A Study Evaluating the Long-term Safety and Efficacy of VX-121 Combination Therapy

July 20, 2026 updated by: Vertex Pharmaceuticals Incorporated

A Phase 3, Open-label Study Evaluating the Long-term Safety and Efficacy of VX-121/TEZ/D-IVA Combination Therapy in Subjects With Cystic Fibrosis

The purpose of this study is to evaluate the long-term safety, tolerability, and efficacy of VX-121/tezacaftor/deutivacaftor (VX-121/TEZ/D-IVA) in participants with cystic fibrosis.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

822

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
      • Camperdown, Australia
        • Royal Prince Alfred Hospital
      • Chermside, Australia
        • The Prince Charles Hospital
      • Melbourne, Australia
        • Alfred Hospital
      • Nedlands, Australia
        • Institute for Respiratory Health
      • Nedlands, Australia
        • Telethon Kids Institute
      • Parkville, Australia
        • The Royal Children's Hospital
      • South Brisbane, Australia
        • Queensland Children's Hospital
      • South Brisbane, Australia
        • Mater Adult Hospital
      • Westmead, Australia
        • Westmead Hospital
  • Austria
      • Graz, Austria
        • University of Graz
      • Innsbruck, Austria
        • Medizinische Universitat Innsbruck
      • Salzburg, Austria
        • Uniklinikum Salzburg - Universitätsklinik für Pneumologie/Lungenheilkunde
      • Vienna, Austria
        • Medizinische Universitat Wien
  • Belgium
      • Brussels, Belgium
        • Universitair Ziekenhuis Brussel - Campus Jette
      • Brussels, Belgium
        • Cliniques universitaires de Bruxelles Hopital Erasme
      • Ghent, Belgium
        • Universitair Ziekenhuis Gent
      • Leuven, Belgium
        • Universitaire Ziekenhuizen Leuven - Campus Gasthuisberg
      • Woluwe-Saint-Lambert, Belgium
        • Cliniques Universitaires Saint-Luc
  • Canada
      • Calgary, Canada
        • University of Calgary Medical Clinic of the Foothills Medical Centre
      • Edmonton, Canada
        • Stollery Children's Hospital
      • London, Canada
        • St. Joseph's Health Care London
      • Montreal, Canada
        • McGill University Health Centre, Glen Site, Montreal Children's Hospital
      • Montreal, Canada
        • Centre Hospitalier de l'Universite de Montreal (CHUM) Hotel-Dieu
      • Québec, Canada
        • Institut Universitaire de Cardiologie et Pneumologie de Quebec - Universite Laval
      • Vancouver, Canada
        • British Columbia Children's Hospital
      • Vancouver, Canada
        • St. Paul's Hospital
  • Czechia
      • Brno, Czechia
        • Klinika Detskych Infekcnich Nemoci
      • Prague, Czechia
        • Fakultni nemocnice v Motole
  • Denmark
      • Aarhus, Denmark
        • Aarhus University Hospital
      • Copenhagen, Denmark
        • Juliane Marie Center, Rigshospitalet
  • France
      • Bordeaux, France
        • Groupe Hospitaler Pellegrin, CHU De Bordeaux
      • Bron, France
        • CHU Lyon - Hopital Femme Mere-Enfant
      • Créteil, France
        • Centre Hospitalier Intercommunal Creteil
      • Lille, France
        • Institut Cœur Poumon, CHU de Lille
      • Montpellier, France
        • Hopital Arnaud de Villeneuve
      • Nice, France
        • Centre Hospitalier Universitaire (CHU) de Nice - Hopital Pasteur
      • Paris, France
        • Hôpital Robert Debré
      • Paris, France
        • Hopital Cochin
      • Pierre-Bénite, France
        • Centre Hospitalier Lyon Sud
      • Roscoff, France
        • Centre de Perharidy
      • Rouen, France
        • CHU de Rouen - Hôpital Charles Nicolle
      • Strasbourg, France
        • Hôpital de Hautepierre, AX5
      • Suresnes, France
        • Hopital Foch (Suresnes), Hopital Foch, Adultes
      • Tours, France
        • Hôpital Bretonneau
  • Germany
      • Berlin, Germany
        • Charite Paediatric Pulmonology Department
      • Erlangen, Germany
        • Friedrich-Alexander University of Erlangen-Nuremberg, University Children's Hospital
      • Essen, Germany
        • Ruhrlandklinik Westdeutsches Lungenzentrum am Klinikum Essen
      • Essen, Germany
        • Kinderklinik III, Abt. fur Pneumologie
      • Frankfurt, Germany
        • Johann Wolfgang Goethe University
      • Giessen, Germany
        • Justus-Liebig-Universität Gießen Zentrum für Kinderheilkunde und Jugendmedizin
      • Hanover, Germany
