Efficacy and safety of topical JTE-052, a Janus kinase inhibitor, in Japanese adult patients with moderate-to-severe atopic dermatitis: a phase II, multicentre, randomized, vehicle-controlled clinical study

Topical Treatments in Atopic Dermatitis: An Expansive Review

Atopic dermatitis (AD) is a common inflammatory skin condition found worldwide. It impacts patient quality of life (QoL) and is thought to arise as an inflammatory response to epidermal barrier dysfunction and hypersensitivity. AD can lead to large out-of-pocket costs and increased healthcare expenses over a lifetime. An analysis of all randomized control trials conducted since 1990 on topical therapies for AD were reviewed, including 207 trials in the final analysis. It was found that an average of 226 patients were enrolled over 2.43 arms. Common topical treatments included corticosteroids, calcineurin inhibitors, JAK inhibitors, and phosphodiesterase inhibitors. The most utilized tools to identify treatment efficacy were the EASI, IGA, SCORAD, and PGA. There was a paucity of data on trials that evaluated efficacy, QoL, and cost of treatment simultaneously. This review highlights the need for comprehensive trials that evaluate multiple aspects of treatment, including financial cost and QoL impact, to ensure each patient has the best treatment modality for the management of their AD.

Selectivity, efficacy and safety of JAKinibs: new evidence for a still evolving story

Fundamental insight gained over the last decades led to the discovery of cytokines as pivotal drivers of inflammatory diseases such as rheumatoid arthritis, psoriasis/psoriasis arthritis, inflammatory bowel diseases, atopic dermatitis and spondylarthritis. A deeper understanding of the pro-inflammatory and anti-inflammatory effects of various cytokines has prompted new cytokine-targeting therapies, which revolutionised the treatment options in the last years for patients with inflammatory disorders. Disease-associated immune responses typically involve a complex interplay of multiple cytokines. Therefore, blockade of one single cytokine does not necessarily lead to a persistent remission in all patients with inflammatory disorders and fostered new therapeutic strategies targeting intracellular pathways shared by multiple cytokines. By inhibiting JAK-STAT signalling pathways common to families of cytokines, JAK-inhibitors (JAKinibs) have created a new paradigm for the treatment of inflammatory diseases. Multiple agents have been approved for various disorders and more are being investigated for several new indications. Second-generation selective JAKinibs have been devised with the aim to achieve an increased selectivity and a possible reduced risk of side effects. In the current review, we will summarise the current body of evidence of pan versus selective JAKinibs and the most recent insights on new side effects and indications, including COVID-19.

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.

Janus Kinase Inhibitors and Adverse Events of Acne: A Systematic Review and Meta-Analysis

Importance

Janus kinase (JAK) inhibitors are increasingly used across a range of dermatologic conditions. Adverse events of acne have been noted in some studies in clinical practice, but the scope of this outcome across JAK inhibitors has not been established.

Objective

To systematically analyze all published phase 2 and 3 placebo-controlled randomized clinical trials (RCTs) of JAK inhibitors for the risk of acne as an adverse effect of these medications.

Data Sources

Comprehensive search of Ovid MEDLINE and PubMed databases through January 31, 2023.

Study Selection

Inclusion criteria were phase 2 and 3 placebo-controlled RCTs of JAK inhibitors published in English with reported adverse events of acne.

Data Extraction and Synthesis

Two reviewers independently reviewed and extracted information from all included studies.

Main Outcomes and Measures

The primary outcome of interest was the incidence of acne following JAK inhibitor use. A meta-analysis was conducted using random-effects models.

Results

A total of 25 unique studies (10 839 unique participants; 54% male and 46% female) were included in the final analysis. The pooled odds ratio (OR) was calculated to be 3.83 (95% CI, 2.76-5.32) with increased ORs for abrocitinib (13.47 [95% CI, 3.25-55.91]), baricitinib (4.96 [95% CI, 2.52-9.78]), upadacitinib (4.79 [95% CI, 3.61-6.37]), deucravacitinib (2.64 [95% CI, 1.44-4.86]), and deuruxolitinib (3.30 [95% CI, 1.22-8.93]). Estimated ORs were higher across studies investigating the use of JAK inhibitors for the management of dermatologic compared with nondermatologic conditions (4.67 [95% CI, 3.10-7.05]) as well as for JAK1-specific inhibitors (4.69 [95% CI, 3.56-6.18]), combined JAK1 and JAK2 inhibitors (3.43 [95% CI, 2.14-5.49]), and tyrosine kinase 2 inhibitors (2.64 [95% CI, 1.44-4.86]).

Conclusions and Relevance

In this systematic review and meta-analysis, JAK inhibitor use was associated with an elevated odds of acne. Patients should be properly counseled on this potential adverse effect of these medications before treatment initiation. Future studies are needed to further elucidate the pathophysiology of this association.

Topical treatments for atopic dermatitis (eczema): Systematic review and network meta-analysis of randomized trials

BACKGROUND

Atopic dermatitis (AD) is a common skin condition with multiple topical treatment options, but uncertain comparative effects.

OBJECTIVE

We sought to systematically synthesize the benefits and harms of AD prescription topical treatments.

METHODS

For the 2023 American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters AD guidelines, we searched MEDLINE, EMBASE, CENTRAL, CINAHL, LILACS, ICTRP, and GREAT databases to September 5, 2022, for randomized trials addressing AD topical treatments. Paired reviewers independently screened records, extracted data, and assessed risk of bias. Random-effects network meta-analyses addressed AD severity, itch, sleep, AD-related quality of life, flares, and harms. The Grading of Recommendations Assessment, Development and Evaluation approach informed certainty of evidence ratings. We classified topical corticosteroids (TCS) using 7 groups-group 1 being most potent. This review is registered in the Open Science Framework (https://osf.io/q5m6s).

RESULTS

The 219 included trials (43,123 patients) evaluated 68 interventions. With high-certainty evidence, pimecrolimus improved 6 of 7 outcomes-among the best for 2; high-dose tacrolimus (0.1%) improved 5-among the best for 2; low-dose tacrolimus (0.03%) improved 5-among the best for 1. With moderate- to high-certainty evidence, group 5 TCS improved 6-among the best for 3; group 4 TCS and delgocitinib improved 4-among the best for 2; ruxolitinib improved 4-among the best for 1; group 1 TCS improved 3-among the best for 2. These interventions did not increase harm. Crisaborole and difamilast were intermediately effective, but with uncertain harm. Topical antibiotics alone or in combination may be among the least effective. To maintain AD control, group 5 TCS were among the most effective, followed by tacrolimus and pimecrolimus.

CONCLUSIONS

For individuals with AD, pimecrolimus, tacrolimus, and moderate-potency TCS are among the most effective in improving and maintaining multiple AD outcomes. Topical antibiotics may be among the least effective.

