Absence of effect of steady state bempedoic acid on cardiac repolarization: Results of a thorough QT/QTc study in healthy volunteers

Abstract

Bempedoic acid is an inhibitor of adenosine triphosphate–citrate lyase approved for use in adults with hypercholesterolemia. Nonclinical studies assessed binding to the human ether-a-go-go–related gene (hERG) potassium channel in vitro and the effect of bempedoic acid on QT/QTc in cynomolgus monkeys. A randomized, double-blind, parallel-design clinical study assessed the effects of steady-state bempedoic acid at a supratherapeutic dose (240 mg/day, 33.3% higher the180 mg/day therapeutic dose), placebo, and moxifloxacin (400 mg) in healthy subjects. In vitro binding potency for bempedoic acid to the hERG potassium channel was weak, with half-maximal inhibition (IC50) estimated at greater than 1000 μM (>1670-fold the bempedoic acid 180 mg/day steady-state unbound maximum concentration). In monkeys, individual rate-corrected QT intervals showed no time- or dose-dependent changes up to 100 mg/kg of bempedoic acid. In human subjects, the upper 90% confidence interval (CI) for the difference in QTc interval, corrected using Fridericia’s formula (QTcF), between bempedoic acid and placebo was less than 5 msec at all time points. Concentration-QTcF analysis showed that maximum bempedoic acid concentration at steady-state was attained at a median 2.1 h postdose, and the predicted mean change (90% CI) in QTcF at the observed mean bempedoic acid concentration 2 h postdose was −0.5 (−5.0, 4.0) msec. The lower bound of the moxifloxacin 90% CI exceeded 5 msec at prespecified time points, establishing study sensitivity. Steady-state bempedoic acid at a supratherapeutic dose of 240 mg was generally well-tolerated and not associated with QTc prolongation in healthy subjects.