A Study to Evaluate the Efficacy and Safety of MABT5102A in Patients With Mild to Moderate Alzheimer's Disease (ABBY)

Inclusion Criteria:

- Diagnosis of probable AD according to the NINCDS-ADRDA criteria

- MMSE score of 18-26 points at screening

- GDS-15 score of < 6

- Completion of 6 years of education (or good work history consistent with exclusion of
mental retardation or other pervasive developmental disorders)

- If receiving concurrent AD treatment, patient must be on the medication for at least
3 months at a stable dose for at least 2 months prior to randomization.

Exclusion Criteria:

- Severe or unstable medical condition that, in the opinion of the investigator or
Sponsor, would interfere with the patient's ability to complete the study assessments
or would require the equivalent of institutional or hospital care

- History or presence of clinically evident vascular disease potentially affecting the
brain

- History of severe, clinically significant (persistent neurologic deficit or
structural brain damage) central nervous system trauma

- Hospitalization within 4 weeks prior to screening

- Previous treatment with MABT5102A or any other therapeutic that targets Abeta

- Treatment with any biologic therapy within 5 half-lives or 3 months prior to
screening, whichever is longer, with the exception of routinely recommended
vaccinations, which are allowed