X0306 4 2017-06-30 false 0001590877 REGENXBIO Inc. RGNX 0001521123 Christmas Patrick J. C/O REGENXBIO INC. 9600 BLACKWELL ROAD, SUITE 210 ROCKVILLE MD 20850 false true false false SVP, General Counsel Common Stock 2017-06-30 4 A false 655.00 15.725 A 655.00 D Common Stock 2017-12-29 4 A false 486.00 17.425 A 1141.00 D Stock Option (Right to Buy) 35.80 2018-01-03 4 A false 43000.00 0.00 A 2028-01-03 Common Stock 43000.00 43000.00 D The reporting person is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the REGENXBIO Inc. Employee Stock Purchase Plan ("ESPP") for the ESPP purchase period of January 1, 2017 through June 30, 2017. This transaction is exempt under Rule 16b-3(c). In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the Issuer's common stock on January 3, 2017. The reporting person is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the ESPP for the ESPP purchase period of July 1, 2017 through December 31, 2017. This transaction is exempt under Rule 16b-3(c). In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the Issuer's common stock on July 3, 2017. 25% of the shares subject to this option shall vest after 12 months of continuous service with the Issuer. The balance will vest in equal monthly installments over the 36 months following January 3, 2019 while the optionee provides continuous service to the Issuer. /s/ Patrick J. Christmas 2018-01-05