OPA-15406, a novel, topical, nonsteroidal, selective phosphodiesterase-4 (PDE4) inhibitor, in the treatment of adult and adolescent patients with mild to moderate atopic dermatitis (AD): A phase-II randomized, double-blind, placebo-controlled study

Topical anti-inflammatory treatments for eczema: network meta-analysis

BACKGROUND

Eczema (atopic dermatitis) is the most burdensome skin condition worldwide and cannot currently be prevented or cured. Topical anti-inflammatory treatments are used to control eczema symptoms, but there is uncertainty about the relative effectiveness and safety of different topical anti-inflammatory treatments.

OBJECTIVES

To compare and rank the efficacy and safety of topical anti-inflammatory treatments for people with eczema using a network meta-analysis.

SEARCH METHODS

We searched the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase and trial registries on 29 June 2023, and checked the reference lists of included studies.

SELECTION CRITERIA

We included within-participant or between-participant randomised controlled trials (RCTs) in people of any age with eczema of any severity, but excluded trials in clinically infected eczema, seborrhoeic eczema, contact eczema, or hand eczema. We included topical anti-inflammatory treatments used for at least one week, compared with another anti-inflammatory treatment, no treatment, or vehicle/placebo. Vehicle is a 'carrier system' for an active pharmaceutical substance, which may also be used on its own as an emollient for dry skin. We excluded trials of topical antibiotics used alone, complementary therapies, emollients used alone, phototherapy, wet wraps, and systemic treatments.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Primary outcomes were patient-reported eczema symptoms, clinician-reported eczema signs and investigator global assessment. Secondary outcomes were health-related quality of life, long-term control of eczema, withdrawal from treatment/study, and local adverse effects (application-site reactions, pigmentation changes and skin thinning/atrophy were identified as important concerns through patient and public involvement). We used CINeMA to quantify our confidence in the evidence for each outcome.

MAIN RESULTS

We included 291 studies involving 45,846 participants with the full spectrum of eczema severity, mainly conducted in high-income countries in secondary care settings. Most studies included adults, with only 31 studies limited to children aged < 12 years. Studies usually included male and female participants, multiple ethnic groups but predominantly white populations. Most studies were industry-funded (68%) or did not report their funding sources/details. Treatment duration and trial participation were a median of 21 and 28 days (ranging from 7 days to 5 years), respectively. Interventions used were topical corticosteroids (TCS) (172), topical calcineurin inhibitors (TCI) (134), phosphodiesterase-4 (PDE-4) inhibitors (55), janus kinase (JAK) inhibitors (30), aryl hydrocarbon receptor activators (10), or other topical agents (21). Comparators included vehicle (170) or other anti-inflammatory treatments. The risk of bias was high in 242 of the 272 (89.0%) trials contributing to data analyses, most commonly due to concerns about selective reporting. Network meta-analysis (NMA) was only possible for short-term outcomes. Patient-reported symptoms NMA of 40 trials (6482 participants) reporting patient-reported symptoms as a binary outcome ranked tacrolimus 0.1% (OR 6.27, 95% CI 1.19 to 32.98), potent TCS (OR 5.99, 95% CI 2.83 to 12.69), and ruxolitinib 1.5% (OR 5.64, 95% CI 1.26 to 25.25) as the most effective, all with low confidence. Mild TCS, roflumilast 0.15%, and crisaborole 2% were the least effective. Class-level sensitivity analysis found potent/very potent TCS had similar effectiveness to potent TCI and was more effective than mild TCI and PDE-4 inhibitors. NMA of 29 trials (3839 participants) reporting patient-reported symptoms as a continuous outcome ranked very potent TCS (SMD -1.99, 95% CI -3.25 to -0.73; low confidence) and tacrolimus 0.03% (SMD -1.57, 95% CI -2.42 to -0.72; moderate confidence) the highest. Direct information for tacrolimus 0.03% was based on one trial of 60 participants at high risk of bias. Roflumilast 0.15%, delgocitinib 0.25% or 0.5%, and tapinarof 1% were the least effective. Class-level sensitivity analysis found potent/very potent TCS had similar effectiveness to potent TCI and JAK inhibitors and mild/moderate TCS was less effective than mild TCI. A further 50 trials (9636 participants) reported patient-reported symptoms as a continuous outcome but could not be included in NMA. Clinician-reported signs NMA of 32 trials (4121 participants) reported clinician signs as a binary outcome and ranked potent TCS (OR 8.15, 95% CI 4.99, 13.57), tacrolimus 0.1% (OR 8.06, 95% CI 3.30, 19.67), ruxolitinib 1.5% (OR 7.72, 95% CI 4.92, 12.10), and delgocitinib 0.5% (OR 7.61, 95% CI 3.72, 15.58) as most effective, all with moderate confidence. Mild TCS, roflumilast 0.15%, crisaborole 2%, and tapinarof 1% were the least effective. Class-level sensitivity analysis found potent/very potent TCS more effective than potent TCI, mild TCI, JAK inhibitors, PDE-4 inhibitors; and mild TCS and PDE-4 inhibitors had similar effectiveness. NMA of 49 trials (5261 participants) reported clinician signs as a continuous outcome and ranked tacrolimus 0.03% (SMD -2.69, 95% CI -3.36, -2.02) and very potent TCS (SMD -1.87, 95% CI -2.69, -1.05) as most effective, both with moderate confidence; roflumilast 0.15%, difamilast 0.3% and tapinarof 1% were ranked as least effective. Direct information for tacrolimus 0.03% was based on one trial in 60 participants with a high risk of bias. For some sensitivity analyses, potent TCS, tacrolimus 0.1%, ruxolitinib 1.5%, delgocitinib 0.5% and delgocitinib 0.25% became some of the most effective treatments. Class-level analysis found potent/very potent TCS had similar effectiveness to potent TCI and JAK inhibitors, and moderate/mild TCS was more effective than mild TCI. A further 100 trials (22,814 participants) reported clinician signs as a continuous outcome but could not be included in NMA. Investigator Global Assessment NMA of 140 trials (23,383 participants) reported IGA as a binary outcome and ranked ruxolitinib 1.5% (OR 9.34, 95% CI 4.8, 18.18), delgocitinib 0.5% (OR 10.08, 95% CI 2.65, 38.37), delgocitinib 0.25% (OR 6.87, 95% CI 1.79, 26.33), very potent TCS (OR 8.34, 95% CI 4.73, 14.67), potent TCS (OR 5.00, 95% CI 3.80, 6.58), and tacrolimus 0.1% (OR 5.06, 95% CI 3.59, 7.13) as most effective, all with moderate confidence. Mild TCS, crisaborole 2%, pimecrolimus 1%, roflumilast 0.15%, difamilast 0.3% and 1%, and tacrolimus 0.03% were the least effective. In a sensitivity analysis of low risk of bias information (12 trials, 1639 participants), potent TCS, delgocitinib 0.5% and delgocitinib 0.25% were most effective, and pimecrolimus 1%, roflumilast 0.15%, difamilast 1% and difamilast 0.3% least effective. Class-level sensitivity analysis found potent/very potent TCS had similar effectiveness to potent TCI and JAK inhibitors and were more effective than PDE-4 inhibitors; mild/moderate TCS were less effective than potent TCI and had similar effectiveness to mild TCI. Longer-term outcomes over 6 to 12 months showed a possible increase in effectiveness for pimecrolimus 1% versus vehicle (4 trials, 2218 participants) in a pairwise meta-analysis, and greater treatment success with mild/moderate TCS than pimecrolimus 1% (based on 1 trial of 2045 participants). Local adverse effects NMA of 83 trials (18,992 participants, 2424 events) reporting application-site reactions ranked tacrolimus 0.1% (OR 2.2, 95% CI 1.53, 3.17; moderate confidence), crisaborole 2% (OR 2.12, 95% CI 1.18, 3.81; high confidence), tacrolimus 0.03% (OR 1.51, 95%CI 1.10, 2.09; low confidence), and pimecrolimus 1% (OR 1.44, 95% CI 1.01, 2.04; low confidence) as most likely to cause site reactions. Very potent, potent, moderate, and mild TCS were least likely to cause site reactions. NMA of eight trials (1786 participants, 3 events) reporting pigmentation changes found no evidence for increased pigmentation changes with TCS and crisaborole 2%, with low confidence for mild, moderate or potent TCS and moderate confidence for crisaborole 2%. NMA of 25 trials (3691 participants, 36 events) reporting skin thinning found no evidence for increased skin thinning with short-term (median 3 weeks, range 1-16 weeks) use of mild TCS (OR 0.72, 95% CI 0.12, 4.31), moderate TCS (OR 0.91, 95% CI 0.16, 5.33), potent TCS (OR 0.96, 95% CI 0.21, 4.43) or very potent TCS (OR 0.88, 95% CI 0.31, 2.49), all with low confidence. Longer-term outcomes over 6 to 60 months showed increased skin thinning with mild to potent TCS versus TCI (3 trials, 4069 participants, 6 events with TCS).

