X0306 4 2021-03-12 0 0001808158 Repare Therapeutics Inc. RPTX 0001473930 Foley Todd C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 1 0 0 0 Common Shares 2021-03-12 4 S 0 376412 28.18 D 2627360 I See Footnote Common Shares 2021-03-15 4 J 0 24271 D 2603089 I See Footnote The shares were sold as follows: 363,887 by MPM BioVentures 2014, L.P. ("BV 2014") and 12,525 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"). The shares are held as follows: 2,364,040 by BV 2014, 181,948 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)") and 81,372 by 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). BV LLC is the manager of AM BV2014. Todd Foley is a managing director of BV LLC. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. Represents a pro rata in-kind distribution from BV 2014(B) to its limited partners for no consideration. The shares are held as follows: 2,364,040 by BV 2014, 157,677 by BV 2014(B) and 81,372 by AM BV2014. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. /s/ Todd Foley 2021-03-15