Are biologics safe in the treatment of atopic dermatitis? A review with a focus on immediate hypersensitivity reactions

Towards personalized treatment in atopic dermatitis

INTRODUCTION

For many years, oral immunosuppressive drugs such as cyclosporine A, azathioprine, mycophenolic acid, and methotrexate were the only treatment options, in addition to topical treatment, in patients with severe atopic dermatitis (AD). Dupilumab, a monoclonal antibody targeting the IL-4 receptor alpha, is the first antibody-based treatment commercially available for the treatment of AD. In the near future, more antibody-based treatments and small molecules will become available in the treatment of severe AD.

AREAS COVERED

This review gives an overview of current and future therapies for severe AD, outlines options to optimize treatment with oral immunosuppressive drugs and gives an insight into the future of personalized treatment in AD.

EXPERT OPINION

Due to the heterogeneous character of AD, it is unlikely that all patients will respond equally to these newly tested drugs. We believe that biomarkers will lead to better identification of patients that will benefit from these highly specific, but expensive new treatments. In addition to a role for biomarkers in new treatments, the use of pharmacogenomic biomarkers can improve the efficacy of currently used oral immunosuppressive drugs in AD, which will still be needed for the treatment of moderate to severe AD in the coming years.

Omalizumab-A Review

Omalizumab is a recombinant, humanized, monoclonal antibody against human immunoglobulin E (IgE). The US FDA has approved this molecule for chronic urticaria.

Unexpected hematologic effects of biotherapeutics in nonclinical species and in humans

Biotherapeutics are expanding the arsenal of therapeutics available for treating and preventing disease. Although initially thought to have limited side effects due to the specificity of their binding, these drugs have now been shown to have potential for adverse drug reactions including effects on peripheral blood cell counts or function. Hematotoxicity caused by a biotherapeutic can be directly related to the activity of the biotherapeutic or can be indirect and due to autoimmunity, biological cascades, antidrug antibodies, or other immune system responses. Biotherapeutics can cause hematotoxicity primarily as a result of cellular activation, cytotoxicity, drug-dependent and independent immune responses, and sequelae from initiating cytokine and complement cascades.  The underlying pathogenesis of biotherapeutic-induced hematotoxicity often is poorly understood. Nonclinical studies have generally predicted clinical hematotoxicity for recombinant cytokines and growth factors.  However, most hematologic liabilities of biotherapeutics are not based on drug class but are species specific, immune-mediated, and of low incidence. Despite the potential for unexpected hematologic toxicity, the risk-benefit profile of most biotherapeutics is favorable; hematologic effects are readily monitorable and managed by dose modification, drug withdrawal, and/or therapeutic intervention.  This article reviews examples of biotherapeutics that have unexpected hematotoxicity in nonclinical or clinical studies. 

Systemic treatment of pediatric atopic dermatitis with azathioprine and mycophenolate mofetil

Severe forms of atopic dermatitis (AD) cause significant morbidity in vulnerable pediatric populations and necessitate treatment with systemic therapy. The existing literature concerning the treatment of severe pediatric AD with azathioprine (AZ) and mycophenolate mofetil (MM) is sparse. The purpose of this case series is to examine the use of these two drugs in the treatment of severe pediatric AD. Medical records of 28 pediatric patients with AD from the University of North Carolina at Chapel Hill pediatric dermatology clinic treated using these two drugs were analyzed for laboratory values, thiopurine methyltransferase (TPMT) levels, symptoms, infections, and other relevant data. Patients were also contacted via the telephone to ascertain outcomes and any missing data. Treatment outcomes were scored into three categories: significant improvement, some improvement, and no improvement. AZ dosing was correlated to TPMT levels successfully, with comparable levels of improvement in the heterozygous and homozygous wild-type groups. Absolute eosinophil count corresponded to AD activity and treatment response across both treatment modalities in 18 of 26 (69%) patients. Seventeen of 28 (61%) patients treated with AZ and eight of 12 (66%) treated with MM reported significant improvement. We had lower rates of laboratory abnormalities and side effects with MM than with AZ but similar rates of cutaneous infections. Treatment outcomes did not appear to differ with race, sex, or TPMT level. We experienced success with AZ and MM in the treatment of severe pediatric AD. Coordinating treatment to each patient's unique morbidities is the best way to choose systemic treatments.

What's new in atopic eczema?

IMPORTANCE OF THE FIELD

Atopic eczema (AE) is a chronic relapsing inflammatory skin condition and one of the most common, potentially debilitating diseases with increasing incidence.

AREAS COVERED IN THIS REVIEW

The complex etiology of AE with multiple systemic and local immunologic and inflammatory responses and interactions between susceptibility genes and environmental factors leading to defects in skin barrier function and eczematous skin lesions is presented. Knowledge of pathogenesis is important for understanding the more innovative treatment approaches discussed.

WHAT THE READER WILL GAIN

Basic therapy consists of hydrating topical treatment and avoidance of specific and unspecific provocation factors. For acute eczematous skin lesions, anti-inflammatory treatment consists mainly of topical glucocorticoids and topical calcineurin inhibitors (tacrolimus and pimecrolimus). Microbial colonization and superinfection may induce skin exacerbation, which can be treated by either topical or systemic antimicrobial treatment. Systemic anti-inflammatory therapy is limited to severe cases and consists of systemic steroids, cyclosporine A or mycophenolate mofetil. Novel anti-inflammatory concepts that go beyond corticosteroids are in the early phases of development. There are targeted therapeutic approaches, such as cytokine and chemokine modulators and it remains to be investigated how effective they will be and what side effects they may carry.

TAKE HOME MESSAGE

Existing treatment modalities such as barrier repair therapy, topical immunosuppressive agents, antiseptic treatment as well as systemic treatment options are discussed. The review aims to summarize the most recent findings of more innovative treatment approaches such as modulation of cytokines or chemokines, modulation of T-cell responses or anti-IgE therapy.

Update on the management of chronic eczema: new approaches and emerging treatment options

Atopic dermatitis (AD) is a common disease with worldwide prevalence, affecting up to 20% of children and 3% of adults. Recent evidence regarding pathogenesis has implicated epidermal barrier defects deriving from filagrin mutations with resulting secondary inflammation. In this report, the authors comprehensively review the literature on atopic dermatitis therapy, including topical and systemic options. Most cases of AD will benefit from emollients to enhance the barrier function of skin. Topical corticosteroids are first-line therapy for most cases of AD. Topical calcineurin inhibitors (tacrolimus ointment, pimecrolimus cream) are considered second line therapy. Several novel barrier-enhancing prescription creams are also available. Moderate to severe cases inadequately controlled with topical therapy may require phototherapy or systemic therapy. The most commonly employed phototherapy modalites are narrow-band UVB, broadband UVB, and UVA1. Traditional systemic therapies include short-term corticosteroids, cyclosporine (considered to be the gold standard), methotrexate, azathioprine, mycophenolate mofetil, and most recently leflunamide. Biologic therapies include recombinant monoclonal antibodies acting on the immunoglobulin E / interleukin-5 pathway (omalizumab, mepolizumab), acting as tumor necrosis factor-α inhibitors (infliximab, etanercept, adalimumab), and acting as T-cell (alefacept) and B-cell (rituxumab) inhibitors, as well as interferon γ and intravenous immunoglobulin. Efficacy, safety, and tolerability are reviewed for each medication.