Therapeutic Potential of Spesolimab-Sbzo in the Management of Generalized Pustular Psoriasis Flares in Adults: Evidence to Date

Generalized pustular psoriasis (GPP) is a rare, chronic, and severe skin disorder characterized by the eruption of non-infectious pustules on an erythematous background often associated with systemic symptoms. It may appear in association with plaque psoriasis or occur in previously healthy individuals. It differs from psoriasis vulgaris in clinical presentation, immunopathogenesis, histology, and therapeutic strategies. Overexpression of interleukin 36 (IL-36) or a loss-of-function mutation of IL-36 receptor antagonist (IL-36RA) are thought to play a pivotal role in the pathogenesis of this disease. There are currently no globally approved guidelines for the treatment of GPP, and the therapies used so far, with variable results, have given unsatisfactory results. Spesolimab, a selective humanized antibody against the IL-36 receptor that blocks its activation, is the first biologic drug approved in Europe in December 2022 for the treatment of GPP flares. It represents a promising therapy, demonstrating efficacy in reducing disease severity and improving patient outcomes. In our review, we have analyzed the latest advancements and findings regarding the efficacy and safety of spesolimab in the context of GPP management.

Treatment Options and Goals for Patients with Generalized Pustular Psoriasis

Generalized pustular psoriasis (GPP) is a rare, severe neutrophilic skin disorder characterized by sudden widespread eruption of superficial sterile pustules with or without systemic inflammation. GPP flares can be life-threatening if untreated due to potential severe complications such as cardiovascular failure and serious infections. Currently, there are no GPP-specific therapies approved in the USA or Europe. Retinoids, cyclosporine, and methotrexate are the most commonly used non-biologic therapies for GPP. The evidence that supports the currently available treatment options is mainly based on case reports and small, open-label, single-arm studies. However, recent advances in our understanding of the pathogenic mechanisms of GPP and the identification of gene mutations linked to the disease have paved the way for the development of specific targeted therapies that selectively suppress the autoinflammatory and autoimmune mechanisms induced during GPP flares. Several biologic agents that target key cytokines involved in the activation of inflammatory pathways, such as tumor necrosis factor-α blockers and interleukin (IL)-17, IL-23, and IL-12 inhibitors, have emerged as potential treatments for GPP, with several being approved in Japan. The evidence supporting the efficacy of these agents is mainly derived from small, uncontrolled trials. A notable recent advance is the discovery of IL36RN mutations and the central role of IL-36 receptor ligands in the pathogenesis of GPP, which has defined key therapeutic targets for the disease. Biologic agents that target the IL-36 pathway have demonstrated promising efficacy in patients with GPP, marking the beginning of a new era of targeted therapy for GPP.

Pathophysiology of Generalized Pustular Psoriasis

Generalized pustular psoriasis (GPP) is a rare, severe form of pustular psoriasis characterized by widespread, recurrent episodes of neutrophil-rich pustule formation in the epidermis, which can be accompanied by fever and systemic inflammation. Recent clinical, histologic, and genetic evidence indicates that GPP is a distinct entity from plaque psoriasis, with different cytokine pathways predominant in the manifestation of each disease. The interleukin-36 (IL-36) signaling cascade plays a key role in regulating the innate immune system, and its dysregulation appears central to the pathogenesis of GPP. The altered expression of various IL-36 pathway constituents has been shown to cause a positive feedback loop of uncontrolled signaling and excess production of inflammatory cytokines, which in turn leads to chemokine induction and neutrophil recruitment in the epidermis. Given the potentially life-threatening nature of GPP episodes, drug interventions that rapidly achieve disease resolution are required. Early phase data indicate that treatments targeting various components of the IL-36 inflammatory cascade represent promising areas of research. However, there are currently no therapeutic agents specifically approved for GPP in the USA or Europe. Understanding the inflammatory pathways, associated risk factors, and role of neutrophils in the manifestation and perpetuation of GPP flares remains a key goal in developing effective therapeutics. In this article, we summarize the current understanding of GPP, describe novel therapeutic opportunities, and detail how the unique pathophysiology of the disease may inform future treatment strategies.

