Observational Study in Cystic Fibrosis Patients Using TOBI® Podhaler™ or Other FDA Approved Inhaled Antipseudomonal Antibacterial Drugs

This study will include CF patients chronically colonized with P. aeruginosa enrolled in the
Cystic Fibrosis Foundation (CFF) PortCF registry and using TOBI Podhaler or another
FDA-approved inhaled antipseudomonal antibiotic. No therapeutic intervention will be assigned
and physicians will use their discretion in choosing a treatment regimen for their patients.

Sputum samples (primarily collected during routine clinical follow-up) from patients able to
spontaneously produce sputum will be sent to a central laboratory for analysis.

In addition, this study will include two optional sub-studies for qualifying patients in the
first study year - Sputum microbiology sub-study and TOBI Podhaler sputum pharmacokinetics
(PK) sub-study.

Inclusion Criteria:

- ≥ 6 years of age.

- Documented FEV1 ≥ 25% predicted in the previous year.

- Diagnosis of cystic fibrosis.

- Established diagnosis of chronic P. aeruginosa infection of the lungs defined as two
or more positive P. aeruginosa cultures in the previous year as documented in the
subject's medical history (this may include a history of one positive culture in the
year prior to enrollment and one positive culture from the specimen collected at the
baseline visit).

- Prescribed and initiated chronic treatment with FDA-approved inhaled antipseudomonal
antibiotic for chronic P. aeruginosa infection (e.g. TOBI Podhaler, TOBI®, Cayston®
and Bethkis®).

- Actively enrolled or willingness to enroll in PortCF registry.

- Willing and able to provide written informed consent or, parent/guardian consent and
where applicable pediatric assent, for participation and use of relevant clinical data
previously captured in PortCF.

- Anticipated to have good adherence to routine visits, defined as the investigator
having good knowledge that the patient has been to at least 2-3 routine visits in the
previous year.

Exclusion Criteria:

- Documented FEV1 < 25% predicted in the previous year.

- Current participation in an interventional clinical study with an inhaled antibiotic
treatment.

- Treatment with compounded tobramycin (e.g. the use of tobramycin IV solution adapted
for use by inhalation).

- Treatment with inhaled antipseudomonal antibacterial drug(s) that are not FDA
approved.

- Patients undergoing an early eradication regimen for CF (first line therapy).