A Two-Part Multicenter Prospective Longitudinal Study of CFTR-dependent Disease Profiling in Cystic Fibrosis (PROSPECT)

Inclusion Criteria Part A COHORT 1:

• 1. Written informed consent (and assent when applicable) obtained from subject or subject's legal representative.
• Be willing and able to adhere to the study visit schedule and other protocol requirements 3. Male or female ≥ 12 years of age at Visit 1. 4. Have a body mass index (BMI) of:
• For subjects ≥ 18 years of age: ≤ 30 kg/m2
• For subjects 12 - 17 years of age: ≤ 95th percentile 5. Be a non-smoker for ≥ 1 year at screening and have ≤ 10 pack-year history of smoking.
• To participate in the optional DNA banking component of this study, subject must have signed the informed consent indicating willingness to participate in the genomic component of the study. Refusal to give consent for this component does not exclude a subject from participation in the study.

Inclusion Cohorts 2-3

• Written informed consent (and assent when applicable) obtained from subject or subject's legal representative.
• Male or female ≥ 12 years of age at Visit 1.
• Documentation of a CF diagnosis as evidenced by one or more clinical features consistent with the CF phenotype and the following criteria: Cohort 2: (Partial Function CFTR CF)
• Two mutations in the CFTR gene:
• At least one allele must be a Class IV or V mutation
• The second allele can be within any CFTR mutation class.
• Pancreatic sufficient (based on the absence of daily PERT use)
• At least one historic sweat chloride ≥60 mEq/L by quantitative pilocarpine iontophoresis test (QPIT) OR sweat chloride results ≥ 40, but 12 weeks prior to visit 1).
• Active treatment for nontuberculous mycobacterial (NTM) infection, consisting of ≥ two antibiotics (oral, IV, and/or inhaled).
• Use of CFTR modulator therapy such as ivacaftor (Kalydeco®) within 28 days prior to Visit 1.
• History of lung or liver transplantation, or listing for organ transplantation.

Exclusion PART B

• Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data.
• Initiation of newly prescribed antibiotics [oral, intravenous (IV), and/or inhaled] for acute respiratory symptoms within 2 weeks of Visit 4.
• Initiation of any new chronic therapy (e.g., ibuprofen, Pulmozyme®, hypertonic saline, azithromycin, TOBI®, Cayston®) within 4 weeks prior to Visit 4.
• Use of an investigational agent within 28 days prior to Visit 4.
• Use of oral corticosteroids in doses exceeding 10 mg prednisone/day or 20 mg prednisone/every other day (subjects on oral steroids will be on stable doses for > 12 weeks prior to Visit 4).
• Active treatment for nontuberculous mycobacterial (NTM) infection, consisting of ≥ two antibiotics (oral, IV, and/or inhaled).
• Use of CFTR modulator therapy such as ivacaftor (Kalydeco®) within 28 days prior to Visit 4.