Possible suppressive effects of baricitinib on serum IL-22 levels in atopic dermatitis

Real-World Evidence for Baricitinib in the Treatment of Atopic Dermatitis and Alopecia Areata: Systematic Literature Review 2020-2023

INTRODUCTION

Baricitinib is an oral selective Janus kinase 1/2 inhibitor approved for the treatment of the immune-mediated inflammatory skin diseases atopic dermatitis (AD) and alopecia areata (AA). We report the findings of a systematic literature review of real-world outcomes with baricitinib in patients with AD or AA.

METHODS

Databases, conference proceedings, and other sources were searched for publications covering July to November 2023 that provided real-world evidence in baricitinib-treated patients; extracted study variables included study population characteristics, interventions, and outcomes.

RESULTS

In total, 76 publications meeting inclusion criteria were identified, most of which were single-centre studies; 1134 unique patients with AD and 598 unique patients with AA were included. Studies in AD mostly focused on effectiveness outcomes, followed by treatment patterns, patient-reported outcomes, and safety. Most AA publications focused on effectiveness outcomes, followed by safety then treatment patterns.

CONCLUSION

Overall, baricitinib consistently improved the signs and symptoms of AD in patients receiving baricitinib in real-world settings, was effective for the treatment of AA in both adult and paediatric patients and was associated with improvements in patient-reported outcomes. The most common reasons for baricitinib discontinuation in AD were ineffectiveness and adverse events, although discontinuation rates due to adverse events were low. Patients initiating baricitinib for AD had often been treated previously with a biologic and were frequently receiving immunosuppressive and topical treatments before treatment initiation. Treatment discontinuation and prior treatment data were limited for studies in AA, but several studies reported concomitant minoxidil use in patients with AA treated with baricitinib. No new safety signals for baricitinib were observed in patients with AD or AA, and no serious adverse events were reported. In conclusion, real-world data on baricitinib in the treatment of AD and AA support the effectiveness and tolerability reported in clinical trials.

Clinical and Laboratory Indexes for Predicting Early and Late Responders to Lebrikizumab in Atopic Dermatitis: A Prospective Cohort Observational Study

Background: An anti-interleukin-13 antibody lebrikizumab is effective for atopic dermatitis (AD). However, predictive factors for responders to lebrikizumab are unknown in real-world practice. Objective: To identify predictive factors for early and late responders to lebrikizumab treatment for AD. Methods: A prospective study was conducted with 112 Japanese patients with AD who received lebrikizumab between May 2024 and February 2025. Early responders were defined as patients who achieved investigator's global assessment (IGA) 0/1 at week 12, and late responders were defined as those who did not achieve IGA 0/1 at week 12 but achieved IGA 0/1 at week 24. We compared patients' background factors and baseline clinical or laboratory indexes between responders and poor responders. Results: Early responders showed lower baseline eczema area and severity index (EASI), thymus and activation-regulated chemokine (TARC), lactate dehydrogenase (LDH), and platelet-to-lymphocyte ratio (PLR) while late responders showed lower baseline immunoglobulin E (IgE), eosinophil-to-lymphocyte ratio (ELR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), PLR, systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) compared with respective poor responders. Conclusions: Patients with AD with lower baseline EASI, TARC, LDH, and PLR may predict early responses, while those with lower baseline IgE, ELR, NLR, MLR, PLR, SII, and SIRI may predict late responses to lebrikizumab.

24-Week Real-World Effectiveness and Safety of Lebrikizumab for Atopic Dermatitis in Japan: An Analysis Stratified by Prior Systemic Therapy

Background: The data are limited on the real-world effectiveness of an anti-interleukin (IL)-13 monoclonal antibody lebrikizumab for atopic dermatitis (AD). Objective: To evaluate the 24-week real-world effectiveness of lebrikizumab in Japanese patients with AD, stratified by the presence or absence of prior systemic therapy. Methods: We conducted a multicenter, prospective study of 134 Japanese AD patients treated with lebrikizumab. We evaluated clinical outcomes throughout a 24-week period in patients with or without prior systemic therapy. Results: Among lebrikizumab-treated patients, eczema area and severity index (EASI) and scores of patient-reported outcomes (peak pruritus numerical rating scale, sleep quality numerical rating scale, AD control tool, dermatology life quality index, and patient-oriented eczema measure) rapidly decreased until week 12, and these improvements persisted until week 24. At week 24, the achievement rates of EASI 75, EASI 90, and investigator's global assessment 0/1 in systemic therapy-naïve patients were 75.6%, 58.5%, and 43.5%, respectively, which were higher than those in systemic therapy-experienced patients, 55.5%, 22.2%, and 26.9%, respectively. There were no serious treatment-emergent adverse events until week 24. Conclusion: Lebrikizumab treatment provided favorable effectiveness and tolerability for AD in real-world practice, with slightly higher effectiveness in systemic therapy-naïve patients compared to therapy-experienced patients.

