JAK/STAT inhibitors for the treatment of atopic dermatitis

Yinxie I Formula attenuates imiquimod-induced psoriasis-like skin inflammation via IL-23/IL-17 axis

Psoriasis is considered a chronic inflammatory skin disorder characterized by keratinocytes hyperproliferation. The IL-23/IL-17 immune pathway has been substantiated in numerous studies to be closely associated with psoriasis progression. Yinxie I Formula is a traditional Chinese medicine made from 9 herbal medicines, which has excellent clinical efficacy in psoriasis. However, to date, the mechanism of action of Yinxie I Formula against psoriasis remains unknown. In this perspective, we discuss the efficacy of Yinxie I Formula in mice with imiquimod (IMQ) induced psoriasis. Yinxie I Formula significantly reduced the area of skin lesions and the inflammatory response in mice with psoriasis. Furthermore, Yinxie I Formula alleviated the expression levels of inflammation-related genes IL-6, IL-17 A, IL-22, IL-23, TNF-α and IL-23, IL-18, IL-6 and IL-1β-related proteins and alleviated the abnormal surge of dendritic cells, macrophages and T cells in the skin and spleen. Meanwhile we found that Yinxie I Formula reduced the release of NO, TNF-α, IL-1β and IL-23 in lipopolysaccharide-induced mouse macrophage RAW264.7 cell line. The results suggest that the therapeutic mechanism of Yinxie I Formula may also be correlated with the STAT signaling pathway. We further analyzed the active ingredient of Yinxie I Formula, Buddleoside, which may be the main substance that exerts the therapeutic effect. In conclusion, we have investigated that Yinxie I Formula attenuates the IMQ-induced inflammatory response in psoriasis by inhibiting the IL-23/IL-17 axis, which lays the foundation for the antipsoriasis mechanism and provides a theoretical basis for the clinical promotion of Yinxie I Formula.

JAK/STAT Inhibition Normalizes Lipid Composition in 3D Human Epidermal Equivalents Challenged with Th2 Cytokines

Derangement of the epidermal barrier lipids and dysregulated immune responses are key pathogenic features of atopic dermatitis (AD). The Th2-type cytokines interleukin IL-4 and IL-13 play a prominent role in AD by activating the Janus Kinase/Signal Transduction and Activator of Transcription (JAK/STAT) intracellular signaling axis. This study aimed to investigate the role of JAK/STAT in the lipid perturbations induced by Th2 signaling in 3D epidermal equivalents. Tofacitinib, a low-molecular-mass JAK inhibitor, was used to screen for JAK/STAT-mediated deregulation of lipid metabolism. Th2 cytokines decreased the expression of elongases 1, 3, and 4 and serine-palmitoyl-transferase and increased that of sphingolipid delta(4)-desaturase and carbonic anhydrase 2. Th2 cytokines inhibited the synthesis of palmitoleic acid and caused depletion of triglycerides, in association with altered phosphatidylcholine profiles and fatty acid (FA) metabolism. Overall, the ceramide profiles were minimally affected. Except for most sphingolipids and very-long-chain FAs, the effects of Th2 on lipid pathways were reversed by co-treatment with tofacitinib. An increase in the mRNA levels of CPT1A and ACAT1, reduced by tofacitinib, suggests that Th2 cytokines promote FA beta-oxidation. In conclusion, pharmacological inhibition of JAK/STAT activation prevents the lipid disruption caused by the halted homeostasis of FA metabolism.

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.

ATI-1777, a Topical Jak1/3 Inhibitor, May Benefit Atopic Dermatitis without Systemic Drug Exposure: Results from Preclinical Development and Phase 2a Randomized Control Study ATI-1777-AD-201

Introduction

Atopic dermatitis, a chronic, pruritic skin disease, affects 10-30% of children and up to 14% of adults in developed countries. ATI-1777, a potent and selective Jak1/3 inhibitor, was designed with multiple sites of metabolism to deliver local efficacy in the skin and limit systemic exposure. In preclinical studies, ATI-1777 selectively inhibited Jak1/3 with limited systemic exposure and without any adverse effects.

Primary objective

The primary goal of this study was to assess the preliminary clinical efficacy of ATI-1777 topical solution in adults with moderate or severe atopic dermatitis.

Design

ATI-1777-AD-201, a phase 2a, first-in-human, randomized, double-blind, vehicle-controlled, parallel-group study, evaluated the efficacy, safety, tolerability, and pharmacokinetics of ATI-1777 topical solution in 48 participants with atopic dermatitis over 4 weeks.

Primary endpoint

The primary endpoint was a reduction of a modified Eczema Area and Severity Index score from baseline.

Results

Reduction was significantly greater in the ATI-1777-treated group on day 28 than in vehicle-treated group (percentage reduction from baseline = 74.45% [standard error = 6.455] and 41.43% [standard error = 6.189], respectively [P < .001]). Average plasma concentrations of ATI-1777 were <5% of the half-maximal inhibitory concentration of ATI-1777 for inhibiting Jak1/3. No deaths or serious adverse events were reported.

Conclusion

Topical ATI-1777 does not lead to pharmacologically relevant systemic drug exposure and may reduce clinical signs of atopic dermatitis.

Trial Registration

The study was registered at ClinicalTrials.gov with the number NCT04598269.

Off-label use of Baricitinib improves moderate and severe atopic dermatitis in China through inhibiting MAPK and PI3K/Akt/mTOR pathway via targeting JAK-STAT signaling of CD4+ cells

As an inflammatory disease with a disrupted immune system, cytokine disorders in atopic dermatitis (AD) are closely related to the abnormal activation of JAK-STAT signal pathway. The critical relevance of the JAK-STAT signaling pathway to the pathogenesis of AD provides a strong rationale for JAK inhibitor research. Baricitinib, a small-molecule oral JAK inhibitor, has been proven to inhibit JAK-STAT signaling in a variety of diseases, including AD. It is currently available in China for off-label use. However, its efficacy in China and its mechanism are rarely reported. In our study, we found that the immune status of patients with moderate and severe AD was hyperactive. Among the 49 known immunotherapy targets, JAK1 and JAK2 genes on lymphocytes of AD patients were significantly upregulated, which was closely related to the symptom severity in moderate and severe AD patients. Baricitinib can improve immune hyperresponsiveness and clinical symptoms in moderate and severe AD by inhibiting the activation of Th2 cell subsets and the secretion of Th2-type cytokines through MAPK, mTOR and PI3K-Akt signaling pathways, providing an important theoretical basis for clinical off-label use of Baricitinib to treat moderate and severe AD.

