LEO Pharma Announces New Long-Term Data for SPEVIGO® (spesolimab-sbzo) Injection in Adults with Generalized Pustular Psoriasis at AAD 2026

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11:20 AM on Friday, March 27

The Associated Press

MADISON, N.J.--(BUSINESS WIRE)--Mar 27, 2026--

LEO Pharma A/S, a global leader in medical dermatology, today announced new long-term results from EFFISAYIL ® ON, an ongoing five-year open-label extension study of the pivotal EFFISAYIL 1 trial and the EFFISAYIL 2 trial, evaluating the efficacy, safety and tolerability of SPEVIGO ® (spesolimab-sbzo) injection in patients with generalized pustular psoriasis (GPP). The findings are being shared at the 2026 American Academy of Dermatology (AAD) Annual Meeting. 1,2

GPP is a systemic, neutrophilic inflammatory skin disease with a heterogeneous clinical course characterized by chronic symptoms and recurrent, unpredictable periods of acute flares. 3,4

Long-Term Data on Flares in GPP Patients
Preliminary results from the EFFISAYIL ON study demonstrated that long-term subcutaneous (SC) SPEVIGO treatment is effective in reducing the cumulative number of flares in patients with GPP. Long-term SPEVIGO SC treatment led to a reduction in the number of flares, from 2.0 flares per year reported before entering the EFFISAYIL program to a cumulative mean of 0.13 flares per year. Of the 118 patients who received three or more years of SPEVIGO SC treatment, 74.6% (n=88) experienced no flares during this period. 1

“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.”

Intravenous SPEVIGO Flare Control in GPP Patients
For patients who experienced flares during the EFFISAYIL ON study, preliminary results showed that intravenous (IV) SPEVIGO is an effective and well tolerated treatment. Of the 131 patients enrolled in EFFISAYIL ON, 21 (16.0%) received SPEVIGO IV to treat a total of 36 flare events. A GPP Physician Global Assessment (GPPGA) pustulation subscore of 0 (clear) was observed in 50.0% (n=18) of flare treatments at Week 1 and 58.3% (n=21) at Week 2. A GPPGA total score of 0/1 (clear/almost clear) was observed in 41.7% (n=15) of flare treatments at Week 1 and 55.6% (n=20) at Week 2. 2

Preliminary safety data remained consistent with the known safety profile of SPEVIGO. The percentage of patients reporting adverse events (AE) leading to treatment discontinuation in the SC arm was 4.2%. In the IV arm, serious AEs were 36.6% and AEs leading to treatment discontinuation was 4.6%. 1,2

“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,” said Arash Mostaghimi, MD, MPH, FAAD, assistant professor of dermatology, Brigham & Women’s Hospital.

The SPEVIGO study presentations are part of LEO Pharma’s extensive data program at AAD, which includes 17 accepted abstracts across the company’s medical dermatology portfolio and pipeline.

About EFFISAYIL ON Study
The primary objective of this ongoing open-label, multicenter, 5-year long-term extension of the EFFISAYIL 1 and EFFISAYIL 2 trials is to assess the long-term safety and efficacy of SPEVIGO ® (spesolimab-sbzo) treatment in patients with GPP. Subjects received SC SPEVIGO (300 mg every 4, 6, or 12 weeks; dose escalation and de-escalation for flare recurrence/resolution allowed per protocol) for up to 252 weeks. In case of a protocol-defined GPP flare, patients received IV SPEVIGO 900 mg (≤2 doses within 1 week). The primary outcome measure of the study was the occurrence of treatment-emergent adverse events (TEAEs) up to Week 252 of maintenance treatment. The secondary outcome measures the reoccurrence of a GPP flare (defined by the GPPGA), the time to first achievement of a GPPGA score of 0 or 1 in patients who received flare rescue treatment, a GPPGA pustulation sub-score of 0 indicating no visible pustules (by visit), and the change from baseline in Psoriasis Symptom Scale (PSS) score (by visit). 1,2,5

About Generalized Pustular Psoriasis
Generalized pustular psoriasis (GPP) is a chronic, heterogeneous, neutrophilic inflammatory disease associated with skin and systemic symptoms that is distinct from plaque psoriasis. GPP is recognized as a separate clinical entity from other forms of psoriasis, with the IL-36 pathway being a key driver of GPP and triggering response to treatment. 3,4 GPP can become life-threatening (mortality rates ranging from 2% to 16%) due to severe complications, such as multisystem organ failure and sepsis requiring urgent hospital care; many GPP patients also suffer from various comorbidities, which contribute to the ongoing burden for the patient and healthcare systems. 6,7 GPP symptoms appear unpredictably and present on a continuum, which greatly impacts a patient’s quality of life, and may cause fear and anxiety over the disease course, as well as long-term impacts on quality of life related to work/school, emotional health, social activities and finances. 7,8

