Early assessment of proarrhythmic risk of drugs using the <i>in vitro</i> data and single-cell-based <i>in silico</i> models: proof of concept

<b>Background and purpose:</b> To determine the predictive performance of <i>in silico</i> models using drug-specific preclinical cardiac electrophysiology data to investigate drug-induced arrhythmia risk (e.g. Torsade de pointes (TdP)) in virtual human subjects. <b>Experimental approach:</b> To assess drug proarrhythmic risk, we used a set of <i>in vitro</i> electrophysiological measurements describing ion channel inhibition triggered by the investigated drugs. The Cardiac Safety Simulator version 2.0 (CSS; Simcyp, Sheffield, UK) platform was used to simulate human left ventricular cardiac myocyte action potential models. <b>Results:</b> This study shows the impact of drug concentration changes on particular ionic currents by using available experimental data. The simulation results display safety threshold according to drug concentration threshold and log (threshold concentration/ effective therapeutic plasma concentration (ETPC)). <b>Conclusion and implications:</b> We reproduced the underlying biophysical characteristics of cardiac cells resulted in effects of drugs associated with cardiac arrhythmias (action potential duration (APD) and QT prolongation and TdP) which were observed in published 3D simulations, yet with much less computational burden.