An open-label, long-term extension study to evaluate safety and efficacy in participants treated with crn04894

Congenital Adrenal Hyperplasia, or CAH, is a medical term used to describe a group of rare diseases of the adrenal glands. The adrenal glands are located on top of the kidneys and produce hormones that control many important functions in the body. A hormone is a tiny chemical messenger that can “talk” to certain cells. The most common cause of CAH is a shortage in the production of an enzyme called 21-hydroxylase, or 21-OHD, resulting in less hormone than needed being produced (for example, cortisol and aldosterone). To compensate for this deficiency, other hormones, such as adrenocorticotropic hormone, or ACTH, increase. This type of CAH (known as classic CAH) affects about 1 in 15,000 people worldwide.Current treatment of CAH involves either putting back or lowering hormones with medicines called glucocorticoids. Using glucocorticoids, it is difficult to strike the right balance between over and under treating CAH, which may result in unwanted side-effects.CRN04894, an investigational study drug, works by blocking the action of ACTH which reduces the level of other hormones. The trial will aim to find out the the long-term safety of CRN04894. CRN04894 is an oral, once daily tablet.The trial will study about 150 people with classic CAH in different countries. There are two groups of participants: Those currently taking CRN04894 in group 1, and those not currently taking CRN04894 in group 2. The total study time is up to 26 months. The tests you might have during the trial include, but are not limited to, physical examinations (doctor’s check-ups), blood and urine (pee) tests, ultrasound or MRIs, and filling out forms with questions. Crinetics Pharmaceuticals, Inc. is the study Sponsor.