title: Discovery of potent hepatitis C virus NS5A inhibitors with dimeric structures.
abstract: The exceptional in vitro potency of the hepatitis C virus (HCV) NS5A inhibitor BMS-790052 has translated into an in vivo effect in proof-of-concept clinical trials. Although the 50% effective concentration (EC(50)) of the initial lead, the thiazolidinone BMS-824, was ~10 nM in the replicon assay, it underwent transformation to other inhibitory species after incubation in cell culture medium. The biological profile of BMS-824, including the EC(50), the drug concentration required to reduce cell growth by 50% (CC(50)), and the resistance profile, however, remained unchanged, triggering an investigation to identify the biologically active species. High-performance liquid chromatography (HPLC) biogram fractionation of a sample of BMS-824 incubated in medium revealed that the most active fractions could readily be separated from the parental compound and retained the biological profile of BMS-824. From mass spectral and nuclear magnetic resonance data, the active species was determined to be a dimer of BMS-824 derived from an intermolecular radical-mediated reaction of the parent compound. Based upon an analysis of the structural elements of the dimer deemed necessary for anti-HCV activity, the stilbene derivative BMS-346 was synthesized. This compound exhibited excellent anti-HCV activity and showed a resistance profile similar to that of BMS-824, with changes in compound sensitivity mapped to the N terminus of NS5A. The N terminus of NS5A has been crystallized as a dimer, complementing the symmetry of BMS-346 and allowing a potential mode of inhibition of NS5A to be discussed. Identification of the stable, active pharmacophore associated with these NS5A inhibitors provided the foundation for the design of more potent inhibitors with broad genotype inhibition. This culminated in the identification of BMS-790052, a compound that preserves the symmetry discovered with BMS-346.
authors.affiliation: Department of Virology, Bristol-Myers Squibb Research, 5 Research Parkway, Wallingford, Connecticut 06492, USA.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Lemm
authors.forename: John E
authors.initials: JE
authors.lastname: Leet
authors.forename: Donald R
authors.initials: DR
authors.lastname: O'Boyle
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Romine
authors.forename: Xiaohua Stella
authors.initials: XS
authors.lastname: Huang
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Schroeder
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Alberts
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Cantone
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Sun
authors.forename: Peter T
authors.initials: PT
authors.lastname: Nower
authors.forename: Scott W
authors.initials: SW
authors.lastname: Martin
authors.forename: Michael H
authors.initials: MH
authors.lastname: Serrano-Wu
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Meanwell
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Snyder
authors.forename: Min
authors.initials: M
authors.lastname: Gao
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D002219:Carbamates; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D001908:Diarrhea Viruses, Bovine Viral / Q000254:growth & development; D055808:Drug Discovery; D024882:Drug Resistance, Viral / Q000235:genetics; D016174:Hepacivirus / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007093:Imidazoles / Q000737:chemistry / Q000494:pharmacology*; D013058:Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular; D011392:Proline / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D011759:Pyrrolidines; D013267:Stilbenes / Q000737:chemistry / Q000494:pharmacology; D053778:Thiazolidines / Q000737:chemistry / Q000494:pharmacology*; D014633:Valine / Q000031:analogs & derivatives; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors*; D014779:Virus Replication / Q000187:drug effects; D012324:RNA-Dependent RNA Polymerase
chemical_list: D000409:Alanine; D000998:Antiviral Agents; D002219:Carbamates; D007093:Imidazoles; D011392:Proline; D011759:Pyrrolidines; D013267:Stilbenes; D053778:Thiazolidines; D014633:Valine; D017361:Viral Nonstructural Proteins; C569664:BMS 346; C569663:BMS 824; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase; C549273:daclatasvir