Adult atopic dermatitis: new and emerging therapies

Cyclic nucleotide phosphodiesterases as drug targets

Cyclic nucleotides are synthesized by adenylyl and/or guanylyl cyclase, and downstream of this synthesis, the cyclic nucleotide phosphodiesterase families (PDEs) specifically hydrolyze cyclic nucleotides. PDEs control cyclic adenosine-3',5'monophosphate (cAMP) and cyclic guanosine-3',5'-monophosphate (cGMP) intracellular levels by mediating their quick return to the basal steady state levels. This often takes place in subcellular nanodomains. Thus, PDEs govern short-term protein phosphorylation, long-term protein expression, and even epigenetic mechanisms by modulating cyclic nucleotide levels. Consequently, their involvement in both health and disease is extensively investigated. PDE inhibition has emerged as a promising clinical intervention method, with ongoing developments aiming to enhance its efficacy and applicability. In this comprehensive review, we extensively look into the intricate landscape of PDEs biochemistry, exploring their diverse roles in various tissues. Furthermore, we outline the underlying mechanisms of PDEs in different pathophysiological conditions. Additionally, we review the application of PDE inhibition in related diseases, shedding light on current advancements and future prospects for clinical intervention. SIGNIFICANCE STATEMENT: Regulating PDEs is a critical checkpoint for numerous (patho)physiological conditions. However, despite the development of several PDE inhibitors aimed at controlling overactivated PDEs, their applicability in clinical settings poses challenges. In this context, our focus is on pharmacodynamics and the structure activity of PDEs, aiming to illustrate how selectivity and efficacy can be optimized. Additionally, this review points to current preclinical and clinical evidence that depicts various optimization efforts and indications.

IL-13 inhibition in the treatment of atopic dermatitis - new and emerging biologic agents

Atopic dermatitis (AD) is a common, chronic, and recurrent inflammatory skin condition that affects a considerable portion of the population, and is particularly prevalent among children. The development of AD is influenced by environmental and genetic factors, which cause epidermal barrier dysfunction, immune dysregulation, and dysbiosis. In immune dysregulation, there is excessive production of cytokines. Among the cytokines, interleukin (IL)-13 plays a major role in the pathogenesis of AD. Searching for new and more selective treatments for moderate-to-severe cases is important because of the considerable effect of AD on the quality of life. Tralokinumab and lebrikizumab are selective IL-13 inhibitors that have demonstrated safety and efficacy as treatment options for AD in phase III trials. Tralokinumab is approved for use in Europe and the USA, while lebrikizumab is approved only in Europe. Cendakimab, which is another IL-13 selective inhibitor, has shown promising results in phase II trials, providing safe and effective outcomes. Eblasakimab, which disrupts IL-13 and IL-4 signaling pathways, is currently in phase II trials following well-tolerated administration in phase I studies. This narrative review aims to outline the current state of knowledge regarding the effectiveness and safety of these four biologic agents targeting IL-13 signaling.

Biologic and Small Molecule Therapy in Atopic Dermatitis

Atopic dermatitis is a chronic inflammatory dermatosis characterized by pruritic, scaly, erythematous lesions. Its incidence varies but is estimated to be approximately 20% in children and between 7 and 14% in adults, with variation amongst countries. It is a multifactorial condition, with a complex interplay between genetic, immunological, and environmental factors. Research into the inflammatory response has identified new therapeutic targets that work to reduce inflammation and subsequently reduce flares. This study explores existing therapeutic agents for atopic dermatitis as well as newer therapies such as biologics and small molecules, drawing upon each agent's mechanism of action, relevant landmark clinical trials, efficacy, and safety profile. Current therapies include emollients, corticosteroids, cyclosporine A, calcineurin inhibitors, phototherapy, and methotrexate. Biologics described include dupilumab, tralokinumab, lebrikizumab, nemolizumab, and rocatinlimab. Small molecules inhibitors include Janus kinase inhibitors, phosphodiesterase 4 inhibitors, transient receptor potential vanilloid subfamily V member 1 antagonist, and aryl hydrocarbon receptor antagonist.

