X0206 3 2019-02-07 0 0001708493 Harpoon Therapeutics, Inc. HARP 0001609492 MPM BioVentures 2014, L.P. C/O MPM CAPITAL 450 KENDALL 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 0001473930 Foley Todd C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 0 0 1 0 0001263048 MPM ASSET MANAGEMENT LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE MA 02142 0 0 1 0 Common Stock 322063 I See Footnote Series A Preferred Stock 0.00 Common Stock 1525164 I See Footnote Series B Preferred Stock 0.00 Common Stock 1578751 I See Footnote Series C Preferred Stock 0.00 Common Stock 417852 I See Footnote Common Stock Warrant (Right to Buy) 0.0492 2015-03-24 2025-03-24 Common Stock 25418 I See Footnote Common Stock Warrant (Right to Buy) 0.0492 2015-07-23 2025-07-23 Common Stock 57192 I See Footnote Common Stock Warrant (Right to Buy) 0.0492 2015-08-19 2025-08-19 Common Stock 171579 I See Footnote Common Stock Warrant (Right to Buy) 0.0492 2015-12-16 2025-12-14 Common Stock 50837 I See Footnote Common Stock Warrant (Right to Buy) 0.0492 2016-11-01 2026-11-01 Common Stock 76256 I See Footnote Common Stock Warrant (Right to Buy) 0.0492 2017-01-10 2027-01-10 Common Stock 50837 I See Footnote The shares are held by MPM Asset Management LLC ("AM LLC"). Luke Evnin and Ansbert Gadicke are the members of AM LLC. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its pecuniary interest therein. All series of convertible preferred stock will automatically 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. The shares are held as follows: 1,382,777 by MPM BioVentures 2014, L.P. ("BV 2014"), 92,229 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)") and 50,158 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: 1,431,365 by BV 2014, 95,467 by BV 2014(B) and 51,919 by AM BV2014. The shares are held as follows: 378,843 by BV 2014, 25,268 by BV 2014(B) and 13,741 by AM BV2014. The warrants are held as follows: 23,046 by BV 2014, 1,537 by BV 2014(B) and 835 by AM BV2014. The warrants are held as follows: 51,854 by BV 2014, 3,458 by BV 2014(B) and 1,880 by AM BV2014. The warrants are held as follows: 155,562 by BV 2014, 10,375 by BV 2014(B) and 5,642 by AM BV2014. The warrants are held as follows: 46,092 by BV 2014, 3,074 by BV 2014(B) and 1,671 by AM BV2014. The warrants are held as follows: 69,138 by BV 2014, 4,611 by BV 2014(B) and 2,507 by AM BV2014. The warrants are held as follows: 46,092 by BV 2014, 3,074 by BV 2014(B) and 1,671 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. 2019-02-07 /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. 2019-02-07 /s/ Howard Rubin, director of MPM Asset Management Investors BV2014 LLC 2019-02-07 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC 2019-02-07 /s/ Ansbert Gadicke, managing director of MPM BioVentures 2014 LLC, the general partner of MPM BioVentures 2014 GP LLC 2019-02-07 /s/ Todd Foley 2019-02-07 /s/ Ansbert Gadicke, member of MPM Asset Management LLC 2019-02-07