This is a Safety and Tolerability Study Evaluating a New Treatment for Subjects With Mild to Moderate Alzheimer's Disease.

This is a Phase 2, open-label, multicenter, 28 week extension study to evaluate the
long-term safety and tolerability of ABT-126 in subjects who complete dosing through Week
24 of Study M10-985. Up to 410 subjects may participate at approximately 30 sites in
several countries.

Inclusion Criteria:

- The subject and caregiver must voluntarily sign and date an informed consent. If the
subject does not have the capacity to provide informed consent, full informed consent
must be obtained from the subject's representative and assent must be obtained from
the subject.

- The subject was randomized into Study M10-985 and completed dosing through Week 24 in
that study.

- With the exception of a diagnosis of mild to moderate AD and the presence of stable
medical conditions, the subject is in general good health, based upon the results of
medical history, physical examination, vital signs, laboratory profile, and a 12-lead
ECG.

- If male, the subject is surgically sterile (vasectomy, is sexually inactive, or is
using a barrier method of birth control (condom) with spermicidal
foam/gel/film/cream/suppository for the duration of the study and for 30 days
following the last dose of study drug. However, if the male subject's partner has
been postmenopausal for at least 2 years or is surgically sterile, then use of a
barrier method of birth control is not required.

- The subject has an identified, reliable caregiver who will provide support and ensure
compliance with the study medication and procedures, and provide accurate information
about the subject's status during the study.

- The subject and caregiver must have sufficient visual, hearing and graphomotor skills
to complete the study procedures.

Exclusion Criteria:

- Experienced an adverse event or abnormal finding in physical examination, vital
signs, laboratory profile and/or ECG measurements in Study M10-985 that indicates the
subject could become medically unstable during the current study.

- The subject is currently taking or is expected to be prescribed any excluded
medications (including acetylcholinesterase inhibitors or memantine), without the
approval of Abbott medical monitor.

- The subject anticipates a move outside the geographic area of the investigative site
or is planning extended travel inconsistent with the recommended visit intervals.

- The subject is currently enrolled in, or plans to participate in, another
experimental study during the course of this trial.

- The subject developed any significant medical or psychiatric condition that, in the
opinion of the investigator, renders the subject an unsuitable candidate to
participate in this study.

- For any other reason the investigator considers the subject to be an unsuitable
candidate to receive ABT-126 or to participate in this study.