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Evaluating the effects of CFTR modulators in young children with cystic fibrosis

A Prospective Study to Evaluate Biological and Clinical Effects of Significantly Corrected CFTR Function in Infants and Young Children (BEGIN Study)

Observational Seattle Children's Hospital · NCT04509050

This study is testing how CFTR modulators affect growth and health in young children with cystic fibrosis over five years.

Quick facts

Study typeObservational
Enrollment210 (estimated)
AgesN/A to 10 Years
SexAll
SponsorSeattle Children's Hospital Academic / other
Locations35 sites (Birmingham, Alabama and 34 other locations)
Trial IDNCT04509050 on ClinicalTrials.gov

What this trial studies

This observational study aims to explore the biological and clinical effects of CFTR modulators in infants and young children diagnosed with cystic fibrosis. It consists of two parts: the first part will track the natural history of hormonal growth factors and assess feasibility over a period of up to five years, while the second part will observe the impact of specific CFTR modulators on growth over a 60-month follow-up. Participants will undergo multiple visits to monitor various health parameters, including lung function and gastrointestinal health. The study is designed to provide insights into the long-term effects of these therapies in a pediatric population.

Who should consider this trial

Good fit: Ideal candidates include children under 10 years of age with a documented diagnosis of cystic fibrosis.

Not a fit: Patients who have recently used investigational drugs or CFTR modulators may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved management and outcomes for children with cystic fibrosis through enhanced understanding of CFTR modulator effects.

How similar studies have performed: Other studies have shown promising results with CFTR modulators in older populations, but this specific approach in young children is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Part A:

  * Less than 10 years of age at the first study visit.
  * Documentation of a CF diagnosis.

Part B:

* Participated in Part A OR less than 7 years of age at the first study visit.
* Documentation of a CF diagnosis.
* CFTR mutations consistent with FDA labeled indication of highly effective modulator therapy (ivacaftor or elexacaftor/tezacaftor/ivacaftor).
* Physician intent to prescribe ivacaftor or elexacaftor/tezacaftor/ivacaftor.

Exclusion Criteria:

* Part A and Part B:
* Use of an investigational drug within 28 days prior to and including the first study visit.
* Use of ivacaftor or elexacaftor/tezacaftor/ivacaftor within the 28 days prior to and including the first study visit.
* Use of chronic oral corticosteroids within the 28 days prior to and including the first study visit.

Where this trial is running

Birmingham, Alabama and 34 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Cystic FibrosisCFCFTR Modulatortriple combination therapyelexacaftortezacaftorivacaftor
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.