OR25-02 A Phase 3 Study of a Modified-Release Hydrocortisone in the Treatment of Congenital Adrenal Hyperplasia

Abstract

Background: Patients with congenital adrenal hyperplasia (CAH) due to classic 21-hydroxylase deficiency have poor health outcomes related to inadequate glucocorticoid (GC) replacement. We compared disease control of adults with classic CAH treated with a modified release hydrocortisone (MRHC), which replicates physiological diurnal cortisol secretion, versus standard GC therapy. Methods: 6 month, open label, study in 122 patients randomised either to treatment with MRHC (Chronocort®, Diurnal Ltd, Cardiff, UK) twice daily at ~ 0700h & ~2300h, or to remain on their standard GC regimen (hydrocortisone, prednisolone, prednisone, dexamethasone). Patients had 24-hr profiling of serum 17-hydroxyprogesterone (17-OHP) at baseline and for dose titration at 4 and 12 weeks. The primary efficacy endpoint was the change from baseline to 24 weeks in the natural logarithm of the mean of the 24-hr standard deviation score (SDS) profile for 17-OHP. Results: Both groups achieved improved hormonal control at 24 weeks. The mean 24-hour 17-OHP SDS was significantly lower on MRHC compared to standard GC at 4 weeks (p = 0.0074) and 12 weeks (p = 0.019), but not at 24 weeks. In post-hoc analyses at 24 weeks, MRHC treatment showed a greater reduction in 17-OHP SDS compared to standard GC in the morning, 0700-1500h (p = 0.0442) and a greater reduction in log transformed 17-OHP 24 hour AUC (p=0.0251). Defining a morning 17-OHP <1200ng/dl (<36 nmol/L) as good control, for patients not controlled at baseline 85% were well controlled at 24 weeks with MHRC versus 50% on standard GC. For patients controlled at baseline 100% were controlled at 24 weeks on MHRC versus 84% with standard GC (p = 0.0018). The variability of 17-OHP over 24 hours was significantly reduced in the MRHC group compared to standard GC: the ratio of amplitude at 24 weeks divided by amplitude at baseline was for MRHC, 0.361 [95% CI: 0.235, 0.651], and standard GC, 0.917 [0.773, 1.366]; (p = 0.0001).There were no adrenal crises on MRHC and fewer stress doses despite similar incidence of inter-current illness to the standard GC group which had 3 adrenal crises. MRHC was associated with patient reported benefit including restoration of menstruation in 4 patients on MRHC and 1 on standard GC and two partner pregnancies in patients on MRHC and none on standard GC. Discussion: This is the largest randomised controlled trial of GC treatment in CAH and showed that intensification of therapy could improve control of the androgen-precursor, 17-OHP, and that this hormonal control was superior in the morning with MRHC. MRHC reduced the fluctuations in 17-OHP such that in the majority of patients the 17-OHP profile was within the reference range throughout 24 hours, providing consistent and optimal disease control. Conclusion: Diurnal cortisol replacement with a MRHC improves the biochemical control of classic CAH with a twice-daily therapeutic regimen.

Congenital Adrenal Hyperplasia—Current Insights in Pathophysiology, Diagnostics, and Management

“…A phase III trial including 122 patients with classic CAH revealed superior hormonal control during the early morning and early afternoon compared to patients receiving standard glucocorticoid therapy (338,385). 5).…”

“…advantage over intermittent bolus administration because of lower variability and avoidance of regular troughs in plasma cortisol levels (385,410), but these two approaches have not been compared directly and clinical outcomes are likely similar. Stress dosing is indicated for pregnant women in active labor, similar to that used in major surgical stress (405).…”

Current and future treatment options for adrenal insufficiency

“…3) [55,56 ▪ ,57]. In the recently concluded phase 3 study ( n = 122) the 0700h-1500h 17-OHP profile was better with Chronocort compared to conventional glucocorticoid treatment ( P = 0.0251) [58 ▪▪ ].…”