Emerging therapies for atopic dermatitis: JAK inhibitors

Janus kinase inhibitors and adverse events of acne in dermatologic indications: a systematic review and network meta-analysis

Background: The occurrence of acne in patients treated with Janus kinase (JAK) inhibitors for skin diseases is a potential issue, which may reduce treatment adherence.

Purpose: To systematically analyzes randomized clinical trials (RCTs) of JAK inhibitors in dermatological indications for the risk of acne as an adverse event.

Methods: A meta-analysis of odds ratios (ORs) for acne incidence was conducted. Data were quantitatively synthesized using random-effects meta-analysis. Surface under the cumulative ranking curve (SUCRA) values representing the relative ranking probabilities of treatments were obtained. Analyses were performed using R statistical software version 4.4.0.

Results: A total of 11,396 patients were included from 24 studies. The incidence of acne for JAK inhibitors was ranked according to the SUCRA as follows: JAK1 inhibitors > TYK2 inhibitors > combined JAK1 and JAK2 inhibitors > combined JAK1 and TYK2 inhibitors > JAK3 + TEC inhibitors > pan-JAK inhibitors. ORs were higher for longer durations of drug use and larger dosages. Subgroup analyses by disease indication revealed increased ORs for psoriasis (5.52 [95% CI, 1.39-21.88]), vitiligo (4.15 [95% CI, 1.27-13.58]), alopecia areata (3.86 [95% CI, 1.58-9.42]), and atopic dermatitis (2.82 [95% CI, 1.75-4.54]). The use of JAK inhibitors in patients with systemic lupus erythematosus (SLE) may not significantly increase the incidence of acne.

Conclusions: There are higher rates of acne following treatment with JAK inhibitors for dermatologic indications, particularly with longer durations and larger dosages. Pan-JAK inhibitors exhibit the lowest incidence of acne.

Cytokine profile of the stratum corneum in atopic dermatitis lesions differs between the face and the trunk

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease with intense pruritus. Dupilumab, an anti-IL-4 receptor alpha antibody, has been revealed to be highly effective against the symptoms of AD; however, dupilumab takes longer to improve facial dermatitis in some patients. We thus examined whether the cytokine profiles in AD lesions differ between different anatomical locations.

METHODS

Stratum corneum was collected by tape stripping from lesions of the forehead and abdomen of 24 patients with moderate to severe AD and at the same anatomical locations of 14 control subjects. These samples were then used to determine the expression profiles of Th1, Th2, and Th17 cytokines/chemokines by multiplex assay and immunocytochemistry.

RESULTS

We found that cytokines/chemokines in the stratum corneum differed in their expression between different anatomical areas in AD patients and also in healthy control subjects. The expression of Th1 and Th17 cytokines/chemokines such as IP-10, MIG, and IL-17 tended to be higher in the forehead than in the abdomen in the AD group. Regarding Th2 cytokines/chemokines, some (e.g., IL-13 and IL-33) were highly expressed in the abdomen, others (e.g., IL-4 and IL-31) were highly expressed in the forehead, and a third group (e.g., TARC and TSLP) did not differ significantly in their expression between the forehead and abdomen. These patterns of Th2 cytokines were almost identical in the stratum corneum of healthy individuals.

CONCLUSIONS

Differences in cytokine/chemokine profiles in the stratum corneum between different anatomical areas might affect the responsiveness to AD treatment.

Unraveling the link between atopic dermatitis and autoimmune diseases in children: Insights from a large-scale cohort study with 15-year follow-up and shared gene ontology analysis

BACKGROUND

Atopic dermatitis and autoimmune diseases are highly heritable conditions that may co-occur from an early age.

METHODS

The primary study is a national administrative cohort study involving 499,428 children born in 2002, tracked until 2017. Atopic dermatitis was defined as five or more principal diagnoses of atopic dermatitis and two or more topical steroid prescriptions. We estimated the risks for the occurrence of 41 autoimmune diseases, controlling for risk factors. In addition, we sourced a gene library from the National Library of Medicine to conduct a comprehensive gene ontology. We used Gene Weaver to identify gene set similarity and clustering, and used GeneMania to generate a network for shared genes.

RESULTS

Exposed and unexposed groups included 39,832 and 159,328 children, respectively. During a mean follow-up of 12 years, the exposed group had an increased risk of autoimmune disease (hazard ratio, 1.27 [95 % confidence interval, 1.23-1.32]) compared to the unexposed group. The hazard ratios of autoimmune illnesses consistently increased with two- and five years lag times and alternative atopic dermatitis definitions. Shared genes between atopic dermatitis and autoimmune diseases were associated with comorbidities such as asthma, bronchiolitis, and specific infections. Genetic interactions of these shared genes revealed clustering in Th1, Th2, Th17, and non-classifiable pathways.

CONCLUSIONS

Atopic dermatitis was significantly associated with an increased risk of subsequent autoimmune disease. we identified the genetically associated disease in atopic dermatitis patients comorbid with autoimmune disease and demonstrated a genetic network between atopic dermatitis and autoimmune diseases.

Safety, efficacy, and pharmacokinetics of delgocitinib ointment in infants with atopic dermatitis: A phase 3, open-label, and long-term study

BACKGROUND

Delgocitinib ointment, a topical Janus kinase inhibitor, is used as treatment of patients with atopic dermatitis (AD) aged ≥2 years in Japan. Although initiating appropriate and early treatment upon the onset of AD in childhood is important, the safety and efficacy of delgocitinib ointment in infants with AD have not been established.

METHODS

This phase 3 study was conducted from October 2020 to June 2022 (number JapicCTI-205412). Eligible Japanese infants with AD aged 6 to <24 months received 0.25% or 0.5% of delgocitinib ointment twice daily for 52 weeks in an open-label uncontrolled manner. Topical corticosteroids were allowed to apply for worsening AD during the treatment period at the investigators' discretion.

RESULTS

A total of 22 infants were enrolled. Adverse events (AEs) were reported in 21 (95.5%) infants and were mostly mild. No treatment-related AEs were reported. The Modified Eczema Area and Severity Index (mEASI) score continuously decreased until week 4, and the score reduction was maintained until week 52. The mean percent changes in the mEASI score from baseline were -73.5% at week 4, -81.7% at week 28, and -81.9% at week 52. Delgocitinib was not detected in the plasma of most infants (68.2%-95.2%).

CONCLUSIONS

Delgocitinib ointment is well tolerated and effective for up to 52 weeks when applied to Japanese infants with AD.

Novel mediator in anaphylaxis: decreased levels of miR-375-3p in serum and within extracellular vesicles of patients

Introduction

Anaphylaxis is among the most severe manifestations of allergic disorders, but its molecular basis remains largely unknown and reliable diagnostic markers are not currently available. MicroRNAs (miRNAs) regulate several pathophysiological processes and have been proposed as non-invasive biomarkers. Therefore, this study aims to evaluate their involvement in anaphylactic reaction and their value as biomarkers.

Methods

Acute (anaphylaxis) and baseline (control) serum samples from 67 patients with anaphylaxis were studied. Among them, 35 were adults with drug-induced anaphylaxis, 13 adults with food-induced anaphylaxis and 19 children with food-induced anaphylaxis. The circulating serum miRNAs profile was characterized by next-generation sequencing (NGS). For this purpose, acute and baseline samples from 5 adults with drug-induced anaphylaxis were used. RNA was extracted, retrotranscribed, sequenced and the readings obtained were mapped to the human database miRBase_20. In addition, a system biology analysis (SBA) was performed with its target genes and revealed pathways related to anaphylactic mediators signaling. Moreover, functional and molecular endothelial permeability assays were conducted with miR-375-3p-transfected cells in response to cAMP.

