Sanofi to pay Regeneron $1 billion upfront in expanded immunology deal

French drugmaker Sanofi EURONEXT:SAN said on Thursday it would pay US partner Regeneron NASDAQ:REGN $1 billion upfront and up to $7 billion more in milestone payments to add four next-generation, long-acting immunology antibodies to the partnership behind their blockbuster eczema drug Dupixent.The…