United States securities and exchange commission logo July 7, 2023 Mark Guerin Chief Operating Officer & Chief Financial Officer Onconova Therapeutics, Inc. 12 Penns Trail Newtown, PA 18940 Re: Onconova Therapeutics, Inc. Registration Statement on Form S-3 Filed June 30, 2023 File No. 333-273081 Dear Mark Guerin: 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 Lauren Hamill at 303-844-1008 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Maddy Anand