Streamlined Treatment of Pulmonary Exacerbations in Pediatrics

Eligibility Criteria

• 1. Age
• 1. For main cohort and non-HEMT cohort: age 6 to \<19 years
• 2. For preschool cohort: age 3 to \<6 years
• 2. Documentation of a CF diagnosis as evidenced by one or more clinical features consistent with the CF phenotype and one or more of the following criteria:
• 1. sweat chloride ≥ 60 mEq/liter
• 2. two disease-causing variants in the cystic fibrosis transmembrane conductive regulator (CFTR) gene
• 3. Written informed consent (and assent when applicable) obtained from participant or participant's legal representative and ability of participant to comply with the requirements of the study
• 4. Highly Effective Modulator Therapy
• 1. For main cohort and preschool cohort: Taking ETI or ivacaftor for at least 3 months at enrollment
• 2. For non-HEMT cohort: not eligible for HEMT based on CFTR genotype or eligible but not taking for at least 3 months and no plans to start HEMT in the next year, and also not taking tezacaftor-ivacaftor or lumacaftor-ivacaftor for at least 3 months
• 5. For main cohort and non-HEMT cohort: able to perform acceptable and reproducible spirometry
• 6. For main cohort and non-HEMT cohort: ppFEV1 ≥ 50% predicted at enrollment based on the Global lung Initiative (GLI) reference equations
• 7. Ability to receive text messages and access the internet
• 1. Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the individual or the quality of the data
• 2. Receiving an acute course of oral or IV antibiotics at the time of enrollment or within the 14 days prior to enrollment. Individuals may be re-screened ≥21 days after completion of antibiotics if they are at their baseline state of health, per self-report
• 3. Treatment with systemic corticosteroids at enrollment or within the 14 days prior to enrollment. Individuals may be re- screened ≥21 days after completion of systemic corticosteroids if they are at their clinical baseline, per self-report
• 4. History of solid organ transplant
• 5. History of positive culture for Mycobacterium abscessus in the 12 months prior to enrollment
• 6. Treatment with antibiotics for any non-tuberculous mycobacteria (NTM) at enrollment
• 7. Three or more IV antibiotic-treated PEx in the 12 months prior to enrollment
• 8. Treatment with chronic oral antibiotics other than azithromycin at enrollment
• 9. Treatment with systemic corticosteroids for allergic bronchopulmonary aspergillosis (ABPA) in the 12 months prior to enrollment