P4‐401: Combination Therapy with a Plaque‐Specific Abeta Antibody And A Bace Inhibitor Results in Dramatic Plaque Reduction in a Dose‐Dependent Manner in Aged Pdapp Transgenic Mice

Abstract

from PBMC following the third vaccination, and will be further followed. Results:High antibody responses were found in both species. In the rabbit, 277.1 6 118.4 mg/ml plasma were measured after 5 immunizations with no significant differences between the dose groups. Antibody levels declined slightly to 246.6 6 109.5 mg/ml after a resting period of two months. Low levels of IFNg and IL-17 secreting splenocytes were found in the ELISPOT assays from rabbit splenocytes. Rhesus monkeys reached mean antibody levels of 114.2 6 41.67 mg/ml plasma after five immunizations. The isotype profile was high on IgG4 antibodies, indicative of a Th2 immune response. After three immunizations, no IL-17 or IFNg producing cells were found in ELISPOT assays from PBMCs. Conclusions: DNA Ab42 immunization leads to high antibody titers in large mammals, and is likely to produce high antibody levels and a safe (Th2 biased) immune response in humans as well.