Results

A total of 334 miRNAs were identified, of which 21 were significant differentially expressed between both phases. Extracellular vesicles (EVs) were characterized by Western blot, electron microscopy and NanoSight. A decrease of miR-375-3p levels was determined by qPCR in both serum and EVs of patients with anaphylaxis (****p<.0001). Precisely, the decrease of miR-375-3p correlated with the increase of two inflammatory cytokines: monocyte chemoattractant protein-1 (MCP-1) and granulocyte macrophage colony-stimulating factor (GM-CSF). On the other hand, functional and molecular data obtained showed that miR-375-3p partially blocked the endothelial barrier maintenance and stabilization by disassembly of cell-cell junctions exhibiting low Rac1-Cdc42 levels.

Discussion

These findings demonstrate a differential serum profile of circulating miRNAs in patients with anaphylaxis and exhibit the miR-375-3p modulation in serum and EVs during drug- and food-mediated anaphylactic reactions. Furthermore, the in silico and in vitro studies show a negative role for miR-375-3p/Rac1-Cdc42 in the endothelial barrier stability.

Evolving cognition of the JAK-STAT signaling pathway: autoimmune disorders and cancer

The Janus kinase (JAK) signal transducer and activator of transcription (JAK-STAT) pathway is an evolutionarily conserved mechanism of transmembrane signal transduction that enables cells to communicate with the exterior environment. Various cytokines, interferons, growth factors, and other specific molecules activate JAK-STAT signaling to drive a series of physiological and pathological processes, including proliferation, metabolism, immune response, inflammation, and malignancy. Dysregulated JAK-STAT signaling and related genetic mutations are strongly associated with immune activation and cancer progression. Insights into the structures and functions of the JAK-STAT pathway have led to the development and approval of diverse drugs for the clinical treatment of diseases. Currently, drugs have been developed to mainly target the JAK-STAT pathway and are commonly divided into three subtypes: cytokine or receptor antibodies, JAK inhibitors, and STAT inhibitors. And novel agents also continue to be developed and tested in preclinical and clinical studies. The effectiveness and safety of each kind of drug also warrant further scientific trials before put into being clinical applications. Here, we review the current understanding of the fundamental composition and function of the JAK-STAT signaling pathway. We also discuss advancements in the understanding of JAK-STAT-related pathogenic mechanisms; targeted JAK-STAT therapies for various diseases, especially immune disorders, and cancers; newly developed JAK inhibitors; and current challenges and directions in the field.

Dual Interleukin-4/Interleukin-13 Blocker-induced Arthralgia Treated Successfully with Upadacitinib in a Patient with Atopic Dermatitis

Abstract is missing (Short communication)

A randomised controlled trial testing the rebound-preventing benefit of four days of prednisolone during the induction of oclacitinib therapy in dogs with atopic dermatitis

BACKGROUND

A rebound of pruritus occasionally occurs after oclacitinib dose reduction in dogs with atopic dermatitis (AD).

OBJECTIVES

To determine whether an initial 4-day course of prednisolone decreases the probability of a pruritus rebound after reducing the frequency of oclacitinib administration.

ANIMALS

Forty dogs with mild-to-moderate AD lesions and moderate-to-severe pruritus.

MATERIALS AND METHODS

Dogs were randomised to receive oclacitinib at 0.4-0.6 mg/kg twice daily for 14 days then once daily, alone or with prednisolone at 0.5 mg/kg, orally, twice daily for the first 4 days. Clinicians graded the Canine Atopic Dermatitis Extent and Severity Index (CADESI)4 and 2D-investigator global assessment (IGA) before and after 28 days; owners assessed the pruritis Visual Analog Scale (PVAS)10 and Owner Global Assessment of Treatment Efficacy (OGATE) on Day (D)0, D4, D14, D21 and D28. We considered a rebound any increase greater than one PVAS10 grade at D21 compared to D14.

RESULTS

On D21, there were significantly fewer rebounds in the dogs receiving prednisolone (three of 20, 15%) compared to those given oclacitinib alone (nine of 20, 45%; Fisher's test, p = 0.041). Compared to oclacitinib monotherapy, the concurrent administration of prednisolone for the first 4 days led to significantly lower PVAS10 on D4 and D28, CADESI4 and 2D-IGA on D28, and OGATE on D21 and D28 (Wilcoxon-Mann-Whitney U-tests). Adverse effects of therapy were minor, intermittent and self-resolving.

CONCLUSIONS AND CLINICAL RELEVANCE

The initial addition of 4 days of prednisolone significantly decreased the probability of a rebound of pruritus 1 week after oclacitinib dose reduction. This short concomitant glucocorticoid administration led to a higher skin lesion improvement and improved perception of treatment efficacy with minimal adverse effects.

Advances in Current Drugs and Formulations for the Management of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disease with a complex pathophysiology. Treatment of AD remains challenging owing to the presence of a wide spectrum of clinical phenotypes and limited response to existing therapies. However, recent genetic, immunological, and pathophysiological insights into the disease mechanism resulted in the invention of novel therapeutic drug candidates. This review provides a comprehensive overview of current therapies and assesses various novel drug delivery strategies currently under clinical investigation. Further, this review majorly emphasizes on various topical treatments including emollient therapies, barrier repair agents, topical corticosteroids (TCS), phosphodiesterase 4 (PDE4) inhibitors, calcineurin inhibitors, and Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway inhibitors. It also discusses biological and systemic therapies, upcoming treatments based on ongoing clinical trials. Additionally, this review scrutinized the use of pharmaceutical inactive ingredients in the approved topical dosage forms for AD treatment.

An evaluation of abrocitinib for moderate-to-severe atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common itchy inflammatory skin condition that affects many individuals. For many years, the landscape of AD treatment remained unchanged; however, there has been developing therapies that directly target the underlying immunological mechanism of AD. Janus kinase (JAK) inhibitors are small molecules that have shown anti-inflammatory and anti-itch effects in AD. Recently, abrocitinib, an oral JAK 1 inhibitor, was approved by the Food and Drug Administration for atopic dermatitis.

AREAS COVERED

By downregulating the immune cascade, abrocitinib has demonstrated the ability to curb symptoms of AD, including rapidly reducing pruritus in 2-3 days, and is safe and well-tolerated overall despite a low increased risk in infection. The data discussed was obtained from a comprehensive literature review utilizing PubMed.

EXPERT OPINION

Abrocitinib has strong efficacy, likely due to its broader mechanism of action provided by the inhibition of key regulatory molecule, JAK. Results have demonstrated that it is more efficacious at curbing symptoms of AD than dupilumab, the current treatment of choice for refractory, moderate-to-severe AD. While abrocitinib provides a great alternative treatment, particularly for non-responders and AD subtypes, it also demonstrates a stronger side effect profile that must be considered.

