The first is a phase 2 study of passive immunotherapy with bapineuzumab, a humanized anti-Abeta monoclonal antibody directed against the N-terminus of Abeta. This trial showed no differences within dose cohorts on the primary efficacy analysis. Exploratory analyses showed potential treatment differences on cognitive and functional endpoints in study completers and apolipoprotein E epsilon4 noncarriers. A safety concern was the occurrence of reversible vasogenic edema.