Regeneron Pharmaceuticals is a Nasdaq-listed (REGN) biotechnology company headquartered in Tarrytown, New York, founded in 1988 by Leonard Schleifer, who still leads it as CEO alongside co-founder and chief scientific officer George Yancopoulos. It invents, develops and manufactures medicines for serious diseases using its own antibody and genetics technologies, has developed 15 approved or authorized medicines, and runs large manufacturing sites in Rensselaer, New York and Limerick, Ireland.