A Phase 1 interventional study of VX-272 and Placebo in Cystic Fibrosis, sponsored by Vertex Pharmaceuticals Incorporated. Recruiting at 1 site in United States. Open to participants aged 18 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-23.
Sponsored by Vertex Pharmaceuticals Incorporated · Phase 1, Interventional, and Treatment
Among 43 studies testing tezacaftor in Cystic Fibrosis — 4 open to participants now, 7 under way, 2 of them phase 3. tezacaftor · Cystic Fibrosis.
Among the 43 studies testing tezacaftor in Cystic Fibrosis, this one is the 14th largest by planned enrollment, is one of 2 that started in 2026, is one of 5 in phase 1, and was the 42nd registered.
1,619 studies on the registry are indexed under Cystic Fibrosis; 199 are open to participants now.
This study's planned enrollment of 160 is above the median of 36 across 1,051 interventional studies indexed under Cystic Fibrosis.
Browse Cystic Fibrosis studies →4 of the 43 studies testing tezacaftor in Cystic Fibrosis are open now, in 2 countries. Each count lists the studies.
tezacaftor: first FDA approval 2024 (ALYFTREK), first EMA approval 2018. What it is approved for, and how studies give it, is on its page →
Of the 154 Cystic Fibrosis studies recruiting now, 95 (62%) set no upper age limit and 43 (28%) stop at 75 or younger; 84 take children under 18; 41 take healthy volunteers.
This study: 18 Years to 55 Years · all sexes · healthy volunteers too.
The full table on the hub →43 studies; the count open now beside each. This study's row is marked.
First in 2012; this study’s year is marked. 2 started in 2026.
Median enrollment 100 across the 43 interventional studies. Of the 36 that completed or were terminated, 31 (86%) have results posted.
39 of 43 have an industry lead sponsor. The 5 most frequent:
Vertex Pharmaceuticals Incorporated is the lead sponsor of 249 studies on the registry; 17 are open to participants now.
Of its 106 completed or terminated interventional studies of FDA-regulated products, 53 (50%) have results posted.
119 studies in Cystic Fibrosis by Vertex Pharmaceuticals Incorporated: 3 open now, 8 under way, 5 of them phase 3. Of 107 finished, 79 (74%) have results posted.
Among the 119 studies in Cystic Fibrosis by Vertex Pharmaceuticals Incorporated, this one is the 34th largest by planned enrollment of the 110 interventional ones, is one of 3 that started in 2026, is one of 24 in phase 1, and was the 118th registered.
Vertex Pharmaceuticals Incorporated’s Cystic Fibrosis studies by the year they started, since 2007.
4 of the studies testing tezacaftor in Cystic Fibrosis that are under way reach primary completion within a year, 2 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT05331183Phase 3Vertex Pharmaceuticals IncorporatedStudy to Evaluate Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) Long-term Safety and Efficacy in Subjects Without F508del | 2027-04-06 |
| NCT06460506Phase 3Vertex Pharmaceuticals IncorporatedEvaluation of Long-term Safety and Efficacy of ELX/TEZ/IVA in Cystic Fibrosis Participants 12 Months of Age and Older | 2027-09-30 |
| NCT07437105Vertex Pharmaceuticals IncorporatedDose Escalation Study Evaluating the Safety and Pharmacokinetics of VX-272 in Healthy Participants | 2027-06-26 |
| NCT07283770Vertex Pharmaceuticals IncorporatedEvaluation of VX-581 in Healthy Participants and in Participants With Cystic Fibrosis | 2027-07-12 |
Among the 43 studies testing tezacaftor in Cystic Fibrosis, from their registry updates:
Among Vertex Pharmaceuticals Incorporated’s 119 in Cystic Fibrosis:
The purpose of this study is to evaluate the safety, tolerability and pharmacokinetics of single and multiple ascending doses of VX-272 in combination with deutivacaftor (D-IVA) with or without tezacaftor (TEZ) in healthy subjects.
