451
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Chun BK, Du J, Zhang HR, Chang W, Ross BS, Jiang Y, Bao D, Espiritu CL, Keilman M, Steuer HMM, Furman PA, Sofia MJ. Synthesis of stable isotope labeled analogs of the anti-hepatitis C virus nucleotide prodrugs PSI-7977 and PSI-352938. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2012; 30:886-96. [PMID: 22060553 DOI: 10.1080/15257770.2011.614308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
In order to support bioanalytical LC/MS method development and plasma sample analysis in preclinical and clinical studies of the anti-hepatitis C-virus nucleotides, PSI-7977 and PSI-352938, the corresponding stable isotope labeled forms were prepared. These labeled compounds were prepared by addition reaction of the freshly prepared Grignard reagent (13)CD(3)MgI to the corresponding 2 '-ketone nucleosides followed by fluorination of the resulting carbinol with DAST. As expected, these 2 '-C-(trideuterated-(13)C-methyl) nucleotide prodrugs showed similar anti-HCV activity to that of the corresponding unlabeled ones.
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Affiliation(s)
- Byoung-Kwon Chun
- Pharmasset, Inc., 303A College Road East, Princeton, NJ 08540, USA.
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452
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Chen KX, Lesburg CA, Vibulbhan B, Yang W, Chan TY, Venkatraman S, Velazquez F, Zeng Q, Bennett F, Anilkumar GN, Duca J, Jiang Y, Pinto P, Wang L, Huang Y, Selyutin O, Gavalas S, Pu H, Agrawal S, Feld B, Huang HC, Li C, Cheng KC, Shih NY, Kozlowski JA, Rosenblum SB, Njoroge FG. A novel class of highly potent irreversible hepatitis C virus NS5B polymerase inhibitors. J Med Chem 2012; 55:2089-101. [PMID: 22247956 DOI: 10.1021/jm201322r] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Starting from indole-based C-3 pyridone HCV NS5B polymerase inhibitor 2, structure-activity relationship (SAR) investigations of the indole N-1 benzyl moiety were performed. This study led to the discovery of irreversible inhibitors with p-fluoro-sulfone- or p-fluoro-nitro-substituted N-1 benzyl groups which achieved breakthrough replicon assay potency (EC(50) = 1 nM). The formation of a covalent bond with adjacent cysteine-366 thiol was was proved by mass spectroscopy and X-ray crystal structure studies. The C-5 ethyl C-2 carboxylic acid derivative 47 had an excellent oral area-under-the-curve (AUC) of 18 μM·h (10 mg/kg). Its oral exposure in monkeys and dogs was also very good. The NMR ALARM assay, mass spectroscopy experiments, in vitro counter screening, and toxicology assays demonstrated that the covalent bond formation between compound 47 and the protein was highly selective and specific. The overall excellent profile of 47 made it an interesting candidate for further investigation.
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Affiliation(s)
- Kevin X Chen
- Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, USA.
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453
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Sofia MJ, Chang W, Furman PA, Mosley RT, Ross BS. Nucleoside, nucleotide, and non-nucleoside inhibitors of hepatitis C virus NS5B RNA-dependent RNA-polymerase. J Med Chem 2012; 55:2481-531. [PMID: 22185586 DOI: 10.1021/jm201384j] [Citation(s) in RCA: 217] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Michael J Sofia
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States.
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454
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Chen KX, Vibulbhan B, Yang W, Sannigrahi M, Velazquez F, Chan TY, Venkatraman S, Anilkumar GN, Zeng Q, Bennet F, Jiang Y, Lesburg CA, Duca J, Pinto P, Gavalas S, Huang Y, Wu W, Selyutin O, Agrawal S, Feld B, Huang HC, Li C, Cheng KC, Shih NY, Kozlowski JA, Rosenblum SB, Njoroge FG. Structure-activity relationship (SAR) development and discovery of potent indole-based inhibitors of the hepatitis C virus (HCV) NS5B polymerase. J Med Chem 2012; 55:754-65. [PMID: 22148957 DOI: 10.1021/jm201258k] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Starting with the indole-based C-3 pyridone lead HCV polymerase inhibitor 2, extensive SAR studies were performed at different positions of the indole core. The best C-5 groups were found to be compact and nonpolar moieties and that the C-6 attachments were not affecting potency. Limited N-1 benzyl-type substituent studies indicated that the best substitutions were fluoro or methyl groups at 2' or 5' positions of the benzyl group. To improve pharmacokinetic (PK) properties, acylsulfonamides were incorporated as acid isosteres at the C-2 position. Further optimization of the combination at N-1, C-2, C-5, and C-6 resulted in the identification of compound 56, which had an excellent potency in both NS5B enzyme (IC(50) = 0.008 μM) and cell-based replicon (EC(50) = 0.02 μM) assays and a good oral PK profile with area-under-the curve (AUC) of 14 and 8 μM·h in rats and dogs, respectively. X-ray structure of inhibitor 56 bound to the enzyme was also reported.
