Sec Form 4 Filing - SCHLEIFER LEONARD S @ REGENERON PHARMACEUTICALS, INC. - 2020-05-11

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 SCHLEIFER LEONARD S 2. Issuer Name and Ticker or Trading Symbol REGENERON PHARMACEUTICALS, INC. [ REGN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) President & CEO (Last) (First) (Middle) 777 OLD SAW MILL RIVER ROAD 3. Date of Earliest Transaction (MM/DD/YY) 05/11/2020 (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 05/11/2020 M( 1 ) 125,000 A $ 30.63 599,499 D Common Stock 05/11/2020 F( 1 ) 64,631 D $ 571.43 534,868 D Common Stock 05/11/2020 M( 1 ) 187,500 A $ 30.63 722,368 D Common Stock 05/11/2020 F( 1 ) 96,947 D $ 571.43 625,421 D Common Stock 05/12/2020 S( 1 ) 2,329 D $ 557.51 ( 2 ) 623,092 D Common Stock 05/12/2020 S( 1 ) 4,162 D $ 558.35 ( 3 ) 618,930 D Common Stock 05/12/2020 S( 1 ) 1,361 D $ 559.52 ( 4 ) 617,569 D Common Stock 05/12/2020 S( 1 ) 3,391 D $ 560.68 ( 5 ) 614,178 D Common Stock 05/12/2020 S( 1 ) 3,994 D $ 561.24 ( 6 ) 610,184 D Common Stock 05/12/2020 S( 1 ) 1,394 D $ 562.75 ( 7 ) 608,790 D Common Stock 05/12/2020 S( 1 ) 2,549 D $ 563.51 ( 8 ) 606,241 D Common Stock 05/12/2020 S( 1 ) 779 D $ 564.41 ( 9 ) 605,462 D Common Stock 05/12/2020 S( 1 ) 3,032 D $ 565.67 ( 10 ) 602,430 D Common Stock 05/12/2020 S( 1 ) 5,810 D $ 566.51 ( 11 ) 596,620 D Common Stock 05/12/2020 S( 1 ) 9,359 D $ 567.57 ( 12 ) 587,261 D Common Stock 05/12/2020 S( 1 ) 18,021 D $ 568.58 ( 13 ) 569,240 D Common Stock 05/12/2020 S( 1 ) 19,982 D $ 569.52 ( 14 ) 549,258 D Common Stock 05/12/2020 S( 1 ) 20,267 D $ 570.49 ( 15 ) 528,991 D Common Stock 05/12/2020 S( 1 ) 15,542 D $ 571.49 ( 16 ) 513,449 D Common Stock 05/12/2020 S( 1 ) 19,984 D $ 572.47 ( 17 ) 493,465 D Common Stock 05/12/2020 S( 1 ) 10,014 D $ 573.27 ( 18 ) 483,451 D Common Stock 05/12/2020 S( 1 ) 4,390 D $ 574.59 ( 19 ) 479,061 D Common Stock 05/12/2020 S( 1 ) 2,196 D $ 575.48 ( 20 ) 476,865 D Common Stock 05/12/2020 S( 1 ) 1,728 D $ 576.51 ( 21 ) 475,137 D Common Stock 05/12/2020 S( 1 ) 638 D $ 577.27 ( 22 ) 474,499 D Common Stock 5,848 I By 401(k) Plan Common Stock 100,000 I by 2019 GRAT

