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Cystic FibrosisPhase 3NCT05444257

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

A Phase 3 study testing VX-121/TEZ/D-IVA in people with Cystic Fibrosis, run by Vertex Pharmaceuticals Incorporated at 195 sites in 23 countries.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
Search all trials

Trial summary

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. Read more about this study

Who is it for?
Ages 12 years and older
Conditions the study is for
Cystic Fibrosis
What is being tested?
VX-121/TEZ/D-IVA
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
822 participants
Where
195 sitesin 23 countries
Study dates
8 Nov 2022to 30 Oct 2026
Phase
Phase 3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 12 years and older
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Who may be able to join

  • 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

Who cannot join

  • 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.

Trial locations and contacts

195 sites in 23 countries.

195 sites in 23 countries

United States72 sites

  • Akron Children's Hospital

    Akron, Ohio, 44308

  • Albany Medical College, Pulmonary and Critical Care Medicine

    Albany, New York, 12208

  • Michigan Medicine

    Ann Arbor, Michigan, 48109

  • The Emory Clinic at Chantilly

    Atlanta, Georgia, 30324

  • Augusta University

    Augusta, Georgia, 30912

  • Children's Hospital of Colorado

    Aurora, Colorado, 80045

  • Billings Clinic

    Billings, Montana, 59101

  • University of Alabama at Birmingham

    Birmingham, Alabama, 35233

  • St. Luke's Cystic Fibrosis Center of Idaho

    Boise, Idaho, 83702

  • Massachusetts General Hospital Cystic Fibrosis Center Clinical Research Center

    Boston, Massachusetts, 02114

  • Boston Children's Hospital

    Boston, Massachusetts, 02115

  • CF Therapeutics Development Center of Western New York

    Buffalo, New York, 14203

  • Atrium Health Levine Children's Hospital

    Charlotte, North Carolina, 28207

  • University of Virginia Health System

    Charlottesville, Virginia, 22908

  • Northwestern Memorial Hospital

    Chicago, Illinois, 60611

  • Vermont Lung Center

    Colchester, Vermont, 05446

  • Childrens Hospital University of Missouri Health Sciences Center

    Columbia, Missouri, 65212

  • Prisma Health Richland Campus

    Columbia, South Carolina, 29203

  • Nationwide Children's Hospital

    Columbus, Ohio, 43205

  • The University of Texas Southwestern Medical Center

    Dallas, Texas, 75390

  • Dayton Children's Hospital

    Dayton, Ohio, 45404

  • National Jewish Health

    Denver, Colorado, 80206

  • Harper University Hospital

    Detroit, Michigan, 48201

  • Cook Children's Health Care System

    Fort Worth, Texas, 76104

  • University of Florida, Shands Hospital

    Gainesville, Florida, 32610

  • Spectrum Health Medical Group Adult Cystic Fibrosis Care Center

    Grand Rapids, Michigan, 49546

  • New York Medical College

    Hawthorne, New York, 10532

  • Joe DiMaggio Cystic Fibrosis & Pulmonary Center

    Hollywood, Florida, 33021

  • Texas Children's Hospital - Baylor College of Medicine

    Houston, Texas, 77030

  • Indiana University

    Indianapolis, Indiana, 46202

  • Riley Hospital for Children at Indiana University Health

    Indianapolis, Indiana, 46202

  • University of Kansas Medical Center

    Kansas City, Kansas, 66160

  • The Children's Mercy Hospital

    Kansas City, Missouri, 64108

  • University of Tennessee Medical Center

    Knoxville, Tennessee, 37920

  • University of Kentucky

    Lexington, Kentucky, 40508

  • University of Arkansas for Medical Sciences

    Little Rock, Arkansas, 72205

  • Miller Children's Hospital / Long Beach Memorial

    Long Beach, California, 90806

  • Children's Hospital Los Angeles

    Los Angeles, California, 90027

  • University Hospital and UW Health Clinics

    Madison, Wisconsin, 53792

  • Dartmouth Hitchcock

    Manchester, New Hampshire, 03104

  • University of Miami Miller School of Medicine

    Miami, Florida, 33136

  • University of Minnesota

    Minneapolis, Minnesota, 55455

  • West Virginia University

    Morgantown, West Virginia, 26506

  • Morristown Medical Center

    Morristown, New Jersey, 07960

  • Vanderbilt University Medical Center, Nephrology Clinical Trials Center

    Nashville, Tennessee, 37232

  • Long Island Jewish Medical Center

    New Hyde Park, New York, 11040

  • Tulane Medical Center

    New Orleans, Louisiana, 70112

  • Columbia University Medical Center

    New York, New York, 10032

  • Kaiser Permanente

    Oakland, California, 94611

  • University of Oklahoma Health Sciences Center

    Oklahoma City, Oklahoma, 73104

  • Santiago Reyes, M.D.

