Lisa A. Beck

Dupilumab Treatment in Adults with Moderate-to-Severe Atopic Dermatitis

BACKGROUND Dupilumab, a fully human monoclonal antibody that blocks interleukin-4 and interleukin-13, has shown efficacy in patients with asthma and elevated eosinophil levels. The blockade by dupilumab of these key drivers of type 2 helper T-cell (Th2)-mediated inflammation could help in the treatment of related diseases, including atopic dermatitis. METHODS We performed randomized, double-blind, placebo-controlled trials involving adults who had moderate-to-severe atopic dermatitis despite treatment with topical glucocorticoids and calcineurin inhibitors. Dupilumab was evaluated as monotherapy in two 4-week trials and in one 12-week trial and in combination with topical glucocorticoids in another 4-week study. End points included the Eczema Area and Severity Index (EASI) score, the investigators global assessment score, pruritus, safety assessments, serum biomarker levels, and disease transcriptome. RESULTS In the 4-week monotherapy studies, dupilumab resulted in rapid and dose-dependent improvements in clinical indexes, biomarker levels, and the transcriptome. The results of the 12-week study of dupilumab monotherapy reproduced and extended the 4-week findings: 85% of patients in the dupilumab group, as compared with 35% of those in the placebo group, had a 50% reduction in the EASI score (EASI-50, with higher scores in the EASI indicating greater severity of eczema) (P<0.001); 40% of patients in the dupilumab group, as compared with 7% in the placebo group, had a score of 0 to 1 (indicating clearing or near-clearing of skin lesions) on the investigators global assessment (P<0.001); and pruritus scores decreased (indicating a reduction in itch) by 55.7% in the dupilumab group versus 15.1% in the placebo group (P<0.001). In the combination study, 100% of the patients in the dupilumab group, as compared with 50% of those who received topical glucocorticoids with placebo injection, met the criterion for EASI-50 (P=0.002), despite the fact that patients who received dupilumab plus glucocorticoids used less than half the amount of topical glucocorticoids used by those who received placebo plus the topical medication (P=0.16). Adverse events, such as skin infection, occurred more frequently with placebo; nasopharyngitis and headache were the most frequent adverse events with dupilumab. CONCLUSIONS Patients treated with dupilumab had marked and rapid improvement in all the evaluated measures of atopic dermatitis disease activity. Side-effect profiles were not dose-limiting. (Funded by Regeneron Pharmaceuticals and Sanofi; ClinicalTrials.gov numbers, NCT01259323, NCT01385657, NCT01639040, and NCT01548404.).

Tight junction defects in patients with atopic dermatitis.

BACKGROUND Atopic dermatitis (AD) is characterized by dry skin and a hyperactive immune response to allergens, 2 cardinal features that are caused in part by epidermal barrier defects. Tight junctions (TJs) reside immediately below the stratum corneum and regulate the selective permeability of the paracellular pathway. OBJECTIVE We evaluated the expression/function of the TJ protein claudin-1 in epithelium from AD and nonatopic subjects and screened 2 American populations for single nucleotide polymorphisms in the claudin-1 gene (CLDN1). METHODS Expression profiles of nonlesional epithelium from patients with extrinsic AD, nonatopic subjects, and patients with psoriasis were generated using Illuminas BeadChips. Dysregulated intercellular proteins were validated by means of tissue staining and quantitative PCR. Bioelectric properties of epithelium were measured in Ussing chambers. Functional relevance of claudin-1 was assessed by using a knockdown approach in primary human keratinocytes. Twenty-seven haplotype-tagging SNPs in CLDN1 were screened in 2 independent populations with AD. RESULTS We observed strikingly reduced expression of the TJ proteins claudin-1 and claudin-23 only in patients with AD, which were validated at the mRNA and protein levels. Claudin-1 expression inversely correlated with T(H)2 biomarkers. We observed a remarkable impairment of the bioelectric barrier function in AD epidermis. In vitro we confirmed that silencing claudin-1 expression in human keratinocytes diminishes TJ function while enhancing keratinocyte proliferation. Finally, CLDN1 haplotype-tagging SNPs revealed associations with AD in 2 North American populations. CONCLUSION Collectively, these data suggest that an impairment in tight junctions contributes to the barrier dysfunction and immune dysregulation observed in AD subjects and that this may be mediated in part by reductions in claudin-1.