Tryptophan, an important link in regulating the complex network of skin immunology response in atopic dermatitis

Atopic dermatitis (AD) is a common chronic relapsing inflammatory skin disease, of which the pathogenesis is a complex interplay between genetics and environment. Although the exact mechanisms of the disease pathogenesis remain unclear, the immune dysregulation primarily involving the Th2 inflammatory pathway and accompanied with an imbalance of multiple immune cells is considered as one of the critical etiologies of AD. Tryptophan metabolism has long been firmly established as a key regulator of immune cells and then affect the occurrence and development of many immune and inflammatory diseases. But the relationship between tryptophan metabolism and the pathogenesis of AD has not been profoundly discussed throughout the literatures. Therefore, this review is conducted to discuss the relationship between tryptophan metabolism and the complex network of skin inflammatory response in AD, which is important to elucidate its complex pathophysiological mechanisms, and then lead to the development of new therapeutic strategies and drugs for the treatment of this frequently relapsing disease.

Medicinal chemistry perspective of JAK inhibitors: synthesis, biological profile, selectivity, and structure activity relationship

JAK-STAT signalling pathway was discovered more than quarter century ago. The JAK-STAT pathway protein is considered as one of the crucial hubs for cytokine secretion which mediates activation of different inflammatory, cellular responses and hence involved in different etiological factors. The various etiological factors involved are haematopoiesis, immune fitness, tissue repair, inflammation, apoptosis, and adipogenesis. The presence of the active mutation V617K plays a significant role in the progression of the JAK-STAT pathway-related disease. Consequently, targeting the JAK-STAT pathway could be a promising therapeutic approach for addressing a range of causative factors. In this current review, we provided a comprehensive discussion for the in-detail study of anatomy and physiology of the JAK-STAT pathway which contributes structural domain rearrangement, activation, and negative regulation associated with the downstream signaling pathway, relationship between different cytokines and diseases. This review also discussed the recent development of clinical trial entities. Additionally, this review also provides updates on FDA-approved drugs. In the current investigation, we have classified recently developed small molecule inhibitors of JAK-STAT pathway according to different chemical classes and we emphasized their synthetic routes, biological evaluation, selectivity, and structure-activity relationship.

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.

The JAK/STAT/NF-κB signaling pathway can be regulated by rosemary essential oil, thereby providing a potential treatment for DNCB-induced in mice

OBJECTIVE

The purpose of this study was to investigate the mechanism through which rosemary essential oil treats atopic dermatitis.

METHODS

A dinitrochlorobenzene (DNCB)-induced atopic dermatitis mouse model was established and treated with low (1%), medium (2%), and high (4%) doses of Rosmarinus officinalis essential oil (EORO). Serum levels of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) in each group were determined using enzyme-linked immunosorbent assay (ELISA). Skin tissues were stained with hematoxylin-eosin and toluidine blue. We used network pharmacology and molecular docking techniques to verify the biological activity of essential proteins and their corresponding compounds in the pathway. Gas chromatography-mass spectrometry (GC-MS) was used for metabolomics analysis and multivariate statistical analysis of mouse serum to screen differential metabolites and metabolic pathway analysis. Protein expression of p-JAK1, CD4+ cells, and IL-4 in the skin tissue was detected by immunohistochemistry analysis. Protein levels of STAT3, p-STAT3, P65, and p-P65 in damaged skin tissues were detected using western blotting.

RESULT

The skin of mice in the model group showed different degrees of erythema, dryness, scratches, epidermal erosion and shedding, and crusting. After treatment, the serum levels of IL-6 and TNF-α in EORO group were significantly decreased, and the expression of p-JAK1,CD4 + cells, IL-4, p-P65 / P65 and p-STAT3 / STAT3 proteins in skin tissues were decreased.

CONCLUSION

EORO can effectively improve DNCB-induced AD-like skin lesions in mice by regulating the JAK/STAT/NF-κB signaling pathway, thereby reducing the production of downstream arachidonic acid metabolites, inhibiting skin inflammation, and restoring epidermal barrier function.

Design of a Supersoft Topical JAK Inhibitor, Which Is Effective in Human Skin but Rapidly Deactivated in Blood

We describe the discovery and characterization of the supersoft topical JAK inhibitor 3(R), which is potent in biochemical and cellular assays as well as in human skin models. In blood, the neutral ester 3(R) is rapidly hydrolyzed (t1/2 ∼ 6 min) to the corresponding charged carboxylic acid 4 exhibiting >30-fold reduced permeability. Consequently, acid 4 does not reach the intracellular JAK kinases and is inactive in cellular assays and in blood. Thus, hydrolysis by blood esterases leads to the rapid deactivation of topically active ester 3(R) at a rate beyond the maximal hepatic clearance.

Abrocitinib for the treatment of atopic dermatitis

Abrocitinib is an oral small molecule which selectively inhibits JAK1, modulating multiple cytokine pathways involved in atopic dermatitis. Both abrocitinib 200 mg and 100 mg reached efficacy results comparable to dupilumab and superior to placebo. Abrocitinib 200 mg was superior to dupilumab in some trials, consistently providing a faster response and itch relief from week 2 to 26. Continuous abrocitinib 200 mg is the most effective at controlling this disease, but with an induction-maintenance approach with abrocitinib 200 mg followed by 100 mg, over 55% of patients did not flare for 40 weeks. Abrocitinib common adverse effects are nonserious. A self-limited dose-related decrease in platelet counts was consistently observed, without clinical repercussion. Abrocitinib demonstrated high efficacy and a favorable safety profile.

Current and Emerging Therapies for Atopic Dermatitis in the Elderly

Atopic dermatitis (AD) in the elderly has recently emerged as a distinct subgroup of AD, garnering widespread concern due to its increasing global incidence rate. Epidermal barrier dysfunction, inflammatory response, and chronic pruritus interact with each other, contributing to the pathogenesis and pathophysiology of AD in the elderly. Although fundamental medications are essential for managing AD in the elderly, older adults often struggle with regular usage of moisturizing emollients, topical medications, and avoidance of environmental triggers, leading to recurrent or even exacerbated disease progression. Therefore, a systematic medication approach is necessary to control pruritus and skin lesions. Traditional systemic treatments may not adequately meet the treatment needs of moderate and severe AD in the elderly and may even pose certain safety risks. Biologics and Janus kinase (JAK) inhibitors, exhibiting excellent clinical efficacy, have made significant breakthroughs in AD treatment. Existing evidence suggests that dupilumab, a human monoclonal IgG4 antibody, has been confirmed as an effective and safe first-line systematic treatment for moderate to severe AD in the elderly, with no notable differences between adults and the elderly. However, the limited inclusion of elderly patients in related clinical studies hinders the generalizability of these findings. As older patients face a higher risk of adverse events with JAK inhibitors, JAK inhibitors are recommended when no other suitable treatment options are available. Obtaining population-specific data is crucial for making evidence-based treatment choices when managing AD in older adults with JAK inhibitors.

