Therapeutic pipeline for atopic dermatitis: End of the drought?

New Insights and Treatments in Atopic Dermatitis

Atopic dermatitis is a complex, chronic inflammatory skin disorder with significant morbidity. It is often a frustrating condition for both children and parents due to chronic and relapsing course. There is now an increasing understanding of the disease pathogenesis resulting in discovery of much wanted newer therapeutics and targeted therapies after a long time. Whether these interventions will result in sustained benefits or long term cure remains to be seen.

Increased IL-26 Expression Promotes T Helper Type 17- and T Helper Type 2-Associated Cytokine Production by Keratinocytes in Atopic Dermatitis

Whereas atopic dermatitis (AD) is considered as a T helper 2 (Th2)-centered disease, IL-17-producing Th (Th17) cells are also activated in AD lesional skin. However, the relationship between Th17 responses and Th2 responses in AD is still to be elucidated. Although Th17 cells are increased in AD skin, the expression and function of IL-26, which is also produced by Th17 cells, in AD are still unknown. In this report, we demonstrated that IL-26 mRNA expression levels were elevated in AD lesional skin compared with healthy controls and that IL-26-producing cells were increased in AD lesional skin by immunohistochemistry. Furthermore, IL-26 promoted IL-8, IL-1β, chemokine (C-C motif) ligand 20, IL-33, and β-defensin 2 production in keratinocytes through phosphorylation of signal transducer and activator of transcription 1 and signal transducer and activator of transcription 3. Selective JAK inhibitors for JAK1, JAK2, and tyrosine kinase 2 blocked IL-26-induced cytokine production in keratinocytes. We also showed that injection of IL-26 exacerbated an oxazolone-induced AD mouse model and upregulated Th2 and Th17 cytokine expression in vivo. Because previous studies indicate that the above molecules induced by IL-26 can promote Th17 and/or Th2 immune responses, IL-26 may play an important role for bridging between Th17 and Th2 responses, resulting in the development of AD.

Phase 2 clinical study of delgocitinib ointment in pediatric patients with atopic dermatitis

BACKGROUND

Topical delgocitinib (JTE-052), a novel Janus kinase inhibitor, had been shown to be clinically effective in adults with atopic dermatitis (AD). However, the efficacy of topical delgocitinib in pediatric patients with AD remained unclear.

OBJECTIVE

We sought to evaluate the efficacy and safety of delgocitinib ointment in pediatric patients with AD.

METHODS

In this phase 2 clinical study (JapicCTI-173553) Japanese patients aged 2 through 15 years with AD were randomized in a 1:1:1 ratio to receive 0.25% or 0.5% delgocitinib ointment or vehicle ointment twice daily for 4 weeks. The primary efficacy end point was the percentage change from baseline in the modified Eczema Area and Severity Index score at the end of treatment (EOT).

RESULTS

At EOT, modified Eczema Area and Severity Index scores in both delgocitinib groups were significantly reduced compared with that in the vehicle group. The least-squares mean percentage change from baseline was -54.2% in the 0.25% group and -61.8% in the 0.5% group versus -4.8% in the vehicle group (P < .001 for both comparisons). Similarly, all other efficacy parameters, including Investigator's Global Assessment and pruritus scores, in both delgocitinib groups were significantly improved compared with those in the vehicle group at EOT. Adverse events in both delgocitinib groups were mild in severity, and no serious adverse events were reported.

CONCLUSIONS

Delgocitinib ointment improved clinical signs and symptoms in pediatric patients with AD and was well tolerated. These study results indicate that delgocitinib ointment can be a promising therapeutic option for pediatric patients with AD.

Derailed Ceramide Metabolism in Atopic Dermatitis (AD): A Causal Starting Point for a Personalized (Basic) Therapy

Active rebuilding, stabilizing, and maintaining the lipid barrier of the skin is an encouraging disease management and care concept for dry skin, atopic dermatitis (eczema, neurodermatitis), and psoriasis. For decades, corticosteroids have been the mainstay of topical therapy for atopic dermatitis; however, innovations within the scope of basic therapy are rare. In (extremely) dry, irritated, or inflammatory skin, as well as in lesions, an altered (sphingo)lipid profile is present. Recovery of a balanced (sphingo)lipid profile is a promising target for topical and personalized treatment and prophylaxis. New approaches for adults and small children are still lacking. With an ingenious combination of commonly used active ingredients, it is possible to restore and reinforce the dermal lipid barrier and maintain refractivity. Lysosomes and ceramide de novo synthesis play a key role in attenuation of the dermal lipid barrier. Linoleic acid in combination with amitriptyline in topical medication offers the possibility to relieve patients affected by dry and itchy skin, mild to moderate atopic dermatitis lesions, and eczemas without the commonly occurring serious adverse effects of topical corticosteroids or systemic antibody administration.

Crisaborole: A Novel Nonsteroidal Topical Treatment for Atopic Dermatitis

Objective: To review the efficacy and safety of crisaborole and its place in therapy for the management of mild to moderate atopic dermatitis (AD). Data Sources: A literature search of PubMed (data inception to February 2019) was performed using the search terms crisaborole and atopic dermatitis. Supplementary sources included the Journal of the American Academy of Dermatology Guidelines of Care for the Management of Atopic Dermatitis, clinicaltrials.gov data, manufacturer prescribing information, and article bibliographies. Study Selection and Data Extraction: Relevant English-language studies and those conducted in humans were considered and reviewed. Abstracts from clinical trials and drug reviews were reviewed. Phases I, II, III, and long-term safety studies were included. Data Synthesis: Data from multiple clinical trials have demonstrated the effectiveness and safety of crisaborole topical ointment. Patients treated with crisaborole experienced improvement in AD symptoms based on improvement in the Investigator's Static Global Assessment and the AD Severity Index scores. Crisaborole has a limited adverse event profile and low systemic absorption. Relevance to Patient Care and Clinical Practice: Crisaborole is the first topical phosphodiesterase 4 inhibitor indicated for the treatment of mild to moderate AD. Its place in therapy is along with topical calcineurin inhibitors as a second-line option for patients who are recalcitrant to or unable to use topical corticosteroids. Conclusions: Crisaborole is a safe and efficacious second-line option for the treatment of mild to moderate AD in patients 2 years of age and older.

