Generalized pustular psoriasis is a disease distinct from psoriasis vulgaris: evidence and expert opinion

The role of interleukin-36 in health and disease states

The interleukin (IL)-1 superfamily upregulates immune responses and maintains homeostasis between the innate and adaptive immune systems. Within the IL-1 superfamily, IL-36 plays a pivotal role in both innate and adaptive immune responses. Of the four IL-36 isoforms, three have agonist activity (IL-36α, IL-36β, IL-36γ) and the fourth has antagonist activity (IL-36 receptor antagonist [IL-36Ra]). All IL-36 isoforms bind to the IL-36 receptor (IL-36R). Binding of IL-36α/β/γ to the IL-36R recruits the IL-1 receptor accessory protein (IL-1RAcP) and activates downstream signalling pathways mediated by nuclear transcription factor kappa B and mitogen-activated protein kinase signalling pathways. Antagonist binding of IL-36Ra to IL-36R inhibits recruitment of IL-1RAcP, blocking downstream signalling pathways. Changes in the balance within the IL-36 cytokine family can lead to uncontrolled inflammatory responses throughout the body. As such, IL-36 has been implicated in numerous inflammatory diseases, notably a type of pustular psoriasis called generalized pustular psoriasis (GPP), a chronic, rare, potentially life-threatening, multisystemic skin disease characterised by recurrent fever and extensive sterile pustules. In GPP, IL-36 is central to disease pathogenesis, and the prevention of IL-36-mediated signalling can improve clinical outcomes. In this review, we summarize the literature describing the biological functions of the IL-36 pathway. We also consider the evidence for uncontrolled activation of the IL-36 pathway in a wide range of skin (e.g., plaque psoriasis, pustular psoriasis, hidradenitis suppurativa, acne, Netherton syndrome, atopic dermatitis and pyoderma gangrenosum), lung (e.g., idiopathic pulmonary fibrosis), gut (e.g., intestinal fibrosis, inflammatory bowel disease and Hirschsprung's disease), kidney (e.g., renal tubulointerstitial lesions) and infectious diseases caused by a variety of pathogens (e.g., COVID-19; Mycobacterium tuberculosis, Pseudomonas aeruginosa, Streptococcus pneumoniae infections), as well as in cancer. We also consider how targeting the IL-36 signalling pathway could be used in treating inflammatory disease states.

Prevalence, incidence, mortality and healthcare resource use for generalized pustular psoriasis, palmoplantar pustulosis and plaque psoriasis in England: a population-based cohort study

BACKGROUND

Generalized pustular psoriasis (GPP) and palmoplantar pustulosis (PPP) are chronic inflammatory skin conditions. Accumulating evidence shows that GPP and PPP have different characteristics to plaque psoriasis and are distinct clinical entities.

OBJECTIVES

To assess the epidemiology, comorbidities, mortality and healthcare use for patients in England with GPP and PPP versus those with plaque psoriasis.

METHODS

We carried out a cohort study involving analyses of longitudinal electronic health record data in the Clinical Practice Research Datalink Aurum database and linked hospital and mortality data between 2008 and 2019. The primary study outcome was the incidence and prevalence rates of GPP, PPP and plaque psoriasis in England. Secondary outcomes included survival rates and healthcare resource use (HCRU) by disease type.

RESULTS

We identified 373 patients with GPP, 1828 with PPP and 224 223 with plaque psoriasis. Mean (SD) age was 55.9 (18.6) years for patients with GPP, 51.5 (16.4) years for those with PPP and 48.5 (19.1) years for those with plaque psoriasis; 62.5% and 65.9% of patients with GPP and PPP, respectively, were women, vs. 49.4% of those with plaque psoriasis. About half of patients were overweight or obese at baseline (GPP 48.6%, PPP 56.0%, plaque psoriasis 45.9%). The incidence rates for GPP, PPP and plaque psoriasis were 0.25 [95% confidence interval (CI) 0.21-0.28], 2.01 (95% CI 1.92-2.11) and 103.2 (95% CI 102.5-103.9) per 100 000 person-years, respectively. From 2008 to 2019, the prevalence rates per 100 000 persons ranged from 1.61 to 3.0 for GPP, from 1.1 to 18.7 for PPP and from 1771.0 to 1903.8 for plaque psoriasis. Survival rates were lower for patients with GPP, particularly those who were > 55 years of age and those with a history of one or more comorbidities in each cohort. HCRU was lower in the cohort with plaque psoriasis and highest in the cohort with GPP, particularly among those who had more than one GPP flare.

CONCLUSIONS

Our results provide further evidence that, in England, GPP is a distinct disease with different epidemiology, lower survival and higher HCRU than plaque psoriasis.

Indian expert Delphi consensus on the diagnosis and management of flares of generalised pustular psoriasis

Generalised pustular psoriasis (GPP) is a chronic, multisystemic, autoinflammatory disease with predominantly cutaneous manifestations, characterised by recurrent episodes of widespread, macroscopic and aseptic pustules. It has a highly unpredictable, heterogeneous and unstable clinical course. There are no consensus guidelines in India for the management of GPP. The objective of this Delphi panel study was to achieve consensus on problem areas in the understanding and management of GPP. Based on the inputs from an expert panel, 19 topics across six domains were identified as being important regarding the understanding and management of GPP. Statements were developed for these 19 topics, and consensus for the statements was sought using the modified Delphi method. Twelve experts evaluated the statements, indicating their agreement or disagreement. Consensus was considered to be reached when ≥80% of experts agreed with a statement. After two rounds of discussion, consensus was reached for 17 out of 19 (89%) statements and no consensus was achieved for two (11%) statements. We have presented the statements along with the respective degrees of consensus. Wherever relevant, clarifications or additional comments by experts are provided in the document.

