X0306 4 2020-08-28 0 0000872589 REGENERON PHARMACEUTICALS, INC. REGN 0001189014 POON CHRISTINE A 777 OLD SAW MILL RIVER ROAD TARRYTOWN NY 10591 1 0 0 0 Common Stock 2020-08-28 4 M 0 15000 33.42 A 16433 D Common Stock 2020-08-28 4 M 0 25000 25.45 A 41433 D Common Stock 2020-08-28 4 S 0 177 598.91 D 41256 D Common Stock 2020-08-28 4 S 0 5730 599.67 D 35526 D Common Stock 2020-08-28 4 S 0 12490 600.44 D 23036 D Common Stock 2020-08-28 4 S 0 8011 601.53 D 15025 D Common Stock 2020-08-28 4 S 0 12899 602.39 D 2126 D Common Stock 2020-08-28 4 S 0 693 603.2 D 1433 D Non-Qualified Stock Option (right to buy) 25.45 2020-08-28 4 M 0 25000 0.0 D 2020-11-12 Common Stock 25000 0 D Non-Qualified Stock Option (right to buy) 33.42 2020-08-28 4 M 0 15000 0.0 D 2021-01-03 Common Stock 15000 0 D Represents volume-weighted average price of sales of 177 shares of Company stock on August 28, 2020 at prices ranging from $598.90 to $598.95. 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 August 28, 2020 at each separate price. Represents volume-weighted average price of sales of 5,730 shares of Company stock on August 28, 2020 at prices ranging from $599.00 to $599.99. 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 August 28, 2020 at each separate price. Represents volume-weighted average price of sales of 12,490 shares of Company stock on August 28, 2020 at prices ranging from $600.00 to $600.96. 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 August 28, 2020 at each separate price. Represents volume-weighted average price of sales of 8,011 shares of Company stock on August 28, 2020 at prices ranging from $601.00 to $601.99. 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 August 28, 2020 at each separate price. Represents volume-weighted average price of sales of 12,899 shares of Company stock on August 28, 2020 at prices ranging from $602.00 to $602.97. 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 August 28, 2020 at each separate price. Represents volume-weighted average price of sales of 693 shares of Company stock on August 28, 2020 at prices ranging from $603.00 to $603.91. 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 August 28, 2020 at each separate price. The stock option becomes exercisable in three equal annual installments, commencing one year after the date of grant. /s/**Christine A. Poon 2020-08-31