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Study on the Effects of Dirocaftor, Posenacaftor, and Nesolicaftor for Adults with Cystic Fibrosis

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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 the effectiveness and safety of three investigational medications: Dirocaftor, Posenacaftor, and Nesolicaftor. These medications are taken as hard capsules and are designed to help improve lung function in people with cystic fibrosis. The trial will also include a placebo, which is a substance with no active medication, to compare the effects of the investigational drugs.

The purpose of the study is to assess how well these medications work over an 8-week period in adults aged 18 and older who have cystic fibrosis with specific rare genetic mutations. Participants will be randomly assigned to receive either the investigational medications or a placebo. The study is designed as a crossover trial, meaning that participants will receive both the investigational medications and the placebo at different times during the study. This helps researchers understand the effects of the medications more clearly.

Throughout the study, participants will have regular check-ups to monitor their health and any changes in their condition. These check-ups will include tests to measure lung function, sweat chloride levels, and body weight, as well as assessments of overall health and any side effects. The study aims to provide valuable information on the potential benefits and safety of Dirocaftor, Posenacaftor, and Nesolicaftor for people living with cystic fibrosis.

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, eligibility is confirmed based on specific criteria, including age, diagnosis of cystic fibrosis, and health stability.

    Participants must have completed a prior study and meet health and lifestyle requirements, such as being a non-smoker.

  2. Step 2

    Treatment phase

    The treatment phase involves taking medications in the form of hard capsules. These include posenacaftor, dirocaftor, and nesolicaftor, all administered orally.

    The treatment lasts for 8 weeks, with regular monitoring of health indicators such as lung function, sweat chloride levels, and body weight.

  3. Step 3

    Monitoring and assessments

    Throughout the study, assessments are conducted to monitor the effectiveness and safety of the treatment.

    These assessments include measuring lung function, sweat chloride levels, body weight, and completing a questionnaire about respiratory health.

  4. Step 4

    Safety evaluations

    Safety evaluations are performed to identify any adverse effects from the treatment.

    These evaluations include laboratory tests, physical examinations, and monitoring of vital signs and heart activity.

  5. Step 5

    Completion of the study

    At the end of the 8-week treatment period, final assessments are conducted to evaluate the overall impact of the treatment.

    Participants' data is analyzed to determine the effectiveness and safety of the medications.

Who can join the trial?

7 criteria

  • Must be a male or female who has completed the HIT-CF Organoid Study and is at least 18 years old on the date of giving consent to participate.
  • Must have a confirmed diagnosis of Cystic Fibrosis (CF). This can be shown by either a sweat chloride value of 60 mmol/L or higher, which is a test that measures the amount of salt in sweat, or by having two CF-causing genetic mutations along with chronic lung or digestive problems.
  • Must have a stable CF condition, meaning no major changes in health, as judged by the study doctor, for at least 28 days before starting the study.
  • Must have a lung function test result, called FEV1, between 40% and 90% of what is expected for a healthy person. FEV1 stands for Forced Expiratory Volume in one second, which measures how much air you can forcefully exhale in one second.
  • Must have a Body Mass Index (BMI) between 16 and 30. BMI is a number calculated from a person's weight and height to assess if they are underweight, normal weight, overweight, or obese.
  • Must not smoke or use tobacco for at least 30 days before the screening and must agree not to smoke or use tobacco during the study.
  • Must be chosen by a team that knows the study details, either based on how their cells respond to the study treatment or by random selection.

Who cannot join the trial?

5 criteria

  • Patients who do not have **Cystic Fibrosis** cannot participate. **Cystic Fibrosis** is a genetic condition that affects the lungs and digestive system.
  • Patients who are not within the specified age range cannot participate. The study is for children aged 3 to 4 years old.
  • Patients who do not belong to the specified clinical trial group cannot participate. This group is determined by specific medical criteria.
  • Both male and female patients are eligible, so gender is not an exclusion factor.
  • Patients who are not considered part of a vulnerable population cannot participate. A vulnerable population includes individuals who may have additional health or social challenges.
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Investigated drugs

  • Dirocaftor

    is a medication being studied for its potential to help people with cystic fibrosis. It works by targeting specific proteins in the body that are affected by the disease, aiming to improve their function and help alleviate symptoms.

  • Posenacaftor

    is another medication included in the study for cystic fibrosis. It is designed to work alongside other treatments to enhance their effectiveness, focusing on improving the health of the lungs and other affected organs.

  • Nesolicaftor

    is part of the combination therapy being tested in the trial. It aims to support the other medications by further improving the function of proteins that are not working properly in people with cystic fibrosis, potentially leading to better overall health outcomes.

What is already known about the treatment

  • Dirocaftor

    This medication is administered orally and is currently being studied in clinical trials for its effectiveness in treating cystic fibrosis. It is not yet widely available in medical practice, as it is still under investigation. Dirocaftor is designed to help improve lung function in patients with cystic fibrosis by targeting and modulating the CFTR protein, which is defective in these patients. It belongs to the pharmacological class of CFTR modulators.

  • Posenacaftor

    Administered orally, this medication is part of ongoing clinical trials aimed at treating cystic fibrosis. It is not yet approved for general medical use. Posenacaftor works by enhancing the function of the CFTR protein, which is crucial for maintaining proper lung function in cystic fibrosis patients. It is classified as a CFTR modulator.

  • Nesolicaftor

    This oral medication is currently being evaluated in clinical trials for its potential to treat cystic fibrosis. It is not yet available for routine medical use. Nesolicaftor acts by correcting the malfunctioning CFTR protein, which is responsible for the symptoms of cystic fibrosis. It is part of the CFTR modulator class of drugs.

Investigated diseases

Cystic Fibrosis – Cystic Fibrosis is a genetic disorder that primarily affects the lungs and digestive system. It is caused by mutations in the CFTR gene, leading to the production of thick and sticky mucus that can clog airways and trap bacteria, resulting in frequent lung infections. Over time, this can cause damage to the lungs and reduce lung function. The disease also affects the pancreas, leading to difficulties in digesting food and absorbing nutrients. Symptoms often include persistent coughing, frequent lung infections, and poor growth or weight gain despite a good appetite. The progression of the disease varies among individuals, with some experiencing more severe symptoms than others.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2022-500410-26-01Protocol codeHIT-CF-001Estimated enrolment52 patientsSponsorUniversitair Medisch Centrum Utrecht

sourced from the EU Clinical Trials Register and site verification

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