AUTHORS' CONCLUSIONS

Potent TCS, JAK inhibitors and tacrolimus 0.1% were consistently ranked as amongst the most effective topical anti-inflammatory treatments for eczema and PDE-4 inhibitors as amongst the least effective. Mild TCS and tapinarof 1% were ranked amongst the least effective treatments in three of five efficacy networks. TCI and crisaborole 2% were ranked most likely to cause local application-site reactions and TCS least likely. We found no evidence for increased skin thinning with short-term TCS but an increase with longer-term TCS.

Topical Treatments in Atopic Dermatitis: An Expansive Review

Atopic dermatitis (AD) is a common inflammatory skin condition found worldwide. It impacts patient quality of life (QoL) and is thought to arise as an inflammatory response to epidermal barrier dysfunction and hypersensitivity. AD can lead to large out-of-pocket costs and increased healthcare expenses over a lifetime. An analysis of all randomized control trials conducted since 1990 on topical therapies for AD were reviewed, including 207 trials in the final analysis. It was found that an average of 226 patients were enrolled over 2.43 arms. Common topical treatments included corticosteroids, calcineurin inhibitors, JAK inhibitors, and phosphodiesterase inhibitors. The most utilized tools to identify treatment efficacy were the EASI, IGA, SCORAD, and PGA. There was a paucity of data on trials that evaluated efficacy, QoL, and cost of treatment simultaneously. This review highlights the need for comprehensive trials that evaluate multiple aspects of treatment, including financial cost and QoL impact, to ensure each patient has the best treatment modality for the management of their AD.

Novel Topical Treatments for Itch

The experience of itch often poses a burden on patient quality of life and has the capacity to inflict significant suffering. Topical therapies are a mainstay of treatment for many cutaneous and systemic diseases and afford patients the opportunity to manage their conditions without many of the systemic side effects of non-topical therapies. We review a multitude of new topical medications targeting the skin, immune system, and neural receptors. The list includes Janus kinase inhibitors, tyrosine kinase inhibitors, phosphodiesterase inhibitors, transient receptor vanilloid inhibitors, topical cannabinoids, and topical acetaminophen. Many of the topical therapies reviewed show promising data in phase 2-3 clinical trials, but further research is needed to compare therapies head-to-head and test their efficacy on a broader range of conditions.

Topical treatments for atopic dermatitis (eczema): Systematic review and network meta-analysis of randomized trials

BACKGROUND

Atopic dermatitis (AD) is a common skin condition with multiple topical treatment options, but uncertain comparative effects.

OBJECTIVE

We sought to systematically synthesize the benefits and harms of AD prescription topical treatments.

METHODS

For the 2023 American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters AD guidelines, we searched MEDLINE, EMBASE, CENTRAL, CINAHL, LILACS, ICTRP, and GREAT databases to September 5, 2022, for randomized trials addressing AD topical treatments. Paired reviewers independently screened records, extracted data, and assessed risk of bias. Random-effects network meta-analyses addressed AD severity, itch, sleep, AD-related quality of life, flares, and harms. The Grading of Recommendations Assessment, Development and Evaluation approach informed certainty of evidence ratings. We classified topical corticosteroids (TCS) using 7 groups-group 1 being most potent. This review is registered in the Open Science Framework (https://osf.io/q5m6s).

RESULTS

The 219 included trials (43,123 patients) evaluated 68 interventions. With high-certainty evidence, pimecrolimus improved 6 of 7 outcomes-among the best for 2; high-dose tacrolimus (0.1%) improved 5-among the best for 2; low-dose tacrolimus (0.03%) improved 5-among the best for 1. With moderate- to high-certainty evidence, group 5 TCS improved 6-among the best for 3; group 4 TCS and delgocitinib improved 4-among the best for 2; ruxolitinib improved 4-among the best for 1; group 1 TCS improved 3-among the best for 2. These interventions did not increase harm. Crisaborole and difamilast were intermediately effective, but with uncertain harm. Topical antibiotics alone or in combination may be among the least effective. To maintain AD control, group 5 TCS were among the most effective, followed by tacrolimus and pimecrolimus.

CONCLUSIONS

For individuals with AD, pimecrolimus, tacrolimus, and moderate-potency TCS are among the most effective in improving and maintaining multiple AD outcomes. Topical antibiotics may be among the least effective.

Discovery of 2-(Methylcarbonylamino) thiazole as PDE4 inhibitors via virtual screening and biological evaluation

Phosphodiesterase-4, the primary enzyme responsible for cAMP degradation in the majority of immune and inflammatory cells, plays a critical role in the regulation of intracellular cAMP levels. Consequently, small molecular entities capable of inhibiting PDE4 have been employed in the treatment of inflammation-associated disorders, such as chronic obstructive pulmonary disease (COPD), psoriasis, atopic dermatitis (AD), inflammatory bowel diseases (IBD), rheumatic arthritis (RA). In the present investigation, a multi-faceted approach was employed to identify novel PDE4 inhibitors, utilizing the co-crystallization structure of PDE4B available in the Protein Data Bank (PDB) database, drug-like screening, false positive filtration, similarity and ADMET screen, as well as molecular docking via multiple software platforms, in conjunction with bioactivity assays. A thiazol-3-propanamides derivative, designated MR9, was discovered to inhibit PDE4B activity with IC50 values of 2.12 μM and suppress cellular inflammatory factor TNF-α release with an EC50 value of 3.587 μM. These findings suggest that the innovative active scaffold of MR9 offers a promising foundation for further structural refinement aimed at developing more potent PDE4 inhibitors.

Synthetic Approaches to the New Drugs Approved During 2021

Each year, new drugs are introduced to the market, representing structures that have affinity for biological targets implicated in human diseases and conditions. These new chemical entities (NCEs), particularly small molecules and antibody-drug conjugates, provide insight into molecular recognition and serve as potential leads for the design of future medicines. This annual review is part of a continuing series highlighting the most likely process-scale synthetic approaches to 35 NCEs that were first approved anywhere in the world during 2021.

Advances in Current Drugs and Formulations for the Management of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disease with a complex pathophysiology. Treatment of AD remains challenging owing to the presence of a wide spectrum of clinical phenotypes and limited response to existing therapies. However, recent genetic, immunological, and pathophysiological insights into the disease mechanism resulted in the invention of novel therapeutic drug candidates. This review provides a comprehensive overview of current therapies and assesses various novel drug delivery strategies currently under clinical investigation. Further, this review majorly emphasizes on various topical treatments including emollient therapies, barrier repair agents, topical corticosteroids (TCS), phosphodiesterase 4 (PDE4) inhibitors, calcineurin inhibitors, and Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway inhibitors. It also discusses biological and systemic therapies, upcoming treatments based on ongoing clinical trials. Additionally, this review scrutinized the use of pharmaceutical inactive ingredients in the approved topical dosage forms for AD treatment.

