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

Abstract 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.