Real-world experience of using Long-Acting Growth Hormone Somatrogon in children and adolescents with growth hormone deficiency

Background: The first Long-Acting Growth Hormone (LAGH) therapy, Somatrogon, has been available in Italy since March 2023 for children with growth hormone deficiency (GHD) older than 3 years, offering a convenient way of administering the treatment once weekly instead of once daily. Clinical trials have demonstrated the efficacy and safety of LAGH treatment in children with GHD. We aimed to evaluate the real-world experience of using Somatrogon at a tertiary pediatric endocrine center in Italy. Methods: We retrospectively collected data on all patients who started treatment with Somatrogon from March 2023 until April 2024. Results: Overall, 20 patients with GHD started treatment with Somatrogon: 9 were naïve to treatment, and 11 were switched from Somatropin treatment (Table 1). Reasons for choosing Somatrogon were: needle phobia (n=9), multiple treatments (n=7), family management simplification (n=2), behavioral problems (n=2). After 1 month of treatment, IGF-1 levels were checked (n=17): median IGF-1 was 0.7 SDS (IQR 0.0;1.6), with a significant increase compared to the start of treatment (p<0.001) (median +0.9 [IQR +0.1;+2.2]); the median of Somatrogon dose after 1 month was 0.64 (IQR 0.63;0.66). After 3 months of treatment (n=11), a significant increase in height SDS from the beginning of treatment was found (p=0.014) (median +0.16 [IQR +0.03;0.31]), with no further significant increase in IGF-1 SDS levels (median -0.19 [IQR -0.65;+0.34]); the dose of Somatrogon (median 0.60 mg/kg/week [IQR 0.53;0.64]) was significantly lower than the beginning (p<0.001). For 8 patients data after 3 months of treatment were available (median 311 days [IQR 287;345]). Height SDS was significantly higher compared to the beginning (p=0.04) (median +0.28 [IQR -0.4;0.36]), with no further significant increase in IGF-1 levels from the first month of treatment (median -0.8 [IQR -1.15;-0.03]); the dose of Somatrogon (median 0.55 mg/kg/week [IQR 0.52;0.63]) was significantly lower than at the beginning (p=0.004). No patients asked to change to daily injections and no side effects were reported.