Efficacy of topical and systemic treatments for atopic dermatitis on pruritus: A systematic literature review and meta-analysis

Introduction

Pruritus is a major and burdensome symptom in atopic dermatitis (AD). The number of systemic treatments available for AD has increased recently, enabling improved patient relief.

Objective

To evaluate the effect of AD treatments on pruritus.

Methods

A systematic literature review and a meta-analysis were conducted to evaluate and compare the effects of treatment used in AD on pruritus. PubMed and Embase databases were searched to find articles published between January 1990 and December 2021. Topical and systemic treatments were studied in patients aged ≥10 years.

Results

Among the 448 articles identified, 56 studies were retained in the systematic review. A total of 15 studies evaluated topical treatments: topical corticosteroids (TCS; 2), calcineurin inhibitors (6), PDE4 inhibitors (3), and Jak inhibitors (4). A total of five studies were included in the meta- analysis. All treatments had a positive effect on pruritus, with a mean overall reduction of 3.32/10, 95% IC [2.32-4.33]. The greatest reduction was observed with halometasone (mean: 4.75), followed by tofacitinib 2% (mean: 4.38). A total of 41 studies evaluated systemic therapies: cyclosporine (6), phototherapy (5), azathioprine (2), dupilumab (9), anti-IL 13 (5), nemolizumab (3), Jak inhibitors (9), mepolizumab (1), and apremilast (1). A total of 17 studies were included in 2 meta-analyses according to the concomitant use or not of TCS. In the meta-analysis without TCS, the overall decrease was 3.07/10, 95% IC [2.58-3.56]. The molecules with the highest efficacy on pruritus were upadacitinib 30 mg (mean: 4.90) and nemolizumab (mean: 4.81).

Discussion

The therapeutic arsenal for AD has increased rapidly, and many molecules are under development. The primary endpoint of clinical trials is most often a score that assesses the severity of AD; however, the assessment of pruritus is also essential. The majority of molecules have a positive effect on pruritus, but the improvement varies between them. Efficacy on pruritus is not always correlated with efficacy on AD lesions; therefore, these two criteria are crucial to evaluate. The limitations of this study were the heterogeneity in the assessment of pruritus, the moment of the assessment, and the concomitant application of TCS or not for studies evaluating systemics. In the future, it would be useful to use standardized criteria for assessing pruritus.

Clinical efficacy and safety of topical difamilast in the treatment of patients with atopic dermatitis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To investigate the clinical efficacy and safety of topical difamilast in mild-to-moderate atopic dermatitis (AD).

METHODS

Only randomized controlled trials (RCTs) that compared topical difamilast with vehicle treatment for patients with AD were included. PubMed, Web of Science, Ovid Medline, Cochrane Library, ClinicalTrials.gov and JapicCTI were searched to 10 April 2022.

RESULTS

Five studies enrolling a total of 1009 patients with mild-to-moderate AD were identified. Compared with the topical vehicle, topical difamilast was associated with a significantly higher success rate according to the Investigator's Global Assessment score at week 4 (relative risk, 2.82; 95% confidence interval [CI]: 2.11-3.77). Compared with the vehicle, difamilast was associated with a significant decrease in day 28 eczema area and severity index scores (mean difference [MD], -4.10; 95% CI: -5.32 to -2.87), verbal rating scale scores (MD, -0.51; 95% CI: -0.71 to -0.32), visual analog scale scores (MD, -12.15; 95% CI: -19.70 to -4.61), patient-oriented eczema measure values (MD, -3.99; 95% CI: -4.91 to -3.07), and total affected body surface area (MD, -6.48; 95% CI: -8.09 to -4.87). No difference in treatment-related adverse events was identified.

CONCLUSIONS

This meta-analysis suggests that topical difamilast is an effective and safe treatment for mild-to-moderate AD.

New and Upcoming Topical Treatments for Atopic Dermatitis: A Review of the Literature

Atopic dermatitis (AD) is a chronic inflammatory dermatosis with periods of exacerbation and remissions. AD is characterized by intense, persistent pruritus and heterogeneity in clinical symptomatology and severity. Therapeutic goals include the amelioration of cutaneous eruptions, diminishing relapses and eventually the disease burden. To date, topical corticosteroids (TCS) and calcineurin inhibitors (TCI) have yet been deemed the mainstay of topical treatments in AD management. Nevertheless, despite their indisputable efficiency, TCS and TCI are not indicated for continuous long-term use given their safety profile. While research in AD has concentrated predominantly on systemic therapies, more than 30 novel topical compounds are under development. The existing data appear encouraging, with some regimens that are already FDA-approved (ruxolitinib was the most recent in September 2021) and several pharmaceutical pipeline products for mild-to-moderate AD that are in an advanced stage of development, such as tapinarof, difamilast and roflumilast. Larger, long-term studies are still required to evaluate the efficacy and safety of these novel compounds in the long run and weigh their advantages over present treatments. In this review, we aim to provide an overview of the latest knowledge about AD topical treatments, echoing upcoming research trends.

Treatment Options for Troublesome Itch

Itch (or pruritus) is an unpleasant sensation, inducing the desire to scratch. It is also a major and distressing symptom of many skin and systemic diseases. The involvement of histamine, which is a major itch mediator, has been extensively examined. Recent studies suggest that histamine-independent pathways may play roles in chronic itch. Therefore, antihistamines are not always effective in the treatment of patients with chronic itch. The development of biologics and κ-opioid receptor (KOR) agonists has contributed to advances in the treatment of itch; however, since biologics are expensive for patients to purchase, some patients may limit or discontinue their use of these agents. Furthermore, KOR agonists need to be prescribed with caution due to risks of side effects in the central nervous system. Janus kinase (JAK) inhibitors are sometimes associated with side effects, such as infection. In this review, we summarize antidepressants, antineuralgics, cyclosporine A, antibiotics, crotamiton, phosphodiesterase 4 inhibitor, botulinum toxin type A, herbal medicines, phototherapy, and acupuncture therapy as itch treatment options other than antihistamines, biologics, opioids, and JAK inhibitors; we also explain their underlying mechanisms of action.

Racial and Ethnic Diversity of US Participants in Clinical Trials for Acne, Atopic Dermatitis, and Psoriasis: A Comprehensive Review

An increasing body of literature describes underreporting of race and ethnicity, and overrepresentation of White individuals in clinical trials. We aimed to evaluate the racial and ethnic diversity of US participants in clinical trials for acne, atopic dermatitis (AD), and psoriasis. We performed a comprehensive review of clinical trials for these common dermatologic diseases that were published between January 2014 and July 2019. Race and ethnicity reporting among all trials, and the racial and ethnic distribution of US participants were compared by skin disease, intervention type, and trial phase. In total, 103 articles representing 119 unique trials were evaluated. Race and ethnicity were reported in only 22.7% of trials. The proportion of White participants (77.5%) was higher than that of the US population (72.5%, p < 0.01); a finding largely driven by psoriasis trials (84.7% White). The proportions of non-White and Hispanic individuals in non-topical (21.0% and 16.3%, respectively) and phase III (20.5% and 18.7%, respectively) trials were lower than those in topical (23.5% and 23.3%, respectively; p < 0.01) and phase I/II trials (25.6% and 22.3%, respectively; p < 0.01). Race and ethnicity remain underreported in dermatologic clinical trials, and US trial participant diversity differs by skin disease, intervention type, and trial phase.