Efficacy and safety of dupilumab in adults with moderate-to-severe atopic dermatitis inadequately controlled by topical treatments: a randomised, placebo-controlled, dose-ranging phase 2b trial

BACKGROUND Data from early-stage studies suggested that interleukin (IL)-4 and IL-13 are requisite drivers of atopic dermatitis, evidenced by marked improvement after treatment with dupilumab, a fully-human monoclonal antibody that blocks both pathways. We aimed to assess the efficacy and safety of several dose regimens of dupilumab in adults with moderate-to-severe atopic dermatitis inadequately controlled by topical treatments. METHODS In this randomised, placebo-controlled, double-blind study, we enrolled patients aged 18 years or older who had an Eczema Area and Severity Index (EASI) score of 12 or higher at screening (≥16 at baseline) and inadequate response to topical treatments from 91 study centres, including hospitals, clinics, and academic institutions, in Canada, Czech Republic, Germany, Hungary, Japan, Poland, and the USA. Patients were randomly assigned (1:1:1:1:1:1), stratified by severity (moderate or severe, as assessed by Investigators Global Assessment) and region (Japan vs rest of world) to receive subcutaneous dupilumab: 300 mg once a week, 300 mg every 2 weeks, 200 mg every 2 weeks, 300 mg every 4 weeks, 100 mg every 4 weeks, or placebo once a week for 16 weeks. We used a central randomisation scheme, provided by an interactive voice response system. Drug kits were coded, providing masking to treatment assignment, and allocation was concealed. Patients on treatment every 2 weeks and every 4 weeks received volume-matched placebo every week when dupilumab was not given to ensure double blinding. The primary outcome was efficacy of dupilumab dose regimens based on EASI score least-squares mean percentage change (SE) from baseline to week 16. Analyses included all randomly assigned patients who received one or more doses of study drug. This trial is registered with ClinicalTrials.gov, number NCT01859988. FINDINGS Between May 15, 2013, and Jan 27, 2014, 452 patients were assessed for eligibility, and 380 patients were randomly assigned. 379 patients received one or more doses of study drug (300 mg once a week [n=63], 300 mg every 2 weeks [n=64], 200 mg every 2 weeks [n=61], 300 mg every 4 weeks [n=65], 100 mg every 4 weeks [n=65]; placebo [n=61]). EASI score improvements favoured all dupilumab regimens versus placebo (p<0·0001): 300 mg once a week (-74% [SE 5·16]), 300 mg every 2 weeks (-68% [5·12]), 200 mg every 2 weeks (-65% [5·19]), 300 mg every 4 weeks (-64% [4·94]), 100 mg every 4 weeks (-45% [4·99]); placebo (-18% [5·20]). 258 (81%) of 318 patients given dupilumab and 49 (80%) of 61 patients given placebo reported treatment-emergent adverse events; nasopharyngitis was the most frequent (28% and 26%, respectively). INTERPRETATION Dupilumab improved clinical responses in adults with moderate-to-severe atopic dermatitis in a dose-dependent manner, without significant safety concerns. Our findings show that IL-4 and IL-13 are key drivers of atopic dermatitis. FUNDING Sanofi and Regeneron Pharmaceuticals.

Skin Barrier Disruption: A Requirement for Allergen Sensitization?

For at least half a century, noninvasive techniques have been available to quantify skin barrier function, and these have shown that a number of human skin conditions and disorders are associated with defects in skin permeability. In the last decade, several genes responsible for skin barrier defects observed in both monogenetic and complex, polygenic disorders have been elucidated and functionally characterized. This has led to an explosion of work in the last six years that has identified pathways connecting epidermal barrier disruption and antigen uptake as well as the quality and/or magnitude of the antigen-specific adaptive immune response. This review will introduce the notion that diseases arise from the dynamic crosstalk that occurs between the skin barrier and immune system using atopic dermatitis or eczema as the disease prototype. Nevertheless, the concepts put forth are highly relevant to a number of antigen-driven disorders for which skin barrier is at least transiently compromised such as psoriasis, allergic contact dermatitis and blistering disorders.

Chemokines and allergic disease

Understanding the chemokine network has become one of the great challenges for researchers interested in inflammatory mechanisms and inflammation-based diseases. The complexity and diversity of the system provide not only a daunting task for its comprehension but also numerous opportunities for development of new, targeted therapies. It is now certain that chemokines are involved as important mediators of allergic inflammation; the fine details and scope of their roles are now under investigation. Presumably, because of distinct pressures on the immune systems of people living in different geographic regions, genetic variation of ligands, receptors, and regulatory regions in the network have emerged. Establishing the roles of these polymorphisms in determining disease susceptibility or progression among individuals and in distinct ethnic groups will provide a basis for improved understanding and treatment of allergic diseases.

