A Phase 2 Multiple Dose, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of ABBV-8E12 in Subjects With Early Alzheimer’s Disease

– Subject who meets the National Institute on Aging and the Alzheimer’s Association
(NIA-AA) clinical criteria for mild cognitive impairment or probable AD, and have:

– Clinical Dementia Rating (CDR)-Global Score of 0.5

– Mini-Mental State Examination (MMSE) score of 22 to 30, inclusive

– Repeatable Battery for the Assessment of Neuropsychological Status-Delayed Memory
Index (RBANS – DMI) score of 85 or lower

– Subject has a positive amyloid Positron Emission Tomography (PET) scan.

– Subject has a Modified Hachinski Ischemic Scale (MHIS) score of ≤ 4.

– The subject has an identified, reliable, study partner (e.g., family member).

– If using medications to treat symptoms related to AD, doses must be stable for at
least 12 weeks prior to randomization.

Exclusion Criteria:

– Subject has any contraindications or inability to tolerate brain magnetic resonance
imaging (MRI), PET scans or lumbar puncture.

– Subject has evidence of any other clinically significant neurological disorder other
than Early AD.

– In the opinion of the investigator, the subject has any clinically significant or
uncontrolled medical or psychiatric illness, or has had an infection requiring medical
intervention in the past 30 days.

– Subject has had a myocardial infarction, unstable angina, stroke, transient ischemic
attack or required intervention for any of these conditions within 6 months of
Screening.