Effect of Age, Sex, Renal Impairment and Hepatic Impairment on the Safety, Pharmacokinetics and Pharmacodynamics of Asundexian.

Introduction: Asundexian is a reversible and selective inhibitor of activated factor XI. It is currently under investigation for the prevention of secondary stroke in at-risk patients; these patients are often characterised by advanced age, impaired organ function and comorbidities. This article summarises results from three Phase I studies that investigated the effects of age and sex (study 1), chronic kidney disease including end-stage kidney disease (ESKD) on dialysis and dialysis-free days (study 2) and Child-Pugh A and B liver disease (study 3) on the safety, pharmacokinetics and pharmacodynamics of a single oral dose of asundexian 25 mg.

Methods: Study 1 was a multicentre, randomised, single-blind, placebo-controlled group-stratification design; study 2 was a single-centre, non-randomised, non-placebo-controlled, non-blinded group-stratification design; and study 3 had a non-randomised, non-blinded, non-placebo-controlled group-stratification design.

Results: Single doses of asundexian 25 mg were generally well tolerated in all three studies, with no asundexian-related bleeding events or treatment-emergent adverse events of special interest. Point estimates (geometric least squares [LS] means) (90% confidence intervals [CIs]) for the total asundexian area under the plasma concentration-time curve (AUC) for participants aged ≥ 65 to < 75 years versus ≥ 18 to < 45 years and ≥ 75 to ≤ 80 years versus ≥ 18 to < 45 years were 1.257 (1.134-1.393) and 1.288 (1.158-1.433), respectively, and for females versus males, it was 1.084 (0.995-1.182). Point estimates (geometric LS means) (90% CIs) for unbound AUC in participants in estimated glomerular filtration rate (eGFR) categories G2 (60-89 mL/min/1.73 m²), G3 (30-59 mL/min/1.73 m²) and G4 (15-29 mL/min/1.73 m²) versus control were 1.003 (0.698-1.443), 0.791 (0.550-1.138) and 0.882 (0.606-1.285), respectively, and in participants with ESKD on dialysis-free day versus control was 0.597 (0.406-0.877). There was no effect of the dialysis procedure on the pharmacokinetics of asundexian. In participants deemed Child-Pugh class A and Child-Pugh class B, geometric LS means (90% CIs) for unbound AUC were 0.834 (0.597-1.164) and 1.143 (0.810-1.612), respectively, when compared to participants with normal liver function. Activated partial thromboplastin time (aPTT) was assessed as a pharmacodynamic variable of interest. Geometric mean maximum aPTT prolongation as a ratio to baseline after administration of asundexian 25 mg ranged from 1.45 to 1.55 in all age and sex groups, 1.49-1.59 in the control and eGFR G2 to G4 groups, 1.38-1.54 in the control and ESKD groups on dialysis and dialysis-free day and 1.38-1.89 in the healthy control and liver impairment groups.

Conclusions: The effects of the investigated intrinsic factors on the exposure of asundexian were small and not considered clinically relevant. The impact of lower exposure in participants with ESKD requires further investigation. Pharmacodynamics were as expected.

Clinical trial registration numbers: EudraCT 2022-000196-38 and 2020-000626-25.