NCT04537793 is a Phase 3 clinical trial of ELX/TEZ/IVA in Cystic Fibrosis, sponsored by Vertex Pharmaceuticals Incorporated.

Who is sponsoring NCT04537793?

NCT04537793 is sponsored by Vertex Pharmaceuticals Incorporated.

What drugs are being tested in NCT04537793?

Interventions in NCT04537793: ELX/TEZ/IVA, IVA.

What condition does NCT04537793 study?

NCT04537793 studies Cystic Fibrosis.

Is NCT04537793 still recruiting?

NCT04537793 is currently completed. Last updated 28 June 2023.

Are results published for NCT04537793?

Yes — primary outcome results have been posted to ClinicalTrials.gov. See the outcomes section above for details.

Last reviewed 2023-06-28 · How we verify

NCT04537793

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

Evaluation of ELX/TEZ/IVA in Cystic Fibrosis (CF) Subjects 2 Through 5 Years

Completed Phase 3 Results posted Last updated 28 June 2023

What this trial tests

Phase 3 trial testing ELX/TEZ/IVA in Cystic Fibrosis in 83 participants. Completed in 3 June 2022.

Timeline

19 November 2020

Primary endpoint
3 June 2022

3 June 2022

Quick facts

Lead sponsor	Vertex Pharmaceuticals Incorporated
Phase	Phase 3
Status	Completed
Study type	INTERVENTIONAL
Allocation	non randomized
Design	sequential
Masking	none
Primary purpose	treatment
Enrollment	83
Start date	19 November 2020
Primary completion	3 June 2022
Estimated completion	3 June 2022
Sites	22 locations across United Kingdom, Germany, Canada, Australia, United States

Drugs / interventions tested

ELX/TEZ/IVA — full drug profile →
IVA — full drug profile →

Conditions studied

Cystic Fibrosis — all drugs for Cystic Fibrosis →

Sponsor

Vertex Pharmaceuticals Incorporated — full company profile →

Who can join

Adults 2 to 5, any sex, with Cystic Fibrosis. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Part A: Observed Pre-dose Concentration (Ctrough) of ELX,TEZ,IVA, and Relevant Metabolites Primary · From Day 1 through Day 15

Day 1: ELX

Group	Value	95% CI
Part A: ELX/TEZ/IVA	0.00	± 0.00

Day 8: ELX

Group	Value	95% CI
Part A: ELX/TEZ/IVA	3.44	± 2.09

Day 15: ELX

Group	Value	95% CI
Part A: ELX/TEZ/IVA	3.69	± 2.11

Day 1: ELX-M23

Group	Value	95% CI
Part A: ELX/TEZ/IVA	0.00	± 0.00

Day 8: ELX-M23

Group	Value	95% CI
Part A: ELX/TEZ/IVA	2.39	± 1.65

Day 15: ELX-M23

Group	Value	95% CI
Part A: ELX/TEZ/IVA	2.47	± 1.65

Day 1: TEZ

Group	Value	95% CI
Part A: ELX/TEZ/IVA	0.00	± 0.00

Day 8: TEZ

Group	Value	95% CI
Part A: ELX/TEZ/IVA	1.86	± 1.07

Part A: Safety and Tolerability as Assessed by Number of Participants With Treatment- Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs) Primary · From Day 1 up to Day 43

Participants with TEAEs

Group	Value	95% CI
Part A: ELX/TEZ/IVA	15

Participants with SAEs

Group	Value	95% CI
Part A: ELX/TEZ/IVA	0

Part B: Safety and Tolerability as Assessed by Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs) Primary · From Day 1 up to Week 28

Participants with TEAEs

Group	Value	95% CI
Part B: ELX/TEZ/IVA	74

Participants with SAEs

Group	Value	95% CI
Part B: ELX/TEZ/IVA	2

Part B: Observed Pre-dose Plasma Concentration (Ctrough) of ELX,TEZ,IVA and Relevant Metabolites Secondary · From Day 1 through Week 16

Day 15: ELX

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	2.91	± 1.38
Part B: ELX/TEZ/IVA (≥14 kg)	3.87	± 2.75

Week 4: ELX

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	3.13	± 1.90
Part B: ELX/TEZ/IVA (≥14 kg)	3.56	± 2.19

Week 12: ELX

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	2.48	± 1.65
Part B: ELX/TEZ/IVA (≥14 kg)	3.49	± 2.22

Week 16: ELX

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	3.01	± 1.11
Part B: ELX/TEZ/IVA (≥14 kg)	3.18	± 2.19

Day 15: ELX-M23

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	1.85	± 1.12
Part B: ELX/TEZ/IVA (≥14 kg)	2.33	± 1.87

Week 4: ELX-M23

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	2.32	± 2.01
Part B: ELX/TEZ/IVA (≥14 kg)	2.22	± 1.66

Week 12: ELX-M23

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	1.48	± 1.27
Part B: ELX/TEZ/IVA (≥14 kg)	2.17	± 1.69

Week 16: ELX-M23

Group	Value	95% CI
Part B: ELX/TEZ/IVA (≥10 kg to <14 kg)	1.73	± 0.828
Part B: ELX/TEZ/IVA (≥14 kg)	1.94	± 1.58

Part B: Absolute Change in Sweat Chloride (SwCl) Secondary · From Baseline through Week 24

Sweat samples were collected using an approved collection device.