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Affiliation(s)
- Kevin X Chen
- Merck Research Laboratories, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, United States.
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455
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New Chemical Entities Entering Phase III Trials in 2011. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2012. [DOI: 10.1016/b978-0-12-396492-2.00030-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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456
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Chen YL, Tang J, Kesler MJ, Sham YY, Vince R, Geraghty RJ, Wang Z. The design, synthesis and biological evaluations of C-6 or C-7 substituted 2-hydroxyisoquinoline-1,3-diones as inhibitors of hepatitis C virus. Bioorg Med Chem 2011; 20:467-79. [PMID: 22100256 DOI: 10.1016/j.bmc.2011.10.058] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 10/13/2011] [Accepted: 10/18/2011] [Indexed: 12/14/2022]
Abstract
C7-Substituted 2-hydroxyisoquinoline-1,3-diones inhibit the strand transfer of HIV integrase (IN) and the reverse-transcriptase-associated ribonuclease H (RNH). Hepatitis C virus (HCV) NS5B polymerase shares a similar active site fold to RNH and IN, suggesting that N-hydroxyimides could be useful inhibitor scaffolds of HCV via targeting the NS5B. Herein we describe the design, chemical synthesis, replicon and biochemical assays, and molecular docking of C-6 or C-7 aryl substituted 2-hydroxyisoquinoline-1,3-diones as novel HCV inhibitors. The synthesis involved an improved and clean cyclization method, which allowed the convenient preparation of various analogs. Biological studies revealed that the C-6 analogs, a previously unknown chemotype, consistently inhibit both HCV replicon and recombinant NS5B at low micromolar range. Molecular modeling studies suggest that these inhibitors may bind to the NS5B active site.
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Affiliation(s)
- Yue-Lei Chen
- Center for Drug Design, Academic Health Center, University of Minnesota, 516 Delaware St. SE, MMC 204, Minneapolis, MN 55455, USA
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457
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Hepatitis C virus nucleotide inhibitors PSI-352938 and PSI-353661 exhibit a novel mechanism of resistance requiring multiple mutations within replicon RNA. J Virol 2011; 85:12334-42. [PMID: 21957306 DOI: 10.1128/jvi.05639-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
PSI-352938, a cyclic phosphate nucleotide, and PSI-353661, a phosphoramidate nucleotide, are prodrugs of β-D-2'-deoxy-2'-α-fluoro-2'-β-C-methylguanosine-5'-monophosphate. Both compounds are metabolized to the same active 5'-triphosphate, PSI-352666, which serves as an alternative substrate inhibitor of the NS5B RNA-dependent RNA polymerase during HCV replication. PSI-352938 and PSI-353661 retained full activity against replicons containing the S282T substitution, which confers resistance to certain 2'-substituted nucleoside/nucleotide analogs. PSI-352666 was also similarly active against both wild-type and S282T NS5B polymerases. In order to identify mutations that confer resistance to these compounds, in vitro selection studies were performed using HCV replicon cells. While no resistant genotype 1a or 1b replicons could be selected, cells containing genotype 2a JFH-1 replicons cultured in the presence of PSI-352938 or PSI-353661 developed resistance to both compounds. Sequencing of the NS5B region identified a number of amino acid changes, including S15G, R222Q, C223Y/H, L320I, and V321I. Phenotypic evaluation of these mutations indicated that single amino acid changes were not sufficient to significantly reduce the activity of PSI-352938 and PSI-353661. Instead, a combination of three amino acid changes, S15G/C223H/V321I, was required to confer a high level of resistance. No cross-resistance exists between the 2'-F-2'-C-methylguanosine prodrugs and other classes of HCV inhibitors, including 2'-modified nucleoside/-tide analogs such as PSI-6130, PSI-7977, INX-08189, and IDX-184. Finally, we determined that in genotype 1b replicons, the C223Y/H mutation failed to support replication, and although the A15G/C223H/V321I triple mutation did confer resistance to PSI-352938 and PSI-353661, this mutant replicated at only about 10% efficiency compared to the wild type.
