Evaluation of VX-121/Tezacaftor/Deutivacaftor in Cystic Fibrosis (CF) Participants 1 Through 11 Years of Age

May 27, 2026 updated by: Vertex Pharmaceuticals Incorporated

A Phase 3 Study Evaluating the Pharmacokinetics, Safety, and Tolerability of VX-121/Tezacaftor/Deutivacaftor Triple Combination Therapy in Cystic Fibrosis Subjects 1 Through 11 Years of Age

The purpose of this study is to evaluate the pharmacokinetics, safety, tolerability and efficacy of VX-121/tezacaftor/deutivacaftor (VX-121/TEZ/D-IVA) in CF participants with at least 1 triple combination responsive (TCR) mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
210

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Australia
      • Nedlands, Australia
        • The Kids Research Institute Australia
      • North Adelaide, Australia
        • Women's and Children's Hospital
      • Parkville, Australia
        • The Royal Children's Hospital
      • South Brisbane, Australia
        • Queensland Children's Hospital
  • Canada
      • Toronto, Canada
        • The Hospital for Sick Children
      • Vancouver, Canada
        • British Columbia Children's Hospital
  • France
      • Bron, France
        • CHU Lyon - Hopital Femme Mere-Enfant
      • Paris, France
        • Hopital Necker, Enfants Malades
  • Germany
      • Berlin, Germany
        • Charité - Paediatric Pulmonology Department
      • Essen, Germany
        • Universitatsklinikum Essen
      • Hanover, Germany
        • Medizinische Hochschule Hannover
  • Netherlands
      • Rotterdam, Netherlands
        • Erasmus Medical Center / Sophia Children's Hospital
  • New Zealand
      • Grafton, New Zealand
        • Starship Children's Hospital
  • Sweden
      • Gothenburg, Sweden
        • Sahlgrenska Universitetssjukhuset
      • Stockholm, Sweden
        • Karolinska University Hospital - Pulmonology
  • Switzerland
      • Bern, Switzerland
        • Inselspital - Universitaetsspital Bern
      • Zurich, Switzerland
        • Kinderspital Zürich
  • United Kingdom
      • Cardiff, United Kingdom
        • Children and Young Adults Research Unit
      • London, United Kingdom
        • Great Ormond Street Hospital for Children
  • United States
    • California
      • Orange, California, United States, 92868
        • Children's Hospital of Orange County
      • Palo Alto, California, United States, 94304
        • Stanford University Clinical and Translational Research Unit
    • Colorado
      • Aurora, Colorado, United States, 80045
        • Children's Hospital of Colorado
    • Georgia
      • Atlanta, Georgia, United States, 30322
        • The Emory Clinic / Children's Healthcare of Atlanta at Egleston
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Ann & Robert H. Lurie Children's Hospital of Chicago
    • Indiana
      • Indianapolis, Indiana, United States, 46202
        • Riley Hospital for Children at Indiana University Health
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Boston Children's Hospital
    • Minnesota
      • Minneapolis, Minnesota, United States, 55404
        • Children's Respiratory and Critical Care Specialists, P.A., Children's Hospitals and Clinics of Minnesota
    • Missouri
      • Kansas City, Missouri, United States, 64108
        • The Children's Mercy Hospital
      • St Louis, Missouri, United States, 63110
        • Washington University School of Medicine / St. Louis Children's Hospital
    • New York
      • Lake Success, New York, United States, 11042
        • Cohen Children's Medical Center
    • Ohio
      • Cincinnati, Ohio, United States, 45229
        • Cincinnati Children's Hospital Medical Center
      • Cleveland, Ohio, United States, 44106
        • Rainbow Babies and Children's Hospital/University Hospitals Cleveland Medical Center
      • Columbus, Ohio, United States, 43205
        • Nationwide Children's Hospital
    • Oregon
      • Portland, Oregon, United States, 97239
        • Oregon Health & Science University
    • Pennsylvania
      • Pittsburgh, Pennsylvania, United States, 15224
        • UPMC Children's Hospital of Pittsburgh
    • Texas
      • Houston, Texas, United States, 77030
        • Texas Children's Hospital - Wallace Tower
    • Vermont
      • Colchester, Vermont, United States, 05446
        • Vermont Lung Center
    • Wisconsin
      • Madison, Wisconsin, United States, 53792
        • American Family Childrens Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

