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* SR ONE CAPITAL MANAGEMENT, LLC (Last) (First) (Middle) 985 OLD EAGLE SCHOOL ROAD SUITE 511 (Street) WAYNE PA 19087 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 02/03/2022	3. Issuer Name and Ticker or Trading Symbol Arcellx, Inc. [ ACLX ]
		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 Preferred Stock	(1)	(1)	Common Stock	1,550,309(2)	(1)	I	See footnote(2)
Series B-1 Preferred Stock	(1)	(1)	Common Stock	666,651(2)	(1)	I	See footnote(2)
Series B-2 Preferred Stock	(1)	(1)	Common Stock	533,389(2)	(1)	I	See footnote(2)
Series C Preferred Stock	(1)	(1)	Common Stock	649,795(2)	(1)	I	See footnote(2)
Series C Preferred Stock	(1)	(1)	Common Stock	433,196(3)	(1)	I	See footnote(3)

1. Name and Address of Reporting Person* SR ONE CAPITAL MANAGEMENT, LLC (Last) (First) (Middle) 985 OLD EAGLE SCHOOL ROAD SUITE 511 (Street) WAYNE PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SR One Capital Fund I Aggregator LP (Last) (First) (Middle) 985 OLD EAGLE SCHOOL ROAD SUITE 511 (Street) WAYNE PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SR ONE CAPITAL PARTNERS I, LP (Last) (First) (Middle) 985 OLD EAGLE SCHOOL ROAD SUITE 511 (Street) WAYNE PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SR One Co-Invest II, LLC (Last) (First) (Middle) 985 OLD EAGLE SCHOOL ROAD SUITE 511 (Street) WAYNE PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* George Simeon (Last) (First) (Middle) 985 OLD EAGLE SCHOOL ROAD SUITE 511 (Street) WAYNE PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. All outstanding shares of Preferred Stock will automatically convert into shares of Common Stock at the Reporting Person's election and automatically upon the closing of the initial public offering of Arcellx, Inc. (the "Issuer"). The Preferred Stock has no expiration date.

2. The reported securities are held directly by SR One Capital Fund I Aggregator, LP. SR One Capital Partners I, LP is the general partner of SR One Capital Fund I Aggregator, LP, and SR One Capital Management, LLC is the general partner of SR One Capital Partners I, LP. Simeon George is the managing member of SR One Capital Management, LLC. Each of SR One Capital Partners I, LP, SR One Capital Management, LLC and Mr. George may each be deemed to have shared power to vote or dispose of these shares, and each disclaims beneficial ownership of the shares except to the extent of any pecuniary interest therein.

3. The reported securities are held directly by SR One Co-Invest II, LLC. SR One Co-Invest Manager II, LLC is the managing member of SR One Co-Invest II, LLC, and SR One Capital Management, LLC is the managing member of SR One Co-Invest Manager II, LLC. Simeon George is the managing member of SR One Capital Management, LLC. Each of SR One Co-Invest Manager II, LLC, SR One Capital Management, LLC and Mr. George may each be deemed to have shared power to vote or dispose of these shares, and each disclaims beneficial ownership of the shares except to the extent of any pecuniary interest therein.

Remarks:

	/s/ Simeon George, Member	02/03/2022
	Simeon George, Member	02/03/2022
	Simeon George, Member	02/03/2022
	Simeon George, Managing Member	02/03/2022
	Simeon George	02/03/2022
	** Signature of Reporting Person	Date
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* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
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