SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Fenimore Christopher R. (Last) (First) (Middle) 777 OLD SAW MILL RIVER RD (Street) TARRYTOWN NY 10591 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 03/02/2017	3. Issuer Name and Ticker or Trading Symbol REGENERON PHARMACEUTICALS INC [ REGN ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) VP, Controller	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	1,328	I	By 401(k) Plan
Common Stock	2,695	I	By GRAT
Common Stock	4,297	I	By Trust(1)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Incentive Stock Option (right to buy)	(2)	12/18/2019	Common Stock	1,375	$21.25	D
Incentive Stock Option (right to buy)	(2)	12/14/2020	Common Stock	4,280	$30.63	D
Incentive Stock Option (right to buy)	(2)	12/16/2021	Common Stock	2,224	$52.03	D
Non-Qualified Stock Option (right to buy)	(2)	12/16/2021	Common Stock	13,776	$52.03	D
Non-Qualified Stock Option (right to buy)	(3)	12/14/2022	Common Stock	23,500	$179.13	D
Non-Qualified Stock Option (right to buy)	(3)	12/13/2023	Common Stock	20,000	$270.43	D
Non-Qualified Stock Option (right to buy)	(3)	12/16/2026	Common Stock	12,283	$381.92	D
Non-Qualified Stock Option (right to buy)	(3)	12/16/2024	Common Stock	17,000	$399.66	D
Non-Qualified Stock Option (right to buy)	(3)	12/16/2025	Common Stock	14,450	$555.67	D

Explanation of Responses:

1. These shares are held in a trust for the benefit of the reporting person's spouse. The reporting person and the reporting person's spouse are trustees of the trust.

2. The stock option award (combined incentive stock option and non-qualified stock option) vests in four equal annual installments, commencing one year after the date of grant.

3. The stock option award vests in four equal annual installments, commencing one year after the date of grant.

	/s/**Christopher R. Fenimore	03/02/2017
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.