Company: RGNX
Filing Date: 2025-06-13
Form Type: S-3
Source: 0001193125-25-140870
Chunk: 18

Company: REGENXBIO Inc.
Filing Date: 2025-06-13
Form: S-3
Chunk 18
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 for cash. In connection with these arrangements, the underwriters or agents may also sell Shares covered
by this prospectus to hedge their positions in these outstanding securities, including in short sale transactions. If so, the underwriters or agents may use the Shares received from the Selling Stockholder under these arrangements to close out any
related open borrowings of securities.

Broker-dealers engaged by the Selling Stockholder may arrange for other broker-dealers to
participate in sales. If the Selling Stockholder effects certain transactions by selling Shares to or through underwriters, broker-dealers or agents, such underwriters, broker-dealers or agents may receive commissions in the form of discounts,

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concessions or commissions from the Selling Stockholder or commissions from purchasers of the Shares for whom they may act as agent or to whom they may sell as principal. Such commissions will be
in amounts to be negotiated, but, except as set forth in a supplement to this prospectus, in the case of an agency transaction will not be in excess of a customary brokerage commission in compliance with applicable rules of the Financial Industry
Regulatory Authority, Inc. (“FINRA”); and in the case of a principal transaction, a markup or markdown in compliance with applicable FINRA rules.

The aggregate proceeds to the Selling Stockholder from the sale of the Shares offered by it will be the purchase price of the Shares less the
Warrant exercise price and discounts or commissions, if any. The Selling Stockholder reserves the right to accept and, together with its agents from time to time, to reject, in whole or in part, any proposed purchase of Shares to be made directly or
through agents. The Selling Stockholder also may resell all or a portion of the Shares in open market transactions in reliance upon Rule 144 under the Securities Act, rather than under this prospectus, provided that it meets the criteria and
conforms to the requirements of that rule.

To the extent required pursuant to Rule 424(b) under the Securities Act, the Shares to be
sold, the name of the Selling Stockholder, the purchase price and public offering price and the net proceeds to be received by the Selling Stockholder from the sale, the names of any agents, dealer or underwriter and the amount of Shares
underwritten or purchased by each of them, if any, any applicable commissions or discounts with respect to a particular offer, any delayed delivery arrangements and any securities exchange or markets on which the Shares may be listed will be set
forth in an accompanying