Supplementary Material for: Somapacitan is Effective and Well Tolerated in Chinese Children with Growth Hormone Deficiency: a Randomised Controlled Phase 3 Study

Introduction: REAL6 is a randomized, multi-centre, open-labelled, active-controlled parallel group phase 3 trial (NCT04970654) investigating once-weekly somapacitan, a reversible albumin-binding growth hormone (GH) derivative, in Chinese children with GH deficiency (GHD). Methods: 110 treatment-naïve patients were randomized 2:1 to somapacitan (0.16 mg/kg/week) or daily GH (Norditropin®; 0.034 mg/kg/day) for 52 weeks. Annualized height velocity (HV; cm/year) at week 52 was the primary measurement. Additional assessments included HV standard deviation score (SDS), height SDS, bone age, insulin-like growth factor-I (IGF¬ I) SDS, and observer-reported outcomes. Results: Estimated mean HV at week 52 was 11.0 and 10.4 cm/year for somapacitan and daily GH, respectively. Non-inferiority of somapacitan compared to daily GH was confirmed. Changes in HVSDS, height SDS, bone age, and IGF-I SDS from baseline to week 52 were similar between groups. At week 52, mean (SD) IGF-I SDS was within intended reference range (-2.0 to +2.0) and comparable between groups: +0.5 (1.4) for somapacitan versus +0.1 (1.2) for daily GH. Somapacitan was well-tolerated with a safety profile consistent with the well-known safety profile of daily GH. A low proportion of injection-site reactions were reported for somapacitan (2.7%), with no reports of injection-site pain during the 52-week treatment period. Disease burden was reduced from baseline to week 52 for both treatments. Somapacitan reduced treatment burden compared to daily GH. Conclusions: Efficacy and safety profiles were comparable for Chinese children with GHD treated with somapacitan or daily GH. Both treatments similarly reduced disease burden, while treatment burden was reduced with somapacitan.