A Randomized, Cross-Over Study Investigating the Comparability of Somatrogon-ghla in 2 Different Drug Product Presentations

Somatrogon-ghla is a long-acting, recombinant human growth hormone approved for the treatment of pediatric patients with growth hormone deficiency. Forty-nine healthy, adult males were enrolled in a randomized, crossover study to compare somatrogon exposure after subcutaneous doses administered using a frozen vial presentation or a prefilled, multiple dose pen. Somatrogon, insulin-like growth factor-I, and IGF-1 binding protein-3 concentrations were collected for up to 240 hours post dose to assess pharmacokinetic and pharmacodynamic responses. There was a 2-week washout between administration of the doses. Seven participants did not complete the study due to withdrawal of consent (n = 2) or loss to follow-up. Two treatment-emergent adverse events, headaches, were judged by the investigator as possibly related to study drug administration. Both were mild. Injection site reactions were observed in 6/48 participants after administration with the pen and 12/46 after administration using the vial. Drug and biomarker concentrations were assessed using validated assays and noncompartmental methods were used to determine pharmacokinetic and pharmacodynamic parameters. Bioequivalence was demonstrated for somatrogon area under the concentration-time curve, but not for the peak somatrogon concentration, where the lower limit of the 90% confidence interval for the ratio of pen/vial was 74.2%, which is less than the lower limit, 80.0%, dictated by bioequivalence criteria. The IGF-1 responses were largely within bioequivalence limits. It was concluded that the 2 formulations are comparable.