TY - JOUR
T1 - Model-Based Analysis of IGF-I Response, Dosing, and Monitoring for Once-Weekly Somapacitan in Children With GH Deficiency
AU - Kildemoes, Rasmus J.
AU - Backeljauw, Philippe F.
AU - Højby, Michael
AU - Blair, Joanne C.
AU - Miller, Bradley S.
AU - Mori, Jun
AU - Lyauk, Yassine K.
N1 - Publisher Copyright:
© The Author(s) 2023.
PY - 2023/11/1
Y1 - 2023/11/1
N2 - Context: Growth hormone (GH) replacement therapy improves longitudinal growth and adult height in children with GH deficiency (GHD). GH stimulates insulin-like growth factor (IGF)-I release, the biomarker used for monitoring GH activity during treatment. Objective: This study aims to provide model-based insights into the dose-IGF-I responses of once-weekly somapacitan, a novel long-acting GH, compared with daily GH in children with GHD. Methods: Analyses included dosing information and 1473 pharmacokinetic samples from 210 somapacitan-treated pediatric patients with GHD across 3 trials, including phase 1 (NCT01973244), phase 2 (NCT02616562; REAL 3), and phase 3 (NCT03811535; REAL 4), as well as 1381 IGF-I samples from 186 patients with GHD treated with somapacitan in REAL 3 and REAL 4. Pharmacokinetic/pharmacodynamic modeling to characterize somapacitan dose-IGF-I response and predict the response to dosing day changes. Results: Relationships were established between somapacitan dose, exposure, change from baseline IGF-I SD score (SDS), and height velocity (HV). A linear model permitted the development of a tool to calculate estimated average weekly IGF-I exposure from a single IGF-I sample obtained at any time within the somapacitan dosing interval at steady state. In practice, the use of this tool requires knowledge of somapacitan injection timing relative to IGF-I sample collection timing. IGF-I SDS simulations support flexible dosing day changes while maintaining at least 4 days between doses. Conclusion: We characterized the dose-IGF-I response of somapacitan in children with GHD. To support physicians in IGF-I monitoring, we present a practical guide about expected weekly average IGF-I concentrations in these patients and provide insights on dosing day flexibility.
AB - Context: Growth hormone (GH) replacement therapy improves longitudinal growth and adult height in children with GH deficiency (GHD). GH stimulates insulin-like growth factor (IGF)-I release, the biomarker used for monitoring GH activity during treatment. Objective: This study aims to provide model-based insights into the dose-IGF-I responses of once-weekly somapacitan, a novel long-acting GH, compared with daily GH in children with GHD. Methods: Analyses included dosing information and 1473 pharmacokinetic samples from 210 somapacitan-treated pediatric patients with GHD across 3 trials, including phase 1 (NCT01973244), phase 2 (NCT02616562; REAL 3), and phase 3 (NCT03811535; REAL 4), as well as 1381 IGF-I samples from 186 patients with GHD treated with somapacitan in REAL 3 and REAL 4. Pharmacokinetic/pharmacodynamic modeling to characterize somapacitan dose-IGF-I response and predict the response to dosing day changes. Results: Relationships were established between somapacitan dose, exposure, change from baseline IGF-I SD score (SDS), and height velocity (HV). A linear model permitted the development of a tool to calculate estimated average weekly IGF-I exposure from a single IGF-I sample obtained at any time within the somapacitan dosing interval at steady state. In practice, the use of this tool requires knowledge of somapacitan injection timing relative to IGF-I sample collection timing. IGF-I SDS simulations support flexible dosing day changes while maintaining at least 4 days between doses. Conclusion: We characterized the dose-IGF-I response of somapacitan in children with GHD. To support physicians in IGF-I monitoring, we present a practical guide about expected weekly average IGF-I concentrations in these patients and provide insights on dosing day flexibility.
KW - dosing
KW - growth hormone deficiency
KW - IGF-I
KW - monitoring
KW - pharmacodynamics
KW - pharmacokinetics
KW - somapacitan
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U2 - 10.1210/jendso/bvad115
DO - 10.1210/jendso/bvad115
M3 - Article
C2 - 37818403
AN - SCOPUS:85184000693
SN - 2472-1972
VL - 7
JO - Journal of the Endocrine Society
JF - Journal of the Endocrine Society
IS - 11
M1 - bvad115
ER -