For people ages 18-65
Part 1 Major Inclusion Criteria:
- Healthy, adult, male or female, 18-55 years of age, inclusive, at screening.
- Body weight greater than or equal to 50 kg and body mass index (BMI) between 16-32 kg/m2, inclusive
- The participant has a forced expiratory volume in one second (FEV1) of at least 80% predicted
- The participant is considered by the investigator to be in good general health as determined by medical history, clinical laboratory test results, vital sign measurements, 12-lead ECG results, and physical examination findings at screening.
- Understands the study procedures in the informed consent form (ICF), and is willing and able to comply with the protocol.
Part 1 Major Exclusion Criteria:
- History or presence of clinically significant medical, surgical, clinical laboratory, or psychiatric condition or disease.
- The participant has supine blood pressure (BP) >150 mm Hg (systolic) or >90 mm Hg (diastolic), following at least 5 minutes of supine rest.
- The participant has abnormal clinical laboratory tests at screening, as assessed by the study-specific laboratory.
- The participant is a smoker or has used nicotine or nicotine-containing products 6 weeks before the first dose of study drug. Former smokers with greater than 10 pack years of smoking history are excluded.
Part 2 Major Inclusion Criteria:
- Confirmed diagnosis of CF
- Forced expiratory volume in 1 second ≥40% and ≤100% of predicted mean value for age, sex, and height
- a) Not eligible for CFTR modulators based on having mutations of CFTR gene on both alleles that are not responsive to CFTR modulator therapy OR
- b) Eligible for CFTR modulators (based on local prescribing information) but not using CFTR modulators due to intolerance or contraindications
Part 2 Major Exclusion Criteria:
- Hepatic cirrhosis with portal hypertension, moderate hepatic impairment (Child Pugh Score 7 to 9), or severe hepatic impairment (Child Pugh Score 10 to 15)
- An acute upper or lower respiratory infection, pulmonary exacerbation, or changes in therapy (including antibiotics) for sinopulmonary disease within 4 weeks before the first dose of study drug
- Lung infection with organisms associated with a more rapid decline in pulmonary status
- Arterial oxygen saturation on room air less than 94% at screening
- Values of AST, ALT, alkaline phosphatase, or gamma-glutamyl transferase (GGT) ≥3×ULN
- Treatment with a CFTR modulator (Kalydeco, Trikafta, Symdeko, or Orkambi) within 12 weeks of Screening
Other protocol defined Inclusion/Exclusion criteria may apply.