of ACV/PNV to HSA, using previously reported site markers, showed that ACV/PNV were bound to HSA within subdomains IIA and IIIA (Sudlow sites I and II). Further confirmation was obtained through molecular docking studies of ACV-HSA and PNV-HSA binding, which confirmed the binding site of ACV/PNV with the most stable configurations of ACV/PNV within the HSA. These ACV/PNV conformers were shown to have free energies of −25.61 and −22.01 kJ·mol−1 for ACV within the HSA sites I and II and −22.97 and −26.53 kJ·mol−1 for PNV in HSA sites I and II, with hydrogen bonding and electrostatic forces being the main binding forces in such conformers.
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Dannaoui E, Trépo C, Zoulim F. Inhibitory Effect of Penciclovir-Triphosphate on Duck Hepatitis B Virus Reverse Transcription. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029700800104] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this study was to investigate the mechanism of inhibition of hepatitis B virus replication by penciclovir-triphosphate, the active metabolite of famciclovir. A recently developed in vitro translation assay for the expression of an enzymatically active duck hepatitis B virus (DHBV) reverse transcriptase was used to assess the inhibitory activity of penciclovir-triphosphate (PCV-TP) in comparison with other guanosine analogue triphosphates. Acyclovir-triphosphate (ACV-TP), the chiral triphosphates of penciclovir (PCV), ( R)-PCV-TP and ( S)-PCV-TP, and carbocyclic 2′-deoxyguanosine-TP (CDG-TP) did inhibit reproducibly minus strand DNA synthesis to different extents. CDG-TP was the most potent inhibitor of dGTP incorporation. The inhibitory effect of these compounds against the incorporation of the first nucleotide of minus strand DNA, dGMP, was similar to that observed with DNA chain elongation. 2′,3′-dideoxyguanosine-TP (ddG-TP), ACV-TP and both ( R) and ( S)-PCV-TP inhibited the incorporation of the next nucleotides in the short DNA primer, whereas CDG-TP did not. These results demonstrate that PCV-TP inhibits hepadnavirus reverse transcription by inhibiting the synthesis of the short DNA primer. The data obtained with the inhibition of the enzymatic activity of the DHBV polymerase provides a new insight into the mechanism of action of penciclovir-triphosphate on HBV replication.
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Affiliation(s)
- E Dannaoui
- INSERM U27l, 151 cours Albert Thomas, 69003 Lyon, France
| | - C Trépo
- INSERM U27l, 151 cours Albert Thomas, 69003 Lyon, France
| | - F Zoulim
- INSERM U27l, 151 cours Albert Thomas, 69003 Lyon, France
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7
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Shakya N, Vedi S, Liang C, Agrawal B, Tyrrell DL, Kumar R. A new class of pyrimidine nucleosides: inhibitors of hepatitis B and C viruses. Bioorg Med Chem Lett 2012; 22:6475-80. [PMID: 22985854 DOI: 10.1016/j.bmcl.2012.08.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/03/2012] [Accepted: 08/13/2012] [Indexed: 01/09/2023]
Abstract
Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are major health threats worldwide leading to liver cirrhosis, liver cancer and mortality. Herein, we report a new category of dideoxy pyrimidine nucleosides possessing a 4'-carboxyl (or carboxymethyl) function (7-9, 13, 16, 17), which are discovered as potential antiviral agents. For the first time, these nucleosides are recognized to be inhibitors of HBV and/or HCV replication. Among 4'-carboxy compounds, 3',4'-didehydrothymidine (16) was most effective against DHBV, HBV and HCV. Modification of the 4'-position in compound 7 from a carboxyl to carboxymethyl group (17) did not affect the anti-HBV activity but greatly increased the anti-HCV activity. Importantly, 17 yielded synergistic antiviral effect when combined with ribavirin without toxicity. The activity exhibited by a single agent towards both hepatitis viruses and no detectable in vitro cytotoxicity make this new class of compounds of interest.
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Affiliation(s)
- Neeraj Shakya
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada
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Kanneti R, Bhavesh D, Paramar D, Shivaprakash R, Bhatt PA. Determination of penciclovir in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry: application to a clinical pharmacokinetic study. Biomed Chromatogr 2011; 25:458-65. [DOI: 10.1002/bmc.1468] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Srivastav NC, Mak M, Agrawal B, Tyrrell DLJ, Kumar R. Antiviral activity of 2,3′-anhydro and related pyrimidine nucleosides against hepatitis B virus. Bioorg Med Chem Lett 2010; 20:6790-3. [DOI: 10.1016/j.bmcl.2010.08.120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2010] [Revised: 08/21/2010] [Accepted: 08/24/2010] [Indexed: 11/29/2022]
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Srivastav NC, Shakya N, Mak M, Liang C, Tyrrell DLJ, Agrawal B, Kumar R. Synthesis and in vitro antiviral activities of 3'-fluoro (or chloro) and 2',3'-difluoro 2',3'-dideoxynucleoside analogs against hepatitis B and C viruses. Bioorg Med Chem 2010; 18:7542-7. [PMID: 20869253 DOI: 10.1016/j.bmc.2010.08.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 08/25/2010] [Accepted: 08/26/2010] [Indexed: 12/27/2022]
Abstract
Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) lead to serious liver diseases worldwide. Co-infection with HBV and HCV is very common and is associated with increased risk of liver pathogenesis, liver cancer, and liver failure. Several 5-substituted 3'-fluoro (or chloro) (1-4, 6, 7, 17-19) and 2',3'-difluoro 2',3'-dideoxynucleosides (15 and 16) were synthesized and evaluated for in vitro antiviral activities against duck hepatitis B virus (DHBV), human hepatitis B virus, and hepatitis C virus. Of these compounds 4, 7, 17, and 19 demonstrated moderate anti-HBV activity, and 2, 4, 7, 8, and 19 were weak inhibitors of HCV. Although 5-iodo derivative (7) was most inhibitory against HCV, it exhibited a reduction in cellular RNA levels in Huh-7 cells. The 5-hydroxymethyl-3'-fluoro-2',3'-dideoxyuridine (4) and 1-(3-chloro-2,3-dideoxy-β-d-erythro-pentofuranosyl)-5-fluorouracil (19) provided the most inhibition of both viruses without cytotoxicity.
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Affiliation(s)
- Naveen C Srivastav
- Department of Laboratory Medicine and Pathology, 1-71 Medical Sciences Building, University of Alberta, Edmonton, AB, Canada T6G 2H7
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Srivastav NC, Shakya N, Mak M, Agrawal B, Tyrrell DL, Kumar R. Antiviral Activity of Various 1-(2′-Deoxy-β-d-lyxofuranosyl), 1-(2′-Fluoro-β-d-xylofuranosyl), 1-(3′-Fluoro-β-d-arabinofuranosyl), and 2′-Fluoro-2′,3′-didehydro-2′,3′-dideoxyribose Pyrimidine Nucleoside Analogues against Duck Hepatitis B Virus (DHBV) and Human Hepatitis B Virus (HBV) Replication. J Med Chem 2010; 53:7156-66. [DOI: 10.1021/jm100803c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Naveen C. Srivastav
- Department of Laboratory Medicine and Pathology, 1-71 Medical Sciences Building
| | - Neeraj Shakya
- Department of Laboratory Medicine and Pathology, 1-71 Medical Sciences Building
| | - Michelle Mak
- Department of Laboratory Medicine and Pathology, 1-71 Medical Sciences Building
| | | | | | - Rakesh Kumar
- Department of Laboratory Medicine and Pathology, 1-71 Medical Sciences Building
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12
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Mendoza A, Sosa-Rivadeneyra M, Sartillo-Piscil F, Quintero L, Flores-Alamo M. 5-Fluoro-1-[(4 S,5 R)-5-(2-hydroxyethyl)-2,2-dimethyl-1,3-dioxolan-4-yl]pyrimidine-2,4(1 H,3 H)-dione. Acta Crystallogr Sect E Struct Rep Online 2010; 66:o1317. [PMID: 21579410 PMCID: PMC2979416 DOI: 10.1107/s1600536810016065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 04/30/2010] [Indexed: 11/17/2022]
Abstract
In the title compound, C11H15FN2O5, the five-membered ring has an envelope conformation, while the six-membered ring is essentially planar, with a maximum deviation of 0.032 (2) Å from the mean plane. The crystal packing is stabilized by intermolecular N—H⋯O and O—H⋯O hydrogen bonds, generating a layer structure parallel to (001).
