Pharmacodynamics of highly potent BACE-1 inhibitors in both Pgp-deficient and normal mice

MEDI 242

Lorin A. Thompson III, lorin.thompson@bms.com, Lawrence R. Marcin, Jianliang Shi, Mendi A. Higgins, Richard E. Olson, Andrew C. Good, Catherine R. Burton, Donna M. Barten, Jodi K. Muckelbauer, Jeremy H. Toyn, Kimberley A. Lentz, James E. Grace, John J Herbst, Anthony M. Marino, Jere E. Meredith, Charlie F. Albright, and John E. Macor. Research and Development, Bristol-Myers Squibb, 5 Research Parkway, Wallingford, CT 06492-7660
Alzheimer's disease pathology includes the accumulation in the brain of extracellular amyloid plaques composed largely of the beta-amyloid peptide, and genetic evidence obtained from familial forms of AD suggests that increased production of the 42 amino acid form of beta-amyloid has a primary role in the disease. As a result, both enzymes involved in beta-amyloid production, BACE1 and gamma secretase, have been investigated as possible targets for therapeutic intervention in this important disease. BACE1 inhibitors with high potency in cellular assays have been described in the literature, however central efficacy in animal models has been difficult to demonstrate. This is primarily a result of poor blood-brain barrier penetration as a result of both poor intrinsic permeability and active efflux by P-gp. This presentation will describe a novel series of BACE inhibitors with subnanomolar potency in cellular assays and present an analysis of the factors influencing brain penetration including the P-gp effect at the BBB by comparing central efficacy in both Pgp-deficient and wild-type mice.