An Overview of PDE4 Inhibitors in Clinical Trials: 2010 to Early 2022

Since the early 1980s, phosphodiesterase 4 (PDE4) has been an attractive target for the treatment of inflammation-based diseases. Several scientific advancements, by both academia and pharmaceutical companies, have enabled the identification of many synthetic ligands for this target, along with the acquisition of precise information on biological requirements and linked therapeutic opportunities. The transition from pre-clinical to clinical phase was not easy for the majority of these compounds, mainly due to their significant side effects, and it took almost thirty years for a PDE4 inhibitor to become a drug i.e., Roflumilast, used in the clinics for the treatment of chronic obstructive pulmonary disease. Since then, three additional compounds have reached the market a few years later: Crisaborole for atopic dermatitis, Apremilast for psoriatic arthritis and Ibudilast for Krabbe disease. The aim of this review is to provide an overview of the compounds that have reached clinical trials in the last ten years, with a focus on those most recently developed for respiratory, skin and neurological disorders.

[Development of new topical substances for the treatment of atopic dermatitis]

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. In everyday clinical practice, about 80% of patients present with mild to moderate disease, which is usually treated with topical therapy. Topical anti-inflammatory therapy thus continues to be the standard of care in addition to the basic therapy. Topical glucocorticoids (TGC) and topical calcineurin inhibitors (TCI) are two potent approved substances that are available. In addition to newly developed systemic therapies for moderate to severe AD, there are also new therapeutic approaches in anti-inflammatory topical treatment. Topical Janus kinase inhibitors show a high therapeutic effect. However, only delgocitinib and ruxolitinib have so far been approved for topical administration in Japan and the USA since 2021. Crisaborole, a phosphodiesterase 4 inhibitor, also received approval in the USA. Other phosphodiesterase inhibitors are currently being investigated in clinical trials. Interesting results of clinical studies give hope for further substances and therapeutic approaches.

Difamilast Ointment in Japanese Adult and Pediatric Patients with Atopic Dermatitis: A Phase III, Long-Term, Open-Label Study

Introduction

Phosphodiesterase 4 (PDE4), which regulates inflammatory cytokine production leading to atopic dermatitis (AD), is selectively inhibited by difamilast. The objective of this phase III, long-term, open-label study was to evaluate the safety and efficacy of topical difamilast in Japanese adult and pediatric patients with AD.

Methods

Adult patients (n = 166) began treatment with difamilast 1% ointment, and pediatric patients began treatment with difamilast 0.3% ointment (n = 144) or difamilast 1% ointment (n = 56). Treatment was continued twice daily for 52 weeks. All patients had an Investigator’s Global Assessment (IGA) score of 2 (mild), 3 (moderate), or 4 (severe/very severe), and an AD-affected body surface area (BSA) of ≥ 5% before treatment, with no restriction on the upper limit for the AD-affected BSA.

Results

During therapy, 120 adult patients (72.3%) and 178 pediatric patients (89.0%) experienced treatment-emergent adverse events (TEAEs), most of which were mild or moderate in severity. Discontinuation due to TEAEs was reported in 13 adult patients (7.8%) and in 7 pediatric patients (3.5%). Treatment-related adverse events were reported in 14 adult patients (8.4%) and 16 pediatric patients (8.0%), most frequently dermatitis atopic (1.8%) and acne (1.2%) in adult patients and dermatitis atopic and pigmentation disorder (each 2.0%) in pediatric patients. The cumulative success rates in Eczema Area and Severity Index (EASI)-75 in adult and pediatric patients were 55.4% and 73.5%, respectively, at week 52, and the cumulative success rates increased from week 4 to week 52. The cumulative success rates in IGA score showed the same trend as those in EASI -75.

Conclusions

This study demonstrates that difamilast ointments are well tolerated and effective in Japanese adult and pediatric patients with AD when applied twice daily for 52 weeks, and are expected to be used for a long-term treatment for AD.

Clinical Trial Registration

Clinical Trials.gov identifier: NCT03961529.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00751-9.

Safety profile and tolerability of topical phosphodiesterase 4 inhibitors for the treatment of atopic dermatitis: A systematic review and meta-analysis

Objective

Methods

Results

Conclusions

Difamilast ointment in adult patients with atopic dermatitis: A phase 3 randomized, double-blind, vehicle-controlled trial

BACKGROUND

Difamilast is a selective phosphodiesterase 4 inhibitor. Phosphodiesterase 4 is involved in cytokine production linked with inflammatory disorders, including atopic dermatitis.

OBJECTIVE

To demonstrate the superiority of difamilast ointment 1% to vehicle in adult Japanese patients with atopic dermatitis.

METHODS

In this phase 3, randomized, double-blind trial, patients aged 15-70 years with an investigator global assessment score of 2 or 3 received topical difamilast ointment 1% (n = 182) or a vehicle (n = 182) twice daily for 4 weeks.

RESULTS

The success rate in investigator global assessment score at week 4 (primary endpoint)-the percentage of patients achieving an investigator global assessment score of 0 or 1 with ≥2-grade improvement-was significantly higher with 1% difamilast than with the vehicle (38.46% vs 12.64%, respectively, P < .0001). The success rates in ≥50%, ≥75%, and ≥90% improvement in overall eczema area and severity index score at week 4 followed the same trend. Difamilast at 1% provided significant mean percent improvement from baseline in overall eczema area and severity index score versus vehicle from week 1 to 4. Treatment-emergent adverse events were mostly mild or moderate and less frequent with difamilast.

LIMITATIONS

Study treatment was limited to 4 weeks.

CONCLUSION

Difamilast ointment 1% demonstrated superiority to the vehicle and favorable safety in adult Japanese patients with atopic dermatitis.

Sensitivity of clinician-assessed efficacy outcome measurement instruments in trials of topical therapies for atopic dermatitis: a systematic review and meta-analysis

The rising prevalence of atopic dermatitis (AD) in developing countries and its substantial socioeconomic impact have furthered research over the last two decades giving way to advances in its aetiopathogenesis and treatment. Topical therapies targeting newly identified AD signalling pathways are being developed. Numerous clinician-assessed disease severity outcome measurement instruments (OMIs) are available to evaluate the efficacy of investigational treatments in proof-of-concept (POC) trials for AD. However, little is known about the comparative sensitivity of these efficacy OMIs. We performed a systematic review and meta-analysis to compare the sensitivity of different OMIs in controlled trials of topical therapies for AD published between January 1, 2000 and April 7, 2020. Treatment effect size of OMIs reported at Week 4 was calculated with 95% Confidence Interval (CI). The sensitivity of OMIs was compared by pooling the standardized difference between means (Cohen's d and Cohen's h) for any two OMI-parameter combinations that were reported in ≥3 studies identified in our systematic review. Assessed parameters were difference between active and vehicle at Week 4 and change from baseline [CFB] and percentage change from baseline [%CFB] at Week 4. We identified a total of 15 studies with 3313 subjects examining 14 different OMIs were included in this quantitative meta-analysis. Continuous OMIs had a significantly higher treatment effect size vs. dichotomous OMIs (P = 0.006). Comparisons of Eczema Area and Severity Index (EASI), Investigator's Global Assessment (IGA), body surface area (BSA) and SCORing Atopic Dermatitis (SCORAD) for available parameters were performed and generally had a similar sensitivity, with BSA showing smaller overall effect size estimates. In conclusion, continuous OMIs used in topical clinical trials for AD had significantly higher treatment effect sizes when compared to dichotomous OMIs. Continuous OMIs could provide more power for POC trials with a small sample size in atopic dermatitis with topical therapies.

