Study: NCT06465472

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Stiripentol Oral Capsule
Description: The target dose of stiripentol will be 50 mg/kg/day with a maximum dose of 3,000 mg/day. Patients allocated to the Stiripentol group will receive this treatment during the first 6 months, and in continuation up to 12 months.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo Oral Capsule
Description: Placebo capsules will be administered for the first 6 months. Then patients will switch to stiripentol over the 6- to 12-month period.

Intervention type: BIOLOGICAL
Group type: PLACEBO_COMPARATOR
Intervention: Urine samples collect
Description: Collections of urine over 24 hours and the first urine in the morning (spot urines) will be carried out. Urine collections will be performed either during hospitalizations, or at home if appropriate conditions are met.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Urine samples collect
Description: Collections of urine over 24 hours and the first urine in the morning (spot urines) will be carried out. Urine collections will be performed either during hospitalizations, or at home if appropriate conditions are met.

Intervention type: BIOLOGICAL
Group type: PLACEBO_COMPARATOR
Intervention: Blood samples collect
Description: Series of blood samples will be taken (serum pregnancy test, Primary Hyperoxaluria genetic characterization, clinical laboratory assessments, vitamin B6 dosage, plasma oxalate dosage, stiripentol pharmacokinetics)

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Blood samples collect
Description: Series of blood samples will be taken (serum pregnancy test, Primary Hyperoxaluria genetic characterization, clinical laboratory assessments, vitamin B6 dosage, plasma oxalate dosage, stiripentol pharmacokinetics)

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Kidney imaging
Description: Kidney imaging will be obtained. Renal ultrasounds will be compulsory for all patients.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Kidney imaging
Description: Kidney imaging will be obtained. Renal ultrasounds will be compulsory for all patients.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Quality of Life questionnaires
Description: Kidney Disease Quality of Life Questionnaire : KDQOL-36 for patients ≥18 years of age at screening, and the Pediatric Quality of Life Inventory (PedsQL) including the generic and KF modules (parent and/or self-report versions) for patients \<18 years of age at screening.~EQ-5D: a standardized instrument consisting of a questionnaire and a visual analog scale pertaining to 5 dimensions. Scoring of the questionnaire is based on degrees of disability. Scoring of the visual analog scale is based on a visual scale ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). Higher scores indicate better health status. The EQ-5D-5L questionnaire (will be utilized in patients ≥18 years of age at screening, and the EQ-5D-Y questionnaire will be utilized in patients \<18 years of age at screening, where available.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Quality of Life questionnaires
Description: Kidney Disease Quality of Life Questionnaire : KDQOL-36 for patients ≥18 years of age at screening, and the Pediatric Quality of Life Inventory (PedsQL) including the generic and KF modules (parent and/or self-report versions) for patients \<18 years of age at screening.~EQ-5D: a standardized instrument consisting of a questionnaire and a visual analog scale pertaining to 5 dimensions. Scoring of the questionnaire is based on degrees of disability. Scoring of the visual analog scale is based on a visual scale ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). Higher scores indicate better health status. The EQ-5D-5L questionnaire (will be utilized in patients ≥18 years of age at screening, and the EQ-5D-Y questionnaire will be utilized in patients \<18 years of age at screening, where available.