Clinical and molecular effects of oral CCR4 antagonist RPT193 in atopic dermatitis: A Phase 1 study

Molecular and cellular mechanisms of itch sensation and the anti-itch drug targets

Itch is an uncomfortable feeling that evokes a desire to scratch. This protective reflex can effectively eliminate parasites that invade the skin. When itchy skin becomes severe or lasts for more than six weeks, it has deleterious effects on both quality of life and productivity. Despite decades of research, the complete molecular and cellular coding of chronic itch remains elusive. This persistent condition often defies treatment, including with antihistamines, and poses a significant societal challenge. Obtaining pathophysiological insights into the generation of chronic itch is essential for understanding its mechanisms and the development of innovative anti-itch medications. In this review we provide a systematic overview of the recent advancement in itch research, alongside the progress made in drug discovery within this field. We have examined the diversity and complexity of the classification and mechanisms underlying the complex sensation of itch. We have also delved into recent advancements in the field of itch mechanism research and how these findings hold potential for the development of new itch treatment medications. But the treatment of clinical itch symptoms still faces significant challenges. Future research needs to continue to delve deeper, not only to discover more itch-related pathways but also to explore how to improve treatment efficacy through multitarget or combination therapy.

Role of skin-homing t-cells in recurrent episodes of atopic dermatitis: a review

Atopic dermatitis (AD) is a chronic relapsing disease with complex pathogenesis. Among them, inflammation is one of the primary pathogenesis of AD. AD is characterized by infiltration of lymphocytes into the skin's dermis, and the skin homing of lymphocytes plays an essential role in the recurrence of AD. Currently, there is more and more evidence to support this view. This article reviews the relevant role of T lymphocyte skin-homing-related molecules in the recurrence of AD to provide a reference for the cure of AD.

Role of chemokines in aging and age-related diseases

Chemokines (chemotactic cytokines) play essential roles in developmental process, immune cell trafficking, inflammation, immunity, angiogenesis, cellular homeostasis, aging, neurodegeneration, and tumorigenesis. Chemokines also modulate response to immunotherapy, and consequently influence the therapeutic outcome. The mechanisms underlying these processes are accomplished by interaction of chemokines with their cognate cell surface G protein-coupled receptors (GPCRs) and subsequent cellular signaling pathways. Chemokines play crucial role in influencing aging process and age-related diseases across various tissues and organs, primarily through inflammatory responses (inflammaging), recruitment of macrophages, and orchestrated trafficking of other immune cells. Chemokines are categorized in four distinct groups based on the position and number of the N-terminal cysteine residues; namely, the CC, CXC, CX3C, and (X)C. They mediate inflammatory responses, and thereby considerably impact aging process across multiple organ-systems. Therefore, understanding the underlying mechanisms mediated by chemokines may be of crucial importance in delaying and/or modulating the aging process and preventing age-related diseases. In this review, we highlight recent progress accomplished towards understanding the role of chemokines and their cellular signaling pathways involved in aging and age-relaed diseases of various organs. Moreover, we explore potential therapeutic strategies involving anti-chemokines and chemokine receptor antagonists aimed at reducing aging and mitigating age-related diseases. One of the modern methods in this direction involves use of chemokine receptor antagonists and anti-chemokines, which suppress the pro-inflammatory response, thereby helping in resolution of inflammation. Considering the wide-spectrum of functional involvements of chemokines in aging and associated diseases, several clinical trials are being conducted to develop therapeutic approaches using anti-chemokine and chemokine receptor antagonists to improve life span and promote healthy aging.

Atopic dermatitis: pathogenesis and therapeutic intervention

The skin serves as the first protective barrier for nonspecific immunity and encompasses a vast network of skin-associated immune cells. Atopic dermatitis (AD) is a prevalent inflammatory skin disease that affects individuals of all ages and races, with a complex pathogenesis intricately linked to genetic, environmental factors, skin barrier dysfunction as well as immune dysfunction. Individuals diagnosed with AD frequently exhibit genetic predispositions, characterized by mutations that impact the structural integrity of the skin barrier. This barrier dysfunction leads to the release of alarmins, activating the type 2 immune pathway and recruiting various immune cells to the skin, where they coordinate cutaneous immune responses. In this review, we summarize experimental models of AD and provide an overview of its pathogenesis and the therapeutic interventions. We focus on elucidating the intricate interplay between the immune system of the skin and the complex regulatory mechanisms, as well as commonly used treatments for AD, aiming to systematically understand the cellular and molecular crosstalk in AD-affected skin. Our overarching objective is to provide novel insights and inform potential clinical interventions to reduce the incidence and impact of AD.

Alopecia areata exhibits cutaneous and systemic OX40 activation across atopic backgrounds

BACKGROUND

Alopecia areata (AA) is a chronic, nonscarring hair-loss disorder associated with significant quality-of-life impairment and limited treatment options. AA has been recently linked to atopy and shown to exhibit both Th1- and Th2-driven inflammation. However, a comprehensive molecular and cellular characterization across blood and scalp compartments in both atopic and nonatopic patients is lacking.

