Leonard S. Schleifer

New Capabilities

Serves as executive chairman; co-architect of Regeneron's science-first model

When the Food and Drug Administration (FDA) approved Dupixent for severe eczema in 2017, it was one drug for one disease. Nine years later, the same molecule has been approved for nine separate conditions, from asthma to a chronic fungal sinus infection that previously had no approved treatment at all. The latest approval, granted on February 24, 2026, covers allergic fungal rhinosinusitis (AFRS), a condition that traps patients in a cycle of repeated sinus surgeries. In a pivotal trial, Dupixent reduced the need for additional surgeries and steroid courses by 92%.

Updated Feb 24