An overview of new and emerging antibody therapies for moderate-severe atopic dermatitis in adults

INTRODUCTION

A comprehensive review of the English-language medical literature was performed searching for ongoing and closed clinical trials concerning new and emerging monoclonal antibody therapies for moderate-to-severe atopic dermatitis in adults.

AREAS COVERED

Atopic dermatitis is a chronic inflammatory cutaneous disease with a complex pathogenesis. In the last years, numerous advances in understanding the atopic dermatitis pathogenesis allowed to obtain several therapeutic options, such as numerous monoclonal antibodies. Some monoclonal antibodies, such as dupilumab (anti-IL-4 Rα) and tralokinumab (anti-IL13) are already approved for the treatment of moderate-to-severe atopic dermatitis, and numerous articles in the literature have demonstrated their efficacy and safety. As there are numerous drugs under investigation, this review focuses on emerging monoclonal antibody therapies.

EXPERT OPINION

There are numerous monoclonal antibodies under investigation that may be approved in the near future for the treatment of atopic dermatitis. Data from phase 2b and phase III clinical trials in moderate-to-severe atopic dermatitis in adults indicate that these drugs have a promising efficacy and safety profile. Monoclonal antibodies currently under investigation will be available in the coming years to enrich the therapeutic choice of new alternatives that are valid both in terms of efficacy and safety.

Targeting Interleukin 13 for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin condition that has a significant impact on a patient's quality of life and requires ongoing management. Conventional topical and systemic therapies do not target specific components of AD pathogenesis and, therefore, have limited efficacy and may be associated with long-term toxicity. Thus, AD management is challenging, with a significant proportion of patients not achieving clear skin or a reduction in pruritus. There remains a large unmet need for effective therapeutic strategies with favorable safety profiles that can be used long-term in patients with refractory AD. The emergence of targeted biological and small molecule therapies has effectively broadened available treatment options for moderate-to-severe AD. Most recently, interleukin 13 (IL-13) inhibitors were shown to be efficacious and well-tolerated, with tralokinumab already approved for use in this patient population. It is important for dermatologists to be aware of the evidence behind this emerging class of biologic agents to guide treatment choices and improve outcomes in patients with AD. The main objective of this paper is to review the current literature regarding the efficacy and safety of current and emerging anti-IL-13 monoclonal antibodies, including tralokinumab, lebrikizumab, cendakimab, and eblasakimab, for the treatment of moderate-to-severe AD.

Annoying Psoriasis and Atopic Dermatitis: A Narrative Review

Skin is an important organ that mainly functions as a barrier. Skin diseases can damage a person's self-confidence and reduce their willingness to socialize, as well as their social behavior and willingness. When the skin appearance is abnormal, in addition to affecting the quality of life, it often leads to personal, social, and psychological dysfunction and even induces depression. Psoriasis and atopic dermatitis are common chronic skin diseases. Their prevalence in the world is 3-10%, and there is an increasing trend year by year. These congenital or acquired factors cause the dysfunction of the immune system and then destroy the barrier function of the skin. Because these patients are flooded with a variety of inflammatory mediators, this causes skin cells to be in chronic inflammation. Therefore, psoriasis and atopic dermatitis are also considered systemic chronic inflammatory diseases. In the healthcare systems of developed countries, it is unavoidable to spend high costs to relieve symptoms of psoriasis and atopic dermatitis patients, because psoriasis and atopic dermatitis have a great influence on individuals and society. Giving a lot of attention and developing effective treatment methods are the topics that the medical community must work on together. Therefore, we used a narrative review manuscript to discuss pathogenesis, clinical classification, incidence, and treatment options, including topical medication, systemic therapeutics, immunosuppressive medication for psoriasis, and atopic dermatitis, as well as also comparing the differences between these two diseases. We look forward to providing readers with comprehensive information on psoriasis and atopic dermatitis through this review article.

