So you say AD is hard nut to crack. As far as goes my experience in all things real the most important is what you think is involved in etiology of the disease. Even FDA published white paper hinting at futility of attacking AD by amyloid or tau plaque removal. Yet, even this voice of reason is shun by many and BP which is like a large tanker not able to stop once set in motion keeps "improving" on dead horse. Today's failure of yet another drug pushing the narrative that AD has something to do with acetylcholine the veritable memory connected neurotransmitter is result of sticking with outdated probable causes of AD. AVXL is the pathblazer here.