Passive anti-beta-amyloid (Aß) immunotherapy has been shown to clear brain Aß deposits. Results from phase III clinical trials in mild-to-moderate Alzheimer's disease (AD) patients with two monoclonal antibodies bapineuzumab and solanezumab and intravenous immunoglobulin have been disappointing. Subsequent analysis of pooled data from both phase III trials with solanezumab showed a reduction in cognitive decline in patients with mild AD. Solanezumab and new monoclonal antibodies are being tested in patients with prodromal and preclinical AD in search for a disease-modifying treatment.