Sanofi — Director's Dealing 2015

Oct 8, 2015

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: REGENERON PHARMACEUTICALS INC (REGN)
CIK: 0000872589
Period of Report: 2015-10-06

Reporting Person: Sanofi (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2015-10-06	Common Stock	P	1965	$470.4102	Acquired	23099495	Indirect
2015-10-06	Common Stock	P	3625	$471.6367	Acquired	23103120	Indirect
2015-10-06	Common Stock	P	2650	$472.3657	Acquired	23105770	Indirect
2015-10-06	Common Stock	P	1000	$473.3125	Acquired	23106770	Indirect
2015-10-06	Common Stock	P	1000	$474.2650	Acquired	23107770	Indirect
2015-10-06	Common Stock	P	700	$476.3543	Acquired	23108470	Indirect
2015-10-06	Common Stock	P	100	$476.8500	Acquired	23108570	Indirect

Footnotes

F1: The number of securities reported represents an aggregate number of shares purchased in multiple market transactions over a range of purchase prices. The price reported represents the weighted average price per share. The Reporting Person undertakes to provide the staff of the SEC, the Issuer, or a stockholder of the Issuer, upon request, the number of shares purchased by the Reporting Person at each separate price within the range.

F2: Represents shares acquired directly by sanofi-aventis Amerique du Nord ("SAAN").

F3: Purchase prices range from $470.00 to $470.99 per share, inclusive.

F4: Indirectly owned through (a) SAAN, a direct, wholly-owned subsidiary of Sanofi, and (b) Aventis Pharmaceuticals Inc. ("Aventis"), an indirect, wholly-owned subsidiary of SAAN. After giving effect to all acquisitions reported on this Form 4, the number of shares beneficially owned directly by SAAN and Aventis was 20,309,018 shares and 2,799,552 shares, respectively. Pursuant to the Amended and Restated Investor Agreement, dated as of January 11, 2014, by and among Sanofi, SAAN, sanofi-aventis US LLC, Aventis (collectively, the "Sanofi Parties") and the Issuer, the Sanofi Parties have agreed to vote their respective shares of the Issuer, subject to specified exceptions, in accordance with the recommendation of the Issuer's Board of Directors.

F5: Purchase prices range from $471.00 to $471.94 per share, inclusive.

F6: Purchase prices range from $472.00 to $472.96 per share, inclusive.

F7: Purchase prices range from $473.00 to $473.76 per share, inclusive.

F8: Purchase prices range from $474.01 to $474.45 per share, inclusive.

F9: Purchase prices range from $475.82 to $476.75 per share, inclusive.

F10: Purchase price was $476.85 per share.