S1PR1 mediates Th17 cell migration from the thymus to the skin in health and disease.

Th17 cells play crucial roles in host defense and the pathogenesis of autoimmune diseases in the skin. While their differentiation mechanisms have been extensively studied, the origin of skin Th17 cells remains unclear. In this study, we analyzed single-cell RNA-sequencing data and identify the presence of Th17 cells in the human thymus. Thymic Th17 cells were characterized by high expression levels of Sphingosine-1-Phosphate Receptor 1 (S1PR1), a receptor crucial for T cell egress from lymphoid tissues. In mice, Th17 cell-specific knockout of S1pr1 resulted in the accumulation of Th17 cells in the thymus and a corresponding decrease in their numbers in the skin. Th17 cells that accumulated in the thymus exhibited a lower IL-17A production capacity compared to those in the skin, indicating that the local environment in the skin is important for maintaining the Th17 cell phenotype. Additionally, using a murine psoriasis model, we demonstrated that Th17 cell-specific knockout of S1pr1 reduced their migration to the inflamed skin, thereby ameliorating disease progression. Collectively, our data suggest that S1PR1 mediates Th17 cell migration from the thymus to the skin, thereby modulating their functional engagement in both homeostatic and inflammatory conditions.

Eczematous reactions in patients with plaque psoriasis receiving biological therapy: an observational study.

OBJECTIVE: The use of biologic agents, mainly tumor necrosis factor (TNF)-α and interleukin (IL)-17A inhibitors, was associated with cutaneous side effects, but the factors associated with eczematous reactions occurring during biologic treatments are not completely known. PATIENTS AND METHODS: An observational, retrospective, multicentre Italian study evaluated the clinical features and the management of eczematous eruptions in 54 patients with chronic plaque psoriasis who developed eczema after treatment with biological agents (anti-IL-17 or 23). RESULTS: Many of these patients had personal and family history of atopy. Eczematous reactions developed between a few days and 3 years after initiation of the biologic drug. The highest proportion of cases associated with eczematous reactions during biologic treatments was seen in patients on anti-IL-17 agents, including brodalumab. We observed that eczema rapidly remitted without relapse in all patients who switched to anti-IL-23 agents. Among our cases, fast responders to psoriasis therapy seem to have more persistent eczematous reactions. CONCLUSIONS: Patients with psoriasis and a history of atopic dermatitis should be treated with an IL-23 inhibitor due to its efficacy in psoriasis and the rarely reported eczematous reaction.

Biological treatment in chronic disease management: from asthma to ulcerative colitis. A review paper.

OBJECTIVE: Aim: The purpose of this article is to review the literature on the applicability of biologic agents, their mechanism of action, safety and factors affecting their choice in selected chronic conditions: asthma, psoriasis, ankylosing spondylitis and ulcerative colitis. PATIENTS AND METHODS: Materials and Methods: The electronic databases MEDLINE/PubMed and ScienceScholar were searched for studies published in English and Polish and indexed from 2018 to April 2024. Dodatkowo uwzgledniono Stanowisko Polskiego Towarzystwa Alergologicznego i Polskiego Towarzystwa Chorób Ukladu Oddechowego, rekomendacje Polskiego Towarzystwa Dermatologicznego, wytyczne Polskiego Towarzystwa Gastroenterologii i konsultanta krajowego w dziedzinie gastroenterologii oraz wytyczne Global Initiative for Asthma (GINA). CONCLUSION: Conclusions: 1. Biological therapy demonstrates a significant reduction in the severity of clinical symptoms and complications associated with a variety of disease entities. An additional value of this therapy is its effectiveness among patients who do not respond to traditional treatment strategies. 2. In the perspective of the future of biologic treatment, it is important to study potential interactions between biologic drugs and other therapeutic methods. 3. To maximize benefits while minimizing complications, requires an individualized approach for each patient.

