Lead investigator Jeffrey Cummings, MD, Professor of Neurology, University of California, Los Angeles (UCLA), David Geffen School of Medicine, and Director, UCLA Alzheimer's Disease Center, Los Angeles, California, United States.

"This reporting on the results of two studies supports the indication already in place for the use of memantine for patients with moderate to severe disease, and, most importantly, it shows that efficacy of treatment extends to patients with mild to moderate Alzheimer's disease," Dr. Cummings said.

The investigators studied the efficacy of memantine for behavioral symptoms of Alzheimer's disease in two 24-week, double-blind, placebo-controlled trials. The first study included 404 patients with moderate to severe Alzheimer's disease also receiving donepezil, and the second study included 403 patients with mild to moderate disease.

The researchers used the Neuropsychiatric Inventory (NPI) to assess the behavioral effects of treatment. The statistical analysis using analysis of covariance was based on the intent-to-treat population, which included all subjects who received at least one dose of memantine and who had at least one post-baseline assessment for the primary efficacy measure.

In the moderate to severe Alzheimer's study, 198 memantine and 197 placebo patients took at least one dose of their assigned treatment and had at least one post-baseline assessment.

Of the total, 85% of the memantine/donepezil group completed the trial compared to 76% of the placebo/donepezil group. Mean age was 76 years and two-thirds of subjects were women. Baseline characteristics between treatment groups were comparable within each trial.

In the mild to moderate Alzheimer's study, 198 memantine and 196 placebo patients took at least one dose of assigned treatment and had at least one post-baseline assessment. Of the total, 82.1% of the memantine group completed the trial compared to 82.7% of the placebo group.

Mean age of subjects was 77.5 years and 58.8% of subjects were female.

For both trials, investigators reported statistical significance in favor of memantine for behavioral symptoms of disease at endpoint (NPI total). NPI domains that showed statistical significance in favor of memantine treatment included in the moderate to severe disease trial were agitation/aggression, irritability/lability and appetite/eating. In the mild to moderate disease trial they included irritability/lability, aberrant motor behavior, appetite/eating.

"Significantly fewer memantine patients asymptomatic at baseline exhibited agitation/aggression, irritability/lability, and nighttime behavioral disturbances (Moderate to Severe trial), and delusions and irritability/lability (Mild to Moderate trial) at study endpoint," the authors noted. "Patients with baseline symptoms exhibited significantly less worsening of agitation/aggression, apathy, irritability (Moderate to Severe Trial), and delusions and apathy (Mild to Moderate trial) at study endpoint."

"These data add to the case that memantine is an effective treatment for the behavioral symptoms of Alzheimer's disease across the full spectrum of patients," Dr. Cummings added.

The research was supported by Forest Laboratories, Inc.


[Presentation title: Effect of Memantine on Behavior in Mild-to-Severe Alzheimer's Disease. Abstract NR744]

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