Safety, Tolerability, and Pharmacokinetics of ARCT-032 in Healthy Adult Subjects and Adults With Cystic Fibrosis.

Phase 1 of this study is a single ascending dose, first-in-human study to determine the safety, tolerability, and pharmacokinetics (PK) of ARCT-032. After screening, healthy adult participants will be randomized 3:1 to inhale a single dose of nebulized ARCT-032 or placebo. There are 4 planned sequential dose cohorts. After dosing, participants will have follow-up assessments over a 4-week period.

Phase 1b in adults with cystic fibrosis will enroll after Phase 1 is completed and safety data are reviewed. Phase 1b is an open-label, two-dose study in adults with cystic fibrosis to assess the safety, tolerability, and pharmacokinetics of ARCT-032. After completion of screening, each participants will inhale two doses of nebulized ARCT-032 two days apart. Participants will have follow-up assessments over a 4-week period.