Validation of TYK2 and exploration of PRSS36 as drug targets for psoriasis using Mendelian randomization.

Psoriasis is a chronic inflammatory skin disorder with multiple causes, including genetic and environmental factors. Despite advances in treatment, there remains a need to identify novel therapeutic targets. A Mendelian randomization (MR) analysis was conducted to identify therapeutic targets for psoriasis. Data on cis-expression quantitative trait loci were obtained from the eQTLGen Consortium (n = 31,684). Summary statistics for psoriasis (outcome) were sourced from the GWAS Catalog with a sample size of 484,598, including 5,427 cases and 479,171 controls. Colocalization analysis was used to assess whether psoriasis risk and gene expression were driven by shared single nucleotide polymorphisms. Drug prediction and molecular docking were utilized to validate the pharmacological value of the drug targets. The MR analysis found that 81 drug targets were significantly associated, and two (TYK2 and PRSS36) were supported by colocalization analysis (PP.H4 > 0.80). Phenome-wide association studies did not show any associations with other traits at the gene level. Biologically, these genes were closely related to immune function. Molecular docking revealed strong binding with drugs and proteins, as supported by available structural data. This study validated TYK2 as a drug target for psoriasis, in line with its existing clinical use, including the development of decucravacitinib. PRSS36 is a potential novel target requiring further investigation.

AI in Psoriatic Disease: Scoping Review.

BACKGROUND: Artificial intelligence (AI) has many applications in numerous medical fields, including dermatology. Although the majority of AI studies in dermatology focus on skin cancer, there is growing interest in the applicability of AI models in inflammatory diseases, such as psoriasis. Psoriatic disease is a chronic, inflammatory, immune-mediated systemic condition with multiple comorbidities and a significant impact on patients' quality of life. Advanced treatments, including biologics and small molecules, have transformed the management of psoriatic disease. Nevertheless, there are still considerable unmet needs. Globally, delays in the diagnosis of the disease and its severity are common due to poor access to health care systems. Moreover, despite the abundance of treatments, we are unable to predict which is the right medication for the right patient, especially in resource-limited settings. AI could be an additional tool to address those needs. In this way, we can improve rates of diagnosis, accurately assess severity, and predict outcomes of treatment. OBJECTIVE: This study aims to provide an up-to-date literature review on the use of AI in psoriatic disease, including diagnostics and clinical management as well as addressing the limitations in applicability. METHODS: We searched the databases MEDLINE, PubMed, and Embase using the keywords "AI AND psoriasis OR psoriatic arthritis OR psoriatic disease," "machine learning AND psoriasis OR psoriatic arthritis OR psoriatic disease," and "prognostic model AND psoriasis OR psoriatic arthritis OR psoriatic disease" until June 1, 2023. Reference lists of relevant papers were also cross-examined for other papers not detected in the initial search. RESULTS: Our literature search yielded 38 relevant papers. AI has been identified as a key component in digital health technologies. Within this field, there is the potential to apply specific techniques such as machine learning and deep learning to address several aspects of managing psoriatic disease. This includes diagnosis, particularly useful for remote teledermatology via photographs taken by patients as well as monitoring and estimating severity. Similarly, AI can be used to synthesize the vast data sets already in place through patient registries which can help identify appropriate biologic treatments for future cohorts and those individuals most likely to develop complications. CONCLUSIONS: There are multiple advantageous uses for AI and digital health technologies in psoriatic disease. With wider implementation of AI, we need to be mindful of potential limitations, such as validation and standardization or generalizability of results in specific populations, such as patients with darker skin phototypes.

The transcription regulators ZNF750 and LSD1/KDM1A dampen inflammation on the skin's surface by silencing pattern recognition receptors.