Considerations for defining and diagnosing generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare, chronic skin disease, characterized by widespread pustules and erythema, often accompanied with systemic signs and symptoms. GPP flares occur episodically but may be protracted. Left untreated, GPP can be life-threatening. Despite being first reported over 100 years ago, definitions and diagnostic criteria for GPP have been inconsistent and varied due, in part, to its rarity and a limited understanding of its pathogenesis. As such, many patients with GPP face delays in diagnosis and subsequent treatment. This manuscript aims to increase the recognition of GPP and provide foundational considerations to aid in the definition and diagnosis of this disease.

[Translated article] Improvements in the Management of Patients With Generalized Pustular Psoriasis in Spain: Recommendations From a Group of Experts

This consensus document analyzed the management and emotional journey of patients with GPP (generalized pustular psoriasis), and the desirable course of the disease while detecting critical points and translating them into needs and recommendations. This project was conducted in 3 phases with participation from an advisory committee (n=8), an expert panel (n=15) and patients with GPP (n=6). The patients' disease progression was heterogeneous due to disease variations, different health care models implemented and available resources, and the lack of diagnostic and treatment guidelines. A total of 45 different recommendations have been made to optimize management and address the emotional component of these patients. Five of them stand out for their impact and viability. Therefore, a roadmap of priorities has been made generally available to improve the management of patients with GPP.

Current Treatments for Generalized Pustular Psoriasis: A Narrative Summary of a Systematic Literature Search

Generalized pustular psoriasis (GPP) is a rare, chronic and potentially life-threatening autoinflammatory skin disease characterized by widespread eruption of sterile pustules, with or without systemic inflammation. GPP can significantly reduce patients' quality of life (QoL). Several therapeutic approaches have been described in the literature, but there is no consensus on optimal treatment. In this review, we summarize published literature on efficacy, safety and QoL outcomes associated with current treatment of GPP with both approved and non-approved products. Embase and MEDLINE databases were searched (1980-September 2023). A search protocol was designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered on the PROSPERO database (CRD42021215437). Details on publication, population, intervention, efficacy, safety and QoL were captured and checked by independent reviewers. In total, 118 publications were included, with only 19% of publications reporting on the results of clinical trials. Treatment modalities reported for GPP included non-biologic systemic therapies such as retinoids, cyclosporine and methotrexate, topical agents, biologics and small molecules, among others. Results were highly heterogeneous and methodological quality was very low, with only the interleukin-36R inhibitor spesolimab reporting results from placebo-controlled randomized trials; based on this, spesolimab is now approved for GPP treatment in regions including the USA, Japan, China, the EU and several other countries. Some other biologics are approved exclusively in Japan and Taiwan for the treatment of GPP based on open-label studies with small patient numbers in lieu of double-blind studies. Non-standardization of clinical outcomes across studies remains a major hurdle in reaching a consensus on optimal treatment. However, recently trials have been conducted using well-defined, disease-specific endpoints to evaluate GPP-targeted treatments, which will hopefully advance patient care. In conclusion, this review highlights the need for prospective randomized studies with GPP-specific endpoints to determine the optimal treatment strategy.

Improvements in the Management of Patients With Generalized Pustular Psoriasis in Spain: Recommendations From a Group of Experts

This consensus document analyzed the management and emotional journey of patients with GPP (generalized pustular psoriasis), and the desirable course of the disease while detecting critical points and translating them into needs and recommendations. This project was conducted in 3 phases with participation from an advisory committee (n=8), an expert panel (n=15) and patients with GPP (n=6). The patients' disease progression was heterogeneous due to disease variations, different health care models implemented and available resources, and the lack of diagnostic and treatment guidelines. A total of 45 different recommendations have been made to optimize management and address the emotional component of these patients. Five of them stand out for their impact and viability. Therefore, a roadmap of priorities has been made generally available to improve the management of patients with GPP.

Molecular aspects of Interleukin-36 cytokine activation and regulation

Interleukin-36 (IL-36) cytokines are structurally similar to other Interleukin-1 superfamily members and are essential to convey inflammatory responses at epithelial barriers including the skin, lung, and gut. Due to their potent effects on immune cells, IL-36 cytokine activation is regulated on multiple levels, from expression and activation to receptor binding. Different IL-36 isoforms convey specific responses as a consequence of particular danger- or pathogen-associated molecular patterns. IL-36 expression and activation are regulated by exogenous pathogens, including fungi, viruses and bacteria but also by endogenous factors such as antimicrobial peptides or cytokines. Processing of IL-36 into potent bioactive forms is necessary for host protection but can elevate tissue damage. Indeed, exacerbated IL-36 signalling and hyperactivation are linked to the pathogenesis of diseases such as plaque and pustular psoriasis, emphasising the importance of understanding the molecular aspects regulating IL-36 activation. Here, we summarise facets of the electrochemical properties, regulation of extracellular cleavage by various proteases and receptor signalling of the pro-inflammatory and anti-inflammatory IL-36 family members. Additionally, this intriguing cytokine subfamily displays many characteristics that are unique from prototypical members of the IL-1 family and these key distinctions are outlined here.

Denosumab-induced Acute Generalized Exanthematous Pustulosis

Abstract is missing (Short communication)

Clinical efficacy and safety of secukinumab in the treatment of generalized pustular psoriasis in the pediatric population: a systematic review of the literature

Background

Generalized pustular psoriasis (GPP) is a severe type of psoriasis. The current treatment primarily relies on corticosteroids and immunosuppressants. In recent years, biologics have been increasingly utilized in the treatment of this disease, and have demonstrated good clinical efficacy. However, children and adolescents are primarily treated with immunosuppressants, which have limited clinical application due to the serious side effects they may cause. At the same time, the effectiveness of current treatments is unsatisfactory. Secukinumab has been widely reported to be effective and safe in treating this disease. However, there are still insufficient data on its use in treating GPP in children.

Objective

To conduct a systematic review of the existing literature on the use of secukinumab for treating generalized pustular psoriasis in children and adolescents, and to evaluate its clinical effectiveness and safety.

