Company: RGNX
Filing Date: 2025-03-13
Form Type: POSASR
Source: 0001193125-25-053917
Chunk: 20

Company: REGENXBIO Inc.
Filing Date: 2025-03-13
Form: POSASR
Chunk 20
---
 with respect to book-entry procedures; |

| • |     | identity of the warrant agent; and |

| • |     | any additional terms of the warrants, including terms, procedures and limitations relating to the exchange and 
 exercise of the warrants.                                                                                      |

Exercise of Warrants Each holder of a warrant will be entitled to purchase, at the exercise price set forth in the applicable prospectus supplement, the number of shares of common stock, shares of preferred stock or the principal amount of debt securities being offered. Holders may exercise warrants at any time up to the close of business on the expiration date set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants are void. Holders may exercise warrants as set forth in the prospectus supplement relating to the warrants being offered. 11

Until a holder exercises the warrants to purchase our shares of common stock, shares of
preferred stock or debt securities, the holder will not have any rights as a holder of our shares of common stock, shares of preferred stock or debt securities, as the case may be, by virtue of ownership of warrants, including, with respect to
equity warrants, any right to vote, consent, receive dividends, or receive notice as stockholders with respect to any meeting of the stockholders for the election of directors or any other matter and with respect to debt warrants, any right to
receive payment of principal or premium, if any, or interest on the debt securities purchasable upon exercise.

12

DESCRIPTION OF DEBT SECURITIES We may issue, separately or together with, or upon conversion, exercise or exchange of other securities, debt securities, including debentures, notes or other evidences of indebtedness as set forth in the applicable prospectus supplement. The debt securities will be issued under one or more separate indentures between us and a trustee to be identified in an accompanying prospectus supplement. The following is a general description of the terms of debt securities we may issue from time to time. Particular terms of any debt securities we offer will be described in the prospectus supplement relating to such debt securities. Because this section is a summary, it does not describe every aspect of any debt securities we may issue or the indenture governing any such debt securities. Particular terms of any debt securities we offer and the applicable indenture will be described in the prospectus supplement relating to such offering, and we urge you to read such description in its entirety, because it, and not this description,