Amyloid-related imaging abnormalities from trials of solanezumab for Alzheimer's disease.

Introduction: Solanezumab, a humanized monoclonal antibody that binds soluble amyloid beta peptide, is being developed for treatment of Alzheimer's disease (AD).

Methods: Patients (n = 2042) with mild and moderate AD were randomized 1:1 to 400-mg solanezumab or placebo infusion every 4 weeks for 80 weeks and 1457 patients entered an open-label extension. Magnetic resonance imaging scans monitored for amyloid-related imaging abnormalities-edema/effusion (ARIA-E) and amyloid-related imaging abnormalities-hemorrhage/hemosiderin deposition.

Results: Sixteen patients (solanezumab, n = 11; placebo, n = 5) developed ARIA-E during the double-blind phase, and 7 patients developed ARIA-E during the open-label extension as of July 31, 2014. Unique cases are discussed including solanezumab patients who were given solanezumab, while ARIA-E was present and a patient who developed ARIA-E during placebo treatment and again during solanezumab treatment.

Discussion: Asymptomatic ARIA-E was detected in solanezumab-treated and placebo-treated AD patients. ARIA-E occurs infrequently during solanezumab and placebo treatments but may occur repeatedly in some patients.