Use of Janus kinase inhibitors in atopic dermatitis - an update

Atopic dermatitis is among the cutaneous inflammatory disorders whose pathophysiology is thought to be influenced by the JAK-STAT intracellular signalling system. The effectiveness of systemic and topical Janus kinase (JAK) inhibitors in the treatment of atopic dermatitis has been shown in clinical trials and case studies. At present, oral abrocitinib (Cibinqo), oral upadacitinib (Rinvoq), oral baricitinib (Olumiant) and topical ruxolitinib (Opzelura) have approval from the US-FDA for their use in the treatment of atopic dermatitis. The efficacy and safety of oral and topical Janus kinase inhibitors for the treatment of atopic dermatitis have been reviewed in this article.

Topical Janus kinase inhibitors in atopic dermatitis: a safety network meta-analysis

BACKGROUND

Topical Janus kinase (JAK) inhibitors are being developed for the treatment of mild to moderate atopic dermatitis. However, comparative evidence on their safety profiles is still limited.

AIM

This study aimed to compare the relative safety of topic JAK inhibitors in patients with atopic dermatitis.

METHOD

Phase 2 and 3 clinical trials (RCTs) evaluating the efficacy and safety of topical JAK inhibitors in atopic dermatitis were searched on Medline, EMBASE and clinicaltrials.gov. The following outcomes were considered: any adverse event (AE), serious AEs, AEs leading to treatment discontinuation, any infection, any application site reaction.

RESULTS

Ten RCTs were included in this network meta-analysis. Tofacitinib was associated with a reduced risk of any AE when compared with ruxolitinib (OR 0.18, 95% CrI 0.03-0.92). The analyses for the remaining outcomes did not identify other statistically significant risk differences between the topical JAK inhibitors.

CONCLUSION

Although tofacitinib seems to present a reduced risk of any adverse event compared with ruxolitinib, this was the only statistically significant result found between JAK inhibitors. Therefore, such findings should be interpreted with caution considering the scarce data available and the heterogeneity between the studies, and there is no robust evidence allowing pointing out clinically important differences between the safety profiles of the existing topical JAK inhibitors. Further pharmacovigilance activities are needed to confirm the safety profile of these drugs.

A phase 2a randomized vehicle-controlled multi-center study of the safety and efficacy of delgocitinib in subjects with moderate-to-severe alopecia areata

Alopecia areata/AA is an autoimmune cause of nonscarring hair loss. The pathogenesis of AA involves many immune axes, including Th1/Th2 pathways. Delgocitinib is a pan-Janus kinase/JAK inhibitor that broadly blocks pro-inflammatory cytokines and has been effective in other inflammatory skin conditions. Recent human studies/reports have shown that use of some systemic JAK inhibitors led to hair regrowth, suggesting this medication class as a potential therapy for AA. However, topical treatment is desirable due to potential systemic side effects. To assess the efficacy and safety of topical delgocitinib in AA, we conducted a double-blind, randomized, vehicle-controlled clinical trial in 31 moderate-to-severe AA patients that were randomized 2:1 to receive delgocitinib ointment 30 mg/g (n = 20) or ointment vehicle (n = 11) for 12 weeks. The primary endpoint was change in severity of Alopecia Tool/SALT score from baseline to week 12. The secondary endpoint included safety profile by reported adverse events. Twenty-three subjects completed the trial, with eight discontinuing mostly due to voluntary withdrawal. Ten patients receiving delgocitinib ointment and three patients receiving vehicle showed SALT score improvements after 12 weeks, but the mean percent SALT improvement at week 12 compared to baseline between the two arms was not significant (p = 0.92). Our study suggests that delgocitinib ointment is not effective in moderate-to-severe AA, likely due to its inability to penetrate sufficiently deeply into the dermis of the scalp, but larger studies are necessary to assess whether a different formulation of topical JAK inhibitors may be suitable to treat mild or more localized forms of AA.

Topical and systemic JAK inhibitors in hand eczema - a narrative review

INTRODUCTION

Hand eczema is a chronic inflammatory skin disease characterized by significant prevalence and impact on patients' Quality of Life (QoL). Because of its complex and diverse clinical picture, HE management requires patient-specific treatment which may constitute a challenge. First described in the 1990s, Janus kinase inhibitors (JAK inhibitors) state a group of modern therapeuticals, which exhibit good bioavailability and are well tolerated by patients in both - topical and systemic - routes of administration. They are an immunomodulating small molecules, impacting JAKs' enzymatic activity.

AREAS COVERED

This review provides a summary of available data concerning JAK inhibitors' use in HE patients, regarding also clinical trials for the HE treatment.

EXPERT OPINION

Recent studies are introducing JAK inhibitors as an alternative for other topical and systemic therapies in HE patients. Treatment targeting specific immune pathways enables precise management and extends range of potential therapeutic options. Despite early promising results, future studies need to evaluate JAK inhibitors' safety, potential risks and benefits resulting from the treatment, as well as impact of the therapy on patients' QoL.

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.

Malignant T cells induce skin barrier defects through cytokine-mediated JAK/STAT signaling in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a devastating lymphoid malignancy characterized by the accumulation of malignant T cells in the dermis and epidermis. Skin lesions cause serious symptoms that hamper quality of life and are entry sites for bacterial infection, a major cause of morbidity and mortality in advanced diseases. The mechanism driving the pathological processes that compromise the skin barrier remains unknown. Here, we report increased transepidermal water loss and compromised expression of the skin barrier proteins filaggrin and filaggrin-2 in areas adjacent to TOX-positive T cells in CTCL skin lesions. Malignant T cells secrete mediators (including cytokines such as interleukin 13 [IL-13], IL-22, and oncostatin M) that activate STAT3 signaling and downregulate filaggrin and filaggrin-2 expression in human keratinocytes and reconstructed human epithelium. Consequently, the repression of filaggrins can be counteracted by a cocktail of antibodies targeting these cytokines/receptors, small interfering RNA-mediated knockdown of JAK1/STAT3, and JAK1 inhibitors. Notably, we show that treatment with a clinically approved JAK inhibitor, tofacitinib, increases filaggrin expression in lesional skin from patients with mycosis fungoides. Taken together, these findings indicate that malignant T cells secrete cytokines that induce skin barrier defects via a JAK1/STAT3-dependent mechanism. As clinical grade JAK inhibitors largely abrogate the negative effect of malignant T cells on skin barrier proteins, our findings suggest that such inhibitors provide novel treatment options for patients with CTCL with advanced disease and a compromised skin barrier.