Atopic dermatitis in adults: An Australian management consensus

BACKGROUND/OBJECTIVES

Atopic dermatitis (AD) has significant negative impact on health-related quality of life, mood, sleep, work productivity and everyday activities. Research into the use of new drugs in the management of AD continues to develop, and international updates and recommendations have been published. However, questions remain in the Australian setting. This consensus aims to provide evidence-based insights and practical advice on the management of adult AD in Australia.

METHODS

A panel (five dermatologists and one clinical immunologist) met to review the literature, critically examine clinical questions of relevance to Australian healthcare practitioners and develop a series of recommendation statements. A consensus panel, comprising the initial panel plus nine additional members, used a 2-round Delphi voting process to determine a set of final guidance statements.

CONSENSUS

≥75% agreement in the range 7-9.

RESULTS

Round 1 voting comprised 66 guidance statements. Of these, consensus was reached on 26, which were retained, and five were removed. The remainder (35) were modified and one new guidance statement was added for inclusion in round 2 voting. After round 2, consensus was reached on 35, which were retained, and one was removed (considered redundant). The 61 guidance statements upon which consensus was reached were then used to support a series of core consensus recommendations and a management flow chart.

CONCLUSIONS

Expert consensus recommendations providing practical guidance of clinical relevance to specialists and primary care physicians in Australia have been developed. Dissemination of this guidance and evaluation of its impact on patient outcomes remain to be undertaken.

What is new in HIES? Recent insights from the interface of primary immune deficiency and atopy

PURPOSE OF REVIEW

Understanding the pathophysiology of monogenic primary immunodeficiency (PID) with atopic presentation has pivotal implications for intervention strategies and potentially wider polygenic atopic-related traits. This review will discuss advances in gene discovery arising from monogenic defects at the interface between PID and atopy, notably the hyper-IgE syndromes.

RECENT FINDINGS

Key molecular pathways underlying development of primary atopic diseases have recently been proposed. We test this classification through reviewing novel genes reported in the last 2 years and compare insights from pathway-analysis of genome-wide association studies (GWAS) of atopic-related traits.Growing access to next-generation sequencing (NGS) has resulted in a surge in gene discovery, highlighting the utility and some pitfalls of this approach in clinical practice. The variability of presenting phenotypes reveals important gene-dosage effects. This has important implications for therapeutic strategies such as protein stabilization and modulators of JAK-STAT or TH2-cytokine signalling. We also consider the therapeutic implications raised by CARD11 deficiency, and wider applications of NGS including polygenic risk score in atopy.

SUMMARY

Disorders presenting at the interface between PID and allergy are often difficult to diagnose, with serious consequences if missed. Application of NGS has already provided critical insights to pathways enabling targeted therapeutic interventions, and potential wider translation to polygenic disorders.

Prostaglandin E2 (PGE2)-EP2 signaling negatively regulates murine atopic dermatitis-like skin inflammation by suppressing thymic stromal lymphopoietin expression

BACKGROUND

Atopic dermatitis (AD) is a common and chronic inflammatory skin disease of type 2 immunity. Keratinocyte-derived cytokines, including thymic stromal lymphopoietin (TSLP) and IL-33, are considered to induce the development of AD. Production of prostanoids, a family of lipid mediators, is increased in AD lesions. However, their physiologic functions remain to be clarified.

OBJECTIVES

We sought to elucidate the functions of prostanoids in the development of AD.

METHODS

The roles of prostanoids were investigated in a mouse model of AD induced by repeated application of hapten and PAM212, a keratinocyte cell line.

RESULTS

Application of indomethacin, which blocks prostanoid synthesis, leads to enhanced TSLP and IL-33 production in the skin, increased serum IgE levels, and exacerbation of skin inflammation in this AD model. The skin inflammation was attenuated in TSLP receptor-deficient mice but not in IL-33-deficient mice, and the indomethacin-enhanced type 2 immune responses were abolished in TSLP receptor-deficient mice. Indomethacin increased protease-activated receptor 2-mediated TSLP production in keratinocytes in vitro, and prostaglandin E₂ reversed the increase in TSLP levels through its receptor, the prostaglandin E₂ receptor (EP2), by downregulating surface expression of protease-activated receptor 2. Administration of an EP2 agonist canceled indomethacin-enhanced TSLP production and type 2 immune responses in the skin, whereas an EP2 antagonist caused an enhancement of TSLP production and type 2 immune responses in the skin.

CONCLUSION

Prostaglandin E₂-EP2 signaling negatively regulates murine AD-like skin inflammation by suppressing TSLP expression.

