What is the relationship between 'Sanofi' and 'Regeneron Pharmaceuticals' in the context of the input sentence.
Options: creator, developer, owner of, legal form

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.
owner of