Utilize the input text as a context reference, choose the right relationship between 'Sanofi' and 'Regeneron Pharmaceuticals' from the options.
Options: stock exchange, owner of, chairperson, chief executive officer

LONDON, July 24 (Reuters) - A new type of cholesterol drug from Sanofi and Regeneron Pharmaceuticals won a green light from European regulators on Friday, two months behind a rival product from Amgen.
owner of