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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.          )

 

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Dear Stockholder:

        You are cordially invited to attend the 2018 Annual Meeting of Stockholders of Leap Therapeutics, Inc. which will be held on Thursday, May 3, 2018 at 11:00 a.m., eastern time, at the offices of Morgan, Lewis & Bockius LLP, One Federal Street, Boston, Massachusetts 02110 USA.

        Details regarding admission to the Annual Meeting and the business to be conducted are described in the accompanying proxy materials. Also included is a copy of our 2017 Annual Report. We encourage you to read this information carefully.

        Your vote is important. Whether or not you plan to attend the Annual Meeting, we hope you will vote as soon as possible. You may vote over the Internet, by telephone or by mailing a proxy card. Voting over the Internet, by telephone or by written proxy will ensure your representation at the Annual Meeting regardless of whether or not you attend in person. Please review the instructions in the Proxy Materials you received in the mail regarding each of these voting options.

Thank you for your ongoing support of Leap Therapeutics, Inc.

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47 Thorndike Street
Suite B1-1
Cambridge, MA 02141

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS
To Be Held on May 3, 2018

        The 2018 Annual Meeting of Stockholders of Leap Therapeutics, Inc. will be held on Thursday, May 3, 2018 at 11:00 a.m., eastern time, at the offices of Morgan, Lewis & Bockius LLP, One Federal Street, Boston, Massachusetts 02110 USA. At the Annual Meeting, stockholders will consider and act upon the following matters:

        1.     To elect two Class I directors nominated by our board of directors, James Cavanaugh and John Littlechild, each to serve for a term ending in 2021, or until his successor has been duly elected and qualified;

        2.     To ratify the appointment of EisnerAmper LLP, an independent registered public accounting firm, as our independent auditors for the year ending December 31, 2018; and

        3.     To transact such other business as may properly come before the Annual Meeting or any adjournment or postponement thereof.

        Stockholders of record on our books at the close of business on March 28, 2018, the record date for the Annual Meeting, are entitled to notice of, and to vote at, the Annual Meeting or any adjournment or postponement thereof. If you are a stockholder of record, please vote in one of these three ways:

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Vote over the Internet, by going to the website of our tabulator, Continental Stock Transfer and Trust Company, at www.cstproxyvote.com, and following the instructions for Internet voting shown on the enclosed proxy card;



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Vote by Telephone, by calling 1-866-894-0536 and following the recorded instructions; or



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Vote by Mail, by completing and signing the enclosed proxy card and mailing it in the enclosed postage prepaid envelope. If you vote over the Internet or by telephone, please do not mail your proxy card.

        If your shares are held in "street name," that is, held for your account by a broker or other nominee, you will receive instructions from the holder of record that you must follow for your shares to be voted.

        Directions to the Annual Meeting are on the back of the proxy statement.

        Whether or not you plan to attend the Annual Meeting in person, we urge you to take the time to vote your shares.

March 16, 2018

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Leap Therapeutics, Inc.
47 Thorndike Street, Suite B1-1
Cambridge, MA 02141

PROXY STATEMENT FOR 2018 ANNUAL MEETING OF STOCKHOLDERS
To Be Held On Thursday, May 3, 2018 at 11:00 a.m. eastern time
At the offices of Morgan, Lewis & Bockius LLP,
At One Federal Street, Boston, Massachusetts 02110 USA

        This proxy statement and the enclosed proxy card are being furnished in connection with the solicitation of proxies by our board of directors for use at the 2018 Annual Meeting of Stockholders of Leap Therapeutics, Inc., or the Annual Meeting, to be held on Thursday, May 3, 2018 at 11:00 a.m., eastern time, at the offices of Morgan, Lewis & Bockius LLP, One Federal Street, Boston, Massachusetts 02110 USA, and at any adjournment or postponement thereof. You are entitled to vote if you are a stockholder of record as of the close of business on March 28, 2018. As used in this proxy statement, the terms "Leap," "we," "us," and "our" mean Leap Therapeutics, Inc. unless the context indicates otherwise.

        All proxies will be voted in accordance with the instructions contained in those proxies. If no choice is specified, the proxies will be voted in favor of the matters set forth in the accompanying Notice of Annual Meeting of Stockholders.

        We are first mailing this proxy statement and the accompanying proxy card to stockholders on or about April 2, 2018.

QUESTIONS AND ANSWERS ABOUT THE ANNUAL MEETING AND VOTING

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PROPOSAL NO. 1—ELECTION OF DIRECTORS

        In accordance with Leap's amended and restated certificate of incorporation and amended and restated bylaws, the Board of Directors is divided into three classes of directors of approximately equal size. The members of each class of directors are elected to serve a three-year term with the term of office of each class ending in successive years. James Cavanaugh and John Littlechild are the Class I directors whose terms expire at Leap's 2018 Annual Meeting of stockholders. Each of James Cavanaugh and John Littlechild has been nominated for, and has agreed to stand for, re-election to the Board to serve as a Class I director of Leap for three years until the 2021 Annual Meeting of Stockholders of Leap and until their successors are duly elected and qualified or until their earlier death, resignation or removal.

        It is intended that, unless you give contrary instructions, shares represented by proxies will be voted for the election of each of the two nominees listed above as director nominees. Leap has no reason to believe that any nominee will be unable to serve. In the event that one or more nominees is unexpectedly not available to serve, proxies may be voted for another person nominated as a substitute by the Board, or the Board may reduce the number of directors to be elected at the Annual Meeting. Information relating to each nominee for election as director and for each continuing director, including his or her period of service as a director of Leap, principal occupation and other biographical material, is included below.

VOTE REQUIRED

        A plurality of the votes cast at the meeting will be required for the election of the Class I director nominees. The two nominees for director with the highest number of affirmative votes will be elected as directors. Broker non-votes and abstentions will not be treated as votes cast for this purpose and, therefore, will not affect the outcome of the election.

THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT YOU VOTE "FOR" EACH
OF THESE NOMINEES FOR CLASS I DIRECTOR.

(PROPOSAL NO. 1 ON YOUR PROXY CARD)

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BOARD OF DIRECTORS AND MANAGEMENT

Information Regarding Directors and Director Nominees

        Our Board of Directors currently consists of seven members divided into three classes with staggered three-year terms. Our amended and restated certificate of incorporation and amended and restated bylaws provide that the number of our directors shall be fixed from time to time by a resolution of the majority of our Board of Directors. Any additional directorships resulting from an increase in the number of directors will be distributed among the three classes so that, as nearly as possible, each class shall consist of one third of the board of directors. In addition, our amended and restated certificate of incorporation and amended and restated bylaws each of which became effective upon consummation of the merger with Macrocure Ltd. on January 23, 2017, provide that a director may be removed only for cause and only by the affirmative vote of the holders of at least two-thirds of the votes that all our stockholders would be entitled to cast in an annual election of directors.

        The division of our Board of Directors into three classes with staggered three-year terms may delay or prevent stockholder efforts to effect a change of our management or a change in control.

        At each annual meeting of the stockholders, a class of directors will be elected for a three-year term to succeed the directors of the same class whose terms are then expiring. The terms of the directors will expire upon the election and qualification of successor directors at the annual meeting of stockholders to be held during the years 2018 for Class I directors, 2019 for Class II directors, and 2020 for Class III directors. Currently, Class I consists of James Cavanaugh and John Littlechild, each with a term expiring at this annual meeting of stockholders to be held in 2018. Class II consists of William Li and Thomas Dietz, each with a term expiring at the annual meeting of stockholders to be held in 2019. Class III consists of Joseph Loscalzo, Nissim Mashiach and Christopher Mirabelli, each with a term expiring at the annual meeting of stockholders to be held in 2020. Our Board of Directors has nominated Dr. Cavanaugh and Mr. Littlechild for election at the Annual Meeting as Class I directors, each to serve until the annual meeting to be held in 2021.

