An evaluation of a supratherapeutic dose of inclisiran on cardiac repolarization in healthy volunteers: A phase I, randomized study

Inclisiran is a small interfering RNA molecule that has been shown to provide an effective and sustained reduction in low-density lipoprotein cholesterol levels. This study aimed to determine whether a supratherapeutic dose of inclisiran affects cardiac repolarization and conduction in healthy volunteers. A phase I, randomized, double-blind, double-dummy, placebo- and positive-controlled, three-way crossover study was performed in 48 healthy volunteers. Volunteers were assigned to three treatments in a randomized sequence: a supratherapeutic dose of inclisiran sodium (900 mg), placebo, or moxifloxacin 400 mg as a positive control, with a minimum 7-day washout period between treatments. Continuous electrocardiogram monitoring was performed from >60 min before dosing until 48 h after dosing. Pharmacokinetics, pharmacodynamics, and safety were also assessed. Inclisiran, at a supratherapeutic dose, did not show a clinically significant effect on the QT interval (Fridericia correction formula [QTcF]; maximal placebo- and baseline-corrected change: 2.5 ms [90% confidence interval: 0.6, 4.5]) near the maximal plasma concentrations at 4 h. In addition, inclisiran did not show any effects on other electrocardiogram intervals or ST- and T-wave morphology. The positive control, moxifloxacin, demonstrated the expected changes in QTcF interval, validating the adequate sensitivity of the study. A supratherapeutic dose of inclisiran sodium (900 mg) had no effect on the QTcF interval or other electrocardiogram parameters, providing additional insight and reassurance regarding the safety profile of inclisiran.