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Kim DK, Kim YW, Lee N. Synthesis of 5-[2-(guanin-9-yl)- and 5-[2-(2-aminopurin-9-yl)ethyl]-2-D-ribo-(1,2′,3′,4′-tetrahydroxybutyl)-1,3-dioxane. J Heterocycl Chem 2009. [DOI: 10.1002/jhet.5570380107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Cavallaro G, Maniscalco L, Caliceti P, Salmaso S, Semenzato A, Giammona G. Glycosilated Macromolecular Conjugates of Antiviral Drugs with a Polyaspartamide. J Drug Target 2008; 12:593-605. [PMID: 15621685 DOI: 10.1080/10611860400013477] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Two new polymeric conjugates for specific liver targeting were prepared by conjugation of sugar moieties and antiviral drugs to alpha, beta-poly[N-2-(hydroxyethyl)-DL-aspartamide] (PHEA). PHEA-galactopyranosylphenylthiocarbamide-mono-O-succinylganciclovir (conjugate 7) and PHEA-mannopyranosylphenylthiocarbamide-O-succinylacyclovir (conjugate 8) were synthesized according to a multi-step procedure which allowed for obtaining high product yield and process standardization. Conjugate 7 contained 7.5 and 8.5% of galactose and ganciclovir (substituent/repeating unit, mol/mol), respectively, and conjugate 8 contained 14.2 and 10.8% of mannose and acyclovir, respectively. In vitro studies demonstrated that both acyclovir and ganciclovir are released from the polymeric adducts at a release rate, which depended on the incubation medium. Though a detailed study evidenced that the two bioconjugates undergo different hydrolysis pathways, in both cases high drug release rate was found in plasma, while the glycosidic moiety was not released. Pharmacokinetic studies carried out by intravenous administration of the bioconjugates to Balb/c mice demonstrated that the conjugation of glycosidic moieties promotes the disappearance of the polymer from the bloodstream. The two derivatives displayed a different pharmacokinetic profile. In particular, the mannosyl conjugation promoted the rapid disposition of the macromolecule in the kidneys and in the liver, while prevented the accumulation in the spleen. On the contrary, the galactosyl derivative was found to dispose in the liver at the same extent of the naked polymer. Few considerations on the different behavior of the conjugates were reported.
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Affiliation(s)
- Gennara Cavallaro
- Dipartimento di Chimica e Tecnologie Farmceutiche, Università degli Studi di Palermo Via Archirafi 32, 90123, Palermo, Italy
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Field HJ. Drug Evaluations: Drug Evaluation Anti-infectives: Famciclovir - origins, progress and prospects. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.5.8.925] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Hugh J Field
- Centre for Veterinary Science, Cambridge University, Madingley Road, Cambridge, CB3 OES, UK
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Moukha-Chafiq O, Taha ML, Mouna A, Lazrek HB, Vasseur JJ, De Clercq E. Synthesis and biological evaluation of some alpha-[6-(1'-carbamoylalkylthio)-1 H-pyrazolo[3,4-D]pyrimidin-4-yl]thioalkylcarboxamide acyclonucleosides. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2007; 26:335-45. [PMID: 17479430 DOI: 10.1080/15257770701296952] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The reaction of 1H-pyrazolo[3,4-d]pyrimidin-4,6-dithione 11 with compounds 12a-c produces ethyl alpha-[6-(1'-carboethoxyalkylthio)-1 H-pyrazolo[3,4-d]pyrimidin-4-yl]thioalkylates 13a-c, respectively. These heterocycles were alkylated, separately, with alkylating agents 14, 15, and 16 to afford, predominately, the N(1)-acyclic nucleosides (17-19)a-c, which were deprotected to give the desired products (20-22)a-c. All synthetic compounds were characterized on the basis of their physical and spectroscopic properties. The acyclic nucleosides (20-22)a-c were evaluated for their inhibitory effects against the replication of varicella-zoster virus, human cytomegalovirus and M. tuberculosis. No marked biological activity was found.
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Affiliation(s)
- Omar Moukha-Chafiq
- Faculté des Sciences, Laboratoire de Chimie Bio-Organique Appliquée, Agadir, Morocco.
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Lee HW, Seo JH, Lee KT. Development and validation of a high-performance liquid chromatography–tandem mass spectrometry for the determination of penciclovir in human plasma: Application to a bioequivalence study. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 852:382-8. [PMID: 17324644 DOI: 10.1016/j.jchromb.2007.01.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 01/05/2007] [Accepted: 01/28/2007] [Indexed: 10/23/2022]
Abstract
We developed and validated a simple high-performance liquid chromatography (HPLC) coupled with positive ion electrospray ionization tandem mass spectrometry (ESI-MS/MS) detection system for determining penciclovir (active metabolite of famciclovir) levels in human plasma using acyclovir as an internal standard (IS). Acquisition was performed in multiple reaction monitoring (MRM) mode by monitoring the transitions: m/z 254.00>152.09 for penciclovir and m/z 226.00>152.09 for IS. The analytes were chromatographed on a Capcellpak MGII C(18) reversed-phase chromatographic column by isocratic elution using 30% methanol and 70% Milli-Q water containing 10 mM ammonium formate (adjusted to pH 3.1 with formic acid). Results were linear over the studied range (0.05-10 microg/ml) with r(2)=0.9999, and the total analysis time for each run was 2 min. Intra- and inter-assay precisions were 2.3-7.8 and 3.7-7.5%, respectively, and intra- and inter-assay relative errors (RE) were 2.0-8.4 and 1.9-9.1%, respectively. The lower limit of quantification (LLOQ) was 0.05 microg/ml. At this concentration mean intra- and inter-assay precisions were 7.8 and 7.5%, respectively, and mean intra- and inter-assay relative errors were 2.2 and 9.1%, respectively. Penciclovir was found to be stable in plasma samples under short-, long-term storage and processing conditions. The developed assay was successfully applied to a bioequivalence study of penciclovir administered as a single oral dose (500 mg as famciclovir) to healthy volunteers.
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Affiliation(s)
- Heon-Woo Lee
- Department of Pharmaceutical Biochemistry, College of Pharmacy, Kyung-Hee University, Hoegi-Dong, Dongdaemun-Ku, Seoul 130-701, South Korea
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Kumar R, Semaine W, Johar M, Tyrrell DLJ, Agrawal B. Effect of Various Pyrimidines Possessing the 1-[(2-Hydroxy-1-(hydroxymethyl)ethoxy)methyl] Moiety, Able To Mimic Natural 2‘-Deoxyribose, on Wild-type and Mutant Hepatitis B Virus Replication. J Med Chem 2006; 49:3693-700. [PMID: 16759112 DOI: 10.1021/jm060102l] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hepatitis B virus (HBV) is the most common cause of chronic liver disease worldwide. Development of drug resistance against clinical anti-HBV drug lamivudine due to long-term use and rebound of viral DNA after cessation of treatment has been a major setback of the current therapy. We have synthesized a series of pyrimidine nucleosides possessing a variety of substituents at the C-5 position, and a 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl] flexible acyclic glycosyl moiety at the N-1 position, that have the ability to mimic the natural 2'-deoxyribosyl moiety. Some of these potential antiviral compounds included variations at both C-5 and C-6 positions of the uracil base. Other variations of the uracil derivatives were the 6-aza congeners. 4-Amino and 4-methoxy pyrimidine derivatives were also made. Compounds in which the base moiety was substituted by 5-chloro- (25), 5-(2-bromovinyl)- (32), or 5-bromo-6-methyl- (37) groups possess significant activity against duck-HBV, wild-type human HBV (2.2.15 cells), and lamivudine-resistant HBV containing single and double mutations. No cytotoxicity was seen in host HepG2 and Vero cells, up to the highest concentration tested. The anti-HBV activity exhibited by compounds 25, 32, and 37 was superior for human HBV and comparable for DHBV to that of the corresponding purine nucleoside, ganciclovir. Further, they were only 10-15-fold less inhibitory against human HBV in 2.2.15 cells than the reference drug, lamivudine. Other compounds in the series were moderately inhibitory against DHBV and wild-type human HBV. The size of the halogen and the electronegativity of the substituents at the 5- and 6-positions are important for antiviral activity toward HBV. These compounds were also evaluated for their antiviral activity for West Nile virus, respiratory syncytial virus, SARS-coronavirus, and hepatitis C virus. They were generally inactive in these antiviral assay systems (at concentrations up to 100 microg/mL). 1-[(2-Hydroxy-1-(hydroxymethyl) ethoxy)methyl]-5-fluorocytosine (34) showed some inhibitory activity against hepatitis C virus. Taken together, these data support our previous observations that the 5-substituted pyrimidine nucleosides containing acyclic glycosyl moieties have potential to serve as a new generation of potent, selective, and nontoxic anti-HBV agents for wild-type and lamivudine-resistant mutant HBV.
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Affiliation(s)
- Rakesh Kumar
- Department of Laboratory Medicine and Pathology, 1-41 Medical Sciences Building, University of Alberta, Edmonton, AB, Canada T6G 2H7.
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Han J, Zhao YL, Shan LM, Huang FJ, Xiao XH. An experiment on standardized cell culture assay in assessing the activities of Composite Artemisia Capillaris Tablets against hepatitis B virus replicationin vitro. Chin J Integr Med 2005; 11:54-6. [PMID: 15975310 DOI: 10.1007/bf02835751] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To explore the activities of Composite Artemisia Capillaris Tablet (CACT) against hepatitis B virus replication in vitro. METHODS By means of radioimmunoassay (RIA), Dot blot and Southern blot, the surface and e antigen production of 2.2.15 cells, HBV DNA in 2.2.15 cell culture medium and that in 2.2.15 cells were examined respectively. RESULTS HBsAg, HBeAg values of 2.2.15 cells treated by CACT were lower than those of the control, the HBV DNA quantities in culture medium and in 2.2.15 cells decreased as compared with those cells with no treatment by CACT given to them. CONCLUSION CACT could inhibit HBV DNA replication, showing its potential antiviral activity in hepatitis B treatment.