Cancer risk with topical calcineurin inhibitors, pimecrolimus and tacrolimus, for atopic dermatitis: a systematic review and meta-analysis

BACKGROUND

Atopic dermatitis is a prevalent condition in children and can be effectively managed with medications such as topical calcineurin inhibitors (pimecrolimus or tacrolimus). A key unresolved safety concern is whether use of topical calcineurin inhibitors is associated with cancer. We systematically reviewed the risk of cancer in patients with atopic dermatitis exposed to topical calcineurin inhibitors.

METHODS

As part of the 2022 American Academy of Allergy, Asthma and Immunology and American College of Allergy, Asthma and Immunology Joint Task Force on Practice Parameters atopic dermatitis guidelines, we searched MEDLINE, Embase, the Latin American and Caribbean Health Sciences Literature database, the Índice Bibliográfico Espanhol de Ciências da Saúde database, the Global Resource of Eczema Trials database, WHO's International Clinical Trials Registry Platform, the US Food and Drug Administration database, the European Medicines Agency database, company registers, and relevant citations from inception to June 6, 2022. We included randomised controlled trials and comparative and non-comparative non-randomised studies in any language addressing cancer risk in patients with atopic dermatitis using topical calcineurin inhibitors. We excluded split-body studies and studies with less than 3 weeks of follow-up. Paired reviewers independently screened records, extracted data, and assessed risk of bias in duplicate. We used Bayesian models to estimate the probability for cancer due to topical calcineurin inhibitor exposure and the GRADE approach to determine the certainty of the evidence. Patients, advocacy groups, and care providers set a priori thresholds of important effects. This study is registered with Open Science Framework, https://osf.io/v4bfc.

FINDINGS

We identified and analysed 110 unique studies (52 randomised controlled trials and 69 non-randomised studies [11 were non-randomised study extensions of randomised controlled trials]) including 3·4 million patients followed up for a mean of 11 months (range 0·7-120). The absolute risk of any cancer with topical calcineurin inhibitor exposure was not different from controls (absolute risk 4·70 per 1000 with topical calcineurin inhibitors vs 4·56 per 1000 without; odds ratio 1·03 [95% credible interval 0·94-1·11]; moderate certainty). For all age groups and using data from observational studies and randomised controlled trials, the use of pimecrolimus (OR 1·05 [95% credible interval 0·94-1·15]) or tacrolimus (0·99 [0·89-1·09]) is likely to have had little to no association with cancer compared with no topical calcineurin inhibitor exposure. For pimecrolimus versus tacrolimus, the finding was similar (0·95 [95% credible interval 0·83-1·07]). Findings were similar in infants, children, and adults, and robust to trial sequential, subgroup, and sensitivity analyses.

INTERPRETATION

Among individuals with atopic dermatitis, moderate-certainty evidence shows that topical calcineurin inhibitors do not increase the risk of cancer. These findings support the safe use of topical calcineurin inhibitors in the optimal treatment of patients with atopic dermatitis.

FUNDING

American Academy of Allergy, Asthma and Immunology and American College of Allergy, Asthma and Immunology via the Joint Task Force on Practice Parameters.

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.

Efficacy of topical and systemic treatments for atopic dermatitis on pruritus: A systematic literature review and meta-analysis

Introduction

Pruritus is a major and burdensome symptom in atopic dermatitis (AD). The number of systemic treatments available for AD has increased recently, enabling improved patient relief.

Objective

To evaluate the effect of AD treatments on pruritus.

Methods

A systematic literature review and a meta-analysis were conducted to evaluate and compare the effects of treatment used in AD on pruritus. PubMed and Embase databases were searched to find articles published between January 1990 and December 2021. Topical and systemic treatments were studied in patients aged ≥10 years.

Results

Among the 448 articles identified, 56 studies were retained in the systematic review. A total of 15 studies evaluated topical treatments: topical corticosteroids (TCS; 2), calcineurin inhibitors (6), PDE4 inhibitors (3), and Jak inhibitors (4). A total of five studies were included in the meta- analysis. All treatments had a positive effect on pruritus, with a mean overall reduction of 3.32/10, 95% IC [2.32-4.33]. The greatest reduction was observed with halometasone (mean: 4.75), followed by tofacitinib 2% (mean: 4.38). A total of 41 studies evaluated systemic therapies: cyclosporine (6), phototherapy (5), azathioprine (2), dupilumab (9), anti-IL 13 (5), nemolizumab (3), Jak inhibitors (9), mepolizumab (1), and apremilast (1). A total of 17 studies were included in 2 meta-analyses according to the concomitant use or not of TCS. In the meta-analysis without TCS, the overall decrease was 3.07/10, 95% IC [2.58-3.56]. The molecules with the highest efficacy on pruritus were upadacitinib 30 mg (mean: 4.90) and nemolizumab (mean: 4.81).

Discussion

The therapeutic arsenal for AD has increased rapidly, and many molecules are under development. The primary endpoint of clinical trials is most often a score that assesses the severity of AD; however, the assessment of pruritus is also essential. The majority of molecules have a positive effect on pruritus, but the improvement varies between them. Efficacy on pruritus is not always correlated with efficacy on AD lesions; therefore, these two criteria are crucial to evaluate. The limitations of this study were the heterogeneity in the assessment of pruritus, the moment of the assessment, and the concomitant application of TCS or not for studies evaluating systemics. In the future, it would be useful to use standardized criteria for assessing pruritus.

JAK-STAT signaling pathway in the pathogenesis of atopic dermatitis: An updated review

Atopic dermatitis (AD) is a chronic, inflammatory, pruritic form of dermatosis with heterogeneous manifestations that can substantially affect patients' quality of life. AD has a complex pathogenesis, making treatment challenging for dermatologists. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway plays a central role in modulating multiple immune axes involved in the immunopathogenesis of AD. In particular, Th2 cytokines, including interleukin (IL)-4, IL-5, IL-13, IL-31, and thymic stromal lymphopoietin, which contribute to the symptoms of chronic inflammation and pruritus in AD, are mediated by JAK-STAT signal transduction. Furthermore, JAK-STAT is involved in the regulation of the epidermal barrier and the modulation of peripheral nerves related to the transduction of pruritus. Targeting the JAK-STAT pathway may attenuate these signals and show clinical efficacy through the suppression of various immune pathways associated with AD. Topical and oral JAK inhibitors with variable selectivity have emerged as promising therapeutic options for AD. Notably, topical ruxolitinib, oral upadacitinib, and oral abrocitinib were approved by the U.S. Food and Drug Administration for treating patients with AD. Accordingly, the present study reviewed the role of JAK-STAT pathways in the pathogenesis of AD and explored updated applications of JAK inhibitors in treating AD.

