SEC Form 4

FORM 4		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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* ONSI DOUGLAS E (Last) (First) (Middle) C/O LEAP THERAPEUTICS, INC. 47 THORNDIKE STREET SUITE B1-1 (Street) CAMBRIDGE MA 02141 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol LEAP THERAPEUTICS, INC. [ LPTX ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner X Officer (give title below) Other (specify below) CFO, GC, Treasurer & Secretary
	3. Date of Earliest Transaction (Month/Day/Year) 02/05/2019
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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	02/05/2019		P		571,428	A	$1.75	4,114,804	I	See footnote(1)
Common Stock								343,889	I	See footnote(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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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	02/05/2019		P		571,428		02/05/2019	02/05/2026	Common Stock, $0.001 par value per share	571,428	(3)	592,797	I	See footnote(1)

Explanation of Responses:

1. The shares are owned directly by HealthCare Ventures IX, L.P. 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 HealthCare Partners IX, L.P. ("HCPIX"), which is the General Partner of HealthCare Ventures IX, L.P. Each of the HCVIX Directors, HCPIX LLC and HCPIX beneficially own and share voting and dispositive power with respect to all of the securities owned by HealthCare Ventures IX, L.P. Douglas E. Onsi disclaims beneficial ownership of these shares except to the extent of his proportionate pecuniary interest in these securities.

2. The shares are owned directly by HealthCare Ventures Strategic Fund, L.P. Christopher K. Mirabelli, Douglas E. Onsi and Augustine Lawlor (collectively, the "HCSP Directors") are the Managing Directors of HealthCare Strategic Partners, LLC ("HCV Strategic LLC"), which is the General Partner of HealthCare Ventures Strategic Fund, L.P. Each of the HCSP Directors, and HCV Strategic LLC beneficially own and share voting and dispositive power with respect to all of the securities owned by HCV Strategic Fund, L.P. Douglas E. Onsi disclaims beneficial ownership of these shares except to the extent of his proportionate pecuniary interest in these securities.

3. The reported securities were included with the 571,428 shares of common stock purchased by HealthCare Ventures IX, L.P. for $1.75 per share. Each such purchased share of common stock was issued with a warrant to purchase one share of common stock.

	/s/ Douglas E. Onsi	02/05/2019
	** Signature of Reporting Person	Date
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