This study consists of two cohorts, and approximately a total of up to 28 healthy male subjects, 14 subjects in Cohort 1, and 14 subjects in Cohort 2, will be enrolled. Cohort 2 will be randomly assigned to Sequence 1 and Sequence 2 according to the ratio of 1:1.~Treatment Group~Cohort 1: subjects will receive a 3 mg ensifentrine single dose, followed by 3 mg repeated dose (twice daily, BID).~Cohort 2: subjects will receive two single doses of 1.5 mg and 6 mg ensifentrine, separated by at least a 7-day washout period using crossover design.
This is a phase 1, open-label, parallel cohort study to evaluate the PK, safety and tolerability of nebulized ensifentrine following administration of single and multiple doses in healthy Chinese male subjects.