Interleukin 13 receptor alpha 2 (IL13Rα2): Expression, signaling pathways and therapeutic applications in cancer

Interleukin 13 receptor alpha 2 (IL13Rα2) is increasingly recognized as a relevant player in cancer invasion and metastasis. Despite being initially considered a decoy receptor for dampening the levels of interleukin 13 (IL-13) in diverse inflammatory conditions, accumulating evidences in the last decades indicate the capacity of IL13Rα2 for mediating IL-13 signaling in cancer cells. The biological reasons behind the expression of this receptor with such extremely high affinity for IL-13 in cancer cells remain unclear. Elevated expression of IL13Rα2 is commonly associated with invasion, late stage and cancer metastasis that results in poor prognosis for glioblastoma, colorectal or breast cancer, among others. The discovery of new mediators and effectors of IL13Rα2 signaling has been critical for deciphering its underlying molecular mechanisms in cancer progression. Still, many questions about the effects of inflammation, the cancer type and the tumor degree in the expression of IL13Rα2 remain largely uncharacterized. Here, we review and discuss the current status of the IL13Rα2 biology in cancer, with particular emphasis in the role of inflammation-driven expression and the regulation of different signaling pathways. As IL13Rα2 implications in cancer continue to grow exponentially, we highlight new targeted therapies recently developed for glioblastoma, colorectal cancer and other IL13Rα2-positive tumors.

Manipulating Microbiota to Treat Atopic Dermatitis: Functions and Therapies

Atopic dermatitis (AD) is a globally prevalent skin inflammation with a particular impact on children. Current therapies for AD are challenged by the limited armamentarium and the high heterogeneity of the disease. A novel promising therapeutic target for AD is the microbiota. Numerous studies have highlighted the involvement of the skin and gut microbiota in the pathogenesis of AD. The resident microbiota at these two epithelial tissues can modulate skin barrier functions and host immune responses, thus regulating AD progression. For example, the pathogenic roles of Staphylococcus aureus in the skin are well-established, making this bacterium an attractive target for AD treatment. Targeting the gut microbiota is another therapeutic strategy for AD. Multiple oral supplements with prebiotics, probiotics, postbiotics, and synbiotics have demonstrated promising efficacy in both AD prevention and treatment. In this review, we summarize the association of microbiota dysbiosis in both the skin and gut with AD, and the current knowledge of the functions of commensal microbiota in AD pathogenesis. Furthermore, we discuss the existing therapies in manipulating both the skin and gut commensal microbiota to prevent or treat AD. We also propose potential novel therapies based on the cutting-edge progress in this area.

Old drugs, new tricks: Emerging role of drug repurposing in the management of atopic dermatitis

Atopic dermatitis is a chronic recurring pruritic inflammatory skin disease manifested by increased pro-inflammatory mediators which lead to dry, thickened, cracked, scaly skin. The current treatment options for atopic dermatitis management comprise drawbacks and leave unmet effective clinical needs. So, the approach for repurposing existing drugs for atopic dermatitis management may potentially overcome these unmet needs. Diseases that share the common pathophysiological pathways with atopic dermatitis can serve as a foundation for the repurposing of drugs. Drugs used in the management of cancer, rheumatoid arthritis, and other immune-mediated diseases such as psoriasis are under investigation to know the potential in atopic dermatitis management by utilizing repurposing strategies for a novel therapeutic indication. This review mainly envisages the probable repurposing of drugs for the management of atopic dermatitis disease; the barriers and regulatory aspects involved in the repurposing of existing drugs.

Break on through: The role of innate immunity and barrier defence in atopic dermatitis and psoriasis

The human skin can be affected by a multitude of diseases including inflammatory conditions such as atopic dermatitis and psoriasis. Here, we describe how skin barrier integrity and immunity become dysregulated during these two most common inflammatory skin conditions. We summarise recent advances made in the field of the skin innate immune system and its interaction with adaptive immunity. We review gene variants associated with atopic dermatitis and psoriasis that affect innate immune mechanisms and skin barrier integrity. Finally, we discuss how current and future therapies may affect innate immune responses and skin barrier integrity in a generalized or more targeted approach in order to ameliorate disease in patients.

Targeting Janus Kinase (JAK) for Fighting Diseases: The Research of JAK Inhibitor Drugs

Janus Kinase (JAK), a nonreceptor protein tyrosine kinase, has emerged as an excellent target through research and development since its discovery in the 1990s. As novel small-molecule targeted drugs, JAK inhibitor drugs have been successfully used in the treatment of rheumatoid arthritis (RA), myofibrosis (MF) and ulcerative colitis (UC). With the gradual development of JAK targets in the market, JAK inhibitors have also received very considerable feedback in the treatment of autoimmune diseases such as atopic dermatitis (AD), Crohn's disease (CD) and graft-versus host disease (GVHD). This article reviews the research progress of JAK inhibitor drugs: introducing the existing JAK inhibitors on the market and some JAK inhibitors in clinical trials currently. In addition, the synthesis of various types of JAK inhibitors were summarized, and the effects of different drug structures on drug inhibition and selectivity.

Gallic Acid Ameliorates Atopic Dermatitis-Like Skin Inflammation Through Immune Regulation in a Mouse Model

Background

Gallic acid (GA) has an anti-inflammatory effect by regulating inflammatory molecules. This study aimed to investigate the effect of GA on atopic dermatitis (AD)-like skin inflammation.

Methods

4-dinitrochlorobenzene (DNCB) was used to induce an AD-like skin inflammation model. The effect of GA on DNCB-induced inflammation was assessed by measuring the thickness and histopathological examination of the ear. Serum IgE and TNF-α levels were detected. The effect of GA on lymph nodes was determined by measuring the weights and mRNA/protein expression levels of TNF-α, IL-4, IFN-γ and IL-17. Ratio of Treg cells and Th17 cells was also analyzed.

Results

It was found that the thickness and pathology of the ear were significantly improved by GA in the DNCB-induced mice. Serum IgE and TNF-α levels were significantly reduced in GA-treated model mice compared to the model group. GA treatment lowered the weight of lymph node and the expression of mRNAs of TNF-α, IL-4, IFN-γ, and IL-17 of lymph node. In the ear, inflammatory factors (IL-4, IL-5, IL-17, or IL-23) showed a significant decrease in GA-treated model mice versus model mice, while the expression levels of IL-10 and TGF-β showed a great increase in GA-treated model mice. ROR-γt showed a decrease in GA-treated model group, along with an increase expression of SOCS3.

Conclusion

GA could ameliorate AD-like skin inflammation possibly through Th17 mediated immune regulation in a DNCB-induced mouse model.

Efficacy and Safety of SHR0302, a Highly Selective Janus Kinase 1 Inhibitor, in Patients with Moderate to Severe Atopic Dermatitis: A Phase II Randomized Clinical Trial

BACKGROUND

Atopic dermatitis is a chronic, inflammatory condition causing a substantial burden to patients and caregivers. SHR0302 is an oral, highly selective, Janus kinase 1 inhibitor under investigation for inflammatory skin diseases.

OBJECTIVE

The aim of this study was to investigate the efficacy and safety of SHR0302 in Chinese patients with moderate to severe atopic dermatitis.

DESIGN AND SETTING

A randomized, double-blind, placebo-controlled, multicenter, phase II trial was conducted in China between October 2019 and August 2020.

PARTICIPANTS

Patients (n = 105) aged 18-75 years with moderate to severe dermatitis and nonresponsive or intolerant to topical or conventional systemic treatments were included.