Methods

We conducted a systematic review of all the literature reporting on the treatment of GPP in children and adolescents with secukinumab.

Results

A total of 7 papers (46 patients) were included in this study. After 12 weeks of treatment, all 46 participants were able to achieve a GPPASI score of 90 or higher, with approximately 96% of patients achieving complete clearing of the lesions (GPPASI 100 or JDA0). Adverse events were reported in 8 patients, the rate of adverse reactions was approximately 17%.

Conclusion

The treatment of GPP in children and adolescents with secukinumab has a rapid onset of action and a high safety profile. However, the results of the literature may be influenced by publication bias.

Spesolimab for generalized pustular psoriasis: a review of two key clinical trials supporting initial US regulatory approval

Generalized pustular psoriasis (GPP) is a chronic, rare, and potentially life-threatening inflammatory disease, characterized by the rapid and widespread eruption of small, sterile pustules with surrounding skin erythema. Abnormal signaling of the interleukin-36 (IL-36) pathway appears to have a central role in GPP immunopathology, and provides a rational therapeutic target. Spesolimab is a first-in-class humanized monoclonal antibody that binds specifically to the IL-36 receptor, and antagonizes IL-36 signaling. Spesolimab obtained regulatory approval in the United States (US) in September 2022 for use in the treatment of GPP flares in adults, and was subsequently approved for GPP flare treatment in many other countries across the world. Recently, regulatory approval was granted for subcutaneous dosing of spesolimab for treatment of GPP when not experiencing a flare. Here, we review data from two key clinical trials that supported the initial US regulatory approval; namely, the phase 1 proof-of-concept trial (ClinicalTrials.gov ID, NCT02978690), and Effisayil™ 1 (NCT03782792), which remains the largest and only randomized clinical trial in patients experiencing GPP flares published to date. In the phase 1 proof-of-concept trial, a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) score of 0 or 1 (clear or almost clear skin) was attained in 5/7 (71%) patients by week 1 and in all 7 patients by week 4; and the mean percent improvement in the Generalized Pustular Psoriasis Area and Severity Index (GPPASI) score from baseline was 59.0% at week 1, 73.2% at week 2, and 79.8% at week 4. In Effisayil™ 1, a GPPGA pustulation subscore of 0 (no visible pustules) was achieved in 19/35 (54%) patients receiving spesolimab at the end of week 1, versus 1/18 (6%) receiving placebo (difference, 49 percentage points; 95% confidence interval [CI], 21 to 67; P<0.001); and a GPPGA total score of 0 or 1 was achieved by 15/35 (43%) patients in the spesolimab group, versus 2/18 (11%) patients in the placebo group (difference, 32 percentage points; 95% CI, 2 to 53; P = 0.02). Infections at week 1 were reported in 6/35 (17%) patients receiving spesolimab and in 1/18 (6%) patients receiving placebo. These data demonstrate the efficacy and safety of spesolimab in providing rapid and sustained clinical improvement for patients with GPP flares, which translates into improved quality of life, by offering a targeted therapy for GPP.

New and Emerging Treatments for Generalized Pustular Psoriasis: Focus on IL-36 Receptor Inhibitors

Generalized Pustular Psoriasis (GPP) is a rare and severe subtype of psoriasis that significantly impacts patients' quality of life. Until recently, no specific treatment modalities were available, and treatment for GPP followed the guidelines for the treatment of plaque psoriasis, consisting of conventional treatments, such as retinoids, methotrexate, and even biologics, which although effective in some cases, may be associated with significant side effects, necessitating more effective and safe options. The pathophysiology of Generalized Pustular Psoriasis is complex and not fully understood, but there is some overlap with the pathogenesis of Plaque Psoriasis. In GPP, the innate immune system seems to play a more significant role, with the interleukin (IL)-36 pathway being fundamentally involved. Spesolimab and imsidolimab, two recently developed therapeutic agents, target the IL-36 inflammatory pathway by binding to the IL-36 receptor (IL-36R). Both biologics have already been evaluated in phase 1 and 2 clinical trials and have shown promising results in terms of safety and efficacy. IL-36 receptor inhibitors demonstrated great efficacy and good safety profile in the management of patients with GPP, demonstrating their potential to emerge as a leading treatment option. This review aims to explore and summarize the current scientific literature on the most recently developed treatments for GPP.

Spesolimab: A Review of the First IL-36 Blocker Approved for Generalized Pustular Psoriasis

OBJECTIVE

This article reviews clinical trial data that assesses the safety, efficacy, and clinical application of spesolimab, an interleukin-36 (IL-36) blocker, for the treatment of generalized pustular psoriasis (GPP).

DATA SOURCES

A review of the literature was conducted using the search terms: "spesolimab," "BI 655130," and "spevigo" in MEDLINE (PubMed) and Clinicaltrials.gov from January 1, 1950 to October 31, 2023.

STUDY SELECTION AND DATA EXTRACTION

Relevant articles in English relating to the pharmacodynamics, pharmacokinetics, efficacy, and safety of spesolimab were included.

DATA SYNTHESIS

In one phase 2 clinical trial evaluating single dose IV spesolimab for GPP flares at day 8, 54% of patients receiving spesolimab had a GPP physician global assessment (GPPGA) pustulation subscore of 0, and 43% had a GPPGA total score of 0 compared with 6% and 11% for the placebo group, respectively. Another phase 2 clinical trial assessing subcutaneous spesolimab found 23% of patients in low-dose, 29% in medium-dose, and 10% of high-dose spesolimab had flares by week 48 compared with 52% of the placebo group. Hazard ratios for time to GPP flare compared with placebo were 0.16 (P = 0.0005), 0.35 (P = 0.0057), and 0.47 (P = 0.027) for the spesolimab groups, respectively. Infection rates were similar across treatment and placebo groups, and severe adverse events such as drug reactions with eosinophilia and systemic symptom (DRESS), cholelithiasis, and breast cancer occurred with spesolimab.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING DRUGS

Spesolimab is a first-in-class IL-36 monoclonal antibody receptor antagonist approved for the treatment of acute GPP flares. It is a safe and effective therapeutic agent in preventing future GPP flares, with no current comparator trials with other GPP agents.