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Affiliation(s)
- Jin Han
- Department of Pharmacy, 302 Hospital of PLA, Beijing, China
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Abstract
Valaciclovir (Valtrex, Zelitrex), the L-valine ester of aciclovir, increases aciclovir bioavailability by 3- to 5-fold over that achievable with oral aciclovir. It addresses many unmet needs of currently available anti-herpesvirus therapies. Valaciclovir extends the efficacy of aciclovir in the treatment of herpes zoster and genital HSV infections, using less frequent dose regimens but retaining the highly acceptable safety profile established for aciclovir. The potential for valaciclovir in CMV prophylaxis has now been proven, and further refining to identify the optimal dose regimen is ongoing. After oral administration, valaciclovir is rapidly absorbed and extensively converted to aciclovir and L-valine, the essential amino acid. The mode of action and spectrum of antiviral activity of valaciclovir are thus identical to aciclovir. The bioavailability of aciclovir after valaciclovir, characterised from studies in healthy adult volunteers, is similar in a wide range of patient populations, including the elderly, those with advanced HIV disease, patients with impaired liver or renal function, or undergoing bone marrow transplantation. No clinically significant drug interactions with valaciclovir have so far been identified. Dosage reductions in clinical use of valaciclovir are only necessary when renal function is severely impaired. In controlled clinical trials in herpes zoster, valaciclovir (1000 mg three times daily) is superior to aciclovir in speeding the resolution of zoster-associated pain and post-herpetic neuralgia. It is as effective as aciclovir in hastening rash healing. In patients with ophthalmic zoster, no differences were evident between valaciclovir and aciclovir treatment on zoster-associated pain or the occurrence of ocular complications. The safety profiles of valaciclovir, aciclovir and placebo were not different in this study programme. In a series of controlled, randomised trials of valaciclovir, aciclovir and placebo for the acute treatment of genital HSV infections in approximately 3000 patients, twice daily valaciclovir was proven as effective as the standard 5 times daily aciclovir regimen in resolving the clinical signs and symptoms of lesional disease. Early patient-initiated valaciclovir therapy (500 mg twice daily) of recurrent genital herpes episodes was shown significantly to increase the chance of prevention of vesicular or ulcerative lesions, a valuable clinical advantage not prospectively proven for aciclovir. When used for periods of up to one year, valaciclovir (500 mg once daily) effectively suppresses genital herpes recurrences. Long-term studies of valaciclovir for HSV suppression, evaluating doses of up to 1000 mg daily in approximately 3000 patients, about 25% of whom were HIV seropositive (CD+ > 100 cells/microl), revealed a highly acceptable clinical tolerability profile for valaciclovir that did not differ from aciclovir or placebo. There were no cases resembling thrombotic microangiopathy in these long-term studies. The aciclovir safety heritage and pharmacokinetic rationale for the development of valaciclovir have been realised through the clinical research programmes in the zoster and HSV indications. Further studies in these and related areas, including CMV prophylaxis, are in progress and aim to expand further the clinical potential of valaciclovir in the future.
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Affiliation(s)
- R Patel
- Department of Genitourinary Medicine, Royal South Hants Hospital, Southampton,Hampshire, SO9 4PE, UK
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21
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Walters KA, Tipples GA, Allen MI, Condreay LD, Addison WR, Tyrrell L. Generation of stable cell lines expressing Lamivudine-resistant hepatitis B virus for antiviral-compound screening. Antimicrob Agents Chemother 2003; 47:1936-42. [PMID: 12760870 PMCID: PMC155849 DOI: 10.1128/aac.47.6.1936-1942.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Lamivudine [beta-L-(-)-2',3'-dideoxy-3'-thiacytidine] is a potent inhibitor of hepadnavirus replication and is used both to treat chronic hepatitis B virus (HBV) infections and to prevent reinfection of transplanted livers. Unfortunately, lamivudine-resistant HBV variants do arise during prolonged therapy, indicating a need for additional antiviral drugs. Replication-competent HBV constructs containing the reverse transcriptase domain L180M/M204V and M204I (rtL180M/M204V and rtM204I) mutations associated with lamivudine resistance were used to produce stable cell lines that express the resistant virus. These cell lines contain stable integrations of HBV sequences and produce both intracellular and extracellular virus. HBV produced by these cell lines was shown to have a marked decrease in sensitivity to lamivudine, with 450- and 3,000-fold shifts in the 50% inhibitory concentrations for the rtM204I and rtL180M/M204V viruses, respectively, compared to that for the wild-type virus. Drug assays indicated that the lamivudine-resistant virus exhibited reduced sensitivity to penciclovir [9-(4-hydroxy-3-hydroxymethyl-but-1-yl) guanine] but was still inhibited by the nucleoside analogues CDG (carbocyclic 2'-deoxyguanosine) and abacavir ([1S,4R]-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclopentene-1-methanol). Screening for antiviral compounds active against the lamivudine-resistant HBV can now be done with relative ease.
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Affiliation(s)
- Kathie-Anne Walters
- Department of Medical Microbiology and Immunology, Glaxo Wellcome-Heritage Research Institute, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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22
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Tatti KM, Korba BE, Stang HL, Peek S, Gerin JL, Tennant BC, Schinazi RF. Mutations in the conserved woodchuck hepatitis virus polymerase FLLA and YMDD regions conferring resistance to lamivudine. Antiviral Res 2002; 55:141-50. [PMID: 12076758 DOI: 10.1016/s0166-3542(02)00019-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
During more than 104 weeks of treatment with lamivudine (3TC) in chronic woodchuck hepatitis virus (WHV) carrier woodchucks, viral recrudescence occurred. Analysis of WHV DNA polymerase from woodchuck serum samples by PCR followed by DNA sequencing demonstrated that all samples were wild type at the conserved YMDD motif in domain C. Four of the six 3TC-treated woodchucks showed a mixture of the wild-type Ala (GCT) and the mutant Thr (ACT) at the conserved amino acid residue 566 (FLLA) in domain B of the WHV polymerase region. The appearance of the A566T mutation was temporally associated with viral recrudescence. This change is analogous with the amino acid 181 (FLLA) in HBV where 3TC selects for a change from Ala to Thr in humans. In the woodchuck, the Ala to Thr change in the polymerase gene results in a mutation of the WHV surface protein (amino acid 377) from Trp (TGG) to an opal codon (TGA), which may prematurely terminates the polypeptide. Three WHV molecular infectious clones were constructed to study this mutation in greater detail in vitro: A566T, analogous to A181T in HBV; M589V, analogous to the M204V in HBV; and the double mutant A566T/M589V, analogous to A181T/M204V in HBV. These mutants exhibited drug-sensitivity and replication profiles that paralleled those reported for analogous HBV variants. In transfected Huh7 cells, WHV containing the M589V mutation conferred at least 100-fold increased resistance to 3TC, but replicated approximately 5-fold less efficiently than wild-type virus as judged by both extracellular virus production and intracellular DNA replicative forms. In contrast, A566T mutant was approximately 10-fold more resistant to 3TC, replicated intracellularly as well as wild type, but produced 10-fold lower levels of virions than wild type. These findings are consistent with the observation that the A566T mutation alters the overlapping WHV surface antigen reading frame. WHV carrying mutations in the conserved YMDD motif, while not directly selected during lamivudine therapy in WHV carrier woodchucks, are replication competent in cell culture indicating the potential for their emergence in treated animals. These results further illustrate the utility of the WHV/woodchuck model to studies of HBV-drug resistance.
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Affiliation(s)
- Kathleen M Tatti
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Veterans Affairs Medical Center and Emory University, Medical Research 151H, 1670 Clairmont Road, Decatur, GA 30033, USA
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23
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Kumar R, Nath M, Tyrrell DLJ. Design and synthesis of novel 5-substituted acyclic pyrimidine nucleosides as potent and selective inhibitors of hepatitis B virus. J Med Chem 2002; 45:2032-40. [PMID: 11985471 DOI: 10.1021/jm010410d] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel class of 5-substituted acyclic pyrimidine nucleosides, 1-[(2-hydroxyethoxy)methyl]-5-(1-azidovinyl)uracil (9a), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl]-5-(1-azidovinyl)uracil (9b), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl]-5-(1-azidovinyl)uracil (9c), were synthesized by regiospecific addition of bromine azide to the 5-vinyl substituent of the respective 5-vinyluracils (2a-c) followed by treatment of the obtained 5-(1-azido-2-bromoethyl) compounds (3a-c) with t-BuOK, to affect the base-catalyzed elimination of HBr. Thermal decomposition of 9b and 9c at 110 degrees C in dioxane yielded corresponding 5-[2-(1-azirinyl)]uracil analogues (10b,c). The 5-(1-azidovinyl)uracil derivatives 9a-c were found to exhibit potent and selective in vitro anti-HBV activity against duck hepatitis B virus (DHBV) infected primary duck hepatocytes at low concentrations (EC(50) = 0.01-0.1 microg/mL range). The most active anti-DHBV agent (9c), possessing a [4-hydroxy-3-(hydroxymethyl)-1-butyl] substituent at N-1, exhibited an activity (EC(50) of 0.01-0.05 microg/mL) comparable to that of reference compound (-)-beta-L-2',3'-dideoxy-3'-thiacytidine (3-TC) (EC(50) = 0.01-0.05 microg/mL). In contrast, related 5-[2-(1-azirinyl)]uracil analogues (10b,c) were devoid of anti-DHBV activity, indicating that an acyclic side chain at C-5 position of the pyrimidine ring is essential for anti-HBV activity. The pyrimidine nucleosides (9a-c, 10b,c) exhibited no cytotoxic activity against a panel of 60 human cancer cell lines. All of the compounds investigated did not show any detectable toxicity to several stationary and proliferating host cell lines or to mitogen stimulated proliferating human T lymphocytes, up to the highest concentration tested.
