SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* STAHL NEIL (Last) (First) (Middle) 777 OLD SAW MILL RIVER ROAD (Street) TARRYTOWN NY 10591 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol REGENERON PHARMACEUTICALS INC [ REGN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) SVP Research and Development S
	3. Date of Earliest Transaction (Month/Day/Year) 09/06/2011
	4. 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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/06/2011		M(1)		82,818	A	$11.64	133,168	D
Common Stock	09/06/2011		F(1)		14,659	D	$65.76	118,509	D
Common Stock	09/06/2011		F(1)		34,399	D	$65.76	84,110	D
Common Stock	09/07/2011		S(1)		1,200	D	$67.47(2)	82,910	D
Common Stock	09/07/2011		S(1)		7,373	D	$68.77(3)	75,537	D
Common Stock	09/07/2011		S(1)		8,286	D	$69.58(4)	67,251	D
Common Stock	09/07/2011		S(1)		16,901	D	$70.4(5)	50,350	D
Common Stock								5,335	I	By 401(k) Plan

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Non-Qualified Stock Option (right to buy)	$11.64	09/06/2011		M(1)			82,818	(6)	12/19/2015	Common Stock	82,818	(7)	0	D

Explanation of Responses:

1. Disposition/acquisition made pursuant to a plan intended to comply with Rule 10b5-1(c).

2. Represents volume-weighted average price of sales of 1,200 shares of Company stock on September 7, 2011 at prices ranging from $67.06 to $67.88 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 trust on September 7, 2011 at each separate price.

3. Represents volume-weighted average price of sales of 7,373 shares of Company stock on September 7, 2011 at prices ranging from $68.06 to $68.97 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 trust on September 7, 2011 at each separate price.

4. Represents volume-weighted average price of sales of 8,286 shares of Company stock on September 7, 2011 at prices ranging from $69.00 to $69.97 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 trust on September 7, 2011 at each separate price.

5. Represents volume-weighted average price of sales of 16,901 shares of Company stock on September 7, 2011 at prices ranging from $70.03 to $70.99 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 trust on September 7, 2011 at each separate price.

6. 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.

7. An exercise date, exercise price, purchase price, sales price and expiration date are not applicable in this case.

	/s/**Neil Stahl	09/08/2011
	** 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 4 (b)(v).
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