X0508 4 2025-05-30 false 0001590877 REGENXBIO Inc. RGNX 0001502785 Tasse Daniel C/O REGENXBIO INC. 9804 MEDICAL CENTER DRIVE ROCKVILLE MD 20850 true false false false false Common Stock 2025-05-30 4 A false 7768.00 0.00 A 19054.00 D Stock Options (Right to Buy) 8.85 2025-05-30 4 A false 39815.00 0.00 A 2035-05-30 Common Stock 39815.00 39815.00 D Represents shares of common stock underlying a time-based restricted stock unit award (RSU). 100% of the shares subject to this RSU will vest on May 1, 2026 subject to the continuous service of the recipient to the Issuer. The option will vest in 12 equal monthly installments following May 30, 2025 subject to the continuous service of the optionee to the Issuer. /s/ Patrick J. Christmas as attorney-in-fact 2025-06-03