A double-blind, placebo-controlled, enriched population study of tacrine in patients with Alzheimer's disease

The efficacy of tacrine in the treatment of patients with probable Alzheimer's disease (AD) was evaluated in a double-blind, placebo-controlled, enriched population multicenter study in France. A total of 280 patients entered the dose titration phase of the study. The assessment of potential benefit of tacrine ("best dose") was based on demonstrating improvement on the Alzheimer's Disease Assessment Scale (ADAS) total score versus a blinded placebo. One hundred and thirty of 242 (54%) patients achieved a "best dose" and were eligible for the double-blind, parallel group (pivotal) phase. Primary efficacy measures were ADAS-Cognitive and Clinical Global Impression of Change; secondary efficacy measures of cognition and activities of daily living were also included. Results indicated that tacrine-treated patients showed improved functioning based on the ADAS-Cognitive in comparison to placebo-treated patients. Transaminase elevations above the upper limit of normal occurred in 32% of patients, were more frequent in women than in men, demonstrated a delayed onset, and returned to normal limits for all patients following discontinuation of treatment The results from this study are supportive of the efficacy of tacrine in the treatment of AD as demonstrated in a study of similar design conducted in the US and studies using different designs.