Director Qualifications

        The following table and biographical descriptions provide information as of March 15, 2018 relating to each director and director nominee, including his age and period of service as a director of our company; his board of directors committee memberships; his business experience during the past five years, including directorships at other public companies; his or community activities; and the other experience, qualifications, attributes or skills that led our Board of Directors to conclude he should serve as a director of our company.

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Executive Officers Who Are Not Directors

        Certain information regarding our executive officers who are not also directors, as of March 15, 2018, is set forth below.

        Augustine Lawlor.    Mr. Lawlor, age 61, has served as our Chief Operating Officer since January 2016. Mr. Lawlor has been a managing director of HealthCare Ventures LLC since June 1999, including serving as the chief executive officer of GITR, Inc. prior to its merger into Leap. Prior to

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joining HealthCare Ventures, Mr. Lawlor served as Chief Operating Officer of LeukoSite Inc., a biotechnology company, from 1997 to 1999. Before joining LeukoSite, Mr. Lawlor served as Chief Financial Officer and Vice President of Corporate Development of Alpha-Beta Technology, Inc., a biotechnology company. He was also previously Chief Financial Officer and Vice President, Business Development, of BioSurface Technologies Corporation, a biofilm company. Mr. Lawlor serves on the board of directors of Cardiovascular Systems, Inc. and Catalyst Biosciences, Inc., each a publicly-traded biopharmaceutical company, and a number of private companies. He received a B.A. from the University of New Hampshire and a master's degree in management from Yale University.

        Douglas E. Onsi.    Mr. Onsi, age 49, has served as our Chief Financial Officer, Treasurer and Secretary since our inception in January 2011. Mr. Onsi has been at HealthCare Ventures since August 2007, including serving as a managing director since 2009 and the chief executive officer of Tensha Therapeutics, Inc. which was sold to Roche Holdings, Inc. in 2016. Prior to joining HealthCare Ventures, Mr. Onsi was at Genzyme Corporation, or Genzyme, where he served in roles as Vice President, Campath Product Operations and Portfolio Management, Oncology from 2005 to 2007 and as Vice President, Business Development from 2004 to 2005. Prior to Genzyme, he was Chief Financial Officer of Tolerx, Inc., a venture capital funded biotechnology company, from 2001 to 2004. Before joining Tolerx, Inc., he was in business development at LeukoSite, a publicly traded biopharmaceutical company that was acquired by Millennium Pharmaceuticals, Inc. He began his career as an attorney at Bingham Dana LLP. Mr. Onsi currently serves as a member of the board of directors of Vaxxas Pty Ltd., a privately-held biotechnology company. He received a Juris Doctor degree from the University of Michigan Law School and a B.S. in biological sciences from Cornell University.

        There are no family relationships among any of our directors or executive officers.

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CORPORATE GOVERNANCE MATTERS

        Our Board of Directors believes that good corporate governance is important to ensure that our company is managed for the long-term benefit of our stockholders. The following sections describes key corporate governance guidelines and practices that we have adopted. Complete copies of our Audit Committee Charter, Compensation Committee Charter, Nominating and Corporate Governance Committee Charter and our Code of Business Conduct and Ethics are available on the Investor Relations section of our website, www.investors.lptx.com, at "Corporate Governance". Alternatively, you can request a copy of any of these documents by writing us at: Leap Therapeutics, Inc., Attn: Secretary, 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141 USA.

Corporate Governance Guidelines

        Our Board of Directors has adopted Corporate Governance Guidelines to assist it in the exercise of its duties and responsibilities and to serve the best interests of our company and our stockholders. These principles, which set forth a framework for the conduct of our Board of Directors' business, provide that:

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the principal responsibility of the directors is to oversee our management and to hold our management accountable for the pursuit of our corporate objectives;



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except as otherwise required by the rules and regulations of the Nasdaq Stock Market, a majority of the members of our Board of Directors must be independent directors;



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the independent directors meet regularly in executive session;



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directors have full and free access to management and, as necessary and appropriate, independent advisors; and



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new directors participate in an orientation program and all directors are encouraged to attend director education programs.

Director Independence

        Rule 5605 of the NASDAQ Listing Rules requires a majority of a listed company's board of directors to be comprised of independent directors within one year of listing. In addition, the NASDAQ Listing Rules require that, subject to specified exceptions, each member of a listed company's audit, compensation and nominating and corporate governance committees be independent under the Securities Exchange Act of 1934, as amended, or the Exchange Act. Audit committee members must also satisfy independence criteria set forth in Rule 10A-3 under the Exchange Act, and compensation committee members must also satisfy the independence criteria set forth in Rule 10C-1 under the Exchange Act. Under Rule 5605(a)(2), a director will only qualify as an "independent director" if, in the opinion of our board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee, accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries or otherwise be an affiliated person of the listed company or any of its subsidiaries. In order to be considered independent for purposes of Rule 10C-1, the board must consider, for each member of a compensation committee of a listed company, all factors specifically relevant to determining whether a director has a relationship to such company which is material to that director's ability to be independent from management in connection with the duties of a compensation committee member, including, but not limited to: the source of compensation of the director, including any consulting advisory or other compensatory fee paid by such company to the director; and whether the director is affiliated with the company or any of its subsidiaries or affiliates.

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        Dr. Cavanaugh and Messrs. Littlechild and Mashiach are the current members of our audit committee; Drs. Dietz and Li and Mr. Littlechild are the current members of our compensation committee; and Drs. Cavanaugh and Loscalzo are the current members of our nominating and corporate governance committee. In March 2018, our Board of Directors undertook a review of the composition of our Board of Directors and its committees and the independence of each director. Based upon information requested from and provided by each director concerning his or her background, employment and affiliations, including family relationships, our Board of Directors has determined that (i) each of our directors, except for Christopher Mirabelli, qualifies as an "independent director" as defined under NASDAQ Listing Rules, (ii) each of our audit committee members was independent pursuant to Rule 10A-3 under the Exchange Act, and (iii) each of our compensation committee members was independent pursuant to Rule 10C-1 under the Exchange Act.

        In making such determinations, our Board of Directors considered the relationships that each such non-employee director has with our company and all other facts and circumstances our Board of Directors deemed relevant in determining independence, including the beneficial ownership of our capital stock by each non-employee director.

Director Nomination Process

        Our nominating and corporate governance committee evaluates director candidates and selects or recommends for selection by the Board of Directors, director nominees. The process followed by the nominating and corporate governance committee to identify and evaluate director candidates may include requests to Board of Directors' members and others for recommendations, meetings from time to time to evaluate biographical information and background material relating to potential candidates, and interviews of selected candidates by members of the Board of Directors.

Criteria and Diversity

        In considering whether to recommend any particular candidate for inclusion in the Board of Directors' slate of recommended director nominees, the nominating and corporate governance committee applies certain criteria as set forth in our Corporate Governance Guidelines. These criteria include the candidate's business experience and skills, independence, character, wisdom, judgment, integrity, ability to make independent analytical inquiries, understanding of our business environment, the ability to commit sufficient time and attention to board activities, and the absence of potential conflicts with our interests. The Board of Directors does not assign specific weights to particular criteria and no particular criterion is a prerequisite for any prospective nominee.