Discovery of a traditional Chinese herbal combination for the treatment of atopic dermatitis: saposhnikoviae radix, astragali radix and cnidium monnieri

Atopic dermatitis (AD) is a skin disease characterized by pruritus. The present study aimed to discover a herbal combination with anti-allergic and anti-inflammatory activities to treat AD. First, the anti-allergic and anti-inflammatory activities of herbs were evaluated by RBL-2H3 degranulation and HaCaT inflammatory models. Subsequently, the optimal proportion of herbs was determined by uniform design-response surface methodology. The effectiveness and synergistic mechanism was further verified. Cnidium monnieri (CM) suppressed β-hexosaminidase (β-HEX) release, saposhnikoviae radix (SR), astragali radix (AR), and CM inhibited the release of IL-8 and MCP-1. The optimal proportion of herbs was SR∶AR∶CM = 1: 2: 1. The in vivo experiments results indicated that the topical application of combination at high (2 ×) and low (1 ×) doses improved dermatitis score and epidermal thickness, and attenuated mast cell infiltration. Network pharmacology and molecular biology further clarified that the combination resisted AD by regulating the MAPK, JAK signaling pathways, and the downstream cytokines such as IL-6, IL-1β, IL-8, IL-10, and MCP-1. Overall, the herbal combination could inhibit inflammation and allergy, improving AD-like symptoms. The present study discovers a promising herbal combination, worthy of further development as a therapeutic drug for AD.

JAK1 inhibitors for the treatment of atopic dermatitis: a focus on pharmacokinetic considerations

INTRODUCTION

Atopic dermatitis (AD) is associated with reduced quality of life, depression, and anxiety, making efficacious and safe treatments a priority. We will focus on the safety, efficacy, and pharmacokinetics of JAK1 inhibitors used in the treatment of AD.

AREAS COVERED

In this review, the pharmacodynamics, pharmacokinetics, safety, and efficacy of JAK1 inhibitors for the treatment of atopic dermatitis are discussed. The data was obtained by searching ClinicalTrials.gov, PubMed, and Google Scholar. Articles between January 2012 and March 2023 were considered for inclusion.

EXPERT OPINION

Given the rare, but serious black box warnings with JAK inhibitors, patients and providers may be weary of initiating treatment. In these instances, clinicians may weigh the risks and benefits of treatment with this class. Risk is relative, and while there are risks to treating AD with JAK inhibitors, there are also risks to untreated or undertreated AD, including infection and impairments in mental, physical, and psychosocial function. While JAK1 inhibitors appear to be safe, they were only recently approved for AD in January 2022, and more long-term safety data is needed. We expect to see additional FDA approval of these drugs, new formulations, and more safety and efficacy data in the future.

Novel Concept for Super-Soft Topical Drugs: Deactivation by an Enzyme-Induced Switch into an Inactive Conformation

We present a novel concept for the design of supersoft topical drugs. Enzymatic cleavage of the carbonate ester of the potent pan Janus kinase (JAK) inhibitor 2 releases hydroxypyridine 3. Due to hydroxypyridine-pyridone tautomerism, 3 undergoes a rapid conformational change preventing the compound to assume the bioactive conformation required for binding to JAK kinases. We demonstrate that the hydrolysis in human blood and the subsequent shape change lead to the deactivation of 2.

Efficacy and safety of abrocitinib and upadacitinib versus dupilumab in adults with moderate-to-severe atopic dermatitis: A systematic review and meta-analysis

Background

The sparsity of head-to-head trials for medications used as in atopic dermatitis (AD) treatment makes therapy options difficult.

Objective

To better compare the efficacy and safety of abrocitinib and upadacitinib with dupilumab in patients with moderate-to-severe AD.

Methods

We systematically searched MEDLINE, EMBASE, and the Cochrane Library database for head-to-head trials.

Results

Three studies with 2256 patients were included. The analysis revealed that improvement of EASI-75 was rapidly registered with abrocitinib/upadacitinib as compared to the dupilumab, even as early as week 2 of treatment. The proportions of patients who reached the endpoint of EASI-75 at week 12 and end of therapy were also higher in the abrocitinib/upadacitinib group. Significant improvement in EASI-90 scores was demonstrated with abrocitinib/upadacitinib at week 2 and at all subsequent time points. The administration of abrocitinib/upadacitinib provided a faster onset of IGA response at week 2. The differences in IGA response remained significant at week 12 and end of therapy. Compared with dupilumab, a larger proportion of patients treated with abrocitinib/upadacitinib achieved early itch relief at 2 weeks. Better results were found later during treatment, in between the 12 weeks to the end of study in abrocitinib/upadacitinib group. The only observed significant result of adverse events were severe adverse events between the abrocitinib/upadacitinib group (n = 40) and the dupilumab group (n = 24) (p = 0.043). TEAEs of any causality that led to treatment discontinuation and serious adverse events have not shown special risks in the patients treated with abrocitinib/upadacitinib.

Conclusions

This study demonstrated that anti-JAK therapy, particularly abrocitinib and upadacitinib, exhibited superiority over dupilumab in achieving fast relief of disease signs with an acceptable safety profile in patients with moderate-to-severe atopic dermatitis.

JAK inhibitors in dermatology: the road travelled and path ahead, a narrative review

INTRODUCTION

Numerous cutaneous dermatoses mediated by cytokines depend on the JAK STAT pathway for intracellular signaling. JAK inhibitors form a useful therapeutic approach in treating these conditions. The literature on effectiveness of JAK inhibitors in treatment of alopecia areata, vitiligo, atopic dermatitis, psoriasis and several other inflammatory and autoimmune diseases is growing, although very few conditions have sufficiently well performed studies to their credit and barring a few indications, their use in rest remains empirical as yet.

AREAS COVERED

A search of the PubMed database was made using the keywords Janus kinase inhibitors OR JAK inhibitors AND dermatology with the time duration limited to the last 5 years. Here, we review the JAK STAT pathway and the various conditions in which JAK inhibitors are currently used in dermatology and other conditions their use is being explored in.

EXPERT OPINION

The pathology of a large number of dermatological disorders is mediated via inflammatory cytokines which signal via the JAK STAT pathway. JAKinibs have shown great promise in treating cutaneous disorders refractory to conventional therapy. Their current clinical use in dermatology is based on robust evidence (for some), and anecdotal evidence for most other dermatoses.

