Targeting immunoglobulin E in atopic dermatitis: A review of the existing evidence

Immunoglobulin E (IgE) plays an essential role in many allergic diseases. This review highlights the role of IgE in atopic dermatitis (AD), a common, chronic, and complex skin inflammation, and the available therapeutic approaches that target IgE in AD. We examine the existing data showing the use of omalizumab, the only biologic anti-IgE therapy available in clinical use, plasma apheresis, and a combination of both therapeutic approaches for the treatment of AD. Existing data on the efficacy of omalizumab in AD are inconclusive. A limited number of randomised controlled studies, few uncontrolled prospective and retrospective reports, as well as multiple case series and case reports observed varying degrees of the efficacy of omalizumab in AD. Omalizumab displays a trend of higher efficacy in AD patients with low IgE levels compared with those with very high-to-extremely high serum IgE concentrations. Plasma apheresis and its combination with omalizumab show good efficacy, even in patients with unusually high serum IgE concentrations. Combining apheresis and anti-IgE treatment may serve as a comprehensive therapeutic approach for patients with elevated levels of IgE. Dedicated clinical studies with robust study designs are needed to establish the therapeutic efficacy of omalizumab in AD.

Update "Systemic treatment of atopic dermatitis" of the S2k-guideline on atopic dermatitis

This guideline is an update from August 2020 the S2k-guideline "Atopic dermatitis" published in 2015. The reason for updating this chapter of the guideline were the current developments in the field of systemic therapy of atopic dermatitis. The agreed recommendations for systemic treatment in atopic dermatitis of the present guideline are based on current scientific data. Due to the approval of dupilumab for the treatment of moderate to severe atopic dermatitis, which cannot be treated sufficiently with topical drugs alone, this part of the guideline has now been adapted and newly consented. The indication for systemic therapy and the therapeutic response to topical and systemic treatment should be recorded and documented in a suitable form in clinic and practice. A standardized documentation of the indication for system therapy in atopic dermatitis can be recommended and is also part of the updated chapter of this guideline.

Roles of omalizumab in various allergic diseases

IgE and mast cells play a pivotal role in various allergic diseases, including asthma, allergic rhinitis, and urticaria. Treatment with omalizumab, a monoclonal anti-IgE antibody, has significantly improved control of these allergic diseases and introduced a new era for the management of severe allergic conditions. About 10 years of experience with omalizumab treatment for severe allergic asthma confirmed its effectiveness and safety, reducing symptoms, frequency of reliever use, and severe exacerbations in patients with intractable conditions. Omalizumab is particularly useful in childhood asthma, where atopic conditions often determine clinical courses of asthma. Recently, omalizumab is approved for the treatment of chronic spontaneous urticaria (CSU) with the fixed dose of 300 mg. Although the mechanisms underlying the actions of omalizumab in CSU are not fully clarified, nearly 90% of patients with CSU showed a complete or a partial response to omalizumab treatment. Furthermore, omalizumab is just approved for the treatment of severe Japanese cedar pollinosis (JC) based on the successful results of an add-on study of omalizumab for inadequately controlled severe pollinosis despite antihistamines and nasal corticosteroids. For proper use of omalizumab to treat severe JC, co-administration of antihistamines is necessary, while patients should meet the criteria including strong sensitization to Japanese cedar pollen (≥class 3) and poor control under standard treatment. In the management of severe allergic diseases using omalizumab, issues including cost and concerns about relapse after its discontinuation should be overcome. At the same time, possibilities for application to other intractable allergic diseases should be considered.

Omalizumab for atopic dermatitis: evidence for and against its use

INTRODUCTION

Omalizumab, has been used for almost two decades, mainly in allergic asthma and chronic spontaneous urticaria for which it is highly beneficial. Smaller studies have evaluated the effects of omalizumab in atopic dermatitis (AD). Current treatments options, such as cyclosporine and azathioprine have limited effect on AD and numerous side effects. The recently introduced biologic dupilumab (anti-IL4) shows promising results, however with conjunctivitis as a prevalent side effect. We evaluate the current evidence for the use of omalizumab in AD.

EVIDENCE ACQUISITION

Systematic literature searches were performed in PubMed, Web of Science, Embase and Clinicaltrials.gov to identify any study (case reports, case series, and controlled trials) evaluating the effect of treatment with omalizumab in AD.

EVIDENCE SYNTHESIS

Thirty-four studies (12 single case studies, 15 case series, 5 prospective studies and 2 small pilot randomized placebo-controlled trials [RCTs]), including a total of 214 patients with median of 3, ranging from 1-35 patients were identified. A total of 169 patients (79.0%) experienced a beneficial effect from treatment, ranging from little to complete response, whereas 45 patients (21.0%) reported no or negative effect from omalizumab treatment.