        Our corporate governance committee and Board of Directors do not have a formal policy with respect to diversity, but an objective of board composition is to bring to our company a variety of perspectives and skills derived from high quality business and professional experience. Our Board of Directors recognizes its responsibility to ensure that nominees for our Board of Directors possess appropriate qualifications and reflect a reasonable diversity of personal and professional experience, skills, backgrounds and perspectives. We believe that the backgrounds and qualifications of our directors, considered as a group, should provide a composite mix of experience, knowledge and abilities that will allow our Board of Directors to promote our strategic objectives and to fulfill its responsibilities to our stockholders.

        The director biographies on pages 10-15 indicate each director's experience, qualifications, attributes and skills that led the Board of Directors to conclude that each should continue to serve as a member of our Board of Directors. Our nominating and corporate governance committee and Board of Directors believes that each of the directors has had substantial achievement in his or her professional and personal pursuits and possesses the background, talents and experience that our Board of Directors desires and that will contribute to the best interests of our company and to long-term stockholder value.

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        For additional information regarding stockholder nominations and other proposals see "Stockholder Proposals for 2018 Annual Meeting."

Board of Directors Meetings and Attendance

        Our Board of Directors met 6 times during 2017, either in person or by teleconference. During 2017, each of our directors attended at least 75% of the aggregate number of the meetings of the Board of Directors and the committees on which they served.

        Our Corporate Governance Guidelines provide that our directors are invited and encouraged to attend our annual meeting of stockholders.

Board of Directors Leadership Structure

        Christopher Mirabelli is the Chairman of our Board of Directors. Dr. Mirabelli has authority, among other things, to call and preside over meetings of our Board of Directions and set meeting agendas. As a result of Dr. Mirabelli's extensive history with and knowledge of Leap Therapeutics, he is able to provide valuable insight and help ensure that the Board of Directors and management act with a common purpose. If Dr. Mirabelli is ever not present at a meeting of the board of directors, an independent director is appointed to chair such meetings. In general, the agenda for every regularly scheduled board of directors meeting includes a meeting of the "Independent Directors" in executive session. In any event, the non-management directors meet in executive session at least semi-annually to discuss, among other matters, the performance of the Chief Executive Officer. The director who presides at these meetings is a non-management director selected by a majority of the non-management directors. There have been 4 meetings of the Independent Directors in executive session in 2017.

        We have a separate chair for each committee of our Board of Directors. The chairs of each committee are expected to report to our Board of Directors on the activities of their committee in fulfilling their responsibilities as detailed in their respective charters, if any. Our Board of Directors delegates substantial responsibilities to the committees, which report their activities and actions back to the full Board of Directors. We believe this structure represents an appropriate allocation of roles and responsibilities for our company at this time because it strikes an effective balance in the participation of management and independent leadership in our Board of Directors' proceedings.

Board of Directors Committees

        Our Board of Directors has established an audit committee, a compensation committee and a nominating and corporate governance committee, each of which operates pursuant to a charter adopted by our Board of Directors. The composition and functioning of all of our committees complies with all applicable requirements of the Sarbanes-Oxley Act of 2002, rules and regulations of the Nasdaq Stock Market and the SEC.

        The composition and responsibilities of each of the committees of our Board of Directors are described below. Members serve on these committees until their resignation or until otherwise determined by our Board of Directors.

Audit Committee

        The members of our audit committee are Thomas Dietz, John Littlechild, and Nissim Mashiach with Thomas Dietz serving as chairman. The financial literacy requirements of the Commission require that each member of our audit committee be able to read and understand fundamental financial statements. In addition, at least one member of our audit committee must be qualified as an audit committee financial expert, as defined in Item 407(d)(5) of Regulation S-K promulgated under the Securities Act, and have financial sophistication in accordance with the NASDAQ stock market rules. Our Board of Directors has determined that Mr. Dietz qualifies as an audit committee financial expert.

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        The primary purpose of our audit committee is to assist the Board of Directors in the oversight of the integrity of our accounting and financial reporting process, the audits of our financial statements, and our compliance with legal and regulatory requirements. The functions of our audit committee will include, among other things:

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hiring the independent registered public accounting firm to conduct the annual audit of our financial statements and monitoring its independence and performance;



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reviewing and approving the planned scope of the annual audit and the results of the annual audit;



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pre-approving all audit services and permissible non-audit services provided by our independent registered public accounting firm;



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reviewing the significant accounting and reporting principles to understand their impact on our financial statements



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reviewing our internal financial, operating and accounting controls with management, our independent registered public accounting firm and our internal audit provider;



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reviewing with management and our independent registered public accounting firm, as appropriate, our financial reports, earnings announcements and our compliance with legal and regulatory requirements;



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reviewing potential conflicts of interest under and violations of our Code of Conduct;



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establishing procedures for the treatment of complaints received by us regarding accounting, internal accounting controls or auditing matters and confidential submissions by our employees of concerns regarding questionable accounting or auditing matters;



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reviewing and approving related-party transactions; and



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reviewing and evaluating, at least annually, our audit committee's charter.

        The audit committee operates under a written charter that satisfies the applicable standards of the Nasdaq Stock Market and the SEC and which is available on our website at www.investors.lptx.com at "Corporate Governance". The Audit Committee met 5 times during 2017, either in person or by teleconference.

Compensation Committee

        The members of our compensation committee are Thomas Dietz, John Littlechild, and William Li, with John Littlechild serving as chairman.

        The primary purpose of our compensation committee is to assist our Board of Directors in exercising its responsibilities relating to compensation of our executive officers and employees and to administer our equity compensation and other benefit plans. In carrying out these responsibilities, this committee will review all components of executive officer and employee compensation for consistency with its compensation philosophy, as in effect from time to time. The functions of our compensation committee will include, among other things:

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designing and implementing competitive compensation policies to attract and retain key personnel;



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reviewing and formulating policy and determining the compensation of our executive officers and employees;



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reviewing and recommending to our board of directors the compensation of our directors;



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administering our equity incentive plans and granting equity awards to our employees and directors under these plans;

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if required from time to time, reviewing with management our disclosures under the caption "Compensation Discussion and Analysis" and recommending to the full board its inclusion in our periodic reports to be filed with the Commission;



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if required from time to time, preparing the report of the compensation committee to be included in our annual proxy statement;



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engaging compensation consultants or other advisors it deems appropriate to assist with its duties; and



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reviewing and evaluating, at least annually, our compensation committee's charter.

        The compensation committee operates under a written charter that satisfies the applicable standards of the Nasdaq Stock Market and which is available on our website at www.investors.lptx.com at "Corporate Governance". The Compensation Committee met 1 time during 2017 in person or by teleconference.

Compensation Committee Interlocks and Insider Participation

        No member of our compensation committee has ever been an executive officer or employee of ours. None of our executive officers currently serves, or has served during the last completed fiscal year, on the compensation committee or board of directors of any other entity that has one or more executive officers serving as a member of our Board of Directors or compensation committee.

Nominating and Corporate Governance Committee

        The members of our nominating and corporate governance committee are James Cavanaugh and Joseph Loscalzo, with James Cavanaugh serving as chairman. Our Board has determined that each of James Cavanaugh and Joseph Loscalzo satisfies the NASDAQ independence standards.

        The primary purpose of our nominating and corporate governance committee is to assist our Board of Directors in promoting the best interests of our company and our stockholders through the implementation of sound corporate governance principles and practices. The functions of our nominating and corporate governance committee will include, among other things:

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identifying, reviewing and evaluating candidates to serve on our board;



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determining the minimum qualifications for service on our board;



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developing and recommending to our board an annual self-evaluation process for our board and overseeing the annual self-evaluation process;



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developing, as appropriate, a set of corporate governance principles, and reviewing and recommending to our board any changes to such principles; and



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periodically reviewing and evaluating our nominating and corporate governance committee's charter.

