Sec Form 4 Filing - Powchik Peter @ REGENERON PHARMACEUTICALS INC - 2012-02-21

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Powchik Peter 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 Clinical Development & Reg (Last) (First) (Middle) 777 OLD SAW MILL RIVER ROAD 3. Date of Earliest Transaction (MM/DD/YY) 02/21/2012 (Street) TARRYTOWN, NY10591 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 02/21/2012 M( 1 ) 49,428 A $ 15.64 64,572 D Common Stock 02/21/2012 F( 1 ) 7,705 D $ 100.32 56,867 D Common Stock 02/21/2012 F( 1 ) 18,530 D $ 100.32 38,337 D Common Stock 02/21/2012 M( 1 ) 20,000 A $ 20.32 58,337 D Common Stock 02/21/2012 F( 1 ) 4,050 D $ 100.32 54,287 D Common Stock 02/21/2012 F( 1 ) 7,347 D $ 100.32 46,940 D Common Stock 02/21/2012 M( 1 ) 25,438 A $ 21.92 72,378 D Common Stock 02/21/2012 F( 1 ) 5,558 D $ 100.32 66,820 D Common Stock 02/21/2012 F( 1 ) 9,158 D $ 100.32 57,662 D Common Stock 02/21/2012 M( 1 ) 15,000 A $ 16.8 72,662 D Common Stock 02/21/2012 F( 1 ) 2,511 D $ 100.32 70,151 D Common Stock 02/21/2012 F( 1 ) 5,753 D $ 100.32 64,398 D Common Stock 02/22/2012 S( 1 ) 4,200 D $ 94.71 ( 2 ) 60,198 D Common Stock 02/22/2012 S( 1 ) 10,800 D $ 95.46 ( 3 ) 49,398 D Common Stock 02/22/2012 S( 1 ) 23,454 D $ 96.45 ( 4 ) 25,944 D Common Stock 02/22/2012 S( 1 ) 9,600 D $ 97.58 ( 5 ) 16,344 D Common Stock 02/22/2012 S( 1 ) 1,200 D $ 98.05 ( 6 ) 15,144 D Common Stock 1,532 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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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) $ 15.64 02/21/2012 M( 1 ) 49,428 ( 7 ) 10/02/2016 Common Stock 49,428 ( 8 ) 0 D Non-Qualified Stock Option (right to buy) $ 16.8 02/21/2012 M( 1 ) 15,000 ( 7 ) 12/17/2018 Common Stock 15,000 ( 8 ) 30,000 D Non-Qualified Stock Option (right to buy) $ 20.32 02/21/2012 M( 1 ) 20,000 ( 9 ) 12/18/2016 Common Stock 20,000 ( 8 ) 0 D Non-Qualified Stock Option (right to buy) $ 21.92 02/21/2012 M( 1 ) 25,438 ( 7 ) 12/17/2017 Common Stock 25,438 ( 8 ) 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Powchik Peter 777 OLD SAW MILL RIVER ROAD TARRYTOWN, NY10591 SVP Clinical Development & Reg Signatures /s/**Peter Powchik 02/23/2012 Signature of Reporting Person Date

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 4,200 shares of Company stock on February 22, 2012 at prices ranging from $94.22 to $94.98. 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 February 22, 2012 at each separate price. ( 3 )Represents volume-weighted average price of sales of 10,800 shares of Company stock on February 22, 2012 at prices ranging from $95.00 to $95.99. 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 reporting person on February 22, 2012 at each separate price. ( 4 )Represents volume-weighted average price of sales of 23,454 shares of Company stock on February 22, 2012 at prices ranging from $96.00 to $96.98. 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 February 22, 2012 at each separate price. ( 5 )Represents volume-weighted average price of sales of 9,600 shares of Company stock on February 22, 2012 at prices ranging from $97.00 to $97.97. 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 reporting person on February 22, 2012 at each separate price. ( 6 )Represents volume-weighted average price of sales of 1,200 shares of Company stock on February 22, 2012 at prices ranging from $98.01 to $98.27. 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 February 22, 2012 at each separate price. ( 7 )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. ( 8 )Exercisable date, exercise date, exercise price, purchase price, sales price, and/or expiration date is/are not applicable in this case. ( 9 )The stock option award vests in four equal annual installments, commencing one year after the date of grant.

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