CONCLUSIONS

Omalizumab is a safe and well-tolerated treatment with some clinical benefit in AD patients. However, the lack of larger RCTs and possible publication bias limit the recommendation of omalizumab for use in clinical practice for AD. Newer and more effective treatments exist and should be prioritized.

Novel Therapeutic Approaches to Atopic Dermatitis

Atopic dermatitis (AD) is one of the most common inflammatory skin diseases. The number of people affected by AD is relatively high and seems to be rising. Although mild and moderate forms of the disease can be well controlled by the use of emollients, topical corticosteroids, and topical calcineurin inhibitors, treatment of severe is still a huge challenge. The new hope is biologic drugs, magic bullets in allergy, targeted at different points of the complex pathomechanism of inflammation in AD. In this review, novel biologic therapies are discussed, including recombinant monoclonal antibodies directed against various interleukin pathways (such as IL-4, IL-13, TSLP, IL-31, and IL-12/23), on immunoglobulin E, molecules acting as T cells, B cells, etc. Of biological drugs, the most promising seems to be anti-IL-4/IL-13 therapy (dupilumab-the biological agent) and phosphodiesterase-4 inhibitor (crisaborole-a small molecule). A deep understanding of the AD pathomechanism provides a new perspective for tailor-made treatment of severe atopic dermatitis.

Systemic Treatment of Adult Atopic Dermatitis: A Review

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that predominantly affects children. However, it can persist in adulthood and/or start at older ages. Due to its chronic nature and frequently occurring relapses, AD has a substantial effect on patients' quality of life, often requiring long-term systemic treatment, especially in adult patients, who are more frequently refractory to adequate topical treatment with mid- to high-potent corticosteroids and/or calcineurin inhibitors. Therefore, treatment with systemic therapies is often needed to take control of the disease, prevent exacerbations and improve quality of life. However, data regarding systemic treatment effectiveness and long-term safety in adult patients with AD are insufficient. Indeed, standardized international guidelines are lacking, and the treatment approach widely differs among diverse countries. This review focuses on the use of systemic treatments in adult AD patients analyzing published literature.

Off-Label Uses of Omalizumab

The off-label use of medicines is a common and extensive clinical practice. Omalizumab has been licensed for use in severe allergic asthma and chronic urticaria. Omalizumab dosing was based on body weight and baseline serum IgE concentration. All patients are required to have a baseline IgE between 30 and 700 IU/ml and body weight not more than 150 kg. The use of off-label drugs may lead to several problems including adverse effects and an increased risk/benefit balance. In this article, there are summarized off-label uses of omalizumab in the last recent years in diseases in which IgE maybe or certainly has a corner role such as allergic rhinitis, allergic bronchopulmonary aspergillosis, anaphylaxis, keratoconjunctivitis, food allergy, drug allergy, urticaria, angioedema, non-atopic asthma, atopic dermatitis, nasal polyps, Churg-Strauss syndrome, eosinophilic otitis media, chronic rhinosinusitis, bullous pemphigoid, contact dermatitis, and others. Use in pregnancy asthmatic women and pre-co-administration with specific immunotherapy will also be revised.

Systemic Agents for Severe Atopic Dermatitis in Children

Atopic dermatitis (AD), or eczema, is a chronic inflammatory skin condition characterized by relapsing pruritic, scaly, erythematous papules and plaques frequently associated with superinfection. The lifelong prevalence of AD is over 20 % in affluent countries. When a child with severe AD is not responding to optimized topical therapy including phototherapy, and relevant triggers cannot be identified or avoided, systemic therapy should be considered. If studies show early aggressive intervention can prevent one from advancing along the atopic march, and relevant triggers such as food allergies cannot be either identified or avoided, systemic therapy may also play a prophylactic role. Though the majority of evidence exists in adult populations, four systemic non-specific immunosuppressive or immunomodulatory drugs have demonstrated efficacy in AD and are used in most patients requiring this level of intervention regardless of age: cyclosporine, mycophenolate mofetil, methotrexate, and azathioprine. This article reviews the use of these medications as well as several promising targeted therapies currently in development including dupilumab and apremilast. We briefly cover several other systemic interventions that have been studied in children with atopic dermatitis.

The use of biologicals in cutaneous allergies - present and future

PURPOSE OF REVIEW

Up-to-date biologicals in cutaneous allergies play - unfortunately - only a minor role. However, this situation might change. Recently, omalizumab was licensed for chronic urticaria; this article reviews recent advances in the use of biologicals in cutaneous allergies.