Tralokinumab for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a relapsing or chronic heterogeneous inflammatory skin disorder with a substantial economic and social impact. AD is a multifactorial disease regulated by a diverse set of environmental and genetic determinants. The main factors involved in the pathogenesis of AD are epidermal barrier dysfunction, immune dysregulation, and dysbiosis. Current data have valued interleukin (IL)-13 as conceivably the crucial cytokine in the underlying inflammation of AD. Advances in understanding AD pathophysiology have driven the progress of targeted immunomodulatory treatments for the treatment of AD, including tralokinumab, a selective IL-13 inhibitor. A phase IIb clinical trial showed that a dosing regimen of 150 or 300 mg every 2 weeks effectively treated moderate-to-severe AD in adults with an acceptable tolerability profile. Phase III clinical trials demonstrated that results with tralokinumab in monotherapy were superior to those with placebo at 16 weeks of treatment. It was also well tolerated up to 52 weeks in the vast majority of patients. In addition, in association with topical corticosteroids, tralokinumab was well tolerated and effective and had a favorable risk-benefit profile. These data provide additional evidence that IL-13 is central to AD pathogenesis, suggesting that tralokinumab may be seen as an innovative option for the treatment of moderate-to-severe AD.

Selective IL-13 inhibitors for the treatment of atopic dermatitis

Background

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases worldwide. AD pathogenesis is multifactorial, involving environmental and genetic factors. IL-13 stands out as one of the main cytokines in the pathophysiology of AD. Currently, dupilumab, which targets both IL-4 and IL-13 signalling, is the only biologic agent approved for the treatment of moderate-to-severe AD. New targeted biologic therapies are being developed, such as lebrikizumab and tralokinumab, two selective IL-13 inhibitors. This article reviews the role of IL-13 in AD and the most recent data on lebrikizumab and tralokinumab.

Methods

A narrative review of the literature was written after retrieving relevant articles in the PubMed database (up until December 2020) using the following keywords present in the title, abstract or body: atopic dermatitis; interleukin 13; IL-13; tralokinumab; lebrikizumab, biologic therapy.

Discussion

A phase IIb trial showed that all three dosing regimens evaluated (lebrikizumab 125 mg every 4 weeks (Q4W), 250 mg Q4W or 250 mg every 2 weeks) achieved rapid and dose-dependent efficacy concerning the signs and symptoms of AD, with a statistically significant improvement, at week 16. Tralokinumab was studied in three phase III clinical trials and reached its primary endpoints at week 16 (ECZTRA 1 and 2 in monotherapy and ECZTRA 3 with concomitant topical corticosteroids), with response maintained over time. Both lebrikizumab and tralokinumab exhibited good safety profiles in AD trials, with adverse effects usually being comparable between the control and treatment groups.

Conclusion

The evidence supports the hypothesis that selective antagonism of IL-13 is sufficient to control AD, providing an improvement in the patient’s quality of life. Therefore, the development of lebrikizumab and tralokinumab represents a new and exciting phase in the management of AD.

The Efficacy and Safety of Abrocitinib as a Treatment Option for Atopic Dermatitis: A Short Report of the Clinical Data

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory skin disease that predominantly affects children. However, it can persist in adulthood and/or start at older ages. Both dysfunction of the epidermal barrier and immune dysregulation are known to play a role in the pathogenesis of AD. In the last years, numerous studies showed that Janus kinase (JAK) enzymes have a key role in AD pathogenesis. Therefore, oral and topical JAK inhibitors are new emerging treatments for AD. We report the data relating to abrocitinib, an oral JAK1 inhibitor. For this purpose, we examined articles already published concerning, in particular, concluded clinical trials. Furthermore, we also report the design of current ongoing clinical trials. The search was carried out considering the main search engines relating to medical literature and clinical trials. From all the data we collected, abrocitinib proved to be an effective drug in significantly reducing the severity of moderate-to-severe AD when compared to placebo. Furthermore, the efficacy was similar to other well-established treatment for AD, such as dupilumab. Adverse events were generally mild; indeed, the drug was definitively suspended only in few patients.

