Director Kathryn Guarini filed a Form 4 with the SEC on November 3, 2026, disclosing the exercise of 400 stock options and same-day sale of 400 shares of Regeneron Pharmaceuticals common stock on October 30, 2026, pursuant to a Rule 10b5-1 plan.

Key Highlights

  • Option exercise: Guarini exercised 400 non-qualified stock options at an exercise price of $719.37 per share on October 30, 2026.
  • Shares sold: 400 shares of common stock were disposed of on October 30, 2026 at a price of $900 per share.
  • Post-transaction ownership: Guarini directly holds 603 shares of common stock following the reported transactions.
  • Remaining options: 758 non-qualified stock options remain beneficially owned directly, with an expiration date of January 2, 2035.
  • 10b5-1 plan: Both transactions were made pursuant to a plan adopted on February 13, 2026, intended to comply with Rule 10b5-1(c).

Guarini's October 2026 Option Exercise and Share Sale at Regeneron

According to the filing, Kathryn Guarini, a director of Regeneron Pharmaceuticals, Inc. (NASDAQ:REGN), reported two transactions in the company's common stock on October 30, 2026. First, she exercised 400 non-qualified stock options at a conversion price of $719.37 per share, coded as an "M" transaction, which added 400 shares to her holdings. Immediately following the exercise, her beneficial ownership stood at 1,003 shares held directly.

The filing further discloses that Guarini disposed of all 400 acquired shares on the same date at a price of $900 per share, reducing her direct holdings to 603 shares. Both the exercise and the sale were made pursuant to a Rule 10b5-1(c) plan that Guarini adopted on February 13, 2026, as noted in the filing's explanation of responses. The filing states that the transactions were coded accordingly to reflect compliance with that plan.

With respect to the derivative securities table, the filing reports that 758 non-qualified stock options remain directly held by Guarini following the exercise, with an expiration date of January 2, 2035. The filing explains that a portion of the original options became exercisable on the date of the company's first annual meeting of shareholders following the grant date, with the remainder becoming exercisable on the first anniversary of the grant date.

What Was Disclosed

Guarini filed a Form 4 disclosing the October 30, 2026 exercise of 400 non-qualified stock options at $719.37 and the same-day sale of 400 common shares at $900, both executed under a Rule 10b5-1 plan adopted February 13, 2026, leaving her with 603 shares and 758 options.