[Form 4] REGENERON PHARMACEUTICALS, INC. Insider Trading Activity

Rhea-AI Filing Summary

Regeneron Pharmaceuticals (REGN) executive Joseph LaRosa reported a stock option exercise and share transactions. On 11/20/2025, he exercised a non-qualified stock option for 14,450 shares of common stock at an exercise price of $555.67 per share. On the same date, 12,686 shares were disposed of in a transaction reported at $736.77 per share, which is typically associated with covering taxes or similar obligations.

Following these transactions, LaRosa directly beneficially owned 22,839 shares of Regeneron common stock. He also indirectly owned 9,000 shares through a 2024 GRAT, 9,000 shares through a 2025 GRAT, and 395 shares through a 401(k) plan. The option award referenced in the filing vested in four equal annual installments starting one year after the grant date and is now fully exercised, with zero derivative securities remaining from this grant.

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

OMB APPROVAL

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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^*

LAROSA JOSEPH J

(Last) (First) (Middle)

777 OLD SAW MILL RIVER ROAD

(Street)

TARRYTOWN NY 10591

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
REGENERON PHARMACEUTICALS, INC. [ REGN ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP General Counsel and Secret

3. Date of Earliest Transaction (Month/Day/Year)
11/20/2025

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	11/20/2025		M		14,450	A	$555.67	35,525	D
Common Stock	11/20/2025		F		12,686	D	$736.77	22,839	D
Common Stock								9,000	I	By 2024 GRAT
Common Stock								9,000	I	By 2025 GRAT
Common Stock								395	I	By 401(k) Plan

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
Non-Qualified Stock Option (right to buy)	$555.67	11/20/2025		M			14,450	(1)	12/16/2025	Common Stock	14,450	$0.0	0	D

Explanation of Responses:

1. The stock option award vested in four equal annual installments, commencing one year after the date of grant.

	/s/ Joseph LaRosa	11/24/2025
	** 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.
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FAQ

What insider transaction did REGN executive Joseph LaRosa report?

LaRosa reported exercising a non-qualified stock option for 14,450 shares of Regeneron common stock on 11/20/2025 at an exercise price of $555.67 per share.

How many REGN shares were sold or withheld in the reported transaction?

On 11/20/2025, LaRosa reported a disposition of 12,686 shares of Regeneron common stock at a reported price of $736.77 per share.

How many REGN shares does Joseph LaRosa own after this Form 4?

After the transactions, LaRosa directly owned 22,839 shares of Regeneron common stock, plus 9,000 shares in a 2024 GRAT, 9,000 shares in a 2025 GRAT, and 395 shares through a 401(k) plan.

What happened to the stock option reported in this REGN Form 4?

The non-qualified stock option with an exercise price of $555.67 covering 14,450 shares was fully exercised on 11/20/2025, leaving 0 derivative securities remaining from that grant.

What was the vesting schedule of the exercised REGN stock option?

The filing states the stock option award vested in four equal annual installments, beginning one year after the date of grant.

What is Joseph LaRosa’s role at Regeneron Pharmaceuticals (REGN)?

Joseph LaRosa is reported as an Officer of Regeneron with the title EVP General Counsel and Secretary.