LUM-201 Elicits Greater GH Response than Standard GH Secretagogues in Pediatric Growth Hormone Deficiency
ENDO 2021 Poster Presentation by Author George Bright, MD
(video and poster below)
March 20, 2021
George Bright, MD, Roy Smith, PhD, Michael O. Thorner, MB, BS, DSc.
Lumos Pharma, Austin, TX, USA.
G. Bright: Consulting Fee; Self; Lumos Pharma. R. Smith: Consulting Fee; Self; Lumos Pharma. M.O. Thorner: Consulting Fee; Self; Lumos Pharma. Stock Owner; Self; Lumos Pharma.
Abstract Title: “LUM-201 Elicits Greater GH Response than Standard GH Secretagogues in Pediatric Growth Hormone Deficiency “Presentation Type: OralScience Type and Topic: Clinical Trial Introduction: LUM-201 (ibutamoren, formerly MK-0677) is an orally administered GH-secretagogue that stimulates the GH secretagogue receptor (GHSR1a) in the hypothalamus and pituitary. LUM-201 is in development for long-term use in a subset of PGHD patients with moderate growth deficiencies. A diagnosis of PGHD is confirmed by low GH responses to standard GH secretagogues (clonidine, arginine, L-dopa, glucagon, insulin) so it is somewhat counter-intuitive to suggest that children who cannot respond to one GH secretagogue might have favorable responses to LUM-201. Objective: To determine if LUM-201 stimulates GH responses differently than standard GH secretagogues. Methods: 68 naïve-to-treatment, prepubertal children with GHD received two standard GH stimulation tests and a test with a single 0.8 mg/kg dose of LUM-201. The 68 subjects included 20 girls and 48 boys. The median (interquartile range) age was 9.2 years (7.2,10.8), bone age 6.0 years (4.5, 7.9), height SDS -3.3 (-4.5, -2.5), pretreatment height velocity 4.0 cm/y (3.2, 4.6), and baseline IGF-1 51 ng/mL (24,111). Results: The median (interquartile range) of maximal GH response to single dose LUM-201 was 15.0 ng/mL (3.5, 49) and to various pairs of standard stimuli was 5.4 ng/mL (1.8-7.6) (p< 0.00001). The median (IQR) for the difference between GH responses to LUM-201 and standard stimuli was 9.6 ng/ml (1.9, 42). In a multivariate analysis (r2 =0.73) differential GH increased with higher values of baseline IGF-I (p < 0.00001) and standard GH stimulation test (p = 0.047) but was not influenced by age (p = 0.16), sex (p = 0.28), baseline HV (p = 0.24), age-bone age differences (p = 0.33) or height-SDS (p = 0.75) . Conclusion: In GHD children, the GH response to single-dose LUM-201 greatly exceeds that observed with standard GH testing agents. The difference is greatest among patients with higher baseline values of IGF-I and higher GH responses to standard stimuli. The synergistic actions of LUM-201 on the physiological mechanisms regulating GH release explain why GH responses are greater in response to LUM-201 compared to traditional tests used to diagnose PGHD.