Abstract
OBJECTIVE: The absorption, distribution and elimination of oral semaglutide, the first oral glucagon-like peptide-1 receptor agonist for treating type 2 diabetes, was investigated using a population pharmacokinetic model based on data from clinical pharmacology trials. METHODS: A previously developed, two-compartment pharmacokinetic model, based on subcutaneous and intravenous semaglutide, was extended to include data from six oral semaglutide trials conducted in either healthy volunteers or subjects with renal or hepatic impairment. Five trials employed multiple doses of oral semaglutide (5-10 mg) and one was a single-dose (10 mg) trial. In a separate analysis, the model was re-estimated using data from a trial in subjects with type 2 diabetes. RESULTS: The model accurately described concentration profiles across trials. Post-dose fasting time, co-ingestion of a large water volume, and body weight were the most important covariates affecting semaglutide exposure. Bioavailability was 0.8% when oral semaglutide was dosed using the recommended dosing conditions (30 min post-dose fasting time, administered with ≤ 120 mL of water), increasing with a longer post-dose fasting time and decreasing with higher water volume. Within-subject variability in bioavailability was 137%, which with once-daily dosing and a long half-life translates into 33% within-subject variability in steady-state exposure. There was no significant difference in oral bioavailability of semaglutide in healthy subjects and subjects with type 2 diabetes. CONCLUSIONS: The updated model provided a general characterisation of semaglutide pharmacokinetics following oral, subcutaneous and intravenous administration in healthy subjects and subjects with type 2 diabetes. Within-individual variation of oral bioavailability was relatively high, but reduced considerably at steady state. CLINICALTRIALS. GOV IDENTIFIERS: NCT01572753, NCT01619345, NCT02014259, NCT02016911, NCT02249871, NCT02172313, NCT02877355.