Haruo Naito, chief executive officer of Eisai Co., at the company's headquarters in Tokyo, Japan, on Wednesday, Oct. 12, 2022. Photographer: Shoko Takayasu/Bloomberg
(Bloomberg Businessweek) -- It’s been three decades since scientists hypothesized that Alzheimer’s is caused by a buildup of amyloid beta protein in the brain. But it wasn’t until last month that drugmakers achieved a major breakthrough, with Japan’s Eisai Co. and its US partner Biogen Inc. releasing results from a large-scale trial showing they were able to blunt the disease’s progression. The companies are seeking accelerated US ...