The study is being conducted to evaluate the safety, tolerability and pharmacokinetics of single and multiple ascending doses of VX-272 in healthy participants. Additionally, VX-272 will be administered in combination with D-IVA with or without TEZ. Note: This clinical trial information was submitted voluntarily under the applicable law and, therefore, certain submission deadlines may not apply. (That is, clinical trial information for this applicable clinical trial was submitted under section 402(j)(4)(A) of the Public Health Service Act and 42 CFR 11.60 and is not subject to the deadlines established by sections 402(j)(2) and (3) of the Public Health Service Act or 42 CFR 11.24 and 11.44.)
Key Inclusion Criteria:
Key Exclusion Criteria:
Other protocol defined Inclusion/Exclusion criteria may apply.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will be randomized to receive a single dose of VX-272.
Drug: VX-272
Participants will be randomized to receive a single dose of placebo matched to VX-272.
Drug: Placebo
Participants will be randomized to receive multiple doses of VX-272.
Drug: VX-272
Participants will be randomized to receive multiple doses of placebo matched to VX-272.
Drug: Placebo
Participants will be randomized to receive VX-272 in combination with TEZ/D-IVA or D-IVA.
Drug: VX-272 · Drug: Tezacaftor · Drug: Deutivacaftor
Participants will be randomized to receive placebo matched to VX-272 in combination with TEZ/D-IVA or D-IVA.
Drug: Placebo · Drug: Tezacaftor · Drug: Deutivacaftor
Suspension for Oral Administration.
Suspension for Oral Administration.
Tablet for oral administration.
Also known as: TEZ, VX-661
Tablet for oral administration.
Also known as: D-IVA, VX-561
Part A: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time frame: From Signing of Informed Consent Form (ICF) up to Safety Follow Up (Up to Day 34)
Part B: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time frame: From Signing of Informed Consent Form (ICF) up to Safety Follow Up (Up to Day 66)
Part C: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time frame: From Signing of Informed Consent Form (ICF) up to Safety Follow Up (Up to Day 66)
Part A: Maximum Observed Plasma Concentration (Cmax) of VX-272
Time frame: From Day 1 up to Day 34
Part A: Area Under the Concentration Versus Time Curve From the Time of Dosing Up to 24 Hours (AUC0-24h) of VX-272
Time frame: From Day 1 up to Day 34
Part B: Maximum Observed Plasma Concentration (Cmax) of VX-272
Time frame: From Day 1 up to Day 66
Part B: Area Under the Concentration Versus Time Curve From the Time of Dosing Up to 24 Hours (AUC0-24h) of VX-272
Time frame: From Day 1 up to Day 66
Part C: Maximum Observed Plasma Concentration (Cmax) of VX-272 and its Metabolites
Time frame: From Day 1 up to Day 66
Part C: Maximum Observed Plasma Concentration (Cmax) of TEZ and D-IVA and their Metabolites
Time frame: From Day 1 up to Day 28
Part C: Area Under the Concentration Versus Time Curve From the Time of Dosing Up to 24 Hours (AUC0-24h) of VX-272 and its Metabolites
Time frame: From Day 1 up to Day 66
Part C: Area Under the Concentration Versus Time Curve From the Time of Dosing Up to 24 Hours (AUC0-24h) of TEZ and D-IVA and their Metabolites
Time frame: From Day 1 up to Day 28
Plan to share: No — Details on Vertex data sharing criteria and process for requesting access can be found at: https://www.vrtx.com/our-science/clinical-trials-data-sharing/
No publications or documents are linked to this record.
Started Feb 2026 (actual). Primary completion is estimated for Jun 2027, 16 months after the start.
Of 39 industry-sponsored phase 1 interventional studies under Cystic Fibrosis, half reached primary completion within 8 months of starting (the median), counting those still running; a quarter within 2 and three quarters within 16. This study's planned 16 months is above that.
Counting every sponsor, half of 62 studies reached it within 10 months; a quarter within 5 and three quarters within 34.
How these figures are worked out, and which studies are left out of them.
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Studies of the drugs tested here: Tezacaftor · Ivacaftor
Vertex Pharmaceuticals Incorporated →