As an interface with the environment, the skin is a complex ecosystem colonized by many microorganisms that coexist in an established balance. The cutaneous microbiome inhibits colonization with ...pathogens, such as Staphylococcus aureus, and is a crucial component for function of the epidermal barrier. Moreover, crosstalk between commensals and the immune system is now recognized because microorganisms can modulate both innate and adaptive immune responses. Host-commensal interactions also have an effect on the developing immune system in infants and, subsequently, the occurrence of diseases, such as asthma and atopic dermatitis (AD). Later in life, the cutaneous microbiome contributes to the development and course of skin disease. Accordingly, in patients with AD, a decrease in microbiome diversity correlates with disease severity and increased colonization with pathogenic bacteria, such as S aureus. Early clinical studies suggest that topical application of commensal organisms (eg, Staphylococcus hominis or Roseomonas mucosa) reduces AD severity, which supports an important role for commensals in decreasing S aureus colonization in patients with AD. Advancing knowledge of the cutaneous microbiome and its function in modulating the course of skin disorders, such as AD, might result in novel therapeutic strategies.
Interleukin 13 (IL-13) is a central pathogenic mediator driving multiple features of atopic dermatitis (AD) pathophysiology.
To evaluate the efficacy and safety of lebrikizumab, a novel, ...high-affinity, monoclonal antibody targeting IL-13 that selectively prevents formation of the IL-13Rα1/IL-4Rα heterodimer receptor signaling complex, in adults with moderate to severe AD.
A phase 2b, double-blind, placebo-controlled, dose-ranging randomized clinical trial of lebrikizumab injections every 4 weeks or every 2 weeks was conducted from January 23, 2018, to May 23, 2019, at 57 US centers. Participants were adults 18 years or older with moderate to severe AD.
Patients were randomized 2:3:3:3 to placebo every 2 weeks or to subcutaneous injections of lebrikizumab at the following doses: 125 mg every 4 weeks (250-mg loading dose LD), 250 mg every 4 weeks (500-mg LD), or 250 mg every 2 weeks (500-mg LD at baseline and week 2).
The primary end point was percentage change in the Eczema Area and Severity Index (EASI) (baseline to week 16). Secondary end points for week 16 included proportion of patients achieving Investigator's Global Assessment score of 0 or 1 (IGA 0/1); EASI improvement of at least 50%, 75%, or 90% from baseline; percentage change in the pruritus numeric rating scale (NRS) score; and pruritus NRS score improvement of at least 4 points. Safety assessments included treatment-emergent adverse events.
A total of 280 patients (mean SD age, 39.3 17.5 years; 166 59.3% female) were randomized to placebo (n = 52) or to lebrikizumab at doses of 125 mg every 4 weeks (n = 73), 250 mg every 4 weeks (n = 80), or 250 mg every 2 weeks (n = 75). Compared with placebo (EASI least squares mean SD percentage change, -41.1% 56.5%), lebrikizumab groups showed dose-dependent, statistically significant improvement in the primary end point vs placebo at week 16: 125 mg every 4 weeks (-62.3% 37.3%, P = .02), 250 mg every 4 weeks (-69.2% 38.3%, P = .002), and 250 mg every 2 weeks (-72.1% 37.2%, P < .001). Differences vs placebo-treated patients (2 of 44 4.5%) in pruritus NRS improvement of at least 4 points were seen as early as day 2 in the high-dose lebrikizumab group (9 of 59 15.3%). Treatment-emergent adverse events were reported in 24 of 52 placebo patients (46.2%) and in lebrikizumab patients as follows: 42 of 73 (57.5%) for 125 mg every 4 weeks, 39 of 80 (48.8%) for 250 mg every 4 weeks, and 46 of 75 (61.3%) for 250 mg every 2 weeks; most were mild to moderate and did not lead to discontinuation. Low rates of injection-site reactions (1 of 52 1.9% in the placebo group vs 13 of 228 5.7% in all lebrikizumab groups), herpesvirus infections (2 3.8% vs 8 3.5%), and conjunctivitis (0% vs 6 2.6%) were reported.