    Oklahoma City, Oklahoma, 73112

  • Nebraska Medical Center

    Omaha, Nebraska, 68114

  • Central Florida Pulmonary Group,PA

    Orlando, Florida, 32803

  • Nemours Children's Specialty Care

    Pensacola, Florida, 32514

  • Children's Hospital of Philadelphia

    Philadelphia, Pennsylvania, 19104

  • UPMC Children's Hospital of Pittsburgh

    Pittsburgh, Pennsylvania, 15224

  • Maine Medical Partners

    Portland, Maine, 04102

  • Oregon Health & Science University

    Portland, Oregon, 97239

  • University of California Davis Medical Center

    Sacramento, California, 95817

  • University of Utah

    Salt Lake City, Utah, 84132

  • University of California San Francisco, Lung Transplant Program

    San Francisco, California, 94143

  • University of Washington Medical Center

    Seattle, Washington, 98195

  • Sanford Children's Speciality Clinic

    Sioux Falls, South Dakota, 57105

  • Providence Pediatric Pulmonary & Cystic Fibrosis Clinic

    Spokane, Washington, 99204

  • Cardinal Glennon Children's Hospital - St. Louis University

    St Louis, Missouri, 63104

  • Washington University School of Medicine / St. Louis Children's Hospital

    St Louis, Missouri, 63110

  • Johns Hopkins All Children's Hospital Outpatient Care Center

    St. Petersburg, Florida, 33701

  • SUNY Upstate Medical University

    Syracuse, New York, 13210

  • ProMedica Toledo Hospital/Toledo Children's Hospital/Pediatric Pulmonary & Cystic Fibrosis Center

    Toledo, Ohio, 43606

  • Banner University of Arizona Medical Center

    Tucson, Arizona, 85724

  • Wake Forest Baptist Health

    Winston-Salem, North Carolina, 27104

  • UMass Memorial Medical Center

    Worcester, Massachusetts, 01655

Other trials in United States

United Kingdom17 sites

  • Birmingham Heartlands Hospital

    Birmingham

  • University Hospitals Bristol and Weston NHS Foundation Trust, Bristol Royal Hospital

    Bristol

  • Royal Papworth Hospital NHS Foundation Trust

    Cambridge

  • Western General Hospital

    Edinburgh

  • Royal Devon University Healthcare NHS Foundation Trust

    Exeter

  • Clinical Research Facility, Queen Elizabeth University Hospital

    Glasgow

  • Leeds General Infirmary

    Leeds

  • St. James University Hospital

    Leeds

  • Liverpool Heart and Chest Hospital

    Liverpool

  • King's College Hospital

    London

  • Royal Brompton Hospital

    London

  • St. Bartholomew's Hospital

    London

  • Royal Manchester Children's Hospital

    Manchester

  • Wythenshawe Hospital

    Manchester

  • Clinical Research Facility

    Newcastle upon Tyne

  • All Wales Adult Cystic Fibrosis Centre, University Hospital Llandough

    Penarth

  • Southampton General Hospital

    Southampton

Other trials in United Kingdom

France14 sites

  • Groupe Hospitaler Pellegrin, CHU De Bordeaux

    Bordeaux

  • CHU Lyon - Hopital Femme Mere-Enfant

    Bron

  • Centre Hospitalier Intercommunal Creteil

    Créteil

  • Institut Cœur Poumon, CHU de Lille

    Lille

  • Hopital Arnaud de Villeneuve

    Montpellier

  • Centre Hospitalier Universitaire (CHU) de Nice - Hopital Pasteur

    Nice

  • Hopital Cochin

    Paris

  • Hopital Robert Debre

    Paris

  • Centre Hospitalier Lyon Sud

    Pierre-Bénite

  • Centre de Perharidy

    Roscoff

  • CHU de Rouen - Hopital Charles Nicolle

    Rouen

  • Hôpital de Hautepierre, AX5

    Strasbourg

  • Hopital Foch (Suresnes), Hopital Foch, Adultes

    Suresnes

  • Hopital Bretonneau

    Tours

Other trials in France

Germany14 sites

  • Charite Paediatric Pulmonology Department

    Berlin

  • Friedrich-Alexander University of Erlangen-Nuremberg, University Children's Hospital