Real-World Effectiveness and Safety of Lebrikizumab for Moderate-to-Severe Atopic Dermatitis: A 16-Week Study in Japan

Background: Real-world data on the effectiveness and safety of lebrikizumab for atopic dermatitis (AD) are limited. Objective: To evaluate the real-world effectiveness and safety of lebrikizumab on Japanese patients with AD. Methods: This two-center study included 126 Japanese patients with moderate-to-severe AD treated with lebrikizumab plus topical corticosteroids for 16 weeks. Eczema area and severity index (EASI), investigator's global assessment (IGA), peak-pruritus (PP)-numerical rating scale (NRS), sleep quality NRS, AD control tool (ADCT), dermatology life quality index (DLQI), patient-oriented eczema measure (POEM), immunoglobulin E (IgE), thymus and activation-regulated chemokine (TARC), lactate dehydrogenase (LDH), and total eosinophil count (TEC) were assessed during the treatment. Results: Lebrikizumab reduced all clinical indexes at week 4, which was maintained until week 16. The achievement rates of EASI 50, 75, 90, 100, and IGA 0/1 at week 16 were 83.1%, 57.1%, 27.3%, 11.7%, and 33.3%, respectively. The achievement rates of ≥4-point reduction in PP-NRS, sleep quality NRS, or DLQI, ADCT <7-point, and POEM ≤7-point at week 16 were 75.9%, 68.8%, 65.9%, 76.9%, and 80.4%, respectively. IgE, TARC, and LDH decreased while TEC increased during the treatment. No new safety concerns were observed. Conclusion: The 16-week treatment with lebrikizumab generated favorable effectiveness and safety in Japanese AD patients in real-world practice.

Biologic and small-molecule therapy for treating moderate to severe atopic dermatitis: Mechanistic considerations

Atopic dermatitis (AD) is a complex and heterogeneous skin disease for which achieving complete clinical clearance for most patients has proven challenging through single cytokine inhibition. Current studies integrate biomarkers and evaluate their role in AD, aiming to advance our understanding of the diverse molecular profiles implicated. Although traditionally characterized as a TH2-driven disease, extensive research has recently revealed the involvement of TH1, TH17, and TH22 immune pathways as well as the interplay of pivotal immune molecules, such as OX40, OX40 ligand (OX40L), thymic stromal lymphopoietin, and IL-33. This review explores the mechanistic effects of treatments for AD, focusing on mAbs and Janus kinase inhibitors. It describes how these treatments modulate immune pathways and examines their impact on key inflammatory and barrier biomarkers.

IL-22 as a target for therapeutic intervention: Current knowledge on its role in various diseases

IL-22 has emerged as a crucial cytokine mediating protective response against pathogens and tissue regeneration. Dysregulated production of IL-22 has been shown to play a pivotal role in the pathogenesis of various diseases like malignant tumours, viral, cardiovascular, allergic and autoimmune disorders. Interleukin 22 belongs to IFN-IL-10 cytokine family. It is a major proinflammatory cytokine secreted by activated Th1 cells (Th22), though can also be secreted by many other immune cells like group 3 innate lymphocytes, γδ T cells, NK cells, NK T cells, and mucosal associated invariant T cells. Th22 cells exclusively release IL-22 but not IL-17 or IFN-γ (as Th1 cells releases IFN-γ along with IL-22 and Th17 cells releases IL-17 along with IL-22) and also express aryl hydrocarbon receptor as the key transcription factor. Th22 cells also exhibit expression of chemokine receptor CCR6 and skin-homing receptors CCR4 and CCR10 indicating the involvement of this subset in bolstering epithelial barrier immunity and promoting secretion of antimicrobial peptides (AMPs) from intestinal epithelial cells. The function of IL-22 is modulated by IL-22 binding protein (binds to IL-22 and inhibits it binding to its cell surface receptor); which serves as a competitor for IL-22R1 chain of IL-22 receptor. The pathogenic and protective nature of the Th22 cells is modulated both by the site of infected tissue and the type of disease pathology. This review aims to discuss key features of IL-22 biology, comparisons between IL and 22 and IFN-γ and its role as a potential immune therapy target in different maladies.

Janus Kinase Inhibitors in Atopic Dermatitis: New Perspectives

The JAK/STAT (Janus kinase/signal transducer and activator of transcription) pathway is an essential final step in the signaling process of most interleukins with a critical role in the pathogenesis of atopic dermatitis. By achieving broad, intermittent inhibition of the activity of multiple cytokines, JAK inhibitors help modulate T helper 2 cell-mediated inflammation, epidermal barrier dysfunction, and itch signaling. This comprehensive blockade, however, can result in a wider range of adverse effects. We review a number of JAK inhibitors that have been recently approved for use in atopic dermatitis, such as baricitinib, upadacitinib, and abrocitinib, as well as others that are currently in the pipeline or under development, such as gusacitinib, delgocitinib, ruxolitinib, brepocitinib, tofacitinib, and cerdulatinib. The use of JAK inhibitors to block the signaling of numerous cytokines with a critical role in the pathogenesis of atopic dermatitis has revolutionized the treatment of this pathogenically complex, phenotypically heterogeneous skin disease.

