Comparison of Chronocort Versus Standard Hydrocortisone Replacement Therapy in Participants Aged 16 Years and Over With Congenital Adrenal Hyperplasia

Exclusion Criteria

• •Clinical or biochemical evidence of hepatic or renal disease e.g. creatinine \>2 times the upper limit of normal (ULN) or elevated liver function tests (alanine aminotransferase \[ALT\] or aspartate aminotransferase \[AST\] \>2 times the ULN).
• •History of bilateral adrenalectomy.
• •History of malignancy (other than basal cell carcinoma successfully treated \>26 weeks prior to entry into the study).
• •Participants who have type 1 diabetes or receive regular insulin, have uncontrolled diabetes, or have a screening HbA1c greater than 8%.
• •Persistent signs of adrenal insufficiency or the participant does not tolerate treatment at the end of the 4-week run-in period.
• •Participants with any other significant medical or psychiatric conditions that in the opinion of the Investigator would preclude participation in the study.
• •Participants on regular daily inhaled, topical, nasal or oral steroids for any indication other than CAH.
• •Co-morbid condition requiring daily administration of a medication or consumption of any material that interferes with the metabolism of glucocorticoids.
• •Participants who are receiving \<10 mg hydrocortisone dose at screening or the hydrocortisone dose equivalent.
• •Participants anticipating regular prophylactic use of additional steroids e.g. for strenuous exercise.
• •Participation in another clinical study of an investigational or licensed drug or device within the 12 weeks prior to screening.
• •Inclusion in any natural history or translational research study that would require evaluation of androgen levels during the study period outside of this protocol's assessments.
• •Participants who have previously been exposed to Chronocort in any Diurnal study.
• •Participants who routinely work night shifts and so do not sleep during the usual night-time hours.
• •Participants, who in the opinion of the Investigator, will be unable to comply with the requirements of the protocol.
• •Participants with a known hypersensitivity to any of the components of the Chronocort capsules, the Cortef tablets, or the placebo capsules.
• •Participants with congenital galactosemia, malabsorption of glucose and galactose, or who are lactase deficient.
• •Participants with a body weight of 45 kg or less.