Sec Form 4 Filing - ONSI DOUGLAS E @ LEAP THERAPEUTICS, INC. - 2021-02-09

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person ONSI DOUGLAS E 2. Issuer Name and Ticker or Trading Symbol LEAP THERAPEUTICS, INC. [ LPTX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) CEO,CFO,Pres.,GC,Treas.,&Sec. (Last) (First) (Middle) C/O LEAP THERAPEUTICS, INC., 47 THORNDIKE STREET SUITE B1-1 3. Date of Earliest Transaction (MM/DD/YY) 02/09/2021 (Street) CAMBRIDGE, MA02141 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Warrant (Right to Buy) $ 1.95 02/09/2021 J( 1 )( 2 ) 571,428 02/05/2019 02/05/2026 Common Stock, $0.001 par value per share 571,428 ( 3 ) 0 D ( 2 ) Warrant (Right to Buy) $ 1.95 02/09/2021 J( 1 )( 4 ) 11,544 02/05/2019 02/05/2026 Common Stock, $0.001 par value per share 11,544 ( 3 ) 11,544 I ( 4 ) See Footnote

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other ONSI DOUGLAS E C/O LEAP THERAPEUTICS, INC. 47 THORNDIKE STREET SUITE B1-1 CAMBRIDGE, MA02141 X CEO,CFO,Pres.,GC,Treas.,&Sec. Signatures /s/ Douglas E. Onsi 02/11/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On February 9, 2020, HealthCare Ventures IX, L.P. ("HCVIX") transferred, for no consideration, all 571,428 warrants to purchase common stock it held (the "Transfer") to the limited partners of HCVIX on a pro rata basis. The term of HCVIX expired on December 31, 2020, at which time HCVIX entered into liquidation. The process of liquidating HCVIX, including the distribution of marketable and non-marketable securities, has commenced in 2021, and HealthCare Partners IX, L.P. ("HCPIX"), the General Partner of HCVIX, as liquidator, will use its best efforts to complete the orderly liquidation of HCVIX. ( 2 )These warrants were owned directly by HCVIX. Christopher K. Mirabelli, Douglas E. Onsi and Augustine Lawlor (collectively, the "HCVIX Directors") are the Managing Directors of HealthCare Partners IX, LLC ("HCPIX LLC"), which is the General Partner of HCPIX, which is the General Partner of HCVIX. Each of the HCVIX Directors, HCPIX LLC and HCPIX indirectly beneficially owns and shares voting and dispositive power with respect to all of the securities owned by HCVIX, and each disclaimed beneficial ownership of the warrants except to the extent of his or its proportionate pecuniary interest therein. ( 3 )The warrants were acquired in connection with the purchase of an equal number of shares of common stock by HCVIX on February 5, 2019 for $1.75 per share. Each such purchased share of common stock was issued with a warrant to purchase one share of common stock. HCVIX will continue to hold 4,144,804 shares of common stock following the Transfer. ( 4 )These warrants were acquired by Nine Capital Partners, LLC ("Nine Capital Partners"), a limited partner of HCVIX, in connection with the Transfer. The reporting person is a member of Nine Capital Partners and may be deemed to indirectly beneficially own and share voting and dispositive power with respect to all securities held by Nine Capital Partners. The reporting person disclaims beneficial ownership of the warrants except to the extent of his proportionate pecuniary interest therein.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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