SAN FRANCISCO—An experimental Alzheimer’s drug from Eisai and Biogen slowed cognitive decline in a closely watched trial but may carry a risk of serious side effects for certain patients, according to detailed data presented on Tuesday.
The drug, lecanemab, was associated with a dangerous type of brain swelling in nearly 13 percent of patients in the trial that spanned 18 months and enrolled nearly 1,800 participants with early-stage Alzheimer’s.
