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* Wedell-Wedellsborg Johan (Last) (First) (Middle) C/O WECO GROUP A/S RUNGSTED STRANDVEJ 113 (Street) RUNGSTED KYST G7 2960 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Y-mAbs Therapeutics, Inc. [ YMAB ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 07/15/2019
	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	07/15/2019		J		860,105	D	(1)	832,391	I	By Weco Group A/S(2)
Common Stock								5,010,000	I	By WG Biotech ApS(3)

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

Explanation of Responses:

1. Weco Group A/S transferred (a) 540,105 shares of the Common Stock of Y-mAbs Therapeutics, Inc. (the "Company") to shareholders of WG Biotech ApS in exchange for 10,781 ordinary shares of WG Biotech ApS; and (b) 320,000 shares of the Company's Common Stock to shareholders of Weco Biotech ApS in exchange for 20,000 shares of Weco Biotech ApS. The closing sale price of the Company's Common Stock on July 15, 2019, the date of the transaction, was $22.95.

2. Reporting Person is the majority owner of Weco Group A/S and as such has sole voting and dispositive power with respect to such shares.

3. Reporting Person is the majority owner of WG Biotech ApS and as such has sole voting and dispositive power with respect to such shares.

	/s/ Johan Wedell-Wedellsborg	07/17/2019
	** Signature of Reporting Person	Date
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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