X0206 3 2018-07-18 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 11050 I By funds Series A Preferred Stock Common Stock 999180 I By funds Series B Preferred Stock Common Stock 967389 I By funds Series D Preferred Stock Common Stock 98683 I By funds Series E Preferred Stock Common Stock 266934 I By funds Series E-1 Preferred Stock Common Stock 282308 I By funds Series F Preferred Stock Common Stock 90840 I By funds Warrant (right to buy) 1.55 2021-05-24 Common Stock 51032 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"). Dr. Tepper is an individual manager of TRV GP LLC. Dr. Tepper disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that he is the beneficial owner of such shares. The Series A Preferred Stock is convertible into Common Stock on a 11.009-for-one basis into the number of shares of Common Stock shown in Column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. The Series B Preferred Stock is convertible into Common Stock on a 11.009-for-one basis into the number of shares of Common Stock shown in Column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. The Series D Preferred Stock is convertible into Common Stock on a 11.009-for-one basis into the number of shares of Common Stock shown in Column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. The Series E Preferred Stock is convertible into Common Stock on a 8.56256-for-one basis into the number of shares of Common Stock shown in Column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. The Series E-1 Preferred Stock is convertible into Common Stock on a 11.009-for-one basis into the number of shares of Common Stock shown in Column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. The Series F Preferred Stock is convertible into Common Stock on a 11.009-for-one basis into the number of shares of Common Stock shown in Column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. The warrant was fully exercisable upon grant. /s/ Kevin Gillis by power of attorney for Dr. Robert Tepper 2018-07-18