During 16 weeks of treatment, lebrikizumab provided rapid, dose-dependent efficacy across a broad range of clinical manifestations in adult patients with moderate to severe AD and demonstrated a favorable safety profile. These data support the central role of IL-13 in AD pathophysiology. If these findings replicate in phase 3 studies, lebrikizumab may meaningfully advance the standard of care for moderate to severe AD.
ClinicalTrials.gov Identifier: NCT03443024.
Provide a review of atopic dermatitis management, focusing on optimizing topical therapy, creating a stepwise approach for treatment plans, and providing guidance on when to start systemic therapy.
...PubMed search of articles in the English language regarding atopic dermatitis in all ages.
Articles on the subject matter were selected and reviewed.
Topical corticosteroids are the first-line treatment for managing atopic dermatitis. Topical nonsteroidal agents, calcineurin inhibitors, crisaborole, and recently, ruxolitinib, which cause no cutaneous atrophy, are options for reducing the use of topical corticosteroids, including on sensitive sites. Emerging topical agents are in clinical trials. Proactive management, with continued application 2 to 3 times weekly of a midpotency topical corticosteroid or tacrolimus, may maintain control for clear (or almost clear) localized sites of dermatitis that rapidly recur when topical anti-inflammatory medication is stopped. If topical therapy alone cannot control disease and quality of life is impacted, reevaluation to confirm the diagnosis, manage comorbid conditions, address compliance and patient-specific concerns, and optimize topical therapy must be undertaken before deciding to advance to systemic medication. Dupilumab, an interleukin-4 receptor inhibitor, has become first-line systemic therapy given its efficacy and safety, allowing long-term treatment without laboratory monitoring. Other biologics and Janus kinase inhibitors are emerging as alternatives that could eliminate the need for immunosuppressants with their higher risks.
Several options are now available for topical treatment. A stepwise approach is needed to consider alternative therapies and diagnoses before advancing to systemic treatment, but the safety of newer immunomodulators will lower the threshold for more aggressive intervention.
Although atopic dermatitis (AD) often starts in early childhood, detailed tissue profiling of early-onset AD in children is lacking, hindering therapeutic development for this patient population with ...a particularly high unmet need for better treatments.
We sought to globally profile the skin of infants with AD compared with that of adults with AD and healthy control subjects.
We performed microarray, RT-PCR, and fluorescence microscopy studies in infants and young children (<5 years old) with early-onset AD (<6 months disease duration) compared with age-matched control subjects and adults with longstanding AD.
Transcriptomic analyses revealed profound differences between pediatric patients with early-onset versus adult patients with longstanding AD in not only lesional but also nonlesional tissues. Although both patient populations harbored TH2-centered inflammation, pediatric AD also showed significant TH17/TH22 skewing but lacked the TH1 upregulation that characterizes adult AD. Pediatric AD exhibited relatively normal expression of epidermal differentiation and cornification products, which is downregulated in adults with AD. Defects in the lipid barrier (eg, ELOVL fatty acid elongase 3 ELOVL3 and diacylglycerol o-acyltransferase 2 DGAT2) and tight junction regulation (eg, claudins 8 and 23) were evident in both groups. However, some lipid-associated mediators (eg, fatty acyl-CoA reductase 2 and fatty acid 2-hydroxylase) showed preferential downregulation in pediatric AD, and lipid barrier genes (FA2H and DGAT2) showed inverse correlations with transepidermal water loss, a functional measure of the epidermal barrier.
Skin samples from children and adult patients with AD share lipid metabolism and tight junction alterations, but epidermal differentiation complex defects are only present in adult AD, potentially resulting from chronic immune aberration that is not yet present in early-onset disease.
