The safety, tolerability, and pharmacokinetics (PKs) of bapineuzumab (AAB-001), 
a humanized monoclonal antibody to amyloid beta, were evaluated in patients with 
mild-to-moderate Alzheimer disease in a phase 1, randomized, third-party 
unblinded, placebo-controlled, single ascending dose trial. Thirty patients 
received bapineuzumab infusion of 0.5, 1.5, or 5 mg/kg or placebo (6 active, 2 
placebo for 0.5 and 1.5-mg/kg cohorts; 10 active, 4 placebo for 5.0-mg/kg 
cohort). Three patients in the highest dose cohort (5.0 mg/kg) developed 
magnetic resonance imaging abnormalities consistent with vasogenic edema, 
predominantly high signal abnormalities on fluid-attenuated inversion recovery 
sequences, all of which resolved over time. Plasma amyloid beta was elevated 
from baseline, peaking approximately 24 hours after infusion. PK analysis 
demonstrated a half-life of 21 to 26 days, supporting a 13-week dosing interval 
for bapineuzumab. This small, single-dose study demonstrated the safety profile 
and PK characteristics of bapineuzumab and was used to design later safety and 
efficacy trials.