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CFTR Modulator

VX-121 Combination Therapy for Cystic Fibrosis

Phase 3
Waitlist Available
Research Sponsored by Vertex Pharmaceuticals Incorporated
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
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
Screening 3 weeks
Treatment Varies
Follow Up from day 1 up to week 100
Awards & highlights
No Placebo-Only Group
Pivotal Trial

Study Summary

This trialstudies the safety and effectiveness of a drug for people with cystic fibrosis over the long-term.

Who is the study for?
This trial is for individuals with cystic fibrosis who previously participated in certain VX-121 studies and completed the treatment or visits, even if they had interruptions. It's not open to pregnant or breastfeeding women or those who couldn't tolerate the drug before.Check my eligibility
What is being tested?
The study is testing the long-term safety and effectiveness of a combination therapy called VX-121/TEZ/D-IVA designed for people with cystic fibrosis to see how well it works over an extended period.See study design
What are the potential side effects?
While specific side effects are not listed here, participants will be monitored for any adverse reactions to ensure the long-term safety and tolerability of the VX-121 combination therapy.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
I completed or was part of the VX20-121-102 or VX20-121-103 study without permanently stopping the study drug.


Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~from day 1 up to week 100
This trial's timeline: 3 weeks for screening, Varies for treatment, and from day 1 up to week 100 for reporting.

Treatment Details

Study Objectives

Outcome measures can provide a clearer picture of what you can expect from a treatment.
Primary outcome measures
Safety and Tolerability as Assessed by Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Secondary outcome measures
Absolute Change From Baseline in Percent Predicted Forced Expiratory Volume in 1 Second (ppFEV1)
Absolute Change From Baseline in Sweat Chloride (SwCl)
Number of Pulmonary Exacerbations (PEx)

Awards & Highlights

No Placebo-Only Group
All patients enrolled in this study will receive some form of active treatment.
Pivotal Trial
The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.

Trial Design

1Treatment groups
Experimental Treatment
Group I: VX-121/TEZ/D-IVAExperimental Treatment1 Intervention
Participants will receive VX-121/TEZ/D-IVA once daily.
First Studied
Drug Approval Stage
How many patients have taken this drug
Not yet FDA approved

Find a Location

Who is running the clinical trial?

Vertex Pharmaceuticals IncorporatedLead Sponsor
238 Previous Clinical Trials
31,339 Total Patients Enrolled
123 Trials studying Cystic Fibrosis
16,841 Patients Enrolled for Cystic Fibrosis

Media Library

VX-121/TEZ/D-IVA (CFTR Modulator) Clinical Trial Eligibility Overview. Trial Name: NCT05444257 — Phase 3
Cystic Fibrosis Research Study Groups: VX-121/TEZ/D-IVA
Cystic Fibrosis Clinical Trial 2023: VX-121/TEZ/D-IVA Highlights & Side Effects. Trial Name: NCT05444257 — Phase 3
VX-121/TEZ/D-IVA (CFTR Modulator) 2023 Treatment Timeline for Medical Study. Trial Name: NCT05444257 — Phase 3

Frequently Asked Questions

These questions and answers are submitted by anonymous patients, and have not been verified by our internal team.

How extensive is the current participation in this research program?

"This medical trial requires 850 individuals, meeting the prerequisites, to sign up and take part. Participants have multiple locations from which they can choose; such as Children's Hospital of Colorado in Aurora, Colorado or ProMedica Toledo Hospital/Toledo Children's Hospital/Pediatric Pulmonary & Cystic fibrosis Center in Toledo, Ohio."

Answered by AI

Are there any remaining openings to partake in this trial?

"Clinicaltrials.gov reports that this medical investigation, initially posted on November 8th 2022 is still actively enlisting patients. It was most recently modified a few weeks ago on the 28th of November."

Answered by AI

Is VX-121/TEZ/D-IVA safe for administering to people?

"VX-121/TEZ/D-IVA has been evaluated and rated a 3 due to its Phase 3 status, with clinical data providing evidence of efficacy and safety."

Answered by AI
~459 spots leftby Oct 2025