Biogen Idec Inc., maker of the multiple sclerosis drugs Avonex, Tysabri and Tecfidera, bought rights to Japan’s Eisai Co.’s experimental Alzheimer’s disease medicines as it seeks to add treatments for brain disorders. Biogen will pay Eisai an upfront payment, and a fixed amount of development and milestones as the drugs -- E2609 and BAN2401 -- reach approval and commercialization. No financial details were provided. Read the full story