X0306 4 2018-08-22 0 0001434418 CONSTELLATION PHARMACEUTICALS INC CNST 0001192595 TEPPER ROBERT I C/O CONSTELLATION PHARMACEUTICALS, INC. 215 FIRST STREET, SUITE 200 CAMBRIDGE MA 02142 1 0 1 0 Common Stock 2018-08-22 4 X 0 51032 1.55 A 3034083 I By Funds Warrant (right to buy) 1.55 2018-08-22 4 X 0 51032 0.00 D 2021-05-24 Common Stock 51032 0 I By Funds These securities are directly held by Third Rock Ventures, L.P. ("TRV"). The general partner of TRV is Third Rock Ventures GP, L.P. ("TRV GP"). The general partner of TRV GP is TRV GP, LLC ("TRV GP LLC"). The individual managers of TRV GP LLC are Mark Levin ("Levin"), Kevin Starr ("Starr") and Dr. Robert Tepper ("Tepper"). Each of TRV GP, TRV GP LLC, Levin, Starr and Tepper disclaims beneficial ownership of the shares except to the extent of its or his pecuniary interest therein, if any, and this report shall not be deemed an admission that it or he is the beneficial owner of such shares. The warrant was fully exercisable upon grant. /s/ Kevin Gillis by power of attorney for Robert Tepper 2018-08-24