Solid lipid nanoparticles and nanostructured lipid carrier-based nanotherapeutics for the treatment of psoriasis

INTRODUCTION

Psoriasis is an auto-immune inflammatory skin disease affecting people worldwide. Its topical therapy via different nanoformulations prevents the long-term side-effects of conventional formulations. Nanocarriers, especially solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), pose extra benefits in topical drug delivery due to their lipid constituents. Although both natural and synthetic anti-psoriatic drugs have been successfully incorporated in these nanoformulations, yet further studies including dual drug-loadings are being carried out for assessing their efficacy.

AREAS COVERED

This review aims at describing the different aspects of SLNs and NLCs in psoriasis, including their skin permeation behavior and the various drug molecules incorporated. The recent studies with single- and dual drug-loaded SLNs and NLCs have also been discussed in the review.

EXPERT OPINION

SLNs and NLCs have been very effective in mitigating psoriasis when compared to commercial formulations. They have also shown promising results when loaded with two drugs, thus overcoming drawbacks of traditional combination therapy. Therefore, various drug/antibody/siRNA combinations can be selected in the upcoming research works to evaluate their synergistic performance against psoriasis. However, the conclusions drawn so far are only based on the pre-clinical studies and hence further investigations are required to obtain their clinical trial outcomes.

Pustular Psoriasis: From Pathophysiology to Treatment

Pustular psoriasis (PP) is a clinicopathological entity encompassing different variants, i.e., acute generalized PP (GPP), PP of pregnancy (impetigo herpetiformis), annular (and circinate) PP, infantile/juvenile PP, palmoplantar PP/palmoplantar pustulosis, and acrodermatitis continua of Hallopeau (ACH), which have in common an eruption of superficial sterile pustules on an erythematous base. Unlike psoriasis vulgaris, in which a key role is played by the adaptive immune system and interleukin (IL)-17/IL-23 axis, PP seems to be characterized by an intense inflammatory response resulting from innate immunity hyperactivation, with prominent involvement of the IL-36 axis. Some nosological aspects of PP are still controversial and debated. Moreover, owing to the rarity and heterogeneity of PP forms, data on prognosis and therapeutic management are limited. Recent progresses in the identification of genetic mutations and immunological mechanisms have promoted a better understanding of PP pathogenesis and might have important consequences on diagnostic refinement and treatment. In this narrative review, current findings in the pathogenesis, classification, clinical features, and therapeutic management of PP are briefly discussed.

Pustular Psoriasis and Acute Generalized Exanthematous Pustulosis

The similarity between pustular psoriasis (PP) and acute generalized exanthematous pustulosis (AGEP) poses problems in the diagnosis and treatment of these two conditions. Significant clinical and histopathologic overlap exists between PP and AGEP. PP is an inflammatory disorder that has numerous clinical subtypes, but all with sterile pustules composed of neutrophils. AGEP is a severe cutaneous adverse reaction that is also characterized by non-follicular sterile pustules. Clinical features that suggest a diagnosis of PP over AGEP include a history of psoriasis and the presence of scaling plaques. Histologically, eosinophilic spongiosis, vacuolar interface dermatitis, and dermal eosinophilia favor a diagnosis of AGEP over PP. Importantly, PP and AGEP vary in clinical course and treatment. PP treatment involves topical steroids, oral retinoids, and systemic immunosuppressants. Newer therapies targeting IL-36, IL-23, IL-1, and PDE-4 have been investigated. The removal of the offending agent is a crucial part of the treatment of AGEP.

