Open-label Comparison of Chronocort® Versus Standard Glucocorticoid Replacement Therapy

This study is an open-label, randomised, titration-blinded, parallel arm, multicenter study to compare twice daily Chronocort® with standard care in participants with Congenital Adrenal Hyperplasia (CAH). This study will be conducted in the USA.

Inclusion Criteria: Participants are eligible to be included in the study only if all of the following criteria apply (note: if a participant fails to meet an inclusion criterion, re-screening is permitted if the Investigator considers that the circumstances leading to screening failure will not be relevant when the participant is re-screened at a later time): Age 1. Participant must be aged 16 years or older at the time of signing the informed consent. 2. In participants aged \ 2 times the upper limit of normal (ULN) or elevated liver function tests (alanine aminotransferase \[ALT\] or aspartate aminotransferase \[AST\] \>2 times the ULN). 2. History of bilateral adrenalectomy. 3. History of malignancy (other than basal cell carcinoma successfully treated \>26 weeks prior to entry into the study). 4. Participants who have type 1 diabetes or any participant who is receiving insulin. 5. Participants with any other significant medical or psychiatric conditions that in the opinion of the Investigator would preclude participation in the study. Prior/Concomitant Therapy 6. Participants on regular daily oral steroids for any indication other than CAH. Note: a participant should not be given any steroids (even on an irregular basis) within 5 days of a study visit. If there is a medical need for steroid treatment within this time frame then the visit should be postponed until a 5-day interval has elapsed. 7. Co-morbid condition requiring daily administration of a medication or consumption of any material that interferes with the metabolism of glucocorticoids (examples provided at http://medicine.iupui.edu/clinpharm/ddis/clinical-table/). 8. Participants who are receiving \