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) $ 30.63 05/11/2020 M( 1 ) 125,000 ( 23 ) 12/14/2020 Common Stock 125,000 $ 0 187,500 D Non-Qualified Stock Option (right to buy) $ 30.63 05/11/2020 M( 1 ) 187,500 ( 23 ) 12/14/2020 Common Stock 187,500 $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SCHLEIFER LEONARD S 777 OLD SAW MILL RIVER ROAD TARRYTOWN, NY10591 X President & CEO Signatures /s/**Leonard S. Schleifer 05/13/2020 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 2,329 shares of Company stock on May 12, 2020 at prices ranging from $557.02 to $557.99. 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 May 12, 2020 at each separate price. ( 3 )Represents volume-weighted average price of sales of 4,162 shares of Company stock on May 12, 2020 at prices ranging from $558.00 to $558.97. 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 May 12, 2020 at each separate price. ( 4 )Represents volume-weighted average price of sales of 1,361 shares of Company stock on May 12, 2020 at prices ranging from $559.02 to $559.84. 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 May 12, 2020 at each separate price. ( 5 )Represents volume-weighted average price of sales of 3,391 shares of Company stock on May 12, 2020 at prices ranging from $560.19 to $560.94. 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 May 12, 2020 at each separate price. ( 6 )Represents volume-weighted average price of sales of 3,994 shares of Company stock on May 12, 2020 at prices ranging from $561.00 to $561.90. 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 May 12, 2020 at each separate price. ( 7 )Represents volume-weighted average price of sales of 1,394 shares of Company stock on May 12, 2020 at prices ranging from $562.33 to $562.96. 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 May 12, 2020 at each separate price. ( 8 )Represents volume-weighted average price of sales of 2,549 shares of Company stock on May 12, 2020 at prices ranging from $563.12 to $563.85. 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 May 12, 2020 at each separate price. ( 9 )Represents volume-weighted average price of sales of 779 shares of Company stock on May 12, 2020 at prices ranging from $564.01 to $564.69. 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 May 12, 2020 at each separate price. ( 10 )Represents volume-weighted average price of sales of 3,032 shares of Company stock on May 12, 2020 at prices ranging from $565.16 to $565.98. Upon request by t he 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 May 12, 2020 at each separate price. ( 11 )Represents volume-weighted average price of sales of 5,810 shares of Company stock on May 12, 2020 at prices ranging from $566.00 to $566.98. 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 May 12, 2020 at each separate price. ( 12 )Represents volume-weighted average price of sales of 9,359 shares of Company stock on May 12, 2020 at prices ranging from $567.00 to $567.97. 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 May 12, 2020 at each separate price. ( 13 )Represents volume-weighted average price of sales of 18,021 shares of Company stock on May 12, 2020 at prices ranging from $568.00 to $568.99. 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 May 12, 2020 at each separate price. ( 14 )Represents volume-weighted average price of sales of 19,982 shares of Company stock on May 12, 2020 at prices ranging from $569.00 to $569.99. 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 May 12, 2020 at each separate price. ( 15 )Represents volume-weighted average price of sales of 20,267 shares of Company stock on May 12, 2020 at prices ranging from $570.01 to $570.98. 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 May 12, 2020 at each separate price. ( 16 )Represents volume-weighted average price of sales of 15,542 shares of Company stock on May 12, 2020 at prices ranging from $571.00 to $571.99. 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 May 12, 2020 at each separate price. ( 17 )Represents volume-weighted average price of sales of 19,984 shares of Company stock on May 12, 2020 at prices ranging from $572.00 to $572.99. 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 May 12, 2020 at each separate price. ( 18 )Represents volume-weighted average price of sales of 10,014 shares of Company stock on May 12, 2020 at prices ranging from $573.00 to $573.92. 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 May 12, 2020 at each separate price. ( 19 )Represents volume-weighted average price of sales of 4,390 shares of Company stock on May 12, 2020 at prices ranging from $574.17 to $574.94. 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 May 12, 2020 at each separate price. ( 20 )Represents volume-weighted average price of sales of 2,196 shares of Company stock on May 12, 2020 at prices ranging from $575.04 to $575.85. 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 May 12, 2020 at each separate price. ( 21 )Represents volume-weighted average price of sales of 1,728 shares of Company stock on May 12, 2020 at prices ranging from $576.04 to $576.99. 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 May 12, 2020 at each separate price. ( 22 )Represents volume-weighted average price of sales of 638 shares of Company stock on May 12, 2020 at prices ranging from $577.15 to $577.55. 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 May 12, 2020 at each separate price. ( 23 )With respect to 125,000 underlying shares (of which 0 remain outstanding), the stock option award vested in four equal annual installments, commencing one year after the date of grant. With respect to 187,500 underlying shares (of which 0 remain outstanding), the option became exercisable on December 31, 2013, based upon the satisfaction by the company of certain performance criteria during the period ended December 31, 2013.

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