1 year to 11 years (Child)

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Participants with stable CF and at least 1 TCR mutation (including F508del) in the CFTR gene

Key Exclusion Criteria:

  • History of solid organ, hematological transplantation, or cancer
  • Hepatic cirrhosis with portal hypertension, moderate hepatic impairment (Child Pugh Score 7 to 9), or severe hepatic impairment (Child Pugh Score 10 to 15)
  • Lung infection with organisms associated with a more rapid decline in pulmonary status

Other protocol defined Inclusion/Exclusion criteria may apply.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Part A: VX-121/TEZ/D-IVA
Participants will receive VX-121/TEZ/D-IVA in the morning.
Drug: VX-121/TEZ/D-IVA
Fixed-dose combination for oral administration.
Other Names:
  • VX-121/VX-661/CTP-656
  • VX-121/VX-661/VX-561
  • VX-121/tezacaftor/deutivacaftor
Experimental: Part B: VX-121/TEZ/D-IVA
Participants will receive VX-121/TEZ/D-IVA in the morning with the dose(s) to be based on the outcome of Part A.
Drug: VX-121/TEZ/D-IVA
Fixed-dose combination for oral administration.
Other Names:
  • VX-121/VX-661/CTP-656
  • VX-121/VX-661/VX-561
  • VX-121/tezacaftor/deutivacaftor

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Part A: Observed Pre-dose Plasma Concentration (Ctrough) of VX-121, TEZ, D-IVA, and Relevant Metabolites
Time Frame: From Day 1 up to Day 22
From Day 1 up to Day 22
Part A: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time Frame: From Day 1 up to Day 50
From Day 1 up to Day 50
Part B: Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time Frame: From Day 1 up to Week 28
From Day 1 up to Week 28

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Part B: Absolute Change in Sweat Chloride (SwCl)
Time Frame: From Baseline Through Week 24
From Baseline Through Week 24
Part B: Observed Pre-dose Plasma Concentration (Ctrough) of VX-121, TEZ, D-IVA, and Relevant Metabolites
Time Frame: From Day 1 up to Week 16
From Day 1 up to Week 16
Part B: Drug Acceptability Assessment Using Modified Facial Hedonic Scale
Time Frame: At Day 1 and Week 24
At Day 1 and Week 24
Part B: Absolute Change in Percent Predicted Forced Expiratory Volume (ppFEV1)
Time Frame: From Baseline Through Week 24
From Baseline Through Week 24
Part B: Number of Pulmonary Exacerbation (PEx)
Time Frame: From Baseline Through Week 24
From Baseline Through Week 24
Part B: Number of CF-Related Hospitalizations
Time Frame: From Baseline Through Week 24
From Baseline Through Week 24
Part B: Absolute Change in Cystic Fibrosis Questionnaire-Revised (CFQ-R) Respiratory Domain (RD) Score
Time Frame: From Baseline Through Week 24
From Baseline Through Week 24
Part B: Absolute Change in Body Mass Index (BMI)
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in BMI-for-age Z-score
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Weight
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Weight-for-age Z-score
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Weight-for-length
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Weight-for-length Z-score
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Height
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Height-for-age Z-score
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Length
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Absolute Change in Length-for-age Z-score
Time Frame: From Baseline at Week 24
From Baseline at Week 24
Part B: Proportion of Participants With SwCl <60 millimole per liter (mmol/L)
Time Frame: From Baseline Through Week 24
From Baseline Through Week 24
Part B: Proportion of Participants With SwCl <30 mmol/L
Time Frame: From Baseline Through Week 24
From Baseline Through Week 24

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Vertex Pharmaceuticals Incorporated

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 21, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2030

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2030

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 13, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 13, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 16, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 28, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • VX21-121-105
  • 2024-513754-29-00 (Other Identifier: EU Trial (CTIS) Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

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/

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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