A Study to Assess the Pharmacokinetics of Intranasally Administered Esketamine in Healthy Japanese and Caucasian Volunteers

This is an open-label single-center study with 2 cohorts (groups). The study will consist of a screening phase, a treatment phase, and a follow-up visit (9 to 13 days after the last dose of the study drug). During the screening phase, participants will be evaluated to determine if they meet the study eligibility criteria. A target of 14 healthy Japanese and 14 healthy Caucasian adult participants (20 to 55 years of age inclusive) will be enrolled in Cohort 1 and Cohort 2, respectively. The participants in each cohort will self-administer each of the 3 different single-dose regimens of intranasal esketamine (Treatments A, B, and C) over the 3 treatment periods (ie, 1 treatment per period) in an open-label manner (both the investigator and the participant knows which intervention the participant receives). The participants will be randomly (like the toss of a coin) assigned to receive Treatment A and Treatment B in the first two periods (ie, Treatment A in Period 1 and Treatment B in Period 2, or the reverse order). All participants will receive Treatment C in Period 3. The regimens differ in the number of sprays to achieve the total dose and the total esketamine dose administered. Safety and tolerability will be evaluated throughout the study and will include assessment of adverse events, targeted nasal examinations, laboratory tests, electrocardiogram, physical examination, pulse oximetery, and vital signs.