X0306 4 2019-06-07 1 0001711675 Nightstar Therapeutics plc NITE 0001629794 New Enterprise Associates 15, L.P. 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 0001630226 Makhzoumi Mohamad 2855 SAND HILL ROAD MENLO PARK CA 94025 0 0 1 0 0001559807 Sonsini Peter W. 2855 SAND HILL ROAD MENLO PARK CA 94025 0 0 1 0 0001005561 BARRIS PETER J 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 0001235952 MAKOWER JOSHUA 1954 GREENSPRING DRIVE, SUITE 600 TIMONIUM MD 21093 0 0 1 0 0001237289 SANDELL SCOTT D 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 0001277631 BASKETT FOREST 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 0001559827 Florence Anthony A. Jr. 5425 WISCONSIN AVENUE SUITE 800 CHEVY CHASE MD 20815 0 0 1 0 0001640033 NEA 15 GP, LLC 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 0001640031 NEA Partners 15, L.P. 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 Ordinary Shares 2019-06-07 4 D 0 6662532 25.50 D 0 D The ordinary shares, nominal value GBP 0.01 per share, of Nightstar Therapeutics plc (the "Issuer") may be represented by American Depositary Shares ("ADSs"). Each ADS represents one ordinary share of the Issuer. The shares are directly held by New Enterprise Associates 15, L.P. ("NEA 15") and indirectly held by NEA Partners 15, L.P. ("NEA Partners 15"), the sole general partner of NEA 15, NEA 15 GP, LLC ("NEA 15 GP"), the sole general partner of NEA Partners 15, and the individual managers of NEA 15 GP (NEA 15, NEA Partners 15, NEA 15 GP and the individual managers of NEA 15 GP, together, the "Indirect Reporting Persons"). The individual managers of NEA 15 GP are Peter J. Barris, Forest Baskett, Anthony A. Florence, Jr., Mohamad Makhzoumi, Josh Makower, David M. Mott, Scott D. Sandell and Peter W. Sonsini. The Indirect Reporting Persons disclaim beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the shares of the Issuer held by NEA 15 in which the Indirect Reporting Persons have no pecuniary interest. /s/ Sasha Keough, attorney-in-fact 2019-06-07