Discovery and Characterization of the Topical Soft JAK Inhibitor CEE321 for Atopic Dermatitis

The JAK kinases JAK1, JAK2, JAK3, and TYK2 play key roles in cytokine signaling. Activation of the JAK/STAT pathways is linked to many diseases involving the immune system, including atopic dermatitis. As systemic JAK inhibitor pharmacology is associated with side effects, topical administration to the skin has been considered to locally restrict the site of action. Several orally bioavailable JAK inhibitors repurposed for topical use have been recently approved or are in clinical development. Here, we disclose our clinical candidate CEE321, which is a potent pan JAK inhibitor in enzyme and cellular assays. In contrast to repurposed oral drugs, CEE321 does not display high potency in blood and has a high clearance in vivo. Therefore, we consider CEE321 to be a "soft drug". When applied topically to human skin that was stimulated with the cytokines IL4 and IL13 ex vivo, CEE321 potently inhibited biomarkers relevant to atopic dermatitis.

Oral Janus kinase inhibitors in the treatment of atopic dermatitis: A systematic review and meta-analysis

Background

Janus kinase (JAK) inhibitors are being evaluated as promising upcoming treatments for atopic dermatitis (AD).

Objectives

To systematically assess the efficacy of oral JAK inhibitors in patients with AD and provide comparisons among JAK inhibitors.

Methods

A systematic literature review of JAK inhibitors in the treatment of AD was conducted and reported based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses using PubMed, ClinicalTrials.gov, CENTRAL, MEDLINE/Ovid, Embase and sponsor websites from inception to 30 September 2021. References of relevant articles were reviewed by two authors. Only RCTs of JAK inhibitors for treating AD with more than one study were included. Data was extracted and the meta-analysis was performed using the metan procedure in STATA version 12.1. Risk of bias was assessed with the Cochrane Risk of Bias Tool. The four outcomes analysed included Eczema Area Severity Index (EASI)-75 response (≥75% improvement of EASI score from baseline), percent change in EASI score, percent of subjects achieving Investigator Global Assessment (IGA) of clear or almost clear (IGA 0/1), and ≥ 4-point improvement in pruritus numerical rating scale (NRS).

Results

Fourteen randomized controlled trials (7051 subjects) assessing three different oral JAK inhibitors (abrocitinib, baricitinib and upadacitinib) in patients with moderate-to-severe AD were included in the meta-analysis. Abrocitinib (100 and 200 mg), baricitinib (1, 2 and 4 mg) and upadacitinib (15 and 30 mg) were all found to be more efficacious compared to placebo in all four outcomes analysed. Upadacitinib 30 mg was more effective than all other dosages of JAK inhibitors in achieving EASI-75, decrease in percent change of EASI, IGA 0/1 response rate, and ≥ 4-point improvement in pruritus NRS.

Conclusions

JAK inhibitors were found to be an effective treatment for AD. Upadacitinib, at 30 mg, was found to be the most efficacious oral JAK inhibitor for AD. More clinical trial studies with comparisons among JAK inhibitors are needed to confirm these results as well as explore long-term efficacy and safety of these molecules.

Efficacy and safety of topical JAK inhibitors in the treatment of atopic dermatitis in paediatrics and adults: A systematic review

Atopic dermatitis (AD) is the most common skin inflammatory disease. Dysregulation of innate and adaptive immune systems plays a major role in the pathophysiology of AD. JAKi (Janus Kinase Inhibitors) reduce the production of pro-inflammatory cytokines and represent a promising novel treatment for AD. To assess and summarize the overall efficacy and safety of topial JAKi in the treatment of AD in adults and pediatrics, a broad search was performed on Ovid Medline, Ovid Embase, Cochrane Library, Web of Sciences, Scopus, CINAHL and Google Scholar until 14 June 2022. After screening, 19 studies remained for the final review. The current systematic review was conducted according to PRISMA, and the protocol was registered in PROSPERO (ID #CRD42022303321). Topical delgocitinib, tofacitinib, ruxolitinib, cerdulatinib and ifidancitinib are effective in treating AD and significantly improve EASI, IGA, pruritus-NRS score and some other indexes in adults. Moreover, topical delgocitinib was observed to have a great efficacy in the treatment of AD in paediatrics. All topical JAKi showed minimal risk of mild-to-moderate adverse effects. Available topical JAKi are effective and safe modalities in treating AD. Nevertheless, further studies with longer duration and head-to-head comparative trials are necessary to find the best option with the least adverse effects.

Allergy: Mechanistic insights into new methods of prevention and therapy

In the past few decades, the prevalence of allergic diseases has increased worldwide. Here, we review the etiology and pathophysiology of allergic diseases, including the role of the epithelial barrier, the immune system, climate change, and pollutants. Our current understanding of the roles of early life and infancy; diverse diet; skin, respiratory, and gut barriers; and microbiome in building immune tolerance to common environmental allergens has led to changes in prevention guidelines. Recent developments on the mechanisms involved in allergic diseases have been translated to effective treatments, particularly in the past 5 years, with additional treatments now in advanced clinical trials.

OX40-OX40L Inhibition for the Treatment of Atopic Dermatitis-Focus on Rocatinlimab and Amlitelimab

Despite the recent emergence of targeted therapeutic options, there are still unmet needs concerning moderate-to-severe atopic dermatitis treatment. This review aims to discuss the OX40-OX40L pathway as a therapeutic target for the treatment of atopic dermatitis. OX40 and OX40L are two checkpoint molecules that bind to potentiate pro-inflammatory T-cell responses that are pivotal to atopic dermatitis pathogenesis. Two OX40-OX40L inhibitors, rocatinlimab and amlitelimab, are being developed for the treatment of atopic dermatitis. Rocatinlimab, an anti-OX40 antibody, was evaluated in phase 2b, a randomized, placebo-controlled clinical trial. At week 16, rocatinlimab groups achieved a greater reduction in the EASI percentage change from the baseline (−48.3% to −61.1%) against the placebo (−15.0%; p < 0.001), and clinical response was maintained 20 weeks after the treatment had ceased. Amlitelimab, an anti-OX40L antibody, was studied in a 12-week treatment phase 2a clinical trial, with a significant efficacy response observed within 2 weeks. At week 16, amlitelimab groups reached the EASI mean percentage change from the baseline of −69.9% and −80.1% versus the placebo (−49.4%; p = 0.072 and p = 0.009). Among the responders, 68% of amlitelimab patients were sustained 24 weeks following the last dose. Both treatments were shown to be safe and well tolerated. Current evidence points to OX40-OX40L inhibitors as future options for atopic dermatitis treatment with potential disease-modifying effects.

