X0508 4 2025-08-01 false 0001590877 REGENXBIO Inc. RGNX 0001521123 Christmas Patrick J. C/O REGENXBIO INC. 9804 MEDICAL CENTER DRIVE ROCKVILLE MD 20850 false true false false Chief Strategy & Legal Officer false Common Stock 2025-08-01 4 F false 4699.00 8.19 D 151411.00 D Represents shares of common stock withheld to pay taxes upon the vesting of restricted stock units originally granted to the reporting person on August 1, 2024. The number of shares withheld was determined based on the closing price of the issuer's common stock on August 1, 2025. /s/ Patrick J. Christmas 2025-08-04