In the EFFISAYIL ON extension, 17 of 20 patients on long-term subcutaneous spesolimab remained flare-free, and intravenous spesolimab cleared pustules in half of 36 breakthrough flares within 1 week
touchDERMATOLOGY coverage from EADV 2026:
Spesolimab (Spevigo; Boehringer Ingelheim, Ingelheim, Germany) is an anti-interleukin-36 (IL-36) receptor monoclonal antibody approved for the treatment of generalized pustular psoriasis (GPP).¹,²
EFFISAYIL ON (NCT03886246) is an ongoing, open-label, 5-year extension of the phase 2 EFFISAYIL 1 and phase 2b EFFISAYIL 2 trials.¹,³⁻⁵ Patients receive subcutaneous spesolimab 300 mg every 4, 6, or 12 weeks, with dose adjustments permitted when flares recur or resolve. Those who experience a protocol-defined flare can receive intravenous spesolimab 900 mg, with up to two doses within 1 week.⁴ Two analyses from the study were presented at EADV 2026 in Vienna, Austria, with Prof. James Krueger (Rockefeller University, New York, NY, USA) and Prof. Kenneth B. Gordon (Medical College of Wisconsin, Milwaukee, WI, USA) as first authors.²,⁴
Most patients on long-term subcutaneous treatment remained flare-free
Twenty patients who received the approved subcutaneous dosing regimen in EFFISAYIL 2 continued subcutaneous spesolimab in EFFISAYIL ON for up to 4 years. Of these, 17 had no flare events, and the mean cumulative number of flares fell from 2.0 per year before EFFISAYIL 2 to 0.1 over 2 years. The authors defined long-term disease control as a GPP Physician Global Assessment (GPPGA) pustulation subscore of 0, or a total score of 0–1, at 90% or more of visits. On these measures, 75% and 80% of patients achieved long-term control, respectively. None of the six patients with an IL36RN mutation had a flare, and all six achieved long-term control on both measures.²
Of 19 patients with evaluable Dermatology Life Quality Index (DLQI) scores, the average DLQI on entering EFFISAYIL 2 was 12.1. During long-term treatment, 63.2% improved to a score of 4 or less and 47.4% to a score of 0–1.²
Intravenous spesolimab for breakthrough flares
Across all 131 patients enrolled from the parent trials, 21 (16.0%) received intravenous spesolimab for a total of 36 flare events: 29 were treated with a single dose and seven with two doses. A GPPGA pustulation subscore of 0 was achieved in 50.0% of flare treatments at Week 1 and 58.3% at Week 2. A GPPGA total score of 0–1 was achieved in 41.7% at Week 1 and 55.6% at Week 2. In both analyses, safety data were consistent with the known safety profile of spesolimab.²,⁴
Concluding their findings, Krueger and colleagues suggest that long-term subcutaneous spesolimab is effective in preventing or reducing flares in patients with GPP, with or without IL36RN mutation, and that its safety profile remains unchanged.²
Gordon and colleagues report sustained efficacy in most patients treated with subcutaneous spesolimab for flare prevention. For patients who do experience flares, they suggest that intravenous spesolimab is an effective and well-tolerated treatment, supporting complementary roles for the two formulations in the long-term management of GPP.⁴
References
- Morita A, Strober B, Burden AD, et al. Efficacy and safety of subcutaneous spesolimab for the prevention of generalised pustular psoriasis flares (Effisayil 2): an international, multicentre, randomised, placebo-controlled trial. Lancet. 2023;402:1541–51.
- Krueger J, Lebwohl MG, Morita A, et al. Long-term disease control with subcutaneous spesolimab in GPP patients with or without IL-36RN mutation: results from the EFFISAYIL ON study. Presented at: EADV Congress 2026, Vienna, Austria, September 30–October 3, 2026. Abstr 525.
- Bachelez H, Choon SE, Marrakchi S, et al. Trial of spesolimab for generalized pustular psoriasis. N Engl J Med. 2021;385:2431–40.
- Gordon KB, Navarini AA, Choon SE, et al. Intravenous spesolimab for (re)treatment of generalized pustular psoriasis flares in patients receiving subcutaneous spesolimab: results from the 5-year, open-label, EFFISAYIL ON extension study. Presented at: EADV Congress 2026, Vienna, Austria, September 30–October 3, 2026. Abstr 532.
- ClinicalTrials.gov. Effisayil ON: a study to test long-term treatment with spesolimab in people with generalized pustular psoriasis who took part in a previous study. ClinicalTrials.gov Identifier: NCT03886246. Available at: https://clinicaltrials.gov/study/NCT03886246 (accessed November 4, 2026)
This article was created by the touchDERMATOLOGY team utilizing AI as an editorial tool (Claude [Large language model]. Anthropic. https://claude.ai). The content was developed and edited by human editors. No funding was received in the publication of this article.
Cite: Spesolimab extension data support long-term flare prevention and rescue in generalized pustular psoriasis. touchDERMATOLOGY. November 4, 2026.
touchDERMATOLOGY coverage of EADV 2026: This content has been developed independently by Touch Medical Media for touchDERMATOLOGY. touchDERMATOLOGY was an official media partner of the EADV Congress 2026. touchDERMATOLOGY is not affiliated with the EADV.
