United States securities and exchange commission logo June 25, 2024 Molly Henderson Chief Financial Officer Phathom Pharmaceuticals, Inc. 100 Campus Drive, Suite 102 Florham Park, New Jersey 07932 Re: Phathom Pharmaceuticals, Inc. Form 10-K for Fiscal Year Ended December 31, 2023 File No. 001-39094 Dear Molly Henderson: We have completed our review of your filings. 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. Sincerely, Division of Corporation Finance Office of Life Sciences