Efficacy of Tezepelumab in Treating Bronchiolitis Obliterans Syndrome in Allogeneic Stem Cell Transplant Recipients

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What is this study about?

The study focuses on Bronchiolitis obliterans syndrome, a rare, long‑lasting lung problem that can develop after an allogeneic hematopoietic stem cell transplantation. This condition causes the small airways in the lungs to become narrowed and scarred, leading to breathing difficulties and frequent flare‑ups called exacerbations. Participants will receive the investigational medicine Tezepelumab (code name TEZEPELUMAB), an antibody designed to block a protein that signals inflammation in the airways.

The purpose of the trial is to see whether regular treatment with Tezepelumab can reduce the number of bronchial exacerbations over a year compared with usual care. After a screening visit, eligible individuals will begin a series of sub‑cutaneous injections (given under the skin) of the study drug for 12 months, with regular clinic visits to monitor health, record any worsening of symptoms, and adjust other medicines such as corticosteroids (anti‑inflammatory drugs). The study will not involve any changes to standard medical care other than the study medication.

During the year, participants will undergo simple breathing tests, including spirometry (a test that measures how fast and how much air can be exhaled) and plethysmography (a test that measures total lung volume). Blood and sputum samples will be taken to check levels of eosinophils (a type of white blood cell) and IgE antibodies, which are linked to allergic inflammation. Questionnaires about breathlessness, cough, and overall quality of life will also be completed to help evaluate any improvement in daily functioning.

1 baseline assessment

after joining the study, a baseline visit is scheduled. during this visit, medical history is recorded and the diagnosis of bronchiolitis obliterans syndrome is confirmed.

a series of tests are performed, including spirometry (a breathing test that measures air flow), pre‑bronchodilator plethysmography (a test that measures lung volumes), and oscillometry (a test that measures airway resistance).

blood is drawn to measure eosinophil count and total IgE level, and sputum may be collected to assess eosinophilia.

the participant completes several questionnaires that evaluate respiratory symptoms, such as the ACQ6 score, the BCSS, and the SGRQ.

an exhaled‑air sample is collected for analysis of volatile organic compounds.

2 first injection of tezepelumab

the participant receives a subcutaneous injection of tezepelumab using a pre‑filled syringe that contains a 210 mg/mL solution. the administered dose is 210 mg.

the injection is performed by a qualified health professional.

3 regular follow‑up visits and ongoing treatment

follow‑up visits are scheduled throughout the 12‑month treatment period. at each visit the participant receives another subcutaneous injection of tezepelumab (210 mg). the exact interval between injections is defined by the study protocol but is not detailed in the provided information.

at every visit the participant records any new or worsening respiratory symptoms and any hospitalizations that last longer than 48 hours.

the same set of assessments performed at baseline is repeated periodically: lung function tests (spirometry, plethysmography, oscillometry), blood and sputum samples, and the three questionnaires (ACQ6, BCSS, SGRQ).

exhaled‑air samples are also collected during the study to monitor changes in volatile organic compounds.

4 monitoring for safety and side effects

throughout the trial the participant is asked to report any adverse events, such as reactions at the injection site or signs of infection.

hospital admissions or the need for additional corticosteroid treatment are documented as part of the safety monitoring.

5 final evaluation at 12 months

after completing 12 months of treatment, a final study visit is conducted.

the participant undergoes the same comprehensive assessments as at baseline: lung function tests, blood and sputum analysis, exhaled‑air sampling, and completion of the three questionnaires.

the number of bronchial exacerbations during the treatment year is compared with the number that occurred in the year before treatment started.

all collected data are used to determine the effectiveness of tezepelumab in reducing exacerbations and improving respiratory health.

Who Can Join the Study?

Adult age: You must be 18 years old or older.
Allogeneic bone marrow or stem cell transplant: You must have received a transplant of blood‑forming stem cells that came from another person.
Time since transplant: At least 3 years must have passed since the transplant was performed.
Bronchiolitis obliterans syndrome (BOS): You must have a new, lasting blockage of the small airways after the transplant, shown by lung function tests that indicate reduced airflow (a low FEV1/FVC ratio and a drop of more than 10% in the amount of air you can force out in one second, called FEV1, within the past two years, together with other measurements of lung volume).
Exacerbation profile: You must have experienced two or more moderate to severe lung flare‑ups (worsening of breathing problems) in the last 12 months.
Optimal inhaled therapy: You must be using inhaled medicines that include at least one long‑acting bronchodilator (a drug that keeps the airways open) and one inhaled corticosteroid (a drug that reduces airway inflammation).
Stable systemic immunosuppressive regimen: Your dose of medicines that suppress the immune system must have been unchanged for at least the past 4 weeks.
National health insurance coverage: You must be covered by your country’s national health insurance plan.
Signed consent form: You must sign a consent form agreeing to take part in the study.

Who Cannot Join the Study?

People who need to increase medicines that suppress the immune system, especially because they have active graft‑versus‑host disease (GVHD), cannot join.
Those with severe GVHD causing skin to become hard and tight (similar to scleroderma) that makes the required under‑the‑skin injection impossible or very difficult are excluded.
Anyone whose lung function test called FEV1 (the amount of air you can force out in one second) is less than 20% of the normal value for their age and size cannot participate.
People who are in prison, otherwise deprived of liberty, or who are under legal guardianship are not eligible.
Individuals who have not signed the study consent form are excluded.
Anyone diagnosed with a worm infection (helminth) within the past six months that has not been treated or did not respond to standard treatment cannot take part.
Patients who develop a lung or airway infection while in the study (including bacterial, viral, fungal, or certain mycobacterial infections) are not allowed to continue.
People who have a recorded history of an immune system reaction called immune complex disease (Type III hypersensitivity) after receiving any biologic medication are excluded.
Women who are pregnant, breastfeeding, or currently feeding a baby (lactating) cannot be enrolled.
Anyone who is allergic (hypersensitivity) to the study drug tezelumab or any of its inactive ingredients (excipients) must not participate.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country	Status
Centre Hospitalier Universitaire De Bordeaux	Bordeaux	France
Centre Hospitalier Universitaire De Lille	Lille	France

Other Sites

Site Name	City	Country
Hospital Foch	Suresnes	France
Centre Hospitalier Universitaire De Caen Normandie	Caen	France
Bzyzwzqi Uinqgnrhuw Hihpudjp Cutizh	Besançon	France
Agvciidxjx Paaptynq Hbjewypk Dr Psaja	Paris	France

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	01.07.2026

Trial locations

Investigated drugs:

Tezepelumab

Tezspire is a specially made protein (a monoclonal antibody) that blocks a substance in the body called TSLP, which can cause inflammation in the airways. In this study, it is given as a liquid injection under the skin. The medicine is being tested to see if it can lower the number of worsening episodes of chronic bronchial disease that can happen after a stem‑cell transplant.

Investigated diseases:

Bronchiolitis

Bronchiolitis obliterans syndrome – Bronchiolitis obliterans syndrome is a condition where the small airways of the lungs become scarred and narrowed. It often develops after an injury to the lung tissue, such as after a stem cell transplant. The scarring reduces airflow, leading to increasing shortness of breath and cough. Over time the narrowing can become more extensive, making breathing progressively harder. Symptoms may worsen slowly or in steps as the airway damage spreads.

Trial ID:

2024-516796-33-00

Trial Phase:

Therapeutic exploratory (Phase II)

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Efficacy of Tezepelumab in Treating Bronchiolitis Obliterans Syndrome in Allogeneic Stem Cell Transplant Recipients

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?