TEXT-EXTRACT 2 filename2.txt United States securities and exchange commission logo December 28, 2022 Richard Paulson President and Chief Executive Officer Karyopharm Therapeutics Inc. 85 Wells Avenue, 2nd Floor Newton, MA 02459 Re: Karyopharm Therapeutics Inc. Registration Statement on Form S-3 Filed December 23, 2022 File No. 333-268991 Dear Richard Paulson: 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 Tim Buchmiller at (202) 551-3635 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Craig Hilts, Esq.