        The nominating and corporate governance committee operates under a written charter that satisfies the applicable standards of the Nasdaq Stock Market and which is available on our website at www.investors.lptx.com at "Corporate Governance". The nominating and corporate governance committee did not meet separately from the Board of Directors during 2017.

Board of Directors' Role in Risk Oversight

        Our Board of Directors oversees the management of risks inherent in the operation of our business and the implementation of our business strategies. Our Board of Directors performs this oversight role by using several different levels of review. In connection with its review of the operations and corporate functions of our company, our Board of Directors addresses the principal risks

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associated with those operations and corporate functions. In addition, our Board of Directors reviews the risks associated with our business strategies periodically throughout the year as part of its consideration of undertaking any such business strategies.

        The audit committee has the responsibility to consider and discuss our major financial risk exposures and the steps our management has taken to monitor and control these exposures, including guidelines and policies to govern the process by which risk assessment and management are undertaken. Our audit committee also monitors compliance with legal and regulatory requirements, in addition to oversight of the performance of our internal audit function and whistleblower protections.

        The compensation committee assesses and monitors the extent to which our incentive compensation policies and programs for all employees may encourage excessive risk-taking and the relationship between risk management policies and practices and compensation, and evaluates compensation policies and practices that could mitigate any such risk.

Communicating with the Directors

        Our Board of Directors will give appropriate attention to written communications that are submitted by stockholders and other interested parties, and will respond if and as appropriate. The General Counsel is primarily responsible for monitoring communications from stockholders and other interested parties and for providing copies or summaries of such communications to the directors as he considers appropriate.

        Under procedures approved by our Board of Directors, communications are forwarded to all directors if they relate to important substantive matters and include suggestions or comments that our General Counsel considers to be important for the directors to know. In general, communications relating to corporate governance and corporate strategy are more likely to be forwarded than communications relating to ordinary business affairs, personal grievances and matters that are duplicative communications.

        Stockholders and other interested parties who wish to send communications on any topic to the Board of Directors should address such communications to: Board of Directors, c/o General Counsel, Leap Therapeutics, Inc., 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141 USA.

        Additionally, we have established a confidential process for reporting, investigating and resolving employee and other third party concerns related to accounting, auditing and similar matters under the Sarbanes-Oxley Act of 2002. Stockholders and other interested parties may confidentially provide information to one or more of our directors by using the confidential and anonymous financial concern hotline that is operated by an independent, third party service. Within the United States and Canada, the Ethics Hotline can be reached by telephone, toll-free, at 1-844-413-0900, e-mailing the Company at LPTX@openboard.info, or visiting http://www.openboard.info/LPTX/.

Code of Business Conduct and Ethics

        We have adopted a Code of Business Conduct and Ethics (the "Code of Conduct") that is applicable to all of our employees, executive officers and directors. The Code of Conduct is available on our website at www.investors.leaptx.com at "Corporate Governance". The nominating and corporate governance committee of our Board of Directors will be responsible for overseeing the Code of Conduct and the General Counsel or Board of Directors approve any waivers of the Code of Conduct for employees, executive officers or directors. We expect that any amendments to the Code of Conduct, or any waivers of its requirements, will be disclosed on our website or in a current report on Form 8-K. We shall provide to any person without charge, upon request, a copy of the Code of Conduct. Any such request must be made in writing to Leap Therapeutics Inc., c/o Investor Relations, 47 Thorndike Street, Suite B1-1, Cambridge, MA 02141.

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EXECUTIVE COMPENSATION

Overview

        The following discussion relates to the compensation of our Chief Executive Officer and President, Christopher Mirabelli, and our next two most highly compensated persons serving as executive officers as of December 31, 2017. Each year, our Compensation Committee reviews and determines the compensation of our executive officers. Our executive compensation program is designed to attract and retain a highly skilled team of key executives and to align the compensation of our executives with the interests of our stockholders by rewarding the achievement of short- and long-term strategic financial goals, which we believe serves to enhance short- and long-term value creation for our stockholders.

Summary Compensation Table

        The following table presents compensation awarded in 2017 to our principal executive officer and our other executive officers as of December 31, 2017, or compensation paid to or accrued for those executive officers for services rendered during 2017. We refer to these executive officers as our "named executive officers".

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Elements of Executive Compensation

        The compensation of our named executive officers consists of base salary, annual cash bonuses, equity awards and employee benefits that are made available to all salaried employees. Our named executive officers are also entitled to certain compensation and benefits upon certain terminations of employment and certain change of control transactions pursuant to employment agreements. In addition to the factors discussed below, the compensation committee also considers recommendations from Dr. Mirabelli, who as our Chief Executive Officer regularly discusses compensation issues with the chairperson of the compensation committee and meets with our compensation committee to discuss these matters.

        The following describes the material terms of the elements of our executive compensation program during fiscal year 2017.

Overview

        Our executive compensation program is based on a pay-for-performance philosophy. We designed our executive compensation program to achieve the following primary objectives: provide compensation and benefit levels that will attract, retain, motivate and reward a highly talented executive team within the context of responsible cost management; establish a direct link between our individual/team performance and results and our executives' compensation; and align the interests and objectives of our executives with those of our stockholders by linking executive equity awards to stockholder value creation. Compensation for our executive officers is composed primarily of the following three main components: base salary, annual cash incentive bonuses, and long-term equity incentives.

Base Salary

        Base salaries are determined on a case-by-case basis for each executive officer (including our three named executive officers), including consideration of each officer's experience, expertise and performance, as well as market compensation levels for similar positions.

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Annual Cash Incentive Bonuses

        Annual cash incentive bonuses are contingent upon our achievement of certain operational and financial objectives, which for 2017 are expected to consist entirely of corporate goals. Each executive officer's target bonus amount is expressed as a percentage of the officer's base salary and is intended to be commensurate with the officer's position and responsibilities. Target bonuses for each officer are 35% of base salary for the year ended December 31, 2017.

Long-term Equity Incentives

        We believe equity awards in the form of options to purchase shares of our common stock provide an incentive for our executive officers to focus on driving growth in our stock price and long-term value creation and help us to attract and retain key talent. In addition, the granting of options helps ensure that the interests of our officers are aligned with those of our stockholders as the options only have value if the value of our common stock increases after the date the option is granted.

        Our officers are entitled to certain benefits if the officer's employment terminates in certain circumstances or if a change of control occurs. Our Board of Directors and our compensation committee review our officers' overall compensation packages on an annual basis or more frequently as it deems appropriate. From time to time, we may retain independent compensation consultants as we consider appropriate to help identify appropriate peer group companies and to obtain and evaluate current executive compensation data. In 2016, we retained compensation consultants in designing our executive compensation programs. Moving forward, we expect that our compensation committee will retain independent compensation consultants.

Employment Agreements

        We have entered into employment agreements with each of our executive officers (including our named executive officers), Messrs. Lawlor and Onsi and Dr. Mirabelli, on the same terms. The following is a summary of the material terms of each employment agreement including terms related to severance and payments upon termination or change of control.

        Our executive employment agreements do not include a specified term as their employment is "at-will". The agreements provide that each executive receives an annual base salary, initially established at $400,000, and that he is eligible for an annual incentive bonus, with his target bonus being 35% of his base salary. The compensation committee of the Board of Directors determines the executive's actual bonus amount based on its assessment of the satisfaction of performance criteria to be established by the compensation committee within the first three months of each fiscal year. The agreement also provides for the executive to participate in our benefit programs made available to our employees generally.

