Safety Study of Passive Immunization for Patients With Mild to Moderate Alzheimer's Disease

Inclusion Criteria: * Diagnosis of probable AD * Age from 50 to 85 years, inclusive * Rosen Modified Hachinski ischemic score less than or equal to 4 * Magnetic Resonance Imaging (MRI) scan consistent with the diagnosis of AD * Fluency in English * Stable doses of medications Exclusion Criteria: * Significant neurological disease other than AD * Major psychiatric disorder * Significant systemic illness * History of stroke or seizure * Weight greater than 120kg (264 lbs.) * History of autoimmune disease * Smoking more than 20 cigarettes per day * Anticonvulsants, anti-Parkinson's, anticoagulant, or narcotic medications * Prior treatment with experimental immunotherapeutics or vaccines for AD * Presence of pacemakers or foreign metal objects in the eyes, skin, or body