title: Effects of standard and supratherapeutic doses of nelfinavir on cardiac repolarization: a thorough QT study.
abstract: This was a randomized, 4-way crossover, third-party-blinded study in 68 healthy subjects to assess the effect of nelfinavir on QTc interval. Treatments included (A) nelfinavir 1250 mg every 12 hours on days 1-4, (B) nelfinavir 1250 mg every 12 hours on days 1-3 plus 3125 mg on day 4, (C) placebo, and (D) moxifloxacin 400 mg every 24 hours on days 1-4. Pharmacokinetics and triplicate 12-lead electrocardiograms were performed over 12 hours on days 1 and 4. Time-matched, placebo-subtracted, baseline-adjusted changes in QT intervals with Fridericia's (QTcF) correction were determined following nelfinavir and moxifloxacin administration. Neither dose of nelfinavir had a clinically relevant effect on the QTcF interval on day 4 (primary endpoint) and day 1 because at every time point the upper 90% confidence limit was below 10 milliseconds and, furthermore, the mean difference was below 5 milliseconds. Additionally, there was no clinically relevant effect on QTcB (Bazett's correction), uncorrected QT, or the RR interval on days 1 or 4. Pharmacokinetics confirmed adequate systemic exposure to nelfinavir and moxifloxacin. While nelfinavir exposure was higher in poor compared with extensive metabolizers of CYP2C19 isozyme, there were no corresponding significant differences in QTcF change from placebo. At clinically relevant, doses nelfinavir is unlikely to cause QTc prolongation.
authors.affiliation: Pfizer Global Research & Development, Pfizer Inc, 685 Third Ave., 685/13/55, New York, NY 10017, USA. bharat.damle@pfizer.com
authors.forename: Bharat
authors.initials: B
authors.lastname: Damle
authors.forename: Cecilia
authors.initials: C
authors.lastname: Fosser
authors.forename: Kaori
authors.initials: K
authors.lastname: Ito
authors.forename: Anh
authors.initials: A
authors.lastname: Tran
authors.forename: Pamela
authors.initials: P
authors.lastname: Clax
authors.forename: Howard
authors.initials: H
authors.lastname: Uderman
authors.forename: Paul
authors.initials: P
authors.lastname: Glue
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics / Q000378:metabolism; D001372:Aza Compounds / Q000494:pharmacology; D018592:Cross-Over Studies; D065731:Cytochrome P-450 CYP2C19; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004562:Electrocardiography; D024841:Fluoroquinolones; D017320:HIV Protease Inhibitors / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008133:Long QT Syndrome / Q000209:etiology; D008875:Middle Aged; D000077266:Moxifloxacin; D019888:Nelfinavir / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D011110:Polymorphism, Genetic; D011804:Quinolines / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D017320:HIV Protease Inhibitors; D011804:Quinolines; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D019888:Nelfinavir; D000077266:Moxifloxacin