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Study on Tacrolimus for Children After Kidney Transplant: Comparing Immediate and Prolonged-Release Forms

Verified siteRegistered drugNo placebo
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What is this trial about?

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

This clinical trial is focused on studying the effects of a medication called tacrolimus in children who have undergone a kidney transplant. The study involves two forms of tacrolimus: Envarsus, which is a prolonged-release tablet, and Prograf, which is an immediate-release capsule. Both medications are used to help prevent the body from rejecting the new kidney by suppressing the immune system, a process known as immunosuppression.

The purpose of the study is to compare how the body processes these two forms of tacrolimus in children who have received a kidney transplant. Participants will be given either Envarsus or Prograf, and their blood will be tested at various times to measure the levels of the medication. This will help determine if the two forms of the medication are equivalent in terms of how they are absorbed and processed by the body.

The study will last for a period of four weeks, during which participants will take the medication orally. The goal is to ensure that the prolonged-release form of tacrolimus, Envarsus, is as effective and safe as the immediate-release form, Prograf, when used in children who have had a kidney transplant. This research is important for improving treatment options and outcomes for pediatric kidney transplant patients.

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 visit

    Upon joining the study, you will attend an initial visit. During this visit, medical staff will review your medical history and current health status. You will be asked to provide informed consent, which means you agree to participate in the study after understanding its purpose and potential risks.

  2. Step 2

    Medication administration

    You will begin taking the study medication, which is a form of tacrolimus. This medication is available in two forms: Envarsus and Prograf. Envarsus is a prolonged-release tablet, and Prograf is a hard capsule. The specific dosage and form will be determined by the study protocol.

    The medication is taken orally, meaning you will swallow it. The dosage and frequency will be explained to you by the study team. It is important to follow the instructions carefully to ensure the study's accuracy.

  3. Step 3

    Blood sample collection

    Throughout the study, blood samples will be collected at specific times to measure the concentration of tacrolimus in your blood. These times include before taking the medication and at intervals of 1.5, 2, 4, 6, 8, 12, 13.5, 14, 16, 20, and 24 hours after administration.

    These samples help the study team understand how the medication is processed in your body and ensure it is working effectively.

  4. Step 4

    Regular health assessments

    You will undergo regular health assessments to monitor your kidney function and overall health. These assessments are crucial to ensure your safety and the effectiveness of the medication.

    The study team will check for any side effects or changes in your health status. It is important to report any new symptoms or concerns to the study team immediately.

  5. Step 5

    Final visit

    At the end of the study, you will have a final visit. During this visit, the study team will conduct a comprehensive health assessment and discuss your experience during the trial.

    The results of the study will be explained to you, and any further steps regarding your treatment will be discussed.

Who can join the trial?

12 criteria

  • Must be a Caucasian child or teenager who has received a kidney transplant.
  • Must be between 8 and 18 years old.
  • Currently taking a medication called tacrolimus (Prograf®) and able to swallow tablets with a minimum dose of 0.75 mg per day of Envarsus®.
  • It has been at least 6 months since the kidney transplant.
  • Has stable kidney function, meaning the kidney is working consistently well over the last 3 months.
  • If a girl or woman who can have children, must either:
    • Not be sexually active, or
    • Only have sexual relationships with female partners or sterile male partners, or
    • Have a negative pregnancy test and agree to use reliable birth control methods during the study and for four weeks after the last dose of the study medication.
    • If not able to have children, must be:
      • Before starting menstruation, or
      • At least 6 weeks after surgical procedures like removal of ovaries or uterus.
      • The patient and their parents or legal guardians must understand the purpose and risks of the study.
      • Must have a signed informed consent from the patient and their parents or legal guardians.

Who cannot join the trial?

3 criteria

  • Patients who are not **Caucasian** (white) children or teenagers who have had a **kidney transplant**.
  • Patients who are not taking their medication as prescribed (non-compliant patients).
  • Patients who have had major deviations from the study protocol (significant changes or mistakes in following the study rules).
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Investigated drugs

Tacrolimus is a medication used to help prevent the body from rejecting a transplanted kidney. It works by suppressing the immune system, which is the body's defense system that can sometimes attack the new organ. In this study, two forms of tacrolimus are being compared: an immediate-release form, known as Prograf, and a prolonged-release form, known as Envarsus. The goal is to see if the prolonged-release form is as effective and safe as the immediate-release form when taken by children who have had a kidney transplant. The prolonged-release form is designed to be taken less frequently, which might make it easier for patients to stick to their medication schedule.

What is already known about the treatment

Tacrolimus – Tacrolimus is administered orally in the form of tablets, with a prolonged-release version available to ensure a steady release of the medication over time. It is currently being studied in clinical trials to evaluate its effectiveness and tolerability in children who have received kidney transplants. The main therapeutic use of tacrolimus is to prevent the body from rejecting a transplanted organ, such as a kidney. At the molecular level, tacrolimus works by inhibiting certain proteins in the immune system, which helps to reduce the immune response that can lead to organ rejection. It is classified as an immunosuppressant, a type of medication that decreases the activity of the immune system.

Investigated diseases

Kidney Transplant Rejection – Kidney transplant rejection occurs when the recipient's immune system identifies the transplanted kidney as foreign and attacks it. This immune response can lead to inflammation and damage to the kidney tissue. Rejection can be acute, happening shortly after the transplant, or chronic, developing over a longer period. Symptoms may include decreased kidney function, swelling, and tenderness over the transplant site. The progression of rejection can vary, with some cases resolving spontaneously while others may lead to significant kidney damage. Monitoring and managing immune response is crucial to prevent further complications.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IVTrial ID2024-516608-40-00Protocol codePro-TacEstimated enrolment30 patientsSponsorUniversitaetsklinikum Essen AöR

sourced from the EU Clinical Trials Register and site verification

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