United States securities and exchange commission logo May 10, 2021 Louis Brenner, M.D. Chief Executive Officer Allena Pharmaceuticals, Inc. One Newton Executive Park, Suite 202 Newton, Massachusetts 02462 Re: Allena Pharmaceuticals, Inc. Registration Statement on Form S-3 Filed May 6, 2021 File No. 333-255837 Dear Louis Brenner: 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 Tom Kluck at 202-551-3233 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Michael H. Bison