X0306 4 2018-10-23 0 0001664106 LogicBio Therapeutics, Inc. LOGC 0001706399 Chimovits Erez C/O LOGICBIO THERAPEUTICS, INC. 610 MAIN STREET, 3RD FLOOR CAMBRIDGE MA 02139 1 0 0 0 Common Stock 2018-10-23 4 C 0 2997760 A 2997760 I See Footnote Common Stock 2018-10-23 4 P 0 490000 10.00 A 3487760 I See Footnote Series A Convertible Preferred Stock 2018-10-23 4 C 0 2678571 0.00 D Common Stock 1402444 0 I See Footnote Series B Convertible Preferred Stock 2018-10-23 4 C 0 3046943 0.00 D Common Stock 1595316 0 I See Footnote The total represents shares received upon conversion of Series A and Series B Convertible Preferred Stock. Upon closing of the Issuer's initial public offering, each share of Series A and Series B Convertible Preferred Stock automatically converted into 0.5235794 shares of Common Stock without payment or further consideration. There was no expiration date for the Series A or Series B Convertible Preferred Stock. The Reporting Person is an employee of OrbiMed Advisors Israel II Limited ("OrbiMed Limited"), which is the managing member of OrbiMed Israel GP II, L.P. ("OIP GP"). OIP GP is the general partner of OrbiMed Israel Partners II, L.P. ("OIP II"), the direct beneficial owner of these securities. By virtue of such relationships, OIP GP and OrbiMed Limited may be deemed to have voting and investment power over the securities held by OIP II. The Reporting Person disclaims beneficial ownership, within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of these securities in which the Reporting Person has no pecuniary interest. /s/ Matthias Jaffe, as Attorney-in-Fact 2018-10-25