Introduction: Generalized pustular psoriasis (GPP) is a rare autoinflammatory skin disease characterized by flares of widespread erythema with sterile pustules, and can be relapsing with recurrent flares, or persistent with intermittent flares. Spesolimab, a humanized anti-interleukin-36 (IL-36) receptor monoclonal antibody, targets the key IL-36 pathogenetic pathway in GPP. A previous study showed that spesolimab treatment led to rapid pustular and skin clearance in patients with GPP flares, which was sustained for up to 12 weeks. This study investigates the long-term effects of spesolimab on GPP flares, for which no specific treatments are currently available. The Effisayil^TM 2 study will assess whether maintenance treatment with subcutaneous spesolimab prevents the occurrence of GPP flares and determine the optimal dosing regimen to achieve this aim.

Methods: Patients will have a documented history of GPP with a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) score of 0 or 1 (clear or almost clear) at screening and randomization. Patients will be randomized 1:1:1:1 to three groups receiving a 600-mg subcutaneous loading dose of spesolimab followed by a 300-mg maintenance dose administered every 4 or 12 weeks, or a 300-mg loading dose followed by a 150-mg maintenance dose administered every 12 weeks, and one group receiving placebo, for 48 weeks. The primary endpoint is time to first GPP flare. If a patient experiences a GPP flare during the randomized maintenance treatment period, an open-label intravenous dose of 900-mg spesolimab will be administered, with an option for a second intravenous dose after 1 week.

Conclusions: Effisayil^TM 2 is the first placebo-controlled study in patients with GPP to investigate whether maintenance treatment with spesolimab can prevent flares and provide sustained disease control. This study will provide valuable insights on the long-term management of patients with this potentially life-threatening skin disease.

Abstract: Generalized pustular psoriasis (GPP) is a rare auto-inflammatory skin disease characterised by acute episodes of sterile pustule formation. Diagnosis and treatment of the disease have historically been complicated by a lack of awareness, and no consistent global definition or clinical coding standards. Now acknowledged as a distinct clinical entity with a recognised genetic component, GPP can take a serious and life-threatening course due to systemic inflammatory complications and its association with various comorbidities. As with other rare diseases, there are significant challenges to understanding the epidemiology of GPP, notably a small patient population, non-standardised study methodologies and ethnic differences in its presentation. A clearer understanding of GPP is therefore required for clinicians to better manage patients with this rare condition. In this review article, we present an overview of the available data on GPP prevalence estimates in key demographics and report the frequency of genetic mutations associated with the disease. We detail the incidence of known comorbidities and summarise the data on mortality and assigned causes of death. Lastly, we discuss the various factors that impact collection, interpretation and comparison of these data.

Abstract: Generalized pustular psoriasis is a potentially life-threatening neutrophilic skin disease characterized by recurrent flares of widespread erythema and eruption of sterile pustules. In the Effisayil^TM 1 study (NCT03782792), 53 patients with a generalized pustular psoriasis flare were treated with placebo or spesolimab, a humanized anti-interleukin-36 receptor monoclonal antibody, the first targeted treatment to be studied in a randomized clinical trial. Spesolimab treatment resulted in rapid pustular and skin clearance, with an acceptable safety profile. Here, we evaluate the efficacy and safety of spesolimab in 29 Asian patients in the Effisayil^TM 1 study. The primary endpoint, a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) pustulation subscore of 0 (no visible pustules) at Week 1, was achieved by 10 patients (62.5%) randomized to spesolimab and one patient (7.7%) randomized to placebo (risk difference 54.8, 95% confidence interval [CI] 17.3-79.8). The key secondary endpoint, a GPPGA total score of 0 or 1 (clear or almost clear skin) at Week 1, was achieved by eight (50.0%) and two (15.4%) patients, respectively (risk difference 34.6, 95% CI -3.1-64.7). This was similar to previously published data in the overall population in whom the primary and key secondary endpoints were achieved by 54% versus 6% and 43% versus 11% of patients, respectively. The percentages of Asian patients randomized to spesolimab with a GPPGA pustulation subscore of 0 and GPPGA total score of 0 or 1 were sustained above 60% for up to 12 weeks. In these patients, patient-reported outcomes also improved and markers of systemic inflammation were normalized. Eleven (68.8%) and eight (61.5%) of spesolimab- and placebo-treated patients, respectively, experienced at least one adverse event. In conclusion, spesolimab improved outcomes in Asian patients compared with placebo, supporting its use in the treatment of generalized pustular psoriasis flares.