Understanding the immune landscape in atopic dermatitis: The era of biologics and emerging therapeutic approaches

Atopic dermatitis (AD) is a chronic, systemic, inflammatory disease that affects the skin and is characterized by persistent itch and marked redness. AD is associated with an increased risk of skin infections and a reduced quality of life. Most AD treatment options to date were not designed to selectively target disease-causing pathways that have been established for this indication. Topical therapies have limited efficacy in moderate-to-severe disease, and systemic agents such as corticosteroids and immunosuppressants present with tolerability issues. Advances in the understanding of AD pathobiology have made possible a new generation of more disease-specific AD therapies. AD is characterized by the inappropriate activation of type 2 T helper (Th2) cells and type 2 innate lymphoid (ILC2) cells, with a predominant increase in type 2 cytokines in the skin, including interleukin (IL)-13 and IL-4. Both cytokines are implicated in tissue inflammation and epidermal barrier dysfunction, and monoclonal antibodies targeting each of these interleukins or their receptors are in clinical development in AD. In March 2017, dupilumab, a human anti-IL-4Rα antibody, became the first biologic to receive approval in the United States for the treatment of moderate-to-severe AD. The anti-IL-13 monoclonal antibodies lebrikizumab and tralokinumab, which bind different IL-13 epitopes with potentially different effects, are currently in advanced-stage trials. Here, we briefly review the underlying pathobiology of AD, the scientific basis for current AD targets, and summarize current clinical studies of these agents, including new research to develop both predictive and response biomarkers to further advance AD therapy in the era of precision medicine.

Clinical onset of atopic eczema: Results from 2 nationally representative British birth cohorts followed through midlife

Background

Atopic eczema onset is described primarily in early childhood, and the frequency and characteristics of adult-onset disease remain controversial.

Objective

We sought to determine the proportion of subjects who report atopic eczema symptoms between birth and midadulthood and to examine demographic, immunologic, and genetic factors associated with period of symptom onset.

Methods

We conducted a longitudinal study using data from 2 nationally representative community-based birth cohorts from the United Kingdom: the British Cohort Studies 1958 and 1970. Subjects were followed from birth through age 42 to 50 years. The primary outcome was the age period of self-reported atopic eczema symptom onset based on repeated measures of self-reported atopic eczema at each survey wave.

Results

The annual period prevalence of atopic eczema ranged from 5% to 15% in 2 cohorts of more than 17,000 participants each followed from birth through middle age. There was no clear trend in prevalence by age, and among adults reporting active atopic eczema during a given year, only 38% had symptom onset reported in childhood. When compared with subjects whose eczema started in childhood, those with adult-onset disease were more likely to be women, from Scotland or Northern England, of lower childhood socioeconomic group, smokers in adulthood, and less likely to have a history of asthma. In a subanalysis using data from the 1958 cohort only, genetic mutations previously associated with atopic eczema, including filaggrin-null mutations, and allergen-specific IgE were more common among those with childhood-onset disease.

Conclusion

Rates of self-reported atopic eczema remain high after childhood, and adult-onset atopic eczema has different risk factor associations than childhood-onset eczema.

[New aspects in systemic treatment of atopic dermatitis]

In severe cases of atopic dermatitis (AD) systemic treatment is indicated. So far, cyclosporine and systemic glucocorticosteroids represented the only systemic treatment options approved for the indications of AD in Germany; however, from clinical practice there is increasing evidence for beneficial therapeutic effects in AD by other immunosuppressive or immunomodulatory substances, such as mycophenolate, methotrexate, alitretinoin and ustekinumab. Beyond this, ongoing research activities focus on a better understanding of genetic and immunological aspects of this chronic inflammatory skin disease. Regarding treatment with mycophenolate, genetic polymorphisms in AD patients could be identified that might predict responsiveness to this medication. Moreover, several new substances specifically targeting inflammation in AD are currently being studied and the first promising treatment effects on skin condition and pruritic symptoms of AD could be observed. As an exceptional result of this development in September 2017 in Europe and therefore in Germany the first biologic as first-line treatment was approved for the indication of moderate to severe AD in adults. Dupilumab is a human monoclonal IgG4 antibody that blocks a subunit of the interleukin (IL)-4 and IL-13 receptors, thus inhibiting the proinflammatory effects of these cytokines. Furthermore, the cytokine IL-13 itself, the IL-31 receptor, which is of particular relevance for pruritus in AD, the histamine-4-receptor and Janus kinases represent further promising targets currently being investigated in clinical trials for the treatment of AD.

Combined culture and metagenomic analyses reveal significant shifts in the composition of the cutaneous microbiome in psoriasis

BACKGROUND

The treatment of psoriasis has been revolutionized by the development of biologic therapies. However, the pathogenesis of psoriasis, in particular the role of the cutaneous microbiome, remains incompletely understood. Moreover, skin microbiome studies have relied heavily on 16S rRNA sequencing data in the absence of bacterial culture.

OBJECTIVES

To characterize and compare the cutaneous microbiome in 20 healthy controls and 23 patients with psoriasis using metagenomic analyses and to determine changes in the microbiome during treatment.

METHODS

Swabs from lesional and nonlesional skin from patients with psoriasis, and from controls matched for site and skin microenvironment, were analysed using both 16S rRNA sequencing and traditional culture combined with mass spectrometry (MALDI-TOF) in a prospective study.

RESULTS

Psoriasis was associated with an increased abundance of Firmicutes and a corresponding reduction in Actinobacteria, most marked in lesional skin, and at least partially reversed during systemic treatment. Shifts in bacterial community composition in lesional sites were reflected in similar changes in culturable bacteria, although changes in the microbiota over repeated swabbing were detectable only with sequencing. The composition of the microbial communities varied by skin site and microenvironment. Prevotella and Staphylococcus were significantly associated with lesional skin, and Anaerococcus and Propionibacterium with nonlesional skin. There were no significant differences in the amount of bacteria cultured from the skin of healthy controls and patients with psoriasis.

