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                           July 8, 2021

       John Valliant, Ph.D.
       Chief Executive Officer
       Fusion Pharmaceuticals Inc.
       Two International Place, Suite 2310
       Boston, MA 02110

                                                        Re: Fusion
Pharmaceuticals Inc.
                                                            Registration
Statement on Form S-3
                                                            Filed July 2, 2021
                                                            File No. 333-257653

       Dear Dr. Valliant:

              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 Jeffrey
Gabor at 202-551-2544 with any questions.




                           Sincerely,


                           Division of Corporation Finance

                           Office of Life Sciences
       cc:                                              Mitchell S. Bloom, Esq.