Modified-Release Hydrocortisone in Congenital Adrenal Hyperplasia

Context Standard glucocorticoid therapy in congenital adrenal hyperplasia (CAH) regularly fails to control androgen excess, causing glucocorticoid overexposure and poor health outcomes. Objective We investigated whether modified-release hydrocortisone (MR-HC), which mimics physiologic cortisol secretion, could improve disease control. Methods A 6-month, randomized, phase 3 study was conducted of MR-HC vs standard glucocorticoid, followed by a single-arm MR-HC extension study. Primary outcomes were change in 24-hour SD score (SDS) of androgen precursor 17-hydroxyprogesterone (17OHP) for phase 3, and efficacy, safety and tolerability of MR-HC for the extension study. Results The phase 3 study recruited 122 adult CAH patients. Although the study failed its primary outcome at 6 months, there was evidence of better biochemical control on MR-HC, with lower 17OHP SDS at 4 (P = .007) and 12 (P = .019) weeks, and between 07:00h to 15:00h (P = .044) at 6 months. The percentage of patients with controlled 09:00h serum 17OHP ( Conclusion MR-HC improved biochemical disease control in adults with reduction in steroid dose over time and patient-reported benefit.