[Form 4] CARGO Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

CARGO Therapeutics insider option disposition tied to merger. A director reported the disposition of 25,000 stock options with a $4.35 exercise price as part of the company’s merger transaction with Concentra Biosciences. Under the Merger Agreement and related CVR Agreement, outstanding options became vested and were either exercised or converted at the merger into a cash payment equal to the excess of the cash offer over the option exercise price and one non-transferable Contingent Value Right per underlying share; options with exercise prices at or above the cash offer were canceled for no consideration. The filing reflects the contractual settlement mechanics used to convert equity awards into cash and CVRs in connection with the takeover.

Positive

• In-the-money options were cashed out per the Merger Agreement, providing immediate value to optionholders equal to the spread over the exercise price
• CVRs issued for each share underlying converted options, preserving potential contingent upside for former optionholders

Negative

• Options with exercise prices equal to or above the cash offer were canceled for no consideration, which provides no recovery for those optionholders
• Reporting person no longer holds the reported 25,000-option position, reducing insider equity alignment in the successor structure

Insights

M&A Specialist

TL;DR: Options were cashed out and converted to CVRs under the merger, reflecting standard consideration mechanics in a buyout.

The reported transaction shows typical merger consideration treatment: vested options were converted into a cash amount equal to the spread between the offer price and exercise price, plus a contingent value right per share. This structure preserves immediate cash value for in-the-money optionholders while allocating future contingent upside via CVRs. For deal-sensitive stakeholders, the allocation between cash and CVRs affects realized proceeds and potential future value capture.

Corporate Governance Expert

TL;DR: Director-level holdings were settled via the merger agreement, reducing insider option exposure post-transaction.

The Form 4 documents a director's option disposition pursuant to the Merger Agreement, which is governance-significant because it alters insider incentive alignment and eliminates those option-based retention levers. The cancellation provision for options with exercise prices at or above the cash amount is notable for equity compensation holders because it results in no payout for certain grants. Disclosure is clear about conversion mechanics and CVR issuance.

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

X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Bassan Abraham

(Last) (First) (Middle)

C/O CARGO THERAPEUTICS, INC.

835 INDUSTRIAL ROAD, SUITE 400

(Street)

SAN CARLOS CA 94070

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
CARGO Therapeutics, Inc. [ CRGX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/19/2025

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

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
Stock Option (Right to Buy)	$4.35	08/19/2025		D			25,000	(1)(2)(3)	06/17/2035	Common Stock	25,000	(1)(2)(3)	0	D

Explanation of Responses:

1. Disposed of pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated as of July 7, 2025, by and among CARGO Therapeutics, Inc. (the "Issuer"), Concentra Biosciences, LLC ("Parent") and Concentra Merger Sub VII, Inc., a wholly owned subsidiary of Parent ("Merger Sub"). On August 18, 2025, Parent and Merger Sub completed a tender offer pursuant to the terms of the Merger Agreement for all outstanding shares of common stock of the Issuer (each, a "Share") for an offer price of (i) $4.379 per Share in cash (the "Cash Amount"), and (ii) one non-transferable contractual contingent value right (each, a "CVR"), subject to and in accordance with the terms of the Contingent Value Rights Agreement (the "CVR Agreement"), in each case, without interest, and subject to any applicable withholding taxes (the Cash Amount plus one CVR, collectively, the "Offer Price"). [continues to Footnote 2]

2. [continues from Footnote 1] Merger Sub thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent (the "Merger"). As of immediately prior to and conditioned upon the effective time of the Merger, pursuant to the Merger Agreement, each outstanding option to purchase Shares (each, an "Option") became fully vested and exercisable, and to the extent not exercised prior to the effective time of the Merger, was canceled and converted into the right to receive (a) an amount in cash (without interest and subject to deduction for any required withholding tax) equal to the product of (1) the excess, if any, of the Cash Amount over the exercise price per share of each such Option and (2) the number of Shares underlying such Option immediately prior to the effective time of the Merger [continues to Footnote 3]

3. [continues from Footnote 2] and (b) one CVR in respect of each Share underlying such Option; provided, however, that if the exercise price per Share of any Option was equal to or greater than the Cash Amount that was then outstanding it was canceled for no consideration.

	/s/ Halley Gilbert, as attorney-in-fact for Abraham Bassan	08/19/2025
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did the Form 4 for CARGO Therapeutics (CRGX) report?

It reported the disposition of 25,000 stock options with a $4.35 exercise price pursuant to the company’s Merger Agreement and related CVR Agreement.

How were outstanding options treated in the merger?

Vested options were converted into a cash payment equal to the excess of the cash offer over the exercise price per share and one CVR per underlying share; options with exercise prices at or above the cash offer were canceled for no consideration.

What is a CVR in this context?

A CVR is a non-transferable Contingent Value Right issued per underlying share to provide potential future payments according to the CVR Agreement.

Who filed the Form 4 on behalf of the reporting person?

The filing was signed by an attorney-in-fact, Halley Gilbert, on behalf of the reporting person, Abraham Bassan.

Does the Form 4 disclose the merger counterparty?

Yes, it identifies Concentra Biosciences, LLC (Parent) and its wholly owned Merger Sub as the counterparties to the Merger Agreement.