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A study testing how well patiromer lowers high potassium levels in the blood in children under 12 years of age with hyperkalemia

Verified siteInvestigationalNo placebo
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What is this trial about?

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

This study is looking at a condition called hyperkalemia, which means having high levels of potassium in the blood. Potassium is an important mineral in the body, but when levels become too high, it can cause health problems. The study will test a medicine called patiromer, which comes as a powder that is mixed with liquid and taken by mouth. The medicine is being tested in children who are younger than 12 years old and have high potassium levels in their blood. Some children in the study may be receiving a treatment called peritoneal dialysis, which is a way to help the kidneys remove waste from the body.

The purpose of this study is to see how well patiromer can lower potassium levels in young children over a period of 28 days when different amounts of the medicine are given. The study will also check how safe the medicine is for children and whether it causes any unwanted effects. During the study, children will take patiromer every day, and doctors will measure their potassium levels at different times, including on days 3, 7, 14, and 28. The medicine can be given through regular feeding or through feeding tubes if needed. Blood tests will be done to check not only potassium levels but also other important substances in the blood like magnesium, calcium, and other minerals to make sure they stay within healthy ranges.

The study is divided into two parts, and there is also an optional period where children can continue taking the medicine for a longer time if their doctor thinks it would be helpful. Throughout the study, doctors will carefully watch for any side effects and will check the children's heart function, vital signs like blood pressure and heart rate, and other blood test results to ensure the medicine is working safely. Children taking certain other medicines for blood pressure or heart conditions must be on a stable dose before joining the study.

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

    Initial assessment and confirmation

    Your potassium levels will be measured using two separate blood tests to confirm that your levels are higher than normal. One sample will be taken at the beginning, and one sample may be from a recent test taken within the last 30 days.

    The average of these two potassium measurements must be above the normal upper limit for your age by at least 0.5 mEq/l (a unit used to measure potassium concentration).

    If you are taking medications such as RAASi (medicines that affect blood pressure and kidney function), beta blockers (heart medications), fludrocortisone, or diuretics (water pills), you must have been on a stable dose for at least 14 days before this assessment.

    If you are receiving peritoneal dialysis (a treatment that uses the lining of your abdomen to filter waste from your blood), you must have been on a stable treatment plan for at least 4 weeks, or 8 weeks if this treatment was recently started.

  2. Step 2

    Treatment period with patiromer

    You will receive patiromer, a powder medication that is mixed with liquid and taken by mouth. The medication comes in doses of 1g or 2g per packet.

    The dose of patiromer will be determined based on your individual needs and age. Your doctor will adjust the amount you receive during the study.

    The medication will be given to you for 28 days. This is called the dose-ranging period.

    The medication can be given through regular feeding or through feeding tubes if you use one, such as a PEG tube (a tube placed through the skin into the stomach) or an entero-gastric feeding tube (a tube that goes into the digestive system).

    Your parent, legal representative, or another designated person will be responsible for giving you the medication exactly as directed by the study site personnel.

  3. Step 3

    Monitoring visits during treatment

    Your potassium levels will be checked at specific times during the treatment period: on Day 3, Day 7, Day 14, and Day 28.

    At these visits, blood samples will be taken to measure not only potassium but also other important substances in your blood, including magnesium, calcium, phosphate, fluoride, creatinine (a measure of kidney function), bicarbonate, and blood urea nitrogen.

    Your vital signs will be measured regularly. These include your blood pressure, heart rate, breathing rate, and temperature.

    A 12-lead ECG (a test that records the electrical activity of your heart) will be performed to monitor your heart function.

    Any side effects or health changes you experience will be recorded and monitored throughout the treatment period.

  4. Step 4

    End of main treatment period

    At the end of the 28-day treatment period, a final assessment will be conducted to evaluate the changes in your potassium levels from the beginning of the study.

    All safety measurements, including blood tests, vital signs, and heart monitoring, will be completed.

    Your overall response to the medication and any side effects you experienced will be reviewed.

  5. Step 5

    Optional safety-extension period

    After completing the 28-day treatment period, you may have the option to continue in a safety-extension period.

    During this extended period, you will continue to receive patiromer treatment.

    Your potassium levels and other safety measurements will continue to be monitored at regular intervals.

    The duration of this optional period will be determined by your doctor based on your individual medical needs.

