A new treatment for Alzheimer’s offers hope—but raises questions, too

FOR DECADES the search for a drug to treat Alzheimer’s disease had seemed . Then, in 2021, a drug called aducanumab received regulatory approval in America. A second, lecanemab, got the nod in January this year. Now a paper published on July 17th in the suggests that a third may not be far behind.In a trial involving 1,736 people showing early symptoms of Alzheimer’s, donanemab, developed by Eli Lilly, an American firm, was shown to have “significantly slowed” the progression of the disease—by 35% after 76 weeks by one measure. The result, which headlined the annual Alzheimer’s Association International Conference, held this year in Amsterdam, was hailed as a “breakthrough” and “turning-point”. That is overblown. But it does mark steady—and welcome—progress.