This study investigates an investigational medication for the treatment of congenital adrenal hyperplasia (CAH). CAH is a genetic condition that affects the adrenal glands, which are responsible for producing important hormones. The condition is often due to a deficiency in an enzyme called 21-hydroxylase, leading to hormone imbalances in the body.
Participants in the study will receive either the investigational medication or a placebo. A placebo is an inactive substance that looks like the investigational medication but does not contain any medicine. Participants will continue their stable regimen of glucocorticoid replacement therapy during the study.
- Who can participate: Adults with a historical diagnosis of classic CAH due to 21-hydroxylase deficiency are eligible. Participants must be on a stable glucocorticoid regimen and agree to follow contraception guidelines. Certain medical conditions and recent use of other investigational drugs may exclude participation.
- Study details: Participants will receive either the investigational medication or a placebo. They will continue their current glucocorticoid therapy.