Efficacy and safety of topical Janus kinase and phosphodiesterase inhibitor-4 inhibitors for the treatment of atopic dermatitis: A network meta-analysis

Topical Janus kinase (JAK) and phosphodiesterase-4 (PDE4) inhibitors are novel treatment approaches for atopic dermatitis (AD). This study aimed to compare the efficacy and safety of JAK and PDE4 inhibitors for AD treatment. The databases of PubMed, EMBASE, Web of Science, and Cochrane Library were searched until June 2021 for eligible studies of AD patients treated with topical JAK and PDE4 inhibitors. Baseline and follow-up data were extracted. Efficacy of JAK inhibitors was evaluated using Investigator's Global Assessment (IGA) achieving "clear" or "almost clear", with 2 points or more improvement from baseline at the end of treatment, referred to as "IGA response"). A Bayesian multiple treatment network meta-analysis with fixed effects was performed. Odds ratio (OR) with 95% credibility interval (CrI) were used for comparing the efficacy of JAK and PDE4 inhibitors with placebo for AD. A total of 10 randomized controlled trials of topical JAK and PDE4 inhibitors with 4689 patients were included for analysis. A total of three topical JAK inhibitors and two topical PDE4 inhibitors were included. Compared with placebo, all JAK and PDE4 inhibitors had higher IGA response at 4 weeks of treatment. Notably, with similar safety profile, tofacitinib 2% b.i.d., ruxolitinib 1.5% b.i.d., and delgocitinib 3% b.i.d. showed favorable IGA response compared with topical tacrolimus and corticosteroids. Ranking analysis suggested that among all included JAK and PDE4 inhibitors, tofacitinib 2% b.i.d. had the highest probability of achieving IGA response (SUCRA = 0.880). Besides, JAK and PDE4 inhibitors showed non-inferior safety profile with placebo. This study confirmed that topical JAK and PDE4 inhibitors had promising treatment efficacy and safety for AD patients. Tofacitinib 2% b.i.d., ruxolitinib 1.5% b.i.d. and delgocitinib 3% b.i.d. showed superior efficacy over other JAK and PDE4 inhibitors.

Atopic dermatitis: an expanding therapeutic pipeline for a complex disease

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a complex pathophysiology that underlies a wide spectrum of clinical phenotypes. AD remains challenging to treat owing to the limited response to available therapies. However, recent advances in understanding of disease mechanisms have led to the discovery of novel potential therapeutic targets and drug candidates. In addition to regulatory approval for the IL-4Ra inhibitor dupilumab, the anti-IL-13 inhibitor tralokinumab and the JAK1/2 inhibitor baricitinib in Europe, there are now more than 70 new compounds in development. This Review assesses the various strategies and novel agents currently being investigated for AD and highlights the potential for a precision medicine approach to enable prevention and more effective long-term control of this complex disease.

Recent advances in understanding of the complex phenotype and mechanisms underlying atopic dermatitis (AD) have revealed multiple new potential targets for pharmacological intervention. Here, Bieber reviews therapeutic strategies and assesses the expanding pipeline for the therapy of AD, highlighting the potential for a precision medicine approach to the management of this complex disorder.

Difamilast ointment, a selective phosphodiesterase 4 inhibitor, in paediatric patients with atopic dermatitis: A phase 3 randomised double-blind, vehicle-controlled trial

Background

In atopic dermatitis (AD), phosphodiesterase 4 (PDE4) inhibition reduces proinflammatory mediators and cytokines. Difamilast is a new selective PDE4 inhibitor.

Objectives

To demonstrate the superiority of topical difamilast to vehicle in Japanese paediatric patients with AD.

Methods

This was a phase III randomized, double‐blind, vehicle‐controlled trial. Patients aged 2–14 years with an Investigator Global Assessment (IGA) score of 2 or 3 received difamilast 0·3% (n = 83), difamilast 1% (n = 85) or vehicle (n = 83) ointment twice daily for 4 weeks.

Results

The primary endpoint was the percentage of patients with an IGA score of 0 or 1 with improvement by at least two grades at week 4. The success rates in IGA score at week 4 were 44·6%, 47·1% and 18·1% in the difamilast 0·3%, difamilast 1% and vehicle groups, respectively. Both difamilast groups demonstrated significantly higher success rates in IGA score compared with vehicle at week 4 [difamilast 0·3% (P < 0·001); difamilast 1% (P < 0·001)]. Regarding secondary endpoints, improvements in Eczema Area and Severity Index (EASI; improvement of ≥ 50%, ≥ 75% and ≥ 90% in overall score) at week 4 were significantly higher in patients in the difamilast 0·3% and 1% groups than those in the vehicle group. EASI score in the difamilast 0·3% and 1% groups was significantly reduced compared with that of patients in the vehicle group at week 1. The significant difference between both the difamilast groups and the vehicle groups was maintained from week 1 through to week 4. Most treatment‐emergent adverse events were mild or moderate, and no serious events or deaths were reported.

Conclusions

Difamilast 0·3% and 1% ointments are superior to vehicle and well tolerated in Japanese paediatric patients with AD.

Experimental Drugs with the Potential to Treat Atopic Eczema

INTRODUCTION

Eczema or atopic dermatitis (AD) is a chronically relapsing dermatosis characterized by pruritus and a significant impact on the quality of life.

METHODS

The authors undertook a structured search of peer-reviewed research articles from PubMed and Google Scholar. Recent and up-to-date studies relevant to the topic were included.

RESULTS

This report overviews current treatment and experimental drug for AD. Topical agents including topical phosphodiesterase E4 (PDE4) inhibitors such as crisaborole are efficacious in the treatment of AD with few side effects. Monoclonal antibodies such as dupilumab given subcutaneously are efficacious for more severe disease. Systemic treatment can ameliorate symptoms in severe and recalcitrant AD. New systemic treatment includes several traditional herbal formulations that have undergone clinical trials using modern research methodology to determine their efficacy and safety. AD is associated with many complicating psychosocial issues. Often suboptimal efficacy is due to unrealistic expectations and poor compliance making treatment difficult in spite of effective treatment and efforts in drug discovery. Randomized trials have shown that novel topical and subcutaneous medications are safe and efficacious. Regarding herbs, a methodology for the investigation of herbal medications is often flawed and scientific evidence is lacking. Experimental drugs include various biologics, PDE4 and JAK inhibitors in topical, oral, subcutaneous or intravenous forms are in various phases of trials.

CONCLUSION

Many novel medications demonstrate efficacy for AD. Experimental drugs include various biologics, PDE4 and JAK inhibitors are in various phases of trials.

Therapeutic New Era for Atopic Dermatitis: Part 2. Small Molecules

Atopic dermatitis (AD) is a chronic, inflammatory cutaneous disease driven by immune dysregulation and skin barrier dysfunction. Currently, we are experiencing a new era of understanding of the pathogenesis of AD and, as a consequence, a new era of innovation in therapeutics, including small molecules and biologic therapy. In contrast to biologics, small molecules are similar to conventional pharmacologic chemical agents used as drugs and are generally prepared by chemical synthesis. Unlike biologics, these drugs often are taken orally or formulated for topical use. The purpose of this review is to summarize the efficacy and safety of the current topical and systemic new therapies in AD by reviewing recently published papers on therapies currently in phase 2 or 3 clinical trials. In this review, it is important to note the characteristics of the study population, the primary endpoints, and whether or not there was concomitant topical therapy allowed. These study design elements may significantly alter the results of studies and should be taken into account. Targeted therapy help push AD treatment into a new era of personalized medicine.

Relationship Among Treatment, Pruritus, Investigator's Static Global Assessment, and Quality of Life in Patients with Atopic Dermatitis

Introduction

The Investigator’s Static Global Assessment (ISGA) is a 5-point rating scale that is recommended by the US Food and Drug Administration for assessing the severity of atopic dermatitis (AD), and ISGA success is a widely used endpoint in AD clinical studies. In this study, we seek to interpret the relationship of ISGA with treatment, pruritus, and quality of life (QoL) by conducting post hoc analyses of pooled data from two phase 3 crisaborole studies.

