United States securities and exchange commission logo November 13, 2020 Terrie Curran President and Chief Executive Officer Phathom Pharmaceuticals, Inc. 100 Campus Drive, Suite 102 Florham Park, New Jersey 07932 Re: Phathom Pharmaceuticals, Inc. Registration Statement on Form S-3 Filed November 10, 2020 File No. 333-250014 Dear Ms. Curran: 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 Abby Adams at (202) 551-6902 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Cheston Larson, Esq.