Who can join the trial?

10 criteria

  • The participant must be a child younger than 12 years of age with hyperkalemia, which means having too much potassium (a mineral in the blood) at the time of screening.
  • If the participant is receiving peritoneal dialysis (a treatment that uses the lining of the belly to filter waste from the blood when the kidneys are not working well), they must have been on a stable treatment plan for at least 4 weeks before screening, or at least 8 weeks before screening if peritoneal dialysis was recently started.
  • The participant must not turn 12 years old during the 28 days of the study treatment period.
  • The participant must be able to receive regular feeding and medication from outside the body, including through tubes such as a PEG tube (a feeding tube placed through the belly into the stomach) or an entero-gastric feeding tube (a tube that delivers nutrition to the stomach or intestines).
  • At screening, the results from 2 separate potassium tests using the same method must show levels above the normal upper limit for the participant's age. At least 1 sample must be taken at screening and 1 sample should be no older than 30 days. The average of the 2 potassium values must be above the normal upper limit plus 0.5 units. If both samples are taken on the screening day, the 2 potassium values must not differ from each other by more than 0.5 units.
  • In the doctor's opinion, the participant is expected to need treatment for hyperkalemia for at least 28 days after joining the study.
  • If the participant is taking certain medications such as RAASi (medicines that help control blood pressure and protect the kidneys), beta blockers (medicines that help control heart rate and blood pressure), fludrocortisone (a medicine that helps balance salt and water in the body), or diuretics (medicines that help the body remove extra fluid), they must have been on a stable dose for at least 14 days before screening.
  • The parent or legally acceptable representative (a person legally allowed to make decisions for the child) must provide written permission for the child to participate in the study, following local rules. If appropriate or required, the child's agreement should also be obtained.
  • The parent, legally authorized representative, or another appropriate person must be available to help ensure the participant attends all scheduled visits, follows the treatment plan, completes laboratory tests, and follows all study procedures. They must also be able to give the study medication to the participant correctly as instructed.
  • For sites outside of Norway: Females who are able to become pregnant must not be breastfeeding, must have a negative pregnancy test at screening, and must have used an effective form of contraception (birth control method, such as not having sexual intercourse) for at least 1 month before receiving the study medication. They must agree to continue using contraception throughout the study and for 1 month after the last dose of the study medication.

Who cannot join the trial?

3 criteria

  • The specific reasons why patients cannot participate in this study have not been provided in the available information
  • If you have questions about whether you or your child can join this study, you will need to discuss this directly with the medical team running the trial
  • General exclusion reasons in clinical trials may include other serious health conditions, use of certain medications, or factors that could affect the safety of the participant or the results of the study
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Investigated drugs

Patiromer is a medication used to treat high potassium levels in the blood, a condition called hyperkalaemia. It works by binding to potassium in your digestive system and helping your body remove the excess potassium through bowel movements. In this study, patiromer is being tested in children under 12 years old to see how well it lowers potassium levels and whether it is safe for use in this younger age group.

What is already known about the treatment

Patiromer – Patiromer is a medication given by mouth, usually mixed with water or soft food, designed to treat hyperkalemia, which is a condition where there is too much potassium in the blood. It works in the intestines by binding to potassium from food and removing it from the body through bowel movements, preventing the potassium from being absorbed into the bloodstream. Patiromer belongs to a class of drugs called potassium binders and is currently approved and used in clinical practice, with ongoing studies evaluating its safety and effectiveness in children under 12 years of age. This medication is particularly important for patients who need to lower their blood potassium levels to prevent serious heart rhythm problems and other complications.

Investigated diseases

Hyperkalemia – Hyperkalemia is a condition characterized by abnormally high levels of potassium in the blood. Potassium is an essential mineral that helps nerves and muscles communicate, including those that control heartbeat. When potassium levels become too elevated, it can disrupt the normal electrical signals in the body. This condition can develop gradually or occur suddenly depending on the underlying cause. Common causes include kidney problems that prevent proper potassium removal, certain medications, or excessive potassium intake. The condition progresses as potassium continues to accumulate in the bloodstream beyond normal ranges.
Trial detailsLast updated 2 Oct 2026
Age0-17PhasePhase IITrial ID2023-505252-21-00Protocol codeRLY5016-208pEstimated enrolment52 patientsSponsorVifor Pharma Inc.

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