Referenced in: none

Automatically associated channels: Kv11.1

Title: Relevance of in vitro SCREENIT results for drug-induced QT interval prolongation in vivo: a database review and analysis.

Authors: B M Dumotier, M Deurinck, Y Yang, M Traebert, W Suter

Journal, date & volume: Pharmacol. Ther., 2008 Aug , 119, 152-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/18462801

Abstract
The use of an isolated rabbit heart model (SCREENIT) to predict drug-induced QTc prolongation in animals was assessed using hERG and telemetry data.We compiled data from (i) hERG assay (IC50s), (ii) SCREENIT assay (APD60) and (iii) in vivo non-rodent telemetry studies (QTc interval) and evaluated the reliability of APD60 to fit with IC50s and QTc prolongation using the ratio to free plasma level (FPL). Eighty-two compounds were separated into three classes based on hERG IC50s (class I: IC50s< or =1 microM, n=7; class II: IC50s>1 microM to < or =10 microM, n=15; class III: IC50s>10 microM, n=60).Three class I compounds did not prolong QTc at the FPL equivalent to their IC50s (43% hERG false positives). There were no false positives in SCREENIT. Six class II compounds prolonged the QTc interval. Results showed 40% hERG false negatives and no SCREENIT false negatives. Nine compounds had no effect on QTc, and two prolonged APD60 at an equivalent concentration/FPL (13% false positives). Three class III compounds prolonged QTc at an FPL lower than maximum SCREENIT concentrations (5% false negatives). Four other compounds generated SCREENIT false positive results (7%).SCREENIT increased the predictability of preclinical results for QTc prolongation without generating any false positive results in class I (13% in class II). Making decisions without isolated heart data increases the risk for eliminating efficient drugs displaying hERG inhibition.