Skip to content
Clinical Trials – home
Not yet recruitingRare disease

Study of atrasentan in children aged 2 to <18 years with primary IgA nephropathy to evaluate proteinuria reduction, safety and tolerability

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 children aged 2 to under 18 who have Primary IgAN, a rare kidney condition in which a protein called immunoglobulin A builds up in the kidneys and can cause blood and protein to appear in the urine. The medication being tested is a tablet containing atrasentan (also known by the code name EXV811), which is taken by mouth. The purpose of the study is to determine whether this drug can reduce the amount of protein that leaks into the urine.

Participants will receive one tablet each day for about nine months. Throughout the study they will visit the clinic regularly, where health care staff will collect a urine sample, usually the first morning urine, and perform a simple test that compares the protein level to a normal waste product to see how much protein is present. Blood samples will also be taken to understand how the body absorbs and clears the medication. Doctors will monitor safety by checking for any side effects, routine lab results, and vital signs during the visits.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline visit

    You will attend an initial visit where the study team will confirm eligibility and collect baseline information.

    A first‑morning urine sample will be taken to measure the urinary protein to creatinine ratio (UPCR), which reflects the amount of protein in the urine.

    Blood tests and other routine safety assessments will also be performed.

  2. Step 2

    Start of study medication

    After baseline assessments, you will begin taking the investigational drug, atrasentan (also called EXV811).

    The medication is a film‑coated tablet to be taken by mouth.

    The prescribed dose is 0.75 mg taken once each day.

  3. Step 3

    Daily medication intake

    You will continue to take the 0.75 mg tablet every day for the duration of the study, which lasts up to 36 weeks.

    The tablet should be swallowed with water and taken at roughly the same time each day.

  4. Step 4

    Regular monitoring visits

    Throughout the study, you will return for scheduled visits, typically every 4 weeks, to allow the study team to check your safety and how the medication is working.

    At each visit a first‑morning urine sample will be collected to measure UPCR, and blood tests will be repeated to monitor kidney function and other safety parameters.

    Any side effects you experience will be recorded and evaluated.

  5. Step 5

    Week 36 final assessment

    At week 36, a final set of assessments will be performed, including a first‑morning urine collection to determine the change in proteinuria compared with baseline.

    Blood tests and a complete safety review will also be completed to assess any lasting effects of the medication.

  6. Step 6

    Study completion

    After the final assessments, the study medication will be stopped and you will receive a summary of the study findings related to your participation.

    Your regular medical care will continue as directed by your own healthcare provider.

Who can join the trial?

6 criteria

  • You must be at least 2 years old but younger than 18 years on the first day of the study.
  • Your kidney function, measured by eGFR (a test that estimates how well the kidneys filter blood), must be 30 or higher using a special calculation called the modified Schwartz formula, checked at screening and again before treatment starts.
  • You need to have a kidney tissue sample (biopsy) that shows primary IgA nephropathy, taken within the past 3 years, and the sample must show less than 50 % damage called tubulointerstitial fibrosis and less than 25 % of a finding called crescents.
  • You must have significant protein in your urine, measured as a urinary protein to creatinine ratio (UPCR) of 1 gram per gram or more, taken from a first‑morning urine sample (or a spot sample in special cases) at screening and on two earlier visits, even though you have been taking the highest dose of an ACE inhibitor or ARB that you can tolerate for at least 120 days.
  • You must be on stable supportive care, meaning you have been taking a steady dose of an ACE inhibitor or ARB at the maximum amount allowed for your weight (or the highest dose you can tolerate) for at least 120 days before the study drug starts. If you also take diuretics (medicines that help you urinate more), other blood‑pressure medicines, SGLT2 inhibitors (a type of diabetes medicine that can protect the kidneys), or GLP‑1 agonists (another diabetes medicine), those doses must also have been stable for at least 120 days.
  • Your body weight must be at least 10 kilograms (about 22 pounds) when you are screened, and this weight must be confirmed on the first day of treatment.

Who cannot join the trial?