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458
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Ross BS, Reddy PG, Zhang HR, Rachakonda S, Sofia MJ. Synthesis of diastereomerically pure nucleotide phosphoramidates. J Org Chem 2011; 76:8311-9. [PMID: 21916475 DOI: 10.1021/jo201492m] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Prodrugs of therapeutic nucleoside monophosphates masked as phosphoramidate derivatives have become an increasingly important class of antiviral drugs in pharmaceutical research for delivering nucleotides in vitro and in vivo. Conventionally, phosphoramidate derivatives are prepared as a mixture of two diastereomers. We report a class of stable phosphoramidating reagents containing an amino acid ester and two phenolic groups, one unsubstituted and the other with electron-withdrawing substituents. The reagents can be isolated as single diastereomers and reacted with the 5'-hydroxyl group of nucleosides through selective nucleophilic displacement of the substituted phenol to prepare single diastereomer phosphoramidate products. This method has been used to prepare the HCV clinical candidate PSI-7977 in high yield and high diastereomeric purity.
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Affiliation(s)
- Bruce S Ross
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States.
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459
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Abstract
HCV infection is a significant worldwide health problem and is a major cause of hepatocellular carcinoma. The current standard of care, interferon and ribavirin, is only effective against a proportion of the patient population infected with HCV. To address the shortcomings of existing therapy, the development of direct acting antiviral agents is under investigation. The HCV RNA dependent RNA polymerase is an essential enzyme for viral replication and is therefore a logical target against which to develop novel anti-HCV agents. Nucleosides have been shown to be effective as antiviral agents for other viral diseases and therefore, have been investigated as inhibitors of HCV replication. The development of prodrugs of nucleoside 5'-monophosphates has been pursued to address limitations associated with poor nucleoside phosphorylation. This is required to produce the nucleoside 5'-triphosphate which is the anabolite that is the actual inhibitor of the polymerase enzyme. Prodrugs of nucleoside 5'-monophosphates have been developed that enable their delivery into cells and in vivo into the liver. The implementation of these prodrug strategies has ultimately led to the identification of several prodrugs of nucleoside 5'-monophosphates that are potent inhibitors of HCV replication in vitro. They have progressed into the clinic and the early data demonstrate greatly reduced viral load levels in HCV-infected patients. This review will survey the state of nucleotide prodrugs for the treatment of HCV.
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460
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Ray AS, Hostetler KY. Application of kinase bypass strategies to nucleoside antivirals. Antiviral Res 2011; 92:277-91. [PMID: 21878354 DOI: 10.1016/j.antiviral.2011.08.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 08/17/2011] [Accepted: 08/17/2011] [Indexed: 12/19/2022]
Abstract
Nucleoside and nucleotide analogs have served as the cornerstones of antiviral therapy for many viruses. However, the requirement for intracellular activation and side-effects caused by distribution to off-target sites of toxicity still limit the efficacy of the current generation of drugs. Kinase bypass strategies, where phosphorylated nucleosides are delivered directly into cells, thereby, removing the requirement for enzyme catalyzed phosphorylation steps, have already changed the face of antiviral therapy in the form of the acyclic nucleoside phosphonates, cidofovir, adefovir (given orally as its dipivoxil prodrug) and tenofovir (given orally as its disoproxil prodrug), currently used clinically. These strategies hold further promise to advance the field of antiviral therapy with at least 10 kinase bypass and tissue targeted prodrugs, representing seven distinct prodrug classes, currently in clinical trials. This article reviews the history of kinase bypass strategies applied to nucleoside antivirals and the evolution of different tissue targeted prodrug strategies, highlighting clinically relevant examples.
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Affiliation(s)
- Adrian S Ray
- Gilead Sciences, Inc., Foster City, CA 94404, USA.
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461
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Bao D, Ross BS, Sofia MJ. A liquid chromatography-tandem mass spectrometry method for the quantitative determination of diastereomers of a phosphoramidate nucleotide prodrug (PSI-7851) in human plasma. Biomed Chromatogr 2011; 26:583-8. [PMID: 21842514 DOI: 10.1002/bmc.1678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 06/24/2011] [Accepted: 06/28/2011] [Indexed: 11/11/2022]
Abstract
A rapid and stereospecific method using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the separation and determination of PSI-7851 diastereomers in human K₂EDTA plasma has been developed. The analytical method involves direct protein precipitation with acetonitrile, followed by separation of the diastereomers on a Luna C₁₈ column, positive mode electrospray ionization and selected reaction monitoring mode mass spectrometry detection. The mobile phase composition and pH were investigated for the resolution of the two diastereomers of PSI-7851. The optimized method showed good resolution (R(s) = 4.8) within short analysis time (approximately 8 min). The assay range was 5-2500 ng/mL for both diastereomers using a 1/x² weighted linear regression analysis for standard curve fitting. Replicate sample analysis indicated that intra- and inter-day accuracy and precision were within ±15.0%. The recovery of diastereomers from human plasma was greater than 85% and no significant matrix effect was observed. The method was demonstrated to be sensitive, selective and robust, and was successfully used to support clinical studies.