How we treat atopic dermatitis now and how that will change over the next 5 years

We live in exciting times in atopic dermatitis therapeutics, with many novel treatments in the clinical trial pipeline. Frustratingly, most of these trials are vehicle- or placebo-controlled, rather than head-to-head comparisons. Network meta-analyses can rank treatments against each other, even for placebo-controlled studies, aiding evidence-based guideline formulation and clinical decision-making. Treatment registries are an important additional vehicle to collect 'real-world' data on the long-term (cost) effectiveness and safety of the new drugs, outside of the stringent and short-term settings of clinical trials. As further agents enter clinical practice, the need for biomarkers of treatment response and drug safety becomes more pressing to move us towards personalized medicine and to avoid wasting healthcare resources. This review takes stock of our current treatment armamentarium for atopic dermatitis, highlights important gaps in our knowledge - including the relatively low number of studies conducted in children - and maps out how our treatment approaches for atopic dermatitis can become more targeted and holistic in the future.

European guideline (EuroGuiDerm) on atopic eczema - part II: non-systemic treatments and treatment recommendations for special AE patient populations

The evidence- and consensus-based guideline on atopic eczema was developed in accordance with the EuroGuiDerm Guideline and Consensus Statement Development Manual. Four consensus conferences were held between December 2020 and July 2021. Twenty-nine experts (including clinicians and patient representatives) from 12 European countries participated. This second part of the guideline includes recommendations and detailed information on basic therapy with emollients and moisturizers, topical anti-inflammatory treatment, antimicrobial and antipruritic treatment and UV phototherapy. Furthermore, this part of the guideline covers techniques for avoiding provocation factors, as well as dietary interventions, immunotherapy, complementary medicine and educational interventions for patients with atopic eczema and deals with occupational and psychodermatological aspects of the disease. It also contains guidance on treatment for paediatric and adolescent patients and pregnant or breastfeeding women, as well as considerations for patients who want to have a child. A chapter on the patient perspective is also provided. The first part of the guideline, published separately, contains recommendations and guidance on systemic treatment with conventional immunosuppressive drugs, biologics and janus kinase (JAK) inhibitors, as well as information on the scope and purpose of the guideline, and a section on guideline methodology.

Executive summary: Japanese guidelines for atopic dermatitis (ADGL) 2021

This is an abridged edition of English version of the Clinical Practice Guidelines for the Management of Atopic Dermatitis 2021. Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. In Japan, from the perspective of evidence-based medicine, the current strategies for the treatment of AD consist of three primary measures: (i) use of topical corticosteroids, tacrolimus ointment, and delgocitinib ointment as the main treatment of the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling, and advice about daily life. In the present revised guidelines, the description about three new drugs, namely, dupilumab, delgocitinib, and baricitinib, has been added. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

English Version of Clinical Practice Guidelines for the Management of Atopic Dermatitis 2021

This is the English version of the Clinical Practice Guidelines for the Management of Atopic Dermatitis 2021. Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. In Japan, from the perspective of evidence-based medicine, the current strategies for the treatment of AD consist of three primary measures: (i) use of topical corticosteroids, tacrolimus ointment, and delgocitinib ointment as the main treatment of the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling, and advice about daily life. In the present revised guidelines, descriptions of three new drugs, namely, dupilumab, delgocitinib, and baricitinib, have been added. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

The JAK/STAT Pathway and Its Selective Inhibition in the Treatment of Atopic Dermatitis: A Systematic Review

In recent years, the broadening understanding of the pathogenesis of atopic dermatitis (AD) has led to the development of novel therapeutic molecules, that target core inflammatory components of the disease. The Janus kinase (JAK)/signal transducer and activation of transcription (STAT) pathway constitutes the principal signaling cascade for a large number of cytokines and growth factors and is involved in intracellular signal transduction and subsequent regulation of gene transcription. Current knowledge suggests that the robust activation of the T-helper (Th)-2 [interleukin (IL)-4, IL-5, IL-13, IL-31] and Th22 (IL-22) immune responses in both skin and serum plays a pivotal role in the immunopathogenesis of AD especially at the acute stage, followed by a variable degree of Th1 (interferon-γ, tumor necrosis factor alpha) and Th17 (IL-17) activation in chronic disease. Of note, most of the aforementioned inflammatory cytokines utilize the JAK/STAT pathway for downstream signal transduction, explaining the emerging role of JAK inhibitors in the therapeutic armamentarium of AD. The present systematic review aims to discuss the involvement of JAK/STAT pathway in the pathogenesis of AD and summarize the clinical data available on the efficacy and safety of JAK inhibitors which have been used in the treatment of AD thus far.

Pharmacodynamics of Janus kinase inhibitors for the treatment of atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is the most common inflammatory skin disorder. Despite the high disease burden, the therapeutic options are limited and their efficacy in controlling AD might be partially satisfactory.

AREAS COVERED

Most of the key mediators in AD pathogenesis act through the JAK/STAT signaling pathway, which represents a valid therapeutic target. The first generation of JAK inhibitors, namely tofacitinib and ruxolitinib, inhibit multiple JAKs, whereas newer JAK inhibitors show more selective inhibitory effects for specific JAKs. The aim of this review was to discuss the role of the JAK/STAT pathway in AD and its inhibition, with a special focus on pharmacodynamic properties. We checked the English-language literature, published in the last 15 years using PubMed, Google Scholar, and Scopus.

EXPERT OPINION

JAK inhibitors have different selectivity for various JAK molecules, which influences their pharmacodynamics, efficacy and safety profile. Since many key cytokines in AD signal through JAK1, and as the selective JAK1 inhibition may be effective, avoiding the concomitant inhibition of JAK2- and JAK3-dependent pathways could be associated with additional safety issues. Therefore, selective JAK1 inhibitors may represent promising therapeutic agents for AD, as they might prevent off-target effects of JAK inhibitors, especially related to the hematologic profile.

Comparative efficacy and safety of abrocitinib, baricitinib and upadacitinib for moderate-to-severe atopic dermatitis: a network meta-analysis

Janus kinase (JAK) inhibitors have become promising treatments for atopic dermatitis (AD), however no study directly comparing JAK inhibitors with each other has been reported. We conducted this network meta‐analysis to determine the comparative efficacy and safety of three common oral JAK inhibitors including abrocitinib, baricitinib, and upadacitinib for moderate‐to‐severe AD. We first identified eligible studies from published meta‐analyzes, then we searched PubMed to obtain additional studies published between February and July 2021. Clinical efficacy and safety were evaluated as primary and secondary outcome, respectively. After extracting data and assessing methodological quality, we utilized ADDIS 1.4 software to conduct pair‐wise and network meta‐analyzes. Ten eligible studies were included in the final analysis. Pooled results that abrocitinib, baricitinib, and upadacitinib obtained higher investigator global assessment (IGA), eczema area, and severity index (EASI) response, however abrocitinib and upadacitinib caused more treatment‐emergent adverse events (TEAEs) regardless of doses, compared with placebo. Network meta‐analyzes revealed that upadacitinib 30 mg was superior to all regimens and upadacitinib 15 mg was better than remaining regimens except for abrocitinib 200 mg in terms of IGA and EASI response. Moreover, abrocitinib 200 mg was superior to abrocitinib 100 mg, baricitinib 1 mg, 2 mg, and 4 mg for clinical efficacy. However, upadacitinib 30 mg caused more TEAEs. Abrocitinib, baricitinib, and upadacitinib were consistently effective therapies in adult and adolescent patients with AD; however, upadacitinib 30 mg may be the optimal option in short‐term studies. More efforts should be done to reduce the risk of TEAEs caused by upadacitinib 30 mg.