        Under each executive's agreement, if his employment is terminated by us without cause or if the executive resigns with good reason (as such terms are defined in the agreement), in either case prior to a change in control or one year after a change in control (as such term is defined in the agreement), he will be entitled to receive cash severance equal to his annualized base salary; a pro-rata bonus, payable within two and one-half months following the end of the fiscal year in which the termination or resignation occurs; any accrued or earned, but unpaid or unreimbursed, base salary, expenses, benefits, bonus, rights to indemnification, or vacation pay; reimbursement of his COBRA premiums for 12 months; and acceleration of vesting on any outstanding equity awards along with extension of the time period to exercise the outstanding equity awards to one year. In the event that such termination or resignation occurs during the one-year period immediately following a change in control, the executive will also receive, an increase in the cash severance amount to double his annualized base salary, an extension of the time period during which Leap will reimburse COBRA premiums to 18 months, and extension of the time period to exercise all outstanding equity awards to two years. An

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executive's right to receive these severance benefits is subject to his providing a release of claims in favor of Leap and return of all company property.

        In the event that a change in control occurs within two years of the effective date of an executive's employment agreement, and the severance and other benefits provided in the agreement are considered "parachute payments" within the meaning of 280G of the Code and are subject to the excise tax imposed by Section 4999 of the code, then the executive will be entitled to receive an additional gross-up payment. This payment shall be in an amount equal to the excise tax and taxes imposed on such payment. Additionally, in the event that such change in control occurs more than two years after the effective date of the executive's employment agreement and the same conditions above are applicable, the executive's severance and other benefits constituting parachute payments will be either (i) delivered in full or (ii) delivered to a lesser extent which would result in no portion of such severance being subject to excise tax under Section 4999 of the Code, whichever provides the greatest amount to the executive. If any reduction in severance and other benefits constituting parachute payments is necessary to achieve the effect of clause (ii) above, then the reduction will occur first from cash severance payments, next from cancellation of accelerated vesting of equity awards and third from reduction of continued employee benefits.

        Each executive's employment agreement incorporates the terms and provisions of a customary employee proprietary information, invention, non-competition and non-solicitation between Leap and the executive. This agreement includes a noncompetition covenant during the period of the executive's employment and for one year thereafter.

Stock Option and Other Compensation Plans

        In connection with the consummation of the merger with Macrocure Ltd., in January 2017, we made an option grant to each executive to purchase 330,303 of shares of Leap's common stock pursuant to our Amended and Restated 2012 Equity Incentive Plan, which is described in further detail below. This option grant is at an exercise price $9.90 per share. Each option granted to an executive will vest 33% on the first anniversary of the date of grant, and thereafter in equal monthly installments over a period of two years, generally subject to the executive's continued employment.

Outstanding Equity Awards at Fiscal Year-End

        The following table sets forth information regarding equity awards held by our named executive officers as of December 31, 2017.

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Retirement Benefits

        We maintain a defined contribution employee retirement plan, or 401(k) plan, for our employees. Our named executive officers are also eligible to participate in the 401(k) plan on the same basis as our other employees. The 401(k) plan is intended to qualify as a tax-qualified plan under Section 401(k) of the Code. The plan provides that each participant may contribute up to the statutory limit, which is $18,000 for calendar year 2017. Participants that are 50 years or older can also make "catch-up" contributions, which in calendar year 2017 may be up to an additional $6,000 above the statutory limit. In general, eligible compensation for purposes of the 401(k) plan includes an employee's earnings reportable on IRS Form W-2 subject to certain adjustments and exclusions required under the Code. We also make matching employer contributions in cash to each employee's 401(k) plan at a rate of 100% of the first 3% of earnings contributed by each such employee and 50% of the next 2% of earnings contributed. Employees participating in the 401(k) plan are fully vested in our matching contributions, and investments are directed by employees. The 401(k) plan currently does not offer the ability to invest in our securities.

EQUITY COMPENSATION PLAN INFORMATION

        The following table contains information about our equity compensation plans as of December 31, 2017.

DIRECTOR COMPENSATION

        Under our director compensation program, we pay our non-employee directors retainers in cash. We do not pay any compensation to our President and Chief Executive Officer in connection with his service on our Board and, consequently, he is not included in the table. The compensation that we pay to our President and Chief Executive Officer is discussed in the "Executive Compensation" section of this Proxy Statement. Each non-employee director receives a cash retainer for service on the Board and for service on each committee(s) on which the director is a member. The chairmen of each committee receive higher retainers for such service. These fees are payable semi-annually in arrears. Each

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non-employee director shall be paid an annual fee of $40,000 and such additional fees as set out in the following table:

        We also continue to reimburse our non-employee directors for reasonable travel and out-of-pocket expenses incurred in connection with attending Board and committee meetings.

        In addition, under our director compensation program, each non-employee director elected to our Board will receive an option to purchase 15,000 shares of our common stock, with each of these options vesting in equal quarterly installments over a three-year period measured from the date of grant, subject to the non-employee director's continued service as a director, and becoming exercisable in full upon a change in control of our Company. Further, we expect to make a grant of options to purchase 7,500 shares of common stock around the time of Leap's 2018 Annual Meeting of the Stockholders, to all Directors whose service will continue. These option grants will be at an exercise price equal to the fair market value of Leap's common stock on the date of grant and will vest quarterly over a one-year period.

        This policy is intended to provide a total compensation package that enables us to attract and retain qualified and experienced individuals to serve as directors and to align our directors' interests with those of our stockholders.

        Our current director compensation arrangements have been in effect since Leap became a public company in January 2017. Prior to that time, we did not have a formal non-employee director compensation policy.

        The following table sets forth information regarding compensation earned by our non-employee directors during fiscal year 2017.

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        The following table sets forth, as of December 31, 2017, the aggregate number of exercisable and unexercisable option awards outstanding held by our non-employee directors at that time.

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AUDIT COMMITTEE REPORT

The report of the Audit Committee is not "soliciting material," is not deemed "filed" with the SEC and is not to be incorporated by reference into any filing of the Company under the Securities Act of 1933 or the Securities Exchange Act of 1934, both as amended.

        The Audit Committee has reviewed the Leap audited consolidated financial statements for the year ended December 31, 2017 and has discussed these statements with management and EisnerAmper LLP, or EisnerAmper, the Company's independent registered public accounting firm. Leap management is responsible for the preparation of the Company's financial statements and for maintaining an adequate system of disclosure controls and procedures and internal control over financial reporting for that purpose. The independent registered public accounting firm audits the annual consolidated financial statements prepared by management, expresses an opinion as to whether those consolidated financial statements present fairly the consolidated financial position, results of operations and cash flows of Leap Therapeutics, Inc. in conformity with U.S. generally accepted accounting principles and discusses any issues they believe should be raised with us. The Audit Committee is responsible for providing independent, objective oversight of the Company's accounting functions and internal controls.

        The Audit Committee also received from, and discussed with, EisnerAmper the written disclosures and other communications that the Company's independent registered public accounting firm is required to provide to the Audit Committee, including the matters required to be discussed by Statement on Auditing Standards No. 61, as amended (Communication with Audit Committees), as adopted by the Public Company Accounting Oversight Board, or PCAOB, in Rule 3200T.

        EisnerAmper also provided the Audit Committee with the written disclosures and the letter required by Rule 3526 of the PCAOB requiring independent registered public accounting firms to annually disclose in writing all relationships that, in their professional opinion may reasonably be thought to bear on independence, to confirm their perceived independence and to engage in a discussion of independence. The Audit Committee has reviewed this disclosure and has discussed with EisnerAmper their independence from Leap.

        Based on its discussions with management and our independent registered public accounting firm as outlined above, and its review of the representations and information provided by management and our independent registered public accounting firm, the Audit Committee recommended to the Board of Directors that the audited consolidated financial statements be included in the Leap Annual Report on Form 10-K for the year ended December 31, 2017, for filing with the Securities and Exchange Commission.

