title: Effect of vicriviroc on the QT/corrected QT interval and central nervous system in healthy subjects.
abstract: Vicriviroc is a CCR5 antagonist in clinical development for the treatment of HIV-1. Two phase I studies were conducted to assess the safety of vicriviroc. One study characterized the drug's potential to prolong the QT/corrected QT (QTc) interval and to induce arrhythmia. In this partially blind, parallel-group study, 200 healthy subjects aged 18 to 50 years were randomized in equal groups to the following regimens: (i) placebo for 9 days and a single dose of moxifloxacin at 400 mg on day 10, (ii) placebo, (iii) vicriviroc-ritonavir (30 and 100 mg), (iv) vicriviroc-ritonavir (150 and 100 mg), and (v) ritonavir (100 mg). The second study characterized the effects of a range of vicriviroc doses on the central nervous system (CNS). In this third-party-blind, parallel-group study, 30 healthy subjects aged 18 to 48 years were randomized to receive a single dose of either vicriviroc at 200, 250, or 300 mg or placebo, followed by multiple (seven) once-daily doses of either vicriviroc at 150, 200, or 250 mg or placebo, respectively. In the first study, vicriviroc produced no clinically meaningful effect on the QT/QTc interval when administered at a supratherapeutic or therapeutic dose concurrently with ritonavir. In the second study, vicriviroc produced no observable seizure activity, nor was it held to be associated with any clinically relevant changes in brain waveforms in the final consensus of reviewers. These findings showed that vicriviroc produced no clinically relevant QTc prolongation cardiac or epileptogenic effects in healthy individuals at exposures as high as five times those expected for HIV-infected patients receiving therapeutic doses of vicriviroc in a ritonavir-boosted protease inhibitor-containing regimen.
authors.affiliation: Merck & Co., Kenilworth, NJ 07033, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: O'Mara
authors.forename: Claudia
authors.initials: C
authors.lastname: Kasserra
authors.forename: John Robert
authors.initials: JR
authors.lastname: Huddlestone
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Wan
authors.forename: Peter
authors.initials: P
authors.lastname: Soni
authors.forename: Maria
authors.initials: M
authors.lastname: Caceres
authors.forename: Matthew
authors.initials: M
authors.lastname: Medlock
authors.forename: Royce
authors.initials: R
authors.lastname: Morrison
authors.forename: Orrin
authors.initials: O
authors.lastname: Devinsky
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D001145:Arrhythmias, Cardiac / Q000139:chemically induced; D065100:CCR5 Receptor Antagonists; D002490:Central Nervous System / Q000187:drug effects*; D004562:Electrocardiography; D004569:Electroencephalography; D005260:Female; D015658:HIV Infections / Q000188:drug therapy; D006321:Heart / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D011743:Pyrimidines / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D019438:Ritonavir / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D065100:CCR5 Receptor Antagonists; D010879:Piperazines; D011743:Pyrimidines; D019438:Ritonavir; C486781:vicriviroc