Aims: Children with GHD are currently treated with daily subcutaneous growth hormone (GH) injections, which can be burdensome. Somapacitan is a long-acting GH derivative in development for once-weekly use in children with GHD.
Methods: REAL 3 (NCT02616562) is a phase 2, multinational, randomised, open‑label, controlled trial assessing efficacy and safety of somapacitan versus daily GH (Norditropin®). Prepubertal, GH-naïve children with GHD received 0.04 (n=16), 0.08 (n=15) or 0.16 (n=14) mg/kg/week somapacitan, or 0.034 mg/kg/day daily GH for 1 year. In a 2-year safety extension, all patients on somapacitan (n=45) received 0.16 mg/kg/week; the daily GH group remained unchanged. In a 4‑year safety extension, the daily GH group switched to 0.16 mg/kg/week somapacitan (daily GH/somapacitan, n=11), while the somapacitan group remained unchanged (somapacitan/somapacitan, n=39). We present results from year 4, the first year of the 4‑year safety extension.
Results: Data are mean (SD). Height velocity (HV) was 7.4 (1.6) cm/year for somapacitan/somapacitan and 6.6 (1.6) cm/year for daily GH/somapacitan, versus 8.3 (1.7) and 7.6 (2.0) cm/year for somapacitan/somapacitan and daily GH, respectively, at year 3. HV SD score (SDS) was 1.55 (1.70) and 0.88 (1.61); change in height SDS from baseline was 2.85 (1.25) and 2.28 (0.97); insulin-like growth factor-I SDS was 1.29 (1.23) and 0.94 (1.60) for somapacitan/somapacitan and daily GH/somapacitan, respectively. The table shows overall scores of GHD‑child treatment burden and GHD‑parent treatment burden, reported by parents/guardians.
During year 4, 20 patients (51.3%) receiving somapacitan/somapacitan experienced 84 adverse events (AEs), and eight patients (72.7%) receiving GH/somapacitan experienced 12 AEs. Most AEs were mild/moderate and unrelated to treatment.
Conclusion: Height-related outcomes were similar between, and as expected for, both treatment arms. Somapacitan may lead to improvement in treatment burden versus daily GH. Somapacitan safety profile was consistent with previous reports.