US biopharmaceutical company Vanda Pharmaceuticals Inc. (NASDAQ: VNDA), said on Monday it has received European Commission orphan designation for imsidolimab, its investigational monoclonal antibody for Generalised Pustular Psoriasis (GPP).

The designation follows a positive opinion from the European Medicines Agency's Committee for Orphan Medicinal Products and is the first time the European Commission has granted orphan status to a treatment for GPP in the European Union.

GPP is clinically distinct from plaque psoriasis and is characterised by widespread pustular eruptions, systemic inflammation and complications associated with increased mortality. Imsidolimab inhibits IL-36 receptor signalling, addressing the deficiency in the endogenous IL-36 receptor antagonist seen in patients with GPP.

Imsidolimab is a fully humanised IgG4 monoclonal antibody in development for GPP, with regulatory and patent exclusivity expected to extend into the late 2030s. Vanda holds an exclusive global licence for its development and commercialisation.

The US Food and Drug Administration and Japan's Ministry of Health, Labour and Welfare have previously granted orphan designation for the drug, and its Biologics License Application for GPP is currently under FDA review with a target action date of 12 December 2026.

EU orphan designation is granted for medicines intended for rare, life-threatening or chronically debilitating conditions affecting fewer than 5 in 10,000 people. Benefits include protocol assistance, reduced regulatory fees and market exclusivity following approval.