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Affiliation(s)
- Donghui Bao
- Pharmasset, Inc., 303A College Road East, Princeton, NJ 08540, USA.
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462
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Cho JH, Amblard F, Coats SJ, Schinazi RF. Efficient synthesis of nucleoside aryloxy phosphoramidate prodrugs utilizing benzyloxycarbonyl protection. Tetrahedron 2011; 67:5487-5493. [PMID: 22993455 DOI: 10.1016/j.tet.2011.05.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
An efficient method for the synthesis of nucleoside phosphoramidates prodrugs (6a-f) has been developed that employs a simple protection/deprotection sequence of the nucleoside with benzyloxycarbonyl (Cbz). The coupling reaction of Cbz-protected derivatives (5a-f) with phenyl-(ethoxy-L-alaninyl)-phosphorochloridate (7), followed by Cbz group removal by hydrogenolysis provided the phenyl phosphoramidate ProTides (6a-f) in excellent overall yields.
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Affiliation(s)
- Jong Hyun Cho
- Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine and Veterans Affairs Medical Center, Atlanta, GA 30033, USA
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463
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Morales EHR, Román CA, Thomann JO, Meier C. Linear Synthesis of Chiral cycloSal-Pronucleotides. European J Org Chem 2011. [DOI: 10.1002/ejoc.201100334] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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464
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Furman PA, Murakami E, Niu C, Lam AM, Espiritu C, Bansal S, Bao H, Tolstykh T, Micolochick Steuer H, Keilman M, Zennou V, Bourne N, Veselenak RL, Chang W, Ross BS, Du J, Otto MJ, Sofia MJ. Activity and the metabolic activation pathway of the potent and selective hepatitis C virus pronucleotide inhibitor PSI-353661. Antiviral Res 2011; 91:120-32. [PMID: 21600932 DOI: 10.1016/j.antiviral.2011.05.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/24/2011] [Accepted: 05/06/2011] [Indexed: 01/18/2023]
Abstract
PSI-353661, a phosphoramidate prodrug of 2'-deoxy-2'-fluoro-2'-C-methylguanosine-5'-monophosphate, is a highly active inhibitor of genotype 1a, 1b, and 2a HCV RNA replication in the replicon assay and of genotype 1a and 2a infectious virus replication. PSI-353661 is active against replicons harboring the NS5B S282T or S96T/N142T amino acid alterations that confer decreased susceptibility to nucleoside/tide analogs as well as mutations that confer resistance to non-nucleoside inhibitors of NS5B. Replicon clearance studies show that PSI-353661 was able to clear cells of HCV replicon RNA and prevent a rebound in replicon RNA. PSI-353661 showed no toxicity toward bone marrow stem cells or mitochondrial toxicity. The metabolism to the active 5'-triphosphate involves hydrolysis of the carboxyl ester by cathepsin A (Cat A) and carboxylesterase 1 (CES1) followed by a putative nucleophilic attack on the phosphorus by the carboxyl group resulting in the elimination of phenol and the alaninyl phosphate metabolite, PSI-353131. Histidine triad nucleotide-binding protein 1 (Hint 1) then removes the amino acid moiety, which is followed by hydrolysis of the methoxyl group at the O(6)-position of the guanine base by adenosine deaminase-like protein 1 (ADAL1) to give 2'-deoxy-2'-fluoro-2'-C-methylguanosine-5'-monophosphate. The monophosphate is phosphorylated to the diphosphate by guanylate kinase. Nucleoside diphosphate kinase is the primary enzyme involved in phosphorylation of the diphosphate to the active triphosphate, PSI-352666. PSI-352666 is equally active against wild-type NS5B and NS5B containing the S282T amino acid alteration.