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Affiliation(s)
- Rakesh Kumar
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada T6G 2H7.
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24
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Sood RK, Bhadti VS, Fattom AI, Naso RB, Korba BE, Kern ER, Chen HM, Hosmane RS. Novel ring-expanded nucleoside analogs exhibit potent and selective inhibition of hepatitis B virus replication in cultured human hepatoblastoma cells. Antiviral Res 2002; 53:159-64. [PMID: 11750942 DOI: 10.1016/s0166-3542(01)00204-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Novel ring-expanded nucleoside (REN) analogs (1-3) containing 5:7 fused ring systems as the heterocyclic base were found to be potent and selective inhibitors of hepatitis B virus (HBV) replication in cultured human hepatoblastoma 2.2.15 cells. The most active compound, 6-amino-4,5-dihydro-8H-1-(beta-D-ribofuranosyl)imidazo[4,5-e][1,3]diazepine-4,8-dione (1), inhibited the synthesis of intracellular HBV replication intermediates and extracellular virion release in 2.2.15 cells with 50% effective concentration (EC50) of 0.604 and 0.131 microM, respectively. All three compounds had no effect on the synthesis of viral ribonucleic acids (RNA) in 2.2.15 cells. These compounds also exhibited low cellular toxicity in stationary and rapidly growing cell systems.
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Affiliation(s)
- Ramesh K Sood
- W.W. Karakawa Microbial Pathogenesis Laboratory, Nabi, Rockville, MD 20852, USA
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25
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26
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Kumar R, Sharma N, Nath M, Saffran HA, Tyrrell DL. Synthesis and antiviral activity of novel acyclic nucleoside analogues of 5-(1-azido-2-haloethyl)uracils. J Med Chem 2001; 44:4225-9. [PMID: 11708924 DOI: 10.1021/jm010227k] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present the discovery of a novel category of 5-substituted acyclic pyrimidine nucleosides as potent antiviral agents. A series of 1-[(2-hydroxyethoxy)methyl] (5-7), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl] (8-10), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl] (11-13) derivatives of 5-(1-azido-2-haloethyl)uracil were synthesized and evaluated for their biological activity in cell culture. 1-[4-Hydroxy-3-(hydroxymethyl)-1-butyl]-5-(1-azido-2-chloroethyl)uracil (12) was the most effective antiviral agent in the in vitro assays against DHBV (EC(50) = 0.31-1.55 microM) and HCMV (EC(50) = 3.1 microM). None of the compounds investigated showed any detectable toxicity to several stationary and proliferating host cells.
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Affiliation(s)
- R Kumar
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton T6G 2H7, Canada.
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27
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Kumar R, Tyrrell DL. Novel 5-vinyl pyrimidine nucleosides with potent anti-hepatitis B virus activity. Bioorg Med Chem Lett 2001; 11:2917-20. [PMID: 11677126 DOI: 10.1016/s0960-894x(01)00589-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Synthesis and antiviral activities of novel N-1 alkyl substituted pyrimidines, 1-[(2-hydroxyethoxy)methyl]-5-vinyluracil (5), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl]-5-vinyluracil (6), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl]-5-vinyluracil (7) are reported. Compounds 6 and 7 were potent inhibitors of DHBV in cell culture, in contrast, all of the compounds described were devoid of activity against TK(+) HSV-1 and TK(-) HSV-1.
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Affiliation(s)
- R Kumar
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton, Canada T6G 2H7.
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28
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Delaney WE, Edwards R, Colledge D, Shaw T, Torresi J, Miller TG, Isom HC, Bock CT, Manns MP, Trautwein C, Locarnini S. Cross-resistance testing of antihepadnaviral compounds using novel recombinant baculoviruses which encode drug-resistant strains of hepatitis B virus. Antimicrob Agents Chemother 2001; 45:1705-13. [PMID: 11353615 PMCID: PMC90535 DOI: 10.1128/aac.45.6.1705-1713.2001] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Long-term nucleoside analog therapy for hepatitis B virus (HBV)-related disease frequently results in the selection of mutant HBV strains that are resistant to therapy. Molecular studies of such drug-resistant variants are clearly warranted but have been difficult to do because of the lack of convenient and reliable in vitro culture systems for HBV. We previously developed a novel in vitro system for studying HBV replication that relies on the use of recombinant baculoviruses to deliver greater than unit length copies of the HBV genome to HepG2 cells. High levels of HBV replication can be achieved in this system, which has recently been used to assess the effects of lamivudine on HBV replication and covalently closed circular DNA accumulation. The further development of this novel system and its application to determine the cross-resistance profiles of drug-resistant HBV strains are described here. For these studies, novel recombinant HBV baculoviruses which encoded the L526M, M550I, and L526M M550V drug resistance mutations were generated and used to examine the effects of these substitutions on viral sensitivity to lamivudine, penciclovir (the active form of famciclovir), and adefovir, three compounds of clinical importance. The following observations were made: (i) the L526M mutation confers resistance to penciclovir and partial resistance to lamivudine, (ii) the YMDD mutations M550I and L526M M550V confer high levels of resistance to lamivudine and penciclovir, and (iii) adefovir is active against each of these mutants. These findings are supported by the limited amount of clinical data currently available and confirm the utility of the HBV-baculovirus system as an in vitro tool for the molecular characterization of clinically significant HBV strains.
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Affiliation(s)
- W E Delaney
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Victoria 3051, Australia
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29
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Abstract
The term 'genotyping' describes the genetic characterization of a genome. The genotype analysis is performed to identify mutations that differentiate one individual or strain from another. The mutations may confer resistance to specific antiviral drugs or they may simply allow classification of a strain as to 'type' and 'subtype'. There are four human viruses for which genotype information is clinically useful. Hepatitis B virus (HBV) infections are being treated with antiretroviral drugs and resistance after prolonged treatment is common. Since HBV cannot be cultured, the only method of detecting resistance-conferring mutations in the genome is a genotypic analysis. Hepatitis C virus (HCV) infection can be cured by treatment with the combination of interferon and ribavirin but certain strains of virus are more resistant to treatment than others. The current recommendations are that all HCV type 1 infections be treated for 12 months whereas other types may be successfully treated in 6 months. Since interferon treatment may have significant side effects, the determination of HCV genotype is an important aspect of this therapeutic regimen. Treatment of cytomegalovirus (CMV) disease with nucleoside analogues occasionally results in resistant virus with mutations in the phosphotransferase gene (UL97) and/or the DNA polymerase gene (UL54) that can be tested with phenotypic or genotypic assays. Since CMV grows very slowly, it may be more clinically useful to perform a rapid genotypic assay although only the UL97 gene can be efficiently genotyped. Finally, the virus for which genotyping has become the standard of care, human immunodeficiency virus type 1 (HIV-1) can now be genotyped routinely by many clinical virology labs experienced with molecular amplification methods and automated DNA sequencing technology. All currently-available antiretroviral drugs are directed against either the protease or reverse transcriptase genes of HIV-1 and the mutations within these genes that confer resistance have been well described. Sequence-based genotyping methods are not necessarily the best approach for routine genotyping of these four viruses, but sequencing is the gold standard from which other methods are developed and against which they are compared.
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Affiliation(s)
- M Arens
- The Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, at St. Louis Children's Hospital, St. Louis, MO 63110, USA.
