Utilize the input text as a context reference, choose the right relationship between Sanofi and Regeneron Pharmaceuticals from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

Elsewhere, French drugmaker Sanofi (NasdaqGM: GCVRZ - news ) advanced as it said it has entered into a research agreement with Regeneron Pharmaceuticals (NasdaqGS: REGN - news ) and will invest $2.17bn to develop new cancer treatments together.

Answer: owner_of