INTERVENTIONS

Patients were randomly assigned in a ratio of 1:1:1 to receive SHR0302 4 mg once daily, SHR0302 8 mg once daily, or placebo for 12 weeks.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was the proportion of patients achieving Investigator's Global Assessment (IGA) response (IGA of 0 [clear] or 1 [almost clear] with improvement of ≥2 grades) at week 12. Secondary efficacy assessments included Eczema Area and Severity Index (EASI) and pruritus Numerical Rating Scale (NRS) scores.

RESULTS

At week 12, IGA response was achieved in nine patients (25.7%; 90% confidence interval [CI] 13.6-37.9%; p = 0.022) in the SHR0302 4 mg group, 19 patients (54.3%; 90% CI 40.4-68.1%; p < 0.001) in the SHR0302 8 mg group, and two patients (5.7%; 90% CI 0.0-12.2%) in the placebo group. EASI75 was achieved in 51.4% (p = 0.013), 74.3% (p < 0.001), and 22.9% of patients in the SHR0302 4 mg, SHR0302 8 mg, and placebo groups, respectively, while an NRS ≥3-point improvement occurred in 65.7% (p < 0.001), 74.3% (p < 0.001), and 22.9% of patients, respectively. Treatment-emergent adverse events were reported in 60.0%, 68.6%, and 51.4% of patients in the SHR0302 4 mg, SHR0302 8 mg, and placebo groups, respectively. The adverse events were mild in most cases. Three serious adverse events were reported, all being worsening of atopic dermatitis. No serious infection was reported.

CONCLUSIONS AND RELEVANCE

Oral SHR0302 was effective and well tolerated in Chinese adult patients with moderate to severe atopic dermatitis.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04162899; URL: https://clinicaltrials.gov/ . Date first registered: 14 November 2019.

Real Clinical Practice Data of Monthly Dupilumab Therapy in Adult Patients With Moderate-to-Severe Atopic Dermatitis: Clinical Efficacy and Predictive Markers for a Favorable Clinical Response

Purpose

Dupilumab is recommended to be administered biweekly to treat adult patients with moderate-to-severe atopic dermatitis (AD). Real clinical practice data on the clinical efficacy of monthly dupilumab therapy are limited. We analyzed real clinical practice data on the clinical efficacy of monthly dupilumab therapy and predictive markers for favorable clinical responses to the therapy.

Methods

Medical records of 57 adult patients with moderate-to-severe AD who received dupilumab therapy every 4 weeks for 16 weeks were analyzed retrospectively. Eczema Area and Severity Index (EASI) were recorded at baseline and week 16. Clinical responses to monthly dupilumab therapy were defined as the proportion of patients with decreased EASI scores of at least 50% or 75% from baseline at week 16 (EASI-50 or EASI-75). Blood eosinophil counts and serum lactate dehydrogenase (LDH) levels were measured at baseline and week 16.

Results

Monthly dupilumab therapy showed EASI-50 and EASI-75 clinical responses in 48 (84.2%) and 27 (47.4%) of 57 patients at week 16, respectively. The percentage decrease in EASI scores from baseline at week 16 was significantly inversely correlated with baseline blood eosinophil count (correlation coefficient [r] = −0.405, P = 0.002) and baseline serum LDH level (r = −0.466, P < 0.001). The EASI-75 response rate was higher in patients with low (< 500/µL, 73.3%) than in those with high (≥ 500/µL, 37.5%) baseline blood eosinophil counts (P = 0.032), and was higher in patients with low (< 400 U/L, 55.6%) than those with high (≥ 400 U/L, 10.0%) baseline serum LDH levels (P = 0.013).

Conclusions

Monthly dupilumab therapy was clinically effective in adult patients with moderate-to-severe AD in real clinical practice. Baseline blood eosinophil count and serum LDH level could be predictive markers for clinical response to dupilumab therapy.

Atopic dermatitis: an expanding therapeutic pipeline for a complex disease

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a complex pathophysiology that underlies a wide spectrum of clinical phenotypes. AD remains challenging to treat owing to the limited response to available therapies. However, recent advances in understanding of disease mechanisms have led to the discovery of novel potential therapeutic targets and drug candidates. In addition to regulatory approval for the IL-4Ra inhibitor dupilumab, the anti-IL-13 inhibitor tralokinumab and the JAK1/2 inhibitor baricitinib in Europe, there are now more than 70 new compounds in development. This Review assesses the various strategies and novel agents currently being investigated for AD and highlights the potential for a precision medicine approach to enable prevention and more effective long-term control of this complex disease.

Recent advances in understanding of the complex phenotype and mechanisms underlying atopic dermatitis (AD) have revealed multiple new potential targets for pharmacological intervention. Here, Bieber reviews therapeutic strategies and assesses the expanding pipeline for the therapy of AD, highlighting the potential for a precision medicine approach to the management of this complex disorder.

Novel pathogenesis of atopic dermatitis from the view of cytokines in mice and humans

Type 2 immunity and inflammation underlie allergic skin disorders, such as atopic dermatitis (AD). In type 2 inflammation, IL-4, IL-13, and IL-5, which are signature type 2 cytokines, are mainly produced by type 2 helper T (Th2) cells and form the characteristic features of AD. Epithelial cell-derived cytokines such as IL-25, IL-33, and TSLP initiate type 2 inflammation by modulating various cells, including group 2 innate lymphoid cells. Moreover, IL-31, a newly identified type 2 cytokine produced mainly by Th2 cells, induces pruritus by acting on sensory neurons in the skin. Based on both basic and clinical findings, several biologics targeting Th2 cytokines have been developed and exhibited significant efficacy as therapeutic reagents for AD. We have summarized the roles of each cytokine (IL-4, 5, 13, 25, 31, and 33, and TSLP) in the development of type 2 inflammation, especially AD, from the view of basic studies in mice and clinical trials/observation in humans.

The IL-4, IL-13 and IL-31 pathways in atopic dermatitis

Introduction: Atopic dermatitis (AD) is the most common inflammatory skin disease. It has a complex pathophysiology, with a combination of immune dysregulation and intrinsic barrier defects driving cutaneous inflammation and allergic symptomatology. The IL-4, IL-13 and IL-31 inflammatory pathways have been identified as hallmark features in the pathogenesis of the disease, contributing uniquely and synergistically to immune and barrier abnormalities as well as the key symptoms, such as pruritis. Novel therapeutics that target these pathways have been under development to find treatments for AD.Areas covered: This review discusses the IL-4, IL-13 and IL-31 pathways in AD. We will also detail novel targeted therapeutics that have recently been or are currently in clinical trials for AD. A literature search was conducted by querying Scopus, Google Scholar, PubMed, and Clinicaltrials.gov up to January 2021 using combinations of the search terms 'IL-4' 'IL-13' 'IL-31' 'atopic dermatitis' 'immune pathway' 'biologics' 'novel therapeutics' 'JAK/STAT inhibitors.'Expert opinion: The complex pathophysiology of AD advocates for innovation. Novel minimally invasive sampling modalities such as tape stripping will allow for a broader characterization of the immunomechanisms behind AD pathophysiology. This will allow for the continued development of a personalized medicine approach to treat AD.

Improvement in sleep and itch and enhanced quality of life in adult patients with moderate-to-severe atopic dermatitis: results from a phase 3 trial of baricitinib therapy

BACKGROUND

Baricitinib previously demonstrated improvements in itch and sleep disturbance versus placebo in adults with moderate-to-severe atopic dermatitis (AD).

