That's news to me that they "aren't working". Working for this class of drugs means stabilizing, or delaying worsening for a while, and only occasionally means improvement in function (my mother seems to be one of the lucky ones).
There are basically two types of drugs in this category, the Acetylcholinesterase inhibitors and the NMDA blockers.
Gotta fund cures for scabies, lice and the new strains of TB.
The pharmaceutical companies invest money where they see profit potential (and technical promise), not where some politician thinks the money should go.
http://www.reviewjournal.com/life/health/alzheimer-s-drugs-not-working-according-ruvo-center-study
This might be from the story I heard on the news.