1. Assessment of Multi-Ion Channel Block in a Phase I Randomized Study Design: Results of the CiPA Phase I ECG Biomarker Validation Study.
- Author
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Vicente J, Zusterzeel R, Johannesen L, Ochoa-Jimenez R, Mason JW, Sanabria C, Kemp S, Sager PT, Patel V, Matta MK, Liu J, Florian J, Garnett C, Stockbridge N, and Strauss DG
- Subjects
- Adult, Cross-Over Studies, Female, Heart Rate drug effects, Humans, Long QT Syndrome drug therapy, Long QT Syndrome metabolism, Male, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, Torsades de Pointes drug therapy, Torsades de Pointes metabolism, Biomarkers metabolism, Electrocardiography drug effects, Ion Channels antagonists & inhibitors, Membrane Transport Modulators therapeutic use, Pharmaceutical Preparations administration & dosage
- Abstract
Balanced multi-ion channel-blocking drugs have low torsade risk because they block inward currents. The Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative proposes to use an in silico cardiomyocyte model to determine the presence of balanced block, and absence of heart rate corrected J-T
peak (J-Tpeak c) prolongation would be expected for balanced blockers. This study included three balanced blockers in a 10-subject-per-drug parallel design; lopinavir/ritonavir and verapamil met the primary end point of ΔΔJ-Tpeak c upper bound < 10 ms, whereas ranolazine did not (upper bounds of 8.8, 6.1, and 12.0 ms, respectively). Chloroquine, a predominant blocker of the potassium channel encoded by the ether-à-go-go related gene (hERG), prolonged ΔΔQTc and ΔΔJ-Tpeak c by ≥ 10 ms. In a separate crossover design, diltiazem (calcium block) did not shorten dofetilide-induced ΔQTc prolongation, but shortened ΔJ-Tpeak c and prolonged ΔTpeak -Tend . Absence of J-Tpeak c prolongation seems consistent with balanced block; however, small sample size (10 subjects) may be insufficient to characterize concentration-response in some cases., (Published 2019. This article is a U.S. Government work and is in the public domain in the USA. Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)- Published
- 2019
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