Since 2007, Regeneron and Sanofi have collaborated to help people with debilitating, difficult-to-treat conditions. Regeneron, a science-based biopharmaceutical company, discovers, invents, develops, manufactures and commercializes medicines to treat serious diseases. Sanofi Genzyme, the specialty care business unit of Sanofi, focuses on rare diseases, multiple sclerosis, oncology and immunology.