Targeting key proximal drivers of type 2 inflammation in disease

Type 2 Inflammation and the Evolving Profile of Uncontrolled Persistent Asthma

The objective of this symposium was to provide an overview of Type 2 inflammation in asthma. The speakers covered the pathophysiology of Type 2 asthma, its heterogeneity, the associated economic burden, and methods for recognising Type 2 inflammation in severe asthma patients in clinical practice. Asthma is a heterogenous disease and multiple phenotypes are common among patients. Type 2 asthma is so named because it is associated with Type 2 inflammation and typically includes allergic asthma and moderate-to-severe eosinophilic asthma, Prof Canonica explained. By contrast, non-Type 2 asthma commonly has an older age of onset and is often associated with obesity and neutrophilic inflammation. Prof Diamant highlighted the scale and severity of uncontrolled persistent asthma. Globally, an estimated 420,000 people die of asthma every year, and many more have uncontrolled disease, putting them at risk of persistent airway inflammation and eventual lung decline. Patients may not recognise that their disease is uncontrolled, despite exacerbations and the impact of their asthma on daily activities. Prof Diamant described the impairments to health-related quality of life and the associated costs of uncontrolled asthma. Prof Dahlén outlined how new predictive biomarkers will be needed to identify the type of asthma an individual patient has. No single biomarker will provide sufficient information, and as such, in the future, profiles of many markers will need to be integrated to produce subgroup-specific profiles for use in personalised medicine. He described ongoing research into protein arrays and lipid mediators in urine, and how cluster analysis and pattern recognition, with the aid of artificial intelligence, will form the basis of future diagnostic tools. Prof Canonica explained that an understanding of the mechanisms of asthma is important in achieving better symptom control. IL-4 and IL-13 are key players in the pathobiology of uncontrolled persistent asthma (IL-4 in inflammation and IL-13 in airway remodelling), but their roles overlap. The heterogenous nature of Type 2 asthma can make it difficult to diagnose; therefore, focussing on a single biomarker is likely to leave some patients sub-optimally controlled.

The fungal metabolite cyclonerodiol inhibits IL-4/IL-13 induced Stat6-signaling through blocking the association of Stat6 with p38, ERK1/2 and p300

The IL-4/IL-13/Stat6 pathway is the key driver of asthma pathophysiology. Therefore the development of inhibitors that specifically modulate IL-13/IL-4 or the downstream signaling molecules like Stat6 may be useful as a therapeutic strategy for the treatment of asthma and multiple allergic diseases. We have previously identified the fungal 2,6-cyclofarnesane cyclonerodiol as an inhibitor of IL-4 induced Stat6-dependent signaling in the alveolar epithelial cell line A549 using a transcriptional reporter. In this study we investigated the underlying mode of action of cyclonerodiol on the IL-4/IL-13/Stat6 pathway. Cyclonerodiol failed to interfere with activation, nuclear transport or binding of Stat6 to the corresponding consensus sequence on the DNA. Our results showed that cyclonerodiol blocked serine phosphorylation of Stat6 by affecting its association with p38 and Erk1/2. Cyclonerodiol also prevented the recruitment of the transcriptional coactivator p300 and Stat6 acetylation. These findings suggest that cyclonerodiol affects IL-4/IL-13 induced expression of asthma related marker genes by blocking transcriptional activation.

Loss of Stat6 affects chromatin condensation in intestinal epithelial cells causing diverse outcome in murine models of inflammation-associated and sporadic colon carcinogenesis

While great advances have been achieved regarding the genetic basis of colorectal cancer, the complex role of cell–cell communication and cytokine-induced signaling during its pathogenesis remains less understood. Signal transducer and activator of transcription 6 (Stat6) is the main transcription factor of interleukin-4 (IL-4) signaling and its participation in the development of various tumor types has been already reported. Here we aimed to examine the contribution of Stat6 in intestinal epithelial cells (IEC) in mouse models of intestinal carcinogenesis. Wild-type (WT), Stat6 knockout (Stat6^−/−), and intestinal epithelial cell-specific IL-4Rα knockout (Il-4rα^ΔIEC) mice were subjected to colitis-associated (AOM/DSS) and colitis-independent (sporadic) carcinogenesis. IEC proliferation, apoptosis and RNA expression were evaluated by immunohistochemical, immunoblot, and RT-PCR analysis. We found that Stat6^−/− mice developed more tumors in the colitis-associated carcinogenesis model. This was accompanied by a more pronounced inflammatory response during colitis and an elevated Stat3-dependent proliferation of IEC. Increased sensitivity to DSS-induced colitis was caused by elevated cell death in response to the initial carcinogen exposure as Stat6 deficiency led to increased chromatin compaction affecting DNA damage response in IEC upon treatment with alkylating agents independently of IL-4Rα engagement. Thus, loss of Stat6 caused more severe colitis and increased tumor load, however loss-of-initiated Stat6^−/− IEC prevented tumor formation in the absence of overt inflammation. Our data unravel unexpected IL-4-independent functions of Stat6 in chromatin compaction in intestinal epithelial cells ultimately providing both tumor suppressive as well as tumor promoting effects in different models of intestinal tumorigenesis.

Dupilumab does not affect correlates of vaccine-induced immunity: A randomized, placebo-controlled trial in adults with moderate-to-severe atopic dermatitis

BACKGROUND

The impact of dupilumab, an anti-interleukin (IL) 4 receptor α antibody that inhibits IL-4 and IL-13 signaling, on vaccine responses of patients with atopic dermatitis (AD) is unknown.

OBJECTIVES

To assess T-cell-dependent and T-cell-independent humoral immune responses to tetanus and meningococcal vaccines, IgE seroconversion to tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination, and dupilumab efficacy and safety.

METHODS

In a randomized, double-blinded, placebo-controlled study (NCT02210780), adults with moderate-to-severe AD received dupilumab (300 mg) or placebo weekly for 16 weeks, and single doses of Tdap and quadrivalent meningococcal polysaccharide vaccines at week 12. Primary endpoint was proportion of patients achieving satisfactory IgG response to tetanus toxoid at week 16.

RESULTS

In total, 178 patients completed the study. Similar positive immune responses (≥4-fold increase in antibody titer, or an antibody titer of ≥8) were achieved in the dupilumab and placebo groups to tetanus (83.3% and 83.7%, respectively) and meningococcal polysaccharide (86.7% and 87.0%, respectively). Dupilumab significantly decreased total serum IgE; most dupilumab-treated patients were Tdap-IgE seronegative at week 32 (62.2% dupilumab and 34.8% placebo). Dupilumab improved key AD efficacy endpoints (P < .001). Injection-site reactions and conjunctivitis were more common with dupilumab; AD exacerbations more frequent with placebo.

LIMITATION

Patients' prior vaccination status was not available before enrollment.

CONCLUSION

Dupilumab did not affect responses to the vaccines studied, significantly decreased IgE, and improved measures of AD severity versus placebo, with an acceptable safety profile.

Epithelial barrier dysfunctions in atopic dermatitis: a skin-gut-lung model linking microbiome alteration and immune dysregulation

BACKGROUND

Atopic dermatitis is a systemic disorder characterized by abnormal barrier function across multiple organ sites. Causes of epidermal barrier breakdown are complex and driven by a combination of structural, genetic, environmental and immunological factors. In addition, alteration in microflora diversity can influence disease severity, duration, and response to treatment. Clinically, atopic dermatitis can progress from skin disease to food allergy, allergic rhinitis, and later asthma, a phenomenon commonly known as the atopic march. The mechanism by which atopic dermatitis progresses towards gastrointestinal or airway disease remains to be elucidated.

