X0306 4 2018-11-26 false 0001590877 REGENXBIO Inc. RGNX 0001192128 BESHAR LUKE M C/O REGENXBIO INC. 9600 BLACKWELL ROAD, SUITE 210 ROCKVILLE MD 20850 true false false false Common Stock 2018-11-26 4 M false 1721.00 49.45 A 1721.00 D Common Stock 2018-11-26 4 S false 1721.00 65.00 D 0.00 D Common Stock 2018-11-27 4 M false 883.00 49.45 A 883.00 D Common Stock 2018-11-27 4 M false 4687.00 22.00 A 5570.00 D Common Stock 2018-11-27 4 M false 6250.00 18.85 A 11820.00 D Common Stock 2018-11-27 4 M false 6250.00 12.74 A 18070.00 D Common Stock 2018-11-27 4 M false 716.00 3.76 A 18786.00 D Common Stock 2018-11-27 4 S false 18786.00 65.03 D 0.00 D Stock Option (Right to Buy) 49.45 2018-11-26 4 M false 1721.00 0.00 D 2028-05-25 Common Stock 1721.00 8175.00 D Stock Option (Right to Buy) 49.45 2018-11-27 4 M false 883.00 0.00 D 2028-05-25 Common Stock 883.00 7292.00 D Stock Option (Right to Buy) 22.00 2018-11-27 4 M false 4687.00 0.00 D 2025-09-16 Common Stock 4687.00 0.00 D Stock Option (Right to Buy) 18.85 2018-11-27 4 M false 6250.00 0.00 D 2027-05-24 Common Stock 6250.00 0.00 D Stock Option (Right to Buy) 12.74 2018-11-27 4 M false 6250.00 0.00 D 2026-06-01 Common Stock 6250.00 0.00 D Stock Option (Right to Buy) 3.76 2018-11-27 4 M false 716.00 0.00 D 2025-05-18 Common Stock 716.00 65784.00 D This transaction was effected pursuant to a Rule 10b5-1 trading plan. This transaction was executed in multiple trades at prices ranging from $65.00 to $65.29. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. The previously granted option, representing a right to purchase a total of 12,500 shares, became exercisable as follows: the option vests in 12 equal monthly installments following May 25, 2018. The previously granted option, representing a right to purchase a total of 9,375 shares, became exercisable as follows: the option vested in nine equal monthly installments following September 16, 2015. The previously granted option, representing a right to purchase a total of 12,500 shares, became exercisable as follows: the option vested in 12 equal monthly installments following May 24, 2017. The previously granted option, representing a right to purchase a total of 12,500 shares, became exercisable as follows: the option vested in 12 equal monthly installments following June 1, 2016. The previously granted option, representing a right to purchase a total of 80,000 shares, became exercisable as follows: 25% of the shares subject to this option vested on May 19, 2015, and the balance vested in equal monthly installments over the 24 months thereafter. /s/ Patrick J. Christmas as attorney-in-fact 2018-11-28