United States securities and exchange commission logo August 7, 2020 Chris Peetz Chief Executive Officer Mirum Pharmaceuticals, Inc. 950 Tower Lane, Suite 1050 Foster City, California 94404 Re: Mirum Pharmaceuticals, Inc. Registration Statement on Form S-3 Filed August 3, 2020 File No. 333-240290 Dear Mr. Peetz: 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 Margaret Schwartz at 202-551-7153 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Jason Kent