Biogen Inc. Loss Submission Form

(1) the larger dataset did not provide necessary data regarding aducanumab’s effectiveness; (2) the EMERGE study did not and would not provide necessary data regarding the effectiveness of aducanumab, Biogen’s investigational human monoclonal antibody studied for the treatment of early Alzheimer’s disease; (3) the PRIME study did not and would not provide necessary data regarding aducanumab’s effectiveness; (4) the data provided by the Company to the U.S. Food and Drug Administration’s Peripheral and Central Nervous System Drugs Advisory Committee did not support finding efficacy of aducanumab; and (5) as a result, Defendants’ statements about its business, operations, and prospects, were materially false and misleading and/or lacked a reasonable basis at all relevant times.