12 and older, 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.
Absolute Change in Percent Predicted Forced Expiratory Volume in 1 Second (ppFEV1)Primary· From Baseline at Week 4
FEV1 is the volume of air that can forcibly be blown out in one second, after full inspiration.
Group
Value
95% CI
TEZ/IVA
0.4
± 0.9
VX-445/TEZ/IVA TC
10.4
± 0.9
Absolute Change in Sweat Chloride (SwCl)Secondary· From Baseline at Week 4
Sweat samples were collected using an approved collection device.
Group
Value
95% CI
TEZ/IVA
1.7
± 1.8
VX-445/TEZ/IVA TC
-43.4
± 1.7
Absolute Change in Cystic Fibrosis Questionnaire-Revised (CFQ-R) Respiratory Domain ScoreSecondary· From Baseline at Week 4
The CFQ-R is a validated participant-reported outcome measuring health-related quality of life for participants with cystic fibrosis. Respiratory domain assessed respiratory symptoms, score range: 0-100; higher scores indicate fewer symptoms and better health-related quality of life.
Group
Value
95% CI
TEZ/IVA
-1.4
± 2.0
VX-445/TEZ/IVA TC
16.0
± 2.0
Safety and Tolerability as Assessed by Number of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)Secondary· From first dose of study drug in TC treatment period up to 28 days after last dose of study drug or to the completion of study participation date, whichever occurs first (up to Week 8)
Participants with AEs
Group
Value
95% CI
TEZ/IVA
33
VX-445/TEZ/IVA TC
32
Participants with SAEs
Group
Value
95% CI
TEZ/IVA
1
VX-445/TEZ/IVA TC
2
Observed Pre-Dose Concentration (Ctrough) of VX-445, TEZ, TEZ Metabolite (M1-TEZ), and IVASecondary· Day 1 and Week 4
VX-445: Day 1
Group
Value
95% CI
VX-445/TEZ/IVA TC
NA
± NA
VX-445: Week 4
Group
Value
95% CI
VX-445/TEZ/IVA TC
4.84
± 2.59
TEZ: Day 1
Group
Value
95% CI
TEZ/IVA
1.71
± 0.942
VX-445/TEZ/IVA TC
1.60
± 1.03
TEZ: Week 4
Group
Value
95% CI
TEZ/IVA
1.48
± 0.829
VX-445/TEZ/IVA TC
1.89
± 0.974
M1-TEZ: Day 1
Group
Value
95% CI
TEZ/IVA
4.84
± 1.71
VX-445/TEZ/IVA TC
4.76
± 1.78
M1-TEZ: Week 4
Group
Value
95% CI
TEZ/IVA
4.86
± 1.74
VX-445/TEZ/IVA TC
5.28
± 2.04
IVA: Day 1
Group
Value
95% CI
TEZ/IVA
0.652
± 0.399
VX-445/TEZ/IVA TC
0.598
± 0.428
IVA: Week 4
Group
Value
95% CI
TEZ/IVA
0.530
± 0.297
VX-445/TEZ/IVA TC
0.652
± 0.542
Adverse events — posted to ClinicalTrials.gov
Time frame: From first dose of study drug in TC treatment period up to 28 days after last dose of study drug or to the completion of study participation date, whichever occurs first (up to Week 8).
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
TEZ/IVA
Serious: 1/52 (2%)
Deaths: 0/52
VX-445/TEZ/IVA TC
Serious: 2/55 (4%)
Deaths: 0/55
Serious adverse events (2 terms)
Reaction
System
TEZ/IVA
VX-445/TEZ/IVA TC
Infective pulmonary exacerbation of cystic fibrosis
Infections and infestations
—
—
Rash
Skin and subcutaneous tissue disorders
—
—
Other adverse events (14 terms — click to expand)
Reaction
System
TEZ/IVA
VX-445/TEZ/IVA TC
Cough
Respiratory, thoracic and mediastinal disorders
—
—
Haemoptysis
Respiratory, thoracic and mediastinal disorders
—
—
Infective pulmonary exacerbation of cystic fibrosis
This study will evaluate the efficacy of VX-445 in triple combination (TC) with tezacaftor (TEZ) and ivacaftor (IVA) in subjects with cystic fibrosis (CF) who are homozygous for the F508del mutation (F/F)
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
NCT03525444 — A Phase 3 Study of VX-445 Combination Therapy in Subjects With Cystic Fibrosis Heterozygous for the F508del Mutation and
· 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
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: 27 January 2020
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/NCT03525548.