Clinical Research Directory

Key Inclusion Criteria: * Medically confirmed diagnosis of classic 21-hydroxylase deficiency (21-OHD) CAH, based on standard, medically accepted criteria. * Stable glucocorticoid (GC) dose regimen for classic CAH for a minimum of 30 days before screening. * If treated with fludrocortisone, the dose should be stable for at least 30 days before screening with an upright plasma renin activity (PRA) \<upper limit of normal (ULN) on participant's usual sodium intake. * Have elevated A4, based on a blood sample collected at screening. * Body weight ≥50 kilograms (kg) for males and ≥45 kg for females. * Negative pregnancy test at screening visit and Day 1. * Participants with ovaries of childbearing potential must agree to use contraception consistently. * Unless considered permanently sterile or vasectomized at least 3 months prior to screening with medically confirmed successful procedure, participants with testes must agree to use effective barrier contraception (that is, condom with spermicide \[cream, spray, foam, gel, suppository, or polymer film\]) consistently. Key Exclusion Criteria: * Pregnant (that is, positive pregnancy test), or lactating, or plan to become pregnant during the study. * Had a clinically significant illness within 30 days of screening. * Have a known or suspected diagnosis of any of the other known forms of classic CAH. Note: Other protocol-defined inclusion and exclusion criteria may apply.