SAT-LB074 Efficacy and Safety of Once-weekly Somapacitan in Adult Growth Hormone Deficiency (AGHD) Confirmed in a 53‑week Real 1 Trial Extension

The 34-week double-blind placebo-controlled main phase of REAL 1 (NCT02229851) has been previously presented (Johannsson G et al. 2018.). Now we report the open-label extension of this trial evaluating efficacy and safety of somapacitan in male/female patients aged 23-79 years with AGHD, for an additional 52 weeks (8 weeks’ dose titration followed by 44 weeks’ fixed-dose treatment) comprising a total of 86 weeks of treatment. Patients who completed the main trial entered the extension: 1) somapacitan-treated patients continued on that treatment; 2) daily GH-treated patients were re-randomized 1:1 to somapacitan or daily GH; 3) patients receiving placebo were switched to somapacitan. Starting doses were age- and gender-dependent and were titrated toward a target IGF-I SDS -0.5 to +1.75. Changes from the original baseline (BL) to end of extension period in body composition were evaluated by DXA (truncal fat %, truncal fat mass, visceral adipose tissue %, visceral adipose tissue, total fat mass, android fat mass, gynoid fat mass, truncal lean body mass, appendicular skeletal muscle mass, and lean body mass). IGF-I SDS and lipid profile were also compared. Exploratory analysis on changes from BL were based on MMRM analysis models comparing somapacitan/somapacitan and daily GH/daily GH arms. 300 patients were treated in the main phase, and 272 (91%) in the extension. Mean age was 45.1 years; 51.7% were female. Mean exposure (during extension alone) was 355 (somapacitan/somapacitan) and 349 days (daily GH/daily GH). After 86 weeks of treatment, target IGF-I SDS was achieved in all treatment arms (mean values [SD], somapacitan/somapacitan: from -2.54 [1.26] to -0.22 [1.27]; placebo/somapacitan: from -2.64 [1.28] to -0.31 [1.08]; daily GH/daily GH: from -2.33 [1.28] to -0.24 [1.32]; daily GH/somapacitan: from -2.75 [1.20] to -0.39 [1.12]). The beneficial effects of somapacitan on body composition observed in the main phase were maintained and did not differ statistically significantly between the somapacitan/somapacitan and daily GH/daily GH arms (p>0.05). There were no statistically significant differences in IGF-I SDS or lipid parameters between the somapacitan/somapacitan and daily GH/daily GH arms. Incidence, severity and type of adverse events were similar for somapacitan and daily GH throughout the trial. Few injection-site reactions were reported and all were mild to moderate in severity. No anti-somapacitan antibodies were detected. In conclusion, the body composition changes and IGF-I SDS level observed in the main phase of REAL 1 were maintained in the trial extension. No new safety signals or tolerability issues were identified for somapacitan. Reference: Johannsson G et al. Endocr Rev. 2018;39(2 Suppl):SUN-632C-LB Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.