METHODS

Lesional and nonlesional scalp biopsies obtained from AA patients with (n = 16) or without (n = 20) atopic history, and 17 demographically matched healthy controls were analyzed with RNA-seq, RT-PCR, and immunohistochemistry. Flow cytometry was also performed on peripheral blood mononuclear cells (PBMCs) from a subset of patients. Differential expression was defined using |fold-change| > 1.5 and false-discovery rate <0.05.

RESULTS

AA scalp exhibited robust upregulation of Th1- (IFNG, CXCL9, CXCL10, CXCL11) and Th2-related products (CCL26, CCR4, IL10, IL13, TSLP, TNFRSF4/OX40) and shared downregulation of hair keratins, regardless of atopic background, with variable Th17/Th22 modulation. AA patients with atopy exhibited greater inflammatory tone and Th2-skewing (IL10, IL13, IL33, CCR4, CCL26). Disease severity correlated significantly with immune and hair keratin biomarkers and with perifollicular cellular infiltrates. Cutaneous OX40/OX40L upregulation was paralleled by increases in circulating OX40+ and OX40L+ leukocytes, regardless of atopic background.

CONCLUSION

Our results suggest some atopy-associated immune differences in AA and highlight the OX40 axis as a potential novel therapeutic target that may broadly benefit AA patients.

Addressing Unmet Needs in Atopic Dermatitis: Evaluating Disease-Modifying Capabilities of Current and Emerging Therapies

Atopic dermatitis (AD) is a highly burdensome inflammatory skin condition affecting nearly one-quarter of the pediatric population and often continuing into adulthood. Despite recent advancements in systemic therapies providing temporary symptom relief over the past decade, AD frequently remains difficult to control, necessitating increased dosages or alternative treatments due to recurrent disease. This review synthesizes current literature to identify unmet needs of treating AD beyond medication-related limitations and evaluates existing therapies for their efficacy in modifying underlying disease mechanisms. Key findings include variability in AD pathophysiology and phenotypes across different age groups and ethnicities, indicating a need for research into endotype-specific treatments. The literature also comprises evidence suggesting that select current drugs, such as targeted biologics and Janus Kinase (JAK) inhibitors, may offer long-term disease-modifying benefits. Future management strategies should explore novel approaches, including manipulation of the microbiome, immune response, and neural function, as these may lead to additional improvements in AD treatment and long-term symptom relief.

The regulatory T cell-selective interleukin-2 receptor agonist rezpegaldesleukin in the treatment of inflammatory skin diseases: two randomized, double-blind, placebo-controlled phase 1b trials

Regulatory T cell (Treg) impairment is implicated in the pathogenesis of chronic inflammatory diseases, but relatively little is known about the therapeutic potential of Treg restoration. Here we present clinical evidence for the Treg-selective interleukin-2 receptor agonist rezpegaldesleukin (REZPEG) in two randomized, double-blind, placebo-controlled Phase 1b trials in patients with moderate-to-severe atopic dermatitis (AD) (NCT04081350) or chronic plaque psoriasis (PsO) (NCT04119557). Key inclusion criteria for AD included an Eczema Area and Severity Index (EASI) score ≥ 16 and a validated Investigator Global Assessment for Atopic Dermatitis (vIGA-AD) ≥ 3, and for PsO included a Psoriasis Area and Severity Index (PASI) score of ≥ 12 and a static Physician's Global Assessment (sPGA) score of ≥ 3. REZPEG is safe and well-tolerated and demonstrates consistent pharmacokinetics in participants receiving subcutaneous doses of 10 to 12 µg/kg or 24 µg/kg once every 2 weeks for 12 weeks, meeting the primary and secondary objectives, respectively. AD patients receiving the higher dose demonstrate an 83% improvement in EASI score after 12 weeks of treatment. EASI improvement of ≥ 75% (EASI-75) and vIGA-AD responses are maintained for 36 weeks after treatment discontinuation in 71% and 80% of week 12 responders, respectively. These exploratory clinical improvements are accompanied by sustained increases in CD25bright Tregs. REZPEG thus represents a homeostatic approach to cutaneous disease therapy and holds clinical potential in providing long-term, treatment-free disease control.

Small-Molecule CCR4 Antagonists in Cutaneous T-cell Lymphoma

SIGNIFICANCE

Our findings are of interest to readers because they bring new evidence that small-molecule CCR4 antagonists may be an alternative therapeutic strategy to target CCR4+ CTCL cells. They may inhibit CCR4 function but not eradicate cells, so the side effects may be avoided or minimized.

Novel therapeutic receptor agonists and antagonists in allergic conjunctivitis

PURPOSE OF REVIEW

Allergic conjunctivitis is characterized by the development of pathophysiological changes to the ocular surface, which occurs when pro-allergic and pro-inflammatory mediators interact with their cognate receptors expressed on immune and nonimmune cells. Traditional treatments with antihistamines and corticosteroids provide relief, but there is a need for more efficacious and tolerable long-term therapy with a better safety profile. This article aims to provide an overview of the mode of action and clinical application of agonist therapies targeting glucocorticoid, melanocortin, and toll-like receptors, as well as antagonist therapies targeting cytokine, chemokine, integrin, and histamine receptors.

