A Phase 3 Multicenter Randomized Double-Blind Placebo-Controlled Parallel-Group Study to Evaluate the Efficacy and Safety of Aducanumab (BIIB037) in Subjects with Early Alzheimer's Disease

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
All women of childbearing potential and all men must practice effective contraception during the study and for 24 weeks after their last dose of study treatment
Must have at least 6 years of education or work experience to exclude mental deficits other than MCI or mild AD
Must have a positive amyloid PET scan
Apart from a clinical diagnosis of early AD, the subject must be in good health as determined by the Investigator, based on medical history and screening assessments
Must consent to apolipoprotein E (ApoE) genotyping
Has one informant/care partner who, in the Investigator's judgment, has frequent and sufficient contact with the subject to be able to provide accurate information about the subject's cognitive and functional abilities
Exclusion Criteria
Any uncontrolled medical or neurological/neurodegenerative condition (other than AD) that, in the opinion of the Investigator, might be a contributing cause of the subject's cognitive impairment
Clinically significant psychiatric illness within 6 months prior to Screening
Transient ischemic attack or stroke or any unexplained loss of consciousness within 1 year prior to Screening
History of bleeding disorder or predisposing conditions, blood clotting or clinically significant abnormal results on coagulation profile at Screening, as determined by the Investigator
History of unstable angina, myocardial infarction, chronic heart failure, or clinically significant conduction abnormalities within 1 year prior to Screening
History of seizure within 10 years prior to Screening
Indication of impaired liver function as shown by an abnormal liver function profile at Screening
History of evidence of an autoimmune disorder considered clinically significant by the Investigator or requiring use of systemic corticosteroids or other immunosuppressants
Recent history (within 1 year of Screening) of alcohol or substance abuse as determined by the Investigator, a positive urine drug or alcohol test at Screening, or use of cannabinoids
Clinically significant systemic illness or serious infection within 30 days prior to or during Screening
History of or positive test result for human immunodeficiency virus (HIV)
History of or positive test result at Screening for hepatitis C virus antibody or hepatitis B virus
History of severe allergic or anaphylactic reactions, or history of hypersensitivity to any of the active ingredients in the drug product
Any other medical conditions that are not stable or controlled, or, which in the opinion of the Investigator, could affect the subject's safety or interfere with the study assessments
Any medication that, in the opinion of the Investigator, may contribute to cognitive impairment, put the subject at higher risk for AEs, or impair the subject's ability to perform cognitive testing or complete study procedures
Use of medications with platelet anti-aggregant or anti-coagulant properties
Use of illicit narcotic medication
Vaccinations within 10 days prior to randomization
Participation in any active immunotherapy study targeting ABeta unless documentation of receipt of placebo is available
Participation in any other passive immunotherapy study targeting ABeta within 48 weeks prior to Screening unless documentation of receipt of placebo is available
Participation in any study with purported disease-modifying effect in AD within 26 weeks prior to screening unless documentation of receipt of placebo is available
Participation in a previous study with aducanumab
Contraindications to having a brain MRI
Contraindication to having a PET scan
A negative PET scan result with any amyloid-targeting ligand within 24 weeks prior to Screening
Have had or plan exposure to experimental radiation within 12 months prior to Screening such that radiochemistry limits would be exceeded by participating in this study
Female subjects who are pregnant or currently breastfeeding
Previous participation in this study
Subject is currently living in an organized care facility with extensive intervention and/or support of daily living activities
Blood donation within 1 month prior to Screening