KEY TAKEAWAY: “We still believe that amyloid beta hypothesis is potentially the right approach for the treatment of Alzheimer’s disease,” an Eisai spokesman told Reuters. What made Wall Street and everyone else, Eli Lilly, AstraZeneca, Merck, and Roche — have reported out decisive late-stage failures over the last year that all point to one conclusion: Targeting amyloid-beta alone in symptomatic patients may hit your biomarkers on effect, but it doesn’t delay the ruthless march of the disease.