    Erlangen

  • Kinderklinik III, Abt. fur Pneumologie

    Essen

  • Ruhrlandklinik Westdeutsches Lungenzentrum am Klinikum Essen

    Essen

  • Johann Wolfgang Goethe University

    Frankfurt

  • Justus-Liebig-Universität Gießen Zentrum für Kinderheilkunde und Jugendmedizin

    Giessen

  • Hannover Medical School

    Hanover

  • Medizinische Hochschule Hannover

    Hanover

  • Mukoviszidose-Zentrum am Universitätsklinikum Jena, Klinik für Kinder- und Jugendmedizin

    Jena

  • Johannes Gutenberg-Universitaet

    Mainz

  • Pneumologisches Studienzentrum Muenchen-West

    München

  • Klinikum Westbrandenburg (CF)

    Potsdam

  • Universitätsklinikum Ulm, Klinik für Kinder- und Jugendmedizin (CF)

    Ulm

  • Universitätsklinikum Würzburg

    Würzburg

Other trials in Germany

Australia9 sites

  • Royal Prince Alfred Hospital

    Camperdown

  • The Prince Charles Hospital

    Chermside

  • Alfred Hospital

    Melbourne

  • Institute for Respiratory Health

    Nedlands

  • Telethon Kids Institute

    Nedlands

  • The Royal Children's Hospital

    Parkville

  • Mater Adult Hospital

    South Brisbane

  • Queensland Children's Hospital

    South Brisbane

  • Westmead Hospital

    Westmead

Other trials in Australia

Canada8 sites

  • University of Calgary Medical Clinic of the Foothills Medical Centre

    Calgary

  • Stollery Children's Hospital

    Edmonton

  • St. Joseph's Health Care London

    London

  • Centre Hospitalier de l'Universite de Montreal (CHUM) Hotel-Dieu

    Montreal

  • McGill University Health Centre, Glen Site, Montreal Children's Hospital

    Montreal

  • Institut Universitaire de Cardiologie et Pneumologie de Quebec - Universite Laval

    Québec

  • British Columbia Children's Hospital

    Vancouver

  • St. Paul's Hospital

    Vancouver

Other trials in Canada

Italy8 sites

  • Azienda Ospedaliero Universitaria Ospedale Riuniti

    Ancona

  • Azienda Ospedaliero Universitaria Ospedale Pediatrico Meyer

    Florence

  • IRCCS Istituto Giannina Gaslini-Ospedale Pediatrico

    Genova

  • Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena

    Milan

  • Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico

    Milan

  • Malattie Apparato Respiratorio 2 - Centro Fibrosi Cistica

    Orbassano

  • Centro Regionale Fibrosi Cistica, A.O. Ospedale San Carlo

    Potenza

  • Azienda Ospedaliera di Verona - Ospedale Civile Maggiore

    Verona

Other trials in Italy

Spain8 sites

  • Hospital Saint Joan de Deu

    Barcelona

  • Hospital Universitari Vall d'Hebron

    Barcelona

  • Hospital Universitario 12 de Octubre

    Madrid

  • Hospital Universitario Ramon y Cajal

    Madrid

  • Hospital Virgen de la Arrixaca

    Murcia

  • Corporacio Sanitaria Parc Tauli - Sabadell Hospital Universitari

    Sabadell

  • Hospital Universitario Virgen del Rocio

    Seville

  • Hospital Universitario y Politecnico La Fe

    Valencia

Other trials in Spain

Belgium5 sites

  • Cliniques Universitaires de Bruxelles Hopital Erasme

    Brussels

  • Universitair Ziekenhuis Brussel - Campus Jette

    Brussels

  • Universitair Ziekenhuis Gent

    Ghent

  • Universitaire Ziekenhuizen Leuven - Campus Gasthuisberg

    Leuven

  • Cliniques Universitaires Saint-Luc

    Woluwe-Saint-Lambert

Other trials in Belgium

Ireland5 sites

  • Cork University Hospital

    Cork

  • Children's Health Ireland at Crumlin

    Dublin

  • Children's Health Ireland at Temple Street

    Dublin

  • St. Vincent's University Hospital

    Dublin

  • University Hospital Limerick (Pediatrics)

    Limerick

Other trials in Ireland

Netherlands5 sites

  • Academisch Medisch Centrum (Academic Medical Centre)