CONCLUSIONS

Shifts in the cutaneous microbiome in psoriasis, particularly during treatment, may shed new light on the pathogenesis of the disease and may be clinically exploited to predict treatment response. What's already known about this topic? Alterations in the composition of the cutaneous microbiome have been described in psoriasis, although methodological differences in study design prevent direct comparison of results. To date, most cutaneous microbiome studies have focused on 16S rRNA sequencing data, including both living and dead bacteria. What does this study add? This prospective observational study confirms that changes in the composition of the cutaneous microbiome, detected by 16S rRNA sequencing, are consistent with those identified by bacterial culture and mass spectrometry. The changes in the microbiome during antipsoriasis therapy should be further investigated to determine whether these represent potential novel biomarkers of treatment response. What is the translational message? Characterization of cutaneous microbiota may ultimately move into the clinic to help facilitate treatment selection, not only by optimizing currently available treatments, but also by identifying new therapeutic targets.

Personalized medicine-concepts, technologies, and applications in inflammatory skin diseases

The current state, tools, and applications of personalized medicine with special emphasis on inflammatory skin diseases like psoriasis and atopic dermatitis are discussed. Inflammatory pathways are outlined as well as potential targets for monoclonal antibodies and small-molecule inhibitors.

Evaluating crisaborole as a treatment option for atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic and recurrent disease presenting with eczematous lesions and pruritus. It impacts patient and family quality of life, increases morbidity, and accounts for large health-care expenditures. Although nonpharmacologic, topical, and systemic treatments exist, management of AD remains challenging due to limited treatment options. Crisaborole is a topical small molecule inhibitor of phosphodiesterase 4 (PDE4), recently approved for the treatment of AD in the United States. Areas covered: The authors review crisaborole in the management of AD based on Phase II, Phase III, and post-marketing studies. Pharmacologic properties such as chemistry, pharmacokinetics, pharmacodynamics and metabolism are discussed. A PubMed systematic review was augmented with Google Scholar searches via keyword, Medical Subject Headings (MeSH), and Boolean operation searches. Expert opinion: Crisaborole showed modest efficacy in short-term trials, but head-to-head trials with topical corticosteroids and tacrolimus are needed to assess its clinical utility. Since crisaborole is non-steroidal, it may reduce the need for topical corticosteroids and address steroid phobia. However, it is likely to suffer from the same factors contributing to intentional non-adherence in topicals: dissatisfaction with efficacy and inconvenience.

Assessment and Clinical Relevance of Serum IL-19 Levels in Psoriasis and Atopic Dermatitis Using a Sensitive and Specific Novel Immunoassay

Because development of reliable biomarkers in psoriasis and atopic dermatitis has lagged behind therapeutic progress, we created a blood-based test to fill the void in objective methods available for dermatological assessments. Our novel interleukin-19 (IL-19) immunoassay was initially tested to determine concentrations of IL-19 serum levels, then correlated with the psoriasis activity and severity index (PASI) in psoriasis, and the eczema area and severity index (EASI) in atopic dermatitis. Not only was IL-19 increased in psoriasis and correlated to PASI, but ixekizumab administration led to rapid, sustained IL-19 decreases to normal levels, with decreases at 2-weeks correlating with PASI improvement at 16-weeks. IL-19 increased upon ixekizumab withdraw, prior to relapse, and decreased following re-treatment. In baricitinib- and etanercept-treated psoriasis patients, IL-19 decreases also correlated with improvement. Many patients with limited skin disease, including genital psoriasis and psoriatic arthritis patients, also had increased IL-19, which was reduced to normal levels upon ixekizumab treatment, correlating with PASI improvement. We also measured IL-19 in baricitinib-treated atopic dermatitis patients. In atopic dermatitis, IL-19 was significantly elevated, correlated with EASI scores, and decreased with skin improvement. Therefore, measurement of serum IL-19 provides clinicians with an objective disease-activity assessment tool for psoriasis and atopic dermatitis patients.

Understanding the Burden of Atopic Dermatitis in Africa and the Middle East

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by intensely pruritic lesions. The prevalence of atopic dermatitis is increasing in developing regions, including Africa and the Middle East. However, these regions are underrepresented in the dermatology literature, and a better understanding of the growing burden of atopic dermatitis in Africa and the Middle East is necessary. Herein, we summarize current knowledge on atopic dermatitis epidemiology, disease burden, and treatment options in Africa and the Middle East, highlighting the unmet needs of patients in these regions. With these needs in mind, we provide clinical recommendations for appropriate management of atopic dermatitis in Africa and the Middle East. FUNDING: Pfizer Inc. Plain language summary available for this article.

Current therapeutic paradigm in pediatric atopic dermatitis: Practical guidance from a national expert panel

INTRODUCTION AND OBJECTIVES

Atopic dermatitis (AD) is the most common cutaneous inflammatory disease in both adults and children. Although emerging therapeutic approaches are being investigated for the management of pediatric AD, it still needs to be managed with conventional treatments. This consensus document is aimed at providing an update on general management and therapies of pediatric AD, defining practical recommendations for using both topical and systemic agents.

MATERIAL AND METHODS

A panel of experts consisting of dermatologists and pediatricians were convened in order to define statements, through a Delphi process, standardizing the management of AD in pediatric subjects in a real-world setting.

RESULTS

A set of practical recommendations obtaining an at least 75% agreement was presented.

CONCLUSIONS

This set of practical recommendations represents a simple and fast snapshot on the pediatric use of common anti-AD therapeutics.

New and Potential Treatments for Atopic Dermatitis: Biologicals and Small Molecules

PURPOSE OF REVIEW

An update on new therapies currently approved or potentially useful in the future for the management of patients suffering moderate-to-severe atopic dermatitis.

