Please assess the completion status of the following clinical trial:

Trial Title: A Study of the Safety and Efficacy of Memantine in Moderate to Severe Alzheimer's Disease

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE3
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Ambulatory patients aged \>/= 50 years~* Diagnostic evidence of probable Alzheimer's disease consistent with criteria from the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR)~* Confirmatory magnetic resonance imaging (MRI) or computed tomographic (CT) scan within the prior 12 months.~* Mini-Mental State Examination (MMSE) scores \>/= 3 and \</= 14 at Screening (Visit 1) and Baseline (Visit 2)~* Ongoing daily acetylcholinesterase inhibitor (AChEI) therapy at a stable dose for at least 3 months prior to Screening (Visit 1). It is preferred that patients continue to receive the same AChEI therapy for the duration of the study.~Exclusion Criteria:~* Patients with a modified Hachinski Ischemia Score greater than 4 at Screening.~* Patients who have taken memantine within one month of Screening (Visit 1)~* Patients who have a known hypersensitivity to memantine, neramexane, rimantadine, or amantadine.~* Patients whose AChEI therapy is likely to be interrupted or discontinued during the course of the study.~* Patients who are receiving therapy with more than one AChEI.~* Patients with computed tomography (CT) or magnetic resonance imaging (MRI) evidence of hydrocephalus, stroke, a space-occupying lesion, cerebral infection, or any clinically significant central nervous system disease other than Alzheimer's disease.~* Patients with a DSM-IV Axis I disorder other than Alzheimer's disease, including amnestic disorders, schizophrenia or schizoaffective disorder, bipolar disorder, current major depressive episode, psychosis, panic, or post-traumatic stress disorder.~* Patients who, in the clinician's judgement, are likely to be placed in a nursing home within the next 6 months.~* Patients who had evidence of other neurological disorders that included, but were not limited to, stroke, Parkinson's disease, seizure disorder, or head injury with loss of consciousness within the prior 5 years~* Patients who had dementia that was complicated by other organic disease~* Patients who had dementia complicated by the presence of predominant delusions

- Gender: ALL
- Minimum Age: 50 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Placebo (Type: PLACEBO_COMPARATOR): Oral administration, once daily.
- Memantine ER (Type: ACTIVE_COMPARATOR): 28mg, once daily. Oral administration for 24 weeks.

Based on this trial design, predict the completion outcome and termination type (if applicable).