OBJECTIVES

This review addresses how epithelial dysfunction linking microbiome alteration and immune dysregulation can predispose to the development of the atopic march.

METHODS

A literature search was conducted using the PubMed database for relevant articles with the keywords 'atopic dermatitis', 'epithelial barrier', 'skin', 'gut', 'lung', 'microbiome' and 'immune dysregulation'.

RESULTS

Initial disruption in the skin epidermal barrier permits allergen sensitization and colonization by pathogens. This induces a T helper 2 inflammatory response and a thymic stromal lymphopoietin-mediated pathway that further promotes barrier breakdown at distant sites, including the intestinal and respiratory tract.

CONCLUSIONS

As there are no immediate cures for food allergy or asthma, early intervention aimed at protecting the skin barrier and effective control of local and systemic inflammation may improve long-term outcomes and reduce allergen sensitization in the airway and gut.

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.

Biologic Therapy for Atopic Dermatitis: Moving Beyond the Practice Parameter and Guidelines

Atopic dermatitis (AD), a common chronic pruritic inflammatory skin disease, impacts the quality of life of patients and caregivers and has become a global health problem. It is increasingly recognized as a disease not only of children but also of adults who may have a persistent or relapsing course from childhood or who develop new-onset adult disease. Besides well-established atopic comorbidities, associations with a number of nonatopic comorbidities have been reported. AD is characterized by both immune dysregulation and epidermal barrier dysfunction. The findings that nonlesional skin in AD has both terminal keratinocyte differentiation defects and immune abnormalities as well as multiple markers of immune and inflammatory activation in the circulation point to the systemic nature of the disease and have important translational implications. Although AD is predominantly associated with type 2 immune responses, activation of other cytokine pathways including T_H1, T_H22, and T_H17/IL-23 has been reported, suggesting potential therapeutic targets and provide a rationale for treatment with novel biologics. Dupilumab, a fully human mAb targeting the IL-4 Rα subunit, blocks signaling of both IL-4 and IL-13 and is the first biologic to be approved for the treatment of moderate-to-severe AD in adult patients. Other biologics in current trials for AD are targeting the IL-31 receptor, IL-13, and the common p40 subunit of IL-12/IL-23.

Cytokine Tuning of Intestinal Epithelial Function

The intestine serves as both our largest single barrier to the external environment and the host of more immune cells than any other location in our bodies. Separating these potential combatants is a single layer of dynamic epithelium composed of heterogeneous epithelial subtypes, each uniquely adapted to carry out a subset of the intestine’s diverse functions. In addition to its obvious role in digestion, the intestinal epithelium is responsible for a wide array of critical tasks, including maintaining barrier integrity, preventing invasion by microbial commensals and pathogens, and modulating the intestinal immune system. Communication between these epithelial cells and resident immune cells is crucial for maintaining homeostasis and coordinating appropriate responses to disease and can occur through cell-to-cell contact or by the release or recognition of soluble mediators. The objective of this review is to highlight recent literature illuminating how cytokines and chemokines, both those made by and acting on the intestinal epithelium, orchestrate many of the diverse functions of the intestinal epithelium and its interactions with immune cells in health and disease. Areas of focus include cytokine control of intestinal epithelial proliferation, cell death, and barrier permeability. In addition, the modulation of epithelial-derived cytokines and chemokines by factors such as interactions with stromal and immune cells, pathogen and commensal exposure, and diet will be discussed.

Liberty Asthma QUEST: Phase 3 Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study to Evaluate Dupilumab Efficacy/Safety in Patients with Uncontrolled, Moderate-to-Severe Asthma

Introduction

Dupilumab, a fully human anti-IL-4Rα monoclonal antibody, inhibits signaling of both interleukin (IL)-4 and IL-13, which are key drivers of type 2-mediated inflammation. Dupilumab is approved in the EU, USA, and other countries for the treatment of adults with inadequately controlled moderate-to-severe atopic dermatitis. Following positive phase 2 results in asthma, the phase 3 Liberty Asthma QUEST trial was initiated to provide further evidence for dupilumab efficacy and safety in patients with uncontrolled, moderate-to-severe asthma.

Methods

Liberty Asthma QUEST is a phase 3, multinational, multicenter, randomized, double-blind, placebo-controlled, parallel-group trial (NCT02414854) in patients with persistent asthma who are receiving continuous treatment with inhaled corticosteroids (ICS) plus one or two other asthma controller medicines. A total of 1902 patients (aged ≥ 12 years) were randomized in a 2:2:1:1 ratio to receive 52 weeks of add-on therapy with subcutaneously administered dupilumab 200 or 300 mg every 2 weeks or matched placebo. The study consisted of a 4 ± 1-week screening period, 52-week randomized treatment period, and 12-week post-treatment follow-up period. All patients continued to receive their prescribed ICS plus up to two additional controller medications. The primary efficacy endpoints were annualized rate of severe exacerbation events during the 52-week treatment period and absolute change from baseline in pre-bronchodilator FEV₁ at week 12.

Conclusion

Uncontrolled asthma patients with persistent symptoms represent a population of significant unmet need, for whom new treatments are required. Patients with severe asthma are at high risk of asthma exacerbations, and face an accelerated decline in lung function and impaired quality of life. QUEST examines the efficacy of dupilumab in this at-risk patient population; it is the largest placebo-controlled study in uncontrolled, moderate-to-severe asthma with a biologic agent to date, and the only phase 3 study of a biologic therapy of asthma that enrolled patients irrespective of baseline type 2 inflammatory biomarker levels.

Funding

Sanofi and Regeneron Pharmaceuticals, Inc.

Clinical Trials.gov Identifier

NCT02414854.

Interactions of the immune and sensory nervous systems in atopy

A striking feature underlying all atopic disorders, such as asthma, atopic dermatitis, and food allergy, is the presence of pathologic sensory responses, reflexes, and behaviors. These symptoms, exemplified by chronic airway irritation and cough, chronic itch and scratching, as well as gastrointestinal discomfort and dysfunction, are often cited as the most debilitating aspects of atopic disorders. Emerging studies have highlighted how the immune system shapes the scope and intensity of sensory responses by directly modulating the sensory nervous system. Additionally, factors produced by neurons have demonstrated novel functions in propagating atopic inflammation at barrier surfaces. In this review, we highlight new studies that have changed our understanding of atopy through advances in characterizing the reciprocal interactions between the immune and sensory nervous systems.

Thymol attenuates the worsening of atopic dermatitis induced by Staphylococcus aureus membrane vesicles

Staphylococcus aureus membrane vesicles (MVs) aggravate atopic dermatitis (AD) through the delivery of bacterial effector molecules to host cells and the stimulation of inflammatory responses. This study investigated the inhibitory effect of thymol, a phenolic monoterpene found in essential oils derived from plants, on the worsening of AD induced by S. aureus MVs both in vitro and in vivo. The sub-minimal inhibitory concentrations of thymol disrupted S. aureus MVs. Intact S. aureus MVs induced the expression of pro-inflammatory cytokine (interleukin (IL)-1β, IL-6, and tumor necrosis factor-α) and chemokine (IL-8 and monocyte chemoattractant protein-1) genes in cultured keratinocytes, whereas thymol-treated S. aureus MVs did not stimulate the expression of these genes. Topical application of thymol-treated S. aureus MVs or treatment with thymol after intact S. aureus MVs to AD-like skin lesions diminished the pathology of AD. This included decreases in epidermal/dermal thickness and infiltration of eosinophils/mast cells, and inhibited expression of pro-inflammatory cytokine and chemokine genes in mouse AD model. Moreover, thymol significantly suppressed the Th1, Th2, and Th17-mediated inflammatory responses in AD-like skin lesions induced by S. aureus MVs, and reduced the serum levels of immunoglobulin (Ig) G2a, mite-specific IgE, and total IgE. In summary, thymol disrupts S. aureus MVs and suppresses inflammatory responses in AD-like skin lesions aggravated by S. aureus MVs. Our results suggest that thymol is a possible candidate for the management of AD aggravation induced by S. aureus colonization or infection in the lesions.

