 Biogen Inc. stock BIIB, -0.17 rose 3 in premarket trade Wednesday, after a new study was unveiled late Tuesday that showed the companys experimental Alzheimers drug being developed with Japans Eisai 4523, 3.83 ESALY, -0.54 moderately reduced cognitive decline after a year and a half. The study assessing lecanemab as a treatment for people with early forms of Alzheimers disease was published Tuesday night by the New England Journal of Medicine. 