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 (NCT03460990) involved 111 people with cystic fibrosis — 57 in one group who received a two-drug combination called TEZ/IVA, and 54 in another group who received a three-drug combination called VX-659/TEZ/IVA (also referred to as the "triple combination"). All participants who started the trial completed it. The trial was primarily measuring changes in lung function, specifically a test called FEV1 — which measures how much air a person can forcefully breathe out in one second — expressed as a percentage of what would normally be expected for someone of that age and size. The reported data shows that, for the primary lung function measure, the TEZ/IVA group had an average change of +0.3 percentage points, while the VX-659/TEZ/IVA triple combination group had an average change of +10.2 percentage points. For a secondary measure — the level of salt (chloride) in sweat, which is a marker commonly tracked in cystic fibrosis — the TEZ/IVA group showed an average change of +1.5 millimoles per litre, while the triple combination group showed an average change of −47.2 millimoles per litre. A questionnaire measuring how participants felt about their respiratory symptoms (scored from 0 to 100, where higher means fewer symptoms) showed an average change of +3.0 points in the TEZ/IVA group and +16.5 points in the triple combination group. Regarding side effects, the reported data shows that 31 out of 57 participants in the TEZ/IVA group and 33 out of 54 in the triple combination group experienced treatment-related side effects of any kind; no serious side effects were recorded in the TEZ/IVA group, while 2 participants in the triple combination group experienced serious side effects. The reported data also includes blood concentration levels of the individual medicines measured during the trial, though the figures varied across the different substances and time points. These drug level measurements were a secondary outcome, and the numbers were reported only for informational purposes as part of the trial's data collection. These are the results as reported to ClinicalTrials.gov. They are not medical advice — always discuss what they mean for you with your doctor.
View full results on ClinicalTrials.gov ↗
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
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 two copies of a specific cystic fibrosis gene change called "F508del" (one inherited from each parent)
- Your lung function test result (measuring how much air you can breathe out in one second) must fall within a specific range — not too low and not too high — based on your age, sex, and height (confirm with trial site for exact values)
Who may not be able to join:
- You have significant scarring of the liver, with or without increased blood pressure in the liver's blood vessels
- You currently have a lung infection caused by certain bacteria or organisms that are known to cause 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 lung, liver, or kidney) or of blood/bone marrow cells
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.
Contact this trial
Australian sites
Contact details sourced from ClinicalTrials.gov. Verify directly with the trial site before attending.
GP referral letter
Print a one-page summary to share with your doctor.
Trial details
Where this trial is recruiting
5 site(s) in Australia. Confirm current status and contact details directly with the trial site.
Primary endpoints
Absolute Change in Percent Predicted Forced Expiratory Volume in 1 Second (ppFEV1)
Can't join this trial?
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.