JAK: Not Just Another Kinase

The JAK/STAT axis is implicated in cancer, inflammation, and immunity. Numerous cytokines/growth factors affect JAK/STAT signaling. JAKs (JAK1, JAK2, JAK3, and TYK2) noncovalently associate with cytokine receptors, mediate receptor tyrosine phosphorylation, and recruit ≥1 STAT proteins (STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, and STAT6). Tyrosine-phosphorylated STATs dimerize and are then transported into the nucleus to function as transcription factors. Signaling is attenuated by specific suppressor of cytokine signaling proteins, creating a negative feedback loop. Both germline mutations and polymorphisms of JAK family members correlate with specific diseases: Systemic lupus erythematosus (TYK2 polymorphisms); severe combined immunodeficiency (JAK3 mutations); pediatric acute lymphoblastic leukemia (TYK2 mutations); and hereditary thrombocytosis (JAK2 mutations). Somatic gain-of-function JAK mutations mainly occur in hematologic malignancies, with the activating JAK2 V617F being a myeloproliferative disorder hallmark; it is also seen in clonal hematopoiesis of indeterminate potential. Several T-cell malignancies, as well as B-cell acute lymphoblastic leukemia, and acute megakaryoblastic leukemia also harbor JAK family somatic alterations. On the other hand, JAK2 copy-number loss is associated with immune checkpoint inhibitor resistance. JAK inhibitors (jakinibs) have been deployed in many conditions with JAK activation; they are approved in myeloproliferative disorders, rheumatoid and psoriatic arthritis, atopic dermatitis, ulcerative colitis, graft-versus-host disease, alopecia areata, ankylosing spondylitis, and in patients hospitalized for COVID-19. Clinical trials are investigating jakinibs in multiple other autoimmune/inflammatory conditions. Furthermore, dermatologic and neurologic improvements have been observed in children with Aicardi-Goutieres syndrome (a genetic interferonopathy) treated with JAK inhibitors.

Various Application of Tofacitinib and Ruxolitinib (Janus Kinase Inhibitors) in Dermatology and Rheumatology: A Review of Current Evidence and Future Perspective

INTRODUCTION

Janus kinase inhibitors (JAKi) are anti-inflammatory medications suppressing Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway by inhibiting various cytokines receptors on the membrane of cells. Mutations and polymorphisms on JAK and STAT proteins can cause dysregulation in the balance of immune system, and ultimately result in autoimmune disorders.

OBJECTIVES

To record and summarize the overall efficacy and safety of JAKi in various autoimmune conditions such as alopecia areata (AA), psoriasis vulgaris (PV), psoriatic arthritis (PsA), atopic dermatitis (AD), vitiligo, hidradenitis suppurative (HS), lichen planus (LP), and pyoderma gangrenosum (PG).

METHODS

A thorough review of articles was performed across PubMed and Google Scholar on meta-analyses, systematic reviews, clinical trials and case studies evaluating the treatment of autoimmune disorders such as AA, PV, PsA, AD, vitiligo, LP, HS, and PG with JAKi. Duplicated data and animal experiments or in vitro/ex vivo studies were excluded.

RESULTS

All the reviewed articles reported beneficial effects of tofacitinib and ruxolitinib application in the treatment of disorders mentioned above with the autoimmune predisposition.

CONCLUSIONS

Tofacitinib and ruxolitinib showed potential efficacy in treating several autoimmune disorders. Based on records in the reviewed studies, both medications had acceptable safety profiles; however, physicians are recommended to outweigh the risks and benefits of such treatments for each specific condition.

Case report: Clinical and histopathological characteristics of psoriasiform erythema and de novo IL-17A cytokines expression on lesioned skin in atopic dermatitis children treated with dupilumab

Background

Atopic dermatitis (AD) is a chronic recurrent inflammatory disease, and dupilumab, a human monoclonal antibody, is the firstly approved biological drug for AD. Psoriasiform erythema (PE) during dupilumab treatment in adults has been reported. This study describes the risk of PE in children after initiation of dupilumab treatment.

Objectives

To evaluate the de novo cytokines gene expression in the transition of atopic dermatitis symptoms to psoriasiform erythema during dupilumab treatment in children.

Methods

Two 17-year-old teenage twin patients with AD were included in this study who developed psoriasiform erythema after initiation of dupilumab. The lesional skin biopsy specimens were obtained for the histopathological investigation and RNA Fluorescence In Situ Hybridization (RNA-FISH). Dermoscopy, cytometry (cytokine detection in the blood), and blood investigations were completed for the pedigree and the lesioned descriptions.

Results

Two twin patients with AD presented with erythematic scaly plaques on the back, scalp, abdomen, and extensor extremities after 20 weeks of dupilumab treatment. The transitional change of AD to psoriasiform erythema treated with dupilumab was observed. Our subjects' dermoscopy showed pinpoint bleeding and white scales on pink background. Histopathology features showed psoriasiform hyperplasia, epidermal hyperplasia (acanthosis), ectatic capillaries, perivascular lymphocytes infiltration, and parakeratosis, with the absence of the granular cell layer. mRNA (RNA-FISH) cytokines gene expression showed a significantly high concentration of IL-17A. Blood investigation results showed a high concentration of (Immunoglobulin E) IgE and Eosinophils, and cytokines detection in blood showed IL-5,6 and IL-17 in one patient; however, only IL-5 in another patient. The dupilumab was discontinued and initiated with Baricitinib. Baricitinib showed a significant reduction in skin lesions.

Conclusion

Psoriasiform erythema can appear during dupilumab treatment in atopic dermatitis children. Potently, by suppressing skewed Th2 activation in patients with AD, the balance might shift toward Th1/Th17 predominance, and psoriasis develops. Baricitinib is a potential drug for psoriasiform erythema with significant therapeutic effects.

Narrative review on the management of moderate-severe atopic dermatitis in pediatric age of the Italian Society of Pediatric Allergology and Immunology (SIAIP), of the Italian Society of Pediatric Dermatology (SIDerP) and of the Italian Society of Pediatrics (SIP)

Currently, there are a few detailed guidelines on the overall management of children and adolescents with moderate-severe atopic dermatitis. AD ​​is a complex disease presenting with different clinical phenotypes, which require an individualized and multidisciplinary approach. Therefore, appropriate interaction between primary care pediatricians, pediatric allergists, and pediatric dermatologists is crucial to finding the best management strategy. In this manuscript, members of the Italian Society of Pediatric Allergology and Immunology (SIAIP), the Italian Society of Pediatric Dermatology (SIDerP), and the Italian Society of Pediatrics (SIP) with expertise in the management of moderate-severe atopic dermatitis have reviewed the latest scientific evidence in the field. This narrative review aims to define a pathway to appropriately managing children and adolescents with moderate-severe atopic dermatitis.

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.

