The Pharmacokinetics, Safety and Tolerability of Aclidinium Bromide 400 μg Administered by Inhalation as Single and Multiple (Twice Daily) Doses in Healthy Chinese Participants

PURPOSE: To date, aclidinium pharmacokinetic (PK) studies have focused on Caucasian populations, and no data are available for Chinese populations. We aimed to characterize the PK and safety profile of aclidinium and its metabolites (LAS34823 and LAS34850) following single and multiple (twice-daily; BID) dosing in healthy Chinese participants, and to compare PK data between Chinese and Caucasian populations. MATERIALS AND METHODS: In this Phase I, open-label study (NCT03276052), healthy participants from a single site in China received aclidinium bromide 400 µg via a dry powder inhaler. The Day 1 single dose was followed by a washout period of 96 hours. On Days 5 through 8, participants received BID doses. RESULTS: Twenty healthy Chinese participants, aged 18–45 years, were enrolled. Aclidinium absorption was rapid (median time to maximum concentration [t(max)] 0.08 hours post-dose following single/multiple doses). LAS34823 had a similar median t(max) of 0.08 hours, whereas LAS34850 t(max) occurred later (median 2.50–3.00 hours). Aclidinium, LAS34823, and LAS34850 concentrations declined in a bi-phasic manner; geometric mean half-life was 13.5 hours (single dosing) and 21.4 hours (multiple dosing), while steady state was generally achieved after 5 days’ continuous dosing. Area under the concentration–time curve during a dosage interval (AUC(τ)) metabolite to parent ratios for LAS34823 were 2.6 (Day 1) and 2.9 (Day 9), while LAS34850 had ratios of 136.0 and 94.8, respectively. Aclidinium accumulation occurred after 5 days of BID dosing (LS mean accumulation ratio for AUC(τ) Day 9/Day 1: 214.1% [90% CI, 176.5, 259.6]); LAS34823 accumulation was similar, while LAS34850 accumulation was lower. Between-participant exposure variability was moderate to high for aclidinium and LAS34823, and low for LAS34850. CONCLUSION: Single and multiple doses of aclidinium were well tolerated in healthy Chinese participants. The safety profile of and exposure to aclidinium was consistent with previous studies conducted in Caucasian populations.