Topical application of nucleic acids offers many potential therapeutic advantages for suppressing genes in the skin, and potentially for systemic gene delivery. However, the epidermal barrier ...typically precludes entry of gene-suppressing therapy unless the barrier is disrupted. We now show that spherical nucleic acid nanoparticle conjugates (SNA-NCs), gold cores surrounded by a dense shell of highly oriented, covalently immobilized siRNA, freely penetrate almost 100% of keratinocytes in vitro, mouse skin, and human epidermis within hours after application. Significantly, these structures can be delivered in a commercial moisturizer or phosphate-buffered saline, and do not require barrier disruption or transfection agents, such as liposomes, peptides, or viruses. SNA-NCs targeting epidermal growth factor receptor (EGFR), an important gene for epidermal homeostasis, are > 100-fold more potent and suppress longer than siRNA delivered with commercial lipid agents in cultured keratinocytes. Topical delivery of 1.5 uM EGFR siRNA (50 nM SNA-NCs) for 3 wk to hairless mouse skin almost completely abolishes EGFR expression, suppresses downstream ERK phosphorylation, and reduces epidermal thickness by almost 40%. Similarly, EGFR mRNA in human skin equivalents is reduced by 52% after 60 h of treatment with 25 nM EGFR SNA-NCs. Treated skin shows no clinical or histological evidence of toxicity. No cytokine activation in mouse blood or tissue samples is observed, and after 3 wk of topical skin treatment, the SNA structures are virtually undetectable in internal organs. SNA conjugates may be promising agents for personalized, topically delivered gene therapy of cutaneous tumors, skin inflammation, and dominant negative genetic skin disorders.
Significance Diabetic patients often suffer from impaired wound healing, which can develop into nonhealing diabetic ulcers, facilitate bacterial infections, and necessitate amputation. Current ...strategies for treatment have failed to achieve the anticipated efficacy and do not address the fundamental molecular abnormalities that prevent efficient wound closure. In this work, we introduce a previously unidentified approach to treating diabetic wound healing by using topically delivered spherical nucleic acids to effect the knockdown of ganglioside-monosialic acid 3 (GM3) synthase, a mediator of impaired wound healing, in type 2 diabetic mice. In addition to laying the groundwork for developing a therapy for a debilitating condition, this work also validates the critical role of GM3 in diabetic wound healing.
Spherical nucleic acid (SNA) gold nanoparticle conjugates (13-nm-diameter gold cores functionalized with densely packed and highly oriented nucleic acids) dispersed in Aquaphor have been shown to penetrate the epidermal barrier of both intact mouse and human skin, enter keratinocytes, and efficiently down-regulate gene targets. ganglioside-monosialic acid 3 synthase (GM3S) is a known target that is overexpressed in diabetic mice and responsible for causing insulin resistance and impeding wound healing. GM3S SNAs increase keratinocyte migration and proliferation as well as insulin and insulin-like growth factor-1 (IGF1) receptor activation under both normo- and hyperglycemic conditions. The topical application of GM3S SNAs (50 nM) to splinted 6-mm-diameter full-thickness wounds in diet-induced obese diabetic mice decreases local GM3S expression by >80% at the wound edge through an siRNA pathway and fully heals wounds clinically and histologically within 12 d, whereas control-treated wounds are only 50% closed. Granulation tissue area, vascularity, and IGF1 and EGF receptor phosphorylation are increased in GM3S SNA-treated wounds. These data capitalize on the unique ability of SNAs to naturally penetrate the skin and enter keratinocytes without the need for transfection agents. Moreover, the data further validate GM3 as a mediator of the delayed wound healing in type 2 diabetes and support regional GM3 depletion as a promising therapeutic direction.
Atopic dermatitis (AD) affects 15% to 25% of children and 4% to 7% of adults. Paradigm-shifting discoveries about AD have been based on adult biomarkers, reflecting decades of disease activity, ...although 85% of cases begin by 5 years. Blood phenotyping shows only TH2 skewing in patients with early-onset pediatric AD, but alterations in early pediatric skin lesions are unknown, limiting advancement of targeted therapies.
We sought to characterize the early pediatric AD skin phenotype and its differences from pediatric control subjects and adults with AD.