Respectfully submitted by the Audit Committee,

/s/ Thomas Dietz, Chair
/s/ John Littlechild
/s/ Nissim Mashiach

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PROPOSAL NO. 2
RATIFICATION OF SELECTION OF INDEPENDENT REGISTERED
PUBLIC ACCOUNTING FIRM

        The Audit Committee has appointed the firm of EisnerAmper LLP, or EisnerAmper, an independent registered public accounting firm, to audit our books, records and accounts for the year ending December 31, 2018. This appointment is being presented to the stockholders for ratification at the Annual Meeting.

        EisnerAmper LLP has audited our financial statements since the fiscal year ended December 31, 2015. EisnerAmper has no direct or indirect material financial interest in our company or our subsidiaries. Representatives of EisnerAmper are expected to be present at the Annual Meeting and will be given the opportunity to make a statement on the firm's behalf if they so desire. The representatives also will be available to respond to appropriate questions.

        Proxies solicited by management will be voted for ratification unless stockholders specify otherwise. Ratification by the stockholders is not required. Although we are not required to submit the appointment of EisnerAmper to a vote of the stockholders, our board of directors believes it is appropriate as a matter of policy to request that the stockholders ratify the appointment of EisnerAmper as our independent registered public accounting firm. As an advisory vote, this proposal is not binding. The outcome of this advisory vote will not overrule any decision by us or our Board of Directors (or any committee thereof). However, if the stockholders do not ratify the appointment, the Audit Committee will investigate the reasons and consider whether to retain EisnerAmper or appoint another independent registered public accounting firm. Even if the appointment is ratified, our Board of Directors and the Audit Committee in their discretion may direct the appointment of a different independent registered public accounting firm at any time if they determine that such a change would be in the best interests of our company and our stockholders.

Policy on Audit Committee Pre-Approval of Audit and Permissible Non-Audit Services of Independent Registered Public Accounting Firm

        Consistent with requirements of the SEC and the Public Company Accounting Oversight board of directors regarding auditor independence, our Audit Committee is responsible for the appointment, compensation and oversight of the work of our independent registered public accounting firm. In recognition of this responsibility, our Audit Committee (or the chair if such approval is needed on a time urgent basis) generally pre-approves all audit and permissible non-audit services provided by the independent registered public accounting firm. These services may include audit services, audit-related services, tax services and other services. The Audit Committee determined that the provision of the non-audit services by EisnerAmper described above is compatible with maintaining EisnerAmper's independence.

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Principal Accounting Fees and Services

        The following table sets forth all fees paid or accrued by us for professional audit services and other services rendered by EisnerAmper LLP during the years ended December 31, 2017 and 2016:

VOTE REQUIRED

        The affirmative vote of a majority of shares of our common stock, present in person or represented by proxy at the Annual Meeting and entitled to vote, is required to ratify the selection of our independent auditors.

THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT YOU VOTE
"FOR" THE RATIFICATION OF THE APPOINTMENT OF EISNERAMPER LLP AS THE
COMPANY'S INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM.

(PROPOSAL NO. 2 ON YOUR PROXY CARD)

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SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

        The following table sets forth certain information as of March 15, 2018 (unless otherwise specified), with respect to the beneficial ownership of our Common Stock by each person who is known to own beneficially more than 5% of the outstanding shares of our Common Stock, each person currently serving as a director, each named executive officer, and all directors and executive officers as a group.

        We have determined beneficial ownership in accordance with the SEC's rules. Shares of our Common Stock subject to options or other rights to purchase which are now exercisable or are exercisable within 60 days after March 15, 2018, are to be considered outstanding for purposes of computing the percentage ownership of the persons holding these options or other rights, but are not to be considered outstanding for the purpose of computing the percentage ownership of any other person. Unless otherwise indicated, the persons or entities identified in this table have sole voting and investment power with respect to all shares shown as beneficially owned by them, subject to any applicable community property laws.

        As of March 15, 2017, there were 12,354,014 shares of our common stock outstanding. Except as otherwise noted below, the address for each person or entity listed in the table is c/o Leap Therapeutics, Inc., 47 Thorndike Street, Suite B1-1, Cambridge, MA 02141.

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CERTAIN RELATIONSHIPS AND RELATED PARTY TRANSACTIONS

        The following is a description of transactions since January 1, 2017, in which we were a party and the amount involved exceeded or will exceed $120,000, and in which any of our executive officers, directors, or holders of more than 5% of any class of our voting securities, or an affiliate or immediate family member thereof, had or will have a direct or indirect material interest. We believe the terms obtained or consideration that we paid or received, as applicable, in connection with the transactions described below were comparable to terms available or amounts that would be paid or received, as applicable, in arm's-length transactions with unrelated third parties.

Notes

        As set forth in the table below, we issued promissory notes to holders of 5% or more of our capital stock. The interest rate on each note is eight percent (8%) per annum beginning on either the date the note was entered into or, if the note contains drawdown dates, commencing to accrue with respect to any principal amount outstanding on the applicable drawdown date of such principal amount.

        We issued a convertible promissory note to HealthCare Ventures VIII, L.P., HealthCare Ventures IX, L.P. and HealthCare Strategic Fund, L.P. The note was originally issued by Leap to the payees on September 1, 2015, in the original principal amount of up to $1,500,000, but was thereafter amended such that the maximum principal amount available to Leap under the note was $31,000,000 and HealthCare Ventures Strategic Fund, L.P. was an additional payee party thereunder. The interest rate on the note was eight percent (8%) per annum, commencing to accrue with respect to any principal amount outstanding on the applicable drawdown date of such principal amount. The note automatically converted into 1,950,768 shares of common stock on January 20, 2017.

Recapitalization and Conversion

        In connection with the consummation of the merger with Macrocure Ltd., all outstanding Notes and Preferred Stock converted into common stock. On January 20, 2017 a 1-for-19.86754 reverse stock split of the Company's common stock outstanding was effected.

Voting Agreements in Connection with the Merger

        In connection with the execution of the merger agreement, on August 29, 2016, Leap entered into a voting agreement with each of Ze'ev Bronfeld, a director of Macrocure, David Ben Ami, a director of Macrocure, Ranan Groban, a director of Macrocure, Vaizra Ventures, Viatcheslav Mirilasvili, Shlomo Kalish,, Pontifax (Israel) II—Individual Investors L.P., Pontifax (Israel) II L.P., Pontifax (Cayman) II L.P., and Nissim Mashiach, the chief executive officer of Macrocure (the "equityholders"), under which each such equityholder agreed to vote in favor of the merger and against any alternative acquisition proposal, agreement or transaction. As of August 29, 2016, these entities collectively beneficially owned or controled approximately 54.28% of the voting power of Macrocure on an as-converted to common stock basis. These voting agreements granted Leap irrevocable proxies to vote any Macrocure ordinary shares over which each such equityholder had voting power in favor of the Macrocure merger proposal and against any alternative acquisition proposal, agreement or transaction.

        In addition, in connection with the execution of the merger agreement, on August 29, 2016, HealthCare Ventures VIII, L.P., HealthCare Ventures IX, L.P., HealthCare Ventures Strategic Fund, L.P. and Eli Lilly and Company, who collectively beneficially owned or control 100% of Leap's outstanding common stock as of August 29, 2016, each entered into a voting agreement with Macrocure Ltd. under which each such stockholder has agreed to (i) vote in favor of the Leap proposals that relate to the merger and against any alternative acquisition proposal, agreement or transaction and (ii) take certain actions necessary to approve and implement certain other requirements

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of Leap upon which Macrocure's obligation to consummate the transactions contemplated in the merger agreement is conditioned. Each of these voting agreements granted Macrocure Ltd. irrevocable proxies to vote any shares of Leap common stock over which each such stockholder has voting power in favor of (i) each of the Leap proposals and against any alternative acquisition proposal, agreement or transaction and (ii) each such other approval necessary to satisfy certain other requirements of Leap upon which Macrocure's obligation to consummate the transactions contemplated in the merger agreement were conditioned.

