A Study to Assess the Efficacy, Safety, and Pharmacokinetics of Debio 4326 in Pediatric Participants With Central Precocious Puberty (LIBELULA™ Clinical Trial)

Eligibility Criteria

• 1. Diagnosis of central precocious puberty.
• 2. Onset of development of sex characteristics (i.e., breast development in girls or testicular enlargement in boys according to the Tanner method) before the age of 8 years in girls and 9 years in boys.
• 3. Initially, only participants aged (a) 5 to 8 years inclusive (i.e., \<9 years) are eligible. The Sponsor will determine based on the recommendation of the DMC following the interim analysis whether participants aged (b) 2 to 4 years inclusive (i.e., \<5 years) and/or (c) 9 to 10 years inclusive (i.e., \<11 years) may be recruited.
• 4. Participant to receive at least 1 year of gonadotropin-releasing hormone agonist (GnRHa) therapy from study treatment start.
• 5. (a) Pre-treated participants: Start of initial GnRHa therapy no later than 18 months after onset of the first signs of CPP.
• 6. (a) Pre-treated participants: Difference between bone age (Greulich and Pyle method) and chronological age of ≥1 year based on historical values at the initiation of the GnRHa therapy.
• 7. (a) Pre-treated participants: Pubertal-type LH response (LH ≥6 IU/L) following a GnRH/GnRHa stimulation test, or random non-stimulated serum LH \>0.5 IU/L (if considered local standard of care), based on historical values prior to the initiation of GnRHa therapy.
• 8. (a) Pre-treated participants: Clinical evidence of puberty, defined as Tanner Staging ≥2 for breast development for girls and testicular volume ≥4 milliliter (mL) (cubic centimeter \[cc\]) for boys, prior to the initiation of GnRHa therapy.
• 1. Gonadotropin-independent (peripheral) precocious puberty: gonadotropin-independent gonadal or adrenal sex steroid secretion.
• 2. (a) Pre-treated participants: Non-progressing, isolated premature thelarche prior to the initial GnRHa therapy.
• 3. Presence of an unstable intracranial tumor or an intracranial tumor potentially requiring neurosurgery or cerebral irradiation. Participants with hamartomas not requiring surgery are eligible.
• 4. Any other condition or chronic illness possibly interfering with growth (e.g., renal failure, diabetes, moderate to severe scoliosis, previously treated intracranial tumor).
• 5. Other than GnRHa therapy in pre-treated participants, any ongoing treatment with a potential effect on serum levels of gonadotropins or sex steroids, or possibly interfering with growth, opioids, central nervous system \[CNS\] stimulants).
• 6. Prior or current therapy with medroxyprogesterone acetate, growth hormone, or Insulin-like growth factor-1 (IGF-1).
• 7. Diagnosis of short stature, i.e., more than 2.25 standard deviations (SD) below the mean height-for-age.
• 8. Known history of seizures, epilepsy, and/or central nervous system disorders that may have been associated with seizures or convulsions.
• 9. Prior (within 2 months of study treatment start) or current use of medications that have been associated with seizures or convulsions.
• 10. Use of anticoagulants (heparin or coumarin derivatives).