Methods

Patients aged ≥ 2 years with baseline ISGA of 2 (mild) or 3 (moderate) were randomly assigned 2:1 to receive crisaborole or vehicle for 28 days. Disease severity, pruritus severity, and QoL were assessed with the ISGA, Severity of Pruritus Scale (SPS), and Dermatology Life Quality Index (DLQI; patients aged ≥ 16 years), or Children’s Dermatology Life Quality Index (CDLQI; patients aged 2–15 years), respectively. The effect of treatment on ISGA and the relationship between ISGA and QoL were analyzed using a longitudinal repeated-measures model. The interrelationship between treatment, disease severity, pruritus, and QoL was analyzed with a mediation model.

Results

Overall, 1522 patients (crisaborole, n = 1016; vehicle, n = 506) were included. Estimated longitudinal profiles indicated changes in ISGA by day 8 were large for crisaborole (effect size [ES]: − 0.68) and small for vehicle (ES: − 0.34). There was a direct relationship between ISGA and DLQI and CDLQI severity bands in the longitudinal repeated-measures model. For both QoL mediation models, treatment effects on QoL were mediated indirectly by reduction in pruritus (DLQI, 42.4%; CDLQI, 58.1%) and disease severity (DLQI, 12.2%; CDLQI, 33.1%).

Conclusions

These post hoc analyses suggest that ISGA success is a clinically meaningful endpoint associated with reduction in the severity of pruritus and improvement in QoL.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-021-00506-y.

New treatments in atopic dermatitis

OBJECTIVE

To discuss the efficacy and safety of novel and emerging topical and systemic therapeutic agents for atopic dermatitis (AD).

DATA SOURCES

The review of the published literature was performed using the PubMed database, published abstracts and virtual presentations from scientific meetings, posted results on ClinicalTrials.gov, and data from industry press releases.

STUDY SELECTIONS

Primary manuscripts with trial results, case reports, case series, clinical trial data from ClinicalTrials.gov, and articles highlighting expert perspectives on management of AD were selected.

RESULTS

Emerging topical and systemic therapies primarily target the type 2 immune pathway. Moreover, 2 newer targeted medications are now approved by the Food and Drug Administration for both children and adults, crisaborole 2% ointment and dupilumab, with several others in the therapeutic pipeline. New directions in developing topical medications include Janus kinase inhibitors, tapinarof (an aryl hydrocarbon receptor agonist), and agents to correct microbial dysbiosis. In addition to the subcutaneously injected monoclonal antibody targeting the interleukin (IL) 4 receptor (dupilumab), other biologics targeting IL-13, IL-31, IL-33, OX40, and thymic stromal lymphopoietin are currently being tested. Oral Janus kinase inhibitors are showing outstanding efficacy and no serious safety signs, but safety concerns remain.

CONCLUSION

Given the tremendous burden of AD on physical, mental, and social health, the need is high to develop new, targeted therapies. Advances in our understanding of AD pathogenesis have paved the way toward the development of new therapies that promise to revolutionize our management of AD. Future research will focus on long-term efficacy and safety and creating predictive models for choosing best management options on a personalized basis.

Emerging drugs for the treatment of chronic pruritic diseases

INTRODUCTION

Chronic pruritus is non-histaminergic and mediated through a complex interplay of peripheral and central immune and neural pathways. Significant developments in the understanding of chronic pruritus have emerged and paved the way for new, emerging therapies.

AREAS COVERED

This review details the emerging drug landscape for chronic pruritus treatment, focusing on monoclonal antibody agents that target key cytokines and their receptors as well as small molecule agents that inhibit mediators of the immune and neural pathways. The article provides background regarding the currently available therapies and the rationale for the development of new agents based on the current market and recent scientific developments.

EXPERT OPINION

Identification of new targets along neuroimmune itch pathways has allowed for the development of targeted drugs which can be utilized for effective therapy. As we enter a new era of chronic itch treatments, we face exciting prospects and challenges.

Emerging treatments for atopic dermatitis

Increasing information on the pathophysiology of atopic dermatitis (AD), accumulating data on cellular and molecular pathways in immunological reactions and inflammation, and the expansion of biotechnology and pharmacology have collectively contributed to the development of new pharmacological agents for AD. Novel pharmaceutical agents, including biologics targeting cytokines, which play pathogenetic roles in AD, for example, interleukin (IL)-4, IL-13, IL-31 and IL-22, Janus kinase inhibitors, phosphodiesterase 4 inhibitors and histamine H₄ receptor antagonists, have been approved or are being developed. These agents are expected to be effective in AD patients with skin signs and/or symptoms that are refractory to conventional treatments. The development of novel drugs will accompany the use of predictive biomarkers for each agent in order to optimize treatment in each patient. Convenient tools that support self-decision-making by patients to reflect their preferences, which will increase treatment satisfaction and adherence, are also anticipated.

Treatments for Childhood Atopic Dermatitis: an Update on Emerging Therapies

Atopic dermatitis (AD) is generally considered a T helper type 2-dominated disease. Pediatric AD is usually less severe than adult AD, but it may present as moderate to severe lesions that are inadequately managed by current modalities including emollients/moisturizers, topical corticosteroids (TCSs), topical calcineurin inhibitors (TCIs), and even systemic immunosuppressants (such as cyclosporine, azathioprine, methotrexate, and mycophenolate mofetil). In addition, systemic immunosuppressants are often not recommended for childhood AD by the current guidelines due to their toxicities. Therefore, there is still an unmet need for a safe and effective long-term therapy for pediatric AD patients whose disease is inadequately controlled or who are intolerant to current treatments. The emerging therapeutics for AD focuses on intervening in the inflammatory pathway by targeting specific cytokines/chemokines or their receptors. Monoclonal antibodies against immunoglobulin E (IgE), interleukin (IL)-4 receptor subunit α, IL-5, IL-13, IL-31 receptor subunit α, IL-33, and thymic stromal lymphopoietin (TSLP) have been evaluated clinically for AD. Encouraging results have been reported for many of the biologics, of which the most exciting is dupilumab. Other emerging systemic therapies include small molecules such as baricitinib, abrocitinib, upadacitinib, and tradipitant. Several novel topical agents are under clinical investigation for the treatment of AD, including topical phosphodiesterase 4 (PDE4) inhibitors, Janus kinase (JAK) inhibitors, aryl hydrocarbon receptor (AhR) modulating agents, and transient receptor potential vanilloid subfamily member 1 (TRPV1) antagonists. Accompanied by thorough characterization of different phenotype and endotype subsets, the application of precision medicine could provide new prospects for the optimal treatment of AD.

Small molecule drugs for the treatment of pruritus in patients with atopic dermatitis

Chronic pruritus is a cardinal symptom of the inflammatory skin disease atopic dermatitis (AD). Pathogenic mechanisms in the periphery, spinal cord and the brain have been implicated in AD-related pruritus. Therefore, both systemic and topical administration of drugs could potentially provide relief. Despite efforts to elucidate the mechanisms behind AD-related pruritus and the relative contribution of peripheral nervous system and central nervous system (CNS), specific and successful treatment options have not yet been developed. Several small molecule drugs are currently being investigated to treat AD and AD-related pruritus. These small molecule drugs can be applied systemically but also topically, as they are able to penetrate into the skin due to their small size. Small molecule drugs specifically targeting peripheral itch transmission, e.g. peripherally selective κ-opioid receptors agonists and neurokinin 1 receptors antagonists, have so far been unable to improve AD-related pruritus when applied systemically, possibly because of the lack of CNS activity. Current evidence from clinical and preclinical trials with centrally acting or peripherally selective oral κ-opioid receptors agonists implies that CNS activity is required for an antipruritic effect. CNS activity is, however, directly associated with CNS-mediated side-effects. On the other hand, topical application of small molecules with anti-inflammatory activity such as Janus kinase inhibitors and phosphodiesterase 4 inhibitors, and also of κ-opioid receptor agonists, has shown promising results regarding their ability to reduce AD-related pruritus. In conclusion, topical application of anti-inflammatory compounds appears to be a highly promising strategy for the treatment of AD-related pruritus.