Generalized Pustular Psoriasis: Divergence of Innate and Adaptive Immunity

Generalized pustular psoriasis (GPP) is a severe, relapsing, immune-mediated disease characterized by the presence of multiple sterile pustules all over the body. The exact pathomechanisms behind GPP remain elusive, although increased interest in the genetic basis and immunological disturbances have provided some revealing insights into the underlying signaling pathways and their mutual interaction. The genetic background of GPP has been thoroughly investigated over the past few years. The conducted studies have identified genetic variants that predispose to pustular forms of psoriasis. The loss-of-function mutation of the interleukin 36 receptor antagonist gene, along with rare gain-of-function mutations in the gene that encodes the keratinocyte signaling molecule (CARD14), are examples of the uncovered abnormalities. Interleukin 36 (IL-36), along with neutrophils, is now considered a central cytokine in GPP pathogenesis, with IL-36 signaling providing a link between innate and adaptive immune responses. More recently, a new concept of inflammation, caused by a predominantly genetically determined abnormal activation of innate immune response and leading to inflammatory keratinization, has arisen. GPP is currently considered a representative of this novel group of skin conditions, called autoinflammatory keratinization diseases. As no therapeutic agents have been approved for GPP to date in the United States and Europe, the novel anti-IL-36R antibodies are particularly promising and may revolutionize management of the disease.

Generalized pustular psoriasis: current management status and unmet medical needs in Japan

INTRODUCTION

Generalized pustular psoriasis (GPP) is a rare, inflammatory skin disease characterized by recurrent flares of pustulation accompanied by systemic symptoms that can be life-threatening. The clinical and humanistic burden of GPP in Japan is high, and it is a designated intractable disease. We reviewed clinical evidence and guidelines for GPP treatment in Japan to identify unmet needs and assess data supporting the development and use of new targeted therapies.

AREAS COVERED

Using specific search terms in PubMed and Embase, with additional back-referencing, we retrieved literature related to GPP in Japan focusing on clinical and pathogenic characteristics, diagnosis, and treatment.

EXPERT OPINION

Although there are approved systemic therapies for GPP in Japan, all present uncertainties in terms of safety and efficacy. Clinical evidence supporting their use comes mostly from studies in patients with mild or moderate disease, and their effectiveness in treating acute phase GPP is unknown. The interleukin-36 pathway appears to be central to GPP pathogenesis. New therapies targeting this pathway show promise in patients presenting with acute phase GPP. The rarity and intermittent course of GPP make it challenging to recruit sufficient patients for trials and robustly investigate the efficacy and safety of these agents to treat GPP.

Infliximab in Combination with Low-Dose Acitretin in Generalized Pustular Psoriasis: A Report of Two Cases and Review of the Literature

Generalized pustular psoriasis (GPP) is a severe, life-threatening disease that represents a major therapeutic challenge. There is a lack of randomized controlled trials assessing the efficacy of various treatment options for GPP. TNFα inhibitors have proven to be effective and are increasingly used in this indication. In the current paper, we present two patients with GPP treated with infliximab (Ifx) and a literature review appraising currently available data on the use of Ifx in GPP. Case 1 was a 73-year-old woman with GPP who exhibited lack of treatment response or primary intolerance to standard therapeutic options (high-dose acitretin, methotrexate, cyclosporine A, and methylprednisolone). However, Ifx therapy combined with low-dose acitretin resulted in rapid and sustained resolution of skin lesions. Case 2 was a 60-year-old man with GPP and numerous comorbidities who was initially treated with Ifx in combination with methotrexate, with good treatment response for 9 months. Following an infection-induced flare of GPP at week 38, methotrexate was discontinued in favor of low-dose acitretin and Ifx continued. This regimen again resulted in rapid resolution of pustules. We present these cases to highlight the advantage of long-term Ifx therapy with low-dose acitretin in GPP.

An update on genetic basis of generalized pustular psoriasis (Review)

Generalized pustular psoriasis (GPP) is a rare and severe auto-inflammatory skin disease that is characterized by recurrent, acute onset, and generalized pustular eruptions on erythematous, inflamed skin. GPP is traditionally classified as a variant of psoriasis vulgaris, even though recent clinical, histological and genetic evidence suggests that it is a heterogeneous disease and requires a separate diagnosis. In recent years, variants of IL36RN, CARD14, AP1S3 and MPO genes have been identified as causative or contributing to genetic defects in a proportion of patients affected by GPP. These disease-related genes are involved in common inflammatory pathways, in particular in the IL-1/IL-36-chemokines-neutrophil pathogenic axis. At present, no standard therapeutic guidelines have been established for GPP management, and there is a profound need for novel efficacious treatments of GPP. Among them, biological agents antagonizing the IL-36 pathway are promising therapeutics. The aim of the present review is to provide the most recent updates on the genetics, genotype-phenotype correlation and pathological basis of GPP, as well as on biologic treatments available for GPP and relative clinical courses.