RECENT FINDINGS

New pathogenic mechanisms involved in atopic dermatitis have permitted to propose novel therapeutic approaches devised to control the inflammatory process observed in involved cutaneous tissues by neutralizing mediators, cytokines, and their receptors. Recent research findings have disclosed important and previously unrecognized pathogenic mechanisms that have resulted in innovative targeted therapies, such as dupilumab, and potentially other biologicals and small molecules. Further studies should permit the sub-classification of patients according to the relevance of different mediators and inflammatory cells. It can be concluded that the treatment of atopic dermatitis has entered into the era of personalized/precision medicine.

Atopic dermatitis yardstick: Practical recommendations for an evolving therapeutic landscape

The implementation of treatment guidelines for atopic dermatitis is challenging, in part because of different guidance documents being used by different groups of specialists and in part because the language of guidelines often reflects the evidence base rather than the practical "how to." The Atopic Dermatitis Yardstick is part of a series developed in response to the need to proactively address the loss of disease control for atopic illnesses at all levels of severity. It presents a comprehensive update on how to conduct a sustained step-up in therapy for the patient with inadequately controlled or poorly controlled atopic dermatitis. Patient profiles, based on current guidelines and the authors' combined clinical experience, provide a practical and clinically meaningful guide to aid physicians in helping their patients achieve the goal of clear to almost clear. The intent is not to replace guidelines but to complement their recommendations incorporating the latest research and therapies.

Efficacy and safety of PAC-14028 cream - a novel, topical, nonsteroidal, selective TRPV1 antagonist in patients with mild-to-moderate atopic dermatitis: a phase IIb randomized trial

Background

Transient receptor potential vanilloid subfamily, member 1 (TRPV1) may play an important role in pruritus and inflammation induction in atopic dermatitis (AD). The treatment effect of TRPV1 antagonist via topical application in patients with AD remains unknown.

Objectives

To assess the clinical efficacy and safety of PAC‐14028, a TRPV1 antagonist, via topical application in patients with AD.

Methods

In this 8‐week, phase IIb, randomized, double‐blind, multicentre, vehicle‐controlled study, patients with mild‐to‐moderate AD were randomized to receive PAC‐14028 cream 0·1%, 0·3%, 1·0% or vehicle cream twice daily. The primary efficacy end point was the Investigator's Global Assessment (IGA) success rate defined as the percentage of patients with an IGA score of 0 or 1 at week 8. The secondary efficacy end points included the severity Scoring of Atopic Dermatitis (SCORAD) index and Eczema Area and Severity Index (EASI) 75/90.

Results

A total of 194 patients were enrolled. IGA success rates at week 8 were 14·58% for vehicle cream, 42·55% for PAC‐14028 cream 0·1% (P = 0·0025 vs. vehicle), 38·30% for PAC‐14028 cream 0·3% (P = 0·0087 vs. vehicle) and 57·45% for PAC‐14028 cream 1·0% (P < 0·001 vs. vehicle). In particular, statistically significant differences were found between the vehicle and treatment groups in the IGA success rates with two‐grade improvement. The SCORAD index, EASI 75/90, sleep disturbance score and pruritus visual analogue scale showed a trend towards improvement. No significant safety issues were reported.

Conclusions

PAC‐14028 cream may be an effective and safe treatment modality for the treatment of patients with mild‐to‐moderate AD.

What is already known about this topic?

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases characterized by pruritic erythematous skin lesions and barrier dysfunction.

Transient receptor potential vanilloid subfamily, member 1 (TRPV1) antagonists suppress the release of pruritic and proinflammatory mediators.

The preclinical results demonstrate the feasibility of TRPV1 as a potential therapeutic target for the treatment of AD.

What does this study add?

TRPV1 regulates inflammation and pruritus in patients with AD.

PAC‐14028 cream, a novel TRPV1 antagonist, was superior to vehicle in improving clinical symptoms and signs with a favourable safety profile in adults with mild‐to‐moderate AD.

TRPV1 antagonism may play a role as a promising nonsteroidal topical treatment target for AD with a new mechanism of action.

Linked Editorial:https://doi.org/10.1111/bjd.17777.

https://doi.org/10.1111/bjd.17802 available online

https://www.bjdonline.com/article/

Current pharmaceutical developments in atopic dermatitis

Atopic dermatitis (AD) is an inflammatory, pruritic, chronic or chronically relapsing skin disease that typically begins in early childhood and is occurring frequently in families with other atopic diseases (bronchial asthma and/or allergic rhino-conjunctivitis). Thanks to immunological and neurobiological research, the era of new treatments is coming as well as it occurred with psoriasis 15 years ago. Many treatments targeting cytokines (IL-4, IL-13, IL-31, TSLP) or neurotransmitters (substance P, opioids) or their respective receptors as well as phosphodiesterase-4 or the Jak/Stat pathways are under development. Antagonists of cytokines and anti-jak have promising effects on pruritus while it is more difficult to discriminate the effects of other drugs from the placebo effect on itch, which is known to be high.

From Bench to Clinic: the Potential of Therapeutic Targeting of the IL-22 Signaling Pathway in Atopic Dermatitis

Atopic dermatitis (AD) is the most common pruritic inflammatory skin disease characterized by thickening of epidermis and dermis as well as by the infiltration of multiple pathogenic polarized T lymphocytes, including Th2, Th17, and Th22 cells. Significant progress has been made to develop targeted therapeutics for treating AD, e.g., Food and Drug Administration-approved dupilumab, an antibody for dual targeting of IL-4 and IL-13 signaling pathways. Additionally, a growing body of published evidence and a promising result from the early stage of the clinical trial with ILV-094, an anti-IL-22 antibody, strongly support the notion that IL-22 is a potential therapeutic target for treating AD. Moreover, we also experimentally proved that IL-22 contributes to the pathophysiology of AD by employing a murine model of AD induced by epicutaneous sensitization. Here, we review recent preclinical and clinical findings that have advanced our understanding of the roles of IL-22 and Th22 cells in skin inflammation. We conclude that blockade of IL-22 signaling may be a promising therapeutic approach for the treatment of AD.

