X0306 4 2021-04-15 0 0001664106 LogicBio Therapeutics, Inc. LOGC 0001640592 Chereau Frederic 65 HAYDEN AVENUE, FLOOR 2 LEXINGTON MA 02421 1 1 0 0 President and Chief Executive Common Stock 2021-04-15 4 M 0 23414 A 261353 D Common Stock 2021-04-16 4 S 0 7542 5.73 D 253811 D Restricted Stock Units 2021-04-15 4 M 0 23414 0.00 D Common Stock 23414 0 D Each restricted stock unit ("RSU") represented a contingent right to receive one share of common stock of LogicBio Therapeutics, Inc. (the "Company"). Relates to shares sold at a weighted average price of $5.73 per share to cover tax withholding obligations in connection with the vesting of RSUs. Shares were sold in multiple transactions at prices ranging from $5.64 to $5.87, inclusive. The reporting person undertakes to provide to the Company, any security holder of the Company or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. All of the RSUs vested on April 15, 2021, subject to the terms and conditions of the award and the Company's 2018 Equity Incentive Plan. /s/ Frederic Chereau 2021-04-19