Investigational Alzheimer Drugs Fail to Improve Cognition or Function in Phase III Trials

The amyloid hypothesis of Alzheimer disease (AD) suggests that overproduction or abnormal clearance of the amyloid-beta (Aβ) peptide is critical to the early pathogenesis of AD. Two investigational monoclonal antibodies designed to decrease amyloid burden in patients with AD were recently assessed in phase 3 clinical trials. Both antibodies were tested in two industry-sponsored trials.

In one trial, researchers randomly administered intravenous bapineuzumab — which recognizes both soluble and aggregated Aβ — or placebo periodically for 78 weeks to patients with mild-to-moderate AD; 1121 patients were APOE ℇ4 carriers and 1331were noncarriers. At the conclusion of the trials, scores on a cognitive scale (cognitive subscale of the Alzheimer's …