Endocrine Abstracts

JOINT1455

Objective: Somapacitan is a long-acting reversible albumin-binding growth hormone (GH) derivative approved for once weekly administration in children with growth hormone deficiency (GHD). We present outcomes from a pooled analysis of data from three clinical trials (REAL 3 [NCT02616562], REAL 4 [NCT03811535] and REAL 6 [NCT04970654]) assessing the efficacy and safety of somapacitan vs daily GH (Norditropin®, Novo Nordisk).

Methods: In each trial, pre-pubertal, GH-treatment-naïve children with GHD were randomised to treatment with somapacitan (REAL 3: 0. 04 vs 0. 08 vs 0. 16 mg/kg/week; REAL 4 and 6: 0. 16 mg/kg/week only) or daily GH (all: 0. 034 mg/kg/day) for 52 weeks. REAL 3 and 4 were conducted internationally, and REAL 6 was conducted in China. For this analysis, efficacy comparisons were conducted vs patients treated with somapacitan 0. 16 mg/kg/week only. Mixed models of repeated measurements were used for comparisons of height velocity (HV), change in height standard deviation score (SDS) and change in insulin-like growth factor-I (IGF-I) SDS. An analysis of covariance model was used to compare changes in bone age/chronological age (BA/CA). Treatment, study, sex, age group, region, GH peak group and sex by age group by region interaction term were included as factors in each model, with the baseline of each respective efficacy measure used as the covariate (for HV, baseline height was used instead).

Results: The analysis included 220 patients treated in total with somapacitan and 118 patients treated with daily GH. Efficacy data are mean (SE). After 52 weeks, HV was 11. 2 (0. 1) cm/year vs 11. 1 (0. 2) cm/year in the pooled somapacitan and daily GH groups, respectively. Change in height SDS from baseline to week 52 was 1. 25 (0. 03) in the pooled somapacitan group and 1. 20 (0. 04) in the pooled daily GH group. Change in IGF-I SDS after 52 weeks was 2. 34 (0. 08) and 2. 10 (0. 11) in the pooled somapacitan and daily GH groups, respectively. Change in BA/CA after 52 weeks was similar between the pooled somapacitan and daily GH groups (0. 06 [0. 01] vs 0. 07 [0. 01], respectively). Differences between groups were non-significant for measures reported above (P > 0. 05). Similar rates of adverse events per 100 patient years of exposure (294. 6 for somapacitan and 289. 0 for daily GH) were reported.

Conclusions: Outcomes from a pooled analysis of REAL 3, REAL 4 and REAL 6 demonstrate similar efficacy of somapacitan compared to daily GH over 52 weeks of treatment, with comparable safety and mean IGF-I SDS change in treatment-naïve children with GHD.