Lecanemab is the first drug that slows cognitive decline in Alzheimer’s patients|Bournemouth Borough|CC BY-NC 2.0

Lecanemab, an Alzheimer's drug by Eisai and Biogen, slowed cognitive decline by 27% over 18 months in 1,795 patients with early disease. It was the final phase of the trial.

Lecanemab—the first medicine to slow the disease—is now awaiting approval from the US Food and Drug Administration (FDA), which is expected in early January. The approval would help the six million people in the country suffering from the disease.

Shares of Eisai Co. and partner Biogen Inc. surged post news of the drug slowing Alzheimer’s.