Influence of long-acting growth hormone analogs on other hypothalamic-pituitary axes: a real-world study

Long‑acting growth hormone (LAGH) formulations have emerged to address poor adherence to daily recombinant human growth hormone (rhGH), offering reduced injection frequency and comparable efficacy. Though their efficacy and safety in children have been demonstrated in registrative trials and in some real-world studies, their impact on other pituitary axes remains unclear.

This observational prospective monocentric study explores hormonal changes in isolate growth hormone deficiency (GHD) children (n = 33) starting LAGH Somatrogon (n = 16, G1) or switching from daily rhGH to the same weekly analogue (n = 17, G2). In all study patients, baseline and post‑treatment assessments (after 3-6 months of weekly LAGH start) included IGF‑I, ACTH, cortisol, TSH, FT4 and FT3 levels.

After LAGH initiation, IGF‑I SDS increased significantly in both groups (p < 0.001), more frequently exceeding 2 SDS in G2 (6/17 vs. 2/16 in G1). No significant changes occurred in TSH, FT3, FT4, ACTH or cortisol levels after LAGH start, nor between‑group differences.

In isolated GHD, adrenal and thyroid function remained stable after LAGH initiation, with comparable results in treatment‑naïve patients and in those already receiving daily therapy. A greater increase in IGF-I levels was observed in switchers, suggesting that a lower starting dose may be appropriate in patients previously treated with rhGH. Further studies are required to clarify the endocrine effects of long‑acting formulations in individuals with associated multiple pituitary hormone deficiencies.