Sec Form 4 Filing - ONSI DOUGLAS E @ LEAP THERAPEUTICS, INC. - 2023-03-17

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) 03/17/2023 (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 Common Stock 03/17/2023 M 660,606 A 661,466 D Common Stock 4,144,804 I By HealthCare Ventures IX, L.P. ( 2 )

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 Restricted Stock Units ( 1 ) 03/17/2023 M 660,606 ( 3 ) ( 3 ) Common Stock 660,606 $ 0 0 D

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 03/21/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Restricted Stock Units convert into common stock on a one-for-one basis. ( 2 )The reporting person is a Managing Director of HealthCare Partners IX, LLC which is the General Partner of HealthCare Partners IX, L.P., which is the General Partner of HealthCare Ventures IX, L.P. The reporting person beneficially owns and shares voting and dispositive power with respect to all of the securities owned by HealthCare Ventures IX, L.P. and disclaims beneficial ownership of these shares except to the extent of his proportionate pecuniary interest therein. ( 3 )On March 17, 2020, the reporting person was granted 660,606 Restricted Stock Units, vesting on March 17, 2023 or upon a change of control, whichever is earlier, provided that the grantee continues to be employed by, or provides service to the Company from the grant date to the vesting date of the Restricted Stock Units. At such time as the Restricted Stock Units vest, one share of Common Stock shall be issued automatically in settlement of each Restricted Stock Unit.

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).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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