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Study of VX-121, Tezacaftor, and Deutivacaftor for Children Aged 1-11 with Cystic Fibrosis

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying Cystic Fibrosis, a genetic condition that affects the lungs and digestive system. The study will evaluate a new treatment involving a combination of three medications: VX-121, Tezacaftor, and Deutivacaftor. These medications are taken as a film-coated tablet and are designed to work together to help improve the function of a protein that is defective in people with Cystic Fibrosis.

The purpose of the study is to assess how the body processes these medications and to ensure they are safe and well-tolerated in children aged 1 to 11 years. Participants will be divided into different groups, and the study will be conducted in two parts. In the first part, the focus will be on understanding how the medications are absorbed and processed by the body. In the second part, the safety and tolerability of the treatment will be monitored over a period of 24 weeks.

Throughout the study, participants will receive either the combination of VX-121, Tezacaftor, and Deutivacaftor or a placebo. The study aims to gather information on any side effects and how the treatment affects the symptoms of Cystic Fibrosis. This research is important for developing new therapies that could improve the quality of life for those living with this condition.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, the patient will begin by taking part in a clinical trial designed to evaluate a new treatment for cystic fibrosis. The trial is divided into two parts: Part A and Part B.

    The patient will be required to take a combination of medications orally. These medications include tezacaftor, deutivacaftor, and vanzacaftor in a film-coated tablet form.

  2. Step 2

    Part a: initial treatment phase

    During Part A, the focus is on understanding how the body processes the medications. This involves monitoring the levels of the drugs in the body and assessing their safety and tolerability.

    The patient will take the combination of tezacaftor, deutivacaftor, and vanzacaftor as prescribed by the study protocol.

  3. Step 3

    Part b: extended treatment phase

    In Part B, the patient will continue to take the same combination of medications for a longer period, up to 24 weeks.

    The goal is to further evaluate the safety and tolerability of the treatment over an extended period.

  4. Step 4

    Monitoring and assessments

    Throughout the trial, the patient will undergo regular assessments to monitor their health and the effects of the medication. This includes checking vital signs, conducting laboratory tests, and performing other necessary evaluations.

    The patient will also be asked to report any side effects or changes in their condition.

  5. Step 5

    Completion of the trial

    At the end of the trial, the patient will have a final assessment to evaluate the overall impact of the treatment.

    The results will contribute to understanding the effectiveness and safety of the new treatment for cystic fibrosis.

Who can join the trial?

11 criteria

  • The patient or their legally authorized representative must sign and date an informed consent form, which is a document that explains the study and confirms their agreement to participate.
  • Female patients who can have children must have a negative pregnancy test before starting the study.
  • Patients who can have children and are sexually active must follow specific birth control guidelines during the study.
  • The patient and their representative must understand the study requirements and be able to follow the instructions given by the study team.
  • Patients must be between 2 and 11 years old, depending on the specific group they are in for the study.
  • The patient's weight must be within certain limits set for the study.
  • The patient must have a confirmed diagnosis of **Cystic Fibrosis (CF)**, a genetic condition that affects the lungs and digestive system.
  • The patient must have at least one specific genetic mutation in the **CFTR gene**, which is related to CF.
  • The patient must have stable CF symptoms at the start of the study, meaning their condition is not worsening.
  • The patient must be willing to continue their regular CF medications, except for certain CF treatments, during the study.
  • For some groups, the patient must be able to swallow tablets.

Who cannot join the trial?

8 criteria

  • Patients who have a medical condition other than Cystic Fibrosis that might interfere with the study.
  • Patients who are not within the specified age range for the study.
  • Patients who are not able to follow the study procedures or take the study medication as required.
  • Patients who are pregnant or breastfeeding.
  • Patients who have participated in another clinical trial recently.
  • Patients who have a history of allergic reactions to any of the study medications.
  • Patients who have a serious medical condition that could affect their safety during the study.
  • Patients who are taking medications that might interfere with the study drugs.
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Investigated drugs

  • VX-121

    is a medication being studied for its effects on cystic fibrosis. It is part of a triple combination therapy aimed at improving the function of a protein that is defective in people with this condition. The study is looking at how the body processes this medication and its safety when used with other drugs.

  • Tezacaftor

    is another medication included in the triple combination therapy for cystic fibrosis. It works by helping the defective protein reach the cell surface, where it can function more effectively. The study is assessing how well this medication is tolerated by young patients.

  • Deutivacaftor

    is the third medication in the triple combination therapy. It is designed to enhance the activity of the protein affected by cystic fibrosis, helping to improve lung function and other symptoms. The trial is evaluating its safety and how it interacts with the other medications in the combination.

What is already known about the treatment

VX-121/Tezacaftor/Deutivacaftor – This medication is administered orally and is currently being studied in clinical trials for its effectiveness in treating cystic fibrosis in children aged 1 to 11 years. The combination is in the phase 3 stage of clinical trials, focusing on its pharmacokinetics, safety, and tolerability. It is designed to help improve lung function and reduce symptoms in patients with cystic fibrosis by targeting and modulating the defective protein responsible for the disease. VX-121, tezacaftor, and deutivacaftor work together to enhance the function of the CFTR protein, which is faulty in cystic fibrosis patients, thereby improving the movement of salt and water in and out of cells. This medication falls under the pharmacological classification of CFTR modulators.

Investigated diseases

Cystic Fibrosis – Cystic Fibrosis is a genetic disorder that affects the respiratory and digestive systems. It is caused by mutations in the CFTR gene, leading to the production of thick and sticky mucus. This mucus can clog the airways, causing breathing difficulties and frequent lung infections. Over time, the buildup of mucus can also affect the pancreas, leading to digestive problems and poor nutrient absorption. The disease is progressive, meaning symptoms typically worsen over time. It is most commonly diagnosed in childhood, but symptoms can vary widely among individuals.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IIITrial ID2024-513754-29-00Protocol codeVX21-121-105Estimated enrolment130 patientsSponsorVertex Pharmaceuticals Inc.

sourced from the EU Clinical Trials Register and site verification

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