REGENXBIO (NASDAQ: RGNX) officer reports tax-related share withholding

Rhea-AI Filing Summary

REGENXBIO Inc. Chief Strategy & Legal Officer Patrick J. Christmas reported a tax-related share withholding transaction. On January 2, 2026, 9,793 shares of REGENXBIO common stock were withheld at a price of $14.4 per share to cover taxes due upon the vesting of previously granted restricted stock units.

These restricted stock units were originally granted on January 3, 2022, January 3, 2023 and January 2, 2024. After this withholding, Christmas beneficially owned 141,618 shares of REGENXBIO common stock, held directly.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Christmas Patrick J.

(Last) (First) (Middle)

C/O REGENXBIO INC.

9804 MEDICAL CENTER DRIVE

(Street)

ROCKVILLE MD 20850

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
REGENXBIO Inc. [ RGNX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Strategy & Legal Officer

3. Date of Earliest Transaction (Month/Day/Year)
01/02/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	01/02/2026		F		9,793(1)	D	$14.4	141,618	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents shares of common stock withheld to pay taxes upon the vesting of restricted stock units originally granted to the reporting person on January 3, 2022, January 3, 2023 and January 2, 2024. The number of shares withheld was determined on January 2, 2026 based on the closing price of the issuer's common stock on December 31, 2025.

Remarks:

	/s/ Patrick J. Christmas	01/06/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did REGENXBIO (RGNX) report on this Form 4?

The filing shows that Chief Strategy & Legal Officer Patrick J. Christmas had 9,793 shares of REGENXBIO common stock withheld on January 2, 2026 to cover tax obligations.

Was the REGENXBIO (RGNX) insider transaction an open-market sale?

No. The F transaction code and footnote explain the 9,793 shares were withheld to pay taxes on vesting restricted stock units, rather than sold in the open market.

At what price were the REGENXBIO (RGNX) shares withheld for taxes?

The filing reports a price of $14.4 per share used to determine the number of REGENXBIO common shares withheld for tax withholding purposes.

How many REGENXBIO (RGNX) shares does Patrick J. Christmas own after this transaction?

Following the tax withholding, Patrick J. Christmas is shown as beneficially owning 141,618 shares of REGENXBIO common stock, held directly.

What awards triggered the REGENXBIO (RGNX) tax withholding event?

The withholding relates to restricted stock units originally granted to Patrick J. Christmas on January 3, 2022, January 3, 2023 and January 2, 2024, which vested and created a tax obligation.

How was the number of REGENXBIO (RGNX) shares withheld for taxes determined?

The number of shares withheld was determined on January 2, 2026 based on the closing price of REGENXBIO common stock on December 31, 2025, as described in the footnote.