Phenotyping acute and chronic atopic dermatitis-like lesions in Stat6VT mice identifies a role for IL-33 in disease pathogenesis

The Stat6VT mouse model of atopic dermatitis (AD) is induced by T-cell-specific expression of a constitutively active form of the protein signal transducer and activator of transcription 6 (STAT6). Although AD-like lesions are known to develop in Stat6VT mice, this study was designed to determine if these mice develop acute and chronic phases of disease similar to humans. To address this, AD-like lesions from Stat6VT mice were harvested at two different timepoints relative to their onset. Lesions harvested within 1 week after development were defined as acute lesions, and those present for 1 month or more were defined as chronic lesions. Acute and chronic AD-like lesions from Stat6VT mice exhibited histologic findings and cytokine expression patterns similar to acute and chronic AD lesions in humans. Further analysis revealed increased levels of interleukin (IL)-33 transcripts in AD-like lesions compared to Stat6VT nonlesional and wild-type skin controls. Immunofluorescence also revealed increased numbers of IL-33+ keratinocytes in Stat6VT lesional skin and localized IL-33+ keratinocytes to a keratin 5+ subset. Furthermore, AD-like disease was more severe in IL-33-deficient Stat6VT mice compared to IL-33-sufficient Stat6VT mice. These studies suggest that Stat6VT mice can serve as a model of acute and chronic AD and that IL-33 may attenuate inflammation in this system.

Non-surgical management of chronic rhinosinusitis with nasal polyps based on clinical-cytological grading: a precision medicine-based approach

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disorder that strongly impacts patients' quality of life. CRSwNP is still a challenge for ENT specialists due to its unknown pathogenesis, difficult control and frequent relapse. We tested the hypothesis that a new standardised therapeutic approach based on individual clinical-cytological grading (CCG), may improve control of the disease and prevent the needing for surgery. We analysed 204 patients suffering from bilateral CRSwNP, 145 patients of whom regularly assumed therapy, respecting the planned check-up, and were considered cases; 59 patients were not assuming therapy as indicated and were considered as controls. After five years of standardised treatment, 15 of 145 (10.5%) improved endoscopic staging, 61 of 145 (42%) did not change their endoscopic staging, and 69 of 145 (47.5%) were worse. In the control group, 49 of 59 (83%) were worse by at least two stages (p < 0.05). Patients and controls were stratified basing on clinical and cytological grading as mild, moderate and severe. After patient stratification, in the mild group (n = 27) 92% patients had a constant trend, with no worsening and no need for surgery over a 5-year period, whereas in the mild CCG control group 1 of 59 (1.6%) required surgery (p < 0.05). In moderate GCC (n = 83), 44% of patients did not modify or improve endoscopic staging and 3.6% needed surgery, compared to 13.6% of controls with moderate GCC (p < 0.05). In severe CCG (n = 35), even though no patients achieved significant amelioration of endoscopic grading, 40% of patients were considered as "clinically controlled" and 5.7% of patients underwent surgery, but the percentage was significantly higher (49%) in the control group significant (p = 0.0000). Finally, statistical analyses revealed a clear trend that polyp size increased at a faster rate in the control group than in the treatment group and for each subgroup (low, moderate and severe). The present study suggests a new approach in the management of CRS according to clinical cytological grading that allows defining the grade of CRSwNP severity and to adapt the intensity of treatment. This approach limited the use of systemic corticosteroids to only moderate-severe CRSwNP with a low corticosteroid dosage in comparison with those previously suggested. Our protocol seems to improve the adherence by patients, control of disease and the need for surgery in the long-term.

Molecular aspects of allergens in atopic dermatitis

PURPOSE OF REVIEW

Molecular allergology uses pure, mainly recombinant and structurally defined allergen molecules and allergen-derived epitopes to study mechanisms of IgE-associated allergy, to diagnose, and even predict the development of allergic manifestations and to treat and prevent IgE-associated allergies. Atopic dermatitis, a chronic inflammatory skin disease is almost always associated with IgE sensitization to allergens. However, also non-IgE-mediated pathomechanisms seem to be operative in atopic dermatitis and it is often difficult to identify the disease-causing allergens. Here we review recent work showing the usefulness of molecular allergology to study mechanisms of atopic dermatitis, for diagnosis and eventually for treatment and prevention of atopic dermatitis.

RECENT FINDINGS

IgE sensitization to airborne, food-derived, microbial allergens, and autoallergens has been found to be associated with atopic dermatitis. Using defined allergen molecules and non-IgE-reactive allergen derivatives, evidence could be provided for the existence of IgE- and non-IgE-mediated mechanisms of inflammation in atopic dermatitis. Furthermore, effects of epicutaneous allergen administration on systemic allergen-specific immune responses have been studied. Multi-allergen tests containing micro-arrayed allergen molecules have been shown to be useful for the identification of culprit allergens in atopic dermatitis and may improve the management of atopic dermatitis by allergen-specific immunotherapy, allergen avoidance, and IgE-targeting therapies in a personalized medicine approach.

SUMMARY

Molecular allergology allows for dissection of the pathomechanisms of atopic dermatitis, provides new forms of allergy diagnosis for identification of disease-causing allergens, and opens the door to new forms of management by allergen-specific and T cells-targeting or IgE-targeting interventions in a personalized medicine approach.

Airway pathological heterogeneity in asthma: Visualization of disease microclusters using topological data analysis

BACKGROUND

Asthma is a complex chronic disease underpinned by pathological changes within the airway wall. How variations in structural airway pathology and cellular inflammation contribute to the expression and severity of asthma are poorly understood.

OBJECTIVES

Therefore we evaluated pathological heterogeneity using topological data analysis (TDA) with the aim of visualizing disease clusters and microclusters.

METHODS

A discovery population of 202 adult patients (142 asthmatic patients and 60 healthy subjects) and an external replication population (59 patients with severe asthma) were evaluated. Pathology and gene expression were examined in bronchial biopsy samples. TDA was applied by using pathological variables alone to create pathology-driven visual networks.

RESULTS

In the discovery cohort TDA identified 4 groups/networks with multiple microclusters/regions of interest that were masked by group-level statistics. Specifically, TDA group 1 consisted of a high proportion of healthy subjects, with a microcluster representing a topological continuum connecting healthy subjects to patients with mild-to-moderate asthma. Three additional TDA groups with moderate-to-severe asthma (Airway Smooth Muscle^High, Reticular Basement Membrane^High, and Remodeling^Low groups) were identified and contained numerous microclusters with varying pathological and clinical features. Mutually exclusive T_H2 and T_H17 tissue gene expression signatures were identified in all pathological groups. Discovery and external replication applied to the severe asthma subgroup identified only highly similar "pathological data shapes" through analyses of persistent homology.