Experts' Consensus on the Use of Pimecrolimus in Atopic Dermatitis in China: A TCS-Sparing Practical Approach

Introduction

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease with rising prevalence. Topical corticosteroids (TCS) are recommended as first-line therapy for patients with AD in China; however, corticophobia is a widespread concern, which can manifest as noncompliance: in a previous Chinese study, almost all parents whose children had AD were very concerned about the side effects of TCS and, as a result, nearly half did not use it in the event of recurrence. We propose a TCS-sparing treatment algorithm for the management of infants, children, adolescents, and adults with mild-to-moderate AD, to guide clinical practice in China.

Methods

A panel of eight experts in AD from China and one expert from Germany formed to develop a practical algorithm for the management of mild-to-moderate AD, focusing on pimecrolimus.

Results

Irrespective of body location, all patients with mild AD (including acute flares) and infants with moderate AD should apply the topical calcineurin inhibitor (TCI) pimecrolimus twice daily to the affected area until symptoms disappear. For children, adolescents, and adults with moderate AD, pimecrolimus should be applied twice daily to sensitive skin areas, and a TCI (either pimecrolimus or tacrolimus) should be applied twice daily to other body locations. Short-term administration of TCS, followed by TCI twice daily, is recommended for most patients with moderate AD experiencing acute flares, regardless of lesion site. Emollients should be used regularly.

Conclusions

The algorithm presented intends to simplify treatment of AD in China and guide clinical decision-making.

Emerging topical drug delivery approaches for the treatment of Atopic dermatitis

BACKGROUND

Atopic dermatitis is a chronic, relapsing skin inflammation disease that generally affects 20% of children and 1-3% of adults. It is characterized by pruritus, inflammatory skin lesions, and skin barrier defect. The pillar treatment is topical therapies that have shown great adherence and incredible results in alleviating symptoms of atopic dermatitis. Topical corticosteroids and calcineurin inhibitors have shown improvement in the symptoms of atopic dermatitis but have certain side effects. There is need to develop new therapies or novel drug delivery approaches which can overcome drawbacks of the conventional formulation and increase the therapeutic efficacy.

AIM

The scope of this review is to describe the new topical therapies including phosphodiesterase inhibitors, Janus kinase inhibitors, and nano-formulations such as nanoemulsion, polymeric and lipid nanoparticles, vesicular system, and micelles.

METHODS

The article reviews and discusses the published literature of the topical drug delivery approaches for treatment of Atopic dermatitis.

RESULTS

The reported literature highlighted the benefits of novel topical formulations exhibiting targeted drug delivery, better penetration, enhanced therapeutic efficacy, and overcome systemic side effects.

CONCLUSION

Literature indicated that the new therapies and novel drug delivery approaches found to be the therapeutically more effective in increasing the efficacy of drugs and reducing the side effects in comparison with the conventional treatments for Atopic dermatitis. This has provided a way to modify and develop more such formulations for dermal delivery.

Peripheral Mechanisms of Itch

Itch is a universally experienced sensation, and chronic itch can be as diabolically debilitating as pain. Recent advances have not only identified the neuronal itch sensing circuitry, but also have uncovered the intricate interactions between skin and immune cells that work together with neurons to identify itch-inducing irritants. In this review, we will summarize the fundamental mechanisms of acute itch detection in the skin, as well as highlight the recent discoveries relating to this topic.

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.

Sensitivity of clinician-assessed efficacy outcome measurement instruments in trials of topical therapies for atopic dermatitis: a systematic review and meta-analysis

The rising prevalence of atopic dermatitis (AD) in developing countries and its substantial socioeconomic impact have furthered research over the last two decades giving way to advances in its aetiopathogenesis and treatment. Topical therapies targeting newly identified AD signalling pathways are being developed. Numerous clinician-assessed disease severity outcome measurement instruments (OMIs) are available to evaluate the efficacy of investigational treatments in proof-of-concept (POC) trials for AD. However, little is known about the comparative sensitivity of these efficacy OMIs. We performed a systematic review and meta-analysis to compare the sensitivity of different OMIs in controlled trials of topical therapies for AD published between January 1, 2000 and April 7, 2020. Treatment effect size of OMIs reported at Week 4 was calculated with 95% Confidence Interval (CI). The sensitivity of OMIs was compared by pooling the standardized difference between means (Cohen's d and Cohen's h) for any two OMI-parameter combinations that were reported in ≥3 studies identified in our systematic review. Assessed parameters were difference between active and vehicle at Week 4 and change from baseline [CFB] and percentage change from baseline [%CFB] at Week 4. We identified a total of 15 studies with 3313 subjects examining 14 different OMIs were included in this quantitative meta-analysis. Continuous OMIs had a significantly higher treatment effect size vs. dichotomous OMIs (P = 0.006). Comparisons of Eczema Area and Severity Index (EASI), Investigator's Global Assessment (IGA), body surface area (BSA) and SCORing Atopic Dermatitis (SCORAD) for available parameters were performed and generally had a similar sensitivity, with BSA showing smaller overall effect size estimates. In conclusion, continuous OMIs used in topical clinical trials for AD had significantly higher treatment effect sizes when compared to dichotomous OMIs. Continuous OMIs could provide more power for POC trials with a small sample size in atopic dermatitis with topical therapies.

Janus kinase inhibitors for the therapy of atopic dermatitis

The JAK-STAT pathway is involved in the signaling of multiple cytokines driving cutaneous inflammation in atopic dermatitis (AD). Janus kinase (JAK) inhibitors target individual receptor-associated kinases, thereby preventing the mediation of inflammatory signals. Several JAK inhibitors with varying mechanism of action, potency, and safety represent potential therapeutic options for AD in both topical and systemic application. The JAK1/2 selective JAK inhibitor baricitinib was the first substance from this class of drugs approved by the EMA for the systemic oral treatment of AD. The clinical development program of the JAK1 selective inhibitors upadacitinib and abrocitinib is finalized with positive results for AD. The PAN-JAK inhibitor delgocitinib was the first substance being approved for the treatment of AD (in Japan). This review article covers the rising data on investigational and approved JAK inhibitors in the context of the treatment of AD.

