Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Crinecerfont in Participants With Classic Congenital Adrenal Hyperplasia (CAH) Who Are Less Than 4 Years Old

The main objective of this study is to assess the safety and tolerability of crinecerfont in pediatric participants 3 months to \<4 years of age with CAH.

Key Inclusion Criteria: * Have a medically confirmed diagnosis of classic CAH (salt wasting or simple virilizing) due to 21-hydroxylase deficiency (21-OHD) * Have received at least 3 months of hydrocortisone treatment before Day 1, with a stable dose for at least 4 weeks before screening. * Have a body weight of at least 4.5 kilograms (kg) at screening. * Have a newborn screen that is otherwise normal except for elevated 17-OHP or any other abnormality on newborn screen that was cleared upon evaluation by a pediatric specialist. Key Exclusion Criteria: * Have a known or suspected diagnosis of any of the other forms of classic CAH. * Have any condition besides CAH that requires chronic daily therapy with orally administered steroids. * Have any other clinically significant medical condition or chronic disease. Note: Other protocol-defined inclusion and exclusion criteria may apply.