What the Alzheimer’s Drug Breakthrough Means for Other Diseases

Finding a winning treatment for dementia, thought to afflict more than 55 million people globally, has been the life’s work of Eisai Chief Executive Officer Haruo Naito, the 74-year-old grandson of the company’s founder. He oversaw the launch of a predecessor drug in 1997—sold under the brand name Aricept—that improved mental function but didn’t slow the advancement of Alzheimer’s, the most common type of dementia. The commercial failure of another Alzheimer’s drug from Eisai and Biogen, Aduhelm, makes the success of lecanemab particularly meaningful. Here, Naito shares the importance of the discovery and why he’s confident about gaining regulatory approval. The interview has been edited for clarity and length.