Evaluation of Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) in Cystic Fibrosis (CF) Participants 12 to Less Than 24 Months of Age

Study Overview
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Brief Summary
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This study will evaluate the pharmacokinetics (PK), safety, tolerability, pharmacodynamics (PD), and efficacy of ELX/TEZ/IVA in CF subjects 12 to less than (<) 24 months of age.

Official Title
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A Phase 3, Open-label Study Evaluating the Pharmacokinetics, Safety, and Tolerability of Elexacaftor/Tezacaftor/Ivacaftor in Cystic Fibrosis Subjects 12 to Less Than 24 Months of Age

Conditions
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Cystic Fibrosis

Intervention / Treatment
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* Drug: ELX/TEZ/IVA
* Drug: IVA


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Participants who have at least 1 F508del mutation in the CF transmembrane conductance regulator (CFTR) gene or another ELX/TEZ/IVA-responsive CFTR mutation Key Exclusion Criteria: History of any illness or any clinical condition that, in the opinion of the investigator, might either confound the results of the study or pose an additional risk in administering study drug(s) to the participant Other protocol defined Inclusion/Exclusion criteria may apply.

Ages Eligible for Study
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Minimum Age: 12 Months
Maximum Age: 24 Months

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Part A<br>Participants will receive ELX/TEZ/IVA in the morning and IVA in the evening. | Drug: ELX/TEZ/IVA<br>* Fixed-dose combination granules for oral administration.<br>* Other names: elexacaftor/tezacaftor/ivacaftor;Drug: IVA<br>* Granules for oral administration<br>* Other names: ivacaftor;|
| Experimental: Part B<br>Participants will receive ELX/TEZ/IVA in the morning and IVA in the evening with the dose(s) to be based on the outcome of Part A. | Drug: ELX/TEZ/IVA<br>* Fixed-dose combination granules for oral administration.<br>* Other names: elexacaftor/tezacaftor/ivacaftor;Drug: IVA<br>* Granules for oral administration<br>* Other names: ivacaftor;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Part A: Observed Pre-dose Concentration (Ctrough) of ELX, TEZ, IVA, and their Relevant Metabolites |  | Day 1 up to Day 15 | 
| Part A: Safety and Tolerability as Assessed by Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs) |  | Day 1 up to Day 43 | 
| Part B: Safety and Tolerability as Assessed by Number of Participants with Adverse Events (AEs) and Serious Adverse Events (SAEs) |  | Day 1 up to Week 28 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Part B: Observed Pre-dose Concentration (Ctrough) of ELX, TEZ, IVA, and their Relevant Metabolites |  | Day 15 up to Week 16 | 
| Part B: Absolute Change in Sweat Chloride (SwCl) |  | From Baseline Through Week 24 |