[Form 4] Y-mAbs Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

WG Biotech ApS reported the disposition of all its Y-mAbs Therapeutics (YMAB) common shares in connection with a completed merger. On 09/16/2025 Purchaser completed a tender offer and merged into the issuer, and each outstanding share was cancelled for $8.60 per share in cash. WG Biotech ApS surrendered 4,559,233 shares and reports beneficial ownership of 0 shares following the transaction. The filing notes Johan Wedell-Wedellsborg is the majority owner of WG Biotech ApS and had sole voting and dispositive power over the shares; he served as a director. The footnotes state the descriptions are qualified by the Merger Agreement.

Positive

• Completed merger with cash consideration of $8.60 per share provides clear, immediate liquidity to tendering shareholders
• Insider reporting clarifies ownership and voting/dispositive power, supporting transparent disclosure around the transaction

Negative

• Public shareholders' equity was cancelled as the issuer became an indirect wholly owned subsidiary, eliminating public float associated with these shares
• WG Biotech ApS now reports 0 shares beneficially owned, removing a previously disclosed 10% insider stake from the public market

Insights

Financial Analyst

TL;DR: A cash-out merger at $8.60 per share extinguished public equity and resulted in full disposition by a 10% insider holder.

The Form 4 documents a material corporate transaction that converts public equity into cash for holders at a fixed price. The reported disposition of 4,559,233 shares for $8.60 each indicates WG Biotech ApS received cash consideration and now holds no public shares. For investors this is a definitive liquidity event: the issuer became an indirect wholly owned subsidiary of the listed buyer, removing free float associated with the reported shares. The filing is transactional and does not disclose pro forma financials or deal financing details; those terms are governed by the Merger Agreement referenced in the footnotes.

Corporate Governance Expert

TL;DR: Insider-linked entity disposed its entire stake due to a merger; disclosure clarifies ownership/control and deputization status.

The filing clarifies that WG Biotech ApS was a reporting person because its majority owner, Johan Wedell-Wedellsborg, served as a director and had sole voting and dispositive power. The Form 4 discloses the legal mechanics of the disposition and explicitly reserves the Merger Agreement as the controlling description of terms. The remarks also state the filing does not admit deputization as a director, which is a defensive disclosure to limit presumptions about governance status. This is a routine but material governance disclosure accompanying a change-in-control transaction.

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

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X

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^*

WG Biotech ApS

(Last) (First) (Middle)

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)
09/16/2025

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	09/16/2025(1)		U		4,559,233	D	$8.6(2)	0	D

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. Pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated as of August 4, 2025, by and among Y-mAbs Therapeutics, Inc. (the "Issuer"), Yosemite Merger Sub, Inc. ("Purchaser"), Perseus BidCo US, Inc., a Delaware corporation ("Parent"), and Stark International Lux, a Luxembourg private limited liability company ("Ultimate Parent"), on September 16, 2025, Purchaser completed a tender offer for shares of common stock of the Issuer (each, a "Share") and thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and an indirect wholly owned subsidiary of Parent (the "Merger").

2. Pursuant to the terms of the Merger Agreement, the Shares were tendered at the Offer Acceptance Time (as defined in the Merger Agreement) in exchange for the right to receive $8.60 per Share, in cash, without interest, subject to any applicable withholding of taxes (the "Merger Consideration"). At the effective time of the Merger (being such date and at such time as the certificate of merger in respect of the Merger was duly filed with the Secretary of State of the State of Delaware in accordance with the DGCL) (the "Effective Time"), each issued and outstanding Share was cancelled in exchange for the Merger Consideration.

Remarks:

The foregoing descriptions in the footnotes to this Form 4 are qualified in their entirety by reference to the terms of the Merger Agreement. In the event of any conflict between the descriptions above and the terms set forth in the Merger Agreement, the terms set forth in the Merger Agreement shall control. Johan Wedell-Wedellsborg is the majority owner of WG Biotech ApS and had sole voting and dispositive power over the shares of the Issuer held by WG Biotech ApS. Mr. Wedell-Wedellsborg served as a director of the Issuer. In connection therewith, WG Biotech ApS may be deemed to be a director by deputization of the Issuer solely for purposes of Section 16(a) of the Exchange Act. As a result, WG Biotech ApS is listed as a "Reporting Person" in Item 1 and the "Director" box is marked in Item 5 of this Form 4. This filing shall not be deemed an admission by Reporting Person on this Form 4 that such person was a director of the Issuer by deputization.

	WG Biotech ApS by /s/ Johan Wedell-Wedellsborg	09/18/2025
	** 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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FAQ

What transaction did the Form 4 report for Y-mAbs Therapeutics (YMAB)?

The Form 4 reports a disposition related to a merger where each share was cancelled and exchanged for $8.60 per share in cash on 09/16/2025.

How many YMAB shares did WG Biotech ApS dispose of and what was ownership after the transaction?

WG Biotech ApS disposed of 4,559,233 shares and reports holding 0 shares following the reported transaction.

Why is WG Biotech ApS listed as a reporting person on this Form 4?

The filing states that Johan Wedell-Wedellsborg is the majority owner of WG Biotech ApS and had sole voting and dispositive power over the shares; he also served as a director, which triggers Section 16 reporting.

What consideration did tendering shareholders receive in the merger?

Tendering shareholders received $8.60 per share in cash, subject to any applicable tax withholdings, as the Merger Consideration.

Does the Form 4 provide full merger agreement details?

No. The Form 4 references and qualifies its descriptions by the Merger Agreement and states the Merger Agreement controls in case of any conflict.