Abstract: Generalized pustular psoriasis is a potentially life-threatening neutrophilic skin disease characterized by recurrent flares of widespread erythema and eruption of sterile pustules. In the Effisayil^TM 1 study (NCT03782792), 53 patients with a generalized pustular psoriasis flare were treated with placebo or spesolimab, a humanized anti-interleukin-36 receptor monoclonal antibody, the first targeted treatment to be studied in a randomized clinical trial. Spesolimab treatment resulted in rapid pustular and skin clearance, with an acceptable safety profile. Here, we evaluate the efficacy and safety of spesolimab in 29 Asian patients in the Effisayil^TM 1 study. The primary endpoint, a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) pustulation subscore of 0 (no visible pustules) at Week 1, was achieved by 10 patients (62.5%) randomized to spesolimab and one patient (7.7%) randomized to placebo (risk difference 54.8, 95% confidence interval [CI] 17.3-79.8). The key secondary endpoint, a GPPGA total score of 0 or 1 (clear or almost clear skin) at Week 1, was achieved by eight (50.0%) and two (15.4%) patients, respectively (risk difference 34.6, 95% CI -3.1-64.7). This was similar to previously published data in the overall population in whom the primary and key secondary endpoints were achieved by 54% versus 6% and 43% versus 11% of patients, respectively. The percentages of Asian patients randomized to spesolimab with a GPPGA pustulation subscore of 0 and GPPGA total score of 0 or 1 were sustained above 60% for up to 12 weeks. In these patients, patient-reported outcomes also improved and markers of systemic inflammation were normalized. Eleven (68.8%) and eight (61.5%) of spesolimab- and placebo-treated patients, respectively, experienced at least one adverse event. In conclusion, spesolimab improved outcomes in Asian patients compared with placebo, supporting its use in the treatment of generalized pustular psoriasis flares.

Abstract: Generalized pustular psoriasis (GPP) is a rare severe variant of psoriasis that is characterized by the abrupt widespread onset of small pustules accompanied by systemic manifestations of inflammation. It can arise in patients with a history of psoriasis as well as in those without, sometimes due to medication initiation or withdrawal, pregnancy, or infection. Generalized pustular psoriasis is thought to be driven primarily by innate immunity and unrestrained IL-36 cytokine activity. Recent genetic analyses have identified 3 genetic mutations that are associated with GPP-IL36RN, CARD14, and AP1S3-though these mutations only account for a minority of cases. There are many cutaneous pustular diseases that must be ruled out in the evaluation of a patient with suspected GPP, especially acute generalized exanthematous pustulosis (AGEP), and histologic analysis is the cornerstone of diagnosis. Although the quality of evidence to generate treatment recommendations for GPP is limited, management often includes utilization of systemic agents and/or biologics, usually with adjunctive topical treatment. Accumulating evidence suggests that biologic agents, especially infliximab, may be considered as first-line treatment of GPP, especially in severe acute cases, due to their abrupt onset of action and favorable side-effect profiles compared with oral systemic agents.

Introduction: Little has been published on the epidemiology of generalized pustular psoriasis (GPP). The aim of this study was to describe and analyze the geographic distribution of hospital admissions for GPP in Spain.

Methods: We performed a cross-sectional study using the hospital discharge database of the Spanish Basic Minimum Data Set (CMBD), which is a mandatory data set of all admissions to public hospitals in the country. We included patients with a primary diagnosis of psoriasis or GPP at discharge for the period 2016 to 2020. We performed a descriptive analysis of clinical and sociodemographic characteristics of patients admitted with GPP, a spatial analysis at the province level assessing the presence of geographic heterogeneity and a GPP disease map.

Results: We detected 949 diagnoses of psoriasis and 744 primary diagnoses of GPP. Mean age of patients admitted with GPP was 62.2 years. Intensive care unit admissions were ordered for 6.1% of patients and 4.8% died. The overall incidence rate of GPP among newly hospitalized patients during the study period was 3.18 cases per 1,000,000 person-years. The geographic distribution varied widely, with higher rates observed in the north-west of the country.

Conclusions: We describe the characteristics of GPP hospitalized patients in Spain and provide the first disease map for the country. The findings could help guide future research and suggest the possibility of genetic or environmental factors driving geographic differences.

Introduction: Generalized pustular psoriasis (GPP) is a rare, severe, clinically heterogeneous disease characterized by flares of widespread, noninfectious, macroscopically visible pustules that occur with or without systemic inflammation, and are associated with significant morbidity and mortality. Historically, GPP has been classified as a variant of psoriasis vulgaris (PV, or plaque psoriasis); however, accumulating evidence indicates that these are distinct conditions, requiring different treatment approaches.

Areas covered: In this perspective article we review evidence that supports the classification of GPP as distinct from PV.

Expert opinion: The histopathologic and clinical appearance of GPP is distinct from that of PV and fundamental differences exist between the two conditions in terms of genetic causes and expression-related mechanisms of disease development. GPP results from dysregulation of the innate immune system, with disruption of the interleukin (IL)-36 inflammatory pathway, induction of inflammatory keratinocyte responses, and recruitment of neutrophils. PV is driven by the adaptive immune system, with a key role played by IL-17. Considering GPP as a separate disease will enable greater focus on its specific pathogenesis and the needs of patients. Many treatments for PV have insufficient efficacy in GPP and a therapeutic approach developed specifically for GPP might lead to better patient outcomes.

