New data shows an experimental Alzheimer's drug modestly slowed the brain disease's inevitable worsening.
The next question is how much difference that might make in people's lives.
Japanese drugmaker Eisai and its U.S. partner Biogen announced earlier this fall that lecanemab appears to work, a badly needed bright spot after disappointments in the quest for better Alzheimer's treatments.
Tuesday, the companies released the full study results.
According to the study, the experimental drug appeared to reduce symptoms of the disease by 27%.
In The New England Journal of Medicine, results from a phase 3 trial showed that in a group study, patients who took the drug showed less cognitive and functional decline compared to those who took a placebo.
Those who participated in the study complained of side effects, including brain swelling, bleeding, and headaches.
Eisai says the drug's benefit translates to about a five-month delay in progression over the 18-month study.
The Food and Drug Administration is expected to decide whether to approve the drug by early January.