RECENT FINDINGS

Interestingly, the mechanism of omalizumab appears to be different in urticaria and allergic asthma for which the drug has been licensed previously. In urticaria dosage is not dependent on serum IgE-levels and response is seen very often after only 12 h. Other indications in cutaneous allergy in which biologicals have been investigated, at least in case reports or small studies, are TNF-α-antagonists and rituximab in chronic urticaria, omalizumab, rituximab and TNF-α-antagonists in atopic dermatitis as well as mepolizumab in this disease. However, all these studies appear to show a benefit for individual patients but not a clear breakthrough for the whole group of patients involved. This, however, might also be one of the future approaches that sub-groups of patients who have different responses to biologicals may be identified, as apparently different cytokine patterns are predominantly involved in the individual patient.

SUMMARY

In conclusion, although currently only one biological is approved in chronic urticaria, there is hope that a rapid better understanding of individual disease factors will support the development of other novel drugs in this field.

Systemic therapy of childhood atopic dermatitis

Atopic dermatitis (AD) is a common childhood inflammatory disease that, in a small percentage of cases, can become severe enough to require potent systemic treatment. Many trials have been conducted with systemic agents for the treatment of severe pediatric AD; we review the evidence here. Although corticosteroids are widely used in practice, they are not generally recommended as a systemic treatment option for AD in children. Most patients experience a relatively rapid and robust response to cyclosporine. Treating children with cyclosporine long term is troubling; however, azathioprine, mycophenolate mofetil, and methotrexate are all reasonable alternatives for maintenance therapy in recalcitrant cases. Several additional options are available for the most refractory cases, including interferon-γ, intravenous immunoglobulin, and various biologics. Phototherapy is another modality that can be effective in treating severe AD. Ultimately the choice of agent is individualized. Systemic therapy options are associated with potentially severe adverse effects and require careful monitoring. Nonsystemic approaches toward prevention of flares and long-term control of atopic dermatitis in pediatric patients should be continued in conjunction with systemic therapy. In the future, more targeted systemic treatments hold the potential for effective control of disease with fewer side effects than broadly immunosuppressive agents.

The protective role of immunoglobulins in fungal infections and inflammation

Increased incidence of fungal infections in the immunocompromised individuals and fungi-mediated allergy and inflammatory conditions in immunocompetent individuals is a cause of concern. Consequently, there is a need for efficient therapeutic alternatives to treat fungal infections and inflammation. Several studies have demonstrated that antibodies or immunoglobulins have a role in restricting the fungal burden and their clearance. However, based on the data from monoclonal antibodies, it is now evident that the efficacy of antibodies in fungal infections is dependent on epitope specificity, abundance of protective antibodies, and their isotype. Antibodies confer protection against fungal infections by multiple mechanisms that include direct neutralization of fungi and their antigens, inhibition of growth of fungi, modification of gene expression, signaling and lipid metabolism, causing iron starvation, inhibition of polysaccharide release, and biofilm formation. Antibodies promote opsonization of fungi and their phagocytosis, complement activation, and antibody-dependent cell toxicity. Passive administration of specific protective monoclonal antibodies could also prove to be beneficial in drug resistance cases, to reduce the dosage and associated toxic symptoms of anti-fungal drugs. The longer half-life of the antibodies and flexibilities to modify their structure/forms are additional advantages. The clinical data obtained with two monoclonal antibodies should incite interests in translating pre-clinical success into the clinics. The anti-inflammatory and immunoregulatory role of antibodies in fungal inflammation could be exploited by intravenous immunoglobulin or IVIg.

Systemic therapy for atopic dermatitis

Systemic therapy for atopic dermatitis (AD) is indicated in patients with severe disease refractory to adequate topical treatment. Currently available drugs aim to decrease inflammation by suppressing and/or modulating immune responses and thus may indirectly improve skin barrier function, resulting in a decrease in clinical signs and symptoms in particular pruritus. Before considering systemic treatment, patient adherence to topical treatment including skin care has to be ensured. The selection of the drug depends on the disease severity, localization, complications, concomitant diseases, and age of the patient, but also on their availability and costs as well as the doctor's experience. Bearing in mind the potential risk of resistance, systemic therapy with antibiotics should be exclusively considered in clinically manifest infections such as in children. Here, we review recently published clinical trials and case reports on systemic therapy of pediatric and adult patients with AD to draw conclusions for clinical practice. Although AD is a common disease, controlled clinical studies investigating the efficacy of systemic drugs are scarce, except for cyclosporine, which has been approved for the therapy of severe AD.