"Targeting Beta-amyloid plaque does not seem to be the answer as they hoped."

Check out this video from Damian Garde of Stat News. Great summary of the history of the amyloid hypothesis.

https://www.statnews.com/2019/05/21/alzheimers-disease-amyloid-hypothesis-history/

Watch: How did the amyloid hypothesis go from promising to perilous in the search for Alzheimer’s treatments?

Although the attempts chronicled in the video failed, this does not necessarily mean that amyloid is not involved in the progression of Alzheimers. It also does not mean that other novel strategies to target amyloid precursor protein (APP) or amyloid beta will fail. Keep in mind that antibodies have a tough time crossing the blood brain barrier. So past failed strategies might be more effective with improved brain penetration. Also, amyloid beta exists in many forms (i.e. monomers, oligomers, large plaques) and some of these forms exist as correctly folded and misfolded forms. Only a subset of these different amyloid forms have been targeted in clinial trials. Finally, it could be that treating patients with pre-existing Alzheimer's is less effective than early intervention strategies to prevent Alzheimer's. Early detection may be key to effective therapeutic intervention. So the amyloid hypothesis has taken some big hits, but is not completely dead yet.

BDAZ