        • Medizinische Hochschule Hannover
      • Hanover, Germany
        • Hannover Medical School
      • Jena, Germany
        • Mukoviszidose-Zentrum am Universitätsklinikum Jena, Klinik für Kinder- und Jugendmedizin
      • Mainz, Germany
        • Johannes Gutenberg-Universitaet
      • München, Germany
        • Pneumologisches Studienzentrum Muenchen-West
      • Potsdam, Germany
        • Klinikum Westbrandenburg (CF)
      • Ulm, Germany
        • Universitätsklinikum Ulm, Klinik für Kinder- und Jugendmedizin (CF)
      • Würzburg, Germany
        • Universitätsklinikum Würzburg
  • Greece
      • Thessaloniki, Greece
        • General Hospital of Thessaloniki 'Hippokratio', 3rd Pediatrics Department of Aristotle University of Thessaloniki
      • Thessaloniki, Greece
        • General Hospital of Thessaloniki "Papanikolaou"
  • Hungary
      • Budapest, Hungary
        • National Koranyi Institute for TBC and Pulmonology
      • Törökbálint, Hungary
        • Pulmonology Institute Torokbalint
  • Ireland
      • Cork, Ireland
        • Cork University Hospital
      • Dublin, Ireland
        • Children's Health Ireland at Crumlin
      • Dublin, Ireland
        • Children's Health Ireland at Temple Street
      • Dublin, Ireland
        • St. Vincent's University Hospital
      • Limerick, Ireland
        • University Hospital Limerick (Pediatrics)
  • Israel
      • Jerusalem, Israel
        • Hadassah Medical Organization
      • Petach Tikvah, Israel
        • Schneider Children's Medical Center of Israel
      • Tel Litwinsky, Israel
        • Sheba Medical Center - The Edmond and Lili Safra Children's Hospital
  • Italy
      • Ancona, Italy
        • Azienda Ospedaliero Universitaria Ospedale Riuniti
      • Florence, Italy
        • Azienda Ospedaliero Universitaria Ospedale Pediatrico Meyer
      • Genova, Italy
        • IRCCS Istituto Giannina Gaslini-Ospedale Pediatrico
      • Milan, Italy
        • Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena
      • Milan, Italy
        • Fondazione IRCCS CA' Granda Ospedale Maggiore Policlinico
      • Orbassano, Italy
        • Malattie Apparato Respiratorio 2 - Centro Fibrosi Cistica
      • Potenza, Italy
        • Centro Regionale Fibrosi Cistica, A.O. Ospedale San Carlo
      • Verona, Italy
        • Azienda Ospedaliera di Verona - Ospedale Civile Maggiore
  • Netherlands
      • Amsterdam, Netherlands
        • Academisch Medisch Centrum (Academic Medical Centre)
      • Nijmegen, Netherlands
        • UMC St. Radboud
      • Rotterdam, Netherlands
        • Erasmus Medical Center
      • The Hague, Netherlands
        • HagaZiekenhuis van den Haag
      • Utrecht, Netherlands
        • University Medical Center, Utrecht, Department of Pulmonology and Tuberculosis
  • New Zealand
      • Christchurch, New Zealand
        • Canterbury District Health Board
      • Grafton, New Zealand
        • Starship Children's Hospital
      • Hamilton, New Zealand
        • Waikato Hospital
      • One Tree Hill, New Zealand
        • Greenlane Clinical Centre
  • Norway
      • Bergen, Norway
        • Haukeland Universitetssjukehus (CF)
      • Oslo, Norway
        • Oslo University Hospital, Department of Paediatric Medicine
  • Poland
      • Gdansk, Poland
        • Pediatric Hospital Polanki named of Maciej Płażyński
      • Łomianki, Poland
        • Klinika Mukowiscydozy IMD Oddozial Chorob Pluc Szpzoz IM. Dzieci WarszaWY
  • Portugal
      • Lisbon, Portugal
        • Hospital de Santa Maria
      • Porto, Portugal
        • Hospital São João
      • Porto, Portugal
        • CHP - Hospital de Santo Antonio
  • Spain
      • Barcelona, Spain
        • Hospital Universitari Vall d'Hebron
      • Barcelona, Spain
        • Hospital Saint Joan de Deu
      • Madrid, Spain
        • Hospital Universitario 12 de Octubre
      • Madrid, Spain
        • Hospital Universitario Ramon Y Cajal
      • Murcia, Spain
        • Hospital Virgen de la Arrixaca
      • Sabadell, Spain
        • Corporacio Sanitaria Parc Tauli - Sabadell Hospital Universitari
      • Seville, Spain
        • Hospital Universitario Virgen del Rocio
      • Valencia, Spain
        • Hospital Universitario y Politecnico La Fe
  • Sweden
      • Gothenburg, Sweden
        • Sahlgrenska universitetssjukhuset
      • Lund, Sweden
        • Lund University Skanes Universitetssjukhus
      • Stockholm, Sweden