From Skin Barrier Dysfunction to Systemic Impact of Atopic Dermatitis: Implications for a Precision Approach in Dermocosmetics and Medicine

: Atopic dermatitis (AD) affects up to 20% of children and is considered the starting point of the atopic march with the development of food allergy, asthma, and allergic rhinitis. The heterogeneous phenotype reflects distinct and/or overlapping pathogenetic mechanisms with varying degrees of epidermal barrier disruption, activation of different T cell subsets and dysbiosis of the skin microbiome. Here, we review current evidence suggesting a systemic impact of the cutaneous inflammation in AD together with a higher risk of asthma and other comorbidities, especially in severe and persistent AD. Thus, early therapy of AD to restore the impaired skin barrier, modified microbiome, and target type 2 inflammation, depending on the (endo)phenotype, in a tailored approach is crucial. We discuss what we can learn from the comorbidities and the implications for preventive and therapeutic interventions from precision dermocosmetics to precision medicine. The stratification of AD patients into biomarker-based endotypes for a precision medicine approach offers opportunities for better long-term control of AD with the potential to reduce the systemic impact of a chronic skin inflammation and even prevent or modify the course, not only of AD, but possibly also the comorbidities, depending on the patient’s age and disease stage.

Atopic dermatitis: pathomechanisms and lessons learned from novel systemic therapeutic options

Atopic dermatitis (AD) is a chronic, heterogenous, inflammatory skin disorder associated with a high skin-related health burden, typically starting in childhood and often persisting into adulthood. AD is characterized by a wide range of clinical phenotypes, reflecting multiple underlying pathophysiological mechanisms and interactions between genetics, immune system dysregulation, and environmental factors. In this review, we describe the diverse cellular and molecular mechanisms involved in AD, including the critical role of T cell-driven inflammation, primarily via T helper (Th) 2- and Th17-derived cytokines, many of which are mediated by the Janus kinase (JAK) signaling pathway. These local inflammatory processes interact with sensory neuronal pathways, contributing to the clinical manifestations of AD, including itch, pain, and sleep disturbance. The recent elucidation of the molecular pathways involved in AD has allowed treatment strategies to evolve from broad-acting systemic immunosuppressive therapies to more targeted agents, including JAK inhibitors and cytokine-specific biologic agents. Evidence from the clinical development of these targeted therapies has reinforced and expanded our understanding of the pathophysiological mechanisms underlying AD and holds promise for individualized treatment strategies tailored to specific AD subtypes.

Quantifying Physician Preferences for Systemic Atopic Dermatitis Treatments Using a Discrete-Choice Experiment

Introduction

As research continues, new drugs will no doubt be added to the current pool of treatments for moderate-to-severe atopic dermatitis (AD). This raises the need for studies to determine prescriber preferences for different pharmacological options and the factors that influence their choice of treatment. Here we aim to explore physician preferences in the systemic treatment of moderate-to-severe AD, identify the sociodemographic characteristics that can influence physician preferences, and evaluate their satisfaction with current AD therapies.

Methods

A discrete-choice experiment (DCE) survey was administered to physicians treating patients with AD in Spain. Results were analyzed using a conditional logit model to estimate the relative importance of each attribute and the maximum risk accepted to achieve therapeutic benefit.

Results

A total of 28 respondents completed the DCE survey (67.9% female, mean age 45.9 years). Participants identified objective clinical efficacy and risk of severe adverse events (AEs) as the most important attributes, followed by improvement in sleep and pruritus and faster onset of action from the start of the treatment. Respondents gave less importance to mode of administration and therapeutic benefit in other atopic conditions. Respondents were willing to accept an increased risk of severe AEs and mild-to-moderate AEs leading to treatment discontinuation due to intolerance in order to obtain improvements in efficacy, sleep, and pruritus, and long-term clinical benefit.

Conclusion

Our findings can help prescribers choose the most appropriate systemic AD therapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00723-z.

Application of Baricitinib in Dermatology

There are four JAK subtypes: JAK1, JAK2, JAK3, and tyrosine kinase 2 (TYK2). Small molecule Janus tyrosine kinase (JAK) inhibitors can inhibit a variety of pro-inflammatory cytokines. Baricitinib is the first generation of JAK1/2 inhibitor targeting the ATPase of JAK, which blocks the intracellular transmission of cytokines through JAK-STATs. Thus far, it has been approved for the treatment of rheumatoid arthritis (RA); however, an increasing number of studies have suggested that baricitinib can be used to treat dermatological diseases, such as atopic dermatitis (AD), psoriasis, vitiligo, and alopecia areata. Baricitinib can be a new choice for the treatment of dermatological diseases, which cannot be treated with conventional drugs. We reviewed the application, efficacy, side effects, precautions, limitations and prospect of baricitinib in atopic dermatitis, psoriasis, vitiligo and alopecia areata (AA) in recent 5 years including clinical trials and case reports. Among them, the application in the field of alopecia areata is the most encouraging, and we reviewed the mechanism in detail.

Polyinosinic:polycytidylic acid aggravates calcipotriol-induced atopic dermatitis-like skin lesions in mice by increasing the expression of thymic stromal lymphopoietin

Background

Polyinosinic:polycytidylic acid [poly (I:C)] is a synthetic viral double-stranded RNA analog that can activate Toll-like receptor 3 (TLR3) and induce the release of thymic stromal lymphopoietin (TSLP). TSLP has been shown to contribute to atopic dermatitis (AD). This study explored the effects of poly (I:C) in a calcipotriol-induced model of murine AD.

Methods

Calcipotriol (MC903) was used to establish AD-like mice model. Mice in the MC903 + poly (I:C) group were then treated with poly (I:C) in a concentration of 5 µg/g bodyweight. The impact of poly (I:C) treatment on these animals was assessed based upon changes in lesions, bodyweight, ear thickness, and histopathological findings. In addition, serum interleukin 4 (IL-4), interferon-γ (IFN-γ), immunoglobulin E (IgE), IL-13, and TSLP levels were measured using enzyme-linked immunosorbent assay (ELISA), while tissue IL-13 and TSLP levels were assessed using ELISA, Western blotting, and immunohistochemical staining, and mast cell infiltration was assessed through toluidine blue (TBO) staining.

Results

Relative to vehicle control treatment, poly (I:C) administration was associated with a significant exacerbation of calcipotriol-induced AD-like murine skin lesions. In animals treated with poly (I:C), the levels of serum IL-4, IL-13 and TSLP increased significantly, while the level of IFN-γ did not change. It also increased IL-13 and TSLP levels in skin lesions relative to the control-group mice and increased dermal mast cell infiltration and IgE production.

Conclusions

These data indicate that poly (I:C) treatment and exogenous activation of TLR3 exacerbate murine calcipotriol-induced AD-like skin lesions in part by increasing the production of TSLP and other T-helper 2 (Th2)-related cytokines.

