Study of AV-1959, an Amyloid Beta Vaccine

Inclusion Criteria: Male or female subjects from 60 to 85 years of age. Mild cognitive impairment (MCI) due to Alzheimer's disease (AD), and must have the following: Mini-Mental State Examination (MMSE) score from 22 to 30; Clinical Dementia Rating (CDR) global score of 0.5 or 1.0. A positive visual Aβ positron emission tomography (PET) scan. Exclusion Criteria: Participation in another investigational drug or device study or treated with an investigational drug within 30 days or 5 half-lives, whichever is longer, before dosing. Prior administration of any amyloid-beta or tau immunotherapy (vaccine, antibody) Magnetic resonance imaging (MRI) showing evidence of existing safety issues. Use of immunomodulatory or growth-stimulating factors within 30 days prior to study entry. Any serious illness requiring systemic treatment and/or hospitalization within 4 weeks prior to study entry. Any major or unstable illness, including unstable ischemic cardiovascular disease, or require the use of excluded medications. Subjects with insulin-dependent diabetes. Subjects with pre-existing autoimmune diseases. A medical condition that in the opinion of the Investigator might be a contributing cause of cognitive impairment. History/evidence of severe local or systemic reactions to vaccination or significant allergic reactions. History of seizure disorder.