A Study to Assess Pharmacokinetics, Safety, and Tolerability of Atumelnant in Healthy Japanese and Caucasian Participants

Inclusion Criteria: * Healthy male or female participants, 18 to 55 years old, inclusive, at the Screening Visit. * Healthy status as defined by the absence of evidence of any clinically significant, in the opinion of the Investigator, active or chronic disease following a detailed medical and surgical history, a complete physical examination including vital signs, 12-lead electrocardiogram (ECG), hematology, clinical chemistry, coagulation, serology, and urinalysis. The tests may be repeated once at Screening and at admission on Day -1 if necessary and deemed appropriate by the Investigator or designee. * Body mass index (BMI) between 18.0 and 30.0 kg/m2, inclusive, at the Screening Visit and at admission on Day -1. * Meeting the criteria at the time of consent for one of the following ethnic groups: * Japanese participants must have been born in Japan to parents and grandparents of Japanese ethnic descent as evidenced by verbal confirmation and documented in a self-reported family tree form, have lived less than 10 years outside of Japan, and have no significant change in lifestyle, including diet, since leaving Japan. * Caucasian participants must be considered White of European descent. * Participant has a peak 30- or 60-minute ACTH stimulated serum cortisol ≥18 μg/dL during 250 μg high-dose ACTH/cosyntropin stimulation test conducted at Screening. * Participant has normal morning serum cortisol collected at approximately 08:00 AM (±2 hours) at admission on Day -1 and do…