Objective

The Comprehensive In Vitro Proarrhythmia Assay (CiPA) is a new mechanistical approach to assess the cardiac risk of drug candidates replacing the insufficient testing on hERG blockage and QT prolongation alone (ICH S7A & S7B). CiPA which has been proposed by expert teams of the Cardiac Safety Research Consortium (CSRC), the Health and Environmental Sciences Institute (HESI) and the Food and Drug Administration (FDA) employ analysis of a panel of cardiac ion channels known to be targeted by drugs resulting in Torsades-de-Pointes in combination with in silico consideration and additional tests using cardiomyocytes. Here we demonstrate the application of patch ready cells which express recombinant ion channels of the CiPA panel. The cells are cryopreserved at a highly functional state and can be used instantly after thawing in patch clamp assays without any prior cultivation or passaging. The cells provide a good and stable membrane seal and display strong and consistent currents of the voltage gated ion channels. A test with selected reference compounds show that patch ready frozen cells are neither hypersensitive nor more resistant to channel blocking effects.