SAT-212 Long-term Safety And Efficacy Of Somapacitan In Short Children Born Small For Gestational Age: 4-year Results From A Global Phase 2 Trial

Abstract Disclosure: A. Juul: Novo Nordisk, Sanofi, Ipsen. M. Hojby: Novo Nordisk. M. Kawai: None. A. Linglart: Novo Nordisk, Alexion Pharmaceuticals, Inc., Pfizer, Inc., Sandoz, Ipsen. J. Mori: Novo Nordisk, Pfizer, Inc.. N. Zuckerman-Levin: None. P.F. Backeljauw: Novo Nordisk, Consultant and/or honoraria. Treatment of short stature in children born small for gestational age (SGA) requires daily growth hormone (GH) injections. Somapacitan is a long-acting GH derivative approved for the treatment of GH deficiency and currently in phase 3 development for other pediatric indications. We report long-term (208-week) results from the global phase 2 trial REAL5 (NCT03878446) investigating the efficacy and safety of once-weekly somapacitan in SGA. In total, 62 (35.5% female) GH-treatment-naïve, prepubertal short children born SGA were randomized 1:1:1:1:1 to one of three somapacitan doses (0.16, 0.20 or 0.24 mg/kg/week) or two daily GH doses (0.035 or 0.067 mg/kg/day) for 52 weeks, all administered subcutaneously. Published results demonstrated similar safety and efficacy for somapacitan 0.24 mg/kg/week and daily GH 0.067 mg/kg/day after 52 weeks. Sixty children were included in the ongoing safety extension, during which all children were switched to somapacitan 0.24 mg/kg/week. Fifty-five children completed 208-weeks of treatment across five treatment groups: 0.16->0.24 mg/kg/week somapacitan (n=12/12), 0.20->0.24 mg/kg/week somapacitan (n=12/13), 0.24->0.24 mg/kg/week somapacitan (n=12/12), 0.035 mg/kg/day->somapacitan 0.24 mg/kg/week (n=8/12), and 0.067 mg/kg/day->somapacitan 0.24 mg/kg/week (n=11/13). Across all treatment arms, height velocity remained above baseline level and continuous increases in height SDS were observed through to week 208. The safety and tolerability profile of somapacitan 0.24 mg/kg/week was similar to the profile of daily GH. Reported AEs were mostly mild/moderate in severity (most unlikely related to trial product). One injection site reaction was reported after switch (pain; mild in severity; unlikely related). No neutralizing anti-drug antibodies were detected. Except for one participant who discontinued treatment at week 52 (type 1 diabetes; unrelated), no clinically relevant findings with respect to glucose metabolism were identified during the 208-week study period. 23/24 patients switching from daily GH to somapacitan completed the GH-patient preference questionnaire: 20/23 (87%) preferred somapacitan, 2/23 (8.7%) had no preference, and 1/23 (4.3%) preferred daily GH. 16/20 (80%) answered they would likely be more adherent to the once-weekly treatment regimen of somapacitan compared to daily GH injections, 4/20 (20%) stated no difference, and no one answered daily GH would result in better adherence. In conclusion, these data support long-term efficacy, safety, and tolerability of once-weekly somapacitan in short children born SGA with up to 4 years of treatment. A clear preference for once-weekly somapacitan was observed. Presentation: Saturday, July 12, 2025