Safety, Tolerability, and Pharmacokinetics of Single Doses of BIIB059 in Healthy Japanese Subjects.

Inclusion Criteria: * Ability to understand the purpose and risks of the study and provide signed and dated informed consent and authorization to use confidential health information in accordance with national and local subject privacy regulations * Must have been born in Japan, and both their biological parents and grandparents must have been of Japanese origin * Aged 18 to 55 years old, inclusive, at the time of informed consent, and must have a body mass index between 18 and 30 kilogram per square meter (kg/m2), and a body weight \>45 kg * All women of childbearing potential and all men must practice highly effective contraception during the study and for 16 weeks after their dose of study treatment Exclusion Criteria: * History of any clinically significant cardiac, endocrine, gastrointestinal, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, or renal disease, or other major disease, as determined by the Investigator * History or positive test result for human immunodeficiency virus. Current active hepatitis C virus infection (defined as hepatitis C virus RNA above the limit of detection). Positive test result for hepatitis B virus (defined as positive for hepatitis B surface antigen or hepatitis B core antibody). Chronic, recurrent, or serious infection (e.g., pneumonia, septicemia), as determined by the Investigator, within 90 days prior to Screening or between Screening and Day -1 * Clinically significant abnormal laboratory test values, as determined by the Investigator, at Screening or Day -1 * Current enrollment or a plan to enroll in any interventional clinical study in which an investigational treatment or approved therapy for investigational use is administered within 5 half-lives prior to Day -1 * History of alcohol or substance abuse (as determined by the Investigator), a positive urine drug or alcohol test at Screening or Day -1, an unwillingness to refrain from illicit or recreational drugs, or an unwillingness to abide by the alcohol restrictions NOTE: Other protocol defined Inclusion/Exclusion criteria may apply