CONCLUSIONS

We have identified and replicated novel pathological phenotypes of asthma using TDA. Our methodology is applicable to other complex chronic diseases.

Targeted Therapy for Severe Asthma: Identifying the Right Patients

Asthma affects over 300 million people worldwide. Most asthmatics are well controlled with inhaled corticosteroids and long-acting beta-agonists; however, a proportion of patients are unresponsive and attain limited disease control. This group represents a considerable healthcare and financial burden, particularly patients who experience frequent exacerbations and require hospital admission. Development of new biological agents and disease biomarkers has provided novel avenues for treatment. These treatments have been highly successful, reducing exacerbations and yielding modest improvements in quality of life and lung function. However, only a proportion of severe asthmatics respond to this targeted treatment, highlighting the heterogeneity of severe asthma. One of the first biological therapies targeted immunoglobulin E (IgE) and demonstrated modest benefit but could only be used in a subgroup of patients. Recent research has shown that treatment aimed at the T helper-2-(Th₂)-high pathways and cytokines such as interleukin (IL)-5, IL-4, and IL-13 may also be effective in another partially overlapping subgroup. A blood eosinophil count over a defined threshold (generally ≥300 cells/μl) was a reliable biomarker and identified the majority of responders in this group. Further discovery and validation of biological markers to define asthmatic phenotypes that may benefit from biological treatments remain an area of intense interest and research. We review the latest information pertaining to biological agents and demonstrate how patient responders may potentially be identified for treatment.

JAK/STAT inhibitors and other small molecule cytokine antagonists for the treatment of allergic disease

OBJECTIVE

To provide an overview of janus kinase (JAK), chemoattractant receptor homologous molecule expressed on T_H2 cells (CRTH2), and phosphodiesterase 4 (PDE4) inhibitors in allergic disorders.

DATA SOURCES

PubMed literature review.

STUDY SELECTIONS

Articles included in this review discuss the emerging mechanism of action of small molecule inhibitors and their use in the treatment of atopic dermatitis (AD), asthma, and allergic rhinitis (AR).

RESULTS

Allergic diseases represent a spectrum of diseases, including AD, asthma, and AR. For decades, these diseases have been primarily characterized by increased T_H2 signaling and downstream inflammation. In recent years, additional research has identified disease phenotypes and subsets of patients with non-Th2 mediated inflammation. The increasing heterogeneity of disease has prompted investigators to move away from wide-ranging treatment approaches with immunosuppressive agents, such as corticosteroids, to consider more targeted immunomodulatory approaches focused on specific pathways. In the past decade, inhibitors that target JAK signaling, PDE4, and CRTH2 have been explored for their potential activity in models of allergic disease and therapeutic benefit in clinical trials. Interestingly, although JAK inhibitors provide an opportunity to interfere with cytokine signaling and could be beneficial in a broad range of allergic diseases, current clinical trials are focused on the treatment of AD. Conversely, both PDE4 and CRTH2 inhibitors have been evaluated in a spectrum of allergic diseases. This review summarizes the varying degrees of success that these small molecules have demonstrated across allergic diseases.

CONCLUSION

Emerging therapies currently in development may provide more consistent benefit to patients with allergic diseases by specifically targeting inflammatory pathways important for disease pathogenesis.

Interleukin-6 Family Cytokines

The interleukin (IL)-6 family cytokines is a group of cytokines consisting of IL-6, IL-11, ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), oncostatin M (OSM), cardiotrophin 1 (CT-1), cardiotrophin-like cytokine (CLC), and IL-27. They are grouped into one family because the receptor complex of each cytokine contains two (IL-6 and IL-11) or one molecule (all others cytokines) of the signaling receptor subunit gp130. IL-6 family cytokines have overlapping but also distinct biologic activities and are involved among others in the regulation of the hepatic acute phase reaction, in B-cell stimulation, in the regulation of the balance between regulatory and effector T cells, in metabolic regulation, and in many neural functions. Blockade of IL-6 family cytokines has been shown to be beneficial in autoimmune diseases, but bacterial infections and metabolic side effects have been observed. Recent advances in cytokine blockade might help to minimize such side effects during therapeutic blockade.

Efficacy and safety of dupilumab in perennial allergic rhinitis and comorbid asthma

BACKGROUND

Dupilumab, an anti-IL-4 receptor α mAb, inhibits IL-4/IL-13 signaling, key drivers of type 2/T_H2 immune diseases (eg, atopic/allergic disease). In a pivotal, phase 2b study (NCT01854047), dupilumab reduced severe exacerbations, improved lung function and quality of life, and was generally well tolerated in patients with uncontrolled persistent asthma despite using medium-to-high-dose inhaled corticosteroids plus long-acting β2-agonists.

OBJECTIVE

To examine dupilumab's effect on the 22-item Sino-Nasal Outcome Test (SNOT-22) total score and its allergic rhinitis (AR)-associated items in asthma patients with comorbid perennial allergic rhinitis (PAR).

METHODS

A post hoc analysis reporting data from the phase 2b study for the 200 and 300 mg every 2 week (q2w) doses under investigation in phase 3 (NCT02414854) was carried out. PAR was defined at study entry as a specific response to typical perennial antigens (IgE ≥0.35 Ku/L).

RESULTS

Overall, 241 (61%) patients had PAR. In asthma patients with PAR, dupilumab 300 mg q2w versus placebo significantly improved SNOT-22 total score (least squares mean difference, -5.98; 95% CI, -10.45 to -1.51; P = .009) and all 4 AR-associated symptoms evaluated (nasal blockage, -0.60; 95% CI, -0.96 to -0.25; runny nose, -0.67; 95% CI, -1.04 to -0.31; sneezing, -0.55; 95% CI, -0.89 to -0.21; postnasal discharge, -0.49; 95% CI, -0.83 to -0.16; all P < .01). Dupilumab 200 mg q2w demonstrated numerical, but not statistically significant, decreases in SNOT-22 total score (-1.82; 95% CI, -6.46 to 2.83; P = .443 vs placebo) and in each AR-associated symptom. In patients without PAR, no differences were observed for these measures versus placebo.

CONCLUSIONS

Dupilumab 300 mg q2w significantly improved AR-associated nasal symptoms in patients with uncontrolled persistent asthma and comorbid PAR.

Initiation of inflammatory tumorigenesis by CTLA4 insufficiency due to type 2 cytokines

CTLA4 insufficiency is genetically associated with stomach cancer. Miska et al. demonstrate that CTLA4 insufficiency causes stomach cancer by autoimmune inflammation, an effect largely attributed to type 2 cytokine stimulation of stomach mucosal cells. These findings suggest preventive strategies against tumor initiation by controlling type 2 inflammation while preserving type 1 immunity.

Genetically predisposed CTLA4 insufficiency in humans is associated with gastric cancer development, which is paradoxical to the prototypical role of CTLA4 in suppressing antitumor immunity. CTLA4 is a critical immune checkpoint against autoimmune disorders. Autoimmunity has been implicated in protumor or antitumor activities. Here, we show that CTLA4 insufficiency initiates de novo tumorigenesis in the mouse stomach through inflammation triggered by host-intrinsic immune dysregulation rather than microbiota, with age-associated progression to malignancy accompanied by epigenetic dysregulation. The inflammatory tumorigenesis required CD4 T cells, but not the T_H1 or T_H17 subsets. Deficiencies in IL-4 and IL-13 or IL-4 receptor α broke the link between inflammation and initiation of tumorigenesis. This study establishes the causality of CTLA4 insufficiency in gastric cancer and uncovers a role of type 2 inflammation in initiating gastric epithelial transformation. These findings suggest possible improvement of immune therapies by blocking tumorigenic type 2 inflammation while preserving antitumor type 1 immunity.

