This study is being conducted to determine the safety and effect on cognitive function of the investigational medication, EVP-6124, in individuals with mild to moderate probable Alzheimer's disease.

This is a randomized, double-blind, placebo-controlled, parallel, 24-week, Phase 2 safety/efficacy study in which three dose levels of EVP-6124 or placebo will be evaluated. Eligible for enrollment will be patients who meet clinical criteria for mild to moderate probable Alzheimer's disease who are either receiving treatment with AChEI medication at a stable dose or who are not presently taking any AChEI or memantine co-medication.

Patients will be randomized to one of the following groups: 0.3 mg, 1 mg or 2 mg or Placebo. Approximately 400 subjects will be randomized to the 4 treatment groups. Study drug will be supplied as capsules and will be orally administered once daily for a total of 24 weeks.

Inclusion Criteria:

• Subjects with Probable Alzheimer's disease
• Mini-Mental State Examination (MMSE) score of 14 to 24 inclusive at screening and a CDR-SB score ≥2 at the screening assessment
• Modified Hachinski Ischemic Score (mHIS) ≤4 at screening
• Female subjects are ≥1 year post-menopausal or are surgically sterile
• Caregiver available; if not living in the same household, caregiver sees subject at least four times each week
• Subject living at home, senior residential setting, or an institutional setting without the need for continuous nursing care
• General health status acceptable for participation in a 24 week clinical trial be administered

Exclusion Criteria:

General

• Participation in another therapeutic clinical trial within 30 days before Baseline
• Prior participation in an amyloid vaccination clinical study
• Inability to swallow capsules
• Likely inability to complete 24 week study
• Inability to be ≥75% compliant with single-blind placebo run-in medication
• Inability to adequately perform cognitive tests
• History of significant cardiovascular disease
• Major depression
• Psychosis
• History of stroke within 18 months of screening
• Head trauma
• Inability to perform any screening or baseline evaluations