Successful treatment of juvenile generalized pustular psoriasis with infliximab therapy: two case reports

Juvenile generalized pustular psoriasis is a rare, severe type of psoriasis that can be life-threatening. Thus far, treatment for juvenile generalized pustular psoriasis has been challenging, and no standardized guidelines are available. Here, we describe two Chinese boys with juvenile generalized pustular psoriasis who were successfully treated with infusions of infliximab. During 12 months of follow-up, no recurrence or exacerbation was observed in either patient. Herpes zoster was observed as an adverse effect in one patient, following the initial infusion of infliximab; the other patient did not experience any adverse reaction. Although infliximab is effective therapy for patients with juvenile generalized pustular psoriasis, there is a need for close monitoring of adverse effects in these patients.

Biologics in the treatment of pustular psoriasis

INTRODUCTION

Pustular psoriasis is a group of skin diseases characterized by neutrophil infiltration in the epidermis and formation of sterile pustules. Conventional treatments, such as retinoids and immunosuppressive drugs, have improved the clinical manifestations; however, many patients suffer from drug-related toxicity or are resistant to therapy.

AREAS COVERED

In this review, the authors focus on the efficacy and safety of these biologics, including anti-IL-1β (gevokizumab and canakinumab), anti-IL-1 R (anakinra), anti-IL-36 R (BI 655130), anti-tumor necrosis factor-α (etanercept, infliximab, and adalimumab), anti-IL-12/23 (ustekinumab), anti-IL-17A (secukinumab and ixekizumab), anti-IL-17RA (brodalumab), anti-IL-2 R (basiliximab), anti-IL-6 R (tocilizumab), and anti-IL-23 (risankizumab and guselkumab), for treating pustular psoriasis.

EXPERT OPINION

Patients with pustular psoriasis treated with biologics demonstrated positive responses. Anti-TNF-α is the most available biologics for the treatment of pustular psoriasis, and anti-IL-12/23 and anti-IL-17A might be considered as the first- or second-line therapy for moderate-to-severe and refractory pustular psoriasis. Anti-IL-17A can be used in the pustular psoriasis patients who failed to respond to anti-TNF agents and anti-IL-12/23. Therapeutic efficacy of biologics in pustular psoriasis might have no association with IL-36 RN mutation status.

Generalized Pustular Psoriasis: Clinical Management and Update on Autoinflammatory Aspects

Generalized pustular psoriasis (GPP) is a chronic, systemic inflammatory disease accompanied by high fever and general malaise. Diffuse erythema and swelling of the extremities occur, with multiple sterile pustules all over the body in GPP patients. GPP often relapses over the lifetime and can be life-threatening. Recent discoveries of the underlying molecular genetic basis of many cases of this disorder have provided major advances to clinicians and researchers towards an understanding of the pathomechanism of GPP. However, the therapeutic management of GPP still faces many challenges and much uncertainty, and an evidence-based review summarizing the available clinical data on the management of this heterogeneous disease is needed. The present review addresses challenges regarding the precise clinical diagnosis and evaluation of clinical symptoms in GPP. In addition, we update and briefly summarize the current understanding of molecular pathomechanisms behind GPP as an autoinflammatory keratinization disease. Recent publications have clarified the genetic backgrounds of patients with GPP and ethnic differences in predisposing factors. Although there are ethnic differences in the prevalences of these pathogenic alleles, from recent reports, at most 60.5% (IL36RN), 5.9% (CARD14), and 10.8% (AP1S3) of GPP patients have the mutations/variations of these genes. All the reported biologics studied seemed effective and relatively well tolerated. Although it is difficult to evaluate therapeutic efficacy from studies on just a few cases, recent findings suggest that biologics can be a useful, powerful tool for controlling skin and systemic inflammation in GPP and for improving the quality of life of GPP patients.

