0000950123-04-005015 424B3 1 20040423 REGENERON PHARMACEUTICALS INC 0000872589 2834 133444607 NY 1231 424B3 33 333-74464 04749847 777 OLD SAW MILL RIVER RD TARRYTOWN NY 10591-6707 9143477000 424B3 1 y96482e424b3.htm REGENERON PHARMACEUTICALS