Study to Assess the Safety, Tolerability, and Pharmacokinetics of BIIB104 in Healthy Japanese and Non-Japanese Participants

A Phase 1, Randomized, Double-Blind, Placebo-Controlled, Multiple-Dose Study to Assess the Safety, Tolerability, and Pharmacokinetics of BIIB104 in Healthy Japanese and Non-Japanese Participants

The primary objective is to evaluate the pharmacokinetics (PK) of BIIB104 in healthy Japanese and non-Japanese participants. The secondary objective is to evaluate the safety and tolerability of multiple, oral doses of BIIB104 administered BID for 9 days, with an additional dose occurring in the morning on Day 10 in healthy Japanese and non-Japanese participants.

Key Inclusion Criteria:

• For Japanese participants, was born in Japan, and biological parents and grandparents were of Japanese origin.
• For Japanese participants, if living outside Japan for more than 5 years, must not have significantly modified diet since leaving Japan.
• Non-Japanese participants must have a screening weight within ±20% of the mean value for Japanese participants.

Key Exclusion Criteria:

• Suicide attempt within the last 2 years. Participants who, in the Investigator's judgment, pose a significant suicide risk or who have suicidal ideation associated with actual intent and a method or plan in the past 6 months (i.e., "Yes" answers on items 4 or 5 of the Columbia Suicide Severity Rating Scale) will be excluded from the study.

Note: Other protocol specific inclusion/exclusion criteria may apply.