X0306 4 2021-09-21 0 0001539029 Clearside Biomedical, Inc. CLSD 0001815426 Ciulla Thomas C/O CLEARSIDE BIOMEDICAL, INC. 900 NORTH POINT PARKWAY, SUITE 200 ALPHARETTA GA 30005 0 1 0 0 Chief Medical Officer Common Stock 2021-09-21 4 S 0 2560 6.40 D 255560 D The sales reported in this Form 4 represents shares required to be sold by the Reporting Person to satisfy tax withholding obligations in connection with the settlement of restricted stock units. The sale occurred automatically to satisfy the tax withholding obligations to be funded by a "sell to cover" transaction pursuant to a Rule 10b5-1 trading plan. Includes 4,998 shares acquired under the Issuer's employee stock purchase plan on June 30, 2021. /s/ Mark Ballantyne, Attorney-in-Fact 2021-09-23