Sanofi pays $1B to Regeneron for Dupixent successor antibodies

Sanofi will pay Regeneron at least $1 billion upfront, with up to $7 billion in milestones, to co-develop antibodies targeting the same pathways as Dupixent, which loses exclusivity in the early 2030s. Dupixent generated over €5 billion in Q2, 45% of Sanofi's revenue, making this deal a strategic hedge against patent cliff. The partnership extends an existing relationship but signals Sanofi's urgency to secure a successor for its top-selling drug.