Potent and selective β-secretase (BACE) inhibitor (IC50 values are 10.2 and 20.3 nM for human BACE2 and BACE1, respectively). Displays >5,000-fold selectivity for BACE over other proteases including cathepsin D, pepsin and renin. Inhibits Aβ1-40 and Aβ1-42 production in cells expressing mutated APP. Reduces hippocampal and cortical Aβ and sAPPβ levels in an Alzheimer's disease mouse model.