By Reuters Staff 2 Min Read FILE PHOTO: Marc Archambault, 70 of South Kingstown, Rhode Island,receives his first intravenous infusion of Aduhelm, Biogen's controversial recently approved drug for early Alzheimer's disease, at Butler Hospital, one of the clinical research sites in Providence, Rhode Island, U.S. June 16, 2021. Jessica Rinaldi/Pool via REUTERS. (Reuters) - Biogen Inc and partner Eisai Co Ltd on Thursday revealed the design of an upcoming study of their controversial Alzheimer’s treatment, Aduhelm. The study, designed to collect real-world, long-term effectiveness and safety data on Aduhelm, will enroll 6,000 patients over fours years in the United States, according to details released during the Alzheimer’s Association International Conference.