About SPEVIGO ® (spesolimab-sbzo)
SPEVIGO ® (spesolimab-sbzo) is a humanized, selective antibody that specifically blocks the activation of the IL-36R, a signaling pathway within the immune system shown to be involved in the pathogenesis of several autoinflammatory diseases, including GPP. 9 It is the first targeted therapy for the treatment of GPP and has been evaluated in the largest clinical program specifically for the treatment of patients with GPP. 10-12

INDICATION AND IMPORTANT SAFETY INFORMATION FOR SPEVIGO ® (SPESOLIMAB)

INDICATION

SPEVIGO is indicated for the treatment of generalized pustular psoriasis (GPP) in adults and pediatric patients 12 years of age or older and weighing at least 40 kg.

CONTRAINDICATIONS

SPEVIGO is contraindicated in patients with severe or life-threatening hypersensitivity to spesolimab-sbzo or to any of the excipients in SPEVIGO. Reported hypersensitivity reactions have included drug reaction with eosinophilia and systemic symptoms (DRESS).

WARNINGS AND PRECAUTIONS

Infections: SPEVIGO may increase the risk of infections. In patients with a chronic infection or a history of recurrent infection, consider the potential risks and expected clinical benefits of treatment prior to prescribing SPEVIGO. Treatment with SPEVIGO is not recommended in patients with any clinically important active infection until the infection resolves or is adequately treated. Instruct patients to seek medical advice if signs or symptoms of clinically important infection occur during or after treatment with SPEVIGO. If a patient develops a clinically important active infection, discontinue SPEVIGO therapy until the infection resolves or is adequately treated.

Risk of Tuberculosis: Evaluate patients for tuberculosis (TB) infection prior to initiating treatment with SPEVIGO. Avoid use of SPEVIGO in patients with active TB infection. Consider initiating anti-TB therapy prior to initiating SPEVIGO in patients with latent TB or a history of TB in whom an adequate course of treatment cannot be confirmed. Monitor patients for signs and symptoms of active TB during and after SPEVIGO treatment.

Hypersensitivity and Infusion-Related Reactions:

SPEVIGO-associated hypersensitivity reactions may include immediate reactions, such as anaphylaxis, and delayed reactions, such as drug reaction with eosinophilia and systemic symptoms (DRESS).
Drug reaction with eosinophilia and systemic symptoms (DRESS) has been reported in clinical trials with spesolimab-sbzo in subjects with GPP.
If a patient develops signs of anaphylaxis or other serious hypersensitivity, discontinue SPEVIGO immediately and initiate appropriate treatment.
If a patient develops mild or moderate hypersensitivity during an intravenous infusion or other infusion-related reactions, stop SPEVIGO infusion and consider appropriate medical therapy (e.g., systemic antihistamines and/or corticosteroids). Upon resolution of the reaction, the infusion may be restarted at a slower infusion rate with gradual increase to complete the infusion.

Vaccinations: Prior to initiating SPEVIGO for treatment of GPP, complete all age-appropriate vaccinations according to current immunization guidelines. Avoid use of live vaccines in patients during and for at least 16 weeks after treatment with SPEVIGO. No specific studies have been conducted in SPEVIGO-treated patients who have recently received live viral or live bacterial vaccines.

ADVERSE REACTIONS

Intravenous SPEVIGO for Treatment of GPP Flare (Study Effisayil-1): Most common adverse reactions reported in ≥5% of patients treated with SPEVIGO in the clinical trial were asthenia and fatigue, nausea and vomiting, headache, pruritus and prurigo, infusion site hematoma and bruising, and urinary tract infection (UTI).

Specific Adverse Reactions

Infections: The most frequent adverse reactions that occurred in subjects treated with intravenous SPEVIGO were infections. During the 1-week placebo-controlled period in Study Effisayil-1, infections were reported in 14% of subjects treated with SPEVIGO compared with 6% of subjects treated with placebo. Serious infection (UTI) was reported in 1 subject (3%) in the SPEVIGO group and no subjects in the placebo group. Infections observed through Week 1 in Study Effisayil-1 in subjects treated with SPEVIGO were mild (29%) to moderate (71%).
Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS): Two cases of DRESS were reported in Study Effisayil-1 in subjects with GPP who were treated with intravenous SPEVIGO. RegiSCAR DRESS validation scoring (with the following categories: “no,” “possible,” “probable,” or “definite” DRESS) was applied to the reported cases. Reported cases were assessed as “no DRESS” and “possible DRESS.”

