Bonnie L. Bassler - 07 Jan 2026 Form 4 Insider Report for REGENERON PHARMACEUTICALS, INC. (REGN)

Reporting relationship: Director
Issuer ticker: REGN
Reported as of: 07 Jan 2026
Net transaction value: -$638,820
SEC form: 4
Accepted by SEC: 08 Jan 2026, 16:03:19 UTC
Prior SEC filing: 06 Jan 2026
Next SEC filing: 31 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ Bonnie L. Bassler

Key filing fact

Bonnie L. Bassler filed Form 4 for REGENERON PHARMACEUTICALS, INC. (REGN) on 08 Jan 2026.

Key facts

This page summarizes Bonnie L. Bassler's Form 4 filing for REGENERON PHARMACEUTICALS, INC. (REGN).
3 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 08 Jan 2026, 16:03.

Change

Previous filing in this sequence was filed on 06 Jan 2026.
Current net transaction value: -$638,820.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001683607 Primary reporting owner

Bassler Bonnie L

Relationship: Director
Address: 777 OLD SAW MILL RIVER ROAD, TARRYTOWN
Signature: /s/ Bonnie L. Bassler
Signature date: 08 Jan 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

REGN transaction

Common Stock

Options Exercise

Transaction value: $561,180
Shares: +1,500
Change %: +88%
Price: $374.12
Shares after: 3,203
Date: 07 Jan 2026
Ownership: Direct
Footnotes: F1

REGN transaction

Common Stock

Sale

Transaction value: $1,200,000
Shares: -1,500
Change %: -47%
Price: $800.00
Shares after: 1,703
Date: 07 Jan 2026
Ownership: Direct
Footnotes: F1, F2

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

REGN transaction Derivative

Non-Qualified Stock Option (right to buy)

Options Exercise

Transaction value: $0
Shares: -1,500
Change %: -34%
Price: $0.000000
Shares after: 2,861
Date: 07 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 1,500
Exercise price: $374.12
Footnotes: F1, F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 3 footnotes

Footnote F1

Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c) adopted on May 2, 2025.

Footnote F2

Represents volume-weighted average price of sales of 1,500 shares of Company stock on January 7, 2026 at prices ranging from $800.00 to $800.01. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting person will provide full information regarding the number of shares sold by the reporting person on January 7, 2026 at each separate price.

Footnote 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.