The surface of the skin is continually exposed to pro-inflammatory stimuli; however, it is unclear why it is not constantly inflamed due to this exposure. Here, we showed undifferentiated keratinocytes residing in the deep epidermis could trigger a strong inflammatory response due to their high expression of pattern recognition receptors (PRRs) that detect damage or pathogens. As keratinocytes differentiated, they migrated outward toward the surface of the skin and decreased their PRR expression, which led to dampened immune responses. ZNF750, a transcription factor expressed only in differentiated keratinocytes, recruited the histone demethylase KDM1A/LSD1 to silence genes coding for PRRs (TLR3, IFIH1/MDA5, and DDX58/RIG1). Loss of ZNF750 or KDM1A in human keratinocytes or mice resulted in sustained and excessive inflammation resembling psoriatic skin, which could be restored to homeostatic conditions upon silencing of TLR3. Our findings explain how the skin's surface prevents excessive inflammation through ZNF750- and KDM1A-mediated suppression of PRRs.

Identification of neutrophil extracellular traps genes as potential biomarkers in psoriasis based on bioinformatics analysis.

The epidermal infiltration of neutrophils is a hallmark of psoriasis (PSO) and its activation leads to the release of neutrophil extracellular traps (NETs). However, the molecular mechanism of NETs-related genes (NETRGs) has not been extensively studied in PSO. To define NETs-related-biomarkers for PSO. The GSE13355 and GSE78097 datasets, and NETRGs gene set were included in this study. The datasets used in this study were all microarray data. The weighted gene co-expression network analysis (WGCNA) and machine learning algorithms were used to mine key genes. Later on, single-gene gene set enrichment analysis (GSEA) and immune infiltration analysis were implemented. Finally, the expression of key genes was verified using quantitative real-time fluorescence PCR (qRT-PCR). A total of 3 key genes (S100A9, CLEC7A, and CXCR4) were derived, and they all had excellent diagnostic performance. The single-gene GSEA enrichment results indicated that the key genes were mainly enriched in the chemokine signaling pathway and humoral immune response in the high-expression group, while focal adhesion was enriched in the low-expression group. The correlation analysis indicated that all key genes were strongly negatively correlated with resting mast cells and TGF-ß family member receptor, while they were strongly positively correlated with activated CD4 memory T cells and antigen processing and presentation. Lastly, the experimental results showed that the expression trends of key genes were consistent with public database. In this study, we successfully screened three potential PSO diagnostic genes (S100A9, CLEC7A and CXCR4) that were closely related to NETs, and these findings not only provided new molecular marker candidates for the precise diagnosis of PSO patients, but also revealed possible future therapeutic targets. However, further in-depth research and validation were necessary.

Botulinum Toxin Treatment of Psoriasis-A Comprehensive Review.

A literature search on the subject of botulinum toxin treatment in psoriasis found 15 relevant articles, 11 on human subjects and 4 on animal studies. Of the human data, eight were clinical trials and three were single case reports. Seven out of eight clinical trials, all open-label, reported improvement in psoriasis following intradermal or subcutaneous botulinum toxin injections. One double-blind, placebo-controlled study, which used a smaller dose than the open-label studies, did not note a healing effect. Animal studies have shown that injection of botulinum toxins in the skin heals psoriatic skin lesions and can reduce the level of interleukins (ILs) and cytokines as well as inflammatory cells in psoriatic plaques. There is a need for controlled, blinded studies conducted in larger numbers of patients with doses that have shown promise in open-label studies.

Clinical features and effects of cyclosporine in the treatment of psoriasis: a systemic review and meta-analysis.