CONCLUSION

Spesolimab is a safe and effective treatment for acute GPP flares in adults. Future clinical trials can establish safety and efficacy compared with other agents.

Epidemiology, Characteristics of Disease, and Unmet Needs of Patients with Generalized Pustular Psoriasis: A Large Italian Delphi Consensus

INTRODUCTION

Generalized pustular psoriasis (GPP) is a rare and chronic, debilitating skin condition characterized, in its acute flare phase, by clinically severe and potentially life-threatening systemic manifestations. Data on GPP are still scanty, particularly in Europe and at a national level. The aim of this study was to provide expert indications on several disease-related and patient-related aspects of GPP, with specific focus to the Italian context.

METHODS

We conducted an iterative eDelphi study following the recommended criteria for reporting methods and results. After a thorough bibliographic review aimed to identify unknown or controversial issues in GPP, the following areas were investigated through a few specific questions/statements for each area: (1) disease epidemiology; (2) disease characteristics, with specific interest toward GPP flares; (3) diagnosis and diagnostic delay; (4) GPP treatment; (5) GPP patient journey and use of healthcare resources in Italy; (6) unmet needs and quality of life. An Executive Board of 9 principal investigators revised and approved the topics to be examined and overviewed the whole project. A total of 35 experts from different Italian areas, including 34 board-certified Italian dermatologists and 1 representative of patients' associations, took part in the study.

RESULTS

A high agreement in responses from Italian experts emerged during two eDelphi iterations on - among several other aspects - GPP prevalence and incidence in Italy, use of European Rare and Severe Psoriasis Expert Network diagnostic criteria, flare frequency and duration, best diagnostic and care pathway, and main unmet needs of Italian patients. On the other hand, a broad spectrum of treatments (of different drug classes) was reported both in the acute and chronic phases of GPP, and no consensus on the issue was thus achieved.

CONCLUSIONS

Consensus findings from this Delphi study of GPP experts may be useful to fill gaps of knowledge and improve awareness of this rare disease, as well as to help clinical and public health management of GPP in Italy.

Regional differences in the prevalence of generalized pustular psoriasis in Japan

Generalized pustular psoriasis (GPP), a rare form of psoriasis, is characterized by neutrophil-rich, sterile pustules. In Japan, GPP has intractable and rare disease designation, which allows patients to access support from national and local governments for medical expenses. Previously, similar numbers of patients in Tokyo and Hokkaido have been shown to have GPP designation, despite different population sizes. Here, we determine whether there are regional differences in the proportion of patients receiving GPP designation status in Japan and aim to identify causal factors. In this descriptive, retrospective cohort study, publicly available data were collected on the number of patients with intractable and rare disease designation for GPP in each prefecture and age classification (April 2018-March 2021). Three other designated intractable and rare disease cohorts were included: pemphigus, rare skin diseases, and all diseases. The primary outcome was the standardized morbidity ratio (SMR) of patients at prefecture level (observed numbers divided by expected). Regional differences were compared with the statistical expectation for the total population and age distribution of each prefecture. Regional differences were observed in all cohorts. Overall, 1910 patients had GPP as a designated intractable and rare disease in 2020. Regional differences in SMRs for GPP were observed with high SMRs (≥1.5) in Hokkaido, Tottori, Kagawa, and Miyazaki, and low SMRs (<0.6) in Gunma and Kanagawa. Regional differences in SMRs for GPP did not correlate with the number of medical doctors or dermatologists or internal migration. The number of medical doctors or dermatologists correlated with SMRs in the rare skin diseases and total cohorts. Regional differences in Japan exist in the number of patients with GPP who have an intractable and rare disease designation. Managing rare diseases is an important public health issue, and further research is required to elucidate the factors contributing to these differences.

Health-related quality of life in patients with generalized pustular psoriasis: A systematic literature review

Generalized pustular psoriasis (GPP) is a rare, chronic, neutrophilic inflammatory skin disease characterized by episodes of widespread eruption of sterile, macroscopic pustules that can be accompanied by systemic inflammation and symptoms. A systematic literature review and narrative synthesis were conducted to determine the impact of GPP on patients' health-related quality of life (HRQoL) and patient-reported severity of symptoms and to compare its impact to patients with plaque psoriasis (plaque PsO). Searches were undertaken in Embase, MEDLINE and the Cochrane Library from 1 January 2002 to 15 September 2022. Screening was carried out by two reviewers independently. Outcome measures included generic (e.g. EQ-5D, SF-36) and dermatology-specific (e.g. DLQI) clinical outcome assessments, and other relevant patient-reported outcome measures (PROMs) (e.g. severity of pain measured by a numerical rating scale). Overall, 20 studies were found to be eligible for inclusion, of which seven also had data for plaque PsO. The DLQI was the most frequently reported outcome measure (16 out of 20 studies). When reported, mean DLQI (SD) scores varied from 5.7 (1.2) to 15.8 (9.6) across the studies, indicating a moderate to very large effect on HRQoL; the wide range of scores and large SDs were explained by the small population sizes (n ≤ 12 for all studies except two). Similar ranges and large SDs were also observed for other measures within individual studies. However, in general, people with GPP reported a greater impact of their skin condition on HRQoL, when compared to people with plaque PsO (i.e. higher DLQI scores) and higher severity for itch, pain and fatigue. This systematic review highlighted the need for studies with a larger population size, a better understanding of the impact of cutaneous and extracutaneous symptoms and comorbidities on HRQoL during and between GPP flares, and outcome measures specifically tailored to the unique symptoms and the natural course/history of GPP.

