X0508 4 2023-08-28 0001811623 PaxMedica, Inc. PXMD 0001940128 Coelho John F C/O PAXMEDICA, INC. 303 SOUTH BROADWAY, SUITE 125 TARRYTOWN NY 10591 1 0 0 0 1 Common Stock 2023-08-28 4 S 0 774 0.5213 D 79683 D Common Stock 2023-08-29 4 S 0 23 0.4859 D 79660 D The sales reported in this Form 4 were effected pursuant to the Reporting Person's pre-existing Rule 10b5-1 trading plan to, inter alia, pay tax withholding on vested RSUs. The sale price represents the weighted average sale price of the shares sold ranging from $0.5202 to $0.5276 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the reporting person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4. The sale price represents the weighted average sale price of the shares sold ranging from $0.485 to $0.486 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the reporting person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4. /s/ Stephen D. Sheldon, Jr. Attorney-in-Fact 2023-08-30