Phase 3 Cystic Fibrosis Trial, Completed NCT03559062 Sponsor: Vertex Pharmaceuticals Incorporated Condition: Cystic Fibrosis
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Trial results

AI generated results summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI

According to the results reported on ClinicalTrials.gov, this trial (NCT03559062) enrolled 67 people in total across three groups: 10 received a placebo (a dummy treatment), 54 received a combination called TEZ/IVA (tezacaftor/ivacaftor), and 3 received ivacaftor alone. The trial was looking at a lung function measure called the Lung Clearance Index (LCI2.5) — essentially a test of how efficiently air moves through the lungs, where a lower number generally reflects more even airflow. It also looked at sweat chloride levels (a common marker measured in cystic fibrosis), a quality-of-life questionnaire focused on breathing symptoms, and the number of people who experienced side effects. All measurements were taken over 8 weeks. The reported data shows that, in the TEZ/IVA group, the average LCI2.5 score changed by −0.51 units from the start to week 8. Sweat chloride levels changed by an average of −12.3 mmol/L (millimoles per litre) over the same period. Scores on the respiratory symptoms questionnaire — which runs from 0 to 100, with higher scores meaning fewer symptoms — changed by an average of +2.3 points in the TEZ/IVA group. These figures represent average changes from each participant's starting point; the data for the placebo and ivacaftor-only groups was not reported for these outcome measures. The reported data shows that, when it came to side effects (called adverse events), 8 out of 10 people in the placebo group, 41 out of 54 in the TEZ/IVA group, and 2 out of 3 in the ivacaftor group experienced at least one treatment-emergent adverse event. No serious adverse events were reported in any of the three groups. These are the results as reported to ClinicalTrials.gov. They are not medical advice — always discuss what they mean for you with your doctor.

These are the results as reported to ClinicalTrials.gov, not medical advice. Verify independently with the trial site and discuss what they mean for you with your doctor.

Phase 3 Cystic Fibrosis Trial, Completed

NCT03559062
Completed Phase 3 🇦🇺 Australian site

Who may be able to join

AI generated eligibility summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI

Who might be able to join this trial:

  • You must have a specific genetic makeup related to cystic fibrosis — either two copies of the F508del gene mutation, or one copy of F508del plus another specific type of mutation (confirm with trial site for exact mutation details)
  • Your lung function test result (measuring how much air you can breathe out) must be 70% or above of what is considered normal for your age, sex, and height
  • A specific breathing test called LCI2.5 must show a result of 7.5 or higher, which measures how evenly air moves in and out of your lungs (confirm with trial site)
  • You must be able to swallow tablets

Who may not be able to join:

  • You have serious liver scarring (cirrhosis), with or without increased pressure in the liver's blood vessels
  • Your lungs are colonised with certain bacteria or organisms known to cause a faster decline in lung health (confirm with trial site for specific organisms)
  • You have previously received a transplant of a solid organ (such as a kidney or liver) or a blood/bone marrow transplant

Important: Always verify eligibility with the trial site directly before applying.

Based on publicly available eligibility criteria from ClinicalTrials.gov. Verify directly with the trial site before acting. This is not medical advice.

This is a simplified plain English summary of the eligibility criteria. Full criteria are set by the trial investigators and may include additional requirements not shown here. Never self-exclude from a trial based on this summary. Contact the trial site directly to confirm your eligibility.
Last synced 23 July 2026
Phase 3: approximately ~65% of drugs entering this phase reach regulatory approval, based on published industry-wide historical data. This is not specific to this trial.
Phase success rates shown are historical industry-wide averages based on published data. They are not a prediction for this specific trial or your individual situation.

Contact this trial

Australian sites

Hunter Medical Research Institute (HMRI), New Lambton Heights,
Princess Margaret Hospital for Children, Perth,
Lady Cilento Children's Hospital, South Brisbane,
The Children's Hospital at Westmead, Westmead,

Contact details sourced from ClinicalTrials.gov. Verify directly with the trial site before attending.

GP referral letter

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Trial details

Status
Completed
Phase
Phase 3
Registry
ClinicalTrials.gov
Start date
17 May 2018
Est. completion
21 December 2018

Where this trial is recruiting

🇦🇺 Australia 🇧🇪 Belgium 🇩🇰 Denmark 🇫🇷 France 🇩🇪 Germany 🇮🇪 Ireland 🇵🇱 Poland 🇨🇭 Switzerland 🇬🇧 United Kingdom

4 site(s) in Australia. Confirm current status and contact details directly with the trial site.

Primary endpoints

Absolute Change in Lung Clearance Index 2.5 (LCI2.5) Through Week 8

Can't join this trial?

Expanded access pathways

If this trial is not available to you, other access pathways may exist. In Australia, the TGA Special Access Scheme allows access to unapproved therapeutic goods for individual patients.

TGA Special Access Scheme information

Find other recruiting trials on ClinicalTrials.gov

Data last synced from ClinicalTrials.gov: 23 July 2026. Trial status can change. Always verify current status directly with the trial site before making any decision.

Trial recruitment status can change without notice between our nightly data updates. Always contact the trial site directly to confirm current recruitment status before making any decisions or travel arrangements.

View original record on ClinicalTrials.gov