Use of biologics in severe food allergies

PURPOSE OF REVIEW

Severe cases of food allergy account for the majority of the burden in terms of risks, quality of life, and resource expenditure. The traditional approach to these forms has been strict avoidance. More recently, Oral ImmunoTherapy (OIT) has gained a role in their management. However, in severe food allergies OIT is often infeasible.

RECENT FINDINGS

Case reports, observational, and prospective studies have recently proposed different approaches to severe food allergy. The majority of them include the use of biologics. Omalizumab has been the most studied drug for severe food allergies, and its role as adjuvant treatment to OIT is well established. Interest has been raised on other biologics, as dupilumab, reslizumab, and mepolizumab. Toll-like receptor agonists, and gene therapy using adeno-associated virus coding for Omalizumab are promising alternatives.

SUMMARY

The recent studies are deeply influencing the clinical practice. We review the modifications of the clinical approach to severe food allergies so far available. We indicate the possible evolutions of treatment with biologics in severe food allergies.

Developments in the field of allergy mechanisms in 2015 through the eyes of Clinical & Experimental Allergy

In the first of two papers we described the development in the field of allergy mechanisms as described by Clinical and Experimental Allergy in 2015. Experimental models of allergic disease, basic mechanisms, clinical mechanisms and allergens are all covered. A second paper will cover clinical aspects.

Microglia M2A Polarization as Potential Link between Food Allergy and Autism Spectrum Disorders

Atopic diseases are frequently co-morbid with autism spectrum disorders (ASD). Allergic responses are associated with an activation of mast cells, innate lymphoid cells, and Th2 cells. These cells produce type-2 cytokines (IL4 and IL13), which stimulate microglia and macrophages to adopt a phenotype referred to as ‘alternative activation’ or ‘M2A’. M2A-polarized macrophages and microglia play a physiological role in tissue repair by secreting growth factors such as brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1. In ASD there is evidence for increased type-2 cytokines, microglia activation, M2A polarization, and increased levels of growth factors. In neurons, these growth factors drive a signal transduction pathway that leads to activation of the enzyme mammalian Target of Rapamycin (mTOR), and thereby to the inhibition of autophagy. Activation of mTOR is an effect that is also common to several of the genetic forms of autism. In the central nervous system, redundant synapses are removed via an autophagic process. Activation of mTOR would diminish the pruning of redundant synapses, which in the context of ASD is likely to be undesired. Based on this line of reasoning, atopic diseases like food allergy, eczema or asthma would represent risk factors for autism spectrum disorders.

The mother-offspring dyad: microbial transmission, immune interactions and allergy development

The increasing prevalence of allergy in affluent countries may be caused by reduced intensity and diversity of microbial stimulation, resulting in abnormal postnatal immune maturation. Most studies investigating the underlying immunomodulatory mechanisms have focused on postnatal microbial exposure, for example demonstrating that the gut microbiota differs in composition and diversity during the first months of life in children who later do or do not develop allergic disease. However, it is also becoming increasingly evident that the maternal microbial environment during pregnancy is important in childhood immune programming, and the first microbial encounters may occur already in utero. During pregnancy, there is a close immunological interaction between the mother and her offspring, which provides important opportunities for the maternal microbial environment to influence the immune development of the child. In support of this theory, combined pre- and postnatal supplementations seem to be crucial for the preventive effect of probiotics on infant eczema. Here, the influence of microbial and immune interactions within the mother-offspring dyad on childhood allergy development will be discussed. In addition, how perinatal transmission of microbes and immunomodulatory factors from mother to offspring may shape appropriate immune maturation during infancy and beyond, potentially via epigenetic mechanisms, will be examined. Deeper understanding of these interactions between the maternal and offspring microbiome and immunity is needed to identify efficacious preventive measures to combat the allergy epidemic.

Efficacy and safety of dupilumab for the treatment of moderate-to-severe atopic dermatitis in adults

Objective

Atopic dermatitis is a chronic, relapsing inflammatory skin disease characterized by intense pruritus, excoriations and limited therapies. Dupilumab, a monoclonal antibody against interleukin-4 receptor alpha, is a promising new treatment option for atopic dermatitis. We sought to systematically summarize the efficacy, safety, and influence on quality of life of dupilumab for the treatment of moderate-to-severe atopic dermatitis in adults.

Results

A total of 7 RCTs containing 2705 subjects were identified. Significantly more patients receiving dupilumab (611/1789) achieved Investigator’s Global Assessment response compared with the control (89/916; RR, 3.95; P < 0.001). Dupilumab was significantly more effective in reducing Eczema Area and Severity Index, peak pruritus numerical rating scale score, and body surface area. Treatment duration rather than administration frequency slightly influenced the efficacy. Dupilumab treatment also contributed to marked improvement in patients’ quality of life and psychological symptoms. Incidence of adverse events was similar in dupilumab group and control group.

Conclusions

Dupilumab is effective and safe for the treatment of moderate-to-severe atopic dermatitis in adults. This meta-analysis supports the role of dupilumab as a primary targeted biologic therapy in adult patients with moderate-to-severe atopic dermatitis.

Materials and Methods

We searched Pubmed, Embase, and the Cochrane Library for eligible trials. Only double-blinded randomized controlled trials (RCTs) investigating the efficacy and safety of dupilumab in treating moderate-to-severe atopic dermatitis were included in this analysis. We made a comparison of dupilumab with control based on the pooled relative risk (RR), weighted mean difference, and their corresponding 95% confidence intervals of different measurements.

The psoriasis-associated IL-17A induces and cooperates with IL-36 cytokines to control keratinocyte differentiation and function

Psoriasis is a T_H17-driven inflammatory disease affecting a significant proportion of the world population. The molecular consequences of IL-17 signaling in the skin are only partially understood. Therefore, we evaluated the IL-17A effects on organotypic 3-dimensional skin models and observed that IL-17A interfered with keratinocyte differentiation. In agreement with this phenotype, IL-17A repressed the expression of many genes encoding structural proteins. Moreover, genes encoding anti-microbial peptides were induced, resulting in a strengthening of the chemical barrier. Finally, we observed enhanced expression of the three IL-36 cytokines IL-36α, β and γ. We found that IL-36γ was secreted from keratinocytes in an inactive form and that neutrophilic proteases, including elastase, were capable of activating this cytokine. Functionally and similar to IL-17A, truncated IL-36 cytokines interfered with keratinocyte differentiation in 3D models. The molecular analysis revealed strong cooperative effects of IL-17A and IL-36 cytokines in regulating target genes, which was dependent on the proteolytic activation of the latter. Together these findings suggest an amplification cycle that can be initiated by IL-17A, involving IL-36 cytokines and immune cell derived proteases and resulting in active IL-36 cytokines which synergize with IL-17A. This amplification cycle might be relevant for a persistent psoriatic phenotype.

