Common Stock

ENTRADA THERAPEUTICS, INC.

ONE DESIGN CENTER PLACE, BOSTON, MA, 02210

The entities and persons filing this statement are MPM BioVentures 2014, L.P. ("BV 2014"), MPM BioVentures 2014 (B), L.P. ("BV 2014(B)"), MPM Asset Management Investors BV2014 LLC ("AM BV2014 LLC"), MPM BioVentures 2018, L.P. ("BV 2018"), MPM BioVentures 2018 (B), L.P. ("BV 2018(B)"), MPM Asset Management Investors BV2018 LLC ("AM BV2018 LLC"), MPM BioVentures 2014 GP LLC ("BV 2014 GP"), MPM BioVentures 2014 LLC ("BV 2014 LLC"), MPM BioVentures 2018 GP LLC ("BV 2018 GP") and MPM BioVentures 2018 LLC ("BV 2018 LLC") (collectively, the "MPM Entities") and Ansbert Gadicke, Luke Evnin and Todd Foley (collectively, the "Listed Persons" and together with the MPM Entities, the "Filing Persons").

The address of the principal place of business for each of the MPM Entities and Ansbert Gadicke, Luke Evnin and Todd Foley is 399 Boylston Street, Boston, MA 02116.

The principal business of each of the Filing Persons is the venture capital investment business.

During the last five years, none of the Filing Persons has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree, or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

Each of the Listed Persons is a United States citizen and each of the MPM Entities is a Delaware limited partnership or limited liability company. In accordance with the provisions of General Instruction C to Schedule 13D, information concerning the managers and each other person controlling the general partners of the MPM Entities required by Item 2 of Schedule 13D is listed on Schedule 1 hereto and is incorporated by reference herein.

See rows (11) and (13) of the Filing Persons Owner Profile of this Amendment No. 1 for the aggregate number of Common Stock and percentages of the shares of Common Stock beneficially owned by the Filing Person. Drs. Gadicke and Evnin and Mr. Foley beneficially own 9.98% of the Common Stock as of the date of this filing, and due to field limitations of the SEC's EDGAR filing system, the percentages in row 11 for each of these Reporting Persons has been rounded to 9.9%. The Common Stock is held as follows: * 1,764,167 shares are held directly by BV 2014; * 117,667 shares are held directly by BV 2014(B); * 60,722 shares are held directly by AM BV2014 LLC; * 1,810,592 shares are held directly by BV 2018; * 96,232 shares are held directly by BV 2018(B); and * 35,735 shares are held directly by AM BV2018 LLC. BV 2014 GP and BV 2014 LLC are the direct and indirect general partners of BV 2014 and BV 2014(B) and, accordingly, may be deemed to beneficially own the shares held by BV 2014 and BV 2014(B). BV 2014 LLC is the manager of AM BV2014 LLC and, accordingly, may be deemed to beneficially own the shares held by AM BV2014 LLC. BV 2018 GP and BV 2018 LLC are the direct and indirect general partners of BV 2018 and BV 2018(B) and, accordingly, may be deemed to beneficially own the shares held by BV 2018 and BV 2018(B). BV 2018 LLC is the manager of AM BV2018 LLC and, accordingly, may be deemed to beneficially own the shares held by AM BV2018 LLC. Drs. Gadicke and Evnin and Mr. Foley are the managing directors of BV 2014 LLC and BV 2018 LLC and, accordingly, may be deemed to beneficially own the shares held by BV 2014, BV 2014(B), AM BV2014 LLC, BV 2018, BV 2018(B) and AM BV2018 LLC. Calculation of the percentage of the shares of Common Stock beneficially owned is based upon 38,936,669 Common Stock outstanding as of July 31, 2026, as reported in the Issuer's Form 10-Q filed with the SEC on August 5, 2026.

See rows (7) through (10) of the Filing Persons Owner Profile of this Amendment No. 1 for the number of shares as to which there is sole power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition.

Except as set forth in Exhibit 99.2, the Reporting Persons have not effected any transactions in the Common Stock in the sixty days preceding the date of this filing.

Inapplicable.

Inapplicable.