Regeneron director Brown sells 1,929 shares

The option exercise and share sale were made pursuant to a plan intended to comply with Rule 10b5-1(c), adopted February 25, 2026.

Available on EDGAR 11/03/2026 - 04:05 PM EST Accepted by SEC EDGAR 11/03/2026 - 04:05 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Regeneron Pharmaceuticals, Inc. director Michael S. Brown exercised non-qualified stock options covering 1,929 shares on October 30, 2026, at an exercise price of $725.89 per share, acquired 1,929 common shares, and sold 1,929 shares at $875.00 per share. The transactions were made pursuant to a plan intended to comply with Rule 10b5-1(c), adopted February 25, 2026.

The reported option position following the transaction was 0 shares. Separately, 5,000 shares were held in a trust for the benefit of Brown’s immediate family, with his spouse as trustee; Brown disclaimed beneficial ownership of those securities. Another reported indirect holding was 6,485 shares held by a Trust.

Insider Trade Summary 10b5-1

Exercise and Sale: 1,929 shares ($288K approx. pre-tax spread)

Exercise and Sale 3 txns

Insider BROWN MICHAEL S

Role Director

Sold 1,929 shs ($1.69M)

Approx. gross sale proceeds $1.69M

Approx. exercise cost $1.40M

Approx. pre-tax spread $288K

Type	Security	Shares	Price	Value
Exercise	Non-Qualified Stock Option (right to buy) F1, F3	1,929	$0.00	$0.00
Exercise	Common Stock F1	1,929	$725.89	$1.40M
Sale	Common Stock F1	1,929	$875.00	$1.69M
Holding	Common Stock F2	--	--	--
Holding	Common Stock	--	--	--

Holdings After Transaction: Non-Qualified Stock Option (right to buy) — 0 contracts (Direct); Common Stock — 1,380 shares (Direct); Common Stock — 5,000 shares (Indirect, by SLAT); Common Stock — 6,485 shares (Indirect, by Trust)

Footnotes (3)

1. F1. Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c) adopted on February 25, 2026.
2. F2. These shares are held in a trust for the benefit of the reporting person's immediate family members. The reporting person's spouse is trustee of the trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.
3. F3. On the date of the Company's first annual meeting of shareholders following the date of grant, a portion of these stock options equal to the portion of one year that had passed from the date of grant became exercisable, and the remainder became exercisable on the first anniversary of the date of grant.

Key Figures

Shares covered by options exercised: 1,929 shares Option exercise price: $725.89 per share Common shares acquired: 1,929 shares +5 more

8 metrics

Shares covered by options exercised 1,929 shares October 30, 2026

Option exercise price $725.89 per share October 30, 2026

Common shares acquired 1,929 shares October 30, 2026

Common shares sold 1,929 shares October 30, 2026

Sale price $875.00 per share October 30, 2026

Reported option position following transaction 0 shares Following the October 30, 2026 transaction

Shares held in trust for immediate family 5,000 shares Brown disclaimed beneficial ownership; his spouse was trustee

Indirect shares held by a Trust 6,485 shares Reported indirect holding

Key Terms

Non-Qualified Stock Option, Rule 10b5-1(c), beneficial ownership

3 terms

Non-Qualified Stock Option financial

"Non-Qualified Stock Option (right to buy)"

A non-qualified stock option (NSO) is a contract that lets an employee or service provider buy company shares at a fixed price for a set period, like a voucher to purchase stock later at today’s price. It matters to investors because exercising NSOs creates ordinary income for the holder and can increase share count, affecting a company’s earnings and ownership mix; think of it as a future sale that can dilute existing shareholders and has immediate tax consequences for the recipient.

Rule 10b5-1(c) regulatory

"plan intended to comply with Rule 10b5-1(c)"

Rule 10b5-1(c) is an SEC guideline that lets company insiders set up a written, pre-planned schedule to buy or sell their company stock when they are not in possession of material, nonpublic information. For investors, it matters because such plans can reduce the appearance of insider trading by separating decisions from inside knowledge—like putting your trades on autopilot—while also requiring scrutiny since pre-planned trades can still affect market confidence and share value.

beneficial ownership regulatory

"disclaims beneficial ownership of these securities"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many REGN shares did director Michael S. Brown sell?

Director Michael S. Brown sold 1,929 common shares at $875.00 per share on October 30, 2026, after exercising options covering 1,929 shares at $725.89 per share. The transactions were made pursuant to a plan intended to comply with Rule 10b5-1(c), adopted February 25, 2026.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

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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).

X

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^*

BROWN MICHAEL S

(Last) (First) (Middle)

777 OLD SAW MILL RIVER ROAD

(Street)

TARRYTOWN NEW YORK 10591

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
10/30/2026

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

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

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

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	10/30/2026		M(1)		1,929	A	$725.89	3,309	D
Common Stock	10/30/2026		S(1)		1,929	D	$875	1,380	D
Common Stock								5,000	I	by SLAT(2)
Common Stock								6,485	I	by Trust

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)	$725.89	10/30/2026		M(1)			1,929	(3)	01/03/2033	Common Stock	1,929	$0.0	0	D

Explanation of Responses:

1. Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c) adopted on February 25, 2026.

2. These shares are held in a trust for the benefit of the reporting person's immediate family members. The reporting person's spouse is trustee of the trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.

3. On the date of the Company's first annual meeting of shareholders following the date of grant, a portion of these stock options equal to the portion of one year that had passed from the date of grant became exercisable, and the remainder became exercisable on the first anniversary of the date of grant.

	/s/ Michael S. Brown	11/03/2026
	** 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.
* Form 4: SEC 1474 (03-26)