Metrifonate therapy in Alzheimer's disease: a pooled analysis of four randomized, double-blind, placebo-controlled trials.

This retrospective analysis assessed the efficacy of metrifonate in the treatment of mild to moderate Alzheimer's disease (AD). Those four studies meeting Food and Drug Administration guidelines for establishing the efficacy of an AD therapeutic agent were pooled for further analysis. Data were included from all patients valid for the intent-to-treat analyses (last observation carried forward). Patients received once daily placebo (n = 550), metrifonate 30-60 mg (by weight, n = 769) or 60/80 mg (by weight, n = 197). Metrifonate 60/80 mg significantly improved the cognitive abilities [AD Assessment Scale - Cognitive Subscale (ADAS-Cog), p = 0.0001; Mini Mental State Examination (MMSE), p = 0.0001], psychiatric and behavioral disturbances (Neuropsychiatric Inventory, p = 0.039; ADAS - Noncognitive Subscale, p = 0.0001), performance of instrumental and basic activities of daily living (Disability Assessment for Dementia, p = 0.0002) and global status (Clinician's Interview-Based Impression of Change with Caregiver Input, p = 0.0001) of AD patients when compared with placebo. Metrifonate effects across these domains were dose related. Metrifonate 60/80 mg significantly improved the cognitive performance relative to both placebo and to baseline as evaluated by both the ADAS-Cog and the MMSE. Metrifonate is the first cholinesterase inhibitor consistently shown under prospective, placebo-controlled conditions to improve significantly behavior in addition to cognition, function in activities of daily living and global functional status of patients with mild to moderate AD.