Design of Effisayil™ 2: A Randomized, Double-Blind, Placebo-Controlled Study of Spesolimab in Preventing Flares in Patients with Generalized Pustular Psoriasis

Introduction: Generalized pustular psoriasis (GPP) is a rare autoinflammatory skin disease characterized by flares of widespread erythema with sterile pustules, and can be relapsing with recurrent flares, or persistent with intermittent flares. Spesolimab, a humanized anti-interleukin-36 (IL-36) receptor monoclonal antibody, targets the key IL-36 pathogenetic pathway in GPP. A previous study showed that spesolimab treatment led to rapid pustular and skin clearance in patients with GPP flares, which was sustained for up to 12 weeks. This study investigates the long-term effects of spesolimab on GPP flares, for which no specific treatments are currently available. The Effisayil™ 2 study will assess whether maintenance treatment with subcutaneous spesolimab prevents the occurrence of GPP flares and determine the optimal dosing regimen to achieve this aim. Methods: Patients will have a documented history of GPP with a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) score of 0 or 1 (clear or almost clear) at screening and randomization. Patients will be randomized 1:1:1:1 to three groups receiving a 600-mg subcutaneous loading dose of spesolimab followed by a 300-mg maintenance dose administered every 4 or 12 weeks, or a 300-mg loading dose followed by a 150-mg maintenance dose administered every 12 weeks, and one group receiving placebo, for 48 weeks. The primary endpoint is time to first GPP flare. If a patient experiences a GPP flare during the randomized maintenance treatment period, an open-label intravenous dose of 900-mg spesolimab will be administered, with an option for a second intravenous dose after 1 week. Conclusions: Effisayil™ 2 is the first placebo-controlled study in patients with GPP to investigate whether maintenance treatment with spesolimab can prevent flares and provide sustained disease control. This study will provide valuable insights on the long-term management of patients with this potentially life-threatening skin disease. Trial Registration Number: NCT04399837.