Director Kathryn Guarini filed a Form 144 notice of proposed sale of 400 shares of Regeneron Pharmaceuticals, Inc. common stock on October 30, 2026, with the transaction to be executed through UBS Financial Services, Inc. on Nasdaq.

Key Highlights

  • Seller and role: Kathryn Guarini, listed as a Director of Regeneron Pharmaceuticals, Inc.
  • Proposed shares: 400 shares of common stock, with an aggregate market value of $360,000.00
  • Source of shares: The 400 shares were acquired on October 30, 2026, through the exercise of a stock option from the issuer, with cash payment
  • Shares outstanding: 101,630,713 shares of common stock outstanding, according to the filing
  • 10b5-1 plan: The filing indicates a Rule 10b5-1 plan adoption date of February 13, 2026
  • Prior sales: Guarini sold 400 shares on August 10, 2026 for gross proceeds of $320,000.00, and 400 shares on September 2, 2026 for gross proceeds of $340,000.00
  • Broker: UBS Financial Services, Inc., Eleven Madison Avenue, 4th Floor, New York, NY 10010

Guarini's October 2026 Proposed Sale Under Rule 144 at Regeneron

According to the Form 144 filing submitted on October 30, 2026, Kathryn Guarini, a Director of Regeneron Pharmaceuticals, Inc. (NASDAQ:REGN), provided notice of a proposed sale of 400 shares of the company's common stock. The aggregate market value of the shares to be sold is listed as $360,000.00. The filing identifies UBS Financial Services, Inc. as the executing broker, with the approximate date of sale given as October 30, 2026.

The filing discloses that the 400 shares subject to this notice were acquired on October 30, 2026, through the exercise of a stock option granted by the issuer, with cash as the nature of payment. The filing also notes a Rule 10b5-1 plan adoption date of February 13, 2026. As required under Form 144, the filing includes a three-month sales history for Guarini: 400 shares sold on August 10, 2026 for gross proceeds of $320,000.00, and 400 shares sold on September 2, 2026 for gross proceeds of $340,000.00.

The total shares of common stock outstanding are reported in the filing as 101,630,713. Regeneron Pharmaceuticals, Inc. is headquartered at 777 Old Saw Mill River Road, Tarrytown, New York 10591. The notice was signed by UBS Financial Services Inc. as attorney-in-fact for Kathryn Guarini.

What Was Disclosed

Director Kathryn Guarini filed a Rule 144 notice proposing to sell 400 shares of Regeneron Pharmaceuticals common stock with an aggregate market value of $360,000.00, acquired via stock option exercise on October 30, 2026, under a 10b5-1 plan adopted February 13, 2026.