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Manns MP, Neuhaus P, Atkinson GF, Griffin KE, Barnass S, Vollmar J, Yeang Y, Young CL. Famciclovir treatment of hepatitis B infection following liver transplantation: a long-term, multi-centre study. Transpl Infect Dis 2001; 3:16-23. [PMID: 11429035 DOI: 10.1034/j.1399-3062.2001.003001016.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Famciclovir is a novel guanosine nucleoside analogue with activity against herpes viruses and hepatitis B virus (HBV). Several preliminary reports have described efficacy of famciclovir in patients with recurrent hepatitis B after orthotopic liver transplantation (OLT). This report describes the largest study to date of long-term famciclovir treatment in patients with de novo or recurrent hepatitis B post-OLT. One hundred thirty patients with detectable serum HBV DNA after OLT received oral famciclovir 500 mg tid on a compassionate-use basis. Safety analyses included all treated patients; efficacy was assessed in all patients and a subgroup of 73 patients with complete baseline HBV DNA and alanine aminotransferase (ALT) data who had received > or =6 months of treatment. Efficacy parameters included serum levels of HBV DNA, ALT, and anti-HBe or anti-HBs seroconversion rates. Of the 70 patients treated for > or =6 months who could be evaluated for response/non-response to famciclovir, 52 (74%) were responders, defined as patients who experienced a 70% decrease or more in HBV DNA levels from baseline, or who became HBV DNA-negative, for at least two consecutive visits. In famciclovir responders, HBV DNA levels decreased by a median of 91% after 12 weeks of treatment, 95% after 6 months and >99% after 18 months of treatment. Marked differentiation between responders and non-responders could be made soon after the onset of treatment. Among anti-HBe positive patients with evidence of HBV replication, 12/13 were responders. Patients with high baseline ALT levels experienced more rapid suppression of HBV DNA during therapy with famciclovir. Famciclovir therapy was safe and well tolerated; serious adverse events were reported infrequently. Famciclovir treatment may be beneficial in patients with hepatitis B infection post-OLT.
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Affiliation(s)
- M P Manns
- Department of Gastroenterology and Hepatology, Center for Internal Medicine, Medical School of Hannover, Hannover, Germany.
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31
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Fu L, Cheng YC. Characterization of novel human hepatoma cell lines with stable hepatitis B virus secretion for evaluating new compounds against lamivudine- and penciclovir-resistant virus. Antimicrob Agents Chemother 2000; 44:3402-7. [PMID: 11083647 PMCID: PMC90212 DOI: 10.1128/aac.44.12.3402-3407.2000] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
L-Nucleoside analogs are new therapeutic agents for treatment of chronic hepatitis B. However, their clinical application was limited by the emergence of viral resistance. It is important to develop a new system to evaluate drug cross-resistance and to test new agents that may overcome resistant virus. In this report, three cell lines HepG2-WT10, HepG2-SM1, and HepG2-DM2 are presented; these cell lines were established by transfection of HepG2 cells with unique fully functional 1.1x hepatitis B virus (HBV) genomes: wild-type HBV-adr and its L526M and L526MM550V variants, respectively. We have demonstrated that these genomes have different susceptibilities to lamivudine [L(-)SddC] and penciclovir (PCV). By examining HBV RNA transcription, antigen expression, progeny DNA replication, and viral susceptibilities to L(-)SddC, PCV, and other nucleoside analogs, it is concluded that the cell lines are able to stably produce L(-)SddC- and PCV-sensitive and -resistant HBV virions. In addition, the relative susceptibilities of the wild-type and mutant HBV produced from the stably transfected cell lines to several anti-HBV nucleoside analogs were also examined and found to be about the same as those found by using a transient infection system. PMEA [9-(2-phosphonylmethoxytehyl)-adenine] and QYL685 are able to suppress L(-)SddC- and PCV-resistant HBV. In conclusion, this cell culture system is a novel and useful tool for evaluating anti-HBV compounds and biologics.
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Affiliation(s)
- L Fu
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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32
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Ying C, De Clercq E, Neyts J. Ribavirin and mycophenolic acid potentiate the activity of guanine- and diaminopurine-based nucleoside analogues against hepatitis B virus. Antiviral Res 2000; 48:117-24. [PMID: 11114413 DOI: 10.1016/s0166-3542(00)00121-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mycophenolic acid [the active metabolite of the immunosuppressive agent mycophenolate mofetil (MMF)] and ribavirin were found to potentiate the anti-HBV activity of the guanine-based nucleoside analogues penciclovir (PCV), lobucavir (LBV) and 3'-fluorodideoxyguanosine (FLG) and diaminopurine dioxolane (DAPD). Ribavirin and mycophenolic acid are both inhibitors of inosine 5'-monophosphate dehydrogenase and cause a depletion of intracellular dGTP levels. It may be assumed that the 5'-triphosphorylated derivatives of the guanine-based nucleoside analogues, in the presence of reduced levels of dGTP, inhibit more efficiently the priming reaction as well as the reverse transcription and DNA-dependent DNA polymerase activity of the HBV polymerase. This assumption is corroborated by the observation that exogenously added guanosine reversed the potentiating effect of ribavirin and mycophenolic acid on the anti-HBV activity of the guanosine analogues. Our observations may have implications for those (liver) transplant recipients that receive MMF as (part of their) immunosuppressive regimen and that, because of de novo or persistent infection with HBV, need specific anti-HBV therapy.
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Affiliation(s)
- C Ying
- Rega Institute for Medical Research, K.U. Leuven, Minderbroedersstraat 10, B-3000, Leuven, Belgium
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33
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Abstract
Hepatitis B virus (HBV) was identified as a cause of viral hepatitis more than 30 years ago and hepatitis B vaccines have been available for almost 20 years, but HBV infection continues to be a global health problem, responsible for about 1.2 million deaths annually. By the end of this year, almost 400 million people--about 5% of the world's population and more than ten times the number infected with human immunodeficiency virus (HIV)--will be infected with HBV. Chemotherapy remains the only treatment option for controlling chronic HBV infection once acquired, but none of the many different chemotherapeutic strategies used in the past has proven consistently successful. Prospects for successful treatment of HBV have improved dramatically during the past decade due to the development of new, well tolerated and efficacious anti-HBV drugs, and to advances in our understanding of HBV replication and pathogenesis. The newer anti-HBV drugs are capable of reducing viral loads very rapidly, but the initial response is invariably followed by very much slower elimination of residual virus. As more effective anti-HBV drugs become available, the emergence of drug resistance during the slower phase of HBV elimination will probably become the most significant obstacle in the way of eventual control of HBV infection. Experience with HIV indicates that combination chemotherapy may suppress or eliminate drug resistance and methods for pre-clinical and clinical assessment of anti-HBV drug combinations are being developed. Basic research into mechanisms of drug action and interaction should assist in the design and optimisation of combination chemotherapy for HBV infection, for which additional new anti-HBV drugs will undoubtedly be required in future.
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Affiliation(s)
- T Shaw
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Australia.
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Abstract
BACKGROUND/AIMS Famciclovir, an orally available nucleoside analogue with potent in vitro activity against HBV, is being investigated for treatment of chronic hepatitis B. METHODS A dose-finding study was conducted in patients with hepatitis B e antigen present in serum. Patients received famciclovir 125 mg, 250 mg, 500 mg three times daily (tid) or placebo for 16 weeks, followed by 8 months post-treatment observation, and 16 weeks open-label treatment. More than 90% of patients had previously received alpha-interferon or had baseline characteristics indicating a high likelihood of poor response to alpha-interferon. RESULTS Famciclovir induced rapid, dose-dependent suppression of viral replication and reduction in alanine aminotransferase (ALT), with greatest efficacy in the 500-mg tid treatment group. HBV DNA reduction was maintained throughout the treatment period. ALT also steadily declined during the treatment period. Approximately 40% of patients with pretreatment ALT>upper limit of normal (ULN) receiving famciclovir 500 mg tid, experienced sustained normalization of ALT at the end of the 8-month follow-up. Anti-HBe seroconversion occurred more frequently in patients receiving famciclovir 500 mg tid compared with placebo (p=0.04). Famciclovir was generally well tolerated; the incidence of adverse events was comparable to placebo. Exacerbation of liver disease or serious ALT flares were not observed. CONCLUSION Famciclovir 500 mg three times daily may offer an alternative to alpha-interferon for treatment for chronic hepatitis B. Anti-HBe seroconversion in the famciclovir 500-mg tid group suggests that 16 weeks treatment has the potential for HBV clearance. Further studies with a longer treatment duration are warranted.
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Affiliation(s)
- C Trépo
- Service d'Hépato-Gastro-Enterologie, Hôpital Hotel-Dieu, Lyon, France
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35
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Abstract
Approximately 5% of the world's human population have an increased risk for developing liver cancer and cirrhosis as a direct consequence of chronic infection with the hepatitis B virus (HBV). Antiviral chemotherapy remains the only option for controlling infection in these individuals, for whom the current licensed hepatitis B vaccines provide no benefit. Interferon (IFN)-alpha has proven benefit in a well-defined group of those with hepatitis B but has made little impact on the global burden of chronic liver disease. The development of more effective chemotherapy for treatment of chronic hepatitis B infection has proven to be extremely challenging, the result of both virus- and host-dependent factors, which will be reviewed in this article. Past attempts to treat chronic hepatitis B infection using nucleoside analogues were disappointing, but more recently, several nucleoside (or nucleotide) analogues have been identified that are potent and selective inhibitors of HBV replication. These agents fall into two broad categories: (1) nucleoside/nucleotides that have modified sugar residues in either cyclic or acyclic configurations and (2) stereoisomers of nucleosides in the "unnatural" L-configuration. Of the analogues that have been used clinically, representatives of the first category are purine derivatives, e.g., adefovir dipivoxil and famciclovir, whereas representatives of the second category are pyrimidine derivatives, such as lamivudine.
