United States securities and exchange commission logo May 23, 2022 Susan H. Alexander, Esq. Executive Vice President and Chief Legal Officer Biogen Inc. 225 Binney Street Cambridge, Massachusetts 02142 Re: Biogen Inc. Registration Statement on Form S-4 Filed May 17, 2022 File No. 333-265023 Dear Ms. Alexander: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Alan Campbell at 202-551-4224 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: John D. Hancock, Esq.