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Background: The orally active dual endothelin receptor antagonist aprocitentan targets a novel pathway in the treatment of hypertension and could be a key player in the treatment of salt/volume-dependent hypertension. Its pharmacokinetic profile supports a once-daily dosing strategy., Objective: As hypertensive patients may also experience concomitant renal disease, the objectives of this study were to evaluate the pharmacokinetics and tolerability of aprocitentan in subjects with severe renal function impairment (SRFI) and compare these with matched healthy subjects., Design, Setting, Participants: In this open-label, single-center, phase 1 study (NCT03165071) eight subjects with SRFI (mean estimated glomerular filtration rate [eGFR] 21.9 mL/min/1.73 m 2 ) and eight healthy subjects (mean eGFR 94.9 mL/min/1.73 m 2 ) received a single dose of 50 mg of aprocitentan followed by an observation period of up to 17 days. Plasma pharmacokinetic parameters of aprocitentan were derived by noncompartmental analysis of the plasma concentration-time profiles. Differences in pharmacokinetic parameters were explored using geometric means ratio (GMR) and 90% confidence intervals (CIs) with SRFI subjects as test group and healthy subjects as reference group. Safety and tolerability evaluations included adverse events (AEs), electrocardiograms, vital signs, and clinical laboratory tests., Results: All 16 subjects received aprocitentan and completed the study. The pharmacokinetics of aprocitentan were similar in SRFI and healthy subjects with maximum plasma concentrations reached at 7.6 h and 5.0 h, respectively. Maximum plasma concentrations did not differ as indicated by a GMR (90% CI) of 1.04 (0.85-1.28). Due to a slightly lower observed clearance in SRFI subjects, half-life was longer (53.2 h compared to 47.4 h in healthy subjects), while exposure expressed as area under the curve was 34% higher (GMR 90% CI 1.13-1.58). There were no differences in plasma protein binding (> 99% bound). Aprocitentan was well tolerated in subjects with SRFI with no notable difference compared to healthy subjects., Conclusions: Based on these single-dose results, subjects with mild, moderate, or severe renal function can be included in clinical studies without the need for dose adjustment.

Background and Objectives: Macitentan is a novel dual endothelin receptor antagonist recently approved for the treatment of pulmonary arterial hypertension (PAH). Warfarin, an anticoagulant often prescribed to patients with PAH, has a narrow therapeutic index and is prone to potential interactions with drugs. This study assessed the effects of macitentan on the pharmacokinetics and pharmacodynamics of single-dose warfarin in healthy subjects., Methods: This was a randomised, open-label, single-centre, two-way crossover (treatment A followed by treatment B, or vice versa), phase I study in 14 healthy male subjects. Treatment A was a loading dose of macitentan 30 mg on Day 1 followed by 10 mg once daily for 8 days, with a single 25 mg dose of warfarin on Day 4. Treatment B was a single dose of warfarin on Day 1. Blood samples were assessed for warfarin pharmacokinetics (R- and S-warfarin) and pharmacodynamics [international normalised ratio (INR) and factor VII]. Plasma trough concentrations of macitentan and its active metabolite (ACT-132577) and the safety and tolerability of each treatment were also assessed., Results: Plasma concentrations of R- and S-warfarin were similar in both treatment periods. Warfarin did not affect the mean trough plasma concentrations of macitentan or ACT-132577. Macitentan did not affect the pharmacodynamics of warfarin; the mean INR and factor VII activity versus time profiles were similar with and without macitentan., Conclusions: The absence of effect of macitentan on the pharmacokinetics and pharmacodynamics of a single dose of warfarin suggests that both drugs can be concomitantly administered without need for dose adjustment.