144 0001663758 XXXXXXXX LIVE 0000872589 REGENERON PHARMACEUTICALS, INC. 000-19034 777 OLD SAW MILL RIVER ROAD TARRYTOWN NY 10591 9148477000 McCourt Marion Officer Common UBS Financial Services Inc.

11 Madison Ave 4th Floor New York NY 10010

1215 1032750.00 101137842 09/02/2026 NASDAQ Common 02/12/2023 RSA Vesting Issuer N 224 02/12/2023 N/A Common 12/09/2024 RSA Vesting Issuer N 263 12/09/2024 N/A Common 12/16/2024 RSA Vesting Issuer N 728 12/16/2024 N/A Y 09/02/2026 02/17/2026 /s/ UBS Financial Services Inc, as attorney-in-fact for Marion McCourt