Drug Design, Development and Therapy (Dec 2014)
A thorough QT study in the context of an uptitration regimen with selexipag, a selective oral prostacyclin receptor agonist
Abstract
Matthias Hoch,1 Borje Darpo,2,3 Tatiana Remenova,4 Randall Stoltz,5 Meijian Zhou,2 Priska Kaufmann,1 Shirin Bruderer,1 Jasper Dingemanse1 1Department of Clinical Pharmacology, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland; 2iCardiac Technologies Inc, Rochester, New York, NY, USA; 3Karolinska Institute, Department of Clinical Sciences, Danderyd’s Hospital, Division of Cardiovascular Medicine, Stockholm, Sweden; 4Drug Safety Department, Actelion Pharmaceuticals Ltd, Allschwil, Switzerland; 5Covance Clinical Research Unit, Evansville, IN, USA Abstract: The effects of selexipag and its active metabolite ACT-333679 on cardiac repolarization were assessed in a thorough QT study as per International Conference on Harmonisation E14 guidance. In this randomized, double-blind, placebo/positive-controlled, parallel-group study, healthy male and female subjects were randomized to receive escalating doses of selexipag (n=91) or placebo/moxifloxacin (n=68). Ascending multiple doses of selexipag in the range of 400-1,600 µg or placebo were administered twice daily for 21 days. Following a nested crossover design, subjects in the moxifloxacin/placebo treatment group received a single oral 400 mg dose of moxifloxacin on day 2 or 24. The primary endpoint (QT interval correction using individualized formula [QTcI]) was chosen based on a prospectively defined test applied to on-treatment data. The mean baseline-adjusted placebo-corrected ΔQTcI (ΔΔQTcI) for selexipag was small at all time points and never exceeded 1.4 msec (upper bound of 90% confidence interval [CI], 3.9 msec) on 800 µg or –0.7 msec (upper bound of 90% CI, 2.1 msec) on 1,600 µg. The mean ΔΔQTcI peak effect for moxifloxacin was 7.5 msec (lower bound of 90% CI, 4.8 msec). The exposure-response analysis did not demonstrate a relevant relationship between plasma concentrations of selexipag or ACT-333679 and ΔΔQTcI but, in contrast, a positive slope within the expected range for moxifloxacin. In conclusion, selexipag does not have an effect on cardiac repolarization. Keywords: prostacyclin, corrected QT, TQT, selexipag, moxifloxacin