15 criteria

  • If you have any form of secondary IgA nephropathy (IgAN) that is linked to other illnesses such as liver scarring (cirrhosis), gluten intolerance (celiac disease), HIV infection, herpes infection, skin rash (dermatitis herpetiformis), a type of arthritis without rheumatoid factor (seronegative arthritis), certain cancers (small‑cell carcinoma, lymphoma), widespread tuberculosis, a lung condition called bronchiolitis obliterans, inflammatory bowel disease, or a genetic fever disorder (familial Mediterranean fever), you cannot join the study.
  • If on the first day of the trial your body weight is lower than the minimum weight allowed for the group you were screened for, and that lower‑weight group is not currently enrolling, you are excluded.
  • If you have a known history of heart problems that you were born with (congenital heart disease), heart failure, or significant fluid buildup such as fluid in the lungs (pulmonary edema), swelling in the legs or arms (peripheral edema), fluid around the lungs (pleural effusion), or fluid in the abdomen (ascites), you cannot participate.
  • If you are currently taking any homeopathic or herbal medicines for IgAN, such as Tripterygium wilfordii (Lei Gong Teng), Caulis sinomenii, or Sinomenium acutum, you are excluded.
  • If your blood pressure is higher than the age‑specific limits (for ages 12‑<18: >150/95 mmHg; ages 6‑<12: >140/90 mmHg; ages 2‑<6: >120/80 mmHg) based on three measurements at screening, or if you have very low blood pressure (hypotension), you cannot join.
  • If you have taken strong immune‑suppressing medicines within the past few months, such as cyclophosphamide, rituximab, infliximab, canakinumab, mycophenolate (MMF or MPS), calcineurin inhibitors, complement inhibitors, oral budesonide, high‑dose steroids (≥0.5 mg/kg/day or >7.5 mg prednisone in one day) within 120 days (or 180 days for rituximab), or endothelin receptor blockers (including sparsentan) within 120 days before the first study drug, you are excluded.
  • If you have major other health problems, such as advanced heart disease (e.g., severe heart failure classified as NYHA class III for ages 6‑<18 or Ross class III for ages 2‑<6), serious lung disease (severe pulmonary disease classified as WHO class III for age 17 or PVRI class III for ages 2‑<17), or active liver disease (like hepatitis) that the doctor thinks would make participation unsafe, you cannot take part.
  • If you have been diagnosed with IgA vasculitis (also called Henoch‑Schönlein purpura), which causes a typical raised rash (palpable purpura) and may include joint pain or belly pain, you are excluded.
  • If you have a significant blockage in the urinary system or any trouble urinating that was found at screening and confirmed at the start of the study, you cannot join.
  • If you have a recent episode of acute kidney injury (AKI) as defined by standard criteria within four weeks before screening, you are excluded.
  • If your kidney function has dropped quickly, defined as a 50 % decline in estimated glomerular filtration rate (eGFR) within three months before screening or during the screening period (a condition called rapidly progressive glomerulonephritis), you cannot participate.
  • If the doctor judges that you have nephrotic syndrome (a kidney condition causing very high protein loss in urine), you are excluded.
  • If a blood test shows a brain‑type natriuretic peptide (BNP) level higher than 200 pg/mL at screening, indicating possible heart stress, you cannot join.
  • If your hemoglobin level is below 9 g/dL (a sign of anemia) at screening or you received a blood transfusion for anemia within the past three months, you are excluded.
  • If your platelet count is less than 80,000 per microliter at screening (a low number of cells that help blood clot), you cannot participate.
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

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

atrasentan is an oral tablet being tested in this study. It works by blocking a hormone pathway that can cause damage to the kidneys. The goal of taking this medication is to lower the amount of protein that leaks into the urine (proteinuria) in children who have primary IgA nephropathy. The trial will look at how well the drug works, how it is processed in the body, and whether it is safe for young patients. This medicine has orphan‑drug status, meaning it is intended for a rare condition.

What is already known about the treatment

  • EXV811

    This oral, film‑coated tablet is taken by mouth in a 0.75 mg dose. It is an investigational drug currently in a phase III trial and has orphan‑drug status for a rare kidney disease. The medicine is meant to lower protein loss in urine for patients with primary IgA nephropathy. It works by blocking a protein called endothelin‑A, which helps reduce pressure in kidney blood vessels, and it is classified as an endothelin receptor antagonist.

  • atrasentan

    This oral, film‑coated tablet is also taken by mouth at a 0.75 mg dose. Atrasentan is an experimental therapy being studied in phase III trials for a rare kidney condition and is designated as an orphan drug. It is intended to reduce the amount of protein that leaks into urine in primary IgA nephropathy. The drug blocks endothelin‑A receptors, lowering blood vessel tightening in the kidneys, and it belongs to the class of endothelin receptor antagonists.

Investigated diseases

Primary IgA nephropathy - It is a kidney disorder in which an antibody called IgA accumulates in the tiny filtering units of the kidneys. The deposits cause inflammation and make the filters leak protein into the urine. As the inflammation continues, kidney function can gradually decline and more protein may appear in the urine. The disease usually begins slowly and can progress at varying speeds in different individuals.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IIITrial ID2025-522824-29-00Protocol codeCEXV811B12301Estimated enrolment28 patientsSponsorNovartis Pharma AG

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

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.