There's some discussion of Ligand's drug in this presentation from a few years back (see p37): http://www.faqs.org/sec-filings/100624/LIGAND-PHARMACEUTICALS-INC_8-K/dex991.htm#b Oral BACE inhibitors that penetrate the blood-brain barrier have been very hard to come by despite a lot of effort. The dramatic failure of a gamma-secretase inhibitor casts at least a shadow over this target as well. Peter