Pharmacological Regulation of Neuropathic Pain Driven by Inflammatory Macrophages

Neuropathic pain can have a major effect on quality of life but current therapies are often inadequate. Growing evidence suggests that neuropathic pain induced by nerve damage is caused by chronic inflammation. Upon nerve injury, damaged cells secrete pro-inflammatory molecules that activate cells in the surrounding tissue and recruit circulating leukocytes to the site of injury. Among these, the most abundant cell type is macrophages, which produce several key molecules involved in pain enhancement, including cytokines and chemokines. Given their central role in the regulation of peripheral sensitization, macrophage-derived cytokines and chemokines could be useful targets for the development of novel therapeutics. Inhibition of key pro-inflammatory cytokines and chemokines prevents neuroinflammation and neuropathic pain; moreover, recent studies have demonstrated the effectiveness of pharmacological inhibition of inflammatory (M1) macrophages. Nicotinic acetylcholine receptor ligands and T helper type 2 cytokines that reduce M1 macrophages are able to relieve neuropathic pain. Future translational studies in non-human primates will be crucial for determining the regulatory mechanisms underlying neuroinflammation-associated neuropathic pain. In turn, this knowledge will assist in the development of novel pharmacotherapies targeting macrophage-driven neuroinflammation for the treatment of intractable neuropathic pain.

Dupilumab for the treatment of asthma

INTRODUCTION

Dupilumab is a fully human IgG4 monoclonal antibody directed against the α subunit of the interleukin (IL)-4 receptor (IL-4Rα). Since the activation of IL-4Rα is utilized by both IL-4 and IL-13 to mediate their pathophysiological effects, dupilumab behaves as a dual antagonist of these two sister cytokines, which blocks IL-4/IL-13-dependent signal transduction. Areas covered: Herein, the authors review the cellular and molecular pathways activated by IL-4 and IL-13, which are relevant to asthma pathobiology. They also review: the mechanism of action of dupilumab, the phase I, II and III studies evaluating the pharmacokinetics as well as the safety, tolerability and clinical efficacy of dupilumab in asthma therapy. Expert opinion: Supported by a strategic mechanism of action, as well as by convincing preliminary clinical results, dupilumab currently appears to be a very promising biological drug for the treatment of severe uncontrolled asthma. It also may have benefits to comorbidities of asthma including atopic dermatitis, chronic sinusitis and nasal polyposis.

Medical therapy, refractory chronic rhinosinusitis, and productivity costs

PURPOSE OF REVIEW

The purpose of this review is to address the most recent advances in the medical therapy for chronic rhinosinusitis (CRS), define recalcitrant and refractory CRS, and discuss the productivity costs associated with CRS.

RECENT FINDINGS

Recent studies evaluating anti-IL-4 receptor α antibodies and calcium channel blockers have demonstrated promising early results during management of CRS. Recent appropriateness criteria have been developed to assist clinicians with defining which patients have 'refractory' CRS and may be considered candidates for endoscopic sinus surgery. Productivity costs appear to be associated with disease severity and can be reduced with appropriate interventions.

SUMMARY

Topical corticosteroid therapy and high volume saline irrigation continue to be the cornerstone to medical therapy, whereas use of systemic corticosteroids and antibiotics depends on CRS phenotype and presence of acute exacerbation. More research is needed before routine use of novel immunomodulatory therapies such as anti-IL5, anti-IgE, anti-IL4, and calcium channel blockers. Clinicians should apply an appropriate definition for refractory CRS when discussing role of sinus surgery. Assessing the degree of work productivity impairment can assist in treatment decision-making and may help predict treatment outcomes.

MicroRNA-98 interferes with thrombospondin 1 expression in peripheral B cells of patients with asthma

Thrombospondin 1 (TSP1)-producing B cells are an important immune regulatory cell fraction in the body, which are compromised in a number of immune diseases. miRs are involved in the immune regulation. The present study aims to elucidate the mechanism by which miR-98 interferes with the expression of TSP1 in B cells of the peripheral blood system. In the present study, peripheral blood samples were collected from patients with allergic asthma. The B cells were isolated from the blood samples to be analyzed for the expression of miR-98 and TSP1. The results showed that the levels of miR-98 were higher, the levels of TSP1 were lower, in B cells isolated from the peripheral blood in patients with asthma. A negative correlation was identified between the data of miR-98 and TSP1 in B cells. Exposure to T helper (Th) 2 (Th2) cytokine, interleukin (IL)-13, increased the expression of miR-98 and suppressed the expression of TSP1 in peripheral B cells, which was abolished by knocking down the miR-98 gene. In conclusion, miR-98 can suppress the expression of TSP1 in the peripheral B cells of patients with allergic asthma.

Host regulation of liver fibroproliferative pathology during experimental schistosomiasis via interleukin-4 receptor alpha

Interleukin-4 receptor (IL-4Rα) is critical for the initiation of type-2 immune responses and implicated in the pathogenesis of experimental schistosomiasis. IL-4Rα mediated type-2 responses are critical for the control of pathology during acute schistosomiasis. However, type-2 responses tightly associate with fibrogranulomatous inflammation that drives host pathology during chronic schistosomiasis. To address such controversy on the role of IL-4Rα, we generated a novel inducible IL-4Rα-deficient mouse model that allows for temporal knockdown of il-4rα gene after oral administration of Tamoxifen. Interrupting IL-4Rα mediated signaling during the acute phase impaired the development of protective type-2 immune responses, leading to rapid weight loss and premature death, confirming a protective role of IL-4Rα during acute schistosomiasis. Conversely, IL-4Rα removal at the chronic phase of schistosomiasis ameliorated the pathological fibro-granulomatous pathology and reversed liver scarification without affecting the host fitness. This amelioration of the morbidity was accompanied by a reduced Th2 response and increased frequencies of FoxP3⁺ Tregs and CD1d^hiCD5⁺ Bregs. Collectively, these data demonstrate that IL-4Rα mediated signaling has two opposing functions during experimental schistosomiasis depending on the stage of advancement of the disease and indicate that interrupting IL-4Rα mediated signaling is a viable therapeutic strategy to ameliorate liver fibroproliferative pathology in diseases like chronic schistosomiasis.

Liver fibroproliferative diseases drive a considerable fraction of the overall human mortality. This is closely linked to the absence of efficient control measures against such diseases. Schistosomiasis, a chronic disease that affects humans, preferentially causes liver fibrosis and is responsible for devastating economic losses in developing nations where the disease is still endemic. Using reverse genetics, loss-of-function mouse models have helped uncover a protective role for Interleukin-4 receptor (IL-4Rα) in the host survival to experimental schistosomiasis. However, given the contributing role for this receptor in the etiology of some models of tissue fibrosis, its role during chronic schistosomiasis where the highly fibrotic liver of the infected individuals mediate the morbidity had not been properly addressed hitherto. Taking advantage of a third generation mouse model of inducible loss of a gene, we found a debilitating role for IL-4 receptor during chronic schistosomiasis as signaling via this receptor supported both liver inflammation and fibrosis. These findings demonstrate that although the host requires IL-4Rα to survive the acute phase of schistosomiasis, the more clinically relevant morbid phase of the disease is driven by the excessive utilization of this receptor. A therapeutic potential of blocking IL-4Rα to ameliorate liver fibroproliferative disease is therefore suggested.

Increased frequencies of basophils, type 2 innate lymphoid cells and Th2 cells in skin of patients with atopic dermatitis but not psoriasis

BACKGROUND

Pathogenesis of atopic dermatitis (AD) involves interaction between type 2 cells that include basophils, mast cells, innate lymphoid type 2 cells (ILC2), and Th2 cells. Levels of IL-4 and IL-13 are elevated in AD patients.

OBJECTIVE

Here, we investigated the distribution of type 2 cells and the source of IL-4 and IL-13 in skin and blood of AD relative to psoriasis.

METHODS

Lesional skin biopsies and blood were collected from patients. Skin cell suspensions were prepared by mild enzymatic digestion and mechanical dissociation. IL-4 and IL-13 expression was analyzed at single-cell level before or after stimulation using flow cytometry.