Group	Value	95% CI
Part B: ELX/TEZ/IVA	-57.9	-61.3 – -54.6

Part B: Absolute Change in Lung Clearance Index 2.5 (LCI 2.5) Secondary · From Baseline through Week 24

The LCI2.5 index is the number of lung turnovers required to reduce the end tidal inert gas concentration to 1/40th of its starting values and is calculated by dividing the sum of exhaled tidal breaths (cumulative exhaled volume (CEV)) by simultaneously measured functional residual capacity (FRC). An LCI of 7.5 and below is normal; values greater than 7.5 are abnormal. LCI is able to detect abnormalities in lung function earlier than more traditional modalities such as spirometry.

Group	Value	95% CI
Part B: ELX/TEZ/IVA	-0.83	-1.01 – -0.66

Adverse events — posted to ClinicalTrials.gov

Time frame: Day 1 Through Safety Follow-up Visit (up to Day 43 for Part A, up to Week 28 for Part B). Reporting threshold: 5%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Part A: ELX/TEZ/IVA

Serious: 0/18 (0%)

Deaths: 0/18

Part B: ELX/TEZ/IVA

Serious: 2/75 (3%)

Deaths: 0/75

Serious adverse events (4 terms)

Reaction	System	Part A: ELX/TEZ/IVA	Part B: ELX/TEZ/IVA
Anal incontinence	Gastrointestinal disorders	—	—
Infective pulmonary exacerbation of cystic fibrosis	Infections and infestations	—	—
Abnormal behaviour	Psychiatric disorders	—	—
Urinary incontinence	Renal and urinary disorders	—	—

Other adverse events (32 terms — click to expand)

Reaction	System	Part A: ELX/TEZ/IVA	Part B: ELX/TEZ/IVA
Cough	Respiratory, thoracic and mediastinal disorders	—	—
Pyrexia	General disorders	—	—
Rhinorrhoea	Respiratory, thoracic and mediastinal disorders	—	—
Vomiting	Gastrointestinal disorders	—	—
COVID-19	Infections and infestations	—	—
Nasal congestion	Respiratory, thoracic and mediastinal disorders	—	—
Rash	Skin and subcutaneous tissue disorders	—	—
Upper respiratory tract infection	Infections and infestations	—	—
Decreased appetite	Metabolism and nutrition disorders	—	—
Infective pulmonary exacerbation of cystic fibrosis	Infections and infestations	—	—
Alanine aminotransferase increased	Investigations	—	—
SARS-CoV-2 test positive	Investigations	—	—
Headache	Nervous system disorders	—	—
Constipation	Gastrointestinal disorders	—	—
Nasopharyngitis	Infections and infestations	—	—
Abdominal discomfort	Gastrointestinal disorders	—	—
Diarrhoea	Gastrointestinal disorders	—	—
Abdominal pain	Gastrointestinal disorders	—	—
Aspartate aminotransferase increased	Investigations	—	—
Gamma-glutamyltransferase increased	Investigations	—	—
Irritability	Psychiatric disorders	—	—
Productive cough	Respiratory, thoracic and mediastinal disorders	—	—
Scratch	Injury, poisoning and procedural complications	—	—
Skin abrasion	Injury, poisoning and procedural complications	—	—
Hyperamylasaemia	Metabolism and nutrition disorders	—	—
Hyperlipasaemia	Metabolism and nutrition disorders	—	—
Product taste abnormal	Product Issues	—	—
Sputum increased	Respiratory, thoracic and mediastinal disorders	—	—
Papule	Skin and subcutaneous tissue disorders	—	—
Pruritus	Skin and subcutaneous tissue disorders	—	—
Rash erythematous	Skin and subcutaneous tissue disorders	—	—
Urticaria	Skin and subcutaneous tissue disorders	—	—

Most-reported serious reactions: Anal incontinence, Infective pulmonary exacerbation of cystic fibrosis, Abnormal behaviour, Urinary incontinence.

Data from ClinicalTrials.gov NCT04537793 adverse events section.

Sponsor's own description

This study will evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and efficacy of elexacaftor (ELX)/tezacaftor (TEZ)/ivacaftor (IVA) triple combination therapy in CF subjects 2 through 5 years of age.

