United States securities and exchange commission logo





                           September 22, 2020

       Douglas Onsi
       Chief Executive Officer
       Leap Therapeutics, Inc.
       47 Thorndike Street, Suite B1-1
       Cambridge, MA 02141

                                                        Re: Leap Therapeutics,
Inc.
                                                            Registration
Statement on Form S-3
                                                            Filed September 14,
2020
                                                            File No. 333-248797

       Dear Mr. Onsi:

              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 Jason L.
Drory at 202-551-8342 with any questions.




                           Sincerely,


                           Division of Corporation Finance

                           Office of Life Sciences
       cc:                                              Julio E. Vega