The study was terminated for strategic reasons.

The main goal of this study is to evaluate the effect of Lu AG06466 on the body and what the body does to Lu AG06466 after single and multiple doses to healthy Japanese and Caucasian participants.

This sequential study will be divided in two parts, Part A and Part B.

Part A will consist of 3 cohorts (Cohorts A1, A2, and A3) in which participants will be randomized to receive a single dose of Lu AG046466 or a matching placebo orally. After completing the safety review of data from Cohort A1, the study will proceed in Cohorts A2 and A3, with an increased dose of Lu AG046466 or matching placebo being administered to Japanese and Caucasian participants.

Part B dosing will only be initiated after completion of Part A. Part B will consist of 1 cohort (Cohort B1), to which multiple dose of Lu AG046466 or matching placebo will be administered after dose titration.

Inclusion Criteria:

• The participant has a BMI ≥18.5 and ≤25 kilograms (kg)/square meter (m^2) or ≤30 kg/m^2 for Japanese and Caucasian participants, respectively, and a body weight ≥50 kilograms (kg) at the screening visit and at the baseline visit.
• The participant is, in the opinion of the investigator, generally healthy based on medical history, a physical examination, a neurological examination, vital signs, electrocardiograms (ECG), and the results of the clinical chemistry, haematology, urinalysis, serology, and other laboratory tests.

Exclusion Criteria:

• The participant has taken disallowed medication <1 week prior to the first dose of study drug or <5 half-lives of the disallowed medication as concomitant use prior to the screening visit.
• The participant has or has had any clinically significant immunological, cardiovascular, respiratory, metabolic, renal, hepatic, gastrointestinal, endocrinological, hematological, dermatological, venereal, neurological, or psychiatric disease or other major disorder.
• The participant has had a clinically significant illness <4 weeks prior to the first dose of study drug.
• The participant has received a SARS-CoV-2 (COVID-19) vaccination <30 days prior to the first dose of study drug.

Note: Other inclusion and exclusion criteria may apply.