Safety and changes in plasma and cerebrospinal fluid amyloid β after a single administration of an amyloid β monoclonal antibody in subjects with Alzheimer disease

Objectives: Active and passive immunization strategies have been suggested as possible options for the treatment of Alzheimer disease (AD). LY2062430 (solanezumab) is a humanized monoclonal antibody being studied as a putative disease-modifying treatment of AD. Methods: Patients with mild to moderate AD were screened and selected for inclusion. Initial screening was performed for 54 subjects, and 29 of these underwent additional screening; after this second screening, a total of 19 subjects were included. Single doses of solanezumab using 0.5, 1.5, 4.0, and 10.0 mg/kg were administered. Safety assessments included gadolinium-enhanced magnetic resonance imaging of the brain and cerebrospinal fluid (CSF) analyses at baseline and 21 days after dosing. Plasma and CSF concentrations of solanezumab and amyloid β (Aβ) and cognitive evaluations were obtained. Results: Administration of solanezumab was generally well tolerated except that mild self-limited symptoms consistent with infusion reactions occurred for 2 of 4 subjects given 10 mg/kg. No evidence of meningoencephalitis, microhemorrhage, or vasogenic edema was present based on magnetic resonance image and CSF analyses. A substantial dose-dependent increase in total (bound plus unbound) Aβ was demonstrated in plasma; CSF total Aβ also increased. No changes in cognitive scores occurred. Conclusions: A single dose of solanezumab was generally well tolerated, although infusion reactions similar to those seen with administration of other proteins may occur with higher doses. A dose-dependent change in plasma and CSF Aβ was observed, although changes in cognitive scores were not noted. Further studies of solanezumab for the treatment of AD are warranted.