Investigating the Bioavailability and Insulin-like Growth Factor-I Release of Two Different Strengths of Somapacitan: A Randomised, Double-Blind Crossover Trial.

Abstract

Randomised, double-blind, crossover trial to confirm bioequivalence of somapacitan, a long-acting growth hormone (GH), in 5mg/1.5mL and 10mg/1.5mL strengths in equimolar doses. Healthy participants were randomised (1:1:1) to subcutaneous somapacitan treatment in one dosing period with 5mg/1.5mL and two periods with 10mg/1.5mL. Eligibility criteria included age 18-45years and body mass index 18.5-24.9kg/m2. Exclusion criteria included history of GH deficiency, previous GH treatment, weight > 100.0kg and participation in any clinical trial of an investigational medicinal product within 45days or five times the half-life of the previous investigational product before screening. Area under the curve from time 0 until last quantifiable observation (AUC0-t), maximum serum concentration (Cmax), time to Cmax and terminal half-life of somapacitan and safety were assessed. In total, 33 participants were randomised. For AUC0-t, estimated treatment ratio (ETR) (5mg/1.5mL versus 10mg/1.5mL) was 0.95 (90% confidence interval [CI] 0.89-1.01). Point estimate and 90%CIs were within the acceptance range (0.80-1.25). For Cmax, ETR was 0.77 (90%CI 0.68-0.89). Point estimate and 90%CIs were outside the acceptance range (0.80-1.25). Mean insulin-like growth factor-I (IGF-I) and IGF-I standard deviation score concentration-time curves for each strength were almost identical. No new safety issues were identified. Bioequivalence criterion for somapacitan 5mg/1.5mL and 10mg/1.5mL was met for AUC0-t but not for Cmax. The two strengths had equivalent IGF-I responses. ClinicalTrials.gov, NCT03905850 (3 April 2019).