OR04-05 Achieving Random LH <1 IU/L Correlated with Achieving Peak LH <4 IU/L with 6-Month Subcutaneous Leuprolide Acetate

Abstract B.S. Miller: Consulting Fee; Self; Abbvie, Bristol-Myers Squibb, Novo Nordisk, Pfizer, Inc., Sanofi, Endo Pharmaceuticals, EMD Serono. Research Investigator; Self; Alexion Pharmaceuticals, Inc., Abbvie, Novo Nordisk, Pfizer, Inc. D. Boldt-Houle: Employee; Self; Tolmar, Inc. R. Daugherty: Employee; Self; Tolmar, Inc. S. Atkinson: Employee; Self; Tolmar, Inc. Background: Gonadotropin-releasing hormone agonists (GnRHa) are the gold-standard treatment for central precocious puberty (CPP). Thus, the availability of effective, long-acting, safe and conveniently administered treatments for CPP is important, especially if the therapy can also be used to monitor efficacy. We conducted secondary analyses using the pivotal trial of the first small-volume, long-acting, subcutaneously (SC) administered GnRHa for CPP to evaluate the correlation of random LH and leuprolide-stimulated peak LH <4.0 IU/L. Methods: 62 children with treatment-naïve CPP received 2 doses of 45 mg subcutaneous leuprolide acetate (SC LA) at 24-week intervals over the 48-week study period. LH concentrations were assessed using a validated central Cobas ECLIA assay with a lower limit of detection of 0.10 IU/L. Results: Out of 62 subjects, 52 (84%), 48 (77%), 39 (63%), and 15 (24%) subjects achieved random LH <1.0, <0.8, <0.6, and <0.3 IU/L, respectively. Within subjects who achieved random LH <1.0, <0.8, <0.6, and <0.3 IU/L, 92%, 92%, 92%, and 100% achieved leuprolide-stimulated peak LH <4.0 IU/L by week 24, respectively. Conclusions: 92% of patients on SC LA who achieved random LH <1.0 IU/L also achieved a leuprolide-stimulated peak LH <4.0 IU/L, suggesting a correlation between the two thresholds. Therefore, these combined data demonstrated successful pubertal suppression by SC LA. Clinicians should consider multiple markers of pubertal suppression when reviewing efficacy as a single value may not provide a complete picture. Funding: Tolmar, Inc. Sunday, June 2, 2024