Y-mAbs Insider Transactions: RSUs and Options Converted to Cash in 2025 Merger

Rhea-AI Filing Summary

John LaRocca, SVP, General Counsel & Secretary of Y-mAbs Therapeutics (YMAB), reported transactions tied to the companys merger completed on 09/16/2025. Pursuant to the Merger Agreement, outstanding restricted stock units (RSUs) and stock options were cancelled and converted into cash payments: RSUs (21,500) were settled for cash at $8.60 per share, and outstanding options were converted into cash equal to the excess of $8.60 over the option exercise price where applicable. Options with an exercise price equal to or above $8.60 were cancelled for no consideration. The filing shows zero shares and zero options beneficially owned by the reporting person after the transactions, and that Y-mAbs became an indirect wholly owned subsidiary of the acquiring parent.

Positive

• Merger completed with a defined cash Merger Consideration of $8.60 per share for outstanding awards
• RSUs and in-the-money options were converted to cash, providing certainty of value for holders with strikes below $8.60
• Reporting person disclosed transactions promptly under Section 16 with Form 4 filing

Negative

• Options with exercise price equal to or above $8.60 were cancelled for no consideration, resulting in loss of potential value for those option holders
• Reporting person holds zero shares and zero options following the transaction, indicating full cash-out of insider equity positions

Insights

M&A Specialist

TL;DR: The merger closed and in-the-money awards were cashed out at $8.60 per share; out-of-the-money options were cancelled.

The Form 4 documents completion of the tender offer and merger on 09/16/2025 converting equity awards into cash under the Merger Agreement. The clear mechanics: RSUs converted to $8.60 per share cash; options converted to cash for the spread when the strike was below $8.60 while higher-strike options were cancelled without consideration. This represents a standard cash-out treatment in a change-of-control transaction and is material to award holders and equity dilution metrics.

Corporate Governance Expert

TL;DR: Insider reported disposition of awards due to corporate transaction; reporting appears complete and routine.

The filing identifies the reporting persons role and discloses cancellations and cash conversions of RSUs and options under the Merger Agreement. It documents the reporting requirements under Section 16 and shows no remaining beneficial ownership post-transaction. The footnotes reference the Merger Agreement as controlling, which is appropriate for disclosure clarity.

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^*

LaRocca John

(Last) (First) (Middle)

C/O Y-MABS THERAPEUTICS, INC.

230 PARK AVENUE

(Street)

NEW YORK NY 10169

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP, General Counsel & Secry

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)		D		21,500(2)	D	(3)	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
Employee Stock Option (right to buy)	$9.83	09/16/2025(1)		D			142,600	(4)	01/18/2034	Common Stock	142,600	(4)	0	D
Employee Stock Option (right to buy)	$6.16	09/16/2025(1)		D			42,900	(4)	01/17/2035	Common Stock	42,900	(4)	0	D

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. Represents restricted stock units ("RSUs") granted to the Reporting Person pursuant to the Issuer's 2018 Equity Incentive Plan. Each RSU represents a contingent right to receive one share of Common Stock on the vesting dates of the RSU.

3. 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"), pursuant to the Merger Agreement, each RSU award outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the total number of Shares issuable in settlement of such RSU award immediately prior to the Effective Time, multiplied by (b) the right to receive $8.60 per Share, in cash, without interest, subject to any applicable withholding of taxes (the "Merger Consideration").

4. At the Effective Time, pursuant to the Merger Agreement, each stock option ("Option") outstanding as of immediately prior to the Effective Time, whether vested or unvested, was cancelled and converted into the right to receive cash, without interest, equal to the product of (a) the total number of Shares subject to such Option immediately prior to the Effective Time, multiplied by (b) the excess of the Merger Consideration over the exercise price payable per Share under such Option. Any Options with an exercise price equal to or in excess of the Merger Consideration were cancelled for no 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.

	/s/ John LaRocca	09/18/2025
	** Signature of Reporting Person	Date
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FAQ

What did John LaRocca report on the Form 4 for YMAB?

The Form 4 reports cancellation and cash conversion of 21,500 RSUs and the disposition of 142,600 and 42,900 stock options due to the 09/16/2025 merger, leaving 0 shares/options beneficially owned.

What was the Merger Consideration per share in the YMAB filing?

The Merger Consideration paid for each share was $8.60 per share in cash, as stated in the Form 4 footnotes.

Were any options cancelled for no consideration in the YMAB transaction?

Yes. Options with an exercise price equal to or exceeding $8.60 were cancelled for no consideration per the Merger Agreement.

Did the reporting person retain any equity in YMAB after the merger?

No. The Form 4 shows the reporting person had 0 shares and 0 derivative securities beneficially owned following the transaction.

When was the merger and related tender offer for YMAB completed?

The tender offer and merger were completed on 09/16/2025, resulting in Y-mAbs becoming an indirect wholly owned subsidiary of the purchaser's parent.