X0206 3 2013-07-23 0 0001439222 AGIOS PHARMACEUTICALS INC AGIO 0001402439 Arch Venture Fund VII LP 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO IL 60631 0 0 1 0 0001544444 ARCH Venture Partners VII, L.P. 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO IL 60631 0 0 1 0 0001544443 ARCH Venture Partners VII, LLC 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO IL 60631 0 0 1 0 0001219043 BYBEE CLINTON 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO IL 60631 0 0 1 0 0001219039 CRANDELL KEITH 8725 WEST HIGGINS ROAD, SUITE 290 CHICAGO IL 60631 0 0 1 0 Series A Convertible Preferred Stock Common Stock 3636362 D Series C-2 Convertible Preferred Stock Common Stock 224374 D The Series A Convertible Preferred Stock is convertible into Common Stock on a 1-for-2.75 basis into the number of shares of Common Stock as shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. These shares are held by ARCH Venture Fund VII, L.P. ("ARCH Fund VII"). The sole general partner of ARCH Fund VII is ARCH Venture Partners VII, L.P. ("ARCH Partners VII"), which may be deemed to be the beneficial owner of the shares held by ARCH Fund VII. The sole general partner of ARCH Partners VII is ARCH Venture Partners VII, LLC ("ARCH VII LLC"), which may be deemed to be the beneficial owner of the shares held by ARCH Fund VII. ARCH Partners VII and ARCH VII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The managing directors of ARCH VII LLC are Keith Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH Fund VII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The Series C-2 Convertible Preferred Stock is convertible into Common Stock on a 1-for-2.75 basis into the number of shares of Common Stock as shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. By: /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of the general partner of the general partner of ARCH Venture Fund VII, L.P. 2013-07-23 By: /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of the general partner of ARCH Venture Partners VII, L.P. 2013-07-23 By: /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of ARCH Venture Partners VII, LLC 2013-07-23 By: /s/ Mark McDonnell, as Attorney-in-Fact for Clinton Bybee 2013-07-23 By: /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell 2013-07-23