Pharmacokinetics of the ghrelin agonist capromorelin in a single ascending dose Phase-I safety trial in spinal cord-injured and able-bodied volunteers

Study design: Single centre, single ascending dose study. Objectives: To compare the pharmacokinetics and assess the safety of capromorelin, a compound that has potential to treat constipation following spinal cord injury (SCI), in groups of able-bodied and SCI volunteers. Setting: Local population from Victoria, Australia. Methods: Following initial screening and baseline blood collections, participants received ascending oral doses (20, 50 and then 100 mg at least 1-week apart) of capromorelin after pre-dose blood collection, followed by blood collections over the following 12 h for pharmacokinetic analysis and 1-week and 4-week follow-up blood collections for safety evaluations. Blood pressure and heart rate were monitored. Results: No serious adverse events were recorded following any dose in either the able-bodied group or the SCI group. There were no abnormal blood pressure or heart rate changes. Minor adverse events resolved quickly without the need for treatment. Pharmacokinetic behaviour was broadly similar between groups, with both exhibiting dose-dependent increases in C-max and AUC(0-infinity). The SCI participants showed greater variance in pharmacokinetic parameters and had a slightly delayed T-max and half-life. Conclusion: Capromorelin at the doses tested was safe and well tolerated in both SCI and able-bodied participants and also showed similar pharmacokinetics with dose-dependent increases in concentration and drug exposure.