X0306 4 2020-02-05 false 0001590877 REGENXBIO Inc. RGNX 0001202285 HAYDEN DONALD J JR C/O REGENXBIO INC. 9600 BLACKWELL ROAD, SUITE 210 ROCKVILLE MD 20850 true false false false Common Stock 2020-02-05 4 M false 2000.00 0.85 A 2000.00 D Common Stock 2020-02-05 4 S false 2000.00 50.00 D 0.00 D Stock Option (Right to Buy) 0.85 2020-02-05 4 M false 2000.00 0.00 D 2024-09-23 Common Stock 2000.00 153900.00 D This transaction was effected pursuant to a Rule 10b5-1 trading plan. This transaction was executed in multiple trades at prices ranging from $50.00 to $50.05. 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 354,100 shares, became exercisable as follows: 237,269 of the shares subject to the option are initial shares ("Initial Shares") and 116,831 of the shares subject to the option are contingent shares ("Contingent Shares"). 60,197 of the Initial Shares vested on September 17, 2014, 44,268 of the Initial Shares vested on September 17, 2015 and an additional 3,689 of the Initial Shares vested each month thereafter. 25% of the Contingent Shares were deemed vested as of September 17, 2014 on January 13, 2015 due to a subsequent event. The remainder of the Contingent Shares vested over four years following September 17, 2014, with 25% of the remaining 75% of Contingent Shares having vested on September 17, 2015 and the remaining Contingent Shares having vested in 36 equal monthly installments thereafter. /s/ Patrick J. Christmas as attorney-in-fact 2020-02-07