OBJECTIVES

Examine if itch and sleep improvements are associated with better quality of life (QoL) and productivity in patients with AD.

METHODS

Data were drawn from BREEZE-AD5 (NCT03435081). Itch and sleep improvement at Week 16 were defined using ≥4-point improvements in the Itch Numeric Rating Scale and ≥1.5 decreases in the number of nighttime awakenings since baseline, respectively. Patients with and without improvements were compared on Dermatology Life Quality Index (DLQI) and Work Productivity and Activity Impairment-AD scores. Changes from baseline were analyzed using ANCOVA with last observation carried forward. Proportions were analyzed using logistic regression with non-responder imputation.

RESULTS

Greater proportions of patients with versus without itch improvement indicated no impact of AD on QoL (37.7 vs. 1.8%). Patients with itch improvement had greater decreases in work time impaired (-29.3 vs. -5.6%). More patients with versus without sleep improvement reported no effect of AD on QoL (25.5 vs. 1.1%); patients with better sleep experienced larger reductions in work time spent impaired (-33.3 vs. -6.1%).

CONCLUSIONS

Patients with AD who experienced itch and sleep improvement had significantly better QoL and productivity.

Delgocitinib ointment in pediatric patients with atopic dermatitis: A phase 3, randomized, double-blind, vehicle-controlled study and a subsequent open-label, long-term study

BACKGROUND

Delgocitinib 0.5% ointment, a topical Janus kinase inhibitor, has been approved in Japan for adult patients with atopic dermatitis (AD).

OBJECTIVE

To evaluate the efficacy and safety of delgocitinib ointment in pediatric patients with AD.

METHODS

Part 1 of this study was a 4-week double-blind period in which Japanese patients aged 2 through 15 years were randomized in a 1:1 ratio to delgocitinib 0.25% ointment or vehicle ointment. Part 2 was a 52-week extension period. Eligible patients entered part 2 to receive 0.25% or 0.5% delgocitinib ointment.

RESULTS

At the initiation of the study, approximately half of the patients had moderate AD. At the end of treatment in part 1, the least-squares mean percent change from baseline in modified Eczema Area and Severity Index score, the primary efficacy endpoint, was significantly greater for delgocitinib ointment than for vehicle (-39.3% vs +10.9%, P < .001). In part 2, improvements in AD were also seen through week 56. Most adverse events were mild and unrelated to delgocitinib across the study periods.

LIMITATIONS

Only Japanese patients were included. In part 2, no control group was included and rescue therapy was allowed.

CONCLUSION

Delgocitinib ointment was effective and well tolerated when applied to Japanese pediatric patients with AD for up to 56 weeks.

Experimental Drugs with the Potential to Treat Atopic Eczema

INTRODUCTION

Eczema or atopic dermatitis (AD) is a chronically relapsing dermatosis characterized by pruritus and a significant impact on the quality of life.

METHODS

The authors undertook a structured search of peer-reviewed research articles from PubMed and Google Scholar. Recent and up-to-date studies relevant to the topic were included.

RESULTS

This report overviews current treatment and experimental drug for AD. Topical agents including topical phosphodiesterase E4 (PDE4) inhibitors such as crisaborole are efficacious in the treatment of AD with few side effects. Monoclonal antibodies such as dupilumab given subcutaneously are efficacious for more severe disease. Systemic treatment can ameliorate symptoms in severe and recalcitrant AD. New systemic treatment includes several traditional herbal formulations that have undergone clinical trials using modern research methodology to determine their efficacy and safety. AD is associated with many complicating psychosocial issues. Often suboptimal efficacy is due to unrealistic expectations and poor compliance making treatment difficult in spite of effective treatment and efforts in drug discovery. Randomized trials have shown that novel topical and subcutaneous medications are safe and efficacious. Regarding herbs, a methodology for the investigation of herbal medications is often flawed and scientific evidence is lacking. Experimental drugs include various biologics, PDE4 and JAK inhibitors in topical, oral, subcutaneous or intravenous forms are in various phases of trials.

CONCLUSION

Many novel medications demonstrate efficacy for AD. Experimental drugs include various biologics, PDE4 and JAK inhibitors are in various phases of trials.

IL13Rα2 Is Involved in the Progress of Renal Cell Carcinoma through the JAK2/FOXO3 Pathway

Previously, we reported a close relationship between type II IL4Rα and IL13Rα1 complex and poor outcomes in renal cell carcinoma (RCC). In this study, we investigated the clinicopathologically significant oncogenic role of IL13Rα2, a kind of the independent receptor for IL13, in 229 RCC patients. The high expression of IL13Rα2 was closely related to relapse-free survival in specific cancers in univariate and multivariate analysis. Then, the oncogenic role of IL13Rα2 was evaluated by performing in vitro assays for cell proliferation, cell cycle arrest, and apoptosis in A498, ACHN, Caki1, and Caki2, four kinds of RCC cells after transfection of siRNA against IL13Rα2. Cell proliferation was suppressed, and apoptosis was induced in A498, ACHN, Caki1, and Caki2 cells by knockdown of IL13Rα2. Interestingly, the knockdown of IL13Rα2 decreased the phosphorylation of JAK2 and increased the expression of FOXO3. Furthermore, the knockdown of IL13Rα2 reduced the protein interaction among IL13Rα2, phosphorylated JAK2, and FOXO3. Since phosphorylation of JAK2 was regulated by IL13Rα2, we tried to screen a novel JAK2 inhibitor from the FDA-approved drug library and selected telmisartan, a clinically used medicine against hypertension, as one of the strongest candidates. Telmisartan treatment decreased the cell proliferation rate and increased apoptosis in A498, ACHN, Caki1, and Caki2 cells. Mechanistically, telmisartan treatment decreased the phosphorylation of JAK2 and increased the expression of FOXO3. Taken together, these results suggest that IL13Rα2 regulates the progression of RCC via the JAK2/FOXO3-signaling path pathway, which might be targeted as the novel therapeutic option for RCC patients.

Biological Therapies for Atopic Dermatitis: A Systematic Review

BACKGROUND

Atopic dermatitis (AD) is a widely acquired, relapsing inflammatory skin disease. Biologics are now widely used in patients with moderate-to-severe AD.

OBJECTIVE

This work aims to summarize both label and off-label biologics on AD treatment in phase II and phase III stages, and compile evidence on the efficacy of the most-studied biologics.

METHODS

We conducted a comprehensive literature search through PubMed, EMBASE, and ClinicalTrials.gov to identify all documented biological therapies for AD. The criteria were further refined to focus on those treatments with the highest evidence level for AD with at least one randomized clinical trial supporting their use. Only studies or articles published in English were enrolled in this study.

FINDINGS

Primary searches identified 525 relevant articles and 27 trials. Duplicated articles and papers without a full text were excluded. Only completed trials were enrolled. We included 28 randomized controlled trials, 4 unpublished trials, 2 observational studies, and 1 meta-analysis. Eight kinds of biologics, including IL-4/IL-13 inhibitors, JAK inhibitors, anti-IL-13 antibodies, anti-IL-22 antibodies, anti-IL-33 antibodies, thymic stromal lymphopoietin inhibitor (TSLP), OX40 antibodies, and H4R-antagonists were included in this work. Dupliumab, as the most widely used and investigated biologic, was reported in 1 meta-analysis and 4 trials exploring its long-term use and application in both adults and pediatric patients. Besides dupilumab, four other IL-4/IL-13 inhibitors recruited were all randomized, clinical trials at phase 2-3 stage. Six different kinds of JAK inhibitors were summarized with strong evidence revealing their significant therapeutic effects on AD. There were 3 trials for nemolizumab, an anti-IL-13 antibody, all of which were in the phase 2 clinical trial stage. Results showed nemolizumab could be another alternative therapy for moderate-to-severe AD with long-term efficiency and safety.