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Affiliation(s)
- J Torresi
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Australia
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36
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Korba BE, Cote P, Hornbuckle W, Schinazi R, Gerin JL, Tennant BC. Enhanced antiviral benefit of combination therapy with lamivudine and famciclovir against WHV replication in chronic WHV carrier woodchucks. Antiviral Res 2000; 45:19-32. [PMID: 10774587 DOI: 10.1016/s0166-3542(99)00072-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Cell culture studies in our laboratory and others have previously demonstrated synergistic antiviral activity for combinations of 3TC (lamivudine) and penciclovir against Hepatitis B Virus (HBV) replication and the Duck Hepatitis B Virus (DHBV). Based on these results, a study was designed to determine if an enhanced antiviral effect with combinations of 3TC and famciclovir (FCV, oral prodrug of penciclovir) could be demonstrated in vivo using the Woodchuck Hepatitis Virus (WHV)/woodchuck experimental model of chronic HBV infection. Both antiviral agents have been shown to be effective against WHV replication in WHV chronic carriers in previous studies by our laboratories. The antiviral effects of four different combinations of lamivudine and FCV were found to be greater than those observed for the corresponding monotherapies. All four combination treatments produced antiviral effects that were at least equal to that expected for additive activity based on estimations generated by Bliss Independence calculations. Two of the combination treatments produced antiviral effects that were significantly greater than that expected for additive effects, indicative of synergistic antiviral interactions. These studies demonstrate that combination therapy of chronic WHV infection has enhanced antiviral benefit over corresponding monotherapies and indicate that combination treatment of chronic HBV infection can be superior to therapies using a single antiviral agent.
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Affiliation(s)
- B E Korba
- Division of Molecular Virology and Immunology, Georgetown University Medical Center, Rockville, MD, USA
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37
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Xiong X, Yang H, Westland CE, Zou R, Gibbs CS. In vitro evaluation of hepatitis B virus polymerase mutations associated with famciclovir resistance. Hepatology 2000; 31:219-24. [PMID: 10613749 DOI: 10.1002/hep.510310132] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Several mutations (V521L, P525L, L528M, T532S, and V555I) in the gene for hepatitis B virus (HBV) polymerase have been identified in HBV isolated from patients that displayed break-through viremia during famciclovir treatment. To determine whether these mutations cause phenotypic resistance to famciclovir, we compared the inhibition constants (K(i)) of penciclovir triphosphate (PCVTP, the active metabolite of famciclovir) for recombinant wild-type and mutant HBV polymerases containing these mutations. In in vitro enzymatic assays, the V555I mutation displayed the most resistance (with K(i) increased by 6.2-fold) to PCVTP. The V521L and L528M mutations showed moderately decreased sensitivity to PCVTP (K(i) increased by >3-fold). We also analyzed the cross-resistance profiles of these variants for adefovir and lamivudine, two other antiviral agents that also inhibit DNA replication by HBV polymerase. All 5 famciclovir-associated mutations were sensitive to adefovir diphosphate (ADVDP) in in vitro enzymatic assays (<2.3-fold decreased sensitivity). The V521L, L528M, and T532S mutations were also sensitive to lamivudine triphosphate (LAMTP); however, the P525L and V555I mutations displayed moderately decreased sensitivity to LAMTP in enzymatic assays (3.6-fold decreased sensitivity). The lamivudine-resistant mutations M552I, M552V, and L528M+M552V, which were previously shown to display 8- to 25-fold resistance to LAMTP, were less resistant (< or = 3.1-fold) to PCVTP.
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Affiliation(s)
- X Xiong
- Gilead Sciences, Foster City, CA 94404, USA.
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38
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Zoulim F. Therapy of chronic hepatitis B virus infection: inhibition of the viral polymerase and other antiviral strategies. Antiviral Res 1999; 44:1-30. [PMID: 10588330 DOI: 10.1016/s0166-3542(99)00056-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic hepatitis B infection remains a major public health problem worldwide. The hepatitis B virus belongs to the family of hepadnaviruses that replicate their DNA genome via a reverse transcription pathway. The chronicity of infection in infected hepatocytes is maintained by the persistence of the viral covalently closed circular DNA. The main strategies to combat chronic HBV infection rely on the stimulation of the specific antiviral immune response and on the inhibition of viral replication. While the prolonged administration of reverse transcriptase inhibitors is most often associated with a control of viral replication rather than eradication, it may select for resistant mutants. The search for new viral targets is therefore mandatory to design combination strategies to prevent the emergence of resistant mutants and eventually clear viral infection.
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39
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Kim DK, Lee N, Ryu DH, Kim YW, Kim JS, Chang K, Im GJ, Choi WS, Cho YB, Kim KH, Colledge D, Locarnini S. Synthesis and evaluation of 2-amino-9-(3-acyloxymethyl-4-alkoxycarbonyloxybut-1-yl)purines and 2-amino-9-(3-alkoxycarbonyloxymethyl-4-alkoxycarbonyloxybut-1- yl)purines as potential prodrugs of penciclovir. Bioorg Med Chem 1999; 7:1715-25. [PMID: 10482463 DOI: 10.1016/s0968-0896(99)00086-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A series of 2-amino-9-(3-acyloxymethyl-4-alkoxycarbonyloxybut-1-yl)purin es (1-8) and 2-amino-9-(3-alkoxycarbonyl-oxymethyl-4-alkoxycarbonyloxybut -1-yl)purines (9-12) were synthesized as potential prodrugs of penciclovir. Treatment of 6-deoxypenciclovir with trimethyl orthoacetate or triethyl orthopropionate (1.2 equiv) in DMF in the presence of p-TsOH.H2O (0.1 equiv) followed by quenching with excess H2O gave the corresponding mono-O-acetyl or mono-O-propionyl compound, 17 or 18, in excellent yields of 95 and 92%, respectively. Reactions of 17 or 18 with an appropriate alkyl (Me, Et, n-Pr, and i-Pr) 4-nitrophenyl carbonate (1.2 equiv) in pyridine in the presence of a catalytic amount of DMAP (0.1 equiv) at 80 degrees C afforded the monoacyl, monocarbonate derivatives of 6-deoxypenciclovir, 1-8, in 86 94% yields. Similar reactions of 6-deoxypenciclovir with 2.1 equiv of alkyl 4-nitrophenyl carbonate produced the dicarbonate derivatives 9 12 in 81-83% yields. Of the prodrugs tested in rats, 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)purine (4) achieved the highest mean urinary recovery of penciclovir (36%), followed in order by compounds 2 (35%), 6 (35%), 7 (34%), 10 (34%), 8 (32%), 3 (32%), and famciclovir (31%). The mean urinary recovery of penciclovir and concentrations of penciclovir in the blood from 4 in mice were also slightly higher than those from famciclovir. The in vivo antiviral efficacy of 4 in HSV-1-infected normal BALB/c mice was higher than those of famciclovir and valaciclovir in terms of mortality (100, 80, and 40%) and mean survival time ( > 21, 13+/-5.0 (SEM), and 13+/-1.6 days). Compound 4 demonstrated an effective anti-hepadnaviral response with intrahepatic viral load being reduced by 90%, the viral supercoiled DNA levels reduced by 70% and Pre-S expression inhibited by 30% against duck hepatitis B virus (DHBV) in vivo, and did not cause any significant hepatotoxicity after 4 weeks of treatment.
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Affiliation(s)
- D K Kim
- Life Science Research Center, SK Chemicals, Kyungki-Do, Korea.
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40
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Abstract
Primarily resulting as a spin-off of the search for effective anti-HSV or anti-HIV agents, several compounds have been identified as effective and promising candidate anti-HBV drugs, i.e. famciclovir (penciclovir), BMS-200475, lamivudine (3TC), (-)FTC, L(-)Fd4C, L-FMAU, DAPD (DXG), bis(POM)-PMEA and bis(POC)-PMPA. They all inhibit HBV replication in Hep G2 2.2.15 at concentrations that are well below the cytotoxicity threshold. All these nucleoside analogues require three phosphorylation steps to be active, in their triphosphate form, as inhibitors of the HBV DNA polymerase, except for PMEA (adefovir) and PMPA (tenofovir), which need only two phosphorylation steps, to PMEApp and PMPApp, respectively, to interact as chain terminators with the HBV DNA polymerase reaction. Several of these compounds (for example, famciclovir, lamivudine and adefovir) have proven to be efficacious in the duck and/or woodchuck hepatitis models, and, accordingly, famciclovir, lamivudine and adefovir have also proven to be effective (i.e. in reducing HBV DNA levels) in patients with chronic HBV infection. Yet, famciclovir and lamivudine may lead to the emergence of resistance mutations (i.e. L528M and M552V/I) in the HBV DNA polymerase upon long-term treatment. These penciclovir- and lamivudine-resistant HBV mutants still retain susceptibility to adefovir, which, in turn, has so far not been found to engender resistance mutations in HBV. As has become obvious from the experience with the treatment of HIV infections, future HBV chemotherapy may reside in combination drug therapy so as to achieve the highest possible virus reduction, thereby minimizing the likelihood of drug resistance development.
