Researchers from Forest Laboratories Inc., announced that in a recently completed 6 month placebo-controlled study of patients with moderate-to-severe Alzheimer's disease, a significant benefit was observed when memantine treatment was added to their background donepezil (Aricept®) therapeutic regimen.
The Phase III trial was a double-blind, parallel arm, placebo-controlled design in which a total of 403 patients with moderate-to-severe Alzheimer's disease were randomized to 6 months of treatment with either memantine 20 mg per day or placebo in addition to their donepezil therapy. To be eligible for study inclusion, patients must have been treated with a stable dose of donepezil for at least 6 months prior to randomization. The primary outcome assessments were the Severe Impairment Battery (SIB) scale, a measure of cognition and the Alzheimer's disease Cooperative Study Inventory – Activities of Daily Living (ADCS-ADL) scale, a measure of daily function. A physician global assessment (CIBIC-Plus) was also performed.
In this study, at the end of the 6 month treatment period, memantine, at a daily dose of 20 mg plus donepezil, was statistically significantly superior to placebo plus donepezil treatment on both primary outcome measures, the ADCS-ADL (function) and the SIB (cognition). In addition, the CIBIC-Plus scores (global measure) demonstrated a statistically significant benefit for the memantine treatment group compared to the placebo treatment group.
“The study results were consistent with the favorable effects previously demonstrated after memantine treatment alone in this same population as previously reported by Reisberg et al. in the Merz sponsored U.S. trial Study 9605 and show the beneficial effects of memantine treatment combined with donepezil as compared to donepezil alone." said Lawrence S. Olanoff, M.D., Ph.D., Executive Vice President – Forest Laboratories. "Further, the study showed that memantine in combination with donepezil produced improvement over the six month study period in cognition in contrast with most other treatment studies in Alzheimer's patients which have demonstrated only a slowing of the expected decline in cognition."
Forest is conducting three additional placebo-controlled trials to further confirm memantine's cognitive and functional benefits and to evaluate its efficacy in patients with mild-to-moderate as well as moderate-to-severe stages of the disease. Results from these investigations are expected in 2003.