Comparative Study of Subcutaneous 6-Month Versus Intramuscular 3-Month Leuprorelin Use in Central Precocious Puberty

Area of Science:

• Pediatric Endocrinology
• Reproductive Medicine
• Pharmacology

Background:

• Central precocious puberty (CPP) involves early onset of puberty, requiring treatment to prevent compromised final height.
• Gonadotropin-releasing hormone analogues (GnRHa) are standard treatment for CPP, with various administration schedules.
• Comparing different GnRHa formulations and intervals is crucial for optimizing treatment efficacy and patient experience.

Purpose of the Study:

• To compare the efficacy and safety of biannual (6-month) subcutaneous leuprorelin with quarterly (3-month) intramuscular leuprorelin in girls with CPP.
• To assess the impact of both treatment protocols on height, pubertal progression, bone age, and adverse events over 18 months.

Main Methods:

• A comparative study involving 23 girls with CPP, divided into two groups: 6-month subcutaneous leuprorelin (n=13) and 3-month intramuscular leuprorelin (n=10).
• Clinical assessments every 3 months, including ultrasounds and luteinizing hormone (LH) measurements post-administration.
• Bone age determination every 6 months over an 18-month treatment period.

Main Results:

• Both protocols successfully halted height loss and stabilized height standard deviation scores.
• The 6-month subcutaneous group showed a significant reduction in the bone age-chronological age gap (p=0.001).
• The 6-month subcutaneous leuprorelin led to decreased breast diameter (p=0.04) and uterine volume (p=0.02), with more frequent and larger local nodules (p=0.03) and increased pain compared to the 3-month intramuscular group.

Conclusions:

• Six-month subcutaneous leuprorelin is effective in decelerating bone age and preserving predicted final height, comparable to 3-month intramuscular leuprorelin.
• The biannual subcutaneous formulation offers additional benefits of reducing uterine and breast volumes.
• While associated with increased local reactions and pain, the 6-month subcutaneous regimen demonstrates a homogeneous LH suppressive effect and does not pose a risk of therapeutic failure.