title: Pharmacodynamic analysis of a serine protease inhibitor, MK-4519, against hepatitis C virus using a novel in vitro pharmacodynamic system.
abstract: The development of new antiviral compounds active against hepatitis C virus (HCV) has surged in recent years. In order for these new compounds to be efficacious in humans, optimal dosage regimens for each compound must be elucidated. We have developed a novel in vitro pharmacokinetic/pharmacodynamic system, the BelloCell system, to identify optimal dosage regimens for anti-HCV compounds. In these experiments, genotype 1b HCV replicon-bearing cells (2209-23 cells) were inoculated onto carrier flakes in BelloCell bottles and treated with MK-4519, a serine protease inhibitor. Our dose-ranging studies illustrated that MK-4519 inhibited replicon replication in a dose-dependent manner, yielding a 50% effective concentration (EC(50)) of 1.8 nM. Dose-fractionation studies showed that shorter dosing intervals resulted in greater replicon suppression, indicating that the time that the concentration is greater than the EC(50) is the pharmacodynamic parameter for MK-4519 linked with inhibition of replicon replication. Mutations associated with resistance to serine protease inhibitors were detected in replicons harvested from all treatment arms. These data suggest that MK-4519 is highly active against genotype 1b HCV, but monotherapy is not sufficient to prevent the amplification of resistant replicons. In summary, our findings show that the BelloCell system is a useful and clinically relevant tool for predicting optimal dosage regimens for anti-HCV compounds.
authors.affiliation: Institute for Therapeutic Innovation, College of Medicine, Department of Medicine, University of Florida—Albany Campus, Albany, New York, USA.
authors.forename: Ashley N
authors.initials: AN
authors.lastname: Brown
authors.forename: James J
authors.initials: JJ
authors.lastname: McSharry
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Adams
authors.forename: Robert
authors.initials: R
authors.lastname: Kulawy
authors.forename: Richard J O
authors.initials: RJ
authors.lastname: Barnard
authors.forename: W
authors.initials: W
authors.lastname: Newhard
authors.forename: A
authors.initials: A
authors.lastname: Corbin
authors.forename: Daria J
authors.initials: DJ
authors.lastname: Hazuda
authors.forename: Arnold
authors.initials: A
authors.lastname: Louie
authors.forename: George L
authors.initials: GL
authors.lastname: Drusano
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D054796:Drug Dosage Calculations; D024882:Drug Resistance, Viral / Q000235:genetics; D017930:Genes, Reporter; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects* / Q000502:physiology; D019698:Hepatitis C, Chronic / Q000821:virology; D006801:Humans; D020128:Inhibitory Concentration 50; D008156:Luciferases; D008954:Models, Biological; D009154:Mutation; D012367:RNA, Viral / Q000037:antagonists & inhibitors*; D012093:Replicon; D057057:Serine Proteases / Q000235:genetics* / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D012367:RNA, Viral; D015842:Serine Proteinase Inhibitors; D017361:Viral Nonstructural Proteins; D008156:Luciferases; D057057:Serine Proteases