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465
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Reddy PG, Chun BK, Zhang HR, Rachakonda S, Ross BS, Sofia MJ. Stereoselective Synthesis of PSI-352938: A β-d-2′-Deoxy-2′-α-fluoro-2′-β-C-methyl-3′,5′-cyclic Phosphate Nucleotide Prodrug for the Treatment of HCV. J Org Chem 2011; 76:3782-90. [DOI: 10.1021/jo200060f] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Ganapati Reddy
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States
| | - Byoung-Kwon Chun
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States
| | - Hai-Ren Zhang
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States
| | - Suguna Rachakonda
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States
| | - Bruce S. Ross
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States
| | - Michael J. Sofia
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, United States
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466
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Inhibition of hepatitis C virus replicon RNA synthesis by PSI-352938, a cyclic phosphate prodrug of β-D-2'-deoxy-2'-α-fluoro-2'-β-C-methylguanosine. Antimicrob Agents Chemother 2011; 55:2566-75. [PMID: 21444700 DOI: 10.1128/aac.00032-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PSI-352938 is a novel cyclic phosphate prodrug of β-D-2'-deoxy-2'-α-fluoro-2'-β-C-methylguanosine 5'-monophosphate that has potent activity against hepatitis C virus (HCV) in vitro. The studies described here characterize the in vitro anti-HCV activity of PSI-352938, alone and in combination with other inhibitors of HCV, and the cross-resistance profile of PSI-352938. The effective concentration required to achieve 50% inhibition for PSI-352938, determined using genotype 1a-, 1b-, and 2a-derived replicons stably expressed in the Lunet cell line, were 0.20, 0.13, and 0.14 μM, respectively. The active 5'-triphosphate metabolite, PSI-352666, inhibited recombinant NS5B polymerase from genotypes 1 to 4 with comparable 50% inhibitory concentrations. In contrast, PSI-352938 did not inhibit the replication of hepatitis B virus or human immunodeficiency virus in vitro. PSI-352666 did not significantly affect the activity of human DNA and RNA polymerases. PSI-352938 and its cyclic phosphate metabolites did not affect the cyclic GMP-mediated activation of protein kinase G. Clearance studies using replicon cells demonstrated that PSI-352938 cleared cells of HCV replicon RNA and prevented replicon rebound. An additive to synergistic effect was observed when PSI-352938 was combined with other classes of HCV inhibitors, including alpha interferon, ribavirin, NS3/4A inhibitors, an NS5A inhibitor, and nucleoside/nucleotide and nonnucleoside inhibitors. Cross-resistance studies showed that PSI-352938 remained fully active against replicons containing the S282T or the S96T/N142T amino acid alteration. Replicons that contain mutations conferring resistance to various classes of nonnucleoside inhibitors also remained sensitive to inhibition by PSI-352938. PSI-352938 is currently being evaluated in a phase I clinical study in genotype 1-infected individuals.
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467
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Chang W, Bao D, Chun BK, Naduthambi D, Nagarathnam D, Rachakonda S, Reddy PG, Ross BS, Zhang HR, Bansal S, Espiritu CL, Keilman M, Lam AM, Niu C, Steuer HM, Furman PA, Otto MJ, Sofia MJ. Discovery of PSI-353661, a Novel Purine Nucleotide Prodrug for the Treatment of HCV Infection. ACS Med Chem Lett 2011; 2:130-5. [PMID: 24900291 DOI: 10.1021/ml100209f] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 12/08/2010] [Indexed: 12/14/2022] Open
Abstract
Hepatitis C virus afflicts approximately 180 million people worldwide, and the development of direct acting antivirals may offer substantial benefit compared to the current standard of care. Accordingly, prodrugs of 2'-deoxy-2'-fluoro-2'-C-methylguanosine monophosphate analogues were prepared and evaluated for their anti-HCV efficacy and tolerability. These prodrugs demonstrated >1000 fold greater potency than the parent nucleoside in a cell-based replicon assay as a result of higher intracellular triphosphate levels. Further optimization led to the discovery of the clinical candidate PSI-353661, which has demonstrated strong in vitro inhibition against HCV without cytotoxicity and equipotent activity against both the wild type and the known S282T nucleoside/tide resistant replicon. PSI-353661 is currently in preclinical development for the treatment of HCV.
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Affiliation(s)
- Wonsuk Chang
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Donghui Bao
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Byoung-Kwon Chun
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Devan Naduthambi
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Dhanapalan Nagarathnam
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Suguna Rachakonda
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - P. Ganapati Reddy
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Bruce S. Ross
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Hai-Ren Zhang
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Shalini Bansal
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Christine L. Espiritu
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Meg Keilman
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Angela M. Lam
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Congrong Niu
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | | | - Phillip A. Furman
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Michael J. Otto
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
| | - Michael J. Sofia
- Pharmasset, Inc., 303A College Road East, Princeton,
New Jersey 08540-6608, United States
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