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MESH Headings
- Acute Disease
- Animals
- Anti-HIV Agents/chemistry
- Anti-HIV Agents/pharmacology
- Antiviral Agents/chemistry
- Antiviral Agents/pharmacology
- Cell Line/virology
- Clinical Trials as Topic/methods
- DNA, Viral/drug effects
- Disease Models, Animal
- Drug Resistance, Microbial
- Ducks
- Hepadnaviridae Infections/drug therapy
- Hepatitis B Virus, Duck
- Hepatitis B Virus, Woodchuck
- Hepatitis B virus/drug effects
- Hepatitis B virus/genetics
- Hepatitis B, Chronic/drug therapy
- Hepatitis B, Chronic/virology
- Hepatitis, Viral, Animal/drug therapy
- Hepatitis, Viral, Animal/virology
- Humans
- Marmota
- Structure-Activity Relationship
- Virus Replication/drug effects
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Affiliation(s)
- E De Clercq
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium.
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41
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Abstract
UNLABELLED Lamivudine is a deoxycytidine analogue that is active against hepatitis B virus (HBV). In patients with chronic hepatitis B, lamivudine profoundly suppresses HBV replication. Clinically significant improvements in liver histology and biochemical parameters were obtained with lamivudine in double-blind, randomised, trials in hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B and compensated liver disease. After 52 weeks of treatment, relative to placebo (< or = 25%), significantly more Chinese (56%) or Western patients (52%) treated with lamivudine 100 mg/day had reductions of > or = 2 or more points in Knodell necro-inflammatory scores. Moreover, significantly fewer lamivudine 100 mg/day than placebo recipients had progressive fibrosis in liver biopsies (< or = 5 vs > or = 15%) and fewer lamivudine- than placebo-treated patients progressed to cirrhosis (1.8 vs 7.1%). More lamivudine 100 mg/day than placebo recipients acquired antibodies to HBeAg after 52 weeks (16 vs 4% in Chinese patients and 17 vs 6% in Western patients). ALT levels normalised in significantly more lamivudine than placebo recipients enrolled in these trials. In HBeAg-negative, HBV DNA positive patients with compensated liver disease enrolled in a double-blind, randomised study, HBV DNA levels were suppressed to below the limit of detection (< 2.5 pg/ml) and ALT levels normalised in 63% and 6% of patients treated with lamivudine 100 mg/day or placebo for 24 weeks. Clinically significant improvements in liver histology were obtained in 60% of patients treated with lamivudine for 52 weeks in this study. Lamivudine 100 mg/day for 52 weeks produced similar or significantly greater improvements in liver histology and ALT levels than 24 weeks' treatment with lamivudine plus interferon-alpha. In liver transplant candidates with chronic hepatitis B and end-stage liver disease, lamivudine 100 mg/day alone, or in combination with hepatitis B immune globulin, generally suppressed HBV replication and appeared to protect the grafted liver from reinfection. Lamivudine 100 mg/day suppressed viral replication and improved liver histology in liver transplant recipients with recurrent or de novo chronic hepatitis B. Lamivudine 300 or 600 mg/day reduced HBV replication in HIV-positive patients. The incidence of adverse events in patients with chronic hepatitis B and compensated liver disease treated with lamivudine 100 mg/day or placebo for 52 to 68 weeks was similar. 3.1- to 10-fold increases in ALT over baseline occurred in 13% of patients during treatment with lamivudine 100 mg/day or placebo for 52 weeks. Post-treatment ALT elevations were more common in lamivudine than placebo recipients; however, these generally resolved spontaneously; < or = 1.5% of lamivudine- or placebo-treated patients experienced hepatic decompensation. CONCLUSION Lamivudine inhibits HBV replication, reduces hepatic necro-inflammatory activity and the progression of fibrosis in patients with chronic hepatitis B, ongoing viral replication and compensated liver disease including HBeAg-negative patients. The drug also suppresses viral replication in liver transplant recipients and HIV-positive patients. Thus, lamivudine is potentially useful in a wide range of patients with chronic hepatitis B and ongoing viral replication.
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Affiliation(s)
- B Jarvis
- Adis International Limited, Auckland, New Zealand.
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42
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Ono-Nita SK, Kato N, Shiratori Y, Lan KH, Yoshida H, Carrilho FJ, Omata M. Susceptibility of lamivudine-resistant hepatitis B virus to other reverse transcriptase inhibitors. J Clin Invest 1999; 103:1635-40. [PMID: 10377169 PMCID: PMC408383 DOI: 10.1172/jci5882] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The emergence of resistant hepatitis B virus (HBV), with mutations in the YMDD motif of the polymerase gene after treatment with lamivudine, is becoming an important clinical problem. In this study, susceptibility of wild-type and lamivudine-resistant HBV M552I, M552V, and L528M/M552V mutants to other reverse transcriptase inhibitors was investigated by transient transfection of full-length HBV DNA into human hepatoma cells. HBV DNA replication was monitored by Southern blot hybridization, which showed the presence of a single-stranded band (representative of the HBV replicative intermediates) in the drug-free, wild-type HBV-transfected cells. This band was diminished in the samples of wild-type HBV DNA treated with either lamivudine, adefovir, or lobucavir. The band intensities from the lamivudine-resistant mutants were not decreased by treatment with lamivudine, but were decreased by the treatments with adefovir or lobucavir. In contrast, penciclovir and nevirapine did not diminish the intensity of the single-stranded band of wild-type HBV or the lamivudine-resistant mutants. These results demonstrate that lamivudine-resistant HBV is susceptible to adefovir and lobucavir. Lamivudine-resistant HBV should be treated with adefovir or lobucavir, and combination therapy with lamivudine and adefovir/lobucavir may prevent the emergence of lamivudine-resistant HBV.
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Affiliation(s)
- S K Ono-Nita
- Department of Gastroenterology, Faculty of Medicine, University of Tokyo, Japan
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43
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Fu L, Liu SH, Cheng YC. Sensitivity of L-(-)2,3-dideoxythiacytidine resistant hepatitis B virus to other antiviral nucleoside analogues. Biochem Pharmacol 1999; 57:1351-9. [PMID: 10353255 DOI: 10.1016/s0006-2952(99)00073-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
L-(-)2',3'-Dideoxythiacytidine (L(-)SddC, Lamivudine) resistant hepatitis B virus (HBV) develops in patients after prolonged treatment. Point mutations detected in the viral genome from these patients have been shown to be responsible for L(-)SddC resistance. Therefore, new drugs active against L(-)SddC resistant HBV are needed. Using a transient transfection system, we studied the sensitivity of L(-)SddC resistant HBV to other anti-HBV nucleoside analogues. It was found that the L526M mutation alone caused greater resistance to penciclovir (PCV) than did the V553I mutation alone. Both mutations also caused the virus to be less sensitive to L(-)SddC and 2'-fluoro-5-methyl-beta-L-arabinofuranosyluracil (L-FMAU), although the degree of resistance was much less than that to PCV. The A546V mutation had no impact on the sensitivity to L(-)SddC, L-FMAU, and PCV. When these single mutations were coupled with the M550V/I mutation, all the double mutants were resistant to those drugs. Although 2',3'-dideoxy-2',3'-didehydro-beta-L(-)-5-fluorocytidine (L(-)Fd4C) was also less active, the IC50 of L(-)Fd4C against the L(-)SddC resistant mutant was at least fifty times lower than that against cell growth in culture. DNA polymerase associated with L(-)SddC resistant virions was also found to be less sensitive than that with wild-type HBV to those L-nucleoside triphosphates. All the L(-)SddC resistant mutants were still sensitive to 9-(2-phosphonylmethoxyethyl)-adenine (PMEA). These results suggest that different mutations in the HBV genome have a different impact on its sensitivity to those compounds, and L(-)SddC resistant HBV may also be resistant to PCV, L-FMAU, and L(-)Fd4C. A nucleoside analogue less toxic than PMEA could be developed against L(-)SddC resistant HBV.
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Affiliation(s)
- L Fu
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
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44
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Günther S, von Breunig F, Santantonio T, Jung MC, Gaeta GB, Fischer L, Sterneck M, Will H. Absence of mutations in the YMDD motif/B region of the hepatitis B virus polymerase in famciclovir therapy failure. J Hepatol 1999; 30:749-54. [PMID: 10365797 DOI: 10.1016/s0168-8278(99)80124-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS Nucleoside analogues such as lamivudine and famciclovir are potent drugs for treatment of chronic hepatitis B virus infection. Breakthrough infections during lamivudine therapy are associated with mutations in the YMDD motif and putative B region of the HBV polymerase. This study investigated whether failure of famciclovir therapy is also associated with presence or emergence of particular mutations in the HBV polymerase. METHODS We analyzed longitudinally the sequence of the priming and polymerase domain in seven patients with primary non-response to therapy and two patients with a breakthrough during therapy. Two patients who responded to therapy served as a control. RESULTS The YMDD motif and the B region were conserved in all isolates. V-->I changes at position 555 just downstream of the YMDD motif were observed before and during therapy in a virus subpopulation of two patients with a primary non-response. In patients with a breakthrough, 378-V-->I and 424-N-->D mutations emerged in the N terminal part of the polymerase domain during follow-up. Lamivudine rescue therapy initiated in four patients, including a patient infected with YMDD(555-V-->I) variants, efficiently reduced viremia. CONCLUSIONS These data indicate that failure of famciclovir therapy can occur independently of mutations in the YMDD motif or B region of the HBV polymerase and provide a rationale for rescue therapy with lamivudine.
