A Phase 3 Study of VX-121 Combination Therapy in Participants With Cystic Fibrosis (CF) Heterozygous for F508del and a Minimal Function Mutation (F/MF)
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT05033080 |
Recruitment Status :
Active, not recruiting
First Posted : September 2, 2021
Last Update Posted : December 23, 2022
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Cystic Fibrosis | Drug: VX-121/TEZ/D-IVA Drug: ELX/TEZ/IVA Drug: IVA Drug: Placebo (matched to VX-121/TEZ/D-IVA) Drug: Placebo (matched to ELX/TEZ/IVA) Drug: Placebo (matched to IVA) | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 436 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | A Phase 3, Randomized, Double-blind, Controlled Study Evaluating the Efficacy and Safety of VX-121 Combination Therapy in Subjects With Cystic Fibrosis (CF) Who Are Heterozygous for F508del and a Minimal Function Mutation (F/MF) |
Actual Study Start Date : | September 14, 2021 |
Estimated Primary Completion Date : | June 2023 |
Estimated Study Completion Date : | January 2024 |

Arm | Intervention/treatment |
---|---|
Experimental: 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 tablets for oral administration.
Other Names:
Drug: Placebo (matched to ELX/TEZ/IVA) Placebo matched to ELX/TEZ/IVA for oral administration. Drug: Placebo (matched to IVA) Placebo matched to IVA for oral administration. |
Active Comparator: ELX/TEZ/IVA
Participants will receive ELX/TEZ/IVA in the morning and IVA in the evening.
|
Drug: ELX/TEZ/IVA
Fixed-dose combination tablets for oral administration.
Other Names:
Drug: IVA Tablet for oral administration.
Other Names:
Drug: Placebo (matched to VX-121/TEZ/D-IVA) Placebo matched to VX-121/TEZ/D-IVA for oral administration. |
- Absolute Change From Baseline in Percent Predicted Forced Expiratory Volume in 1 Second (ppFEV1) Through Week 24 [ Time Frame: From Baseline Through Week 24 ]
- Absolute Change From Baseline in Sweat Chloride (SwCl) Through Week 24 [ Time Frame: From Baseline Through Week 24 ]
- Proportion of Participants With SwCl <60 Millimole per Liter (mmol/L) Through Week 24 (Pooled With Data From Study VX20-121-103) [ Time Frame: From Baseline Through Week 24 ]
- Proportion of Participants With SwCl <30 mmol/L Through Week 24 (Pooled With Data From Study VX20-121-103) [ Time Frame: From Baseline Through Week 24 ]

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 12 Years and older (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Key Inclusion Criteria:
- Heterozygous for F508del and a minimal function mutation (F/MF genotype)
- Forced expiratory volume in 1 second (FEV1) value >=40% and <=90% of predicted mean for age, sex, and height for participants currently receiving ELX/TEZ/IVA therapy; FEV1 >=40% and <=80% for participants not currently receiving ELX/TEZ/IVA
Key Exclusion Criteria:
- History of solid organ or hematological transplantation
- 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
- Pregnant or breast-feeding females
Other protocol defined Inclusion/Exclusion criteria may apply

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05033080

Responsible Party: | Vertex Pharmaceuticals Incorporated |
ClinicalTrials.gov Identifier: | NCT05033080 |
Other Study ID Numbers: |
VX20-121-102 2021-000712-31 ( EudraCT Number ) |
First Posted: | September 2, 2021 Key Record Dates |
Last Update Posted: | December 23, 2022 |
Last Verified: | April 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
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 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Cystic Fibrosis Fibrosis Pathologic Processes Pancreatic Diseases Digestive System Diseases Lung Diseases Respiratory Tract Diseases |
Genetic Diseases, Inborn Infant, Newborn, Diseases Ivacaftor Elexacaftor Chloride Channel Agonists Membrane Transport Modulators Molecular Mechanisms of Pharmacological Action |