Effect of High-Dose Subcutaneous Spesolimab on Skin Manifestations: Results from the Pivotal Effisayil 2 Trial of Flare Prevention in Generalized Pustular Psoriasis

Introduction & Objectives: Generalized pustular psoriasis (GPP) is a chronic, rare and potentially life-threatening skin disease, characterized by flares of sterile pustules. Spesolimab, an anti-interleukin-36 receptor monoclonal antibody, is an effective and approved treatment for GPP flares in adults. Effisayil 2 (NCT04399837) was a pivotal, randomized controlled trial that evaluated the efficacy and safety of subcutaneous spesolimab in preventing GPP flares. Here, we report the effect of high-dose spesolimab versus placebo on GPP lesions. Materials & Methods: Eligible patients with a history of GPP were randomized (1:1:1:1) to receive one of three subcutaneous spesolimab regimens or placebo for 48 weeks. High-dose spesolimab regimen was loading dose 600 mg, followed by maintenance dose 300 mg every 4 weeks. GPP Physician Global Assessment (GPPGA) subscores for erythema, pustules and scaling/crusting, and total score were compared between high-dose spesolimab and placebo groups at baseline and over the treatment period (scale: 0, clear to 4, severe). Results: Proportion of patients with baseline score of 0 for each GPPGA subscore and total score was generally similar between treatment groups, except erythema; (high-dose spesolimab [n=30] vs placebo [n=31]: erythema, 13.3% vs 22.6%; pustules, 66.7% vs 67.7%; scaling/crusting, 23.3% vs 22.6%; total score, 10.0% vs 12.9%). By Week 4, proportion of patients with scores of 0 increased with high-dose spesolimab versus placebo, (erythema, 33.3% vs 19.4%; pustules, 80.0% vs 41.9%; scaling/crusting, 30.0% vs 19.4%; total score, 26.7% vs 16.1%), and high-dose spesolimab group had fewer flares (10.0% vs 35.5%). This trend was maintained at Week 24 (erythema, 36.7% vs 22.6%; pustules, 63.3% vs 45.2%; scaling/crusting, 36.7% vs 19.4%; total score, 33.3% vs 19.4%) and Week 48 (erythema, 36.7% vs 22.6%; pustules, 66.7% vs 45.2%; scaling/crusting, 43.3% vs 25.8%; total score, 36.7% vs 22.6%). There were no new flares after Week 4 in high-dose spesolimab group; however, flares increased with placebo (45.2% at Week 24; 51.6% at Week 48). Conclusion: Versus placebo, high-dose subcutaneous spesolimab resulted in a greater proportion of patients maintaining GPPGA scores of 0, a lower proportion having flares at Week 4, and no new flares after Week 4. This was sustained at Weeks 24 and 48.