Study of Benralizumab Safety, Pharmacokinetics, and Efficacy in Children with Eosinophilic Disease

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What is this study about?

The trial focuses on children who have an Eosinophilic Disease, a condition in which a type of white blood cell called an eosinophil is unusually high and can cause inflammation in organs such as the lungs, skin, or gut. The medication being tested is benralizumab, which is given as a small amount injected just under the skin (a subcutaneous injection). The purpose of the study is to see how safe the drug is for children and how the body absorbs and uses it.

Participants will receive the injection at set times over several months and will visit the clinic for regular check‑ups, blood tests, and simple questionnaires about symptoms. Researchers will watch for any unwanted effects, measure the amount of drug in the blood, and track changes in eosinophil levels. The study also includes groups of children with specific forms of the condition, such as EGPA and HES, to see if the drug helps keep the disease in remission (meaning symptoms are minimal or absent) and to record any relapses or flares (times when symptoms get worse). All information gathered will help determine whether benralizumab can be used safely and effectively in this young population.

1 enrollment and consent

the patient signs the informed consent form and is officially entered into the trial.

initial demographic information and medical history are recorded.

2 baseline assessments

a physical examination is performed.

blood samples are taken to measure eosinophil count and to establish baseline serum concentrations of benralizumab (although the drug has not yet been given).

any required safety laboratory tests are completed.

3 first benralizumab injection

a subcutaneous injection of the benralizumab solution for injection is administered.

the dose is 30 mg (provided as a 30 mg/ml solution).

the injection is given by qualified study staff.

4 scheduled follow‑up visits

the patient returns to the study site at predefined intervals (for example, week 4, week 8, week 12, etc.) for safety monitoring.

at each visit blood is drawn to assess serum concentrations of benralizumab and to measure peripheral blood eosinophil count.

the patient is asked about any adverse events (any unwanted medical occurrences).

5 subsequent benralizumab injections

additional subcutaneous injections of 30 mg benralizumab are given according to the trial schedule.

the exact frequency and total duration are defined by the study protocol.

6 end‑of‑treatment assessment

at the conclusion of the treatment period a final evaluation is performed.

safety is reviewed by recording any adverse events that occurred during the trial.

efficacy measures such as remission status (for the egpa cohort) and changes in eosinophil count are documented.

Who Can Join the Study?

Must be a boy or girl who is at least 6 years old but younger than 18 years old when signing the assent form, and a parent or caregiver must also sign the informed consent form.
Must weigh at least 15 kilograms (about 33 pounds).
For the EGPA group, must be taking oral corticosteroids at a dose higher than 0.1 mg per kilogram each day (but not more than 50 mg total per day), and that dose must have stayed the same for at least 4 weeks before the first study visit.
For the EGPA group, if taking immunosuppressive therapy (medicines that lower the activity of the immune system), the dose must have been stable for at least 4 weeks before the first study visit.
For the HES group, must have a confirmed diagnosis of hypereosinophilic syndrome (HES), meaning a history of high eosinophilia (more than 1500 eosinophil cells per microliter) on two separate tests at least one month apart, with no other known cause, and evidence that the high eosinophils are affecting an organ.
For the HES group, must have active symptoms of HES, or have had a prior flare of the disease, or be judged by the doctor to have disease severity that fits the study.
For the HES group, must have an absolute eosinophil count (AEC) of at least 1000 cells per microliter measured at the first visit.
For the HES group, must have a negative test for the FIP1L1‑PDGFRA gene fusion (a specific genetic change that can cause a different type of disease).

Who Cannot Join the Study?

Having had a severe allergic reaction called anaphylaxis to any biologic medicine (a treatment made from living cells) or vaccine.
Being diagnosed with systemic mastocytosis, a rare condition where certain immune cells (mast cells) grow too much throughout the body.
Having any important existing health problems that affect major body systems, such as hormone (endocrine), immune (autoimmune), metabolism, nerves (neurological), kidneys (renal), stomach/intestines (gastrointestinal), liver (hepatic), blood (haematological), lungs (respiratory), or any other major organ.
Having taken the study drug benralizumab before in another clinical trial.
Being diagnosed with granulomatosis with polyangiitis (formerly called Wegener’s granulomatosis) or microscopic polyangiitis, which are types of blood‑vessel inflammation.
Having a worsening of EGPA (eosinophilic granulomatosis with polyangiitis) or organ‑threatening EGPA that, in the doctor’s view, makes the disease unstable within the three months before screening and up to the first dose of the study drug.
Having EGPA that is immediately life‑threatening, as judged by the doctor, within the three months before screening and up to the first dose of the study drug.
Having a current cancer (called a malignancy) or a past history of cancer.
Having life‑threatening HES (hypereosinophilic syndrome) or serious complications from HES, as judged by the doctor.
Having a high level of eosinophils (a type of white blood cell) called hypereosinophilia when the cause is unknown.

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 Lille	Lille	France

Other Sites

Site Name	City	Country	Status
Centre Hospitalier Universitaire De Montpellier	Montpellier	France
Ecxbwez Usapoyecloar Mqoskol Cxuevhu Rhenxaqyp (zeaymdn Myr	Rotterdam	The Netherlands

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	29.05.2026
The Netherlands	Not yet recruiting	29.05.2026

Trial locations

Investigated drugs:

Benralizumab

Benralizumab is a medication given as a subcutaneous injection. It is a type of antibody that specifically targets and reduces certain immune cells called eosinophils, which are often high in children with eosinophilic diseases. In this trial, the drug is being studied to see how it behaves in the body, how it affects the disease, and whether it is safe and well‑tolerated for children.

Fasenra is the brand name for the same medication, benralizumab, also provided as a solution for injection in a pre‑filled syringe. Like the generic version, it is administered under the skin and works by lowering eosinophil levels. The trial uses this product to evaluate its safety, how the body processes it, its effect on the disease, and whether the body produces any immune response against it.

Investigated diseases:

Eosinophilic Granulomatosis with Polyangiitis – A rare condition in which a type of white blood cell called eosinophils builds up in small blood vessels, causing inflammation. It often starts with asthma or allergic symptoms and can later affect the lungs, skin, nerves, and other organs. Over time, the inflammation can lead to swelling, pain, and reduced function in the affected areas. The disease may show periods of worsening symptoms followed by quieter phases. Patients usually notice a gradual increase in breathing difficulty, skin rashes, or numbness in the limbs.

Hypereosinophilic Syndrome – A disorder marked by persistently high numbers of eosinophils in the blood without an obvious cause. The excess eosinophils can infiltrate the heart, lungs, gastrointestinal tract, skin, and other tissues. As the disease progresses, organ damage may develop, leading to symptoms such as shortness of breath, abdominal pain, or skin itching. Flare‑ups can cause sudden worsening of these signs, while quieter periods may have few complaints. The condition often follows a pattern of alternating activity and remission.

Eosinophilic Disease – A group of illnesses characterized by an overabundance of eosinophils, a type of immune cell. These cells can accumulate in various tissues, causing inflammation and swelling. The disease may begin with mild allergic signs and advance to affect organs like the lungs, heart, or gastrointestinal tract. Symptoms typically grow more noticeable as the eosinophil count rises and the affected organs become irritated. The course often involves cycles of symptom increase followed by periods of relative calm.

Trial ID:

2023-508533-14-00

Protocol code:

D3255C00004

NCT ID:

NCT06512883

Trial Phase:

Therapeutic confirmatory (Phase III)

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Study of Benralizumab Safety, Pharmacokinetics, and Efficacy in Children with Eosinophilic Disease

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