CONCLUSION

The biological therapies with the most robust evidence on efficacy and long-term safety for AD treatment include dupilumab, barcitinib, abrocitinib, and delgocitinib. Most of the biologics mentioned in this review were still at the exploratory stage. This review will help practitioners advise patients seeking suitable biological therapies and offer experimental study directions for treatment.

The Efficacy and Safety of Abrocitinib as a Treatment Option for Atopic Dermatitis: A Short Report of the Clinical Data

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease that predominantly affects children. However, it can persist in adulthood and/or start at older ages. Both dysfunction of the epidermal barrier and immune dysregulation are known to play a role in the pathogenesis of AD. In the last years, numerous studies showed that Janus kinase (JAK) enzymes have a key role in AD pathogenesis. Therefore, oral and topical JAK inhibitors are new emerging treatments for AD. We report the data relating to abrocitinib, an oral JAK1 inhibitor. For this purpose, we examined articles already published concerning, in particular, concluded clinical trials. Furthermore, we also report the design of current ongoing clinical trials. The search was carried out considering the main search engines relating to medical literature and clinical trials. From all the data we collected, abrocitinib proved to be an effective drug in significantly reducing the severity of moderate-to-severe AD when compared to placebo. Furthermore, the efficacy was similar to other well-established treatment for AD, such as dupilumab. Adverse events were generally mild; indeed, the drug was definitively suspended only in few patients.

Janus kinase inhibitors for atopic dermatitis: a promising treatment modality

Atopic dermatitis (AD) is chronic, pruritic, inflammatory skin disease that affects a significant portion of the population in industrialized nations. For nonresponders to conventional therapies, AD can significantly reduce sleep quality and quality of life. AD pathogenesis is multifactorial and involves multiple immune pathways, with recent evidence of T helper (Th)2, Th17 and Th22 axis attenuation in various AD endotypes and racial subtypes. Inhibition of the conserved Janus kinase (JAK) signalling pathway represents a promising therapeutic avenue to reduce the activation of multiple proinflammatory mediators involved in AD pathogenesis. JAK inhibitors exist in both oral and topical forms with variable specificity for the receptor tyrosine kinases JAK1, JAK2, JAK3 and tyrosine kinase 2. Oral formulations include abrocitinib, upadacitinib, baricitinib and gusacitinib, and are most appropriate for patients with moderate to severe AD. Emerging topical formulation in development include ruxolitinib and deglocitinib, which may be used in patients with localized AD and also adjunctively with systemic therapy in patients with more severe disease. With observed rapidity in itch relief and accompanying dramatic reduction in inflammatory lesion count, JAK inhibitors represent a promising new treatment to revolutionize the management of AD.

Ruxolitinib Cream Has Dual Efficacy on Pruritus and Inflammation in Experimental Dermatitis

The goal of this study was to elucidate the anti-pruritic and anti-inflammatory efficacy of ruxolitinib cream in experimentally-induced dermatitis. Atopic dermatitis (AD), the most common chronic relapsing inflammatory skin disease, significantly impairs patients' quality of life, with pruritus being a common complaint. The sensation of itch results from the interplay between epidermal barrier dysfunction, upregulated immune signaling and the activation of the central nervous system. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway plays a central role in pro-inflammatory cytokine signaling in AD. Ruxolitinib cream is a potent and selective JAK1/2 inhibitor currently undergoing clinical evaluation in adults with mild-to-moderate AD (NCT03745638, NCT03920852 and NCT03745651). The efficacy of ruxolitinib cream was tested in murine models of acute and chronic dermatitis and was also characterized in an ex vivo human skin dermatitis model. Ruxolitinib cream was highly effective at ameliorating disease symptoms in multiple murine dermatitis models through downregulation of T helper (Th)2-driven inflammation, resulting in reduced skin thickening and decreased itch. Pathway analysis of mouse ear tissue and human skin explants underscored the role for ruxolitinib in ameliorating inflammation and reducing itch via modulation of the JAK-STAT pathway. Together, the data offer a strong rationale for the use of ruxolitinib cream as a potent therapeutic agent for the clinical management of atopic dermatitis.

Air pollution and skin disorders

Air pollution is being shown to play an increasing causation role in our most common skin diseases. Acne, hyperpigmentation, atopic dermatitis, and psoriasis have been shown to be influenced by air pollution. It is important for pollution to be added as a risk factor for these skin disorders, and thus we must discuss mitigating its negative affects with patients. Air pollution is the contamination of outdoor (ambient) and indoor (household) environments by any chemical, physical, or biological agent that modifies the natural characteristics of the atmosphere. Nearly all (90%) of the world's population experience daily pollution. In 2019, air pollution was considered by the World Health Organization to be the biggest environmental health risk to humans, responsible for killing more than 7 million people prematurely every year. Preliminary studies link air pollution to COVID-19 deaths, as there were high death tolls in some of the most globally polluted areas. Air pollution affects many organ systems such as cardiovascular, pulmonary, central nervous, reproductive, and integumentary systems. In this study, we detail the current evidence linking specific skin and health disorders to air pollution.

Emerging systemic JAK inhibitors in the treatment of atopic dermatitis: a review of abrocitinib, baricitinib, and upadacitinib

The Janus kinases (JAK) are a group of molecules, composed of JAK1, JAK2, JAK3, and tyrosine kinase 2 (TYK2), which are key components within the JAK–signal transducers and activators of transcription pathway, where cytokine receptor signaling takes place. These molecules play a foundational role in the underlying pathogenesis of multiple immune-related conditions such as atopic dermatitis (AD), rheumatoid arthritis, psoriatic arthritis, inflammatory bowel disease, and others. Thus far, JAK inhibitors for inflammatory conditions have only been marketed for the treatment of rheumatoid arthritis and psoriatic arthritis, but ongoing phase II and phase III clinical trials for other immune-mediated diseases, such as AD, have also shown promising results. This review summarizes the clinical data available from various trials and reports on the safety and efficacy of abrocitinib, baricitinib, and upadacitinib, the three oral systemic JAK inhibitors used in the treatment of AD. The safety and efficacy of JAK inhibitors for the treatment of AD are emerging in the literature. It is important that dermatologists are aware of any potential adverse events or risks associated with the use of JAK inhibitors in order to promote a higher standard of treatment and quality of living.

Abrocitinib for the treatment of atopic dermatitis

INTRODUCTION

Janus kinase (JAK) inhibitors are emerging treatments in dermatology. Also known as JAKinibs, these agents target JAK-signal transducers and activators of transcription (JAK-STAT) pathway for intracellular signaling. Among the various immune-mediated inflammatory skin diseases that the JAK-STAT pathway plays a role in, atopic dermatitis (AD) is an important one. AD has a complex and multifactorial pathophysiology that is not fully understood. Immune dysregulation can result in epidermal barrier disruption and intensify atopic dermatitis. The newly developed abrocitinib (PF-04965842) selectively inhibits the JAK1 protein, which is believed to modulate cytokines involved in AD pathophysiology.