[Translated article] Janus Kinase Inhibitors in Atopic Dermatitis: New Perspectives

The JAK/STAT (Janus kinase/signal transducer and activator of transcription) pathway is an essential final step in the signaling process of most interleukins with a critical role in the pathogenesis of atopic dermatitis. By achieving broad, intermittent inhibition of the activity of multiple cytokines, JAK inhibitors help to modulate T helper 2 cell-mediated inflammation, epidermal barrier dysfunction, and itch signaling. This comprehensive blockade, however, can result in a wider range of adverse effects. We review a number of JAK inhibitors that have been recently approved for use in atopic dermatitis, such as baricitinib, upadacitinib, and abrocitinib, as well as others that are currently in the pipeline or under development, such as gusacitinib, delgocitinib, ruxolitinib, brepocitinib, tofacitinib, and cerdulatinib. The use of JAK inhibitors to block the signaling of numerous cytokines with a critical role in the pathogenesis of atopic dermatitis has revolutionized the treatment of this pathogenically complex, phenotypically heterogeneous skin disease.

Oral Janus kinase inhibitors for atopic dermatitis

Atopic dermatitis (AD) is one of the most common inflammatory skin conditions. The pathogenesis of AD involves skin barrier disruption and immune activation of T-helper (T_H)2 and T_H22 and varying degrees of T_H1 and T_H17 activation in various patient subtypes. Although AD is mainly driven by T_H2, the molecular and clinical heterogeneity of AD underscores the need for more efficacious treatments that target multiple immune axes. Janus kinase (JAK) inhibitors are novel therapeutics that broadly block many AD-related proinflammatory cytokines (interleukin [IL]-4, IL-5, IL-13, IL-31, thymic stromal lymphopoietin, interferon gamma, IL-12, IL-23, IL-17) across different immune pathways. Oral JAK inhibitors have been found to be efficacious in AD, with 2 (abrocitinib and upadacitinib) recently gaining US Food and Drug Administration approval and several others under investigation in clinical trials with promising results. These systemic agents have surpassed conventional thresholds of treatment response, with many patients achieving complete or almost complete skin clearance, and provide a fast-acting alternative therapy for patients who are not responsive to biologics or other conventional therapies. However, systemic JAK inhibitors come with health concerns, requiring additional long-term clinical trials to characterize their safety profile in patients with AD. This review summarizes the current literature on the safety and efficacy of oral JAK inhibitors in AD and discusses future directions for research.

Atopic Dermatitis and Water: Is There an Optimum Water Intake Level for Improving Atopic Skin?

Water is a vital nutrient with innumerable functions for every living cell. The functions of human skin include protection against dehydration of the body. Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease that presents with dry skin, erythematous and eczematous lesions, and lichenification. This paper discusses the question of whether extra water intake in children with AD affects skin hydration and the skin barrier function. Among the methods used to treat dry skin, topical leave-on products are the first-line treatment, intended to improve hydration and the skin barrier function. The effectiveness of adequate water intake as a measure to treat dry skin is still under debate. Normal skin hydration increases with dietary water intake, particularly in those with prior lower water consumption. Skin dryness in AD is instrumental to the itch and inflammation cycle, contributing to barrier impairment and aggravating disease severity and flares. Certain emollients provide significant hydration to AD skin, with relief of dryness and reduction in barrier impairment, disease severity, and flares. Further investigations are needed to evaluate the optimum water intake levels in children with AD, as important questions remain unanswered, namely, does oral hydration provide relief of skin dryness and reduce barrier impairment, disease severity, and flares; is there any additional benefit from using mineral or thermal spring water; or is there a need to specifically study the fluid/water intake in children with AD and food allergy (FA) restrictions?

The Role of T Helper 22 Cells in Dermatological Disorders

T helper 22 (Th22) cells are a newly identified subset of CD4+ T cells that secrete the effector cytokine interleukin 22 (IL-22) upon specific antigen stimulation, barely with IFN-γ or IL-17. Increasing studies have demonstrated that Th22 cells and IL-22 play essential roles in skin barrier defense and skin disease pathogenesis since the IL-22 receptor is widely expressed in the skin, especially in keratinocytes. Herein, we reviewed the characterization, differentiation, and biological activities of Th22 cells and elucidated their roles in skin health and disease. We mainly focused on the intricate crosstalk between Th22 cells and keratinocytes and provided potential therapeutic strategies targeting the Th22/IL-22 signaling pathway.