Vanda Pharmaceuticals Inc., headquartered in Washington, D.C., announced on August 24, 2026 that the European Commission granted Orphan Designation to imsidolimab for the treatment of Generalized Pustular Psoriasis (GPP), marking the first orphan designation granted to any GPP treatment in the EU. President, CEO, and Chairman Dr. Mihael H. Polymeropoulos said: “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. 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.”
A Third Orphan Designation for a Severe, Rare Skin Disease
GPP is a severe, chronic, and potentially life-threatening inflammatory skin disease. Vanda describes it as clinically distinct from plaque psoriasis, causing widespread pustular eruptions, systemic inflammation, and serious complications that can lead to increased mortality. To qualify for EU orphan status, a condition must, among other criteria, affect fewer than 5 in 10,000 people in the EU — the regulatory threshold for rare-disease designation, not a specific prevalence figure for GPP itself. The EU designation follows earlier Orphan Drug Designations from the FDA and Japan’s Ministry of Health, Labour and Welfare, making this the third major regulatory region to grant the drug orphan status.
What Comes Next
In the EU, orphan designation entitles Vanda to protocol assistance, reduced regulatory fees, and market exclusivity provisions following approval, though the release doesn’t specify the exclusivity period. In the U.S., imsidolimab’s Biologics License Application is already under FDA review, with a target action date of December 12, 2026.
About Imsidolimab and Vanda Pharmaceuticals
Imsidolimab is a fully humanized IgG4 monoclonal antibody that inhibits IL-36 receptor signaling and is being developed for GPP, a rare orphan indication. Regulatory and patent exclusivity for imsidolimab is expected to extend into the late 2030s. Vanda holds an exclusive global license for the development and commercialization of imsidolimab.
Vanda is a leading global biopharmaceutical company focused on the development and commercialization of innovative therapies to address high unmet medical needs and improve the lives of patients. Its commercial portfolio includes HETLIOZ, for Non-24-Hour Sleep-Wake Disorder and nighttime sleep disturbances in Smith-Magenis Syndrome; Fanapt, for schizophrenia; and PONVORY, for relapsing forms of multiple sclerosis. For references and more information, visit www.vandapharma.com.