Distinct transcriptomic profiles of early-onset atopic dermatitis in blood and skin of pediatric patients

BACKGROUND

Atopic dermatitis (AD) predominantly affects young children, but our understanding of AD pathogenesis is based on skin and blood samples from long-standing adult AD. Genomic biopsy profiling from early pediatric AD showed significant Th2 and Th17/Th22-skewing, without the characteristic adult Th1 up-regulation. Because obtaining pediatric biopsies is difficult, blood gene expression profiling may provide a surrogate for the pediatric skin signature.

OBJECTIVE

To define the blood profile and associated biomarkers of early moderate-to-severe pediatric AD.

METHODS

We compared microarrays and reverse transcription polymerase chain reaction (RT-PCR) of blood cells from 28 AD children (<5 years and within 6 months of disease onset) to healthy control blood cells. Differentially expressed genes (DEGs) in blood (fold change [FCH] > 1.2 and false discovery rate [FDR] < 0.05) were then compared with skin DEGs.

RESULTS

Eosinophil and Th2 markers (IL5RA, IL1RL1/ST2, HRH4, CCR3, SIGLEC8, PRSS33, CLC from gene arrays; IL13/IL4/CCL22 from RT-PCR) were up-regulated in early pediatric AD blood, whereas IFNG/Th1 was decreased. Th1 markers were negatively correlated with clinical severity (EASI, pruritus, transepidermal water loss [TEWL]), whereas Th2/Th17-induced interleukin (IL)-19 was positively correlated with SCORAD. Although a few RT-PCR-defined immune markers (IL-13/CCL22) were increased in blood, as previously also reported for skin, minimal overlap based on gene array DEGs was seen.

CONCLUSION

The whole blood signature of early moderate-to-severe pediatric AD blood cells show predominantly a Th2/eosinophil profile; however, markers largely differ from the skin profile. Given their complementarity, pooling of biomarkers from blood and skin may improve profiling and predictions, providing insight regarding disease course, allergic comorbidity development, and response to systemic medications.

The epithelial immune microenvironment (EIME) in atopic dermatitis and psoriasis

The skin provides both a physical barrier and an immunologic barrier to external threats. The protective machinery of the skin has evolved to provide situation-specific responses to eliminate pathogens and to provide protection against physical dangers. Dysregulation of this machinery can give rise to the initiation and propagation of inflammatory loops in the epithelial microenvironment that result in inflammatory skin diseases in susceptible people. A defective barrier and microbial dysbiosis drive an interleukin 4 (IL-4) loop that underlies atopic dermatitis, while in psoriasis, disordered keratinocyte signaling and predisposition to type 17 responses drive a pathogenic IL-17 loop. Here we discuss the pathogenesis of atopic dermatitis and psoriasis in terms of the epithelial immune microenvironment-the microbiota, keratinocytes and sensory nerves-and the resulting inflammatory loops.

Approach to the Assessment and Management of Adult Patients With Atopic Dermatitis: A Consensus Document. Section IV: Treatment Options for the Management of Atopic Dermatitis

The objectives of therapy for atopic dermatitis (AD) are to reduce skin inflammation and pruritus, restore skin barrier function, and improve quality of life (QoL). Treatments can be classified as moisturizing and basic care, topical therapy, phototherapy, and systemic therapy. In this review, we summarize the treatments for AD and recommendations for their use.

Atopic dermatitis: the skin barrier and beyond

BACKGROUND

Atopic dermatitis is the most common chronic inflammatory skin disorder, affecting up to 20% of children and 10% of adults in industrialized countries. This highly debilitating condition poses a considerable burden to both the individual and society at large. The pathophysiology of atopic dermatitis is complex, encompassing both genetic and environmental risk factors.

METHODS

This is a narrative review based on a systematic literature search.

CONCLUSIONS

Dysregulation of innate and adaptive immunity plays a key role; however, recent epidemiological, genetic and molecular research has focused interest on skin barrier dysfunction as a common precursor and pathological feature. Current understanding of the aetiology of atopic dermatitis highlights disruption of the epidermal barrier leading to increased permeability of the epidermis, pathological inflammation in the skin, and percutaneous sensitization to allergens. Thus, most novel treatment strategies seek to target specific aspects of the skin barrier or cutaneous inflammation. Several studies have also shown promise in preventing atopic dermatitis, such as the early use of emollients in high-risk infants. This may have broader implications in terms of halting the progression to atopic comorbidities including food allergy, hay fever and asthma.

Recent Developments in Atopic Dermatitis

Atopic dermatitis (AD) is a bothersome and common skin disease affecting ∼10.7% of children in the United States. This skin condition significantly decreases quality of life in not only patients, but in their families as well. Pediatricians are often the first physicians to diagnose and manage these patients and thus are relied on by families to answer questions about this disease. AD is complex, multifactorial, and has historically had limited therapeutic options, but the landscape of this disease is now rapidly changing. Pathways contributing to the pathogenesis of this disease are continually being discovered, and new therapies for AD are being developed at an unprecedented rate. With this article, we will review the current guidelines regarding the management of AD, outline updates in the current understanding of its pathophysiology, and highlight novel developments available for the treatment of this burdensome disease.

