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 OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	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* SING GEORGE L (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 ] Foreign Trading Symbol	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 11/02/2026
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) 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	11/02/2026		M		7,830	A	$376.69	38,837	D
Common Stock	11/02/2026		M		7,439	A	$380.95	46,276	D
Common Stock	11/02/2026		S		1,224	D	$960.57(1)	45,052	D
Common Stock	11/02/2026		S		540	D	$961.85(2)	44,512	D
Common Stock	11/02/2026		S		2,522	D	$962.61(3)	41,990	D
Common Stock	11/02/2026		S		4,338	D	$963.47(4)	37,652	D
Common Stock	11/02/2026		S		2,670	D	$964.57(5)	34,982	D
Common Stock	11/02/2026		S		7,073	D	$965.38(6)	27,909	D
Common Stock	11/02/2026		S		1,522	D	$966.27(7)	26,387	D
Common Stock	11/02/2026		S		1,040	D	$967.07(8)	25,347	D
Common Stock	11/02/2026		S		200	D	$970.18(9)	25,147	D
Common Stock								750	I	by Spouse
Common Stock								400	I	by Spouse/Cust Son
Common Stock								1,000	I	by Trust for Son

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)	$376.69	11/02/2026		M			7,830	(10)	01/03/2027	Common Stock	7,830	$0.0	0	D
Non-Qualified Stock Option (right to buy)	$380.95	11/02/2026		M			7,439	(10)	01/02/2028	Common Stock	7,439	$0.0	0	D

Explanation of Responses:

1. Represents volume-weighted average price of sales of 1,224 shares of Company stock on November 2, 2026 at prices ranging from $960.03 to $960.94. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

2. Represents volume-weighted average price of sales of 540 shares of Company stock on November 2, 2026 at prices ranging from $961.76 to $961.89. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

3. Represents volume-weighted average price of sales of 2,522 shares of Company stock on November 2, 2026 at prices ranging from $962.07 to $962.99. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

4. Represents volume-weighted average price of sales of 4,338 shares of Company stock on November 2, 2026 at prices ranging from $963.00 to $963.99. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

5. Represents volume-weighted average price of sales of 2,670 shares of Company stock on November 2, 2026 at prices ranging from $964.10 to $964.97. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

6. Represents volume-weighted average price of sales of 7,073 shares of Company stock on November 2, 2026 at prices ranging from $965.00 to $965.98. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

7. Represents volume-weighted average price of sales of 1,522 shares of Company stock on November 2, 2026 at prices ranging from $966.02 to $966.87. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

8. Represents volume-weighted average price of sales of 1,040 shares of Company stock on November 2, 2026 at prices ranging from $967.00 to $967.26. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

9. Represents volume-weighted average price of sales of 200 shares of Company stock on November 2, 2026 at prices ranging from $970.16 to $970.19. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on November 2, 2026 at each separate price.

10. The stock option vested in three equal annual installments, commencing one year after the date of grant.

	/s/ George L. Sing	11/04/2026
	** Signature of Reporting Person	Date
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