X0206 3 2021-06-23 0 0001826457 Monte Rosa Therapeutics, Inc. GLUE 0001624108 Landsman Liza 1954 GREENSPRING DRIVE SUITE 600 TIMONIUM MD 21093 0 0 1 0 Series A-2 convertible preferred stock Common Stock 2715968 I See Note 2 Series B convertible preferred stock Common Stock 3257328 I See Note 2 Series C convertible preferred stock Common Stock 669002 I See Note 2 Each share of Series A-2 convertible preferred stock, Series B convertible preferred stock and Series C convertible preferred stock (collectively, the "Preferred Stock") is convertible into shares of the Issuer's Common Stock on a 3.5305-for-one basis. Upon the closing of the Issuer's initial public offering, all shares of Preferred Stock will convert into the number of shares of Common Stock of the Issuer shown in column 3. The Preferred Stock has no expiration date. The Reporting Person is a manager of NEA 17 GP, LLC ("NEA 17 GP"), which is the sole general partner of NEA Partners 17, L.P. ("NEA Partners 17"). NEA Partners 17 is the sole general partner of New Enterprise Associates 17, L.P. ("NEA 17"), 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 securities held by NEA 17 in which the Reporting Person has no pecuniary interest. /s/ Sasha Keough, attorney-in-fact 2021-06-23