BACKGROUND:\ud Generalized pustular psoriasis (GPP) is a rare, life-threatening, inflammatory skin\ud disease characterized by widespread eruption of sterile pustules. Interleukin-36\ud signaling is involved in the pathogenesis of this disorder. Spesolimab, a humanized anti–interleukin-36 receptor monoclonal antibody, is being studied for the\ud treatment of GPP flares.\ud METHODS:\ud In a phase 2 trial, we randomly assigned patients with a GPP flare in a 2:1 ratio to\ud receive a single 900-mg intravenous dose of spesolimab or placebo. Patients in both\ud groups could receive an open-label dose of spesolimab on day 8, an open-label dose\ud of spesolimab as a rescue medication after day 8, or both and were followed to week\ud 12. The primary end point was a Generalized Pustular Psoriasis Physician Global\ud Assessment (GPPGA) pustulation subscore of 0 (range, 0 [no visible pustules] to 4\ud [severe pustulation]) at the end of week 1. The key secondary end point was a GPPGA total score of 0 or 1 (clear or almost clear skin) at the end of week 1; scores\ud range from 0 to 4, with higher scores indicating greater disease severity.\ud RESULTS:\ud A total of 53 patients were enrolled: 35 were assigned to receive spesolimab and 18\ud to receive placebo. At baseline, 46% of the patients in the spesolimab group and 39%\ud of those in the placebo group had a GPPGA pustulation subscore of 3, and 37% and\ud 33%, respectively, had a pustulation subscore of 4. At the end of week 1, a total of\ud 19 of 35 patients (54%) in the spesolimab group had a pustulation subscore of 0, as\ud compared with 1 of 18 patients (6%) in the placebo group (difference, 49 percentage\ud points; 95% confidence interval [CI], 21 to 67; P
