X0306 4 2021-11-02 0 0001689375 Entrada Therapeutics, Inc. TRDA 0001609492 MPM BioVentures 2014, L.P. C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 0001134657 EVNIN LUKE C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 012421 0 0 1 0 0001134655 GADICKE ANSBERT C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 0001609493 MPM BioVentures 2014 (B), L.P. C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 0001609495 MPM Asset Management Investors BV2014 LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 0001765021 MPM BioVentures 2014 LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 0001765091 MPM BioVentures 2014 GP LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 0001729504 MPM BIOVENTURES 2018 (B), L.P. C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 0001734817 MPM ASSET MANAGEMENT INVESTORS BV2018 LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 01242 0 0 1 0 Common Stock 2021-11-02 4 C 0 3816760 A 3816760 I See Footnote Common Stock 2021-11-02 4 C 0 509024 A 4325784 I See Footnote Common Stock 2021-11-02 4 P 0 100000 20.00 A 4425784 I See Footnote Series A Preferred Stock 2021-11-02 4 C 0 27617675 0.00 D Common Stock 3816760 0 I See Footnote Series B Preferred Stock 2021-11-02 4 C 0 3683241 0.00 D Common Stock 509024 0 I See Footnote The shares were converted as follows: 1,733,129 by MPM BioVentures 2014, L.P. ("BV 2014"), 115,596 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 59,655 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"), 1,778,737 by MPM BioVentures 2018, L.P. ("BV 2018"), 94,538 by MPM BioVentures 2018 (B), L.P. ("BV 2018(B)") and 35,105 by MPM Asset Management Investors BV2018 LLC ("AM BV2018"). MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV2014 LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). BV2014 LLC is the manager of AM BV2014. MPM BioVentures 2018 GP LLC and MPM BioVentures 2018 LLC ("BV2018 LLC") are the direct and indirect general partners of BV 2018 and BV 2018(B). BV 2018 LLC is the manager of AM BV2018. Messrs. Evnin and Gadicke are managing directors of BV 2014 LLC and BV 2018 LLC. . Each share of the Issuer's Series A Preferred Stock and Series B Preferred Stock automatically converted into one (1) share of the Issuer's Common Stock immediately upon the closing of the Issuer's initial public offering. These amounts reflect a 1-for-7.235890014 reverse stock split which became effective on October 22, 2021. The Series A Preferred Stock and Series B Preferred Stock have no expiration date. The shares are held as follows: 1,733,129 by BV 2014, 115,596 by BV 2014(B), 59,655 by AM BV2014, 1,778,737 by BV 2018, 94,538 by BV 2018(B) and 35,105 by AM BV2018. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein. The shares were converted as follows: 231,139 by BV 2014, 15,417 by BV 2014(B), 7,956 by AM BV2014, 237,222 by BV 2018, 12,608 by BV 2018(B) and 4,682 by AM BV2018. The shares are held as follows: 1,964,268 by BV 2014, 131,013 by BV 2014(B), 67,611 by AM BV2014, 2,015,959 by BV 2018, 107,146 by BV 2018(B) and 39,787 by AM BV2018. The shares were purchased as follows: 45,408 by BV 2014, 3,029 by BV 2014(B), 1,563 by AM BV2014, 46,603 by BV 2018, 2,477 by BV 2018(B) and 920 by AM BV2018. The shares are held as follows: 2,009,676 by BV 2014, 134,042 by BV 2014(B), 69,174 by AM BV2014, 2,062,562 by BV 2018, 109,623 by BV 2018(B) and 40,707 by AM BV2018. See Form 4 for MPM BioVentures 2018, L.P for additional members of this joint filing. /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the managing member of MPM BioVentures 2014 GP LLC, the general partner of MPM BioVentures 2014, L.P. 2021-11-04 /s/ Luke Evnin 2021-11-04 /s/ Ansbert Gadicke 2021-11-04 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the managing member of MPM BioVentures 2014 GP LLC, the general partner of MPM BioVentures 2014 (B), L.P. 2021-11-04 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the manager of MPM Asset Management Investors BV2014 LLC 2021-11-04 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC 2021-11-04 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the managing member of MPM BioVentures 2014 GP LLC 2021-11-04 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2018 LLC, the managing member of MPM BioVentures 2018 GP LLC, the general partner of MPM BioVentures 2018 (B), L.P. 2021-11-04 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2018 LLC, the manager of MPM Asset Management Investors BV2018 LLC 2021-11-04