Not yet recruiting

Long‑Term Safety and Tolerability Study of Oral KT‑621 in Adults with Uncontrolled Moderate‑to‑Severe Eosinophilic Asthma

Verified siteInvestigationalNo placebo

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

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

The study focuses on Uncontrolled Moderate to Severe Eosinophilic Asthma, a type of asthma in which breathing is frequently difficult and a specific white blood cell called an eosinophil is often elevated, causing inflammation in the airways. Participants will receive an oral tablet containing KT-621, which is taken by mouth once daily. The medication is being tested to see how it works over an extended period in people whose asthma has not been well controlled with existing treatments.

The main goal is to evaluate the long‑term safety and tolerability of the drug. After enrollment, participants will continue taking the tablet for up to one year, returning for regular check‑ins where doctors will look for any side effects and will assess lung function using a test called FEV1, which measures how much air can be exhaled forcefully in one second. Symptom control will be measured with a short questionnaire known as the ACQ-5, and overall quality of life related to asthma will be evaluated with the AQLQ(S) questionnaire. These visits help ensure participants are monitored closely while remaining on the study medication.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

Step 1
Baseline visit and assessments
You attend the first study visit after joining the trial. this visit is called the baseline visit.
The study team will perform tests to measure your lung function, such as pre‑bronchodilator FEV1 (the amount of air you can force out of your lungs in one second before using a medication that opens the airways) and post‑bronchodilator FEV1 (the same measurement after using that medication).
You will also complete questionnaires about your asthma symptoms (ACQ‑5) and your asthma‑related quality of life (AQLQ(S)).
Step 2
Start study medication
After the baseline assessments, you will begin taking the study drug kt‑621.
kt‑621 is an oral tablet taken by mouth.
The dose specified in the study is 0 mg per tablet; you will follow the dosing schedule provided by the study team and continue the medication for up to week 52 (one year).
Step 3
Regular safety monitoring
Throughout the 52‑week period you will be asked to report any new health problems or side effects. these are called treatment‑emergent adverse events (TEAEs) and are recorded from the baseline visit until week 52.
If a serious health problem occurs, it will be recorded as a treatment‑emergent serious adverse event (SAE).
The study team may schedule additional visits or phone contacts to check your safety, but the exact timing is not specified beyond the baseline and week‑52 visits.
Step 4
Final visit at week 52
At the end of the 52‑week period you will return for a final study visit.
The same lung function tests (pre‑ and post‑bronchodilator FEV1) and questionnaires (ACQ‑5 and AQLQ(S)) that were done at baseline will be repeated to see how they have changed.
Blood samples will be taken to measure the concentration of kt‑621 in your plasma.
The study will also summarize any adverse events that occurred during the year.

Who can join the trial?

6 criteria

Must have uncontrolled moderate to severe eosinophilic asthma – a type of asthma that is not well‑controlled with usual medicines and involves high levels of a white‑blood cell called eosinophils.
Must have finished all visits of the earlier parent study up to its end‑of‑treatment visit.
Must be willing and able to attend scheduled visits, follow the treatment plan, give laboratory samples, complete study procedures, and fill out an electronic diary (e‑diary) for the whole study.
Must agree to use birth control as required by the study and local regulations (contraceptive requirements).
Both males and females are allowed to participate.
Participants of any age that the study permits (including children and adults) may be eligible.

Who cannot join the trial?

5 criteria

You cannot join if you had a clinically significant change in health status during the earlier study, meaning a health change that doctors consider important enough to affect safety, study measurements, or your ability to follow study steps.
You cannot join if you experienced an adverse event (AE) in the earlier study that doctors felt could make continued treatment unsafe for you.
You cannot join if you were permanently taken off the earlier study for any reason, known as meeting permanent discontinuation criteria or having the study treatment stopped.
You cannot join if you are a member of the company running the study (Sponsor) or the study site’s research team, or if you are an immediate family member of anyone on that team.
You cannot join if the doctor believes you are unsuitable for any other reason, such as a likely risk of not following the study procedures (noncompliance).

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Responsive
Azienda Ospedaliero-Universitaria Sant Andre
Rome, Italy
Responsive
Cliniques Universitaires Saint-Luc
Woluwe-Saint-Lambert, Belgium
Responsive
Pneumocare
Namur, Belgium

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not yet recruiting

Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

KT-621 is an experimental oral tablet being studied to see if it is safe and well‑tolerated when taken for a long time by people with asthma. In this trial, participants who have already taken KT-621 in an earlier study continue to receive the same medication, and researchers closely monitor them for any side effects or health concerns over an extended period. The goal is to learn whether the drug can be used safely in the long term for managing asthma.

What is already known about the treatment

KT-621 - This medication is taken by mouth as a tablet and is still in the investigational stage, meaning it is not yet approved for general use. It is being studied for people who have uncontrolled moderate to severe eosinophilic asthma, a type of asthma with high levels of a certain white blood cell. KT-621 works by blocking a molecular signal that tells these white blood cells to grow and cause inflammation in the lungs. It belongs to the class of oral small‑molecule anti‑inflammatory drugs that target the immune system.

Investigated diseases

Uncontrolled moderate-to-severe eosinophilic asthma - This is a type of asthma characterized by high levels of eosinophils, a type of white blood cell, in the airways. It causes frequent wheezing, shortness of breath, and coughing that are not well controlled with standard inhaled therapies. Symptoms tend to worsen over time, leading to more frequent flare‑ups and increased need for rescue medication. The inflammation can cause the airways to become increasingly narrow and less responsive to treatment. As the disease progresses, patients may experience greater limitation in daily activities due to persistent breathing difficulty.