Experimental Cystic Fibrosis Drug in Healthy Subjects

This trial will consist of two parts: Part 1 and Part 2. Part 1 will enroll adult healthy volunteers (HV) into four treatment groups. The first group will enroll HV into a single ascending dose (SAD) treatment group consisting of three cohorts. The second group will enroll HV into a multiple ascending dose (MAD) treatment group consisting of three cohorts. The third group will enroll HV into a food effect (FE) treatment group consisting of one cohort. The fourth group will enroll HV into a drug-drug interactions (DDI) treatment group consisting of one cohort. Approximately 76 subjects will be enrolled in Part 1. Part 2 Cohorts 1 through 3 will enroll adult subjects with cystic fibrosis (CF) currently on stable ivacaftor/lumacaftor background therapy for a minimum of three months. Part 2 Cohorts 4 and Cohort 5 will enroll adult subjects with CF not currently receiving cystic fibrosis conductance regulator (CFTR) modulator therapy within 30 days prior to Day 1. Part 2 Cohort 6 will enroll adult subjects with cystic fibrosis on stable tezacaftor/ivacaftor background therapy. Approximately 104 subjects will be enrolled in Part 2.