X0306 4 2017-08-21 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 2017-08-21 4 M false 15000.00 0.85 A 15000.00 D Common Stock 2017-08-21 4 S false 15000.00 20.03 D 0.00 D Employee Stock Option (Right to Buy) 0.85 2017-08-21 4 M false 15000.00 0.00 D 2024-11-03 Common Stock 15000.00 202900.00 D This transaction was effected pursuant to a Rule 10b5-1 trading plan. This transaction was executed in multiple trades at prices ranging from $19.95 to $20.20. 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 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 2017-08-23