AREAS COVERED

This work is a review of the current literature related to abrocitinib, including the phase I, II, and III clinical trials, for the treatment of AD. Immunological considerations of abrocitinib and JAK inhibition are also explored.

EXPERT OPINION

Abrocitinib is among the first JAK inhibitors evaluated for the treatment of AD. Similar to other JAKinhibs that mechanistically block the signaling of several cytokines, abrocitinib possesses both positive and negative clinical attributes. Nonetheless, the risk-benefit profile of abrocitinib remains favorable. Up to 61% of AD patients achieve an EASI 75 response while a minority of responding patients experience mild to moderate symptoms related to tolerability.

Novel therapies based on the pathophysiology of atopic dermatitis

Our understanding of the mechanisms underlying atopic dermatitis has been instrumental in the development of novel pharmacological agents. Worldwide, more than seventy companies are currently developing at least one new drug for the treatment of atopic dermatitis. Based on our current understanding of the pathophysiology of the disease, the present review article highlights the most important novel therapeutic strategies.

Abrocitinib: a potential treatment for moderate-to-severe atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common and debilitating dermatosis that often impacts the physical and psychological quality of life in children and adults. A limited number of treatment options are available for AD, and often these treatments result in an insufficient response or may be contraindicated for some patients. This treatment gap creates an increasing demand for alternative AD therapies. The Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathway is known to play a critical role in the dysregulation of immune responses in AD. Inhibition of the JAK enzymes in the JAK-STAT pathway has shown potential for the treatment of this chronic skin condition.

AREAS COVERED

We review the evolving efficacy and safety profile of abrocitinib, an oral JAK1 inhibitor, in the treatment of AD based on the data available from phase I, II, and III clinical trials.

EXPERT OPINION

Evidence supports clinical efficacy, improved pruritus and an acceptable safety profile, making abrocitinib a viable alternative to conventional AD therapies. Pivotal phase III trials included subjects aged 12 years and above, providing a new mechanism of action for future treatment of adolescent and adult AD. Further investigations are required to have a thorough understanding of abrocitinib in the treatment of AD.

Caffeoyl-Prolyl-Histidine Amide Inhibits Fyn and Alleviates Atopic Dermatitis-Like Phenotypes via Suppression of NF-κB Activation

Caffeic acid (CA) is produced from a variety of plants and has diverse biological functions, including anti-inflammation activity. It has been recently demonstrated that caffeoyl-prolyl-histidine amide (CA-PH), which is CA conjugated with proline-histidine dipeptide, relieves atopic dermatitis (AD)-like phenotypes in mouse. In this study, we investigated the molecular mechanism underlying CA-PH-mediated alleviation of AD-like phenotypes using cell line and AD mouse models. We confirmed that CA-PH suppresses AD-like phenotypes, such as increased epidermal thickening, infiltration of mast cells, and dysregulated gene expression of cytokines. CA-PH suppressed up-regulation of cytokine expression through inhibition of nuclear translocation of NF-κB. Using a CA-PH affinity pull-down assay, we found that CA-PH binds to Fyn. In silico molecular docking and enzyme kinetic studies revealed that CA-PH binds to the ATP binding site and inhibits Fyn competitively with ATP. CA-PH further suppressed spleen tyrosine kinase (SYK)/inhibitor of nuclear factor kappa B kinase (IKK)/inhibitor of nuclear factor kappa B (IκB) signaling, which is required for nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. In addition, chronic application of CA-PH, in contrast with that of glucocorticoids, did not induce up-regulation of regulated in development and DNA damage response 1 (REDD1), reduction of mammalian target of rapamycin (mTOR) signaling, or skin atrophy. Thus, our study suggests that CA-PH treatment may help to reduce skin inflammation via down-regulation of NF-κB activation, and Fyn may be a new therapeutic target of inflammatory skin diseases, such as AD.

IgE autoantibodies and autoreactive T cells and their role in children and adults with atopic dermatitis

The pathophysiology of atopic dermatitis (AD) is highly complex and understanding of disease endotypes may improve disease management. Immunoglobulins E (IgE) against human skin epitopes (IgE autoantibodies) are thought to play a role in disease progression and prolongation. These antibodies have been described in patients with severe and chronic AD, suggesting a progression from allergic inflammation to severe autoimmune processes against the skin. This review provides a summary of the current knowledge and gaps on IgE autoreactivity and self-reactive T cells in children and adults with AD based on a systematic search. Currently, the clinical relevance and the pathomechanism of IgE autoantibodies in AD needs to be further investigated. Additionally, it is unknown whether the presence of IgE autoantibodies in patients with AD is an epiphenomenon or a disease endotype. However, increased knowledge on the clinical relevance and the pathophysiologic role of IgE autoantibodies and self-reactive T cells in AD can have consequences for diagnosis and treatment. Responses to the current available treatments can be used for better understanding of the pathways and may shed new lights on the treatment options for patients with AD and autoreactivity against skin epitopes. To conclude, IgE autoantibodies and self-reactive T cells can contribute to the pathophysiology of AD based on the body of evidence in literature. However, many questions remain open. Future studies on autoreactivity in AD should especially focus on the clinical relevance, the contribution to the disease progression and chronicity on cellular level, the onset and therapeutic strategies.

Dupilumab for the treatment of adolescents with atopic dermatitis

INTRODUCTION

Dupilumab is a treatment option newly licensed for adolescents with moderate to severe atopic dermatitis (AD). It reduces type 2 inflammation by blocking the shared receptor subunit for IL-4/-13. Dupilumab affects three disease mechanisms in atopic dermatitis: the skin barrier, the Th2-cell differentiation and the class switch to IgE. This report is based on a systematic literature search of the PubMed Database.

AREAS COVERED

Dupilumab showed promising results in improving AD signs, symptoms and quality of life in adolescents with moderate to severe AD. The safety profile of dupilumab in adolescents with moderate to severe AD closely resembled the known safety profile of dupilumab in adults with moderate to severe AD. Injection-site reactions and conjunctivitis were the relevant side-effects. Skin infections were less frequently observed compared to placebo.

EXPERT COMMENTARY

Dupilumab was approved by the Food and Drug Administration in March 2019 and by the European Medicines Agency in August 2019 for the treatment of adolescents with moderate to severe atopic dermatitis whose disease is not adequately controlled with topical therapies or when those therapies are not advisable. Since it is the first licensed drug it will likely become the reference drug for adolescents with moderate to severe AD.