Clinical and Disease Burden of Patients with Generalized Pustular Psoriasis: A Review of Real-World Evidence

Generalized pustular psoriasis (GPP) is a chronic, rare, and potentially life-threatening disease. There is limited understanding of patient characteristics in GPP and their correlation with disease progression or healthcare resource utilization. Our review aims to examine real-world evidence on these characteristics and the associated disease burden as related to economic and quality of life factors. Results showed that most patients with GPP experienced flares once a year, lasting from 2 weeks to 3 months, with > 80% of patients having residual disease post-flare, with/without treatment, indicating the long-term nature of GPP. The impact of GPP on patients' daily activities was significant, even in the absence of a flare. GPP adversely affected mental health, and anxiety and depression were reported regularly. Patients with GPP had more comorbidities, were prescribed more medication, and had more inpatient and outpatient visits than in matched plaque psoriasis or general population cohorts. Improving the education of healthcare providers in diagnosing GPP, defining disease flares, and managing the disease, as well as making globally accepted clinical guidelines for GPP treatment available, could help to reduce the burden on patients with GPP. Effective therapies that control and prevent GPP flares and manage chronic disease are needed.

Clinical characteristics and heterogeneity of generalized pustular psoriasis: A comparative study in a large retrospective cohort

Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening skin disease and the clinical heterogeneity of which is largely unknown. Retrospective cohort analysis was conducted on hospitalized GPP patients between January 2010 and November 2022. A total of 416 patients with GPP and psoriasis vulgaris (PV) respectively were included, matched 1:1 by sex and age. The heterogeneity of GPP was stratified by PV history and age. Compared with PV, GPP was significantly associated with prolonged hospitalization (11.7 vs. 10.3 day, p < 0.001), elevated neutrophil lymphocyte ratio (NLR) (5.93 vs. 2.44, p < 0.001) and anemia (13.9% vs. 1.2%, p < 0.001). Moreover, GPP alone (without PV history) was a relatively severer subtype with higher temperature (37.6°C vs. 38.0°C, p = 0.002) and skin infections (5.2% vs. 11.4%, p = 0.019) than GPP with PV. For patients across different age, compared with juvenile patients, clinical features support a severer phenotype in middle-aged, including higher incidence of anaemia (7.5% vs. 16.0%, p = 0.023) and NLR score (3.83 vs. 6.88, p < 0.001). Interleukin-6 (r = 0.59), high density lipoprotein cholesterol (r = -0.56), albumin (r = -0.53) and C-reactive protein-to-albumin ratio (r = 0.49) were the most relevant markers of severity in GPP alone, GPP with PV, juvenile and middle-aged GPP, respectively. This retrospective cohort suggests that GPP is highly heterogeneous and GPP alone and middle-aged GPP exhibit severe disease phenotypes. More attention on the heterogeneity of this severe disease is warranted to meet the unmet needs and promote the individualized management of GPP.

The role of the interleukin-36 axis in generalized pustular psoriasis: a review of the mechanism of action of spesolimab

Generalized pustular psoriasis (GPP) is a rare, chronic, inflammatory skin disorder characterized by recurrent flares associated with skin erythema, desquamation, and widespread superficial sterile pustules, which may be severe ("lakes of pus"). Systemic symptoms are often present, including malaise, fever, and skin pain. In GPP, innate immune responses are driven by abnormal activation of the interleukin (IL)-36-chemokine-neutrophil axis and excessive neutrophil infiltration. This review highlights the IL-36 pathway in the context of the IL-1 superfamily and describes how unopposed IL-36 signaling can lead to the development of GPP. Targeted inhibition of the IL-36 receptor (IL-36R) is an attractive therapeutic strategy in the treatment of GPP, including flare prevention and sustained disease control. Spesolimab is a first-in-class, humanized, monoclonal antibody that binds specifically to the IL-36R and antagonizes IL-36 signaling. Spesolimab was approved by the US Food and Drug Administration in September 2022 to treat GPP flares in adults and was subsequently approved for GPP flare treatment in other countries across the world. Anti-IL-36R therapy, such as spesolimab, can mitigate flares and address flare prevention in GPP, presumably through rebalancing IL-36 signaling and modulating the pro-inflammatory response of the downstream effectors.

Exploring the Quality-of-Life Impact, Disease Burden, and Management Challenges of GPP: The Provider and Patient Perspective [Podcast]

Generalized pustular psoriasis (GPP) is a rare, chronic, and debilitating disease characterized by flares of widespread erythema, desquamation, and pustule formation. GPP flares can be accompanied by systemic symptoms including fever, fatigue, malaise, and skin pain; severe cases may be fatal if untreated. Although GPP may occur concurrently with plaque psoriasis, they represent two distinct inflammatory conditions. Patients with GPP experience a substantial burden of disease, and the impact of GPP on an individual's mental health and quality-of-life (QoL) goes far beyond skin pain and discomfort. The rarity of GPP may result in a misdiagnosis, as the sudden onset of skin pustules may be mistaken for a primary infection. Misdiagnosis with a subsequent delay in treatment has tremendous negative consequences for the affected patient. In September 2022, spesolimab became the first FDA-approved medication in the US for the treatment of GPP flares in adults. Spesolimab has since been approved by regulatory agencies in numerous countries, including Japan, Mainland China, and the EU. Prior to spesolimab, the clinical management of GPP relied on the off-label use of systemic or biologic therapies approved for plaque psoriasis or other inflammatory conditions. There is a need for increased education among healthcare providers regarding the clinical diagnosis, risk stratification, and therapeutic management of this rare disease, including the other novel GPP-specific therapies in development. In this podcast, two dermatologists and a patient who has plaque psoriasis and GPP discuss the clinical presentation, symptoms, disease burden, QoL impacts, diagnostic challenges, and therapeutic strategies for the management of GPP.

