MON-246 - Efficacy and Safety of 3-Month Leuprorelin Acetate Microspheres in Chinese Children with Central Precocious Puberty: A Prospective Multicenter Study

Background: Central precocious puberty (CPP) results from premature activation of the hypothalamic–pituitary–gonadal axis in children, leading to early puberty onset. In China, its prevalence has increased significantly in recent years. Long-acting gonadotropin-releasing hormone (GnRH) analogues improve compliance compared to monthly formulations. Leuprorelin acetate microspheres (11.25 mg), a 3-month formulation approved in China, provide sustained GnRH suppression and better adherence. However, the clinical evidence in Chinese children remains limited. This study evaluated its efficacy and safety in CPP treatment.

Methods: This open-label, multicenter, single-arm, prospective study enrolled children with secondary sexual characteristics (≤8 years in girls and ≤9 years in boys) and CPP confirmed by GnRH stimulation test (GnRH-ST). Primary efficacy endpoint was the percentage of patients with suppressed LH peak in the GnRH-ST at Week 24 (W24). Secondary endpoints included percentage of patients with Tanner regression or no progression at W24 compared to baseline; basal LH and FSH levels at baseline, W24, and W36; reduction in bone age (BA)/ chronological age (CA) ratio (W24), decrease in first morning voided (FMV) urinary (U) gonadotropins (Gn) at W24; and incidence of treatment-emergent adverse events (TEAEs).

Results: A total of 79 patients (98.7% female; mean age 7.6 ± 1.0 years) were enrolled for a mean of 167.6±19.17 days. LH suppression was achieved in 94.94% at W12 and 97.47% at W24. Tanner stage regression or no progression at W24 was 97.47% (95% CI: 91.15–99.69). Basal LH decreased from 1.22 ± 1.41 IU/L at baseline to 0.45 ± 0.30 IU/L at W24 and remained stable at W36. FSH showed similar trends. At W24, BA/CA ratio improved in 84.81% (95% CI: 74.97–91.90), and urinary-LH and FSH decreased by 62.03% (95% CI: 50.41–72.72) and 63.29% (95% CI: 51.69–73.86), respectively. TEAEs occurred in 34.18% (n=27) mostly grade ≤2, with upper respiratory tract infection being the most common (5.06%). Grade ≥3 TEAEs occurred in 6.33% (n=5) including 1 serious adverse event (acute appendicitis, grade 4). Treatment-related events occurred in 5.06% (n=4): injection site reactions (2), 1 elevated ALT (1), and 1 myalgia (1).

Conclusion: The 3-month leuprorelin acetate microsphere formulation effectively suppressed the pituitary-gonadal axis and slowed pubertal progression in children with CPP, with a tolerable safety profile.