RESULTS

Frequencies of basophils, ILC2 and Th2 but not mast cells were significantly elevated in skin, and not blood, of AD relative to psoriasis. IL-4 production by circulating basophils and Th2 cells, and IL-13 by ILCs and Th2 cells was similar in both diseases. In contrast, skin T cells expressed IL-4 and IL-13 prior to stimulation in AD when compared to psoriasis. Moreover, skin basophils, which were detected in AD only, expressed IL-4 following stimulation. Interestingly, basophils and ILC2 were positively correlated in skin, whereas skin basophils were inversely correlated with blood ILC2.

CONCLUSIONS

Lesional AD skin harbors a distinctive innate and adaptive type 2 profile, which is characterized by basophils producing IL-4, Th2 cells expressing IL-4 or IL-13, and ILC2. This underlies the therapeutic efficacy of targeting IL-4 and IL-13 signaling pathways in AD.

GATA-3-specific DNAzyme - A novel approach for stratified asthma therapy

It is now well established that type-2 immune mechanisms drive the inflammation in about 50% of asthma patients. The major cellular and molecular players regulating this important network have been identified. In terms of therapeutic intervention, cytokine and cytokine-receptor pathways have been given major attention, since these molecules are relatively easily accessible for a blockade through monoclonal antibodies, and a number of positive clinical results support this concept. However, targeting events controlling the type-2 immunity network upstream of selective cytokine pathways would be equally attractive. Type-2 immunity is regulated through a delicate interplay of several transcription factors (including GATA-3, STAT-6, NFAT, IRF4, c-maf), with GATA-3 as master regulator in this regard. Since transcription factors are intracellularly located they cannot be directly targeted by monoclonal antibodies. For intracellular targets, antisense technologies such as antisense DNA and siRNA have been shown to be a promising approach, and have recently made major advances toward clinical application. Here, we summarize the development of a GATA-3-specific DNAzyme-a molecule class that combines the superior specificity of antisense molecules with an inherent RNA-cleaving enzymatic activity-for the treatment of type-2-driven asthma from preclinical development toward a proof-of-concept clinical study.

Ovatodiolide suppresses allergic airway inflammation and hyperresponsiveness in a murine model of asthma

Asthma, a complex pulmonary allergic disease, major therapy is applied of drugs to control the disease, but quickly recur after the drugs are stopped. In patients with severe asthma may show steroid resistance and would benefit from the development of novel therapeutic drugs. Ovatodiolide, a unique macrocyclic diterpenoid isolated from Anisomeles indica, showed therapeutic potential for the treatment of allergic asthma. As a model of allergic inflammation, we used ovalbumin (OVA)-immunized mice, which displayed T helper cell type 2 (T_H2) cytokine expression in bronchoalveolar lavage fluid (BALF), as well as airway inflammation and hyperresponsiveness (AHR). The results showed that ovatodiolide suppressed T_H2 activation, including cell proliferation and production of the T_H2 related cytokines, interleukin (IL)-4, IL-5, IL-13, IL-33, eosinophil chemotactic protein (eotaxin), and also reduced airway hyperresponsiveness. In this study, ovatodiolide inhibited allergic asthma through downregulation of T_H2 responses in a murine model of asthma.

Long-term management of moderate-to-severe atopic dermatitis with dupilumab and concomitant topical corticosteroids (LIBERTY AD CHRONOS): a 1-year, randomised, double-blinded, placebo-controlled, phase 3 trial

BACKGROUND

Dupilumab (an anti-interleukin-4-receptor-α monoclonal antibody) blocks signalling of interleukin 4 and interleukin 13, type 2/Th2 cytokines implicated in numerous allergic diseases ranging from asthma to atopic dermatitis. Previous 16-week monotherapy studies showed that dupilumab substantially improved signs and symptoms of moderate-to-severe atopic dermatitis with acceptable safety, validating the crucial role of interleukin 4 and interleukin 13 in atopic dermatitis pathogenesis. We aimed to evaluate the long-term efficacy and safety of dupilumab with medium-potency topical corticosteroids versus placebo with topical corticosteroids in adults with moderate-to-severe atopic dermatitis.

METHODS

In this 1-year, randomised, double-blinded, placebo-controlled, phase 3 study (LIBERTY AD CHRONOS), adults with moderate-to-severe atopic dermatitis and inadequate response to topical corticosteroids were enrolled at 161 hospitals, clinics, and academic institutions in 14 countries in Europe, Asia-Pacific, and North America. Patients were randomly assigned (3:1:3) to subcutaneous dupilumab 300 mg once weekly (qw), dupilumab 300 mg every 2 weeks (q2w), or placebo via a central interactive voice/web response system, stratified by severity and global region. All three groups were given concomitant topical corticosteroids with or without topical calcineurin inhibitors where inadvisable for topical corticosteroids. Topical corticosteroids could be tapered, stopped, or restarted on the basis of disease activity. Coprimary endpoints were patients (%) achieving Investigator's Global Assessment (IGA) 0/1 and 2-point or higher improvement from baseline, and Eczema Area and Severity Index 75% improvement from baseline (EASI-75) at week 16. Week 16 efficacy and week 52 safety analyses included all randomised patients; week 52 efficacy included patients who completed treatment by US regulatory submission cutoff. This study is registered with ClinicalTrials.gov, NCT02260986.

FINDINGS

Between Oct 3, 2014, and July 31, 2015, 740 patients were enrolled: 319 were randomly assigned to dupilumab qw plus topical corticosteroids, 106 to dupilumab q2w plus topical corticosteroids, and 315 to placebo plus topical corticosteroids. 623 (270, 89, and 264, respectively) were evaluable for week 52 efficacy. At week 16, more patients who received dupilumab plus topical corticosteroids achieved the coprimary endpoints of IGA 0/1 (39% [125 patients] who received dupilumab plus topical corticosteroids qw and 39% [41 patients] who received dupilumab q2w plus topical corticosteroids vs 12% [39 patients] who received placebo plus topical corticosteroids; p<0·0001) and EASI-75 (64% [204] and 69% [73] vs 23% [73]; p<0·0001). Week 52 results were similar. Adverse events were reported in 261 (83%) patients who received dupilumab qw plus topical corticosteroids, 97 (88%) patients who received dupilumab q2w, and 266 (84%) patients who received placebo, and serious adverse events in nine (3%), four (4%), and 16 (5%) patients, respectively. No significant dupilumab-induced laboratory abnormalities were noted. Injection-site reactions and conjunctivitis were more common in patients treated with dupilumab plus topical corticosteroids-treated patients than in patients treated with placebo plus topical corticosteroids.

INTERPRETATION

Dupilumab added to standard topical corticosteroid treatment for 1 year improved atopic dermatitis signs and symptoms, with acceptable safety.

FUNDING

Sanofi and Regeneron Pharmaceuticals Inc.

Dupilumab Improves General Health-Related Quality-of-Life in Patients with Moderate-to-Severe Atopic Dermatitis: Pooled Results from Two Randomized, Controlled Phase 3 Clinical Trials

Introduction

Patients with moderate-to-severe atopic dermatitis (AD) report a multidimensional disease burden that includes impaired health-related quality-of-life (HRQoL). Changes in overall health status and specific dimensions that contribute to HRQoL were evaluated in adults with moderate-to-severe AD who participated in phase 3 clinical trials of dupilumab, which is a fully human monoclonal antibody that inhibits signaling of cytokines IL-4 and IL-13.

