Single and Multiple Ascending Dose Study of Aducanumab (BIIB037) in Japanese Participants With Alzheimer's Disease

Key Inclusion Criteria: * Must be ambulatory * Must have a clinical diagnosis of mild to moderate AD * Must be in good health as determined by the Investigator, based on medical history and Screening assessments * Must have a caregiver who, understands the study and assents to accompany the subject to all study site visits, provide information to the Investigator/study site staff, specifically about cognitive abilities and AEs/SAEs and return for per-protocol follow-up visits and procedures * Must consent to blood sample collection for deoxyribonucleic acid (DNA; genotyping) and ribonucleic acid (RNA; for potential future analysis). Key Exclusion Criteria: * Any medical or neurological condition (other than AD) that in the opinion of the Investigator could be a contributing cause of the subject's dementia * Transient ischemic attack or stroke or any unexplained loss of consciousness within 1 year prior to Screening * Poorly controlled diabetes mellitus, as defined by having dosage adjustment of diabetic medication within the 3 months prior to Day 1 * History of unstable angina, myocardial infarction, chronic heart failure * Chronic, uncontrolled hypertension * History of seizure within 3 years prior to Screening * History within the past 6 months or evidence of clinically significant psychiatric illness * History of severe allergic or anaphylactic reactions, or history of hypersensitivity to any of the inactive ingredients in the drug product NOTE: Other protocol defined Inclusion/Exclusion criteria may apply