X0306 4 2017-09-05 false 0001590877 REGENXBIO Inc. RGNX 0001652825 Yoo Stephen C/O REGENXBIO INC. 9600 BLACKWELL ROAD, SUITE 210 ROCKVILLE MD 20850 false true false false Chief Medical Officer Common Stock 2017-09-05 4 M false 31803.00 0.85 A 31803.00 D Common Stock 2017-09-05 4 S false 31803.00 25.00 D 0.00 D Common Stock 2017-09-06 4 M false 855.00 0.85 A 855.00 D Common Stock 2017-09-06 4 S false 855.00 25.00 D 0.00 D Employee Stock Option (Right to Buy) 0.85 2017-09-05 4 M false 31803.00 0.00 D 2024-11-03 Common Stock 31803.00 171097.00 D Employee Stock Option (Right to Buy) 0.85 2017-09-06 4 M false 855.00 0.00 D 2024-11-03 Common Stock 855.00 170242.00 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 247,900 shares, became exercisable as follows: 165,200 of the shares subject to the option are initial shares ("Initial Shares") and 82,700 of the shares subject to the option are contingent shares ("Contingent Shares"). 23,600 of the Initial Shares vested on October 13, 2014, 35,400 of the Initial Shares vested on October 13, 2015 and an additional 2,950 of the Initial Shares vest upon each month of continuous service to the Company thereafter. 15% of the Contingent Shares were deemed vested as of October 13, 2014 on January 13, 2015 due to a subsequent event. The remainder of the Contingent Shares vest over four years of service following October 13, 2014, with 25% of the remaining 85% of Contingent Shares having vested on October 13, 2015 and the remaining Contingent Shares vesting in 36 equal monthly installments thereafter. /s/ Stephen Yoo 2017-09-07