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Pediatric and Adolescent Endocrinology

MON-223 - Injection-Site Pain with Two Once-Weekly Growth Hormone Products in Children: A Sequential within-Subject Comparison of Somatrogon and Somapacitan

Monday, June 15, 2026
9:00 AM - 2:00 PM CT
Location: ENDOExpo; Poster Floor


Background: Once-weekly growth hormone (GH) such as somatrogon and somapacitan has improved treatment adherence compared to daily GH by reducing injection frequency. However, head-to-head comparisons using within-subject evaluations of patient-reported injection-site pain are lacking.

Objective: To evaluate changes in perceived injection-site pain following a switch from somatrogon to somapacitan in children with growth hormone deficiency.

Methods: This single-arm, sequential within-subject study included 19 children who had experienced injection-site pain while using somatrogon for at least 4 weeks. After switching to somapacitan for another 4 weeks, injection-site pain was evaluated using the Numerical Rating Scale (NRS) or Faces Rating Scale (FRS), depending on age. A structured 5-point Likert scale questionnaire assessed device usability, pain perception (during and after injection), and treatment preference. Statistical analyses included paired t-tests for pain scores and binomial tests for questionnaire results.

Results: The mean age of participants was 9.6 ± 2.6 years. Diagnoses included growth hormone deficiency (n=17) and panhypopituitarism following craniopharyngioma surgery (n=2). Pain scores significantly decreased after switching to somapacitan (NRS: 6.5±2.6 vs 1.6±1.7; FRS: 3.8±1.1 vs 1.1±1.1; both p< 0.001). All participants expressed a preference for continuing somapacitan (p < 0.001). Device usability and pain during injection were rated significantly better for somapacitan.

Conclusion: In pediatric patients experiencing injection-site pain with somatrogon, switching to somapacitan resulted in significant pain reduction in a within-subject comparison. These findings support the clinical importance of formulation choice and may facilitate shared decision-making in pediatric growth hormone therapy.

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*