Filaggrin mutations that confer risk of atopic dermatitis confer greater risk for eczema herpeticum.

BACKGROUND Loss-of-function null mutations R501X and 2282del4 in the skin barrier gene, filaggrin (FLG), represent the most replicated genetic risk factors for atopic dermatitis (AD). Associations have not been reported in African ancestry populations. Atopic dermatitis eczema herpeticum (ADEH) is a rare but serious complication of AD resulting from disseminated cutaneous herpes simplex virus infections. OBJECTIVE We aimed to determine whether FLG polymorphisms contribute to ADEH susceptibility. METHODS Two common loss-of-function mutations plus 9 FLG single nucleotide polymorphisms were genotyped in 278 European American patients with AD, of whom 112 had ADEH, and 157 nonatopic controls. Replication was performed on 339 African American subjects. RESULTS Significant associations were observed for both the R501X and 2282del4 mutations and AD among European American subjects (P = 1.46 x 10(-5), 3.87 x 10(-5), respectively), but the frequency of the R501X mutation was 3 times higher (25% vs 9%) for ADEH than for AD without eczema herpeticum (EH) (odds ratio [OR], 3.4; 1.7-6.8; P = .0002). Associations with ADEH were stronger with the combined null mutations (OR, 10.1; 4.7-22.1; P = 1.99 x 10(-11)). Associations with the R501X mutation were replicated in the African American population; the null mutation was absent among healthy African American subjects, but present among patients with AD (3.2%; P = .035) and common among patients with ADEH (9.4%; P = .0049). However, the 2282del4 mutation was absent among African American patients with ADEH and rare (<1%) among healthy individuals. CONCLUSION The R501X mutation in the gene encoding filaggrin, one of the strongest genetic predictors of AD, confers an even greater risk for ADEH in both European and African ancestry populations, suggesting a role for defective skin barrier in this devastating condition.

Glucocorticosteroid inhibition of cytokine production : relevance to antiallergic actions

We believe that there are the following four classes of glucocorticoid-sensitive cytokines that are involved in cell recruitment: (1) those that activate endothelium nonspecifically; (2) those that activate endothelium specifically; (3) those that activate, prime, and prolong the survival of eosinophils; and (4) those that stimulate movement of cells up into the epithelium. Glucocorticoids inhibit the generation of these cytokines and thereby prevent several different aspects of inflammation, including the activation and recruitment of inflammatory cells (eosinophils, basophils, and lymphocytes) and the release of inflammatory mediators. We believe such pleiotropic actions account for the efficacy and widespread use of glucocorticoids in the treatment of asthma.

Phenotype of Atopic Dermatitis Subjects with a History of Eczema Herpeticum

BACKGROUND A subset of subjects with atopic dermatitis (AD) are susceptible to serious infections with herpes simplex virus, called eczema herpeticum, or vaccina virus, called eczema vaccinatum. OBJECTIVE This National Institute of Allergy and Infectious Diseases-funded multicenter study was performed to establish a database of clinical information and biologic samples on subjects with AD with and without a history of eczema herpeticum (ADEH(+) and ADEH(-) subjects, respectively) and healthy control subjects. Careful phenotyping of AD subsets might suggest mechanisms responsible for disseminated viral infections and help identify at-risk individuals. METHODS We analyzed the data from 901 subjects (ADEH(+) subjects, n = 134; ADEH(-) subjects, n = 419; healthy control subjects, n = 348) enrolled between May 11, 2006, and September 16, 2008, at 7 US medical centers. RESULTS ADEH(+) subjects had more severe disease based on scoring systems (Eczema Area and Severity Index and Rajka-Langeland score), body surface area affected, and biomarkers (circulating eosinophil counts and serum IgE, thymus and activation-regulated chemokine, and cutaneous T cell-attracting chemokine) than ADEH(-) subjects (P < .001). ADEH(+) subjects were also more likely to have a history of food allergy (69% vs 40%, P < .001) or asthma (64% vs 44%, P < .001) and were more commonly sensitized to many common allergens (P < .001). Cutaneous infections with Staphylococcus aureus or molluscum contagiosum virus were more common in ADEH(+) subjects (78% and 8%, respectively) than in ADEH(-) subjects (29% and 2%, respectively; P < .001). CONCLUSION Subjects with AD in whom eczema herpeticum develops have more severe T(H)2-polarized disease with greater allergen sensitization and more commonly have a history of food allergy, asthma, or both. They are also much more likely to experience cutaneous infections with S. aureus or molluscum contagiosum.