Generalized pustular psoriasis: practical recommendations for Spanish primary care and emergency physicians

Generalized pustular psoriasis (GPP) is a rare chronic inflammatory skin disease that can lead to life-threatening complications and require emergency medical treatment. Recurrent GPP flares are characterized by the sudden onset of widespread erythematous skin rash with sterile pustules, at times associated with fever, chills, general malaise, and other systemic inflammatory manifestations. Systemic complications such as cardiorespiratory failure, infections, and sepsis are potentially life-threatening and can result in an emergency department visit and/or hospitalization. Acute GPP episodes can be difficult to recognize and diagnose. The low incidence of the disease, its relapsing nature, the unpredictability of flare onset, and the lack of standardized diagnostic criteria are major obstacles to achieving rapid recognition and diagnosis in both the emergency department and the hospital setting.There is scarce evidence supporting the efficacy and safety of treatments commonly used for GPP; consequently, there is an unmet need for therapies that specifically target the condition. Our aim is to present a multidisciplinary approach to GPP to achieve a rapid diagnosis ensuring that the patient receives the most appropriate treatment for their pathology. The main recommendation for primary care and emergency physicians is to contact a dermatologist immediately for advice or to refer the patient when GPP or a flare is suspected.

Efficacy and safety of subcutaneous spesolimab for the prevention of generalised pustular psoriasis flares (Effisayil 2): an international, multicentre, randomised, placebo-controlled trial

BACKGROUND

Spesolimab is an anti-interleukin-36 receptor monoclonal antibody approved to treat generalised pustular psoriasis (GPP) flares. We aimed to assess the efficacy and safety of spesolimab for GPP flare prevention.

METHODS

This multicentre, randomised, placebo-controlled, phase 2b trial was done at 60 hospitals and clinics in 20 countries. Eligible study participants were aged between 12 and 75 years with a documented history of GPP as per the European Rare and Severe Psoriasis Expert Network criteria, with a history of at least two past GPP flares, and a GPP Physician Global Assessment (GPPGA) score of 0 or 1 at screening and random assignment. Patients were randomly assigned (1:1:1:1) to receive subcutaneous placebo, subcutaneous low-dose spesolimab (300 mg loading dose followed by 150 mg every 12 weeks), subcutaneous medium-dose spesolimab (600 mg loading dose followed by 300 mg every 12 weeks), or subcutaneous high-dose spesolimab (600 mg loading dose followed by 300 mg every 4 weeks) over 48 weeks. The primary objective was to demonstrate a non-flat dose-response curve on the primary endpoint, time to first GPP flare.

FINDINGS

From June 8, 2020, to Nov 23, 2022, 157 patients were screened, of whom 123 were randomly assigned. 92 were assigned to receive spesolimab (30 high dose, 31 medium dose, and 31 low dose) and 31 to placebo. All patients were either Asian (79 [64%] of 123) or White (44 [36%]). Patient groups were similar in sex distribution (76 [62%] female and 47 [38%] male), age (mean 40·4 years, SD 15·8), and GPP Physician Global Assessment score. A non-flat dose-response relationship was established on the primary endpoint. By week 48, 35 patients had GPP flares; seven (23%) of 31 patients in the low-dose spesolimab group, nine (29%) of 31 patients in the medium-dose spesolimab group, three (10%) of 30 patients in the high-dose spesolimab group, and 16 (52%) of 31 patients in the placebo group. High-dose spesolimab was significantly superior versus placebo on the primary outcome of time to GPP flare (hazard ratio [HR]=0·16, 95% CI 0·05-0·54; p=0·0005) endpoint. HRs were 0·35 (95% CI 0·14-0·86, nominal p=0·0057) in the low-dose spesolimab group and 0·47 (0·21-1·06, p=0·027) in the medium-dose spesolimab group. We established a non-flat dose-response relationship for spesolimab compared with placebo, with statistically significant p values for each predefined model (linear p=0·0022, emax1 p=0·0024, emax2 p=0·0023, and exponential p=0·0034). Infection rates were similar across treatment arms; there were no deaths and no hypersensitivity reactions leading to discontinuation.

INTERPRETATION

High-dose spesolimab was superior to placebo in GPP flare prevention, significantly reducing the risk of a GPP flare and flare occurrence over 48 weeks. Given the chronic nature of GPP, a treatment for flare prevention is a significant shift in the clinical approach, and could ultimately lead to improvements in patient morbidity and quality of life.

FUNDING

Boehringer Ingelheim.

Exploring the Clinical Assessment, Guidelines, and Options for the Treatment of Generalized Pustular Psoriasis [Podcast]

Acute episodes of generalized pustular psoriasis (GPP), known as "flares", are characterized by the widespread appearance of pustules with surrounding skin erythema, and are often accompanied by systemic symptoms. The clinical course of GPP is unpredictable, and symptoms vary in extent and severity; the disease may be relapsing-remitting with recurrent episodes of pustulosis, or be more persistent. The triggers that may lead to flares include withdrawal of corticosteroids, stress, pregnancy, and infections. GPP-specific assessment tools, such as the Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) and the General Pustular Psoriasis Area and Severity Index (GPPASI), were developed to evaluate the severity of disease, and to monitor the patient's response to therapy during clinical trials. Spesolimab is the first GPP-specific treatment available in the United States for the treatment of GPP flares in adults, and was approved by the US FDA in September 2022. To date, spesolimab has been approved by regulatory agencies in almost 40 countries, including Japan, Mainland China, and the European Union. Spesolimab is a first-in-class humanized monoclonal antibody that targets the interleukin-36 receptor, and blocks the downstream effects of the interleukin-36 pathway, which is associated with GPP pathogenesis. Data from clinical trials demonstrate the safety and efficacy of spesolimab in providing rapid clinical improvement for patients with GPP flares. Standardized international guidelines for the diagnosis and management of GPP are needed, and no recent GPP guidelines are available in the US. This podcast discusses clinical assessment tools for GPP (GPPGA and GPPASI), the evolution of GPP management guidelines, the therapeutic landscape of GPP, efficacy and safety data for spesolimab, and examines important considerations for patients living with this condition.