An overview of drug discovery efforts for eczema: why is this itch so difficult to scratch?

Introduction: Atopic dermatitis (AD) is a type of allergic/inflammatory dermatitis characterized by itch and an impairment in quality of life.Areas covered: Herein, the authors review drug discovery efforts for AD, highlighting the clinical efficacy of novel drugs, with a particular focus on the relief of pruritus. Topical agents include emollients, topical antihistamines, corticosteroids, calcineurin inhibitors and herbs. Recently, topical phosphodiesterase E4 (PDE4) inhibitors like crisaborole have become available and are efficacious for mild to moderate AD with few side effects. For more severe AD, monoclonal antibodies like dupilumab are considered as efficacious subcutaneous treatment options. In severe and recalcitrant AD, systemic treatment can ameliorate AD symptoms.Expert opinion: Many topical and systemic medications have demonstrated therapeutic benefits for AD. Indeed, randomized trials have shown that topical PDE4 inhibitors and subcutaneous dupilumab are safe and efficacious. Objective tools to evaluate itch and gauge treatment efficacy is important, but current methodology relies primarily on clinical scores. AD is a systemic atopic disease with a lot of complicated psychosocial issues. Suboptimal efficacy is often due to poor compliance and unrealistic expectation of curative treatment, rendering treatment difficult despite the existence of effective medications.

Application of Topical Phosphodiesterase 4 Inhibitors in Mild to Moderate Atopic Dermatitis: A Systematic Review and Meta-analysis

Importance

Topical medication is the central treatment for patients with atopic dermatitis (AD), but the options are limited. Phosphodiesterase 4 (PDE4) inhibitors are a new candidate for AD therapy.

Objective

To evaluate the efficacy and safety of topical PDE4 inhibitors in mild to moderate AD.

Data Sources

Clinical trials were identified from MEDLINE, Embase, Cochrane Controlled Register of Trials, Chinese medical databases (Wanfang, Chinese National Knowledge Infrastructure, Chinese Biomedical Literature Database, and China Science and Technology Journal Database), ClinicalTrials.gov, and other trial registries from inception to August 15, 2018. No restrictions on languages were placed.

Study Selection

Only double-blind randomized clinical trials with topical PDE4 inhibitors vs topical vehicle treatment for patients with mild to moderate AD were included.

Data Extraction and Synthesis

Two reviewers independently extracted study features, intervention details, and outcomes. A meta-analysis was performed using the random-effects model. The Cochrane Collaboration's risk of bias assessment tool was used to assess the risk of bias. Funnel plots and Egger tests were used to assess the publication bias.

Main Outcomes and Measures

Changes from baseline in target lesion score were expressed in terms of standardized mean differences (SMDs) with 95% CIs. Outcomes of investigators' assessment and safety were expressed in terms of relative risk with 95% CIs.

Results

Seven studies were identified, which included 1869 patients with mild to moderate AD. Overall, compared with the topical vehicle control, topical application of PDE4 inhibitors was associated with a significant decrease in target lesion score (SMD -0.40; 95% CI, -0.61 to -0.18; P < .001) and a higher response rate in investigators' assessment of clear or almost clear skin (relative risk, 1.50; 95% CI, 1.33-1.70; P < .001). There was no difference in treatment-related adverse events or in adverse events that required discontinuation of therapy. Subgroup analyses indicated that after 14 and 28 days of therapy with PDE4 inhibitors, target lesion score was significantly decreased. However, these beneficial effects were displayed only for the PDE4 inhibitors crisaborole and AN2898 (crisaborole at day 14: SMD, -0.59; 95% CI, -1.15 to -0.02; P = .04; AN2898 at day 14: SMD, -0.76; 95% CI, -1.38 to -0.13; P = .02; crisaborole at day 28: SMD, -0.86; 95% CI, -1.44 to -0.28; P = .004; AN2898 at day 28: SMD, -0.68; 95% CI, -1.30 to -0.05; P = .03). Heterogeneity was not significant across studies.

Conclusions and Relevance

This meta-analysis suggests that topical PDE4 inhibitors are a safe and effective treatment for mild to moderate AD. Current evidence supports the use of crisaborole or AN2898 as the choice of maintenance or sequential therapy for mild to moderate AD.

Phase 2, randomized, double-blind, placebo-controlled, 4-week study to evaluate the safety and efficacy of OPA- 15406 (difamilast), a new topical selective phosphodiesterase type-4 inhibitor, in Japanese pediatric patients aged 2-14 years with atopic dermatitis

The safety and efficacy of OPA-15406 (international non-proprietary name, difamilast; also referred to as MM36), a new topical, selective phosphodiesterase type-4 inhibitor, in Japanese pediatric patients with atopic dermatitis aged 2-14 years were evaluated in a phase 2, randomized, double-blind, vehicle-controlled, 4-week study. Seventy-three patients were randomized 1:1:1 to receive OPA-15406 0.3%, OPA-15406 1% or vehicle ointment twice daily for 4 weeks. The mean age of patients was similar across treatment groups. No deaths or serious treatment-emergent adverse events were reported; all treatment-emergent adverse events were mild or moderate in severity. The incidence of treatment-emergent adverse events leading to treatment discontinuation was 4.2% (1/24) in the OPA-15406 0.3% group, 4.0% (1/25) in the OPA-15406 1% group and 16.7% (4/24) in the vehicle group, all of which were worsening of atopic dermatitis. Both OPA-15406 groups demonstrated a higher incidence of success in the Investigator Global Assessment score compared with the vehicle group over the 4-week study. The OPA-15406 groups also showed greater improvements from baseline compared with the vehicle group in the Investigator Global Assessment score, Eczema Area and Severity Index overall score and subscale (erythema, induration/papulation, excoriation and lichenification) scores, Visual Analog Scale pruritus score, Patient-Oriented Eczema Measure score, and percentage of affected body surface area over the 4-week study. Topical OPA-15406 twice daily for 4 weeks was considered a safe and effective treatment option in this phase 2 study in pediatric patients with atopic dermatitis, and phase 3 development is currently ongoing.

Pathophysiology of Atopic Dermatitis and Psoriasis: Implications for Management in Children

Atopic dermatitis (AD) and psoriasis are chronic inflammatory skin diseases associated with a significant cutaneous and systemic burden of disease as well as a poor health-related quality of life. Here, we review the complex pathophysiology of both AD and psoriasis and discuss the implications for treatment with current state-of-the-art and emerging topical and systemic therapies. Both AD and psoriasis are caused by a complex combination of immune dysregulation, skin-barrier disruption, genetic factors, and environmental influences. Previous treatments for both diseases were limited to anti-inflammatory agents that broadly suppress inflammation. Emerging insights into relevant pathways, including recognition of the role of T-helper type 2 driven inflammation in AD and T-helper 1 and 17 driven inflammation in psoriasis, have led to a therapeutic revolution. There are a number of novel treatment options available for AD and psoriasis with many more currently under investigation.