Intractable Itch in Atopic Dermatitis: Causes and Treatments

Itch or pruritus is the hallmark of atopic dermatitis and is defined as an unpleasant sensation that evokes the desire to scratch. It is also believed that itch is a signal of danger from various environmental factors or physiological abnormalities. Because histamine is a well-known substance inducing itch, H₁-antihistamines are the most frequently used drugs to treat pruritus. However, H₁-antihistamines are not fully effective against intractable itch in patients with atopic dermatitis. Given that intractable itch is a clinical problem that markedly decreases quality of life, its treatment in atopic dermatitis is of high importance. Histamine-independent itch may be elicited by various pruritogens, including proteases, cytokines, neuropeptides, lipids, and opioids, and their cognate receptors, such as protease-activated receptors, cytokine receptors, Mas-related G protein-coupled receptors, opioid receptors, and transient receptor potential channels. In addition, cutaneous hyperinnervation is partly involved in itch sensitization in the periphery. It is believed that dry skin is a key feature of intractable itch in atopic dermatitis. Treatment of the underlying conditions that cause itch is necessary to improve the quality of life of patients with atopic dermatitis. This review describes current insights into the pathophysiology of itch and its treatment in atopic dermatitis.

New emergent therapies for atopic dermatitis: A review of safety profile with respect to female fertility, pregnancy, and breastfeeding

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. Systemic treatment is usually mandatory in moderate-to-severe AD of the adult; these patients need to be informed about safe and effective management of AD also regarding the reproduction. Treating a pregnant woman with AD with systemic drugs may affect the unborn child. While effects of traditional systemic treatments for AD on female fertility, pregnancy, and breastfeeding are largely known, data about new emergent therapies for AD are still poor. Treating pregnant or lactating women with AD can be a challenge since no large clinical studies on its possible effects and side-effects on conception, pregnancy, the unborn child and lactation are currently available for new AD treatments.

Saponin from Periploca forrestii Schltr Mitigates Oxazolone-Induced Atopic Dermatitis via Modulating Macrophage Activation

Atopic dermatitis (AD) is a relapsing, acute, and chronic skin disease featured by intractable itching, eczematous skin. Conventional therapies based on immunosuppression such as corticosteroids are associated with multiple adverse reactions. Periploca forrestii Schltr saponin (PFS) was shown to potently inhibit murine arthritis by protecting bone and cartilage injury and suppressing NF-κB activation. However, its therapeutic effect on oxazolone-induced atopic dermatitis (AD) and the underlying mechanisms on macrophage are still unclear. The AD-like dermatitis was induced by repeated oxazolone challenge to the skin of BALB/c mice in vivo. Blood and ears were biochemically or histologically processed. RT-PCR, western blotting, and ELISA were conducted to evaluate the expression of macrophage factors. Mouse bone marrow-derived macrophages (BMDMs) stimulated with lipopolysaccharide (LPS) were used as a model in vitro. PFS treatment inhibited AD-like dermatitis development. PFS downregulated epidermis thickness and cell infiltration, with histological analysis of the skin lesion. PFS alleviated plasma immunoglobulin (Ig) E, IgG2a, and IgG1 levels. PFS downregulated the expression of M1 macrophage factors, tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, monocyte chemotactic protein-1 (MCP-1), and nitric oxide synthase2 (NOS2), and M2 macrophage factors, IL-4, arginase1 (Arg1) and CD163 in AD-like skin, which were confirmed by western blot and ELISA analysis. In addition, PFS inhibited LPS-induced macrophage polarization via the inhibition of the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and nuclear translocation of NF-κB p65. These results suggest that PFS exerted an antidermatitis effect against oxazolone by modulating macrophage activation. PFS administration might be useful in the treatment of AD and inflammatory skin diseases.

