X0609 4 2026-09-01 false 0001590877 REGENXBIO Inc. RGNX 0002062007 Malzahn Craig false C/O REGENXBIO INC. 9804 MEDICAL CENTER DRIVE ROCKVILLE MD 20850 false true false false Chief Technology Officer false Common Stock 2026-09-01 4 F false 234.00 9.32 D 81960.00 D Represents shares of common stock withheld to pay taxes upon the vesting of restricted stock units originally granted to the reporting person on September 1, 2022. The number of shares withheld was determined based on the closing price of the issuer's common stock on September 1, 2026. /s/ Patrick J. Christmas as attorney-in-fact 2026-09-03