RECENT FINDINGS

There has been considerable advancement in immunology and pharmacology, as well as a greater understanding of the cellular and molecular mechanisms of allergic conjunctivitis. Recent research advancing therapy for allergic conjunctivitis has focused on developing synthetic molecules and biologics that can interfere with the process of the allergic immune reaction.

SUMMARY

This review discusses novel therapeutic receptors being explored agonistically or antagonistically to develop alternative treatment options for allergic conjunctivitis. These novel approaches hold promise for improving the management of allergic eye diseases, offering patients hope for more effective and safer treatment options in the future.

Emerging drugs for the treatment of atopic dermatitis: a focus on phase 2 and phase 3 trials

INTRODUCTION

Atopic dermatitis (AD) is an inflammatory skin condition that affects millions of pediatric and adult patients with well-studied impact on morbidity and quality of life. Management occurs in a stepwise fashion beginning with preventative measures before immunomodulators are introduced. However, challenges remain in treatment of moderate-to-severe atopic dermatitis that is refractory to first- and second-line treatments and there are only few topical anti-inflammatory options, especially for pediatric patients.

AREAS COVERED

New medications are required to address these gaps as lesions may persist despite treatment or patients may discontinue treatment due to actual or anticipated adverse effects of mainstay medications. Emerging research into the pathophysiology of AD and the immune system at large has provided opportunities for novel interventions aimed at stopping AD mechanisms at new checkpoints. Clinical trials for 36 agents currently in phase 2 or phase 3 are evaluated with particular focus on the studies for, B244, CBP-201, tapinarof, lebrikizumab, nemolizumab, amlitelimab, and rocatinlimab as they explore novel pathways and have some of the most promising results.

EXPERT OPINION

These clinical trials contribute to the evolution of AD treatment toward greater precision based on salient pathways with a particular focus on moderate-to-severe AD to enhance efficacy and minimize adverse effects.

T cell trafficking in human chronic inflammatory diseases

Circulating T cells, which migrate from the periphery to sites of tissue inflammation, play a crucial role in the development of various chronic inflammatory conditions. Recent research has highlighted subsets of tissue-resident T cells that acquire migratory capabilities and re-enter circulation, referred to here as "recirculating T cells." In this review, we examine recent advancements in understanding the biology of T cell trafficking in diseases where T cell infiltration is pivotal, such as multiple sclerosis and inflammatory bowel diseases, as well as in metabolic disorders where the role of T cell migration is less understood. Additionally, we discuss current insights into therapeutic strategies aimed at modulating T cell circulation across tissues and the application of state-of-the-art technologies for studying recirculation in humans. This review underscores the significance of investigating T trafficking as a novel potential target for therapeutic interventions across a spectrum of human chronic inflammatory diseases.

Monoclonal antibodies for moderate-to-severe atopic dermatitis: a look at phase III and beyond

INTRODUCTION

The understanding of atopic dermatitis (AD) pathogenesis has rapidly expanded in recent years, catalyzing the development of new targeted monoclonal antibody treatments for AD.

AREAS COVERED

This review aims to summarize the latest clinical and molecular data about monoclonal antibodies that are in later stages of development for AD, either in Phase 3 trials or in the pharmacopoeia for up to 5 years, highlighting the biologic underpinning of each drug's mechanism of action and the potential modulation of the AD immune profile.

EXPERT OPINION

The therapeutic pipeline of AD treatments is speedily progressing, introducing the potential for a personalized medical approach in the near future. Understanding how targeting pathogenic players in AD modifies disease progression and symptomatology is key in improving therapeutic choices for patients and identifying ideal patient candidates.

A Narrative Review of the State of the Art of CCR4-Based Therapies in Cutaneous T-Cell Lymphomas: Focus on Mogamulizumab and Future Treatments

The CCR4 receptor is a pivotal target in cutaneous T-cell lymphoma (CTCL) therapy due to its role in impairing immune responses against malignant T-cells and expression profiles. Monoclonal antibodies like mogamulizumab effectively bind to CCR4, reducing tumour burden and enhancing patient outcomes by inhibiting the receptor's interaction with ligands, thereby hindering malignant T-cell migration and survival. Combining CCR4 antibodies with chemotherapy, radiation, and other drugs is being explored for synergistic effects. Additionally, small-molecular inhibitors, old pharmacological agents interacting with CCR4, and CAR-T therapies are under investigation. Challenges include drug resistance, off-target effects, and patient selection, addressed through ongoing trials refining protocols and identifying biomarkers. Despite advancements, real-life data for most of the emerging treatments are needed to temper expectations. In conclusion, CCR4-targeted therapies show promise for CTCL management, but challenges persist. Continued research aims to optimise treatments, enhance outcomes, and transform CTCL management. This review aims to elucidate the biological rationale and the several agents under various stages of development and clinical evaluation with the actual known data.