        • Karolinska Universitetssjukhuset, Huddinge
  • Switzerland
      • Zurich, Switzerland
        • Kinderspital Zuerich
  • United Kingdom
      • Birmingham, United Kingdom
        • Birmingham Heartlands Hospital
      • Bristol, United Kingdom
        • University Hospitals Bristol and Weston NHS Foundation Trust, Bristol Royal Hospital
      • Cambridge, United Kingdom
        • Royal Papworth Hospital NHS Foundation Trust
      • Edinburgh, United Kingdom
        • Western General Hospital
      • Exeter, United Kingdom
        • Royal Devon University Healthcare NHS Foundation Trust
      • Glasgow, United Kingdom
        • Clinical Research Facility, Queen Elizabeth University Hospital
      • Leeds, United Kingdom
        • Leeds General Infirmary
      • Leeds, United Kingdom
        • St. James University Hospital
      • Liverpool, United Kingdom
        • Liverpool Heart and Chest Hospital
      • London, United Kingdom
        • Royal Brompton Hospital
      • London, United Kingdom
        • King's College Hospital
      • London, United Kingdom
        • St. Bartholomew's Hospital
      • Manchester, United Kingdom
        • Wythenshawe Hospital
      • Manchester, United Kingdom
        • Royal Manchester Children's Hospital
      • Newcastle upon Tyne, United Kingdom
        • Clinical Research Facility
      • Penarth, United Kingdom
        • All Wales Adult Cystic Fibrosis Centre, University Hospital Llandough
      • Southampton, United Kingdom
        • Southampton General Hospital
  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35233
        • University of Alabama at Birmingham
    • Arizona
      • Tucson, Arizona, United States, 85724
        • Banner University of Arizona Medical Center
    • Arkansas
      • Little Rock, Arkansas, United States, 72205
        • University of Arkansas for Medical Sciences
    • California
      • Long Beach, California, United States, 90806
        • Miller Children's Hospital / Long Beach Memorial
      • Los Angeles, California, United States, 90027
        • Children's Hospital Los Angeles
      • Oakland, California, United States, 94611
        • Kaiser Permanente
      • Sacramento, California, United States, 95817
        • University of California Davis Medical Center
      • San Francisco, California, United States, 94143
        • University of California San Francisco, Lung Transplant Program
    • Colorado
      • Aurora, Colorado, United States, 80045
        • Children's Hospital of Colorado
      • Denver, Colorado, United States, 80206
        • National Jewish Health
    • Florida
      • Gainesville, Florida, United States, 32610
        • University of Florida, Shands Hospital
      • Hollywood, Florida, United States, 33021
        • Joe DiMaggio Cystic Fibrosis & Pulmonary Center
      • Miami, Florida, United States, 33136
        • University of Miami Miller School of Medicine
      • Orlando, Florida, United States, 32803
        • Central Florida Pulmonary Group,PA
      • Pensacola, Florida, United States, 32514
        • Nemours Children's Specialty Care
      • St. Petersburg, Florida, United States, 33701
        • Johns Hopkins All Children's Hospital Outpatient Care Center
    • Georgia
      • Atlanta, Georgia, United States, 30324
        • The Emory Clinic at Chantilly
      • Augusta, Georgia, United States, 30912
        • Augusta University
    • Idaho
      • Boise, Idaho, United States, 83702
        • St. Luke's Cystic Fibrosis Center of Idaho
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Northwestern Memorial Hospital
    • Indiana
      • Indianapolis, Indiana, United States, 46202
        • Indiana University
      • Indianapolis, Indiana, United States, 46202
        • Riley Hospital for Children at Indiana University Health
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • University of Kansas Medical Center
    • Kentucky
      • Lexington, Kentucky, United States, 40508
        • University of Kentucky
    • Louisiana
      • New Orleans, Louisiana, United States, 70112
        • Tulane Medical Center
    • Maine
      • Portland, Maine, United States, 04102
        • Maine Medical Partners
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Boston Children's Hospital
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital Cystic Fibrosis Center Clinical Research Center
      • Worcester, Massachusetts, United States, 01655
        • UMass Memorial Medical Center