To systematically evaluate clinical features and effects of cyclosporine in the treatment of psoriasis. Databases including Web of Science, PubMed, The Cochrane Library, Embase, CNKI, Wan Fang, and VIP were electronically searched for studies on the use of cyclosporine in the treatment of psoriasis, from inception to March 2024. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies. A meta-analysis was then performed. A total of 12 randomised controlled trial (RCT) studies were included. Compared with the control group, there were statistically significant differences in the effective rate, recurrence rate, erythema regression time, pustular resolution time, fever resolution time, and Psoriasis Area Severity Index (PASI) score of cyclosporine in the treatment of psoriasis. Moreover, the sub-group analysis showed that the effective rate of patients aged less than 40 years was significantly higher than that of the control group and the recurrence rate was significantly lower than that of the control group. The effective rate of psoriasis patients without nail lesions was significantly higher than that of control group. The effective rate of cyclosporin was significantly higher than that of dexamethasone acetate. There was no significant change in pooled sensitivity and specificity after each study was excluded one by one, indicating the stability of the meta-analysis. Cyclosporine had a high effective rate and low recurrence rate in the treatment of psoriasis, but it still had similar rate of adverse reactions compared to other drugs. This study systematically evaluated the effect of cyclosporine in the treatment of psoriasis and provided reference for clinical practice.

Unveiling the genetic link and pathogenesis between psoriasis and IgA nephropathy based on Mendelian randomization and transcriptome data analyses.

It has been reported that many people with psoriasis have been diagnosed with secondary IgA nephropathy (IgAN). However, the mechanisms behind the association between psoriasis and IgAN have not been well clarified. The connection between psoriasis and IgAN deserves deeper exploration. Mendelian randomization (MR) analysis would be employed to explore the link of causality between IgAN and psoriasis, psoriasis vulgaris, other and unspecified psoriasis, guttate psoriasis, and arthropathic psoriasis. Transcriptomic analyses were carried out against the Gene Expression Omnibus databases. We identified crosstalk genes through the analysis of Differentially expressed genes and weight gene co-expression network analysis. Functional annotations were enriched for these crosstalk genes. Subsequently, we established a protein-protein interaction network, and candidate genes would be discovered through the utilization of the MCODE and CytoHubba plug-in applications. Lastly, the predictive efficacy of these genes was examined via creating receiver operating characteristic curves. The MR analysis suggested that psoriasis vulgaris patients were at a higher risk for IgAN. [OR = 1.040, 95%CI (1.005,1.076), p = 0.026 < 0.05]. Additionally, arthropathic psoriasis may augment the incidence of IgAN [OR = 1.081, 95%CI (1.040-1.124), p < 0.01] in the European population. Through the analysis of DEGs and WGCNA, we identified 12 significant genes (NETO2, RRM2, SLAMF7, GBP1, KIF20A, CCL4, MMP1, IL1ß, NDC80, CXCL9, C15orf48, GSTA3), which may be potential crosstalk genes between the two diseases. Then, the functional annotation results indicated that the crosstalk genes seemed primarily involved in immune and inflammatory responses. By establishing the PPI network, we further discovered that CXCL9, IL1ß, CCL4, and MMP1 play a vital part in psoriasis and IgAN, and all have good diagnostic values. Our MR analysis provided evidence that genetic vulnerability to IgAN may be associated with an elevated risk of psoriasis vulgaris and arthropathic psoriasis respectively among Europeans. Doctors should be aware of these associations when patients with psoriasis present with renal dysfunction, especially those with psoriasis vulgaris and arthropathic psoriasis. Chronic inflammation, drug effects, and immunity may contribute to the generation and development of both diseases. IL1ß, CXCL9, CCL4, and MMP1 may be core biomarkers for psoriasis and IgAN.

IL-23 inhibition for chronic inflammatory disease.

Biological monoclonal antibody drugs inhibit overactive cytokine signalling that drives chronic inflammatory disease in different organ systems. In the last 10 years, interleukin (IL)-23 inhibitors have attained an important position in the treatment of psoriatic skin and joint disease as well as inflammatory bowel diseases. Addressing an upstream pathological mechanism shared between these disorders, this drug class has high efficacy rates and a durable response that extends dosing intervals up to 3 months. Pooled clinical trial data show objective disease improvement for more than 70% of patients with psoriasis and up to 50% of patients with inflammatory bowel disease. The first antibody inhibitor for IL-23A targeted a p40 subunit shared with IL-12. Subsequently, even greater improvement was established for inhibitors of the p19 protein unique to IL-23A. IL-23 p19 inhibitors elicit clinical response in both bio-naive and bio-exposed patients and show superiority to tumour necrosis factor α inhibitors in plaque psoriasis. Reported differences in efficacy between p19 inhibitors suggest that individual drug action might be modulated by antibody affinity. Although long-term safety data are accumulating, rates of serious adverse events and infections for interleukin (IL)-23 inhibitors are similar to the rates for placebo across approved indications.

