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Study on Stiripentol for Patients Aged 6 and Older with Primary Hyperoxaluria Types 1, 2, or 3

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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 a rare condition called Primary Hyperoxaluria, which has three subtypes: PH1, PH2, and PH3. This condition causes the body to produce too much of a substance called oxalate, which can lead to kidney stones and other health issues. The trial will evaluate the effectiveness and safety of a medication called stiripentol, which is taken in the form of hard capsules. Stiripentol is being tested to see if it can help reduce the amount of oxalate in the urine of patients who are 6 years and older.

The purpose of the study is to determine if stiripentol can decrease urinary oxalate excretion, which is the amount of oxalate that is passed out of the body through urine. Participants in the study will receive either stiripentol or a placebo, which looks like the medication but does not contain the active ingredient. The study will last for a period of up to 60 days, during which participants will take the medication orally, meaning by mouth. The trial will monitor changes in the amount of oxalate in the urine over time, as well as any changes in kidney function and the occurrence of kidney stones.

Throughout the study, participants will be regularly assessed to track their health and any side effects they may experience. The trial aims to provide valuable information on whether stiripentol can be a beneficial treatment for those living with Primary Hyperoxaluria. This research could potentially lead to new treatment options for managing this challenging condition.

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

    Initial assessment

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes verifying age, diagnosis of primary hyperoxaluria type 1, 2, or 3, and current management of the condition.

    A urine or serum pregnancy test is required for pubescent patients and adult females of childbearing potential. This test must be negative to proceed.

  2. Step 2

    Baseline measurements

    Baseline measurements are taken, including 24-hour urinary oxalate excretion and estimated glomerular filtration rate (eGFR).

    These measurements help establish a starting point for evaluating changes during the trial.

  3. Step 3

    Medication administration

    Participants receive either Diacomit 250 mg or Diacomit 500 mg hard capsules, or a matched placebo. The capsules are taken orally.

    The dosage and frequency are determined based on individual needs and study protocols.

  4. Step 4

    Follow-up assessments

    Follow-up assessments occur at Month 3 and Month 6. These include measuring changes in 24-hour urinary oxalate excretion and urine oxalate/creatinine ratios.

    Additional assessments include monitoring kidney stone events and changes in biological parameters related to kidney stone formation.

  5. Step 5

    Quality of life evaluation

    Quality of life is evaluated using specific questionnaires. For patients under 18, the Pediatric Quality of Life Inventory is used. For those 18 and older, the Kidney Disease Quality of Life Questionnaire is administered.

    The Euro Quality of Life Health State Profile Questionnaire and Visual Analog Scale are also used to assess overall health status.

  6. Step 6

    Completion of trial

    The trial is estimated to conclude by December 4, 2028. Final assessments are conducted to evaluate the overall efficacy and safety of the treatment.

    Participants are informed of the results and any further steps if necessary.

Who can join the trial?

7 criteria

  • Male or female participants must be at least 6 years old at the time they agree to join the study.
  • Participants must have a confirmed diagnosis of **primary hyperoxaluria**, which is a condition that affects the kidneys, and the specific type (type 1, 2, or 3) must be confirmed through genetic testing.
  • Participants should be receiving the best possible care for their condition, which may include drinking more fluids, taking vitamin B6, and using potassium citrate, with or without other approved medications like lumasiran.
  • Participants must have a certain level of **urinary oxalate excretion**, which is a measure of oxalate in the urine, from two valid 24-hour urine collections. The level should be at least 0.70 mmol per 24 hours per 1.73 square meters of body surface area.
  • Participants must have an **estimated Glomerular Filtration Rate (eGFR)** of at least 45 mL per minute per 1.73 square meters. This is a measure of how well the kidneys are working.
  • Female participants who have started puberty and adult women who can have children must have a negative pregnancy test within 60 days before the first dose of the study treatment. If the urine test is positive or unclear, a blood test will be needed, and it must be negative for the participant to join the study.
  • Participants must be able to understand and agree to follow the study requirements and provide written consent. If the participant is under the legal age to give consent, their legal guardian(s) must provide consent, and the participant should agree to participate according to local and national rules.

Who cannot join the trial?

10 criteria

  • Patients who are not diagnosed with Primary Hyperoxaluria (PH), which is a condition that affects the kidneys and other organs.
  • Patients who are not within the specified age range for the study.
  • Patients who are not able to follow the study procedures or take the study medication as required.
  • Patients who have other medical conditions that might interfere with the study or make it unsafe for them to participate.
  • Patients who are pregnant or breastfeeding, as the study may not be safe for them or their baby.
  • Patients who are currently participating in another clinical trial, as this could affect the results of the study.
  • Patients who have a history of allergic reactions to the study medication or similar medications.
  • Patients who have a history of substance abuse, which could interfere with the study.
  • Patients who have had a recent major surgery or are planning to have surgery during the study period.
  • Patients who have any other reason that the study doctors believe would make it unsafe or inappropriate for them to participate.
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Investigated drugs

Stiripentol is being studied for its effectiveness and safety in patients aged 6 years and older who have primary hyperoxaluria types 1, 2, or 3. The main goal of the trial is to see if stiripentol can help reduce the amount of oxalate in the urine, which is important for managing this condition.

What is already known about the treatment

Stiripentol – Stiripentol is administered orally in the form of capsules or powder for suspension. It is currently being studied for its effectiveness in treating primary hyperoxaluria, a rare condition that leads to excessive oxalate production in the body. The main therapeutic indication for stiripentol in this context is to reduce urinary oxalate excretion in patients with primary hyperoxaluria types 1, 2, and 3. At the molecular level, stiripentol works by enhancing the activity of certain enzymes that help break down oxalate, thereby reducing its accumulation. It is classified pharmacologically as an anticonvulsant, although its use in primary hyperoxaluria is an emerging area of research.

Investigated diseases

Primary Hyperoxaluria – Primary Hyperoxaluria is a rare genetic disorder characterized by the overproduction of oxalate, a substance that combines with calcium to form kidney stones. This condition is caused by a deficiency in specific liver enzymes, leading to excessive oxalate in the urine. Over time, the accumulation of oxalate can result in kidney damage and the formation of stones in the urinary tract. There are three main subtypes: PH1, PH2, and PH3, each associated with different enzyme deficiencies. The disease often begins in childhood, but symptoms can vary widely, ranging from mild to severe. As the condition progresses, it can lead to complications such as kidney failure if not managed properly.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-508062-15-00Protocol codeSTP226Estimated enrolment42 patientsSponsorBiocodex

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