Regeneron officer LaRosa proposes $4.31M share sale

UBS Financial Services Inc. is listed as broker for the proposed transaction, with an approximate sale date of November 2, 2026.

Available on EDGAR 11/02/2026 - 04:11 PM EST Accepted by SEC EDGAR 11/02/2026 - 04:11 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Regeneron Pharmaceuticals, Inc. (REGN) officer Joseph LaRosa reported a proposed sale of 4,466 common shares, with an aggregate market value of $4,311,875.12 and an approximate sale date of November 2, 2026. UBS Financial Services Inc. is listed as broker, and NASDAQ as the exchange. The notice also lists 9,507 common shares acquired from the company through a stock option exercise on January 3, 2024.

Key Figures

Proposed sale: 4,466 common shares Aggregate market value: $4,311,875.12 Shares outstanding: 101,630,713 shares +1 more

4 metrics

Proposed sale 4,466 common shares Approximate sale date: November 2, 2026

Aggregate market value $4,311,875.12 Proposed sale of common shares

Shares outstanding 101,630,713 shares Count listed in the proposed-sale information

Shares acquired 9,507 common shares Stock option exercise on January 3, 2024

Key Terms

Rule 144, Stock Option Exercise, attorney-in-fact

3 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Stock Option Exercise financial

"Stock Option Exercise"

A stock option exercise is the act of using a previously granted right to buy shares of a company's stock at a specific, predetermined price by paying that price and receiving the shares. It matters to investors because exercising changes who owns the shares (which can dilute existing ownership), can trigger taxable events and shift potential gains or losses, and affects voting power and the company’s outstanding share count—like turning a voucher into an actual product that becomes part of circulating supply.

attorney-in-fact regulatory

"as attorney-in-fact for Joseph LaRosa"

An attorney-in-fact is the person or entity given legal authority through a power of attorney to act on behalf of another for specific tasks, such as signing documents, voting shares, or handling transactions. For investors, this matters because it lets a trusted representative make timely decisions or complete paperwork when the owner cannot, much like handing keys to someone to run errands on your behalf—so checks on scope and limits of that authority are important.

FAQ

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

How many REGN shares did Joseph LaRosa propose to sell?

The notice lists 4,466 common shares for proposed sale, with an aggregate market value of $4,311,875.12 and an approximate sale date of November 2, 2026.

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

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Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001238303
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Regeneron Pharmaceuticals, Inc.
SEC File Number	000-19034
Address of Issuer	777 Old Saw Mill River Road 10591 Tarrytown NEW YORK 10591
Phone	914-847-7000
Name of Person for Whose Account the Securities are To Be Sold	Joseph LaRosa
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
common stock	UBS Financial Services Inc 1000 Harbor Blvd 3rd Floor Weehawken NJ 07086	4466	4311875.12	101630713	11/02/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	01/03/2024	Stock Option Exercise	Company			9507	01/03/2024	Stock

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Nothing to Report

144: Remarks and Signature

Remarks
Date of Notice	11/02/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/Mijo Suric, for UBS Financial Services Inc, as attorney-in-fact for Joseph LaRosa
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)