Effectiveness of tildrakizumab 200 mg: an Italian multicenter study.

Introduction: Psoriasis is a chronic immune-mediated disease that can be challenging to treat, especially in patients with severe disease or high body weight. Tildrakizumab is a monoclonal antibody which inhibits IL-23, approved for moderate-to-severe psoriasis with a standard 100 mg dose. A 200 mg dose may provide greater efficacy for patients over 90 kg or with high disease burden.Methods: This multicenter, prospective study evaluated the effectiveness and safety of tildrakizumab 200 mg in patients with moderate-to-severe psoriasis, focusing on those with specific challenges: body weight over 90 kg, baseline PASI ≥20, and difficult-to-treat areas. The study also compared bio-naive versus bio-experienced and male versus female patients. Adults received tildrakizumab 200 mg subcutaneously at weeks 0 and 4, then every 12 weeks.Results: Clinical improvements were assessed using PASI, DLQI, genital PASI, and NAPSI scores. After 24 weeks, the mean PASI score dropped from 14.6 to 0.4, with PASI 90 and PASI 100 scores exceeding 80% (100.0% and 80.3%, respectively). DLQI scores improved from 14.2 to 1.8, and significant improvements were seen in genital PASI and NAPSI scores. No significant adverse events occurred.Conclusions: Tildrakizumab 200 has been shown to be an effective therapeutic option, particularly for patients with high body weight, significant disease burden, and involvement of sensitive areas with no new safety signals.

The Pathophysiology, Diagnosis and Management of Chronic Inflammatory Skin Diseases.

Atopic dermatitis, psoriasis, rosacea, seborrheic dermatitis, allergic contact dermatitis, and irritant contact dermatitis comprise a large proportion of chronic inflammatory dermatoses. This paper reviews the clinical presentations, pathophysiology, and therapeutics of inflammatory dermatoses, highlighting recent drug developments such as lebrikizumab for atopic dermatitis as well as deucravacitinib and spesolimab for psoriasis. Chronic inflammatory dermatoses significantly impact patient quality of life and contribute to substantial healthcare costs. Effective management of severe cases often requires systemic therapies and biological therapies. A thorough clinical evaluation with a tailored therapeutic approach is essential for delivering optimal care to individuals with chronic inflammatory skin diseases.

BML-111 Modulates and Alleviates p38/MAPK Signaling Pathway and Th1/Th2/Th17 Cytokine Response in Murine Psoriasis-Like Dermatitis.

