In a landmark decision, the U.S. Food and Drug Administration (FDA) has approved Dupixent (dupilumab) as the first targeted therapy for bullous pemphigoid (BP)—a rare, chronic autoimmune skin disorder that primarily affects older adults and causes painful, itchy blisters and lesions.

Developed by Sanofi and Regeneron, Dupixent is already known for treating conditions like eczema and asthma. This new approval marks a major expansion of its use and a significant breakthrough for the estimated 27,000 Americans living with BP, many of whom have had to rely on long-term steroid treatments with serious side effects.

The FDA’s decision was based on results from the ADEPT clinical trial, which showed that patients receiving Dupixent experienced a five-fold increase in sustained remission compared to those on placebo. Additionally, 41% of patients achieved a 90% or greater reduction in disease severity, and many reported dramatic relief from itching—one of the most debilitating symptoms of the disease.

“This is a historic moment for patients with bullous pemphigoid,” said Patrick Dunn, Executive Director of the International Pemphigus and Pemphigoid Foundation. “For the first time, they have access to a treatment that targets the disease at its source and offers the potential for long-term relief.”

With this approval, Dupixent is now authorized to treat eight different conditions driven by type 2 inflammation. Sanofi and Regeneron are also pursuing regulatory approvals for BP in other countries, including the EU, Japan, and China.