Methods

Two dupilumab phase 3 clinical trials of identical design included the 5-dimension 3-level EuroQol (EQ-5D) as a measure of HRQoL. EQ-5D data from the two trials were pooled in an analysis that, using analysis of covariance, compared subcutaneous dupilumab 300 mg once weekly (qw) or every 2 weeks (q2w) versus placebo for EQ-5D utility score change from baseline overall and for clinical responders. The proportions of patients who reported different levels of problems on the individual dimension of the EQ-5D were also compared by treatment group.

Results

Patients (n = 1379) were 57.9% male with a mean (SD) age of 38.3 (14.3) years; baseline EQ-5D utility scores ranged from 0.611 to 0.629 across treatment groups. EQ-5D least squares mean change from baseline at week 16 was 0.031 with placebo, and was significantly greater with dupilumab qw (0.207) and q2w (0.210) (both P < 0.0001), which exceeded the minimal clinically important difference and resulted in scores that approached population norms. Changes from baseline among patients who achieved AD clinical response were greater than changes among the total population. Improvements were driven by the individual EQ-5D dimensions with the greatest burden at baseline (i.e., pain/discomfort, anxiety/depression and usual activities).

Conclusion

In adults with moderate-to-severe AD, dupilumab resulted in improvements in HRQoL that were statistically significant relative to placebo and were clinically meaningful.

Funding

Sanofi and Regeneron Pharmaceuticals, Inc.

Trial registration

ClinicalTrials.gov identifiers, NCT02277743 and NCT02277769, EudraCT Numbers 2014-001198-15 and 2014-002619-40.

Clinical predictors of remission and persistence of adult-onset asthma

BACKGROUND

Adult-onset asthma is an important but relatively understudied asthma phenotype and little is known about its natural course and prognosis. The remission rate is believed to be low, and it is still obscure which factors predict remission or persistence of the disease.

OBJECTIVE

This study sought to determine the remission rate and identify predictors of persistence and remission of adult-onset asthma.

METHODS

Two hundred adult patients with recently diagnosed (<1 year) asthma were recruited from secondary and tertiary pulmonary clinics and prospectively followed for 5 years. Clinical, functional, and inflammatory parameters were assessed at baseline and at yearly visits. Asthma remission was defined as absence of asthma symptoms for ≥1 year and no asthma medication use for ≥1 year. Descriptive statistics and logistic regression analysis were performed.

RESULTS

Five-year follow-up data of 170 patients (85%) was available. Of these, 27 patients (15.9%) experienced asthma remission. Patients with asthma persistence were older, had worse asthma control, required higher doses of inhaled corticosteroids, had more severe airway hyperresponsiveness, more often nasal polyps, and higher levels of blood neutrophils as compared to patients who experienced clinical remission. In a multivariable logistic regression analysis, only moderate to severe bronchial hyperresponsiveness and nasal polyps were independent predictors of asthma persistence. Patients with these 2 characteristics had <1% chance of asthma remission.

CONCLUSIONS

One in 6 patients with adult-onset asthma experiences remission within the first 5 years of the disease. In patients with moderate to severe bronchial hyperresponsiveness and nasal polyposis, the chance of remission is close to zero.

Epigenetics and allergy: from basic mechanisms to clinical applications

Allergic diseases are on the rise in the Western world and well-known allergy-protecting and -driving factors such as microbial and dietary exposure, pollution and smoking mediate their influence through alterations of the epigenetic landscape. Here, we review key facts on the involvement of epigenetic modifications in allergic diseases and summarize and critically evaluate the lessons learned from epigenome-wide association studies. We show the potential of epigenetic changes for various clinical applications: as diagnostic tools, to assess tolerance following immunotherapy or possibly predict the success of therapy at an early time point. Furthermore, new technological advances such as epigenome editing and DNAzymes will allow targeted alterations of the epigenome in the future and provide novel therapeutic tools.

Commonality of the IL-4/IL-13 pathway in atopic diseases

INTRODUCTION

Allergy results from an aberrant Type 2 inflammatory response, triggered by a wide range of environmental antigens (allergens) that lead to various immune responses, culminating in the production of immunoglobulin E (IgE). Two key cytokines, interleukin (IL)-4 and IL-13, are critical to the induction and perpetuation of the Type 2 response, and have been implicated in multiple atopic diseases. Area covered: This review summarizes recent milestone developments that have elucidated components of the pathogenesis of atopic diseases such as atopic dermatitis (AD), asthma, and chronic sinusitis with nasal polyposis (CSwNP). Expert commentary: Several therapeutic agents that selectively target potentiators of the Type 2 pathway have shown efficacy in one or more of these atopic diseases, but few agents have proven to be broadly applicable across all three atopic diseases. Dupilumab, a human monoclonal antibody that simultaneously inhibits signaling of IL-4 and IL-13, has demonstrated significant clinical efficacy in AD, asthma, and CSwNP. The fact that these diseases often occur as comorbidities and respond to the same therapy suggests that there is a common underlying pathogenic pathway, and that IL-4 and IL-13 cytokines are central to regulating the pathogenesis of these atopic diseases.

Galectin-3: an early predictive biomarker of modulation of airway remodeling in patients with severe asthma treated with omalizumab for 36 months

Background

Bronchial asthma is a heterogeneous disease characterized by three cardinal features: chronic inflammation, variable airflow obstruction, and airway hyperresponsiveness. Asthma has traditionally been defined using nonspecific clinical and physiologic variables that encompass multiple phenotypes and are treated with nonspecific anti-inflammatory therapies. Based on the modulation of airway remodeling after 12 months of anti-immunoglobulin E (IgE) treatment, we identified two phenotypes (omalizumab responder, OR; and non-omalizumab responder, NOR) and performed morphometric analysis of bronchial biopsy specimens. We also found that these two phenotypes were correlated with the presence/absence of galectin-3 (Gal-3) at baseline (i.e., before treatment). The aims of the present study were to investigate the histological and molecular effects of long-term treatment (36 months) with anti-IgE and to analyze the behavior of OR and NOR patients.

Methods

All patients were treated with the monoclonal antibody anti-IgE omalizumab for 36 months. The bronchial biopsy specimens were evaluated using morphometric, eosinophilic, and proteomic analysis (MudPIT). New data were compared with previous data, and unsupervised cluster analysis of protein profiles was performed.

Results

After 36 months of treatment with omalizumab, reduction of reticular basement membrane (RBM) thickness was confirmed in OR patients (Gal-3-positive at baseline); similarly, the protein profiles (over 500 proteins identified) revealed that, in the OR group, levels of proteins specifically related to fibrosis and inflammation (e.g., smooth muscle and extracellular matrix proteins (including periostin), Gal-3, and keratins decreased by between 5- and 50-fold. Eosinophil levels were consistent with molecular data and decreased by about tenfold less in ORs and increased by twofold to tenfold more in NORs. This tendency was confirmed (p < 0.05) based on both fold change and DAVE algorithms, thus indicating a clear response to anti-IgE treatment in Gal-3-positive patients.

Conclusions

Our results showed that omalizumab can be considered a disease-modifying treatment in OR. The proteomic signatures confirmed the presence of Gal-3 at baseline to be a biomarker of long-term reduction in bronchial RBM thickness, eosinophilic inflammation, and muscular and fibrotic components in omalizumab-treated patients with severe asthma. Our findings suggest a possible relationship between Gal-3 positivity and improved pulmonary function.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-017-0143-1) contains supplementary material, which is available to authorized users.