title: Mutations conferring resistance to a hepatitis C virus (HCV) RNA-dependent RNA polymerase inhibitor alone or in combination with an HCV serine protease inhibitor in vitro.
abstract: Compounds A-782759 (an N-1-aza-4-hydroxyquinolone benzothiadiazine) and BILN-2061 are specific anti-hepatitis C virus (HCV) agents that inhibit the RNA-dependent RNA polymerase and the NS3 serine protease, respectively. Both compounds display potent activity against HCV replicons in tissue culture. In order to characterize the development of resistance to these anti-HCV agents, HCV subgenomic 1b-N replicon cells were cultured with A-782759 alone or in combination with BILN-2061 at concentrations 10 times above their corresponding 50% inhibitory concentrations in the presence of neomycin. Single substitutions in the NS5B polymerase gene (H95Q, N411S, M414L, M414T, or Y448H) resulted in substantial decreases in susceptibility to A-782759. Similarly, replicons containing mutations in the NS5B polymerase gene (M414L or M414T), together with single mutations in the NS3 protease gene (A156V or D168V), conferred high levels of resistance to both A-782759 and BILN-2061. However, the A-782759-resistant mutants remained susceptible to nucleoside and two other classes of nonnucleoside NS5B polymerase inhibitors, as well as interferon. In addition, we found that the frequency of replicons resistant to both compounds was significantly lower than the frequency of resistance to the single compound. Furthermore, the dually resistant mutants displayed significantly reduced replication capacities compared to the wild-type replicon. These findings provide strategic guidance for the future treatment of HCV infection.
authors.affiliation: Antiviral Research, Abbott Laboratories Global Pharmaceutical Research and Development, Abbott Park, Illinois, USA. Hongmei.Mo@abbott.com
authors.forename: Hongmei
authors.initials: H
authors.lastname: Mo
authors.forename: Liangjun
authors.initials: L
authors.lastname: Lu
authors.forename: Tami
authors.initials: T
authors.lastname: Pilot-Matias
authors.forename: Ron
authors.initials: R
authors.lastname: Pithawalla
authors.forename: Rubina
authors.initials: R
authors.lastname: Mondal
authors.forename: Sherie
authors.initials: S
authors.lastname: Masse
authors.forename: Tatyana
authors.initials: T
authors.lastname: Dekhtyar
authors.forename: Teresa
authors.initials: T
authors.lastname: Ng
authors.forename: Gennadiy
authors.initials: G
authors.lastname: Koev
authors.forename: Vincent
authors.initials: V
authors.lastname: Stoll
authors.forename: Kent D
authors.initials: KD
authors.lastname: Stewart
authors.forename: John
authors.initials: J
authors.lastname: Pratt
authors.forename: Pam
authors.initials: P
authors.lastname: Donner
authors.forename: Todd
authors.initials: T
authors.lastname: Rockway
authors.forename: Clarence
authors.initials: C
authors.lastname: Maring
authors.forename: Akhteruzzaman
authors.initials: A
authors.lastname: Molla
mesh_terms: D001665:Binding Sites; D002460:Cell Line; D024882:Drug Resistance, Viral / Q000235:genetics*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D016174:Hepacivirus / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics*; D008958:Models, Molecular; D015394:Molecular Structure; D009154:Mutation; D011485:Protein Binding; D012367:RNA, Viral / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000037:antagonists & inhibitors*; D012093:Replicon / Q000235:genetics; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D012367:RNA, Viral; D015842:Serine Proteinase Inhibitors; D012324:RNA-Dependent RNA Polymerase