Critical Role of TSLP Receptor on CD4 T Cells for Exacerbation of Skin Inflammation

Thymic stromal lymphopoietin (TSLP) is a key cytokine that initiates and promotes allergic inflammation both in humans and mice. It is well known that TSLP is important in initial step of inflammation by stimulating dendritic cells to promote Th2 differentiation of naive T cells. However, TSLP is abundantly produced in the late phase of inflammation, as well; therefore, we focused on the function of TSLP in chronic Th2-type inflammation. By establishing a novel (to our knowledge) chronic allergic skin inflammation mouse model with repetitive challenges of hapten after sensitization, we demonstrated that CD4 T cell-specific deletion of TSLP receptor (TSLPR) resulted in near-complete ablation of ear swelling and infiltration of CD4 T cells and eosinophils, but after second challenge. Of note, TSLPR deletion on CD4 T cells did not affect acute inflammation. As expected, transfer of Ag-sensitized wild-type CD4T cells, but not of TSLPR-deficient CD4T cells, increased skin inflammation in the model upon challenge. Furthermore, production of IL-4 from TSLPR-deficient CD4T cells in inflamed ear lesions was markedly diminished, demonstrating that TSLP-dependent IL-4 production from CD4T cells was critical for the exacerbation of skin inflammation. Similar results were obtained in Th2-type allergic skin inflammation model using MC903. Collectively, these results indicate that TSLP acts directly on CD4 T cells to elicit pathogenesis of Th2 cells, thereby having a critical role in exacerbation of skin inflammation in the chronic phase.

Perphenazine Attenuates the Pro-Inflammatory Responses in Mouse Models of Th2-Type Allergic Dermatitis

Developing dermatitis therapeutics has been faced with challenges including adverse effects of topical steroid and high cost of new developing drugs. Here, we found the expression levels of dopamine receptor D2 is higher in skin biopsies of dermatitis patients and an oxazolone-induced animal model of dermatitis. We used perphenazine, an FDA-approved dopamine receptor antagonist to determine the therapeutic effect. Two different animal models including 12-o-tetradecanoylphorbol-13-acetate (TPA) and oxazolone (OXA)-induced dermatitis were employed. TPA and OXA-mediated ear swelling was attenuated by perphenazine. Moreover, perphenazine inhibited infiltrated mast cells into lesion area. We found levels of serum IgE, histamine and cytokines are decreased in mice cotreated with perphenazine and OXA compared to OXA-treated mice. Overall, this is a first study showing that the FDA-approved, anti-psychotic drug, perphenazine, alleviates animal models of dermatitis.

A biofabricated vascularized skin model of atopic dermatitis for preclinical studies

Three-dimensional (3D) biofabrication techniques enable the production of multicellular tissue models as assay platforms for drug screening. The increased cellular and physiological complexity in these 3D tissue models should recapitulate the relevant biological environment found in the body. Here we describe the use of 3D bioprinting techniques to fabricate skin equivalent tissues of varying physiological complexity, including human epidermis, non-vascularized and vascularized full-thickness skin tissue equivalents, in a multi-well platform to enable drug screening. Human keratinocytes, fibroblasts, and pericytes, and induced pluripotent stem cell-derived endothelial cells were used in the biofabrication process to produce the varying complexity. The skin equivalents exhibit the correct structural markers of dermis and epidermis stratification, with physiological functions of the skin barrier. The robustness, versatility and reproducibility of the biofabrication techniques are further highlighted by the generation of atopic dermatitis (AD)-disease like tissues. These AD models demonstrate several clinical hallmarks of the disease, including: (i) spongiosis and hyperplasia; (ii) early and terminal expression of differentiation proteins; and (iii) increases in levels of pro-inflammatory cytokines. We show the pre-clinical relevance of the biofabricated AD tissue models to correct disease phenotype by testing the effects of dexamethasone, an anti-inflammatory corticosteroid, and three Janus Kinase inhibitors from clinical trials for AD. This study demonstrates the development of a versatile and reproducible bioprinting approach to create human skin equivalents with a range of cellular complexity for disease modeling. In addition, we establish several assay readouts that are quantifiable, robust, AD relevant, and can be scaled up for compound screening. The results show that the cellular complexity of the tissues develops a more physiologically relevant AD disease model. Thus, the skin models in this study offer an in vitro approach for the rapid understanding of pathological mechanisms, and testing for efficacy of action and toxic effects of drugs.

Nintedanib ameliorates animal model of dermatitis

Nintedanib, a receptor tyrosine kinase (RTK) inhibitor has been developed as therapeutics for idiopathic pulmonary fibrosis and non-small lung cancer. We found that the expression levels of RTK, especially VEGFR1 is increased in skin biopsies of dermatitis patients from multiple independent datasets. Moreover, VEGFR1 is highly expressed by infiltrated cells in dermis from oxazolone (OXA) treated mice. Interestingly, nintedanib alleviates dermatitis symptom in OXA-induced animal model. Especially, levels of epidermis thickness, infiltrated immune cells including mast cells and eosinophils were decreased from mice cotreated with nintedanib and OXA compared with OXA treated mice. Moreover, serum IgE and Th2 cytokines including IL-4 and IL-13 were decreased by nintedanib treatment. These results suggest an evidence that nintedanib alleviates animal model of dermatitis.

Safety considerations when using drugs to treat pruritus

Introduction: Treatment for chronic pruritus ranges from use of topical formulations to newer biologic agents. Targeting treatment to the underlying etiology is key in reducing the burden of disease while avoiding systemic or adverse effects.Areas covered: This review details the effective medical treatments used in various etiologies of chronic itch with a focus on the potential adverse effects and safety data available for each.Expert opinion: New drug developments in the areas of neural signaling and immune targeting show great promise for the future of chronic itch treatment. These new therapies broaden the available treatment options but also pose new considerations for safety and adverse effects.

Delgocitinib ointment, a topical Janus kinase inhibitor, in adult patients with moderate to severe atopic dermatitis: A phase 3, randomized, double-blind, vehicle-controlled study and an open-label, long-term extension study

BACKGROUND

Previous studies showed the potential effectiveness of delgocitinib ointment, a novel topical Janus kinase inhibitor, in atopic dermatitis (AD).

OBJECTIVE

This study aimed to evaluate the efficacy and safety of delgocitinib 0.5% ointment.

METHODS

In part 1, a 4-week double-blind period, Japanese patients aged 16 years or older with moderate or severe AD were randomly assigned in a 2:1 ratio to delgocitinib 0.5% ointment or vehicle ointment. Eligible patients entered part 2, a 24-week extension period, to receive delgocitinib 0.5% ointment.

RESULTS

At the end of treatment in part 1, the least-squares mean percent changes from baseline in the modified Eczema Area and Severity Index score, the primary efficacy endpoint, were significantly greater in the delgocitinib group than in the vehicle group (-44.3% vs 1.7%, P < .001). The improvement in modified Eczema Area and Severity Index score was maintained in part 2. Most adverse events were mild and unrelated to delgocitinib across the study periods.

LIMITATIONS

Only Japanese patients were included. The vehicle-controlled period lasted only 4 weeks. In part 2, topical corticosteroids were allowed for the treatment of worsening of AD.

CONCLUSION

Delgocitinib ointment was effective and well tolerated in Japanese adult patients with moderate to severe AD for up to 28 weeks.

Profile of Baricitinib and Its Potential in the Treatment of Moderate to Severe Atopic Dermatitis: A Short Review on the Emerging Clinical Evidence

Atopic dermatitis (AD) is the most common chronic cutaneous inflammatory disease of childhood, affecting up to 25% of children; its prevalence in adulthood is currently unknown, since studies reported that AD may affect 0.3-14.3% of adult population. In the last decade, the advanced understanding of AD molecular pathways along with patient's and physician's demand for more effective therapies, led to the introduction of new therapeutic agents. Baricitinib is an oral JAK inhibitor highly selective for JAK1 and JAK2. Treatment with baricitinib improved the signs and symptoms of moderate-to-severe AD compared to placebo, but it will be essential to better understand the safety profile of this drug.