Joint AAD-NPF guidelines of care for the management and treatment of psoriasis with biologics

Psoriasis is a chronic, inflammatory multisystem disease that affects up to 3.2% of the US population. This guideline addresses important clinical questions that arise in psoriasis management and care, providing recommendations based on the available evidence. The treatment of psoriasis with biologic agents will be reviewed, emphasizing treatment recommendations and the role of the dermatologist in monitoring and educating patients regarding benefits as well as associated risks.

Japanese guidelines for the management and treatment of generalized pustular psoriasis: The new pathogenesis and treatment of GPP

Generalized pustular psoriasis (GPP) is a rare disease characterized by recurrent fever and systemic flushing accompanied by extensive sterile pustules. The committee of the guidelines was founded as a collaborative project between the Japanese Dermatological Association and the Study Group for Rare Intractable Skin Diseases under the Ministry of Health, Labour, and Welfare Research Project on Overcoming Intractable Diseases. The aim of the guidelines was to provide current information to aid in the treatment of patients with GPP in Japan. Its contents include the diagnostic and severity classification criteria for GPP, its pathogenesis, and recommendations for the treatment of GPP. Since there are few clinical trial data with high levels of evidence for this rare disease, recommendations by the committee are described in the present guidelines.

Clinical and immunological effects of adsorptive myeloid lineage leukocyte apheresis in patients with immune disorders

Adsorptive granulocyte and monocyte apheresis (GMA) with the Adacolumn^® is an extracorporeal treatment, which uses cellulose acetate (CA) beads as adsorptive leukocytapheresis carriers designed to remove elevated and potentially activated myeloid lineage leukocytes. Reports on the clinical efficacy of GMA in patients with skin lesions have appeared in the published work. Dermatological diseases, which are known to respond to GMA, include pyoderma gangrenosum, skin lesions of Behçet's disease, rheumatoid arthritis, pustular psoriasis, psoriatic arthritis, adult-onset Still's disease, Sweet's syndrome, cutaneous allergic vasculitis and systemic lupus erythematosus rashes. In association with clinical studies, efforts to understand the mechanisms of GMA have made significant progress. GMA selectively depletes elevated myeloid lineage leukocytes through binding between blood immunoglobulin G or complement iC3b, which form on the surface of CA beads and the Fcγ receptors or complement receptors expressed on the myeloid lineage cells. However, GMA has immunomodulatory effects including down-modulation of inflammatory cytokine profile, changes in leukocyte surface receptors and induction of regulatory T cells. These actions render GMA a unique non-pharmacological treatment option for patients with chronic dermatoid conditions, which are difficult to treat with pharmacological preparations.

Nanotechnological approaches for the effective management of psoriasis

Psoriasis is a chronic disorder with erythematous scaly patches, which typically affects the exposed surfaces of the body and scalp. Various factors such as bacterial infection, genetic and environmental factors, and immune disorders play an important role in causing psoriasis. Different types of psoriasis can be observed, such as guttate psoriasis, inverse psoriasis, pustular psoriasis, and psoriatic arthritis. Various ancient, topical, and systemic approaches have been used to control the disease, but have failed to achieve a complete reduction of the disease, besides causing toxic effects. Therefore, our main aim in this review article is to introduce the different advanced nanotechnological approaches for effective treatment of psoriasis.

IL-6 as a druggable target in psoriasis: focus on pustular variants

Psoriasis vulgaris (PV) is a cutaneous inflammatory disorder stemming from abnormal, persistent activation of the interleukin- (IL-)23/Th17 axis. Pustular psoriasis (PP) is a clinicopathological variant of psoriasis, histopathologically defined by the predominance of intraepidermal collections of neutrophils. Although PP pathogenesis is thought to largely follow that of (PV), recent evidences point to a more central role for IL-1, IL-36, and IL-6 in the development of PP. We review the role of IL-6 in the pathogenesis of PV and PP, focusing on its cross-talk with cytokines of the IL-23/Th17 axis. Clinical inhibitors of IL-6 signaling, including tocilizumab, have shown significant effectiveness in the treatment of several inflammatory rheumatic diseases, including rheumatoid arthritis and juvenile idiopathic arthritis; accordingly, anti-IL-6 agents may potentially represent future promising therapies for the treatment of PP.