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • Michigan Medicine
      • Detroit, Michigan, United States, 48201
        • Harper University Hospital
      • Grand Rapids, Michigan, United States, 49546
        • Spectrum Health Medical Group Adult Cystic Fibrosis Care Center
    • Minnesota
      • Minneapolis, Minnesota, United States, 55455
        • University of Minnesota
    • Missouri
      • Columbia, Missouri, United States, 65212
        • Childrens Hospital University of Missouri Health Sciences Center
      • 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
      • St Louis, Missouri, United States, 63104
        • Cardinal Glennon Children's Hospital - St. Louis University
    • Montana
      • Billings, Montana, United States, 59101
        • Billings Clinic
    • Nebraska
      • Omaha, Nebraska, United States, 68198
        • Nebraska Medical Center
    • New Hampshire
      • Manchester, New Hampshire, United States, 03104
        • Dartmouth Hitchcock
    • New Jersey
      • Morristown, New Jersey, United States, 07960
        • Morristown Medical Center
    • New York
      • Albany, New York, United States, 12208
        • Albany Medical College, Pulmonary and Critical Care Medicine
      • Buffalo, New York, United States, 14203
        • CF Therapeutics Development Center of Western New York
      • New Hyde Park, New York, United States, 11040
        • Long Island Jewish Medical Center
      • New York, New York, United States, 10032
        • Columbia University Medical Center
      • Syracuse, New York, United States, 13210
        • SUNY Upstate Medical University
      • Valhalla, New York, United States, 10595
        • New York Medical College
    • North Carolina
      • Charlotte, North Carolina, United States, 28207
        • Atrium Health Levine Children's Hospital
      • Winston-Salem, North Carolina, United States, 27104
        • Wake Forest Baptist Health
    • Ohio
      • Akron, Ohio, United States, 44308
        • Akron Children's Hospital
      • Columbus, Ohio, United States, 43205
        • Nationwide Children's Hospital
      • Dayton, Ohio, United States, 45404
        • Dayton Children's Hospital
      • Toledo, Ohio, United States, 43606
        • ProMedica Toledo Hospital/Toledo Children's Hospital/Pediatric Pulmonary & Cystic Fibrosis Center
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73104
        • University of Oklahoma Health Sciences Center
      • Oklahoma City, Oklahoma, United States, 73112
        • Santiago Reyes, M.D.
    • Oregon
      • Portland, Oregon, United States, 97239
        • Oregon Health & Science University
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • Children's Hospital of Philadelphia
      • Pittsburgh, Pennsylvania, United States, 15224
        • UPMC Children's Hospital of Pittsburgh
    • South Carolina
      • Columbia, South Carolina, United States, 29203
        • Prisma Health Richland Campus
    • South Dakota
      • Sioux Falls, South Dakota, United States, 57105
        • Sanford Children's Speciality Clinic
    • Tennessee
      • Knoxville, Tennessee, United States, 37920
        • University of Tennessee Medical Center
      • Nashville, Tennessee, United States, 37232
        • Vanderbilt University Medical Center, Nephrology Clinical Trials Center
    • Texas
      • Dallas, Texas, United States, 75390
        • The University of Texas Southwestern Medical Center
      • Fort Worth, Texas, United States, 76104
        • Cook Children's Health Care System
      • Houston, Texas, United States, 77030
        • Texas Children's Hospital - Baylor College of Medicine
    • Utah
      • Salt Lake City, Utah, United States, 84132
        • University of Utah
    • Vermont
      • Colchester, Vermont, United States, 05446
        • Vermont Lung Center
    • Virginia
      • Charlottesville, Virginia, United States, 22908
        • University of Virginia Health System
    • Washington
      • Seattle, Washington, United States, 98195
        • University of Washington Medical Center
      • Spokane, Washington, United States, 99204
        • Providence Pediatric Pulmonary & Cystic Fibrosis Clinic
    • West Virginia
      • Morgantown, West Virginia, United States, 26506
        • West Virginia University
    • Wisconsin
      • Madison, Wisconsin, United States, 53792
        • University Hospital and UW Health Clinics