A narrative review of the socioeconomic burden associated with generalised pustular psoriasis

Generalised pustular psoriasis (GPP) is a rare, chronic and life-threatening inflammatory skin disease characterised by widespread eruption of sterile pustules. With the approval of a GPP flare treatment in several countries occurring only recently, the socioeconomic burden associated with GPP is not well established. To highlight current evidence for patient burden, healthcare resource utilization (HCRU) and costs associated with GPP. Patient burden results from serious complications including sepsis and cardiorespiratory failure causing hospitalization and death. HCRU is driven by high hospitalization rates and treatment costs. The mean duration of a GPP hospital stay ranges from 10 to 16 days. A quarter of patients require intensive care, and the mean intensive care stay is 18 days. In comparison to patients with plaque psoriasis (PsO), patients with GPP have: a 64% higher score on the Charlson Comorbidity Index; higher hospitalization rates (≤36.3% vs. ≤23.3%); lower overall quality of life, and higher symptom scores for pain, itch, fatigue, anxiety and depression; direct costs associated with treatment 1.3- to 4.5-fold higher; higher rates of disabled work status (20.0% vs. 7.6%); and increased presenteeism (i.e. worse impairment at work), impaired daily activities, and medically related absenteeism. Current medical management and drug treatment utilising non-GPP-specific therapies impose a significant patient and direct economic burden. GPP also imposes an indirect economic burden by increasing work productivity impairment and medically related absenteeism. This high level of socioeconomic burden reinforces the need for new therapies with proven efficacy in the treatment of GPP.

Current management of generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare subset of psoriasis involving episodes of sterile pustules accompanied by inflammation and, often, systemic involvement. The inflammatory nature of GPP has potential for severe multisystem complications including high-output cardiac failure, infections, digestive system issues, and disfiguring or lethal acute flare episodes. The disease tends to have higher prevalence in females and Asians. The IL-1/IL-36 inflammatory pathway is a critical facet of GPP's pathology. Genetic mutations that are associated with GPP include modifications of Interleukin 36 Receptor Antagonist (IL36RN), Caspase Recruitment Domain Family Member 14 (CARD14), Adaptor Related Protein Complex 1 Subunit Sigma 3 (AP1S3), Myeloperoxidase (MPO) and Serpin Peptidase Inhibitor Clade A Member 3 (SERPINA3) genes. Treatment guidelines for GPP are not well-entrenched. Currently, only one GPP-specific treatment, the interleukin-36 receptor antagonist (IL-36Ra) spesolimab, has been approved for use in the United States. Additional anti-IL-36 pathway therapies are currently being developed. Other treatment options include other biologic therapies such as IL-17 inhibitors, IL-23 inhibitors and TNFα inhibitors. Non-biologic therapeutic options include retinoids, cyclosporine and methotrexate. Treatment options differ throughout the world; most countries utilize retinoids, cyclosporine and methotrexate as first-line non-biologic options. China and United Kingdom have no GPP-specific biologic therapies approved for use, while several biologic therapies are approved for use in Japan. This review aims to serve as an update on the current global management of GPP while also including relevant aspects of disease pathogenesis, diagnosis, clinical presentation, histopathology, aetiology and epidemiology.

Efficacy of spesolimab for the treatment of generalized pustular psoriasis flares across pre-specified patient subgroups in the Effisayil 1 study

Effisayil 1 was a multicentre, randomized, double-blind, placebo-controlled study of the anti-interleukin (IL)-36 receptor monoclonal antibody, spesolimab, in patients presenting with a generalized pustular psoriasis (GPP) flare. Previously published data from this study revealed that within 1 week, rapid pustular and skin clearance were observed in patients receiving spesolimab versus placebo. In this pre-specified subgroup analysis, the efficacy of spesolimab was evaluated according to patient demographic and clinical characteristics at baseline in patients receiving spesolimab (n = 35) or placebo (n = 18) on Day 1. Efficacy was by assessed by achievement of primary endpoint (Generalized Pustular Psoriasis Physician Global Assessment [GPPGA] pustulation subscore of 0 at Week 1) and key secondary endpoint (GPPGA total score of 0 or 1 at Week 1). Safety was assessed at Week 1. Spesolimab was found to be efficacious and had a consistent and favourable safety profile in patients presenting with a GPP flare, regardless of patient demographics and clinical characteristics at baseline.

Genetics of Generalized Pustular Psoriasis: Current Understanding and Implications for Future Therapeutics

Psoriasis is a chronic inflammatory skin disease characterized by the appearance of clearly demarcated erythematous and scaly plaques. It can be divided into various types, including plaque, nail, guttate, inverse, and pustular psoriasis. Plaque psoriasis is the most commonly occurring type, though there is another rare but severe pustular autoinflammatory skin disease called generalized pustular psoriasis (GPP), which manifests with acute episodes of pustulation and systemic symptoms. Though the etiopathogenesis of psoriasis is not yet fully understood, a growing body of literature has demonstrated that both genetic and environmental factors play a role. The discovery of genetic mutations associated with GPP has shed light on our comprehension of the mechanisms of the disease, promoting the development of targeted therapies. This review will summarize genetic determinants as known and provide an update on the current and potential treatments for GPP. The pathogenesis and clinical presentation of the disease are also included for a comprehensive discussion.

