The company said the positive opinion would mark the first orphan drug designation recognition in the EU for a generalized pustular psoriasis treatment, while its U.S. BLA review continues toward a December 12, 2026 decision.
Vanda Pharmaceuticals Inc. said the Committee for Orphan Medicinal Products at the European Medicines Agency (EMA) adopted a positive opinion recommending orphan drug designation for imsidolimab, its investigational medicinal product for generalized pustular psoriasis, or GPP. The company said this is the first time the EMA has granted orphan drug designation recognition for a drug to treat GPP in the European Union. Imsidolimab is described as a high-affinity humanized immunoglobulin G4 monoclonal antibody that inhibits interleukin-36 receptor signaling. Vanda said that mechanism is intended to address the deficiency in the endogenous IL-36 receptor antagonist commonly observed in patients with GPP, a severe, chronic and potentially life-threatening inflammatory skin disease that is genetically and clinically distinct from plaque psoriasis. Under EMA rules, orphan designation applies to medicines aimed at life-threatening or chronically debilitating rare diseases affecting fewer than 5 in 10,000 people in the EU. Vanda said the status can provide protocol assistance, reduced regulatory fees and EU market exclusivity provisions following approval. Dr. Mihael H. Polymeropoulos called the EMA's positive opinion "a significant milestone" that reinforces clinical data for imsidolimab and formally recognizes GPP as an orphan disease in the EU for the first time. The company added that similar regulatory recognitions have already been secured in the United States and Japan, and that the Biologics License Application, or BLA (application to market a biologic drug), for imsidolimab in GPP is under FDA (U.S. drug regulator) review with a target action date of December 12, 2026.