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

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

210

Phase

  • 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 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
        • Universitätsklinikum 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 Zurich
  • 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

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
Intervention / Treatment
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

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

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

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)

June 21, 2022

Primary Completion (Estimated)

June 30, 2030

Study Completion (Estimated)

June 30, 2030

Study Registration Dates

First Submitted

June 13, 2022

First Submitted That Met QC Criteria

June 13, 2022

First Posted (Actual)

June 16, 2022

Study Record Updates

Last Update Posted (Actual)

May 28, 2026

Last Update Submitted That Met QC Criteria

May 27, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID 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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