title: A 7-deaza-adenosine analog is a potent and selective inhibitor of hepatitis C virus replication with excellent pharmacokinetic properties.
abstract: Improved treatments for chronic hepatitis C virus (HCV) infection are needed due to the suboptimal response rates and deleterious side effects associated with current treatment options. The triphosphates of 2'-C-methyl-adenosine and 2'-C-methyl-guanosine were previously shown to be potent inhibitors of the HCV RNA-dependent RNA polymerase (RdRp) that is responsible for the replication of viral RNA in cells. Here we demonstrate that the inclusion of a 7-deaza modification in a series of purine nucleoside triphosphates results in an increase in inhibitory potency against the HCV RdRp and improved pharmacokinetic properties. Notably, incorporation of the 7-deaza modification into 2'-C-methyl-adenosine results in an inhibitor with a 20-fold-increased potency as the 5'-triphosphate in HCV RdRp assays while maintaining the inhibitory potency of the nucleoside in the bicistronic HCV replicon and with reduced cellular toxicity. In contrast, while 7-deaza-2'-C-methyl-GTP also displays enhanced inhibitory potency in enzyme assays, due to poor cellular penetration and/or metabolism, the nucleoside does not inhibit replication of a bicistronic HCV replicon in cell culture. 7-Deaza-2'-C-methyl-adenosine displays promising in vivo pharmacokinetics in three animal species, as well as an acute oral lethal dose in excess of 2,000 mg/kg of body weight in mice. Taken together, these data demonstrate that 7-deaza-2'-C-methyl-adenosine is an attractive candidate for further investigation as a potential treatment for HCV infection.
authors.affiliation: Department of Biological Chemistry, Merck Research Laboratories, West Point, Pennsylvania 19486, USA. david_olsen@merck.com
authors.forename: David B
authors.initials: DB
authors.lastname: Olsen
authors.forename: Anne B
authors.initials: AB
authors.lastname: Eldrup
authors.forename: Linda
authors.initials: L
authors.lastname: Bartholomew
authors.forename: Balkrishen
authors.initials: B
authors.lastname: Bhat
authors.forename: Michele R
authors.initials: MR
authors.lastname: Bosserman
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ceccacci
authors.forename: Lawrence F
authors.initials: LF
authors.lastname: Colwell
authors.forename: John F
authors.initials: JF
authors.lastname: Fay
authors.forename: Osvaldo A
authors.initials: OA
authors.lastname: Flores
authors.forename: Krista L
authors.initials: KL
authors.lastname: Getty
authors.forename: Jay A
authors.initials: JA
authors.lastname: Grobler
authors.forename: Robert L
authors.initials: RL
authors.lastname: LaFemina
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Markel
authors.forename: Giovanni
authors.initials: G
authors.lastname: Migliaccio
authors.forename: Marija
authors.initials: M
authors.lastname: Prhavc
authors.forename: Mark W
authors.initials: MW
authors.lastname: Stahlhut
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Tomassini
authors.forename: Malcolm
authors.initials: M
authors.lastname: MacCoss
authors.forename: Daria J
authors.initials: DJ
authors.lastname: Hazuda
authors.forename: Steven S
authors.initials: SS
authors.lastname: Carroll
mesh_terms: D000818:Animals; D000998:Antiviral Agents; D046508:Culture Techniques; D024882:Drug Resistance, Viral; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects* / Q000201:enzymology; D006526:Hepatitis C / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D019169:Jurkat Cells; D007928:Lethal Dose 50; D051379:Mice; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism; D012313:RNA / Q000096:biosynthesis; D012319:RNA Polymerase II / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism; D013936:Thymidine / Q000494:pharmacology; D014372:Tubercidin / Q000493:pharmacokinetics* / Q000494:pharmacology*; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D012313:RNA; D012319:RNA Polymerase II; D011062:Polynucleotide Adenylyltransferase; D012324:RNA-Dependent RNA Polymerase; D014372:Tubercidin; D013936:Thymidine