A Systematic Scoping Literature Review of Publications Supporting Treatment Guidelines for Pediatric Atopic Dermatitis in Contrast to Clinical Practice Patterns

INTRODUCTION

Treatment guidelines endorse a variety of strategies for atopic dermatitis (AD) which may vary from published data and clinical practice patterns. The objective of this review was to quantify the volume of available medical literature supporting pediatric AD treatments and compare these patterns to those recommended by published guidelines and/or clinical practice patterns.

METHODS

Searches of Embase (2005-2016) and abstracts from selected meetings (2014-2016) related to AD treatment in patients younger than 17 years of age yielded references that were assessed by study design, primary treatment, age groups, and AD severity.

RESULTS

Published literature partially supports clinical guidelines, with emollients and topical medications being the most investigated. There were disproportionately more publications for topical calcineurin inhibitors (TCI) compared with topical corticosteroids (TCS); however, the search interval may have biased the results toward treatments approved near the beginning of the time frame. In contrast, publications documenting clinical practice patterns reflect greater use of emollients and TCS (over TCI), as well as systemic corticosteroids. Data is relatively limited for long-term and combination treatment, treatment of severe AD, and patients younger than 2 years of age, and completely lacking for systemic corticosteroids.

CONCLUSION

This scoping review demonstrates that available medical literature largely supports published guidelines for topical therapy; however, clinical practice patterns are less aligned. There is a lack of data for older, more frequently used generic treatments, including oral antihistamines, oral antibiotics, and systemic corticosteroids. Overall, literature is lacking for long-term treatment, treatment for patients younger than 2 years of age, and for systemic treatment for severe disease.

FUNDING

Regeneron Pharmaceuticals Inc.

Systemic immunomodulatory treatments for atopic dermatitis: protocol for a systematic review with network meta-analysis

INTRODUCTION

There are numerous new systemic treatments for atopic dermatitis in various stages of development and most are being compared with placebo rather than active comparators. In order to understand the relative efficacy and safety of existing and new treatments for atopic dermatitis, robust mixed comparisons (ie, direct and indirect) would be beneficial. To address this gap, this protocol describes methods for a systematic review and network meta-analysis of systemic treatments for atopic dermatitis.

METHODS AND ANALYSIS

We will update the search of a previous systematic review, including searches of the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Latin American and Caribbean Health Science Information database and the Global Resource of EczemA Trials database in addition to clinical trial protocol registries. Title, abstract and full paper screening as well as data extraction will be conducted in duplicate by independent researchers. Primary outcomes include efficacy with regards to clinician-reported signs and patient-reported symptoms and safety with regards to withdrawal from treatment due to adverse events and the occurrence of serious adverse events. Secondary outcomes will include change in quality of life and itch severity. Where possible and appropriate, network meta-analysis will be performed for each outcome using a random-effects model within a Bayesian framework. If appropriate, the review will be transitioned to a living review with continuous updating of the analysis.

ETHICS AND DISSEMINATION

Dissemination in a peer-reviewed scientific journal is planned.

PROSPERO REGISTRATION NUMBER

CRD42018088112; Pre-results.

Testing biologics and intracellular signaling inhibitors on pediatric atopic dermatitis: a stairway to modern therapeutic approaches

INTRODUCTION

Atopic dermatitis (AD) is the most common cutaneous inflammatory disease in adults and children. In the last few years, the pathogenesis of AD has been profoundly revised, and this has led to the identification of novel druggable targets and the development of new agents targeting specific molecular pathways. Despite the high prevalence of AD in the pediatric population, the clinical development of new treatments, either topical or systemic, has been focused on the adult population in recent years; only a limited number of these new agents have been tested in pediatric cohorts.

AREAS COVERED

In this review, we describe the pathogenic model of pediatric AD which shows similarities and substantial differences when compared to adult AD. The identification of therapeutic targets is highlighted, and novel targeted therapies, both topical and systemic, are discussed.

EXPERT OPINION

The current therapeutic armamentarium for pediatric AD is very limited, and this represents a critical unmet need. The enhancement of clinical research on pediatric patients is necessary to facilitate an increase in the number of new targeted therapeutic options being available on the market.

Dupilumab: A Review in Moderate-to-Severe Atopic Dermatitis

Dupilumab (Dupixent^®), a subcutaneously administered, fully human IgG4 monoclonal antibody directed against the IL (interleukin)-4 receptor α subunit, blocks the signalling of IL-4 and IL-13, two T helper cell type 2 cytokines implicated in the immunopathology of atopic dermatitis (AD). It is the first biologic therapy to have been approved for the treatment of adult patients with moderate-to-severe AD in the EU and USA. In phase III trials in adults with moderate-to-severe AD who were inadequately controlled with topical medications and/or systemic treatments, such as ciclosporin, or for whom these therapies were not advisable, 16 weeks' treatment with dupilumab as monotherapy or in combination with topical corticosteroids (TCS) improved multiple measures of disease severity, pruritus, sleep disturbance, anxiety and depression, and quality of life compared with placebo. Moreover, the benefits of combination therapy at week 16 were maintained during long-term treatment for up to 1 year. Dupilumab, alone or added to TCS, was generally well tolerated, with low rates of serious adverse events and treatment discontinuations due to adverse events. Common adverse reactions included conjunctivitis, injection-site reactions and oral herpes. Thus, dupilumab represents a valuable new treatment option for adults with moderate-to-severe AD deemed appropriate for systemic therapy, a patient population for whom historically there has been a lack of safe and effective long-term treatments.

