v3.26.1
Document and Entity Information
Jul. 16, 2026
Cover [Abstract]  
Amendment Flag false
Entity Central Index Key 0001590877
Document Type 8-K
Document Period End Date Jul. 16, 2026
Entity Registrant Name REGENXBIO Inc.
Entity Incorporation State Country Code DE
Entity File Number 001-37553
Entity Tax Identification Number 47-1851754
Entity Address, Address Line One 9804 Medical Center Drive
Entity Address, City or Town Rockville
Entity Address, State or Province MD
Entity Address, Postal Zip Code 20850
City Area Code 240
Local Phone Number 552-8181
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Security 12b Title Common Stock, par value $0.0001 per share
Trading Symbol RGNX
Security Exchange Name NASDAQ
Entity Emerging Growth Company false