7128 Efficacy and Safety of Leuprolide Acetate 3M Depot in Chinese Children with Central Precocious Puberty: Interim Analysis of Multicenter, Single-Arm, Prospective Study

Abstract Disclosure: X. Luo: Advisory Board Member; Self; Takeda. L. Hou: Advisory Board Member; Self; Takeda. Y. Li: Advisory Board Member; Self; Takeda. Y. Sun: Advisory Board Member; Self; Takeda. X.K. Jin: Employee; Self; Takeda. Background: Central precocious puberty (CPP) due to early activation of the hypothalamic-pituitary-gonadal axis leads to early puberty. CPP has a negative impact on adult height. Leuprolide acetate (LA), a gonadotropin-releasing hormone agonist (GnRHa) is the standard treatment for CPP. As CPP requires prolonged treatment, a 3-month (3M) depot formulation would increase patient compliance and reduce the injection burden. This interim analysis presents the effect of LA 3M depot on the gonadotropic axis and assesses safety in children with CPP. Methods: In this open-label, multicenter, single-arm, and prospective study, 31 children with CPP were included. Key inclusion criteria were the appearance of secondary sexual characteristics below the age of eight years in girls and nine years in boys with a confirmed diagnosis of CPP. Children treated with prior GnRHa and/or having underlying medical conditions were excluded. Eligible children were treated with LA 11.25 mg subcutaneously every 12 weeks. The primary endpoint of this interim analysis was the proportion of children achieving inhibition of peak LH defined as peak LH ≤ 3.0 IU/L in the GnRH stimulation test at weeks 24. The secondary endpoint was safety analysis in the children receiving at least one dose of LA 3M depot. Results: At baseline, 30 girls and one boy were enrolled. The median (95% CI) chronological age (CA) of the girls was 8.0 (7.0, 9.0) years and the boy was 10 years old. Girls had a median height of 136.95 (131.5, 139.7) cm, weight of 30 (27, 34) kg, and BMI of 16.4 (15.1, 17.9) kg/m2. Baseline bone (BA) age was 11 (10, 11) years, and BA/CA was 1.24 (1.2, 1.3). Boy’s characteristics at baseline differed in CA (10 years), height (144 cm), and BMI (17.4 kg/m2) from girls of this cohort. Due to the data collection time points for the interim analysis, 8 out of the 31 enrolled subjects had a visit at week 24, and 30 subjects reached the week 12 visit time point and had a visit at week 12. The percentage of children achieving inhibition of peak LH (≤ 3.0 IU/L) in the GnRH stimulation test at week 12 was 100 (88.4, 100) %. At week 24, all of them achieved inhibition of LH in the GnRH stimulation test 100 (63, 100) %. Decreases in BA/CA from baseline at weeks 12 and 24 are 93 (77.9, 99.2) % and 50 (15.7, 84.3) % respectively. No progression of the Tanner stage was observed in 96.7 (82.8, 99.9) % and 100 (63, 100) % at weeks 12 and 24. At the data cut-off, 4 (13.33%) patients experienced a total of 5 treatment-emergent adverse events (TEAEs) in the safety population of 30 subjects. No grade ≥3 AE or serious AE was reported. The incidence of injection site reaction was 3.33%. Conclusion: LA at 11.25mg/3M depot effectively suppresses the gonadotropic axis at weeks 12 and 24, normalizing growth and reversibly slowing the early onset of puberty in children with CPP. LA in a 3-month injecting frequency is a safe and convenient treatment option to improve patient compliance. Presentation: 6/3/2024