X0306 4 2021-08-06 0 0001659352 Codiak BioSciences, Inc. CDAK 0001867898 Sathyanarayanan Sriram C/O CODIAK BIOSCIENCES, INC. 35 CAMBRIDGEPARK DRIVE, SUITE 500 CAMBRIDGE MA 02140 0 1 0 0 Chief Scientific Officer Common Stock 2021-08-06 4 M 0 1300 3.29 A 1300 D Common Stock 2021-08-06 4 S 0 1300 20.1585 D 0 D Common Stock 2021-08-09 4 M 0 1300 3.29 A 1300 D Common Stock 2021-08-09 4 S 0 751 21.3083 D 549 D Common Stock 2021-08-09 4 S 0 549 21.7892 D 0 D Stock Option (Right to Buy) 3.29 2021-08-06 4 M 0 1300 0.00 A 2027-07-24 Common Stock 1300 49966 D Stock Option (Right to Buy) 3.29 2021-08-09 4 M 0 1300 0.00 A 2027-07-24 Common Stock 1300 48666 D The transactions reported in this Form 4 were inadvertently reported late due to an administrative oversight related to communications of the transactions. The sales reported in this Form 4 were effected pursuant to a previously adopted Rule 10b5-1 trading plan. The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $20.03 to $20.26 per share. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $20.72 to $21.71 per share. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $21.72 to $21.91 per share. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. The shares underlying this option are fully vested. /s/ Yalonda Howze, by Power of Attorney for Sriram Sathyanarayanan 2021-09-28