X0306 4 2019-03-31 0 0001571498 Epizyme, Inc. EPZM 0001219871 MOTT DAVID M 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 1 0 0 0 Common Stock, par value $0.0001 2019-03-31 4 A 0 1891 12.39 A 13979 D Common Stock, par value $0.0001 6471018 I See Note 2 Common Stock, par value $0.0001 406500 I See Note 3 Common Stock, par value $0.0001 651 I See Note 4 Stock Option (Right to Buy) 13.74 2019-05-31 4 A 0 17633 0.00 A 2029-05-30 Common Stock 17633 17633 D The shares were issued to the Reporting Person pursuant to his election under the Company's director compensation program to receive such shares in lieu of cash fees of $23,437.50 for Board services for the first fiscal quarter of 2019. The shares were issued on the last day of the first fiscal quarter and the number of shares was calculated by dividing the cash fees to be paid for the quarter by the closing price of the Company's common stock on the last trading day of the quarter. The Reporting Person is a director of NEA 13 GP, LTD, which is the sole general partner of NEA Partners 13, L.P. ("NEA Partners 13"). NEA Partners 13 is the sole general partner of New Enterprise Associates 13, L.P. ("NEA 13"), which is the direct beneficial owner of the securities. The Reporting Person disclaims beneficial ownership, within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the NEA 13 shares in which the Reporting Person has no pecuniary interest. The Reporting Person is a director of NEA 13 GP, LTD, which is the sole general partner of NEA Partners 13. NEA Partners 13 is the sole general partner of NEA 13, which is the sole member of Growth Equity Opportunities Fund II, LLC ("GEO II"), the direct beneficial owner of the securities. The Reporting Person disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the GEO II shares in which the Reporting Person has no pecuniary interest. The shares are directly held by the David Mott Declaration of Trust dated May 31, 2001 as amended (the "Mott Trust"). The Reporting Person disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of the shares held by the Mott Trust, except to the extent of his pecuniary interest therein. This option will vest in full on May 31, 2020, subject to Reporting Person's continued service as a director. In the event of a change in control of the Issuer, the option will become exercisable in full. /s/ Sasha Keough, attorney-in-fact 2019-06-07