    Amsterdam

  • UMC St. Radboud

    Nijmegen

  • Erasmus Medical Center

    Rotterdam

  • HagaZiekenhuis van den Haag

    The Hague

  • University Medical Center, Utrecht, Department of Pulmonology and Tuberculosis

    Utrecht

Other trials in Netherlands

Austria4 sites

  • University of Graz

    Graz

  • Medizinische Universität Innsbruck

    Innsbruck

  • Uniklinikum Salzburg - Universitätsklinik für Pneumologie/Lungenheilkunde

    Salzburg

  • Medizinische Universität Wien

    Vienna

Other trials in Austria

New Zealand4 sites

  • Canterbury District Health Board

    Christchurch

  • Starship Children's Hospital

    Grafton

  • Waikato Hospital

    Hamilton

  • Greenlane Clinical Centre

    One Tree Hill

Other trials in New Zealand

Israel3 sites

  • Hadassah Medical Organization

    Jerusalem

  • Clalit Health Services

    Petach Tikvah

  • Safra Children's Hospital

    Tel HaShomer

Other trials in Israel

Portugal3 sites

  • Hospital de Santa Maria

    Lisbon

  • CHP - Hospital de Santo Antonio

    Porto

  • Hospital Sao Joao

    Porto

Other trials in Portugal

Sweden3 sites

  • Sahlgrenska Universitetssjukhuset

    Gothenburg

  • Lund University Skanes Universitetssjukhus

    Lund

  • Karolinska Universitetssjukhuset, Huddinge

    Stockholm

Other trials in Sweden

Czechia2 sites

  • Klinika Detskych Infekcnich Nemoci

    Brno

  • Fakultni nemocnice v Motole

    Prague

Other trials in Czechia

Denmark2 sites

  • Aarhus University Hospital

    Aarhus

  • Juliane Marie Center, Rigshospitalet

    Copenhagen

Other trials in Denmark

Greece2 sites

  • General Hospital of Thessaloniki "Papanikolaou"

    Thessaloniki

  • General Hospital of Thessaloniki 'Hippokratio', 3rd Pediatrics Department of Aristotle University of Thessaloniki

    Thessaloniki

Other trials in Greece

Hungary2 sites

  • National Koranyi Institute for TBC and Pulmonology

    Budapest

  • Pulmonology Institute Torokbalint

    Törökbálint

Other trials in Hungary

Norway2 sites

  • Haukeland Universitetssjukehus (CF)

    Bergen

  • Oslo University Hospital, Department of Paediatric Medicine

    Oslo

Other trials in Norway

Poland2 sites

  • Pediatric Hospital Polanki named of Maciej Płażyński

    Gdansk

  • Klinika Mukowiscydozy IMD Oddozial Chorob Pluc Szpzoz IM. Dzieci WarszaWY

    Łomianki

Other trials in Poland

Switzerland1 site

  • Kinderspital Zuerich

    Zurich

Other trials in Switzerland

About this study

Official title: 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.

Conditions
Cystic Fibrosis
Being tested
VX-121/TEZ/D-IVA
Medical subject headings
Cystic Fibrosis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • VX-121/TEZ/D-IVADrug

    Also called VX-121/VX-661/CTP-656, VX-121/VX-661/VX-561, VX-121/tezacaftor/deutivacaftor

    Fixed-dose combination tablets for oral administration.

Study groups in NCT05444257
Study groupRoleWhat they receive
VX-121/TEZ/D-IVAExperimentalPart 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.
Receives: Drug: VX-121/TEZ/D-IVA

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)

    Measured: From Baseline up to Week 148

Secondary outcomes (3)

  1. Absolute Change From Baseline in Percent Predicted Forced Expiratory Volume in 1 Second (ppFEV1)

    Measured: From Baseline up to Week 144

  2. Absolute Change From Baseline in Sweat Chloride (SwCl)

    Measured: From Baseline up to Week 144

  3. Number of Pulmonary Exacerbations (PEx)

    Measured: From Baseline up to Week 144

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Jul 2022
  2. Study start8 Nov 2022
  3. Primary completion30 Oct 2026 (estimated)
  4. Study completion30 Oct 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
822 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05444257
Sponsor's protocol ID
VX20-121-104
Other IDs
2021-000713-17, 2024-514173-22-00
Status last verified
Oct 2026
First submitted
29 Jun 2022
Last updated
9 Oct 2026
Results posted
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No: 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

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing VX-121/TEZ/D-IVA in people with Cystic Fibrosis, run by Vertex Pharmaceuticals Incorporated at 195 sites in 23 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 195 sites in United States, United Kingdom, France, Germany, Australia and 18 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

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). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05444257.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Oct 2026.

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