Using immunohistochemistry and quantitative real-time PCR, we assessed biopsy specimens from 19 children with AD younger than 5 years within 6 months of disease onset in comparison with adults with AD or psoriasis and pediatric and adult control subjects.
In lesional skin children showed comparable or greater epidermal hyperplasia (thickness and keratin 16) and cellular infiltration (CD3+, CD11c+, and FcεRI+) than adults with AD. Similar to adults, strong activation of the TH2 (IL-13, IL-31, and CCL17) and TH22 (IL-22 and S100As) axes and some TH1 skewing (IFN-γ and CXCL10) were present. Children showed significantly higher induction of TH17-related cytokines and antimicrobials (IL-17A, IL-19, CCL20, LL37, and peptidase inhibitor 3/elafin), TH9/IL-9, IL-33, and innate markers (IL-8) than adults (P < .02). Despite the characteristic downregulation in adult patients with AD, filaggrin expression was similar in children with AD and healthy children. Nonlesional skin in pediatric patients with AD showed higher levels of inflammation (particularly IL-17A and the related molecules IL-19 and LL37) and epidermal proliferation (keratin 16 and S100As) markers (P < .001).
The skin phenotype of new-onset pediatric AD is substantially different from that of adult AD. Although excess TH2 activation characterizes both, TH9 and TH17 are highly activated at disease initiation. Increases in IL-19 levels might link TH2 and TH17 activation.
An Investigator Global Assessment (IGA) is recommended by health agencies for drug registration in atopic dermatitis (AD). Current IGA scales lack standardization.
To develop an IGA scale, training ...module, and clinical certification examination for use in AD trials; establish content validity; and assess reliability.
Expert dermatologists participated in the development of the validated IGA for AD (vIGA-ADTM). Reliability (interrater and intrarater) was assessed by 2 web-based surveys. Clinical certification for investigators consisted of a training module and examination.
Expert consensus was achieved around a 5-point IGA scale including morphologic descriptions, and content validity was established. Survey 1 showed strong interrater reliability (Kendall's coefficient of concordance W Kendall's W, 0.809; intraclass correlation ICC, 0.817) and excellent agreement (weighted kappa, 0.857). Survey 2, completed 5 months after training of dermatologists, showed improvements in scale reliability (Kendall's W, 0.819; ICC, 0.852; weighted kappa, 0.889). In this study, 627 investigators completed vIGA-AD training and certification.
Ratings were assessed on photographs.
A validated IGA scale and training module were developed with the intent of harmonizing assessment of disease severity in AD trials. Strong reliability and excellent agreement between assessments were observed.
Tapinarof is a topical therapeutic aryl hydrocarbon receptor modulating agent under investigation for atopic dermatitis (AD) and psoriasis treatment.
A phase 2b, double-blind, vehicle-controlled ...study randomly assigned adolescents and adults with AD to receive tapinarof cream 0.5%, 1%, or vehicle, once or twice daily, for 12 weeks with a 4-week follow-up. Outcomes included Investigator Global Assessment (IGA), Eczema Area and Severity Index (EASI), body surface area affected, pruritus numeric rating scale scores, patients' impressions of AD and pruritus symptom severity, and Patient-Oriented Eczema Measure (POEM) scores.
Overall, 191 of 247 randomized patients completed the study. Week 12 IGA responses were higher in the tapinarof groups versus the vehicle group, reaching statistical significance with tapinarof 1% twice daily, ≥75%/90% improvement in EASI from baseline were significantly higher in the tapinarof groups (except 0.5% once daily and 0.5% twice daily), EASI scores were significantly improved in all tapinarof groups, and body surface area affected was significantly reduced in the tapinarof groups (except 0.5% twice daily). More patients reported AD and pruritus symptom severity as very/moderately improved in tapinarof groups, and POEM improvements were observed in all groups. Most adverse events were mild or moderate.
Larger prospective studies are required to confirm the reported analyses.
Tapinarof is a potential important advance in topical medicine development for AD.
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