Keywords

Atopic dermatitis (AD); polyinosinic:polycytidylic acid [poly (I:C)]; thymic stromal lymphopoietin (TSLP); Toll-like receptor 3 (TLR3)

Baicalin ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in mice through modulating skin barrier function, gut microbiota and JAK/STAT pathway

Baicalin has distinct therapeutic effects in various skin diseases animal models such as atopic dermatitis (AD) and psoriasis. In this study, we aimed to investigate the anti-atopic dermatitis (AD) effects of baicalin in 2,4-dinitrochlorobenzene (DNCB)-treated mice. Female BALB/c mice treated with DNCB to induce AD-like skin lesions and orally administrated with baicalin daily for 14 consecutive days. Baicalin significantly inhibited dorsal skin thickness and trans-epidermal water loss and epidermal thickness in dorsal skin. In addition, baicalin also significantly up-regulated the protein expressions of filaggrin, involucrin, and loricrin, but inhibited the inflammatory response and the activation of NF-κB and JAK/STAT pathways in the dorsal skin of the DNCB-treated mice. Furthermore, baicalin significantly restored the abundance of probiotics in the gut microbiota of the DNCB-treated mice. Pseudo germ-free (GF) DNCB-treated mice receiving fecal microbiota from baicalin donors reduced the dorsal skin thickness and skin EASI score, and inhibited the release of IgE, histamine, TNF-α and IL-4 in serum of mice. In summary, baicalin ameliorates AD-like skin lesions induced by DNCB in mice via regulation of the Th1/Th2 balance, improvement of skin barrier function and modulation of gut dysbiosis, and inhibition of inflammation through suppressing the activation of NF-κB and JAK/STAT pathways.

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.

Evaluating topical JAK inhibitors as a treatment option for atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic, inflammatory skin condition mediated by cytokines that utilize the Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) signaling cascade. Topical JAK inhibitors are an emerging alternative in the treatment of AD.

AREAS COVERED

This expert review presents an overview of the underlying molecular pathophysiology of AD, current standards of care, and evaluation of the efficacy and safety of topical JAK inhibitors. A PubMed database search was utilized with a focus on the evidence from double-blind, randomized Phase I, II, and III clinical trials published between January 2015 and July 2021.

EXPERT OPINION

Current topical therapies for AD are efficacious but limited by their adverse side effects. Long-term topical corticosteroid use leads to loss of pigmentation, striae, and skin atrophy. Patients may be concerned about topical calcineurin inhibitors' black box warning of increased risk of malignancy. Topical crisaborole, a phosphodiesterase four inhibitor, is limited by application site burning. Topical ruxolitinib is a JAK inhibitor comparable to triamcinolone in efficacy without the adverse effects seen with long-term topical corticosteroid use. Although topical JAK inhibitors have promising efficacy and safety profiles, poor medication adherence common to topical treatments may limit their utility in a clinical setting.

Drug Repurposing for Atopic Dermatitis by Integration of Gene Networking and Genomic Information

Atopic Dermatitis (AD) is a chronic and relapsing skin disease. The medications for treating AD are still limited, most of them are topical corticosteroid creams or antibiotics. The current study attempted to discover potential AD treatments by integrating a gene network and genomic analytic approaches. Herein, the Single Nucleotide Polymorphism (SNPs) associated with AD were extracted from the GWAS catalog. We identified 70 AD-associated loci, and then 94 AD risk genes were found by extending to proximal SNPs based on r2 > 0.8 in Asian populations using HaploReg v4.1. Next, we prioritized the AD risk genes using in silico pipelines of bioinformatic analysis based on six functional annotations to identify biological AD risk genes. Finally, we expanded them according to the molecular interactions using the STRING database to find the drug target genes. Our analysis showed 27 biological AD risk genes, and they were mapped to 76 drug target genes. According to DrugBank and Therapeutic Target Database, 25 drug target genes overlapping with 53 drugs were identified. Importantly, dupilumab, which is approved for AD, was successfully identified in this bioinformatic analysis. Furthermore, ten drugs were found to be potentially useful for AD with clinical or preclinical evidence. In particular, we identified filgotinub and fedratinib, targeting gene JAK1, as potential drugs for AD. Furthermore, four monoclonal antibody drugs (lebrikizumab, tralokinumab, tocilizumab, and canakinumab) were successfully identified as promising for AD repurposing. In sum, the results showed the feasibility of gene networking and genomic information as a potential drug discovery resource.

Janus Kinase Inhibitors for the Treatment of Atopic Dermatitis: Focus on Abrocitinib, Baricitinib, and Upadacitinib

Atopic dermatitis (AD) is a clinically heterogenous, inflammatory skin condition with a high impact on patients' daily activities that remains difficult to treat. The knowledge acquired over the last decade on AD pathophysiology and disease burden led to the development of new targeted therapeutic options that enable clinicians to better manage AD patients. The JAK/STAT signaling pathway modulates several immune pathways (T helper (Th)1, Th2, Th17, and Th22 cells) that have been found to be involved in AD pathogenesis. For this reason, JAK inhibitors emerged as a possible therapy for AD. Baricitinib, upadacitinib, and abrocitinib are the three oral JAK inhibitors already approved or in advanced clinical development for this purpose. The results showed that this drug class is highly effective achieving symptomatic relief (itch control) in the short term, as well as improving disease severity in the short and medium term. However, their efficacy should be balanced with possible side effects, that have been reported in clinical trials. More data on the long-term efficacy and safety, as well as from head-to-head comparisons and from real-world setting will be crucial to position oral JAK inhibitors in the AD therapeutic armamentarium.

Effects of topical application of a tri-herb formula on inflammatory dry-skin condition in mice with oxazolone-induced atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic relapsing inflammatory and pruritic skin disease, affecting 10-20% of the population worldwide. Paeonia suffruticosa Andrews (Paeoniaceae) (Cortex Moutan) and Mentha haplocalyx Briq. (Labiatae) (Herba Menthae) have shown beneficial effects on AD. Calendula officinalis L. (Asteraceae) is commonly used for treating skin rashes and wounds.

PURPOSE

In the present study, a three-herbs formula including Cortex Moutan and Herba Menthae, together with C. officinalis at 1:1:1 weight ratio was used as a topical agent and its therapeutic effects on AD was investigated.

METHODS

In vitro effects of individual herbs and three-herbs formula (0.125-1 mg/ml) were examined using cytokine release assay on human mast HMC-1 cells, inflammation test on murine macrophage RAW cells and human keratinocyte (HaCaT) cells, and migration scratch assay on human umbilical vein endothelial cells (HUVEC). The contributing functional pathway of three-herbs formula in AD was explored using Western Blot assay in HMC-1 cells. Oxazolone-induced AD-like mice model was also used to investigate the in vivo therapeutic effect of the topical application of the three-herbs formula.

