X0306 4 2017-09-05 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 2017-09-05 4 M false 20000.00 0.85 A 20000.00 D Common Stock 2017-09-05 4 S false 20000.00 24.95 D 0.00 D Stock Option (Right to Buy) 0.85 2017-09-05 4 M false 20000.00 0.00 D 2024-09-23 Common Stock 20000.00 314100.00 D This transaction was effected pursuant to a Rule 10b5-1 trading plan. 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 shall vest upon each month of continuous service to the Company 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 vest over four years of service following September 17, 2014, with 25% of the remaining 75% of Contingent Shares having vested on September 17, 2015 and the remaining Contingent Shares vesting in 36 equal monthly installments thereafter. /s/ Patrick J. Christmas as attorney-in-fact 2017-09-07