Biologics in Chronic Rhinosinusitis: An Update and Thoughts for Future Directions

Background Potential biologic therapies for chronic rhinosinusitis (CRS) is a growing field of interest and research. Biologics target specific immune cells or inflammatory pathways within a disease process, increasing drug efficacy while reducing complications. The success of biologics in other inflammatory conditions such as asthma and atopic dermatitis has spurred much of the corresponding research in CRS. A rapid expansion in the volume of research concerning biologic therapies with potential crossover to treating CRS has made it difficult to stay current. Furthermore, much of the literature has been focused on allergy, asthma, and immunology subspecialties. As the role for biologic therapies in CRS continues to expand, it is increasingly important for otolaryngologists to remain up to date on their progression. Objective The objectives of this review are to provide an update on the growing field of biologics for otolaryngologists who treat CRS and discuss potential future areas of research. Methods A literature review of biologic therapies studied in CRS was performed. In addition, a detailed review of all biologic therapies targeting inflammatory markers involved in Th1-, Th2-, and Th17-mediated inflammation was performed to identify potential areas for future research. The role for biologic therapies in CRS, endotypes of CRS, current biologic therapies studies in CRS, and future areas for research were reviewed. Results Sixty-nine unique biologic therapies have been developed for Th1-, Th2-, and Th17-mediated inflammation. Five biologics are currently being investigated for use in patients with CRS with nasal polyposis. Conclusions As the field of biologics continues to expand, remaining up to date on the current literature may help clinicians identify patients who may benefit from biologic therapies. In addition, ongoing research in other inflammatory disorders with shared pathophysiology to CRS may reveal other potential therapies for CRS that have not previously been investigated.

Atopic dermatitis

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease, with a lifetime prevalence of up to 20% and substantial effects on quality of life. AD is characterized by intense itch, recurrent eczematous lesions and a fluctuating course. AD has a strong heritability component and is closely related to and commonly co-occurs with other atopic diseases (such as asthma and allergic rhinitis). Several pathophysiological mechanisms contribute to AD aetiology and clinical manifestations. Impairment of epidermal barrier function, for example, owing to deficiency in the structural protein filaggrin, can promote inflammation and T cell infiltration. The immune response in AD is skewed towards T helper 2 cell-mediated pathways and can in turn favour epidermal barrier disruption. Other contributing factors to AD onset include dysbiosis of the skin microbiota (in particular overgrowth of Staphylococcus aureus), systemic immune responses (including immunoglobulin E (IgE)-mediated sensitization) and neuroinflammation, which is involved in itch. Current treatments for AD include topical moisturizers and anti-inflammatory agents (such as corticosteroids, calcineurin inhibitors and cAMP-specific 3',5'-cyclic phosphodiesterase 4 (PDE4) inhibitors), phototherapy and systemic immunosuppressants. Translational research has fostered the development of targeted small molecules and biologic therapies, especially for moderate-to-severe disease.

Early-onset pediatric atopic dermatitis is characterized by TH2/TH17/TH22-centered inflammation and lipid alterations

BACKGROUND

Although atopic dermatitis (AD) often starts in early childhood, detailed tissue profiling of early-onset AD in children is lacking, hindering therapeutic development for this patient population with a particularly high unmet need for better treatments.

OBJECTIVE

We sought to globally profile the skin of infants with AD compared with that of adults with AD and healthy control subjects.

METHODS

We performed microarray, RT-PCR, and fluorescence microscopy studies in infants and young children (<5 years old) with early-onset AD (<6 months disease duration) compared with age-matched control subjects and adults with longstanding AD.

RESULTS

Transcriptomic analyses revealed profound differences between pediatric patients with early-onset versus adult patients with longstanding AD in not only lesional but also nonlesional tissues. Although both patient populations harbored TH2-centered inflammation, pediatric AD also showed significant TH17/TH22 skewing but lacked the TH1 upregulation that characterizes adult AD. Pediatric AD exhibited relatively normal expression of epidermal differentiation and cornification products, which is downregulated in adults with AD. Defects in the lipid barrier (eg, ELOVL fatty acid elongase 3 [ELOVL3] and diacylglycerol o-acyltransferase 2 [DGAT2]) and tight junction regulation (eg, claudins 8 and 23) were evident in both groups. However, some lipid-associated mediators (eg, fatty acyl-CoA reductase 2 and fatty acid 2-hydroxylase) showed preferential downregulation in pediatric AD, and lipid barrier genes (FA2H and DGAT2) showed inverse correlations with transepidermal water loss, a functional measure of the epidermal barrier.

CONCLUSIONS

Skin samples from children and adult patients with AD share lipid metabolism and tight junction alterations, but epidermal differentiation complex defects are only present in adult AD, potentially resulting from chronic immune aberration that is not yet present in early-onset disease.

Dupilumab in atopic dermatitis: rationale, latest evidence and place in therapy

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. The prevalence of AD is increasing and is currently estimated at 10-20% in adults worldwide. In the majority of patients, AD can be adequately controlled with topical treatment or ultraviolet light therapy, but there is a high unmet need for effective and safe therapeutics in patients with more severe or difficult to treat AD. During the past decade, new advances in the understanding of the underlying immune pathogenesis of AD have led to the development of new, more targeted therapies. Dupilumab, a fully human monoclonal antibody targeting the interleukin (IL)-4 receptor α, thereby blocking the IL-4 and IL-13 pathway, is one of the first biologics that has been developed for AD. Dupilumab has shown promising results in phase III trials and has recently been approved by the US Food and Drug Administration and the European Commission for the treatment of moderate to severe AD. With the approval of dupilumab, we are entering a new era of biological therapeutics in AD management. The place of dupilumab should be established in the current treatment standards. Based on current treatment guidelines and experts' opinions in the management of AD, we have built a proposal for a treatment algorithm for systemic treatment of AD in European countries.