Absolute Bioavailability of Esaxerenone and Food Effects on its Pharmacokinetics After a Single Oral Dose in Healthy Japanese Subjects: An Open-Label Crossover Study.

Introduction: To investigate the absolute bioavailability of esaxerenone and the effects of food on its pharmacokinetics (PK) after a single oral dose in healthy Japanese subjects.

Methods: Twenty-four Japanese males aged 20-45 years were randomised to six groups (each n = 4) in this single-centre, open-label, three-way, three-period crossover study. Esaxerenone (5 mg) was administered in the fasting state as a single oral dose, single intravenous infusion over 1 h, or in the postprandial state as a single oral dose. Plasma samples were taken before and during the 96 h after drug administration. Drug concentrations were measured using liquid chromatography-tandem mass spectrometry. PK parameters were calculated using noncompartmental analysis, and safety was assessed.

Results: After fasting intravenous administration, total body clearance was 3.69 L h and volume of distribution was 92.7 L. The plasma concentration-time profile of esaxerenone was similar after fasting and postprandial administration. Absolute bioavailability of a single oral 5-mg dose of esaxerenone was 89.0% in the fasting state and 90.8% postprandially. Point estimates (1.010 and 1.019, respectively) and 90% confidence intervals for geometric least squares mean peak plasma concentrations and area under the plasma concentration-time curve ratios after postprandial versus fasting oral esaxerenone were within the prespecified range (0.80, 1.25). No severe adverse events occurred throughout the study.

Conclusions: Esaxerenone has a high absolute bioavailability of approximately 90% and food has no effect on esaxerenone PK after a single oral dose of 5 mg in healthy Japanese subjects. Additionally, no safety concerns were identified.

Clinical Trial Registration: JapicCTI No. 163452.

Funding: Daiichi Sankyo Co., Ltd.