Efficacy, Safety and Tolerability Study of AVP-923 (Dextromethorphan/Quinidine) for Treatment of Symptoms of Agitation in Alzheimer's Patients

Eligible patients for this study must have a diagnosis of probable AD and must have
clinically meaningful agitation secondary to AD.

This is a multicenter, randomized, double-dummy, double-blind, placebo-controlled study,
consisting of 10 weeks of treatment.

Up to 200 patients will be enrolled at approximately 30-40 centers in the US.

Study medication will be administered orally twice-daily from Day 1 through Day 70. Screening
must occur within within approximately 4 weeks prior to randomization. Following screening
procedures for assessment of inclusion and exclusion criteria, eligible patients will be
randomized into the study.

Key Inclusion Criteria:

Diagnosis of probable Alzheimer's disease (AD).

The patient has clinically significant symptoms of agitation secondary to AD, that
interfere with daily routine and for which a prescription medication is deemed indicated,
in the opinion of the investigator.

Either out-patients or residents of an assisted-living facility or a skilled nursing home.

CGI-S score is ≥ 4 (moderately ill) at screening and baseline.

Mini Mental State Examination (MMSE) score at screening between 8 and 28 (inclusive).

Caregiver who is able and willing to comply with all required study procedures, ensuring
that the patient attends all study visits and takes the study medication as instructed. In
order to qualify as a caregiver for this study, the individual should spend time with the
patient for a minimum of 4 hours on 4 separate days per week.

Key Exclusion Criteria:

Patient has other type of dementia (e.g., vascular dementia, frontotemporal dementia,
Parkinson's disease, substance-induced dementia).

Patients with co-existent clinically significant or unstable systemic diseases that could
confound the interpretation of the safety results of the study (e.g. malignancy, poorly
controlled diabetes, poorly controlled hypertension, unstable pulmonary, renal or hepatic
disease, unstable ischemic cardiac disease, dilated cardiomyopathy, certain cardiac
conduction abnormalities including QTc prolongation, or unstable valvular heart disease).

Patients with myasthenia gravis.