Retrospective Comparative Evaluation of One-Year Efficacy and Safety Outcomes of Somatropin and Somatrogon in Children with Growth Hormone Deficiency: A Single-Center Experience

Objectives: To compare one-year growth, insulin-like growth factor 1 (IGF-1), anthropometric, and safety outcomes of once-weekly somatrogon and once-daily somatropin in children with isolated growth hormone deficiency (GHD). Methods: This single-center retrospective cohort included 150 treatment-naïve children (75 per group); treatment was selected by parental preference. Outcomes were analyzed using repeated-measures general linear models and multivariable regression adjusted for baseline age, sex, Tanner stage, peak stimulated GH, and the corresponding baseline value. Results: Mean height gain was 9.41 ± 1.48 cm with somatrogon and 9.04 ± 1.42 cm with somatropin (p = 0.126). Adjusted differences were not significant for height gain (0.35 cm; 95% CI, −0.12 to 0.82) or height standard deviation score (SDS) change (0.04; 95% CI, −0.06 to 0.15). Weight, weight SDS, body mass index (BMI), and BMI SDS increased more with somatrogon after adjustment (all p ≤ 0.001). Adjusted one-year increases were also greater with somatrogon for IGF-1 (29.3 ng/mL; 95% CI, 8.2–50.4) and IGF-1 SDS (0.34; 95% CI, 0.11–0.58). IGF-1 SDS >+2 occurred in 16.0% versus 4.0% of patients (difference, 12.0 percentage points; 95% CI, 2.3–22.3; p = 0.027); in 9 of the 12 somatrogon-treated patients, samples were obtained <96 h after injection. Adverse events were recorded in 24.0% and 28.0% of patients, respectively, most commonly injection-site pain; no serious adverse events occurred. Conclusions: One-year linear growth did not differ significantly between treatments, whereas somatrogon was associated with greater increases in IGF-1, weight, and BMI. Non-randomized treatment selection, residual confounding, and variable IGF-1 sampling times limit causal interpretation.