SR One Co-Invest II, LLC

SEC source: 0001209191-23-029610 · doc4.xml · nonDerivative · entry 4

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Note 3

Disclosed balance after: 1,658,780

F4 · price: The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $46.00 to $46.56 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F3 · ownership.nature: The securities are directly held by SR One Co-Invest II, LLC ("SR One Co-Invest II"). SR One Co-Invest II Manager, LLC ("SR One Co-Invest II Manager") is the managing member of SR One Co-Invest II and SR One Capital Management is the managing member of SR One Co-Invest II Manager. Dr. George is the managing member of SR One Capital Management (SR One Co-Invest II Manager, SR One Capital Management, and Dr. George together, the "Co-Invest II Indirect Reporting Persons"). The Co-Invest II Indirect Reporting Persons disclaim beneficial ownership within the meaning of Section 16 or otherwise of such portion of the securities held by SR One Co-Invest II in which the Co-Invest II Indirect Reporting Persons have no pecuniary interest.

SEC source: 0001209191-23-029610 · doc4.xml · nonDerivative · entry 3

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Note 2

Disclosed balance after: 2,828,394

F4 · price: The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $46.00 to $46.56 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The securities are directly held by SR One Capital Fund I Aggregator, LP ("SR One Fund I Aggregator"). SR One Capital Partners I, LP ("SR One Partners I") is the sole general partner of SR One Fund I Aggregator, and SR One Capital Management, LLC ("SR One Capital Management") is the sole general partner of SR One Partners I. Simeon George, M.D. is the managing member of SR One Capital Management (SR One Partners I, SR One Capital Management, and Dr. George together, the "Fund I Indirect Reporting Persons"). The Fund I Indirect Reporting Persons disclaim beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"), or otherwise of such portion of the securities held by SR One Fund I Aggregator in which the Fund I Indirect Reporting Persons have no pecuniary interest.

SEC source: 0001209191-23-029610 · doc4.xml · nonDerivative · entry 2

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Note 3

Disclosed balance after: 1,662,584

F1 · price: The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $45.00 to $45.745 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F3 · ownership.nature: The securities are directly held by SR One Co-Invest II, LLC ("SR One Co-Invest II"). SR One Co-Invest II Manager, LLC ("SR One Co-Invest II Manager") is the managing member of SR One Co-Invest II and SR One Capital Management is the managing member of SR One Co-Invest II Manager. Dr. George is the managing member of SR One Capital Management (SR One Co-Invest II Manager, SR One Capital Management, and Dr. George together, the "Co-Invest II Indirect Reporting Persons"). The Co-Invest II Indirect Reporting Persons disclaim beneficial ownership within the meaning of Section 16 or otherwise of such portion of the securities held by SR One Co-Invest II in which the Co-Invest II Indirect Reporting Persons have no pecuniary interest.

SEC source: 0001209191-23-029610 · doc4.xml · nonDerivative · entry 1

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Note 2

Disclosed balance after: 2,834,879

F1 · price: The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $45.00 to $45.745 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The securities are directly held by SR One Capital Fund I Aggregator, LP ("SR One Fund I Aggregator"). SR One Capital Partners I, LP ("SR One Partners I") is the sole general partner of SR One Fund I Aggregator, and SR One Capital Management, LLC ("SR One Capital Management") is the sole general partner of SR One Partners I. Simeon George, M.D. is the managing member of SR One Capital Management (SR One Partners I, SR One Capital Management, and Dr. George together, the "Fund I Indirect Reporting Persons"). The Fund I Indirect Reporting Persons disclaim beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended ("Section 16"), or otherwise of such portion of the securities held by SR One Fund I Aggregator in which the Fund I Indirect Reporting Persons have no pecuniary interest.

SEC source: 0001209191-22-008281 · doc4.xml · derivative · entry 12

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 433,196 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: 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.

F1 · price: 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.

F1 · derivative.exercise_date: 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.

F1 · derivative.expiration_date: 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.

F4 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · derivative · entry 11

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 649,795 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: 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.

F1 · price: 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.

F1 · derivative.exercise_date: 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.

F1 · derivative.expiration_date: 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.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · derivative · entry 10

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 533,389 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: 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.

F1 · price: 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.

F1 · derivative.exercise_date: 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.

F1 · derivative.expiration_date: 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.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · derivative · entry 9

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 666,651 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: 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.

F1 · price: 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.

F1 · derivative.exercise_date: 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.

F1 · derivative.expiration_date: 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.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · derivative · entry 8

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 1,550,309 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: 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.

F1 · price: 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.

F1 · derivative.exercise_date: 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.

F1 · derivative.expiration_date: 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.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · nonDerivative · entry 7

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,033,196

F5 · shares: SR One Co-Invest II, LLC purchased 1,600,000 shares of Common Stock of the Issuer in connection with the Issuer's public offering.

F4 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · nonDerivative · entry 6

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 433,196

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: 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.

F4 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · nonDerivative · entry 5

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,466,811

F3 · shares: SR One Capital Fund I Aggregator, LP purchased 66,667 shares of Common Stock of the Issuer in connection with the Issuer's public offering.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · nonDerivative · entry 4

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,400,144

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: 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.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · nonDerivative · entry 3

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,750,349

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: 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.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · nonDerivative · entry 2

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 2,216,960

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: 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.

F2 · ownership.nature: 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.

SEC source: 0001209191-22-008281 · doc4.xml · nonDerivative · entry 1

SR ONE CAPITAL MANAGEMENT, LLC · CIK 0001853723 · 10% owner

SR ONE CAPITAL PARTNERS I, LP · CIK 0001853724 · 10% owner

SR One Capital Fund I Aggregator LP · CIK 0001848319 · 10% owner

SR One Co-Invest II, LLC · CIK 0001867644 · 10% owner

George Simeon · CIK 0001595117 · 10% owner

SR One Co-Invest II Manager, LLC · CIK 0001910324 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 1,550,309

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: 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.

F2 · ownership.nature: 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.