Refer to the input text as context and select the correct relationship between 'Sanofi' and 'Regeneron Pharmaceuticals' from the available options.
Options: chairperson, chief executive officer, owner of, stock exchange

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