Efficacy and safety of topical Janus kinase and phosphodiesterase inhibitor-4 inhibitors for the treatment of atopic dermatitis: A network meta-analysis

Topical Janus kinase (JAK) and phosphodiesterase-4 (PDE4) inhibitors are novel treatment approaches for atopic dermatitis (AD). This study aimed to compare the efficacy and safety of JAK and PDE4 inhibitors for AD treatment. The databases of PubMed, EMBASE, Web of Science, and Cochrane Library were searched until June 2021 for eligible studies of AD patients treated with topical JAK and PDE4 inhibitors. Baseline and follow-up data were extracted. Efficacy of JAK inhibitors was evaluated using Investigator's Global Assessment (IGA) achieving "clear" or "almost clear", with 2 points or more improvement from baseline at the end of treatment, referred to as "IGA response"). A Bayesian multiple treatment network meta-analysis with fixed effects was performed. Odds ratio (OR) with 95% credibility interval (CrI) were used for comparing the efficacy of JAK and PDE4 inhibitors with placebo for AD. A total of 10 randomized controlled trials of topical JAK and PDE4 inhibitors with 4689 patients were included for analysis. A total of three topical JAK inhibitors and two topical PDE4 inhibitors were included. Compared with placebo, all JAK and PDE4 inhibitors had higher IGA response at 4 weeks of treatment. Notably, with similar safety profile, tofacitinib 2% b.i.d., ruxolitinib 1.5% b.i.d., and delgocitinib 3% b.i.d. showed favorable IGA response compared with topical tacrolimus and corticosteroids. Ranking analysis suggested that among all included JAK and PDE4 inhibitors, tofacitinib 2% b.i.d. had the highest probability of achieving IGA response (SUCRA = 0.880). Besides, JAK and PDE4 inhibitors showed non-inferior safety profile with placebo. This study confirmed that topical JAK and PDE4 inhibitors had promising treatment efficacy and safety for AD patients. Tofacitinib 2% b.i.d., ruxolitinib 1.5% b.i.d. and delgocitinib 3% b.i.d. showed superior efficacy over other JAK and PDE4 inhibitors.

Efficacy and Safety of Janus Kinase Inhibitors for the Treatment of Atopic Dermatitis: A Systematic Review and Meta-Analysis

Background

Current therapeutic options for atopic dermatitis (AD) are limited. Janus kinase (JAK) inhibitors may be viable alternatives.

Objectives

To assess the efficacy and safety of JAK inhibitors for AD treatment.

Methods

We searched PubMed, Embase, the Cochrane Controlled Register of Trials, Web of Science, Global Resource of Eczema Trials database, and ClinicalTrials.gov from inception to September 1, 2020. Randomized clinical trials (RCTs) comparing JAK inhibitors with placebo/vehicle treatment for AD patients were included. The primary study outcomes included (1) the change (%) from the Eczema Area and Severity Index (EASI) baseline expressed as weighted mean difference (WMD) and 95% confidence interval (95% CI), and (2) the Investigator's Global Assessment (IGA) response and safety outcomes expressed as relative risk (RR) and 95% CI.

Results

We included 14 RCTs published in 13 studies (3,822 patients). Treatment with JAK inhibitors significantly improved IGA response (RR 2.83, 95% CI 2.25–3.56, p < 0.001) and EASI score (WMD −28.82, 95% CI −34.48 to −23.16, p < 0.001). JAK inhibitor treatment achieved the largest improvement in both IGA response (RR 3.59, 95% CI 2.66–4.84, p < 0.001) and EASI score (WMD −42.00, 95% CI −48.64 to −35.36, p < 0.001) by week 4 of treatment. Topical JAK inhibitors were significantly more efficacious than oral inhibitors. Upadacitinib treatment for 4 weeks was most effective in reducing EASI score (WMD −53.92, 95% CI −69.26 to −38.58, p < 0.001), while abrocitinib for 4 weeks led to the most effective IGA response (RR 5.47, 95% CI 2.74–10.93, p < 0.001). There was no difference in the frequency of adverse events (AEs) leading to discontinuation; however, JAK inhibitors use, especially abrocitinib, led to a higher incidence of treatment-emergent AEs (RR 1.25, 95% CI 1.10–1.42, p = 0.001).

Conclusion

Our results imply that JAK inhibitors are an effective and safe AD treatment. Nevertheless, further trials with longer duration and head-to-head comparisons of different JAK inhibitors are needed.

JAK inhibitors in the treatment of atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disorder associated with heterogenous presentation and often immense patient burden. Safe, targeted treatment options are currently limited. This focused review of the published literature, including clinical trial results, case reports, and abstracts, as well as presentations from scientific meetings and data from industry press releases, describes the use of topical and systemic Janus kinase (JAK) inhibitors in the treatment of AD. New topical JAK inhibitors include ruxolitinib (JAK1/2) and delgocitinib (pan-JAK). Ruxolitinib cream met all primary and secondary endpoints in phase 3 clinical trials for mild-to-moderate AD with minimal treatment-emergent adverse events. Delgocitinib ointment was recently approved in Japan for pediatric and adult AD. Oral JAK inhibitors include baricitinib (JAK1/2), abrocitinib (JAK1-selective), and upadacitinib (JAK1-selective). All 3 met primary and secondary endpoints across numerous trials for moderate-to-severe AD. Treatment-emergent adverse events were mainly mild to moderate and included acne, nausea, headache, upper respiratory tract infection, and to a lesser degree, herpes infection and selected laboratory abnormalities. JAK inhibitors hold great promise as the next generation of targeted AD therapy. While their outstanding efficacy is balanced by a favorable safety profile in clinical trials, real-world data are needed to better understand long-term safety, durability, and treatment success.

Safety of Janus kinase (JAK) inhibitors in the short-term treatment of atopic dermatitis

Atopic dermatitis (AD) is a chronic heterogeneous condition characterized by erythematous, pruritic, and inflamed skin. Janus kinase (JAK) inhibitors are a new class of drugs that target proteins in the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. These drugs can be administered orally or topically to inhibit signaling of the JAK-STAT pathway and minimize the production of proinflammatory cytokines. The efficacy and safety of JAK inhibitors have been investigated in phase 2 and 3 clinical trials for AD. The safety of new medications, which are immunosuppressive by nature, is of utmost concern for the prescriber and patient alike. Herein we summarize the safety results of clinical trials using oral abrocitinib, upadacitinib, and baricitinib, as well as topical ruxolitinib and delgocitinib for the treatment of AD. The most prevalent (2-5% occurrence rate) treatment-emergent adverse events from oral JAK inhibitor use in AD were nausea, upper respiratory tract infection, headache, herpes zoster, herpes simplex, acne, increased blood creatine phosphokinase levels, and decreased platelet counts. Topical JAK inhibitors were not associated with systemic effects. All studies reported that JAK inhibitors were well tolerated in patients with AD in comparison with the control group. While the use of JAK inhibitors in patients suffering from AD is very promising, trials reported to date are of short duration (maximum 16 weeks), and more information on the long-term safety of these novel agents is required.

