United States securities and exchange commission logo March 10, 2021 Chris Schelling President and Chief Executive Officer Acer Therapeutics Inc. One Gateway Center, 300 Washington Street, Suite 351 Newton MA 02458 Re: Acer Therapeutics Inc. Registration Statement on Form S-1 Filed March 3, 2021 File No. 333-253838 Dear Mr. Schelling: 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 Chris Edwards at 202-551-6761 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Patty M. DeGaetano, Esq.