BACKGROUND: Psoriasis is a prevalent cutaneous inflammatory disorder characterized by elevated keratinocyte inflammation. 5(S)-6(R)-7-trihydroxyheptanoic-acid-methyl-ester (BML-111), an established analogue of lipoxin A4, is known for its potent anti-inflammatory properties. However, the precise role of BML-111 within a murine psoriasis-like dermatitis model requires further clarification. This research aims to investigate the modulatory effects of BML-111 on inflammatory responses, the p38/mitogen-activated protein kinase (MAPK) signaling cascade, and T helper type 1 (Th1), Th2, and Th17 cell responses within the context of a murine psoriasis-like dermatitis model. METHODS: A psoriasis-like dermatitis model was established by applying 5% imiquimod (IMQ) cream to the backs of C57BL/6 mice, which were pretreated intraperitoneally with or without BML-111 prior to IMQ application. Hematoxylin-eosin staining was utilized to detect the pathological alterations of the murine dorsal skin tissue. Furthermore, the psoriasis area and severity index (PASI) scoring system was used to assess the dynamic cutaneous alterations in the mice. The levels of tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin (IL)-1ß, IL-6, IL-4, and IL-17A in the murine serum samples were quantified by means of enzyme-linked immunosorbent assays (ELISA). Western blotting was conducted to detect the proteins of TNF-α, IL-1ß, IL-6, phospho-p38 (p-p38), and p38 in murine skin tissues. Lastly, a flow cytometry analysis was executed to evaluate the expression of peripheral blood Th1/Th2/Th17 cell subsets. RESULTS: BML-111 attenuated IMQ-induced pathological changes in skin tissue of psoriasis-like dermatitis mice. BML-111 treatment substantially reduced TNF-α, IL-1ß, IL-6, IFN-γ and IL-17A levels and elevated IL-4 levels in serum and skin lesion tissues of IMQ-induced mice (p < 0.01, p < 0.01, p < 0.01, p < 0.05, p < 0.05, p < 0.05, respectively). The ratio of Th1/Th17 cells in the peripheral blood of BML-111-treated mice was substantially diminished and the ratio of Th2 cells was substantially augmented (p < 0.05, p < 0.01, p < 0.001, respectively). Mechanistically, p-p38 protein level was substantially reduced in the skin tissues of BML-111-treated mice (p < 0.05). While, dehydrocorydaline (DHC, a p38/MAPK pathway agonists) reversed the reduction of p-p38 protein level induced by BML-111 treatment in psoriasis-like mice (p < 0.05). CONCLUSION: BML-111 modulates the p38/MAPK signaling pathway and Th1/Th2/Th17 cytokine response, and alleviates psoriasis-like dermatitis in mice.

Psoriasis localization patterns in the Swiss Psoriasis Registry (SDNTT) over 11 years: an analysis by sex and age.

Real-world data on anatomically localized psoriasis and its response to systemic therapy across different age-groups and sexes is limited. This study aimed to evaluate the severity and distribution of psoriasis over time in female and male patients receiving systemic therapies, categorized by age within the Swiss psoriasis registry (SDNTT). Patient-data was obtained over 11 years through the SDNTT. The localized Psoriasis Area and Severity Index (locPASI) of the head, trunk, upper and lower extremities was analyzed over two years following the start of systemic non-/biologic treatment. A total of 316 female and 517 male patients were analyzed. Male patients had a higher baseline locPASI for legs, trunk and arms (p < 0.001), but not for the head (p = 0.961). The locPASI for the head in younger female patients (18-40 years) had a higher score than those aged 55 + (p = 0.022) and after two years, middle aged (41-54) showed a lower score compared to younger patients (p = 0.045). Younger male patients revealed a lower score after two years of therapy in the leg- and arm-area compared to older (p = 0.018 and p = 0.048, respectively). Female patients on non-biologics had a fast initial response, converging with male patients' scores over 24 months. Over 75% locPASI reduction was observed for female head-area (81.4%), male trunk (82.7%) and legs (76.1%). Absolute locPASI ≤ 2 was achieved 3-6 months for all locations with interleukin (IL)-17, IL-12/23 and IL-23-inhibitors, except for the legs of male patients on anti-IL-17 and female patients on anti-IL-12/23 and -IL-23. After two years, male patients did not achieve a locPASI ≤ 2 for any biologic-treatment in the legs, nor for the arms on anti-TNF-α. Significant disparities in localized PASI were observed between female and male patients. The age, sex and severity of distinct localizations should be considered to optimize treatment goals.

Development of 3D printed microneedles of varied needle geometries and lengths, designed to improve the dermal delivery of topically applied psoriasis treatments.

