Pharmacokinetics, Pharmacodynamics, and Safety Evaluation of the Novel HIF-PH Inhibitor Enarodustat: An Open-Label Phase I Study in Healthy Chinese Participants.

Background And Objectives: Enarodustat is a hypoxia-inducible factor-prolyl hydroxylase inhibitor. We evaluated the pharmacokinetics, pharmacodynamics, and safety profile of domestic enarodustat (SAL-0951) and analyzed the influence of ethnic factors.

Methods: In this phase I study, healthy Chinese participants received single and multiple oral doses (1, 5, and 15 mg) of SAL-0951 while in a fasted state. We monitored the pharmacokinetics, pharmacodynamics, and safety characteristics and analyzed the impact of ethnicity on pharmacokinetic characteristics.

Results: In total, 33 healthy Chinese participants were enrolled; the mean age was 31.2 ± a standard deviation of 5.5 years. After single doses of 1, 5, and 15 mg were administered under fasted conditions, SAL-0951 was rapidly absorbed. Mean maximum plasma concentration and area under the plasma concentration-time curve from time 0 to the last quantifiable concentration increased dose proportionately from 0.14 to 2.54 μg/mL and from 0.63 to 9.50 h × μg/mL, respectively. The elimination half-life was 6.13, 6.32, and 6.74 h, respectively, in these three groups, and the mean value of apparent clearance ranged from 1.64 to 1.89 L/h. SAL-0951 was excreted mostly as the parent compound. It reached a stable concentration after 5 days of multiple-dose administration. We observed no drug accumulation or time-dependent pharmacokinetic characteristics and no significant difference in pharmacokinetic characteristics between Chinese and Japanese participants.

Conclusion: SAL-0951 was safe and well tolerated in healthy Chinese participants and had a linear pharmacokinetic profile. We found no ethnic differences in the pharmacokinetic characteristics of the drug between Chinese and Japanese populations.

Clinical Trial Registration: Registered at Chinadrugtrials.org.cn, registration number CTR2020245.