This trial is a study to evaluate the efficacy and safety of ensifentrine inhalation suspension administered via nebulization (3 mg BID) compared to placebo in subjects with non-cystic fibrosis bronchiectasis (NCFBE). Approximately 180 eligible subjects meeting all inclusion and no exclusion criteria will participate at approximately 45 sites in North America, the United Kingdom, and the European Union. Only subjects completing the Screening Period, meeting all inclusion, meeting no exclusion criteria, and meeting none of the randomization exclusion criteria will be randomized to receive blinded study medication: ensifentrine or placebo. The study has 3 periods: a Screening Period (up to 4 weeks, or 28 days), a Study Treatment Period (24 weeks or longer), and a Follow-up Period (4 to 10 days after your last dose of the study drug).