Albicanol antagonizes PFF-induced mitochondrial damage and reduces inflammatory factors by regulating innate immunity

As an environmental pollutant, profenofos (PFF) can seriously endanger human health through the food chain. Albicanol is a sesquiterpene compound with antioxidant, anti-inflammatory, and anti-aging properties. Previous studies have shown that Albicanol can antagonize apoptosis and genotoxicity caused by PFF exposure. However, the toxicity mechanism of PFF regulating hepatocyte immune function, apoptosis, and programmed necrosis and the role of Albicanol in this process have not been reported yet. In this study, grass carp hepatocytes (L8824) were treated with PFF (200 μM) or combined with Albicanol (5 ×10^-5 μg mL^-1) for 24 h to establish an experimental model. The results of JC-1 probe staining and Fluo-3 AM probe staining showed increased free calcium ions and decreased mitochondrial membrane potential in L8824 cells after PFF exposure, suggesting that PFF exposure may lead to mitochondrial damage. Real-time quantitative PCR and Western blot results showed that PFF exposure could increase the transcription of innate immunity-related factors (C3, Pardaxin 1, Hepcidin, INF-γ, IL-8, and IL-1β) in L8824 cells. PFF up-regulated the TNF/NF-κB signaling pathway and the expression of caspase-3, caspase-9, Bax, MLKL, RIPK1, and RIPK3 and down-regulated the expression of Caspase-8 and Bcl-2. Albicanol can antagonize the above-mentioned effects caused by PFF exposure. In conclusion, Albicanol antagonized the mitochondrial damage, apoptosis, and necroptosis of grass carp hepatocytes caused by PFF exposure by inhibiting the TNF/NF-κB pathway in innate immunity.

Characteristics of Patients Experiencing a Flare of Generalized Pustular Psoriasis: A Multicenter Observational Study

Background: Generalized pustular psoriasis (GPP) is a rare, severe inflammatory skin disease characterized by recurrent episodes of flares. Characteristics of patients experiencing a flare are hardly described in a real-life setting. The aim of the study is to investigate the clinical characteristics of patients experiencing a flare of GPP. Methods: Multicenter retrospective observational study on consecutive patients experiencing a flare of GPP between 2018 and 2022. Disease severity and quality of life were assessed by Generalized Pustular Psoriasis Area, Body Surface Area (BSA), and Severity Index (GPPASI), and Dermatology life quality index (DLQI) questionnaire, respectively. Visual analogue scale (VAS) of itch and pain, triggers, complications, comorbidities, pharmacological therapies, and outcome were collected. Results: A total of 66 patients, 45 (68.2%) females, mean age 58.1 ± 14.9 years, were included. The GPPASI, BSA, and DLQI were 22.9 ± 13.5 (mean ± standard deviation), 47.9 ± 29.1, and 21.0 ± 5.0, respectively. The VAS of itch and pain were 6.2 ± 3.3 and 6.2 ± 3.0, respectively. Fever (>38 °C) and leukocytosis (WBC > 12 × 109/L) were found in 26 (39.4%) and 39 (59.1%) patients, respectively. Precipitating triggers were identified in 24 (36.3%) and included infections (15.9%), drugs (10.6%), stressful life events (7.6%), and corticosteroids withdrawal (3.0%). Fourteen (21.2%) patients were hospitalized because of complications including infections in 9 (13.6%) leading to death in one case and hepatitis in 3 (4.5%). Conclusions: GPP flares can be severe and cause severe pain and itch with significant impact on the quality of life. In about one-third of patients the flare may have a persistent course and, with complications, lead to hospitalization.

A Familial Novel Putative-Pathogenic Mutation Identified in Plaque-Psoriasis by a Multigene Panel Analysis

Psoriasis is a chronic multifactorial skin disorder with an immune basis. It is characterized by patches of skin that are usually red, flaky and crusty, and that often release silvery scales. The patches appear predominantly on the elbows, knees, scalp and lower back, although they may also appear on other body areas and severity may be variable. The majority of patients (about 90%) present small patches known as "plaque psoriasis". The roles of environmental triggers such as stress, mechanical trauma and streptococcal infections are well described in psoriasis onset, but much effort is still needed to unravel the genetic component. The principal aim of this study was to use a next-generation sequencing technologies-based approach together with a 96 customized multigene panel in the attempt to determine if there are germline alterations that can explain the onset of the disease, and thus to find associations between genotypes and phenotypes. To this aim, we analyzed a family in which the mother showed mild psoriasis, and her 31-year-old daughter had suffered from psoriasis for several years, whereas an unaffected sister served as a negative control. We found variants already associated directly to psoriasis in the TRAF3IP2 gene, and interestingly we found a missense variant in the NAT9 gene. The use of multigene panels in such a complex pathology such as psoriasis can be of great help in identifying new susceptibility genes, and in being able to make early diagnoses especially in families with affected subjects.

Generalized Pustular Psoriasis: A Review on Clinical Characteristics, Diagnosis, and Treatment

Generalized pustular psoriasis (GPP) is a rare, chronic, and severe inflammatory skin disorder characterized by sudden eruption of sterile pustules, often accompanied by systemic inflammation. GPP flares can be life-threatening if untreated, owing to potential serious complications such as sepsis and cardiovascular failure. Diagnosis and clinical measurement of disease severity in GPP are often difficult. Lack of standardized criteria in the international guidelines and the heterogeneity of cutaneous and extracutaneous symptoms make the diagnosis of GPP difficult. Clinical criteria for description and diagnosis of pustular conditions, including GPP, are variable and there is no specific agreement on commonly sustained concepts. Differentiation of GPP from other similar conditions/diseases is important and requires careful assessments. The evidence that supports current topical or systemic therapies is largely based on case reports and small studies. Some biologic agents that target key cytokines involved in the activation of inflammatory pathways have been used as treatments for GPP. Recently, spesolimab, an IL-36R antagonist, has been approved in the USA and Japan for the treatment of GPP flares in adults, but there are no currently approved treatments for GPP in Europe. The IL-36 pathway has recently emerged as a central axis driving the pathogenic inflammatory mechanisms of GPP. Biologic agents that inhibit the IL-36 pathway have shown efficacy and safety in patients with GPP, addressing a generally considered unmet medical need.