AAD 2026: Extended Study Highlights Dual Role of Subcutaneous and Intravenous Spesolimab for GPP Management

Long-term extension data from the EFFISAYIL clinical program, presented at the 2026 American Academy of Dermatology (AAD) Annual Meeting, provide new insights into the sustained efficacy and safety of spesolimab-sbzo (SPEVIGO) in generalized pustular psoriasis (GPP), as well as its role in acute flare management. Two posters with data from the ongoing EFFISAYIL ON study, alongside a supporting press release from LEO Pharma, collectively highlight the complementary utility of subcutaneous (SC) maintenance therapy and intravenous (IV) rescue treatment in this rare disease.

“The long-term data from the EFFISAYIL ON study further strengthen the evidence base for SPEVIGO as an effective treatment for generalized pustular psoriasis, a rare, chronic, and often-overlooked disease,” said Shannon Schneider, Vice President of North America Medical Affairs for LEO Pharma. “LEO Pharma is committed to addressing the serious impact of GPP on people living with this condition, through continued data generation and clinical insights.”¹

Long-Term Flare Prevention with Subcutaneous Spesolimab

The first poster presented by Gudjonsson et al. reported long-term outcomes from patients receiving SC spesolimab as maintenance therapy in the EFFISAYIL ON extension study, an open-label, multicenter trial enrolling patients who completed the pivotal EFFISAYIL 1 and 2 studies.² Patients received 300 mg SC spesolimab at intervals of every 4 to 12 weeks for up to 5 years, with dose adjustments permitted based on disease activity.

Among 131 enrolled patients, the majority (84.0%; n = 110) remained entirely flare-free throughout the observation period, reinforcing the durability of response previously observed in earlier phases of the clinical program. Notably, only 21 patients experienced flare events, and just 2 patients had flares within the first 4 weeks of initiating SC maintenance therapy.

Baseline characteristics indicated a representative GPP population, and safety outcomes remained consistent with the established profile of spesolimab. Additionally, no new safety signals emerged during long-term follow-up.

Intravenous Spesolimab for Acute Flare Management

The second poster by Gordon et al. focuses on the efficacy of IV spesolimab for the treatment of acute GPP flares in patients receiving SC maintenance therapy within the same extension study.³ Patients experiencing protocol-defined flares were treated with IV spesolimab 900 mg (up to 2 doses within 1 week), followed by resumption or intensification of SC dosing.

A total of 36 flare events in 21 patients were analyzed. Rapid clinical improvement was observed, with 50.0% of flare episodes achieving a GPP Physician Global Assessment (GPPGA) pustulation subscore of 0 (indicating no visible pustules) at week 1, increasing to 58.3% by week 2. Similarly, 41.7% and 55.6% of flare events achieved a GPPGA total score of 0 or 1 (clear or almost clear) at weeks 1 and 2, respectively.

Long-term SC treatment reduced the annualized flare rate from approximately 2.0 flares per year prior to study entry to 0.13 flares per year during treatment. Among patients treated for 3 or more years, nearly 75% experienced no flares.

These findings demonstrate the rapid onset of action of IV spesolimab in controlling acute inflammatory activity during GPP flares. Importantly, flare resolution was achieved even among patients with prior exposure to spesolimab, suggesting maintained responsiveness. Safety findings were also consistent with prior reports, with no unexpected adverse events observed in the context of flare treatment.

Conclusion

These study presentations are part of LEO Pharma’s data program at AAD, which includes 17 accepted abstracts, its largest body of research at AAD to date.

“Generalized pustular psoriasis is a serious and unpredictable disease that often requires both rapid intervention and sustained management. Longer‑term data are critical to understanding how therapies perform across the full course of disease, Arash Mostaghimi, MD, MPH, FAAD, assistant professor of dermatology at Brigham & Women’s Hospital in Boston, Massachusetts, told Dermatology Times. “Together these findings highlight the complementary roles of IV and SC SPEVIGO in the long-term management of GPP, supporting a treatment approach that helps address the full course of this chronic and unpredictable disease.”

References

1. LEO Pharma Announces New Long-Term Data for SPEVIGO® (spesolimab-sbzo) Injection in Adults with Generalized Pustular Psoriasis at AAD 2026. News release. Business Wire. Published March 27, 2026. Accessed March 27, 2026. https://www.businesswire.com/news/home/20260327527368/en/LEO-Pharma-Announces-New-Long-Term-Data-for-SPEVIGO-spesolimab-sbzo-Injection-in-Adults-with-Generalized-Pustular-Psoriasis-at-AAD-2026

2. Gudjonsson J, Navarini A, Langley R, et al. Long-term (≥3 year) efficacy and safety of subcutaneous spesolimab for treatment of Generalized Pustular Psoriasis: Results from the EFFISAYIL® program. Poster presented at the 2026 American Academy of Dermatology Annual Meeting. Denver, Colorado. March 27-31, 2026.

3. Gordan K, Navarini A, Eng Choon S, 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 Poster presented at the 2026 American Academy of Dermatology Annual Meeting. Denver, Colorado. March 27-31, 2026.