Cutting edge: Expression of the C-C chemokine receptor CCR3 in human airway epithelial cells

Chemokine-induced eosinophil chemotaxis is mediated primarily through the C-C chemokine receptor, CCR3. We have now detected CCR3 immunoreactivity on epithelial cells in biopsies of patients with asthma and other respiratory diseases. CCR3 mRNA was detected by Northern blot analysis after TNF-α stimulation of the human primary bronchial epithelial cells as well as the epithelial cell line, BEAS-2B; IFN-γ potentiated the TNF-α-induced expression. Western blots and flow cytometry confirmed the expression of CCR3 protein. This receptor is functional based on studies demonstrating eotaxin-induced intracellular Ca2+ flux and tyrosine phosphorylation of cellular proteins. The specificity of this functional response was confirmed by blocking these signaling events with anti-CCR3 mAb (7B11) or pertussis toxin. Furthermore, 125I-eotaxin binding assay confirmed that CCR3 expressed on epithelial cells have the expected ligand specificity. These studies indicate that airway epithelial cells express CCR3 and suggest that CCR3 ligands may influence epithelial cell functions.

Detection of the chemokine RANTES and endothelial adhesion molecules in nasal polyps

BACKGROUND To better understand the mechanisms of eosinophil recruitment into the upper airways, we examined human nasal polyps for the expression of the chemotactic cytokine RANTES and the endothelial adhesion molecules E-selectin and vascular cell adhesion molecule-1 (VCAM-1). METHODS Routine histologic examination and immunostaining with antibodies to RANTES, E-selectin, and VCAM-1 were performed on three types of tissues: nasal polyps, sinus mucosa, or turbinates from patients undergoing other elective procedures (S/T), and nasal biopsy specimens from nonallergic volunteers (NA). To further quantify the expression of endothelial adhesion molecules, some tissue samples were homogenized, and the resulting supernatants were assayed with sandwich ELISAs for VCAM-1 and E-selectin. RESULTS Polyp eosinophil counts ranged from 19/mm2 to 1818/mm2 (763 +/- 120/mm2, mean +/- SEM) and were significantly higher than those found in the control tissues (5 +/- 2 in S/T samples and 20 +/- 9 in NA samples, p < 0.002). Immunochemical staining for RANTES was observed in 11 of 14 polyps; intense staining for RANTES (grade 3) was observed in six of 14 polyps. None of nine S/T samples or five NA samples demonstrated grade 3 staining. Staining with anti-RANTES was largely localized to airway and glandular epithelium. There was no significant correlation between counts of eosinophils or the combined total of eosinophils plus mononuclear cells and the intensity of epithelial RANTES staining in all nasal tissues. Staining for VCAM-1, as well as for E-selectin, was detected in 11 of 14 polyps and eight of 13 control tissues. VCAM-1 detected by ELISA in polyp tissues (6.8 +/- 1.3 micrograms/gm) was higher than that found in six S/T samples (1.2 +/- 0.3 micrograms/gm, p < 0.005) and in two NA samples (1.8 +/- 0.02 micrograms/gm, p = 0.08). E-selectin values in polyps (1.4 +/- 0.3 micrograms/gm) were not statistically different from those detected in six S/T samples (0.5 +/- 0.2 microgram/gm) or two NA samples (1.6 +/- 0.4 microgram/gm). Counts of eosinophils and eosinophils plus mononuclear cells displayed a strong correlation with VCAM-1 ELISA values (p < 0.005 and p < 0.004, respectively) but not with VCAM-1 staining. VCAM-1 staining correlated with EG2-positive eosinophils in nasal polyp tissues (p < 0.01). E-selectin staining did not correlate with either neutrophil or eosinophil counts. CONCLUSIONS These studies demonstrate that the chemokine RANTES is produced in vivo predominantly to nasal epithelium. Endothelial activation, as indicated by adhesion molecule expression, occurs in human nasal polyp tissues and in control tissues, possibly reflecting the continued antigen exposure of the nasal mucosa. The correlations found in this study suggest that expression of VCAM-1 plays a role in the selective recruitment of eosinophils and mononuclear cells into nasal polyp tissues and that RANTES may be more important in localizing eosinophils to the epithelium.