Abrocitinib: a potential treatment for moderate-to-severe atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common and debilitating dermatosis that often impacts the physical and psychological quality of life in children and adults. A limited number of treatment options are available for AD, and often these treatments result in an insufficient response or may be contraindicated for some patients. This treatment gap creates an increasing demand for alternative AD therapies. The Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathway is known to play a critical role in the dysregulation of immune responses in AD. Inhibition of the JAK enzymes in the JAK-STAT pathway has shown potential for the treatment of this chronic skin condition.

AREAS COVERED

We review the evolving efficacy and safety profile of abrocitinib, an oral JAK1 inhibitor, in the treatment of AD based on the data available from phase I, II, and III clinical trials.

EXPERT OPINION

Evidence supports clinical efficacy, improved pruritus and an acceptable safety profile, making abrocitinib a viable alternative to conventional AD therapies. Pivotal phase III trials included subjects aged 12 years and above, providing a new mechanism of action for future treatment of adolescent and adult AD. Further investigations are required to have a thorough understanding of abrocitinib in the treatment of AD.

Impact of sun exposure on adult patients affected by atopic dermatitis

BACKGROUND

Atopic dermatitis management is challenging and usually requires intermittent or continuous, long-term treatment with topical and/or systemic anti-inflammatory agents and appropriate skin care. Most patients affected by atopic dermatitis improve during sun exposure. It has been reported that the change from a subartic/temperate to a subtropical climate for 4 weeks improved significantly skin symptoms and quality of life in children, even for 3 months after return. However, until now the effect of sun exposure on adult patients with atopic dermatitis has never been investigated.

METHODS

We conducted a retrospective study to assess the short-term effect of sun exposure during summer holidays on skin symptoms of adults affected by AD.

RESULTS

One hundred and fourteen patients were enrolled in the study (62 males; aged 18-72 years, mean age 35.3±12.6). Seventy-three out of 114 patients (64%) spent their holidays at the seaside, and 41/114 (36%) in the mountains; 38/41 (92.7%) subjects from the latter group reported that during their holidays they frequented outdoor swimming pools or solariums almost every day of their vacation. The sunlight effect was considered beneficial by 68/114 (59.6%) of patients. In particular, 38/114 patients (33.3%%) reported the improvement of AD and 30/114 (26.3%) the complete resolution of the disease during summer holiday.

CONCLUSIONS

Our data seem to suggest that sun exposure is beneficial in most patients, but not in all patients. In fact, sun exposure does not appear to improve skin symptoms or even aggravate them in about 4 out of 10 patients. This could be particularly important also considering ongoing climate changes that may affect the clinical history of several skin diseases, among which AD.

Profile of Baricitinib and Its Potential in the Treatment of Moderate to Severe Atopic Dermatitis: A Short Review on the Emerging Clinical Evidence

Atopic dermatitis (AD) is the most common chronic cutaneous inflammatory disease of childhood, affecting up to 25% of children; its prevalence in adulthood is currently unknown, since studies reported that AD may affect 0.3-14.3% of adult population. In the last decade, the advanced understanding of AD molecular pathways along with patient's and physician's demand for more effective therapies, led to the introduction of new therapeutic agents. Baricitinib is an oral JAK inhibitor highly selective for JAK1 and JAK2. Treatment with baricitinib improved the signs and symptoms of moderate-to-severe AD compared to placebo, but it will be essential to better understand the safety profile of this drug.

Dupilumab and alopecia: A Janus effect

Atopic dermatitis (AD) and alopecia areata (AA) are two common skin diseases that can coexist in the same patient, sharing some pathogenetic mechanisms such as the overexpression of interleukin 4 (IL4) and interleukin 13 (IL13). Recently, cases of AA healing during treatment with anti-IL4/IL13 monoclonal antibody dupilumab (D) for AD were reported. However, cases of appearance of AA have been described during D treatment too. We report two patients that experienced these two opposite effects of D.