        The voting agreements terminated upon the effective time of the merger on January 23, 2017.

Equity Investment

        On January 20, 2017, pursuant to the terms of the merger agreement and their respective voting agreements, HealthCare Ventures IX, L.P. invested approximately $10.0 million into Leap by purchase of 1,010,225 shares of common stock of Leap.

Royalty Agreement

        On January 20, 2017, Leap declared a special distribution of certain royalty rights to each of its holders of common stock outstanding immediately prior to the effective time of the merger with Macrocure. The royalty rights were set forth in a royalty agreement, referred to herein as the Royalty Agreement, by and between Leap and a special purpose vehicle formed by those holders of Leap's common stock prior to the merger, specifically, HealthCare Ventures VIII, L.P., HealthCare Ventures IX, L.P., HealthCare Ventures Strategic Fund, L.P. and Eli Lilly and Company. These holders collectively beneficially owned or controlled 100% of Leap's outstanding common stock as of the date of the merger.

        Pursuant to the Royalty Agreement, Leap will pay to the special purpose vehicle (i) 5% of Leap's net sales of products incorporating its TRX518 compound and (ii) 2% of Leap's net sales of products incorporating its DKN-01 compound. Net sales will be calculated as the gross amount invoiced by Leap, its affiliates, assignees or sublicensees to a third party, but shall be reduced by any discounts, refunds, rebates, product returns, bad debts, sales taxes, VAT and other similar taxes. The calculation of the gross amount invoiced shall also be discounted in the event that Leap's product is sold as part of a combination product. Royalties will be payable by Leap to the special purpose vehicle every calendar quarter. Among other customary terms for licensing transactions of this type, the special purpose vehicle will have the right no more than once a year to have an independent certified public accountant audit Leap's records to determine the accuracy of royalty payments received. The Royalty Agreement has an indefinite term, and neither Leap nor the special purpose vehicle has the right to terminate.

Registration Rights Agreement

        Leap entered into a Registration Rights Agreement with each of its holders of common stock outstanding immediately prior to the effective time of the merger. In addition, to the former holders of Leap's common stock, certain larger holders of Leap's common stock following the merger (who were among the largest holders of Macrocure ordinary shares prior to the merger) are parties to the Registration Right Agreement.

PIPE Transaction and Voting Agreement

        On November 14, 2017, Leap entered into purchase agreements (collectively, the "Purchase Agreement") with certain existing and new institutional accredited investors and strategic partners (collectively, the "Purchasers"), including HealthCare Ventures IX, L.P. and Eli Lilly and Company. Each of the Purchase Agreements was on terms and conditions substantially similar to each other Purchase Agreement and pursuant to such Purchase Agreements, the Company, in a private placement,

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agreed to issue and sell to the Purchasers an aggregate of 2,958,094 shares (the "Shares") of unregistered common stock, par value $0.001 per share, of the Company (the "Common Stock"), at a price per share of $6.085, each share issued with a warrant (the "Warrants") to purchase one share of Common Stock (the "Warrant Shares") at an exercise price of $6.085 (the "Exercise Price") with an exercise period expiring seven years after closing (the "Term"), for gross proceeds of approximately $18.0 million (the "Private Placement"). If all of the Warrants are exercised at the Exercise Price during the Term, the Company will receive proceeds of approximately $18.0 million in cash and will issue an aggregate of 2,958,094 Warrant Shares.

        HealthCare Ventures IX, L.P. and Eli Lilly and Company, each a more than 5% direct holder of our Common Stock prior to the closing of the Private Placement, purchased Common Stock and Warrants pursuant to a Purchase Agreement in the Private Placement. Each of HealthCare Ventures IX, L.P. and Eli Lilly and Company agreed to purchase the Common Stock and Warrants on the same terms and conditions as the other Purchasers.

        Christopher K. Mirabelli, our Chief Executive Officer, Douglas E. Onsi, our Chief Financial Officer, General Counsel, Treasurer and Secretary, and Augustine Lawlor, our Chief Operating Officer (collectively, the "HCVIX Directors") are the Managing Directors of HealthCare Partners IX, LLC ("HCPIX LLC"), which is the General Partner of HealthCare Partners IX, L.P. ("HCPIX"). HCPIX is the General Partner of HealthCare Ventures IX, L.P. Each of the HCVIX Directors, HCPIX LLC and HCPIX indirectly beneficially own and share voting and dispositive power with respect to all of the securities owned by HealthCare Ventures IX, L.P.

        The Warrants include full ratchet anti-dilution protection provisions. The inclusion of such provisions was subject to stockholder approval. Therefore, the Company held a special meeting of stockholders for the stockholders to approve the full ratchet anti-dilution protection. In connection with such approval, the Company, on November 14, 2017, entered into a voting agreement with HealthCare Ventures VIII, L.P., HealthCare Ventures IX, L.P. and HealthCare Ventures Strategic Fund, L.P. (collectively, the "HealthCare Parties"), which together hold a majority of the shares entitled to vote at the special meeting of stockholders, pursuant to which the HealthCare Parties agreed to vote all of their beneficially owned shares in favor of the any approval proposed at the special meeting of stockholders.

Indemnification Agreements

        We have entered into indemnification agreements with each of our directors and certain executive officers. These agreements require us to indemnify these individuals and, in certain cases, affiliates of such individuals, to the fullest extent permissible under Delaware law against liabilities that may arise by reason of their service to us or at our direction, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified.

        Our amended and restated certificate of incorporation also provides that we will indemnify each of our executive officers and directors to the fullest extent permitted by the Delaware General Corporation Law against liabilities that may arise by reason of their service to us or at our direction, and to advance expenses to each indemnitee in connection with any proceeding in which indemnification is available. Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, we have been informed that in the opinion of the SEC such indemnification is against public policy and is therefore unenforceable.

Related Party Transaction Approval Policy

        In connection with the completion of the merger with Macrocure Ltd., we adopted a related party transactions policy that requires all future transactions between us and any director, executive officer, holder of 5% or more of any class of our capital shares or any member of the immediate family of, or

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entities affiliated with, any of them, or any other related persons (as defined in Item 404 of Regulation S-K) or their affiliates, in which the amount involved is equal to or greater than $120,000, be approved in advance by our nominating and corporate governance committee. Any request for such a transaction must first be presented to our General Counsel who will promptly notify our nominating and corporate governance committee for their review, consideration and approval. In approving or rejecting any such proposal, our nominating and corporate governance committee is to consider the relevant facts and circumstances available and deemed relevant to the nominating and corporate governance, including, but not limited to, the extent of the related party's interest in the transaction, and whether the transaction is on terms no less favorable to us than terms we could have generally obtained from an unaffiliated third party under the same or similar circumstances. The nominating and corporate governance committee has reviewed certain interested transactions and determined that they are pre-approved. These pre-approved interested transactions include, subject to certain limitations, employment or compensation of executive officers, director compensation, certain transactions with other companies, certain company charitable contributions, transaction sin which all shareholders receive proportional benefits and transactions involving competitive bids.

        Certain of the transactions described above were entered into prior to the adoption of this written policy but each such transaction was approved by our Board of Directors. Prior to our Board of Directors' consideration of a transaction with a related person, the material facts as to the related person's relationship or interest in the transaction were disclosed to our board of directors, and the transaction was not approved by our Board of Directors unless a majority of the disinterested directors approved the transaction.

