Regeneron officer McCourt plans $969K stock sale

Officer Marion McCourt has filed a Rule 144 notice to potentially sell 1,131 shares of Regeneron common stock, with a prior 1,215-share sale disclosed for the past three months.

Rhea-AI Filing Summary

REGENERON PHARMACEUTICALS, INC. (REGN) is named as the issuer in a Rule 144 notice covering a proposed sale of common stock for the account of officer Marion McCourt. The notice relates to 1,131 shares, to be sold through UBS Financial Services Inc. on NASDAQ.

The shares were acquired from the issuer via RSA vesting on December 12, 2023. The filing also lists a prior sale by Marion McCourt of 1,215 shares of common stock during the past three months.

Key Figures

Proposed shares to be sold: 1,131 shares Aggregate market value (securities information): $969,267.00 Shares sold in past 3 months: 1,215 shares +3 more

6 metrics

Proposed shares to be sold 1,131 shares Common stock covered by the Rule 144 notice for REGENERON PHARMACEUTICALS, INC.

Aggregate market value (securities information) $969,267.00 Value associated with the 1,131 shares of common stock in the securities information section

Shares sold in past 3 months 1,215 shares Common stock sold by Marion McCourt on September 2, 2026

Value of past 3 months sale $1,032,750.00 Total value for 1,215 shares of common stock sold on September 2, 2026

Acquisition date of shares to be sold December 12, 2023 Date the 1,131 shares were acquired via RSA vesting from the issuer

Planned sale date reference September 3, 2026 Date associated with securities information for the proposed sale on NASDAQ

Key Terms

Rule 144, RSA Vesting, 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.

RSA Vesting financial

"Common | 12/12/2023 | RSA Vesting | Issuer"

attorney-in-fact regulatory

"UBS Financial Services Inc, as attorney-in-fact for Marion McCourt"

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

What does the Form 144 filing related to REGN disclose?

It discloses that officer Marion McCourt has filed a Rule 144 notice for a proposed sale of 1,131 shares of REGENERON PHARMACEUTICALS, INC. common stock through UBS Financial Services Inc. on NASDAQ.

How many REGN shares are proposed to be sold under this Form 144?

The notice covers a proposed sale of 1,131 shares of REGENERON PHARMACEUTICALS, INC. common stock, with an aggregate market value listed as $969,267.00 for those securities information details.

How and when were the REGN shares to be sold acquired by Marion McCourt?

The 1,131 shares covered by the notice were acquired from the issuer on December 12, 2023 through RSA Vesting, which the filing identifies as the nature of acquisition from REGENERON PHARMACEUTICALS, INC.

What prior REGN stock sales by Marion McCourt are disclosed in this Form 144?

During the past three months, the filing lists a sale by Marion McCourt of 1,215 shares of Regeneron common stock on September 2, 2026, with a total value of $1,032,750.00.

Which broker is handling the proposed REGN share sale in this Form 144?

The proposed sale of 1,131 shares of REGENERON PHARMACEUTICALS, INC. common stock is listed under securities information with UBS Financial Services Inc., 11 Madison Ave, New York, as the broker, with trading on NASDAQ.

Who signed the Form 144 related to REGN and in what capacity?

The Form 144 is signed “/s/ UBS Financial Services Inc, as attorney-in-fact for Marion McCourt”, indicating UBS Financial Services Inc. executed the filing under power of attorney on behalf of Marion McCourt.

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

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Available on EDGAR 09/03/2026 - 05:17 PM Accepted by SEC EDGAR 09/03/2026 - 04:07 PM Learn about SEC filing dates

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	0001663758
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 TARRYTOWN NEW YORK 10591
Phone	9148477000
Name of Person for Whose Account the Securities are To Be Sold	McCourt Marion
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	UBS Financial Services Inc. 11 Madison Ave 4th Floor New York NY 10010	1131	969267.00	101137842	09/03/2026	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	12/12/2023	RSA Vesting	Issuer			1131	12/12/2023	N/A

* 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

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Marion McCourt 777 OLD SAW MILL RIVER ROAD TARRYTOWN NY 10591	Common	09/02/2026	1215	1032750.00

144: Remarks and Signature

Remarks
Date of Notice	09/03/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	02/17/2026
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/ UBS Financial Services Inc, as attorney-in-fact for Marion McCourt
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)