Although the QT/QTc interval is overall an imperfect biomarker, it is currently the best available clinical surrogate for the development of drug-induced torsades de pointes.The following results from cardiovascular telemetry studies should be considered for appraising QT interval prolongation risk: Dose-or concentration-dependent increases in mean QTca compared to mean time matched vehicle control QTca are considered to be a signal for a potential to delay the ventricular repolarization.The magnitude of the increase in QTca will be considered in relationship to the increase induced by the positive control substance, moxifloxacin, in the respective species (historical data).A relevant non-clinical effect of moxifloxacin is defined as an increase of 5-10 ms (sensitivity threshold =signal).