X0306 4 2020-10-16 0 0001659352 Codiak BioSciences, Inc. CDAK 0001724575 Flagship Ventures Fund V General Partner LLC 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001627639 Flagship Ventures Fund V, L.P. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001724939 Flagship V VentureLabs Rx Fund, L.P. 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 0001222012 AFEYAN NOUBAR 55 CAMBRIDGE PARKWAY, SUITE 800E CAMBRIDGE MA 02142 0 0 1 0 Common Stock 2020-10-16 4 C 0 543686 A 543686 I See Footnote Common Stock 2020-10-16 4 C 0 543686 A 543686 I See Footnote Common Stock 2020-10-16 4 C 0 338630 A 882316 I See Footnote Common Stock 2020-10-16 4 C 0 338630 A 882316 I See Footnote Common Stock 2020-10-16 4 C 0 95861 A 978177 I See Footnote Common Stock 2020-10-16 4 C 0 95861 A 978177 I See Footnote Common Stock 2020-10-16 4 P 0 165000 15.00 A 1143177 I See Footnote Common Stock 485949 I See Footnote Series A Preferred Stock 2020-10-16 4 C 0 4250000 D Common Stock 543686 0 I See Footnote Series A Preferred Stock 2020-10-16 4 C 0 4250000 D Common Stock 543686 0 I See Footnote Series B Preferred Stock 2020-10-16 4 C 0 2416666 D Common Stock 338630 0 I See Footnote Series B Preferred Stock 2020-10-16 4 C 0 2416666 D Common Stock 338630 0 I See Footnote Series C Preferred Stock 2020-10-16 4 C 0 660048 D Common Stock 95861 0 I See Footnote Series C Preferred Stock 2020-10-16 4 C 0 660048 D Common Stock 95861 0 I See Footnote Each share of Series A Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.8170 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. Shares held by Flagship Ventures Fund V, L.P. ("Flagship Fund V"). Flagship Ventures Fund V General Partner LLC ("Flagship V GP") is the general partner of Flagship Fund V. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein. Shares held by Flagship V VentureLabs Rx Fund, L.P. ("Flagship Fund V Rx"). Flagship V GP is the general partner of Flagship Fund V Rx. Noubar B. Afeyan, Ph.D. serves as the sole manager of Flagship V GP. Each of the reporting persons except for Flagship Fund V Rx disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein. Each share of Series B Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-7.1366 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series B Preferred Stock was convertible based on a 1-for-7.1295 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering. Each share of Series C Preferred Stock automatically converted into the Issuer's Common Stock on a 1-for-6.8855 basis upon the closing of the Issuer's initial public offering on October 16, 2020 and had no expiration date. The reporting person previously reported shares of common stock into which the Series C Preferred Stock was convertible based on a 1-for-6.8758 conversion ratio estimated at pricing of the Issuer's initial public offering, which reflected a fixed conversion price plus an estimated adjustment based on the issuance of shares in the Issuer's initial public offering. Shares held by Flagship VentureLabs V LLC ("VentureLabs V"). Flagship Fund V is a member of VentureLabs V. Flagship VentureLabs V Manager LLC ("VentureLabs V Manager") is the manager of VentureLabs V. Flagship Pioneering, Inc. ("Flagship Pioneering") is the manager of VentureLabs V Manager. The general partner of Flagship Fund V is Flagship V GP. Noubar B. Afeyan, Ph.D. serves as the sole director of Flagship Pioneering and as the sole manager of Flagship V GP. Each of the reporting persons except for VentureLabs V disclaims beneficial ownership of such shares except to the extent of his or its pecuniary interest therein. Flagship Ventures Fund V General Partner LLC, By: /s/ Noubar B. Afeyan, Name: Noubar B. Afeyan, Ph.D., Title: Manager 2020-10-20 Flagship Ventures Fund V, L.P., By: Flagship Ventures Fund V General Partner LLC, its general partner, By: /s/ Noubar B. Afeyan, Name: Noubar B. Afeyan, Ph.D., Title: Manager 2020-10-20 Flagship V VentureLabs Rx Fund, L.P., By: Flagship Ventures Fund V General Partner LLC, its general partner, By: /s/ Noubar B. Afeyan, Name: Noubar B. Afeyan, Ph.D., Title: Manager 2020-10-20 /s/ Noubar B. Afeyan, Noubar B. Afeyan, Ph.D. 2020-10-20