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Affiliation(s)
- S Günther
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität, Hamburg, Federal Republic of Germany
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45
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Schinazi RF, Ilan E, Black PL, Yao X, Dagan S. Cell-based and animal models for hepatitis B and C viruses. Antivir Chem Chemother 1999; 10:99-114. [PMID: 10431609 DOI: 10.1177/095632029901000301] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Reliable cell-based assays and animal models have been developed for evaluating agents against hepatitis B virus. Although much progress has been made, in vitro and in vivo assays for hepatitis C virus are still on the horizon. Advances towards establishing inexpensive and reliable experimental models have accelerated the development of therapeutic modalities for these life-threatening viral infections. The characterization of well-defined viral targets coupled with improved molecular diagnostic technologies have illuminated this field.
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Affiliation(s)
- R F Schinazi
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA.
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46
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Abstract
Chemotherapy for chronic hepatitis B virus (HBV) infection is inherently difficult for a variety of reasons that are related to unusual features of both HBV replication strategy and host cell metabolism. Previous attempts to treat chronic HBV infection using nucleoside analogues have been almost universally disappointing, but several recently developed nucleoside analogues have been identified as potent, non-toxic inhibitors of HBV replication. These fall into two broad categories: nucleosides having the 'unnatural' L-configuration, and deoxyguanosine analogues with modified-sugar configurations, represented by lamivudine and penciclovir respectively. Both lamivudine and penciclovir (in its orally available form, famciclovir) have progressed to phase III clinical trials against chronic HBV infection, with promising preliminary results. However, chemotherapy for chronic HBV is necessarily long term, which increases the risks for development of viral resistance and cumulative toxicity. Such risks might be minimized by the use of appropriate drug combinations, rational selection of which requires knowledge of the pharmacokinetics and mechanisms of action of the individual agents. An appreciation of cellular deoxynucleoside metabolism and its regulation, the complexities of which are still emerging, is an indispensable aid to understanding the biological activities of deoxynucleoside analogues. The modes of action of lamividine and penciclovir, and how these two deoxynucleoside analogues may interact in vitro and in vivo as inhibitors of HBV replication, are examined here in the context of cellular deoxynucleoside metabolism.
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Affiliation(s)
- T Shaw
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Victoria, Australia
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47
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Abstract
Chronic hepatitis B infection is the most important cause of cirrhosis and hepatocellular carcinoma worldwide. Interferon-alpha has been shown to be effective in approximately one third of patients, and response seems to be sustained in long-term follow-up studies in Western countries. New treatments using lamivudine and other nucleoside analogues such as famciclovir, lobucavir, and adfovir showed promising results although sustained suppression of viral replication is unusual after discontinuation of therapy. The results of recent clinical studies using these nucleoside analogues are discussed in detail in this review. Other important issues such as drug resistance and the role of combination therapy are also addressed.
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Affiliation(s)
- F Yao
- California Pacific Medical Center, 2340 Clay Street, Suite 251, San Francisco, CA 94115, USA
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48
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Pichoud C, Seignères B, Wang Z, Trépo C, Zoulim F. Transient selection of a hepatitis B virus polymerase gene mutant associated with a decreased replication capacity and famciclovir resistance. Hepatology 1999; 29:230-7. [PMID: 9862871 DOI: 10.1002/hep.510290119] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Prolonged therapy for chronic hepatitis B (HBV) with nucleoside analogs may result in the emergence of HBV mutants resistant to antivirals. Here, we describe the transient selection of an HBV polymerase gene mutant that was associated with viral persistence in an immune competent patient treated with famciclovir. Viral polymerase gene sequence was analyzed directly on polymerase chain reaction (PCR) products and also after cloning. The results showed the transient selection of a V542I mutant in the C domain of the viral polymerase. This mutation was associated with a stop codon at amino acid position 199 in the overlapping S gene. The mutated sequence was subcloned in a vector expressing the entire HBV pregenome to study its replication capacity after transient transfection in cultured hepatoma cells. The results showed that the V542I mutant has a decreased replication capacity compared with wild type virus and does not produce HBsAg. The sensitivity of the V542I mutant to penciclovir, the active metabolite of famciclovir, was further studied in tissue culture. This mutant was shown to be resistant to penciclovir, but remained sensitive to lamivudine, as was subsequently observed in vivo. These findings indicate that a prolonged administration of famciclovir may allow for the selection of HBV polymerase gene mutants in immune competent patients. The impaired replication capacity of this V542I mutant may have contributed to the absence of outgrowth of this viral strain in vivo. The study of the in vitro sensitivity of HBV polymerase mutants to nucleoside analogs will be important to design new anti-HBV strategies.
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49
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Périgaud C, Gosselin G, Girardet JL, Korba BE, Imbach JL. The S-acyl-2-thioethyl pronucleotide approach applied to acyclovir: part I. Synthesis and in vitro anti-hepatitis B virus activity of bis(S-acyl-2-thioethyl)phosphotriester derivatives of acyclovir. Antiviral Res 1999; 40:167-78. [PMID: 10027651 DOI: 10.1016/s0166-3542(98)00059-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The synthesis and in vitro anti-hepatitis B virus (HBV) activity of two mononucleoside phosphotriester derivatives of acyclovir incorporating S-acyl-2-thioethyl (SATE) groups are reported. In contrast to the parent nucleoside, the described phosphotriesters emerged as potent and selective inhibitors of HBV replication in HepG2.2.15 cells. This result can be attributed to the unique cellular metabolism of the SATE pronucleotides giving rise to the delivery to acyclovir 5'-monophosphate inside the infected cells. Moreover, the in vitro anti-HBV activities of one of these bis(SATE)phosphotriesters and of (-)-beta-L-2',3'-dideoxy-3'-thiacytidine (lamivudine, 3TC) were compared alone and in combination. Analysis of the combination data indicates that 3TC and the studied SATE pronucleotide of acyclovir exhibited strong synergistic interactions. The present study provides an example where the use of a pronucleotide approach extends the antiviral spectrum of a nucleoside analogue. Given the potency of SATE pronucleotides of acyclovir against HBV in HepG2.2.15 cells, further studies including animal experiments seem warranted to evaluate the potential of these compounds as anti-HBV agents.
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Affiliation(s)
- C Périgaud
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université Montpellier II, France.
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50
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Genovesi EV, Lamb L, Medina I, Taylor D, Seifer M, Innaimo S, Colonno RJ, Standring DN, Clark JM. Efficacy of the carbocyclic 2'-deoxyguanosine nucleoside BMS-200475 in the woodchuck model of hepatitis B virus infection. Antimicrob Agents Chemother 1998; 42:3209-17. [PMID: 9835516 PMCID: PMC106024 DOI: 10.1128/aac.42.12.3209] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Daily oral treatment with the cyclopentyl 2'-deoxyguanosine nucleoside BMS-200475 at doses ranging from 0.02 to 0.5 mg/kg of body weight for 1 to 3 months effectively reduced the level of woodchuck hepatitis virus (WHV) viremia in chronically infected woodchucks as measured by reductions in serum WHV DNA levels and endogenous hepadnaviral polymerase activity. Within 4 weeks of daily therapy with 0.5 or 0.1 mg of BMS-200475 per kg, endogenous viral polymerase levels in serum were reduced about 1,000-fold compared to pretreatment levels. Serum WHV DNA levels determined by a dot blot hybridization technique were comparably decreased in these treated animals. In the 3-month study, the sera of animals that had undetectable levels of WHV DNA by the dot blot technique were further analyzed by a highly sensitive semiquantitative PCR assay. The results indicate that BMS-200475 therapy reduced mean WHV titers by 10(7)- to 10(8)-fold, down to levels as low as 10(2) to 10(3) virions/ml of serum. Southern blot hybridization analysis of liver biopsy samples taken from animals during and after BMS-200475 treatment showed remarkable reductions in the levels of WHV DNA replicative intermediates and in the levels of covalently closed circular viral DNA. WHV viremia in BMS-200475-treated WHV carriers eventually returned to pretreatment levels after therapy was stopped. These results indicate that BMS-200475 should be evaluated in clinical trials for the therapy of chronic human hepatitis B virus infections.
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Affiliation(s)
- E V Genovesi
- Pharmaceutical Research Institute, Bristol-Myers Squibb, Wallingford, Connecticut 06492, USA.
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