A new study, published in the journal Brain, found that the accumulation of dysfunctional tau protein is the real source of cognitive decline and memory loss seen in Alzheimer's.
The study from the Mayo Clinic may revive a long-running debate over whether the drug industry is focusing on the right target in developing therapies to treat the disease.
Tau destabilizes tracks used by cells to transport food and messages throughout the brain, the research found.
Biogen's drug BIIB037 and several others focus instead on the buildup of different set of protein fragments, called beta amyloid.
Amyloid has a relationship with cognitive decline, but if you're looking at both of them together, tau is the bad guy," said Melissa Murray, a neuroscientist at the Mayo Clinic campus in Jacksonville, Florida.
Companies including Johnson & Johnson, Biogen and AbbVie Inc. have products in the early stages of development that target tau in the brain. TauRx Pharmaceuticals Ltd., a closely held, Singapore-based drug developer, is testing a tau-targeting compound in broader human trials.
"I don't know that any one player is telling you beta amyloid is the only target. There are a lot of people postulating that combination therapy may be the best way forward," said Christopher Raymond, an analyst at Robert W. Baird & Co.