Item 4 is hereby amended to add the following: On July 28, 2026, the Issuer entered into an Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, Caldera Therapeutics, Inc., a Delaware corporation ("Caldera"), Sonic Holdco, Inc., a Delaware corporation ("Parent"), Yellowstone Merger Sub, Inc., a Delaware corporation and a direct, wholly owned subsidiary of Parent ("Caldera Merger Sub"), and Sonic Merger Sub, Inc., a Delaware corporation and a direct, wholly owned subsidiary of Parent ("Synlogic Merger Sub"). Pursuant to and subject to the terms of the Merger Agreement, among other things, the Issuer will be merged with and into Synlogic Merger Sub, with the Issuer surviving as a wholly owned subsidiary of Parent (the "Merger"), as more fully described in the Form 8-K filed by the Issuer with the Securities and Exchange Commission on July 29, 2026. Concurrently with the execution of the Merger Agreement, the Reporting Persons entered into a Support Agreement (the "Support Agreement") with Caldera and the Issuer. Under the terms of the Support Agreement, the Reporting Persons have agreed to vote all of their Shares in favor of the Merger and the adoption of the Merger Agreement and against any proposal made in opposition to, or in competition with, the Merger Agreement or the Merger. In addition, the Reporting Persons have agreed not to take certain actions, including (i) selling or transferring any Shares (subject to certain exceptions), (ii) granting any proxies or powers of attorney with respect to the Shares, and (iii) exercising any appraisal rights with respect to the Merger. The Reporting Persons have, subject to certain conditions, also granted an irrevocable proxy to the Issuer to vote the Shares on the supported matters. The Support Agreement terminates in certain circumstances, including, among others, upon the valid termination of the Merger Agreement in accordance with its terms and by written agreement of the parties thereto. The foregoing description of the Support Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the form of Support Agreement, which is attached hereto as Exhibit 99.1 and is incorporated herein by reference.