The US Food and Drug Administration (FDA) and Japan's Ministry of Health, Labour and Welfare have previously granted Orphan Drug Designation to imsidolimab for the treatment of GPP.

This marks the first time the European Commission has granted orphan designation recognition for a drug to treat GPP in the European Union (EU). GPP is clinically distinct from plaque psoriasis and is characterized by widespread pustular eruptions, systemic inflammation, and serious complications that can lead to increased mortality.2,3,4 Imsidolimab inhibits IL-36 receptor signaling, addressing the deficiency in the endogenous IL-36 receptor antagonist commonly observed in patients with GPP.

Orphan Designation in the EU is granted by the European Commission following an opinion from EMA's COMP for medicines intended for the diagnosis, prevention, or treatment of life-threatening or chronically debilitating rare conditions. Among other criteria, the condition must affect fewer than 5 in 10,000 people in the EU. Benefits include protocol assistance, reduced regulatory fees, and market exclusivity provisions in the EU following approval.

"The European Commission's Orphan Designation for imsidolimab represents an important milestone for the GPP community and for our efforts to bring this investigational therapy to patients in Europe," said Dr. Mihael H. Polymeropoulos, Vanda's President, CEO and Chairman of the Board. "With orphan designations now received in Europe, the United States and Japan, we remain focused on advancing imsidolimab for patients in these markets who need new treatment options."

This designation follows similar regulatory recognitions in the United States and Japan. Additionally, the imsidolimab Biologics License Application (BLA) for GPP is currently under review by the FDA with a target action date of December 12, 2026.