ESPE2023 Free Communications Late Breaking (6 abstracts)
1Institute of Maternal and Child Research, University of Chile, Santiago, Chile. 2University of Virginia-Emeritus, Charlottesville, USA. 3Lumos Pharma, Inc., Austin, USA
An oral GH secretagogue (GHS), LUM-201, stimulates GHSR-1a receptor to enhance endogenous GH pulsatile release. In moderate iPGHD, pulses of GH are found but at reduced levels, resulting in decreased IGF-1 and poor growth. The impact of LUM-201 on GH profiles during treatment of such children has not been reported.
Objective: To characterize GH profiles, defined by deconvolution analysis, based on GH concentration in a time series and its simultaneous clearance, at baseline and after 6 months of therapy with daily oral LUM-201 to illustrate how it affects annualized height velocity (AHV), serum IGF-1 and IGFBP3 in individuals with moderate iPGHD.
Patients & Methods: 15 prepubertal, naive iPGHD subjects were screened with a predictive enrichment marker (PEM) test to assess their acute response to oral LUM-201 (0.8mg/kg), with a positive test having a peak GH >5 ng/ml with a basal IGF-1 >30 ng/ml. At baseline, subjects (10M:5F) were (mean ± SD) aged 7.9±1.4 years, with IGF-1 SDS -0.82±0.9, and peak GH 7.2±2.2 ng/mL (clonidine stimulation), consistent with moderate iPGHD. Deconvolution was performed on serum GH measured every 10 minutes (0800 h to 2000 h). Patients were randomized to receive 1.6 mg/kg/day or 3.2 mg/kg/day of oral LUM-201. GH responses to the PEM test (P=0.9) and the first treatment doses were not different between the groups (34.8±6.6ng/ml for 1.6mg/kg and 38.2±11.2 ng/ml for 3.2mg/kg, P=0.7). The groups were therefore combined for this analysis.
Results: At 6 months GH & IGF parameters, and AHV increased 1.2-2.4 fold: See Table for means (SD).
Baseline | 6 Month | t test, p value | |
GH total* | 1.45 (0.89) | 2.32 (1.25) | 0.013 |
GH pulsatile* | 1.28 (0.83) | 1.93 (1.17) | 0.035 |
GH basal * | 0.17 (0.11) | 0.40 (0.28) | 0.008 |
AHV (cm/year) | 4.7 (1.3) | 7.6 (1.1) | < 0.00001 |
IGF-1 (ng/mL) | 115.5 (46.6) | 205.4 (63.9) | 0.0004 |
IGFBP3 (nmol/L) | 139.3 (32.6) | 169.0 (30.1) | 0.0004 |
IGF-1:IGFBP3 | 0.108 (0.031) | 0.157 (0.050) | 0.0044 |
*daytime secretion μg/kg body weight per 12hr |
Conclusions: LUM-201 generated the expected AHV in this iPGHD cohort. LUM-201 enhanced pulsatile GH secretion to similar levels observed in normal growing children, estimated at ~3.5?g/kg/12h (Albertsson-Wikland et al JCEM 1994); restoring physiological pulsatile GH secretion and IGF-1 were sufficient to support normal growth. LUM-201 in the treatment of moderate iPGHD has the advantages of being taken orally, enhancing endogenous pulsatile GH secretion, and therefore maintaining normal feedback mechanisms, to restore normal growth