RESULTS

Herba Menthae, Cortex Moutan, and three-herbs formula significantly reduced the production of IL-6 and tumor necrosis factor (TNF)-α in HMC-1 cells, inhibited the expression of IL-6, IL-8 and CCL2 in TNF-α/IFN-γ stimulated HaCaT cells, and suppressed the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells. Moreover, Herba Menthae and three-herbs formula significantly suppressed CCL2 and TNF-α production in LPS-induced RAW 264.7 cells. C. officinalis and three-herbs formula promoted wound healing in HUVEC. For intracellular mechanisms, three-herbs formula inhibited the expressions of molecules in STAT1 and STAT3-dependent pathways. In vivo model showed that topical application of three-herbs formula on challenged ear reduced ear swelling and mice scratching frequencies. H&E and toluidine blue staining of the challenged ear tissue demonstrated that three-herbs formula reduced the epidermal thickness and mast cell infiltration, respectively.

CONCLUSION

The three-herbs formula of Cortex Moutan, Herba Menthae and C. officinalis at 1:1:1 (w/w) exhibited anti-inflammatory effect and promotion of cell migration in vitro. It also alleviated ear redness, swelling, epidermal thickness and inflammation of the OXA-induced AD mice. These findings suggest a potential beneficial role of the topical application of the three-herbs formula for treatment of AD.

Differential Diagnosis and Treatment of Itching in Children and Adolescents

Itching is prevalent in children with skin disorders and associated with effects on their mood, quality of life, and social functioning. Surprisingly, there are no data on childhood prevalence of pruritus in the general population. The aim of this article is to explore the epidemiology, clinical manifestation, and treatment for itch (pruritus) in the pediatric population (from infancy to adolescence), and to be helpful to primary care physicians who assess and diagnose pediatric patients with itching. In this study, we searched for specific keywords using PubMed and MEDLINE (Ovid) and, then, refined the retrieved searches for each cause and treatment. As a result of reviewing the literature, atopic dermatitis was shown to be the most common cause of itching, especially during infancy and through preschool. Not only skin disorders but also systemic diseases, drugs, and postburn states can predispose an individual to itching in childhood. There are traditional and newly developed treatment modalities for itching in pediatric patients. However, because the pharmacokinetics and pharmacodynamics of childhood are different from those of adults, the medications for itching have to be applied carefully for these age groups. There are many areas to be elucidated regarding the prevalence and objective assessment of pruritus in pediatric patients. Moreover, the safety profiles of medications in the pediatric population need to be better understood. Further studies to investigate itching in childhood are warranted.

Pharmacokinetics of Ruxolitinib in Patients with Atopic Dermatitis Treated With Ruxolitinib Cream: Data from Phase II and III Studies

BACKGROUND

Pathogenesis of atopic dermatitis (AD) involves the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. A cream formulation of ruxolitinib, a potent selective JAK1/JAK2 inhibitor, was developed for topical delivery.

METHOD

Pharmacokinetic data were obtained from three double-blind, vehicle-controlled studies in patients with AD: a phase II study with ruxolitinib cream 0.15%, 0.5%, or 1.5% once daily or 1.5% twice daily (BID), and two phase III studies with 0.75% or 1.5% BID. Effects of baseline characteristics on pharmacokinetics were examined. Correlations were attempted between plasma concentrations and change in hematological parameters over time.

RESULTS

Ruxolitinib plasma concentrations at steady-state (Css) increased with cream strength in a less-than-dose-proportional manner. In the phase III studies, overall mean (standard deviation [SD]) Css after ruxolitinib cream 0.75% and 1.5% BID (23.8 [35.0] and 35.7 [55.0] nM) were a fraction of the half-maximal inhibitory concentration for thrombopoietin-stimulated phosphorylated STAT3 inhibition (281 nM), a JAK/STAT signaling marker. Three covariates were identified for Css: dose, percent body surface area (%BSA) treated, and baseline Investigator's Global Assessment score. Mean (SD) bioavailability of ruxolitinib cream 1.5% BID was 6.22% (7.66%). There were no correlations between Css and any hematological changes except for a transient increase in platelets at week 2.

CONCLUSIONS

Plasma ruxolitinib concentrations after treatment with topical ruxolitinib cream in patients with up to 20% BSA affected by AD are not expected to lead to systemic plasma concentrations that may be associated with adverse effects commonly associated with oral JAK inhibitors. CLINICALTRIALS.GOV: NCT03011892; NCT03745638; NCT03745651.

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.

Itch in Atopic Dermatitis - What Is New?

Atopic dermatitis (AD) is among the most frequent inflammatory skin diseases in humans, affecting up to 20% of children and 10% of adults in higher income countries. Chronic pruritus is a disease-defining symptom of AD, representing the most burdensome symptom for patients. Severe chronic pruritus causes significant sleep disturbances and impaired quality of life, as well as increased anxiety, depression and suicidal behavior. Until recently, skin care, topical corticosteroids, and calcineurin-inhibitors were primarily used to treat mild to moderate AD, while phototherapy and immunosuppressive agents such as corticosteroids, cyclosporine, and methotrexate were used to treat patients with moderate to severe AD. The potential short- and long-term adverse events associated with these treatments or their insufficient therapeutic efficacy limited their use in controlling pruritus and eczema in AD patients over longer periods of time. As our understanding of AD pathophysiology has improved and new systemic and topical treatments have appeared on the market, targeting specific cytokines, receptors, or their intracellular signaling, a new era in atopic dermatitis and pruritus therapy has begun. This review highlights new developments in AD treatment, placing a specific focus on their anti-pruritic effects.

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.

Biologics and Novel Therapies for Food Allergy

Food allergy is a significant public health burden affecting around 10% of adults and 8% of children. Although the first peanut oral immunotherapy product received Food and Drug Administration approval in 2020, there is still an unmet need for more effective therapeutic options that minimize the risk of anaphylaxis, nutritional deficiencies, and patient's quality of life. Biologics are promising modalities, as they may improve compliance, target multiple food allergies, and treat other concomitant atopic diseases. Although omalizumab has been evaluated extensively, most biologics are more novel and have broader immunologic impact. Careful evaluation of their safety profile should therefore be conducted.

Therapeutic manipulation of innate lymphoid cells

Since their relatively recent discovery, innate lymphoid cells (ILCs) have been shown to be tissue-resident lymphocytes that are critical mediators of tissue homeostasis, regeneration, and pathogen response. However, ILC dysregulation contributes to a diverse spectrum of human diseases, spanning virtually every organ system. ILCs rapidly respond to environmental cues by altering their own phenotype and function as well as influencing the behavior of other local tissue-resident cells. With a growing understanding of ILC biology, investigators continue to elucidate mechanisms that expand our ability to phenotype, isolate, target, and expand ILCs ex vivo. With mounting preclinical data and clinical correlates, the role of ILCs in both disease pathogenesis and resolution is evident, justifying ILC manipulation for clinical benefit. This Review will highlight areas of ongoing translational research and critical questions for future study that will enable us to harness the full therapeutic potential of these captivating cells.