Pharmacokinetic (PK), Pharmacodynamic (PD) and Tolerability of Osilodrostat in Pediatric Patients With Cushing's Syndrome

To join this study, children and teenagers need to be between 2 and 17 years old and have Cushing's syndrome that started naturally within their body, not from taking certain medications. This is for those who have had surgery that didn't fully work, are waiting for surgery, or can't have surgery right now. They also need to weigh more than 10 kilograms (about 22 pounds).

Doctors will need to have a clear diagnosis of Cushing's syndrome. This often involves looking at growth patterns, certain blood or urine tests that measure cortisol levels, and a special test called a dexamethasone suppression test. Participants must also be able to swallow study tablets whole, or the contents of capsules mixed with water. Parents or legal guardians must be able to give permission for their child to take part.

However, some children might not be suitable for the study. This includes those with large growths (macroadenomas) that are already causing serious problems or need urgent surgery. Also, if a child has recently taken other medicines to lower cortisol, they might need to wait a certain period before joining. Finally, if they are involved in other research studies with new medications, they usually can't join this one.

If you decide to take part, your child will first go through a screening period for up to 4 weeks. This is to make sure they meet all the study requirements and that any previous medications that affect cortisol have left their system. During this time, they’ll have checks and tests to confirm their condition and suitability.

The main treatment period will last 12 weeks. Your child will receive the study medication, osilodrostat, which they'll need to swallow either as a whole tablet or as contents of a capsule mixed with water. Throughout these 12 weeks, the study team will carry out assessments to see how the medication is working, how it's affecting your child's body, and to check for any side effects. These assessments will involve various tests and check-ups.

After 12 weeks, if your child is benefiting from the treatment and the study doctor agrees, there's an optional extension period of 9 months. During this longer period, they will continue to take the medication, and safety and how well it's working will be monitored. If your child doesn't join the extension period, they will have one final safety check-up visit about 4 weeks later. The total duration for some patients, especially those awaiting surgery, might be less than 12 weeks.