The efficacy of Janus kinase inhibitors in patients with atopic dermatitis: A systematic review and network meta-analysis

Janus kinase (JAK) inhibitors are novel treatment approaches for atopic dermatitis (AD). This study was aimed to compare the efficacy of JAK inhibitors for AD treatment. The database of PubMed, EMBASE, Web of Science, and Cochrane Library were searched until March 28, 2021, for randomized control trials (RCTs) of AD patients treated with JAK inhibitors. Baseline and follow-up data were extracted. Efficacy of JAK inhibitors was evaluated using 50% improvement in Eczema Area and Severity Index (EASI-50). A Bayesian multiple treatment network meta-analysis with fixed effects was performed. Odds ratio (OR) with 95% credibility interval (CrI) were used for comparing the efficacy of JAK inhibitors with placebo for AD. A total of seven RCTs of JAK inhibitors with 2530 patients were included for analysis. After excluded one study with high risk of bias, a total of six JAK inhibitors with 17 different formulations and doses were analyzed. The severity of atopic dermatitis of included patients was almost moderate to severe (93.4%). Compared with placebo, all JAK inhibitors had higher EASI-50 at 4 weeks of treatment, except for baricitinib with 1 mg once daily (QD) (OR: 1.4, 95% Crl: 0.9-2.1), ruxolitinib with 0.15% QD (OR: 2.3, 95% Crl: 0.8-11.4), and ruxolitinib with 0.5% QD (OR: 3.4, 95% Crl: 0.9-18.1). Among all included, upadacitinib had the highest probability of being the best treatment (SUCRA value of 0.936). In topical JAK inhibitors, delgocitinib 3% twice a day (BID) had the highest probability of being the best treatment (SUCRA value of 0.849). JAK inhibitors had promising treatment efficacy for AD patients. Upadacitinib with 30 mg QD had the best efficacy among all included JAK inhibitors, and delgocitinib 3% BID showed superior efficacy over other topical JAK inhibitors for AD treatment.

The efficacy and safety of JAK inhibitors for atopic dermatitis: a systematic review and meta-analysis

BACKGROUND

Atopic dermatitis (AD) is one of the serious global problems. There were wide concerns about whether Janus kinase (JAK) inhibitor was an alternative treatment for AD.

METHOD

Eight databases were searched from the earliest publication date available to January 2, 2021. We included randomized controlled trials comparing JAK inhibitors with control treatment for AD. Data were pooled using Stata.14 software and performed as mean differences (MD) and risk ratios (RR) with 95% CIs. We did subgroup analysis based on specific outcomes.

RESULTS

A total of studies, ten randomized controlled trials, with 2583 patients were included in the final synthesis. This meta-analysis showed JAK inhibitor resulted in significant improvement on EASI total score (MD = -0.31; 95%CI, -0.46 to -0.17; p = .000; I² = 90.0%, p = .000) and pruritus numerical rating scale (NRS) score (MD = -1.15; 95%CI, -1.48 to -0.83; p = .000; I² = 95.9%, p = .000), without the higher risk of total adverse effects (RR = 1.02; 95%CI, 0.90-1.16; p = .745; I² =27.9%, p = .206).

CONCLUSIONS

JAK inhibitor was a promising option for atopic dermatitis. More data and surveillance will be needed to identify efficacy, safety, and the risk of adverse effects.

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.

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.

Janus Kinase Inhibitors in Dermatology: Part 2: Applications in Psoriasis, Atopic Dermatitis, and Other Dermatoses

Dermatologists' interest in the Janus-associated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway has been growing as evidence builds to support its key role in the pathogenesis of inflammatory skin diseases. Because certain proinflammatory cytokines use the JAK/STAT pathway for signal transduction, it has become a promising therapeutic target in diseases where selective modulation of the immune system can be useful. We aim to review current knowledge of the JAK/STAT signaling pathway and its role in immune-mediated skin diseases. In the second part of the review we cover the efficacy and safety of oral and topical JAK inhibitors in the treatment of psoriasis, atopic dermatitis, and other skin diseases.

Atopic dermatitis: Role of the skin barrier, environment, microbiome, and therapeutic agents

Atopic dermatitis (AD) is a chronic, inflammatory skin disorder characterized by eczematous and pruritic skin lesions. In recent decades, the prevalence of AD has increased worldwide, most notably in developing countries. The enormous progress in our understanding of the complex composition and functions of the epidermal barrier allows for a deeper appreciation of the active role that the skin barrier plays in the initiation and maintenance of skin inflammation. The epidermis forms a physical, chemical, immunological, neuro-sensory, and microbial barrier between the internal and external environment. Not only lesional, but also non-lesional areas of AD skin display many morphological, biochemical and functional differences compared with healthy skin. Supporting this notion, genetic defects affecting structural proteins of the skin barrier, including filaggrin, contribute to an increased risk of AD. There is evidence to suggest that natural environmental allergens and man-made pollutants are associated with an increased likelihood of developing AD. A compromised epidermal barrier predisposes the skin to increased permeability of these compounds. Numerous topical and systemic therapies for AD are currently available or in development; while anti-inflammatory therapy is central to the treatment of AD, some existing and novel therapies also appear to exert beneficial effects on skin barrier function. Further research on the skin barrier, particularly addressing epidermal differentiation and inflammation, lipid metabolism, and the role of bacterial communities for skin barrier function, will likely expand our understanding of the complex etiology of AD and lead to identification of novel targets and the development of new therapies.

Application of Janus Kinase Inhibitors in Atopic Dermatitis: An Updated Systematic Review and Meta-Analysis of Clinical Trials

Janus kinase (JAK) inhibitors are promising treatments for atopic dermatitis (AD). The aim of this study was to assess the efficacy and safety of JAK inhibitors for AD treatment via the “Grading of Recommendations Assessment, Development, and Evaluation” approach. We identified 15 randomized controlled trials comparing oral or topical JAK inhibitors against placebo to treat AD. A random-effects meta-analysis was performed, and the numbers-needed-to-treat (NNTs)/numbers-needed-to-harm (NNHs) were calculated. Patients treated with JAK inhibitors were associated with higher rates of achieving eczema area and severity index-75 (rate ratio (RR): 2.84; 95% confidence interval (CI): 2.20–3.67; I²: 38.9%; NNT = 3.97), Investigator’s Global Assessment response (RR: 2.99; 95% CI: 2.26–3.95; I²: 0%; NNT = 5.72), and pruritus numerical rating scale response (RR: 2.52; 95% CI: 1.90–3.35; I²: 39.4%; NNT = 4.91) than those treated with placebo. Moreover, patients treated with JAK inhibitors had a higher risk of treatment-emergent adverse events (RR: 1.14; 95% CI: 1.02–1.28; I²: 52%; NNH = 14.80) but not adverse events leading to drug discontinuation. According to the evidence-based results, JAK inhibitors are potentially effective strategies (certainty of evidence: “moderate”) for treating AD with tolerable side effects (certainty of evidence: “low”). Nevertheless, long-term follow-up is required.