Efficacy and safety of topical OPA-15406, a new phosphodiesterase 4 inhibitor, in Japanese patients with atopic dermatitis for 8 weeks: A phase 2, randomized, double-blind, placebo-controlled study

The efficacy and safety of topical OPA-15406, a new phosphodiesterase 4 inhibitor, were examined in Japanese patients aged 15-70 years with atopic dermatitis in a phase 2, randomized, double-blind, vehicle-controlled study. Two hundred patients were randomized to three treatment groups at a 1:1:1 ratio to receive OPA-15406 0.3%, OPA-15406 1% or vehicle ointment twice daily for 8 weeks. The OPA-15406 1% group was superior to the vehicle group in terms of the incidence of success based on the Investigator Global Assessment score at week 4 (P = 0.0328), which was the primary end-point, while the OPA-15406 0.3% group showed a trend toward improvement in the primary end-point. The mean Eczema Area and Severity Index total score and subscale (erythema, induration/papulation, excoriation and lichenification) scores, the Visual Analog Scale pruritus score and the Patient-Oriented Eczema Measure score were significantly improved and the percentage of affected body surface area was significantly decreased in both OPA-15406 groups relative to the vehicle group as early as week 1, and the improved scores and decreased percentages were generally maintained until week 8. No deaths or serious treatment-emergent adverse events occurred in the OPA-15406 treatment groups. Treatment-emergent adverse events frequently observed across treatment groups were worsening of atopic dermatitis, viral upper respiratory tract infection and pruritus, all of which were mild or moderate in severity in the OPA-15406 groups. OPA-15406 1% ointment showed favorable efficacy and safety profiles, indicating a promising treatment option for patients with atopic dermatitis.

Evaluating crisaborole as a treatment option for atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic and recurrent disease presenting with eczematous lesions and pruritus. It impacts patient and family quality of life, increases morbidity, and accounts for large health-care expenditures. Although nonpharmacologic, topical, and systemic treatments exist, management of AD remains challenging due to limited treatment options. Crisaborole is a topical small molecule inhibitor of phosphodiesterase 4 (PDE4), recently approved for the treatment of AD in the United States. Areas covered: The authors review crisaborole in the management of AD based on Phase II, Phase III, and post-marketing studies. Pharmacologic properties such as chemistry, pharmacokinetics, pharmacodynamics and metabolism are discussed. A PubMed systematic review was augmented with Google Scholar searches via keyword, Medical Subject Headings (MeSH), and Boolean operation searches. Expert opinion: Crisaborole showed modest efficacy in short-term trials, but head-to-head trials with topical corticosteroids and tacrolimus are needed to assess its clinical utility. Since crisaborole is non-steroidal, it may reduce the need for topical corticosteroids and address steroid phobia. However, it is likely to suffer from the same factors contributing to intentional non-adherence in topicals: dissatisfaction with efficacy and inconvenience.

Current therapeutic paradigm in pediatric atopic dermatitis: Practical guidance from a national expert panel

INTRODUCTION AND OBJECTIVES

Atopic dermatitis (AD) is the most common cutaneous inflammatory disease in both adults and children. Although emerging therapeutic approaches are being investigated for the management of pediatric AD, it still needs to be managed with conventional treatments. This consensus document is aimed at providing an update on general management and therapies of pediatric AD, defining practical recommendations for using both topical and systemic agents.

MATERIAL AND METHODS

A panel of experts consisting of dermatologists and pediatricians were convened in order to define statements, through a Delphi process, standardizing the management of AD in pediatric subjects in a real-world setting.

RESULTS

A set of practical recommendations obtaining an at least 75% agreement was presented.

CONCLUSIONS

This set of practical recommendations represents a simple and fast snapshot on the pediatric use of common anti-AD therapeutics.

Topical agents for the treatment of atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is perhaps the most common inflammatory skin disorder worldwide, with an increasing incidence in developed countries. The mainstay treatment for patients with AD is topical therapies, which are used not only by the mild patients but also by the moderate-to-severe patients, in conjunction with systemic treatment. While topical steroids and calcineurin antagonists are widely used, these are associated with long-term cutaneous adverse effects (AEs) or a black box warning, preventing their chronic use. Areas covered: The aim of this review is to provide a comprehensive overview of new and upcoming topical therapies currently in development and undergoing clinical trials, as well as their safety and efficacy profiles, and discuss current topicals used in the management of AD. Expert opinion: AD is a heterogeneous disease with complex pathophysiology. Treatments available to date for AD provide disease control; however, patients struggle to find an optimized therapeutic regimen they may use long term and without severe effects. Novel therapies are currently under investigation, with the hope of shifting the paradigm of AD management from symptom control to disease eradication.

Phosphodiesterase-4 Inhibitors for the Treatment of Inflammatory Diseases

Phosphodiesterase-4 (PDE4), mainly present in immune cells, epithelial cells, and brain cells, manifests as an intracellular non-receptor enzyme that modulates inflammation and epithelial integrity. Inhibition of PDE4 is predicted to have diverse effects via the elevation of the level of cyclic adenosine monophosphate (cAMP) and the subsequent regulation of a wide array of genes and proteins. It has been identified that PDE4 is a promising therapeutic target for the treatment of diverse pulmonary, dermatological, and severe neurological diseases. Over the past decades, numerous PDE4 inhibitors have been designed and synthesized, among which roflumilast, apremilast, and crisaborole were approved for the treatment of inflammatory airway diseases, psoriatic arthritis, and atopic dermatitis, respectively. It is regrettable that the dramatic efficacies of a drug are often accompanied by adverse effects, such as nausea, emesis, and gastrointestinal reactions. However, substantial advances have been made to mitigate the adverse effects and obtain better benefit-to-risk ratio. This review highlights the dialectical role of PDE4 in drug discovery and the disquisitive details of certain PDE4 inhibitors to provide an overview of the topics that still need to be addressed in the future.

Consensus-based European guidelines for treatment of atopic eczema (atopic dermatitis) in adults and children: part I

This guideline was developed as a joint interdisciplinary European project, including physicians from all relevant disciplines as well as patients. It is a consensus-based guideline, taking available evidence from other guidelines, systematic reviews and published studies into account. This first part of the guideline covers methods, patient perspective, general measures and avoidance strategies, basic emollient treatment and bathing, dietary intervention, topical anti-inflammatory therapy, phototherapy and antipruritic therapy, whereas the second part covers antimicrobial therapy, systemic treatment, allergen-specific immunotherapy, complementary medicine, psychosomatic counselling and educational interventions. Management of AE must consider the individual clinical variability of the disease; highly standardized treatment rules are not recommended. Basic therapy is focused on treatment of disturbed barrier function by hydrating and lubricating topical treatment, besides further avoidance of specific and unspecific provocation factors. Topical anti-inflammatory treatment based on glucocorticosteroids and calcineurin inhibitors is used for flare management and for proactive therapy for long-term control. Topical corticosteroids remain the mainstay of therapy, whereas tacrolimus and pimecrolimus are preferred in sensitive skin areas and for long-term use. Topical phosphodiesterase inhibitors may be a treatment alternative when available. Adjuvant therapy includes UV irradiation, preferably with UVB 311 nm or UVA1. Pruritus is targeted with the majority of the recommended therapies, but some patients may need additional antipruritic therapy. Antimicrobial therapy, systemic anti-inflammatory treatment, immunotherapy, complementary medicine and educational intervention will be addressed in part II of the guideline.

Recent Developments in Atopic Dermatitis

Atopic dermatitis (AD) is a bothersome and common skin disease affecting ∼10.7% of children in the United States. This skin condition significantly decreases quality of life in not only patients, but in their families as well. Pediatricians are often the first physicians to diagnose and manage these patients and thus are relied on by families to answer questions about this disease. AD is complex, multifactorial, and has historically had limited therapeutic options, but the landscape of this disease is now rapidly changing. Pathways contributing to the pathogenesis of this disease are continually being discovered, and new therapies for AD are being developed at an unprecedented rate. With this article, we will review the current guidelines regarding the management of AD, outline updates in the current understanding of its pathophysiology, and highlight novel developments available for the treatment of this burdensome disease.