Assessment of Testing Methods for Drug-Induced Repolarization Delay and Arrhythmias in an iPS Cell–Derived Cardiomyocyte Sheet: Multi-site Validation Study

Abstract

Abstract.A prospective comparison study across 3 independent research laboratories of a pure I Kr blocker E-4031 was conducted by using the same batch of human iPS cell-derived cardiomyocytes in order to verify the utility and reliability of our original standard protocol. Field potential waveforms were recorded with a multi-electrode array system to measure the inter-spike interval and field potential duration. The effects of E-4031 at concentrations of 1 to 100 nM were sequentially examined every 10 min. In each facility, E-4031 significantly prolonged the field potential duration corrected by Fridericia's formula and caused early afterdepolarizations occasionally resulting in triggered activities, whereas it tended to decrease the rate of spontaneous contraction. These results were qualitatively and quantitatively consistent with previous nonclinical in vitro and in vivo studies as well as clinical reports. There were inter-facility differences in some absolute values of the results, which were not observed when the values were normalized as percentage change. Information described in this paper may serve as a guide when predicting the drug-induced repolarization delay and arrhythmias with this new technology of stem cells.

Characterization of human iPS cell-derived cardiomyocyte sheets as a model to detect drug-induced conduction disturbance

“…Cryopreserved hiPSC-CMs (iCell Cardiomyocytes; Cellular Dynamics International (CDI), Madison, WI, USA) were cultured as previously described (Nakamura et al, 2014;Uesugi et al, 2014). The 64-microelectrode array (MED probe; MED-P515A, Alpha MED Scientific, Inc., Osaka, Japan) was placed into a 25-mmdiameter chamber.…”

“…The cultured cardiomyocytes in the 6-well tissue-culture plates were dispersed with 0.25% trypsin-EDTA and resuspended in culture medium (Maintenance Media, CDI) at 1.5 × 10 4 cells/μL. A volume of 2 μL of the cell suspension was plated onto the coated area of each MED probe according to the previous study (Nakamura et al, 2014). The cells were incubated overnight at 37°C with 5% CO 2 in humidified conditions to promote cell attachment onto the microelectrode array, and then 1 mL of the culture medium was added into each chamber.…”

“…In order to evaluate the utility of hiPSC-CMs as a tool for detecting drug-induced electrophysiological modifications, the effects of various drugs and chemical compounds have been assessed on the action potential waveform of single hiPSC-CM (Gibson et al, 2014;Peng et al, 2010) as well as the field potential configuration of two-dimensional cell sheets of hiPSC-CMs (Harris et al, 2013;Mehta et al, 2013;Nakamura et al, 2014;Nozaki et al, 2014;Uesugi et al, 2014). Thus, hiPSC-CMs have been well recognized as a new strategy that can provide reliable information for predicting drug-induced repolarization delay in the human heart.…”

CiPA: Ongoing testing, future qualification procedures, and pending issues

“…However, expected FDP prolongation by established drugs appears to occur across hSC-CM lines. For instance, dofetilide or E-4031, two pure I I Kr blockers, consistently prolong FPD and induce arrhythmias (Clements and Thomas, 2014;Nakamura et al, 2014).…”

“…Inter-facility differences in BP and FPD initial values were noted (Fig. 3) but these were resolved when data were normalized as the percentage changes from baseline values [for experimental protocol see (Nakamura et al, 2014)]. …”