X0508 4 2023-10-23 0001990550 Ambrx Biopharma, Inc. AMAM 0001583977 Cormorant Asset Management, LP 200 CLARENDON STREET 52ND FLOOR BOSTON MA 02116 true 0001599214 Chen Bihua C/O CORMORANT ASSET MANAGEMENT, LP 200 CLARENDON STREET, 52ND FLOOR BOSTON MA 02116 true 0001618442 Cormorant Global Healthcare Master Fund, LP 200 CLARENDON STREET 52ND FLOOR BOSTON MA 02116 true 0001817320 Cormorant Private Healthcare Fund III LP 200 CLARENDON STREET 52ND FLOOR BOSTON MA 02116 true false Common Stock 2023-10-23 4 P 0 1307311 6.9911 A 11231000 I See Footnotes Represents the weighted average sale price of shares of common stock purchased in a series of open market transactions on the transaction date at prices ranging from $6.57 to $7.10 per share. The Reporting Persons undertake to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased at each price. All of these shares were purchased by the Master Fund (as defined below). The number of shares of common stock of the issuer reported herein give effect to the automatic conversion of each ordinary share of Ambrx Biopharma Cayman, Inc. (formerly Ambrx Biopharma Inc., the "Predecessor Issuer") into one-seventh of one share of common stock of the Issuer in connection with the merger of the Predecessor Issuer into a wholly-owned subsidiary of the issuer on October 11, 2023, as reported in the Issuer's Current Report on Form 8-K, filed with the Securities and Exchange Commission on October 12, 2023. Information reported herein relates to shares of common stock owned by Cormorant Global Healthcare Master Fund, LP (the "Master Fund") and Cormorant Private Healthcare Fund III, LP ("Fund III"). Cormorant Asset Management, LP ("Cormorant") serves as the investment manager of the Master Fund and Fund III. Cormorant Global Healthcare GP, LLC ("GP LLC") and Cormorant Private Healthcare GP III, LLC ("GP III") serve as General Partner of the Master Fund and Fund III, respectively. Bihua Chen serves as manager of Cormorant, GP LLC and GP III. Each of the Reporting Persons disclaims beneficial ownership of the shares reported herein except to the extent of its or her pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any such shares for purposes of Section 16(a) of the Securities Exchange Act of 1934 or for any other purpose. Represents (i) 8,725,040 shares of common stock beneficially owned by the Master Fund and (ii) 2,505,960 shares of common stock beneficially owned by Fund III. /s/ CORMORANT ASSET MANAGEMENT, LP By: Cormorant Asset Management GP, LLC, its General Partner, By: Bihua Chen, Managing Member 2023-10-25 /s/ Bihua Chen 2023-10-25 /s/ CORMORANT GLOBAL HEALTHCARE MASTER FUND, LP, By: Cormorant Global Healthcare GP, LLC, its General Partner By: Bihua Chen, Managing Member 2023-10-25 /s/ CORMORANT PRIVATE HEALTHCARE FUND III, LP By: Cormorant Private Healthcare GP III, LLC, its General Partner By: Bihua Chen, Managing Member 2023-10-25