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

Rhea-AI Filing Summary

CARGO Therapeutics insider transactions tied to a completed merger. Anup Radhakrishnan, an officer serving as Interim Chief Executive Officer, Chief Financial Officer and Chief Operating Officer, reported disposition of 63,436 shares of CARGO Therapeutics common stock through a tender offer and merger. The reported cash consideration per share was $4.379 and each share also conveys one non-transferable Contingent Value Right (CVR) under the CVR Agreement.

The filing states the tender offer closed on August 18, 2025 and the merger became effective on August 19, 2025. Outstanding restricted stock units accelerated and converted into cash and CVRs; outstanding stock options became fully vested and then were canceled and converted into cash and CVRs (or canceled for no consideration if their exercise price was at or above $4.379). Following the reported transactions, the reporting person shows 0 shares beneficially owned.

Positive

• Merger completed through a tender offer and merger, providing a defined cash consideration of $4.379 per share.
• Each share receives a CVR in addition to cash, preserving contingent upside mechanisms for holders.
• RSUs and options were accelerated and converted into the transaction consideration, ensuring payout to holders of vested awards.

Negative

• Reporting person’s beneficial ownership reduced to 0 shares following the reported transactions.
• Some options were canceled for no consideration where the exercise price was equal to or greater than $4.379.

Insights

Corporate Governance Expert

TL;DR: Insider dispositions resulted from a contractual merger process and reflect standard treatment of equity awards in an acquisition.

The Form 4 documents dispositions and conversions that were effectuated by the Merger Agreement and related tender offer. RSUs accelerated and were converted to cash plus CVRs; options vested and were converted similarly or canceled if out-of-the-money. The filing shows the officer’s direct beneficial ownership reduced to zero following consummation. This pattern aligns with common deal mechanics rather than unilateral insider selling decisions.

M&A Specialist

TL;DR: The merger closed with per-share cash consideration of $4.379 plus CVRs, triggering standard equity treatment and payout mechanics.

The disclosure confirms a completed tender offer on August 18, 2025 and the merger effective August 19, 2025. Deal terms provided cash per share and one CVR per share; RSUs and options were accelerated and converted into the same consideration framework, with options out-of-the-money canceled for no consideration. These are material transaction outcomes that determine exit value realization for equity holders.

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

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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).

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^*

Radhakrishnan Anup

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
08/18/2025

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	08/18/2025		U		57,345(1)(2)	D	$4.379	63,436	D
Common Stock	08/19/2025		D		63,436(3)(4)	D	$4.379	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
Stock Option (Right to Buy)	$1.09	08/19/2025		D			14,679	(5)(6)	10/06/2032	Common Stock	14,679	(5)(6)	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 (the "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, effective as of August 19, 2025 (the "Effective Time"), with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent (the "Merger").

3. Pursuant to the terms of the Merger Agreement, immediately prior to the time at which Parent first irrevocably accepts for purchase the Shares tendered in the Tender Offer, each restricted stock unit award with respect to Shares that is, at the time of determination, subject to vesting or forfeiture conditions ("RSU Award") that is outstanding as of immediately prior thereto, shall (a) accelerate and become fully vested, and (b) by virtue of the Merger automatically (except as otherwise provided in the Merger Agreement) and without any action on the part of the Issuer, Parent or the holder thereof, be canceled and terminated and converted into the right to receive [continues to Footnote 4]

4. [continues from Footnote 3] (i) an amount in cash without interest, subject to any applicable tax withholding, equal to the product of the number of Shares underlying such RSU Award immediately prior to the Effective Time and $4.379 in cash, plus (ii) one CVR with respect to each Share subject to such RSU Award immediately prior to the Effective Time.

5. As of immediately prior to and conditioned upon the Effective Time, 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 [continues to Footnote 6]

6. [continues from Footnote 5] 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.

Remarks:

Title: Interim Chief Executive Officer, Chief Financial Officer and Chief Operating Officer

	/s/ Halley Gilbert, as attorney-in-fact for Anup Radhakrishnan	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).
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FAQ

What was the per-share cash price paid in the CARGO Therapeutics (CRGX) tender offer?

The tender offer paid $4.379 per share in cash plus one Contingent Value Right (CVR) per share.

When did the tender offer and merger for CARGO Therapeutics (CRGX) occur?

The tender offer completed on August 18, 2025 and the merger became effective on August 19, 2025.

How were restricted stock units (RSUs) and stock options treated in the transaction?

Outstanding RSUs accelerated and converted into cash equal to $4.379 per underlying share plus one CVR per share. Options vested and were converted into cash plus CVRs, but options with exercise prices >= $4.379 were canceled for no consideration.

How many shares did Anup Radhakrishnan dispose of and what is his post-transaction ownership?

The filing reports dispositions totaling 63,436 shares and shows 0 shares beneficially owned following the transactions.

What roles did the reporting person hold at CARGO Therapeutics at the time of the filing?

The reporting person was disclosed as Interim Chief Executive Officer, Chief Financial Officer and Chief Operating Officer.