Growth Response Of Oral LUM-201 In OraGrowtH210 And OraGrowtH212 Trials In Idiopathic Pediatric Growth Hormone Deficiency (iPGHD): Combined Analysis Interim Analysis Data

Abstract

Background: LUM-201 (ibutamoren), a growth hormone (GH) secretagogue receptor 1a (GHSR1a) agonist, is a potent, long-acting investigational oral GH secretagogue currently studied in three Idiopathic Pediatric GH Deficiency (iPGHD) studies. The LUM-201 predictive enrichment marker (PEM) is used to identify patients diagnosed with iPGHD (peak stimulated GH >3<10 ng/mL) who are likely to respond to LUM-201. PEM positivity is defined as a baseline insulin-like growth factor-1 (IGF-1) level >30 ng/mL and a peak GH of ≥5 ng/mL in response to a single 0.8 mg/kg dose of LUM-201. Objectives: Report the growth response analyzing the combined interim analysis (IA) data from two Phase 2 trials studying LUM-201 at two different doses (1.6 mg/kg/day or 3.2 mg/kg/day). Methods: IA data from both studies were combined and analyzed for calculated annualized height velocity (AHV). Baseline demographics were analyzed for the two combined cohorts. Results: After 6 months of treatment with LUM-201, the calculated AHV (mean ±SD ) was 8.1±1.9 cm/year in the 1.6 mg/kg/day group and 8.0±1.5 cm/year in the 3.2 mg/kg/day group (N=15 in both groups). After 9 months of treatment, the calculated AHV was 7.8±1.7 cm/ year in the 1.6 mg/kg/day group and 7.3±1.7 cm/year in the 3.2 mg/kg/day group (N=10 in both groups). After 12 months of treatment, the calculated AHV was 7.8±1.7 cm/ year in the 1.6 mg/kg/day group and 7.4 ±1.2 cm/year in the 3.2 mg/kg/day group (N=6 in both groups). LUM-201 was well tolerated; no safety concerns were identified across the dose range in adverse events (AE) data, laboratory values, and ECG values. Conclusions: As the growth velocity was comparable for the two doses of oral LUM-201, this analysis of the combined IA data appears to strongly support 1.6 mg/kg/day as the optimal dose for the Phase 3 trial, as doubling the dose appeared to offer no meaningful improvement in efficacy. Final determination will await final full data set analysis of both studies.