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

12 years and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Part A: Completed study drug treatment in a parent study VX20-121-102 (NCT05033080) and VX20-121-103 (NCT05076149); or had study drug interruption(s) in a parent study but did not permanently discontinue study drug, and completed study visits up to the last scheduled visit of the Treatment Period in the parent study
  • Part B: Completed study drug treatment in Part A; or had study drug interruption(s) in Part A, but did not permanently discontinue study drug, and completed study visits up to the last scheduled visit of the Treatment Period of Part A

Key Exclusion Criteria:

  • History of drug intolerance in a parent study
  • Pregnant or breast-feeding females at the time of enrollment in Part A

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: VX-121/TEZ/D-IVA

Part A: Participants will receive VX-121/TEZ/D-IVA once daily for 96 weeks.

Part B: Participants will receive VX-121/TEZ/D-IVA once daily for an additional 48 weeks.
Drug: VX-121/TEZ/D-IVA
Fixed-dose combination tablets 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
Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time Frame: From Baseline up to Week 148
From Baseline up to Week 148

Secondary Outcome Measures

Outcome Measure
Time Frame
Absolute Change From Baseline in Percent Predicted Forced Expiratory Volume in 1 Second (ppFEV1)
Time Frame: From Baseline up to Week 144
From Baseline up to Week 144
Absolute Change From Baseline in Sweat Chloride (SwCl)
Time Frame: From Baseline up to Week 144
From Baseline up to Week 144
Number of Pulmonary Exacerbations (PEx)
Time Frame: From Baseline up to Week 144
From Baseline up to Week 144

Collaborators and Investigators

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

Sponsor

Vertex Pharmaceuticals Incorporated

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)

November 8, 2022

Primary Completion (Estimated)

October 30, 2026

Study Completion (Estimated)

October 30, 2026

Study Registration Dates

First Submitted

June 29, 2022

First Submitted That Met QC Criteria

June 29, 2022

First Posted (Actual)

July 5, 2022

Study Record Updates

Last Update Posted (Actual)

July 21, 2026

Last Update Submitted That Met QC Criteria

July 20, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VX20-121-104
  • 2021-000713-17 (EudraCT Number)
  • 2024-514173-22-00 (Other Identifier: EU CT 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/independent-research/clinical-trial-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

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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