Clinical Evaluation of QTc Interval Prolongation With the Dual Endothelin Receptor Antagonist Aprocitentan

IntroductionAprocitentan, is an orally active, once-daily administered, dual endothelin receptor antagonist that was recently approved for the treatment of hypertension in combination with other antihypertensive drugs, to lower blood pressure in adult patients who are not adequately controlled on other drugs.MethodsThe potential of aprocitentan to affect the QT interval was investigated in this thorough QT/QTc study that was performed as a multiple-dose, randomized, double-blind, placebo- and moxifloxacin-controlled (open-label), crossover study in healthy male and female subjects. Concentration-QT modeling, using a linear mixed-effects model, was performed on data extracted from continuous Holter electrocardiogram recordings.ResultsOf the 48 subjects enrolled in the study, 32 subjects completed study treatment. The main reasons for stopping study treatment were the occurrence of adverse events and withdrawal of consent. The dosing regimen of 25 mg aprocitentan o.d. (the highest approved therapeutic dose in the European Union; C_max = 3.68 µg/mL) was safe and well tolerated; the supratherapeutic dosing regimen of 100 mg aprocitentan o.d. showed limited tolerability. Results indicated that ΔΔQTcF increased with increasing aprocitentan concentrations. The predicted upper bound of the 2-sided 90% ΔΔQTcF confidence interval exceeded the 10 ms threshold of regulatory concern at 16.10 µg/mL, which was close to the geometric mean maximum concentration (ie, 16.77 µg/mL) obtained with a 100 mg supratherapeutic dose.ConclusionsAt the highest therapeutic dose of 25 mg, there was no clinically significant prolongation of QTc. The risk of QT prolongation with therapeutic doses of aprocitentan is considered low.