The aim of this study was to investigate the impact of using microneedle patches in addition to topical therapy for the treatment of psoriasis. Using continuous liquid interface production (CLIP) 3D printing we manufactured round microneedle array patches (MAPs) with a diameter of 14 mm. Needle geometries were varied from square pyramidal, conical, and obelisk, with varied needle lengths of 400 µm, 600 µm, 800 µm, or 1000 µm. MAPs were characterized for force to fracture, skin penetration, skin damage, as well as their ability to deliver a novel oleogel-based corticosteroid (betamethasone dipropionate (BDP) formulation into ex-vivo porcine skin. We found that the obelisk shaped MAPs are more durable compared to the conical and square pyramidal-shaped MAPs. When the obelisk shaped MAPs were used in combination with the oleogel-based BDP formulation, the amount of BDP penetrating the skin was significantly increased with greater needle lengths.

The Contribution of the Skin Microbiome to Psoriasis Pathogenesis and Its Implications for Therapeutic Strategies.

Psoriasis is a common chronic inflammatory skin disease, associated with significant morbidity and a considerable negative impact on the patients' quality of life. The complex pathogenesis of psoriasis is still incompletely understood. Genetic predisposition, environmental factors like smoking, alcohol consumption, psychological stress, consumption of certain drugs, and mechanical trauma, as well as specific immune dysfunctions, contribute to the onset of the disease. Mounting evidence indicate that skin dysbiosis plays a significant role in the development and exacerbation of psoriasis through loss of immune tolerance to commensal skin flora, an altered balance between Tregs and effector cells, and an excessive Th1 and Th17 polarization. While the implications of skin dysbiosis in psoriasis pathogenesis are only starting to be revealed, the progress in the characterization of the skin microbiome changes in psoriasis patients has opened a whole new avenue of research focusing on the modulation of the skin microbiome as an adjuvant treatment for psoriasis and as part of a long-term plan to prevent disease flares. The skin microbiome may also represent a valuable predictive marker of treatment response and may aid in the selection of the optimal personalized treatment. We present the current knowledge on the skin microbiome changes in psoriasis and the results of the studies that investigated the efficacy of the different skin microbiome modulation strategies in the management of psoriasis, and discuss the complex interaction between the host and skin commensal flora.

The regulatory T cell-selective interleukin-2 receptor agonist rezpegaldesleukin in the treatment of inflammatory skin diseases: two randomized, double-blind, placebo-controlled phase 1b trials.

Regulatory T cell (Treg) impairment is implicated in the pathogenesis of chronic inflammatory diseases, but relatively little is known about the therapeutic potential of Treg restoration. Here we present clinical evidence for the Treg-selective interleukin-2 receptor agonist rezpegaldesleukin (REZPEG) in two randomized, double-blind, placebo-controlled Phase 1b trials in patients with moderate-to-severe atopic dermatitis (AD) (NCT04081350) or chronic plaque psoriasis (PsO) (NCT04119557). Key inclusion criteria for AD included an Eczema Area and Severity Index (EASI) score ≥ 16 and a validated Investigator Global Assessment for Atopic Dermatitis (vIGA-AD) ≥ 3, and for PsO included a Psoriasis Area and Severity Index (PASI) score of ≥ 12 and a static Physician's Global Assessment (sPGA) score of ≥ 3. REZPEG is safe and well-tolerated and demonstrates consistent pharmacokinetics in participants receiving subcutaneous doses of 10 to 12 µg/kg or 24 µg/kg once every 2 weeks for 12 weeks, meeting the primary and secondary objectives, respectively. AD patients receiving the higher dose demonstrate an 83% improvement in EASI score after 12 weeks of treatment. EASI improvement of ≥ 75% (EASI-75) and vIGA-AD responses are maintained for 36 weeks after treatment discontinuation in 71% and 80% of week 12 responders, respectively. These exploratory clinical improvements are accompanied by sustained increases in CD25bright Tregs. REZPEG thus represents a homeostatic approach to cutaneous disease therapy and holds clinical potential in providing long-term, treatment-free disease control.