Therapeutic New Era for Atopic Dermatitis: Part 2. Small Molecules

Atopic dermatitis (AD) is a chronic, inflammatory cutaneous disease driven by immune dysregulation and skin barrier dysfunction. Currently, we are experiencing a new era of understanding of the pathogenesis of AD and, as a consequence, a new era of innovation in therapeutics, including small molecules and biologic therapy. In contrast to biologics, small molecules are similar to conventional pharmacologic chemical agents used as drugs and are generally prepared by chemical synthesis. Unlike biologics, these drugs often are taken orally or formulated for topical use. The purpose of this review is to summarize the efficacy and safety of the current topical and systemic new therapies in AD by reviewing recently published papers on therapies currently in phase 2 or 3 clinical trials. In this review, it is important to note the characteristics of the study population, the primary endpoints, and whether or not there was concomitant topical therapy allowed. These study design elements may significantly alter the results of studies and should be taken into account. Targeted therapy help push AD treatment into a new era of personalized medicine.

Atopic dermatitis: new insight into the etiology, pathogenesis, diagnosis and novel treatment strategies

Atopic dermatitis (AD) is the long-lasting chronic inflammatory skin condition associated with cutaneous hyper-reactivity and triggered by environmental factors. The attributes of AD include dry skin, pruritus, lichenification and frequent eczematous abrasions. This has a strong heritable aspect and typically occurs with asthma and allergic rhinitis. The complex pathological mechanism behind AD etiology is epidermal barrier destruction resulting in the lack of filaggrin protein that can induce inflammation and T-cell infiltration. T-helper 2 cell-mediated pathways also bear the responsibility of damage to the epidermal barrier. Certain causative factors for AD include microbial imbalance of skin microbiota, immunoglobulin-E-induced sensitization and neuro-inflammation. Numerous beneficial topical and oral treatments have been available to patients and there are even more drugs in the pipeline for the treatment of AD. Topical moisturizers, corticosteroids, anti-inflammatory agents such as calcineurin inhibitors, phototherapy, cAMP-specific 3, 5 half-cyclic phosphodiesterase 4 inhibitors and systemic immunosuppressants are widely available for AD treatments. Different positions and pathways inside the immune system including JAK-STAT, phosphodiesterase 4, aryl hydrocarbon receptor and T-helper 2 cytokines are targeted by above-mentioned drug treatments. Instead of the severe side effects of topical steroids and oral antihistamines, herbal plants and their derived phytoconstituents are commonly used for the treatment of AD. A clear understanding of AD's cellular and molecular pathogenesis through substantial advancement in genetics, skin immunology and psychological factors resulted in advancement of AD management. Therefore, the review highlights the recent advancements in the understanding of clinical features, etiology, pathogenesis, treatment and management and non-adherence to AD treatment.

Skin barrier dysfunction and filaggrin

Skin barrier dysfunction caused by endogenous or exogenous factors can lead to various disorders such as xerosis cutis, ichthyoses, and atopic dermatitis. Filaggrin is a pivotal structural protein of the stratum corneum (SC) and provides natural moisturizing factors that play a role in skin barrier functions. Filaggrin aggregates keratin filaments, resulting in the formation of a keratin network, which binds cornified envelopes and collapse keratinocytes to flattened corneocytes. This complex network contributes to the physical strength of the skin. Filaggrin is degraded by caspase-14, calpain 1, and bleomycin hydrolases into amino acids and amino acid metabolites such as trans-urocanic acid and pyrrolidone carboxylic acid, which are pivotal natural moisturizing factors in the SC. Accordingly, filaggrin is important for the pathophysiology of skin barrier disorders, and its deficiency or dysfunction leads to a variety of skin disorders. Here, the roles and biology of filaggrin, related skin diseases, and a therapeutic strategy targeting filaggrin are reviewed. In addition, several drug candidates of different mode of actions targeting filaggrin, along with their clinical efficacy, are discussed.

Janus Kinase Inhibitors in Dermatology: Part 2: Applications in Psoriasis, Atopic Dermatitis, and Other Dermatoses

Dermatologists' interest in the Janus-associated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway has been growing as evidence builds to support its key role in the pathogenesis of inflammatory skin diseases. Because certain proinflammatory cytokines use the JAK/STAT pathway for signal transduction, it has become a promising therapeutic target in diseases where selective modulation of the immune system can be useful. We aim to review current knowledge of the JAK/STAT signaling pathway and its role in immune-mediated skin diseases. In the second part of the review we cover the efficacy and safety of oral and topical JAK inhibitors in the treatment of psoriasis, atopic dermatitis, and other skin diseases.

Brief Academic Review and Clinical Practice Guidelines for Pediatric Atopic Dermatitis

In this clinical guidelines article, we first include a brief review of the epidemiology, pathogenesis, clinical diagnoses, and scoring-scales for pediatric atopic dermatitis (AD). We then offer a set of pharmacologic treatment guidelines for infants and toddlers (<2 years), children (2-12 years), and adolescents (>12 years). We recommend irritant avoidance and liberal emollient usage as the cornerstone of treatment in all age-groups. In infants <2 years, we recommend topical corticosteroids as first-line medication-based therapy. In infants as young as 3 months, pimecrolimus, a topical calcineurin inhibitor, may also be used. As a last resort in patients <2 years, non-traditional therapies, such as the Aron regime, may be a safer option for refractory or resistant AD before off- label medications are considered. In children and adolescents >2 years, topical corticosteroids are still considered first-line therapies, but there is sufficient safety data to utilize topical calcineurin inhibitors and topical PDE4 inhibitors as well. In children ages 2-12 years whose atopic dermatitis fails to respond to prior treatments, oral systemic immunosuppressants can be used. For adolescents >12, the biologic, dupilumab, is an additional therapeutic option. A trial of phototherapy may also be utilized in children, particularly in adolescents >12 years, if they have access to treatment. Although not currently approved for the treatment of AD, Janus-kinase (JAK) inhibitors represent a promising new class of biologics with recently completed phase III clinical trials (JADE-- MONO1/2).