Abstract: Generalized pustular psoriasis (GPP) is a rare, severe neutrophilic skin disease characterized by sudden widespread eruption of sterile pustules with or without systemic symptoms. GPP may be life threatening in cases with severe complications such as cardiovascular failure, acute respiratory distress syndrome, and serious infections. Impetigo herpetiformis (IH) is a GPP that is induced and exacerbated by pregnancy and occurs most frequently during the last trimester. IH may result in poor or fatal neonatal outcomes, including placental insufficiency, fetal abnormalities, stillbirth, and early neonatal death. Most patients have prompt remission in the postpartum period; however, earlier appearance and more severe symptoms are observed during subsequent pregnancies. Appropriate treatment and close monitoring of the mother and fetus are vital for the management of patients with IH. Particular attention is required for the management of patients with IH to avoid an influence on the fetus. However, data regarding treatments for GPP in pregnant women are sparse. Over the last decade, many patients with IH have been treated with cyclosporine, corticosteroids, tumor necrosis factor-α inhibitors, interleukin (IL)-17 and IL-12/23 inhibitors, and granulocyte and monocyte adsorption apheresis (GMA). GMA may be an important option for patients with IH as it is presently one of the safest available therapeutic options, but there have been no reports to fully confirm its safety in pregnant patients with GPP. Alternatively, based on recent advances in the understanding of the role of the IL-36 axis in the pathogenesis of GPP, biologic agents that target the IL-36 pathway may demonstrate promising efficacy in IH.

Background: Generalized pustular psoriasis (GPP) is a rare, severe, and sometimes fatal form of childhood psoriasis. The first line therapies include acitretin, cyclosporin A, and methotrexate which take effect slowly and have varying long-term side effects for children. Recently, the anti-tumor necrosis factor-alpha (TNF-α), adalimumab has shown efficacy in adult patients with pustular psoriasis; however, there is lack of evidence of its usage in the pediatric population.

Methods: Data on efficacy of adalimumab in treating pediatric GPP along with a literature review are presented.

Results: A total of seven patients had marked clearance and reduction in PGA and systemic/laboratory score within the first week of first injection and achieved almost complete clearance of skin lesions by 1-month follow up. In literature, adalimumab treating pustular psoriasis in pediatric has been described in six children who failed in prior treatment. All six patients showed a satisfactory therapeutic effect.

Conclusions: Subcutaneous injection of adalimumab every other week in the treatment of children with GPP has significant clinical efficacy with rapid clearance of skin lesions, providing a novel alternative for children with pustular psoriasis who responded poorly to traditional treatment or are not suitable for traditional treatment.

Abstract: Elderly-onset (> 60 years of age) atopic dermatitis and psoriasis have been reported to present special clinical phenotypes; however, the study of elderly-onset generalized pustular psoriasis (GPP) has been limited, mainly due to its rarity. Previous studies have shown that the mean age of GPP onset is around 40 years, and onset at > 60 years of age is extremely rare. We report a case series of seven patients with elderly-onset GPP. The clinical features of the seven patients were assessed, and all seven patient were analysed for presence of the c.115+6T>C mutation in the gene encoding for interleukin-36 receptor antagonist (IL36RN). These patients had an atypical clinical course and a lower frequency of the IL36RN c.115+6T>C mutation. IL36RN mutations may have a significant, dose-dependent effect on the onset age of GPP.

Background: Generalized pustular psoriasis (GPP) is a rare and severe inflammatory disease characterized by widespread and superficial sterile pustules on an erythematous background.

Objectives: This multicentre study aimed to determine the clinical profile and course in a large cohort of patients with GPP.

Methods: One hundred and fifty-six GPP patients (mean age, 44.2 ± 18.7 years) who met the diagnostic criteria of the European Consensus Report of GPP were included in the study. Sociodemographic characteristics, quality of life, triggering factors of the disease, clinical, laboratory, treatment and prognostic features were evaluated.

Results: 61.5% of the patients were female. The rate of working at or below the minimum wage (≤$332.5/month) was 44.9%. Drugs (36.5%) were the most common trigger. While hypocalcaemia (35.7%) was the most important cause of GPP during pregnancy, systemic steroid withdrawal (20%) was the most frequently reported trigger for infantile/juvenile and mixed-type GPP (15%) (P < 0.05). Acute GPP (53.8%) was the most common clinic. Nails were affected in 43.6% of patients, and subungual yellow spots (28.2%) were the most common change. In annular GPP, fever (P < 0.001) and relapse frequency (P = 0.006) were lower than other subtypes, and the number of hospitalizations (P = 0.002) was lower than acute GPP. GPP appeared at a later age in those with a history of psoriasis (P = 0.045). DLQI score (P = 0.049) and joint involvement (P = 0.016) were also higher in this group. Infantile/juvenile GPP was observed in 16.02% of all patients, and arthritis was lower in this group (24.4 vs. 16%). GPP of pregnancy had the worst prognosis due to abortion observed in three patients.

Conclusions: Recent advances in treatment have improved mortality associated with GPP, but abortion remains a significant complication. Although TNF-α inhibitors have proven efficacy in GPP, they can also trigger the disease. Mixed-type GPP is more similar to acute GPP than annular GPP with systemic manifestations and course.