After 190 Tries, Are We Any Closer to a Cure for Alzheimer’s?

Eli Lilly has spent almost three decades working on drugs for Alzheimer’s disease with not much to show for it yet. This year the company began human tests using a totally new approach. Its latest drug targets an aberrant protein called tau that spreads through the brain as Alzheimer’s progresses, accumulating in telltale tangles that strangle brain cells.

Lilly’s tau drug marks a shift in Alzheimer’s research. Drug companies have long focused on a different protein called amyloid that clumps in the brains of Alzheimer’s patients and is thought to trigger the disease. Companies have poured billions into amyloid-blocking drugs with little success. In 2010, Eli Lilly halted trials of semagacestat after patients on the drug deteriorated more quickly than those on a placebo. In 2012, Pfizer and Johnson & Johnson released results of large trials that showed their amyloid treatment didn’t slow progression of the disease. All told, at least 190 Alzheimer’s drugs have failed in human trials, according to Bernard Munos, a senior fellow at FasterCures, a health nonprofit.