Treatment of Children With GH in the United States and Europe: Long-Term Follow-Up From NordiNet(®) IOS and ANSWER Program

CONTEXT: Understanding real-world prescribing of GH may help improve treatment of eligible patients. OBJECTIVE: Overall: to assess real-world effectiveness and safety of GH (Norditropin). This analysis: to compare clinical characteristics of GH-treated children in the United States and Europe. DESIGN: The American Norditropin Studies: Web-Enabled Research Program (ANSWER; 2002 to 2016, United States) and the NordiNet International Outcome Study (NordiNet IOS; 2006 to 2016, Europe) were multicenter longitudinal observational cohort studies. SETTING: Data were recorded in 207 (United States) and 469 (Europe) clinics. PARTICIPANTS: Patients with GH deficiency, Turner syndrome, Noonan syndrome, idiopathic short stature, Prader–Willi syndrome, or born small for gestational age, who commenced GH treatment aged <1 year. INTERVENTION: GH was prescribed by treating physicians according to local practice. MAIN OUTCOMES MEASURES: Baseline data and drug doses were recorded. Data on effectiveness and safety were collected. RESULTS: ANSWER had 19,847 patients in the full analysis set (FAS; patients with birthdate information and one or more GH prescription) and 12,660 in the effectiveness analysis set (EAS; GH-naive patients with valid baseline information). NordiNet IOS had 17,711 (FAS) and 11,967 (EAS). Boys accounted for 69% (ANSWER) and 57% (NordiNet IOS). Treatment start occurred later than optimal to improve growth. The proportion of boys treated was generally larger, children were older at treatment start, and GH doses were higher in the United States vs Europe. No new safety signals of concern were noted. CONCLUSIONS: In most indications, more boys than girls were treated, and treatment started late. Earlier diagnosis of GH-related disorders is needed. The data support a favorable benefit–risk profile of GH therapy in children.