X0206 3 2020-06-18 0 0001808158 Repare Therapeutics Inc. RPTX 0001609492 MPM BioVentures 2014, L.P. C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 0 0 1 0 0001134657 EVNIN LUKE C/O MPM CAPITAL 450 KENDAL STREET CAMBRIDGE MA 02142 0 0 1 0 0001609493 MPM BioVentures 2014 (B), L.P. C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 0 0 1 0 0001609495 MPM Asset Management Investors BV2014 LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 0 0 1 0 0001765021 MPM BioVentures 2014 LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 0 0 1 0 0001765091 MPM BioVentures 2014 GP LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 0 0 1 0 Class A Preferred Shares 0.00 Common Stock 1801581 I See Footnote Class B Preferred Shares 0.00 Common Stock 952191 I See Footnote All series of convertible preferred shares will convert into the number of shares of the Issuer's common stock on a 1-for-1 basis, for no additional consideration, immediately prior to the closing of the Issuer's initial public offering and have no expiration date. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its pecuniary interest therein. The shares are held as follows: 1,636,136 by MPM BioVentures 2014, L.P. ("BV 2014"), 109,128 by MPM BioVentures 2014(B), L.P. ("BV2014(B)") and 56,317 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"). MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). Luke Evnin, Ansbert Gadicke and Todd Foley are the members of BV LLC. The shares are held as follows: 864,749 by BV 2014, 57,677 by BV 2014(B) and 29,765 by AM BV2014. /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the general partner of MPM BioVentures 2014 GP LLC, the general partner of MPM BioVentures 2014, L.P. 2020-06-18 /s/ Luke Evnin 2020-06-18 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the general partner of MPM BioVentures 2014 GP LLC, the general partner of MPM BioVentures 2014 (B), L.P. 2020-06-18 /s/ Howard Rubin, director of MPM Asset Management Investors BV2014 LLC 2020-06-18 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC 2020-06-18 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the general partner of MPM BioVentures 2014 GP LLC 2020-06-18