CARGO Therapeutics, Inc. Common Stock (CRGX) Form 3 Initial statement of insider ownership

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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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1. Name and Address of Reporting Person^*

Third Rock Ventures V, L.P.

(Last) (First) (Middle)

C/O THIRD ROCK VENTURES, LLC

201 BROOKLINE AVE, SUITE 1401

(Street)

BOSTON MA 02215

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
11/09/2023

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

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

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

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A-1 Preferred Stock	(1)	(1)	Common Stock	1,737,216	(1)	D(2)(4)
Series A-1 Preferred Stock	(1)	(1)	Common Stock	473,786	(1)	I	See Footnotes(3)(4)

1. Name and Address of Reporting Person^*

Third Rock Ventures V, L.P.

(Last) (First) (Middle)

C/O THIRD ROCK VENTURES, LLC

201 BROOKLINE AVE, SUITE 1401

(Street)

BOSTON MA 02215

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Third Rock Ventures GP V, LP

(Last) (First) (Middle)

201 BROOKLINE AVE, SUITE 1401

(Street)

BOSTON MA 02215

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

TRV GP V, LLC

(Last) (First) (Middle)

201 BROOKLINE AVE, SUITE 1401

(Street)

BOSTON MA 02215

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Third Rock Ventures VI, L.P.

(Last) (First) (Middle)

201 BROOKLINE AVE, SUITE 1401

(Street)

BOSTON MA 02215

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

Third Rock Ventures GP VI, L.P.

(Last) (First) (Middle)

201 BROOKLINE AVE, SUITE 1401

(Street)

BOSTON MA 02215

(City) (State) (Zip)

1. Name and Address of Reporting Person^*

TRV GP VI, LLC

(Last) (First) (Middle)

201 BROOKLINE AVE, SUITE 1401

(Street)

BOSTON MA 02215

(City) (State) (Zip)

Explanation of Responses:

1. The Series A-1 Preferred Stock is convertible into common stock on a 13.5685-for-1 basis into the number of shares of common stock shown in Column 3 without payment of further consideration at the holder's election or upon closing of the initial public offering of the Issuer's common stock. The shares have no expiration date.

2. These shares are directly held by Third Rock Ventures V, L.P. ("TRV V"). The general partner of TRV V is Third Rock Ventures GP V, L.P. ("TRV GP V"). The general partner of TRV GP V is TRV GP V, LLC ("TRV GP V LLC"). Each of TRV GP V, and TRV GP V LLC, disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it or he is the beneficial owner of such shares.

3. These shares are directly held by Third Rock Ventures VI, L.P. ("TRV VI"). The general partner of TRV VI is Third Rock Ventures GP VI, L.P. ("TRV GP VI"). The general partner of TRV GP VI is TRV GP VI, LLC ("TRV GP VI LLC"). Each of TRV GP VI, and TRV GP VI LLC, disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it or he is the beneficial owner of such shares.

4. Each of Reporting Persons disclaims the existence of a Section 13(d) "group" as between the TRV V related parties and the TRV VI related parties and this report shall not be deemed an admission that any of such parties is or may be part of such a group with any of the other parties.

Remarks:

	/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.	11/09/2023
	/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P.	11/09/2023
	/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC	11/09/2023
	/s/ Kevin Gillis, Chief Operating Officer of TRV GP VI, LLC, general partner of Third Rock Ventures GP VI, L.P., general partner of Third Rock Ventures VI, L.P.	11/09/2023
	/s/ Kevin Gillis, Chief Operating Officer of TRV GP VI, LLC, general partner of Third Rock Ventures GP VI, L.P.	11/09/2023
	/s/ Kevin Gillis, Chief Operating Officer of TRV GP VI, LLC	11/09/2023
	** Signature of Reporting Person	Date
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