Subcutaneous SPEVIGO for Treatment of GPP When Not Experiencing a Flare (Study Effisayil-2): Regarding the exposure-adjusted incidence rates for subjects on randomized treatment prior to receiving rescue treatment for flare or completing trial without a flare, the rate per 100-patient years for injection site reaction (including erythema, pain, swelling, induration, urticaria, and warmth at the injection site) was 31.6 for the subcutaneous SPEVIGO cohort (600 mg loading dose followed by 300 mg every 4 weeks) vs 12.7 for the placebo cohort. The rate per 100-patient years for UTI was 18 for SPEVIGO vs 0 for placebo. The rate per 100-patient years for pruritus was 8.8 for SPEVIGO vs 0 for placebo. The rate per 100-patient years for arthralgia was 13.3 for SPEVIGO vs 6 for the placebo cohort. There were 3 subjects who discontinued subcutaneous SPEVIGO due to treatment-emergent adverse events of psoriasis compared to no subjects in the placebo cohort who discontinued placebo for any treatment-emergent adverse event.

Safety in Study Effisayil-2 After Flare: In Effisayil-2, subjects who experienced a GPP flare and received at least one dose of an open-label single intravenous 900 mg dose of SPEVIGO were treated with open-label subcutaneous SPEVIGO 300 mg. These subjects (n=19) received subcutaneous dosing at every 12 weeks, which could have been increased to every 4 weeks based on GPPPGA total score or pustulation subscore increased by ≥1 from any previous open-label maintenance visit. The reported safety profile of open-label subcutaneous SPEVIGO use after treatment of GPP flare with open-label intravenous SPEVIGO use was consistent with the safety profiles of use of SPEVIGO from Trial Effisayil-1 and randomized controlled data from Trial Effisayil-2.

Clinical Development of Spesolimab-sbzo

Guillain-Barre Syndrome (GBS): Among approximately 835 subjects exposed to spesolimab-sbzo during clinical development, GBS was reported in 3 subjects who received various doses of spesolimab-sbzo via various methods of administration in clinical trials for unapproved indications.

SPECIFIC POPULATIONS

Pediatric Use: The safety and effectiveness of SPEVIGO for the treatment of GPP have been established in pediatric patients 12 years of age and older and weighing at least 40 kg. Use of SPEVIGO for this indication is supported by data from a randomized, placebo-controlled study, which included 6 pediatric subjects 14 to 17 years of age with a history of GPP treated with subcutaneous SPEVIGO (Study Effisayil-2), and evidence from an adequate and well-controlled study of intravenous SPEVIGO in adults with GPP (Study Effisayil-1), with additional pharmacokinetic analyses showing similar drug exposure levels in adults and pediatric subjects 12 years of age and older and weighing 40 kg or more. The safety and effectiveness of SPEVIGO in pediatric patients younger than 12 years of age or in pediatric patients weighing less than 40 kg have not been established.

Please see SPEVIGOPrescribing Information, includingMedication Guide.

About LEO Pharma
LEO Pharma is a global leader in medical dermatology. We deliver innovative solutions for skin health, building on a century of experience with breakthrough medicines in healthcare. We are committed to making a fundamental difference in people’s lives, and our broad portfolio of treatments serves close to 100 million patients in over 70 countries annually. LEO Pharma is co-owned by majority shareholder the LEO Foundation and, since 2021, Nordic Capital. Headquartered in Denmark, LEO Pharma has a team of 4,000 people worldwide. Together, we reach far beyond the skin. For more information, visit www.leo-pharma.com.

References

Gudjonsson J, Navarini A, Langley R, et al. Long‑term (≥3‑year) efficacy of subcutaneous spesolimab treatment for prevention of flares in patients with generalized pustular psoriasis: results from the EFFISAYIL program. Presented at the 2026 AAD Conference, March 27–31, Denver, CO. Poster Presentation.
Gordon K, Navarini A, 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 the 2026 AAD Conference, March 27–31, Denver, CO. Poster Presentation.
Marrakchi S, Puig L. Pathophysiology of generalized pustular psoriasis. Am J Clin Dermatol. 2022;23:13–19.
Prinz JC, Choon SE, Griffiths CEM, et al. Prevalence, comorbidities and mortality of generalized pustular psoriasis: A literature review. J Eur Acad Dermatol Venereol. 2023;37:256–273.
ClinicalTrials.gov. National Library of Medicine (U.S.). Effisayil™ ON: A Study to Test Long-term Treatment With Spesolimab in People With Generalized Pustular Psoriasis Who Took Part in a Previous Study. Identifier: NCT03886246. Accessed March 2026.
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SPEVIGO ® (spesolimab-sbzo). Prescribing Information. FDA. October 2025.
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Choon SE, Lebwohl MG, Marrakchi S, et al. Study protocol of the global Effisayil 1 Phase II, multicentre, randomised, double-blind, placebo-controlled trial of spesolimab in patients with generalized pustular psoriasis presenting with an acute flare. BMJ Open. 2021;11:e043666.
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