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SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

        Section 16(a) of the Exchange Act requires our directors, executive officers and beneficial owners of more than 10% of our common stock to file reports of holdings and transactions in our common stock and our other securities with the Securities Exchange Commission. Our directors, executive officers and beneficial owners of more than 10% of our common stock did not become subject to such Section 16(a) reporting requirements until January 20, 2017. Based solely on our review of reports that reporting persons have filed with the SEC and furnished to us and written representations that no other reports were required, we believe that during 2017, other than as set forth below, our directors, executive officers and beneficial owners of more than 10% of our common stock timely complied with all applicable filing requirements.

        We believe that HealthCare Partners IX, L.P., the general partner of HealthCare Ventures IX, L.P., inadvertently did not file a Form 3 with the SEC in connection with becoming a more than 10% owner of our common stock on January 20, 2017. Immediately upon recognition of this error, on November 16, 2017, HealthCare Ventures IX, L.P. filed an amended Form 3 to include HealthCare Partners IX, L.P. as a reporting person.

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GENERAL MATTERS

Stockholder Proposals and Nominations

        Requirements for Stockholder Proposals to be Considered for Inclusion in our Proxy Materials.    Under Rule 14a-8(e) of the Exchange Act, to submit a proposal for inclusion in our Proxy Statement for the 2019 Annual Meeting of Stockholders, stockholder proposals must be received by December 3, 2018 by our Secretary at our principal executive offices at 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141.

        Requirements for Stockholder to bring Business and Nominations Before the 2019 Annual Meeting.    Our amended and restated bylaws provide that, for stockholder nominations to the Board or other business to be considered at the 2019 Annual Meeting of Stockholders, the stockholder must have given timely notice thereof in writing to the Secretary at Leap Therapeutics, Inc., 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141. To be timely for the 2019 Annual Meeting of Stockholders, the stockholder's notice must be delivered to or mailed and received by us not earlier than the close of business on the 120th day nor later than the close of business on the 90th day prior to the anniversary date of the previous year's annual meeting of stockholders, or, if later, the 10th day following the day on which we first provide notice or public disclosure of the date of the 2019 Annual Meeting of Stockholders. Therefore, notice must be received not earlier than January 3, 2019 and not later than February 2, 2019. Such notice must provide the information required by Section 2.4 and 2.5 of our amended and restated bylaws with respect to each nomination or matter the stockholder proposes to bring before the 2019 Annual Meeting of Stockholders and must be sent to our Secretary at our principal executive offices at 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141.

Householding of Proxy Materials

        The SEC has adopted rules that permit companies and intermediaries, such as brokers or other nominees, to satisfy delivery requirements for annual reports and proxy statements with respect to two or more stockholders sharing the same address by delivering a single annual report and/or proxy statement addressed to those stockholders. This process, which is commonly referred to as "householding," potentially provides extra convenience for stockholders and cost savings for companies. We and some brokers or other nominees household annual reports and proxy materials, delivering a single annual report and/or proxy statement to multiple stockholders sharing an address unless contrary instructions have been received from the affected stockholders.

        Once you have received notice from your broker or other nominee or us that they or we will be householding materials to your address, householding will continue until you are notified otherwise or until you revoke your consent. You may request to receive at any time, and we will then promptly deliver, a separate copy of our annual report or proxy statement, by sending a written request to us at: Leap Therapeutics, Inc., Attn: Secretary, 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141 USA or calling us at: (617) 714-0360.

        If, at any time, (1) you no longer wish to participate in householding and would prefer to receive a separate annual report and/or proxy statement in the future or (2) you and another stockholder sharing the same address wish to participate in householding and prefer to receive a single copy of our annual report and/or proxy statement, please notify your broker or other nominee if your shares are held in a brokerage account or us if you hold registered shares. You can notify us by sending a written request to us at: Leap Therapeutics, Inc., Attn: Secretary, 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141 USA or calling us at: (617) 714-0360.

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Miscellaneous

        Even if you plan to attend the Annual Meeting in person, please complete, sign, date and return the enclosed proxy promptly. Should you attend the Annual Meeting, you may revoke the proxy and vote in person. A postage-paid, return-addressed envelope is enclosed for your convenience. No postage need be affixed if mailed in the United States. Your cooperation in giving this your immediate attention will be appreciated.

        You may obtain a copy of our Annual Report on Form 10-K (without exhibits) filed with the Securities and Exchange Commission for the year ended December 31, 2017 without charge upon written request to: Leap Therapeutics, Inc., Attn: Secretary, 47 Thorndike Street, Suite B1-1, Cambridge, Massachusetts 02141 USA.

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        As of the date of this proxy statement, we know of no matter not specifically referred to above as to which any action is expected to be taken at the Annual Meeting. The persons named as proxies will vote the proxies, insofar as they are not otherwise instructed, regarding such other matters and the transaction of such other business as may be properly brought before the Annual Meeting, as they determine to be in the best interest of our company and our stockholders.

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DIRECTIONS TO MORGAN, LEWIS & BOCKIUS LLP
ONE FEDERAL STREET
BOSTON, MASSACHUSETTS 02110

Address:

One Federal Street
Boston, Massachusetts 02110-1726
Tel:                617.341.7700
Fax:                617.341.7701

Directions:

FROM POINTS NORTH:

•

From I-93 South and the Tobin Bridge, take Exit 23 (Purchase Street/South Station).



•

Upon exiting, proceed on Purchase Street and turn right onto Pearl Street.



•

Turn left onto Franklin Street.



•

Then turn right onto Federal Street.



•

The Parking Garage entrance is on the left at the corner of Federal and Milk Streets.

FROM POINTS SOUTH:

•

Take I-93 North to Exit 20 (Mass. Turnpike/South Station); stay in left lane.



•

While on this long ramp, follow the sign for South Station/Chinatown.



•

Continue straight; at the 4th traffic light, turn right onto Summer Street.



•

Take next left onto High Street.



•

Then take first left onto Federal Street.



•

The Parking Garage entrance is on the left at the corner of Federal and Milk Streets.

FROM POINTS WEST:

•

Take the Mass. Turnpike (I-90) to Exit 24-A (South Station), following signs for Atlantic Avenue.



•

At the 3rd traffic light, turn left onto Summer Street.



•

Continue on Summer Street through 2 traffic lights.



•

Turn right onto High Street.



•

Then take first left onto Federal Street.



•

The Parking Garage entrance is on the left at the corner of Federal and Milk Streets.

FROM LOGAN AIRPORT:

•

Follow the "exit" signs from the airport to the Summer Tunnel.



•

Stay in the left lane of the tunnel.



•

At the end of the tunnel, bear left and follow signs for Government Center.



•

Turn left onto Congress Street.



•

Follow Congress Street to Purchase Street.



•

Turn right onto Purchase Street.

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•

Follow Purchase Street to Summer Street.



•

Turn right onto Summer Street



•

Turn right at the next set of lights (High Street).



•

On High Street, take first left onto Federal Street.



•

The Parking Garage entrance is on the left at the corner of Federal and Milk Streets.

FROM THE MBTA RED LINE, AMTRAK, AND COMMUTER RAIL (SOUTH STATION):

•

Coming out of South Station onto Sumer Street, cross Surface Road and walk straight onto Federal Street.



•

Continue on Federal Street, eventually crossing over Franklin Street. One Federal Street is on the left side of the street.

PARKING INSTRUCTIONS AT GARAGE:

•

Enter the Parking Garage, taking a ticket from the machine to open the gate.



•

Drive to the first level. A Parking Attendant will park your vehicle after issuing a valet check, to be used for retrieving your vehicle when leaving the building.



•

Upon leaving the Parking Garage, present your ticket to the cashier.

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Appendix A

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