Sanofi to pay Regeneron up to $8 billion to add new antibodies under Dupixent partnership ↧ ↧ Sanofi to pay Regeneron up to $8 billion to add new antibodies unde... Sanofi said on Thursday it would pay US partner Regeneron $1 billion upfront and up to $7 billion in milestone payments ​to bring four new antibodies under the partnership ​behind their blockbuster eczema drug Dupixent, which sent ⁠the French drugmaker's shares 2% higher in early ​trading.