Publications & conference data

6 peer-reviewed publications reference this trial (live from Europe PMC):

Phase 3 Open-Label Clinical Trial of Elexacaftor/Tezacaftor/Ivacaftor in Children Aged 2-5 Years with Cystic Fibrosis and at Least One <i>F508del</i> Allele.
Goralski JL, Hoppe JE, Mall MA, McColley SA, et al · · 2023 · cited 94× · PMID 36921081 · DOI 10.1164/rccm.202301-0084oc
Real-world disparities and ethical considerations with access to CFTR modulator drugs: Mind the gap!
Zampoli M, Morrow BM, Paul G. · · 2023 · cited 46× · PMID 37050905 · DOI 10.3389/fphar.2023.1163391
Corrector therapies (with or without potentiators) for people with cystic fibrosis with class II CFTR gene variants (most commonly F508del).
Southern KW, Murphy J, Sinha IP, Nevitt SJ. · · 2020 · cited 32× · PMID 33331662 · DOI 10.1002/14651858.cd010966.pub3
Corrector therapies (with or without potentiators) for people with cystic fibrosis with class II CFTR gene variants (most commonly F508del).
Heneghan M, Southern KW, Murphy J, Sinha IP, et al · · 2023 · cited 10× · PMID 37983082 · DOI 10.1002/14651858.cd010966.pub4
Dynamic Perfluorinated Gas MRI Shows Improved Lung Ventilation in People with Cystic Fibrosis after Elexacaftor/Tezacaftor/Ivacaftor: An Observational Study.
Goralski JL, Chung SH, Ceppe AS, Powell MZ, et al · · 2022 · cited 10× · PMID 36294480 · DOI 10.3390/jcm11206160
Advancing Therapeutic Strategies for Nonsense-Related Diseases: From Small Molecules to Nucleic Acid-Based Innovations.
Ricci D, Cruciata I, Fiduccia I, Vitale E, et al · · 2025 · cited 7× · PMID 40420818 · DOI 10.1002/iub.70027

Verify or expand the search:

Other trials of ELX/TEZ/IVA

Trials testing the same drug.

NCT06460506 — Evaluation of Long-term Safety and Efficacy of ELX/TEZ/IVA in Cystic Fibrosis Participants 12 Months of Age and Older · Phase 3 · active not recruiting
NCT05882357 — Evaluation of Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) in Cystic Fibrosis (CF) Participants 12 to Less Than 24 Mon · Phase 3 · completed
NCT05331183 — Study to Evaluate Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) Long-term Safety and Efficacy in Subjects Without F508d · Phase 3 · active not recruiting
NCT05274269 — Evaluation of Efficacy and Safety of Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) in Cystic Fibrosis Subjects Without · Phase 3 · completed
NCT05153317 — Evaluation of Long-term Safety and Efficacy of ELX/TEZ/IVA in Cystic Fibrosis (CF) Participants 2 Years and Older · Phase 3 · completed

Other recruiting trials for Cystic Fibrosis

Currently open trials in the same condition.

NCT07437105 — Dose Escalation Study Evaluating the Safety and Pharmacokinetics of VX-272 in Healthy Participants · Phase 1 · recruiting
NCT07283770 — Dose Escalation Study Evaluating the Safety and Pharmacokinetics of VX-581 in Healthy Participants · Phase 1 · recruiting
NCT07274631 — A Cohort for Inflammatory Respiratory Diseases: From Phenotyping to Personalised Medicine · recruiting
NCT06810167 — Assessing Tenapanor as a Treatment of CF-related Constipation. · Phase 3 · recruiting
NCT06962852 — A Long-term Study to Monitor the Health Status of People With Cystic Fibrosis Who Took Part in a Previous Study With BI · Phase 1, PHASE2 · active not recruiting

Other Vertex Pharmaceuticals Incorporated trials

Trials by the same sponsor.

NCT05951205 — Evaluation of Efficacy and Safety of a Single Dose of Exa-cel in Participants With Severe Sickle Cell Disease, βS/ βC Ge · Phase 3 · withdrawn
NCT07501702 — A Phase 2 Study to Evaluate Povetacicept in Adults With Generalized Myasthenia Gravis · Phase 2 · not yet recruiting
NCT07437105 — Dose Escalation Study Evaluating the Safety and Pharmacokinetics of VX-272 in Healthy Participants · Phase 1 · recruiting
NCT07378865 — Evaluation of the Excretion of Suzetrigine Into Breast Milk in Healthy Lactating Female Participants · Phase 1 · recruiting
NCT07349394 — Effect of Vanzacaftor/Tezacaftor/Deutivacaftor (VNZ/TEZ/D-IVA) on the PK of Rosuvastatin in Healthy Participants · Phase 1 · completed

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT04537793 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Vertex Pharmaceuticals Incorporated
Last refreshed: 28 June 2023

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT04537793.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing