Spesolimab Demonstrates Sustained Reduction in Flare Rates Over 3 Years in Generalized Pustular Psoriasis

Long-term data from the EFFISAYIL program suggest that subcutaneous (SC) spesolimab provides durable disease control in patients with generalized pustular psoriasis (GPP), significantly reducing flare frequency over at least 3 years of treatment.

The study included 118 patients who received ≥3 years of subcutaneous spesolimab following participation in EFFISAYIL 1 or EFFISAYIL 2 trials. Outcomes focused on flare frequency and safety, with flares defined using stringent clinical criteria including GPP Physician Global Assessment scores and pustular involvement. 

Spesolimab demonstrated substantial reductions in disease activity over time. The cumulative mean number of flares decreased from a baseline median of 2.0 flares per year to just 0.13 flares per year during long-term treatment (0.40 total flares over 3 years). Notably, 74.6% of patients remained completely flare free, while only 25.4% experienced at least one flare. 

Among patients who did experience flares, most had infrequent episodes (<3 flares), suggesting sustained disease suppression in most treated individuals. 

Safety findings were consistent with prior studies. Adverse events occurred in 91.5% of patients, with grade 3/4 events in 22.0% and treatment discontinuation in only 4.2%. No new safety signals emerged with long-term exposure. 

“Preliminary results from this open-label study demonstrated that long-term (≥3 years) SC spesolimab, a highly targeted anti–IL-36 monoclonal antibody, is effective in reducing the cumulative number of disease flares in patients with GPP,” the authors concluded. “Additionally, the safety profile of spesolimab remains unchanged with long-term use.” 

These findings support spesolimab as a durable long-term treatment option for GPP, offering sustained flare control in a disease characterized by recurrent and potentially severe episodes.

Reference

Gudjonsson JE, Navarini AA, Langley RG, et al. Long-term (≥3 year) efficacy and safety of subcutaneous spesolimab for treatment of generalized pustular psoriasis: results from the EFFISAYIL program. Presented at: American Academy of Dermatology Annual Meeting; March 27–31, 2026; Denver, Colorado.