A Study to Evaluate the Pharmacokinetics, Safety and Tolerability of Nebulized Ensifentrine in Healthy Chinese Subjects

14 Subjects enrolled will use one 3 mg/2.5 mL ampule for the 3 mg dose, subjects will receive a 3 mg ensifentrine single dose, followed by 3 mg repeated dose (twice daily, BID). On the dosing day (Day 1), subjects will receive a single dose of 3 mg ensifentrine. On Day 4, subjects will receive multiple doses of 3 mg ensifentrine BID for 3 days (Day 4 to Day 6), and a morning dose will be administered on Day 7.

14 subjects will be enrolled in this cohort, then randomly assigned to one of 2 treatment sequences (6mg and 1.5mg single dose). Subjects will 2 different dose levels of study drug. Two 3 mg/2.5 mL ampules will be needed for the 6 mg dose (5 mL total volume) and the 1.5 mg dose will be achieved using an appropriate dilution protocol described in the pharmacy manual.